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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2106.08239 | Oleh Savchuk | Oleh Savchuk, Volodymyr Vovchenko, Volker Koch, Jan Steinheimer, Horst
Stoecker | Constraining baryon annihilation in the hadronic phase of heavy-ion
collisions via event-by-event fluctuations | 6 pages, 4 figures | Phys. Lett. B 827, 136983 (2022) | 10.1016/j.physletb.2022.136983 | null | hep-ph nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | We point out that the variance of net-baryon distribution normalized by the
Skellam distribution baseline, $\kappa_2[B-\bar{B}]/\langle B+\bar{B}\rangle$,
is sensitive to the possible modification of (anti)baryon yields due to
$B\bar{B}$ annihilation in the hadronic phase. The corresponding measurements
can thus place stringent limits on the magnitude of the $B\bar{B}$ annihilation
and its inverse reaction. We perform Monte Carlo simulations of the hadronic
phase in Pb-Pb collisions at the LHC via the recently developed subensemble
sampler + UrQMD afterburner and show that the effect survives in net-proton
fluctuations, which are directly accessible experimentally. The available
experimental data of the ALICE Collaboration on net-proton fluctuations
disfavors a notable suppression of (anti)baryon yields in $B\bar{B}$
annihilations predicted by the present version of UrQMD if only global baryon
conservation is incorporated. On the other hand, the annihilations improve the
data description when local baryon conservation is imposed. The two effects can
be disentangled by measuring $\kappa_2[B+\bar{B}]/\langle B+\bar{B}\rangle$,
which at the LHC is notably suppressed by annihilations but virtually
unaffected by baryon number conservation.
| [
{
"created": "Tue, 15 Jun 2021 15:43:36 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Mar 2022 21:36:37 GMT",
"version": "v2"
}
] | 2022-03-22 | [
[
"Savchuk",
"Oleh",
""
],
[
"Vovchenko",
"Volodymyr",
""
],
[
"Koch",
"Volker",
""
],
[
"Steinheimer",
"Jan",
""
],
[
"Stoecker",
"Horst",
""
]
] | We point out that the variance of net-baryon distribution normalized by the Skellam distribution baseline, $\kappa_2[B-\bar{B}]/\langle B+\bar{B}\rangle$, is sensitive to the possible modification of (anti)baryon yields due to $B\bar{B}$ annihilation in the hadronic phase. The corresponding measurements can thus place stringent limits on the magnitude of the $B\bar{B}$ annihilation and its inverse reaction. We perform Monte Carlo simulations of the hadronic phase in Pb-Pb collisions at the LHC via the recently developed subensemble sampler + UrQMD afterburner and show that the effect survives in net-proton fluctuations, which are directly accessible experimentally. The available experimental data of the ALICE Collaboration on net-proton fluctuations disfavors a notable suppression of (anti)baryon yields in $B\bar{B}$ annihilations predicted by the present version of UrQMD if only global baryon conservation is incorporated. On the other hand, the annihilations improve the data description when local baryon conservation is imposed. The two effects can be disentangled by measuring $\kappa_2[B+\bar{B}]/\langle B+\bar{B}\rangle$, which at the LHC is notably suppressed by annihilations but virtually unaffected by baryon number conservation. |
0912.4511 | Hao Zhang | Hao Zhang, Qing-Hong Cao, Chuan-Ren Chen, Chong Sheng Li | Effective Dark Matter Model: Relic density, CDMS II, Fermi LAT and LHC | null | JHEP 1108:018,2011 | 10.1007/JHEP08(2011)018 | ANL-HEP-PR-09-107, EFI-09-31, IPMU09-0162 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Cryogenic Dark Matter Search recently announced the observation of two
signal events with a 77% confidence level. Although statistically inconclusive,
it is nevertheless suggestive. In this work we present a model-independent
analysis on the implication of a positive signal in dark matter scattering off
nuclei. Assuming the interaction between (scalar, fermion or vector) dark
matter and the standard model induced by unknown new physics at the scale
$\Lambda$, we examine various dimension-6 tree-level induced operators and
constrain them using the current experimental data, e.g. the WMAP data of the
relic abundance, CDMS II direct detection of the spin-independent scattering,
and indirect detection data (Fermi LAT cosmic gamma-ray), etc. Finally, the LHC
reach is also explored.
