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/9501380 | David Brahm | D. Boyanovsky, David E. Brahm, A. Gonzalez-Ruiz, R. Holman, F.I.
Takakura | Domain Walls in a FRW Universe | 23 pages, LaTeX, 7 figures using epsf.tex. Now auto-generates PS | Phys.Rev.D52:5516-5528,1995 | 10.1103/PhysRevD.52.5516 | CMU-HEP94-36 | hep-ph astro-ph | null | We solve the equations of motion for a scalar field with domain wall boundary
conditions in a Friedmann-Robertson-Walker (FRW) spacetime. We find (in
agreement with Basu and Vilenkin) that no domain wall solutions exist in de
Sitter spacetime for h = H/m >= 1/2, where H is the Hubble parameter and m is
the scalar mass. In the general FRW case we develop a systematic perturbative
expansion in h to arrive at an approximate solution to the field equations. We
calculate the energy momentum tensor of the domain wall configuration, and show
that the energy density can become negative at the core of the defect for some
values of the non-minimal coupling parameter xi. We develop a translationally
invariant theory for fluctuations of the wall, obtain the effective Lagrangian
for these fluctuations, and quantize them using the Bunch-Davies vacuum in the
de Sitter case. Unlike previous analyses, we find that the fluctuations act as
zero-mass (as opposed to tachyonic) modes. This allows us to calculate the
distortion and the normal-normal correlators for the surface. The normal-normal
correlator decreases logarithmically with the distance between points for large
times and distances, indicating that the interface becomes rougher than in
Minkowski spacetime.
| [
{
"created": "Thu, 26 Jan 1995 03:28:38 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Jan 1995 22:37:22 GMT",
"version": "v2"
},
{
"created": "Tue, 14 Nov 1995 06:14:16 GMT",
"version": "v3"
}
] | 2011-07-19 | [
[
"Boyanovsky",
"D.",
""
],
[
"Brahm",
"David E.",
""
],
[
"Gonzalez-Ruiz",
"A.",
""
],
[
"Holman",
"R.",
""
],
[
"Takakura",
"F. I.",
""
]
] | We solve the equations of motion for a scalar field with domain wall boundary conditions in a Friedmann-Robertson-Walker (FRW) spacetime. We find (in agreement with Basu and Vilenkin) that no domain wall solutions exist in de Sitter spacetime for h = H/m >= 1/2, where H is the Hubble parameter and m is the scalar mass. In the general FRW case we develop a systematic perturbative expansion in h to arrive at an approximate solution to the field equations. We calculate the energy momentum tensor of the domain wall configuration, and show that the energy density can become negative at the core of the defect for some values of the non-minimal coupling parameter xi. We develop a translationally invariant theory for fluctuations of the wall, obtain the effective Lagrangian for these fluctuations, and quantize them using the Bunch-Davies vacuum in the de Sitter case. Unlike previous analyses, we find that the fluctuations act as zero-mass (as opposed to tachyonic) modes. This allows us to calculate the distortion and the normal-normal correlators for the surface. The normal-normal correlator decreases logarithmically with the distance between points for large times and distances, indicating that the interface becomes rougher than in Minkowski spacetime. |
hep-ph/0012357 | K. Matsuda | K.Matsuda, N.Takeda, T.Fukuyama, H.Nishiura | MNS Parameters from Neutrino Oscillations, Single Beta Decay and Double
Beta Decay | 25pages, 10figures | Phys.Rev.D64:013001,2001 | 10.1103/PhysRevD.64.013001 | null | hep-ph | null | We examine the constraints on the MNS lepton mixing matrix =66rom the present
and future experimental data of the neutrino oscillation, tritium beta decay,
and neutrinoless double beta decay for Majorana neutrinos. We show that the
small mixing angle solutions for solar neutrino problem are disfavored for
small averaged mass ($<m_\nu>$) of neutrinoless double beta decay ($\leq 0.01$
eV) in the inverse neutrino mass hierarchy scenario. This is the case even in
the normal mass hierarchy scenario except for very restrictive value of the
averaged neutrino mass ($\bar{m_\nu}$) of single beta decay. The lower mass
bound for $\bar{m_\nu}$ is given from the present neutrino oscillation data. We
obtain some relations between $<m_\nu>$ and $\bar{m_\nu}$. The constraints on
the Majorana CP violating phases are also given.
| [
{
"created": "Thu, 28 Dec 2000 12:51:44 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Jan 2001 10:05:56 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Matsuda",
"K.",
""
],
[
"Takeda",
"N.",
""
],
[
"Fukuyama",
"T.",
""
],
[
"Nishiura",
"H.",
""
]
] | We examine the constraints on the MNS lepton mixing matrix =66rom the present and future experimental data of the neutrino oscillation, tritium beta decay, and neutrinoless double beta decay for Majorana neutrinos. We show that the small mixing angle solutions for solar neutrino problem are disfavored for small averaged mass ($<m_\nu>$) of neutrinoless double beta decay ($\leq 0.01$ eV) in the inverse neutrino mass hierarchy scenario. This is the case even in the normal mass hierarchy scenario except for very restrictive value of the averaged neutrino mass ($\bar{m_\nu}$) of single beta decay. The lower mass bound for $\bar{m_\nu}$ is given from the present neutrino oscillation data. We obtain some relations between $<m_\nu>$ and $\bar{m_\nu}$. The constraints on the Majorana CP violating phases are also given. |
hep-ph/0306127 | James Wells | James D. Wells (MCTP) | Implications of Supersymmetry Breaking with a Little Hierarchy between
Gauginos and Scalars | 12 pages, To appear in Proceedings of SUSY 2003 (Tucson, Arizona),
5-10 June 2003. v2: added refs; v3: minor clarifications on gluino decays | null | null | null | hep-ph | null | From a theoretical point of view it is not hard to imagine gaugino masses
being much lighter than scalar masses. The dominant contributions to gaugino
masses are then their anomaly-mediated values. Given current lower bounds on
gauginos, which are near the W-mass scale, considering a little hierarchy
between weak-scale gauginos and much heavier scalars requires suspending normal
intuition on finetuning and naturalness of the Higgs potential. Nevertheless,
tantalizing perks come from the hypothesis: lessened flavor and CP violation
problems, more compatibility with gauge coupling unification and third
generation Yukawa unification, suppressed dimension-five proton decay
operators, and no problems satisfying the current Higgs mass constraint for any
value of tan(beta) consistent with the top and bottom Yukawa couplings
remaining finite up to the grand unified scale. The Tevatron has little chance
of finding any evidence of this theory given current constraints. The LHC does
well looking for pair production of gluinos which three-body decay into
potentially spectacular final states. Dark matter relic abundance can be
cosmologically interesting, but table-top experiments will not see LSPs
scattering off nucleons. On the other hand, experiments looking for
monochromatic photons from LSP annihilations in the galactic halo may find
them.
| [
{
"created": "Fri, 13 Jun 2003 19:27:00 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Jun 2003 18:45:21 GMT",
"version": "v2"
},
{
"created": "Fri, 29 Aug 2003 15:40:55 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Wells",
"James D.",
"",
"MCTP"
]
] | From a theoretical point of view it is not hard to imagine gaugino masses being much lighter than scalar masses. The dominant contributions to gaugino masses are then their anomaly-mediated values. Given current lower bounds on gauginos, which are near the W-mass scale, considering a little hierarchy between weak-scale gauginos and much heavier scalars requires suspending normal intuition on finetuning and naturalness of the Higgs potential. Nevertheless, tantalizing perks come from the hypothesis: lessened flavor and CP violation problems, more compatibility with gauge coupling unification and third generation Yukawa unification, suppressed dimension-five proton decay operators, and no problems satisfying the current Higgs mass constraint for any value of tan(beta) consistent with the top and bottom Yukawa couplings remaining finite up to the grand unified scale. The Tevatron has little chance of finding any evidence of this theory given current constraints. The LHC does well looking for pair production of gluinos which three-body decay into potentially spectacular final states. Dark matter relic abundance can be cosmologically interesting, but table-top experiments will not see LSPs scattering off nucleons. On the other hand, experiments looking for monochromatic photons from LSP annihilations in the galactic halo may find them. |
2304.03978 | Eduard Paryev Ph.D | E.Ya.Paryev | On the possibility of testing the two-peak structure of the LHCb
hidden-charm strange pentaquark $P_{cs}(4459)^0$ in near-threshold
antikaon-induced charmonium production on protons and nuclei | 30 pages, 13 figures; arXiv admin note: text overlap with
arXiv:2211.16037, references and some additional comments are added | Nucl.Phys.A 1037(2023)122687 | 10.1016/j.nuclphysa.2023.122687 | null | hep-ph hep-ex nucl-ex | http://creativecommons.org/licenses/by/4.0/ | Accounting for the LHCb observation that the reported hidden-charm strange
pentaquark $P_{cs}(4459)^0$ can split into two substructures, $P_{cs}(4455)^0$
and $P_{cs}(4468)^0$, with a mass difference of 13 MeV as well as the newly
observed hidden-charm pentaquark resonance $P_{cs}(4338)^0$ with strangeness,
we study within the double-peak scenario for the $P_{cs}(4459)^0$ state the
near-threshold $J/\psi$ meson production from protons and nuclei by considering
incoherent direct non-resonant (${K^-}p \to {J/\psi}\Lambda$) and two-step
resonant (${K^-}p \to P_{csi}^0 \to {J/\psi}\Lambda$, $i=1$, 2, 3;
$P_{cs1}^{0}=P_{cs}(4338)^0$, $P_{cs2}^{0}=P_{cs}(4455)^0$,
$P_{cs3}^{0}=P_{cs}(4468)^0$) charmonium production processes with the main
goal of clarifying the possibility to observe within this scenario both above
two substructures contributing to the $P_{cs}(4459)^0$ state and the
$P_{cs}(4338)^0$ resonance in this production. We calculate the absolute
excitation functions, energy and momentum distributions for the non-resonant,
resonant and for the combined (non-resonant plus resonant) production of
$J/\psi$ mesons on protons as well as on carbon and tungsten target nuclei at
near-threshold incident antikaon beam momenta by assuming the spin-parity
assignments of the hidden-charm resonances $P_{cs}(4338)^0$, $P_{cs}(4455)^0$
and $P_{cs}(4468)^0$ as $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within
four different realistic choices for the branching ratios of their decays to
the ${J/\psi}\Lambda$ mode (0.125, 0.25, 0.5 and 1\%) as well as for two
options for the branching fraction of their decays to the $K^-p$ channel (0.01
and 0.001\%). We show that these combined observables reveal clear sensitivity
to these scenarios. Hence, they may be an important tool to provide further
evidence for the existence of the above strange hidden-charm pentaquark
resonances.
| [
{
"created": "Sat, 8 Apr 2023 10:18:31 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Jun 2023 09:37:40 GMT",
"version": "v2"
}
] | 2023-06-12 | [
[
"Paryev",
"E. Ya.",
""
]
] | Accounting for the LHCb observation that the reported hidden-charm strange pentaquark $P_{cs}(4459)^0$ can split into two substructures, $P_{cs}(4455)^0$ and $P_{cs}(4468)^0$, with a mass difference of 13 MeV as well as the newly observed hidden-charm pentaquark resonance $P_{cs}(4338)^0$ with strangeness, we study within the double-peak scenario for the $P_{cs}(4459)^0$ state the near-threshold $J/\psi$ meson production from protons and nuclei by considering incoherent direct non-resonant (${K^-}p \to {J/\psi}\Lambda$) and two-step resonant (${K^-}p \to P_{csi}^0 \to {J/\psi}\Lambda$, $i=1$, 2, 3; $P_{cs1}^{0}=P_{cs}(4338)^0$, $P_{cs2}^{0}=P_{cs}(4455)^0$, $P_{cs3}^{0}=P_{cs}(4468)^0$) charmonium production processes with the main goal of clarifying the possibility to observe within this scenario both above two substructures contributing to the $P_{cs}(4459)^0$ state and the $P_{cs}(4338)^0$ resonance in this production. We calculate the absolute excitation functions, energy and momentum distributions for the non-resonant, resonant and for the combined (non-resonant plus resonant) production of $J/\psi$ mesons on protons as well as on carbon and tungsten target nuclei at near-threshold incident antikaon beam momenta by assuming the spin-parity assignments of the hidden-charm resonances $P_{cs}(4338)^0$, $P_{cs}(4455)^0$ and $P_{cs}(4468)^0$ as $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within four different realistic choices for the branching ratios of their decays to the ${J/\psi}\Lambda$ mode (0.125, 0.25, 0.5 and 1\%) as well as for two options for the branching fraction of their decays to the $K^-p$ channel (0.01 and 0.001\%). We show that these combined observables reveal clear sensitivity to these scenarios. Hence, they may be an important tool to provide further evidence for the existence of the above strange hidden-charm pentaquark resonances. |
0903.5506 | Kuang-Ta Chao | Bai-Qing Li, Kuang-Ta Chao | Higher Charmonia and X,Y,Z states with Screened Potential | Total width of X(3872) reestimated, references added; 12 pages, 1
figure; published version in PRD | Phys.Rev.D79:094004,2009 | 10.1103/PhysRevD.79.094004 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We incorporate the color-screening effect due to light quark pair creation
into the heavy quark-antiquark potential, and investigate the effects of
screened potential on the spectrum of higher charmonium. We calculate the
masses, electromagnetic decays, and E1 transitions of charmonium states in the
screened potential model, and propose possible assignments for the newly
discovered charmonium or charmonium-like $"X,Y,Z"$ states. We find the masses
of higher charmonia with screened potential are considerably lower than those
with unscreened potential. The $\chi_{c2}(2P)$ mass agrees well with that of
the Z(3930), and the mass of $\psi(4415)$ is compatible with $\psi(5S)$ rather
than $\psi(4S)$. In particular, the discovered four $Y$ states in the ISR
process, i.e., $Y(4008), Y(4260), Y(4320/4360), Y(4660)$ may be assigned as the
$\psi(3S), \psi(4S), \psi(3D), \psi(6S)$ states respectively. The X(3940) and
X(4160) found in the double charmonium production in $e^+e^-$ annihilation may
be assigned as the $\eta_c(3S)$ and $\chi_{c0}(3P)$ states. Based on the
calculated E1 transition widths for $\chi_{c1}(2P)\to \gamma J/\psi$ and
$\chi_{c1}(2P)\to \gamma \psi(2S)$ and other results, we argue that the X(3872)
may be a $\chi_{c1}(2P)$ dominated charmonium state with some admixture of the
$D^0\bar{D}^{*0}$ component. Possible problems encountered in these assignments
and comparisons with other interpretations for these $X,Y,Z$ states are
discussed in detail. We emphasize that more theoretical and experimental
investigations are urgently needed to clarify these assignments and other
interpretations.
| [
{
"created": "Tue, 31 Mar 2009 15:49:02 GMT",
"version": "v1"
},
{
"created": "Thu, 7 May 2009 15:15:49 GMT",
"version": "v2"
}
] | 2009-10-29 | [
[
"Li",
"Bai-Qing",
""
],
[
"Chao",
"Kuang-Ta",
""
]
] | We incorporate the color-screening effect due to light quark pair creation into the heavy quark-antiquark potential, and investigate the effects of screened potential on the spectrum of higher charmonium. We calculate the masses, electromagnetic decays, and E1 transitions of charmonium states in the screened potential model, and propose possible assignments for the newly discovered charmonium or charmonium-like $"X,Y,Z"$ states. We find the masses of higher charmonia with screened potential are considerably lower than those with unscreened potential. The $\chi_{c2}(2P)$ mass agrees well with that of the Z(3930), and the mass of $\psi(4415)$ is compatible with $\psi(5S)$ rather than $\psi(4S)$. In particular, the discovered four $Y$ states in the ISR process, i.e., $Y(4008), Y(4260), Y(4320/4360), Y(4660)$ may be assigned as the $\psi(3S), \psi(4S), \psi(3D), \psi(6S)$ states respectively. The X(3940) and X(4160) found in the double charmonium production in $e^+e^-$ annihilation may be assigned as the $\eta_c(3S)$ and $\chi_{c0}(3P)$ states. Based on the calculated E1 transition widths for $\chi_{c1}(2P)\to \gamma J/\psi$ and $\chi_{c1}(2P)\to \gamma \psi(2S)$ and other results, we argue that the X(3872) may be a $\chi_{c1}(2P)$ dominated charmonium state with some admixture of the $D^0\bar{D}^{*0}$ component. Possible problems encountered in these assignments and comparisons with other interpretations for these $X,Y,Z$ states are discussed in detail. We emphasize that more theoretical and experimental investigations are urgently needed to clarify these assignments and other interpretations. |
2107.00276 | Guojun Huang | Guojun Huang and Pengfei Zhuang | Treating divergence in quark matter by using energy projectors | 10 pages, 2 figures | Phys. Rev. D 104, 074001 (2021) | 10.1103/PhysRevD.104.074001 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate gluon self-energy using quark energy projectors in a general
quark-gluon plasma. By separating the quark field into a positive- and a
negative-energy mode, the quark loop constructed with the same mode is always
convergent, and the divergence appears only in the mixed loop with different
modes and is medium independent. After removing the divergence in vacuum, we
obtain the one-loop gluon self-energy at finite temperature, chemical potential
and quarks mass without approximation. With the method of quark loop
resummation, we calculate non-perturbatively the gluon Debye mass and
thermodynamic potential. In the limit of small gluon momentum in comparison
with temperature, chemical potential and quark mass, our calculation comes back
to the known HTL/HDL results in literature.
| [
{
"created": "Thu, 1 Jul 2021 08:01:29 GMT",
"version": "v1"
},
{
"created": "Sat, 3 Jul 2021 10:32:53 GMT",
"version": "v2"
}
] | 2021-10-13 | [
[
"Huang",
"Guojun",
""
],
[
"Zhuang",
"Pengfei",
""
]
] | We calculate gluon self-energy using quark energy projectors in a general quark-gluon plasma. By separating the quark field into a positive- and a negative-energy mode, the quark loop constructed with the same mode is always convergent, and the divergence appears only in the mixed loop with different modes and is medium independent. After removing the divergence in vacuum, we obtain the one-loop gluon self-energy at finite temperature, chemical potential and quarks mass without approximation. With the method of quark loop resummation, we calculate non-perturbatively the gluon Debye mass and thermodynamic potential. In the limit of small gluon momentum in comparison with temperature, chemical potential and quark mass, our calculation comes back to the known HTL/HDL results in literature. |
hep-ph/0608085 | Jonathan Rosner | Michael Gronau, Jonathan L. Rosner, and Jure Zupan | Updated bounds on CP asymmetries in $B^0 \to \eta' K_S$ and $B^0 \to
\pi^0 K_S$ | 10 pages, 3 figures. To be published in Phys. Rev. D. Discussion and
references expanded; data updated | Phys.Rev.D74:093003,2006 | 10.1103/PhysRevD.74.093003 | SLAC-PUB-12043; EFI 06-17 | hep-ph hep-ex | null | New rate measurements of $B^0$ decays into $\pi^0\pi^0, \pi^0\eta,
\pi^0\eta', \eta\eta, \eta\eta', \eta'\eta'$ and $K^+ K^-$ are used in
conjunction with flavor SU(3) to constrain the coefficients $S$ and $C$ of
$\sin\Delta mt$ and $\cos\Delta mt$ in the time-dependent CP asymmetries of
$B^0 \to \eta' K_S$ and $B^0 \to \pi^0 K_S$. Experimental values of $S_{\eta'
K}$ are now seen to be closer to the Standard Model expectations, fully
consistent with the new improved bounds.
| [
{
"created": "Mon, 7 Aug 2006 21:28:59 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Aug 2006 16:55:08 GMT",
"version": "v2"
},
{
"created": "Tue, 5 Sep 2006 16:34:18 GMT",
"version": "v3"
},
{
"created": "Fri, 27 Oct 2006 21:29:19 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Gronau",
"Michael",
""
],
[
"Rosner",
"Jonathan L.",
""
],
[
"Zupan",
"Jure",
""
]
] | New rate measurements of $B^0$ decays into $\pi^0\pi^0, \pi^0\eta, \pi^0\eta', \eta\eta, \eta\eta', \eta'\eta'$ and $K^+ K^-$ are used in conjunction with flavor SU(3) to constrain the coefficients $S$ and $C$ of $\sin\Delta mt$ and $\cos\Delta mt$ in the time-dependent CP asymmetries of $B^0 \to \eta' K_S$ and $B^0 \to \pi^0 K_S$. Experimental values of $S_{\eta' K}$ are now seen to be closer to the Standard Model expectations, fully consistent with the new improved bounds. |
hep-ph/9811437 | null | F. Gangemi, G. Montagna, M. Moretti, O. Nicrosini and F. Piccinini | Six-fermion production and Higgs boson physics at future $e^+ e^-$
colliders | LaTeX, 27 pages, 13 figures included. Minor changes, final version to
appear in Eur. Phys. J. C | Eur.Phys.J.C9:31-41,1999 | 10.1007/s100520050510 | CERN/TH 98-238, FNT/T 98/07 | hep-ph hep-ex | null | The six-fermion production processes $e^+e^-\to q\bar q l^+ l^-\nu\bar\nu$,
with all the lepton flavours and $q=u,d,c,s$, relevant to the study of the
intermediate-mass Higgs boson at future $e^+e^-$ linear colliders, are
analysed. A Monte Carlo program, taking into account the whole set of
tree-level scattering amplitudes and the relevant radiative effects, is
developed to provide integrated cross sections and generation of unweighted
events. The complete calculation is compared with the available results of real
Higgs production, and the opportunities of precision studies with event
generation are discussed, demonstrating the relevance of a full six-fermion
calculation. Numerical results for integrated cross sections with various
kinematical cuts and including radiative effects are given and commented. In
the analysis of event samples, several distributions are studied and found to
be sensitive to the presence and to the properties of the Higgs boson.
| [
{
"created": "Mon, 23 Nov 1998 11:30:18 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Jan 1999 11:14:21 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Gangemi",
"F.",
""
],
[
"Montagna",
"G.",
""
],
[
"Moretti",
"M.",
""
],
[
"Nicrosini",
"O.",
""
],
[
"Piccinini",
"F.",
""
]
] | The six-fermion production processes $e^+e^-\to q\bar q l^+ l^-\nu\bar\nu$, with all the lepton flavours and $q=u,d,c,s$, relevant to the study of the intermediate-mass Higgs boson at future $e^+e^-$ linear colliders, are analysed. A Monte Carlo program, taking into account the whole set of tree-level scattering amplitudes and the relevant radiative effects, is developed to provide integrated cross sections and generation of unweighted events. The complete calculation is compared with the available results of real Higgs production, and the opportunities of precision studies with event generation are discussed, demonstrating the relevance of a full six-fermion calculation. Numerical results for integrated cross sections with various kinematical cuts and including radiative effects are given and commented. In the analysis of event samples, several distributions are studied and found to be sensitive to the presence and to the properties of the Higgs boson. |
hep-ph/0608202 | Antoni Szczurek | Marta Luszczak and Antoni Szczurek | Charmed Meson Production in Proton - (ANTI)PROTON Collisions | presented by M. Luszczak at the international conference MESON2006,
June 2006, Cracow, 6 pages, 5 figures | Int.J.Mod.Phys.A22:555-560,2007 | 10.1142/S0217751X07035823 | null | hep-ph | null | We discuss and compare different approaches to include gluon transverse
momenta for heavy quark-antiquark pair and meson production. The results are
illustrated with the help of different unintegrated gluon distributions (UGDF)
from the literature. We compare results obtained with on-shell and off-shell
matrix elements and kinematics. The results are compared with recent
experimental results of the CDF collaboration.
| [
{
"created": "Fri, 18 Aug 2006 08:14:29 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Luszczak",
"Marta",
""
],
[
"Szczurek",
"Antoni",
""
]
] | We discuss and compare different approaches to include gluon transverse momenta for heavy quark-antiquark pair and meson production. The results are illustrated with the help of different unintegrated gluon distributions (UGDF) from the literature. We compare results obtained with on-shell and off-shell matrix elements and kinematics. The results are compared with recent experimental results of the CDF collaboration. |
1903.00013 | Rakhi Mahbubani | Rakhi Mahbubani and Kin Mimouni | Boosting the dark matter signal with Coulomb resonances | 29 pages, 9 figures. v2: published version. Few typos corrected and
added comment on perturbative unitarity | JCAP 1909 (2019) no.09, 056 | 10.1088/1475-7516/2019/09/056 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that the presence of nearby Coulombic resonances at finite energy
could lead to the enhancement of the dark matter annihilation cross section at
specific non-zero velocities correlated with the mass splitting between the
dark matter pair and that of the resonance. If one of these resonant velocities
approximately matches the velocity of dark matter in our local neighbourhood,
we would see this enhancement in existing indirect-detection measurements, such
as the measurements of the continuum photon spectrum made by HESS and
Fermi-LAT. We explore this effect in the context of pure Higgsino and Wino dark
matter with a variable splitting between charged and neutral components,
controlled by the Wilson coefficient of a higher-dimension operator. For
electroweak WIMPs a relevant and appreciable enhancement from Coulomb
resonances requires tuning the charged-neutral splitting to be of order the
Coulomb binding energies. This leads to strong exclusions of Higgsino dark
matter with charged-neutral splittings in the narrow ranges (2, 2.5) and (8.5,
10.5) MeV. In contrast, by decreasing the charged-neutral splitting for the
thermal Wino, we can move the Yukawa resonance away from the thermal relic
mass, decreasing the indirect-detection signal to a level that is compatible
with HESS measurements in the window (25, 35) MeV.
| [
{
"created": "Thu, 28 Feb 2019 19:00:01 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Jan 2020 13:02:55 GMT",
"version": "v2"
}
] | 2020-01-29 | [
[
"Mahbubani",
"Rakhi",
""
],
[
"Mimouni",
"Kin",
""
]
] | We show that the presence of nearby Coulombic resonances at finite energy could lead to the enhancement of the dark matter annihilation cross section at specific non-zero velocities correlated with the mass splitting between the dark matter pair and that of the resonance. If one of these resonant velocities approximately matches the velocity of dark matter in our local neighbourhood, we would see this enhancement in existing indirect-detection measurements, such as the measurements of the continuum photon spectrum made by HESS and Fermi-LAT. We explore this effect in the context of pure Higgsino and Wino dark matter with a variable splitting between charged and neutral components, controlled by the Wilson coefficient of a higher-dimension operator. For electroweak WIMPs a relevant and appreciable enhancement from Coulomb resonances requires tuning the charged-neutral splitting to be of order the Coulomb binding energies. This leads to strong exclusions of Higgsino dark matter with charged-neutral splittings in the narrow ranges (2, 2.5) and (8.5, 10.5) MeV. In contrast, by decreasing the charged-neutral splitting for the thermal Wino, we can move the Yukawa resonance away from the thermal relic mass, decreasing the indirect-detection signal to a level that is compatible with HESS measurements in the window (25, 35) MeV. |
2403.08854 | Rikab Gambhir | Rikab Gambhir, Athis Osathapan, and Jesse Thaler | Moments of Clarity: Streamlining Latent Spaces in Machine Learning using
Moment Pooling | 15+7 pages, 14 figures, 7 tables. Code available at
https://github.com/athiso/moment and https://github.com/rikab/MomentAnalysis | null | null | MIT-CTP 5689 | hep-ph cs.LG stat.ML | http://creativecommons.org/licenses/by/4.0/ | Many machine learning applications involve learning a latent representation
of data, which is often high-dimensional and difficult to directly interpret.
