id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0205348 | Igor Shovkovy | V. A. Miransky and I. A. Shovkovy | Magnetic catalysis and anisotropic confinement in QCD | 10 pages, 1 figure. REVTeX. Minor correction. To appear in Phys. Rev.
D | Phys.Rev. D66 (2002) 045006 | 10.1103/PhysRevD.66.045006 | null | hep-ph hep-lat hep-th nucl-th | null | The expressions for dynamical masses of quarks in the chiral limit in QCD in
a strong magnetic field are obtained. A low energy effective action for the
corresponding Nambu-Goldstone bosons is derived and the values of their decay
constants as well as the velocities are calculated. The existence of a
threshold value of the number of colors $N^{thr}_c$, dividing the theories with
essentially different dynamics, is established. For the number of colors $N_c
\ll N^{thr}_c$, an anisotropic dynamics of confinement with the confinement
scale much less than $\Lambda_{QCD}$ and a rich spectrum of light glueballs is
realized. For $N_c$ of order $N^{thr}_c$ or larger, a conventional confinement
dynamics takes place. It is found that the threshold value $N^{thr}_c$ grows
rapidly with the magnetic field [$N^{thr}_c \gtrsim 100$ for $|eB| \gtrsim
(1{GeV})^2$]. In contrast to QCD with a nonzero baryon density, there are no
principal obstacles for checking these results and predictions in lattice
computer simulations.
| [
{
"created": "Fri, 31 May 2002 18:09:07 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Jun 2002 18:06:20 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Jun 2002 17:07:35 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Miransky",
"V. A.",
""
],
[
"Shovkovy",
"I. A.",
""
]
] | The expressions for dynamical masses of quarks in the chiral limit in QCD in a strong magnetic field are obtained. A low energy effective action for the corresponding Nambu-Goldstone bosons is derived and the values of their decay constants as well as the velocities are calculated. The existence of a threshold value of the number of colors $N^{thr}_c$, dividing the theories with essentially different dynamics, is established. For the number of colors $N_c \ll N^{thr}_c$, an anisotropic dynamics of confinement with the confinement scale much less than $\Lambda_{QCD}$ and a rich spectrum of light glueballs is realized. For $N_c$ of order $N^{thr}_c$ or larger, a conventional confinement dynamics takes place. It is found that the threshold value $N^{thr}_c$ grows rapidly with the magnetic field [$N^{thr}_c \gtrsim 100$ for $|eB| \gtrsim (1{GeV})^2$]. In contrast to QCD with a nonzero baryon density, there are no principal obstacles for checking these results and predictions in lattice computer simulations. |
2009.11947 | Ulrich Jentschura | Ulrich D. Jentschura | Squeezing the Parameter Space for Lorentz Violation in the Neutrino
Sector by Additional Decay Channels | 16 pages; LaTeX | Particles 3 (2020) 630-641 | 10.3390/particles3030041 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hypothesis of Lorentz violation in the neutrino sector has intrigued
scientists for the last two to three decades. A number of theoretical arguments
support the emergence of such violations first and foremost for neutrinos,
which constitute the "most elusive" and "least interacting" particles known to
mankind. It is of obvious interest to place stringent bounds on the
Lorentz-violating parameters in the neutrino sector. In the past, the most
stringent bounds have been placed by calculating the probability of neutrino
decay into a lepton pair, a process made kinematically feasible by Lorentz
violation in the neutrino sector, above a certain threshold. However, even more
stringent bounds can be placed on the Lorentz-violating parameters if one takes
into account, additionally, the possibility of neutrino splitting, i.e., of
neutrino decay into a neutrino of lower energy, accompanied by "neutrino-pair
Cerenkov radiation". This process has negligible threshold and can be used to
improve the bounds on Lorentz-violating parameters in the neutrino sector.
Finally, we take the opportunity to discuss the relation of Lorentz and gauge
symmetry breaking, with a special emphasis on the theoretical models employed
in our calculations.
| [
{
"created": "Tue, 22 Sep 2020 20:13:37 GMT",
"version": "v1"
}
] | 2020-10-06 | [
[
"Jentschura",
"Ulrich D.",
""
]
] | The hypothesis of Lorentz violation in the neutrino sector has intrigued scientists for the last two to three decades. A number of theoretical arguments support the emergence of such violations first and foremost for neutrinos, which constitute the "most elusive" and "least interacting" particles known to mankind. It is of obvious interest to place stringent bounds on the Lorentz-violating parameters in the neutrino sector. In the past, the most stringent bounds have been placed by calculating the probability of neutrino decay into a lepton pair, a process made kinematically feasible by Lorentz violation in the neutrino sector, above a certain threshold. However, even more stringent bounds can be placed on the Lorentz-violating parameters if one takes into account, additionally, the possibility of neutrino splitting, i.e., of neutrino decay into a neutrino of lower energy, accompanied by "neutrino-pair Cerenkov radiation". This process has negligible threshold and can be used to improve the bounds on Lorentz-violating parameters in the neutrino sector. Finally, we take the opportunity to discuss the relation of Lorentz and gauge symmetry breaking, with a special emphasis on the theoretical models employed in our calculations. |
hep-ph/0109101 | Jong-Phil Lee | Jong-Phil Lee (Yonsei Univ.) | Non-factorizable effects on $\Bbar^0\to D^{(*)0}\pi^0$ | 10 pages, 3 figures | null | null | null | hep-ph | null | Non-factorizable effects on the color-suppressed $B\to D^{(*)}\pi$ decay
modes are analyzed. Recent observations of $\Bbar^0\to D^{(*)0}\pi^0$ by Belle
and CLEO strongly suggest that there exists a non-zero strong phase difference
between color-allowed and color-suppressed decay modes, and the factorization
parameter $a_2$ associated with the color-suppressed decay mode is process
dependent. In the heavy quark limit where $b$ and $c$ are heavy, the process
dependence of $a_2(D\pi,D^*\pi)$ is due to the different configuration of the
heavy quark spin relative to the light degrees of freedom. From the
experimental data, the heavy quark spin symmetry breaking contributions to the
non-fatorizable effects are estimated to be $23-28%$.
| [
{
"created": "Wed, 12 Sep 2001 11:23:34 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lee",
"Jong-Phil",
"",
"Yonsei Univ."
]
] | Non-factorizable effects on the color-suppressed $B\to D^{(*)}\pi$ decay modes are analyzed. Recent observations of $\Bbar^0\to D^{(*)0}\pi^0$ by Belle and CLEO strongly suggest that there exists a non-zero strong phase difference between color-allowed and color-suppressed decay modes, and the factorization parameter $a_2$ associated with the color-suppressed decay mode is process dependent. In the heavy quark limit where $b$ and $c$ are heavy, the process dependence of $a_2(D\pi,D^*\pi)$ is due to the different configuration of the heavy quark spin relative to the light degrees of freedom. From the experimental data, the heavy quark spin symmetry breaking contributions to the non-fatorizable effects are estimated to be $23-28%$. |
1410.1657 | Dimiter Stamenov | Elliot Leader, Alexander V. Sidorov, Dimiter B. Stamenov | New analysis concerning the strange quark polarization puzzle | 8 pages, 3 figures, 3 tables; misprints for the values of
$\chi^2/DOF$ in page 5 corrected | Phys. Rev. D 91, 054017 (2015) | 10.1103/PhysRevD.91.054017 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The fact that analyses of semi-inclusive deep inelastic scattering suggest
that the polarized strange quark density $\Delta s(x) + \Delta \bar{s}(x)$ is
positive in the measured region of Bjorken x, whereas all analyses of inclusive
deep inelastic scattering yield significantly negative values of this quantity,
is known as the "strange quark polarization puzzle". We have analyzed the world
data on inclusive deep inelastic scattering, including the COMPASS 2010 proton
data on the spin asymmetries, and for the first time, the new extremely precise
JLab CLAS data on the proton and deuteron spin structure functions. Despite
allowing in our parametrization, for a possible sign change, our results
confirm that the inclusive data yield significantly negative values for the
polarized strange quark density.
| [
{
"created": "Tue, 7 Oct 2014 09:49:32 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Oct 2014 09:19:23 GMT",
"version": "v2"
},
{
"created": "Fri, 6 Mar 2015 08:39:49 GMT",
"version": "v3"
},
{
"created": "Thu, 9 Jul 2015 14:01:49 GMT",
"version": "v4"
}
] | 2015-07-10 | [
[
"Leader",
"Elliot",
""
],
[
"Sidorov",
"Alexander V.",
""
],
[
"Stamenov",
"Dimiter B.",
""
]
] | The fact that analyses of semi-inclusive deep inelastic scattering suggest that the polarized strange quark density $\Delta s(x) + \Delta \bar{s}(x)$ is positive in the measured region of Bjorken x, whereas all analyses of inclusive deep inelastic scattering yield significantly negative values of this quantity, is known as the "strange quark polarization puzzle". We have analyzed the world data on inclusive deep inelastic scattering, including the COMPASS 2010 proton data on the spin asymmetries, and for the first time, the new extremely precise JLab CLAS data on the proton and deuteron spin structure functions. Despite allowing in our parametrization, for a possible sign change, our results confirm that the inclusive data yield significantly negative values for the polarized strange quark density. |
hep-ph/0507073 | Michael Klasen | G. Bozzi, B. Fuks, and M. Klasen (LPSC Grenoble) | Non-Diagonal and Mixed Squark Production at Hadron Colliders | 22 pages, 11 figures | Phys.Rev.D72:035016,2005 | 10.1103/PhysRevD.72.035016 | LPSC 05-048 | hep-ph hep-ex | null | We calculate squared helicity amplitudes for non-diagonal and mixed squark
pair production at hadron colliders, taking into account not only loop-induced
QCD diagrams, but also previously unconsidered electroweak channels, which turn
out to be dominant. Mixing effects are included for both top and bottom
squarks. Numerical results are presented for several SUSY benchmark scenarios
at both the CERN LHC and the Fermilab Tevatron, including the possibilities of
light stops or sbottoms. The latter should be easily observed at the Tevatron
in associated production of stops and sbottoms for a large range of stop masses
and almost independently of the stop mixing angle. Asymmetry measurements for
light stops at the polarized BNL RHIC collider are also briefly discussed.
| [
{
"created": "Wed, 6 Jul 2005 15:24:29 GMT",
"version": "v1"
}
] | 2011-01-27 | [
[
"Bozzi",
"G.",
"",
"LPSC Grenoble"
],
[
"Fuks",
"B.",
"",
"LPSC Grenoble"
],
[
"Klasen",
"M.",
"",
"LPSC Grenoble"
]
] | We calculate squared helicity amplitudes for non-diagonal and mixed squark pair production at hadron colliders, taking into account not only loop-induced QCD diagrams, but also previously unconsidered electroweak channels, which turn out to be dominant. Mixing effects are included for both top and bottom squarks. Numerical results are presented for several SUSY benchmark scenarios at both the CERN LHC and the Fermilab Tevatron, including the possibilities of light stops or sbottoms. The latter should be easily observed at the Tevatron in associated production of stops and sbottoms for a large range of stop masses and almost independently of the stop mixing angle. Asymmetry measurements for light stops at the polarized BNL RHIC collider are also briefly discussed. |
1611.03201 | Ho-Meoyng Choi | Ho-Meoyng Choi (Kyungpook National Univ.) and Chueng-Ryong Ji (NCSU) | Twist-3 Distribution Amplitudes of Pion in the Light-Front Quark Model | 6 pages, 2 figures, Contribution to Light Cone 2016, Sep. 5-8,
Lisbon, version to appear in Few-Body Syst | null | 10.1007/s00601-016-1208-8 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyzed two twist-3 distribution amplitudes of pion, i.e. pseudoscalar
$\phi^P_{3;\pi}(x)$ and pseudotensor $\phi^\sigma_{3;\pi}(x)$, within the LFQM.
Our LFQM descriptions both for twist-3 $\phi^P_{3;\pi}$ and
$\phi^\sigma_{3;\pi}$ not only satisfy the fundamental constraint required from
the isospin symmetry, but also reproduce exactly the asymptotic forms
anticipated from QCD's conformal limit.
| [
{
"created": "Thu, 10 Nov 2016 07:14:12 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Jan 2017 01:33:29 GMT",
"version": "v2"
}
] | 2017-02-01 | [
[
"Choi",
"Ho-Meoyng",
"",
"Kyungpook National Univ."
],
[
"Ji",
"Chueng-Ryong",
"",
"NCSU"
]
] | We analyzed two twist-3 distribution amplitudes of pion, i.e. pseudoscalar $\phi^P_{3;\pi}(x)$ and pseudotensor $\phi^\sigma_{3;\pi}(x)$, within the LFQM. Our LFQM descriptions both for twist-3 $\phi^P_{3;\pi}$ and $\phi^\sigma_{3;\pi}$ not only satisfy the fundamental constraint required from the isospin symmetry, but also reproduce exactly the asymptotic forms anticipated from QCD's conformal limit. |
1802.01222 | Gilberto Tavares-Velasco | R. S\'anchez-V\'elez, G.Tavares-Velasco | Decays $A \to Z\gamma\gamma$ and $\phi \to Z\gamma\gamma$ ($\phi=h,H$)
in two-Higgs doublet models | 24 pages, 13 figures, 2 tables | Phys. Rev. D 97, 095038 (2018) | 10.1103/PhysRevD.97.095038 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The one-loop contributions to the decays of the $CP$-odd and $CP$-even scalar
bosons $A\to Z\gamma\gamma$ and $\phi\to Z\gamma\gamma$ ($\phi=h,H$) are
calculated within the framework of $CP$-conserving THDMs, where they are
induced by box and reducible Feynman diagrams. The behavior of the
corresponding branching ratios are then analyzed within the type-II THDM in a
region of the parameter space around the alignment limit and still consistent
with experimental data. It is found that the $A\to Z\gamma\gamma$ branching
ratio is only relevant when $m_A>m_H+m_Z$, but it is negligible otherwise. For
$m_A>600$ GeV and $t_\beta\simeq O(1)$, $BR(A\to Z\gamma\gamma)$ can reach
values of the order of $10^{-5}-10^{-4}$, but it decreases by about one order
of magnitude as $t_\beta$ increases up to 10. A similar behavior is followed by
the $H\to Z\gamma\gamma$ decay, which only has a non-negligible branching ratio
when $m_H>m_A+m_Z$ and can reach the level of $10^{-4}-10^{-3}$ for $m_H>600$
GeV and $t_\beta\simeq O(1)$. We also estimated the branching ratios of these
rare decays in the type-I THDM, where they can be about one order of magnitude
larger than in type-II THDM. As far as the $h\to Z\gamma\gamma$ decay is
concerned, since the properties of this scalar boson must be nearly identical
to those of the SM Higgs boson, the $h\to Z\gamma\gamma$ branching ratio does
not deviates significantly from the SM prediction, where it is negligibly
small, of the order of $10^{-9}$. This result is in agreement with previous
calculations.
| [
{
"created": "Mon, 5 Feb 2018 00:15:36 GMT",
"version": "v1"
},
{
"created": "Wed, 2 May 2018 04:29:39 GMT",
"version": "v2"
}
] | 2018-06-06 | [
[
"Sánchez-Vélez",
"R.",
""
],
[
"Tavares-Velasco",
"G.",
""
]
] | The one-loop contributions to the decays of the $CP$-odd and $CP$-even scalar bosons $A\to Z\gamma\gamma$ and $\phi\to Z\gamma\gamma$ ($\phi=h,H$) are calculated within the framework of $CP$-conserving THDMs, where they are induced by box and reducible Feynman diagrams. The behavior of the corresponding branching ratios are then analyzed within the type-II THDM in a region of the parameter space around the alignment limit and still consistent with experimental data. It is found that the $A\to Z\gamma\gamma$ branching ratio is only relevant when $m_A>m_H+m_Z$, but it is negligible otherwise. For $m_A>600$ GeV and $t_\beta\simeq O(1)$, $BR(A\to Z\gamma\gamma)$ can reach values of the order of $10^{-5}-10^{-4}$, but it decreases by about one order of magnitude as $t_\beta$ increases up to 10. A similar behavior is followed by the $H\to Z\gamma\gamma$ decay, which only has a non-negligible branching ratio when $m_H>m_A+m_Z$ and can reach the level of $10^{-4}-10^{-3}$ for $m_H>600$ GeV and $t_\beta\simeq O(1)$. We also estimated the branching ratios of these rare decays in the type-I THDM, where they can be about one order of magnitude larger than in type-II THDM. As far as the $h\to Z\gamma\gamma$ decay is concerned, since the properties of this scalar boson must be nearly identical to those of the SM Higgs boson, the $h\to Z\gamma\gamma$ branching ratio does not deviates significantly from the SM prediction, where it is negligibly small, of the order of $10^{-9}$. This result is in agreement with previous calculations. |
2102.02197 | Alan Hern\'andez | A. I. Hern\'andez-Ju\'arez, A. Moyotl, G. Tavares-Velasco | Contributions to $ZZV^\ast$ ($V=\gamma,Z,Z'$) couplings from $CP$
violating flavor changing couplings | null | null | 10.1140/epjc/s10052-021-09093-w | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The one-loop contributions to the trilinear neutral gauge boson couplings
$ZZV^\ast$ ($V=\gamma,Z,Z'$), parametrized in terms of one $CP$-conserving
$f_5^{V}$ and one $CP$-violating $f_4^{V}$ form factors, are calculated in
models with $CP$-violating flavor changing neutral current couplings mediated
by the $Z$ gauge boson and an extra neutral gauge boson $Z'$. Analytical
results are presented in terms of both Passarino-Veltman scalar functions and
closed form functions. Constraints on the vector and axial couplings of the $Z$
gauge boson $\left|g_{{VZ}}^{tu}\right|< 0.0096$ and
$\left|g_{{VZ}}^{tc}\right|<0.011$ are obtained from the current experimental
data on the $t\rightarrow Z q$ decays. It is found that in the case of the
$ZZ\gamma^\ast$ vertex the only non-vanishing form factor is $f_5^{\gamma}$,
which can be of the order of $10^{-3}$, whereas for the $ZZZ^\ast$ vertex both
form factors $f_5^{Z}$ and $f_4^{Z}$ are non-vanishing and can be of the order
of $10^{-6}$ and $10^{-5}$, respectively. Our estimates for $f_5^{\gamma}$ and
$f_5^{Z}$ are smaller than those predicted by the standard model, where
$f_4^{Z}$ is absent up to the one loop level. We also estimate the $ZZ{Z'}^{*}$
form factors arising from both diagonal and non-diagonal $Z'$ couplings within
a few extension models. It is found that in the diagonal case $f_{5}^{Z'}$ is
the only non-vanishing form factor and its real and imaginary parts can be of
the order of $10^{-1}-10^{-2}$ and $ 10^{-2}-10^{-3}$, respectively, with the
dominant contributions arising from the light quarks and leptons. In the
non-diagonal case $f_{5}^{Z^\prime}$ can be of the order of $10^{-4}$, whereas
$f_4^{Z'}$ can reach values as large as $10^{-7}-10^{-8}$, with the largest
contributions arising from the $Z'tq$ couplings.
| [
{
"created": "Wed, 3 Feb 2021 18:49:16 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Mar 2021 02:02:33 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Apr 2021 00:39:59 GMT",
"version": "v3"
},
{
"created": "Sat, 10 Apr 2021 18:14:06 GMT",
"version": "v4"
}
] | 2021-04-13 | [
[
"Hernández-Juárez",
"A. I.",
""
],
[
"Moyotl",
"A.",
""
],
[
"Tavares-Velasco",
"G.",
""
]
] | The one-loop contributions to the trilinear neutral gauge boson couplings $ZZV^\ast$ ($V=\gamma,Z,Z'$), parametrized in terms of one $CP$-conserving $f_5^{V}$ and one $CP$-violating $f_4^{V}$ form factors, are calculated in models with $CP$-violating flavor changing neutral current couplings mediated by the $Z$ gauge boson and an extra neutral gauge boson $Z'$. Analytical results are presented in terms of both Passarino-Veltman scalar functions and closed form functions. Constraints on the vector and axial couplings of the $Z$ gauge boson $\left|g_{{VZ}}^{tu}\right|< 0.0096$ and $\left|g_{{VZ}}^{tc}\right|<0.011$ are obtained from the current experimental data on the $t\rightarrow Z q$ decays. It is found that in the case of the $ZZ\gamma^\ast$ vertex the only non-vanishing form factor is $f_5^{\gamma}$, which can be of the order of $10^{-3}$, whereas for the $ZZZ^\ast$ vertex both form factors $f_5^{Z}$ and $f_4^{Z}$ are non-vanishing and can be of the order of $10^{-6}$ and $10^{-5}$, respectively. Our estimates for $f_5^{\gamma}$ and $f_5^{Z}$ are smaller than those predicted by the standard model, where $f_4^{Z}$ is absent up to the one loop level. We also estimate the $ZZ{Z'}^{*}$ form factors arising from both diagonal and non-diagonal $Z'$ couplings within a few extension models. It is found that in the diagonal case $f_{5}^{Z'}$ is the only non-vanishing form factor and its real and imaginary parts can be of the order of $10^{-1}-10^{-2}$ and $ 10^{-2}-10^{-3}$, respectively, with the dominant contributions arising from the light quarks and leptons. In the non-diagonal case $f_{5}^{Z^\prime}$ can be of the order of $10^{-4}$, whereas $f_4^{Z'}$ can reach values as large as $10^{-7}-10^{-8}$, with the largest contributions arising from the $Z'tq$ couplings. |
1906.09062 | Krzysztof Marek Kutak | Michal Deak, Krzysztof Kutak, Wanchen Li, Anna M. Sta\'sto | On the different forms of the kinematical constraint in BFKL | 22 pages | null | 10.1140/epjc/s10052-019-7171-z | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a detailed analysis of the different forms of the kinematical
constraint imposed on the low $x$ evolution that appear in the literature. We
find that all of them generate the same leading anti-collinear poles in Mellin
space which agree with BFKL up to NLL order and up to NNLL in $N=4$ sYM. The
coefficients of subleading poles vanish up to NNLL order for all constraints
and we prove that this property should be satisfied to all orders. We then
demonstrate that the kinematical constraints differ at further subleading
orders of poles. We quantify the differences between the different forms of the
constraints by performing numerical analysis both in Mellin space and in
momentum space. It can be shown that in all three cases BFKL equation can be
recast into the differential form, with the argument of the longitudinal
variable shifted by the combination of the transverse coordinates.
| [
{
"created": "Fri, 21 Jun 2019 11:02:04 GMT",
"version": "v1"
}
] | 2019-09-04 | [
[
"Deak",
"Michal",
""
],
[
"Kutak",
"Krzysztof",
""
],
[
"Li",
"Wanchen",
""
],
[
"Staśto",
"Anna M.",
""
]
] | We perform a detailed analysis of the different forms of the kinematical constraint imposed on the low $x$ evolution that appear in the literature. We find that all of them generate the same leading anti-collinear poles in Mellin space which agree with BFKL up to NLL order and up to NNLL in $N=4$ sYM. The coefficients of subleading poles vanish up to NNLL order for all constraints and we prove that this property should be satisfied to all orders. We then demonstrate that the kinematical constraints differ at further subleading orders of poles. We quantify the differences between the different forms of the constraints by performing numerical analysis both in Mellin space and in momentum space. It can be shown that in all three cases BFKL equation can be recast into the differential form, with the argument of the longitudinal variable shifted by the combination of the transverse coordinates. |
2305.12304 | Alessio Celeste | Alessio T. B. Celeste and Adriano M. Santos | Lorentz violation in $\gamma$-pair production ($e^{+}e^{-} \rightarrow
\gamma\gamma$) | null | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper specifically focuses on the choice of a temporal background field
over a spatial one in the context of Lorentz symmetry breaking. By examining
the implications of this choice, we aim to understand the effects of Lorentz
violation in different scenarios, with an emphasis on the consequences of
adopting a purely temporal background field. In the analysis of $\gamma$-pair
production, a brief approach in QED is presented, exploring the production of a
pair of photons. Furthermore, the study investigates Lorentz violation with
vectorial nonminimal coupling, analyzing the modifications introduced by this
coupling in the scattering amplitude at the vertex. Additionally, Lorentz
violation with axial-like nonminimal coupling is explored, with a particular
focus. The additional coupling introduces further modifications to the
scattering amplitude, highlighting the intricate nature of Lorentz symmetry
breaking in different scenarios.
| [
{
"created": "Sun, 21 May 2023 00:25:05 GMT",
"version": "v1"
},
{
"created": "Sat, 3 Jun 2023 15:56:41 GMT",
"version": "v2"
},
{
"created": "Sat, 1 Jul 2023 03:23:47 GMT",
"version": "v3"
}
] | 2023-07-04 | [
[
"Celeste",
"Alessio T. B.",
""
],
[
"Santos",
"Adriano M.",
""
]
] | This paper specifically focuses on the choice of a temporal background field over a spatial one in the context of Lorentz symmetry breaking. By examining the implications of this choice, we aim to understand the effects of Lorentz violation in different scenarios, with an emphasis on the consequences of adopting a purely temporal background field. In the analysis of $\gamma$-pair production, a brief approach in QED is presented, exploring the production of a pair of photons. Furthermore, the study investigates Lorentz violation with vectorial nonminimal coupling, analyzing the modifications introduced by this coupling in the scattering amplitude at the vertex. Additionally, Lorentz violation with axial-like nonminimal coupling is explored, with a particular focus. The additional coupling introduces further modifications to the scattering amplitude, highlighting the intricate nature of Lorentz symmetry breaking in different scenarios. |
hep-ph/9506238 | Jifang Zhang | J.-F. Zhang, Nimai C. Mukhopadhyay and M. Benmerrouche | Photoproduction of the Eta-Prime Mesons as a New Tool to Probe Baryon
Resonances | Will be published in Phys. Rev. C | Phys.Rev.C52:1134-1137,1995 | 10.1103/PhysRevC.52.1134 | RPI-N100 | hep-ph | null | We examine eta prime photoproduction, as a novel tool to study baryon
resonances around 2 GeV, of particular interest to the quark shell model, which
predicts a number of them. We find important roles of the form factors at the
strong vertices, and show that the N^*(2080) can be probed efficiently by this
reaction.
| [
{
"created": "Mon, 5 Jun 1995 14:52:16 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Zhang",
"J. -F.",
""
],
[
"Mukhopadhyay",
"Nimai C.",
""
],
[
"Benmerrouche",
"M.",
""
]
] | We examine eta prime photoproduction, as a novel tool to study baryon resonances around 2 GeV, of particular interest to the quark shell model, which predicts a number of them. We find important roles of the form factors at the strong vertices, and show that the N^*(2080) can be probed efficiently by this reaction. |
1111.6799 | Bastian Kubis | Bastian Kubis, Franz Niecknig, Sebastian P. Schneider | On the role of final-state interactions in Dalitz plot studies | 5 pages, 5 figures; to appear in the proceedings of the International
Workshop on e+e- collisions from Phi to Psi, September 19-22, 2011,
Novosibirsk, Russia; partial textual overlap with arXiv:1108.5866 | Nucl. Phys. B (Proc. Suppl.) 225-227 (2012) 75-79 | 10.1016/j.nuclphysbps.2012.02.017 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The study of Dalitz plots of heavy-meson decays to multi-hadron final states
has received intensified interest by the possibility to gain access to
precision investigations of CP violation. A thorough understanding of the
hadronic final-state interactions is a prerequisite to achieve a highly
sensitive, model-independent study of such Dalitz plots. We illustrate some of
the theoretical tools, predominantly taken from dispersion theory, available
for these and related purposes, and discuss the low-energy decays omega, phi
--> 3pi in some more detail.
| [
{
"created": "Tue, 29 Nov 2011 12:56:36 GMT",
"version": "v1"
}
] | 2012-06-05 | [
[
"Kubis",
"Bastian",
""
],
[
"Niecknig",
"Franz",
""
],
[
"Schneider",
"Sebastian P.",
""
]
] | The study of Dalitz plots of heavy-meson decays to multi-hadron final states has received intensified interest by the possibility to gain access to precision investigations of CP violation. A thorough understanding of the hadronic final-state interactions is a prerequisite to achieve a highly sensitive, model-independent study of such Dalitz plots. We illustrate some of the theoretical tools, predominantly taken from dispersion theory, available for these and related purposes, and discuss the low-energy decays omega, phi --> 3pi in some more detail. |
hep-ph/0511289 | Paride Paradisi | A. Masiero, P. Paradisi, R. Petronzio | Probing New Physics through mu-e Universality in K->lnu | v2: 5 pages, 1 figure. Comments and 2 references added | Phys.Rev.D74:011701,2006 | 10.1103/PhysRevD.74.011701 | null | hep-ph | null | The recent NA48/2 improvement on R_K=Gamma(K->e nu_e)/Gamma(K->mu nu_mu)
emphasizes the role of K_l2 decays in probing the mu-e universality.