| [
{
"created": "Tue, 22 Dec 2009 20:52:19 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Aug 2011 00:55:18 GMT",
"version": "v2"
}
] | 2011-09-08 | [
[
"Zhang",
"Hao",
""
],
[
"Cao",
"Qing-Hong",
""
],
[
"Chen",
"Chuan-Ren",
""
],
[
"Li",
"Chong Sheng",
""
]
] | The Cryogenic Dark Matter Search recently announced the observation of two signal events with a 77% confidence level. Although statistically inconclusive, it is nevertheless suggestive. In this work we present a model-independent analysis on the implication of a positive signal in dark matter scattering off nuclei. Assuming the interaction between (scalar, fermion or vector) dark matter and the standard model induced by unknown new physics at the scale $\Lambda$, we examine various dimension-6 tree-level induced operators and constrain them using the current experimental data, e.g. the WMAP data of the relic abundance, CDMS II direct detection of the spin-independent scattering, and indirect detection data (Fermi LAT cosmic gamma-ray), etc. Finally, the LHC reach is also explored. |
2308.04410 | Najmul Haque | Jobin Sebastian, Lata Thakur, Hiranmaya Mishra, and Najmul Haque | Heavy quarkonia in QGP medium in an arbitrary magnetic field | 13 pages, 6 figures, Published version | PhysRevD.108 (2023)094001 | 10.1103/PhysRevD.108.094001 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We compute the heavy quarkonium complex potential in an arbitrary magnetic
field strength generated in the relativistic heavy-ion collision. First, the
one-loop gluon polarization tensor is obtained in the presence of an external,
constant, and homogeneous magnetic field using the Schwinger proper time
formalism in Euclidean space. The gluon propagator is computed from the gluon
polarization tensor, and it is used to calculate the dielectric permittivity in
the presence of the magnetic field in the static limit. The modified dielectric
permittivity is then used to compute the heavy quarkonium complex potential. We
find that the heavy quarkonium complex potential is anisotropic in nature,
which depends on the angle between the quark-antiquark ($Q\bar{Q}$) dipole axis
and the direction of the magnetic field. We discuss the effect of the magnetic
field strength and the angular orientation of the dipole on the heavy
quarkonium potential. We discuss how the magnetic field influences the thermal
widths of quarkonium states. Further, we also discuss the limitation of the
strong-field approximation as done in literature in the light of heavy-ion
observables, as the effect of the magnetic field is very nominal to the
quarkonium potential.
| [
{
"created": "Tue, 8 Aug 2023 17:14:16 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Nov 2023 10:14:14 GMT",
"version": "v2"
}
] | 2023-11-03 | [
[
"Sebastian",
"Jobin",
""
],
[
"Thakur",
"Lata",
""
],
[
"Mishra",
"Hiranmaya",
""
],
[
"Haque",
"Najmul",
""
]
] | We compute the heavy quarkonium complex potential in an arbitrary magnetic field strength generated in the relativistic heavy-ion collision. First, the one-loop gluon polarization tensor is obtained in the presence of an external, constant, and homogeneous magnetic field using the Schwinger proper time formalism in Euclidean space. The gluon propagator is computed from the gluon polarization tensor, and it is used to calculate the dielectric permittivity in the presence of the magnetic field in the static limit. The modified dielectric permittivity is then used to compute the heavy quarkonium complex potential. We find that the heavy quarkonium complex potential is anisotropic in nature, which depends on the angle between the quark-antiquark ($Q\bar{Q}$) dipole axis and the direction of the magnetic field. We discuss the effect of the magnetic field strength and the angular orientation of the dipole on the heavy quarkonium potential. We discuss how the magnetic field influences the thermal widths of quarkonium states. Further, we also discuss the limitation of the strong-field approximation as done in literature in the light of heavy-ion observables, as the effect of the magnetic field is very nominal to the quarkonium potential. |
1205.6232 | Marcin Badziak | Marcin Badziak | Yukawa unification in SUSY SO(10) in light of the LHC Higgs data | 17 pages, 3 figures, invited brief review to appear in MPLA | Mod. Phys. Lett. A, Vol. 27, No. 22 (2012) 1230020 | 10.1142/S0217732312300200 | Cavendish-HEP-12/10; DAMTP-2012-41 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The status of top-bottom-tau Yukawa coupling unification in supersymmetric