In this work, we propose "Moment Pooling", a natural extension of Deep Sets
networks which drastically decrease latent space dimensionality of these
networks while maintaining or even improving performance. Moment Pooling
generalizes the summation in Deep Sets to arbitrary multivariate moments, which
enables the model to achieve a much higher effective latent dimensionality for
a fixed latent dimension. We demonstrate Moment Pooling on the collider physics
task of quark/gluon jet classification by extending Energy Flow Networks (EFNs)
to Moment EFNs. We find that Moment EFNs with latent dimensions as small as 1
perform similarly to ordinary EFNs with higher latent dimension. This small
latent dimension allows for the internal representation to be directly
visualized and interpreted, which in turn enables the learned internal jet
representation to be extracted in closed form.
| [
{
"created": "Wed, 13 Mar 2024 18:00:01 GMT",
"version": "v1"
}
] | 2024-03-15 | [
[
"Gambhir",
"Rikab",
""
],
[
"Osathapan",
"Athis",
""
],
[
"Thaler",
"Jesse",
""
]
] | Many machine learning applications involve learning a latent representation of data, which is often high-dimensional and difficult to directly interpret. In this work, we propose "Moment Pooling", a natural extension of Deep Sets networks which drastically decrease latent space dimensionality of these networks while maintaining or even improving performance. Moment Pooling generalizes the summation in Deep Sets to arbitrary multivariate moments, which enables the model to achieve a much higher effective latent dimensionality for a fixed latent dimension. We demonstrate Moment Pooling on the collider physics task of quark/gluon jet classification by extending Energy Flow Networks (EFNs) to Moment EFNs. We find that Moment EFNs with latent dimensions as small as 1 perform similarly to ordinary EFNs with higher latent dimension. This small latent dimension allows for the internal representation to be directly visualized and interpreted, which in turn enables the learned internal jet representation to be extracted in closed form. |
hep-ph/9501205 | null | N.V.Krasnikov | Upper bound on the supersymmetry breaking scale in supersymmetric SU(5)
model. | 9 pages, latex, no figures | JETP Lett. 61 (1995) 245-250 | null | Preprint INR 869/94 | hep-ph | null | The status of coupling constant unification in standard supersymmetric SU(5)
model and its extensions is discussed. Taking into account uncertainties
related with the initial coupling constants and threshold corrections at low
and high scales we find that in supersymmetric SU(5) model the scale of
supersymmetry breaking could be up to $10^8$ Gev. In the extensions of standard
SU(5) model it is possible to increase the supersymmetry breaking scale up to
$10^{11}$ Gev.
| [
{
"created": "Tue, 3 Jan 1995 07:45:08 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Krasnikov",
"N. V.",
""
]
] | The status of coupling constant unification in standard supersymmetric SU(5) model and its extensions is discussed. Taking into account uncertainties related with the initial coupling constants and threshold corrections at low and high scales we find that in supersymmetric SU(5) model the scale of supersymmetry breaking could be up to $10^8$ Gev. In the extensions of standard SU(5) model it is possible to increase the supersymmetry breaking scale up to $10^{11}$ Gev. |
hep-ph/0408274 | Alfredo Valcarce | J. Vijande, H. Garcilazo, A. Valcarce, F. Fernandez | Spectroscopy of doubly charmed baryons | 6 pages, 1 figure, accepted for publication in Phys. Rev. D | Phys.Rev. D70 (2004) 054022 | 10.1103/PhysRevD.70.054022 | null | hep-ph hep-ex nucl-th | null | We study the mass spectrum of baryons with two and three charmed quarks. For
double charm baryons the spin splitting is found to be smaller than standard
quark-model potential predictions. This splitting is not influenced either by
the particular form of the confining potential or by the regularization taken
for the contact term of the spin-spin potential. We consistently predict the
spectra for triply charmed baryons.
| [
{
"created": "Wed, 25 Aug 2004 08:43:06 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Vijande",
"J.",
""
],
[
"Garcilazo",
"H.",
""
],
[
"Valcarce",
"A.",
""
],
[
"Fernandez",
"F.",
""
]
] | We study the mass spectrum of baryons with two and three charmed quarks. For double charm baryons the spin splitting is found to be smaller than standard quark-model potential predictions. This splitting is not influenced either by the particular form of the confining potential or by the regularization taken for the contact term of the spin-spin potential. We consistently predict the spectra for triply charmed baryons. |
2106.01377 | Alan Barr | Alan Barr | Testing Bell inequalities in Higgs boson decays | Sign corrections to Eqns. (12) (13) (23). Results and conclusions
unchanged | Physics Letters B 825 (2022) 136866 | 10.1016/j.physletb.2021.136866 | null | hep-ph hep-ex quant-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | Higgs boson decays produce pairs of $W$ bosons in a maximally entangled
state, the spins of which can be expected to violate Bell inequalities. We show
that the spin density matrix of the $W^\pm$ pair may be reconstructed
experimentally from the directions of the charged lepton decay products, and
from it the expectation values of various Bell operators determined. Numerical
simulations of $H\rightarrow WW^*$ decays indicate that violation of a
generalised CHSH inequality is unlikely to be measurable, however the CGLMP
inequality is near-maximally violated. Experimental Bell tests could be
performed at a variety of colliders and in different production channels. If
reconstruction effects and backgrounds can be controlled then statistically
significant violations could be observable even with datasets comparable to
those already collected at the LHC.
| [
{
"created": "Wed, 2 Jun 2021 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Nov 2021 10:51:11 GMT",
"version": "v2"
},
{
"created": "Thu, 16 Jun 2022 16:03:17 GMT",
"version": "v3"
},
{
"created": "Tue, 26 Jul 2022 11:25:04 GMT",
"version": "v4"
}
] | 2022-07-27 | [
[
"Barr",
"Alan",
""
]
] | Higgs boson decays produce pairs of $W$ bosons in a maximally entangled state, the spins of which can be expected to violate Bell inequalities. We show that the spin density matrix of the $W^\pm$ pair may be reconstructed experimentally from the directions of the charged lepton decay products, and from it the expectation values of various Bell operators determined. Numerical simulations of $H\rightarrow WW^*$ decays indicate that violation of a generalised CHSH inequality is unlikely to be measurable, however the CGLMP inequality is near-maximally violated. Experimental Bell tests could be performed at a variety of colliders and in different production channels. If reconstruction effects and backgrounds can be controlled then statistically significant violations could be observable even with datasets comparable to those already collected at the LHC. |
hep-ph/9403224 | Craig Roberts | C. D. Roberts and A. G. Williams | Dyson-Schwinger Equations and the Application to Hadronic Physics | 110 pages, LaTeX. Replaced only to facilitate retrieval. Also
available at /u/ftp/pub/Review.uu via anonymnous-ftp | Prog.Part.Nucl.Phys.33:477-575,1994 | 10.1016/0146-6410(94)90049-3 | null | hep-ph nucl-th | null | We review the current status of nonperturbative studies of gauge field theory
using the Dyson-Schwinger equation formalism and its application to hadronic
physics. We begin with an introduction to the formalism and a discussion of
renormalisation in this approach. We then review the current status of studies
of Abelian gauge theories [e.g., strong coupling quantum electrodynamics]
before turning our attention to the non-Abelian gauge theory of the strong
interaction, quantum chromodynamics. We discuss confinement, dynamical chiral
symmetry breaking and the application and contribution of these techniques to
our understanding of the strong interactions.
| [
{
"created": "Thu, 3 Mar 1994 22:34:27 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Aug 1997 23:07:07 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Roberts",
"C. D.",
""
],
[
"Williams",
"A. G.",
""
]
] | We review the current status of nonperturbative studies of gauge field theory using the Dyson-Schwinger equation formalism and its application to hadronic physics. We begin with an introduction to the formalism and a discussion of renormalisation in this approach. We then review the current status of studies of Abelian gauge theories [e.g., strong coupling quantum electrodynamics] before turning our attention to the non-Abelian gauge theory of the strong interaction, quantum chromodynamics. We discuss confinement, dynamical chiral symmetry breaking and the application and contribution of these techniques to our understanding of the strong interactions. |
hep-ph/0207073 | Giulia Zanderighi | G.Zanderighi | Out-of-plane QCD radiation in DIS events with high $P_T$ Jets | 5 pages, 1 figure, talk given at X International Workshop on Deep
Inelastic Scattering (DIS2002), Krakov, Poland | Acta Phys.Polon. B33 (2002) 3317-3322 | null | IPPP-02/32, DCPT-02/64 | hep-ph | null | We present the QCD analysis of the out-of-event-plane momentum distribution
in DIS events with high $p_t$ jets. The achieved accuracy allows the
measurement of the running coupling and the study of non-perturbative effects,
in particular the test of universality of power corrections in a new
experimental regime.
| [
{
"created": "Thu, 4 Jul 2002 14:10:50 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Zanderighi",
"G.",
""
]
] | We present the QCD analysis of the out-of-event-plane momentum distribution in DIS events with high $p_t$ jets. The achieved accuracy allows the measurement of the running coupling and the study of non-perturbative effects, in particular the test of universality of power corrections in a new experimental regime. |
hep-ph/9905498 | null | S. Willenbrock (U. of Illinois) | Thinking About Top within the Standard Model | 12 pages, LateX, 9 figures. Presented at the Thinkshop on Top-Quark
Physics for the Tevatron Run II, Fermilab, October 16-18, 1998 | null | null | null | hep-ph hep-ex | null | I present an overview of standard-model top-quark physics at the Fermilab
Tevatron. Topics discussed include the top-quark mass, weak interaction, strong
interaction, and rare decays.
| [
{
"created": "Wed, 26 May 1999 17:02:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Willenbrock",
"S.",
"",
"U. of Illinois"
]
] | I present an overview of standard-model top-quark physics at the Fermilab Tevatron. Topics discussed include the top-quark mass, weak interaction, strong interaction, and rare decays. |
hep-ph/0102268 | Georges Sardin | G.Sardin | Fundamentals of the Orbital Conception of Elementary Particles and of
their Application to the Neutron and Nuclear Structure | PDF 194 KB. You may get more information at http://www.sardin.com | Phys.Essays 12 (1999) 204-220 | 10.4006/1.3025378 | null | hep-ph | null | An alternative approach to the Standard Model is outlined, being motivated by
the increasing theoretical and experimental difficulties encountered by this
model, which furthermore fails to be unitary. In particular, the conceptual
uneasiness generated by the excessive multiplicity of fundamental elements of
the Quark Model, 36 different quarks whose cohesion needs 8 different types of
gluons, has logically led some physicists to propose a variety of quark
substructures in an effort to reach unity. In order to avoid the forward escape
corresponding to the attribution of a substructure to quarks and to stand away
from the conceptual strangling to which the Standard model has led, we have
instead opted for different fundamentals. These, in contrast to those of the
Standard Model, are extremely simple and based on the assumption of a single
fundamental corpuscle, of dual manifestation as corpuscle and anticorpuscle, to
which is always associated an orbital that determines the structure of
particles. In such a frame particles differentiate through the diversity of
quantum states of their structuring orbital, in contrast to the strategy used
by the Standard Model based instead on the particle's multiplicity of
composition through the variety of the quark's content, furthermore limited to
hadrons. Instead the orbital conception of particles is unitary, unifying all
of them as well as their interactions. As an outstanding feature, nuclear
forces derive from the neutron orbital structure, based on a proton core and a
shell. This shell constitutes the cohesive element of nuclear structure.
| [
{
"created": "Wed, 21 Feb 2001 17:49:22 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Mar 2001 09:07:59 GMT",
"version": "v2"
}
] | 2015-06-25 | [
[
"Sardin",
"G.",
""
]
] | An alternative approach to the Standard Model is outlined, being motivated by the increasing theoretical and experimental difficulties encountered by this model, which furthermore fails to be unitary. In particular, the conceptual uneasiness generated by the excessive multiplicity of fundamental elements of the Quark Model, 36 different quarks whose cohesion needs 8 different types of gluons, has logically led some physicists to propose a variety of quark substructures in an effort to reach unity. In order to avoid the forward escape corresponding to the attribution of a substructure to quarks and to stand away from the conceptual strangling to which the Standard model has led, we have instead opted for different fundamentals. These, in contrast to those of the Standard Model, are extremely simple and based on the assumption of a single fundamental corpuscle, of dual manifestation as corpuscle and anticorpuscle, to which is always associated an orbital that determines the structure of particles. In such a frame particles differentiate through the diversity of quantum states of their structuring orbital, in contrast to the strategy used by the Standard Model based instead on the particle's multiplicity of composition through the variety of the quark's content, furthermore limited to hadrons. Instead the orbital conception of particles is unitary, unifying all of them as well as their interactions. As an outstanding feature, nuclear forces derive from the neutron orbital structure, based on a proton core and a shell. This shell constitutes the cohesive element of nuclear structure. |
hep-ph/9403385 | Markus Finkemeier | Roger Decker and Markus Finkemeier | Short and Long Distance Effects in the Decay $\tau \to \pi \nu_\tau
(\gamma)$ | 39 pages, Latex [19 figures, not included]: A complete postscript
file, including figures, is available via anonymous ftp at
ttpux2.physik.uni-karlsruhe.de (129.13.102.139) as /pub/ttp94-05/ttp94-05.ps,
Local preprint# TTP94-5. Revised version: In the previous version of this
paper we used a relative sign $s = - 1$ between internal bremsstrahlung and
the structure dependent radiation. However, as explained in TTP93-1A
(hep-ph/940538), we now believe that $s = + 1$ is the physical choice | Nucl.Phys. B438 (1995) 17-53 | 10.1016/0550-3213(95)00597-L | null | hep-ph | null | We calculate the radiative corrections to the decays $\tau\to M \nu_\tau$ and
$\pi \to l \nu_\l$, where the meson $M$ is $M=\pi$ or $K$ and the lepton $l$ is
$l = e$ or $\mu$. We perform a complete calculation, which includes internal
bremsstrahlung and structure dependent radiation in the radiative decays and
point meson, hadronic structure dependent and short distance contributions in
the virtual corrections. Our result for the radiative correction to the ratio
$\Gamma(\tau\to\pi\nu_\tau(\gamma))/ \Gamma(\pi\to\mu\nu_\mu(\gamma))$ is
$\delta R_{\tau/\pi} = \left(0.16_{\T - 0.14}^{\T+0.09}\right) \%$. For the
ratio $\Gamma(\tau\to K\nu_\tau(\gamma)) / \Gamma(K\to \mu\nu_\mu(\gamma))$, we
obtain $\delta R_{\tau/K } = \left(0.90_{\T - 0.26}^{\T + 0.17}\right) \%$. For
completeness we have also calculated the ratio of the electronic and muonic
decay modes of the pion.
| [
{
"created": "Tue, 29 Mar 1994 14:43:55 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Jun 1994 14:25:33 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Decker",
"Roger",
""
],
[
"Finkemeier",
"Markus",
""
]
] | We calculate the radiative corrections to the decays $\tau\to M \nu_\tau$ and $\pi \to l \nu_\l$, where the meson $M$ is $M=\pi$ or $K$ and the lepton $l$ is $l = e$ or $\mu$. We perform a complete calculation, which includes internal bremsstrahlung and structure dependent radiation in the radiative decays and point meson, hadronic structure dependent and short distance contributions in the virtual corrections. Our result for the radiative correction to the ratio $\Gamma(\tau\to\pi\nu_\tau(\gamma))/ \Gamma(\pi\to\mu\nu_\mu(\gamma))$ is $\delta R_{\tau/\pi} = \left(0.16_{\T - 0.14}^{\T+0.09}\right) \%$. For the ratio $\Gamma(\tau\to K\nu_\tau(\gamma)) / \Gamma(K\to \mu\nu_\mu(\gamma))$, we obtain $\delta R_{\tau/K } = \left(0.90_{\T - 0.26}^{\T + 0.17}\right) \%$. For completeness we have also calculated the ratio of the electronic and muonic decay modes of the pion. |
hep-ph/9711354 | Javier Magnin | E. Cuatle, G. Herrera and J. Magnin | D+- and D0 (anti D0) production asymetries in pion-proton collisions | Typos corrected, final version to appear in Z. Phys. C | Eur.Phys.J.C2:473-476,1998 | 10.1007/s100520050153 | CBPF-NF-075/97 | hep-ph | null | We use a two-component model to describe the production mechanism of D mesons
in pi-p collisions. The model combines the usual QCD processes plus
fragmentation and recombination of charm that has been produced by
nonperturbative QCD mechanisms. A hard charm component in the pion must be
responsible of the particle anti-particle production asymmetries observed.
| [
{
"created": "Mon, 17 Nov 1997 16:37:07 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Dec 1997 17:05:32 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Cuatle",
"E.",
""
],
[
"Herrera",
"G.",
""
],
[
"Magnin",
"J.",
""
]
] | We use a two-component model to describe the production mechanism of D mesons in pi-p collisions. The model combines the usual QCD processes plus fragmentation and recombination of charm that has been produced by nonperturbative QCD mechanisms. A hard charm component in the pion must be responsible of the particle anti-particle production asymmetries observed. |
hep-ph/9903350 | Andrei Linde | Gary Felder, Lev Kofman, and Andrei Linde | Inflation and Preheating in NO models | 10 pages, revtex | Phys.Rev.D60:103505,1999 | 10.1103/PhysRevD.60.103505 | SU-ITP-99-15 | hep-ph astro-ph gr-qc hep-th | null | We study inflationary models in which the effective potential of the inflaton
field does not have a minimum, but rather gradually decreases at large $\phi$.