Supersymmetric (SUSY) extensions of the Standard Model can exhibit mu-e
non-universal contributions. Their origin is twofold: those deriving from
lepton flavor conserving couplings are subdominant with respect to those
arising from lepton flavor violating (LFV) sources. We show that mu-e
non-universality in K_l2 is quite effective in constraining relevant regions of
SUSY models with LFV (for instance, supergravities with a see-saw mechanism for
neutrino masses). A comparison with analogous bounds coming from tau LFV decays
proves the relevance of the measurement of R_K to probe LFV in SUSY.
| [
{
"created": "Thu, 24 Nov 2005 14:53:20 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Jul 2006 13:40:04 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Masiero",
"A.",
""
],
[
"Paradisi",
"P.",
""
],
[
"Petronzio",
"R.",
""
]
] | The recent NA48/2 improvement on R_K=Gamma(K->e nu_e)/Gamma(K->mu nu_mu) emphasizes the role of K_l2 decays in probing the mu-e universality. Supersymmetric (SUSY) extensions of the Standard Model can exhibit mu-e non-universal contributions. Their origin is twofold: those deriving from lepton flavor conserving couplings are subdominant with respect to those arising from lepton flavor violating (LFV) sources. We show that mu-e non-universality in K_l2 is quite effective in constraining relevant regions of SUSY models with LFV (for instance, supergravities with a see-saw mechanism for neutrino masses). A comparison with analogous bounds coming from tau LFV decays proves the relevance of the measurement of R_K to probe LFV in SUSY. |
hep-ph/0507200 | Alexander Studenikin | Alexander Grigoriev, Alexander Studenikin and Alexei Ternov | Spin Light of Neutrino in Dense Matter | 15 pages, 7 figures, in: Proceedings of Les Recontres de Physique de
la Vallee d'Aoste ("Results and Perspectives in Particle Physics", March
2005, La Thuile, Italy), ed. by Mario Greco, Frascati Physics Series, Italy,
2005; modified version is accepted for publication in Phys.Lett.B | Phys.Lett. B622 (2005) 199 | 10.1016/j.physletb.2005.07.034 | null | hep-ph | null | We develop the quantum theory of the spin light of neutrino ($SL\nu$) exactly
accounting for the effect of background matter. Contrary to the already
performed studies of the $SL\nu$, in this paper we derive explicit and closed
expressions for the $SL\nu$ rate and power and for the emitted photon energy,
which are valid for an arbitrary matter density (including very high values).
The spatial distribution of the radiation power and the dependence of the
emitted photon energy on the direction of radiation are also studied in detail
for the first time. We analyze the $SL\nu$ polarization properties and show
that within a wide range of neutrino momenta and matter densities the $SL\nu$
radiation is circularly polarized. Conditions for effective $SL\nu$ photon
propagation in the electron plasma are discussed. It is also shown that in
dense matter the average energy of the emitted photon can reach values in the
range from one third of the neutrino momentum up to one half of the neutrino
energy in matter. The main features of the studied radiation are summarized,
and possibilities for the $SL\nu$ production during different astrophysical and
cosmology processes are discussed.
| [
{
"created": "Sat, 16 Jul 2005 11:32:16 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Grigoriev",
"Alexander",
""
],
[
"Studenikin",
"Alexander",
""
],
[
"Ternov",
"Alexei",
""
]
] | We develop the quantum theory of the spin light of neutrino ($SL\nu$) exactly accounting for the effect of background matter. Contrary to the already performed studies of the $SL\nu$, in this paper we derive explicit and closed expressions for the $SL\nu$ rate and power and for the emitted photon energy, which are valid for an arbitrary matter density (including very high values). The spatial distribution of the radiation power and the dependence of the emitted photon energy on the direction of radiation are also studied in detail for the first time. We analyze the $SL\nu$ polarization properties and show that within a wide range of neutrino momenta and matter densities the $SL\nu$ radiation is circularly polarized. Conditions for effective $SL\nu$ photon propagation in the electron plasma are discussed. It is also shown that in dense matter the average energy of the emitted photon can reach values in the range from one third of the neutrino momentum up to one half of the neutrino energy in matter. The main features of the studied radiation are summarized, and possibilities for the $SL\nu$ production during different astrophysical and cosmology processes are discussed. |
1712.08621 | Felix Anger | F. R. Anger, F. Febres Cordero, S. H\"oche, D. Ma\^itre | Weak Vector Boson Production with Many Jets at the LHC $\sqrt{s}= 13$
TeV | null | Phys. Rev. D 97, 096010 (2018) | 10.1103/PhysRevD.97.096010 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Signatures with an electroweak vector boson and many jets play a crucial role
at the Large Hadron Collider, both in the measurement of Standard-Model
parameters and in searches for new physics. Precise predictions for these
multi-scale processes are therefore indispensable. We present next-to-leading
order QCD predictions for $W^\pm/Z$+jets at $\sqrt{s}=13$ TeV, including up to
five/four jets in the final state. All production channels are included and
leptonic decays of the vector bosons are considered at the amplitude level. We
assess theoretical uncertainties arising from renormalization- and
factorization-scale dependence by considering fixed-order dynamical scales
based on the $H_{\rm T}$ variable as well as on the MiNLO procedure. We also
explore uncertainties associated to different choices of parton-distribution
functions. We provide event samples that can be explored through publicly
available $n$-tuple sets, generated with BlackHat in combination with SHERPA.
| [
{
"created": "Fri, 22 Dec 2017 19:00:07 GMT",
"version": "v1"
}
] | 2018-05-30 | [
[
"Anger",
"F. R.",
""
],
[
"Cordero",
"F. Febres",
""
],
[
"Höche",
"S.",
""
],
[
"Maître",
"D.",
""
]
] | Signatures with an electroweak vector boson and many jets play a crucial role at the Large Hadron Collider, both in the measurement of Standard-Model parameters and in searches for new physics. Precise predictions for these multi-scale processes are therefore indispensable. We present next-to-leading order QCD predictions for $W^\pm/Z$+jets at $\sqrt{s}=13$ TeV, including up to five/four jets in the final state. All production channels are included and leptonic decays of the vector bosons are considered at the amplitude level. We assess theoretical uncertainties arising from renormalization- and factorization-scale dependence by considering fixed-order dynamical scales based on the $H_{\rm T}$ variable as well as on the MiNLO procedure. We also explore uncertainties associated to different choices of parton-distribution functions. We provide event samples that can be explored through publicly available $n$-tuple sets, generated with BlackHat in combination with SHERPA. |
hep-ph/0207333 | Yu-Qi Chen | Yu-Qi Chen | Renormalization in Reparameterization Invariance | revised version, reorganized, adding a new section, 4 figures. 28
pages | Phys.Rev. D69 (2004) 096001 | 10.1103/PhysRevD.69.096001 | null | hep-ph | null | The renormalization issue of the reparameterization invariance in heavy quark
effective theory and NRQCD is investigated. I argue that the renormalization of
the transformation of the heavy quark field under the variation of the velocity
parameter V is attributed to the renormalization of the small component field
in the proposed transformation. I show that the matching condition for
determining the renormalized small component field can be obtained by imposing
an infinitesimal transformation of V on the relations between the Green's
functions in QCD full theory and those in the effective theory. As an
application, I determine the renormalized transformation to order 1/m^2 using
the matching condition. The obtained result is in disagreement with that
determined by indirect method.
| [
{
"created": "Sat, 27 Jul 2002 18:00:20 GMT",
"version": "v1"
},
{
"created": "Sun, 27 Jul 2003 03:18:24 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Chen",
"Yu-Qi",
""
]
] | The renormalization issue of the reparameterization invariance in heavy quark effective theory and NRQCD is investigated. I argue that the renormalization of the transformation of the heavy quark field under the variation of the velocity parameter V is attributed to the renormalization of the small component field in the proposed transformation. I show that the matching condition for determining the renormalized small component field can be obtained by imposing an infinitesimal transformation of V on the relations between the Green's functions in QCD full theory and those in the effective theory. As an application, I determine the renormalized transformation to order 1/m^2 using the matching condition. The obtained result is in disagreement with that determined by indirect method. |
0910.5472 | Tilman Plehn | Tilman Plehn, Gavin P. Salam, Michael Spannowsky | Fat Jets for a Light Higgs | v1: 6 pages; v2: minimal changes in numerics, final result slightly
improved | Phys.Rev.Lett.104:111801,2010 | 10.1103/PhysRevLett.104.111801 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | At the LHC associated top quark and Higgs boson production with a Higgs decay
to bottom quarks has long been a heavily disputed search channel. Recently, it
has been found to not be viable. We show how it can be observed by tagging
massive Higgs and top jets. For this purpose we construct boosted top and Higgs
taggers for Standard Model processes in a complex QCD environment.
| [
{
"created": "Wed, 28 Oct 2009 20:35:34 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Dec 2009 17:31:23 GMT",
"version": "v2"
}
] | 2010-04-06 | [
[
"Plehn",
"Tilman",
""
],
[
"Salam",
"Gavin P.",
""
],
[
"Spannowsky",
"Michael",
""
]
] | At the LHC associated top quark and Higgs boson production with a Higgs decay to bottom quarks has long been a heavily disputed search channel. Recently, it has been found to not be viable. We show how it can be observed by tagging massive Higgs and top jets. For this purpose we construct boosted top and Higgs taggers for Standard Model processes in a complex QCD environment. |
hep-ph/9907280 | Markus Wobisch | M. Wobisch, T. Wengler | Hadronization Corrections to Jet Cross Sections in Deep-Inelastic
Scattering | 10 pages, 7 figures, to appear in: Proceedings of the Workshop on
Monte Carlo Generators for HERA Physics | null | null | PITHA 99/16 | hep-ph | null | The size of non-perturbative corrections to high E_T jet production in
deep-inelastic scattering is reviewed. Based on predictions from fragmentation
models, hadronization corrections for different jet definitions are compared
and the model dependence as well as the dependence on model parameters is
investigated. To test whether these hadronization corrections can be applied to
next-to-leading order (NLO) calculations, jet properties and topologies in
different parton cascade models are compared to those in NLO. The size of the
uncertainties in estimating the hadronization corrections is compared to the
uncertainties of perturbative predictions. It is shown that for the inclusive
k_\perp ordered jet clustering algorithm the hadronization corrections are
smallest and their uncertainties are of the same size as the uncertainties of
perturbative NLO predictions.
| [
{
"created": "Thu, 8 Jul 1999 16:22:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Wobisch",
"M.",
""
],
[
"Wengler",
"T.",
""
]
] | The size of non-perturbative corrections to high E_T jet production in deep-inelastic scattering is reviewed. Based on predictions from fragmentation models, hadronization corrections for different jet definitions are compared and the model dependence as well as the dependence on model parameters is investigated. To test whether these hadronization corrections can be applied to next-to-leading order (NLO) calculations, jet properties and topologies in different parton cascade models are compared to those in NLO. The size of the uncertainties in estimating the hadronization corrections is compared to the uncertainties of perturbative predictions. It is shown that for the inclusive k_\perp ordered jet clustering algorithm the hadronization corrections are smallest and their uncertainties are of the same size as the uncertainties of perturbative NLO predictions. |
1109.1400 | Dilip Kumar Ghosh | Debajyoti Choudhury, Anindya Datta, Dilip Kumar Ghosh and Kirtiman
Ghosh | Exploring two Universal Extra Dimensions at the CERN LHC | 29 pages, 11 postscript figures, one typo corrected | null | 10.1007/JHEP04(2012)057 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the signatures, at the LHC, of the (1,0)-th Kaluza-Klein (KK)
gluon and quarks in the framework of the two universal extra dimensional (2UED)
model. Once produced, these particles typically suffer a cascade of decays
terminating in the Dark Matter candidate apart from Standard Model particles.
In this article, we are interested in focus on a particular signature of 2UED
wherein the final state comprises of at least four jets in association with a
hard photon and missing transverse energy. Several kinematic cuts are devised
to enhance the signal to background ratio. Finally, as a road map to parameter
determination at the LHC, we point out an interesting correlation between the
peak position of the M_eff distributions with the compactification radius R and
the cut-off scale M_s.
| [
{
"created": "Wed, 7 Sep 2011 09:43:37 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Sep 2011 08:33:56 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Choudhury",
"Debajyoti",
""
],
[
"Datta",
"Anindya",
""
],
[
"Ghosh",
"Dilip Kumar",
""
],
[
"Ghosh",
"Kirtiman",
""
]
] | We discuss the signatures, at the LHC, of the (1,0)-th Kaluza-Klein (KK) gluon and quarks in the framework of the two universal extra dimensional (2UED) model. Once produced, these particles typically suffer a cascade of decays terminating in the Dark Matter candidate apart from Standard Model particles. In this article, we are interested in focus on a particular signature of 2UED wherein the final state comprises of at least four jets in association with a hard photon and missing transverse energy. Several kinematic cuts are devised to enhance the signal to background ratio. Finally, as a road map to parameter determination at the LHC, we point out an interesting correlation between the peak position of the M_eff distributions with the compactification radius R and the cut-off scale M_s. |
2202.03952 | Rajeev Singh Mr. | Victor E. Ambrus, Radoslaw Ryblewski, Rajeev Singh | Spin waves in spin hydrodynamics | 11 pages; 3 captioned figures; published version | Phys.Rev.D 106 (2022) 1, 014018 | 10.1103/PhysRevD.106.014018 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | The propagation properties of spin degrees of freedom are analyzed in the
framework of relativistic hydrodynamics with spin based on the de Groot--van
Leeuwen--van Weert definitions of the energy-momentum and spin tensors. We
derive the analytical expression for the spin wave velocity for arbitrary
statistics and show that it goes to half the speed of light in the
ultra-relativistic limit. We find that only the transverse degrees of freedom
propagate, analogously to electromagnetic waves. Finally, we consider the
effect of dissipative corrections and calculate the damping coefficients for
the case of Maxwell-J\"uttner statistics.
| [
{
"created": "Tue, 8 Feb 2022 16:03:22 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Sep 2022 16:45:29 GMT",
"version": "v2"
}
] | 2022-09-02 | [
[
"Ambrus",
"Victor E.",
""
],
[
"Ryblewski",
"Radoslaw",
""
],
[
"Singh",
"Rajeev",
""
]
] | The propagation properties of spin degrees of freedom are analyzed in the framework of relativistic hydrodynamics with spin based on the de Groot--van Leeuwen--van Weert definitions of the energy-momentum and spin tensors. We derive the analytical expression for the spin wave velocity for arbitrary statistics and show that it goes to half the speed of light in the ultra-relativistic limit. We find that only the transverse degrees of freedom propagate, analogously to electromagnetic waves. Finally, we consider the effect of dissipative corrections and calculate the damping coefficients for the case of Maxwell-J\"uttner statistics. |
1812.05864 | Sven Heinemeyer | S. Heinemeyer, T. Stefaniak | A Higgs Boson at 96 GeV?! | 9 pages, 3 figures. Invited talk given at Prospects for Charged Higgs
Discovery at Colliders - CHARGED2018, 25-28 September 2018, Uppsala, Sweden.
Based partially on arXiv:1712.07475 and arXiv:1807.06322 | null | null | IFT-UAM/CSIC-18-125, DESY 18-221 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We briefly summarize some searches for Higgs bosons with a mass of m_phi <=
110 GeV at LEP and the LHC. We discuss a possible signal in the diphoton decay
mode at m_phi = 96 GeV as reported by CMS, together with a 2 sigma hint in the
bb final state at LEP. We briefly review possible interpretation of such a new
particle in various BSM models. We focus on possible explanations as reported
within the NMSSM and the munuSSM. Conclusions for future collider projects are
briefly outlined.
| [
{
"created": "Fri, 14 Dec 2018 11:32:23 GMT",
"version": "v1"
}
] | 2018-12-17 | [
[
"Heinemeyer",
"S.",
""
],
[
"Stefaniak",
"T.",
""
]
] | We briefly summarize some searches for Higgs bosons with a mass of m_phi <= 110 GeV at LEP and the LHC. We discuss a possible signal in the diphoton decay mode at m_phi = 96 GeV as reported by CMS, together with a 2 sigma hint in the bb final state at LEP. We briefly review possible interpretation of such a new particle in various BSM models. We focus on possible explanations as reported within the NMSSM and the munuSSM. Conclusions for future collider projects are briefly outlined. |
hep-ph/0206069 | Tsushima | K. Tsushima (Department of Physics and Astronomy, University of
Georgia) | Hadron properties in nuclear medium and their impacts on observables | Latex, 10 pages, embedded figures, uses ws-procs9x6.cls (included),
invited talk given at the Joint Workshop of CSSM and Japan Hadron Facility
(JHF), "Physics at JHF", March 14 - 21, 2002, Adelaide, Australia | null | 10.1142/9789812776662_0029 | null | hep-ph hep-ex nucl-ex nucl-th | null | The effect of changes in hadron properties in a nuclear medium on physical
observables is discussed. Highlighted results are, (1) hypernuclei, (2)
meosn-nuclear bound states, (3) $K$-meson production in heavy ion collisions,
and (4) $J/\Psi$ dissociation in a nuclear medium. In addition, results for the
near-threshold $\omega$- and $\phi$-meson productions in proton proton
collisions are reported.
| [
{
"created": "Thu, 6 Jun 2002 14:28:39 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Tsushima",
"K.",
"",
"Department of Physics and Astronomy, University of\n Georgia"
]
] | The effect of changes in hadron properties in a nuclear medium on physical observables is discussed. Highlighted results are, (1) hypernuclei, (2) meosn-nuclear bound states, (3) $K$-meson production in heavy ion collisions, and (4) $J/\Psi$ dissociation in a nuclear medium. In addition, results for the near-threshold $\omega$- and $\phi$-meson productions in proton proton collisions are reported. |
1105.5561 | Ivica Picek | Ivica Picek and Branimir Radovcic | Testing New TeV-scale Seesaw Mediators at the LHC | 2 pages, 1 figure | PoS(ICHEP 2010)329 | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose TeV-scale Dirac fermions producing Majorana masses of the known
neutrinos via tree-level seesaw, different from standard type I and III seesaw.
The employed weak five-plet with nonzero hypercharge leads to new seesaw
formula m_\nu ~ v^6/M^5 and to empirical masses m_\nu ~ 10^{-1} eV for M ~ TeV
new states. For a limited range of the parameter space, where M < a few 100
GeV, the proposed mechanism is testable at the LHC via characteristic decays of
Dirac type heavy leptons, produced by a Drell-Yan fusion.
| [
{
"created": "Fri, 27 May 2011 13:53:17 GMT",
"version": "v1"
}
] | 2011-05-30 | [
[
"Picek",
"Ivica",
""
],
[
"Radovcic",
"Branimir",
""
]
] | We propose TeV-scale Dirac fermions producing Majorana masses of the known neutrinos via tree-level seesaw, different from standard type I and III seesaw. The employed weak five-plet with nonzero hypercharge leads to new seesaw formula m_\nu ~ v^6/M^5 and to empirical masses m_\nu ~ 10^{-1} eV for M ~ TeV new states. For a limited range of the parameter space, where M < a few 100 GeV, the proposed mechanism is testable at the LHC via characteristic decays of Dirac type heavy leptons, produced by a Drell-Yan fusion. |
hep-ph/0201111 | Jean-Philippe Lansberg | J.P. Lansberg (Liege U.) | Heavy quarkonium production in hadronic collisions | 4 pages, 8 figures. Presented at the JJC2001 -Journees Jeunes
Chercheurs-, La Hume, France, 10-14 December 2001 | null | null | null | hep-ph | null | Different theoretical models which attempt to describe hadronic production of
heavy quarkonia are reviewed. Firstly, we consider the Color Singlet Model and
point out the large discrepancies between the theoretical predictions and the
results from the Tevatron detectors. Then some other models are introduced,
quickly discussed and confronted with experimental results. Finally, we suggest
possible ways to understand the source of the remaining discrepancies.
| [
{
"created": "Sun, 13 Jan 2002 18:30:14 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lansberg",
"J. P.",
"",
"Liege U."
]
] | Different theoretical models which attempt to describe hadronic production of heavy quarkonia are reviewed. Firstly, we consider the Color Singlet Model and point out the large discrepancies between the theoretical predictions and the results from the Tevatron detectors. Then some other models are introduced, quickly discussed and confronted with experimental results. Finally, we suggest possible ways to understand the source of the remaining discrepancies. |
1311.3137 | Sho Ozaki | Sho Ozaki | QCD effective potential with strong U(1)_{em} magnetic fields | 35 pages, 6 figures. Version published in Phys. Rev. D | Phys. Rev. D 89, 054022 (2014) | 10.1103/PhysRevD.89.054022 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive the analytic expression for the one-loop $SU(N_{c})$ QCD effective
potential including $N_{f}$ flavor quarks which non-linearly interact with the
chromo-magnetic background field and the external $U(1)_{em}$ magnetic field.
After the renormalization of couplings and fields, we obtain the correct
one-loop $\beta$ functions of both QCD and QED, and the resulting effective
potential satisfies the renormalization group equation. We investigate the
effect of the magnetic field on the QCD vacuum by using the effective
potential, in particular for the color $SU(3)$ case with the three flavors ($u,
d, s$). Our result shows that the chromo-magnetic field prefers to be parallel
to the external magnetic field. Furthermore, quark loop contributions to the
effective potential with the magnetic field enhance gluonic contributions, and
then the chromo-magnetic condensate increases with an increasing magnetic
field. This result supports the recent observed gluonic magnetic catalysis at
zero-temperature in lattice QCD.
| [
{
"created": "Wed, 13 Nov 2013 14:14:14 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Mar 2014 10:34:16 GMT",
"version": "v2"
}
] | 2014-03-26 | [
[
"Ozaki",
"Sho",
""
]
] | We derive the analytic expression for the one-loop $SU(N_{c})$ QCD effective potential including $N_{f}$ flavor quarks which non-linearly interact with the chromo-magnetic background field and the external $U(1)_{em}$ magnetic field. After the renormalization of couplings and fields, we obtain the correct one-loop $\beta$ functions of both QCD and QED, and the resulting effective potential satisfies the renormalization group equation. We investigate the effect of the magnetic field on the QCD vacuum by using the effective potential, in particular for the color $SU(3)$ case with the three flavors ($u, d, s$). Our result shows that the chromo-magnetic field prefers to be parallel to the external magnetic field. Furthermore, quark loop contributions to the effective potential with the magnetic field enhance gluonic contributions, and then the chromo-magnetic condensate increases with an increasing magnetic field. This result supports the recent observed gluonic magnetic catalysis at zero-temperature in lattice QCD. |
2110.02174 | Thomas Rink | CONUS Collaboration: H. Bonet (1), A. Bonhomme (1), C. Buck (1), K.