SO(10) models is reviewed with a particular emphasis on the implications of the
Higgs boson mass in the vicinity of 125 GeV, as suggested by the LHC Higgs
data. In addition, the recently proposed model with negative \mu, D-term
splitting of the soft scalar masses and non-universal gaugino masses generated
by a non-zero F-term in a 24-dimensional representation of SU(5) \subset SO(10)
is re-analysed in the context of the 125 GeV Higgs. The condition of
top-bottom-tau Yukawa unification together with the Higgs mass of about 125 GeV
impose strong lower mass limits on SUSY particles. Nevertheless, some of the
MSSM particles may be within the reach of the LHC. In the case of models with
positive \mu this is the gluino. While in the case of negative \mu these are
the pseudoscalar Higgs, the lighter sbottom (sometimes strongly degenerate with
the LSP leading to sbottom coannihilations), the right-handed down squark and
the gluino.
| [
{
"created": "Mon, 28 May 2012 23:13:10 GMT",
"version": "v1"
}
] | 2012-07-12 | [
[
"Badziak",
"Marcin",
""
]
] | The status of top-bottom-tau Yukawa coupling unification in supersymmetric SO(10) models is reviewed with a particular emphasis on the implications of the Higgs boson mass in the vicinity of 125 GeV, as suggested by the LHC Higgs data. In addition, the recently proposed model with negative \mu, D-term splitting of the soft scalar masses and non-universal gaugino masses generated by a non-zero F-term in a 24-dimensional representation of SU(5) \subset SO(10) is re-analysed in the context of the 125 GeV Higgs. The condition of top-bottom-tau Yukawa unification together with the Higgs mass of about 125 GeV impose strong lower mass limits on SUSY particles. Nevertheless, some of the MSSM particles may be within the reach of the LHC. In the case of models with positive \mu this is the gluino. While in the case of negative \mu these are the pseudoscalar Higgs, the lighter sbottom (sometimes strongly degenerate with the LSP leading to sbottom coannihilations), the right-handed down squark and the gluino. |
hep-ph/0106280 | Stephen P. Martin | Stephen P. Martin | Predictions of the sign of \mu from supersymmetry breaking models | 18 pages | Phys.Rev. D65 (2002) 035003 | 10.1103/PhysRevD.65.035003 | null | hep-ph | null | The sign of the supersymmetric Higgs mass \mu is usually taken as an
independent input parameter in analyses of the supersymmetric standard model. I
study the role of theories of supersymmetry breaking in determining the sign of
\mu as an output. Models with vanishing soft scalar couplings at the apparent
gauge coupling unification scale are known to predict positive \mu. I
investigate more general results for the sign of \mu as a function of the
holomorphic soft scalar couplings, and compare to predictions of models with
gaugino mass dominance at higher scales. In a significant region of the
B_0/m_{1/2} versus A_0/m_{1/2} plane including A_0 = B_0 = 0, \mu must be
positive. In another region, \mu is definitely negative. Only in a smaller
intermediate region does knowledge of the supersymmetry breaking mechanism not
permit a definite prediction of the sign of \mu. The last region will shrink
considerably as the top quark mass becomes more accurately known.
| [
{
"created": "Mon, 25 Jun 2001 22:13:04 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Martin",
"Stephen P.",
""
]
] | The sign of the supersymmetric Higgs mass \mu is usually taken as an independent input parameter in analyses of the supersymmetric standard model. I study the role of theories of supersymmetry breaking in determining the sign of \mu as an output. Models with vanishing soft scalar couplings at the apparent gauge coupling unification scale are known to predict positive \mu. I investigate more general results for the sign of \mu as a function of the holomorphic soft scalar couplings, and compare to predictions of models with gaugino mass dominance at higher scales. In a significant region of the B_0/m_{1/2} versus A_0/m_{1/2} plane including A_0 = B_0 = 0, \mu must be positive. In another region, \mu is definitely negative. Only in a smaller intermediate region does knowledge of the supersymmetry breaking mechanism not permit a definite prediction of the sign of \mu. The last region will shrink considerably as the top quark mass becomes more accurately known. |
1708.09390 | Wouter Dekens | V. Cirigliano, W. Dekens, J. de Vries, M. L. Graesser, and E.