In such models the inflaton field does not oscillate after inflation, and its
effective mass becomes vanishingly small, so the standard theory of reheating
based on the decay of the oscillating inflaton field does not apply. For a long
time the only mechanism of reheating in such non-oscillatory (NO) models was
based on gravitational particle production in an expanding universe. This
mechanism is very inefficient. We will show that it may lead to cosmological
problems associated with large isocurvature fluctuations and overproduction of
dangerous relics such as gravitinos and moduli fields. We also note that the
setting of initial conditions for the stage of reheating in these models should
be reconsidered. All of these problems can be resolved in the context of the
recently proposed scenario of instant preheating if there exists an interaction
${g^2} \phi^2\chi^2$ of the inflaton field $\phi$ with another scalar field
$\chi$. We show that the mechanism of instant preheating in NO models is much
more efficient than the usual mechanism of gravitational particle production
even if the coupling constant $g^2$ is extremely small, $10^{-14} \ll g^2 \ll
1$.
| [
{
"created": "Tue, 16 Mar 1999 00:55:13 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Apr 1999 00:33:32 GMT",
"version": "v2"
},
{
"created": "Mon, 21 Jun 1999 18:33:03 GMT",
"version": "v3"
}
] | 2009-09-29 | [
[
"Felder",
"Gary",
""
],
[
"Kofman",
"Lev",
""
],
[
"Linde",
"Andrei",
""
]
] | We study inflationary models in which the effective potential of the inflaton field does not have a minimum, but rather gradually decreases at large $\phi$. In such models the inflaton field does not oscillate after inflation, and its effective mass becomes vanishingly small, so the standard theory of reheating based on the decay of the oscillating inflaton field does not apply. For a long time the only mechanism of reheating in such non-oscillatory (NO) models was based on gravitational particle production in an expanding universe. This mechanism is very inefficient. We will show that it may lead to cosmological problems associated with large isocurvature fluctuations and overproduction of dangerous relics such as gravitinos and moduli fields. We also note that the setting of initial conditions for the stage of reheating in these models should be reconsidered. All of these problems can be resolved in the context of the recently proposed scenario of instant preheating if there exists an interaction ${g^2} \phi^2\chi^2$ of the inflaton field $\phi$ with another scalar field $\chi$. We show that the mechanism of instant preheating in NO models is much more efficient than the usual mechanism of gravitational particle production even if the coupling constant $g^2$ is extremely small, $10^{-14} \ll g^2 \ll 1$. |
1006.0144 | Rui Santos | Alexander Belyaev, Renato Guedes, Stefano Moretti and Rui Santos | BSM Higgs searches in the gluon fusion process pp -> h +jet -> tau^+
tau^- + jet at the LHC | 5 pages, 4 figures | PoS DIS2010:207,2010 | null | SHEP-10-17 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The mass of the Standard Model (SM) Higgs boson was constrained by the Large
Electron-Positron (LEP) collider to be above 114.4 GeV. Simple extensions of
the scalar sector like adding singlets and/or doublets allow the lightest Higgs
to be much lighter via a reduction in its coupling to gauge bosons. Such a
light Higgs could have evaded the LEP searches but could be detected at the
Large Hadron Collider (LHC) in the process pp -> h j -> tau^+ tau^- j, where j
is a resolved jet. We conclude that in some Beyond the Standard Model (BSM)
extensions of the scalar sector, a very light Higgs state could be detected at
the 14 TeV LHC with early data.
| [
{
"created": "Tue, 1 Jun 2010 14:49:59 GMT",
"version": "v1"
}
] | 2010-11-19 | [
[
"Belyaev",
"Alexander",
""
],
[
"Guedes",
"Renato",
""
],
[
"Moretti",
"Stefano",
""
],
[
"Santos",
"Rui",
""
]
] | The mass of the Standard Model (SM) Higgs boson was constrained by the Large Electron-Positron (LEP) collider to be above 114.4 GeV. Simple extensions of the scalar sector like adding singlets and/or doublets allow the lightest Higgs to be much lighter via a reduction in its coupling to gauge bosons. Such a light Higgs could have evaded the LEP searches but could be detected at the Large Hadron Collider (LHC) in the process pp -> h j -> tau^+ tau^- j, where j is a resolved jet. We conclude that in some Beyond the Standard Model (BSM) extensions of the scalar sector, a very light Higgs state could be detected at the 14 TeV LHC with early data. |
1107.3247 | Enrique Ruiz Arriola | J. Nieves, A. Pich, E. Ruiz Arriola | Large-Nc Properties of the rho and f0(600) Mesons from Unitary Resonance
Chiral Dynamics | 27 pages, 10 figures | null | 10.1103/PhysRevD.84.096002 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct pi-pi amplitudes that fulfill exact elastic unitarity, account
for one loop Chiral Perturbation Theory contributions and include all 1/Nc
leading terms, with the only limitation of considering just the lowest-lying
nonet of exchanged resonances. Within such scheme, the Nc dependence of sigma
and rho masses and widths is discussed. Robust conclusions are drawn in the
case of the rho resonance, confirming that it is a stable meson in the limit of
a large number of QCD colors, Nc. Less definitive conclusions are reached in
the scalar-isoscalar sector. With the present quality of data, we cannot firmly
conclude whether or not the Nc=3 f0(600) resonance completely disappears at
large Nc or it has a sub-dominant component in its structure, which would
become dominant for a number of quark colors sufficiently large.
| [
{
"created": "Sat, 16 Jul 2011 19:09:10 GMT",
"version": "v1"
}
] | 2013-05-29 | [
[
"Nieves",
"J.",
""
],
[
"Pich",
"A.",
""
],
[
"Arriola",
"E. Ruiz",
""
]
] | We construct pi-pi amplitudes that fulfill exact elastic unitarity, account for one loop Chiral Perturbation Theory contributions and include all 1/Nc leading terms, with the only limitation of considering just the lowest-lying nonet of exchanged resonances. Within such scheme, the Nc dependence of sigma and rho masses and widths is discussed. Robust conclusions are drawn in the case of the rho resonance, confirming that it is a stable meson in the limit of a large number of QCD colors, Nc. Less definitive conclusions are reached in the scalar-isoscalar sector. With the present quality of data, we cannot firmly conclude whether or not the Nc=3 f0(600) resonance completely disappears at large Nc or it has a sub-dominant component in its structure, which would become dominant for a number of quark colors sufficiently large. |
2108.01792 | Jose M. Gracia-Bondia | Christian Ga\ss, Jos\'e M. Gracia-Bond\'ia and Jens Mund | Revisiting the Okubo-Marshak argument | Latex, 16 pages. To the memory of Bob Marshak and Daniel Testard | Symmetry 13 (2021) 1645 | 10.3390/sym13091645 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Modular localization and the theory of string-localized fields have
revolutionized several key aspects of quantum field theory. They reinforce the
contention that local symmetry emerges directly from quantum theory, but global
gauge invariance remains in general an unwarranted assumption, to be examined
case by case. Armed with those modern tools, we reconsider here the classical
Okubo-Marshak argument on the non-existence of a "strong CP problem" in quantum
chromodynamics.
| [
{
"created": "Tue, 3 Aug 2021 23:59:10 GMT",
"version": "v1"
},
{
"created": "Sun, 12 Sep 2021 02:32:02 GMT",
"version": "v2"
}
] | 2021-09-14 | [
[
"Gaß",
"Christian",
""
],
[
"Gracia-Bondía",
"José M.",
""
],
[
"Mund",
"Jens",
""
]
] | Modular localization and the theory of string-localized fields have revolutionized several key aspects of quantum field theory. They reinforce the contention that local symmetry emerges directly from quantum theory, but global gauge invariance remains in general an unwarranted assumption, to be examined case by case. Armed with those modern tools, we reconsider here the classical Okubo-Marshak argument on the non-existence of a "strong CP problem" in quantum chromodynamics. |
2011.01946 | Anders Eller Thomsen Ph.D. | Lukas Allwicher, Gino Isidori and Anders Eller Thomsen | Stability of the Higgs Sector in a Flavor-Inspired Multi-Scale Model | 17 pages, 1 figure, 2 tables | null | 10.1007/JHEP01(2021)191 | ZU-TH-41/20 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the stability of the Higgs sector of a three-site model with
flavor-non-universal gauge interactions, whose spectrum of non-Standard-Model
states spans three orders of magnitude. This model is inspired by
deconstructing a five-dimensional theory where the generation index is in
one-to-one relation to the position in the fifth dimension. It provides a good
description of masses and mixing of the SM fermions in terms of scale
hierarchies. We demonstrate that, within this construction, the mass term of
the SM-like Higgs does not receive large corrections proportional to the
highest mass scales. The model suffers only of the unavoidable "little
hierarchy problem" between the electroweak scale and the lightest NP states,
which are expected to be at the TeV scale.
| [
{
"created": "Tue, 3 Nov 2020 19:00:03 GMT",
"version": "v1"
}
] | 2021-05-12 | [
[
"Allwicher",
"Lukas",
""
],
[
"Isidori",
"Gino",
""
],
[
"Thomsen",
"Anders Eller",
""
]
] | We analyze the stability of the Higgs sector of a three-site model with flavor-non-universal gauge interactions, whose spectrum of non-Standard-Model states spans three orders of magnitude. This model is inspired by deconstructing a five-dimensional theory where the generation index is in one-to-one relation to the position in the fifth dimension. It provides a good description of masses and mixing of the SM fermions in terms of scale hierarchies. We demonstrate that, within this construction, the mass term of the SM-like Higgs does not receive large corrections proportional to the highest mass scales. The model suffers only of the unavoidable "little hierarchy problem" between the electroweak scale and the lightest NP states, which are expected to be at the TeV scale. |
2209.03340 | Diana Parno | Carlo Giunti, Julieta Gruszko, Benjamin Jones, Lisa Kaufman, Diana
Parno, and Andrea Pocar | Report of the Topical Group on Neutrino Properties for Snowmass 2021 | Topical Group Report for NF05 (Neutrino Frontier Topical Group on
Neutrino Properties) for Snowmass 2021. 51 pages excluding references | null | null | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Neutrinos are the most elusive among the known elementary particles, because
of their feeble interactions with ordinary matter. They are also the most
mysterious, because of their tiny masses that suggest a novel mass generating
mechanism, their unknown Dirac or Majorana nature, and their big quantum mixing
leading to large-amplitude flavor oscillations. This Topical Group focuses on
neutrino properties that are not directly investigated in other Topical Groups
of the Neutrino Frontier: in particular, the absolute value of the neutrino
masses, the Dirac or Majorana nature of neutrinos, their electromagnetic
properties, their lifetime, and hypothetical exotic properties.
| [
{
"created": "Wed, 7 Sep 2022 17:53:37 GMT",
"version": "v1"
}
] | 2022-09-08 | [
[
"Giunti",
"Carlo",
""
],
[
"Gruszko",
"Julieta",
""
],
[
"Jones",
"Benjamin",
""
],
[
"Kaufman",
"Lisa",
""
],
[
"Parno",
"Diana",
""
],
[
"Pocar",
"Andrea",
""
]
] | Neutrinos are the most elusive among the known elementary particles, because of their feeble interactions with ordinary matter. They are also the most mysterious, because of their tiny masses that suggest a novel mass generating mechanism, their unknown Dirac or Majorana nature, and their big quantum mixing leading to large-amplitude flavor oscillations. This Topical Group focuses on neutrino properties that are not directly investigated in other Topical Groups of the Neutrino Frontier: in particular, the absolute value of the neutrino masses, the Dirac or Majorana nature of neutrinos, their electromagnetic properties, their lifetime, and hypothetical exotic properties. |
hep-ph/0107125 | Hiroyuki Abe | Hiroyuki Abe, Kenji Fukazawa and Tomohiro Inagaki | Chiral phase transition of bulk Abelian gauge theories in the
Randall-Sundrum brane world | 18 pages, 7 figures, REVTeX | Prog.Theor.Phys. 107 (2002) 1047-1060 | 10.1143/PTP.107.1047 | HUPD-010, KUNS-1726 | hep-ph | null | The chiral phase transition of strong-coupling Abelian gauge theories is
investigated in the brane world. It is assumed that gauge boson propagates in
an extra dimension, i.e. bulk gauge theories. The phase structure is
analytically evaluated by using the low-energy effective theories. We also
numerically solve the ladder Schwinger-Dyson equation for the full fermion
propagator including Kaluza-Klein (KK) excitation modes of the gauge field. It
is found that the chiral phase transition is of the second order, and the
critical value of the coupling constant is obtained. The extra dimension has a
large influence on the chiral phase transition for the Randall-Sundrum (RS)
brane world. It is studied how the number of KK modes affect the chiral phase
transition.
| [
{
"created": "Wed, 11 Jul 2001 12:42:56 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Abe",
"Hiroyuki",
""
],
[
"Fukazawa",
"Kenji",
""
],
[
"Inagaki",
"Tomohiro",
""
]
] | The chiral phase transition of strong-coupling Abelian gauge theories is investigated in the brane world. It is assumed that gauge boson propagates in an extra dimension, i.e. bulk gauge theories. The phase structure is analytically evaluated by using the low-energy effective theories. We also numerically solve the ladder Schwinger-Dyson equation for the full fermion propagator including Kaluza-Klein (KK) excitation modes of the gauge field. It is found that the chiral phase transition is of the second order, and the critical value of the coupling constant is obtained. The extra dimension has a large influence on the chiral phase transition for the Randall-Sundrum (RS) brane world. It is studied how the number of KK modes affect the chiral phase transition. |
hep-ph/0302108 | Ratindranath Akhoury | R. Akhoury and Y.-P. Yao | Minimal Length Uncertainty Relation and the Hydrogen Spectrum | 8 pages, no figure. Corrected typos, added a reference with comments | Phys.Lett. B572 (2003) 37-42 | 10.1016/j.physletb.2003.07.084 | MCTP-03-05 | hep-ph | null | Modifications of Heisenberg's uncertainty relations have been proposed in the
literature which imply a minimum position uncertainty. We study the low energy
effects of the new physics responsible for this by examining the consequent
change in the quantum mechanical commutation relations involving position and
momenta. In particular, the modifications to the spectrum of the hydrogen atom
can be naturally interpreted as a varying (with energy) fine structure
constant. From the data on the energy levels we attempt to constrain the scale
of the new physics and find that it must be close to or larger than the weak
scale. Experiments in the near future are expected to change this bound by at
least an additional order of magnitude.
| [
{
"created": "Thu, 13 Feb 2003 20:56:45 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Feb 2003 18:43:30 GMT",
"version": "v2"
}
] | 2010-04-05 | [
[
"Akhoury",
"R.",
""
],
[
"Yao",
"Y. -P.",
""
]
] | Modifications of Heisenberg's uncertainty relations have been proposed in the literature which imply a minimum position uncertainty. We study the low energy effects of the new physics responsible for this by examining the consequent change in the quantum mechanical commutation relations involving position and momenta. In particular, the modifications to the spectrum of the hydrogen atom can be naturally interpreted as a varying (with energy) fine structure constant. From the data on the energy levels we attempt to constrain the scale of the new physics and find that it must be close to or larger than the weak scale. Experiments in the near future are expected to change this bound by at least an additional order of magnitude. |
2112.13745 | Vadim Naumov A | Igor D. Kakorin, Konstantin S. Kuzmin, Vadim A. Naumov | Running axial mass of the nucleon as a phenomenological tool for
calculating QE neutrino-nucleus cross sections | 58 pages, 37 figures | null | 10.1140/epjc/s10052-021-09945-5 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We suggest an empirical rule-of-thumb for calculating the cross sections of
charged-current quasielastic (CCQE) and CCQE-like interactions of neutrinos and
antineutrinos with nuclei. The approach is based on the standard relativistic
Fermi-gas model and on the notion of neutrino energy dependent axial-vector
mass of the nucleon, governed by a couple of adjustable parameters, one of
which is the conventional charged-current axial-vector mass. The inelastic
background contributions and final-state interactions are therewith simulated
using GENIE 3 neutrino event generator. An extensive comparison of our
calculations with earlier and current accelerator CCQE and CCQE-like data for
different nuclear targets shows good or at least qualitative overall agreement
over a wide energy range. We also discuss some problematical issues common to
several competing contemporary models of the CCQE (anti)neutrino-nucleus
scattering and to the current neutrino interaction generators.
| [
{
"created": "Mon, 27 Dec 2021 15:48:23 GMT",
"version": "v1"
}
] | 2021-12-28 | [
[
"Kakorin",
"Igor D.",
""
],
[
"Kuzmin",
"Konstantin S.",
""
],
[
"Naumov",
"Vadim A.",
""
]
] | We suggest an empirical rule-of-thumb for calculating the cross sections of charged-current quasielastic (CCQE) and CCQE-like interactions of neutrinos and antineutrinos with nuclei. The approach is based on the standard relativistic Fermi-gas model and on the notion of neutrino energy dependent axial-vector mass of the nucleon, governed by a couple of adjustable parameters, one of which is the conventional charged-current axial-vector mass. The inelastic background contributions and final-state interactions are therewith simulated using GENIE 3 neutrino event generator. An extensive comparison of our calculations with earlier and current accelerator CCQE and CCQE-like data for different nuclear targets shows good or at least qualitative overall agreement over a wide energy range. We also discuss some problematical issues common to several competing contemporary models of the CCQE (anti)neutrino-nucleus scattering and to the current neutrino interaction generators. |
1105.3676 | Matthew Schwartz | Randall Kelley, Robert M. Schabinger, Matthew D. Schwartz and Hua Xing
Zhu | The two-loop hemisphere soft function | 26 pages, 6 figures. Discussion of exponentiation of non-global logs
added in v2 | Phys.Rev.D84:045022,2011 | 10.1103/PhysRevD.84.045022 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hemisphere soft function is calculated to order alpha_s^2. This is the
first multi-scale soft function calculated to two loops. The renormalization
scale dependence of the result agrees exactly with the prediction from
effective field theory. This fixes the unknown coefficients of the singular
parts of the two-loop thrust and heavy-jet mass distributions. There are four
such coefficients, for 2 event shapes and 2 color structures, which are shown
to be in excellent agreement with previous numerical extraction. The asymptotic
behavior of the soft function has double logs in the CF CA color structure,
which agree with non-global log calculations, but also has sub-leading single
logs for both the CF CA and CF TF nf color structures. The general form of the
soft function is complicated, does not factorize in a simple way, and disagrees
with the Hoang-Kluth ansatz. The exact hemisphere soft function will remove one
source of uncertainty on the alpha_s fits from e+e- event shapes.
| [
{
"created": "Wed, 18 May 2011 16:09:05 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Jun 2011 20:47:05 GMT",
"version": "v2"
}
] | 2011-09-16 | [
[
"Kelley",
"Randall",
""
],
[
"Schabinger",
"Robert M.",
""
],
[
"Schwartz",
"Matthew D.",
""
],
[
"Zhu",
"Hua Xing",
""
]
] | The hemisphere soft function is calculated to order alpha_s^2. This is the first multi-scale soft function calculated to two loops. The renormalization scale dependence of the result agrees exactly with the prediction from effective field theory. This fixes the unknown coefficients of the singular parts of the two-loop thrust and heavy-jet mass distributions. There are four such coefficients, for 2 event shapes and 2 color structures, which are shown to be in excellent agreement with previous numerical extraction. The asymptotic behavior of the soft function has double logs in the CF CA color structure, which agree with non-global log calculations, but also has sub-leading single logs for both the CF CA and CF TF nf color structures. The general form of the soft function is complicated, does not factorize in a simple way, and disagrees with the Hoang-Kluth ansatz. The exact hemisphere soft function will remove one source of uncertainty on the alpha_s fits from e+e- event shapes. |
2301.06441 | Hui Zhang | Yuanyuan Hu and Hui Zhang | Production of $X_{cs\bar{c}\bar{s}}$ in heavy ion collisions | 6 pages, 4 figures | Chinese Physics C, Vol. 47, No. 5 (2023) 051001 | 10.1088/1674-1137/acc3f4 | null | hep-ph nucl-th | http://creativecommons.org/publicdomain/zero/1.0/ | The yields of $X_{cs\bar{c}\bar{s}}$ with its two possible configurations,
i.e., the hadronic molecular state and tetraquark state, for Pb-Pb collisions
at $\sqrt{s_{NN}}=5.02~\rm{TeV}$ is studied. A volume effect is found from the
centrality distribution of $X_{cs\bar{c}\bar{s}}$, which could help to
distinguish the inner structure of $X_{cs\bar{c}\bar{s}}$. We also show the
rapidity and the transverse momentum distributions of $X_{cs\bar{c}\bar{s}}$
production as well as its elliptic flow coefficient as a function of the
transverse momentum.
| [
{
"created": "Mon, 16 Jan 2023 14:11:51 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Mar 2023 13:57:42 GMT",
"version": "v2"
}
] | 2023-04-03 | [
[
"Hu",
"Yuanyuan",
""
],
[
"Zhang",
"Hui",
""
]
] | The yields of $X_{cs\bar{c}\bar{s}}$ with its two possible configurations, i.e., the hadronic molecular state and tetraquark state, for Pb-Pb collisions at $\sqrt{s_{NN}}=5.02~\rm{TeV}$ is studied. A volume effect is found from the centrality distribution of $X_{cs\bar{c}\bar{s}}$, which could help to distinguish the inner structure of $X_{cs\bar{c}\bar{s}}$. We also show the rapidity and the transverse momentum distributions of $X_{cs\bar{c}\bar{s}}$ production as well as its elliptic flow coefficient as a function of the transverse momentum. |
hep-ph/0506022 | Phung Dong Van | Phung Van Dong and Hoang Ngoc Long | U(1)_Q invariance and SU(3)_C X SU(3)_L X U(1)_X models with beta
arbitrary | 10 pages | Eur.Phys.J.C42:325-329,2005 | 10.1140/epjc/s2005-02314-x | null | hep-ph | null | Using the U(1)_Q invariance, the photon eigenstate and matching gauge
coupling constants in SU(3)_C X SU(3)_L X U(1)_X models with beta arbitrary are
given. The mass matrix of neutral gauge bosons is exactly diagonalized, and the
photon eigenstate is independent on the symmetry breaking parameters - VEV's of
Higgs scalars. By obtaining the electromagnetic vertex, the model is embedded
naturally into the standard model.
| [
{
"created": "Fri, 3 Jun 2005 09:28:46 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Van Dong",
"Phung",
""
],
[
"Long",
"Hoang Ngoc",
""
]
] | Using the U(1)_Q invariance, the photon eigenstate and matching gauge coupling constants in SU(3)_C X SU(3)_L X U(1)_X models with beta arbitrary are given. The mass matrix of neutral gauge bosons is exactly diagonalized, and the photon eigenstate is independent on the symmetry breaking parameters - VEV's of Higgs scalars. By obtaining the electromagnetic vertex, the model is embedded naturally into the standard model. |
hep-ph/0410373 | Cristine Nunes Ferreira | H. Chavez (UFRJ), C. N. Ferreira (CEFET-Campos) and J.A. Helayel-Neto
(CBPF) | Physics Beyond the Standard Model: Focusing on the Muon Anomaly | 14 RevTeX pages, 5 figures | Phys.Rev.D74:033006,2006 | 10.1103/PhysRevD.74.033006 | null | hep-ph | null | We present a model based on the implication of an exceptional E_{6}-GUT
symmetry for the anomalous magnetic moment of the muon. We follow a particular
chain of breakings with Higgses in the 78 and 351 representations. We analyse
the radiative correction contributions to the muon mass and the effects of the
breaking of the so-called Weinberg symmetry. We also estimate the range of
values of the parameters of our model.
| [
{
"created": "Wed, 27 Oct 2004 21:41:32 GMT",
"version": "v1"
},
{
"created": "Sun, 14 May 2006 20:27:20 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Chavez",
"H.",
"",
"UFRJ"
],
[
"Ferreira",
"C. N.",
"",
"CEFET-Campos"
],
[
"Helayel-Neto",
"J. A.",
"",
"CBPF"
]
] | We present a model based on the implication of an exceptional E_{6}-GUT symmetry for the anomalous magnetic moment of the muon. We follow a particular chain of breakings with Higgses in the 78 and 351 representations. We analyse the radiative correction contributions to the muon mass and the effects of the breaking of the so-called Weinberg symmetry. We also estimate the range of values of the parameters of our model. |
0712.2675 | Utpal Sarkar | Utpal Sarkar | Leptogenesis, Dark Energy, Dark Matter and the neutrinos | Invited talk appeared in International Workshop in Theoretical High
Energy Physics, ed. A. Misra, AIP Conf. Proc. 939 (2007) 124-133 | null | 10.1063/1.2803796 | null | hep-ph | null | In this review we discuss how the models of neutrino masses can accommodate
solutions to the problem of matter-antimatter asymmetry in the universe, dark
energy or cosmological constant problem and dark matter candidates. The
matter-antimatter asymmetry is explained by leptogenesis, originating from the
lepton number violation associated with the neutrino masses. The dark energy
problem is correlated with a mass varying neutrinos, which could originate from
a pseudo-Nambu-Goldstone boson. In some radiative models of neutrino masses,
there exists a Higgs doublet that does not acquire any vacuum expectation
value. This field could be inert and the lightest inert particle could then be
a dark matter candidate. We reviewed these scenarios in connection with models
of neutrino masses with right-handed neutrinos and with triplet Higgs scalars.
| [
{
"created": "Mon, 17 Dec 2007 11:16:40 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Sarkar",
"Utpal",
""
]
] | In this review we discuss how the models of neutrino masses can accommodate solutions to the problem of matter-antimatter asymmetry in the universe, dark energy or cosmological constant problem and dark matter candidates. The matter-antimatter asymmetry is explained by leptogenesis, originating from the lepton number violation associated with the neutrino masses. The dark energy problem is correlated with a mass varying neutrinos, which could originate from a pseudo-Nambu-Goldstone boson. In some radiative models of neutrino masses, there exists a Higgs doublet that does not acquire any vacuum expectation value. This field could be inert and the lightest inert particle could then be a dark matter candidate. We reviewed these scenarios in connection with models of neutrino masses with right-handed neutrinos and with triplet Higgs scalars. |
1305.7343 | Maurizio Lusignoli | Franco Buccella, Maurizio Lusignoli, Alessandra Pugliese, Pietro
Santorelli | CP violation in D meson decays: would it be a sign of new physics ? | 9 pages, added references, minor changes in the text, results
unchanged. Accepted for publication in Physical Review D | Phys.Rev. D 88, 074011 (2013) | 10.1103/PhysRevD.88.074011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Ascribing the large SU(3) violations in the Cabibbo forbidden decays of
neutral D mesons to the final state interactions, one gets large strong phase
differences, necessary for substantial direct CP violation. While the absolute
value of the CP violating asymmetries depend on the uncertain strength of the
penguin contribution, we predict an asymmetry for the decays into charged pions
more than twice as large and having opposite sign with respect to that for
charged kaons.
| [
{
"created": "Fri, 31 May 2013 09:52:34 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Sep 2013 17:04:25 GMT",
"version": "v2"
}
] | 2013-12-17 | [
[
"Buccella",
"Franco",
""
],
[
"Lusignoli",
"Maurizio",
""
],
[
"Pugliese",
"Alessandra",
""
],
[
"Santorelli",
"Pietro",
""
]
] | Ascribing the large SU(3) violations in the Cabibbo forbidden decays of neutral D mesons to the final state interactions, one gets large strong phase differences, necessary for substantial direct CP violation. While the absolute value of the CP violating asymmetries depend on the uncertain strength of the penguin contribution, we predict an asymmetry for the decays into charged pions more than twice as large and having opposite sign with respect to that for charged kaons. |
1301.3448 | Gabriel Lopez-Castro | C. Barbero, Ling-Fong Li, G. Lopez Castro and A. Mariano | Matrix elements of four-quark operators and \Delta L=2 hyperon decays | 13 pages, 2 .eps figures | Phys. Rev. D87, 036010 (2013) | 10.1103/PhysRevD.87.036010 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The study of neutrinoless double beta decays of nuclei and hyperons require
the calculation of hadronic matrix elements of local four-quark operators that
change the total charge by two units \Delta Q=2 . Using a low energy effective
Lagrangian that induces these transitions, we compute these hadronic matrix
elements in the framework of the MIT bag model. As an illustrative example we
evaluate the amplitude and transition rate of \Sigma- -> p e- e-, a decay
process that violates lepton number by two units (\Delta L=2). The relevant
matrix element is evaluated without assuming the usual factorization
approximation of the four-quark operators and the results obtained in both
approaches are compared.
| [
{
"created": "Tue, 15 Jan 2013 18:42:34 GMT",
"version": "v1"
}
] | 2013-07-29 | [
[
"Barbero",
"C.",
""
],
[
"Li",
"Ling-Fong",
""
],
[
"Castro",
"G. Lopez",
""
],
[
"Mariano",
"A.",
""
]
] | The study of neutrinoless double beta decays of nuclei and hyperons require the calculation of hadronic matrix elements of local four-quark operators that change the total charge by two units \Delta Q=2 . Using a low energy effective Lagrangian that induces these transitions, we compute these hadronic matrix elements in the framework of the MIT bag model. As an illustrative example we evaluate the amplitude and transition rate of \Sigma- -> p e- e-, a decay process that violates lepton number by two units (\Delta L=2). The relevant matrix element is evaluated without assuming the usual factorization approximation of the four-quark operators and the results obtained in both approaches are compared. |
hep-ph/0101068 | T. P. Cheng | T. P. Cheng (Univ of Missouri - St Louis) and Ling-Fong Li (Carnegie
Mellon Univ) | Heavy particle electroweak loop effects in extra-dimensional models with
bulk neutrinos | 13 pages; new citations added in Ref [3] and [11] | Phys.Lett. B502 (2001) 152-158 | 10.1016/S0370-2693(01)00202-7 | CMU-HEP-01-01 | hep-ph | null | One way to detect the presence of new particles in theories beyond the
standard model is through their contribution to electroweak loop effects. We
comment on the importance of a consistent inclusion of their mixing angles to
ensure that the physical requirement of heavy particle decoupling is fulfilled.
