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1509.07727 | Antoni Szczurek | Antoni Szczurek | Exploring double-parton scattering effects for jets with large rapidity
separation and in four-jet production at the LHC | 8 pages, 5 figures a talk presented at the 16th conference on Elastic
and Diffractive Scattering, EDS Blois 2015, Borgo, Corsica, France, June/July
2015 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an estimation of the contribution of double parton scattering
(DPS) for jets widely separated in rapidity and for four-jet sample. In the
case of four-jet production we calculate cross section for both single-parton
scattering (SPS) using the code ALPGEN as well as for DPS in LO collinear
approach. The DPS contribution is calculated within the so-called factorized
Ansatz and each step of DPS is calculated in the LO collinear approximation. We
show that the relative (with respect to SPS dijets and to the BFKL
Mueller-Navelet (MN) jets) contribution of DPS is growing at large rapidity
distance between jets. The calculated differential cross sections as a function
of rapidity distance between the most remote in rapidity jets are compared with
recent results of LL and NLL BFKL calculations for the Mueller-Navelet jet
production at $\sqrt{s} = 7$ TeV. Our results for four-jet sample are compared
with experimental data obtained recently by the CMS collaboration and a rather
good agreement is achieved. We propose to impose different cuts in order to
enhance the relative DPS contribution. The relative DPS contribution increases
when decreasing the lower cut on the jet transverse momenta as well as when a
low lower cut on the rapidity distance between the most remote jets is imposed.
| [
{
"created": "Fri, 25 Sep 2015 14:04:33 GMT",
"version": "v1"
}
] | 2015-09-28 | [
[
"Szczurek",
"Antoni",
""
]
] | We present an estimation of the contribution of double parton scattering (DPS) for jets widely separated in rapidity and for four-jet sample. In the case of four-jet production we calculate cross section for both single-parton scattering (SPS) using the code ALPGEN as well as for DPS in LO collinear approach. The DPS contribution is calculated within the so-called factorized Ansatz and each step of DPS is calculated in the LO collinear approximation. We show that the relative (with respect to SPS dijets and to the BFKL Mueller-Navelet (MN) jets) contribution of DPS is growing at large rapidity distance between jets. The calculated differential cross sections as a function of rapidity distance between the most remote in rapidity jets are compared with recent results of LL and NLL BFKL calculations for the Mueller-Navelet jet production at $\sqrt{s} = 7$ TeV. Our results for four-jet sample are compared with experimental data obtained recently by the CMS collaboration and a rather good agreement is achieved. We propose to impose different cuts in order to enhance the relative DPS contribution. The relative DPS contribution increases when decreasing the lower cut on the jet transverse momenta as well as when a low lower cut on the rapidity distance between the most remote jets is imposed. |
hep-ph/9801239 | El Hassan Elaaoud | E. El aaoud | $D_s^+ \to \phi \rho^+$ Decay | 7 pages, LaTex | Phys. Rev. D 58, 037502 (1998) | 10.1103/PhysRevD.58.037502 | Alberta Thy-01-98 | hep-ph | null | Motivated by the experimental measurement of the decay rate, $\Gamma$, and
the longitudinal polarization, $P_L$, in the Cabibbo favored decay $D_s^+\to
\phi {\rho}^{+}$, we have studied theoretical prediction within the context of
factorization approximation invoking several form factors models. We were able
to obtain agreement with experiment for both $\Gamma$ and $P_L$ by using
experimentally measured values of the form factors $A_1^{D_s\phi}(0)$,
$A_2^{D_s\phi}(0)$ and $V^{D_s\phi}(0)$ in the semi-leptonic decay $D_s^+\to
\phi l^{+}\nu_{l}$. We have also included in our calculation the effect of the
final state interaction ($fsi$) by working with the partial waves amplitudes
$S$, $P$ and $D$. Numerical calculation shows that the decay amplitude is
dominated by $S$ wave, and that the polarization is sensitive to the
interference between $S$ and $D$ waves. The range of the phase difference
$\delta_{SD} = \delta_S - \delta_D$ accommodated by experimental error in $P_L$
is large.
| [
{
"created": "Thu, 8 Jan 1998 06:05:53 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"aaoud",
"E. El",
""
]
] | Motivated by the experimental measurement of the decay rate, $\Gamma$, and the longitudinal polarization, $P_L$, in the Cabibbo favored decay $D_s^+\to \phi {\rho}^{+}$, we have studied theoretical prediction within the context of factorization approximation invoking several form factors models. We were able to obtain agreement with experiment for both $\Gamma$ and $P_L$ by using experimentally measured values of the form factors $A_1^{D_s\phi}(0)$, $A_2^{D_s\phi}(0)$ and $V^{D_s\phi}(0)$ in the semi-leptonic decay $D_s^+\to \phi l^{+}\nu_{l}$. We have also included in our calculation the effect of the final state interaction ($fsi$) by working with the partial waves amplitudes $S$, $P$ and $D$. Numerical calculation shows that the decay amplitude is dominated by $S$ wave, and that the polarization is sensitive to the interference between $S$ and $D$ waves. The range of the phase difference $\delta_{SD} = \delta_S - \delta_D$ accommodated by experimental error in $P_L$ is large. |
hep-ph/9505438 | Rey Soo Jong | John Ellis, D.V. Nanopoulos, Keith A. Olive and Soo-Jong REY | On the Thermal Regeneration Rate for Light Gravitinos in the Early
Universe | REVTEX 32 pages, two encapsulated ps figure files | Astropart.Phys.4:371-386,1996 | 10.1016/0927-6505(96)00006-0 | ACT-07/95, CERN-TH/95-88, CTP-TAMU-21/95, UMN-TH-1349/95, SNUTP
95-041 | hep-ph astro-ph | null | We investigate the light gravitino regeneration rate in the early Universe in
models based on $N=1$ supergravity. Motivated by a recent claim by Fischler, we
evaluate finite-temperature effects on the gravitino regeneration rate due to
the hot primordial plasma for a wide range of the supersymmetry-breaking scale
$F$. We find that thermal corrections to the gravitino pole mass and to the
Goldstino coupling are negligible for a wide range of temperatures, thereby
justifying the extension of the equivalence theorem for the helicity-1/2
gravitino and Goldstino to a hot primordial plasma background. Utilizing the
Braaten-Pisarski resummation method, the helicity-1/2 gravitino regeneration
rate is found to be $0.25 \alpha_s(T) \log(1/\alpha_s(T))|{m_{\rm soft}/F}|^2
T^3(1 + \alpha_s(T) \log(1/\alpha_s(T)) + T^2 / |F|)$ up to a calculable,
model-dependent ${\cal O}(1)$ numerical factor. We review the implications of
this regeneration rate for supergravity cosmology, focusing in particular on
scenaria for baryogenesis.
| [
{
"created": "Wed, 31 May 1995 15:38:07 GMT",
"version": "v1"
},
{
"created": "Wed, 31 May 1995 16:45:02 GMT",
"version": "v2"
}
] | 2009-09-11 | [
[
"Ellis",
"John",
""
],
[
"Nanopoulos",
"D. V.",
""
],
[
"Olive",
"Keith A.",
""
],
[
"REY",
"Soo-Jong",
""
]
] | We investigate the light gravitino regeneration rate in the early Universe in models based on $N=1$ supergravity. Motivated by a recent claim by Fischler, we evaluate finite-temperature effects on the gravitino regeneration rate due to the hot primordial plasma for a wide range of the supersymmetry-breaking scale $F$. We find that thermal corrections to the gravitino pole mass and to the Goldstino coupling are negligible for a wide range of temperatures, thereby justifying the extension of the equivalence theorem for the helicity-1/2 gravitino and Goldstino to a hot primordial plasma background. Utilizing the Braaten-Pisarski resummation method, the helicity-1/2 gravitino regeneration rate is found to be $0.25 \alpha_s(T) \log(1/\alpha_s(T))|{m_{\rm soft}/F}|^2 T^3(1 + \alpha_s(T) \log(1/\alpha_s(T)) + T^2 / |F|)$ up to a calculable, model-dependent ${\cal O}(1)$ numerical factor. We review the implications of this regeneration rate for supergravity cosmology, focusing in particular on scenaria for baryogenesis. |
2006.00660 | Yoshimasa Kurihara | Hieu Minh Tran, Yoshimasa Kurihara | Tau $g-2$ at $e^-e^+$ colliders with momentum dependent form factor | 18 pages, 6 figures | null | 10.1140/epjc/s10052-021-08846-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The deviation between the standard model prediction and the measurement of
the muon g-2 is currently at 3-4 sigma (can be up to 7 sigma in the upcoming
experiment E989). If new physics is responsible for such discrepancy, it is
expected that the new contributions to tau g-2 are even larger than that for
muon due to its large mass. In spite of that, the tau g-2 is much more
difficult to be directly measured because of its short lifetime. In this paper,
we consider the effect of the tau g-2 at $e^-e^+$ colliders in a model
independent way. Using the tau pair production channel at the Large Electron
Position Collider (LEP), we have found the allowed range for the new physics
contribution of the tau g-2 assuming a $q^2$-dependence ansatz for the magnetic
form factor. In our analysis, we take into account the standard model one-loop
correction as well as the initial state photon radiation. We have also
investigated the prospect at future $e^-e^+$ colliders, and determine the
expected allowed range for the new physics contribution to the tau g-2. Given
the proposed beam polarization configuration at the International Linear
Collider (ILC), we have analyzed the dependence of this allowed range on the
integrated luminosity as well as the relative systematic error.
| [
{
"created": "Mon, 1 Jun 2020 01:28:41 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Jun 2020 02:38:15 GMT",
"version": "v2"
}
] | 2021-02-24 | [
[
"Tran",
"Hieu Minh",
""
],
[
"Kurihara",
"Yoshimasa",
""
]
] | The deviation between the standard model prediction and the measurement of the muon g-2 is currently at 3-4 sigma (can be up to 7 sigma in the upcoming experiment E989). If new physics is responsible for such discrepancy, it is expected that the new contributions to tau g-2 are even larger than that for muon due to its large mass. In spite of that, the tau g-2 is much more difficult to be directly measured because of its short lifetime. In this paper, we consider the effect of the tau g-2 at $e^-e^+$ colliders in a model independent way. Using the tau pair production channel at the Large Electron Position Collider (LEP), we have found the allowed range for the new physics contribution of the tau g-2 assuming a $q^2$-dependence ansatz for the magnetic form factor. In our analysis, we take into account the standard model one-loop correction as well as the initial state photon radiation. We have also investigated the prospect at future $e^-e^+$ colliders, and determine the expected allowed range for the new physics contribution to the tau g-2. Given the proposed beam polarization configuration at the International Linear Collider (ILC), we have analyzed the dependence of this allowed range on the integrated luminosity as well as the relative systematic error. |
hep-ph/9810205 | Bodo Lampe | K.J.Abraham and Bodo Lampe | Possible Nonstandard Effects in Z+Gamma Events at LEP2 | 13 pages latex with 4 eps figures | Phys.Lett. B446 (1999) 163-169 | 10.1016/S0370-2693(98)01528-7 | MPI-PhT/98-71 | hep-ph | null | We point out that the so--called 'radiative return' events at LEP2 are suited
to the study of nonstandard physics, particularly if the vector bosons are
emitted into the central detector region. An effective vertex is constructed
which contains the most general gauge invariant eeZGamma interaction and its
phenomenological consequences are examined. Low Energy Constraints on the
effective vertex are discussed as well.
| [
{
"created": "Thu, 1 Oct 1998 09:15:05 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Abraham",
"K. J.",
""
],
[
"Lampe",
"Bodo",
""
]
] | We point out that the so--called 'radiative return' events at LEP2 are suited to the study of nonstandard physics, particularly if the vector bosons are emitted into the central detector region. An effective vertex is constructed which contains the most general gauge invariant eeZGamma interaction and its phenomenological consequences are examined. Low Energy Constraints on the effective vertex are discussed as well. |
hep-ph/0507186 | Juan Jose Sanz-Cillero | J.J. Sanz-Cillero | Spin-1 Correlators at Large NC: Matching OPE and Resonance Theory up to
O(alpha_s) | 36 pages, 19 figures. Minor changes (added reference,...). Paper as
finally appeared in press | Nucl.Phys. B732 (2006) 136-168 | 10.1016/j.nuclphysb.2005.10.021 | null | hep-ph | null | The relation between the quark-gluon description of QCD and the hadronic
picture is studied up to order alpha_s. The analysis of the spin-1 correlators
is developed within the large NC framework. Both representations are shown to
be equivalent in the euclidean domain, where the Operator Product Expansion is
valid. By considering different models for the hadronic spectrum at high
energies, one is able to recover the alpha_s running in the correlators, to fix
the rho(770) and a1(1260) couplings, and to produce a prediction for the values
of the condensates. The Operator Product Expansion is improved by the large NC
resonance theory, extending its range of validity. Dispersion relations are
employed in order to study the minkowskian region and some convenient sum
rules, specially sensitive to the resonance structure of QCD, are worked out. A
first experimental estimate of these sum rules allows a cross-check of former
determinations of the QCD parameters and helps to discern and to discard some
of the considered hadronical models. Finally, the truncated resonance theory
and the Minimal Hadronical Approximation arise as a natural approach to the
full resonance theory, not as a model.
| [
{
"created": "Fri, 15 Jul 2005 10:46:13 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Aug 2006 18:33:06 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Sanz-Cillero",
"J. J.",
""
]
] | The relation between the quark-gluon description of QCD and the hadronic picture is studied up to order alpha_s. The analysis of the spin-1 correlators is developed within the large NC framework. Both representations are shown to be equivalent in the euclidean domain, where the Operator Product Expansion is valid. By considering different models for the hadronic spectrum at high energies, one is able to recover the alpha_s running in the correlators, to fix the rho(770) and a1(1260) couplings, and to produce a prediction for the values of the condensates. The Operator Product Expansion is improved by the large NC resonance theory, extending its range of validity. Dispersion relations are employed in order to study the minkowskian region and some convenient sum rules, specially sensitive to the resonance structure of QCD, are worked out. A first experimental estimate of these sum rules allows a cross-check of former determinations of the QCD parameters and helps to discern and to discard some of the considered hadronical models. Finally, the truncated resonance theory and the Minimal Hadronical Approximation arise as a natural approach to the full resonance theory, not as a model. |
hep-ph/0202157 | Ted Barnes | T. Barnes | Hadron 2001 Conference Summary: Theory | 17 pages, 5 figures. Presented at HADRON2001 (Protvino, Russia, 25
Aug - 1 Sep 2001) | AIP Conf.Proc. 619 (2002) 447-462 | 10.1063/1.1482473 | null | hep-ph nucl-th | null | This contribution reviews some of the theoretical issues and predictions that
were discussed at HADRON2001. The topics are divided into principle areas, 1)
exotics, 2) vectors, 3) scalars, and 4) higher-mass states. The current status
of theoretical predictions for each area are summarized, together with a brief
description of experiment. New and detailed experimental results are presented
in the companion Experimental Summary by Klempt.
| [
{
"created": "Fri, 15 Feb 2002 21:07:10 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Barnes",
"T.",
""
]
] | This contribution reviews some of the theoretical issues and predictions that were discussed at HADRON2001. The topics are divided into principle areas, 1) exotics, 2) vectors, 3) scalars, and 4) higher-mass states. The current status of theoretical predictions for each area are summarized, together with a brief description of experiment. New and detailed experimental results are presented in the companion Experimental Summary by Klempt. |
1202.4630 | Fr\'ed\'eric Jugeau Dr. | Frederic Jugeau | On the form factors of semileptonic baryon decays in Heavy Quark
Effective Theory | Invited talk at the 5th High-Energy Physics International Conference
HEP-MAD 11, Antananarivo, Madagascar, August 25-31 2011 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study consequences of the non-forward amplitude for the semileptonic
baryon decay Lambda_b into Lambda_c which will be measured in detail at LHCb.
We obtain a sum rule for the subleading elastic Isgur-Wise (IW) function A(w)
that originates from the kinetic part of the O(1/mQ) effective Lagrangian
perturbation. In the sum rule appear only the intermediate states J^P=1/2+, the
same that contribute to the O(1/mQ)^2 correction to the axial-vector form
factor G1(w) involved in the differential decay rate at zero recoil w=1. This
allows us to obtain a lower bound on the correction -delta^(G1)_(1/mQ^2) in
terms of A(w) and the shape of the leading elastic IW function xi(w). Another
theoretical implication is that A'(1) must vanish in the limit where the slope
of the xi(w) saturates its lower bound. A strong correlation between the
leading IW function and the subleading one A(w) is thus established in the case
of the baryons.
| [
{
"created": "Tue, 21 Feb 2012 13:17:57 GMT",
"version": "v1"
}
] | 2012-02-22 | [
[
"Jugeau",
"Frederic",
""
]
] | We study consequences of the non-forward amplitude for the semileptonic baryon decay Lambda_b into Lambda_c which will be measured in detail at LHCb. We obtain a sum rule for the subleading elastic Isgur-Wise (IW) function A(w) that originates from the kinetic part of the O(1/mQ) effective Lagrangian perturbation. In the sum rule appear only the intermediate states J^P=1/2+, the same that contribute to the O(1/mQ)^2 correction to the axial-vector form factor G1(w) involved in the differential decay rate at zero recoil w=1. This allows us to obtain a lower bound on the correction -delta^(G1)_(1/mQ^2) in terms of A(w) and the shape of the leading elastic IW function xi(w). Another theoretical implication is that A'(1) must vanish in the limit where the slope of the xi(w) saturates its lower bound. A strong correlation between the leading IW function and the subleading one A(w) is thus established in the case of the baryons. |
hep-ph/9408341 | Ed Yao | Kassa Adel and York-Peng Yao | Renormalization of four-quark operators, effective theory, and the role
of evanescent operators | 39 pages plain TeX and 10 Postscript figures available upon request,
McGill/ 94-14 and UM-TH-94-29 | Phys.Rev. D53 (1996) 374-388 | 10.1103/PhysRevD.53.374 | null | hep-ph | null | We present, in the context of dimensional regularization, a prescription to
renormalize Feynman diagrams with an arbitrary number of external fermions.
This prescription, which is based on the original t'Hooft-Veltman proposal to
keep external particles in four dimensions, is particularly useful to define
the 'renormalization' (in the context of effective Lagrangian) of physical
four-quark operators without introducing any evanescent operator. The results
obtained for $b\rightarrow s$ processes agree with those from the so-called
naive prescription, but disagree with the ones with the introduction of
evanescent operators in a renormalization group analysis. We also present an
explicit two loop calculation of the mixing of the evanescent operators with
the physical dimension five operators for the same processes. Particular
attention is paid to the unboundedness nature of such mixing and how a formal
finite transformation is effected to decouple. The inevitable mass dependence
of one of these schemes in the literature is pointed out as the cause for the
difference mentioned.
| [
{
"created": "Mon, 22 Aug 1994 15:43:27 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Adel",
"Kassa",
""
],
[
"Yao",
"York-Peng",
""
]
] | We present, in the context of dimensional regularization, a prescription to renormalize Feynman diagrams with an arbitrary number of external fermions. This prescription, which is based on the original t'Hooft-Veltman proposal to keep external particles in four dimensions, is particularly useful to define the 'renormalization' (in the context of effective Lagrangian) of physical four-quark operators without introducing any evanescent operator. The results obtained for $b\rightarrow s$ processes agree with those from the so-called naive prescription, but disagree with the ones with the introduction of evanescent operators in a renormalization group analysis. We also present an explicit two loop calculation of the mixing of the evanescent operators with the physical dimension five operators for the same processes. Particular attention is paid to the unboundedness nature of such mixing and how a formal finite transformation is effected to decouple. The inevitable mass dependence of one of these schemes in the literature is pointed out as the cause for the difference mentioned. |
hep-ph/0411273 | Roman Nevzorov | C. Froggatt, L. Laperashvili, R.Nevzorov, H.B.Nielsen | No--scale supergravity and the Multiple Point Principle | To appear in the proceedings of International Workshop on What Comes
Beyond the Standard Model?, Bled, Slovenia, 19-30 Jul 2004 | null | null | null | hep-ph | null | We review symmetries protecting a zero value for the cosmological constant in
no--scale supergravity and reveal the connection between the Multiple Point
Principle, no--scale and superstring inspired models.
| [
{
"created": "Sat, 20 Nov 2004 16:05:40 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Froggatt",
"C.",
""
],
[
"Laperashvili",
"L.",
""
],
[
"Nevzorov",
"R.",
""
],
[
"Nielsen",
"H. B.",
""
]
] | We review symmetries protecting a zero value for the cosmological constant in no--scale supergravity and reveal the connection between the Multiple Point Principle, no--scale and superstring inspired models. |
2006.14089 | Ningqiang Song | Joseph Bramante, Ningqiang Song | Electric But Not Eclectic: Thermal Relic Dark Matter for the XENON1T
Excess | 8 pages, 2 figures, added references and discussion of invisible V
decay and CMB constraints, matched published version | Phys. Rev. Lett. 125, 161805 (2020) | 10.1103/PhysRevLett.125.161805 | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The identity of dark matter is being sought with increasingly sensitive and
voluminous underground detectors. Recently the XENON1T collaboration reported
excess electronic recoil events, with most of these having recoil energies
around $1-30$ keV. We show that a straightforward model of inelastic dark
matter produced via early universe thermal freeze-out annihilation can account
for the XENON1T excess. Remarkably, this dark matter model consists of a few
simple elements: sub-GeV mass Dirac fermion dark matter coupled to a lighter
dark photon kinetically mixed with the Standard Model photon. A scalar field
charged under the dark U(1) gauge symmetry can provide a mass for the dark
photon and splits the Dirac fermion component state masses by a few keV, which
survive in equal abundance and interact inelastically with electrons and
nuclei.
| [
{
"created": "Wed, 24 Jun 2020 22:40:34 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Jun 2020 14:34:14 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Oct 2020 01:38:28 GMT",
"version": "v3"
}
] | 2020-10-21 | [
[
"Bramante",
"Joseph",
""
],
[
"Song",
"Ningqiang",
""
]
] | The identity of dark matter is being sought with increasingly sensitive and voluminous underground detectors. Recently the XENON1T collaboration reported excess electronic recoil events, with most of these having recoil energies around $1-30$ keV. We show that a straightforward model of inelastic dark matter produced via early universe thermal freeze-out annihilation can account for the XENON1T excess. Remarkably, this dark matter model consists of a few simple elements: sub-GeV mass Dirac fermion dark matter coupled to a lighter dark photon kinetically mixed with the Standard Model photon. A scalar field charged under the dark U(1) gauge symmetry can provide a mass for the dark photon and splits the Dirac fermion component state masses by a few keV, which survive in equal abundance and interact inelastically with electrons and nuclei. |
1202.4882 | Yu. A. Simonov | A. M. Badalian, V. D. Orlovsky, Yu. A. Simonov (Institute of
Theoretical and Experimental Physics, Moscow, Russia) and B. L. G. Bakker
(Dept.of Physics and Astronomy, Vrije Universiteit, Amsterdam, The
Netherlands) | The ratio of decay widths of X(3872) to $ \psi^{\prime}\gamma $ and $
J/\psi\gamma$ as a test of the X(3872) dynamical structure | 14 pages,2 Tables | Phys. Rev. D 85, 114002 (2012) | 10.1103/PhysRevD.85.114002 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Radiative decays of X(3872) with $J^{PC}=1^{++}$ are studied in the
coupled-channel approach, where the $c\bar c$ states are described by
relativistic string Hamiltonian, while for the decay channels $DD^*$ a string
breaking mechanism is used. Within this method a sharp peak and correct mass
shift of the $2 {}^3P_1$ charmonium state just to the $D^0D^{*0}$ threshold was
already obtained for a prescribed channel coupling to the $DD^*$ decay
channels. For the same value of coupling the normalized wave function (w.f.) of
X(3872) acquires admixture of the $1 {}^3P_1$ component with the w.f. fraction
$c_1=0.153 (\theta=8.8^\circ$), which increases the transition rate
$\Gamma(X(3872)\rightarrow J/\psi\gamma)$ up to 50-70 keV, making the ratio
$R=\frac{\mathcal{B}(X(3872)\rightarrow
\psi^{\prime}\gamma)}{\mathcal{B}(X(3872)\rightarrow J/\psi \gamma)}=0.8\pm
0.20 (th)$ significantly smaller, as compared to $R\simeq 5$ for X(3872) as a
purely $2 {}^3P_1$ state.