F\"ulber (2), J. Hakenm\"uller (1), G. Heusser (1), T. Hugle (1), M. Lindner
(1), W. Maneschg (1), T. Rink (1), H. Strecker (1), R. Wink (2) ((1)
Max-Planck-Institut f\"ur Kernphysik, Heidelberg, Germany, (2)
PreussenElektra GmbH, Osterende, Brokdorf, Germany) | Novel constraints on neutrino physics beyond the standard model from the
CONUS experiment | 35 pages, 6 figures, 3 tables; v2: Figure 2 and further references
added, other CE$\nu$NS limits included in result plots, matches published
version in JHEP | JHEP 05 (2022) 085 | 10.1007/JHEP05(2022)085 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The measurements of coherent elastic neutrino-nucleus scattering (CE$\nu$NS)
experiments have opened up the possibility to constrain neutrino physics beyond
the standard model of elementary particle physics. Furthermore, by considering
neutrino-electron scattering in the keV-energy region, it is possible to set
additional limits on new physics processes. Here, we present constraints that
are derived from CONUS germanium data on beyond the standard model (BSM)
processes like tensor and vector non-standard interactions (NSIs) in the
neutrino-quark sector, as well as light vector and scalar mediators. Thanks to
the realized low background levels in the CONUS experiment at ionization
energies below 1 keV, we are able to set the world's best limits on tensor NSIs
from CE$\nu$NS and constrain the scale of corresponding new physics to lie
above 360 GeV. For vector NSIs, the derived limits strongly depend on the
assumed ionization quenching factor within the detector material, since small
quenching factors largely suppress potential signals for both, the expected
standard model CE$\nu$NS process and the vector NSIs. Furthermore, competitive
limits on scalar and vector mediators are obtained from the CE$\nu$NS channel
at reactor-site which allow to probe coupling constants as low as
$5\cdot10^{-5}$ of low mediator masses, assuming the currently favored
quenching factor regime. The consideration of neutrino-electron scatterings
allows to set even stronger constraints for mediator masses below $\sim1$ MeV
and $\sim 10$ MeV for scalar and vector mediators, respectively.
| [
{
"created": "Tue, 5 Oct 2021 17:02:45 GMT",
"version": "v1"
},
{
"created": "Mon, 23 May 2022 16:33:44 GMT",
"version": "v2"
}
] | 2022-05-24 | [
[
"CONUS Collaboration",
"",
""
],
[
"Bonet",
"H.",
""
],
[
"Bonhomme",
"A.",
""
],
[
"Buck",
"C.",
""
],
[
"Fülber",
"K.",
""
],
[
"Hakenmüller",
"J.",
""
],
[
"Heusser",
"G.",
""
],
[
"Hugle",
"T.",
""
],
[
"Lindner",
"M.",
""
],
[
"Maneschg",
"W.",
""
],
[
"Rink",
"T.",
""
],
[
"Strecker",
"H.",
""
],
[
"Wink",
"R.",
""
]
] | The measurements of coherent elastic neutrino-nucleus scattering (CE$\nu$NS) experiments have opened up the possibility to constrain neutrino physics beyond the standard model of elementary particle physics. Furthermore, by considering neutrino-electron scattering in the keV-energy region, it is possible to set additional limits on new physics processes. Here, we present constraints that are derived from CONUS germanium data on beyond the standard model (BSM) processes like tensor and vector non-standard interactions (NSIs) in the neutrino-quark sector, as well as light vector and scalar mediators. Thanks to the realized low background levels in the CONUS experiment at ionization energies below 1 keV, we are able to set the world's best limits on tensor NSIs from CE$\nu$NS and constrain the scale of corresponding new physics to lie above 360 GeV. For vector NSIs, the derived limits strongly depend on the assumed ionization quenching factor within the detector material, since small quenching factors largely suppress potential signals for both, the expected standard model CE$\nu$NS process and the vector NSIs. Furthermore, competitive limits on scalar and vector mediators are obtained from the CE$\nu$NS channel at reactor-site which allow to probe coupling constants as low as $5\cdot10^{-5}$ of low mediator masses, assuming the currently favored quenching factor regime. The consideration of neutrino-electron scatterings allows to set even stronger constraints for mediator masses below $\sim1$ MeV and $\sim 10$ MeV for scalar and vector mediators, respectively. |
hep-ph/9711245 | Gerrit Schierholz | M. G\"ockeler, R. Horsley, H. Perlt, P. Rakow, G. Schierholz, A.
Schiller and P. Stephenson | Spin Structure Functions from Lattice QCD | DESY 97-217, HUB-EP-97/85; talk given by G. Schierholz at the
International Workshop `Deep-Inelastic Scattering off Polarized Targets:
Theory Meets Experiment', Zeuthen, September 1-5, 1997 | null | null | null | hep-ph hep-lat | null | We report on new results of the spin dependent structure functions $g_1$ and
$h_1$ of the nucleon. An attempt is made to convert the moments, which is what
one computes on the lattice, to quark distribution functions.
| [
{
"created": "Wed, 5 Nov 1997 20:58:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Göckeler",
"M.",
""
],
[
"Horsley",
"R.",
""
],
[
"Perlt",
"H.",
""
],
[
"Rakow",
"P.",
""
],
[
"Schierholz",
"G.",
""
],
[
"Schiller",
"A.",
""
],
[
"Stephenson",
"P.",
""
]
] | We report on new results of the spin dependent structure functions $g_1$ and $h_1$ of the nucleon. An attempt is made to convert the moments, which is what one computes on the lattice, to quark distribution functions. |
hep-ph/9904380 | Thomas G. Rizzo | Thomas G. Rizzo | Tests of Low Scale Gravity via Gauge Boson Pair Production in $\gamma
\gamma$ Collisions | 28 pages, 8 figs, LaTex, references and text updated | Phys.Rev.D60:115010,1999 | 10.1103/PhysRevD.60.115010 | SLAC-PUB-8114 | hep-ph | null | Arkani-Hamed, Dimopoulos and Dvali have recently proposed that gravity may
become strong at energies near 1 TeV thus removing the hierarchy problem. This
scenario can be tested in several ways at present and future colliders. In this
paper we examine the exchange of towers of Kaluza-Klein gravitons and their
influence on the production of pairs of massive gauge bosons in $\gamma \gamma$
collisions. These tower exchanges are shown to lead to a new dimension-8
operator that can significant alter the Standard Model expectations for these
processes. The role of polarization for both the initial state photons and the
final state gauge bosons in improving sensitivity to graviton exchange is
emphasized. We find that the discovery reach for graviton tower exchange in the
$\gamma \gamma \to W^+W^-$ channel to be significantly greater than for any
other process so far examined.
| [
{
"created": "Sun, 18 Apr 1999 19:58:06 GMT",
"version": "v1"
},
{
"created": "Mon, 17 May 1999 12:24:05 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Rizzo",
"Thomas G.",
""
]
] | Arkani-Hamed, Dimopoulos and Dvali have recently proposed that gravity may become strong at energies near 1 TeV thus removing the hierarchy problem. This scenario can be tested in several ways at present and future colliders. In this paper we examine the exchange of towers of Kaluza-Klein gravitons and their influence on the production of pairs of massive gauge bosons in $\gamma \gamma$ collisions. These tower exchanges are shown to lead to a new dimension-8 operator that can significant alter the Standard Model expectations for these processes. The role of polarization for both the initial state photons and the final state gauge bosons in improving sensitivity to graviton exchange is emphasized. We find that the discovery reach for graviton tower exchange in the $\gamma \gamma \to W^+W^-$ channel to be significantly greater than for any other process so far examined. |
hep-ph/9604322 | Thorsten Feldmann | D. Ebert and T. Feldmann (HU Berlin) | Heavy Hadron Spectrum and Interactions | 10 pages LateX, 3 figures included as postscript, uses hsproc.sty | null | null | null | hep-ph | null | Starting from the approximate symmetries of QCD, namely chiral symmetry for
light quarks and spin and flavor symmetry for heavy quarks, we investigate the
low-energy properties of heavy hadrons. For this purpose we construct a
consistent picture of quark-antiquark and quark-diquark interactions as a
low-energy approximation to the flavor dynamics in heavy mesons and heavy
baryons, respectively. Using standard functional integration tools, we derive
an effective Lagrangian in terms of heavy hadron fields and discuss several
properties, like the mass spectrum, coupling and decay constants, Isgur-Wise
form factors.
| [
{
"created": "Mon, 15 Apr 1996 16:09:19 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ebert",
"D.",
"",
"HU Berlin"
],
[
"Feldmann",
"T.",
"",
"HU Berlin"
]
] | Starting from the approximate symmetries of QCD, namely chiral symmetry for light quarks and spin and flavor symmetry for heavy quarks, we investigate the low-energy properties of heavy hadrons. For this purpose we construct a consistent picture of quark-antiquark and quark-diquark interactions as a low-energy approximation to the flavor dynamics in heavy mesons and heavy baryons, respectively. Using standard functional integration tools, we derive an effective Lagrangian in terms of heavy hadron fields and discuss several properties, like the mass spectrum, coupling and decay constants, Isgur-Wise form factors. |
2404.18607 | Li-Sheng Geng | Zhi-Wei Liu, Jun-Xu Lu, Ming-Zhu Liu, and Li-Sheng Geng | Femtoscopy can tell whether $Z_c(3900)$ and $Z_{cs}(3985)$ are
resonances or virtual states | 4 pages, 2 figures. Comments are welcome | null | null | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | There have been extended and heated discussions on the nature of the two
exotic states, $Z_c(3900)$ and $Z_{cs}(3985)$, particularly whether they are
resonances or virtual states. We demonstrate for the first time that the
femtoscopic technique can be used to unambiguously distinguish between such two
scenarios. More concretely, we show that the $D^0D^{*-}$/$D^0D_s^{*-}$
correlation functions are significantly different in the high-momentum region,
especially in small collision systems of the order of 1 fm, as produced in pp
collisions at the LHC, which can unambiguously tell whether
$Z_c(3900)$/$Z_{cs}(3985)$ is a resonant or a virtual state. For the
$Z_{cs}(3985)$, the $D^0D_s^{*-}$ results at zero momentum are significantly
different in the two scenarios. We hope all these discoveries can stimulate
further experimental studies and help clarify the nature of the many exotic
states discovered.
| [
{
"created": "Mon, 29 Apr 2024 11:21:38 GMT",
"version": "v1"
}
] | 2024-04-30 | [
[
"Liu",
"Zhi-Wei",
""
],
[
"Lu",
"Jun-Xu",
""
],
[
"Liu",
"Ming-Zhu",
""
],
[
"Geng",
"Li-Sheng",
""
]
] | There have been extended and heated discussions on the nature of the two exotic states, $Z_c(3900)$ and $Z_{cs}(3985)$, particularly whether they are resonances or virtual states. We demonstrate for the first time that the femtoscopic technique can be used to unambiguously distinguish between such two scenarios. More concretely, we show that the $D^0D^{*-}$/$D^0D_s^{*-}$ correlation functions are significantly different in the high-momentum region, especially in small collision systems of the order of 1 fm, as produced in pp collisions at the LHC, which can unambiguously tell whether $Z_c(3900)$/$Z_{cs}(3985)$ is a resonant or a virtual state. For the $Z_{cs}(3985)$, the $D^0D_s^{*-}$ results at zero momentum are significantly different in the two scenarios. We hope all these discoveries can stimulate further experimental studies and help clarify the nature of the many exotic states discovered. |
hep-ph/0212351 | Xiangdong Ji | Andrei V. Belitsky, Xiangdong Ji, Feng Yuan | Perturbative QCD Analysis of the Nucleon's Pauli Form Factor F_2(Q^2) | 4 papes, 3 figures included | Phys.Rev.Lett. 91 (2003) 092003 | 10.1103/PhysRevLett.91.092003 | UM-PP#-03/031 | hep-ph nucl-ex nucl-th | null | We perform a perturbative QCD analysis of the nucleon's Pauli form factor
$F_2(Q^2)$ in the asymptotically large $Q^2$ limit. We find that the leading
contribution to $F_2(Q^2)$ has a $1/Q^6$ power behavior, consistent with the
well-known result in the literature. Its coefficient depends on the leading-
and subleading-twist light-cone wave functions of the nucleon, the latter
describing the quarks with one unit of orbital angular momentum. We also derive
at the logarithmic accurary the asymptotic scaling $F_2(Q^2)/F_1(Q^2) \sim
(\log^2 Q^2/\Lambda^2)/Q^2$ which describes recent Jefferson Lab data well.
| [
{
"created": "Mon, 23 Dec 2002 23:06:44 GMT",
"version": "v1"
},
{
"created": "Sat, 1 Mar 2003 03:09:20 GMT",
"version": "v2"
},
{
"created": "Wed, 16 Jul 2003 00:21:59 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Belitsky",
"Andrei V.",
""
],
[
"Ji",
"Xiangdong",
""
],
[
"Yuan",
"Feng",
""
]
] | We perform a perturbative QCD analysis of the nucleon's Pauli form factor $F_2(Q^2)$ in the asymptotically large $Q^2$ limit. We find that the leading contribution to $F_2(Q^2)$ has a $1/Q^6$ power behavior, consistent with the well-known result in the literature. Its coefficient depends on the leading- and subleading-twist light-cone wave functions of the nucleon, the latter describing the quarks with one unit of orbital angular momentum. We also derive at the logarithmic accurary the asymptotic scaling $F_2(Q^2)/F_1(Q^2) \sim (\log^2 Q^2/\Lambda^2)/Q^2$ which describes recent Jefferson Lab data well. |
1608.04798 | Gudrun Heinrich | S.Borowka, N.Greiner, G.Heinrich, S.P.Jones, M.Kerner, J.Schlenk,
T.Zirke | Full top quark mass dependence in Higgs boson pair production at NLO | 41 pages, 14 figures | null | 10.1007/JHEP10(2016)107 | MPP-2016-261, ZU-TH-31/16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of the exact top-quark mass dependent two-loop
corrections to Higgs boson pair production by gluon fusion at the LHC and at a
100 TeV hadron collider. We perform a detailed comparison of the full
next-to-leading order result to various approximations at the level of
differential distributions and also analyse non-standard Higgs self-coupling
scenarios. We find that the different next-to-leading order approximations
differ from the full result by up to 50 percent in relevant differential
distributions. This clearly stresses the importance of the full NLO result.
| [
{
"created": "Tue, 16 Aug 2016 22:30:01 GMT",
"version": "v1"
}
] | 2016-11-23 | [
[
"Borowka",
"S.",
""
],
[
"Greiner",
"N.",
""
],
[
"Heinrich",
"G.",
""
],
[
"Jones",
"S. P.",
""
],
[
"Kerner",
"M.",
""
],
[
"Schlenk",
"J.",
""
],
[
"Zirke",
"T.",
""
]
] | We study the effects of the exact top-quark mass dependent two-loop corrections to Higgs boson pair production by gluon fusion at the LHC and at a 100 TeV hadron collider. We perform a detailed comparison of the full next-to-leading order result to various approximations at the level of differential distributions and also analyse non-standard Higgs self-coupling scenarios. We find that the different next-to-leading order approximations differ from the full result by up to 50 percent in relevant differential distributions. This clearly stresses the importance of the full NLO result. |
hep-ph/9311233 | null | Nathan Weiss | Introduction to $Z_N$ Symmetry in $SU_N$ Gauge Theories at Finite
Temperatures | Talk Presented at "Thermal Fields Workshop" Aug. 1993 in Banff,
Canada, 7 pages, 2 figures available by anonymous FTP at
black_hole.physics.ubc.ca in directory outgoing/banff, UBCTP93-23 | null | null | null | hep-ph | null | There have been several talks at this workshop on the physical interpretation
and consequences of the $Z_N$ symmetry which is present in the Euclidean Path
Integral formulation of $SU_N$ Gauge Theories at finite temperature. The
purpose of this paper is to present an introduction to this subject. After a
brief review of Gluodynamics at finite temperature, the nature of the $Z_N$
symmetry in this system is described and its relationship to confinement is
discussed. $Z_N$ domain walls and bubbles are then described as is their
relationship to the confining--deconfining phase transition. The effect of
Fermions is then considered and the presence of metastable extrema of the
Effective Potential for the Polyakov--Wilson Line is described. It is then
argued that these metastable extrema do not correspond to physically realizable
metastable states.
| [
{
"created": "Fri, 5 Nov 1993 18:24:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Weiss",
"Nathan",
""
]
] | There have been several talks at this workshop on the physical interpretation and consequences of the $Z_N$ symmetry which is present in the Euclidean Path Integral formulation of $SU_N$ Gauge Theories at finite temperature. The purpose of this paper is to present an introduction to this subject. After a brief review of Gluodynamics at finite temperature, the nature of the $Z_N$ symmetry in this system is described and its relationship to confinement is discussed. $Z_N$ domain walls and bubbles are then described as is their relationship to the confining--deconfining phase transition. The effect of Fermions is then considered and the presence of metastable extrema of the Effective Potential for the Polyakov--Wilson Line is described. It is then argued that these metastable extrema do not correspond to physically realizable metastable states. |
hep-ph/0204101 | Joaquim Matias | Robert Fleischer, Joaquim Matias | Exploring CP Violation through Correlations in B --> pi K, B_d -->
pi^+pi^-, B_s --> K^+K^- Observable Space | 34 pages, LaTeX, 12 figures. More detailed introduction and a few
Comments added, conclusions unchanged. To appear in Phys. Rev. D | Phys.Rev.D66:054009,2002 | 10.1103/PhysRevD.66.054009 | DESY 02-040, UAB-FT-523 | hep-ph | null | We investigate allowed regions in observable space of B --> pi K, B_d -->
pi^+pi^- and B_s --> K^+K^- decays, characterizing these modes in the Standard
Model. After a discussion of a new kind of contour plots for the $B\to\pi K$
system, we focus on the mixing- induced and direct CP asymmetries of the decays
B_d --> pi^+pi^- and B_s--> K^+K^-. Using experimental information on the
CP-averaged B_d --> pi^{+/-}K^{+/-} and B_d --> pi^+pi^- branching ratios, the
relevant hadronic penguin parameters can be constrained,implying certain
allowed regions in observable space. In the case of B_d --> pi^+pi^-, an
interesting situation arises now in view of the recent B-factory measurements
of CP violation in this channel, allowing us to obtain new constraints on the
CKM angle gamma as a function of the B^0_d--\bar{B^0_d} mixing phase
phi_d=2beta, which is fixed through A_{CP}^{mix}(B_d --> J/psi K_S) up to a
twofold ambiguity. If we assume that A_{CP}^{mix}(B_d --> pi^+pi^-) is
positive, as indicated by recent Belle data, and that phi_d is in agreement
with the ``indirect'' fits of the unitarity triangle, also the corresponding
values for gamma around 60 degrees can be accommodated. On the other hand, for
the second solution of phi_d, we obtain a gap around gamma ~ 60 degrees. The
allowed region in the space of A_{CP}^{mix}(B_s --> K^+K^-) and
A_{CP}^{dir}(B_s --> K^+K^-) is very constrained in the Standard Model, thereby
providing a narrow target range for run II of the Tevatron and the experiments
of the LHC era.
| [
{
"created": "Tue, 9 Apr 2002 14:54:07 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Jul 2002 12:03:13 GMT",
"version": "v2"
}
] | 2011-03-23 | [
[
"Fleischer",
"Robert",
""
],
[
"Matias",
"Joaquim",
""
]
] | We investigate allowed regions in observable space of B --> pi K, B_d --> pi^+pi^- and B_s --> K^+K^- decays, characterizing these modes in the Standard Model. After a discussion of a new kind of contour plots for the $B\to\pi K$ system, we focus on the mixing- induced and direct CP asymmetries of the decays B_d --> pi^+pi^- and B_s--> K^+K^-. Using experimental information on the CP-averaged B_d --> pi^{+/-}K^{+/-} and B_d --> pi^+pi^- branching ratios, the relevant hadronic penguin parameters can be constrained,implying certain allowed regions in observable space. In the case of B_d --> pi^+pi^-, an interesting situation arises now in view of the recent B-factory measurements of CP violation in this channel, allowing us to obtain new constraints on the CKM angle gamma as a function of the B^0_d--\bar{B^0_d} mixing phase phi_d=2beta, which is fixed through A_{CP}^{mix}(B_d --> J/psi K_S) up to a twofold ambiguity. If we assume that A_{CP}^{mix}(B_d --> pi^+pi^-) is positive, as indicated by recent Belle data, and that phi_d is in agreement with the ``indirect'' fits of the unitarity triangle, also the corresponding values for gamma around 60 degrees can be accommodated. On the other hand, for the second solution of phi_d, we obtain a gap around gamma ~ 60 degrees. The allowed region in the space of A_{CP}^{mix}(B_s --> K^+K^-) and A_{CP}^{dir}(B_s --> K^+K^-) is very constrained in the Standard Model, thereby providing a narrow target range for run II of the Tevatron and the experiments of the LHC era. |
2402.00100 | Joshua Eby | Joshua Eby and Volodymyr Takhistov | Diffuse Axion Background | 56 pages, 19 figures. Updated with additional references and new
sources of relativistic axion emission | null | null | KEK-QUP-2024-0001, KEK-TH-2596, KEK-Cosmo-0337, IPMU24-0003 | hep-ph astro-ph.CO astro-ph.HE hep-ex | http://creativecommons.org/licenses/by/4.0/ | Relativistic axions can be readily produced in a broad variety of transient
sources, such as axion star bosenova explosions, supernovae or even evaporating
primordial black holes. We develop a general framework describing the resulting
persistent diffuse axion background (D$a$B) due to accumulated axions from
historic transient events. We derive strong constraints on the D$a$B flux from
light axions $m\lesssim 10^{-3}\,{\rm eV}$ emitted from sources with energies
$\omega \gtrsim{\rm MeV}$ considering the non-observation of excess photons
associated with axion-photon coupling from experiments, including COMPTEL,
NuSTAR, XMM-Newton, INTEGRAL, EGRET and Fermi. Future searches in experiments
such as SKA, JWST, XRISM, Vera C. Rubin Observatory, AMEGO/e-ASTROGAM will
allow probing D$a$B and associated axion-photon couplings with unprecedented
sensitivity covering a wide range of possible source energies as low as
$0.1\,\mu$eV and multiple decades in axion masses. We highlight the differences
between astrophysical and dark sector sources of D$a$B. Further, we discuss
complementarity with direct detection as well as prospects for other D$a$B
searches. Our analysis demonstrates that D$a$B can act as a promising probe of
populations of axion emission sources as well as emission mechanisms.
| [
{
"created": "Wed, 31 Jan 2024 19:00:00 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Mar 2024 12:38:54 GMT",
"version": "v2"
}
] | 2024-03-13 | [
[
"Eby",
"Joshua",
""
],
[
"Takhistov",
"Volodymyr",
""
]
] | Relativistic axions can be readily produced in a broad variety of transient sources, such as axion star bosenova explosions, supernovae or even evaporating primordial black holes. We develop a general framework describing the resulting persistent diffuse axion background (D$a$B) due to accumulated axions from historic transient events. We derive strong constraints on the D$a$B flux from light axions $m\lesssim 10^{-3}\,{\rm eV}$ emitted from sources with energies $\omega \gtrsim{\rm MeV}$ considering the non-observation of excess photons associated with axion-photon coupling from experiments, including COMPTEL, NuSTAR, XMM-Newton, INTEGRAL, EGRET and Fermi. Future searches in experiments such as SKA, JWST, XRISM, Vera C. Rubin Observatory, AMEGO/e-ASTROGAM will allow probing D$a$B and associated axion-photon couplings with unprecedented sensitivity covering a wide range of possible source energies as low as $0.1\,\mu$eV and multiple decades in axion masses. We highlight the differences between astrophysical and dark sector sources of D$a$B. Further, we discuss complementarity with direct detection as well as prospects for other D$a$B searches. Our analysis demonstrates that D$a$B can act as a promising probe of populations of axion emission sources as well as emission mechanisms. |
2304.13045 | Daniel Simons | Daniel Simons, Erik Gustafson, and Yannick Meurice | Self-consistent optimization of the $z$-Expansion for $B$ meson decays | null | null | null | null | hep-ph hep-lat | http://creativecommons.org/licenses/by/4.0/ | We discuss the self-consistency imposed by the analyticity of regular parts
of form factors, appearing in the $z$-expansion for semileptonic $B$-meson
decays, when fitted in different kinematic regions. Relying on the uniqueness
of functions defined by analytic continuation, we propose four metrics which
measure the departure from the ideal analytic self-consistency. We illustrate
the process using Belle data for $B\rightarrow D\ell \nu_\ell$. For this
specific example, the metrics provide consistent indications that some choices
(order of truncation, BGL or BCL) made in the form of the $z$-expansion can be
optimized. However, other choices ($z$-origin, location of isolated poles and
threshold constraints) appear to have very little effect on these metrics. We
briefly discuss the implication for optimization of the $z$-expansion for
nucleon form factors relevant for neutrino oscillation experiments.
| [
{
"created": "Tue, 25 Apr 2023 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 10 May 2023 23:11:25 GMT",
"version": "v2"
}
] | 2023-05-12 | [
[
"Simons",
"Daniel",
""
],
[
"Gustafson",
"Erik",
""
],
[
"Meurice",
"Yannick",
""
]
] | We discuss the self-consistency imposed by the analyticity of regular parts of form factors, appearing in the $z$-expansion for semileptonic $B$-meson decays, when fitted in different kinematic regions. Relying on the uniqueness of functions defined by analytic continuation, we propose four metrics which measure the departure from the ideal analytic self-consistency. We illustrate the process using Belle data for $B\rightarrow D\ell \nu_\ell$. For this specific example, the metrics provide consistent indications that some choices (order of truncation, BGL or BCL) made in the form of the $z$-expansion can be optimized. However, other choices ($z$-origin, location of isolated poles and threshold constraints) appear to have very little effect on these metrics. We briefly discuss the implication for optimization of the $z$-expansion for nucleon form factors relevant for neutrino oscillation experiments. |
0902.3267 | Dirk Seidel | Dirk Seidel | Threshold corrections to the gamma t anti-t vertex at O(alpha alpha(s)) | LCWS08 proceedings | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these proceedings a recent calculation of the last missing piece of the
two-loop O(alpha alpha(s)) corrections to gamma t anti-t vertex at the t anti-t
threshold due to the exchange of a W boson and a gluon is summarised. The
calculation constitutes a building block of the top quark threshold production
cross section at electron positron colliders.
| [
{
"created": "Wed, 18 Feb 2009 21:59:08 GMT",
"version": "v1"
}
] | 2009-02-20 | [
[
"Seidel",
"Dirk",
""
]
] | In these proceedings a recent calculation of the last missing piece of the two-loop O(alpha alpha(s)) corrections to gamma t anti-t vertex at the t anti-t threshold due to the exchange of a W boson and a gluon is summarised. The calculation constitutes a building block of the top quark threshold production cross section at electron positron colliders. |
2106.14297 | Raghunath Sahoo | Girija Sankar Pradhan, Dushmanta Sahu, Suman Deb, and Raghunath Sahoo | Hadron gas in the presence of a magnetic field using non-extensive
statistics: A transition from diamagnetic to paramagnetic system | Same as the published version | J. Phys. G: Nucl. Part. Phys. 50 (2023) 055104 | 10.1088/1361-6471/acc478 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by-sa/4.0/ | Non-central heavy-ion collisions at ultra-relativistic energies are unique in
producing magnetic fields of the largest strength in the laboratory. Such
fields being produced at the early stages of the collision could affect the
properties of Quantum Chromodynamics (QCD) matter formed in the relativistic
heavy-ion collisions. The transient magnetic field leaves its reminiscence,
which in principle, can affect the thermodynamic and transport properties of
the final state dynamics of the system. In this work, we study the
thermodynamic properties of a hadron gas in the presence of an external static
magnetic field using a thermodynamically consistent non-extensive Tsallis
distribution function. Various thermodynamical observables such as energy
density ($\epsilon$), entropy density ($s$), pressure ($P$) and speed of sound
($c_{\rm s}$) are studied. Investigation of magnetization ($M$) is also
performed and this analysis reveals an interplay of diamagnetic and
paramagnetic nature of the system in the presence of a magnetic field of
varying strength. Further, to understand the system dynamics under equilibrium
and non-equilibrium conditions, the effect of the non-extensive parameter ($q$)
on the above observables is also studied.
| [
{
"created": "Sun, 27 Jun 2021 17:52:16 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Apr 2023 05:56:08 GMT",
"version": "v2"
}
] | 2023-04-11 | [
[
"Pradhan",
"Girija Sankar",
""
],
[
"Sahu",
"Dushmanta",
""
],
[
"Deb",
"Suman",
""
],
[
"Sahoo",
"Raghunath",
""
]
] | Non-central heavy-ion collisions at ultra-relativistic energies are unique in producing magnetic fields of the largest strength in the laboratory. Such fields being produced at the early stages of the collision could affect the properties of Quantum Chromodynamics (QCD) matter formed in the relativistic heavy-ion collisions. The transient magnetic field leaves its reminiscence, which in principle, can affect the thermodynamic and transport properties of the final state dynamics of the system. In this work, we study the thermodynamic properties of a hadron gas in the presence of an external static magnetic field using a thermodynamically consistent non-extensive Tsallis distribution function. Various thermodynamical observables such as energy density ($\epsilon$), entropy density ($s$), pressure ($P$) and speed of sound ($c_{\rm s}$) are studied. Investigation of magnetization ($M$) is also performed and this analysis reveals an interplay of diamagnetic and paramagnetic nature of the system in the presence of a magnetic field of varying strength. Further, to understand the system dynamics under equilibrium and non-equilibrium conditions, the effect of the non-extensive parameter ($q$) on the above observables is also studied. |
1705.04365 | Valentin V. Khoze | Valentin V. Khoze | Multiparticle production in the large lambda n limit: Realising
Higgsplosion in a scalar QFT | 21 pages, 2 figures, v2: minor corrections, matches version accepted
in JHEP, v3: extended discussion below Eq. (4.10), minor corrections, v4: few
typos (signs and factors) corrected in intermediate results | null | 10.1007/JHEP06(2017)148 | IPPP/17/36 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a scalar theory which we use as a simplified model for the Higgs sector,
we adopt the semiclassical formalism of Son for computations of $n$-particle
production cross-sections in the high-multiplicity $n\to \infty$ weak-coupling
$\lambda \to 0$ regime with the value of $\lambda n$ held fixed and large. The
approach relies on the use of singular classical solutions to a certain
boundary value problem. In the past this formalism has been successfully used
and verified in computations of perturbative multi-particle processes at
tree-level, and also at the next-to-leading order level in the small $\lambda
n$ expansion near the multi-particle mass threshold. We apply this singular
solutions formalism in the regime of ultra-high multiplicities where $\lambda n
\gg 1$, and compute the leading positive $\sim n\,\sqrt{\lambda n}$
contribution to the exponent of the multi-particle rate in this large $\lambda
n$ limit. The computation is carried out near the multi-particle mass threshold
where the multiplicity $n$ approaches its maximal value allowed by kinematics.