We illustrate our points by a detailed discussion of the lepton flavor changing
effect mu-e-gamma, investigated recently by Kitano, in the Randall-Sundrum
model. Our remarks are equally applicable to models with large compactified
dimensions where bulk neutrinos are introduced to account for the observed
neutrino oscillations.
| [
{
"created": "Mon, 8 Jan 2001 22:28:24 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Jan 2001 15:22:26 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Cheng",
"T. P.",
"",
"Univ of Missouri - St Louis"
],
[
"Li",
"Ling-Fong",
"",
"Carnegie\n Mellon Univ"
]
] | One way to detect the presence of new particles in theories beyond the standard model is through their contribution to electroweak loop effects. We comment on the importance of a consistent inclusion of their mixing angles to ensure that the physical requirement of heavy particle decoupling is fulfilled. We illustrate our points by a detailed discussion of the lepton flavor changing effect mu-e-gamma, investigated recently by Kitano, in the Randall-Sundrum model. Our remarks are equally applicable to models with large compactified dimensions where bulk neutrinos are introduced to account for the observed neutrino oscillations. |
hep-ph/9610328 | Gino Isidori | S. Bellucci, G. Isidori | The role of chiral loops in $\eta\to\pi^0\pi^0\gamma\gamma$ | 10 pages, Latex. Discussion on the resonant background enlarged, sign
error corrected, basic results unchanged. To appear in Phys. Lett. B | Phys.Lett. B405 (1997) 334-340 | 10.1016/S0370-2693(97)00669-2 | LNF-053(P) | hep-ph | null | We consider the rare decay $\eta\to\pi^0\pi^0\gamma\gamma$ and calculate the
non-resonant contribution to the amplitude to one loop in Chiral Perturbation
Theory. We display our result as both a diphoton energy spectrum and a partial
decay rate as a function of the photon energy cut. It turns out that the
one-loop correction can be numerically very important and could be detected, at
sufficiently large center-of-mass photon energies, from a measurement of the
partial decay width.
| [
{
"created": "Fri, 11 Oct 1996 08:20:21 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jun 1997 18:05:49 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Bellucci",
"S.",
""
],
[
"Isidori",
"G.",
""
]
] | We consider the rare decay $\eta\to\pi^0\pi^0\gamma\gamma$ and calculate the non-resonant contribution to the amplitude to one loop in Chiral Perturbation Theory. We display our result as both a diphoton energy spectrum and a partial decay rate as a function of the photon energy cut. It turns out that the one-loop correction can be numerically very important and could be detected, at sufficiently large center-of-mass photon energies, from a measurement of the partial decay width. |
1302.6587 | Jonathan Feng | Jonathan L. Feng | Naturalness and the Status of Supersymmetry | 38 pages, to appear in Annual Review of Nuclear and Particle Science;
v2: fixed typos, updated Higgs results, added references and a parable,
published version | null | 10.1146/annurev-nucl-102010-130447 | UCI-TR-2013-01 | hep-ph astro-ph.CO hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For decades, the unnaturalness of the weak scale has been the dominant
problem motivating new particle physics, and weak-scale supersymmetry has been
the dominant proposed solution. This paradigm is now being challenged by a
wealth of experimental data. In this review, we begin by recalling the
theoretical motivations for weak-scale supersymmetry, including the gauge
hierarchy problem, grand unification, and WIMP dark matter, and their
implications for superpartner masses. These are set against the leading
constraints on supersymmetry from collider searches, the Higgs boson mass, and
low-energy constraints on flavor and CP violation. We then critically examine
attempts to quantify naturalness in supersymmetry, stressing the many
subjective choices that impact the results both quantitatively and
qualitatively. Finally, we survey various proposals for natural supersymmetric
models, including effective supersymmetry, focus point supersymmetry,
compressed supersymmetry, and R-parity-violating supersymmetry, and summarize
their key features, current status, and implications for future experiments.
| [
{
"created": "Tue, 26 Feb 2013 21:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 13 May 2013 06:12:13 GMT",
"version": "v2"
}
] | 2013-10-24 | [
[
"Feng",
"Jonathan L.",
""
]
] | For decades, the unnaturalness of the weak scale has been the dominant problem motivating new particle physics, and weak-scale supersymmetry has been the dominant proposed solution. This paradigm is now being challenged by a wealth of experimental data. In this review, we begin by recalling the theoretical motivations for weak-scale supersymmetry, including the gauge hierarchy problem, grand unification, and WIMP dark matter, and their implications for superpartner masses. These are set against the leading constraints on supersymmetry from collider searches, the Higgs boson mass, and low-energy constraints on flavor and CP violation. We then critically examine attempts to quantify naturalness in supersymmetry, stressing the many subjective choices that impact the results both quantitatively and qualitatively. Finally, we survey various proposals for natural supersymmetric models, including effective supersymmetry, focus point supersymmetry, compressed supersymmetry, and R-parity-violating supersymmetry, and summarize their key features, current status, and implications for future experiments. |
2009.04444 | Danny Marfatia | Wai-Yee Keung, Danny Marfatia, Po-Yan Tseng | Stellar cooling, inelastic dark matter, and XENON | 14 pages, 7 figures. Version to appear in JHEAp | JHEAp 30 : 9-15 (2021) | 10.1016/j.jheap.2021.02.001 | null | hep-ph astro-ph.CO astro-ph.SR hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a novel scenario of dark photon-mediated inelastic dark matter to
explain the white dwarf cooling excess suggested by its luminosity function,
and the excess in electron recoil events at XENON1T. In the Sun, the dark
photon $A'$ is produced mainly via thermal processes, and the heavier dark
matter $\chi_2$ is produced by the scattering of halo dark matter $\chi_1$ with
electrons. The XENON1T signal arises primarily by solar $A'$ scattering, and
$A'$ emission by white dwarfs accommodates the extra cooling while maintaining
consistency with other stellar cooling observations. A tritium component in the
XENON1T detector is also required. We show for parameters that explain the
XENON1T data, but not the white dwarf cooling anomaly, that a second signal
peak may be buried in the XENON1T data and revealable at XENONnT. However, the
parameters that give the double peak in the spectrum are incompatible with
constraints from horizontal branch stars.
| [
{
"created": "Wed, 9 Sep 2020 17:48:25 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Feb 2021 23:37:12 GMT",
"version": "v2"
}
] | 2021-03-18 | [
[
"Keung",
"Wai-Yee",
""
],
[
"Marfatia",
"Danny",
""
],
[
"Tseng",
"Po-Yan",
""
]
] | We consider a novel scenario of dark photon-mediated inelastic dark matter to explain the white dwarf cooling excess suggested by its luminosity function, and the excess in electron recoil events at XENON1T. In the Sun, the dark photon $A'$ is produced mainly via thermal processes, and the heavier dark matter $\chi_2$ is produced by the scattering of halo dark matter $\chi_1$ with electrons. The XENON1T signal arises primarily by solar $A'$ scattering, and $A'$ emission by white dwarfs accommodates the extra cooling while maintaining consistency with other stellar cooling observations. A tritium component in the XENON1T detector is also required. We show for parameters that explain the XENON1T data, but not the white dwarf cooling anomaly, that a second signal peak may be buried in the XENON1T data and revealable at XENONnT. However, the parameters that give the double peak in the spectrum are incompatible with constraints from horizontal branch stars. |
2104.04495 | Franz Gross | Franz Gross | Removal of singularities from the covariant spectator theory | 21 pages; 17 figures (many with two panels) | Phys. Rev. D 104, 054020 (2021) | 10.1103/PhysRevD.104.054020 | JLAB-THY-21-3347 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A modification of the one boson exchange (OBE) kernel for the covariant
spectator theory (CST) is presented and discussed. When applied to the
scattering of two identical particles, the previously used kernels either
introduced spurious singularities, or removed them in an ad-hoc way. The new
modification not only removes these singularities, but also maintains the
convergence of the two-body CST equation (sometimes called the Gross equation)
when used to describe the scattering of two identical scalar particles.
| [
{
"created": "Fri, 9 Apr 2021 17:25:01 GMT",
"version": "v1"
}
] | 2021-09-22 | [
[
"Gross",
"Franz",
""
]
] | A modification of the one boson exchange (OBE) kernel for the covariant spectator theory (CST) is presented and discussed. When applied to the scattering of two identical particles, the previously used kernels either introduced spurious singularities, or removed them in an ad-hoc way. The new modification not only removes these singularities, but also maintains the convergence of the two-body CST equation (sometimes called the Gross equation) when used to describe the scattering of two identical scalar particles. |
hep-ph/9501266 | null | T.W.B. Kibble and Alexander Vilenkin | Phase equilibration in bubble collisions | 20 pages, REVTEX | Phys.Rev.D52:679-688,1995 | 10.1103/PhysRevD.52.679 | IMPERIAL/TP/94-95/11, TUTP-95-2, NI94039 | hep-ph astro-ph | null | In the context of an Abelian gauge symmetry, spontaneously broken at a
first-order transition, we discuss the evolution of the phase difference
between the Higgs fields in colliding bubbles. We show that the effect of
dissipation, represented by a finite plasma conductivity, is to cause the
phases to equlibrate on a time-scale, determined by the conductivity, which can
be much smaller than the bubble radii at the time of collision. Currents
induced during the phase equilibration generate a magnetic flux, which is
determined by the initial phase difference. In a three-bubble collision, the
fluxes produced by each pair of bubbles combine, and a vortex can be formed. We
find that, under most conditions, the probability of trapping magnetic flux to
form a vortex is correctly given by the ``geodesic rule''.
| [
{
"created": "Wed, 11 Jan 1995 09:03:30 GMT",
"version": "v1"
}
] | 2011-08-01 | [
[
"Kibble",
"T. W. B.",
""
],
[
"Vilenkin",
"Alexander",
""
]
] | In the context of an Abelian gauge symmetry, spontaneously broken at a first-order transition, we discuss the evolution of the phase difference between the Higgs fields in colliding bubbles. We show that the effect of dissipation, represented by a finite plasma conductivity, is to cause the phases to equlibrate on a time-scale, determined by the conductivity, which can be much smaller than the bubble radii at the time of collision. Currents induced during the phase equilibration generate a magnetic flux, which is determined by the initial phase difference. In a three-bubble collision, the fluxes produced by each pair of bubbles combine, and a vortex can be formed. We find that, under most conditions, the probability of trapping magnetic flux to form a vortex is correctly given by the ``geodesic rule''. |
1610.03848 | Raymond Co | Raymond T. Co, Keisuke Harigaya, Yasunori Nomura | Chiral Dark Sector | 6 pages, 5 figures; references added | Phys. Rev. Lett. 118, 101801 (2017) | 10.1103/PhysRevLett.118.101801 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a simple and natural dark sector model in which dark matter
particles arise as composite states of hidden strong dynamics and their
stability is ensured by accidental symmetries. The model has only a few free
parameters. In particular, the gauge symmetry of the model forbids the masses
of dark quarks, and the confinement scale of the dynamics provides the unique
mass scale of the model. The gauge group contains an Abelian symmetry $U(1)_D$,
which couples the dark and standard model sectors through kinetic mixing. This
model, despite its simple structure, has rich and distinctive phenomenology. In
the case where the dark pion becomes massive due to $U(1)_D$ quantum
corrections, direct and indirect detection experiments can probe thermal relic
dark matter which is generically a mixture of the dark pion and the dark
baryon, and the Large Hadron Collider can discover the $U(1)_D$ gauge boson.
Alternatively, if the dark pion stays light due to a specific $U(1)_D$ charge
assignment of the dark quarks, then the dark pion constitutes dark radiation.
The signal of this radiation is highly correlated with that of dark baryons in
dark matter direct detection.
| [
{
"created": "Wed, 12 Oct 2016 20:00:00 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Mar 2017 08:12:55 GMT",
"version": "v2"
}
] | 2017-03-15 | [
[
"Co",
"Raymond T.",
""
],
[
"Harigaya",
"Keisuke",
""
],
[
"Nomura",
"Yasunori",
""
]
] | We present a simple and natural dark sector model in which dark matter particles arise as composite states of hidden strong dynamics and their stability is ensured by accidental symmetries. The model has only a few free parameters. In particular, the gauge symmetry of the model forbids the masses of dark quarks, and the confinement scale of the dynamics provides the unique mass scale of the model. The gauge group contains an Abelian symmetry $U(1)_D$, which couples the dark and standard model sectors through kinetic mixing. This model, despite its simple structure, has rich and distinctive phenomenology. In the case where the dark pion becomes massive due to $U(1)_D$ quantum corrections, direct and indirect detection experiments can probe thermal relic dark matter which is generically a mixture of the dark pion and the dark baryon, and the Large Hadron Collider can discover the $U(1)_D$ gauge boson. Alternatively, if the dark pion stays light due to a specific $U(1)_D$ charge assignment of the dark quarks, then the dark pion constitutes dark radiation. The signal of this radiation is highly correlated with that of dark baryons in dark matter direct detection. |
1208.4675 | Chaehyun Yu | P. Ko, Yuji Omura, Chaehyun Yu (KIAS) | Top A_{FB} and charge asymmetry in flavor-dependent chiral U(1)' model | 4 pages, 2 figures, proceedings for Flavor Physics and CP Violation
(FPCP 2012) Conference | null | null | KIAS-PREPRINT-P12048 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the flavor-dependent chiral U(1)' model where only the right-handed
up-type quarks are charged under U(1)$^\prime$ and additional Higgs doublets
charged with U(1)' charges are introduced to give proper Yukawa interactions.
We find that in some parameter regions, this model is not accommodated only
with the top forward-backward asymmetry at the Tevatron, but also with the
charge asymmetry at the LHC. At the same time, the cross section for the
same-sign top-quark pair production in this model could be below the upper
limit at the LHC.
| [
{
"created": "Thu, 23 Aug 2012 06:11:55 GMT",
"version": "v1"
}
] | 2012-08-24 | [
[
"Ko",
"P.",
"",
"KIAS"
],
[
"Omura",
"Yuji",
"",
"KIAS"
],
[
"Yu",
"Chaehyun",
"",
"KIAS"
]
] | We study the flavor-dependent chiral U(1)' model where only the right-handed up-type quarks are charged under U(1)$^\prime$ and additional Higgs doublets charged with U(1)' charges are introduced to give proper Yukawa interactions. We find that in some parameter regions, this model is not accommodated only with the top forward-backward asymmetry at the Tevatron, but also with the charge asymmetry at the LHC. At the same time, the cross section for the same-sign top-quark pair production in this model could be below the upper limit at the LHC. |
hep-ph/0307020 | Abdelhak Djouadi | Michael Dittmar, Abdelhak Djouadi and Anne-Sylvie Nicollerat | Z' studies at the LHC: an update | 14 pages, latex, 6 figures | Phys.Lett. B583 (2004) 111-120 | 10.1016/j.physletb.2003.09.103 | CERN TH/2003-145, ETHZ-IPP PR-2003-01, PM/03-14 | hep-ph hep-ex | null | We reanalyse the potential of the LHC to discover new $Z'$ gauge bosons and
to discriminate between various theoretical models. Using a fast LHC detector
simulation, we have investigated how well the characteristics of $Z'$ bosons
from different models can be measured. For this analysis we have combined the
information coming from the cross section measurement, which provides also the
$Z'$ mass and total width, the forward-backward charge asymmetries on- and
off-peak, and the $Z'$ rapidity distribution, which is sensitive to its $u
\bar{u}$ and $d \bar{d}$ couplings. We confirm that new $Z'$ bosons can be
observed in the process $pp \to Z' \to l^+ l^-$, up to masses of about 5 TeV
for an integrated luminosity of 100 fb$^{-1}$. The off- and on-resonance peak
forward-backward charge asymmetries $A_{\rm FB}^{l}$ show that interesting
statistical accuracies can be obtained up to $Z'$ masses of the order of 2 TeV.
We then show how the different experimental observables allow for a diagnosis
of the $Z'$ boson and the distinction between the various considered models.
| [
{
"created": "Tue, 1 Jul 2003 17:06:51 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Dittmar",
"Michael",
""
],
[
"Djouadi",
"Abdelhak",
""
],
[
"Nicollerat",
"Anne-Sylvie",
""
]
] | We reanalyse the potential of the LHC to discover new $Z'$ gauge bosons and to discriminate between various theoretical models. Using a fast LHC detector simulation, we have investigated how well the characteristics of $Z'$ bosons from different models can be measured. For this analysis we have combined the information coming from the cross section measurement, which provides also the $Z'$ mass and total width, the forward-backward charge asymmetries on- and off-peak, and the $Z'$ rapidity distribution, which is sensitive to its $u \bar{u}$ and $d \bar{d}$ couplings. We confirm that new $Z'$ bosons can be observed in the process $pp \to Z' \to l^+ l^-$, up to masses of about 5 TeV for an integrated luminosity of 100 fb$^{-1}$. The off- and on-resonance peak forward-backward charge asymmetries $A_{\rm FB}^{l}$ show that interesting statistical accuracies can be obtained up to $Z'$ masses of the order of 2 TeV. We then show how the different experimental observables allow for a diagnosis of the $Z'$ boson and the distinction between the various considered models. |
0902.0108 | Shigeki Matsumoto | Shigeki Matsumoto, Eri Asakawa, Masaki Asano, Keisuke Fujii, Tomonori
Kusano, Rei Sasaki, Yosuke Takubo, Hitoshi Yamamoto | How accurately is the property of the Little Higgs Dark Matter
determined at the ILC? | 4 pages, 3 figures, talk given at LCWS08, Chicago, November 2008 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Little Higgs scenario provides us a new solution for the hierarchy problem of
the Standard Model. The Littlest Higgs model with T-parity, which is one of
models in the scenario, solves the dark matter problem in our universe. In this
talk, we discuss how accurately the property of the dark matter is determined
at linear collides. We also mention how precisely does the thermal abundance of
the dark matter determined at the 500 GeV and 1 TeV collides, and compare the
results with those at the LHC.
| [
{
"created": "Sun, 1 Feb 2009 06:26:46 GMT",
"version": "v1"
}
] | 2009-02-03 | [
[
"Matsumoto",
"Shigeki",
""
],
[
"Asakawa",
"Eri",
""
],
[
"Asano",
"Masaki",
""
],
[
"Fujii",
"Keisuke",
""
],
[
"Kusano",
"Tomonori",
""
],
[
"Sasaki",
"Rei",
""
],
[
"Takubo",
"Yosuke",
""
],
[
"Y... | Little Higgs scenario provides us a new solution for the hierarchy problem of the Standard Model. The Littlest Higgs model with T-parity, which is one of models in the scenario, solves the dark matter problem in our universe. In this talk, we discuss how accurately the property of the dark matter is determined at linear collides. We also mention how precisely does the thermal abundance of the dark matter determined at the 500 GeV and 1 TeV collides, and compare the results with those at the LHC. |
0710.5443 | Jonathan Parry | J.K. Parry (Tsinghua U., Beijing), Hong-hao Zhang (Zhongshan U.) | B(d,s)-anti-B(d,s) mixing and Lepton Flavour Violation in SUSY GUTs:
impact of the first measurements of phi(s) | 8 pages, 7 jpeg figures using pdflatex. Version published in Nuclear
Physics B | Nucl.Phys.B802:63-76,2008 | 10.1016/j.nuclphysb.2008.05.010 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we re-examine the correlation between B(d,s)-anti-B(d,s) mixing
and Lepton Flavour Violation in the light of recent experimental measurements
in the $B_s$ system. We perform a generic SUSY analysis of the allowed down
squark mass insertion parameter space. In the SUSY GUT scenario this parameter
space is then used to make predictions for LFV branching ratios. We find that
the recent measurement for the CP phase $\phi_s$ excludes the lowest rates for
tau --> mu + gamma and provides a lower bound of ~ 3E-9 for tan beta = 10.
Future experimental improvements in the bound on tau --> mu + gamma and the
measurement of phi(s) will constitute a strong test of the SUSY GUT scenario.
| [
{
"created": "Mon, 29 Oct 2007 15:03:17 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Apr 2008 06:56:46 GMT",
"version": "v2"
},
{
"created": "Fri, 11 Jul 2008 11:27:17 GMT",
"version": "v3"
}
] | 2010-04-05 | [
[
"Parry",
"J. K.",
"",
"Tsinghua U., Beijing"
],
[
"Zhang",
"Hong-hao",
"",
"Zhongshan U."
]
] | In this work we re-examine the correlation between B(d,s)-anti-B(d,s) mixing and Lepton Flavour Violation in the light of recent experimental measurements in the $B_s$ system. We perform a generic SUSY analysis of the allowed down squark mass insertion parameter space. In the SUSY GUT scenario this parameter space is then used to make predictions for LFV branching ratios. We find that the recent measurement for the CP phase $\phi_s$ excludes the lowest rates for tau --> mu + gamma and provides a lower bound of ~ 3E-9 for tan beta = 10. Future experimental improvements in the bound on tau --> mu + gamma and the measurement of phi(s) will constitute a strong test of the SUSY GUT scenario. |
0903.0569 | Xavier Garcia i Tormo | Geoffrey T. Bodwin (Argonne), Xavier Garcia i Tormo (Argonne & Alberta
U.), Jungil Lee (Korea U.) | Factorization of low-energy gluons in exclusive processes | 18 pages, 10 figures, 2 tables, version published in Physical Review
D | Phys.Rev.D81:114005,2010 | 10.1103/PhysRevD.81.114005 | ANL-HEP-PR-09-6, Alberta Thy 08-10 | hep-ph | http://creativecommons.org/licenses/publicdomain/ | We outline a proof of factorization in exclusive processes, taking into
account the presence of soft and collinear modes of arbitrarily low energy,
which arise when the external lines of the process are taken on shell.