| [
{
"created": "Wed, 22 Feb 2012 11:12:31 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Mar 2012 08:36:29 GMT",
"version": "v2"
}
] | 2014-01-29 | [
[
"Badalian",
"A. M.",
"",
"Institute of\n Theoretical and Experimental Physics, Moscow, Russia"
],
[
"Orlovsky",
"V. D.",
"",
"Institute of\n Theoretical and Experimental Physics, Moscow, Russia"
],
[
"Simonov",
"Yu. A.",
"",
"Institute of\n Theoretical an... | Radiative decays of X(3872) with $J^{PC}=1^{++}$ are studied in the coupled-channel approach, where the $c\bar c$ states are described by relativistic string Hamiltonian, while for the decay channels $DD^*$ a string breaking mechanism is used. Within this method a sharp peak and correct mass shift of the $2 {}^3P_1$ charmonium state just to the $D^0D^{*0}$ threshold was already obtained for a prescribed channel coupling to the $DD^*$ decay channels. For the same value of coupling the normalized wave function (w.f.) of X(3872) acquires admixture of the $1 {}^3P_1$ component with the w.f. fraction $c_1=0.153 (\theta=8.8^\circ$), which increases the transition rate $\Gamma(X(3872)\rightarrow J/\psi\gamma)$ up to 50-70 keV, making the ratio $R=\frac{\mathcal{B}(X(3872)\rightarrow \psi^{\prime}\gamma)}{\mathcal{B}(X(3872)\rightarrow J/\psi \gamma)}=0.8\pm 0.20 (th)$ significantly smaller, as compared to $R\simeq 5$ for X(3872) as a purely $2 {}^3P_1$ state. |
hep-ph/0510094 | Edmond Iancu | E. Iancu, G. Soyez and D.N. Triantafyllopoulos | On the Probabilistic Interpretation of the Evolution Equations with
Pomeron Loops in QCD | 31 pages, 2 figures | Nucl.Phys. A768 (2006) 194-221 | 10.1016/j.nuclphysa.2006.01.013 | SACLAY-T05/138 | hep-ph | null | We study some structural aspects of the evolution equations with Pomeron
loops recently derived in QCD at high energy and for a large number of colors,
with the purpose of clarifying their probabilistic interpretation. We show
that, in spite of their appealing dipolar structure and of the self-duality of
the underlying Hamiltonian, these equations cannot be given a meaningful
interpretation in terms of a system of dipoles which evolves through
dissociation (one dipole splitting into two) and recombination (two dipoles
merging into one). The problem comes from the saturation effects, which cannot
be described as dipole recombination, not even effectively. We establish this
by showing that a (probabilistically meaningful) dipolar evolution in either
the target or the projectile wavefunction cannot reproduce the actual evolution
equations in QCD.
| [
{
"created": "Fri, 7 Oct 2005 15:17:49 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Iancu",
"E.",
""
],
[
"Soyez",
"G.",
""
],
[
"Triantafyllopoulos",
"D. N.",
""
]
] | We study some structural aspects of the evolution equations with Pomeron loops recently derived in QCD at high energy and for a large number of colors, with the purpose of clarifying their probabilistic interpretation. We show that, in spite of their appealing dipolar structure and of the self-duality of the underlying Hamiltonian, these equations cannot be given a meaningful interpretation in terms of a system of dipoles which evolves through dissociation (one dipole splitting into two) and recombination (two dipoles merging into one). The problem comes from the saturation effects, which cannot be described as dipole recombination, not even effectively. We establish this by showing that a (probabilistically meaningful) dipolar evolution in either the target or the projectile wavefunction cannot reproduce the actual evolution equations in QCD. |
2310.00631 | Duanyuan Gao | Duan-yuan Gao and Yuan-Chuan Zou | Jet Lorentz factor constraint for GRB 221009A based on the optical depth
of the TeV photons | ApJL accepted | null | null | null | hep-ph astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | The recent detection of tera-electronvolt (TeV) photons from the
record-breaking gamma-ray burst GRB 221009A during its prompt phase poses
challenges for constraining its Lorentz factor. We re-evaluate the constraints
on the jet Lorentz factor considering a two-zone model, wherein the TeV photons
originate from the external shock region while the lower energy MeV photons
come from the internal prompt emission region. By properly accounting for the
evolution of the MeV photon spectrum and light curve, we calculate the optical
depth for TeV photons and derive a minimum Lorentz factor about 300. It is
consistent with the afterglow modeling for the TeV emission.
| [
{
"created": "Sun, 1 Oct 2023 09:52:08 GMT",
"version": "v1"
}
] | 2023-10-04 | [
[
"Gao",
"Duan-yuan",
""
],
[
"Zou",
"Yuan-Chuan",
""
]
] | The recent detection of tera-electronvolt (TeV) photons from the record-breaking gamma-ray burst GRB 221009A during its prompt phase poses challenges for constraining its Lorentz factor. We re-evaluate the constraints on the jet Lorentz factor considering a two-zone model, wherein the TeV photons originate from the external shock region while the lower energy MeV photons come from the internal prompt emission region. By properly accounting for the evolution of the MeV photon spectrum and light curve, we calculate the optical depth for TeV photons and derive a minimum Lorentz factor about 300. It is consistent with the afterglow modeling for the TeV emission. |
1207.4207 | Sally Dawson | S. Dawson, T. Han, W. K. Lai, A. K. Leibovich, and I. Lewis | Resummation Effects in Vector-Boson and Higgs Associated Production | 25 pages, references updated | null | 10.1103/PhysRevD.86.074007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Fixed-order QCD radiative corrections to the vector-boson and Higgs
associated production channels, pp -> VH (V=W, Z), at hadron colliders are well
understood. We combine higher order perturbative QCD calculations with
soft-gluon resummation of both threshold logarithms and logarithms which are
important at low transverse momentum of the VH pair. We study the effects of
both types of logarithms on the scale dependence of the total cross section and
on various kinematic distributions. The next-to-next-to-next-to-leading
logarithmic (NNNLL) resummed total cross sections at the LHC are almost
identical to the fixed-order perturbative next-to-next-to-leading order (NNLO)
rates, indicating the excellent convergence of the perturbative QCD series.
Resummation of the VH transverse momentum (p_T) spectrum provides reliable
results for small values of p_T and suggests that implementing a jet-veto will
significantly decrease the cross sections.
| [
{
"created": "Tue, 17 Jul 2012 20:07:01 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Jul 2012 19:03:13 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Dawson",
"S.",
""
],
[
"Han",
"T.",
""
],
[
"Lai",
"W. K.",
""
],
[
"Leibovich",
"A. K.",
""
],
[
"Lewis",
"I.",
""
]
] | Fixed-order QCD radiative corrections to the vector-boson and Higgs associated production channels, pp -> VH (V=W, Z), at hadron colliders are well understood. We combine higher order perturbative QCD calculations with soft-gluon resummation of both threshold logarithms and logarithms which are important at low transverse momentum of the VH pair. We study the effects of both types of logarithms on the scale dependence of the total cross section and on various kinematic distributions. The next-to-next-to-next-to-leading logarithmic (NNNLL) resummed total cross sections at the LHC are almost identical to the fixed-order perturbative next-to-next-to-leading order (NNLO) rates, indicating the excellent convergence of the perturbative QCD series. Resummation of the VH transverse momentum (p_T) spectrum provides reliable results for small values of p_T and suggests that implementing a jet-veto will significantly decrease the cross sections. |
2301.13439 | Dao-Neng Gao | Dao-Neng Gao | Rare $W$-boson decays into a vector meson and lepton pair | 8 pages, 3 figures. Some discussions added. Published version | Phys. Rev. D 107, 113001 (2023); Erratum: Phys. Rev. D 108, 039904
(2023) | 10.1103/PhysRevD.107.113001 | USTC-ICTS/PCFT-23-04 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have presented a theoretical study of exclusive rare $W$-boson decays,
$W\to V\ell\bar{\nu}_\ell$ with $V$ denoting a neutral vector meson and
$\ell=e$ or $\mu$, in the standard model. The leading-order contributions to
these processes are given by $W\to \gamma^*\ell\bar{\nu}_\ell$ with the
subsequent $\gamma^*\to V$ transition. Branching fractions of these decay
modes, for $V=\rho$, $\omega$, $\phi$, and $J/\Psi$, respectively, have been
calculated and predicted around $10^{-6}\sim 10^{-7}$, which are surprisingly
larger than those of two-body hadronic radiative decays $W^\pm\to M^\pm \gamma$
with $M$ denoting a pseudoscalar or vector meson. Thus it is expected that rare
$W$ decays into a neutral vector meson plus lepton pair may be the promising
channels in future experimental facilities with a large number of $W$-boson
events produced.
| [
{
"created": "Tue, 31 Jan 2023 06:33:36 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Jun 2023 09:34:07 GMT",
"version": "v2"
}
] | 2023-09-19 | [
[
"Gao",
"Dao-Neng",
""
]
] | We have presented a theoretical study of exclusive rare $W$-boson decays, $W\to V\ell\bar{\nu}_\ell$ with $V$ denoting a neutral vector meson and $\ell=e$ or $\mu$, in the standard model. The leading-order contributions to these processes are given by $W\to \gamma^*\ell\bar{\nu}_\ell$ with the subsequent $\gamma^*\to V$ transition. Branching fractions of these decay modes, for $V=\rho$, $\omega$, $\phi$, and $J/\Psi$, respectively, have been calculated and predicted around $10^{-6}\sim 10^{-7}$, which are surprisingly larger than those of two-body hadronic radiative decays $W^\pm\to M^\pm \gamma$ with $M$ denoting a pseudoscalar or vector meson. Thus it is expected that rare $W$ decays into a neutral vector meson plus lepton pair may be the promising channels in future experimental facilities with a large number of $W$-boson events produced. |
1405.0069 | Yoshio Koide | Yoshio Koide and Hiroyuki Nishiura | Universal Bilinear Form of Quark and Lepton Mass Matrices | 17 pages, 2 figures, Accepted for publication in PRD | Phys.Rev. D 90, 016009 (2014) | 10.1103/PhysRevD.90.016009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the so-called ``yukawaon" model, the (effective) Yukawa coupling constants
$Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$
(yukawaons) with $3\times 3$ components. In the present model, all of the VEV
matrices $\langle Y_f \rangle$ are given by a bilinear form of VEVs of flavons
$\Phi_f$, $\langle Y_f \rangle_i^{\ j} = k_f \langle \Phi_f\rangle_{ik} \langle
\bar{\Phi}_f\rangle^{kj}$, where $\Phi_f$ is assigned to ${\bf 6}$ of U(3)
family symmetry. As input parameters with family-number dependent values, we
use only charged lepton mass values. Under this formulation, we can give
reasonable values of quark and lepton masses and their mixings. A $CP$
violating phase $\delta_{CP}^\ell=26^\circ$ in the lepton sector is predicted.
The effective Majorana neutrino mass is also predicted.
| [
{
"created": "Thu, 1 May 2014 01:04:45 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Jun 2014 01:55:49 GMT",
"version": "v2"
}
] | 2015-06-10 | [
[
"Koide",
"Yoshio",
""
],
[
"Nishiura",
"Hiroyuki",
""
]
] | In the so-called ``yukawaon" model, the (effective) Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (yukawaons) with $3\times 3$ components. In the present model, all of the VEV matrices $\langle Y_f \rangle$ are given by a bilinear form of VEVs of flavons $\Phi_f$, $\langle Y_f \rangle_i^{\ j} = k_f \langle \Phi_f\rangle_{ik} \langle \bar{\Phi}_f\rangle^{kj}$, where $\Phi_f$ is assigned to ${\bf 6}$ of U(3) family symmetry. As input parameters with family-number dependent values, we use only charged lepton mass values. Under this formulation, we can give reasonable values of quark and lepton masses and their mixings. A $CP$ violating phase $\delta_{CP}^\ell=26^\circ$ in the lepton sector is predicted. The effective Majorana neutrino mass is also predicted. |
hep-ph/0406183 | Ana Babic | A. Babic, B. Guberina, B. Melic, H. Stefancic | Cabibbo-suppressed decays of the Omega_c^0 - feedback to the Xi_c^+
lifetime | 9 pages, 3 figures | Phys.Rev. D70 (2004) 117501 | 10.1103/PhysRevD.70.117501 | null | hep-ph hep-ex | null | We investigate a possible background of the type Omega_c^0 --> Xi_c^+ pi^- to
the CLEO Xi_c^+ lifetime measurement. This decay mode may lead to an
overestimate of the Xi_c^+ decay length and, therefore, increase the measured
Xi_c^+ lifetime. The branching ratio Gamma(Omega_c^0 --> Xi_c^+
pi^-)/Gamma(Omega_c^0 --> Omega^- pi^+) is analyzed in the framework of the
pole model and the modified current algebra. We find that the Omega_c^0 -->
Xi_c^+ pi^- decay mode could not generate a substantial systematic error in the
Xi_c^+ lifetime measurement. Also, it cannot significantly reduce the
disagreement between theoretical and experimental values of the Xi_c^+
lifetime.
| [
{
"created": "Wed, 16 Jun 2004 20:41:38 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Babic",
"A.",
""
],
[
"Guberina",
"B.",
""
],
[
"Melic",
"B.",
""
],
[
"Stefancic",
"H.",
""
]
] | We investigate a possible background of the type Omega_c^0 --> Xi_c^+ pi^- to the CLEO Xi_c^+ lifetime measurement. This decay mode may lead to an overestimate of the Xi_c^+ decay length and, therefore, increase the measured Xi_c^+ lifetime. The branching ratio Gamma(Omega_c^0 --> Xi_c^+ pi^-)/Gamma(Omega_c^0 --> Omega^- pi^+) is analyzed in the framework of the pole model and the modified current algebra. We find that the Omega_c^0 --> Xi_c^+ pi^- decay mode could not generate a substantial systematic error in the Xi_c^+ lifetime measurement. Also, it cannot significantly reduce the disagreement between theoretical and experimental values of the Xi_c^+ lifetime. |
2002.03262 | Xin-Qiang Li | Guido Bell, Martin Beneke, Tobias Huber and Xin-Qiang Li | Two-loop non-leptonic penguin amplitude in QCD factorization | 45 pages, 9 figures, 6 tables. Expressions for the 2-loop
hard-scattering kernels before and after the convolution with the light-meson
LCDA are attached in electronic form to the source of the present submission | null | 10.1007/JHEP04(2020)055 | TUM-HEP-1250/20, SI-HEP-2019-17, QFET-2019-12 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We complete the calculation of the QCD penguin amplitude at
next-to-next-to-leading order in the QCD factorization approach to non-leptonic
B-meson decays. This provides the last missing piece in the computation of the
QCD correction to direct CP asymmetries at leading power in the heavy-quark
expansion.
| [
{
"created": "Sun, 9 Feb 2020 01:33:47 GMT",
"version": "v1"
}
] | 2020-05-20 | [
[
"Bell",
"Guido",
""
],
[
"Beneke",
"Martin",
""
],
[
"Huber",
"Tobias",
""
],
[
"Li",
"Xin-Qiang",
""
]
] | We complete the calculation of the QCD penguin amplitude at next-to-next-to-leading order in the QCD factorization approach to non-leptonic B-meson decays. This provides the last missing piece in the computation of the QCD correction to direct CP asymmetries at leading power in the heavy-quark expansion. |
1601.08081 | Alan D. Martin | V.A. Khoze, A.D. Martin, M.G. Ryskin and V.A. Schegelsky | Two scales in Bose-Einstein correlations | 7 pages, 1 figure | null | 10.1140/epjc/s10052-016-4055-3 | IPPP/16/08, DCPT/16/16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We argue that the secondaries produced in high energy hadron collisions are
emitted by small size sources distributed over a much larger area in impact
parameter space occupied by the interaction amplitude. That is, Bose-Einstein
correlation of two emitted identical particles should be described by a
`two-radii' parametrization ansatz. We discuss the expected energy, charged
multiplicity and transverse momentum of the pair (that is, $\sqrt{s},~N_{\rm
ch}, k_t$) behaviour of both the small and large size components.
| [
{
"created": "Fri, 29 Jan 2016 12:39:03 GMT",
"version": "v1"
}
] | 2016-05-04 | [
[
"Khoze",
"V. A.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Ryskin",
"M. G.",
""
],
[
"Schegelsky",
"V. A.",
""
]
] | We argue that the secondaries produced in high energy hadron collisions are emitted by small size sources distributed over a much larger area in impact parameter space occupied by the interaction amplitude. That is, Bose-Einstein correlation of two emitted identical particles should be described by a `two-radii' parametrization ansatz. We discuss the expected energy, charged multiplicity and transverse momentum of the pair (that is, $\sqrt{s},~N_{\rm ch}, k_t$) behaviour of both the small and large size components. |
hep-ph/9409453 | Matthias Neubert | Matthias Neubert | Higher-Order Perturbative Corrections to $b\to c$ Transitions at Zero
Recoil | 9 pages LaTeX, CERN-TH.7454/94 | Phys.Lett.B341:367-371,1995 | 10.1016/0370-2693(94)01326-8 | null | hep-ph | null | We estimate the two-loop perturbative corrections to zero-recoil matrix
elements of the flavour-changing currents $\bar c\,\gamma^\mu b$ and $\bar
c\,\gamma^\mu\gamma_5\,b$ by calculating the terms of order $n_f\,\alpha_s^2$
and substituting the dependence on the number of flavours by the first
coefficient of the $\beta$-function. Both for vector and axial vector currents,
we find moderate two-loop corrections below 1\% in magnitude. Using the
Brodsky--Lepage--Mackenzie prescription to set the scale in the
order-$\alpha_s$ corrections in the $\overline{\rm MS}$ scheme, we obtain
$\mu_V\simeq 0.92\sqrt{m_b m_c}$ and $\mu_A\simeq 0.51\sqrt{m_b m_c}$ in the
two cases. These scales are sufficiently large for perturbation theory to be
well-behaved. The implications of our results to the extraction of $|\,V_{cb}|$
are briefly discussed.
| [
{
"created": "Fri, 30 Sep 1994 11:39:58 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Neubert",
"Matthias",
""
]
] | We estimate the two-loop perturbative corrections to zero-recoil matrix elements of the flavour-changing currents $\bar c\,\gamma^\mu b$ and $\bar c\,\gamma^\mu\gamma_5\,b$ by calculating the terms of order $n_f\,\alpha_s^2$ and substituting the dependence on the number of flavours by the first coefficient of the $\beta$-function. Both for vector and axial vector currents, we find moderate two-loop corrections below 1\% in magnitude. Using the Brodsky--Lepage--Mackenzie prescription to set the scale in the order-$\alpha_s$ corrections in the $\overline{\rm MS}$ scheme, we obtain $\mu_V\simeq 0.92\sqrt{m_b m_c}$ and $\mu_A\simeq 0.51\sqrt{m_b m_c}$ in the two cases. These scales are sufficiently large for perturbation theory to be well-behaved. The implications of our results to the extraction of $|\,V_{cb}|$ are briefly discussed. |
hep-ph/9305230 | Daniel Ng | Ernest Ma and Daniel Ng | New Supersymmetric Option for Two Higgs Doublets | 10 pages, UCRHEP-T107,TRI-PP-93-17(3 figures are appended) | Phys.Rev. D49 (1994) 6164-6167 | 10.1103/PhysRevD.49.6164 | null | hep-ph | null | If the standard electroweak gauge model is embedded in a larger theory which
is supersymmetric and the latter breaks down to the former at some mass scale,
then the reduced Higgs potential at the electroweak mass scale may differ from
that of the well-known minimal supersymmetric extension. Specifically, if the
larger theory is based on $\rm {SU(2)_L \times SU(2)_R \times U(1)}$, an
interesting alternative exists for two Higgs doublets.
| [
{
"created": "Fri, 7 May 1993 23:32:23 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Ma",
"Ernest",
""
],
[
"Ng",
"Daniel",
""
]
] | If the standard electroweak gauge model is embedded in a larger theory which is supersymmetric and the latter breaks down to the former at some mass scale, then the reduced Higgs potential at the electroweak mass scale may differ from that of the well-known minimal supersymmetric extension. Specifically, if the larger theory is based on $\rm {SU(2)_L \times SU(2)_R \times U(1)}$, an interesting alternative exists for two Higgs doublets. |
hep-ph/0101353 | Abdelhak Djouadi | Aseshkrishna Datta, Abdelhak Djouadi and Jean-Loic Kneur | Probing the SUSY Higgs boson couplings to scalar leptons at high-energy
$e^+e^-$ colliders | 10 pages, latex, axodraw.sty, 2 psfigures | Phys.Lett. B509 (2001) 299-306 | 10.1016/S0370-2693(01)00533-0 | PM/01-06 | hep-ph | null | We discuss the production at $e^+e^-$ colliders of Higgs bosons in
association with both the scalar leptons and the lightest neutralinos in the
Minimal Supersymmetric extension of the Standard Model. While the rates for
associated Higgs production with neutralinos and first/second generation
sleptons are rather tiny, the cross section for the production of the lightest
Higgs boson $h$ with scalar $\tau$ lepton pairs can reach the femtobarn level
at c.m. energies at and above 500 GeV in favorable regions of the parameter
space, making this process potentially detectable at a high-luminosity $\ee$
collider, in particular in the $\gamma \gamma$ option. This would provide a
determination of the $h \tilde{\tau} \tilde{\tau}$ coupling and opens up the
possibility of measuring the parameter $\tan \beta$.
| [
{
"created": "Wed, 31 Jan 2001 18:38:46 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Datta",
"Aseshkrishna",
""
],
[
"Djouadi",
"Abdelhak",
""
],
[
"Kneur",
"Jean-Loic",
""
]
] | We discuss the production at $e^+e^-$ colliders of Higgs bosons in association with both the scalar leptons and the lightest neutralinos in the Minimal Supersymmetric extension of the Standard Model. While the rates for associated Higgs production with neutralinos and first/second generation sleptons are rather tiny, the cross section for the production of the lightest Higgs boson $h$ with scalar $\tau$ lepton pairs can reach the femtobarn level at c.m. energies at and above 500 GeV in favorable regions of the parameter space, making this process potentially detectable at a high-luminosity $\ee$ collider, in particular in the $\gamma \gamma$ option. This would provide a determination of the $h \tilde{\tau} \tilde{\tau}$ coupling and opens up the possibility of measuring the parameter $\tan \beta$. |
1207.7275 | George W. S. Hou | George W.-S. Hou | Theory Summary {\large (a Perspective} | 9 pages, 3 figures, theory summary talk at FPCP 2012 held at USTC,
Hefei, China | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is the Theory Summary of the "Flavor Physics and CP Violation 2012"
conference, with emphasis on New Physics. Besides covering the theory part of
the conference, we pay attention also to the physics highlights of experimental
talks. I then give my perspective on the false "Godot sightings" of the past
decade, with some firsthand accounts. With all coming to naught (well, SM) at
the moment, I look ahead to the near future, and to 2015 and beyond. An
Epilogue is added with the advent of "the Higgs" at the LHC.
| [
{
"created": "Tue, 31 Jul 2012 15:01:07 GMT",
"version": "v1"
}
] | 2012-08-01 | [
[
"Hou",
"George W. -S.",
""
]
] | This is the Theory Summary of the "Flavor Physics and CP Violation 2012" conference, with emphasis on New Physics. Besides covering the theory part of the conference, we pay attention also to the physics highlights of experimental talks. I then give my perspective on the false "Godot sightings" of the past decade, with some firsthand accounts. With all coming to naught (well, SM) at the moment, I look ahead to the near future, and to 2015 and beyond. An Epilogue is added with the advent of "the Higgs" at the LHC. |
hep-ph/0104249 | Edward Shuryak | Edward V. Shuryak | Nonperturbative Phenomena and Phases of QCD | Lectures in Schladming winter school 2001, 40 pages | Lect.Notes Phys. 583 (2002) 251-290 | null | null | hep-ph | null | Lectures discuss applications of semiclassical methods based on instantons to
vacuum structure (chiral symmetry breaking), hadronic structure (various
correlation functions), and high energy collisions of hadrons and heavy ions.