This calculation relies on the idea of Gorsky and Voloshin to use a thin wall
approximation for the singular solutions that resemble critical bubbles. This
approximation is justified in precisely the high-multiplicity $\sqrt{\lambda n}
\to \infty$ regime of interest. Based on our results we show that the scalar
theory with a spontaneous symmetry breaking used here as a simplified model for
the Higgs sector, is very likely to realise the high-energy Higgsplosion
phenomenon.
| [
{
"created": "Thu, 11 May 2017 19:37:42 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Jun 2017 14:54:41 GMT",
"version": "v2"
},
{
"created": "Fri, 17 Nov 2017 18:09:28 GMT",
"version": "v3"
},
{
"created": "Wed, 13 Jun 2018 07:24:01 GMT",
"version": "v4"
}
] | 2018-06-14 | [
[
"Khoze",
"Valentin V.",
""
]
] | In a scalar theory which we use as a simplified model for the Higgs sector, we adopt the semiclassical formalism of Son for computations of $n$-particle production cross-sections in the high-multiplicity $n\to \infty$ weak-coupling $\lambda \to 0$ regime with the value of $\lambda n$ held fixed and large. The approach relies on the use of singular classical solutions to a certain boundary value problem. In the past this formalism has been successfully used and verified in computations of perturbative multi-particle processes at tree-level, and also at the next-to-leading order level in the small $\lambda n$ expansion near the multi-particle mass threshold. We apply this singular solutions formalism in the regime of ultra-high multiplicities where $\lambda n \gg 1$, and compute the leading positive $\sim n\,\sqrt{\lambda n}$ contribution to the exponent of the multi-particle rate in this large $\lambda n$ limit. The computation is carried out near the multi-particle mass threshold where the multiplicity $n$ approaches its maximal value allowed by kinematics. This calculation relies on the idea of Gorsky and Voloshin to use a thin wall approximation for the singular solutions that resemble critical bubbles. This approximation is justified in precisely the high-multiplicity $\sqrt{\lambda n} \to \infty$ regime of interest. Based on our results we show that the scalar theory with a spontaneous symmetry breaking used here as a simplified model for the Higgs sector, is very likely to realise the high-energy Higgsplosion phenomenon. |
hep-ph/0511113 | Andreas Vogt | S. Moch (DESY, Zeuthen), A. Vogt (Durham Univ., IPPP), J. Vermaseren
(NIKHEF, Amsterdam) | Sudakov Resummations at Higher Orders | 12 pages, LaTeX, 2 eps-figures. Uses modification appbav.cls
(included) of the appolb.cls style. Presented by S.M. and A.V. at the
conferences `Matter to the Deepest', Ustron (Poland), September '05, and
RADCOR 2005, Shonan Village (Japan), October '05. To appear, in the latter
case in shortened form, in the proceedings | Nucl.Phys.Proc.Suppl. 157 (2006) 179-186; Acta Phys.Polon. B36
(2005) 3295-3308 | 10.1016/j.nuclphysbps.2006.03.022 | DESY 05-226, DCPT/05/140, IPPP/05/70 | hep-ph | null | We summarize our recent results on the resummation of hard-scattering
coefficient functions and on-shell form factors in massless perturbative QCD.
The threshold resummation has been extended to the fourth logarithmic order for
deep-inelastic scattering, Drell-Yan lepton pair production and Higgs
production via gluon-gluon fusion. The leading six infrared pole terms have
been derived to all orders in the strong coupling constant for the
photon-quark-quark and the (heavy-top) Higgs-gluon-gluon form factors. These
results have many implications, most notably they lead to a new best estimate
for the Higgs production cross section at the LHC.
| [
{
"created": "Wed, 9 Nov 2005 12:49:21 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Moch",
"S.",
"",
"DESY, Zeuthen"
],
[
"Vogt",
"A.",
"",
"Durham Univ., IPPP"
],
[
"Vermaseren",
"J.",
"",
"NIKHEF, Amsterdam"
]
] | We summarize our recent results on the resummation of hard-scattering coefficient functions and on-shell form factors in massless perturbative QCD. The threshold resummation has been extended to the fourth logarithmic order for deep-inelastic scattering, Drell-Yan lepton pair production and Higgs production via gluon-gluon fusion. The leading six infrared pole terms have been derived to all orders in the strong coupling constant for the photon-quark-quark and the (heavy-top) Higgs-gluon-gluon form factors. These results have many implications, most notably they lead to a new best estimate for the Higgs production cross section at the LHC. |
1604.01039 | Jonathan Cornell | Jeremie Choquette, James M. Cline, Jonathan M. Cornell | p-wave Annihilating Dark Matter from a Decaying Predecessor and the
Galactic Center Excess | 14 pages, 9 figures, 2 tables. Added discussion of isotropic
gamma-ray background and effect of substructure on galaxy cluster limits.
Matches published version | Phys. Rev. D 94, 015018 (2016) | 10.1103/PhysRevD.94.015018 | null | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dark matter (DM) annihilations have been widely studied as a possible
explanation of excess gamma rays from the galactic center seen by Fermi/LAT.
However most such models are in conflict with constraints from dwarf
spheroidals. Motivated by this tension, we show that p-wave annihilating dark
matter can easily accommodate both sets of observations due to the lower DM
velocity dispersion in dwarf galaxies. Explaining the DM relic abundance is
then challenging. We outline a scenario in which the usual thermal abundance is
obtained through s-wave annihilations of a metastable particle, that eventually
decays into the p-wave annihilating DM of the present epoch. The couplings and
lifetime of the decaying particle are constrained by big bang nucleosynthesis,
the cosmic microwave background and direct detection, but significant regions
of parameter space are viable. A sufficiently large p-wave cross section can be
found by annihilation into light mediators, that also give rise to Sommerfeld
enhancement. A prediction of the scenario is enhanced annihilations in galaxy
clusters.
| [
{
"created": "Mon, 4 Apr 2016 20:01:13 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Apr 2016 02:53:22 GMT",
"version": "v2"
},
{
"created": "Thu, 21 Jul 2016 03:01:09 GMT",
"version": "v3"
}
] | 2016-07-22 | [
[
"Choquette",
"Jeremie",
""
],
[
"Cline",
"James M.",
""
],
[
"Cornell",
"Jonathan M.",
""
]
] | Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the galactic center seen by Fermi/LAT. However most such models are in conflict with constraints from dwarf spheroidals. Motivated by this tension, we show that p-wave annihilating dark matter can easily accommodate both sets of observations due to the lower DM velocity dispersion in dwarf galaxies. Explaining the DM relic abundance is then challenging. We outline a scenario in which the usual thermal abundance is obtained through s-wave annihilations of a metastable particle, that eventually decays into the p-wave annihilating DM of the present epoch. The couplings and lifetime of the decaying particle are constrained by big bang nucleosynthesis, the cosmic microwave background and direct detection, but significant regions of parameter space are viable. A sufficiently large p-wave cross section can be found by annihilation into light mediators, that also give rise to Sommerfeld enhancement. A prediction of the scenario is enhanced annihilations in galaxy clusters. |
2407.00627 | Sheng-Qin Feng | Xiao-Long Wang and Sheng-Qin Feng | Rotation effect on the spectral function of heavy vector mesons in
holographic QCD | 17 pages, 7 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Exploring heavy vector mesons of the $ J / \psi$ and $ \Upsilon ( 1 S )$ is
crucial for understanding the quark gluon plasma (QGP) formed in heavy ion
collisions. The influences of rotational effect on the properties of the $ J /
\psi$ and the $ \Upsilon ( 1 S )$ are investigated by incorporating rotation
medium into the holographic QCD. It is found that temperature, chemical
potential, and rotational radius effects enhance the dissociation process of
the $ J / \psi$ and the $ \Upsilon ( 1 S )$ states within the medium. This
rotation-induced effect is more significant for heavy vector mesons in the
transverse direction than that of the longitudinal direction. The first
holographic study on the influence of the radius of a homogeneous rotating
system on the vector meson spectrum is proposed. It is found that increasing in
rotation radius promotes the dissociation of vector mesons of the $ J / \psi$
and $ \Upsilon ( 1 S )$. We also find that the dissociation perpendicular to
the direction of rotational angular velocity is more significant than that
parallel to it at large rational radius.
| [
{
"created": "Sun, 30 Jun 2024 08:53:25 GMT",
"version": "v1"
}
] | 2024-07-02 | [
[
"Wang",
"Xiao-Long",
""
],
[
"Feng",
"Sheng-Qin",
""
]
] | Exploring heavy vector mesons of the $ J / \psi$ and $ \Upsilon ( 1 S )$ is crucial for understanding the quark gluon plasma (QGP) formed in heavy ion collisions. The influences of rotational effect on the properties of the $ J / \psi$ and the $ \Upsilon ( 1 S )$ are investigated by incorporating rotation medium into the holographic QCD. It is found that temperature, chemical potential, and rotational radius effects enhance the dissociation process of the $ J / \psi$ and the $ \Upsilon ( 1 S )$ states within the medium. This rotation-induced effect is more significant for heavy vector mesons in the transverse direction than that of the longitudinal direction. The first holographic study on the influence of the radius of a homogeneous rotating system on the vector meson spectrum is proposed. It is found that increasing in rotation radius promotes the dissociation of vector mesons of the $ J / \psi$ and $ \Upsilon ( 1 S )$. We also find that the dissociation perpendicular to the direction of rotational angular velocity is more significant than that parallel to it at large rational radius. |
1212.4671 | Long-Fei Gan | Long-Fei Gan, Yong-Lu Liu, Wen-Bo Chen, Ming-Qiu Huang | Improved Light-cone QCD Sum Rule Analysis Of The Rare Decays
$\Lambda_b\rightarrow\Lambda\gamma$ And $\Lambda_b\rightarrow\Lambda l^+l^-$ | 21 pages,4 figures | Communications in Theoretical Physics 58(6)(2012)872-882 | 10.1088/0253-6102/58/6/14 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a systematic light-cone QCD sum rule study of the exclusive rare
radiative decay $\Lambda_b\rightarrow\Lambda\gamma$ and rare semileptonic decay
$\Lambda_b\rightarrow\Lambda l^+l^-$ within the framework of the standard
model. Although some LCSR studies on these rare processes can be found in
different literatures, it is necessary to reanalyze them systematically for the
reason that either the baryonic distribution amplitudes are improved or
different interpolating currents for the $\Lambda_b$ baryon may lead to quite
different results. In addition, the rare process
$\Lambda_b\rightarrow\Lambda\gamma$ has not yet been analyzed by LCSR with the
Ioffe-type current. Taking all these reasons into account, we perform LCSR
calculations of both the processes with two types of interpolating currents.
Our calculations show that the choice of the interpolating current for the
$\Lambda_b$ baryon can affect the predictions significantly, especially for the
rare radiative decay process.
| [
{
"created": "Wed, 19 Dec 2012 14:34:23 GMT",
"version": "v1"
}
] | 2015-06-12 | [
[
"Gan",
"Long-Fei",
""
],
[
"Liu",
"Yong-Lu",
""
],
[
"Chen",
"Wen-Bo",
""
],
[
"Huang",
"Ming-Qiu",
""
]
] | We present a systematic light-cone QCD sum rule study of the exclusive rare radiative decay $\Lambda_b\rightarrow\Lambda\gamma$ and rare semileptonic decay $\Lambda_b\rightarrow\Lambda l^+l^-$ within the framework of the standard model. Although some LCSR studies on these rare processes can be found in different literatures, it is necessary to reanalyze them systematically for the reason that either the baryonic distribution amplitudes are improved or different interpolating currents for the $\Lambda_b$ baryon may lead to quite different results. In addition, the rare process $\Lambda_b\rightarrow\Lambda\gamma$ has not yet been analyzed by LCSR with the Ioffe-type current. Taking all these reasons into account, we perform LCSR calculations of both the processes with two types of interpolating currents. Our calculations show that the choice of the interpolating current for the $\Lambda_b$ baryon can affect the predictions significantly, especially for the rare radiative decay process. |
hep-ph/9812460 | Emanuel Norrbin | Emanuel Norrbin | Heavy Quark Fragmentation | 10 pages, 6 figures, to appear in the proceedings of the Workshop on
Heavy Quarks at Fixed Target, editors H.W.K. Cheung and J.N. Butler | null | 10.1063/1.57765 | LU TP 98-24 | hep-ph | null | I present the main aspects of open charm production in $\pi^-\p$ collisions
in the context of the Lund String Fragmentation Model as implemented in the
Monte Carlo program PYTHIA. The emphasis is on the transition from large to
small strings and the dependence on model parameters. A modified version is
presented and compared with experimental results both on asymmetries,
single-charm spectra and correlations.
| [
{
"created": "Mon, 21 Dec 1998 17:29:00 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Norrbin",
"Emanuel",
""
]
] | I present the main aspects of open charm production in $\pi^-\p$ collisions in the context of the Lund String Fragmentation Model as implemented in the Monte Carlo program PYTHIA. The emphasis is on the transition from large to small strings and the dependence on model parameters. A modified version is presented and compared with experimental results both on asymmetries, single-charm spectra and correlations. |
hep-ph/0310213 | Baldicchi Massimiliano | M. Baldicchi, G. M. Prosperi | Light mesons and infrared behavior of the running coupling constant in
QCD | 20 pages, 3 figures. This is an expanded version of the proceeding of
the talk given at the "International Conference on Color Confinement and
Hadrons in Quantum Chromodynamics (Confinement 2003)", Riken,Tokyo, July
21-24, 2003 | null | 10.1142/9789812702845_0014 | null | hep-ph | null | A previous method for handling bound states in QCD is briefly revisited.
Taking advantage of the Feynman-Schwinger representation for the iterated quark
propagator in an external field, it is possible to give closed representations
for certain appropriate (second order) two point and four point Green
functions, H^(2)(x-y) and H^(4)(x_1,x_2,y_1,y_2), as path integrals on quark
world lines. Then, starting from reasonable assumptions on the Wilson line
correlators, a Bethe-Salpeter equation for H^(4) and a Dyson-Schwinger equation
for H^(2) can be obtained, which are consistent with the Goldstone theorem in
the chiral limit. Such equations are too complicate to be solved directly.
However, a reduced Salpeter equation can be derived which is tractable and has
been applied to a calculation of the meson spectrum. The results are in general
good agreement with the data, but with the important exceptions of the light
pseudo scalars (that are related to the breaking of the chiral symmetry). In
this scenario two important improvements can be introduced: a) the fixed
coupling constant can be replaced by a running coupling constant
\alpha_{s}(Q^2) appropriately modified in the infrared region; b) the fixed
mass in the reduced equation can be replaced for light quarks by an effective
mass depending on the momentum of the particle, as suggested by the form of the
DS equation. Then even the light pseudo scalar mesons can be made to agree with
to their experimental value.
| [
{
"created": "Fri, 17 Oct 2003 14:54:51 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Baldicchi",
"M.",
""
],
[
"Prosperi",
"G. M.",
""
]
] | A previous method for handling bound states in QCD is briefly revisited. Taking advantage of the Feynman-Schwinger representation for the iterated quark propagator in an external field, it is possible to give closed representations for certain appropriate (second order) two point and four point Green functions, H^(2)(x-y) and H^(4)(x_1,x_2,y_1,y_2), as path integrals on quark world lines. Then, starting from reasonable assumptions on the Wilson line correlators, a Bethe-Salpeter equation for H^(4) and a Dyson-Schwinger equation for H^(2) can be obtained, which are consistent with the Goldstone theorem in the chiral limit. Such equations are too complicate to be solved directly. However, a reduced Salpeter equation can be derived which is tractable and has been applied to a calculation of the meson spectrum. The results are in general good agreement with the data, but with the important exceptions of the light pseudo scalars (that are related to the breaking of the chiral symmetry). In this scenario two important improvements can be introduced: a) the fixed coupling constant can be replaced by a running coupling constant \alpha_{s}(Q^2) appropriately modified in the infrared region; b) the fixed mass in the reduced equation can be replaced for light quarks by an effective mass depending on the momentum of the particle, as suggested by the form of the DS equation. Then even the light pseudo scalar mesons can be made to agree with to their experimental value. |
1208.5722 | Thomas A. Trainor | Thomas A. Trainor | The "soft ridge" - is it initial-state geometry or modified jets? | 8 pages, 10 figures, Talk given at the 11th International Conference
on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June
1, 2012. To appear in the NN2012 Proceedings in Journal of Physics:
Conference Series (JPCS) | null | 10.1088/1742-6596/420/1/012026 | null | hep-ph nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A same-side (SS, on azimuth $\phi$) 2D peak in measured angular correlations
from 200 GeV \pp collisions exhibits properties expected for jet formation. In
more-central \auau collisions the SS peak becomes elongated on pseudorapidity
$\eta$ and the transverse momentum $p_t$ structure is modified. In the latter
case the SS 2D peak has been referred to as a "Soft Ridge", and arguments have
been presented that the elongated peak represents flow phenomena ("triangular"
and "higher harmonic" flows), possibly related to the initial-state \aa
geometry. In this presentation I demonstrate that "higher harmonic flows" are
related to SS 2D peak properties and review evidence for a jet interpretation
of the SS peak for all \auau centralities.
| [
{
"created": "Tue, 28 Aug 2012 17:24:47 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Trainor",
"Thomas A.",
""
]
] | A same-side (SS, on azimuth $\phi$) 2D peak in measured angular correlations from 200 GeV \pp collisions exhibits properties expected for jet formation. In more-central \auau collisions the SS peak becomes elongated on pseudorapidity $\eta$ and the transverse momentum $p_t$ structure is modified. In the latter case the SS 2D peak has been referred to as a "Soft Ridge", and arguments have been presented that the elongated peak represents flow phenomena ("triangular" and "higher harmonic" flows), possibly related to the initial-state \aa geometry. In this presentation I demonstrate that "higher harmonic flows" are related to SS 2D peak properties and review evidence for a jet interpretation of the SS peak for all \auau centralities. |
1406.0567 | Luan Cheng | Luan Cheng, Jia Liu, Enke Wang | Flow Effects on Jet Energy Loss with Detailed Balance | arXiv admin note: substantial text overlap with arXiv:0902.1896 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the presence of collective flow a new model potential describing the
interaction of the hard jet with scattering centers is derived based on the
static color-screened Yukawa potential. The flow effect on jet quenching with
detailed balance is investigated in pQCD. It turns out, considering the
collective flow with velocity $v_z$ along the jet direction, the collective
flow decreases the LPM destructive interference comparing to that in the static
medium. The gluon absorption plays a more important role in the moving medium.
The collective flow increases the energy gain from gluon absorption, however,
decreases the energy loss from gluon radiation, which is $(1 - v_z )$ times as
that in the static medium to the first order of opacity. In the presence of
collective flow, the second order in opacity correction is relatively small
compared to the first order. So that the total effective energy loss is
decreased. The flow dependence of the energy loss will affect the suppression
of high $p_T$ hadron spectrum and anisotropy parameter $v_2$ in high-energy
heavy-ion collisions.
| [
{
"created": "Tue, 3 Jun 2014 03:04:29 GMT",
"version": "v1"
}
] | 2014-06-04 | [
[
"Cheng",
"Luan",
""
],
[
"Liu",
"Jia",
""
],
[
"Wang",
"Enke",
""
]
] | In the presence of collective flow a new model potential describing the interaction of the hard jet with scattering centers is derived based on the static color-screened Yukawa potential. The flow effect on jet quenching with detailed balance is investigated in pQCD. It turns out, considering the collective flow with velocity $v_z$ along the jet direction, the collective flow decreases the LPM destructive interference comparing to that in the static medium. The gluon absorption plays a more important role in the moving medium. The collective flow increases the energy gain from gluon absorption, however, decreases the energy loss from gluon radiation, which is $(1 - v_z )$ times as that in the static medium to the first order of opacity. In the presence of collective flow, the second order in opacity correction is relatively small compared to the first order. So that the total effective energy loss is decreased. The flow dependence of the energy loss will affect the suppression of high $p_T$ hadron spectrum and anisotropy parameter $v_2$ in high-energy heavy-ion collisions. |
1707.07228 | Vinicius Rodrigues Debastiani | V. R. Debastiani, Wei-Hong Liang, Ju-Jun Xie and E. Oset | Production of $f_0(500)$, $f_0(980)$ and $a_0(980)$ in the $\chi_{c1}
\to \eta \pi^+ \pi^-$ and $\eta_c \to \eta \pi^+ \pi^-$ decays | Presented at Excited QCD 2017, Sintra (Portugal), 7-13 May 2017, 6
pages, 5 figures | Acta Phys. Polon. Supp. 10, no. 4, 1067 (2017) | 10.5506/APhysPolBSupp.10.1067 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the chiral unitary approach in coupled channels and $SU(3)$ symmetry we
describe the production of $f_0(500)$, $f_0(980)$ and $a_0(980)$ in the
$\chi_{c1} \to \eta \pi^+ \pi^-$ reaction, recently performed by the BESIII
collaboration. A very strong peak for the $a_0(980)$ can be seen in the
$\eta\pi$ invariant mass, while clear signals for the $f_0(500)$ and $f_0(980)$
appear in the one of $\pi^+\pi^-$. Next, we make predictions for the analogous
decay $\eta_c \to \eta \pi^+ \pi^-$, which could also be measured
experimentally. We discuss the differences of these reactions which are
interesting to test the picture where these scalar mesons are dynamically
generated from the interaction of pairs of pseudoscalars.
| [
{
"created": "Sat, 22 Jul 2017 22:55:10 GMT",
"version": "v1"
}
] | 2018-04-03 | [
[
"Debastiani",
"V. R.",
""
],
[
"Liang",
"Wei-Hong",
""
],
[
"Xie",
"Ju-Jun",
""
],
[
"Oset",
"E.",
""
]
] | Using the chiral unitary approach in coupled channels and $SU(3)$ symmetry we describe the production of $f_0(500)$, $f_0(980)$ and $a_0(980)$ in the $\chi_{c1} \to \eta \pi^+ \pi^-$ reaction, recently performed by the BESIII collaboration. A very strong peak for the $a_0(980)$ can be seen in the $\eta\pi$ invariant mass, while clear signals for the $f_0(500)$ and $f_0(980)$ appear in the one of $\pi^+\pi^-$. Next, we make predictions for the analogous decay $\eta_c \to \eta \pi^+ \pi^-$, which could also be measured experimentally. We discuss the differences of these reactions which are interesting to test the picture where these scalar mesons are dynamically generated from the interaction of pairs of pseudoscalars. |
1308.4097 | Dong Phung Van | P. V. Dong, T. Phong Nguyen, D. V. Soa | The 3-3-1 model with inert scalar triplet | 28 pages, 2 figures, revised version, to appear in PRD | Phys. Rev. D 88, 095014 (2013) | 10.1103/PhysRevD.88.095014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that the typical 3-3-1 models are only self-consistent if they
contain interactions explicitly violating the lepton number. The 3-3-1 model
with right-handed neutrinos can by itself work as an economical 3-3-1 model as
a natural recognition of the above criteria while it also results an inert
scalar triplet (\eta) responsible for dark matter. This is ensured by a Z_2
symmetry (assigned so that only \eta is odd while all other multiplets which
perform the economical 3-3-1 model are even), which is not broken by the
vacuum. The minimal 3-3-1 model can provide a dark matter by a similar
realization. Taking the former into account, we show that the dark matter
candidate (H_\eta) contained in \eta transforms as a singlet in effective limit
under the standard model symmetry and being naturally heavy. The H_\eta relic
density and direct detection cross-section will get right values when the
H_\eta mass is in TeV range as expected. The model predicts the H_\eta mass
m_{H_\eta}=\lambda_5\times 2 TeV and the H_\eta-nucleon scattering
cross-section \sigma_{H_\eta-N}=1.56\times 10^{-44} cm^2, provided that the new
neutral Higgs boson is heavy enough than the dark matter.
| [
{
"created": "Mon, 19 Aug 2013 18:55:04 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Nov 2013 09:49:14 GMT",
"version": "v2"
}
] | 2013-11-21 | [
[
"Dong",
"P. V.",
""
],
[
"Nguyen",
"T. Phong",
""
],
[
"Soa",
"D. V.",
""
]
] | We show that the typical 3-3-1 models are only self-consistent if they contain interactions explicitly violating the lepton number. The 3-3-1 model with right-handed neutrinos can by itself work as an economical 3-3-1 model as a natural recognition of the above criteria while it also results an inert scalar triplet (\eta) responsible for dark matter. This is ensured by a Z_2 symmetry (assigned so that only \eta is odd while all other multiplets which perform the economical 3-3-1 model are even), which is not broken by the vacuum. The minimal 3-3-1 model can provide a dark matter by a similar realization. Taking the former into account, we show that the dark matter candidate (H_\eta) contained in \eta transforms as a singlet in effective limit under the standard model symmetry and being naturally heavy. The H_\eta relic density and direct detection cross-section will get right values when the H_\eta mass is in TeV range as expected. The model predicts the H_\eta mass m_{H_\eta}=\lambda_5\times 2 TeV and the H_\eta-nucleon scattering cross-section \sigma_{H_\eta-N}=1.56\times 10^{-44} cm^2, provided that the new neutral Higgs boson is heavy enough than the dark matter. |
hep-ph/9710332 | Arthur Lue | Arthur Lue (Columbia U.) | Quantum Effects on Higgs Winding Configurations | 6 pages REVTEX, no figures. To be published in the proceedings of A
CRM-Fields-CAP Summer Workshop in Theoretical Physics: Solitons, Properties,
Dynamics, Interactions and Applications, Kingston, Ontario, Canada, 20-26 Jul
1997 | null | null | CU-TP-865 | hep-ph | null | We examine the quantum corrections to the static energy for Higgs winding
configurations. We evaluate the effective action for such configurations in
Weinberg-Salam theory without U(1)-gauge fields or fermions. For a
configuration whose size is much smaller than the inverse W-mass, quantum
contributions to the energy are comparable to the classical energy. Moreover,
it is insufficient to consider only one-loop corrections, even as hbar --> 0.