Specifically, we examine the process of e^+e^- annihilation through a virtual
photon into two light mesons. In an intermediate step, we establish a
factorized form that contains a soft function that is free of collinear
divergences. In contrast, in soft-collinear effective theory, the low-energy
collinear modes factor most straightforwardly into the soft function. We point
out that the cancellation of the soft function, which relies on the
color-singlet nature of the external hadrons, fails when the soft function
contains low-energy collinear modes.
| [
{
"created": "Tue, 3 Mar 2009 17:03:11 GMT",
"version": "v1"
},
{
"created": "Thu, 9 Jul 2009 15:08:52 GMT",
"version": "v2"
},
{
"created": "Sat, 19 Sep 2009 04:39:33 GMT",
"version": "v3"
},
{
"created": "Thu, 24 Dec 2009 18:30:38 GMT",
"version": "v4"
},
{
"cre... | 2010-06-28 | [
[
"Bodwin",
"Geoffrey T.",
"",
"Argonne"
],
[
"Tormo",
"Xavier Garcia i",
"",
"Argonne & Alberta\n U."
],
[
"Lee",
"Jungil",
"",
"Korea U."
]
] | We outline a proof of factorization in exclusive processes, taking into account the presence of soft and collinear modes of arbitrarily low energy, which arise when the external lines of the process are taken on shell. Specifically, we examine the process of e^+e^- annihilation through a virtual photon into two light mesons. In an intermediate step, we establish a factorized form that contains a soft function that is free of collinear divergences. In contrast, in soft-collinear effective theory, the low-energy collinear modes factor most straightforwardly into the soft function. We point out that the cancellation of the soft function, which relies on the color-singlet nature of the external hadrons, fails when the soft function contains low-energy collinear modes. |
hep-ph/9609319 | Robert Harris | Robert M. Harris (Fermilab) | Discovery Mass Reach for Excited Quarks at Hadron Colliders | 5 pages, 3 Figures, LaTex, macros epsf.sty, snowtimes.sty, and
snow2e.cls. To appear in the proceedings of DPF/DPB Summer Study on New
Directions for High Energy Physics, Snowmass, Colorado, June 25-July 12,
1996. Postscript file of full paper also available at
http://www-cdf.fnal.gov/physics/conf96/cdf3874_snow_excited_quarks.ps | ECONFC960625:NEW164,1996 | null | Fermilab-Conf-96/285-E. | hep-ph hep-ex | null | If quarks are composite particles then excited states are expected. We
estimate the discovery mass reach as a function of integrated luminosity for
excited quarks decaying to dijets at the Tevatron, LHC, and a Very Large Hadron
Collider (VLHC). At the Tevatron the mass reach is 0.94 TeV for Run II (2
fb^-1) and 1.1 TeV for TeV33 (30 fb^-1). At the LHC the mass reach is 6.3 TeV
for 100 fb^-1. At a VLHC with a center of mass energy, sqrt(s), of 50 TeV (200
TeV) the mass reach is 25 TeV (78 TeV) for an integrated luminosity of 10^4
fb^-1. However, an excited quark with a mass of 25 TeV would be discovered at a
hadron collider with sqrt(s)=100 TeV and an integrated luminosity of 13 fb^-1,
illustrating a physics example where a factor of 2 in machine energy is worth a
factor of 1000 in luminosity.
| [
{
"created": "Wed, 11 Sep 1996 03:35:16 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Harris",
"Robert M.",
"",
"Fermilab"
]
] | If quarks are composite particles then excited states are expected. We estimate the discovery mass reach as a function of integrated luminosity for excited quarks decaying to dijets at the Tevatron, LHC, and a Very Large Hadron Collider (VLHC). At the Tevatron the mass reach is 0.94 TeV for Run II (2 fb^-1) and 1.1 TeV for TeV33 (30 fb^-1). At the LHC the mass reach is 6.3 TeV for 100 fb^-1. At a VLHC with a center of mass energy, sqrt(s), of 50 TeV (200 TeV) the mass reach is 25 TeV (78 TeV) for an integrated luminosity of 10^4 fb^-1. However, an excited quark with a mass of 25 TeV would be discovered at a hadron collider with sqrt(s)=100 TeV and an integrated luminosity of 13 fb^-1, illustrating a physics example where a factor of 2 in machine energy is worth a factor of 1000 in luminosity. |
1101.5981 | Bennie F. L. Ward | B.F.L. Ward (1 and 2) ((1) Dept. of Physics, Baylor University, Waco,
TX, USA, (2) TH Unit, CERN, Geneva, Switzerland) | Chinese Magic in Loop Integrals | 11 pages, 1 figure; improved figure, improved text and
references;added CERN report number;extended text; corrected misprint;
extended text, improved figure; improved text, fonts and style; extended text
for publication in Phys. Rev. D (title changed in journal) | Phys. Rev. D 83 (2011) 113014 | 10.1103/PhysRevD.83.113014 | BU-HEPP-10-07; CERN-PH-TH/2011-029 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an approach to higher point loop integrals using Chinese magic in
the virtual loop integration variable. We show, using the five point function
in the important e^+e^-\to f\bar{f}+\gamma process for ISR as a pedagogical
vehicle, that we get an expression for it directly reduced to one scalar
5-point function and 4-, 3-, and 2- point integrals, thereby avoiding the
computation of the usual three tensor 5-pt Passarino-Veltman reduction. We
argue that this offers potential for greater numerical stability.
| [
{
"created": "Mon, 31 Jan 2011 14:30:48 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Feb 2011 16:16:23 GMT",
"version": "v2"
},
{
"created": "Mon, 21 Feb 2011 17:50:22 GMT",
"version": "v3"
},
{
"created": "Sat, 5 Mar 2011 14:16:47 GMT",
"version": "v4"
},
{
"cr... | 2015-05-27 | [
[
"Ward",
"B. F. L.",
"",
"1 and 2"
]
] | We present an approach to higher point loop integrals using Chinese magic in the virtual loop integration variable. We show, using the five point function in the important e^+e^-\to f\bar{f}+\gamma process for ISR as a pedagogical vehicle, that we get an expression for it directly reduced to one scalar 5-point function and 4-, 3-, and 2- point integrals, thereby avoiding the computation of the usual three tensor 5-pt Passarino-Veltman reduction. We argue that this offers potential for greater numerical stability. |
2401.12875 | Tom\'a\v{s} Je\v{z}o | Anton Andronic, Tom\'a\v{s} Je\v{z}o, Michael Klasen, Christian
Klein-B\"osing, Alexander Puck Neuwirth | Di-electron production at the LHC: Unravelling virtual-photon and
heavy-flavour contributions | 25 pages, 16 figures | null | null | MS-TP-23-22 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The production of virtual photons is a very sensitive probe of the properties
of the quark-gluon plasma. As they are experimentally detected by lepton pairs,
they suffer from a large background arising from hadron decays. Light-flavour
hadrons dominate at low invariant masses below $m_{ee}\sim0.5$ GeV and heavy
flavours above. These contributions must therefore also be taken into account
in experimental analyses at the LHC. In this paper, we calculate the direct
contribution from virtual photons produced in the Drell-Yan process with an
additional jet in POWHEG and find that it is significant at low invariant
masses. We also simulate the background contributions from $c\bar c$ and $b
\bar b$ production with POWHEG and quantify the theoretical uncertainties due
to variations of the perturbative scales and parton distribution functions. We
find larger relative and absolute uncertainties for the lighter $c$ quarks than
for heavier $b$ quarks.
| [
{
"created": "Tue, 23 Jan 2024 16:10:23 GMT",
"version": "v1"
}
] | 2024-01-24 | [
[
"Andronic",
"Anton",
""
],
[
"Ježo",
"Tomáš",
""
],
[
"Klasen",
"Michael",
""
],
[
"Klein-Bösing",
"Christian",
""
],
[
"Neuwirth",
"Alexander Puck",
""
]
] | The production of virtual photons is a very sensitive probe of the properties of the quark-gluon plasma. As they are experimentally detected by lepton pairs, they suffer from a large background arising from hadron decays. Light-flavour hadrons dominate at low invariant masses below $m_{ee}\sim0.5$ GeV and heavy flavours above. These contributions must therefore also be taken into account in experimental analyses at the LHC. In this paper, we calculate the direct contribution from virtual photons produced in the Drell-Yan process with an additional jet in POWHEG and find that it is significant at low invariant masses. We also simulate the background contributions from $c\bar c$ and $b \bar b$ production with POWHEG and quantify the theoretical uncertainties due to variations of the perturbative scales and parton distribution functions. We find larger relative and absolute uncertainties for the lighter $c$ quarks than for heavier $b$ quarks. |
1901.04313 | Vishnudath K. N. | Vishnudath K. N., Sandhya Choubey and Srubabati Goswami | A New Sensitivity Goal for Neutrino-less Double Beta Decay Experiments | Matches with the published version | Phys. Rev. D 99, 095038 (2019) | 10.1103/PhysRevD.99.095038 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the implications of the Dark-LMA solution to the solar neutrino
problem for neutrino-less double beta decay ($0\nu\beta\beta$ ). We show that
while the predictions for the effective mass governing $0\nu\beta\beta$ remains
unchanged for the inverted mass scheme, that for normal ordering becomes higher
for the Dark-LMA parameter space and moves into the "desert region" between the
two. This sets a new goal for sensitvity reach for the next generation
experiments if no signal is found for the inverted ordering by the future
search programmes.
| [
{
"created": "Mon, 14 Jan 2019 13:48:31 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Dec 2019 09:05:05 GMT",
"version": "v2"
}
] | 2019-12-17 | [
[
"N.",
"Vishnudath K.",
""
],
[
"Choubey",
"Sandhya",
""
],
[
"Goswami",
"Srubabati",
""
]
] | We study the implications of the Dark-LMA solution to the solar neutrino problem for neutrino-less double beta decay ($0\nu\beta\beta$ ). We show that while the predictions for the effective mass governing $0\nu\beta\beta$ remains unchanged for the inverted mass scheme, that for normal ordering becomes higher for the Dark-LMA parameter space and moves into the "desert region" between the two. This sets a new goal for sensitvity reach for the next generation experiments if no signal is found for the inverted ordering by the future search programmes. |
2112.04122 | Bin Zhou | Yuxuan Wang, Li Lin Yang, Bin Zhou | FastGPL: a C++ library for fast evaluation of generalized polylogarithms | 17 pages, 2 figures, 4 tables. Code is available at
https://github.com/llyang/FastGPL | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present FastGPL, a C++ library for the fast evaluation of generalized
polylogarithms which appear in many multi-loop Feynman integrals. We implement
the iterative algorithm proposed by Vollinga and Weinzierl in a two-step
approach, i.e., we generate concise expressions using an external program and
hard-code them into the numeric library. This allows efficient and accurate
numeric evaluations of generalized polylogarithms suitable for Monte Carlo
integration and event generation. Floating-point arithmetics are carefully
taken care of to avoid loss of accuracy. As an application and demonstration,
we calculate the two-loop corrections for Higgs boson production in the vector
boson fusion channel at electron-positron colliders. FastGPL is expected to be
useful for event generators at the next-to-next-to-leading order accuracy.
| [
{
"created": "Wed, 8 Dec 2021 05:30:20 GMT",
"version": "v1"
}
] | 2021-12-09 | [
[
"Wang",
"Yuxuan",
""
],
[
"Yang",
"Li Lin",
""
],
[
"Zhou",
"Bin",
""
]
] | We present FastGPL, a C++ library for the fast evaluation of generalized polylogarithms which appear in many multi-loop Feynman integrals. We implement the iterative algorithm proposed by Vollinga and Weinzierl in a two-step approach, i.e., we generate concise expressions using an external program and hard-code them into the numeric library. This allows efficient and accurate numeric evaluations of generalized polylogarithms suitable for Monte Carlo integration and event generation. Floating-point arithmetics are carefully taken care of to avoid loss of accuracy. As an application and demonstration, we calculate the two-loop corrections for Higgs boson production in the vector boson fusion channel at electron-positron colliders. FastGPL is expected to be useful for event generators at the next-to-next-to-leading order accuracy. |
hep-ph/0512363 | Michael Trusov | I.M.Narodetskii and M.A.Trusov | \Theta^+ and \Lambda(1520) production in pp reactions at high energies | Contribution to the PANIC05 Conference, Santa Fe, NM USA, October
2005 | null | 10.1063/1.2220309 | null | hep-ph | null | We estimate the cross sections for the inclusive production of $\Theta^+$ and
$\Lambda(1520)$ in $pp$ collisions at high energy using the $K$ exchange
diagrams. We find that inclusive $\Theta^+$ production should be at the level
of 1 $\mu$b at energies~ $\sqrt{s}~\gtrsim~10~{\rm GeV}$. The ratio of
$\Theta^+(1540)$ to $\Lambda(1520)$ production cross-sections is $\sim 1%$.
| [
{
"created": "Thu, 29 Dec 2005 17:13:16 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Jan 2006 16:11:50 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Narodetskii",
"I. M.",
""
],
[
"Trusov",
"M. A.",
""
]
] | We estimate the cross sections for the inclusive production of $\Theta^+$ and $\Lambda(1520)$ in $pp$ collisions at high energy using the $K$ exchange diagrams. We find that inclusive $\Theta^+$ production should be at the level of 1 $\mu$b at energies~ $\sqrt{s}~\gtrsim~10~{\rm GeV}$. The ratio of $\Theta^+(1540)$ to $\Lambda(1520)$ production cross-sections is $\sim 1%$. |
hep-ph/0201301 | Joanne Gillett | V.A. Khoze (Durham), A.D. Martin (Durham), and M.G. Ryskin (St.
Petersburg) | Photon-exchange processes at hadron colliders as a probe of the dynamics
of diffraction | 23 pages, 10 figures, Latex; some minor typos corrected, version to
appear in Eur.Phys.J. C | Eur.Phys.J.C24:459-468,2002 | 10.1007/s10052-002-0964-4 | IPPP/02/03, DCPT/02/04 | hep-ph | null | The rich structure of photon-exchange processes at hadron colliders is
studied. We discuss central vector meson production pp --> p + J/psi + p, W
production pp --> p + W + X and mu+ mu- production. Each process has distinct,
and large, soft pp rescattering effects, which can be directly observed by
detecting the outgoing protons. This allows a probe of the optical density of
the proton, which plays a crucial role in the evaluation of the rapidity gap
survival probabilities in diffractive-like processes at hadron colliders. We
note that an alternative mechanism for J/psi production is odderon, instead of
photon, exchange; and that the ratio of odderon to photon contributions is
enhanced (suppressed) for phi(Upsilon) vector meson production.
| [
{
"created": "Thu, 31 Jan 2002 09:56:51 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Apr 2002 09:57:07 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Khoze",
"V. A.",
"",
"Durham"
],
[
"Martin",
"A. D.",
"",
"Durham"
],
[
"Ryskin",
"M. G.",
"",
"St.\n Petersburg"
]
] | The rich structure of photon-exchange processes at hadron colliders is studied. We discuss central vector meson production pp --> p + J/psi + p, W production pp --> p + W + X and mu+ mu- production. Each process has distinct, and large, soft pp rescattering effects, which can be directly observed by detecting the outgoing protons. This allows a probe of the optical density of the proton, which plays a crucial role in the evaluation of the rapidity gap survival probabilities in diffractive-like processes at hadron colliders. We note that an alternative mechanism for J/psi production is odderon, instead of photon, exchange; and that the ratio of odderon to photon contributions is enhanced (suppressed) for phi(Upsilon) vector meson production. |
hep-ph/0611242 | Soren Wiesenfeldt | Tim Stelzer, Soren Wiesenfeldt, and Scott Willenbrock (U. of Illinois
at Urbana-Champaign) | Higgs at the Tevatron in Extended Supersymmetric Models | 3 pages | Phys.Rev.D75:077701,2007 | 10.1103/PhysRevD.75.077701 | null | hep-ph | null | Supersymmetric models with an additional singlet field offer the Higgs boson
the possibility to decay to two pseudoscalars, a. If the mass of these
pseudoscalars is above the b bbar threshold, a -> b bbar is generically the
dominant decay mode. The decay h -> a a -> b bbar b bbar may be seen above
backgrounds at the Tevatron if the Higgs production cross section is enhanced
relative to that of the standard model.
| [
{
"created": "Mon, 20 Nov 2006 04:34:29 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Stelzer",
"Tim",
"",
"U. of Illinois\n at Urbana-Champaign"
],
[
"Wiesenfeldt",
"Soren",
"",
"U. of Illinois\n at Urbana-Champaign"
],
[
"Willenbrock",
"Scott",
"",
"U. of Illinois\n at Urbana-Champaign"
]
] | Supersymmetric models with an additional singlet field offer the Higgs boson the possibility to decay to two pseudoscalars, a. If the mass of these pseudoscalars is above the b bbar threshold, a -> b bbar is generically the dominant decay mode. The decay h -> a a -> b bbar b bbar may be seen above backgrounds at the Tevatron if the Higgs production cross section is enhanced relative to that of the standard model. |
1410.7139 | Vladimir Saleev | Maxim Nefedov, Anton Karpishkov, Vladimir Saleev, and Alexandera
Shipilova | Open charm production in the parton Reggeization approach: from Tevatron
to LHC | 16 pages, 12 figures | Phys. Rev. D 91, 054009 (2015) | 10.1103/PhysRevD.91.054009 | DESY-14-199 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the inclusive hadroproduction of D^0, D^+, D^star+, and D_s^+ mesons
at leading order in the parton Reggeization approach endowed with universal
fragmentation functions fitted to $e^+e^-$ annihilation data from CERN LEP1. We
have described $D$-meson transverse momentum distributions measured in the
central region of rapidity by the CDF Collaboration at Tevatron (|y|<1) and
ALICE Collaboration at LHC (|y|<0.5) within uncertainties and without free
parameters, using Kimber-Martin-Ryskin unintegrated gluon distribution function
in a proton. The forward D-meson production (|y|>2.0) measured by the LHCb
Collaboration also has been studied and expected disagreement between our
theoretical predictions and data has been obtained.
| [
{
"created": "Mon, 27 Oct 2014 07:28:07 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Oct 2014 04:49:54 GMT",
"version": "v2"
}
] | 2015-03-18 | [
[
"Nefedov",
"Maxim",
""
],
[
"Karpishkov",
"Anton",
""
],
[
"Saleev",
"Vladimir",
""
],
[
"Shipilova",
"Alexandera",
""
]
] | We study the inclusive hadroproduction of D^0, D^+, D^star+, and D_s^+ mesons at leading order in the parton Reggeization approach endowed with universal fragmentation functions fitted to $e^+e^-$ annihilation data from CERN LEP1. We have described $D$-meson transverse momentum distributions measured in the central region of rapidity by the CDF Collaboration at Tevatron (|y|<1) and ALICE Collaboration at LHC (|y|<0.5) within uncertainties and without free parameters, using Kimber-Martin-Ryskin unintegrated gluon distribution function in a proton. The forward D-meson production (|y|>2.0) measured by the LHCb Collaboration also has been studied and expected disagreement between our theoretical predictions and data has been obtained. |
2012.12304 | Aditya Pathak | Brad Bachu, Andr\'e H. Hoang, Vicent Mateu, Aditya Pathak, Iain W.
Stewart | Boosted Top Quarks in the Peak Region with N$^3$LL Resummation | Added explanations for expected size of power corrections. Results
unchanged | Phys. Rev. D 104, 014026 (2021) | 10.1103/PhysRevD.104.014026 | MIT-CTP 5237; UWThPh-2020-24; IFT-UAM/CSIC-20-134; MAN/HEP/2020/012 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We present results for the 2-jettiness differential distribution for boosted
top quark pairs produced in $e^+e^-$ collisions in the peak region accounting
for QCD large-logarithm resummation at next-to-next-to-next-to-leading
logarithmic (N$^3$LL) order and fixed-order corrections to matrix elements at
next-to-next-to-leading order (NNLO) calculated in the framework of
soft-collinear effective theory and boosted heavy quark effective theory.
Electroweak and finite-width effects are included at leading order. We study
the perturbative convergence of the cross section in the pole and MSR mass
schemes, with and without soft gap subtractions. We find that there is a
partial cancellation between the pole mass and soft function renormalons. When
renormalon subtractions concerning the top mass and the soft function are
implemented, the perturbative uncertainties are, however, systematically
smaller and an improvement in the stability of the peak position is observed.
We find that the top MSR mass may be determined with perturbative uncertainties
well below $100$\,MeV from the peak position of the 2-jettiness distribution.
This result has important applications for Monte Carlo top quark mass
calibrations.
| [
{
"created": "Tue, 22 Dec 2020 19:26:27 GMT",
"version": "v1"
},
{
"created": "Mon, 31 May 2021 21:14:14 GMT",
"version": "v2"
}
] | 2021-08-04 | [
[
"Bachu",
"Brad",
""
],
[
"Hoang",
"André H.",
""
],
[
"Mateu",
"Vicent",
""
],
[
"Pathak",
"Aditya",
""
],
[
"Stewart",
"Iain W.",
""
]
] | We present results for the 2-jettiness differential distribution for boosted top quark pairs produced in $e^+e^-$ collisions in the peak region accounting for QCD large-logarithm resummation at next-to-next-to-next-to-leading logarithmic (N$^3$LL) order and fixed-order corrections to matrix elements at next-to-next-to-leading order (NNLO) calculated in the framework of soft-collinear effective theory and boosted heavy quark effective theory. Electroweak and finite-width effects are included at leading order. We study the perturbative convergence of the cross section in the pole and MSR mass schemes, with and without soft gap subtractions. We find that there is a partial cancellation between the pole mass and soft function renormalons. When renormalon subtractions concerning the top mass and the soft function are implemented, the perturbative uncertainties are, however, systematically smaller and an improvement in the stability of the peak position is observed. We find that the top MSR mass may be determined with perturbative uncertainties well below $100$\,MeV from the peak position of the 2-jettiness distribution. This result has important applications for Monte Carlo top quark mass calibrations. |
1808.05417 | Ernest Ma | Ernest Ma (UC Riverside and HKUST/JCIAS) | Baryon-Lepton Duplicity as the Progenitor of Long-Lived Dark Matter | 12 pages, 1 figure (published version) | null | 10.1016/j.physletb.2018.11.049 | UCRHEP-T593 (Aug 2018) | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In an $SU(2)_R$ extension of the standard model, it is shown how the neutral
fermion $N$ in the doublet $(N,e)_R$ may be assigned baryon number $B=1$, in
contrast to its $SU(2)_L$ counterpart $\nu$ in the doublet $(\nu,e)_L$ which
has lepton number $L=1$. This baryon-lepton duplicity allows a scalar $\sigma$
which couples to $N_L N_L$ to be long-lived dark matter.
| [
{
"created": "Thu, 16 Aug 2018 11:08:38 GMT",
"version": "v1"
},
{
"created": "Sat, 5 Jan 2019 18:47:13 GMT",
"version": "v2"
}
] | 2019-01-08 | [
[
"Ma",
"Ernest",
"",
"UC Riverside and HKUST/JCIAS"
]
] | In an $SU(2)_R$ extension of the standard model, it is shown how the neutral fermion $N$ in the doublet $(N,e)_R$ may be assigned baryon number $B=1$, in contrast to its $SU(2)_L$ counterpart $\nu$ in the doublet $(\nu,e)_L$ which has lepton number $L=1$. This baryon-lepton duplicity allows a scalar $\sigma$ which couples to $N_L N_L$ to be long-lived dark matter. |
2403.09773 | Fabian Wunder | Fabian Wunder | Asymptotic behavior of angular integrals in the massless limit | 6 pages, 3 figures, typo in email address corrected | Phys. Rev. D 109, 076022 -- Published 23 April 2024 | 10.1103/PhysRevD.109.076022 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the small-mass asymptotics of a class of massive $d$
dimensional angular integrals. These integrals arise in a wide range of
perturbative quantum field theory calculations. We derive expressions
characterizing their behavior in the vicinity of the massless limit for all
cases with up to two denominators. The results established in this work are
applicable to phase-space calculations where an integration over virtuality
including the massless limit is required.
| [
{
"created": "Thu, 14 Mar 2024 18:00:03 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Mar 2024 12:38:58 GMT",
"version": "v2"
}
] | 2024-05-01 | [
[
"Wunder",
"Fabian",
""
]
] | We investigate the small-mass asymptotics of a class of massive $d$ dimensional angular integrals. These integrals arise in a wide range of perturbative quantum field theory calculations. We derive expressions characterizing their behavior in the vicinity of the massless limit for all cases with up to two denominators. The results established in this work are applicable to phase-space calculations where an integration over virtuality including the massless limit is required. |
hep-ph/9403288 | null | Tadashi Kon, Tetsuro Kobayashi and Shoichi Kitamura | Signatures of Scalar Top with R-parity Breaking Coupling at HERA | 11 pages (LaTeX), 6 figures not included (available on request) ;
ITP-SU-94/01 | Phys.Lett. B333 (1994) 263-270 | 10.1016/0370-2693(94)91042-1 | null | hep-ph | null | In the framework of the minimal supersymmetric standard model with an
R-parity breaking coupling of the scalar top quark (stop) we investigate
production processes and decay properties of the stop at HERA energies. The
model is characterized by a light stop possibly lighter than the other squarks.