We discuss phase diagram of hot/dense hadronic matter, and in the last lecture
review current puzzles/lesons from the first RHIC run in summer of 2000.
| [
{
"created": "Tue, 24 Apr 2001 16:23:41 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Shuryak",
"Edward V.",
""
]
] | Lectures discuss applications of semiclassical methods based on instantons to vacuum structure (chiral symmetry breaking), hadronic structure (various correlation functions), and high energy collisions of hadrons and heavy ions. We discuss phase diagram of hot/dense hadronic matter, and in the last lecture review current puzzles/lesons from the first RHIC run in summer of 2000. |
0708.3905 | Inanc Sahin | B. Sahin and I. Sahin | Top Quark Spin Polarization in e \gamma Collision | 5 pages, 3 figures | Mod. Phys. Lett. A 23, 519-525 (2008) | 10.1142/S021773230802433X | null | hep-ph | null | We investigate the degree of spin polarization of single top quarks in the
$e\gamma$ collision via the process $e^{+} \gamma \to t \bar{b} \bar{\nu_{e}}$
with center of mass energies $\sqrt{s}$=0.5, 1 and 1.5 TeV of the parental
linear $e^{+}e^{-}$ collider. Dominant spin fractions and spin asymmetries for
the various top quark spin bases are investigated. We show that $e^{+}$-beam
direction is the favorite top quark spin decomposition axis. It is found to be
comparable with the ones in $pp$ and $ep$ collisions.
| [
{
"created": "Wed, 29 Aug 2007 08:37:06 GMT",
"version": "v1"
}
] | 2008-04-02 | [
[
"Sahin",
"B.",
""
],
[
"Sahin",
"I.",
""
]
] | We investigate the degree of spin polarization of single top quarks in the $e\gamma$ collision via the process $e^{+} \gamma \to t \bar{b} \bar{\nu_{e}}$ with center of mass energies $\sqrt{s}$=0.5, 1 and 1.5 TeV of the parental linear $e^{+}e^{-}$ collider. Dominant spin fractions and spin asymmetries for the various top quark spin bases are investigated. We show that $e^{+}$-beam direction is the favorite top quark spin decomposition axis. It is found to be comparable with the ones in $pp$ and $ep$ collisions. |
0708.3620 | Larry McLerran | Larry McLerran | Heavy Ion Collisions and New Forms of Matter | Plenary talk presented at PASCOS 2007 | AIPConf.Proc.957:117-123,2007 | 10.1063/1.2823746 | null | hep-ph | null | I discuss forms of high energy density matter in QCD. These include the Color
Glass Condensate, the Glasma and the Quark Gluon Plasma. They all might be
studied in ultra-relativistic heavy ion collisions, nd the Color Glass
Condensate might also be probed in electron-hadron collisions. I present the
properties of such matter and some aspects of what is known of their
properties.
| [
{
"created": "Mon, 27 Aug 2007 14:41:49 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"McLerran",
"Larry",
""
]
] | I discuss forms of high energy density matter in QCD. These include the Color Glass Condensate, the Glasma and the Quark Gluon Plasma. They all might be studied in ultra-relativistic heavy ion collisions, nd the Color Glass Condensate might also be probed in electron-hadron collisions. I present the properties of such matter and some aspects of what is known of their properties. |
1003.3426 | Ashot Gasparyan | A. Gasparyan and M.F.M. Lutz | Photon- and pion-nucleon interactions in a unitary and causal effective
field theory based on the chiral Lagrangian | 76 pages, 23 figures, one additional figure, Tables 4,5 and Figure 4
are corrected, a few references and comments are added. The role of higher
partial waves in pion photoproduction is clarified | Nucl.Phys.A848:126-182,2010 | 10.1016/j.nuclphysa.2010.08.006 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present and apply a novel scheme for studying photon- and pion-nucleon
scattering beyond the threshold region. Partial-wave amplitudes for the
$\gamma\, N$ and $\pi N$ states are obtained by an analytic extrapolation of
subthreshold reaction amplitudes computed in chiral perturbation theory, where
the constraints set by electromagnetic-gauge invariance, causality and
unitarity are used to stabilize the extrapolation. Based on the chiral
Lagrangian we recover the empirical s- and p-wave amplitudes up to energies
$\sqrt{s}\simeq 1300$ MeV in terms of the parameters relevant at order $Q^3$.
| [
{
"created": "Wed, 17 Mar 2010 18:37:29 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Jul 2010 13:43:40 GMT",
"version": "v2"
}
] | 2015-03-13 | [
[
"Gasparyan",
"A.",
""
],
[
"Lutz",
"M. F. M.",
""
]
] | We present and apply a novel scheme for studying photon- and pion-nucleon scattering beyond the threshold region. Partial-wave amplitudes for the $\gamma\, N$ and $\pi N$ states are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by electromagnetic-gauge invariance, causality and unitarity are used to stabilize the extrapolation. Based on the chiral Lagrangian we recover the empirical s- and p-wave amplitudes up to energies $\sqrt{s}\simeq 1300$ MeV in terms of the parameters relevant at order $Q^3$. |
hep-ph/9609239 | Carlo Ewerz | J. Bartels, C. Ewerz, H. Lotter, M. Wuesthoff, M. Diehl | Quark-Antiquark Jets in DIS Diffractive Dissociation | 6 pages, latex, 6 figures included (needs epsfig.sty), To appear in
the proceedings of the Workshop "Future Physics at HERA" | null | 10.1016/0370-2693(96)00412-1 | null | hep-ph | null | We report on investigations concerning the production of large transverse
momentum jets in DIS diffractive dissociation. These processes constitute a new
class of events that allow for a clean test of perturbative QCD and of the hard
(perturbative) pomeron picture. The measurement of the corresponding cross
sections might possibly serve to determine the gluon density of the proton.
| [
{
"created": "Tue, 3 Sep 1996 16:17:54 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Bartels",
"J.",
""
],
[
"Ewerz",
"C.",
""
],
[
"Lotter",
"H.",
""
],
[
"Wuesthoff",
"M.",
""
],
[
"Diehl",
"M.",
""
]
] | We report on investigations concerning the production of large transverse momentum jets in DIS diffractive dissociation. These processes constitute a new class of events that allow for a clean test of perturbative QCD and of the hard (perturbative) pomeron picture. The measurement of the corresponding cross sections might possibly serve to determine the gluon density of the proton. |
hep-ph/0307393 | Jose Illana | J.I. Illana, M. Masip | Quasi-Degenerate Neutrinos and Lepton Flavour Violation in
Supersymmetric Models | 13 pages, 4 figures. v3: introduction and discussion improved and
references added; version to appear in EPJC | Eur.Phys.J.C35:365-372,2004 | 10.1140/epjc/s2004-01816-3 | UG-FT-152/03, CAFPE-22/03 | hep-ph | null | In supersymmetric (SUSY) models the misalignment between fermion and sfermion
families introduces unsuppressed flavor-changing processes. Even if the mass
parameters are chosen to give no flavor violation, family dependent radiative
corrections make this adjustment not stable. We analyze the rate of l --> l'
gamma in SUSY-GUT models with three quasi-degenerate neutrinos and universal
scalar masses at the Planck scale. We pay special attention to a recently
proposed scenario where the low-energy neutrino mixings are generated from
identical quark and lepton mixings at large scales. We show that: (i) To take
universal slepton masses at the GUT scale is a very poor approximation, even in
no-scale models. (ii) For large neutrino Yukawa couplings the decay mu --> e
gamma would be observed in the planned experiment at PSI. (iii) For large
values of tanbeta the tau coupling gives important corrections, pushing mu -->
e gamma and tau --> mu gamma to accessible rates. In particular, the
non-observation of these processes in the near future would exclude the
scenario with unification of quark and lepton mixing angles. (iv) The absence
of lepton flavor violating decays in upcoming experiments would imply a low
value of tanbeta, small neutrino couplings, and large (>~ 250$ GeV)
SUSY-breaking masses.
| [
{
"created": "Thu, 31 Jul 2003 16:21:38 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Oct 2003 17:26:29 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Mar 2004 17:51:53 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Illana",
"J. I.",
""
],
[
"Masip",
"M.",
""
]
] | In supersymmetric (SUSY) models the misalignment between fermion and sfermion families introduces unsuppressed flavor-changing processes. Even if the mass parameters are chosen to give no flavor violation, family dependent radiative corrections make this adjustment not stable. We analyze the rate of l --> l' gamma in SUSY-GUT models with three quasi-degenerate neutrinos and universal scalar masses at the Planck scale. We pay special attention to a recently proposed scenario where the low-energy neutrino mixings are generated from identical quark and lepton mixings at large scales. We show that: (i) To take universal slepton masses at the GUT scale is a very poor approximation, even in no-scale models. (ii) For large neutrino Yukawa couplings the decay mu --> e gamma would be observed in the planned experiment at PSI. (iii) For large values of tanbeta the tau coupling gives important corrections, pushing mu --> e gamma and tau --> mu gamma to accessible rates. In particular, the non-observation of these processes in the near future would exclude the scenario with unification of quark and lepton mixing angles. (iv) The absence of lepton flavor violating decays in upcoming experiments would imply a low value of tanbeta, small neutrino couplings, and large (>~ 250$ GeV) SUSY-breaking masses. |
1403.3287 | Mohamed Mohamed | M. Abu-Shady | Linear Sigma Model at Finite Temperature and Baryonic Chemical Potential
Using the Midpoint Technique | 9 pages, 6 figures | Physics Research International, Volume 2014, 435023, (2014) | 10.1155/2014/435023 | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | A baryonic chemical potential is included in the linear sigma model at finite
temperature. The effective mesonic potential is numerically calculated using
the midpoint technique. The meson masses are investigated as functions of the
temperature at fixed value of baryonic chemical potential. The pressure and
energy density are investigated as functions of temperature at fixed value of
chemical potential. The obtained results are in good agreement in comparison
with other techniques. We conclude that the calculated effective potential
successfully predicts the meson properties and thermodynamic properties at
finite baryonic chemical potential.
| [
{
"created": "Thu, 13 Mar 2014 14:54:03 GMT",
"version": "v1"
}
] | 2014-03-14 | [
[
"Abu-Shady",
"M.",
""
]
] | A baryonic chemical potential is included in the linear sigma model at finite temperature. The effective mesonic potential is numerically calculated using the midpoint technique. The meson masses are investigated as functions of the temperature at fixed value of baryonic chemical potential. The pressure and energy density are investigated as functions of temperature at fixed value of chemical potential. The obtained results are in good agreement in comparison with other techniques. We conclude that the calculated effective potential successfully predicts the meson properties and thermodynamic properties at finite baryonic chemical potential. |
2206.04965 | Christophe Royon | C. Baldenegro, P. Gonzalez Duran, M. Klasen, C. Royon, J. Salomon | Jets separated by a large pseudorapidity gap at the Tevatron and at the
LHC | null | null | 10.1007/JHEP08(2022)250 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a phenomenological analysis of events with two high transverse
momentum ($p_T$) jets separated by a large (pseudo-)rapidity interval void of
particle activity, also known as jet-gap-jet events. In the limit where the
collision energy $\sqrt{s}$ is much larger than any other momentum scale, the
jet-gap-jet process is described in terms of perturbative pomeron exchange
between partons within the Balitsky--Fadin--Kuraev--Lipatov (BFKL) limit of
perturbative quantum chromodynamics (QCD). The BFKL pomeron exchange
amplitudes, with resummation at the next-to-leading logarithmic approximation,
have been embedded in the PYTHIA8 Monte Carlo event generator. Standard QCD
dijet events are simulated at next-to-leading order in $\alpha_s$ matched to
parton showers with POWHEG+PYTHIA8. We compare our calculations to measurements
by the CDF, D0, and CMS experiments at center-of-mass energies of 1.8, 7 and 13
TeV. The impact of the theoretical scales, the parton densities, final- and
initial-state radiation effects, multiple parton interactions, and $p_T$
thresholds and multiplicities of the particles in the rapidity gap on the
jet-gap-jet signature is studied in detail. With a strict gap definition (no
particle allowed in the gap), the shapes of most distributions are well
described except for the CMS azimuthal-angle distribution at 13 TeV. The
survival probability is surprisingly well modelled by multiparton interactions
in PYTHIA8. Without multiparton interactions, theoretical predictions based on
two-channel eikonal models agree qualitatively with fits to the experimental
data.
| [
{
"created": "Fri, 10 Jun 2022 09:38:21 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Aug 2022 07:20:13 GMT",
"version": "v2"
}
] | 2022-09-14 | [
[
"Baldenegro",
"C.",
""
],
[
"Duran",
"P. Gonzalez",
""
],
[
"Klasen",
"M.",
""
],
[
"Royon",
"C.",
""
],
[
"Salomon",
"J.",
""
]
] | We present a phenomenological analysis of events with two high transverse momentum ($p_T$) jets separated by a large (pseudo-)rapidity interval void of particle activity, also known as jet-gap-jet events. In the limit where the collision energy $\sqrt{s}$ is much larger than any other momentum scale, the jet-gap-jet process is described in terms of perturbative pomeron exchange between partons within the Balitsky--Fadin--Kuraev--Lipatov (BFKL) limit of perturbative quantum chromodynamics (QCD). The BFKL pomeron exchange amplitudes, with resummation at the next-to-leading logarithmic approximation, have been embedded in the PYTHIA8 Monte Carlo event generator. Standard QCD dijet events are simulated at next-to-leading order in $\alpha_s$ matched to parton showers with POWHEG+PYTHIA8. We compare our calculations to measurements by the CDF, D0, and CMS experiments at center-of-mass energies of 1.8, 7 and 13 TeV. The impact of the theoretical scales, the parton densities, final- and initial-state radiation effects, multiple parton interactions, and $p_T$ thresholds and multiplicities of the particles in the rapidity gap on the jet-gap-jet signature is studied in detail. With a strict gap definition (no particle allowed in the gap), the shapes of most distributions are well described except for the CMS azimuthal-angle distribution at 13 TeV. The survival probability is surprisingly well modelled by multiparton interactions in PYTHIA8. Without multiparton interactions, theoretical predictions based on two-channel eikonal models agree qualitatively with fits to the experimental data. |
1110.6435 | Diego Aristizabal | D. Aristizabal Sierra | One-loop finite corrections to seesaw neutrino masses | 3 pages, 2 figures. Prepared for the proceedings of the International
Europhysics Conference on High Energy Physics, EPS-HEP 2011, Grenoble,
France, July 21-27 2011 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the standard seesaw model, finite corrections to the neutrino mass matrix
arise from one-loop self-energy diagrams mediated by heavy neutrinos. We
discuss the impact that these corrections may have on the different entries of
the tree-level effective neutrino mass matrix, paying special attention to
their dependence with the seesaw model parameters. We also briefly comment on
the implications these corrections might have on low-energy neutrino
observables.
| [
{
"created": "Fri, 28 Oct 2011 19:56:51 GMT",
"version": "v1"
}
] | 2011-10-31 | [
[
"Sierra",
"D. Aristizabal",
""
]
] | In the standard seesaw model, finite corrections to the neutrino mass matrix arise from one-loop self-energy diagrams mediated by heavy neutrinos. We discuss the impact that these corrections may have on the different entries of the tree-level effective neutrino mass matrix, paying special attention to their dependence with the seesaw model parameters. We also briefly comment on the implications these corrections might have on low-energy neutrino observables. |
0901.2245 | Mikhail Vysotsky | M.I.Vysotsky | FSI and rare B decays: B-->\pi\pi, \rho\rho | talk at PANIC08, Eilat, Israel | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The final state interactions (FSI) model, in which soft rescattering of low
mass intermediate states dominate, is suggested. It explains why the strong
interaction phases are large in the $B_d\to\pi\pi$ channel and are considerably
smaller in the $B_d\to\rho\rho$ one.
| [
{
"created": "Thu, 15 Jan 2009 13:56:23 GMT",
"version": "v1"
}
] | 2009-01-16 | [
[
"Vysotsky",
"M. I.",
""
]
] | The final state interactions (FSI) model, in which soft rescattering of low mass intermediate states dominate, is suggested. It explains why the strong interaction phases are large in the $B_d\to\pi\pi$ channel and are considerably smaller in the $B_d\to\rho\rho$ one. |
hep-ph/0205037 | Jamal Jalilian-Marian | Francois Gelis and Jamal Jalilian-Marian | Photon production in high energy proton-nucleus collisions | 15 pages, 2 figures | Phys.Rev. D66 (2002) 014021 | 10.1103/PhysRevD.66.014021 | BNL-NT-02/9, LPT-ORSAY-02/40 | hep-ph nucl-th | null | We calculate the photon production cross-section in $pA$ collisions under the
assumption that the nucleus has reached the saturation regime, while the proton
can be described by the standard parton distribution functions. We show that
due to the strong classical field $O(1/g)$ of the nucleus, bremsstrahlung
diagrams become dominant over the direct photon diagrams. In particular, we
show that $\gamma-$jet transverse momentum spectrum and correlations are very
sensitive to gluon saturation effects in the nucleus.
| [
{
"created": "Fri, 3 May 2002 20:01:56 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Gelis",
"Francois",
""
],
[
"Jalilian-Marian",
"Jamal",
""
]
] | We calculate the photon production cross-section in $pA$ collisions under the assumption that the nucleus has reached the saturation regime, while the proton can be described by the standard parton distribution functions. We show that due to the strong classical field $O(1/g)$ of the nucleus, bremsstrahlung diagrams become dominant over the direct photon diagrams. In particular, we show that $\gamma-$jet transverse momentum spectrum and correlations are very sensitive to gluon saturation effects in the nucleus. |
2205.09131 | V\'ictor Enguita-Vileta | Victor Enguita Vileta, Belen Gavela, Rachel Houtz, Pablo Quilez | Discrete Goldstone Bosons | 44 pages, 13 figures | Phys. Rev. D 107, 035009 (2023) | 10.1103/PhysRevD.107.035009 | DESY-22-082, IFT-UAM/CSIC-20-144, FTUAM-20-21, IPPP/22/31 | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | Exact discrete symmetries, if non-linearly realized, can reduce the
ultraviolet sensitivity of a given theory. The scalars stemming from
spontaneous symmetry breaking are massive without breaking the discrete
symmetry, and those masses are protected from divergent quadratic corrections.
This is in contrast to non-linearly realized continuous symmetries, for which
the masses of pseudo-Goldstone bosons require an explicit breaking mechanism.
The symmetry-protected masses and potentials of those discrete Goldstone bosons
offer promising physics avenues, both theoretically and in view of the blooming
experimental search for ALPs. We develop this theoretical setup using invariant
theory and focusing on the maximally natural minima of the potential. For
these, we show that typically a subgroup of the ultraviolet discrete symmetry
remains explicit in the spectrum, i.e. realized "\`a la Wigner"; this subgroup
can be either abelian or non-abelian. This suggests tell-tale experimental
signals for those minima: at least two (three) degenerate scalars produced
simultaneously if abelian (non-abelian), while the specific ratios of
multi-scalar amplitudes provide a hint of the full ultraviolet discrete
symmetry. Examples of exact ultraviolet $A_4$ and $A_5$ symmetries are explored
in substantial detail.
| [
{
"created": "Wed, 18 May 2022 18:00:04 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Feb 2023 17:25:43 GMT",
"version": "v2"
}
] | 2023-02-16 | [
[
"Vileta",
"Victor Enguita",
""
],
[
"Gavela",
"Belen",
""
],
[
"Houtz",
"Rachel",
""
],
[
"Quilez",
"Pablo",
""
]
] | Exact discrete symmetries, if non-linearly realized, can reduce the ultraviolet sensitivity of a given theory. The scalars stemming from spontaneous symmetry breaking are massive without breaking the discrete symmetry, and those masses are protected from divergent quadratic corrections. This is in contrast to non-linearly realized continuous symmetries, for which the masses of pseudo-Goldstone bosons require an explicit breaking mechanism. The symmetry-protected masses and potentials of those discrete Goldstone bosons offer promising physics avenues, both theoretically and in view of the blooming experimental search for ALPs. We develop this theoretical setup using invariant theory and focusing on the maximally natural minima of the potential. For these, we show that typically a subgroup of the ultraviolet discrete symmetry remains explicit in the spectrum, i.e. realized "\`a la Wigner"; this subgroup can be either abelian or non-abelian. This suggests tell-tale experimental signals for those minima: at least two (three) degenerate scalars produced simultaneously if abelian (non-abelian), while the specific ratios of multi-scalar amplitudes provide a hint of the full ultraviolet discrete symmetry. Examples of exact ultraviolet $A_4$ and $A_5$ symmetries are explored in substantial detail. |
1403.2756 | David M. Straub | Matthias K\"onig, Matthias Neubert and David M. Straub | Dipole operator constraints on composite Higgs models | 30 pages, 2 figures, 11 tables. v3: Misprints in table 8 corrected.