Indeed, all loop orders contribute equally to the static energy. Nevertheless,
quantum fluctuations do not stabilize winding configurations.
| [
{
"created": "Mon, 13 Oct 1997 14:29:56 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lue",
"Arthur",
"",
"Columbia U."
]
] | We examine the quantum corrections to the static energy for Higgs winding configurations. We evaluate the effective action for such configurations in Weinberg-Salam theory without U(1)-gauge fields or fermions. For a configuration whose size is much smaller than the inverse W-mass, quantum contributions to the energy are comparable to the classical energy. Moreover, it is insufficient to consider only one-loop corrections, even as hbar --> 0. Indeed, all loop orders contribute equally to the static energy. Nevertheless, quantum fluctuations do not stabilize winding configurations. |
1502.04057 | Markus Huber Q. | Markus Q. Huber | On gluon and ghost propagators in linear covariant gauges | 9 pages, 3 figures, agrees with version published in PRD | Phys. Rev. D 91, 085018 (2015) | 10.1103/PhysRevD.91.085018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the gluon and ghost propagators of Yang-Mills theory in linear
covariant gauges from the coupled system of Dyson-Schwinger equations. For
small values of the gauge fixing parameter $\xi\sim 0.1$, the deviations to the
Landau gauge already become clearly visible. For the ghost dressing function,
this is reflected in a logarithmic infrared suppression. Also, the gluon
dressing function changes - but only quantitatively - and the gluon propagator
remains finite at zero momentum. From the results, a running coupling is
extracted.
| [
{
"created": "Fri, 13 Feb 2015 17:01:00 GMT",
"version": "v1"
},
{
"created": "Sun, 12 Apr 2015 15:29:15 GMT",
"version": "v2"
}
] | 2015-04-14 | [
[
"Huber",
"Markus Q.",
""
]
] | We compute the gluon and ghost propagators of Yang-Mills theory in linear covariant gauges from the coupled system of Dyson-Schwinger equations. For small values of the gauge fixing parameter $\xi\sim 0.1$, the deviations to the Landau gauge already become clearly visible. For the ghost dressing function, this is reflected in a logarithmic infrared suppression. Also, the gluon dressing function changes - but only quantitatively - and the gluon propagator remains finite at zero momentum. From the results, a running coupling is extracted. |
2106.13720 | Antonino Di Piazza | A. Di Piazza and T. P\u{a}tuleanu | The electron mass shift in an intense plane wave | 22 pages, 3 figures | Phys. Rev. D 104, 076003 (2021) | 10.1103/PhysRevD.104.076003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Upcoming experiments on the interaction of electrons with intense laser
fields are envisaged to become more and more accurate, which calls for
theoretical computations of rates and probabilities with correspondingly higher
precision. In strong-field QED this requires the knowledge of radiative
corrections to be added to leading-order results. Here, we first derive the
mass operator in momentum space of an off-shell electron in the presence of an
arbitrary plane wave. By taking the average of the mass operator in momentum
space over an on-shell electron state, we obtain a new representation,
equivalent to but more compact than the known one computed in [Sov. Phys. JETP
\textbf{42}, 400 (1975)]. Moreover, we use the obtained mass operator to
determine the electron mass shift in an arbitrary plane wave, which generalizes
the already known expression in a constant crossed field. The spin-dependent
part of the electron mass shift can be related to the anomalous magnetic moment
of the electron in the plane wave. We show that within the locally constant
field approximation it is possible to conveniently define a local expression of
the electron anomalous magnetic moment, which reduces to the known expression
in a constant crossed field. Beyond the locally constant field approximation,
however, the interaction between the electron and the plane wave is non-local
such that it is not possible to conveniently introduce an electron anomalous
magnetic moment.
| [
{
"created": "Fri, 25 Jun 2021 16:00:24 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Oct 2021 14:32:54 GMT",
"version": "v2"
}
] | 2021-10-13 | [
[
"Di Piazza",
"A.",
""
],
[
"Pătuleanu",
"T.",
""
]
] | Upcoming experiments on the interaction of electrons with intense laser fields are envisaged to become more and more accurate, which calls for theoretical computations of rates and probabilities with correspondingly higher precision. In strong-field QED this requires the knowledge of radiative corrections to be added to leading-order results. Here, we first derive the mass operator in momentum space of an off-shell electron in the presence of an arbitrary plane wave. By taking the average of the mass operator in momentum space over an on-shell electron state, we obtain a new representation, equivalent to but more compact than the known one computed in [Sov. Phys. JETP \textbf{42}, 400 (1975)]. Moreover, we use the obtained mass operator to determine the electron mass shift in an arbitrary plane wave, which generalizes the already known expression in a constant crossed field. The spin-dependent part of the electron mass shift can be related to the anomalous magnetic moment of the electron in the plane wave. We show that within the locally constant field approximation it is possible to conveniently define a local expression of the electron anomalous magnetic moment, which reduces to the known expression in a constant crossed field. Beyond the locally constant field approximation, however, the interaction between the electron and the plane wave is non-local such that it is not possible to conveniently introduce an electron anomalous magnetic moment. |
1912.11624 | Bao-Xi Sun | Bao-Xi Sun, Zheng-Ran Zhang, Hai-Lin Wu, Si-Yu Zhao and Fang-Yong Dong | The pseudoscalar meson and baryon octet interaction in the unitary
coupled-channel approximation | 5 pages. Talk given at the XVIII International Conference on Hadron
Spectroscopy and Structure(HADRON2019), August 16-21, Guilin, China | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The pseudoscalar meson-baryon octet interaction is studied within a nonlinear
realized Lagrangian, and then the Bethe-Salpeter equation is solved in the
unitary coupled-channel approximation. In sector of strangeness $S=-1$ and
isospin $I=0$, only one pole is generated dynamically in the 1400MeV region,
which might correspond to the $\Lambda(1405)$ particle. When the case of
strangeness zero is studied, the $s-$ and $u-$ potentials are taken into
account in the kernel, and a resonance state is produced in the 1500MeV region,
which might be a counterpart of the N(1535) particle.
| [
{
"created": "Wed, 25 Dec 2019 08:27:41 GMT",
"version": "v1"
}
] | 2019-12-30 | [
[
"Sun",
"Bao-Xi",
""
],
[
"Zhang",
"Zheng-Ran",
""
],
[
"Wu",
"Hai-Lin",
""
],
[
"Zhao",
"Si-Yu",
""
],
[
"Dong",
"Fang-Yong",
""
]
] | The pseudoscalar meson-baryon octet interaction is studied within a nonlinear realized Lagrangian, and then the Bethe-Salpeter equation is solved in the unitary coupled-channel approximation. In sector of strangeness $S=-1$ and isospin $I=0$, only one pole is generated dynamically in the 1400MeV region, which might correspond to the $\Lambda(1405)$ particle. When the case of strangeness zero is studied, the $s-$ and $u-$ potentials are taken into account in the kernel, and a resonance state is produced in the 1500MeV region, which might be a counterpart of the N(1535) particle. |
hep-ph/0009021 | null | I.I. Bigi | Flavour Dynamics - Central Mysteries of the Standard Model | 21 pages, LaTex, Plenary Talk given at ICHEP2000, July 27 - August 2,
2000, Osaka, Japan; some typos and references corrected | null | null | UND-HEP-00-BIG06 | hep-ph | null | After pointing out the amazing success of the CKM description in
accommodating the phenomenology of flavour changing neutral currents I review
the status of theoretical technologies for extracting CKM parameters from data.
I sketch novel directions, namely attempts to deal with quark-hadron duality in
a (semi)quantitative way and to develop a QCD description of two-body modes of
$B$ mesons. After commenting on predictions for $\epsilon ^{\prime}/\epsilon$
and CP asymmetries in B decays I address indirect probes for New Physics in
$D^0$ oscillations and CP violation, in $K_{\mu 3}$ decays and electric dipole
moments. I describe in which way searching for New Physics in B decays provides
an exciting adventure with novel challenges not encountered before.
| [
{
"created": "Mon, 4 Sep 2000 04:04:52 GMT",
"version": "v1"
},
{
"created": "Sat, 16 Sep 2000 03:49:24 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Bigi",
"I. I.",
""
]
] | After pointing out the amazing success of the CKM description in accommodating the phenomenology of flavour changing neutral currents I review the status of theoretical technologies for extracting CKM parameters from data. I sketch novel directions, namely attempts to deal with quark-hadron duality in a (semi)quantitative way and to develop a QCD description of two-body modes of $B$ mesons. After commenting on predictions for $\epsilon ^{\prime}/\epsilon$ and CP asymmetries in B decays I address indirect probes for New Physics in $D^0$ oscillations and CP violation, in $K_{\mu 3}$ decays and electric dipole moments. I describe in which way searching for New Physics in B decays provides an exciting adventure with novel challenges not encountered before. |
hep-ph/0701021 | Amarjit Soni | David Atwood, Tim Gershon, Masashi Hazumi and Amarjit Soni | Clean Signals of CP-violating and CP-conserving New Physics in B->P V
gamma Decays at B Factories and Hadron Colliders | latex, 16 pages | null | null | BNL-HET-06/15 | hep-ph hep-ex | null | In radiative B decays to final states containing one spin zero meson, one
spin one meson and a photon, the photon polarization can be measured from the
angular distribution of the final state. The P-odd, C-even components of this
distribution lead to triple correlation asymmetries that are very sensitive to
new physics as they are likely to receive only tiny contributions from the
Standard Model. There are also (CP-conserving) forward-backward asymmetries to
which there may be SM contributions of a few percent; nevertheless there is a
data driven means to overcome the SM ``pollution''. These latter observables
can be used to search for a class of New Physics which does not necessarily
possess a new CP-odd phase, and wherein the current structure is different from
the left-handed electroweak theory of the Standard Model. The mode $B^\pm \to
K^\pm \phi \gamma$ is particularly useful due to the relatively large branching
ratio and its distinctive final state but there are dozens of such final states
in the decays of $B_u$, $B_d$ and $B_s$ mesons where the analysis is
applicable. In many cases, after the decay of the spin one resonance, several
of these channels lead to only charged mesons and a photon in the final state,
so they may well be accessible in a hadronic environment in addition, of
course, to $e^+ e^-$ (Super) $B$ Factories. In passing we also briefly explain
why the CP-conserving forward-backward asymmetries in $B \to P V \gamma$ decays
is a more reliable signal of new physics compared to the (CP-conserving)
transverse polarization in $B \to V_1 V_2$ modes even though, of course, the
latter may be somewhat more abundant.
| [
{
"created": "Thu, 4 Jan 2007 12:57:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Atwood",
"David",
""
],
[
"Gershon",
"Tim",
""
],
[
"Hazumi",
"Masashi",
""
],
[
"Soni",
"Amarjit",
""
]
] | In radiative B decays to final states containing one spin zero meson, one spin one meson and a photon, the photon polarization can be measured from the angular distribution of the final state. The P-odd, C-even components of this distribution lead to triple correlation asymmetries that are very sensitive to new physics as they are likely to receive only tiny contributions from the Standard Model. There are also (CP-conserving) forward-backward asymmetries to which there may be SM contributions of a few percent; nevertheless there is a data driven means to overcome the SM ``pollution''. These latter observables can be used to search for a class of New Physics which does not necessarily possess a new CP-odd phase, and wherein the current structure is different from the left-handed electroweak theory of the Standard Model. The mode $B^\pm \to K^\pm \phi \gamma$ is particularly useful due to the relatively large branching ratio and its distinctive final state but there are dozens of such final states in the decays of $B_u$, $B_d$ and $B_s$ mesons where the analysis is applicable. In many cases, after the decay of the spin one resonance, several of these channels lead to only charged mesons and a photon in the final state, so they may well be accessible in a hadronic environment in addition, of course, to $e^+ e^-$ (Super) $B$ Factories. In passing we also briefly explain why the CP-conserving forward-backward asymmetries in $B \to P V \gamma$ decays is a more reliable signal of new physics compared to the (CP-conserving) transverse polarization in $B \to V_1 V_2$ modes even though, of course, the latter may be somewhat more abundant. |
2009.10848 | Anton Motornenko | Anton Motornenko, Somenath Pal, Abhijit Bhattacharyya, Jan
Steinheimer, and Horst Stoecker | Repulsive properties of hadrons in lattice QCD data and neutron stars | 11 pages, 9 figures | Phys. Rev. C 103, 054908 (2021) | 10.1103/PhysRevC.103.054908 | null | hep-ph astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Second-order susceptibilities $\chi^{11}_{ij}$ of baryon, electric, and
strangeness, $B$, $Q$, and $S$, charges, are calculated in the Chiral Mean
Field (CMF) model and compared to available lattice QCD data. The
susceptibilities are sensitive to the short range repulsive interactions
between different hadron species, especially to the hardcore repulsion of
hyperons. Decreasing the hyperons size, as compared to the size of the
non-strange baryons, does improve significantly the agreement of the CMF model
results with the Lattice QCD data. The electric charge-dependent
susceptibilities are sensitive to the short range repulsive volume of mesons.
The comparison with lattice QCD data suggests that strange baryons, non-strange
mesons and strange mesons have significantly smaller excluded volumes than
non-strange baryons. The CMF model with these modified hadron volumes allows
for a mainly hadronic description of the QCD susceptibilities significantly
above the chiral pseudo-critical temperature. This improved CMF model which is
based on the lattice QCD data, has been used to study the properties of both
cold QCD matter and neutron star matter. The phase structure in both cases is
essentially unchanged, i.e. a chiral first-order phase transition occurs at low
temperatures ($T_{\rm CP}\approx 17$ MeV), and hyperons survive deconfinement
to higher densities than non-strange hadrons. The neutron star maximal mass
remains close to 2.1$M_\odot$ and the mass-radius diagram is only modified
slightly due to the appearance of hyperons and is in agreement with
astrophysical observations.
| [
{
"created": "Tue, 22 Sep 2020 22:42:17 GMT",
"version": "v1"
},
{
"created": "Thu, 27 May 2021 09:34:18 GMT",
"version": "v2"
}
] | 2021-05-28 | [
[
"Motornenko",
"Anton",
""
],
[
"Pal",
"Somenath",
""
],
[
"Bhattacharyya",
"Abhijit",
""
],
[
"Steinheimer",
"Jan",
""
],
[
"Stoecker",
"Horst",
""
]
] | Second-order susceptibilities $\chi^{11}_{ij}$ of baryon, electric, and strangeness, $B$, $Q$, and $S$, charges, are calculated in the Chiral Mean Field (CMF) model and compared to available lattice QCD data. The susceptibilities are sensitive to the short range repulsive interactions between different hadron species, especially to the hardcore repulsion of hyperons. Decreasing the hyperons size, as compared to the size of the non-strange baryons, does improve significantly the agreement of the CMF model results with the Lattice QCD data. The electric charge-dependent susceptibilities are sensitive to the short range repulsive volume of mesons. The comparison with lattice QCD data suggests that strange baryons, non-strange mesons and strange mesons have significantly smaller excluded volumes than non-strange baryons. The CMF model with these modified hadron volumes allows for a mainly hadronic description of the QCD susceptibilities significantly above the chiral pseudo-critical temperature. This improved CMF model which is based on the lattice QCD data, has been used to study the properties of both cold QCD matter and neutron star matter. The phase structure in both cases is essentially unchanged, i.e. a chiral first-order phase transition occurs at low temperatures ($T_{\rm CP}\approx 17$ MeV), and hyperons survive deconfinement to higher densities than non-strange hadrons. The neutron star maximal mass remains close to 2.1$M_\odot$ and the mass-radius diagram is only modified slightly due to the appearance of hyperons and is in agreement with astrophysical observations. |
hep-ph/9709436 | Christian Weiss | M.V. Polyakov and C. Weiss | Nucleon structure functions from the instanton vacuum: Leading and
non-leading twists | 13 pages, Latex, 1 figure included using epsf. To appear in
Proceedings of the XXXVII Cracow School of Theoretical Physics, Zakopane, May
30 - June 10, 1997. New references added | Acta Phys.Polon.B28:2751-2764,1997 | null | RUB-TPII-9/97 | hep-ph | null | We review the description of nucleon structure functions in the instanton
vacuum. This includes the calculation of the twist-2 parton distributions at a
low normalization point as well as higher-twist matrix elements. The instanton
vacuum with its inherent small parameter, the packing fraction of the instanton
medium, $\bar\rho / R$, provides a consistent picture of the non-perturbative
gluon degrees of freedom at the scale $\bar\rho^{-1} \simeq 600 MeV$. The
twist-2 quark and antiquark distributions are of order unity, while the twist-2
gluon distribution is of order $(\bar\rho / R)^4$. Twist-4 matrix elements
determining power corrections to the Bjorken, Ellis-Jaffe and
Gross-Llewellyn-Smith sum rules are found to be of order $(\bar\rho / R)^0$. We
present numerical estimates for the parametrically large quantities.
| [
{
"created": "Tue, 23 Sep 1997 21:20:08 GMT",
"version": "v1"
},
{
"created": "Sun, 2 Nov 1997 20:30:34 GMT",
"version": "v2"
}
] | 2011-04-15 | [
[
"Polyakov",
"M. V.",
""
],
[
"Weiss",
"C.",
""
]
] | We review the description of nucleon structure functions in the instanton vacuum. This includes the calculation of the twist-2 parton distributions at a low normalization point as well as higher-twist matrix elements. The instanton vacuum with its inherent small parameter, the packing fraction of the instanton medium, $\bar\rho / R$, provides a consistent picture of the non-perturbative gluon degrees of freedom at the scale $\bar\rho^{-1} \simeq 600 MeV$. The twist-2 quark and antiquark distributions are of order unity, while the twist-2 gluon distribution is of order $(\bar\rho / R)^4$. Twist-4 matrix elements determining power corrections to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules are found to be of order $(\bar\rho / R)^0$. We present numerical estimates for the parametrically large quantities. |
hep-ph/0407327 | V\'eronique Pag\'e | Veronique Page | New Physics Signals through CP Violation in B -> rho,pi | 8 pages, 4 figures, talk given at MRST 2004: From Quarks to
Cosmology, Concordia University, Montreal, May 2004 | Int.J.Mod.Phys. A19 (2004) 5477-5484 | 10.1142/S0217751X04022724 | UdeM-GPP-TH-04-12 | hep-ph | null | We describe here a method for detecting physics beyond the standard model via
CP violation in B->rho,pi decays. Using a Dalitz-plot analysis to obtain alpha,
along with an analytical extraction of the various tree (T) and penguin (P)
amplitudes, we obtain a criterion for the absence of new physics (NP). This
criterion involves the comparison of the measured |P/T| ratio with its value as
predicted by QCD factorization. We show that the detection of NP via this
method has a good efficiency when compared with the corresponding technique
using B->pi,pi decays.
| [
{
"created": "Wed, 28 Jul 2004 23:07:12 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Page",
"Veronique",
""
]
] | We describe here a method for detecting physics beyond the standard model via CP violation in B->rho,pi decays. Using a Dalitz-plot analysis to obtain alpha, along with an analytical extraction of the various tree (T) and penguin (P) amplitudes, we obtain a criterion for the absence of new physics (NP). This criterion involves the comparison of the measured |P/T| ratio with its value as predicted by QCD factorization. We show that the detection of NP via this method has a good efficiency when compared with the corresponding technique using B->pi,pi decays. |
1512.02152 | Dmitry Zhuridov Dr. | Dmitry Zhuridov | Leptomeson contribution to the muon g-2 | 17 pages, 7 figures. v3: references and comments added | Phys. Rev. D 93, 035025 (2016) | 10.1103/PhysRevD.93.035025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Many models on the market allow for particles carrying both lepton number and
color, e.g., leptoquarks and leptogluons. Some of the models with this feature
can also accommodate color-singlet leptohadrons. We have found that the
long-standing discrepancy between the experimental result and the Standard
Model prediction for the muon anomalous magnetic moment can be explained by the
effect of leptomesons within the wide allowed range of their masses and
couplings. These new particles are testable at the current run of the LHC.
| [
{
"created": "Mon, 7 Dec 2015 18:21:47 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Feb 2016 13:13:05 GMT",
"version": "v2"
},
{
"created": "Tue, 8 Mar 2016 09:05:57 GMT",
"version": "v3"
}
] | 2016-03-09 | [
[
"Zhuridov",
"Dmitry",
""
]
] | Many models on the market allow for particles carrying both lepton number and color, e.g., leptoquarks and leptogluons. Some of the models with this feature can also accommodate color-singlet leptohadrons. We have found that the long-standing discrepancy between the experimental result and the Standard Model prediction for the muon anomalous magnetic moment can be explained by the effect of leptomesons within the wide allowed range of their masses and couplings. These new particles are testable at the current run of the LHC. |
1906.07942 | XiaoHai Liu | Xiao-Hai Liu, Gang Li, Ju-Jun Xie, Qiang Zhao | Visible narrow cusp structure in $\Lambda_c^+\to p K^- \pi^+$ enhanced
by triangle singularity | 6 pages, 4 figures | Phys. Rev. D 100, 054006 (2019) | 10.1103/PhysRevD.100.054006 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A resonance-like structure as narrow as 10 MeV is observed in the $K^-p$
invariant mass distributions in $\Lambda_c^+\to p K^- \pi^+$ at Belle. Based on
the large data sample of about 1.5 million events and the small bin width of
just 1 MeV for the $K^-p$ invariant mass spectrum, the narrow peak is found
precisely lying at the $\Lambda\eta$ threshold. While lacking evidence for a
quark model state with such a narrow width at this mass region, we find that
this narrow structure can be naturally identified as a threshold cusp but
enhanced by the nearby triangle singularity via the $\Lambda$-$a_0(980)^+$ or
$\eta$-$\Sigma(1660)^+$ rescatterings.
| [
{
"created": "Wed, 19 Jun 2019 06:59:43 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Jun 2019 10:43:04 GMT",
"version": "v2"
}
] | 2019-09-11 | [
[
"Liu",
"Xiao-Hai",
""
],
[
"Li",
"Gang",
""
],
[
"Xie",
"Ju-Jun",
""
],
[
"Zhao",
"Qiang",
""
]
] | A resonance-like structure as narrow as 10 MeV is observed in the $K^-p$ invariant mass distributions in $\Lambda_c^+\to p K^- \pi^+$ at Belle. Based on the large data sample of about 1.5 million events and the small bin width of just 1 MeV for the $K^-p$ invariant mass spectrum, the narrow peak is found precisely lying at the $\Lambda\eta$ threshold. While lacking evidence for a quark model state with such a narrow width at this mass region, we find that this narrow structure can be naturally identified as a threshold cusp but enhanced by the nearby triangle singularity via the $\Lambda$-$a_0(980)^+$ or $\eta$-$\Sigma(1660)^+$ rescatterings. |
hep-ph/0306272 | Jan Kalinowski | J. Kalinowski | CP-violation in the neutralino system | 9 pages, latex, 2 figures. Dedicated to J. Kwiecinski on his 65th
birthday | Acta Phys.Polon.B34:3441-3449,2003 | null | IFT-03/011 | hep-ph | null | Supersymmetric extensions of the Standard Model provide new sources of CP
violation. Here the CP properties of neutralinos are described and possible
experimental signatures of CP--violation in the neutralino production processes
at e+e- linear colliders are discussed.
| [
{
"created": "Fri, 27 Jun 2003 10:26:04 GMT",
"version": "v1"
}
] | 2009-12-15 | [
[
"Kalinowski",
"J.",
""
]
] | Supersymmetric extensions of the Standard Model provide new sources of CP violation. Here the CP properties of neutralinos are described and possible experimental signatures of CP--violation in the neutralino production processes at e+e- linear colliders are discussed. |
hep-ph/0311076 | Fernand Renard M. | G.J. Gounaris, J. Layssac, P.I. Porfyriadis and F.M. Renard | Neutralino pair production in a $\gamma \gamma$ Collider | 14 pages and 9 figures | Eur.Phys.J.C32:561-574,2004 | 10.1140/epjc/s2003-01520-x | PM/03-27, THES-TP 2003-04 | hep-ph | null | We present a complete 1-loop study of the process $\gamma \gamma \to
\tchi^0_i \tchi^0_j$ and the predicted cross section in a $\gamma\gamma$ Linear
Collider. A suitable numerical code PLATONlc, valid for any set of real MSSM
parameters, is released. This study and code are complementary to those
suitable for Dark Matter detection through the inverse process $\tchi^0_i
\tchi^0_j \to \gamma\gamma$ describing neutralino-neutralino annihilation at
rest, which were presented previously. If SUSY is realized in Nature, both
codes should be very helpful in future astrophysical and collider studies of
the neutralino sector.
| [
{
"created": "Thu, 6 Nov 2003 13:08:55 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Aug 2006 10:22:44 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Gounaris",
"G. J.",
""
],
[
"Layssac",
"J.",
""
],
[
"Porfyriadis",
"P. I.",
""
],
[
"Renard",
"F. M.",
""
]
] | We present a complete 1-loop study of the process $\gamma \gamma \to \tchi^0_i \tchi^0_j$ and the predicted cross section in a $\gamma\gamma$ Linear Collider. A suitable numerical code PLATONlc, valid for any set of real MSSM parameters, is released. This study and code are complementary to those suitable for Dark Matter detection through the inverse process $\tchi^0_i \tchi^0_j \to \gamma\gamma$ describing neutralino-neutralino annihilation at rest, which were presented previously. If SUSY is realized in Nature, both codes should be very helpful in future astrophysical and collider studies of the neutralino sector. |
2304.06298 | Sujay Shil | Arindam Das, Sanjoy Mandal and Sujay Shil | Testing electroweak scale seesaw models at $e^{-} \gamma$ and $\gamma
\gamma$ colliders | 53 pages, 30 figures | Phys. Rev. D 108, 015022 (2023) | 10.1103/PhysRevD.108.015022 | EPHOU-22-017 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the possibilities of probing the electroweak scale seesaw
scenarios such as type-I, type-II and type-III seesaw at $e^-\gamma$ and
$\gamma\gamma$ colliders. For the case of type-I seesaw, the heavy neutrinos
can be produced at $e^{-}\gamma$ colliders in association with a $W$ boson. We
study a variety of final states in this case including single and multilepton
modes in association with jets to estimate bounds on the light-heavy neutrino
mixing angle. In case of type-II seesaw, doubly charged multiplets of the
SU$(2)_L$ triplet scalar can be produced in pair at $\gamma \gamma$ collider.