Mereghetti | Neutrinoless double beta decay in chiral effective field theory: lepton
number violation at dimension seven | Matches version published in JHEP | null | 10.1007/JHEP12(2017)082 | LA-UR-17-27799, Nikhef 2017-039 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze neutrinoless double beta decay ($0\nu\beta\beta$) within the
framework of the Standard Model Effective Field Theory. Apart from the
dimension-five Weinberg operator, the first contributions appear at dimension
seven. We classify the operators and evolve them to the electroweak scale,
where we match them to effective dimension-six, -seven, and -nine operators. In
the next step, after renormalization group evolution to the QCD scale, we
construct the chiral Lagrangian arising from these operators. We develop a
power-counting scheme and derive the two-nucleon $0\nu\beta\beta$ currents up
to leading order in the power counting for each lepton-number-violating
operator. We argue that the leading-order contribution to the decay rate
depends on a relatively small number of nuclear matrix elements. We test our
power counting by comparing nuclear matrix elements obtained by various methods
and by different groups. We find that the power counting works well for nuclear
matrix elements calculated from a specific method, while, as in the case of
light Majorana neutrino exchange, the overall magnitude of the matrix elements
can differ by factors of two to three between methods. We calculate the
constraints that can be set on dimension-seven lepton-number-violating
operators from $0\nu\beta\beta$ experiments and study the interplay between
dimension-five and -seven operators, discussing how dimension-seven
contributions affect the interpretation of $0\nu\beta\beta$ in terms of the
effective Majorana mass $m_{\beta \beta}$.
| [
{
"created": "Wed, 30 Aug 2017 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Dec 2017 22:52:06 GMT",
"version": "v2"
}
] | 2017-12-29 | [
[
"Cirigliano",
"V.",
""
],
[
"Dekens",
"W.",
""
],
[
"de Vries",
"J.",
""
],
[
"Graesser",
"M. L.",
""
],
[
"Mereghetti",
"E.",
""
]
] | We analyze neutrinoless double beta decay ($0\nu\beta\beta$) within the framework of the Standard Model Effective Field Theory. Apart from the dimension-five Weinberg operator, the first contributions appear at dimension seven. We classify the operators and evolve them to the electroweak scale, where we match them to effective dimension-six, -seven, and -nine operators. In the next step, after renormalization group evolution to the QCD scale, we construct the chiral Lagrangian arising from these operators. We develop a power-counting scheme and derive the two-nucleon $0\nu\beta\beta$ currents up to leading order in the power counting for each lepton-number-violating operator. We argue that the leading-order contribution to the decay rate depends on a relatively small number of nuclear matrix elements. We test our power counting by comparing nuclear matrix elements obtained by various methods and by different groups. We find that the power counting works well for nuclear matrix elements calculated from a specific method, while, as in the case of light Majorana neutrino exchange, the overall magnitude of the matrix elements can differ by factors of two to three between methods. We calculate the constraints that can be set on dimension-seven lepton-number-violating operators from $0\nu\beta\beta$ experiments and study the interplay between dimension-five and -seven operators, discussing how dimension-seven contributions affect the interpretation of $0\nu\beta\beta$ in terms of the effective Majorana mass $m_{\beta \beta}$. |
hep-ph/0203005 | Hee-Jung Lee | Hee-Jung Lee | The Proton Spin Problem in the Chiral Bag Model | Ph. D. Thesis, 133 pages | null | null | null | hep-ph nucl-th | null | The flavor singlet axial charge has been a source of study in the last years
due to its relation to the so called {\it Proton Spin Problem}. The relevant
flavor singlet axial current is anomalous, i.e., its divergence contains a
piece which is the celebrated $U_A(1)$ anomaly. This anomaly is intimately
associated with the $\eta^\prime$ meson, which gets its mass from it. When the
gauge degrees of freedom of QCD are confined within a volume as is presently
understood, the $U_A(1)$ anomaly is known to induce color anomaly leading to
"leakage" of the color out of the confined volume (or bag). For consistency of
the theory, this anomaly should be cancelled by a boundary term. This ``color
boundary term" inherits part or most of the dynamics of the volume (i.e., QCD).