Numerics and conclusions unchanged | Eur.Phys.J. C74 (2014) 7, 2945 | 10.1140/epjc/s10052-014-2945-9 | MITP/14-017 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Flavour- and CP-violating electromagnetic or chromomagnetic dipole operators
in the quark sector are generated in a large class of new physics models and
are strongly constrained by measurements of the neutron electric dipole moment
and observables sensitive to flavour-changing neutral currents, such as the
$B\to X_s\gamma$ branching ratio and $\epsilon'/\epsilon$. After a
model-independent discussion of the relevant constraints, we analyze these
effects in models with partial compositeness, where the quarks get their masses
by mixing with vector-like composite fermions. These scenarios can be seen as
the low-energy limit of composite Higgs or warped extra dimensional models. We
study different choices for the electroweak representations of the composite
fermions motivated by electroweak precision tests as well as different flavour
structures, including flavour anarchy and $U(3)^3$ or $U(2)^3$ flavour
symmetries in the strong sector. In models with "wrong-chirality" Yukawa
couplings, we find a strong bound from the neutron electric dipole moment,
irrespective of the flavour structure. In the case of flavour anarchy, we also
find strong bounds from flavour-violating dipoles, while these constraints are
mild in the flavour-symmetric models.
| [
{
"created": "Tue, 11 Mar 2014 21:00:16 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Mar 2014 10:47:15 GMT",
"version": "v2"
},
{
"created": "Fri, 18 Dec 2015 08:29:17 GMT",
"version": "v3"
}
] | 2015-12-21 | [
[
"König",
"Matthias",
""
],
[
"Neubert",
"Matthias",
""
],
[
"Straub",
"David M.",
""
]
] | Flavour- and CP-violating electromagnetic or chromomagnetic dipole operators in the quark sector are generated in a large class of new physics models and are strongly constrained by measurements of the neutron electric dipole moment and observables sensitive to flavour-changing neutral currents, such as the $B\to X_s\gamma$ branching ratio and $\epsilon'/\epsilon$. After a model-independent discussion of the relevant constraints, we analyze these effects in models with partial compositeness, where the quarks get their masses by mixing with vector-like composite fermions. These scenarios can be seen as the low-energy limit of composite Higgs or warped extra dimensional models. We study different choices for the electroweak representations of the composite fermions motivated by electroweak precision tests as well as different flavour structures, including flavour anarchy and $U(3)^3$ or $U(2)^3$ flavour symmetries in the strong sector. In models with "wrong-chirality" Yukawa couplings, we find a strong bound from the neutron electric dipole moment, irrespective of the flavour structure. In the case of flavour anarchy, we also find strong bounds from flavour-violating dipoles, while these constraints are mild in the flavour-symmetric models. |
2011.14668 | Suman Kumbhakar | Ashutosh Kumar Alok, Suman Kumbhakar, Jyoti Saini, S Uma Sankar | New physics in $b\rightarrow se^+e^-$: A model independent analysis | Accepted to publish in Nucl. Phys. B | Nucl. Phys. B 967 (2021) 115419 | 10.1016/j.nuclphysb.2021.115419 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The lepton universality violating flavor ratios $R_K/R_{K^*}$ indicate new
physics either in $b \to s \mu^+ \mu^-$ or in $b \to s e^+ e^-$ or in both. If
the new physics is only $b \to s e^+ e^-$ transition, the corresponding new
physics operators, in principle, can have any Lorentz structure. In this work,
we perform a model independent analysis of new physics only in $b \to se^+e^-$
decay by considering effective operators either one at a time or two similar
operators at a time. We include all the measurements in $b\rightarrow se^+e^-$
sector along with $R_K/R_{K^*}$ in our analysis. We show that various new
physics scenarios with vector/axial-vector operators can account for
$R_K/R_{K^*}$ data but those with scalar/pseudoscalar operators and with tensor
operators can not. We also show that the azimuthal angular observable $P_1$ in
$B \to K^* e^+ e^-$ decay is most suited to discriminate between the different
allowed solutions.
| [
{
"created": "Mon, 30 Nov 2020 10:25:26 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Apr 2021 04:33:58 GMT",
"version": "v2"
}
] | 2021-05-12 | [
[
"Alok",
"Ashutosh Kumar",
""
],
[
"Kumbhakar",
"Suman",
""
],
[
"Saini",
"Jyoti",
""
],
[
"Sankar",
"S Uma",
""
]
] | The lepton universality violating flavor ratios $R_K/R_{K^*}$ indicate new physics either in $b \to s \mu^+ \mu^-$ or in $b \to s e^+ e^-$ or in both. If the new physics is only $b \to s e^+ e^-$ transition, the corresponding new physics operators, in principle, can have any Lorentz structure. In this work, we perform a model independent analysis of new physics only in $b \to se^+e^-$ decay by considering effective operators either one at a time or two similar operators at a time. We include all the measurements in $b\rightarrow se^+e^-$ sector along with $R_K/R_{K^*}$ in our analysis. We show that various new physics scenarios with vector/axial-vector operators can account for $R_K/R_{K^*}$ data but those with scalar/pseudoscalar operators and with tensor operators can not. We also show that the azimuthal angular observable $P_1$ in $B \to K^* e^+ e^-$ decay is most suited to discriminate between the different allowed solutions. |
1706.07331 | Francesco Coradeschi | Leandro Cieri, Francesco Coradeschi, Daniel de Florian and Nerina
Fidanza | Transverse-momentum resummation for the signal-background interference
in the $H \to \gamma\gamma$ channel at the LHC | 9 pages, 7 fiugres | Phys. Rev. D 96, 054003 (2017) | 10.1103/PhysRevD.96.054003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an upgraded calculation of the effects of resonance-continuum
interference for the Higgs boson decaying to two photons at the Large Hadron
Collider, at next-to-leading order in the strong coupling $\alpha_S$,
$O(\alpha_S^3)$, and including transverse-momentum ($q_T$) resummation at
next-to-leading logarithmic accuracy. We study the importance of the
interference contribution in different transverse-momentum regions, with a
particular focus on the low $q_T$ region $q_T^2 << Q^2$ (with $Q^2$ being the
invariant diphoton mass) where resummation becomes essential for a reliable
calculation.
| [
{
"created": "Thu, 22 Jun 2017 14:09:32 GMT",
"version": "v1"
}
] | 2017-09-13 | [
[
"Cieri",
"Leandro",
""
],
[
"Coradeschi",
"Francesco",
""
],
[
"de Florian",
"Daniel",
""
],
[
"Fidanza",
"Nerina",
""
]
] | We present an upgraded calculation of the effects of resonance-continuum interference for the Higgs boson decaying to two photons at the Large Hadron Collider, at next-to-leading order in the strong coupling $\alpha_S$, $O(\alpha_S^3)$, and including transverse-momentum ($q_T$) resummation at next-to-leading logarithmic accuracy. We study the importance of the interference contribution in different transverse-momentum regions, with a particular focus on the low $q_T$ region $q_T^2 << Q^2$ (with $Q^2$ being the invariant diphoton mass) where resummation becomes essential for a reliable calculation. |
hep-ph/0308153 | Peter Zeiler Skands | Torbj\"orn Sj\"ostrand, Leif L\"onnblad, Stephen Mrenna, Peter Skands | PYTHIA 6.3 Physics and Manual | 8 + 454 pages | null | null | LU TP 03-38 | hep-ph | null | The PYTHIA program can be used to generate high-energy-physics `events', i.e.
sets of outgoing particles produced in the interactions between two incoming
particles. The objective is to provide as accurate as possible a representation
of event properties in a wide range of reactions, with emphasis on those where
strong interactions play a role, directly or indirectly, and therefore
multihadronic final states are produced. The physics is then not understood
well enough to give an exact description; instead the program has to be based
on a combination of analytical results and various QCD-based models. This
physics input is summarized here, for areas such as hard subprocesses, initial-
and final-state parton showers, beam remnants and underlying events,
fragmentation and decays, and much more. Furthermore, extensive information is
provided on all program elements: subroutines and functions, switches and
parameters, and particle and process data. This should allow the user to tailor
the generation task to the topics of interest.
| [
{
"created": "Thu, 14 Aug 2003 17:05:17 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Sjöstrand",
"Torbjörn",
""
],
[
"Lönnblad",
"Leif",
""
],
[
"Mrenna",
"Stephen",
""
],
[
"Skands",
"Peter",
""
]
] | The PYTHIA program can be used to generate high-energy-physics `events', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, with emphasis on those where strong interactions play a role, directly or indirectly, and therefore multihadronic final states are produced. The physics is then not understood well enough to give an exact description; instead the program has to be based on a combination of analytical results and various QCD-based models. This physics input is summarized here, for areas such as hard subprocesses, initial- and final-state parton showers, beam remnants and underlying events, fragmentation and decays, and much more. Furthermore, extensive information is provided on all program elements: subroutines and functions, switches and parameters, and particle and process data. This should allow the user to tailor the generation task to the topics of interest. |
1707.07904 | Shao-Feng Ge | Shao-Feng Ge, Werner Rodejohann, Kai Zuber | Half-life Expectations for Neutrinoless Double Beta Decay in Standard
and Non-Standard Scenarios | 18 pages, 10 figures, and 4 tables | Phys. Rev. D 96, 055019 (2017) | 10.1103/PhysRevD.96.055019 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the half-life expectations for neutrinoless double beta decay
by applying statistical distributions of neutrino mixing observables, neutrino
mass constraints from cosmology and nuclear matrix elements. The analysis is
performed in the standard scenario of active Majorana neutrino exchange, when
light sterile neutrinos are added, and within TeV-scale left-right symmetric
frameworks. The latter two cases correspond to a modified phenomenology of
double beta decay for a normal and inverted mass ordering, and thus different
discovery potential for future experiments.
| [
{
"created": "Tue, 25 Jul 2017 10:38:28 GMT",
"version": "v1"
}
] | 2017-09-20 | [
[
"Ge",
"Shao-Feng",
""
],
[
"Rodejohann",
"Werner",
""
],
[
"Zuber",
"Kai",
""
]
] | We investigate the half-life expectations for neutrinoless double beta decay by applying statistical distributions of neutrino mixing observables, neutrino mass constraints from cosmology and nuclear matrix elements. The analysis is performed in the standard scenario of active Majorana neutrino exchange, when light sterile neutrinos are added, and within TeV-scale left-right symmetric frameworks. The latter two cases correspond to a modified phenomenology of double beta decay for a normal and inverted mass ordering, and thus different discovery potential for future experiments. |
1412.0503 | Andrea Beraudo | A. Beraudo, A. De Pace, M. Monteno, M. Nardi, F. Prino | Heavy flavours in high-energy nuclear collisions: quenching, flow and
correlations | Proceedings of the conference Hot Quarks 2014 | null | 10.1088/1742-6596/612/1/012035 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present results for the quenching, elliptic flow and azimuthal
correlations of heavy flavour particles in high-energy nucleus-nucleus
collisions obtained through the POWLANG transport setup, developed in the past
to study the propagation of heavy quarks in the Quark-Gluon Plasma and here
extended to include a modeling of their hadronization in the presence of a
medium. Hadronization is described as occurring via the fragmentation of
strings with endpoints given by the heavy (anti-)quark Q(Qbar) and a thermal
parton $qbar(q)$ from the medium. The flow of the light quarks is shown to
affect significantly the R_AA} and v_2 of the final D mesons, leading to a
better agreement with the experimental data.
| [
{
"created": "Mon, 1 Dec 2014 15:08:29 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Beraudo",
"A.",
""
],
[
"De Pace",
"A.",
""
],
[
"Monteno",
"M.",
""
],
[
"Nardi",
"M.",
""
],
[
"Prino",
"F.",
""
]
] | We present results for the quenching, elliptic flow and azimuthal correlations of heavy flavour particles in high-energy nucleus-nucleus collisions obtained through the POWLANG transport setup, developed in the past to study the propagation of heavy quarks in the Quark-Gluon Plasma and here extended to include a modeling of their hadronization in the presence of a medium. Hadronization is described as occurring via the fragmentation of strings with endpoints given by the heavy (anti-)quark Q(Qbar) and a thermal parton $qbar(q)$ from the medium. The flow of the light quarks is shown to affect significantly the R_AA} and v_2 of the final D mesons, leading to a better agreement with the experimental data. |
1901.02472 | J\"urgen Eser | Florian Divotgey, J\"urgen Eser, and Mario Mitter | Dynamical generation of low-energy couplings from quark-meson
fluctuations | null | Phys. Rev. D 99, 054023 (2019) | 10.1103/PhysRevD.99.054023 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We extend our recent computation of the low-energy limit of the linear O(4)
Quark-Meson Model. The present analysis focuses on the transformation of the
resulting effective action into a nonlinearly realized effective pion action,
whose higher-derivative interaction terms are parametrized by so-called
low-energy couplings. Their counterparts in the linear model are determined
from the Functional Renormalization Group flow of the momentum-dependent
four-pion vertex, which is calculated in a fully O(4)-symmetric approximation
by including also momentum-dependent {\sigma}{\pi} interactions as well as
{\sigma} self-interactions. Consequently, these higher-derivative couplings are
dynamically generated solely from quark and meson fluctuations, initialized at
a hadronic scale. Despite our restriction to low-energy degrees of freedom, we
find that the qualitative features of the fluctuation dynamics allow us to
comment on the range of validity and on appropriate renormalization scales for
purely pionic effective models.
| [
{
"created": "Tue, 8 Jan 2019 19:11:34 GMT",
"version": "v1"
}
] | 2019-04-03 | [
[
"Divotgey",
"Florian",
""
],
[
"Eser",
"Jürgen",
""
],
[
"Mitter",
"Mario",
""
]
] | We extend our recent computation of the low-energy limit of the linear O(4) Quark-Meson Model. The present analysis focuses on the transformation of the resulting effective action into a nonlinearly realized effective pion action, whose higher-derivative interaction terms are parametrized by so-called low-energy couplings. Their counterparts in the linear model are determined from the Functional Renormalization Group flow of the momentum-dependent four-pion vertex, which is calculated in a fully O(4)-symmetric approximation by including also momentum-dependent {\sigma}{\pi} interactions as well as {\sigma} self-interactions. Consequently, these higher-derivative couplings are dynamically generated solely from quark and meson fluctuations, initialized at a hadronic scale. Despite our restriction to low-energy degrees of freedom, we find that the qualitative features of the fluctuation dynamics allow us to comment on the range of validity and on appropriate renormalization scales for purely pionic effective models. |
hep-ph/0003147 | Rajiv V. Gavai | R. V. Gavai (TIFR, Mumbai) | Quark-Gluon Plasma: Status of Heavy Ion Physics | 11 Pages, LaTeX, Plenary talk given at 6th Workshop in High Energy
Physics Phenomenology (WHEPP 6), Chennai (Madras), India, 3-15 Jan 2000 To
appear in Pramana, Journal of Physics | Pramana 55:125-135,2000 | 10.1007/s12043-000-0089-y | TIFR/TH/00-13 | hep-ph | null | Lattice quantum chromodynamics (QCD), defined on a discrete space time
lattice, leads to a spectacular non-perturbative prediction of a new state of
matter, called quark-gluon plasma (QGP), at sufficiently high temperatures or
equivalently large energy densities. The experimental programs of CERN, Geneva
and BNL, New York of relativistic heavy ion collisions are expected to produce
such energy densities, thereby providing us a chance to test the above
prediction. After a brief introduction of the necessary theoretical concepts, I
will present a critical review of the experimental results already obtained by
the various experiments in order to examine whether QGP has already been
observed by them.
| [
{
"created": "Wed, 15 Mar 2000 12:53:30 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Gavai",
"R. V.",
"",
"TIFR, Mumbai"
]
] | Lattice quantum chromodynamics (QCD), defined on a discrete space time lattice, leads to a spectacular non-perturbative prediction of a new state of matter, called quark-gluon plasma (QGP), at sufficiently high temperatures or equivalently large energy densities. The experimental programs of CERN, Geneva and BNL, New York of relativistic heavy ion collisions are expected to produce such energy densities, thereby providing us a chance to test the above prediction. After a brief introduction of the necessary theoretical concepts, I will present a critical review of the experimental results already obtained by the various experiments in order to examine whether QGP has already been observed by them. |
1005.2841 | S. Atag | S. Atag and A.A. Billur | Possibility of Determining $\tau$ Lepton Electromagnetic Moments in
${\gamma\gamma \to \tau^{+}\tau^{-}}$ Process at the CERN-LHC | null | JHEP 1011:060,2010 | 10.1007/JHEP11(2010)060 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Potential of the LHC to determine the electromagnetic couplings of the $\tau$
lepton is discussed via the process ${\gamma\gamma \to \tau^{+}\tau}^{-}$.
Highly improved constraints of the anomalous magnetic and electric dipole
moments have been obtained compared to the LEP sensitivity.
| [
{
"created": "Mon, 17 May 2010 08:48:43 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Oct 2010 08:09:45 GMT",
"version": "v2"
}
] | 2011-03-17 | [
[
"Atag",
"S.",
""
],
[
"Billur",
"A. A.",
""
]
] | Potential of the LHC to determine the electromagnetic couplings of the $\tau$ lepton is discussed via the process ${\gamma\gamma \to \tau^{+}\tau}^{-}$. Highly improved constraints of the anomalous magnetic and electric dipole moments have been obtained compared to the LEP sensitivity. |
hep-ph/9912550 | Johannes Bluemlein | J. Bl\"umlein | On the Relations Between Polarized Structure Functions | 7 pages LATEX, 6 style files, to be published in the Proceedings of
the 1999 Circum-Pan-Pacific RIKEN Symposium on High Energy Spin Physics,
Riken, Japan, November 1999 | RIKEN Rev.28:126-129,2000 | null | null | hep-ph hep-ex | null | The status of the twist--2 and the twist--3 integral relations between
polarized structure functions in deep inelastic scattering for electromagnetic
and electroweak interactions is reviewed. One novel integral relation for the
twist--3 contributions can be tested in the upcoming high statistics
measurements of the structure function $g_2(x,Q^2)$ in the range $Q^2 \gsim
M_p^2$.
| [
{
"created": "Fri, 31 Dec 1999 06:28:26 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Blümlein",
"J.",
""
]
] | The status of the twist--2 and the twist--3 integral relations between polarized structure functions in deep inelastic scattering for electromagnetic and electroweak interactions is reviewed. One novel integral relation for the twist--3 contributions can be tested in the upcoming high statistics measurements of the structure function $g_2(x,Q^2)$ in the range $Q^2 \gsim M_p^2$. |
hep-ph/0006042 | Martin Maul | Johan Bijnens and Martin Maul | Large Extra Dimensions in Rare Decays | 11 pages, 3 figures, LaTeX, minor stylistic changes, version to be
published in JHEP | JHEP 0010 (2000) 003 | 10.1088/1126-6708/2000/10/003 | LU TP 00-25 | hep-ph | null | The prospect of experimental verification of the large extra dimension
scenario in rare decays is discussed. The case of J/\Psi and \Upsilon to photon
+ missing energy is calculated in detail, and it is shown that the limit on the
compactification scale M_S lies at present in the ten GeV range. In contrast to
the quarkonium systems, signals in Kaon and Pion decays will be small.
| [
{
"created": "Mon, 5 Jun 2000 08:41:48 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Jul 2000 12:18:57 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Nov 2000 08:34:26 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Bijnens",
"Johan",
""
],
[
"Maul",
"Martin",
""
]
] | The prospect of experimental verification of the large extra dimension scenario in rare decays is discussed. The case of J/\Psi and \Upsilon to photon + missing energy is calculated in detail, and it is shown that the limit on the compactification scale M_S lies at present in the ten GeV range. In contrast to the quarkonium systems, signals in Kaon and Pion decays will be small. |
hep-ph/9208217 | Ghosh | Tarun Souradeep and Varun Sahni | Density Perturbations,Gravity Waves and the Cosmic Microwave Background | 10 Pages. (5 Figures available on request.) IUCAA -07-92 | Mod.Phys.Lett. A7 (1992) 3541-3552 | 10.1142/S0217732392002950 | null | hep-ph astro-ph | null | We asses the contribution to the observed large scale anisotropy of the
cosmic microwave background radiation, arising from both gravity waves as well
as adiabatic density perturbations, generated by a common inflationary
mechanism in the early Universe.
We find that for inflationary models predicting power law primordial spectra
%$a(t) \propto t^p, p > 1$, $\dk^2 \propto k^n$, the relative contribution to
the quadrupole anisotropy from gravity waves and scalar density perturbations,
depends crucially upon $n$. For $n < 0.87$, gravity waves perturb the CMBR by a
larger amount than density perturbations, whereas for $n > 0.87$ the reverse is
true. %For nearly exponential inflation, on the other hand, the contribution to
the %microwave anisotropy from scalar density perturbations always exceeds
%that due to gravity waves. Normalising the amplitude of the density
perturbation spectrum at large scales, using the observed value of the COBE
quadrupole, we determine $(\delta M /M)_{16}$ -- the rms density contrast on
scales $\sim 16 h_{50}^{-1}$ Mpc, for cosmological models with cold dark
matter. We find that for $n < 0.75$, a large amount of biasing is required in
order to reconcile theory with observations.
| [
{
"created": "Mon, 10 Aug 1992 14:11:58 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Souradeep",
"Tarun",
""
],
[
"Sahni",
"Varun",
""
]
] | We asses the contribution to the observed large scale anisotropy of the cosmic microwave background radiation, arising from both gravity waves as well as adiabatic density perturbations, generated by a common inflationary mechanism in the early Universe. We find that for inflationary models predicting power law primordial spectra %$a(t) \propto t^p, p > 1$, $\dk^2 \propto k^n$, the relative contribution to the quadrupole anisotropy from gravity waves and scalar density perturbations, depends crucially upon $n$. For $n < 0.87$, gravity waves perturb the CMBR by a larger amount than density perturbations, whereas for $n > 0.87$ the reverse is true. %For nearly exponential inflation, on the other hand, the contribution to the %microwave anisotropy from scalar density perturbations always exceeds %that due to gravity waves. Normalising the amplitude of the density perturbation spectrum at large scales, using the observed value of the COBE quadrupole, we determine $(\delta M /M)_{16}$ -- the rms density contrast on scales $\sim 16 h_{50}^{-1}$ Mpc, for cosmological models with cold dark matter. We find that for $n < 0.75$, a large amount of biasing is required in order to reconcile theory with observations. |
0905.4080 | Matthias Burkardt | Matthias Burkardt (NMSU/Jefferson Lab) | GPDs and DVCS with Positrons | 5 pages, 2 figures, invited talk at `Workshop on Positrons at
Jefferson Lab' | null | 10.1063/1.3232029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The beam charge asymmetry helps to isolate the real part of the deeply
virtual Compton scattering (DVCS) amplitude. It is discussed what information
can be gained both from the real and imaginary part of the DVCS amplitude.
| [
{
"created": "Mon, 25 May 2009 20:23:48 GMT",
"version": "v1"
}
] | 2015-05-13 | [
[
"Burkardt",
"Matthias",
"",
"NMSU/Jefferson Lab"
]
] | The beam charge asymmetry helps to isolate the real part of the deeply virtual Compton scattering (DVCS) amplitude. It is discussed what information can be gained both from the real and imaginary part of the DVCS amplitude. |
1912.12155 | Marco Zanetti | Raffaele Tito D'Agnolo, Gaia Grosso, Maurizio Pierini, Andrea Wulzer
and Marco Zanetti | Learning Multivariate New Physics | null | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss a method that employs a multilayer perceptron to detect deviations
from a reference model in large multivariate datasets. Our data analysis
strategy does not rely on any prior assumption on the nature of the deviation.
It is designed to be sensitive to small discrepancies that arise in datasets
dominated by the reference model. The main conceptual building blocks were
introduced in Ref. [1]. Here we make decisive progress in the algorithm
implementation and we demonstrate its applicability to problems in high energy
physics. We show that the method is sensitive to putative new physics signals
in di-muon final states at the LHC. We also compare our performances on toy
problems with the ones of alternative methods proposed in the literature.
| [
{
"created": "Fri, 27 Dec 2019 15:29:22 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Feb 2020 22:32:14 GMT",
"version": "v2"
},
{
"created": "Thu, 23 Sep 2021 15:37:44 GMT",
"version": "v3"
}
] | 2021-09-24 | [
[
"D'Agnolo",
"Raffaele Tito",
""
],
[
"Grosso",
"Gaia",
""
],
[
"Pierini",
"Maurizio",
""
],
[
"Wulzer",
"Andrea",
""
],
[
"Zanetti",
"Marco",
""
]
] | We discuss a method that employs a multilayer perceptron to detect deviations from a reference model in large multivariate datasets. Our data analysis strategy does not rely on any prior assumption on the nature of the deviation. It is designed to be sensitive to small discrepancies that arise in datasets dominated by the reference model. The main conceptual building blocks were introduced in Ref. [1]. Here we make decisive progress in the algorithm implementation and we demonstrate its applicability to problems in high energy physics. We show that the method is sensitive to putative new physics signals in di-muon final states at the LHC. We also compare our performances on toy problems with the ones of alternative methods proposed in the literature. |
2310.08436 | Jingwei Lian | Junjie Cao, Xinglong Jia, Jingwei Lian, Lei Meng | 95 GeV Diphoton and $b \bar{b}$ Excesses in the General Next-to-Minimal
Supersymmetric Standard Model | 34 pages, 11 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The CMS and ATLAS collaborations recently published their results searching
for light Higgs bosons, using the complete Run 2 data of the LHC. Both reported
an excess in the diphoton invariant mass distribution at $m_{\gamma \gamma}
\simeq 95.4~{\rm GeV}$ with compatible signal strengths. The combined result
corresponded to a local significance of $3.1\sigma$. Besides, the mass of the
diphoton signal coincided with that of the $b\bar{b}$ excess observed at the
LEP. Given the remarkable theoretical advantages of the general Next-to-Minimal
Supersymmetric Standard Model, we interpret these excesses by the resonant
productions of the singlet-dominated CP-even Higgs boson predicted by the
theory. Using both analytic formulae and numerical results, we show that the
idea can interpret the excesses by broad parameter space without contradicting
current experimental restrictions, including those from the 125~{\rm GeV} Higgs
data, the dark matter relic abundance and direct detection experiments, and the
collider searches for supersymmetry and extra Higgs bosons. Although the
explanations are scarcely affected by present Higgs data and the LHC search for
supersymmetry, the dark matter physics may leave footprints on them. We also
survey the other signals of the light Higgs boson at the LHC.
| [
{
"created": "Thu, 12 Oct 2023 15:58:58 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Oct 2023 03:33:40 GMT",
"version": "v2"
}
] | 2023-10-23 | [
[
"Cao",
"Junjie",
""
],
[
"Jia",
"Xinglong",
""
],
[
"Lian",
"Jingwei",
""
],
[
"Meng",
"Lei",
""
]
] | The CMS and ATLAS collaborations recently published their results searching for light Higgs bosons, using the complete Run 2 data of the LHC. Both reported an excess in the diphoton invariant mass distribution at $m_{\gamma \gamma} \simeq 95.4~{\rm GeV}$ with compatible signal strengths. The combined result corresponded to a local significance of $3.1\sigma$. Besides, the mass of the diphoton signal coincided with that of the $b\bar{b}$ excess observed at the LEP. Given the remarkable theoretical advantages of the general Next-to-Minimal Supersymmetric Standard Model, we interpret these excesses by the resonant productions of the singlet-dominated CP-even Higgs boson predicted by the theory. Using both analytic formulae and numerical results, we show that the idea can interpret the excesses by broad parameter space without contradicting current experimental restrictions, including those from the 125~{\rm GeV} Higgs data, the dark matter relic abundance and direct detection experiments, and the collider searches for supersymmetry and extra Higgs bosons. Although the explanations are scarcely affected by present Higgs data and the LHC search for supersymmetry, the dark matter physics may leave footprints on them. We also survey the other signals of the light Higgs boson at the LHC. |
0805.4735 | Arata Yamamoto | Arata Yamamoto, Hideo Suganuma (Kyoto U.), Hideaki Iida (Kyoto U.,
Yukawa Inst., Kyoto) | Heavy-heavy-light quark potential in two approaches | Talk given at YITP International Symposium: Fundamental Problems in
Hot and/or Dense QCD, Kyoto, Japan, 3-6 March 2008 | Prog.Theor.Phys.Suppl.174:270-273,2008 | 10.1143/PTPS.174.270 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform the first study about the heavy-heavy-light quark potential in
lattice QCD and a potential model. We find that the inter-two-quark confining
force is reduced by valence quark motional effects compared to the string
tension.
| [
{
"created": "Fri, 30 May 2008 12:08:22 GMT",
"version": "v1"
}
] | 2009-01-14 | [
[
"Yamamoto",
"Arata",
"",
"Kyoto U."