We study the multi-leptonic decay modes coming from this pair production of
doubly charged Higgs and show how one can probe neutrino mass hierarchy. We
also study same sign $W$ boson production from the doubly charged Higgs to
study multilepton modes in association with missing energy. From the type-III
seesaw, we study same sign dilepton+jets and trilepton+jets modes at
$e^-\gamma$ collider which are coming from the neutral and charged component of
the triplet fermion in association with a $W$ boson and $Z$ boson,
respectively. Due to the existing limits on the triplet fermions from the LHC
we choose heavier mass so that the gauge boson originated from the decay of a
neutral multiplet can be sufficiently boosted producing a fat-jet signature in
association with same sign dilepton and trilepton. Finally we estimate bounds
on the light neutrino-heavy triplet fermion mixing angle and compare with the
existing bounds.
| [
{
"created": "Thu, 13 Apr 2023 07:10:13 GMT",
"version": "v1"
},
{
"created": "Fri, 21 Jul 2023 12:57:10 GMT",
"version": "v2"
}
] | 2023-07-25 | [
[
"Das",
"Arindam",
""
],
[
"Mandal",
"Sanjoy",
""
],
[
"Shil",
"Sujay",
""
]
] | We investigate the possibilities of probing the electroweak scale seesaw scenarios such as type-I, type-II and type-III seesaw at $e^-\gamma$ and $\gamma\gamma$ colliders. For the case of type-I seesaw, the heavy neutrinos can be produced at $e^{-}\gamma$ colliders in association with a $W$ boson. We study a variety of final states in this case including single and multilepton modes in association with jets to estimate bounds on the light-heavy neutrino mixing angle. In case of type-II seesaw, doubly charged multiplets of the SU$(2)_L$ triplet scalar can be produced in pair at $\gamma \gamma$ collider. We study the multi-leptonic decay modes coming from this pair production of doubly charged Higgs and show how one can probe neutrino mass hierarchy. We also study same sign $W$ boson production from the doubly charged Higgs to study multilepton modes in association with missing energy. From the type-III seesaw, we study same sign dilepton+jets and trilepton+jets modes at $e^-\gamma$ collider which are coming from the neutral and charged component of the triplet fermion in association with a $W$ boson and $Z$ boson, respectively. Due to the existing limits on the triplet fermions from the LHC we choose heavier mass so that the gauge boson originated from the decay of a neutral multiplet can be sufficiently boosted producing a fat-jet signature in association with same sign dilepton and trilepton. Finally we estimate bounds on the light neutrino-heavy triplet fermion mixing angle and compare with the existing bounds. |
hep-ph/9807400 | Phillip Page | Leonid Burakovsky and Philip R. Page | Scalar Glueball Mixing and Decay | 25 pages, LaTeX, 1 encapsulated postscript figure. Formula changed in
Appendix A. Eq. (5.1) changed and two-photon width predictions changed | Phys.Rev.D59:014022,1999; Erratum-ibid.D59:079902,1999 | 10.1103/PhysRevD.59.014022 10.1103/PhysRevD.59.079902 | null | hep-ph hep-lat | null | We provide the first explanation of the counter-intuitive scalar glueball
couplings to pseudoscalar mesons found in lattice QCD and predict hitherto
uncalculated decay modes. Significant a_1 pi and (pi pi)_S (pi pi)_S couplings
are found. We demonstrate the equivalence of linear and quadratic mass matrices
for glueball-quarkonium mixing. The equivalence of formalisms which deal with a
glueball-quarkonium basis and only a quarkonium basis is demonstrated. We show
that the f_0(1500) is not the heaviest state arising from glueball-quarkonium
mixing for a glueball mass consistent with lattice QCD. The masses and
couplings of scalar mesons, as well as their valence content, are calculated.
| [
{
"created": "Fri, 17 Jul 1998 00:48:55 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Sep 1998 01:00:56 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Oct 1998 21:31:08 GMT",
"version": "v3"
},
{
"created": "Wed, 25 Nov 1998 23:38:32 GMT",
"version": "v4"
}
] | 2014-11-17 | [
[
"Burakovsky",
"Leonid",
""
],
[
"Page",
"Philip R.",
""
]
] | We provide the first explanation of the counter-intuitive scalar glueball couplings to pseudoscalar mesons found in lattice QCD and predict hitherto uncalculated decay modes. Significant a_1 pi and (pi pi)_S (pi pi)_S couplings are found. We demonstrate the equivalence of linear and quadratic mass matrices for glueball-quarkonium mixing. The equivalence of formalisms which deal with a glueball-quarkonium basis and only a quarkonium basis is demonstrated. We show that the f_0(1500) is not the heaviest state arising from glueball-quarkonium mixing for a glueball mass consistent with lattice QCD. The masses and couplings of scalar mesons, as well as their valence content, are calculated. |
1901.00875 | Sydney Otten | Sydney Otten, Sascha Caron, Wieske de Swart, Melissa van Beekveld, Luc
Hendriks, Caspar van Leeuwen, Damian Podareanu, Roberto Ruiz de Austri and
Rob Verheyen | Event Generation and Statistical Sampling for Physics with Deep
Generative Models and a Density Information Buffer | 22 pages, 9 figures | null | null | null | hep-ph hep-ex physics.data-an | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a study for the generation of events from a physical process with
deep generative models. The simulation of physical processes requires not only
the production of physical events, but also to ensure these events occur with
the correct frequencies. We investigate the feasibility of learning the event
generation and the frequency of occurrence with Generative Adversarial Networks
(GANs) and Variational Autoencoders (VAEs) to produce events like Monte Carlo
generators. We study three processes: a simple two-body decay, the processes
$e^+e^-\to Z \to l^+l^-$ and $p p \to t\bar{t} $ including the decay of the top
quarks and a simulation of the detector response. We find that the tested GAN
architectures and the standard VAE are not able to learn the distributions
precisely. By buffering density information of encoded Monte Carlo events given
the encoder of a VAE we are able to construct a prior for the sampling of new
events from the decoder that yields distributions that are in very good
agreement with real Monte Carlo events and are generated several orders of
magnitude faster. Applications of this work include generic density estimation
and sampling, targeted event generation via a principal component analysis of
encoded ground truth data, anomaly detection and more efficient importance
sampling, e.g. for the phase space integration of matrix elements in quantum
field theories.
| [
{
"created": "Thu, 3 Jan 2019 19:01:09 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Mar 2019 22:52:50 GMT",
"version": "v2"
},
{
"created": "Tue, 11 Jun 2019 10:22:51 GMT",
"version": "v3"
},
{
"created": "Wed, 4 Dec 2019 13:12:01 GMT",
"version": "v4"
},
{
"created": "Thu, 25 Feb 2021 16:27:33 GMT",
"version": "v5"
}
] | 2021-02-26 | [
[
"Otten",
"Sydney",
""
],
[
"Caron",
"Sascha",
""
],
[
"de Swart",
"Wieske",
""
],
[
"van Beekveld",
"Melissa",
""
],
[
"Hendriks",
"Luc",
""
],
[
"van Leeuwen",
"Caspar",
""
],
[
"Podareanu",
"Damian",
""
],
[
"de Austri",
"Roberto Ruiz",
""
],
[
"Verheyen",
"Rob",
""
]
] | We present a study for the generation of events from a physical process with deep generative models. The simulation of physical processes requires not only the production of physical events, but also to ensure these events occur with the correct frequencies. We investigate the feasibility of learning the event generation and the frequency of occurrence with Generative Adversarial Networks (GANs) and Variational Autoencoders (VAEs) to produce events like Monte Carlo generators. We study three processes: a simple two-body decay, the processes $e^+e^-\to Z \to l^+l^-$ and $p p \to t\bar{t} $ including the decay of the top quarks and a simulation of the detector response. We find that the tested GAN architectures and the standard VAE are not able to learn the distributions precisely. By buffering density information of encoded Monte Carlo events given the encoder of a VAE we are able to construct a prior for the sampling of new events from the decoder that yields distributions that are in very good agreement with real Monte Carlo events and are generated several orders of magnitude faster. Applications of this work include generic density estimation and sampling, targeted event generation via a principal component analysis of encoded ground truth data, anomaly detection and more efficient importance sampling, e.g. for the phase space integration of matrix elements in quantum field theories. |
hep-ph/9812371 | Antonio Pineda Ruiz | A. Pineda and F.J. Yndurain | Comment on "Calculation of Quarkonium Spectrum and m_b, m_c to Order
alpha^4" | 7 pages, TeX | Phys.Rev.D61:077505,2000 | 10.1103/PhysRevD.61.077505 | FTUAM/98-27; CERN-TH/98-402 | hep-ph | null | In a recent paper, we included two loop, relativistic one loop and second
order relativistic tree level corrections, plus leading nonperturbative
contributions, to obtain a calculation of the lower states in the heavy
quarkonium spectrum correct up to, and including, $O(\alpha_s^4)$ and leading
$\Lambdav^4/m^4$ terms. The results were obtained with, in particular, the
value of the two loop static coefficient due to Peter; this been recently
challenged by Schr\"oder. In our previous paper we used Peter's result; in the
present one we now give results with Schr\"oder's, as this is likely to be the
correct one. The variation is slight as the value of $b_1$ is only one among
the various $O(\alpha_s^4)$ contributions. With Schr\"oder's expression we now
have, $$m_b=5\,001^{+104}_{-66}\;\mev;\quad
\bar{m}_b(\bar{m}_b^2)=4\,440^{+43}_{-28}\;\mev,$$
$$m_c=1\,866^{+190}_{-154}\;\mev;\quad
\bar{m}_c(\bar{m}_c^2)=1\,531^{+132}_{-127}\;\mev.$$ Moreover,
$$\Gammav(\Upsilonv\rightarrow e^+e^-)=1.07\pm0.28\;\kev
\;(\hbox{exp.}=1.320\pm0.04\,\kev)$$ and the hyperfine splitting is predicted
to be $$M(\Upsilonv)-M(\eta)=47^{+15}_{-13}\;\mev.$$
| [
{
"created": "Tue, 15 Dec 1998 17:02:15 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Pineda",
"A.",
""
],
[
"Yndurain",
"F. J.",
""
]
] | In a recent paper, we included two loop, relativistic one loop and second order relativistic tree level corrections, plus leading nonperturbative contributions, to obtain a calculation of the lower states in the heavy quarkonium spectrum correct up to, and including, $O(\alpha_s^4)$ and leading $\Lambdav^4/m^4$ terms. The results were obtained with, in particular, the value of the two loop static coefficient due to Peter; this been recently challenged by Schr\"oder. In our previous paper we used Peter's result; in the present one we now give results with Schr\"oder's, as this is likely to be the correct one. The variation is slight as the value of $b_1$ is only one among the various $O(\alpha_s^4)$ contributions. With Schr\"oder's expression we now have, $$m_b=5\,001^{+104}_{-66}\;\mev;\quad \bar{m}_b(\bar{m}_b^2)=4\,440^{+43}_{-28}\;\mev,$$ $$m_c=1\,866^{+190}_{-154}\;\mev;\quad \bar{m}_c(\bar{m}_c^2)=1\,531^{+132}_{-127}\;\mev.$$ Moreover, $$\Gammav(\Upsilonv\rightarrow e^+e^-)=1.07\pm0.28\;\kev \;(\hbox{exp.}=1.320\pm0.04\,\kev)$$ and the hyperfine splitting is predicted to be $$M(\Upsilonv)-M(\eta)=47^{+15}_{-13}\;\mev.$$ |
2011.10397 | Shusuke Ueda | Masahiro Kawasaki and Shusuke Ueda | Affleck-Dine inflation in supergravity | 14 pages, 5 figures | null | 10.1088/1475-7516/2021/04/049 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | Affleck-Dine inflation is a recently proposed model in which a single complex
scalar field, nonminimally coupled to gravity, drives inflation and
simultaneously generates the baryon asymmetry of universe via Affleck-Dine
mechanism. In this paper we investigate the supersymmetric implementation of
Affleck-Dine inflation in the use of two chiral superfields with appropriate
superpotential and K\"ahler potential. The scalar potential has a similar form
to the potential of original Affleck-Dine inflation, and it gives successful
inflation and baryogenesis. We also consider the isocurvature perturbation
evolving after crossing the horizon, and find that it is ignorable and hence
consistent with the observations.
| [
{
"created": "Fri, 20 Nov 2020 13:25:27 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Dec 2020 01:02:29 GMT",
"version": "v2"
}
] | 2021-04-28 | [
[
"Kawasaki",
"Masahiro",
""
],
[
"Ueda",
"Shusuke",
""
]
] | Affleck-Dine inflation is a recently proposed model in which a single complex scalar field, nonminimally coupled to gravity, drives inflation and simultaneously generates the baryon asymmetry of universe via Affleck-Dine mechanism. In this paper we investigate the supersymmetric implementation of Affleck-Dine inflation in the use of two chiral superfields with appropriate superpotential and K\"ahler potential. The scalar potential has a similar form to the potential of original Affleck-Dine inflation, and it gives successful inflation and baryogenesis. We also consider the isocurvature perturbation evolving after crossing the horizon, and find that it is ignorable and hence consistent with the observations. |
1209.3747 | Rijun Huang | Bo Feng, Rijun Huang | The classification of two-loop integrand basis in pure four-dimension | 52 pages, 9 figures. v2 reference added, v3 published version | null | 10.1007/JHEP02(2013)117 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we have made the attempt to classify the integrand basis of
all two-loop diagrams in pure four-dimension space-time. Our classification
includes the topology of two-loop diagrams which determines the structure of
denominators, and the set of numerators under different kinematic
configurations of external momenta by using Gr\"{o}bner basis method. In our
study, the variety defined by setting all propagators to on-shell has played an
important role. We discuss the structure of variety and how it splits to
various irreducible branches when external momenta at each corner of diagrams
satisfy some special kinematic conditions. This information is crucial to the
numerical or analytical fitting of coefficients for integrand basis in
reduction process.
| [
{
"created": "Mon, 17 Sep 2012 18:42:23 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Nov 2012 09:57:10 GMT",
"version": "v2"
},
{
"created": "Tue, 19 Mar 2013 08:09:52 GMT",
"version": "v3"
}
] | 2015-06-11 | [
[
"Feng",
"Bo",
""
],
[
"Huang",
"Rijun",
""
]
] | In this paper, we have made the attempt to classify the integrand basis of all two-loop diagrams in pure four-dimension space-time. Our classification includes the topology of two-loop diagrams which determines the structure of denominators, and the set of numerators under different kinematic configurations of external momenta by using Gr\"{o}bner basis method. In our study, the variety defined by setting all propagators to on-shell has played an important role. We discuss the structure of variety and how it splits to various irreducible branches when external momenta at each corner of diagrams satisfy some special kinematic conditions. This information is crucial to the numerical or analytical fitting of coefficients for integrand basis in reduction process. |
1210.7943 | Cai-Dian Lu | Cai-Dian Lu (IHEP, Beijing) | Recent theoretical improvement of hadronic $B_s$ decays | 11 pages, 2 figures, Presented at Flavor Physics and CP Violation
(FPCP 2012), Hefei, China, May 21-25, 2012 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this mini-review, we show that a lot of theoretical efforts have been made
for the theoretical study of two body hadronic $B_{(s)}$ and $B_c$ decays. In
addition to many next-to-leading order or even next-to-next-to leading order
$\alpha_s$ corrections made, we also study many of the previously unknown
next-to-leading order power corrections. While the former corrections are
theoretically solid, the latter corrections are phenomenologically more
important. In the QCD factorization approach based on collinear factorization,
there is difficulty to deal with the power correction diagrams due to the
endpoint singularity. Thus many of these analysis use phenomenological method.
In the perturbative QCD approach based on $k_T$ factorization, the endpoint
singularity is killed by including the quark transverse momentum. Therefore we
can calculate the annihilation type diagrams quantitatively, which give the
right sign for the direct CP asymmetry parameters. More and more $B_{(s)}$
decays channels, especially the pure annihilation type decays have been
measured by the recent experiments to confirm our theoretical predictions. More
channels are predicted for future experiments, such as the charmless and
charmed $B_s$ and $B_c$ hadronic decays and the decays involving a scalar,
axial vector, even a tensor meson in the final states.
| [
{
"created": "Tue, 30 Oct 2012 09:44:59 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Nov 2012 07:15:38 GMT",
"version": "v2"
}
] | 2012-11-30 | [
[
"Lu",
"Cai-Dian",
"",
"IHEP, Beijing"
]
] | In this mini-review, we show that a lot of theoretical efforts have been made for the theoretical study of two body hadronic $B_{(s)}$ and $B_c$ decays. In addition to many next-to-leading order or even next-to-next-to leading order $\alpha_s$ corrections made, we also study many of the previously unknown next-to-leading order power corrections. While the former corrections are theoretically solid, the latter corrections are phenomenologically more important. In the QCD factorization approach based on collinear factorization, there is difficulty to deal with the power correction diagrams due to the endpoint singularity. Thus many of these analysis use phenomenological method. In the perturbative QCD approach based on $k_T$ factorization, the endpoint singularity is killed by including the quark transverse momentum. Therefore we can calculate the annihilation type diagrams quantitatively, which give the right sign for the direct CP asymmetry parameters. More and more $B_{(s)}$ decays channels, especially the pure annihilation type decays have been measured by the recent experiments to confirm our theoretical predictions. More channels are predicted for future experiments, such as the charmless and charmed $B_s$ and $B_c$ hadronic decays and the decays involving a scalar, axial vector, even a tensor meson in the final states. |
hep-ph/0109038 | Piet Mulders | P.J. Mulders | Azimuthal asymmetries in semi-inclusive leptoproduction | 11 pages Latex; Talk at the Ringberg Workshop: New Trends in HERA
Physics 2001 Ringberg Castle, Germany, Jun. 17- 22, 2001; reference corrected | J.Phys.G28:801-810,2002 | 10.1088/0954-3899/28/5/307 | null | hep-ph | null | We point out the role of intrinsic transverse momentum of partons in the
study of azimuthal asymmetries in deep-inelastic 1-particle inclusive
leptoproduction. Leading asymmetries often appear in combination with spin
asymmetries. This leads not only to transverse momentum dependence in the
parton distribution functions, but also to functions beyond the ones known from
inclusive deep-inelastic scattering (DIS). We use Lorentz invariance and the
QCD equations of motion to study the evolution of functions that appear at
leading (zeroth) order in a 1/Q expansion in azimuthal asymmetries. This
includes the evolution equation of the Collins fragmentation function. The
moments of these functions are matrix elements of known twist two and twist
three operators. We give the evolution in the large $N_c$ limit, restricted to
the non-singlet case for the chiral-even functions.
| [
{
"created": "Wed, 5 Sep 2001 14:48:39 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Dec 2001 13:25:56 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Mulders",
"P. J.",
""
]
] | We point out the role of intrinsic transverse momentum of partons in the study of azimuthal asymmetries in deep-inelastic 1-particle inclusive leptoproduction. Leading asymmetries often appear in combination with spin asymmetries. This leads not only to transverse momentum dependence in the parton distribution functions, but also to functions beyond the ones known from inclusive deep-inelastic scattering (DIS). We use Lorentz invariance and the QCD equations of motion to study the evolution of functions that appear at leading (zeroth) order in a 1/Q expansion in azimuthal asymmetries. This includes the evolution equation of the Collins fragmentation function. The moments of these functions are matrix elements of known twist two and twist three operators. We give the evolution in the large $N_c$ limit, restricted to the non-singlet case for the chiral-even functions. |
1611.08133 | Seng Pei Liew | Seng Pei Liew, Feng Luo | Effects of QCD bound states on dark matter relic abundance | 31 pages, 6 figures, added references, added comments on thermal
masses and higher energy levels of bound states, journal version | J. High Energ. Phys. (2017) 2017: 91 | 10.1007/JHEP02(2017)091 | UT-16-33, IPMU-16-0176 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study scenarios where there exists an exotic massive particle charged
under QCD in the early Universe. We calculate the formation and dissociation
rates of bound states formed by pairs of these particles, and apply the results
in dark matter (DM) coannihilation scenarios, including also the Sommerfeld
effect. We find that on top of the Sommerfeld enhancement, bound-state effects
can further significantly increase the largest possible DM masses which can
give the observed DM relic abundance, by $\sim 30 - 100\%$ with respect to
values obtained by considering the Sommerfeld effect only, for the color
triplet or octet exotic particles we consider. In particular, it indicates that
the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the
Minimal Supersymmetric extension of the Standard Model (MSSM) can reach $\sim
2.5$ TeV, even though the potential between the stop and antistop prior to
forming a bound state is repulsive. We also apply the bound-state effects in
the calculations of relic abundance of long-lived or metastable massive colored
particles, and discuss the implications on the BBN constraints and the
abundance of a super-weakly interacting DM. The corrections for the bound-state
effect when the exotic massive colored particles also carry electric charges,
and the collider bounds are also discussed.
| [
{
"created": "Thu, 24 Nov 2016 10:58:07 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Mar 2017 10:14:47 GMT",
"version": "v2"
}
] | 2017-03-13 | [
[
"Liew",
"Seng Pei",
""
],
[
"Luo",
"Feng",
""
]
] | We study scenarios where there exists an exotic massive particle charged under QCD in the early Universe. We calculate the formation and dissociation rates of bound states formed by pairs of these particles, and apply the results in dark matter (DM) coannihilation scenarios, including also the Sommerfeld effect. We find that on top of the Sommerfeld enhancement, bound-state effects can further significantly increase the largest possible DM masses which can give the observed DM relic abundance, by $\sim 30 - 100\%$ with respect to values obtained by considering the Sommerfeld effect only, for the color triplet or octet exotic particles we consider. In particular, it indicates that the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the Minimal Supersymmetric extension of the Standard Model (MSSM) can reach $\sim 2.5$ TeV, even though the potential between the stop and antistop prior to forming a bound state is repulsive. We also apply the bound-state effects in the calculations of relic abundance of long-lived or metastable massive colored particles, and discuss the implications on the BBN constraints and the abundance of a super-weakly interacting DM. The corrections for the bound-state effect when the exotic massive colored particles also carry electric charges, and the collider bounds are also discussed. |
1011.6364 | Mu-Chun Chen | Mu-Chun Chen, K.T. Mahanthappa | Geometrical Origin of CP Violation and CKM and MNS Matrices in SU(5) x
T' | Talk presented at the 35th International Conference of High Energy
Physics - ICHEP2010, July 22-28, 2010, Paris France | PoS ICHEP2010:407,2010 | null | UCI-TR-2010-30 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose the complex group theoretical Clebsch-Gordon coefficients as a
novel origin of CP violation. This is manifest in our model based on SUSY SU(5)
combined with the double tetrahedral group, T', as a family symmetry. Due to
the presence of the doublet representations in T', there exist complex CG
coefficients, leading to explicit CP violation in the model, while the Yukawa
couplings and the vacuum expectation values of the scalar fields remain real.
The tri-bimaximal neutrino mixing matrix arises from the CG coefficients of T'.