In this thesis, we exploit this mapping of the volume to the surface via the
color boundary condition to perform a complete analysis of the flavor singlet
axial charge in the chiral bag model using the Cheshire Cat Principle. This
enables us to obtain the hitherto missing piece in the axial charge associated
with the gluon Casimir effect. The result is that the flavor singlet axial
charge is small independent of the confinement (bag) size ranging from the
skyrmion picture to the MIT bag picture, thereby confirming the (albeit
approximate) Cheshire Cat phenomenon.
| [
{
"created": "Fri, 1 Mar 2002 07:22:22 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Lee",
"Hee-Jung",
""
]
] | The flavor singlet axial charge has been a source of study in the last years due to its relation to the so called {\it Proton Spin Problem}. The relevant flavor singlet axial current is anomalous, i.e., its divergence contains a piece which is the celebrated $U_A(1)$ anomaly. This anomaly is intimately associated with the $\eta^\prime$ meson, which gets its mass from it. When the gauge degrees of freedom of QCD are confined within a volume as is presently understood, the $U_A(1)$ anomaly is known to induce color anomaly leading to "leakage" of the color out of the confined volume (or bag). For consistency of the theory, this anomaly should be cancelled by a boundary term. This ``color boundary term" inherits part or most of the dynamics of the volume (i.e., QCD). In this thesis, we exploit this mapping of the volume to the surface via the color boundary condition to perform a complete analysis of the flavor singlet axial charge in the chiral bag model using the Cheshire Cat Principle. This enables us to obtain the hitherto missing piece in the axial charge associated with the gluon Casimir effect. The result is that the flavor singlet axial charge is small independent of the confinement (bag) size ranging from the skyrmion picture to the MIT bag picture, thereby confirming the (albeit approximate) Cheshire Cat phenomenon. |
hep-ph/0109219 | Stefano Forte | Stefano Forte | Highlights of Short Baseline Physics at a Neutrino Factory | 14 pages, 3 figures, latex with elsart.cls; invited plenary talk at
Nufac01 | Nucl.Instrum.Meth. A503 (2001) 87-95 | 10.1016/S0168-9002(03)00646-6 | RM3-TH 01/11 | hep-ph | null | We review the physics potential for experiments with intense neutrino beams
at the front-end of a muon storage ring, stressing the way the spin and flavour
structure of neutrino interactions with matter can be used to shed light on the
structure of the strong and electroweak interactions. Specifically, we discuss
precision tests of the standard model, studies of polarized and unpolarized
structure functions of the nucleon, and several new and exotic physics items.
| [
{
"created": "Mon, 24 Sep 2001 16:22:44 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Forte",
"Stefano",
""
]
] | We review the physics potential for experiments with intense neutrino beams at the front-end of a muon storage ring, stressing the way the spin and flavour structure of neutrino interactions with matter can be used to shed light on the structure of the strong and electroweak interactions. Specifically, we discuss precision tests of the standard model, studies of polarized and unpolarized structure functions of the nucleon, and several new and exotic physics items. |
hep-ph/9301261 | Faraggi Alon | Alon E. Faraggi and Edi Halyo | Cabibbo Mixing in Superstring Derived Standard--like Models | WIS--92/3/JAN--PH, 15 pages | Phys.Lett. B307 (1993) 305-310 | 10.1016/0370-2693(93)90225-7 | null | hep-ph hep-th | null | We examine the problem of generation mixing in realistic superstring derived
standard--like models, constructed in the free fermionic formulation. We study
the possible sources of family mixing in these models . In a specific model we
estimate the Cabibbo angle. We argue that a Cabibbo angle of the correct order
of magnitude can be obtained in these models.