We show that the stop could be singly produced not only in the neutral current
processes but also in associated processes whose final states contain some
heavy flavor quarks, bottom and top quarks. These signatures would be useful to
discriminate the stop from leptoquarks.
| [
{
"created": "Tue, 15 Mar 1994 14:50:33 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Kon",
"Tadashi",
""
],
[
"Kobayashi",
"Tetsuro",
""
],
[
"Kitamura",
"Shoichi",
""
]
] | In the framework of the minimal supersymmetric standard model with an R-parity breaking coupling of the scalar top quark (stop) we investigate production processes and decay properties of the stop at HERA energies. The model is characterized by a light stop possibly lighter than the other squarks. We show that the stop could be singly produced not only in the neutral current processes but also in associated processes whose final states contain some heavy flavor quarks, bottom and top quarks. These signatures would be useful to discriminate the stop from leptoquarks. |
2207.10536 | Gael Alguero | Gael Alguero, Genevieve Belanger, Sabine Kraml, Alexander Pukhov | Co-scattering in micrOMEGAs: a case study for the singlet-triplet dark
matter model | 22 pages, 11 figures; typos corrected | SciPost Phys. 13, 124 (2022) | 10.21468/SciPostPhys.13.6.124 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In scenarios with very small dark matter (DM) couplings and small mass
splittings between the DM and other dark sector particles, so-called
"co-scattering" or "conversion-driven freeze-out" can be the dominant mechanism
for DM production. We present the inclusion of this mechanism in micrOMEGAs
together with a case study of the phenomenological implications in the
fermionic singlet-triplet model. For the latter, we focus on the transition
between co-annihilation and co-scattering processes. We observe that
co-scattering is needed to describe the thermal behaviour of the DM for very
small couplings, opening up a new region in the parameter space of the model.
The triplet states are often long-lived in this region; we therefore also
discuss LHC constraints from long-lived signatures obtained with SModelS.
| [
{
"created": "Thu, 21 Jul 2022 15:21:32 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Nov 2022 15:54:02 GMT",
"version": "v2"
}
] | 2022-12-28 | [
[
"Alguero",
"Gael",
""
],
[
"Belanger",
"Genevieve",
""
],
[
"Kraml",
"Sabine",
""
],
[
"Pukhov",
"Alexander",
""
]
] | In scenarios with very small dark matter (DM) couplings and small mass splittings between the DM and other dark sector particles, so-called "co-scattering" or "conversion-driven freeze-out" can be the dominant mechanism for DM production. We present the inclusion of this mechanism in micrOMEGAs together with a case study of the phenomenological implications in the fermionic singlet-triplet model. For the latter, we focus on the transition between co-annihilation and co-scattering processes. We observe that co-scattering is needed to describe the thermal behaviour of the DM for very small couplings, opening up a new region in the parameter space of the model. The triplet states are often long-lived in this region; we therefore also discuss LHC constraints from long-lived signatures obtained with SModelS. |
1311.5398 | Zhou Gao-Liang | Gao-Liang Zhou | QCD Factorization of Semi-inclusive DIS process at Operator Level | arXiv admin note: text overlap with arXiv:1307.4194 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The operator level proof of factorization theorem exhibited in [1] is
extended to the semi-inclusive deep inelastic scattering process(SIDIS).
Factorization theorem can be proved at operator level if there are not detected
soft hadrons.
| [
{
"created": "Thu, 21 Nov 2013 13:31:42 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Nov 2013 05:28:40 GMT",
"version": "v2"
}
] | 2013-11-25 | [
[
"Zhou",
"Gao-Liang",
""
]
] | The operator level proof of factorization theorem exhibited in [1] is extended to the semi-inclusive deep inelastic scattering process(SIDIS). Factorization theorem can be proved at operator level if there are not detected soft hadrons. |
hep-ph/9207215 | null | R. E. Cutkosky | Isospin Splitting in the Baryon Octet and Decuplet | 9 pages, LATEX inc. 2 LATEX "pictures", CMU-HEP91-24-R92 | null | 10.1103/PhysRevC.47.367 | null | hep-ph | null | Baryon mass splittings are analyzed in terms of a simple model with general
pairwise interactions. At present, the $\Delta$ masses are poorly known from
experiments. Improvement of these data would provide an opportunity to make a
significant test of our understanding of electromagnetic and quark-mass
contributions to hadronic masses. The problem of determining resonance masses
from scattering and production data is discussed.
| [
{
"created": "Sat, 4 Jul 1992 21:36:18 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Cutkosky",
"R. E.",
""
]
] | Baryon mass splittings are analyzed in terms of a simple model with general pairwise interactions. At present, the $\Delta$ masses are poorly known from experiments. Improvement of these data would provide an opportunity to make a significant test of our understanding of electromagnetic and quark-mass contributions to hadronic masses. The problem of determining resonance masses from scattering and production data is discussed. |
1010.5707 | Alexander Smirnov D. | A. V. Povarov, A. D. Smirnov | Scalar Leptoquark Contributions into $l_i\to l_j\gamma$ Processes | 7 pages, 4 figures. Submitted to Proceedings of the 16th
International Seminar on High Energy Physics "QUARKS-2010", Kolomna, Russia,
6-12 June, 2010 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The contributions of scalar leptoquarks in lepton flavor violating (LFV)
processes of type $l_i\to l_j \gamma$ are investigated in frame of the minimal
model with the four color symmetry and Higgs mechanism of quark and lepton mass
generation. It is shown that experimental data on the decays $\mu\to e \gamma$,
$\tau \to \mu \gamma$, $\tau\to e \gamma$ allow the existence of light scalar
leptoquarks of type under consideration, with masses of order 1 TeV or below.
| [
{
"created": "Wed, 27 Oct 2010 14:50:54 GMT",
"version": "v1"
}
] | 2010-10-28 | [
[
"Povarov",
"A. V.",
""
],
[
"Smirnov",
"A. D.",
""
]
] | The contributions of scalar leptoquarks in lepton flavor violating (LFV) processes of type $l_i\to l_j \gamma$ are investigated in frame of the minimal model with the four color symmetry and Higgs mechanism of quark and lepton mass generation. It is shown that experimental data on the decays $\mu\to e \gamma$, $\tau \to \mu \gamma$, $\tau\to e \gamma$ allow the existence of light scalar leptoquarks of type under consideration, with masses of order 1 TeV or below. |
1508.03434 | Heikki M\"antysaari | T. Lappi, H. M\"antysaari | Solving the Balitsky-Kovchegov equation at next to leading order
accuracy | 4 pages, 4 figures. Talk given by H.M. at the 7th International
Conference on Hard and Electromagnetic Probes of High-Energy Nuclear
Collisions (Hard Probes 2015) | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the first numerical solution to the next to leading order
Balitsky-Kovchegov (BK) equation in coordinate space in the
large-$N_\mathrm{c}$ limit. In addition to the dipole operator we also solve
the evolution of the "conformal dipole" for which the conformal invariance
breaking double logarithmic term is absent from the evolution equation. The NLO
corrections are shown to slow down the evolution. We show that the solution
depends strongly on the details of the initial condition, and that the solution
to the equation is not positive definite with all initial conditions relevant
for phenomenological applications.
| [
{
"created": "Fri, 14 Aug 2015 08:10:04 GMT",
"version": "v1"
}
] | 2015-08-17 | [
[
"Lappi",
"T.",
""
],
[
"Mäntysaari",
"H.",
""
]
] | We present the first numerical solution to the next to leading order Balitsky-Kovchegov (BK) equation in coordinate space in the large-$N_\mathrm{c}$ limit. In addition to the dipole operator we also solve the evolution of the "conformal dipole" for which the conformal invariance breaking double logarithmic term is absent from the evolution equation. The NLO corrections are shown to slow down the evolution. We show that the solution depends strongly on the details of the initial condition, and that the solution to the equation is not positive definite with all initial conditions relevant for phenomenological applications. |
1605.05868 | Kwei-Chou Yang | Kwei-Chou Yang | Comment on "Dark Matter with Pseudoscalar-Mediated Interactions Explains
the DAMA Signal and the Galactic Center Excess" | 1 page, 2 figures | null | null | CYCU-HEP-16-05 | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Arina et al. have proposed the Dirac fermionic dark matter with
pseudoscalar-mediated interactions to explain the Galactic Center excess,
correct relic density and DAMA signal. They have assumed that contact
interactions remain roughly valid in calculating scattering rates at the direct
detection even when the mediator mass is the same order as the typical momentum
transfer. We show that such a replacement is not suitable. Adopting the full
form of interactions, we show that the gamma-ray excess allowed parameters are
completely outside of the DAMA iodine 3$\sigma$ region, even for
heavy-flavor-universal couplings, for which $m_{DM} \sim 40$ GeV in the
gamma-ray excess fit. As for Higgs-like couplings, the two regions overlap for
$m_a\lesssim$ 15 MeV, where long-range interactions, instead of contact
interactions, occur at the DAMA.
| [
{
"created": "Thu, 19 May 2016 09:41:07 GMT",
"version": "v1"
}
] | 2016-05-20 | [
[
"Yang",
"Kwei-Chou",
""
]
] | Arina et al. have proposed the Dirac fermionic dark matter with pseudoscalar-mediated interactions to explain the Galactic Center excess, correct relic density and DAMA signal. They have assumed that contact interactions remain roughly valid in calculating scattering rates at the direct detection even when the mediator mass is the same order as the typical momentum transfer. We show that such a replacement is not suitable. Adopting the full form of interactions, we show that the gamma-ray excess allowed parameters are completely outside of the DAMA iodine 3$\sigma$ region, even for heavy-flavor-universal couplings, for which $m_{DM} \sim 40$ GeV in the gamma-ray excess fit. As for Higgs-like couplings, the two regions overlap for $m_a\lesssim$ 15 MeV, where long-range interactions, instead of contact interactions, occur at the DAMA. |
1111.1054 | Pratishruti Saha | Debajyoti Choudhury, Rohini M. Godbole, Pratishruti Saha | Dijet resonances, widths and all that | Version published in JHEP | JHEP 1201:155,2012 | 10.1007/JHEP01(2012)155 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The search for heavy resonances in the dijet channel is part of the on-going
physics programme, both at the Tevatron and at the LHC. Lower limits have been
placed on the masses of dijet resonances predicted in a wide variety of models.
However, across experiments, the search strategy assumes that the effect of the
new particles is well-approximated by on-shell production and subsequent decay
into a pair of jets. We examine the impact of off-shell effects on such
searches, particularly for strongly interacting resonances.
| [
{
"created": "Fri, 4 Nov 2011 06:56:33 GMT",
"version": "v1"
},
{
"created": "Sun, 11 Dec 2011 06:51:19 GMT",
"version": "v2"
},
{
"created": "Sat, 18 Feb 2012 17:23:03 GMT",
"version": "v3"
}
] | 2012-02-21 | [
[
"Choudhury",
"Debajyoti",
""
],
[
"Godbole",
"Rohini M.",
""
],
[
"Saha",
"Pratishruti",
""
]
] | The search for heavy resonances in the dijet channel is part of the on-going physics programme, both at the Tevatron and at the LHC. Lower limits have been placed on the masses of dijet resonances predicted in a wide variety of models. However, across experiments, the search strategy assumes that the effect of the new particles is well-approximated by on-shell production and subsequent decay into a pair of jets. We examine the impact of off-shell effects on such searches, particularly for strongly interacting resonances. |
1409.2082 | Amitava Raychaudhuri | Biswajoy Brahmachari (Vidyasagar Evening College) and Amitava
Raychaudhuri (University of Calcutta) | Kinetic mixing and symmetry breaking dependent interactions of the dark
photon | Latex, Nuclear Physics B (to appear) | null | 10.1016/j.nuclphysb.2014.08.015 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine spontaneous symmetry breaking of a renormalisable U(1) x U(1)
gauge theory coupled to fermions when kinetic mixing is present. We do not
assume that the kinetic mixing parameter is small. A rotation plus scaling is
used to remove the mixing and put the gauge kinetic terms in the canonical
form. Fermion currents are also rotated in a non-orthogonal way by this basis
transformation. Through suitable redefinitions the interaction is cast into a
diagonal form. This framework, where mixing is absent, is used for subsequent
analysis. The symmetry breaking determines the fermionic current which couples
to the massless gauge boson. The strength of this coupling as well as the
couplings of the massive gauge boson are extracted. This formulation is used to
consider a gauged model for dark matter by identifying the massless gauge boson
with the photon and the massive state to its dark counterpart. Matching the
coupling of the residual symmetry with that of the photon sets a lower bound on
the kinetic mixing parameter. We present analytical formulae of the couplings
of the dark photon in this model and indicate some physics consequences.
| [
{
"created": "Sun, 7 Sep 2014 04:48:34 GMT",
"version": "v1"
}
] | 2014-09-09 | [
[
"Brahmachari",
"Biswajoy",
"",
"Vidyasagar Evening College"
],
[
"Raychaudhuri",
"Amitava",
"",
"University of Calcutta"
]
] | We examine spontaneous symmetry breaking of a renormalisable U(1) x U(1) gauge theory coupled to fermions when kinetic mixing is present. We do not assume that the kinetic mixing parameter is small. A rotation plus scaling is used to remove the mixing and put the gauge kinetic terms in the canonical form. Fermion currents are also rotated in a non-orthogonal way by this basis transformation. Through suitable redefinitions the interaction is cast into a diagonal form. This framework, where mixing is absent, is used for subsequent analysis. The symmetry breaking determines the fermionic current which couples to the massless gauge boson. The strength of this coupling as well as the couplings of the massive gauge boson are extracted. This formulation is used to consider a gauged model for dark matter by identifying the massless gauge boson with the photon and the massive state to its dark counterpart. Matching the coupling of the residual symmetry with that of the photon sets a lower bound on the kinetic mixing parameter. We present analytical formulae of the couplings of the dark photon in this model and indicate some physics consequences. |
hep-ph/9705426 | Larry McLerran | L. McLerran (Theoretical Physics Institute, University of Minnesota) | Small x Physics and Why It's Interesting | 9 Pages, Latex, 0 figures | null | null | TPI-MINN-97-12 Journal Ref: | hep-ph | null | I discuss small x physics and its implications at very high energies. At very
high energy the density of partons becomes so large that much of the physics
can be described using weak coupling methods in QCD. This may allow for a
solution to problems such as the asymptotic nature of deep inelastic scattering
at fixed momentum transfer, unitarization, and multiparticle production.
| [
{
"created": "Mon, 26 May 1997 11:16:06 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"McLerran",
"L.",
"",
"Theoretical Physics Institute, University of Minnesota"
]
] | I discuss small x physics and its implications at very high energies. At very high energy the density of partons becomes so large that much of the physics can be described using weak coupling methods in QCD. This may allow for a solution to problems such as the asymptotic nature of deep inelastic scattering at fixed momentum transfer, unitarization, and multiparticle production. |
0806.3757 | Andreas Weiler | Csaba Csaki, Adam Falkowski, and Andreas Weiler | A Simple Flavor Protection for RS | 15 pages | Phys.Rev.D80:016001,2009 | 10.1103/PhysRevD.80.016001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a simple variation of warped flavor models where the hierarchies
of fermion masses and mixings are still explained but dangerous flavor
violating effects in the Kaon sector are greatly reduced. The key new
ingredients are two horizontal U(1) symmetries. These symmetries forbid flavor
violation in the down quark sector (with the exception of small IR brane
localized kinetic mixing terms for the left-handed quarks) while allowing for
flavor violation in the up quark sector. The leading flavor constraints come
from D - anti-D mixing, and are safely satisfied for the KK mass scale of order
3 TeV. Our analysis of the flavor constraints also includes the constraints due
to the (usually ignored) localized kinetic mixing terms. We also comment on the
effects of the additional U(1) gauge bosons.
| [
{
"created": "Tue, 24 Jun 2008 19:25:00 GMT",
"version": "v1"
}
] | 2009-09-02 | [
[
"Csaki",
"Csaba",
""
],
[
"Falkowski",
"Adam",
""
],
[
"Weiler",
"Andreas",
""
]
] | We present a simple variation of warped flavor models where the hierarchies of fermion masses and mixings are still explained but dangerous flavor violating effects in the Kaon sector are greatly reduced. The key new ingredients are two horizontal U(1) symmetries. These symmetries forbid flavor violation in the down quark sector (with the exception of small IR brane localized kinetic mixing terms for the left-handed quarks) while allowing for flavor violation in the up quark sector. The leading flavor constraints come from D - anti-D mixing, and are safely satisfied for the KK mass scale of order 3 TeV. Our analysis of the flavor constraints also includes the constraints due to the (usually ignored) localized kinetic mixing terms. We also comment on the effects of the additional U(1) gauge bosons. |
hep-ph/0107238 | Michael Eides | Michael I. Eides, Howard Grotch, and Valery A. Shelyuto | Two-Loop Polarization Contributions to Radiative-Recoil Corrections to
Hyperfine Splitting in Muonium | 15 pages, 11 figures | Phys.Rev. D65 (2002) 013003 | 10.1103/PhysRevD.65.013003 | UK/01-03 | hep-ph physics.atom-ph | null | We calculate radiative-recoil corrections of order
$\alpha^2(Z\alpha)(m/M)E_F$ to hyperfine splitting in muonium generated by the
diagrams with electron and muon polarization loops. These corrections are
enhanced by the large logarithm of the electron-muon mass ratio. The leading
logarithm cubed and logarithm squared contributions were obtained a long time
ago. The single-logarithmic and nonlogarithmic contributions calculated here
improve the theory of hyperfine splitting, and affect the value of the
electron-muon mass ratio extracted from the experimental data on the muonium
hyperfine splitting.
| [
{
"created": "Mon, 23 Jul 2001 19:01:47 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Eides",
"Michael I.",
""
],
[
"Grotch",
"Howard",
""
],
[
"Shelyuto",
"Valery A.",
""
]
] | We calculate radiative-recoil corrections of order $\alpha^2(Z\alpha)(m/M)E_F$ to hyperfine splitting in muonium generated by the diagrams with electron and muon polarization loops. These corrections are enhanced by the large logarithm of the electron-muon mass ratio. The leading logarithm cubed and logarithm squared contributions were obtained a long time ago. The single-logarithmic and nonlogarithmic contributions calculated here improve the theory of hyperfine splitting, and affect the value of the electron-muon mass ratio extracted from the experimental data on the muonium hyperfine splitting. |
hep-ph/0308300 | Alan Kostelecky | Alan Kostelecky and Matthew Mewes | Lorentz and CPT Violation in the Neutrino Sector | 4 pages REVTeX, accepted as a Rapid Communication, Phys. Rev. D | Phys.Rev.D70:031902,2004 | 10.1103/PhysRevD.70.031902 | IUHET 456, July 2003 | hep-ph | null | We consider neutrino oscillations in the minimal Standard-Model Extension
describing general Lorentz and CPT violation. Among the models without neutrino
mass differences is one with two degrees of freedom that reproduces most major
observed features of neutrino behavior.
| [
{
"created": "Thu, 28 Aug 2003 16:27:17 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Jun 2004 22:08:16 GMT",
"version": "v2"
}
] | 2009-07-09 | [
[
"Kostelecky",
"Alan",
""
],
[
"Mewes",
"Matthew",
""
]
] | We consider neutrino oscillations in the minimal Standard-Model Extension describing general Lorentz and CPT violation. Among the models without neutrino mass differences is one with two degrees of freedom that reproduces most major observed features of neutrino behavior. |
hep-ph/0405290 | Sonny Mantry | Sonny Mantry | Heavy Quark Symmetry in Nonleptonic B-Decays to Excited Charmed Mesons | 22 pages, 5 figures, typos corrected, references added, discussion on
subleading effects clarified, replaced version accepted for publication in
Phys.Rev.D | Phys.Rev. D70 (2004) 114006 | 10.1103/PhysRevD.70.114006 | MIT-CTP-3497 | hep-ph | null | We show in a model independent way the equality of the branching fractions
and strong phases for B-> D_1M and B-> D_2^*M at leading order in Lambda
_{QCD}/Q and alpha_s(Q) where Q={m_b,m_c,E_M} and M is a light meson. These
results apply in the color allowed and color suppressed channels and follow
from a factorization theorem in SCET combined with heavy quark symmetry. The
expected heavy quark symmetry suppression of leading order contributions in the
color allowed sector based on analysis of semileptonic decays, is shown to
disappear at maximum recoil. Subleading corrections are suppressed by at least
one power of Lambda_{QCD}/Q and this is explicitly verified for subleading
semileptonic form factors at maximum recoil.
| [
{
"created": "Sat, 29 May 2004 18:31:48 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Dec 2004 22:42:37 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Mantry",
"Sonny",
""
]
] | We show in a model independent way the equality of the branching fractions and strong phases for B-> D_1M and B-> D_2^*M at leading order in Lambda _{QCD}/Q and alpha_s(Q) where Q={m_b,m_c,E_M} and M is a light meson. These results apply in the color allowed and color suppressed channels and follow from a factorization theorem in SCET combined with heavy quark symmetry. The expected heavy quark symmetry suppression of leading order contributions in the color allowed sector based on analysis of semileptonic decays, is shown to disappear at maximum recoil. Subleading corrections are suppressed by at least one power of Lambda_{QCD}/Q and this is explicitly verified for subleading semileptonic form factors at maximum recoil. |
hep-ph/0610108 | Egle Tomasi-Gustafsson | Egle Tomasi-Gustafsson | On radiative corrections for unpolarized electron proton elastic
scattering | 11 pagex, 5 figures | Phys.Part.Nucl.Lett.4:281-288,2007 | 10.1134/S1547477107040012 | null | hep-ph | null | A statistical analysis of the elastic unpolarized electron proton scattering
data shows that, at large momentum transfer, the size and the $\epsilon$
dependence of the radiative corrections, as traditionally calculated and
applied, may induce large correlations of the parameters of the Rosenbluth fit,
which prevent a correct extraction of the electric proton form factor. Using
the electron QED structure (radiation) function approach the cross section of
elastic electron-proton scattering in leading and next-to leading
approximations is calculated and expressed as a correction to the Born cross
section, which is different for the electric and the magnetic contribution.