In addition to the prediction for theta_{13} ~ (1/ (3\sqrt{2}) theta_{c}, the
model gives rise to a sum rule, tan^{2} theta_{sol} ~ tan^{2} theta_{sol, TBM}}
+ (1/2) theta_{c} cos(delta_{lep}), which is a consequence of the
Georgi-Jarlskog relations in the charged fermion sector. The predicted leptonic
Dirac CP phase, delta_{lep}, gives the correct value of the solar mixing angle,
and the predicted CP violation measures in the quark sector are consistent with
the current experimental data. Since the Dirac CP phase is the only
non-vanishing phase predicted in the lepton sector, there is a connection
between leptogenesis and low energy leptonic CP violating processes in our
model.
| [
{
"created": "Mon, 29 Nov 2010 20:46:15 GMT",
"version": "v1"
}
] | 2011-08-09 | [
[
"Chen",
"Mu-Chun",
""
],
[
"Mahanthappa",
"K. T.",
""
]
] | We propose the complex group theoretical Clebsch-Gordon coefficients as a novel origin of CP violation. This is manifest in our model based on SUSY SU(5) combined with the double tetrahedral group, T', as a family symmetry. Due to the presence of the doublet representations in T', there exist complex CG coefficients, leading to explicit CP violation in the model, while the Yukawa couplings and the vacuum expectation values of the scalar fields remain real. The tri-bimaximal neutrino mixing matrix arises from the CG coefficients of T'. In addition to the prediction for theta_{13} ~ (1/ (3\sqrt{2}) theta_{c}, the model gives rise to a sum rule, tan^{2} theta_{sol} ~ tan^{2} theta_{sol, TBM}} + (1/2) theta_{c} cos(delta_{lep}), which is a consequence of the Georgi-Jarlskog relations in the charged fermion sector. The predicted leptonic Dirac CP phase, delta_{lep}, gives the correct value of the solar mixing angle, and the predicted CP violation measures in the quark sector are consistent with the current experimental data. Since the Dirac CP phase is the only non-vanishing phase predicted in the lepton sector, there is a connection between leptogenesis and low energy leptonic CP violating processes in our model. |
1007.2526 | V. V. Sinev | V.V. Sinev | Geoneutrinos and the Earth inner parts structure | Preprint INR RAS LaTeX file and 10 eps figures | null | null | INR RAS 1257/2010 | hep-ph physics.geo-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The connection between geoneutrino registration and the Earth theory test is
discussed. We compare standard theory of lithosphere plates and hypothesis of
hydride Earth. Last hypothesis adds additional neutrino source $-$ planet core
in which the initial Earth composition is conserved. Large volume scintillation
detector is supposed to install at Baksan neutrino observatory INR RAS at
Caucasus. The detector will register all possible neutrino fluxes, but mainly
geo-neutrinos. So kind a detector (or detector net) placed in a number of sites
on the Earth surface can measure all radioactivity from $^{238}$U and
$^{232}$Th, because their neutrino energy exceeds the inverse beta-decay
reaction threshold. By this way it will it possible to understand if there are
any more neutrino sources in the Earth other than the crust and mantle.
| [
{
"created": "Thu, 15 Jul 2010 10:23:47 GMT",
"version": "v1"
}
] | 2010-07-16 | [
[
"Sinev",
"V. V.",
""
]
] | The connection between geoneutrino registration and the Earth theory test is discussed. We compare standard theory of lithosphere plates and hypothesis of hydride Earth. Last hypothesis adds additional neutrino source $-$ planet core in which the initial Earth composition is conserved. Large volume scintillation detector is supposed to install at Baksan neutrino observatory INR RAS at Caucasus. The detector will register all possible neutrino fluxes, but mainly geo-neutrinos. So kind a detector (or detector net) placed in a number of sites on the Earth surface can measure all radioactivity from $^{238}$U and $^{232}$Th, because their neutrino energy exceeds the inverse beta-decay reaction threshold. By this way it will it possible to understand if there are any more neutrino sources in the Earth other than the crust and mantle. |
1401.2275 | Jan O. Eeg | Svjetlana Fajfer and Jan O. Eeg | Colored scalars and the neutron electric dipole moment | 14 pages, 5 figures, 53 references | null | 10.1103/PhysRevD.89.095030 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate new contributions to the neutron electric dipole moment
induced by colored scalars.
As an example, we evaluate contributions coming from the color octet, weak
doublet scalar, accommodated within a modified Minimal Flavor Violating
framework. These flavor non-diagonal couplings of the color octet scalar might
account for the $A_{CP} (D^0 \to K^- K^+) - A_{CP} (D^0 \to \pi^+ \pi^-)$
asymmetry on the tree level. Using these charm asymmetry constrained couplings,
we calculate two-loop contributions to the neutron electric dipole moment and
find that they are of the same order as the experimental bound. We comment also
on contributions of higher dimensional operators to the neutron electric dipole
moment within this framework.
| [
{
"created": "Fri, 10 Jan 2014 10:08:23 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Jan 2014 11:14:10 GMT",
"version": "v2"
},
{
"created": "Thu, 20 Mar 2014 12:27:30 GMT",
"version": "v3"
},
{
"created": "Mon, 28 Apr 2014 13:31:40 GMT",
"version": "v4"
}
] | 2015-06-18 | [
[
"Fajfer",
"Svjetlana",
""
],
[
"Eeg",
"Jan O.",
""
]
] | We investigate new contributions to the neutron electric dipole moment induced by colored scalars. As an example, we evaluate contributions coming from the color octet, weak doublet scalar, accommodated within a modified Minimal Flavor Violating framework. These flavor non-diagonal couplings of the color octet scalar might account for the $A_{CP} (D^0 \to K^- K^+) - A_{CP} (D^0 \to \pi^+ \pi^-)$ asymmetry on the tree level. Using these charm asymmetry constrained couplings, we calculate two-loop contributions to the neutron electric dipole moment and find that they are of the same order as the experimental bound. We comment also on contributions of higher dimensional operators to the neutron electric dipole moment within this framework. |
hep-ph/9502329 | null | Gustavo Burdman, Eugene Golowich, JoAnne L. Hewett and Sandip Pakvasa | Radiative Weak Decays of Charm Mesons | 44 pages, LaTeX, 4 figures (not included) | Phys.Rev.D52:6383-6399,1995 | 10.1103/PhysRevD.52.6383 | FERMILAB-Pub-94/412-T; UMHEP-415; SLAC-PUB-6692; UH-511-811-94 | hep-ph | null | We address Standard Model predictions for flavor-changing radiative
transitions of the pseudoscalar charm mesons. Short-distance contributions in
$D$ radiative transitions are contrasted with those in B decays. A full
analysis is presented of the $c\to u+\gamma$ electromagnetic penguin amplitude
with QCD radiative corrections included. Given the importance of long-range
effects for the charm sector, special attention is paid to such contributions
as the vector dominance and pole amplitudes. A number of two-body final states
in exclusive charm radiative decays is considered and the corresponding
branching ratio predictions are given.
| [
{
"created": "Thu, 16 Feb 1995 18:36:10 GMT",
"version": "v1"
}
] | 2010-04-06 | [
[
"Burdman",
"Gustavo",
""
],
[
"Golowich",
"Eugene",
""
],
[
"Hewett",
"JoAnne L.",
""
],
[
"Pakvasa",
"Sandip",
""
]
] | We address Standard Model predictions for flavor-changing radiative transitions of the pseudoscalar charm mesons. Short-distance contributions in $D$ radiative transitions are contrasted with those in B decays. A full analysis is presented of the $c\to u+\gamma$ electromagnetic penguin amplitude with QCD radiative corrections included. Given the importance of long-range effects for the charm sector, special attention is paid to such contributions as the vector dominance and pole amplitudes. A number of two-body final states in exclusive charm radiative decays is considered and the corresponding branching ratio predictions are given. |
hep-ph/9704407 | null | Euy Soo Na and Barry R. Holstein | Isospin Mixing and Model Dependence | 8 page standard Latex file | Phys.Rev. D56 (1997) 4404-4407 | 10.1103/PhysRevD.56.4404 | null | hep-ph | null | We show that recent calculations of \Delta I=3/2 effects in nonleptonic
hyperon decay induced by m_d-m_u\neq 0 are subject to significant model
dependence.
| [
{
"created": "Fri, 25 Apr 1997 16:43:35 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Na",
"Euy Soo",
""
],
[
"Holstein",
"Barry R.",
""
]
] | We show that recent calculations of \Delta I=3/2 effects in nonleptonic hyperon decay induced by m_d-m_u\neq 0 are subject to significant model dependence. |
1703.05845 | Robert Hambrock | R. Hambrock, W. A. Horowitz | AdS/CFT predictions for azimuthal and momentum correlations of
$b\bar{b}$ pairs in heavy ion collisions | 4 pages, 4 figures. Proceedings for Hard Probes 2016 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use an energy loss model sensitive to thermal fluctuations to compute the
azimuthal and momentum correlations of $b\bar{b}$ pairs traversing a strongly
coupled plasma from Pb+Pb collisions at LHC ($\sqrt{s}=2.76\text{TeV}$). The
azimuthal correlations are compared with those from perturbative QCD based
simulations. When restricted to leading order production processes, we find
that the strongly coupled correlations of high transverse momentum pairs
($>4\text{GeV}$) are broadened less efficiently than the corresponding weak
coupling based correlations, while low transverse momentum pairs (1-4GeV) are
broadened with similar efficiency, but with an order of magnitude more
particles ending up in this momentum class.
The strong coupling momentum correlations we compute account for initial
correlations and reveal that the particle pairs suppressed from initially high
momenta to the low momentum domain do not suffice to explain the stark
difference to the weak coupling results in momentum correlations for 1-4GeV.
From this, we conclude that $b\bar{b}$ pairs are more likely to stay
correlated in momentum when propagating through a strongly coupled plasma than
a weakly coupled one.
| [
{
"created": "Thu, 16 Mar 2017 23:00:52 GMT",
"version": "v1"
}
] | 2017-03-20 | [
[
"Hambrock",
"R.",
""
],
[
"Horowitz",
"W. A.",
""
]
] | We use an energy loss model sensitive to thermal fluctuations to compute the azimuthal and momentum correlations of $b\bar{b}$ pairs traversing a strongly coupled plasma from Pb+Pb collisions at LHC ($\sqrt{s}=2.76\text{TeV}$). The azimuthal correlations are compared with those from perturbative QCD based simulations. When restricted to leading order production processes, we find that the strongly coupled correlations of high transverse momentum pairs ($>4\text{GeV}$) are broadened less efficiently than the corresponding weak coupling based correlations, while low transverse momentum pairs (1-4GeV) are broadened with similar efficiency, but with an order of magnitude more particles ending up in this momentum class. The strong coupling momentum correlations we compute account for initial correlations and reveal that the particle pairs suppressed from initially high momenta to the low momentum domain do not suffice to explain the stark difference to the weak coupling results in momentum correlations for 1-4GeV. From this, we conclude that $b\bar{b}$ pairs are more likely to stay correlated in momentum when propagating through a strongly coupled plasma than a weakly coupled one. |
0711.3215 | Igor Strakovsky | Ya. Azimov (PNPI), K. Goeke (Ruhr-Univ.), I. Strakovsky (GWU) | How is Exotics Produced ? Where to Search for it ? | Presented at MeNu2007, Sep 10-14, 2007, Juelich, Germany; Latex, 4
pages, uses conference.cls and Header.eps (included) | ECONF C070910:206,2007 | null | null | hep-ph | null | On the basis of existing data, we suggest such a mechanism of production for
exotic hadrons that can explain, at least qualitatively, why the Theta+-baryon
is seen in some experiments and not in others. With our hypothesis, production
of exotic hadrons is a new kind of hard processes. We also can propose new
experiments to check (and confirm?) existence of exotics and to provide new
important information about both exotic and conventional hadrons [The talk is
based on the papers by Ya. Azimov, K. Goeke, and I. Strakovsky, Phys Rev D 76,
074013 (2007)]
| [
{
"created": "Tue, 20 Nov 2007 21:25:37 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Azimov",
"Ya.",
"",
"PNPI"
],
[
"Goeke",
"K.",
"",
"Ruhr-Univ."
],
[
"Strakovsky",
"I.",
"",
"GWU"
]
] | On the basis of existing data, we suggest such a mechanism of production for exotic hadrons that can explain, at least qualitatively, why the Theta+-baryon is seen in some experiments and not in others. With our hypothesis, production of exotic hadrons is a new kind of hard processes. We also can propose new experiments to check (and confirm?) existence of exotics and to provide new important information about both exotic and conventional hadrons [The talk is based on the papers by Ya. Azimov, K. Goeke, and I. Strakovsky, Phys Rev D 76, 074013 (2007)] |
2209.04972 | Kevin Ingles | Eric Braaten, Roberto Bruschini, Li-Ping He, Kevin Ingles, Jun Jiang | Evolution of charm-meson ratios in an expanding hadron gas | 7 pages, 1 figure | null | 10.1103/PhysRevD.107.076006 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study the time evolution of the numbers of charm mesons after the kinetic
freeze-out of the hadron gas produced by a central heavy-ion collision. The
$\pi D^\ast \to \pi D^\ast$ reaction rates have $t$-channel singularities that
give contributions inversely proportional to the thermal width of the $D$. The
ratio of the $D^0$ and $D^+$ production rates can differ significantly from
those predicted using the measured $D^\ast$ branching fractions.
| [
{
"created": "Mon, 12 Sep 2022 01:06:55 GMT",
"version": "v1"
}
] | 2023-04-19 | [
[
"Braaten",
"Eric",
""
],
[
"Bruschini",
"Roberto",
""
],
[
"He",
"Li-Ping",
""
],
[
"Ingles",
"Kevin",
""
],
[
"Jiang",
"Jun",
""
]
] | We study the time evolution of the numbers of charm mesons after the kinetic freeze-out of the hadron gas produced by a central heavy-ion collision. The $\pi D^\ast \to \pi D^\ast$ reaction rates have $t$-channel singularities that give contributions inversely proportional to the thermal width of the $D$. The ratio of the $D^0$ and $D^+$ production rates can differ significantly from those predicted using the measured $D^\ast$ branching fractions. |
2107.13112 | Ke-Pan Xie | Ligong Bian, Xuewen Liu and Ke-Pan Xie | Probing superheavy dark matter with gravitational waves | 13 pages + references; 2 figures and 2 tables. To appear on JHEP | null | 10.1007/JHEP11(2021)175 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We study the superheavy dark matter (DM) scenario in an extended $B-L$ model,
where one generation of right-handed neutrino $\nu_R$ is the DM candidate. If
there is a new lighter sterile neutrino that co-annihilate with the DM
candidate, then the annihilation rate is exponentially enhanced, allowing a DM
mass much heavier than the Griest-Kamionkowski bound ($\sim10^5$ GeV). We
demonstrate that a DM mass $M_{\nu_R}\gtrsim10^{13}$ GeV can be achieved.
Although beyond the scale of any traditional DM searching strategy, this
scenario is testable via gravitational waves (GWs) emitted by the cosmic
strings from the $U(1)_{B-L}$ breaking. Quantitative calculations show that the
DM mass $\mathcal{O}(10^9-10^{13}~{\rm GeV})$ can be probed by future GW
detectors.
| [
{
"created": "Wed, 28 Jul 2021 00:52:49 GMT",
"version": "v1"
},
{
"created": "Sun, 21 Nov 2021 23:42:05 GMT",
"version": "v2"
}
] | 2021-12-08 | [
[
"Bian",
"Ligong",
""
],
[
"Liu",
"Xuewen",
""
],
[
"Xie",
"Ke-Pan",
""
]
] | We study the superheavy dark matter (DM) scenario in an extended $B-L$ model, where one generation of right-handed neutrino $\nu_R$ is the DM candidate. If there is a new lighter sterile neutrino that co-annihilate with the DM candidate, then the annihilation rate is exponentially enhanced, allowing a DM mass much heavier than the Griest-Kamionkowski bound ($\sim10^5$ GeV). We demonstrate that a DM mass $M_{\nu_R}\gtrsim10^{13}$ GeV can be achieved. Although beyond the scale of any traditional DM searching strategy, this scenario is testable via gravitational waves (GWs) emitted by the cosmic strings from the $U(1)_{B-L}$ breaking. Quantitative calculations show that the DM mass $\mathcal{O}(10^9-10^{13}~{\rm GeV})$ can be probed by future GW detectors. |
hep-ph/9610358 | null | Howard Baer, Michal Brhlik, Chih-hao Chen and Xerxes Tata | Signals for the Minimal Gauge-mediated Supersymmetry Breaking Model at
the Fermilab Tevatron Collider | 18 page REVTEX file plus 11 PS figures | Phys.Rev. D55 (1997) 4463-4474 | 10.1103/PhysRevD.55.4463 | FSU-HEP-961002, UH-511-855-96 | hep-ph | null | We investigate the experimental implications of the minimal gauge-mediated
low energy supersymmetry breaking (GMLESB) model for Fermilab Tevatron collider
experiments. We map out the regions of parameter space of this model that have
already been excluded by collider searches and by limits on $b\to s\gamma$. We
use ISAJET to compute the cross sections for a variety of topological
signatures which include photons in assocation with multiple leptons, jets and
missing transverse energy. The reach in the parameter $\Lambda$, which fixes
the scale of sparticle masses, is estimated to be $\sim 60$, 100 and 135 TeV
for Tevatron integrated luminosities of 0.1, 2 and 25 fb$^{-1}$, respectively.
The largest signals occur in photon(s) plus lepton(s) plus multi-jet channels;
jet-free channels containing just photons plus leptons occur at much smaller
rates, at least within this minimal framework.
| [
{
"created": "Mon, 14 Oct 1996 22:55:34 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Baer",
"Howard",
""
],
[
"Brhlik",
"Michal",
""
],
[
"Chen",
"Chih-hao",
""
],
[
"Tata",
"Xerxes",
""
]
] | We investigate the experimental implications of the minimal gauge-mediated low energy supersymmetry breaking (GMLESB) model for Fermilab Tevatron collider experiments. We map out the regions of parameter space of this model that have already been excluded by collider searches and by limits on $b\to s\gamma$. We use ISAJET to compute the cross sections for a variety of topological signatures which include photons in assocation with multiple leptons, jets and missing transverse energy. The reach in the parameter $\Lambda$, which fixes the scale of sparticle masses, is estimated to be $\sim 60$, 100 and 135 TeV for Tevatron integrated luminosities of 0.1, 2 and 25 fb$^{-1}$, respectively. The largest signals occur in photon(s) plus lepton(s) plus multi-jet channels; jet-free channels containing just photons plus leptons occur at much smaller rates, at least within this minimal framework. |
hep-ph/9803432 | Stephen P. Martin | Nima Arkani-Hamed, Michael Dine and Stephen P. Martin | Dynamical supersymmetry breaking in models with a Green-Schwarz
mechanism | 14 pages, LaTeX | Phys.Lett. B431 (1998) 329-338 | 10.1016/S0370-2693(98)00494-8 | SLAC-PUB-7770, SCIPP-98/09 | hep-ph | null | We consider supersymmetry breaking in theories with gaugino condensation in
the presence of an anomalous U(1) symmetry with anomaly cancellation by the
Green-Schwarz mechanism. In these models, a Fayet-Iliopoulos D-term can give
important contributions to the soft supersymmetry-breaking scalar masses. Most
discussions of this possibility have ignored the dilaton field. We argue that
this is not appropriate in general, and show that the F-term contributions to
the soft breaking terms are comparable to or much larger than the D-term
contributions, depending on how the dilaton is stabilized. We discuss
phenomenological implications of these results.
| [
{
"created": "Mon, 23 Mar 1998 23:06:12 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Arkani-Hamed",
"Nima",
""
],
[
"Dine",
"Michael",
""
],
[
"Martin",
"Stephen P.",
""
]
] | We consider supersymmetry breaking in theories with gaugino condensation in the presence of an anomalous U(1) symmetry with anomaly cancellation by the Green-Schwarz mechanism. In these models, a Fayet-Iliopoulos D-term can give important contributions to the soft supersymmetry-breaking scalar masses. Most discussions of this possibility have ignored the dilaton field. We argue that this is not appropriate in general, and show that the F-term contributions to the soft breaking terms are comparable to or much larger than the D-term contributions, depending on how the dilaton is stabilized. We discuss phenomenological implications of these results. |
2004.14188 | Sudhanwa Patra Dr. | Chandini Dash, Snigdha Mishra (Berhampur U.), Sudhanwa Patra,
Purushottam Sahu (Indian Inst. Tech., Bhilai) | Threshold effects on prediction for proton decay in non-supersymmetric
$E_6$ GUT with intermediate trinification symmetry | 9 pages, detailed derivation included for GUT Threshold effects | null | 10.1016/j.nuclphysb.2020.115239 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a non-supersymmetric $E_6$ Grand Unified Theory (GUT) with
intermediate trinification symmetry $SU(3)_C \times SU(3)_L \times SU(3)_R
\times D$ (D denoted as D-parity for discrete left-right symmetry) and study
the effect of one-loop threshold corrections arising due to every class of
superheavy particles (scalars, fermions and vectors). It is observed that, the
intermediate mass scale $M_I$ and $\sin^2\theta_W$ remain unaffected by GUT
threshold contributions. The threshold modified unification mass scale $M_U$ is
in excellent agreement with the present experimental proton decay constraint.
The novel feature of the model is that GUT threshold uncertainty of $M_U$ is
found to be controlled by superheavy scalars only, leading to a very predictive
scenario for proton decay, which can be verifiable within the foreseeable
experiments.
| [
{
"created": "Wed, 29 Apr 2020 13:32:16 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Jun 2020 09:58:33 GMT",
"version": "v2"
}
] | 2021-02-03 | [
[
"Dash",
"Chandini",
"",
"Berhampur U."
],
[
"Mishra",
"Snigdha",
"",
"Berhampur U."
],
[
"Patra",
"Sudhanwa",
"",
"Indian Inst. Tech., Bhilai"
],
[
"Sahu",
"Purushottam",
"",
"Indian Inst. Tech., Bhilai"
]
] | We consider a non-supersymmetric $E_6$ Grand Unified Theory (GUT) with intermediate trinification symmetry $SU(3)_C \times SU(3)_L \times SU(3)_R \times D$ (D denoted as D-parity for discrete left-right symmetry) and study the effect of one-loop threshold corrections arising due to every class of superheavy particles (scalars, fermions and vectors). It is observed that, the intermediate mass scale $M_I$ and $\sin^2\theta_W$ remain unaffected by GUT threshold contributions. The threshold modified unification mass scale $M_U$ is in excellent agreement with the present experimental proton decay constraint. The novel feature of the model is that GUT threshold uncertainty of $M_U$ is found to be controlled by superheavy scalars only, leading to a very predictive scenario for proton decay, which can be verifiable within the foreseeable experiments. |
1405.7371 | Teppei Kitahara | Kazuya Ishikawa, Teppei Kitahara, Masahiro Takimoto | Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale
Supersymmetry | 12 pages, 5 figures; to be published in Physical Review Letters | Phys. Rev. Lett. 113, 131801 (2014) | 10.1103/PhysRevLett.113.131801 | UT-14-26 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a singlino Dark Matter (DM) scenario in a singlet extension model
of the Minimal Supersymmetric Standard Model, which is so-called the Nearly
MSSM (nMSSM). We find that with high-scale supersymmetry breaking the singlino
can obtain a sizable radiative correction to the mass, which opens a window for
the DM scenario with resonant annihilation via the exchange of the Higgs boson.