| [
{
"created": "Fri, 22 Jan 1993 16:24:55 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Faraggi",
"Alon E.",
""
],
[
"Halyo",
"Edi",
""
]
] | We examine the problem of generation mixing in realistic superstring derived standard--like models, constructed in the free fermionic formulation. We study the possible sources of family mixing in these models . In a specific model we estimate the Cabibbo angle. We argue that a Cabibbo angle of the correct order of magnitude can be obtained in these models. |
hep-ph/9703344 | null | S. Balk, J.G. K\"orner and D. Pirjol | Inclusive Semileptonic Decays of Polarized $\Lambda_b$ Baryons into
Polarized $\tau$-Leptons | 32 pages RevTex with 2 included figures | Eur.Phys.J.C1:221-233,1998 | 10.1007/BF01245811 | TECHNION-PH 97-02, MZ-TH/95-21 | hep-ph | null | We employ OPE techniques within HQET to calculate the inclusive semileptonic
decays of polarized $\Lambda_b$ baryons. Lepton mass effects are included which
enables us to also discuss rates into polarized $\tau$-leptons. We present
explicit results for the longitudinal polarization of the $\tau$ in the
$\Lambda_b$ rest frame as well as in the $(\tau ^-, \bar \nu_\tau)$ c.m. frame.
In both cases we make use of novel calculational techniques which considerably
simplify the calculations. The transverse polarization components of the $\tau$
are calculated in the $(\tau^-,\bar\nu_\tau)$ c.m. frame. We delineate how to
measure the full set of 14 polarized and unpolarized structure functions of the
decay process by angular correlation measurements. A set of observables are
identified that allow one to isolate the contributions of the two $O(1/m_b^2)$
nonperturbative matrix elements $K_b$ and $\epsilon_b$.
| [
{
"created": "Mon, 17 Mar 1997 16:02:31 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Balk",
"S.",
""
],
[
"Körner",
"J. G.",
""
],
[
"Pirjol",
"D.",
""
]
] | We employ OPE techniques within HQET to calculate the inclusive semileptonic decays of polarized $\Lambda_b$ baryons. Lepton mass effects are included which enables us to also discuss rates into polarized $\tau$-leptons. We present explicit results for the longitudinal polarization of the $\tau$ in the $\Lambda_b$ rest frame as well as in the $(\tau ^-, \bar \nu_\tau)$ c.m. frame. In both cases we make use of novel calculational techniques which considerably simplify the calculations. The transverse polarization components of the $\tau$ are calculated in the $(\tau^-,\bar\nu_\tau)$ c.m. frame. We delineate how to measure the full set of 14 polarized and unpolarized structure functions of the decay process by angular correlation measurements. A set of observables are identified that allow one to isolate the contributions of the two $O(1/m_b^2)$ nonperturbative matrix elements $K_b$ and $\epsilon_b$. |
hep-ph/9306292 | Yuval Grossman | Yuval Grossman and Yosef Nir | Implications of $b\rightarrow s\gamma$ for CP Violation in Charged
Scalar Exchange | 11 pages, 3 figures available upon request, TeX, WIS-93/51/Jun-PH | Phys.Lett.B313:126-130,1993 | 10.1016/0370-2693(93)91201-W | null | hep-ph | null | In models of three or more scalar doublets, new CP violating phases appear in
charged scalar exchange. These phases affect CP asymmetries in neutral $B$
decays, even if Natural Flavor Conservation holds. The recent upper bound on
the decay $b\rightarrow s\gamma$ constrains the effect to be at most of order a
few percent. Modifications of constraints on the CKM parameters open an
interesting new region in the $\sin2\alpha-\sin2\beta$ plane even in the
absence of new phases.