],
[
"Suganuma",
"Hideo",
"",
"Kyoto U."
],
[
"Iida",
"Hideaki",
"",
"Kyoto U.,\n Yukawa Inst., Kyoto"
]
] | We perform the first study about the heavy-heavy-light quark potential in lattice QCD and a potential model. We find that the inter-two-quark confining force is reduced by valence quark motional effects compared to the string tension. |
1205.2486 | Kwang Sik Jeong | Kwang Sik Jeong, Yutaro Shoji, Masahiro Yamaguchi | Singlet-doublet Higgs mixing and its implications on the Higgs mass in
the PQ-NMSSM | 26 pages, 3 figures; published in JHEP | null | 10.1007/JHEP09(2012)007 | TU-907 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the implications of singlet-doublet Higgs mixing on the properties
of a Standard Model (SM)-like Higgs boson within the Peccei-Quinn invariant
extension of the NMSSM (PQ-NMSSM). The SM singlet added to the Higgs sector
connects the PQ and visible sectors through a PQ-invariant non-renormalizable
K\"ahler potential term, making the model free from the tadpole and domain-wall
problems. For the case that the lightest Higgs boson is dominated by the
singlet scalar, the Higgs mixing increases the mass of a SM-like Higgs boson
while reducing its signal rate at collider experiments compared to the SM case.
The Higgs mixing is important also in the region of parameter space where the
NMSSM contribution to the Higgs mass is small, but its size is limited by the
experimental constraints on the singlet-like Higgs boson and on the lightest
neutralino constituted mainly by the singlino whose Majorana mass term is
forbidden by the PQ symmetry. Nonetheless the Higgs mixing can increase the
SM-like Higgs boson mass by a few GeV or more even when the Higgs signal rate
is close to the SM prediction, and thus may be crucial for achieving a 125 GeV
Higgs mass, as hinted by the recent ATLAS and CMS data. Such an effect can
reduce the role of stop mixing.
| [
{
"created": "Fri, 11 May 2012 11:22:13 GMT",
"version": "v1"
},
{
"created": "Mon, 28 May 2012 12:38:00 GMT",
"version": "v2"
},
{
"created": "Thu, 5 Jul 2012 09:44:13 GMT",
"version": "v3"
},
{
"created": "Thu, 13 Sep 2012 16:31:11 GMT",
"version": "v4"
}
] | 2015-06-05 | [
[
"Jeong",
"Kwang Sik",
""
],
[
"Shoji",
"Yutaro",
""
],
[
"Yamaguchi",
"Masahiro",
""
]
] | We examine the implications of singlet-doublet Higgs mixing on the properties of a Standard Model (SM)-like Higgs boson within the Peccei-Quinn invariant extension of the NMSSM (PQ-NMSSM). The SM singlet added to the Higgs sector connects the PQ and visible sectors through a PQ-invariant non-renormalizable K\"ahler potential term, making the model free from the tadpole and domain-wall problems. For the case that the lightest Higgs boson is dominated by the singlet scalar, the Higgs mixing increases the mass of a SM-like Higgs boson while reducing its signal rate at collider experiments compared to the SM case. The Higgs mixing is important also in the region of parameter space where the NMSSM contribution to the Higgs mass is small, but its size is limited by the experimental constraints on the singlet-like Higgs boson and on the lightest neutralino constituted mainly by the singlino whose Majorana mass term is forbidden by the PQ symmetry. Nonetheless the Higgs mixing can increase the SM-like Higgs boson mass by a few GeV or more even when the Higgs signal rate is close to the SM prediction, and thus may be crucial for achieving a 125 GeV Higgs mass, as hinted by the recent ATLAS and CMS data. Such an effect can reduce the role of stop mixing. |
0802.1758 | Naoyuki Haba | Naoyuki Haba | Meta-stable SUSY Breaking Model in Supergravity | 13 pages | JHEP0803:059,2008 | 10.1088/1126-6708/2008/03/059 | OU-HET 598/2008 | hep-ph | null | We analyze a supersymmetry (SUSY) breaking model proposed by Intriligator,
Seiberg and Shih in a supergravity (SUGRA) framework. This is a simple and
natural setup which demands neither extra superpotential interactions nor an
additional gauge symmetry. In the SUGRA setup, the U(1)R symmetry is explicitly
broken by the constant term in the superpotential, and pseudo-moduli field
naturally takes non-zero vacuum expectation value through a vanishing
cosmological constant condition. Sfermions tend to be heavier than gauginos,
and the strong-coupling scale is determined once a ratio of sfermion to gaugino
masses is fixed.
| [
{
"created": "Wed, 13 Feb 2008 03:52:51 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Mar 2008 12:47:07 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Haba",
"Naoyuki",
""
]
] | We analyze a supersymmetry (SUSY) breaking model proposed by Intriligator, Seiberg and Shih in a supergravity (SUGRA) framework. This is a simple and natural setup which demands neither extra superpotential interactions nor an additional gauge symmetry. In the SUGRA setup, the U(1)R symmetry is explicitly broken by the constant term in the superpotential, and pseudo-moduli field naturally takes non-zero vacuum expectation value through a vanishing cosmological constant condition. Sfermions tend to be heavier than gauginos, and the strong-coupling scale is determined once a ratio of sfermion to gaugino masses is fixed. |
1504.04016 | Brian Batell | Brian Batell, Matthew McCullough | Neutrino Masses from Neutral Top Partners | 18 pages, 5 figures; v2: references added, additional discussion of
proton decay | Phys. Rev. D 92, 073018 (2015) | 10.1103/PhysRevD.92.073018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present theories of `Natural Neutrinos' in which neutral fermionic top
partner fields are simultaneously the right-handed neutrinos (RHN), linking
seemingly disparate aspects of the Standard Model structure: a) The RHN top
partners are responsible for the observed small neutrino masses, b) They help
ameliorate the tuning in the weak scale and address the little hierarchy
problem, and c) The factor of $3$ arising from $N_c$ in the top-loop Higgs mass
corrections is countered by a factor $3$ from the number of vector-like
generations of RHN. The RHN top partners may arise in
pseudo-Nambu-Goldstone-Boson (pNGB) Higgs models such as the Twin Higgs, as
well as more general Composite, Little, and Orbifold Higgs scenarios, and three
simple example models are presented. This framework firmly predicts a TeV-scale
seesaw, as the RHN masses are bounded to be below the TeV scale by naturalness.
The generation of light neutrino masses relies on a collective breaking of
lepton number, allowing for comparatively large neutrino Yukawa couplings and a
rich associated phenomenology. The structure of the neutrino mass mechanism
realizes in certain limits the Inverse or Linear classes of seesaw. Natural
Neutrino models are testable at a variety of current and future experiments,
particularly in tests of lepton universality, searches for lepton flavor
violation, and precision electroweak and Higgs coupling measurements possible
at high energy $e^+ e^-$ and hadron colliders.
| [
{
"created": "Wed, 15 Apr 2015 20:00:38 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Aug 2015 09:52:53 GMT",
"version": "v2"
}
] | 2015-11-04 | [
[
"Batell",
"Brian",
""
],
[
"McCullough",
"Matthew",
""
]
] | We present theories of `Natural Neutrinos' in which neutral fermionic top partner fields are simultaneously the right-handed neutrinos (RHN), linking seemingly disparate aspects of the Standard Model structure: a) The RHN top partners are responsible for the observed small neutrino masses, b) They help ameliorate the tuning in the weak scale and address the little hierarchy problem, and c) The factor of $3$ arising from $N_c$ in the top-loop Higgs mass corrections is countered by a factor $3$ from the number of vector-like generations of RHN. The RHN top partners may arise in pseudo-Nambu-Goldstone-Boson (pNGB) Higgs models such as the Twin Higgs, as well as more general Composite, Little, and Orbifold Higgs scenarios, and three simple example models are presented. This framework firmly predicts a TeV-scale seesaw, as the RHN masses are bounded to be below the TeV scale by naturalness. The generation of light neutrino masses relies on a collective breaking of lepton number, allowing for comparatively large neutrino Yukawa couplings and a rich associated phenomenology. The structure of the neutrino mass mechanism realizes in certain limits the Inverse or Linear classes of seesaw. Natural Neutrino models are testable at a variety of current and future experiments, particularly in tests of lepton universality, searches for lepton flavor violation, and precision electroweak and Higgs coupling measurements possible at high energy $e^+ e^-$ and hadron colliders. |
2209.00916 | Zhao Xin | C. Giunti, Y.F. Li, C.A. Ternes, O. Tyagi, Z.Xin | Gallium Anomaly: Critical View from the Global Picture of $\nu_{e}$ and
$\bar\nu_{e}$ Disappearance | 20 pages, 10 figures. With more discussions, version accepted for
publication at Journal of High Energy Physics | null | 10.1007/JHEP10(2022)164 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The significance of the Gallium Anomaly, from the BEST, GALLEX, and SAGE
radioactive source experiments, is quantified using different theoretical
calculations of the neutrino detection cross section, and its explanation due
to neutrino oscillations is compared with the bounds from the analyses of
reactor rate and spectral ratio data, $\beta$-decay data, and solar neutrino
data. In the 3+1 active-sterile neutrino mixing scheme, the Gallium Anomaly is
in strong tension with the individual and combined bounds of these data sets.
In the combined scenario with all available data, the parameter goodness of fit
is below 0.042%, corresponding to a severe tension of 4-5$\sigma$, or stronger.
Therefore, we conclude that one should pursue other possible solutions beyond
short-baseline oscillations for the Gallium Anomaly. We also present a new
global fit of $\nu_e$ and $\bar\nu_e$ disappearance data, showing that there is
a 2.6-3.3$\sigma$ preference in favor of short-baseline oscillations, which is
driven by an updated analysis of reactor spectral ratio data.
| [
{
"created": "Fri, 2 Sep 2022 09:50:50 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Sep 2022 16:03:08 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Nov 2022 13:02:10 GMT",
"version": "v3"
}
] | 2022-11-09 | [
[
"Giunti",
"C.",
""
],
[
"Li",
"Y. F.",
""
],
[
"Ternes",
"C. A.",
""
],
[
"Tyagi",
"O.",
""
],
[
"Xin",
"Z.",
""
]
] | The significance of the Gallium Anomaly, from the BEST, GALLEX, and SAGE radioactive source experiments, is quantified using different theoretical calculations of the neutrino detection cross section, and its explanation due to neutrino oscillations is compared with the bounds from the analyses of reactor rate and spectral ratio data, $\beta$-decay data, and solar neutrino data. In the 3+1 active-sterile neutrino mixing scheme, the Gallium Anomaly is in strong tension with the individual and combined bounds of these data sets. In the combined scenario with all available data, the parameter goodness of fit is below 0.042%, corresponding to a severe tension of 4-5$\sigma$, or stronger. Therefore, we conclude that one should pursue other possible solutions beyond short-baseline oscillations for the Gallium Anomaly. We also present a new global fit of $\nu_e$ and $\bar\nu_e$ disappearance data, showing that there is a 2.6-3.3$\sigma$ preference in favor of short-baseline oscillations, which is driven by an updated analysis of reactor spectral ratio data. |
hep-ph/9604351 | Paolo Nason | S. Catani, M.L. Mangano, P. Nason and L. Trentadue | The Resummation of Soft Gluon in Hadronic Collisions | 45 pages, Latex, epsfig, 10 figures. Minor corrections to text,
notation and references. The previously quoted HERAb NLO bottom production
cross section was wrong, and it has been fixed. Accepted for Publication on
Nucl. Phys. B | Nucl.Phys. B478 (1996) 273-310 | 10.1016/0550-3213(96)00399-9 | CERN-TH/96-86 | hep-ph | null | We compute the effects of soft gluon resummation for the production of high
mass systems in hadronic collisions. We carefully analyse the growth of the
perturbative expansion coefficients of the resummation formula. We propose an
expression consistent with the known leading and next-to-leading resummation
results, in which the coefficients grow much less than factorially. We apply
our formula to Drell--Yan pair production, heavy flavour production, and the
production of high invariant mass jet pairs in hadronic collisions. We find
that, with our formula, resummation effects become important only fairly close
to the threshold region. In the case of heavy flavour production we find that
resummation effects are small in the experimental configurations of practical
interest.
| [
{
"created": "Thu, 18 Apr 1996 10:45:17 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Jul 1996 09:52:42 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Catani",
"S.",
""
],
[
"Mangano",
"M. L.",
""
],
[
"Nason",
"P.",
""
],
[
"Trentadue",
"L.",
""
]
] | We compute the effects of soft gluon resummation for the production of high mass systems in hadronic collisions. We carefully analyse the growth of the perturbative expansion coefficients of the resummation formula. We propose an expression consistent with the known leading and next-to-leading resummation results, in which the coefficients grow much less than factorially. We apply our formula to Drell--Yan pair production, heavy flavour production, and the production of high invariant mass jet pairs in hadronic collisions. We find that, with our formula, resummation effects become important only fairly close to the threshold region. In the case of heavy flavour production we find that resummation effects are small in the experimental configurations of practical interest. |
hep-ph/9701387 | Tilo Wettig | T. Wettig, T. Guhr, A. Sch\"afer, and H. A. Weidenm\"uller | The chiral phase transition, random matrix models, and lattice data | added a reference and a comment to the model in Section 3 | null | null | null | hep-ph | null | We present two pieces of evidence in support of the conjecture that the
microscopic spectral density of the Dirac operator is a universal quantity.
First, we compare lattice data to predictions from random matrix theory.
Second, we show that the functional form of the microscopic spectral
correlations remains unchanged in random matrix models which take account of
finite temperature. Furthermore, we present a random matrix model for the
chiral phase transition in which all Matsubara frequencies are included.
| [
{
"created": "Mon, 27 Jan 1997 15:39:05 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Feb 1997 12:52:23 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Wettig",
"T.",
""
],
[
"Guhr",
"T.",
""
],
[
"Schäfer",
"A.",
""
],
[
"Weidenmüller",
"H. A.",
""
]
] | We present two pieces of evidence in support of the conjecture that the microscopic spectral density of the Dirac operator is a universal quantity. First, we compare lattice data to predictions from random matrix theory. Second, we show that the functional form of the microscopic spectral correlations remains unchanged in random matrix models which take account of finite temperature. Furthermore, we present a random matrix model for the chiral phase transition in which all Matsubara frequencies are included. |
2209.07612 | Qian Song | Ayres Freitas and Qian Song | Two-Loop Electroweak Corrections with Fermion Loops to $e^+ e^- \to ZH$ | 6 pages, 3 figures, 1 table. Ref.8 is changed | null | 10.1103/PhysRevLett.130.031801 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a complete calculation of the next-to-next-to-leading (NNLO)
electroweak corrections involving closed fermion loops to the $e^+ e^- \to ZH$
process. This has been achieved by using a semi-numerical technique for the
two-loop vertex and box diagrams, which is based on Feynman parameters and
dispersion relations for one of the two sub-loops. UV divergences are treated
with suitable subtraction terms. Numerical results for the unpolarized
differential and integrated cross-section at center-of-mass energy
$\sqrt{s}=240~\text{GeV}$ are provided. Combining the NNLO contributions with
one and two closed fermions loops, they are found to increase the NLO
cross-section by 0.7\%.
| [
{
"created": "Thu, 15 Sep 2022 21:20:02 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jan 2023 17:31:55 GMT",
"version": "v2"
}
] | 2023-02-01 | [
[
"Freitas",
"Ayres",
""
],
[
"Song",
"Qian",
""
]
] | We present a complete calculation of the next-to-next-to-leading (NNLO) electroweak corrections involving closed fermion loops to the $e^+ e^- \to ZH$ process. This has been achieved by using a semi-numerical technique for the two-loop vertex and box diagrams, which is based on Feynman parameters and dispersion relations for one of the two sub-loops. UV divergences are treated with suitable subtraction terms. Numerical results for the unpolarized differential and integrated cross-section at center-of-mass energy $\sqrt{s}=240~\text{GeV}$ are provided. Combining the NNLO contributions with one and two closed fermions loops, they are found to increase the NLO cross-section by 0.7\%. |
1104.0602 | Shao-Feng Ge | Shao-Feng Ge, Duane A. Dicus and Wayne W. Repko | Z_2 Symmetry Prediction for the Leptonic Dirac CP Phase | 5 pages, 4 figures; Condensed version or PLB with references added;
for more details see the previous version | Phys.Lett.B702:220-223,2011 | 10.1016/j.physletb.2011.06.096 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Model-independent consequences of applying a generalized hidden horizontal
Z_2 symmetry to the neutrino mass matrix are explored. The Dirac CP phase
delta_D can be expressed in terms of the three mixing angles as 4 c_a s_a c_s
s_s s_x cos delta_D = (s^2_s - c^2_s s^2_x) (c^2_a - s^2_a) where the s_i, c_i
are sines and cosines of the atmospheric, solar, and reactor angles. This
relation is independent of neutrino masses and whether neutrinos are Dirac- or
Majorana-type. Given the present constraints on the angles, delta_D is
constrained to be almost maximal, a result which can be explored in experiments
such as NOvA and T2K. The Majorana CP phases do not receive any constraint and
are thus model-dependent. Also a distribution of theta_x with a lower limit is
obtained without specifying delta_D.
| [
{
"created": "Mon, 4 Apr 2011 15:35:18 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Aug 2011 01:11:12 GMT",
"version": "v2"
}
] | 2011-08-11 | [
[
"Ge",
"Shao-Feng",
""
],
[
"Dicus",
"Duane A.",
""
],
[
"Repko",
"Wayne W.",
""
]
] | Model-independent consequences of applying a generalized hidden horizontal Z_2 symmetry to the neutrino mass matrix are explored. The Dirac CP phase delta_D can be expressed in terms of the three mixing angles as 4 c_a s_a c_s s_s s_x cos delta_D = (s^2_s - c^2_s s^2_x) (c^2_a - s^2_a) where the s_i, c_i are sines and cosines of the atmospheric, solar, and reactor angles. This relation is independent of neutrino masses and whether neutrinos are Dirac- or Majorana-type. Given the present constraints on the angles, delta_D is constrained to be almost maximal, a result which can be explored in experiments such as NOvA and T2K. The Majorana CP phases do not receive any constraint and are thus model-dependent. Also a distribution of theta_x with a lower limit is obtained without specifying delta_D. |
hep-ph/0006194 | Mrinal Dasgupta | Mrinal Dasgupta | Soft gluon resummation for shape variable distributions in DIS | 4 pages, talk presented at the 8th International workshop on Deep
Inelastic Scattering and QCD, Liverpool, April 2000 | null | null | null | hep-ph | null | We discuss the procedure to resum large logarithms to all orders for DIS
event shape variable distributions.
Results are described for two variants of the thrust variable, both defined
wrt the boson axis in the current hemisphere of the Breit frame, but with
different normalisations.
| [
{
"created": "Fri, 16 Jun 2000 15:17:51 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Dasgupta",
"Mrinal",
""
]
] | We discuss the procedure to resum large logarithms to all orders for DIS event shape variable distributions. Results are described for two variants of the thrust variable, both defined wrt the boson axis in the current hemisphere of the Breit frame, but with different normalisations. |
1904.09382 | Stefan H\"oche | Stefan H\"oche, Johannes Krause, Frank Siegert | Multi-jet merging in a variable flavor number scheme | 18 pages, 5 figures, 1 table | Phys. Rev. D 100, 014011 (2019) | 10.1103/PhysRevD.100.014011 | FERMILAB-PUB-19-148-T, MCNET-19-07 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a novel technique for the combination of multi-jet merged
simulations in the five-flavor scheme with calculations for the production of
b-quark associated final states in the four-flavor scheme. We show the
equivalence of our algorithm to the FONLL method at the fixed-order and
logarithmic accuracy inherent to the matrix-element and parton-shower
simulation employed in the multi-jet merging. As a first application we discuss
Zbb production at the Large Hadron Collider.
| [
{
"created": "Sat, 20 Apr 2019 01:03:56 GMT",
"version": "v1"
}
] | 2019-07-17 | [
[
"Höche",
"Stefan",
""
],
[
"Krause",
"Johannes",
""
],
[
"Siegert",
"Frank",
""
]
] | We propose a novel technique for the combination of multi-jet merged simulations in the five-flavor scheme with calculations for the production of b-quark associated final states in the four-flavor scheme. We show the equivalence of our algorithm to the FONLL method at the fixed-order and logarithmic accuracy inherent to the matrix-element and parton-shower simulation employed in the multi-jet merging. As a first application we discuss Zbb production at the Large Hadron Collider. |
2203.09561 | Admir Greljo | Admir Greljo, Ajdin Palavri\'c, Anders Eller Thomsen | Adding Flavor to the SMEFT | 55 pages, no figures, many tables. V2: Numerical estimates for the
flavor spurions added. Referances expanded. Published in JHEP | null | 10.1007/JHEP10(2022)005 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We study the flavor structure of the lepton and baryon number--conserving
dimension-6 operators in the Standard Model effective field theory (SMEFT).