We show that the current DM relic abundance and the Higgs boson mass can be
explained simultaneously. This scenario can be fully probed by XENON1T.
| [
{
"created": "Wed, 28 May 2014 20:00:19 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Sep 2014 06:58:14 GMT",
"version": "v2"
}
] | 2014-09-26 | [
[
"Ishikawa",
"Kazuya",
""
],
[
"Kitahara",
"Teppei",
""
],
[
"Takimoto",
"Masahiro",
""
]
] | We consider a singlino Dark Matter (DM) scenario in a singlet extension model of the Minimal Supersymmetric Standard Model, which is so-called the Nearly MSSM (nMSSM). We find that with high-scale supersymmetry breaking the singlino can obtain a sizable radiative correction to the mass, which opens a window for the DM scenario with resonant annihilation via the exchange of the Higgs boson. We show that the current DM relic abundance and the Higgs boson mass can be explained simultaneously. This scenario can be fully probed by XENON1T. |
0705.0746 | Heidi Rzehak | S. Heinemeyer, W. Hollik, H. Rzehak, G. Weiglein | The Higgs sector of the complex MSSM at two-loop order: QCD
contributions | 15 pages, 7 figures; minor changes; published version | Phys.Lett.B652:300-309,2007 | 10.1016/j.physletb.2007.07.030 | DCPT/07/34, IPPP/07/17, MPP-2007-52, PSI-PR-07-02 | hep-ph | null | Results are presented for the leading two-loop contributions of O(alpha_t
alpha_s) to the masses and mixing effects in the Higgs sector of the MSSM with
complex parameters. They are obtained in the Feynman-diagrammatic approach
using on-shell renormalization. The full dependence on all complex phases is
taken into account. The renormalization of the appropriate contributions of the
Higgs-boson sector and the scalar top and bottom sector is discussed. Our
numerical analysis for the lightest MSSM Higgs-boson mass is based on the new
two-loop corrections, supplemented by the full one-loop result. The corrections
induced by the phase variation in the scalar top sector are enhanced by the
two-loop contributions. We find that the corresponding shift in M_h1 can amount
to 5 GeV.
| [
{
"created": "Mon, 7 May 2007 16:37:36 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Nov 2007 18:00:08 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Heinemeyer",
"S.",
""
],
[
"Hollik",
"W.",
""
],
[
"Rzehak",
"H.",
""
],
[
"Weiglein",
"G.",
""
]
] | Results are presented for the leading two-loop contributions of O(alpha_t alpha_s) to the masses and mixing effects in the Higgs sector of the MSSM with complex parameters. They are obtained in the Feynman-diagrammatic approach using on-shell renormalization. The full dependence on all complex phases is taken into account. The renormalization of the appropriate contributions of the Higgs-boson sector and the scalar top and bottom sector is discussed. Our numerical analysis for the lightest MSSM Higgs-boson mass is based on the new two-loop corrections, supplemented by the full one-loop result. The corrections induced by the phase variation in the scalar top sector are enhanced by the two-loop contributions. We find that the corresponding shift in M_h1 can amount to 5 GeV. |
2006.14938 | Ilya F. Ginzburg | Ilya F. Ginzburg, Gleb L. Kotkin | Photon Collider for energies 1-2 TeV | 23 pages, 8figures (12), 6 tables. arXiv admin note: substantial text
overlap with arXiv:1910.13961 | null | 10.1134/S1063779621050038 | null | hep-ph hep-ex | http://creativecommons.org/publicdomain/zero/1.0/ | We discuss a photon collider based on the $e^+e^-$ \ linear collider with
energies of $2E = 1\div 2$ TeV in cms (ILC, CLIC, ...). Previously, this energy
range was considered hopeless for the experiment in the foreseeable future. We
discuss the realization of the TeV PLC based on modern lasers. A small
modification of the laser-optical system prepared for the photon collider with
energy of $E \approx 250$ GeV will be sufficient if the parameters are chosen
optimally. The high-energy part of the photon spectrum does not depend on
design details and is well separated from the low-energy part. That is a narrow
band near the upper boundary, about 5\% wide. The high-energy integrated \ggam
luminosity is about 1/5 and the maximum differential luminosity is about 1/4 of
the corresponding values for the photon collider with $E \approx 250$ GeV.
| [
{
"created": "Thu, 25 Jun 2020 11:49:08 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Aug 2021 13:20:28 GMT",
"version": "v2"
}
] | 2021-10-13 | [
[
"Ginzburg",
"Ilya F.",
""
],
[
"Kotkin",
"Gleb L.",
""
]
] | We discuss a photon collider based on the $e^+e^-$ \ linear collider with energies of $2E = 1\div 2$ TeV in cms (ILC, CLIC, ...). Previously, this energy range was considered hopeless for the experiment in the foreseeable future. We discuss the realization of the TeV PLC based on modern lasers. A small modification of the laser-optical system prepared for the photon collider with energy of $E \approx 250$ GeV will be sufficient if the parameters are chosen optimally. The high-energy part of the photon spectrum does not depend on design details and is well separated from the low-energy part. That is a narrow band near the upper boundary, about 5\% wide. The high-energy integrated \ggam luminosity is about 1/5 and the maximum differential luminosity is about 1/4 of the corresponding values for the photon collider with $E \approx 250$ GeV. |
2203.15813 | Juri Smirnov | Pouya Asadi, Eric David Kramer, Eric Kuflik, Tracy R. Slatyer, Juri
Smirnov | Glueballs in a Thermal Squeezeout Model | 10 pages, 8 figures, and three Appendices on thermodynamics and Phase
Transitions and heavier Glueball states. Version published in JHEP | Journal of High Energy Physics, 6, (2022) | 10.1007/JHEP07(2022)006 | MIT-CTP/5412 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | It has been shown that a first order confinement phase transition can
drastically change the relic dark matter abundance in confining dark sectors
with only heavy dark quarks. We study the phenomenology of one such model with
a Z' portal to Standard Model. We find that dark glueballs are long-lived in
this setup and dilute the dark matter abundance after their decay to Standard
Model. With this effect, the correct relic abundance is obtained with dark
matter masses up to $\mathcal{O}(10^6)$~TeV. We find that while a part of the
parameter space is already ruled out by direct detection and collider searches,
there is still a broad space of viable scenarios that can be probed by future
experiments.
| [
{
"created": "Tue, 29 Mar 2022 18:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jul 2022 11:55:31 GMT",
"version": "v2"
}
] | 2022-07-06 | [
[
"Asadi",
"Pouya",
""
],
[
"Kramer",
"Eric David",
""
],
[
"Kuflik",
"Eric",
""
],
[
"Slatyer",
"Tracy R.",
""
],
[
"Smirnov",
"Juri",
""
]
] | It has been shown that a first order confinement phase transition can drastically change the relic dark matter abundance in confining dark sectors with only heavy dark quarks. We study the phenomenology of one such model with a Z' portal to Standard Model. We find that dark glueballs are long-lived in this setup and dilute the dark matter abundance after their decay to Standard Model. With this effect, the correct relic abundance is obtained with dark matter masses up to $\mathcal{O}(10^6)$~TeV. We find that while a part of the parameter space is already ruled out by direct detection and collider searches, there is still a broad space of viable scenarios that can be probed by future experiments. |
hep-ph/0205017 | Zuo-tang Liang | Zuo-tang Liang (Shandong U.) | Spin Effects in High Energy Fragmentation Processes | Plenary talk given at the 3rd Circum-Pan-Pacifc Symposium on High
Energy Spin Physics, October 2001, 8 pages, 4 figures | Int.J.Mod.Phys. A18 (2003) 1229-1236 | 10.1142/S0217751X03014551 | null | hep-ph | null | Recent measurements, in particular those on $\Lambda$ polarization and spin
alignment of vector mesons in $e^+e^-$ annihilation at LEP, and those on the
azimuthal asymmetry at HERA, have attracted much attention on the spin effects
in high energy fragmentation processes. In this talk, we make a brief
introduction to the different topics studied in this connection and a short
summary of the available data. After that, we present a short summary of the
main theoretical results that we obtained in studying these different topics.
The talk was mainly based on the publications [5-9] which have been finished in
collaboration with C.Boros, Liu Chun-xiu and Xu Qing-hua.
| [
{
"created": "Thu, 2 May 2002 12:33:30 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Liang",
"Zuo-tang",
"",
"Shandong U."
]
] | Recent measurements, in particular those on $\Lambda$ polarization and spin alignment of vector mesons in $e^+e^-$ annihilation at LEP, and those on the azimuthal asymmetry at HERA, have attracted much attention on the spin effects in high energy fragmentation processes. In this talk, we make a brief introduction to the different topics studied in this connection and a short summary of the available data. After that, we present a short summary of the main theoretical results that we obtained in studying these different topics. The talk was mainly based on the publications [5-9] which have been finished in collaboration with C.Boros, Liu Chun-xiu and Xu Qing-hua. |
1701.02754 | Aaron C. Vincent | Celine Boehm, Celine Degrande, Olivier Mattelaer, Aaron C. Vincent | Circular polarisation: a new probe of dark matter and neutrinos in the
sky | 12 pages, published in JCAP | JCAP05(2017)043 | 10.1088/1475-7516/2017/05/043 | CERN-TH-2017-003,CP3-17-01 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The study of anomalous electromagnetic emission in the sky is the basis of
indirect searches for dark matter. It is also a powerful tool to constrain the
radiative decay of active neutrinos. Until now, quantitative analyses have
focused on the flux and energy spectrum of such an emission; polarisation has
never been considered. Here we show that we could be missing out on an
essential piece of information. The radiative decay of neutrinos, as well as
the interactions of dark matter and neutrinos with Standard Model particles can
generate a circular polarisation signal in X-rays or \gamma-rays. If observed,
this could reveal important information about their spatial distribution and
particle-antiparticle ratio, and could even reveal the nature of the
high-energy particle physics processes taking place in astrophysical sites. The
question of the observability of these polarised signatures and their
separation from background astrophysical sources is left for future work.
| [
{
"created": "Tue, 10 Jan 2017 19:01:30 GMT",
"version": "v1"
},
{
"created": "Sun, 28 May 2017 10:07:25 GMT",
"version": "v2"
}
] | 2017-05-31 | [
[
"Boehm",
"Celine",
""
],
[
"Degrande",
"Celine",
""
],
[
"Mattelaer",
"Olivier",
""
],
[
"Vincent",
"Aaron C.",
""
]
] | The study of anomalous electromagnetic emission in the sky is the basis of indirect searches for dark matter. It is also a powerful tool to constrain the radiative decay of active neutrinos. Until now, quantitative analyses have focused on the flux and energy spectrum of such an emission; polarisation has never been considered. Here we show that we could be missing out on an essential piece of information. The radiative decay of neutrinos, as well as the interactions of dark matter and neutrinos with Standard Model particles can generate a circular polarisation signal in X-rays or \gamma-rays. If observed, this could reveal important information about their spatial distribution and particle-antiparticle ratio, and could even reveal the nature of the high-energy particle physics processes taking place in astrophysical sites. The question of the observability of these polarised signatures and their separation from background astrophysical sources is left for future work. |
hep-ph/0307090 | Magno Machado | V.P. Goncalves (1), M.V.T. Machado (1 and 2) ((1) Instituto de Fisica
e Matematica, UFPel, (2) High Energy Phenomenology Group, GFPAE IF-UFRGS) | Geometric Scaling in Inclusive Charm Production | 4 pages, 2 figures. Version to be published in Physical Review
Letters | Phys.Rev.Lett.91:202002,2003 | 10.1103/PhysRevLett.91.202002 | null | hep-ph hep-ex nucl-th | null | We show that the cross section for inclusive charm production exhibits
geometric scaling in a large range of photon virtualities. In the HERA
kinematic domain the saturation momentum $Q_{sat}^2(x)$ stays below the hard
scale $\mu_c^2=4m_c^2$, implying charm production probing mostly the color
transparency regime and unitarization effects being almost negligible. We
derive our results considering two saturation models which are able to describe
the DESY ep collider HERA data for the proton structure function at small
values of the Bjorken variable $x$. A striking feature is the scaling on
$\tau=Q_2^2/Q_{sat}^2(x)$ above saturation limit, corroborating recent
theoretical studies.
| [
{
"created": "Mon, 7 Jul 2003 15:41:27 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Oct 2003 09:40:15 GMT",
"version": "v2"
}
] | 2011-01-25 | [
[
"Goncalves",
"V. P.",
"",
"1 and 2"
],
[
"Machado",
"M. V. T.",
"",
"1 and 2"
]
] | We show that the cross section for inclusive charm production exhibits geometric scaling in a large range of photon virtualities. In the HERA kinematic domain the saturation momentum $Q_{sat}^2(x)$ stays below the hard scale $\mu_c^2=4m_c^2$, implying charm production probing mostly the color transparency regime and unitarization effects being almost negligible. We derive our results considering two saturation models which are able to describe the DESY ep collider HERA data for the proton structure function at small values of the Bjorken variable $x$. A striking feature is the scaling on $\tau=Q_2^2/Q_{sat}^2(x)$ above saturation limit, corroborating recent theoretical studies. |
0808.3168 | Kenji Morita | Su Houng Lee, Kenji Morita, Marina Nielsen | Width of exotics from QCD sum rules : tetraquarks or molecules? | 6 pages, 6 figures | Phys.Rev.D78:076001,2008 | 10.1103/PhysRevD.78.076001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the widths of the recently observed charmonium like resonances
X(3872), Z(4430) and Z_2(4250) using QCD sum rules. Extending previous analyses
regarding these states as diquark-antiquark states or molecules of D mesons, we
introduce the Breit-Wigner function in the pole term. We find that introducing
the width increases the mass at small Borel window region. Using the OPE up to
dimension eight, we find that the sum rules based on interpolating current with
molecular components give a stable Borel curve from which both the masses and
widths of these resonances can be well obtained. Thus the QCD sum rule approach
strongly favors the molecular description of these states.
| [
{
"created": "Sat, 23 Aug 2008 08:00:52 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Oct 2008 08:44:19 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Lee",
"Su Houng",
""
],
[
"Morita",
"Kenji",
""
],
[
"Nielsen",
"Marina",
""
]
] | We investigate the widths of the recently observed charmonium like resonances X(3872), Z(4430) and Z_2(4250) using QCD sum rules. Extending previous analyses regarding these states as diquark-antiquark states or molecules of D mesons, we introduce the Breit-Wigner function in the pole term. We find that introducing the width increases the mass at small Borel window region. Using the OPE up to dimension eight, we find that the sum rules based on interpolating current with molecular components give a stable Borel curve from which both the masses and widths of these resonances can be well obtained. Thus the QCD sum rule approach strongly favors the molecular description of these states. |
hep-ph/9408296 | John Learned | John G. Learned and Sandip Pakvasa | Detecting Tau Neutrino Oscillations at PeV Energies | 18 pages latex, incl 3 figs, UH-511-799-94 | Astropart.Phys.3:267-274,1995 | 10.1016/0927-6505(94)00043-3 | null | hep-ph astro-ph hep-ex | null | It is suggested that a large deep underocean (or ice) neutrino detector,
given the presence of significant numbers of neutrinos in the PeV energy range
as predicted by various models of Active Galactic Nuclei, can make unique
measurements of the properties of neutrinos. It will be possible to observe the
existence of the tau neutrino, measure its mixing with other flavors, in fact
test the mixing pattern for all three flavors based upon the mixing parameters
suggested by the atmospheric and solar neutrino data, and measure the tau
neutrino cross section. The key signature is the charged current tau neutrino
interaction, which produces a double cascade, one at either end of a lightly
radiating track. At a few PeV these cascades would be separated by roughly 100
m, and thus be easily resolvable in next generation DUMAND-like detectors.
First examples might be found in detectors presently under construction. Future
applications are precise neutrino astronomy and earth tomography. This paper is
an expanded version of hep-ph/9405296, for publication.
| [
{
"created": "Tue, 16 Aug 1994 03:18:10 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Learned",
"John G.",
""
],
[
"Pakvasa",
"Sandip",
""
]
] | It is suggested that a large deep underocean (or ice) neutrino detector, given the presence of significant numbers of neutrinos in the PeV energy range as predicted by various models of Active Galactic Nuclei, can make unique measurements of the properties of neutrinos. It will be possible to observe the existence of the tau neutrino, measure its mixing with other flavors, in fact test the mixing pattern for all three flavors based upon the mixing parameters suggested by the atmospheric and solar neutrino data, and measure the tau neutrino cross section. The key signature is the charged current tau neutrino interaction, which produces a double cascade, one at either end of a lightly radiating track. At a few PeV these cascades would be separated by roughly 100 m, and thus be easily resolvable in next generation DUMAND-like detectors. First examples might be found in detectors presently under construction. Future applications are precise neutrino astronomy and earth tomography. This paper is an expanded version of hep-ph/9405296, for publication. |
hep-ph/9709508 | Bingsong Zou | X.Q.Li (CCAST, World Laboratory, Beijing & Department of Physics,
Nankai University, Tianjin, China.) B.S.Zou (Queen Mary & Westfield College,
London) | Inelastic Rescattering and CP Asymmetries in D -> pi+ pi-, pi0 pi0 | 9 pages | Phys.Rev.D57:1518-1523,1998 | 10.1103/PhysRevD.57.1518 | null | hep-ph | null | We study the direct CP violation induced by inelastic final state interaction
(FSI) rescattering in $D\to\pi\pi$ modes, and find that the resultant CP
asymmetry is about $10^{-4}$ which is larger than $\epsilon'$ in the K-system.
Our estimation is based on well-established theories and experiment measured
data, so there are almost no free parameters except the weak phase
$\delta_{13}$ in the CKM matrix.
| [
{
"created": "Tue, 30 Sep 1997 16:44:38 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Li",
"X. Q.",
"",
"CCAST, World Laboratory, Beijing & Department of Physics,\n Nankai University, Tianjin, China."
],
[
"Zou",
"B. S.",
"",
"Queen Mary & Westfield College,\n London"
]
] | We study the direct CP violation induced by inelastic final state interaction (FSI) rescattering in $D\to\pi\pi$ modes, and find that the resultant CP asymmetry is about $10^{-4}$ which is larger than $\epsilon'$ in the K-system. Our estimation is based on well-established theories and experiment measured data, so there are almost no free parameters except the weak phase $\delta_{13}$ in the CKM matrix. |
1208.4477 | Pere Masjuan | P. Masjuan, E. R. Arriola, W. Broniowski | Radial and angular-momentum Regge trajectories: a systematic approach | 3 pages, 9 figures, presented by PM at MESON2012 - 12th International
Workshop on Meson Production, Properties and Interaction, Krakow, Poland, 31
May - 5 June 2012 | null | 10.1051/epjconf/20123709024 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the analysis of Ref.[1] of the radial (n) and angular-momentum (J)
Regge trajectories for all light-quark meson states listed in the Particle Data
Tables. The parameters of the trajectories are obtained with linear regression,
with weight of each resonance inversely proportional to its half-width squared,
(\Gamma/2)^2. The joint analysis in the (n,J,M^2) Regge plane indicates, at the
4.5 standard deviation level, that the slopes in n are larger from the slopes
in J. Thus no strict universality of slopes occurs in the light non-strange
meson sector. We also extend our analysis to the kaon sector.
| [
{
"created": "Wed, 22 Aug 2012 11:22:15 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Masjuan",
"P.",
""
],
[
"Arriola",
"E. R.",
""
],
[
"Broniowski",
"W.",
""
]
] | We present the analysis of Ref.[1] of the radial (n) and angular-momentum (J) Regge trajectories for all light-quark meson states listed in the Particle Data Tables. The parameters of the trajectories are obtained with linear regression, with weight of each resonance inversely proportional to its half-width squared, (\Gamma/2)^2. The joint analysis in the (n,J,M^2) Regge plane indicates, at the 4.5 standard deviation level, that the slopes in n are larger from the slopes in J. Thus no strict universality of slopes occurs in the light non-strange meson sector. We also extend our analysis to the kaon sector. |
hep-ph/9804447 | null | O.G. Tchikilev (IHEP, Protvino, Russia) | Multiplicity distributions at high energies as a sum of Poissonian-like
distributions | 16 pages, Latex, 4 EPS figures | Phys. Rev. D 59, 094008 (1999) | 10.1103/PhysRevD.59.094008 | null | hep-ph | null | It is shown that at collider energies experimental multiplicity distributions
are well parameterized by a sum of Gupta-Sarma distributions. This extends
earlier description of the lower energy data by the two parameter sum of
Poissonians. Implications of the proposed parametrization for LHC are
discussed.
| [
{
"created": "Wed, 29 Apr 1998 17:19:13 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"Tchikilev",
"O. G.",
"",
"IHEP, Protvino, Russia"
]
] | It is shown that at collider energies experimental multiplicity distributions are well parameterized by a sum of Gupta-Sarma distributions. This extends earlier description of the lower energy data by the two parameter sum of Poissonians. Implications of the proposed parametrization for LHC are discussed. |
1708.02458 | Rui-Lin Zhu | Wei Wang, Shuai Zhao, Ruilin Zhu | Gluon quasidistribution function at one loop | 26 pages,8 figures;accepted by Eur.Phys.J C | Eur. Phys. J. C (2018) 78:147 | 10.1140/epjc/s10052-018-5617-3 | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the unpolarized gluon quasidistribution function in the nucleon at
one loop level in the large momentum effective theory. For the quark
quasidistribution, power law ultraviolet divergences arise in the cut-off
scheme and an important observation is that they all are subjected to Wilson
lines. However for the gluon quasidistribution function, we first point out
that the linear ultraviolet divergences also exist in the real diagram which is
not connected to any Wilson line. We then study the one loop corrections to
parton distribution functions in both cut-off scheme and dimensional
regularization to deal with the ultraviolet divergences. In addition to the
ordinary quark and gluon distributions, we also include the quark to gluon and
gluon to quark splitting diagrams. The complete one-loop matching factors
between the quasi and light cone parton distribution functions are presented in
the cut-off scheme. We derive the $P^z$ evolution equation for quasi parton
distribution functions, and find that the $P^z$ evolution kernels are identical
to the DGLAP evolution kernels.
| [
{
"created": "Tue, 8 Aug 2017 12:18:18 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Aug 2017 15:34:59 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Feb 2018 14:50:27 GMT",
"version": "v3"
}
] | 2018-02-22 | [
[
"Wang",
"Wei",
""
],
[
"Zhao",
"Shuai",
""
],
[
"Zhu",
"Ruilin",
""
]
] | We study the unpolarized gluon quasidistribution function in the nucleon at one loop level in the large momentum effective theory. For the quark quasidistribution, power law ultraviolet divergences arise in the cut-off scheme and an important observation is that they all are subjected to Wilson lines. However for the gluon quasidistribution function, we first point out that the linear ultraviolet divergences also exist in the real diagram which is not connected to any Wilson line. We then study the one loop corrections to parton distribution functions in both cut-off scheme and dimensional regularization to deal with the ultraviolet divergences. In addition to the ordinary quark and gluon distributions, we also include the quark to gluon and gluon to quark splitting diagrams. The complete one-loop matching factors between the quasi and light cone parton distribution functions are presented in the cut-off scheme. We derive the $P^z$ evolution equation for quasi parton distribution functions, and find that the $P^z$ evolution kernels are identical to the DGLAP evolution kernels. |
hep-ph/9904381 | Rohini Godbole | R.M. Godbole | Predictions for Higgs and SUSY Higgs properties and their signatures at
the Hadron Colliders | 12 pages, 7 figures, Latex, requires mprocl.sty included, Invited
talk at the 'Hadron Collider Physics XIII', Jan.14-20, 1999, Bombay, India.
(To appear in the proceedings) | null | null | IISc-CTS/5/99 | hep-ph | null | In this talk I present a discussion of the theoretical bounds on the mass of
the Higgs in the Standard Model (SM) as well as in the Minimal Supersymmetric
Standard Model (MSSM). Then I will point out a few facts about the couplings of
scalars that are relevant for its search at hadronic colliders. After that I
discuss the search possibilities at the Tevatron and the LHC, paying special
attention to the issue of how well one can establish the quantum numbers and
the couplings of the Higgs, when (if) it is discovered.
| [
{
"created": "Mon, 19 Apr 1999 05:40:31 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Godbole",
"R. M.",
""
]
] | In this talk I present a discussion of the theoretical bounds on the mass of the Higgs in the Standard Model (SM) as well as in the Minimal Supersymmetric Standard Model (MSSM). Then I will point out a few facts about the couplings of scalars that are relevant for its search at hadronic colliders. After that I discuss the search possibilities at the Tevatron and the LHC, paying special attention to the issue of how well one can establish the quantum numbers and the couplings of the Higgs, when (if) it is discovered. |
0809.2262 | Andreas Metz | S. Arnold, A. Metz, M. Schlegel | Dilepton production from polarized hadron hadron collisions | references added, minor stylistic changes, to appear in PRD | Phys.Rev.D79:034005,2009 | 10.1103/PhysRevD.79.034005 | JLAB-THY-08-877 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we present a comprehensive formalism for dilepton production
from the collision of two polarized spin-$\tfrac{1}{2}$ hadrons by identifying
the general angular distribution of the cross section in combination with a
complete set of structure functions. The various structure functions are
computed in the parton model approximation where we mainly consider the case
when the transverse momentum of the dilepton pair is much smaller than its
invariant mass. In this kinematical region dilepton production can be described
in terms of transverse momentum dependent parton distributions.
| [
{
"created": "Fri, 12 Sep 2008 18:05:52 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jan 2009 22:54:06 GMT",
"version": "v2"
}
] | 2009-07-24 | [
[
"Arnold",
"S.",
""
],
[
"Metz",
"A.",
""
],
[
"Schlegel",
"M.",
""
]
] | In this paper we present a comprehensive formalism for dilepton production from the collision of two polarized spin-$\tfrac{1}{2}$ hadrons by identifying the general angular distribution of the cross section in combination with a complete set of structure functions. The various structure functions are computed in the parton model approximation where we mainly consider the case when the transverse momentum of the dilepton pair is much smaller than its invariant mass. In this kinematical region dilepton production can be described in terms of transverse momentum dependent parton distributions. |
1310.8404 | Yi Sun | Yi Sun and Dao-Neng Gao | Higgs decays to $\gamma$ and invisible particles in the standard model | 7 pages, 3 figures | Phys. Rev. D 89, 017301 (2014) | 10.1103/PhysRevD.89.017301 | USTC-ICTS-13-14 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the Higgs boson mass $m_h=125$ GeV, the radiative Higgs decays
$h\rightarrow\gamma \nu_l\bar\nu_l$ with $\nu_l = \nu_e,\,\nu_\mu$ and
$\nu_\tau$ are analyzed in the standard model. Our calculation shows that the
inclusive width of these processes, i.e., the sum of
$\Gamma(h\to\gamma\nu_l\bar\nu_l)$ for ${\nu_l=\nu_e,\nu_\mu,\nu_\tau}$, is
$1.41$ keV, which is about $15\%$ of $\Gamma(h\to\gamma\gamma)$. Therefore, the
observation of these channels in the future precise experiments may provide us
some useful information on the Higgs physics both in the standard model and in
its possible extensions.
| [
{
"created": "Thu, 31 Oct 2013 06:56:33 GMT",
"version": "v1"
}
] | 2014-02-05 | [
[
"Sun",
"Yi",
""
],
[
"Gao",
"Dao-Neng",
""
]
] | Using the Higgs boson mass $m_h=125$ GeV, the radiative Higgs decays $h\rightarrow\gamma \nu_l\bar\nu_l$ with $\nu_l = \nu_e,\,\nu_\mu$ and $\nu_\tau$ are analyzed in the standard model. Our calculation shows that the inclusive width of these processes, i.e., the sum of $\Gamma(h\to\gamma\nu_l\bar\nu_l)$ for ${\nu_l=\nu_e,\nu_\mu,\nu_\tau}$, is $1.41$ keV, which is about $15\%$ of $\Gamma(h\to\gamma\gamma)$. Therefore, the observation of these channels in the future precise experiments may provide us some useful information on the Higgs physics both in the standard model and in its possible extensions. |
hep-ph/0603053 | David Maybury | Bruce A. Campbell, and David W. Maybury | Triviality and the (Supersymmetric) See-Saw | 27 pages, 7 figures, references added | JHEP 0704:077,2007 | 10.1088/1126-6708/2007/04/077 | OUTP-06 06 | hep-ph | null | For the D=5 Majorana neutrino mass operator to have a see-saw ultraviolet
completion that is viable up to the Planck scale, the see-saw scale is bounded
above due to triviality limits on the see-saw couplings. For supersymmetric
see-saw models, with realistic neutrino mass textures, we compare constraints
on the see-saw scale from triviality bounds, with those arising from
experimental limits on induced charged-lepton flavour violation, for both the
CMSSM and for models with split supersymmetry.
| [
{
"created": "Tue, 7 Mar 2006 16:47:09 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Oct 2006 11:40:27 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Campbell",
"Bruce A.",
""
],
[
"Maybury",
"David W.",
""
]
] | For the D=5 Majorana neutrino mass operator to have a see-saw ultraviolet completion that is viable up to the Planck scale, the see-saw scale is bounded above due to triviality limits on the see-saw couplings. For supersymmetric see-saw models, with realistic neutrino mass textures, we compare constraints on the see-saw scale from triviality bounds, with those arising from experimental limits on induced charged-lepton flavour violation, for both the CMSSM and for models with split supersymmetry. |
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