| [
{
"created": "Sun, 20 Jun 1993 13:19:32 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Grossman",
"Yuval",
""
],
[
"Nir",
"Yosef",
""
]
] | In models of three or more scalar doublets, new CP violating phases appear in charged scalar exchange. These phases affect CP asymmetries in neutral $B$ decays, even if Natural Flavor Conservation holds. The recent upper bound on the decay $b\rightarrow s\gamma$ constrains the effect to be at most of order a few percent. Modifications of constraints on the CKM parameters open an interesting new region in the $\sin2\alpha-\sin2\beta$ plane even in the absence of new phases. |
hep-ph/9707358 | Carlo Giunti | S.M. Bilenky, C. Giunti, W. Grimus | Neutrino masses and mixing from neutrino oscillation data | 4 pages, including 2 figures. Talk presented by S.M. Bilenky at the
XVI International Workshop on Weak Interactions and Neutrinos, Capri, Italy,
June 22-28 1997 | Nucl.Phys.Proc.Suppl. 66 (1998) 404-407 | 10.1016/S0920-5632(98)00074-7 | DFTT 45/97 | hep-ph | null | We discuss what information about the neutrino mass spectrum and the elements
of the neutrino mixing matrix can be inferred from the results of neutrino
oscillation experiments. The cases of three and four massive neutrinos are
considered. It is shown that the general characteristics of the neutrino mixing
matrix are quite different from those of the quark mixing matrix.
| [
{
"created": "Wed, 16 Jul 1997 13:08:24 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Bilenky",
"S. M.",
""
],
[
"Giunti",
"C.",
""
],
[
"Grimus",
"W.",
""
]
] | We discuss what information about the neutrino mass spectrum and the elements of the neutrino mixing matrix can be inferred from the results of neutrino oscillation experiments. The cases of three and four massive neutrinos are considered. It is shown that the general characteristics of the neutrino mixing matrix are quite different from those of the quark mixing matrix. |
1602.08506 | Carlos Alvarado | Carlos Alvarado, Rodolfo M. Capdevilla, Antonio Delgado and Adam
Martin | Minimal Models of Loop-Induced Higgs Lepton Flavor Violation | 23 pages, 9 figures, 1 table; v2: references added, discussion on
renormalized A-term diagrams added, clarifying comments on two Higgs doublet
model added | Phys. Rev. D 94, 075010 (2016) | 10.1103/PhysRevD.94.075010 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The LHC has recently reported a slight excess in the $h\rightarrow \tau \mu$
channel. If this lepton flavor violating (LFV) decay is confirmed, an extension
of the Standard Model (SM) will be required to explain it. In this paper we
investigate two different possibilities to accommodate such a LFV process: the
first scenario is based on flavor off-diagonal $A$-terms in the Minimal
Supersymmetric Standard Model (MSSM), and the second is a model where the Higgs
couples to new vectorlike fermions that couple to the SM leptons through a LFV
four fermion interaction. In the supersymmetric model, we find that the sizes
of the $A$-terms needed to accommodate the $h\rightarrow \tau\mu$ excess are in
conflict with charge- and color-breaking vacuum constraints. In the second
model, the excess can be successfully explained while satisfying all other
flavor constrains, with order one couplings, vectorlike fermion masses as low
as 15 TeV, and a UV scale higher than 35 TeV.
| [
{
"created": "Fri, 26 Feb 2016 21:12:37 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Mar 2016 19:41:23 GMT",
"version": "v2"
}
] | 2016-10-26 | [
[
"Alvarado",
"Carlos",
""
],
[
"Capdevilla",
"Rodolfo M.",
""
],
[
"Delgado",
"Antonio",
""
],
[
"Martin",
"Adam",
""
]
] | The LHC has recently reported a slight excess in the $h\rightarrow \tau \mu$ channel. If this lepton flavor violating (LFV) decay is confirmed, an extension of the Standard Model (SM) will be required to explain it. In this paper we investigate two different possibilities to accommodate such a LFV process: the first scenario is based on flavor off-diagonal $A$-terms in the Minimal Supersymmetric Standard Model (MSSM), and the second is a model where the Higgs couples to new vectorlike fermions that couple to the SM leptons through a LFV four fermion interaction. In the supersymmetric model, we find that the sizes of the $A$-terms needed to accommodate the $h\rightarrow \tau\mu$ excess are in conflict with charge- and color-breaking vacuum constraints. In the second model, the excess can be successfully explained while satisfying all other flavor constrains, with order one couplings, vectorlike fermion masses as low as 15 TeV, and a UV scale higher than 35 TeV. |
1206.6888 | Patrick Meade | David Curtin, Prerit Jaiswal, and Patrick Meade | Charginos Hiding In Plain Sight | 7 pages, 3 figures v2:significant updates incorporating summer
experimental results, conclusions strengthened | null | 10.1103/PhysRevD.87.031701 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent 7 TeV 5/fb measurements by ATLAS and CMS have measured both overall
and differential WW cross sections that differ from NLO SM predictions. While
these measurements aren't statistically significant enough to rule out the SM,
we demonstrate that the data from both experiments can be better fit with the
inclusion of electroweak gauginos with masses of O(100) GeV. We show that these
new states are consistent with other experimental searches/measurements and can
have ramifications for Higgs phenomenology. Additionally, we show how the first
measurements of the WW cross section at 8 TeV by CMS strengthen our
conclusions.