Building on the work of [1], we define several well-motivated flavor symmetries
and symmetry-breaking patterns that serve as competing hypotheses about the
ultraviolet (UV) dynamics beyond the SM, not far above the TeV scale. In
particular, we consider four different structures in the quark sector and seven
in the charged lepton sector. The set of flavor-breaking spurions is (almost)
always taken to be the minimal one needed to reproduce the observed charged
fermion masses and mixings. For each case, we explicitly construct and count
the operators to the first few orders in the spurion expansion, providing
ready-for-use setups for phenomenological studies and global fits. We provide a
Mathematica package SMEFTflavor to facilitate similar analyses for flavor
symmetries not covered in this work.
| [
{
"created": "Thu, 17 Mar 2022 18:49:06 GMT",
"version": "v1"
},
{
"created": "Thu, 25 May 2023 15:54:11 GMT",
"version": "v2"
}
] | 2023-05-26 | [
[
"Greljo",
"Admir",
""
],
[
"Palavrić",
"Ajdin",
""
],
[
"Thomsen",
"Anders Eller",
""
]
] | We study the flavor structure of the lepton and baryon number--conserving dimension-6 operators in the Standard Model effective field theory (SMEFT). Building on the work of [1], we define several well-motivated flavor symmetries and symmetry-breaking patterns that serve as competing hypotheses about the ultraviolet (UV) dynamics beyond the SM, not far above the TeV scale. In particular, we consider four different structures in the quark sector and seven in the charged lepton sector. The set of flavor-breaking spurions is (almost) always taken to be the minimal one needed to reproduce the observed charged fermion masses and mixings. For each case, we explicitly construct and count the operators to the first few orders in the spurion expansion, providing ready-for-use setups for phenomenological studies and global fits. We provide a Mathematica package SMEFTflavor to facilitate similar analyses for flavor symmetries not covered in this work. |
1106.0375 | Sandy S. C. Law | Sandy S. C. Law | Constraints on exotic lepton doublets with minimal coupling to the
standard model | 18 pages, 1 figure, 2 tables (REVTeX4.1); v2: added discussions in
Sec.II, III & IX and new ref. To appear in JHEP. arXiv admin note: text
overlap with arXiv:1011.4730 | null | 10.1007/JHEP02(2012)127 | CYCU-HEP-11-07 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the consequences of introducing a set of exotic doublet
leptons which couple to the standard model leptons in a minimal way. Through
these additional gauge invariant and renormalizable coupling terms, new sources
of tree-level flavor changing currents are induced via mixing. In this work, we
derive constraints on the parameters that govern the couplings to the exotic
doublets by invoking the current low-energy experimental data on processes such
as leptonic Z decays, $\ell \rightarrow 3 \ell'$, $\ell \rightarrow \ell'
\gamma$, and $\mu$-$e$ conversion in atomic nuclei. Moreover, we have analyzed
the role these doublets play on the lepton anomalous magnetic moments, and
found that their contribution is negligible.
| [
{
"created": "Thu, 2 Jun 2011 07:04:28 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Feb 2012 06:58:09 GMT",
"version": "v2"
}
] | 2015-05-28 | [
[
"Law",
"Sandy S. C.",
""
]
] | We investigate the consequences of introducing a set of exotic doublet leptons which couple to the standard model leptons in a minimal way. Through these additional gauge invariant and renormalizable coupling terms, new sources of tree-level flavor changing currents are induced via mixing. In this work, we derive constraints on the parameters that govern the couplings to the exotic doublets by invoking the current low-energy experimental data on processes such as leptonic Z decays, $\ell \rightarrow 3 \ell'$, $\ell \rightarrow \ell' \gamma$, and $\mu$-$e$ conversion in atomic nuclei. Moreover, we have analyzed the role these doublets play on the lepton anomalous magnetic moments, and found that their contribution is negligible. |
1108.3772 | Qiang Zhao | Jia-Jun Wu, Xiao-Hai Liu, Qiang Zhao, and Bing-Song Zou | The puzzle of anomalously large isospin violations in
$\eta(1405/1475)\to 3\pi$ | 4 pages and 7 eps figures; Journal-matched version | Phys. Rev. Lett. 108, 081803 (2012) | 10.1103/PhysRevLett.108.081803 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The BES-III Collaboration recently report the observation of anomalously
large isospin violations in $J/\psi\to \gamma\eta(1405/1475) \to \gamma \pi^0
f_0(980)\to \gamma +3\pi$, where the $f_0(980)$ in the $\pi\pi$ invariant mass
spectrum appears to be much narrower ($\sim$ 10 MeV) than the peak width
($\sim$50 MeV) measured in other processes. We show that a mechanism, named as
triangle singularity (TS), can produce a narrow enhancement between the charged
and neutral $K\bar{K}$ thresholds, i.e., $2m_{K^\pm}\sim 2m_{K^0}$. It can also
lead to different invariant mass spectra for $\eta(1405/1475)\to a_0(980)\pi$
and $K\bar{K}^*+c.c.$, which can possibly explain the long-standing puzzle
about the need for two close states $\eta(1405)$ and $\eta(1475)$ in
$\eta\pi\pi$ and $K\bar{K}\pi$, respectively. The TS could be a key to our
understanding of the nature of $\eta(1405/1475)$ and advance our knowledge
about the mixing between $a_0(980)$ and $f_0(980)$.
| [
{
"created": "Thu, 18 Aug 2011 14:53:46 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Jan 2012 01:42:52 GMT",
"version": "v2"
},
{
"created": "Thu, 23 Feb 2012 04:50:53 GMT",
"version": "v3"
}
] | 2015-05-30 | [
[
"Wu",
"Jia-Jun",
""
],
[
"Liu",
"Xiao-Hai",
""
],
[
"Zhao",
"Qiang",
""
],
[
"Zou",
"Bing-Song",
""
]
] | The BES-III Collaboration recently report the observation of anomalously large isospin violations in $J/\psi\to \gamma\eta(1405/1475) \to \gamma \pi^0 f_0(980)\to \gamma +3\pi$, where the $f_0(980)$ in the $\pi\pi$ invariant mass spectrum appears to be much narrower ($\sim$ 10 MeV) than the peak width ($\sim$50 MeV) measured in other processes. We show that a mechanism, named as triangle singularity (TS), can produce a narrow enhancement between the charged and neutral $K\bar{K}$ thresholds, i.e., $2m_{K^\pm}\sim 2m_{K^0}$. It can also lead to different invariant mass spectra for $\eta(1405/1475)\to a_0(980)\pi$ and $K\bar{K}^*+c.c.$, which can possibly explain the long-standing puzzle about the need for two close states $\eta(1405)$ and $\eta(1475)$ in $\eta\pi\pi$ and $K\bar{K}\pi$, respectively. The TS could be a key to our understanding of the nature of $\eta(1405/1475)$ and advance our knowledge about the mixing between $a_0(980)$ and $f_0(980)$. |
1509.05919 | Kirill Kanshin | K. Kanshin | One loop effective nonlinear Lagrangian with a light H-boson | presented at the 50th Rencontres de Moriond session, "Electroweak
interactions and unified theories", La Thuile, March 14-21, 2015 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study one loop structure of the scalar sector of non-linear electroweak
chiral Lagrangian (EWChL) with a light (composite) H-boson up to four
derivatives. First, we introduce relevant Lagrangian terms in general
parametrization of would-be Goldstone modes, taking into account potential and
finite mass of the scalar. Then we compute 1-, 2-, 3- and 4-point functions and
perform complete off-shell renormalization of the processes considered. On the
way we found new divergencies involving also the H-boson which cannot be
absorbed by the parameters of chiral invariant Lagrangian. We have demonstrated
explicitly how these divergencies can be removed by field redefinition, and
therefore proved that they are non-physical and give no contribution to the
on-shell amplitudes. As a physical result renormalization group equations are
derived to be used for future H-boson data analyses.
| [
{
"created": "Sat, 19 Sep 2015 18:09:01 GMT",
"version": "v1"
}
] | 2015-09-22 | [
[
"Kanshin",
"K.",
""
]
] | We study one loop structure of the scalar sector of non-linear electroweak chiral Lagrangian (EWChL) with a light (composite) H-boson up to four derivatives. First, we introduce relevant Lagrangian terms in general parametrization of would-be Goldstone modes, taking into account potential and finite mass of the scalar. Then we compute 1-, 2-, 3- and 4-point functions and perform complete off-shell renormalization of the processes considered. On the way we found new divergencies involving also the H-boson which cannot be absorbed by the parameters of chiral invariant Lagrangian. We have demonstrated explicitly how these divergencies can be removed by field redefinition, and therefore proved that they are non-physical and give no contribution to the on-shell amplitudes. As a physical result renormalization group equations are derived to be used for future H-boson data analyses. |
hep-ph/9703316 | null | M. Suzuki | Removing flavor changing neutral interactions from leptoquark exchange | Latex 10 pages with no figure | null | null | LBNL 40111 | hep-ph | null | We look for a mechanism that removes without numerical fine tuning the strong
constraint imposed by the flavor changing neutral current interaction of
leptoquark exchange. If n x n degenerate leptoquarks couple universally to n
generations of quarks and leptons in the weak basis, not only can the neutral
current interactions be flavor diagonal, but also the charge current
interaction takes exactly the same form as W exchange at low energies. Atomic
parity violation still imposes tight constraints. Electroweak doublets with
some left-right symmetry have the best chance to be the lightest leptoquarks.
| [
{
"created": "Thu, 13 Mar 1997 18:44:45 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Suzuki",
"M.",
""
]
] | We look for a mechanism that removes without numerical fine tuning the strong constraint imposed by the flavor changing neutral current interaction of leptoquark exchange. If n x n degenerate leptoquarks couple universally to n generations of quarks and leptons in the weak basis, not only can the neutral current interactions be flavor diagonal, but also the charge current interaction takes exactly the same form as W exchange at low energies. Atomic parity violation still imposes tight constraints. Electroweak doublets with some left-right symmetry have the best chance to be the lightest leptoquarks. |
hep-ph/0012009 | Dmitri Antonov | Dmitri Antonov (INFN, Pisa) | Confining strings in the Abelian-projected SU(3)-gluodynamics II.
4D-case with $\theta$-term | 8 pages, LaTeX2e, no figures, to appear in Europhys. Letters | Europhys.Lett.54:715-721,2001 | 10.1209/epl/i2001-00311-6 | null | hep-ph | null | The generalization of 4D confining string theory to the SU(3)-inspired case
is derived. It describes string representation of the Wilson loop in the
SU(3)-analogue of compact QED extended by the $\theta$-term. It is shown that
although the obtained theory of confining strings differs from that of compact
QED, their low-energy limits have the same functional form. This fact leads to
the appearance of the string $\theta$-term in the low-energy limit of the
SU(3)-inspired confining string theory. In particular, it is shown that in the
extreme strong coupling regime, the crumpling of string world sheets could
disappear owing to the string $\theta$-term at $\theta=\pi/12$. Finally, some
characteristic features of the SU(N)-case are pointed out.
| [
{
"created": "Fri, 1 Dec 2000 11:42:31 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Apr 2001 09:20:56 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Antonov",
"Dmitri",
"",
"INFN, Pisa"
]
] | The generalization of 4D confining string theory to the SU(3)-inspired case is derived. It describes string representation of the Wilson loop in the SU(3)-analogue of compact QED extended by the $\theta$-term. It is shown that although the obtained theory of confining strings differs from that of compact QED, their low-energy limits have the same functional form. This fact leads to the appearance of the string $\theta$-term in the low-energy limit of the SU(3)-inspired confining string theory. In particular, it is shown that in the extreme strong coupling regime, the crumpling of string world sheets could disappear owing to the string $\theta$-term at $\theta=\pi/12$. Finally, some characteristic features of the SU(N)-case are pointed out. |
1002.2531 | Ying Li | Juan Hua, C.s Kim, Ying Li | Annihilation-Type Charmless Radiative Decays of B Meson in Non-universal
Z^\prime Model | 13 pages, 8 figures | Eur.Phys.J.C69:139-146,2010 | 10.1140/epjc/s10052-010-1395-2 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study charmless pure annihilation type radiative B decays within the QCD
factorization approach. After adding the vertex corrections to the naive
factorization approach, we find that the branching ratios of
$\bar{B}^0_d\to\phi\gamma$, $\bar{B}^0_s\to\rho^0\gamma$ and
$\bar{B}^0_s\to\omega\gamma$ within the standard model are at the order of
$\mathcal{O}(10^{-12})$, $\mathcal{O}(10^{-10})$ and $\mathcal{O}(10^{-11})$,
respectively. The smallness of these decays in the standard model makes them
sensitive probes of flavor physics beyond the standard model. To explore their
physics potential, we have estimated the contribution of $Z^\prime$ boson in
the decays. Within the allowed parameter space, the branching ratios of these
decay modes can be enhanced remarkably in the non-universal $Z^\prime$ model:
The branching ratios can reach to $\mathcal{O}(10^{-8})$ for $\bar B_s^0 \to
\rho^0(\omega)\gamma$ and $\mathcal{O}(10^{-10})$ for the $\bar B_d^0 \to \phi
\gamma$, which are large enough for LHC-b and/or Super B-factories to detect
those channels in near future. Moreover, we also predict large CP asymmetries
in suitable parameter space. The observation of these modes could in turn help
us to constrain the $Z'$ mass within the model.
| [
{
"created": "Fri, 12 Feb 2010 11:52:34 GMT",
"version": "v1"
}
] | 2011-02-09 | [
[
"Hua",
"Juan",
""
],
[
"Kim",
"C. s",
""
],
[
"Li",
"Ying",
""
]
] | We study charmless pure annihilation type radiative B decays within the QCD factorization approach. After adding the vertex corrections to the naive factorization approach, we find that the branching ratios of $\bar{B}^0_d\to\phi\gamma$, $\bar{B}^0_s\to\rho^0\gamma$ and $\bar{B}^0_s\to\omega\gamma$ within the standard model are at the order of $\mathcal{O}(10^{-12})$, $\mathcal{O}(10^{-10})$ and $\mathcal{O}(10^{-11})$, respectively. The smallness of these decays in the standard model makes them sensitive probes of flavor physics beyond the standard model. To explore their physics potential, we have estimated the contribution of $Z^\prime$ boson in the decays. Within the allowed parameter space, the branching ratios of these decay modes can be enhanced remarkably in the non-universal $Z^\prime$ model: The branching ratios can reach to $\mathcal{O}(10^{-8})$ for $\bar B_s^0 \to \rho^0(\omega)\gamma$ and $\mathcal{O}(10^{-10})$ for the $\bar B_d^0 \to \phi \gamma$, which are large enough for LHC-b and/or Super B-factories to detect those channels in near future. Moreover, we also predict large CP asymmetries in suitable parameter space. The observation of these modes could in turn help us to constrain the $Z'$ mass within the model. |
1909.04384 | Muhammad Jamil Aslam | Arslan Sikandar, M. Jamil Aslam, Ishtiaq Ahmed, and Saba Shafaq | Vertex renormalization and hard scattering symmetry breaking corrections
to $B$ to axial vector meson form factors at large recoil | 21 pages, 5 figures, Alberta Thy 10-19, A version Accepted for
publication in Phys. Rev. D | Phys. Rev. D 100, 056013 (2019) | 10.1103/PhysRevD.100.056013 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The symmetries arise due to heavy quark and large energy limit help us to
reduce the number of independent form factors in the heavy-to-light $B$-meson
decays. It is expected that these symmetry relations are not exact and are
broken by the perturbative effects, namely, the vertex corrections and the
hard-spectator scatterings. The former are included in the form factors via
vertex renormalization whereas the later are calculated through light-cone
distribution amplitudes. We first calculate these symmetry breaking corrections
to the form factors involved in semileptonic $B$-meson to an axial-vector
$(K_{1})$-meson decay. Later, by using these form factors we see their effect
on the physical observables such as the zero-position of the forward-backward
$(\mathcal{A}_{FB})$ asymmetry and the longitudinal lepton polarization ($P_L$)
asymmetry in $B\rightarrow K_1(1270) \mu^+\mu^-$ decay. We find that as a
result of these corrections to the form factors, the zero-position of the
forward-backward asymmetry is shifted by $10\%$ from its SM value while the
effects on $P_L$ are rather insignificant.
| [
{
"created": "Tue, 10 Sep 2019 10:08:56 GMT",
"version": "v1"
}
] | 2019-09-25 | [
[
"Sikandar",
"Arslan",
""
],
[
"Aslam",
"M. Jamil",
""
],
[
"Ahmed",
"Ishtiaq",
""
],
[
"Shafaq",
"Saba",
""
]
] | The symmetries arise due to heavy quark and large energy limit help us to reduce the number of independent form factors in the heavy-to-light $B$-meson decays. It is expected that these symmetry relations are not exact and are broken by the perturbative effects, namely, the vertex corrections and the hard-spectator scatterings. The former are included in the form factors via vertex renormalization whereas the later are calculated through light-cone distribution amplitudes. We first calculate these symmetry breaking corrections to the form factors involved in semileptonic $B$-meson to an axial-vector $(K_{1})$-meson decay. Later, by using these form factors we see their effect on the physical observables such as the zero-position of the forward-backward $(\mathcal{A}_{FB})$ asymmetry and the longitudinal lepton polarization ($P_L$) asymmetry in $B\rightarrow K_1(1270) \mu^+\mu^-$ decay. We find that as a result of these corrections to the form factors, the zero-position of the forward-backward asymmetry is shifted by $10\%$ from its SM value while the effects on $P_L$ are rather insignificant. |
0910.3016 | Guang-You Qin | Guang-You Qin, Abhijit Majumder | A pQCD-based description of heavy and light flavor jet quenching | v2, 4 pages, 3 figures | Phys.Rev.Lett.105:262301,2010 | 10.1103/PhysRevLett.105.262301 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a successful description of the medium modification of light and
heavy flavor jets within a perturbative QCD (pQCD) based approach. Only the
couplings involving hard partons are assumed to be weak. The effect of the
medium on a hard parton, per unit time, is encoded in terms of three
non-perturbative, related transport coefficients which describe the transverse
momentum squared gained, the elastic energy loss and diffusion in elastic
energy transfer. A fit of the centrality dependence of the suppression and the
azimuthal anisotropy of leading hadrons tends to favor somewhat larger
transport coefficients for heavy quarks. Imposing additional constraints based
on leading order (LO) Hard Thermal Loop (HTL) effective theory, leads to a
worsening of the fit.
| [
{
"created": "Fri, 16 Oct 2009 01:55:34 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Sep 2010 17:06:43 GMT",
"version": "v2"
}
] | 2010-12-28 | [
[
"Qin",
"Guang-You",
""
],
[
"Majumder",
"Abhijit",
""
]
] | We present a successful description of the medium modification of light and heavy flavor jets within a perturbative QCD (pQCD) based approach. Only the couplings involving hard partons are assumed to be weak. The effect of the medium on a hard parton, per unit time, is encoded in terms of three non-perturbative, related transport coefficients which describe the transverse momentum squared gained, the elastic energy loss and diffusion in elastic energy transfer. A fit of the centrality dependence of the suppression and the azimuthal anisotropy of leading hadrons tends to favor somewhat larger transport coefficients for heavy quarks. Imposing additional constraints based on leading order (LO) Hard Thermal Loop (HTL) effective theory, leads to a worsening of the fit. |
1711.07388 | Jean-Nicolas Lang | Ansgar Denner, Jean-Nicolas Lang, Sandro Uccirati | Recola2: REcursive Computation of One-Loop Amplitudes 2 | 48 pages, 1 figure, matches published version | null | 10.1016/j.cpc.2017.11.013 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the Fortran95 program Recola2 for the perturbative computation of
next-to-leading-order transition amplitudes in the Standard Model of particle
physics and extended Higgs sectors. New theories are implemented via model
files in the 't Hooft-Feynman gauge in the conventional formulation of quantum
field theory and in the Background-Field method. The present version includes
model files for the Two-Higgs-Doublet Model and the Higgs-Singlet Extension of
the Standard Model. We support standard renormalization schemes for the
Standard Model as well as many commonly used renormalization schemes in
extended Higgs sectors. Within these models the computation of
next-to-leading-order polarized amplitudes and squared amplitudes, optionally
summed over spin and colour, is fully automated for any process. Recola2 allows
the computation of colour- and spin-correlated leading-order squared amplitudes
that are needed in the dipole subtraction formalism. Recola2 is publicly
available for download at http://recola.hepforge.org.
| [
{
"created": "Mon, 20 Nov 2017 15:52:27 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jan 2018 23:31:02 GMT",
"version": "v2"
}
] | 2018-01-10 | [
[
"Denner",
"Ansgar",
""
],
[
"Lang",
"Jean-Nicolas",
""
],
[
"Uccirati",
"Sandro",
""
]
] | We present the Fortran95 program Recola2 for the perturbative computation of next-to-leading-order transition amplitudes in the Standard Model of particle physics and extended Higgs sectors. New theories are implemented via model files in the 't Hooft-Feynman gauge in the conventional formulation of quantum field theory and in the Background-Field method. The present version includes model files for the Two-Higgs-Doublet Model and the Higgs-Singlet Extension of the Standard Model. We support standard renormalization schemes for the Standard Model as well as many commonly used renormalization schemes in extended Higgs sectors. Within these models the computation of next-to-leading-order polarized amplitudes and squared amplitudes, optionally summed over spin and colour, is fully automated for any process. Recola2 allows the computation of colour- and spin-correlated leading-order squared amplitudes that are needed in the dipole subtraction formalism. Recola2 is publicly available for download at http://recola.hepforge.org. |
1306.1039 | Giulia Ricciardi | Giulia Ricciardi | Magnitudes of V(xb) CKM matrix elements | 12 pages, no figs.; in Proceedings of the 14th International
Conference on B-Physics at Hadron Machines, April 8-12, 2013, Bologna, Italy | PoS (Beauty 2013) 040 | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the current status of the absolute values of the CKM matrix
elements V(xb), with particular attention to latest determinations.
| [
{
"created": "Wed, 5 Jun 2013 10:04:24 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jul 2013 15:10:50 GMT",
"version": "v2"
}
] | 2013-10-01 | [
[
"Ricciardi",
"Giulia",
""
]
] | We review the current status of the absolute values of the CKM matrix elements V(xb), with particular attention to latest determinations. |
2102.11257 | Lingfeng Li | Leo WH Fung, Lingfeng Li, Tao Liu, Hoang Nhan Luu, Yu-Cheng Qiu, S.-H.