When properly applied to the data, it may give the solution to the problem of
the discrepancy of the polarized and unpolarized results on electron proton
scattering.
| [
{
"created": "Tue, 10 Oct 2006 07:46:05 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Tomasi-Gustafsson",
"Egle",
""
]
] | A statistical analysis of the elastic unpolarized electron proton scattering data shows that, at large momentum transfer, the size and the $\epsilon$ dependence of the radiative corrections, as traditionally calculated and applied, may induce large correlations of the parameters of the Rosenbluth fit, which prevent a correct extraction of the electric proton form factor. Using the electron QED structure (radiation) function approach the cross section of elastic electron-proton scattering in leading and next-to leading approximations is calculated and expressed as a correction to the Born cross section, which is different for the electric and the magnetic contribution. When properly applied to the data, it may give the solution to the problem of the discrepancy of the polarized and unpolarized results on electron proton scattering. |
1310.6805 | Zhenjun Xiao | Shan Cheng, Ying-Ying Fan, Zhen-Jun Xiao | $B \to K \etap$ decays in the SM with fourth generation fermions | 9 pages, no figure. two references added. to be published in Chinese
Physics C | null | 10.1088/1674-1137/38/7/073102 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By employing the perturbative QCD (pQCD) factorization approach, we calculate
the new physics contributions to the four $B \to K \etap$ decays in the
Standard Model (SM) with a fourth generation of fermions (SM4), induced by the
loop diagrams involving $\tp$ quark. Within the considered parameter space of
the SM4 we find that (a) the next-to-leading order (NLO) pQCD predictions for
the branching ratios and CP-violating asymmetries in both the SM and SM4
generally agree with the data within one standard deviation; (b) for $Br(B \to
K \eta)$, the inclusion of the fourth generation contributions can improve the
agreement between the theoretical predictions and the data effectively; (c) for
$Br(B \to K \etar)$, however, the decrease due to $\tp$ loops is disfavored by
the data; and (d) the new physics corrections to the CP-violating asymmetries
of the considered decays are about 10% only.
| [
{
"created": "Fri, 25 Oct 2013 02:16:43 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Nov 2013 11:48:26 GMT",
"version": "v2"
},
{
"created": "Wed, 27 Nov 2013 02:12:14 GMT",
"version": "v3"
}
] | 2015-06-17 | [
[
"Cheng",
"Shan",
""
],
[
"Fan",
"Ying-Ying",
""
],
[
"Xiao",
"Zhen-Jun",
""
]
] | By employing the perturbative QCD (pQCD) factorization approach, we calculate the new physics contributions to the four $B \to K \etap$ decays in the Standard Model (SM) with a fourth generation of fermions (SM4), induced by the loop diagrams involving $\tp$ quark. Within the considered parameter space of the SM4 we find that (a) the next-to-leading order (NLO) pQCD predictions for the branching ratios and CP-violating asymmetries in both the SM and SM4 generally agree with the data within one standard deviation; (b) for $Br(B \to K \eta)$, the inclusion of the fourth generation contributions can improve the agreement between the theoretical predictions and the data effectively; (c) for $Br(B \to K \etar)$, however, the decrease due to $\tp$ loops is disfavored by the data; and (d) the new physics corrections to the CP-violating asymmetries of the considered decays are about 10% only. |
2210.08000 | Andreas Helset | Andreas Helset, Elizabeth E. Jenkins, Aneesh V. Manohar | Geometry in Scattering Amplitudes | 7 pages. Updated references and corrected typo | null | 10.1103/PhysRevD.106.116018 | CALT-TH-2022-036 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We formulate the field-space geometry for an effective field theory of
scalars and gauge bosons. Geometric invariants such as the field-space
curvature enter in both scattering amplitudes and the renormalization group
equations, with the scalar and gauge results unified in a single expression.
| [
{
"created": "Fri, 14 Oct 2022 17:58:56 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Mar 2024 08:54:12 GMT",
"version": "v2"
}
] | 2024-03-21 | [
[
"Helset",
"Andreas",
""
],
[
"Jenkins",
"Elizabeth E.",
""
],
[
"Manohar",
"Aneesh V.",
""
]
] | We formulate the field-space geometry for an effective field theory of scalars and gauge bosons. Geometric invariants such as the field-space curvature enter in both scattering amplitudes and the renormalization group equations, with the scalar and gauge results unified in a single expression. |
hep-ph/9904330 | Nora Brambilla | Nora Brambilla (U. Vienna) and Antonio Vairo (HEPHY, Vienna) | Quark Confinement and the Hadron Spectrum | 70 pages, 20 figures, uses sprocl.sty. Lectures given at HUGS at
CEBAF, 13th Annual Hampton University Graduate Studies at the Continuous
Electron Beam Facility, May 26-June 12, 1998 | null | null | HEPHY-PUB 696/98, UWThPh-1998-33 | hep-ph hep-lat hep-th | null | These lectures contain an introduction to the following topics: 1)
Phenomenology of the hadron spectrum; 2) The static Wilson loop in perturbative
and in lattice QCD. Confinement and the flux tube formation; 3) Non static
properties: effective field theories and relativistic corrections to the
quarkonium potential; 4) The QCD vacuum: minimal area law, Abelian projection
and dual Meissner effect, stochastic vacuum.
| [
{
"created": "Wed, 14 Apr 1999 15:07:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Brambilla",
"Nora",
"",
"U. Vienna"
],
[
"Vairo",
"Antonio",
"",
"HEPHY, Vienna"
]
] | These lectures contain an introduction to the following topics: 1) Phenomenology of the hadron spectrum; 2) The static Wilson loop in perturbative and in lattice QCD. Confinement and the flux tube formation; 3) Non static properties: effective field theories and relativistic corrections to the quarkonium potential; 4) The QCD vacuum: minimal area law, Abelian projection and dual Meissner effect, stochastic vacuum. |
2004.14852 | Wolfgang Hollik | Wolfgang Gregor Hollik, Cheng Li, Gudrid Moortgat-Pick, Steven Paasch | Phenomenology of a Supersymmetric Model Inspired by Inflation | 21 pages, 10 figures; v2 matches published version | The European Physical Journal C volume 81, Article number: 141
(2021) | 10.1140/epjc/s10052-021-08869-4 | DESY-20-059, TTP-2020-017, P3H-20-013 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The current challenges in High Energy Physics and Cosmology are to build
coherent particle physics models to describe the phenomenology at colliders in
the laboratory and the observations in the universe. From these observations,
the existence of an inflationary phase in the early universe gives guidance for
particle physics models. We study a supersymmetric model which incorporates
successfully inflation by a non-minimal coupling to supergravity and shows a
unique collider phenomenology. Motivated by experimental data, we set a special
emphasis on a new singlet-like state at 97 GeV and single out possible
observables for a future linear collider that permit a distinction of the model
from a similar scenario without inflation. We define a benchmark scenario that
is in agreement with current collider and Dark Matter constraints, and study
the influence of the non-minimal coupling on the phenomenology. Measuring the
singlet-like state with high precision on the percent level seems to be
promising for resolving the models, even though the Standard Model-like Higgs
couplings deviate only marginally. However, a hypothetical singlet-like state
with couplings of about 20% compared to a Standard Model Higgs at 97 GeV
encourages further studies of such footprint scenarios of inflation.
| [
{
"created": "Thu, 30 Apr 2020 15:05:20 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Feb 2021 09:39:14 GMT",
"version": "v2"
}
] | 2021-02-11 | [
[
"Hollik",
"Wolfgang Gregor",
""
],
[
"Li",
"Cheng",
""
],
[
"Moortgat-Pick",
"Gudrid",
""
],
[
"Paasch",
"Steven",
""
]
] | The current challenges in High Energy Physics and Cosmology are to build coherent particle physics models to describe the phenomenology at colliders in the laboratory and the observations in the universe. From these observations, the existence of an inflationary phase in the early universe gives guidance for particle physics models. We study a supersymmetric model which incorporates successfully inflation by a non-minimal coupling to supergravity and shows a unique collider phenomenology. Motivated by experimental data, we set a special emphasis on a new singlet-like state at 97 GeV and single out possible observables for a future linear collider that permit a distinction of the model from a similar scenario without inflation. We define a benchmark scenario that is in agreement with current collider and Dark Matter constraints, and study the influence of the non-minimal coupling on the phenomenology. Measuring the singlet-like state with high precision on the percent level seems to be promising for resolving the models, even though the Standard Model-like Higgs couplings deviate only marginally. However, a hypothetical singlet-like state with couplings of about 20% compared to a Standard Model Higgs at 97 GeV encourages further studies of such footprint scenarios of inflation. |
hep-ph/9902434 | Tilman Plehn | Tilman Plehn, David Rainwater, and Dieter Zeppenfeld (University of
Wisconsin, Madison) | Probing the MSSM Higgs Sector via Weak Boson Fusion at the LHC | 8 pages, LaTeX2e, RevTeX3.1, 4 figures included | Phys.Lett.B454:297-303,1999 | 10.1016/S0370-2693(99)00408-6 | MADPH-99-1101 | hep-ph hep-ex | null | In the MSSM weak boson fusion produces the two CP even Higgs bosons with a
combined strength equivalent to the production of the Standard Model Higgs
boson. The tau tau decay mode --- supplemented by gamma gamma --- provides a
highly significant signal for at least one of the CP even Higgs bosons at the
LHC with reasonable luminosity. The accessible parameter space covers the
entire physical range which will be left unexplored by LEP2.
| [
{
"created": "Tue, 23 Feb 1999 00:09:30 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Plehn",
"Tilman",
"",
"University of\n Wisconsin, Madison"
],
[
"Rainwater",
"David",
"",
"University of\n Wisconsin, Madison"
],
[
"Zeppenfeld",
"Dieter",
"",
"University of\n Wisconsin, Madison"
]
] | In the MSSM weak boson fusion produces the two CP even Higgs bosons with a combined strength equivalent to the production of the Standard Model Higgs boson. The tau tau decay mode --- supplemented by gamma gamma --- provides a highly significant signal for at least one of the CP even Higgs bosons at the LHC with reasonable luminosity. The accessible parameter space covers the entire physical range which will be left unexplored by LEP2. |
2301.06748 | Benjamin Rien\"acker | Benjamin Rien\"acker | Antimatter Research: Advances of AEgIS | Presented at the Ninth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, May 17-26, 2022 | null | null | null | hep-ph physics.atom-ph | http://creativecommons.org/licenses/by/4.0/ | The AEgIS collaboration is underway to directly measure the gravitational
free-fall of neutral antimatter atoms. The experiment recently succeded in
producing a pulsed cold antihydrogen source for the first time, and has now
entered into its second phase, which aims at the formation of a slow
antihydrogen beam and subseuqently a first proof-of-concept gravitational
measurement. Major upgrades have been made, such as an improved antihydrogen
production scheme and a new state-of-the-art antiproton trap. AEgIS was also
connected to CERN's new antiproton deceleration facility ELENA and achieved
first antiproton catching in late 2021.
| [
{
"created": "Tue, 17 Jan 2023 08:18:43 GMT",
"version": "v1"
}
] | 2023-01-18 | [
[
"Rienäcker",
"Benjamin",
""
]
] | The AEgIS collaboration is underway to directly measure the gravitational free-fall of neutral antimatter atoms. The experiment recently succeded in producing a pulsed cold antihydrogen source for the first time, and has now entered into its second phase, which aims at the formation of a slow antihydrogen beam and subseuqently a first proof-of-concept gravitational measurement. Major upgrades have been made, such as an improved antihydrogen production scheme and a new state-of-the-art antiproton trap. AEgIS was also connected to CERN's new antiproton deceleration facility ELENA and achieved first antiproton catching in late 2021. |
hep-ph/9303268 | null | D. Atwood G. Eilam A. Soni | Transverse Tau Polarization in Decays of the Top and Bottom Quarks in
the Weinberg Model of CP Non-conservation | 11,1 figure, SLAC-PUB-6083 | Phys.Rev.Lett.71:492-495,1993 | 10.1103/PhysRevLett.71.492 | null | hep-ph | null | We show that the transverse polarization asymmetry of the $\tau$-lepton in
the decay $t\rightarrow b \tau \nu$ is extremely sensitive to CP violating
phases arising from the charged Higgs exchange in the Weinberg model of CP
non-conservation. Qualitatively, the polarization asymmetries are enhanced over
rate or energy asymmetries by a factor of $\approx {m_t\over m_\tau}\approx
O(100)$. Thus for optimal values of the parameters the method requires $\approx
10^4$ top pairs to be observable rather than $10^7$ needed for rate or energy
asymmetries. We also examine $\tau$ polarization in b decays via $b \rightarrow
c \nu \tau$ and find that it can also be very effective in constraining the CP
violation parameters of the extended Higgs sector.
| [
{
"created": "Tue, 16 Mar 1993 22:16:00 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Soni",
"D. Atwood G. Eilam A.",
""
]
] | We show that the transverse polarization asymmetry of the $\tau$-lepton in the decay $t\rightarrow b \tau \nu$ is extremely sensitive to CP violating phases arising from the charged Higgs exchange in the Weinberg model of CP non-conservation. Qualitatively, the polarization asymmetries are enhanced over rate or energy asymmetries by a factor of $\approx {m_t\over m_\tau}\approx O(100)$. Thus for optimal values of the parameters the method requires $\approx 10^4$ top pairs to be observable rather than $10^7$ needed for rate or energy asymmetries. We also examine $\tau$ polarization in b decays via $b \rightarrow c \nu \tau$ and find that it can also be very effective in constraining the CP violation parameters of the extended Higgs sector. |
1210.0500 | Mohammadmehdi Ettefaghi | M. M. Ettefaghi | Two-photon annihilation of singlet cold dark matters due to
noncommutative space-time | 14 pages, 1 figure: version to appear in PRD | null | 10.1103/PhysRevD.86.085038 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Detecting the cosmic rays, in particular gamma-ray, coming from the dark
matter annihilation or decay is an indirect way to survey the nature of the
dark matter. In the commutative space-time, the annihilation of the dark matter
candidates (WIMPs) to photons proceeds through loop corrections. However, it is
possible for WIMPs as well as the other standard model singlet particles to
couple with photons directly in the noncommutative space-time. In this paper,
we study two-photon annihilation of singlet WIMPs in the noncommutative
space-time. If the noncommutative interactions are relevant to the relic
abundance, one can exclude some dark matter masses using Fermi-Lat data.
| [
{
"created": "Mon, 1 Oct 2012 18:42:50 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Ettefaghi",
"M. M.",
""
]
] | Detecting the cosmic rays, in particular gamma-ray, coming from the dark matter annihilation or decay is an indirect way to survey the nature of the dark matter. In the commutative space-time, the annihilation of the dark matter candidates (WIMPs) to photons proceeds through loop corrections. However, it is possible for WIMPs as well as the other standard model singlet particles to couple with photons directly in the noncommutative space-time. In this paper, we study two-photon annihilation of singlet WIMPs in the noncommutative space-time. If the noncommutative interactions are relevant to the relic abundance, one can exclude some dark matter masses using Fermi-Lat data. |
hep-ph/0506150 | Daniel de Florian | Daniel de Florian and Werner Vogelsang | Threshold resummation for the prompt-photon cross section revisited | 12 pages, 5 figures | Phys.Rev. D72 (2005) 014014 | 10.1103/PhysRevD.72.014014 | BNL-NT-05/20 and RBRC-527 | hep-ph | null | We study the resummation of large logarithmic perturbative corrections to the
partonic cross sections relevant for the process pp->gamma X at high transverse
momentum of the photon.These corrections arise near the threshold for the
partonic reaction and are associated with soft-gluon emission. We especially
focus on the resummation effects for the contribution to the cross section
where the photon is produced in jet fragmentation. Previous calculations in
perturbation theory at fixed-order have established that this contribution is a
subdominant part of the cross section. We find, however, that it is subject to
much larger resummation effects than the direct (non-fragmentation) piece and
therefore appears to be a significant contribution in the fixed-target regime,
not much suppressed with respect to the direct part. Inclusion of threshold
resummation for the fragmentation piece leads to some improvement in
comparisons between theoretical calculations and experimental data.
| [
{
"created": "Wed, 15 Jun 2005 18:37:09 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"de Florian",
"Daniel",
""
],
[
"Vogelsang",
"Werner",
""
]
] | We study the resummation of large logarithmic perturbative corrections to the partonic cross sections relevant for the process pp->gamma X at high transverse momentum of the photon.These corrections arise near the threshold for the partonic reaction and are associated with soft-gluon emission. We especially focus on the resummation effects for the contribution to the cross section where the photon is produced in jet fragmentation. Previous calculations in perturbation theory at fixed-order have established that this contribution is a subdominant part of the cross section. We find, however, that it is subject to much larger resummation effects than the direct (non-fragmentation) piece and therefore appears to be a significant contribution in the fixed-target regime, not much suppressed with respect to the direct part. Inclusion of threshold resummation for the fragmentation piece leads to some improvement in comparisons between theoretical calculations and experimental data. |
0912.4361 | Walter Grimus | W. Grimus, L. Lavoura | TeV-scale seesaw mechanism catalyzed by the electron mass | 13 pages, one figure, matches published version | Phys.Lett.B687:188-193,2010 | 10.1016/j.physletb.2010.03.025 | UWThPh-2009-16, CFTP/09-041 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct a model in which the neutrino Dirac mass terms are of order the
electron mass and the seesaw mechanism proceeds via right-handed neutrinos with
masses of order TeV. In our model the spectra of the three light and of the
three heavy neutrinos are closely related. Since the mixing between light and
heavy neutrinos is small, the model predicts no effects in pp and p \bar p
colliders. Possible signatures of the model are the lepton-number-violating
process e- e- --> H- H-, where H- is a charged scalar particle,
lepton-flavour-violating decays like mu- --> e- e+ e-, or a sizable
contribution to the anomalous magnetic dipole moment of the muon.
| [
{
"created": "Tue, 22 Dec 2009 10:45:48 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Feb 2010 17:38:39 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Jul 2010 15:36:25 GMT",
"version": "v3"
}
] | 2010-07-20 | [
[
"Grimus",
"W.",
""
],
[
"Lavoura",
"L.",
""
]
] | We construct a model in which the neutrino Dirac mass terms are of order the electron mass and the seesaw mechanism proceeds via right-handed neutrinos with masses of order TeV. In our model the spectra of the three light and of the three heavy neutrinos are closely related. Since the mixing between light and heavy neutrinos is small, the model predicts no effects in pp and p \bar p colliders. Possible signatures of the model are the lepton-number-violating process e- e- --> H- H-, where H- is a charged scalar particle, lepton-flavour-violating decays like mu- --> e- e+ e-, or a sizable contribution to the anomalous magnetic dipole moment of the muon. |
hep-ph/0209086 | Sorina Lazanu | I. Lazanu and S. Lazanu | Long-term damage induced by hadrons in silicon detectors for uses at the
LHC-accelerator and in space missions | 13 pages, 4 figures, submitted to Physica Scripta, place of the last
figure changed | Phys.Scripta 67 (2003) 388-394 | 10.1238/Physica.Regular.067a00388 | null | hep-ph astro-ph hep-ex | null | In the present paper, the phenomenological model developed by the authors in
previous papers has been used to evaluate the degradation induced by hadron
irradiation at the future accelerator facilities or by cosmic protons in high
resistivity silicon detectors. The damage has been analysed at the microscopic
(defects production and their evolution toward equilibrium) and at the
macroscopic level (changes in the leakage current of the p-n junction). The
rates of production of primary defects, as well as their evolution toward
equilibrium have been evaluated considering explicitly the type of the
projectile particle and its energy. Vacancy-interstitial annihilation,
interstitial migration to sink, complex (VP, VO, CiOi, CiCs) and divacancy
formation are taken into account for different initial silicon material. The
influence of these defects on the leakage detector current has been calculated
in the frame of the Schokley-Read-Hall model.
| [
{
"created": "Mon, 9 Sep 2002 06:02:09 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Sep 2002 07:23:44 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Lazanu",
"I.",
""
],
[
"Lazanu",
"S.",
""
]
] | In the present paper, the phenomenological model developed by the authors in previous papers has been used to evaluate the degradation induced by hadron irradiation at the future accelerator facilities or by cosmic protons in high resistivity silicon detectors. The damage has been analysed at the microscopic (defects production and their evolution toward equilibrium) and at the macroscopic level (changes in the leakage current of the p-n junction). The rates of production of primary defects, as well as their evolution toward equilibrium have been evaluated considering explicitly the type of the projectile particle and its energy. Vacancy-interstitial annihilation, interstitial migration to sink, complex (VP, VO, CiOi, CiCs) and divacancy formation are taken into account for different initial silicon material. The influence of these defects on the leakage detector current has been calculated in the frame of the Schokley-Read-Hall model. |
hep-ph/9401205 | Kim Milton | Dean Miller, Kimball A. Milton, and Stephan Siegemund-Broka | Finite-element quantum electrodynamics. II. Lattice propagators, current
commutators, and axial-vector anomalies | 19 pages, REVTex, 4 figures. REVISED (Major changes in Section 3, on
the small h expansion of the anomalies, and in the addition of an Appendix,
discussing the nonlocal current derived from a Euclidean action. Figures are
unchanged.) | null | null | OKHEP-93-11 | hep-ph | null | We apply the finite-element lattice equations of motion for quantum
electrodynamics given in the first paper in this series to examine anomalies in
the current operators. By taking explicit lattice divergences of the vector and
axial-vector currents we compute the vector and axial-vector anomalies in two
and four dimensions. We examine anomalous commutators of the currents to
compute divergent and finite Schwinger terms. And, using free lattice
propagators, we compute the vacuum polarization in two dimensions and hence the
anomaly in the Schwinger model. A discussion of our choice of gauge-invariant
current is provided.
| [
{
"created": "Mon, 3 Jan 1994 22:23:51 GMT",
"version": "v1"
},
{
"created": "Tue, 24 May 1994 08:05:55 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Miller",
"Dean",
""
],
[
"Milton",
"Kimball A.",
""
],
[
"Siegemund-Broka",
"Stephan",
""
]
] | We apply the finite-element lattice equations of motion for quantum electrodynamics given in the first paper in this series to examine anomalies in the current operators. By taking explicit lattice divergences of the vector and axial-vector currents we compute the vector and axial-vector anomalies in two and four dimensions. We examine anomalous commutators of the currents to compute divergent and finite Schwinger terms. And, using free lattice propagators, we compute the vacuum polarization in two dimensions and hence the anomaly in the Schwinger model. A discussion of our choice of gauge-invariant current is provided. |
1512.05611 | Christopher Harman Mr | Christopher P. D. Harman and Stephan J. Huber | Does zero temperature decide on the nature of the electroweak phase
transition? | Published version | JHEP06(2016)005 | 10.1007/JHEP06(2016)005 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Taking on a new perspective of the electroweak phase transition, we
investigate in detail the role played by the depth of the electroweak minimum
("vacuum energy difference"). We find a strong correlation between the vacuum
energy difference and the strength of the phase transition. This correlation
only breaks down if a negative eigenvalue develops upon thermal corrections in
the squared scalar mass matrix in the broken vacuum before the critical
temperature. As a result the scalar fields slide across field space toward the
symmetric vacuum, often causing a significantly weakened phase transition.
Phenomenological constraints are found to strongly disfavour such sliding
scalar scenarios. For several popular models, we suggest numerical bounds that
guarantee a strong first order electroweak phase transition. The zero
temperature phenomenology can then be studied in these parameter regions
without the need for any finite temperature calculations. For almost all
non-supersymmetric models with phenomenologically viable parameter points, we
find a strong phase transition is guaranteed if the vacuum energy difference is
greater than $-8.8\times 10^7$~\text{GeV}$^4$. For the GNMSSM, we guarantee a
strong phase transition for phenomenologically viable parameter points if the
vacuum energy difference is greater than $-6.9\times 10^7$~\text{GeV}$^4$.
Alternatively, we capture more of the parameter space exhibiting a strong phase
transition if we impose a simultaneous bound on the vacuum energy difference
and the singlet mass.
| [
{
"created": "Thu, 17 Dec 2015 14:48:56 GMT",
"version": "v1"
},
{
"created": "Sat, 18 Jun 2016 19:57:20 GMT",
"version": "v2"
}
] | 2016-06-21 | [
[
"Harman",
"Christopher P. D.",
""
],
[
"Huber",
"Stephan J.",
""
]
] | Taking on a new perspective of the electroweak phase transition, we investigate in detail the role played by the depth of the electroweak minimum ("vacuum energy difference"). We find a strong correlation between the vacuum energy difference and the strength of the phase transition. This correlation only breaks down if a negative eigenvalue develops upon thermal corrections in the squared scalar mass matrix in the broken vacuum before the critical temperature. As a result the scalar fields slide across field space toward the symmetric vacuum, often causing a significantly weakened phase transition. Phenomenological constraints are found to strongly disfavour such sliding scalar scenarios. For several popular models, we suggest numerical bounds that guarantee a strong first order electroweak phase transition. The zero temperature phenomenology can then be studied in these parameter regions without the need for any finite temperature calculations. For almost all non-supersymmetric models with phenomenologically viable parameter points, we find a strong phase transition is guaranteed if the vacuum energy difference is greater than $-8.8\times 10^7$~\text{GeV}$^4$. For the GNMSSM, we guarantee a strong phase transition for phenomenologically viable parameter points if the vacuum energy difference is greater than $-6.9\times 10^7$~\text{GeV}$^4$. Alternatively, we capture more of the parameter space exhibiting a strong phase transition if we impose a simultaneous bound on the vacuum energy difference and the singlet mass. |
0904.3823 | James P. Kneller | James P. Kneller, Gail C. McLaughlin | Three Flavor Neutrino Oscillations in Matter: Flavor Diagonal
Potentials, the Adiabatic Basis and the CP phase | null | Phys.Rev.D80:053002,2009 | 10.1103/PhysRevD.80.053002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the three neutrino flavor evolution problem with general,
flavor-diagonal, matter potentials and a fully parameterized mixing matrix that
includes CP violation, and derive expressions for the eigenvalues, mixing
angles and phases. We demonstrate that, in the limit that the mu and tau
potentials are equal, the eigenvalues and matter mixing angles theta_12 and
theta_13 are independent of the CP phase, although theta_23 does have CP
dependence. Since we are interested in developing a framework that can be used
for S matrix calculations of neutrino flavor transformation, it is useful to
work in a basis that contains only off-diagonal entries in the Hamiltonian. We
derive the "non-adiabaticity" parameters that appear in the Hamiltonian in this
basis. We then introduce the neutrino S matrix, derive its evolution equation
and the integral solution. We find that this new Hamiltonian, and therefore the
S matrix, in the limit that the mu and tau neutrino potentials are the same, is
independent of both theta_23 and the CP violating phase. In this limit, any CP
violation in the flavor basis can only be introduced via the rotation matrices,
and so effects which derive from the CP phase are then straightforward to
determine. We show explicitly that the electron neutrino and electron
antineutrino survival probability is independent of the CP phase in this limit.