Henry Tye | Axi-Higgs Cosmology | 52 pages, 8 figures. Matches the published version in JCAP | JCAP 08 (2021) 057 | 10.1088/1475-7516/2021/08/057 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If the electroweak Higgs vacuum expectation value $v$ in early universe is
$\sim 1 \%$ higher than its present value $v_0=246$ GeV, the $^7$Li puzzle in
BBN and the CMB/$\Lambda$CDM tension with late-universe measurements on Hubble
parameter are mitigated. We propose a model of an axion coupled to the Higgs
field, named ``axi-Higgs'', with its mass $m_a \sim 10^{-30} - 10^{-29}\,{\rm
eV}$ and decay constant $f_a \sim 10^{17} - 10^{18}\,{\rm GeV}$, to achieve
this goal. The axion initial value $a_{\rm ini}$ yields an initial $\Delta
v_{\rm ini}/v_0 \sim 0.01$ throughout the BBN-recombination epoch and a percent
level contribution to the total matter density today. Because of its very large
de Broglie wavelength, this axion matter density $\omega_a$ suppresses the
matter power spectrum, alleviating the CMB/$\Lambda$CDM $S_8/\sigma_8$ tension
with the weak-lensing data. It also explains the recently reported isotropic
cosmic birefringence by its coupling with photons. Adding the axion ($m \sim
10^{-22}\,$eV) in the fuzzy dark matter model to the axi-Higgs model allows
bigger $\Delta v_{\rm rec}$ and $\omega_a$ to address the Hubble and
$S_8/\sigma_8$ tensions simultaneously. The model predicts that $\Delta v$ may
be detected by the spectral measurements of quasars, while its oscillation may
be observed in the atomic clock measurements.
| [
{
"created": "Mon, 22 Feb 2021 18:41:02 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Mar 2021 08:06:03 GMT",
"version": "v2"
},
{
"created": "Fri, 3 Sep 2021 15:51:11 GMT",
"version": "v3"
}
] | 2021-09-06 | [
[
"Fung",
"Leo WH",
""
],
[
"Li",
"Lingfeng",
""
],
[
"Liu",
"Tao",
""
],
[
"Luu",
"Hoang Nhan",
""
],
[
"Qiu",
"Yu-Cheng",
""
],
[
"Tye",
"S. -H. Henry",
""
]
] | If the electroweak Higgs vacuum expectation value $v$ in early universe is $\sim 1 \%$ higher than its present value $v_0=246$ GeV, the $^7$Li puzzle in BBN and the CMB/$\Lambda$CDM tension with late-universe measurements on Hubble parameter are mitigated. We propose a model of an axion coupled to the Higgs field, named ``axi-Higgs'', with its mass $m_a \sim 10^{-30} - 10^{-29}\,{\rm eV}$ and decay constant $f_a \sim 10^{17} - 10^{18}\,{\rm GeV}$, to achieve this goal. The axion initial value $a_{\rm ini}$ yields an initial $\Delta v_{\rm ini}/v_0 \sim 0.01$ throughout the BBN-recombination epoch and a percent level contribution to the total matter density today. Because of its very large de Broglie wavelength, this axion matter density $\omega_a$ suppresses the matter power spectrum, alleviating the CMB/$\Lambda$CDM $S_8/\sigma_8$ tension with the weak-lensing data. It also explains the recently reported isotropic cosmic birefringence by its coupling with photons. Adding the axion ($m \sim 10^{-22}\,$eV) in the fuzzy dark matter model to the axi-Higgs model allows bigger $\Delta v_{\rm rec}$ and $\omega_a$ to address the Hubble and $S_8/\sigma_8$ tensions simultaneously. The model predicts that $\Delta v$ may be detected by the spectral measurements of quasars, while its oscillation may be observed in the atomic clock measurements. |
1001.5013 | Dmitri Antonov | D. Antonov, J.E.F.T. Ribeiro | Quantifying zigzag motion of quarks | 27 pages, 5 figures | Phys.Rev.D81:054027,2010 | 10.1103/PhysRevD.81.054027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The quark condensate is calculated in terms of the effective string tension
and the constituent quark mass. For 3 colors and 2 light flavors, the
constituent mass is bounded from below by the value of 460 MeV. This value is
only accessible when the string tension decreases linearly with the Schwinger
proper time. For this reason, the Hausdorff dimension of a light-quark
trajectory is equal to 4, indicating that these trajectories are similar to
branched polymers, which can describe a weak first-order deconfinement phase
transition in SU(3) Yang-Mills theory. Using this indication, we develop a
gluon-chain model based on such trajectories.
| [
{
"created": "Wed, 27 Jan 2010 20:15:26 GMT",
"version": "v1"
},
{
"created": "Fri, 14 May 2010 18:39:03 GMT",
"version": "v2"
}
] | 2010-05-18 | [
[
"Antonov",
"D.",
""
],
[
"Ribeiro",
"J. E. F. T.",
""
]
] | The quark condensate is calculated in terms of the effective string tension and the constituent quark mass. For 3 colors and 2 light flavors, the constituent mass is bounded from below by the value of 460 MeV. This value is only accessible when the string tension decreases linearly with the Schwinger proper time. For this reason, the Hausdorff dimension of a light-quark trajectory is equal to 4, indicating that these trajectories are similar to branched polymers, which can describe a weak first-order deconfinement phase transition in SU(3) Yang-Mills theory. Using this indication, we develop a gluon-chain model based on such trajectories. |
2401.00903 | LieJuan Li | Lie-Juan Li, Xiao-Wei Sun, Melike Mohamedsedik, Li Wang, Li-Na Hu and
Bai-Song Xie | Enhanced pair production in multi-pulse trains electric fields with
oscillation | 24 pages, 14 figures | null | null | null | hep-ph physics.optics | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For different alternating-sign multi-pulse trains electric fields with
oscillation, the effects of the electric field pulse number and the relative
phase of the combined electric field on pair production are investigated by
solving quantum Vlasov equation. It is found that the number density of created
particles in the combined electric fields is increased by more than one order
of magnitude compared to the results without oscillating structure for both
zero transverse momentum and full momentum space. In the case of zero
transverse momentum, the created particles longitudinal momentum spectrum are
monochromatic for large pulse numbers and some suitable relative phases. The
number density depends nonlinearly on the relative phase that enables the
optimal relative phase parameters for the number density. Moreover, for the
full momentum space, the created particles number density and momentum spectrum
under different multi-pulse trains electric fields are given and discussed. We
also find that the number density as a function of pulse number satisfies the
power law with index 5.342 for the strong but slowly varying electric field
with large pulse numbers.
| [
{
"created": "Sun, 31 Dec 2023 16:27:58 GMT",
"version": "v1"
}
] | 2024-01-03 | [
[
"Li",
"Lie-Juan",
""
],
[
"Sun",
"Xiao-Wei",
""
],
[
"Mohamedsedik",
"Melike",
""
],
[
"Wang",
"Li",
""
],
[
"Hu",
"Li-Na",
""
],
[
"Xie",
"Bai-Song",
""
]
] | For different alternating-sign multi-pulse trains electric fields with oscillation, the effects of the electric field pulse number and the relative phase of the combined electric field on pair production are investigated by solving quantum Vlasov equation. It is found that the number density of created particles in the combined electric fields is increased by more than one order of magnitude compared to the results without oscillating structure for both zero transverse momentum and full momentum space. In the case of zero transverse momentum, the created particles longitudinal momentum spectrum are monochromatic for large pulse numbers and some suitable relative phases. The number density depends nonlinearly on the relative phase that enables the optimal relative phase parameters for the number density. Moreover, for the full momentum space, the created particles number density and momentum spectrum under different multi-pulse trains electric fields are given and discussed. We also find that the number density as a function of pulse number satisfies the power law with index 5.342 for the strong but slowly varying electric field with large pulse numbers. |
hep-ph/9603414 | Matthias Neubert | Irinel Caprini (Bucharest) and Matthias Neubert (CERN) | Improved Bounds for the Slope and Curvature of $\bar B\to
D^{(*)}\ell\bar\nu$ Form Factors | 13 pages LaTeX, 2 figures appended | Phys.Lett. B380 (1996) 376-384 | 10.1016/0370-2693(96)00509-6 | CERN-TH/95-255 | hep-ph | null | We derive a theoretically allowed domain for the slope $\widehat\varrho^2$
and curvature $\widehat c$ of the physical form factor appearing in the decay
$\bar B\to D^*\ell\bar\nu$. Using heavy-quark symmetry, we relate this function
to a particular $\bar B \to D$ form factor free of ground-state $B_c$ poles
below the threshold for $B D$ production, for which almost model-independent
constraints are derived from QCD using unitarity and analyticity. Our results
are of interest for the extraction of $|V_{cb}|$ from the recoil spectrum in
exclusive semileptonic $B$ decays. Making conservative estimates of the
theoretical uncertainties, we find (up to $1/m_Q$ corrections)
$\widehat\varrho^2<1.11$ and $\widehat c\simeq 0.66\widehat\varrho^2-0.11$. We
also derive the corresponding bounds for the form factor in the decay $\bar
B\to D\ell\bar\nu$.
| [
{
"created": "Tue, 26 Mar 1996 17:31:10 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Caprini",
"Irinel",
"",
"Bucharest"
],
[
"Neubert",
"Matthias",
"",
"CERN"
]
] | We derive a theoretically allowed domain for the slope $\widehat\varrho^2$ and curvature $\widehat c$ of the physical form factor appearing in the decay $\bar B\to D^*\ell\bar\nu$. Using heavy-quark symmetry, we relate this function to a particular $\bar B \to D$ form factor free of ground-state $B_c$ poles below the threshold for $B D$ production, for which almost model-independent constraints are derived from QCD using unitarity and analyticity. Our results are of interest for the extraction of $|V_{cb}|$ from the recoil spectrum in exclusive semileptonic $B$ decays. Making conservative estimates of the theoretical uncertainties, we find (up to $1/m_Q$ corrections) $\widehat\varrho^2<1.11$ and $\widehat c\simeq 0.66\widehat\varrho^2-0.11$. We also derive the corresponding bounds for the form factor in the decay $\bar B\to D\ell\bar\nu$. |
hep-ph/0603132 | Yury Bystritskiy | Yu. M. Bystritskiy, E. A. Kuraev, E. Tomasi-Gustafsson | The structure function method applied to polarized and unpolarized
electron-proton scattering: a solution of the G_E(p)/G_M(p) discrepancy | 22 pages, 8 figures, revision of two-photon exchange K-factor
calculation | null | 10.1103/PhysRevC.75.015207 | null | hep-ph | null | The cross section for polarized and unpolarized electron-proton scattering is
calculated taking into account radiative corrections in leading and next-to
leading logarithmic approximation. The expression of the cross section is
formally similar to the cross section of the Drell-Yan process, where the
structure functions of the electron play the role of Drell-Yan probability
distributions. The interference of the Born amplitude with the two photon
exchange amplitude (box-type diagrams) is expressed as a contribution to
K-factor and it is larger when the momentum is equally shared between the two
photons, assuming that proton form factors decrease rapidly with the momentum
transfer squared. The calculation of the box amplitude is done when the
intermediate state is a proton or the Delta-resonance. The results of numerical
estimations show that the present calculation of radiative corrections can
bring into agreement the conflicting experimental results on proton
electromagnetic form factors an that the two photon contribution is very small.
| [
{
"created": "Fri, 17 Mar 2006 14:10:30 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Aug 2006 13:43:10 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Bystritskiy",
"Yu. M.",
""
],
[
"Kuraev",
"E. A.",
""
],
[
"Tomasi-Gustafsson",
"E.",
""
]
] | The cross section for polarized and unpolarized electron-proton scattering is calculated taking into account radiative corrections in leading and next-to leading logarithmic approximation. The expression of the cross section is formally similar to the cross section of the Drell-Yan process, where the structure functions of the electron play the role of Drell-Yan probability distributions. The interference of the Born amplitude with the two photon exchange amplitude (box-type diagrams) is expressed as a contribution to K-factor and it is larger when the momentum is equally shared between the two photons, assuming that proton form factors decrease rapidly with the momentum transfer squared. The calculation of the box amplitude is done when the intermediate state is a proton or the Delta-resonance. The results of numerical estimations show that the present calculation of radiative corrections can bring into agreement the conflicting experimental results on proton electromagnetic form factors an that the two photon contribution is very small. |
hep-ph/0404273 | Richard F. Lebed | Richard F. Lebed, Daniel R. Martin | Hyperon Radiative Decays in the 1/N_c Expansion | 4 pages, 1 table, ReVTeX | Phys.Rev. D70 (2004) 057901 | 10.1103/PhysRevD.70.057901 | null | hep-ph | null | Using a recent calculation of transition magnetic moments in the 1/N_c
expansion and a calculation showing the suppression of E2/M1 by powers of N_c,
we compute the widths for the radiative decays Sigma^* --> Sigma gamma, Sigma^*
--> Lambda gamma, and Xi^* --> Xi gamma.
| [
{
"created": "Thu, 29 Apr 2004 18:50:31 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Lebed",
"Richard F.",
""
],
[
"Martin",
"Daniel R.",
""
]
] | Using a recent calculation of transition magnetic moments in the 1/N_c expansion and a calculation showing the suppression of E2/M1 by powers of N_c, we compute the widths for the radiative decays Sigma^* --> Sigma gamma, Sigma^* --> Lambda gamma, and Xi^* --> Xi gamma. |
2110.12512 | Manfred Kraus | Manfred Kraus | Parton shower effects in $t\bar{t}W^\pm$ production at NLO QCD | Contribution to the proceedings of the European Physical Society
Conference on High Energy Physics (EPS-HEP2021), 26-30 July 2021 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a selection of results from our recent study of $pp\to
t\bar{t}W^\pm$ production matched to partons showers at NLO QCD at the LHC.
Theoretical predictions are obtained at perturbative orders
$\mathcal{O}(\alpha_s^3\alpha)$ and $\mathcal{O}(\alpha_s\alpha^3)$, where the
different contributions are studied first separately at the inclusive level
before being combined within a realistic two same-sign lepton signature. We
investigate in detail uncertainties originating from missing higher-order
corrections and from the parton-shower matching scheme employed.
| [
{
"created": "Sun, 24 Oct 2021 19:29:10 GMT",
"version": "v1"
}
] | 2021-10-26 | [
[
"Kraus",
"Manfred",
""
]
] | We present a selection of results from our recent study of $pp\to t\bar{t}W^\pm$ production matched to partons showers at NLO QCD at the LHC. Theoretical predictions are obtained at perturbative orders $\mathcal{O}(\alpha_s^3\alpha)$ and $\mathcal{O}(\alpha_s\alpha^3)$, where the different contributions are studied first separately at the inclusive level before being combined within a realistic two same-sign lepton signature. We investigate in detail uncertainties originating from missing higher-order corrections and from the parton-shower matching scheme employed. |
0809.2395 | Sven Heinemeyer | S. Heinemeyer | How To Determine SUSY Mass Scales Now | 6 pages, 6 figures, plenary talk given at SUSY08, Seoul, Korea | AIP Conf.Proc.1078:57-62,2009 | 10.1063/1.3052033 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Currently available experimental data from electroweak precision observables
(EWPO), B-physics observables (BPO) and cosmological data can be combined to
extract the preferred value of SUSY mass scales. We review recent results on
the predictions of the masses of supersymmetric particles and the indirect
determination of the lightest Higgs boson mass. Special emphasis is put on
models going beyond the Constrained Minimal Supersymmetric Standard Model
(CMSSM), such as the Non-Universal Higgs Model type I (NUHM1), or gauge and
anomaloy mediated SUSY breaking.
| [
{
"created": "Sun, 14 Sep 2008 13:05:36 GMT",
"version": "v1"
}
] | 2009-02-02 | [
[
"Heinemeyer",
"S.",
""
]
] | Currently available experimental data from electroweak precision observables (EWPO), B-physics observables (BPO) and cosmological data can be combined to extract the preferred value of SUSY mass scales. We review recent results on the predictions of the masses of supersymmetric particles and the indirect determination of the lightest Higgs boson mass. Special emphasis is put on models going beyond the Constrained Minimal Supersymmetric Standard Model (CMSSM), such as the Non-Universal Higgs Model type I (NUHM1), or gauge and anomaloy mediated SUSY breaking. |
hep-ph/0101042 | Ian Balitsky | I. Balitsky | High-Energy QCD and Wilson Lines | 110 pages, Latex, 40 eps figures, sprocl.sty. To be published in the
Boris Ioffe Festschrift ``At the Frontier of Particle Physics/Handbook of
QCD'', edited by M. Shifman (World Scientific, Singapore, 2001) | null | 10.1142/9789812810458_0030 | JLAB-THY-00-44 | hep-ph | null | At high energies the particles move very fast so their trajectories can be
approximated by straight lines collinear to their velocities. The proper
degrees of freedom for the fast gluons moving along the straight lines are the
Wilson-line operators -- infinite gauge factors ordered along the straight
line. I review the study of the high-energy scattering in terms of Wilson-line
degrees of freedom.
| [
{
"created": "Fri, 5 Jan 2001 03:36:59 GMT",
"version": "v1"
}
] | 2016-11-23 | [
[
"Balitsky",
"I.",
""
]
] | At high energies the particles move very fast so their trajectories can be approximated by straight lines collinear to their velocities. The proper degrees of freedom for the fast gluons moving along the straight lines are the Wilson-line operators -- infinite gauge factors ordered along the straight line. I review the study of the high-energy scattering in terms of Wilson-line degrees of freedom. |
1508.06084 | Bingwei Long | Bingwei Long | Chiral dynamics of S-wave baryon resonances | 12 pages, 2 figures. The introductory text was modified. Matches the
published version | Phys. Rev. D 94, 011503 (2016) | 10.1103/PhysRevD.94.011503 | CTP-SCU/2015011 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | As the pion mass approaches a critical value $m_\pi^\star$ from below, an
$S$-wave resonance crosses pion-baryon threshold and becomes a bound state with
arbitrarily small binding energy, thus driving the scattering length to
diverge. I explore the consequences of chiral symmetry for the values of
$m_\pi$ close to $m_\pi^\star$. It turns out that chiral symmetry is crucial
for an $S$-wave resonance to be able to stand very near threshold and in the
meantime to remain narrow, provided that the mass splitting is reasonably
small. The effective range of pion-baryon scattering is unexpectedly large,
proportional to $ 4\pi f_\pi^2/m_\pi^3$ when $m_\pi$ is around $m_\pi^\star$.
As a result, this unexpected large length scale causes universality relations
to break down much sooner than naively expected.
| [
{
"created": "Tue, 25 Aug 2015 09:31:52 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jul 2016 16:01:08 GMT",
"version": "v2"
}
] | 2016-07-27 | [
[
"Long",
"Bingwei",
""
]
] | As the pion mass approaches a critical value $m_\pi^\star$ from below, an $S$-wave resonance crosses pion-baryon threshold and becomes a bound state with arbitrarily small binding energy, thus driving the scattering length to diverge. I explore the consequences of chiral symmetry for the values of $m_\pi$ close to $m_\pi^\star$. It turns out that chiral symmetry is crucial for an $S$-wave resonance to be able to stand very near threshold and in the meantime to remain narrow, provided that the mass splitting is reasonably small. The effective range of pion-baryon scattering is unexpectedly large, proportional to $ 4\pi f_\pi^2/m_\pi^3$ when $m_\pi$ is around $m_\pi^\star$. As a result, this unexpected large length scale causes universality relations to break down much sooner than naively expected. |
hep-ph/0211028 | Oleg Teryaev | I.V. Anikin, O.V. Teryaev | Genuine twist 3 in exclusive electroproduction of transversely polarized
vector mesons | 14 pages, 6 ps. figures | Phys.Lett. B554 (2003) 51-63 | 10.1016/S0370-2693(02)03195-7 | CPHT RR075.1102 | hep-ph | null | We present the detailed analysis of genuine twist-3 contributions to the
exclusive electroproduction amplitude of transversely polarized vector mesons.
Using the formalism based on the QCD factorization in the momentum
representation we calculated all the genuine twist-3 terms and found the total
expression of this amplitude at 1/Q level. Generally speaking, these terms
violate standard factorization owing to the existence of the infrared
divergencies in the amplitude of hard sub-processes, although the strongest
divergencies cancel due to the QCD equations of motion. We discuss the possible
treatment of surviving divergencies.
| [
{
"created": "Mon, 4 Nov 2002 16:32:10 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Dec 2002 09:47:14 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Anikin",
"I. V.",
""
],
[
"Teryaev",
"O. V.",
""
]
] | We present the detailed analysis of genuine twist-3 contributions to the exclusive electroproduction amplitude of transversely polarized vector mesons. Using the formalism based on the QCD factorization in the momentum representation we calculated all the genuine twist-3 terms and found the total expression of this amplitude at 1/Q level. Generally speaking, these terms violate standard factorization owing to the existence of the infrared divergencies in the amplitude of hard sub-processes, although the strongest divergencies cancel due to the QCD equations of motion. We discuss the possible treatment of surviving divergencies. |
hep-ph/0011169 | Thomas Schwetz | W. Grimus, T. Schwetz | Elastic $\nu e^-$ scattering of solar neutrinos with electromagnetic
moments | 4 pages, Talk given by T. Schwetz at EuroConference on Frontiers in
Particle Astrophysics and Cosmology, San Feliu de Guixols, Spain, 30 Sept.-5
Oct. 2000 | Nucl.Phys.Proc.Suppl. 95 (2001) 169-172 | 10.1016/S0920-5632(01)01077-5 | UWThPh-2000-45 | hep-ph | null | We consider the azimuthal asymmetry of the recoil electrons in elastic $\nu
e^-$ scattering of solar neutrinos, which can arise if neutrinos have
electromagnetic moments and there is a large solar magnetic field. We show that
using this effect it is not possible to distinguish between magnetic and
electric dipole moment in the 1-Dirac and 2-Majorana neutrino cases and that
averaging over neutrino energy is important and suppresses the azimuthal
asymmetry in the 2-Majorana case.
| [
{
"created": "Mon, 13 Nov 2000 15:41:56 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Grimus",
"W.",
""
],
[
"Schwetz",
"T.",
""
]
] | We consider the azimuthal asymmetry of the recoil electrons in elastic $\nu e^-$ scattering of solar neutrinos, which can arise if neutrinos have electromagnetic moments and there is a large solar magnetic field. We show that using this effect it is not possible to distinguish between magnetic and electric dipole moment in the 1-Dirac and 2-Majorana neutrino cases and that averaging over neutrino energy is important and suppresses the azimuthal asymmetry in the 2-Majorana case. |
1603.03250 | Shi-Yuan Li | Yi Jin and Shi-Yuan Li | Large production rate of new $B^0_s \pi^{\pm}$ and $D^{\pm}_s \pi^{\pm}$
states in high energy multi-production process | 10 pages, 2 figures | Published in Phys.Rev. D94 (2016) no.1, 014023 | 10.1103/PhysRevD.94.014023 | SDU-TH/2016001 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The production rate of the X(5568) observed by D0 collabotation is quite
large and can not be understood by various general hadronization mechanism. We
propose an inclusive resonance production formulation to calculate the cross
section and extract the value of the effective wave function at origin. Based
on these results we suspect X($D_s \pi^{\pm}$) can be copiously produced and
observable at high enenrgy scatterings (the relative production ratio to D_s is
larger than 10 %).
In the updated version the discussions on cluster model and FI are added.
Both cases can not give large rate.
Then we show that pion in X(5568) decay can only gain a very small momentum.
In the pseudo-rapidity region [2,5], large part of the signal pions will be
dismissed by the detector since the transverse mometum is too small and/or
total momentum too small. If further requirement on pion tranverse mometum
larger than 1GeV/c added, almost all signal pions are rejected. But for the
charm partner, this problem does not exist since the charm partner can give a
larger boost factor. A 3D distribution of signal pions are added
| [
{
"created": "Thu, 10 Mar 2016 13:09:56 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Mar 2016 06:04:41 GMT",
"version": "v2"
},
{
"created": "Sun, 20 Mar 2016 11:40:49 GMT",
"version": "v3"
},
{
"created": "Mon, 28 Mar 2016 13:11:26 GMT",
"version": "v4"
},
{
"c... | 2016-10-17 | [
[
"Jin",
"Yi",
""
],
[
"Li",
"Shi-Yuan",
""
]
] | The production rate of the X(5568) observed by D0 collabotation is quite large and can not be understood by various general hadronization mechanism. We propose an inclusive resonance production formulation to calculate the cross section and extract the value of the effective wave function at origin. Based on these results we suspect X($D_s \pi^{\pm}$) can be copiously produced and observable at high enenrgy scatterings (the relative production ratio to D_s is larger than 10 %). In the updated version the discussions on cluster model and FI are added. Both cases can not give large rate. Then we show that pion in X(5568) decay can only gain a very small momentum. In the pseudo-rapidity region [2,5], large part of the signal pions will be dismissed by the detector since the transverse mometum is too small and/or total momentum too small. If further requirement on pion tranverse mometum larger than 1GeV/c added, almost all signal pions are rejected. But for the charm partner, this problem does not exist since the charm partner can give a larger boost factor. A 3D distribution of signal pions are added |
2302.12450 | Shu Lin | Shu Lin and Jiayuan Tian | Medium Correction to Gravitational Form Factors | 26 pages, 4 figures. Translated from contribution by the same authors
to appear in Acta Physica Sinica (in Chinese) | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We generalize the gravitational form factor for chiral fermion in vacuum,
which reproduces the well-known spin-vorticity coupling. We also calculate
radiative correction to the gravitational form factors in quantum
electrodynamics plasma. We find two structures in the form factors contributing
to the scattering amplitude of fermion in vorticity field, one is from the
fermion self-energy correction, pointing to suppression of spin-vorticity
coupling in medium; the other structure comes from graviton-fermion vertex
correction, which does not adopt potential interpretation, but corresponds to
transition matrix element between initial and final states. Both structures
contribute to axial chiral vortical effect. The net effect is that radiative
correction enhances the axial chiral vortical effect. Our results clarify the
relation and difference between spin-vorticity coupling and axial chiral
vortical effect from the perspective of form factors. We also discuss the
application of the results in quantum chromodynamic plasma, indicating
radiative correction might have an appreciable effect in spin polarization
effect in heavy ion collisions.
| [
{
"created": "Fri, 24 Feb 2023 04:34:58 GMT",
"version": "v1"
}
] | 2023-02-27 | [
[
"Lin",
"Shu",
""
],
[
"Tian",
"Jiayuan",
""
]
] | We generalize the gravitational form factor for chiral fermion in vacuum, which reproduces the well-known spin-vorticity coupling. We also calculate radiative correction to the gravitational form factors in quantum electrodynamics plasma. We find two structures in the form factors contributing to the scattering amplitude of fermion in vorticity field, one is from the fermion self-energy correction, pointing to suppression of spin-vorticity coupling in medium; the other structure comes from graviton-fermion vertex correction, which does not adopt potential interpretation, but corresponds to transition matrix element between initial and final states. Both structures contribute to axial chiral vortical effect. The net effect is that radiative correction enhances the axial chiral vortical effect. Our results clarify the relation and difference between spin-vorticity coupling and axial chiral vortical effect from the perspective of form factors. We also discuss the application of the results in quantum chromodynamic plasma, indicating radiative correction might have an appreciable effect in spin polarization effect in heavy ion collisions. |
1105.4878 | Andre Lessa | Genevi\`eve B\'elanger, Sabine Kraml and Andre Lessa | Light Sneutrino Dark Matter at the LHC | 25 pages, 16 figures | JHEP 1107:083,2011 | 10.1007/JHEP07(2011)083 | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In supersymmetric (SUSY) models with Dirac neutrino masses, a weak-scale
trilinear A-term that is not proportional to the small neutrino Yukawa
couplings can induce a sizable mixing between left and right-handed sneutrinos.
The lighter sneutrino mass eigenstate can hence become the lightest SUSY
particle (LSP) and a viable dark matter candidate. In particular, it can be an
excellent candidate for light dark matter with mass below ~10 GeV. Such a light
mixed sneutrino LSP has a dramatic effect on SUSY signatures at the LHC, as
charginos decay dominantly into the light sneutrino plus a charged lepton, and
neutralinos decay invisibly to a neutrino plus a sneutrino. We perform a
detailed study of the LHC potential to resolve the light sneutrino dark matter
scenario by means of three representative benchmark points with different
gluino and squark mass hierarchies. We study in particular the determination of
the LSP (sneutrino) mass from cascade decays involving charginos, using the mT2
variable. Moreover, we address measurements of additional invisible sparticles,
in our case the lightest neutralino, and the question of discrimination against
the MSSM.
| [
{
"created": "Tue, 24 May 2011 20:00:06 GMT",
"version": "v1"
},
{
"created": "Tue, 31 May 2011 19:12:29 GMT",
"version": "v2"
}
] | 2015-03-19 | [
[
"Bélanger",
"Geneviève",
""
],
[
"Kraml",
"Sabine",
""
],
[
"Lessa",
"Andre",
""
]
] | In supersymmetric (SUSY) models with Dirac neutrino masses, a weak-scale trilinear A-term that is not proportional to the small neutrino Yukawa couplings can induce a sizable mixing between left and right-handed sneutrinos. The lighter sneutrino mass eigenstate can hence become the lightest SUSY particle (LSP) and a viable dark matter candidate. In particular, it can be an excellent candidate for light dark matter with mass below ~10 GeV. Such a light mixed sneutrino LSP has a dramatic effect on SUSY signatures at the LHC, as charginos decay dominantly into the light sneutrino plus a charged lepton, and neutralinos decay invisibly to a neutrino plus a sneutrino. We perform a detailed study of the LHC potential to resolve the light sneutrino dark matter scenario by means of three representative benchmark points with different gluino and squark mass hierarchies. We study in particular the determination of the LSP (sneutrino) mass from cascade decays involving charginos, using the mT2 variable. Moreover, we address measurements of additional invisible sparticles, in our case the lightest neutralino, and the question of discrimination against the MSSM. |
2208.05000 | Haowu Duan | Haowu Duan, Alexander Kovner, Vladimir V. Skokov | CGC for Ultra-Peripheral Pb+Pb Collisions at the Large Hadron Collider:
a more realistic calculation | 35 pages,8 figures | null | 10.1007/JHEP12(2022)077 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | We provide the first calculation of two-gluon production at mid-rapidity in
ultra-peripheral collisions in the Color Glass Condensate framework. To
estimate systematic uncertainty associated with poor understanding of the wave
function of the nearly real photon, we consider two diametrically different
models: the dilute quark-antiquark dipole approximation and a vector meson, in
which color charge density is approximated by McLerran-Venugopalan model. In
the experimentally relevant range, the target nucleus can be faithfully
approximated by a highly saturated state. This simplification enables us to
perform efficient numerical simulations and extract the two-gluon correlation
functions and the associated azimuthal harmonics.
| [
{
"created": "Tue, 9 Aug 2022 19:04:27 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Dec 2022 18:37:03 GMT",
"version": "v2"
}
] | 2022-12-28 | [
[
"Duan",
"Haowu",
""
],
[
"Kovner",
"Alexander",
""
],
[
"Skokov",
"Vladimir V.",
""
]
] | We provide the first calculation of two-gluon production at mid-rapidity in ultra-peripheral collisions in the Color Glass Condensate framework. To estimate systematic uncertainty associated with poor understanding of the wave function of the nearly real photon, we consider two diametrically different models: the dilute quark-antiquark dipole approximation and a vector meson, in which color charge density is approximated by McLerran-Venugopalan model. In the experimentally relevant range, the target nucleus can be faithfully approximated by a highly saturated state. This simplification enables us to perform efficient numerical simulations and extract the two-gluon correlation functions and the associated azimuthal harmonics. |
hep-ph/0411304 | Klaus Moenig | A. Freitas, K. Moenig | Corrections to Quark Asymmetries at LEP | null | Eur.Phys.J.C40:493,2005 | 10.1140/epjc/s2005-02164-6 | FERMILAB-Pub-04/352-T, DESY 04-225 | hep-ph | null | The most precise measurement of the weak mixing angle sin^2(theta) at LEP is
from the forward-backward asymmetry e+e- --> bbbar at the Z-pole. In this note
the QED and electroweak radiative corrections to obtain the pole asymmetry from
the measured asymmetry for b- and c-quarks have been calculated using ZFITTER,
which has been amended to allow a consistent treatment of partial two-loop
corrections for the b-quark final asymmetries.
A total correction of dAfbb=0.0019+/-0.0002 and dAfbc=0.0064+/-0.0001 has
been found, where the remaining theoretical uncertainty is much too small to
explain the apparent discrepancy between sin^2(theta) obtained from Afbb and
from the left-right asymmetry at SLD.
| [
{
"created": "Tue, 23 Nov 2004 09:00:40 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Freitas",
"A.",
""
],
[
"Moenig",
"K.",
""
]
] | The most precise measurement of the weak mixing angle sin^2(theta) at LEP is from the forward-backward asymmetry e+e- --> bbbar at the Z-pole. In this note the QED and electroweak radiative corrections to obtain the pole asymmetry from the measured asymmetry for b- and c-quarks have been calculated using ZFITTER, which has been amended to allow a consistent treatment of partial two-loop corrections for the b-quark final asymmetries. A total correction of dAfbb=0.0019+/-0.0002 and dAfbc=0.0064+/-0.0001 has been found, where the remaining theoretical uncertainty is much too small to explain the apparent discrepancy between sin^2(theta) obtained from Afbb and from the left-right asymmetry at SLD. |
hep-ph/0509089 | Allan Widom | G. Castellani, S. Reucroft, Y.N. Srivastava, J. Swain, A. Widom | Final State Interactions and the Effects of Potentials on Particle
Reactions | 13 pages 5 *.eps figures plain LaTeX | null | null | null | hep-ph | null | In nuclear physics, it is well known that the electromagnetic (Coulomb)
interaction between final state products can drastically effect particle
reaction rates. Near thresholds, for example, nuclear alpha decay is suppressed
while nuclear beta decay is enhanced by final state Coulomb interactions. Here
we discuss high energy physics enhancement and/or suppression of reactions
wherein the potentials must include weak and strong as well as electromagnetic
interactions. Potentials due to the exchange of gluons and the exchange of a
hypothetical Higgs particle are explicitly considered.
| [
{
"created": "Fri, 9 Sep 2005 22:53:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Castellani",
"G.",
""
],
[
"Reucroft",
"S.",
""
],
[
"Srivastava",
"Y. N.",
""
],
[
"Swain",
"J.",
""
],
[
"Widom",
"A.",
""
]
] | In nuclear physics, it is well known that the electromagnetic (Coulomb) interaction between final state products can drastically effect particle reaction rates. Near thresholds, for example, nuclear alpha decay is suppressed while nuclear beta decay is enhanced by final state Coulomb interactions. Here we discuss high energy physics enhancement and/or suppression of reactions wherein the potentials must include weak and strong as well as electromagnetic interactions. Potentials due to the exchange of gluons and the exchange of a hypothetical Higgs particle are explicitly considered. |
2303.13503 | Marco Drewes | Marco Drewes, Lei Ming, Isabel Oldengott | LiteBIRD and CMB-S4 Sensitivities to Reheating in Plateau Models of
Inflation | 86 pages, 43 figures; matches version to appear in JCAP | JCAP 05 (2024) 081 | 10.1088/1475-7516/2024/05/081 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the sensitivity of LiteBIRD and CMB-S4 to the reheating temperature
and the inflaton coupling in three types of plateau-potential models of
inflation, namely mutated hilltop inflation, radion gauge inflation, and
$\alpha$-attractor T models. We first find relations between model parameters
and CMB observables in all models. We then perform Monte Carlo Markov Chain
based forecasts to quantify the information gain on the reheating temperature,
the inflaton coupling, and the scale of inflation that can be achieved with
LiteBIRD and CMB-S4, assuming a fiducial tensor-to-scalar ratio $\bar{r} \sim
0.02$ and neglecting foreground contamination of the B-mode polarization
spectrum. We compare the results of the forecasts to those obtained from a
recently proposed simple analytic method. We find that both LiteBIRD and CMB-S4
can simultaneously constrain the scale of inflation and the reheating
temperature in all three types of models. They can for the first time obtain
both an upper and lower bound on the latter, comprising the first ever
measurement of the big bang temperature. In the mutated hilltop inflation and
radion gauge inflation models this can be translated into a measurement of the
inflaton coupling in parts of the parameter space. Constraining this
microphysical parameter will help to understand how these models of inflation
may be embedded into a more fundamental theory of particle physics.
| [
{
"created": "Thu, 23 Mar 2023 17:57:46 GMT",
"version": "v1"
},
{
"created": "Fri, 3 May 2024 09:38:25 GMT",
"version": "v2"
}
] | 2024-05-16 | [
[
"Drewes",
"Marco",
""
],
[
"Ming",
"Lei",
""
],
[
"Oldengott",
"Isabel",
""
]
] | We study the sensitivity of LiteBIRD and CMB-S4 to the reheating temperature and the inflaton coupling in three types of plateau-potential models of inflation, namely mutated hilltop inflation, radion gauge inflation, and $\alpha$-attractor T models. We first find relations between model parameters and CMB observables in all models. We then perform Monte Carlo Markov Chain based forecasts to quantify the information gain on the reheating temperature, the inflaton coupling, and the scale of inflation that can be achieved with LiteBIRD and CMB-S4, assuming a fiducial tensor-to-scalar ratio $\bar{r} \sim 0.02$ and neglecting foreground contamination of the B-mode polarization spectrum. We compare the results of the forecasts to those obtained from a recently proposed simple analytic method. We find that both LiteBIRD and CMB-S4 can simultaneously constrain the scale of inflation and the reheating temperature in all three types of models. They can for the first time obtain both an upper and lower bound on the latter, comprising the first ever measurement of the big bang temperature. In the mutated hilltop inflation and radion gauge inflation models this can be translated into a measurement of the inflaton coupling in parts of the parameter space. Constraining this microphysical parameter will help to understand how these models of inflation may be embedded into a more fundamental theory of particle physics. |
0712.1417 | Martin Schumacher | Martin Schumacher | Properties of the $\pi^0$, $\eta$, $\eta'$, $\sigma$, $f_0(980)$ and
$a_0(980)$ mesons and their relevance for the polarizabilities of the nucleon | null | Eur.Phys.J.A34:293-301,2007 | 10.1140/epja/i2007-10506-3 | null | hep-ph | null | The signs and values of the two-photon couplings $F_{M\gamma\gamma}$ of
mesons $(M)$ and their couplings $g_{MNN}$ to the nucleon as entering into the
$t$-channel parts of the difference of the electromagnetic polarizabilities
$(\alpha-\beta)$ and the backward angle spin polarizabilities $\gamma_\pi$ are
determined. The excellent agreement achieved with the experimental
polarizabilities of the proton makes it possible to make reliable predictions
for the neutron. The results obtained are $\alpha_n=13.4\pm 1.0$,
$\beta_n=1.8\mp 1.0$ ($10^{-4}$ fm$^3$), and $\gamma^{(n)}_\pi=57.6\pm 1.8$
($10^{-4}$ fm$^4$). New empirical information on the flavor wave functions of
the $f_0(980)$ and the $a_0(980)$ meson is obtained.
| [
{
"created": "Mon, 10 Dec 2007 10:00:42 GMT",
"version": "v1"
}
] | 2013-06-26 | [
[
"Schumacher",
"Martin",
""
]
] | The signs and values of the two-photon couplings $F_{M\gamma\gamma}$ of mesons $(M)$ and their couplings $g_{MNN}$ to the nucleon as entering into the $t$-channel parts of the difference of the electromagnetic polarizabilities $(\alpha-\beta)$ and the backward angle spin polarizabilities $\gamma_\pi$ are determined. The excellent agreement achieved with the experimental polarizabilities of the proton makes it possible to make reliable predictions for the neutron. The results obtained are $\alpha_n=13.4\pm 1.0$, $\beta_n=1.8\mp 1.0$ ($10^{-4}$ fm$^3$), and $\gamma^{(n)}_\pi=57.6\pm 1.8$ ($10^{-4}$ fm$^4$). New empirical information on the flavor wave functions of the $f_0(980)$ and the $a_0(980)$ meson is obtained. |
hep-ph/0207098 | Daniel Arndt | Daniel Arndt and Patrick J. Fox | Saxion Emission from SN1987A | 18 pages, 2 figures; minor changes, typos corrected, version to
appear in JHEP | JHEP 0302:036,2003 | 10.1088/1126-6708/2003/02/036 | UW-PT-02-11, NT@UW-02-0014 | hep-ph astro-ph nucl-th | null | We study the possibility of emission of the saxion, a superpartner of the
axion, from SN1987A. The fact that the observed neutrino pulse from SN1987A is
in excellent agreement with the current theory of supernovae places a strong
bound on the energy loss into any non-standard model channel, therefore
enabling bounds to be placed on the decay constant, f_a, of a light saxion. The
low-energy coupling of the saxion, which couples at high energies to the QCD
gauge field strength, is expected to be enhanced from QCD scaling, making it
interesting to investigate if the saxion could place stronger bounds on f_a
than the axion itself. Moreover, since the properties of the saxion are
determined by f_a, a constraint on this parameter can be translated into a
constraint on the supersymmetry breaking scale. We find that the bound on f_a
from saxion emission is comparable with the one derived from axion emission due
to a cancellation of leading-order terms in the soft-radiation expansion.
| [
{
"created": "Sun, 7 Jul 2002 03:15:23 GMT",
"version": "v1"
},
{
"created": "Sat, 22 Feb 2003 01:41:03 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Arndt",
"Daniel",
""
],
[
"Fox",
"Patrick J.",
""
]
] | We study the possibility of emission of the saxion, a superpartner of the axion, from SN1987A. The fact that the observed neutrino pulse from SN1987A is in excellent agreement with the current theory of supernovae places a strong bound on the energy loss into any non-standard model channel, therefore enabling bounds to be placed on the decay constant, f_a, of a light saxion. The low-energy coupling of the saxion, which couples at high energies to the QCD gauge field strength, is expected to be enhanced from QCD scaling, making it interesting to investigate if the saxion could place stronger bounds on f_a than the axion itself. Moreover, since the properties of the saxion are determined by f_a, a constraint on this parameter can be translated into a constraint on the supersymmetry breaking scale. We find that the bound on f_a from saxion emission is comparable with the one derived from axion emission due to a cancellation of leading-order terms in the soft-radiation expansion. |
1105.4743 | Mikhail Vysotsky | M.I.Vysotsky | Coulomb law and energy levels in a superstrong magnetic field | 8 pages, 4 figures; presented at Les Rencontres de Physique de la
Vallee d'Aoste, La Thuile, Aosta Valley, Italy, February 27 - March 5, 2011 | null | 10.1393/ncc/i2012-11138-4 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Analytical expression for the Coulomb potential in the presence of
superstrong magnetic field is derived. Structure of hydrogen levels originating
from LLL is analyzed.
| [
{
"created": "Tue, 24 May 2011 12:22:40 GMT",
"version": "v1"
}
] | 2022-03-02 | [
[
"Vysotsky",
"M. I.",
""
]
] | Analytical expression for the Coulomb potential in the presence of superstrong magnetic field is derived. Structure of hydrogen levels originating from LLL is analyzed. |
hep-ph/0312049 | Hilmar Forkel | Hilmar Forkel (IFT - UNESP and U. Heidelberg) | Direct instantons, topological charge screening and QCD glueball sum
rules | 49 pages, 8 figures | Phys.Rev. D71 (2005) 054008 | 10.1103/PhysRevD.71.054008 | IFT-P.039/2003 | hep-ph | null | Nonperturbative Wilson coefficients of the operator product expansion (OPE)
for the spin-0 glueball correlators are derived and analyzed. A systematic
treatment of the direct instanton contributions is given, based on realistic
instanton size distributions and renormalization at the operator scale. In the
pseudoscalar channel, topological charge screening is identified as an
additional source of (semi-) hard nonperturbative physics. The screening
contributions are shown to be vital for consistency with the anomalous axial
Ward identity, and previously encountered pathologies (positivity violations
and the disappearance of the 0^{-+} glueball signal) are traced to their
neglect. On the basis of the extended OPE, a comprehensive quantitative
analysis of eight Borel-moment sum rules in both spin-0 glueball channels is
then performed. The nonperturbative OPE coefficients turn out to be
indispensable for consistent sum rules and for their reconciliation with the
underlying low-energy theorems. The topological short-distance physics strongly
affects the sum rule results and reveals a rather diverse pattern of glueball
properties. New predictions for the spin-0 glueball masses and decay constants
and an estimate of the scalar glueball width are given, and several
implications for glueball structure and experimental glueball searches are
discussed.
| [
{
"created": "Wed, 3 Dec 2003 13:44:10 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Forkel",
"Hilmar",
"",
"IFT - UNESP and U. Heidelberg"
]
] | Nonperturbative Wilson coefficients of the operator product expansion (OPE) for the spin-0 glueball correlators are derived and analyzed. A systematic treatment of the direct instanton contributions is given, based on realistic instanton size distributions and renormalization at the operator scale. In the pseudoscalar channel, topological charge screening is identified as an additional source of (semi-) hard nonperturbative physics. The screening contributions are shown to be vital for consistency with the anomalous axial Ward identity, and previously encountered pathologies (positivity violations and the disappearance of the 0^{-+} glueball signal) are traced to their neglect. On the basis of the extended OPE, a comprehensive quantitative analysis of eight Borel-moment sum rules in both spin-0 glueball channels is then performed. The nonperturbative OPE coefficients turn out to be indispensable for consistent sum rules and for their reconciliation with the underlying low-energy theorems. The topological short-distance physics strongly affects the sum rule results and reveals a rather diverse pattern of glueball properties. New predictions for the spin-0 glueball masses and decay constants and an estimate of the scalar glueball width are given, and several implications for glueball structure and experimental glueball searches are discussed. |
1407.1623 | Paolo Torrielli | Paolo Torrielli | Rare Standard Model processes for present and future hadronic colliders | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk I present the total cross sections, accurate at the NLO in QCD,
for rare Standard-Model hadroproduction processes involving multi-Higgs-boson,
multi-electroweak-boson and multi-top-quark final states. The comparison
between cross sections at the LHC and at a future circular hadronic collider
with up to 100 TeV centre-of-mass energy is detailed. Results relevant to the
hadronic production of five electroweak bosons, and of a top-antitop pair in
association with an electroweak vector boson and two jets are presented here
for the first time with NLO accuracy.
| [
{
"created": "Mon, 7 Jul 2014 08:38:37 GMT",
"version": "v1"
}
] | 2014-07-08 | [
[
"Torrielli",
"Paolo",
""
]
] | In this talk I present the total cross sections, accurate at the NLO in QCD, for rare Standard-Model hadroproduction processes involving multi-Higgs-boson, multi-electroweak-boson and multi-top-quark final states. The comparison between cross sections at the LHC and at a future circular hadronic collider with up to 100 TeV centre-of-mass energy is detailed. Results relevant to the hadronic production of five electroweak bosons, and of a top-antitop pair in association with an electroweak vector boson and two jets are presented here for the first time with NLO accuracy. |
hep-ph/9810311 | Bing An Li | Bing An Li(Univ. of Kentucky) | Low energy limit of effective chiral theory of mesons | 18 pages | null | null | null | hep-ph | null | Based on an effective chiral theory of pseudoscalar, vector, and axial-vector
mesons, the coefficients of the chiral perturbation theory are predicted. There
is no new parameter in these predictions.
| [
{
"created": "Fri, 9 Oct 1998 14:41:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Li",
"Bing An",
"",
"Univ. of Kentucky"
]
] | Based on an effective chiral theory of pseudoscalar, vector, and axial-vector mesons, the coefficients of the chiral perturbation theory are predicted. There is no new parameter in these predictions. |
hep-ph/0309025 | Alan Kostelecky | Alan Kostelecky and Matthew Mewes | Lorentz and CPT Violation in Neutrinos | 25 pages REVTeX | Phys.Rev.D69:016005,2004 | 10.1103/PhysRevD.69.016005 | IUHET 459, August 2003 | hep-ph | null | A general formalism is presented for violations of Lorentz and CPT symmetry
in the neutrino sector. The effective hamiltonian for neutrino propagation in
the presence of Lorentz and CPT violation is derived, and its properties are
studied. Possible definitive signals in existing and future
neutrino-oscillation experiments are discussed. Among the predictions are
direction-dependent effects, including neutrino-antineutrino mixing, sidereal
and annual variations, and compass asymmetries. Other consequences of Lorentz
and CPT violation involve unconventional energy dependences in oscillation
lengths and mixing angles. A variety of simple models both with and without
neutrino masses are developed to illustrate key physical effects. The
attainable sensitivities to coefficients for Lorentz violation in the
Standard-Model Extension are estimated for various types of experiments. Many
experiments have potential sensitivity to Planck-suppressed effects, comparable
to the best tests in other sectors. The lack of existing experimental
constraints, the wide range of available coefficient space, and the variety of
novel effects imply that some or perhaps even all of the existing data on
neutrino oscillations might be due to Lorentz and CPT violation.
| [
{
"created": "Tue, 2 Sep 2003 16:03:46 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Kostelecky",
"Alan",
""
],
[
"Mewes",
"Matthew",
""
]
] | A general formalism is presented for violations of Lorentz and CPT symmetry in the neutrino sector. The effective hamiltonian for neutrino propagation in the presence of Lorentz and CPT violation is derived, and its properties are studied. Possible definitive signals in existing and future neutrino-oscillation experiments are discussed. Among the predictions are direction-dependent effects, including neutrino-antineutrino mixing, sidereal and annual variations, and compass asymmetries. Other consequences of Lorentz and CPT violation involve unconventional energy dependences in oscillation lengths and mixing angles. A variety of simple models both with and without neutrino masses are developed to illustrate key physical effects. The attainable sensitivities to coefficients for Lorentz violation in the Standard-Model Extension are estimated for various types of experiments. Many experiments have potential sensitivity to Planck-suppressed effects, comparable to the best tests in other sectors. The lack of existing experimental constraints, the wide range of available coefficient space, and the variety of novel effects imply that some or perhaps even all of the existing data on neutrino oscillations might be due to Lorentz and CPT violation. |
hep-ph/0410045 | Ivan Vitev | Ivan Vitev | Jets in nuclear collisions | Proceedings of the XXXIV International Symposium on Multiparticle
Dynamics. To be published in Acta Physica Polonica B. 7 pages, 3 figures | Acta Phys.Polon. B36 (2005) 461-468 | null | null | hep-ph nucl-th | null | Ultra-relativistic heavy ion collisions at RHIC and the LHC open exciting new
possibilities for jet physics studies in the presence of hot and dense nuclear
matter. Recent theoretical advances in understanding the QCD multi-parton
dynamics provide a good description of the quenching in the single and double
inclusive high-pT hadron spectra. Measurement of the redistribution of the lost
energy and the corresponding increase in the soft hadron multiplicities is the
next critical step in elucidating the modification of the jet properties in the
nuclear environment.
| [
{
"created": "Sun, 3 Oct 2004 23:38:36 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Vitev",
"Ivan",
""
]
] | Ultra-relativistic heavy ion collisions at RHIC and the LHC open exciting new possibilities for jet physics studies in the presence of hot and dense nuclear matter. Recent theoretical advances in understanding the QCD multi-parton dynamics provide a good description of the quenching in the single and double inclusive high-pT hadron spectra. Measurement of the redistribution of the lost energy and the corresponding increase in the soft hadron multiplicities is the next critical step in elucidating the modification of the jet properties in the nuclear environment. |
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