Conversely, if the CP phase is nonzero and mu and tau matter potentials are not
equal, then the electron neutrino survival probability cannot be independent of
the CP phase.
| [
{
"created": "Fri, 24 Apr 2009 09:24:14 GMT",
"version": "v1"
}
] | 2009-10-13 | [
[
"Kneller",
"James P.",
""
],
[
"McLaughlin",
"Gail C.",
""
]
] | We discuss the three neutrino flavor evolution problem with general, flavor-diagonal, matter potentials and a fully parameterized mixing matrix that includes CP violation, and derive expressions for the eigenvalues, mixing angles and phases. We demonstrate that, in the limit that the mu and tau potentials are equal, the eigenvalues and matter mixing angles theta_12 and theta_13 are independent of the CP phase, although theta_23 does have CP dependence. Since we are interested in developing a framework that can be used for S matrix calculations of neutrino flavor transformation, it is useful to work in a basis that contains only off-diagonal entries in the Hamiltonian. We derive the "non-adiabaticity" parameters that appear in the Hamiltonian in this basis. We then introduce the neutrino S matrix, derive its evolution equation and the integral solution. We find that this new Hamiltonian, and therefore the S matrix, in the limit that the mu and tau neutrino potentials are the same, is independent of both theta_23 and the CP violating phase. In this limit, any CP violation in the flavor basis can only be introduced via the rotation matrices, and so effects which derive from the CP phase are then straightforward to determine. We show explicitly that the electron neutrino and electron antineutrino survival probability is independent of the CP phase in this limit. Conversely, if the CP phase is nonzero and mu and tau matter potentials are not equal, then the electron neutrino survival probability cannot be independent of the CP phase. |
1612.09224 | Sudip Jana | K.S. Babu, Sudip Jana | Probing Doubly Charged Higgs Bosons at the LHC through Photon Initiated
Processes | 20 Pages, 11 Figures | Phys. Rev. D 95, 055020 (2017) | 10.1103/PhysRevD.95.055020 | OSU-HEP-16-11 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that the photon-photon fusion process contributes significantly to
the pair production of doubly charged Higgs bosons at the LHC at a level
comparable to the Drell-Yan production. We reinterpret the ATLAS lower limit of
570 GeV (420 GeV) on the mass of $\Delta_{L}^{\pm\pm}$ ($\Delta_{R}^{\pm\pm}$)
arising from $SU(2)_L$ triplet (singlet) scalar by including the photon
initiated process and derive a new lower limit of 748 GeV (570 GeV), assuming
that $\Delta^{\pm \pm}$ decays into $e^\pm e^\pm$ 100% of the time. We have
also shown that the 5$\sigma$ discovery reach for ${\Delta_{L}^{\pm\pm}}$
(${\Delta_{R}^{\pm\pm}}$) is 846 GeV (783 GeV) with 100 fb$^{-1}$ luminosity at
13 TeV LHC. We derive a somewhat more stringent limit on the mass when the
doubly charged scalar arises from higher dimensional representations of
$SU(2)_L$.
| [
{
"created": "Thu, 29 Dec 2016 18:03:48 GMT",
"version": "v1"
}
] | 2017-03-29 | [
[
"Babu",
"K. S.",
""
],
[
"Jana",
"Sudip",
""
]
] | We show that the photon-photon fusion process contributes significantly to the pair production of doubly charged Higgs bosons at the LHC at a level comparable to the Drell-Yan production. We reinterpret the ATLAS lower limit of 570 GeV (420 GeV) on the mass of $\Delta_{L}^{\pm\pm}$ ($\Delta_{R}^{\pm\pm}$) arising from $SU(2)_L$ triplet (singlet) scalar by including the photon initiated process and derive a new lower limit of 748 GeV (570 GeV), assuming that $\Delta^{\pm \pm}$ decays into $e^\pm e^\pm$ 100% of the time. We have also shown that the 5$\sigma$ discovery reach for ${\Delta_{L}^{\pm\pm}}$ (${\Delta_{R}^{\pm\pm}}$) is 846 GeV (783 GeV) with 100 fb$^{-1}$ luminosity at 13 TeV LHC. We derive a somewhat more stringent limit on the mass when the doubly charged scalar arises from higher dimensional representations of $SU(2)_L$. |
0806.1235 | Markus A. Luty | Markus A. Luty | Strong Conformal Dynamics at the LHC and on the Lattice | v2: Generalized discussion of lattice measurement of hadron masses,
references added, minor clarifications v3: references added, minor changes | JHEP 0904:050,2009 | 10.1088/1126-6708/2009/04/050 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Conformal technicolor is a paradigm for new physics at LHC that may solve the
problems of strong electroweak symmetry breaking for quark masses and precision
electroweak data. We give explicit examples of conformal technicolor theories
based on a QCD-like sector. We suggest a practical method to test the conformal
dynamics of these theories on the lattice.
| [
{
"created": "Fri, 6 Jun 2008 21:08:53 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Feb 2009 18:48:55 GMT",
"version": "v2"
},
{
"created": "Fri, 27 Mar 2009 16:47:57 GMT",
"version": "v3"
}
] | 2009-04-17 | [
[
"Luty",
"Markus A.",
""
]
] | Conformal technicolor is a paradigm for new physics at LHC that may solve the problems of strong electroweak symmetry breaking for quark masses and precision electroweak data. We give explicit examples of conformal technicolor theories based on a QCD-like sector. We suggest a practical method to test the conformal dynamics of these theories on the lattice. |
1408.3107 | Stefano Di Vita | Stefano Di Vita, Pierpaolo Mastrolia, Ulrich Schubert and Valery
Yundin | Three-loop master integrals for ladder-box diagrams with one massive leg | 44 pages, 5 figures, 2 ancillary files | null | 10.1007/JHEP09(2014)148 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The three-loop master integrals for ladder-box diagrams with one massive leg
are computed from an eighty-five by eighty-five system of differential
equations, solved by means of Magnus exponential. The results of the considered
box-type integrals, as well as of the tower of vertex- and bubble-type master
integrals associated to subtopologies, are given as a Taylor series expansion
in the dimensional regulator parameter epsilon = (4-d)/2. The coefficients of
the series are expressed in terms of uniform weight combinations of multiple
polylogarithms and transcendental constants up to weight six. The considered
integrals enter the next-to-next-to-next-to-leading order virtual corrections
to scattering processes like the three-jet production mediated by vector boson
decay, V* -> jjj, as well as the Higgs plus one-jet production in gluon fusion,
pp -> Hj.
| [
{
"created": "Wed, 13 Aug 2014 19:57:37 GMT",
"version": "v1"
}
] | 2015-06-22 | [
[
"Di Vita",
"Stefano",
""
],
[
"Mastrolia",
"Pierpaolo",
""
],
[
"Schubert",
"Ulrich",
""
],
[
"Yundin",
"Valery",
""
]
] | The three-loop master integrals for ladder-box diagrams with one massive leg are computed from an eighty-five by eighty-five system of differential equations, solved by means of Magnus exponential. The results of the considered box-type integrals, as well as of the tower of vertex- and bubble-type master integrals associated to subtopologies, are given as a Taylor series expansion in the dimensional regulator parameter epsilon = (4-d)/2. The coefficients of the series are expressed in terms of uniform weight combinations of multiple polylogarithms and transcendental constants up to weight six. The considered integrals enter the next-to-next-to-next-to-leading order virtual corrections to scattering processes like the three-jet production mediated by vector boson decay, V* -> jjj, as well as the Higgs plus one-jet production in gluon fusion, pp -> Hj. |
hep-ph/0501149 | St\'ephane Munier | S. Munier (Ecole Polytechnique and Florence University) | High energy scattering in QCD as a statistical process | 4 pages, 2 figures; talk presented at Baryons 2004, Palaiseau,
France, October 2004 | Nucl.Phys. A755 (2005) 622-625 | 10.1016/j.nuclphysa.2005.03.106 | CPHT-PC-091.1204 | hep-ph | null | The scattering of two hadronic objects at high energy is similar to a
reaction-diffusion process described by the stochastic Fisher-Kolmogorov
equation. This basic observation enables us to derive universal properties of
the scattering amplitudes in a straightforward way, by borrowing some general
results from statistical physics.
| [
{
"created": "Mon, 17 Jan 2005 09:08:41 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Munier",
"S.",
"",
"Ecole Polytechnique and Florence University"
]
] | The scattering of two hadronic objects at high energy is similar to a reaction-diffusion process described by the stochastic Fisher-Kolmogorov equation. This basic observation enables us to derive universal properties of the scattering amplitudes in a straightforward way, by borrowing some general results from statistical physics. |
1601.05004 | Arlene Cristina Aguilar | C. T. Figueiredo and A. C. Aguilar | Mass generation and the problem of seagull divergences | Proceedings of the Workshop "XIII International Workshop on Hadron
Physics", 22-27 March 2015, Angra dos Reis - RJ, Brazil. 8 pages, 4 figures | null | 10.1088/1742-6596/706/5/052007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The gluon mass generation is a purely non-perturbative effect, and the
natural framework to study it in the continuum are the Schwinger-Dyson
equations (SDEs) of the theory. At the level of the SDEs the generation of such
a mass is associated with the existence of infrared finite solutions for the
gluon propagator. From the theoretical point of view, the dynamical gluon mass
generation has been traditionally plagued with seagull divergences. In this
work, we will review how such divergences can be eliminated completely by
virtue of a characteristic identity, valid in dimensional regularization. As a
pedagogical example, we will first discuss in the context of scalar QED how it
is possible to eliminate all seagull divergences, by triggering the
aforementioned special identity, which enforces the masslessness of the photon.
Then, we will discuss what happens in QCD and present an Ansatz for the three
gluon vertex, which completely eliminates all seagull divergences and at same
time allows for the possibility of a dynamical gluon mass generation.
| [
{
"created": "Tue, 19 Jan 2016 17:23:42 GMT",
"version": "v1"
}
] | 2016-06-22 | [
[
"Figueiredo",
"C. T.",
""
],
[
"Aguilar",
"A. C.",
""
]
] | The gluon mass generation is a purely non-perturbative effect, and the natural framework to study it in the continuum are the Schwinger-Dyson equations (SDEs) of the theory. At the level of the SDEs the generation of such a mass is associated with the existence of infrared finite solutions for the gluon propagator. From the theoretical point of view, the dynamical gluon mass generation has been traditionally plagued with seagull divergences. In this work, we will review how such divergences can be eliminated completely by virtue of a characteristic identity, valid in dimensional regularization. As a pedagogical example, we will first discuss in the context of scalar QED how it is possible to eliminate all seagull divergences, by triggering the aforementioned special identity, which enforces the masslessness of the photon. Then, we will discuss what happens in QCD and present an Ansatz for the three gluon vertex, which completely eliminates all seagull divergences and at same time allows for the possibility of a dynamical gluon mass generation. |
0908.0822 | Zhi-Zhong Xing | Aik Hui Chan, Hwee Boon Low, Zhi-zhong Xing | Friedberg-Lee symmetry and tri-bimaximal neutrino mixing in the inverse
seesaw mechanism | RevTeX 16 pages. Minor changes. Accepted for publication in Phys.
Rev. D | Phys.Rev.D80:073006,2009 | 10.1103/PhysRevD.80.073006 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The inverse seesaw mechanism with three pairs of gauge-singlet neutrinos
offers a natural interpretation of the tiny masses of three active neutrinos at
the TeV scale. We combine this picture with the newly-proposed Friedberg-Lee
(FL) symmetry in order to understand the observed pattern of neutrino mixing.
We show that the FL symmetry requires only two pairs of the gauge-singlet
neutrinos to be massive, implying that one active neutrino must be massless. We
propose a phenomenological ansatz with broken FL symmetry and exact \mu-\tau
symmetry in the gauge-singlet neutrino sector and obtain the tri-bimaximal
neutrino mixing pattern by means of the inverse seesaw relation. We demonstrate
that non-unitary corrections to this result are possible to reach the percent
level and a soft breaking of \mu-\tau symmetry can give rise to CP violation in
such a TeV-scale seesaw scenario.
| [
{
"created": "Thu, 6 Aug 2009 09:14:20 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Sep 2009 11:30:38 GMT",
"version": "v2"
}
] | 2009-10-29 | [
[
"Chan",
"Aik Hui",
""
],
[
"Low",
"Hwee Boon",
""
],
[
"Xing",
"Zhi-zhong",
""
]
] | The inverse seesaw mechanism with three pairs of gauge-singlet neutrinos offers a natural interpretation of the tiny masses of three active neutrinos at the TeV scale. We combine this picture with the newly-proposed Friedberg-Lee (FL) symmetry in order to understand the observed pattern of neutrino mixing. We show that the FL symmetry requires only two pairs of the gauge-singlet neutrinos to be massive, implying that one active neutrino must be massless. We propose a phenomenological ansatz with broken FL symmetry and exact \mu-\tau symmetry in the gauge-singlet neutrino sector and obtain the tri-bimaximal neutrino mixing pattern by means of the inverse seesaw relation. We demonstrate that non-unitary corrections to this result are possible to reach the percent level and a soft breaking of \mu-\tau symmetry can give rise to CP violation in such a TeV-scale seesaw scenario. |
1402.7081 | Martin Hoferichter | Gilberto Colangelo, Martin Hoferichter, Massimiliano Procura, Peter
Stoffer | Dispersive approach to hadronic light-by-light scattering | 33 pages, 4 figures; version accepted for publication in JHEP,
improved presentation, including non-diagonal kernels for the S-waves | null | 10.1007/JHEP09(2014)091 | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Based on dispersion theory, we present a formalism for a model-independent
evaluation of the hadronic light-by-light contribution to the anomalous
magnetic moment of the muon. In particular, we comment on the definition of the
pion pole in this framework and provide a master formula that relates the
effect from pi pi intermediate states to the partial waves for the process
gamma^* gamma^* --> pi pi. All contributions are expressed in terms of on-shell
form factors and scattering amplitudes, and as such amenable to an experimental
determination.
| [
{
"created": "Thu, 27 Feb 2014 21:00:22 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Aug 2014 10:20:24 GMT",
"version": "v2"
}
] | 2015-06-18 | [
[
"Colangelo",
"Gilberto",
""
],
[
"Hoferichter",
"Martin",
""
],
[
"Procura",
"Massimiliano",
""
],
[
"Stoffer",
"Peter",
""
]
] | Based on dispersion theory, we present a formalism for a model-independent evaluation of the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. In particular, we comment on the definition of the pion pole in this framework and provide a master formula that relates the effect from pi pi intermediate states to the partial waves for the process gamma^* gamma^* --> pi pi. All contributions are expressed in terms of on-shell form factors and scattering amplitudes, and as such amenable to an experimental determination. |
hep-ph/9806335 | Per Elmfors | Per Elmfors and David Persson | Stability of large scale chromomagnetic fields in the early universe | 16 pages, Latex, 1 ps figure, now format | Nucl.Phys. B538 (1999) 309-320 | 10.1016/S0550-3213(98)00627-0 | SUITP-98-9 | hep-ph astro-ph hep-th | null | It is well known that Yang-Mills theory in vacuum has a perturbative
instability to spontaneously form a large scale magnetic field (the Savvidy
mechanism) and that a constant field is unstable so that a possible ground
state has to be inhomogenous over the non-perturbative scale Lambda (the
Copenhagen vacuum). We argue that this spontaneous instability does not occur
at high temperature when the induced field strength gB ~ Lambda^2 is much
weaker than the magnetic mass squared (g^2T)^2. At high temperature
oscillations of gauge fields acquire a thermal mass M ~ gT and we show that
this mass stabilizes a magnetic field which is constant over length scales
shorter than the magnetic screening length (g^2T)^{-1}. We therefore conclude
that there is no indication for any spontaneous generation of weak non-abelian
magnetic fields in the early universe.
| [
{
"created": "Wed, 10 Jun 1998 12:05:49 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Sep 1998 11:33:04 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Elmfors",
"Per",
""
],
[
"Persson",
"David",
""
]
] | It is well known that Yang-Mills theory in vacuum has a perturbative instability to spontaneously form a large scale magnetic field (the Savvidy mechanism) and that a constant field is unstable so that a possible ground state has to be inhomogenous over the non-perturbative scale Lambda (the Copenhagen vacuum). We argue that this spontaneous instability does not occur at high temperature when the induced field strength gB ~ Lambda^2 is much weaker than the magnetic mass squared (g^2T)^2. At high temperature oscillations of gauge fields acquire a thermal mass M ~ gT and we show that this mass stabilizes a magnetic field which is constant over length scales shorter than the magnetic screening length (g^2T)^{-1}. We therefore conclude that there is no indication for any spontaneous generation of weak non-abelian magnetic fields in the early universe. |
1406.5599 | Boris Blankleider | A. N. Kvinikhidze and B. Blankleider | Covariant equations for the tetraquark and more | 17 pages, 8 figures | Phys. Rev. D 90, 045042 (2014) | 10.1103/PhysRevD.90.045042 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive covariant equations for a system of two quarks and two antiquarks
where the effect of quark-antiquark annihilation is taken into account. In our
approach, only pair-wise interactions are retained, while all possibilities of
overcounting are excluded by (i) keeping terms in the kernel that are
consistent with a meson-meson and diquark-antidiquark substructure, and (ii)
introducing 4-body equations with a novel structure that specifically avoids
the generation of overcounted terms. The resulting tetraquark bound state
equations are given for the case of general two-body interactions, and for the
specific case of separable interactions that lead to a description of the
tetraquark in terms of meson-meson and diquark-antidiquark degrees of freedom
where the effects of quark-antiquark annihilation is included. The inclusion of
$2q2\bar{q}$- and $q\bar{q}$-channel coupling in our approach enables a wide
variety of applications of our equations to other processes within the
$2q2\bar{q}$ system, and to other 2-particle plus 2-antiparticle systems.
| [
{
"created": "Sat, 21 Jun 2014 11:33:35 GMT",
"version": "v1"
}
] | 2014-10-06 | [
[
"Kvinikhidze",
"A. N.",
""
],
[
"Blankleider",
"B.",
""
]
] | We derive covariant equations for a system of two quarks and two antiquarks where the effect of quark-antiquark annihilation is taken into account. In our approach, only pair-wise interactions are retained, while all possibilities of overcounting are excluded by (i) keeping terms in the kernel that are consistent with a meson-meson and diquark-antidiquark substructure, and (ii) introducing 4-body equations with a novel structure that specifically avoids the generation of overcounted terms. The resulting tetraquark bound state equations are given for the case of general two-body interactions, and for the specific case of separable interactions that lead to a description of the tetraquark in terms of meson-meson and diquark-antidiquark degrees of freedom where the effects of quark-antiquark annihilation is included. The inclusion of $2q2\bar{q}$- and $q\bar{q}$-channel coupling in our approach enables a wide variety of applications of our equations to other processes within the $2q2\bar{q}$ system, and to other 2-particle plus 2-antiparticle systems. |
1901.09766 | Jean-Philippe Lansberg | Yu Feng, Jibo He, Jean-Philippe Lansberg, Hua-Sheng Shao, Andrii
Usachov, Hong-Fei Zhang | Phenomenological NLO analysis of eta(c) production at the LHC in the
collider and fixed-target modes | 10 pages, 4 figures, 1 table, LaTeX uses elsarticle | null | 10.1016/j.nuclphysb.2019.114662 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In view of the good agreement between the LHCb prompt-eta(c) data at
sqrt(s)=7 and 8 TeV and the NLO colour-singlet model predictions --i.e. the
leading v^2 NRQCD contribution--, we provide predictions in the LHCb acceptance
for the forthcoming 13 TeV analysis bearing on data taken during the LHC Run2.
We also provide predictions for sqrt(s)=115 GeV for proton-hydrogen collisions
in the fixed-target mode which could be studied during the LHC Run3. Our
predictions are complemented by a full theoretical uncertainty analysis. In
addition to cross section predictions, we elaborate on the uncertainties on the
p bar-p branching ratio --necessary for data-theory comparison-- and discuss
other usable branching fractions for future studies.
| [
{
"created": "Mon, 28 Jan 2019 16:13:54 GMT",
"version": "v1"
}
] | 2019-06-26 | [
[
"Feng",
"Yu",
""
],
[
"He",
"Jibo",
""
],
[
"Lansberg",
"Jean-Philippe",
""
],
[
"Shao",
"Hua-Sheng",
""
],
[
"Usachov",
"Andrii",
""
],
[
"Zhang",
"Hong-Fei",
""
]
] | In view of the good agreement between the LHCb prompt-eta(c) data at sqrt(s)=7 and 8 TeV and the NLO colour-singlet model predictions --i.e. the leading v^2 NRQCD contribution--, we provide predictions in the LHCb acceptance for the forthcoming 13 TeV analysis bearing on data taken during the LHC Run2. We also provide predictions for sqrt(s)=115 GeV for proton-hydrogen collisions in the fixed-target mode which could be studied during the LHC Run3. Our predictions are complemented by a full theoretical uncertainty analysis. In addition to cross section predictions, we elaborate on the uncertainties on the p bar-p branching ratio --necessary for data-theory comparison-- and discuss other usable branching fractions for future studies. |
0912.3156 | Elena Ginina | E. Christova, H. Eberl, E. Ginina | Charged Higgs production at the LHC and CP asymmetries | A contributed talk given by E. Ginina at the 17th International
Conference on Supersymmetry and the Unification of Fundamental Interactions,
SUSY09, June 2009, Boston, US, to appear in the proceedings of the conference | null | 10.1063/1.3327663 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study CP violation in associated production of a charged Higgs boson and a
top quark at the LHC, $pp \to tH^\pm +X$. The asymmetry between the total cross
sections for $H^+$ and $H^-$ production at next-to-leading order in the MSSM is
calculated analytically and a detailed numerical analysis is performed.
Furthermore, subsequent decays of $H^\pm$ to $tb$ and $ \tau^\pm \nu_\tau$ are
considered. In the case with $H^\pm \to tb$ decay the asymmetry can go up to
$\sim$~12%.
| [
{
"created": "Wed, 16 Dec 2009 14:59:10 GMT",
"version": "v1"
}
] | 2015-05-14 | [
[
"Christova",
"E.",
""
],
[
"Eberl",
"H.",
""
],
[
"Ginina",
"E.",
""
]
] | We study CP violation in associated production of a charged Higgs boson and a top quark at the LHC, $pp \to tH^\pm +X$. The asymmetry between the total cross sections for $H^+$ and $H^-$ production at next-to-leading order in the MSSM is calculated analytically and a detailed numerical analysis is performed. Furthermore, subsequent decays of $H^\pm$ to $tb$ and $ \tau^\pm \nu_\tau$ are considered. In the case with $H^\pm \to tb$ decay the asymmetry can go up to $\sim$~12%. |
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