| [
{
"created": "Thu, 28 Jun 2012 20:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Aug 2012 18:20:12 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Curtin",
"David",
""
],
[
"Jaiswal",
"Prerit",
""
],
[
"Meade",
"Patrick",
""
]
] | Recent 7 TeV 5/fb measurements by ATLAS and CMS have measured both overall and differential WW cross sections that differ from NLO SM predictions. While these measurements aren't statistically significant enough to rule out the SM, we demonstrate that the data from both experiments can be better fit with the inclusion of electroweak gauginos with masses of O(100) GeV. We show that these new states are consistent with other experimental searches/measurements and can have ramifications for Higgs phenomenology. Additionally, we show how the first measurements of the WW cross section at 8 TeV by CMS strengthen our conclusions. |
1009.0104 | Kang Young Lee | Kang Young Lee | Lepton flavour violation in a nonuniversal gauge interaction model | 5 pages, 2 figures | null | 10.1103/PhysRevD.82.097701 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The flavour-changing neutral currents (FCNC) are derived at tree level if the
electroweak gauge group depends on the fermion family, which are absent in the
standard model. We study the lepton flavour violation (LFV) through the FCNC
interactions in a nonuniversal gauge interaction model where the third
generation fermions are subjected to the separate SU(2)$_L$ gauge group.
| [
{
"created": "Wed, 1 Sep 2010 07:44:52 GMT",
"version": "v1"
}
] | 2015-05-19 | [
[
"Lee",
"Kang Young",
""
]
] | The flavour-changing neutral currents (FCNC) are derived at tree level if the electroweak gauge group depends on the fermion family, which are absent in the standard model. We study the lepton flavour violation (LFV) through the FCNC interactions in a nonuniversal gauge interaction model where the third generation fermions are subjected to the separate SU(2)$_L$ gauge group. |
hep-ph/0205300 | Vasily V. Kabachenko | V. Ammosov, V. Garkusha, A. Ivanilov, V. Kabachenko, E. Melnikov, F.
Novoskoltsev, A. Soldatov and A. Zaitsev (Institute for High Energy Physics,
Protvino, Russia) | Prospects to measure neutrino oscillation pattern with very large area
underground detector at very long baselines | 23 pages, 17 figures, LaTeX2e. Submitted to XX International
Conference on Neutrino Physics and Astrophysics (Neutrino 2002), Munich,
Germany, May 2002 | null | null | IHEP 2002-19 | hep-ph | null | The concept of a very long baseline neutrino experiment with quasi
monochromatic neutrino beam and very large area underground detector is
discussed. The detector could be placed in the existing 20 km tunnel at IHEP,
Protvino. The High Intensity Proton Accelerators (HIPA) which are planned to be
built in Japan (JAERI-KEK, baseline of 7000 km) and Germany (GSI, baseline of
2000 km) as well as the Main Injector at Fermilab (7600 km) are considered as
possible sources of neutrino beams. The oscillations are analysed in the
three-neutrino scheme taking into account terrestrial matter effects. In the
proposed experiment it is feasible to observe the oscillation pattern as an
unique proof of the existence of neutrino oscillations. Precise measurements of
disappearance oscillation parameters of the muon neutrinos and antineutrinos
can be done within a reasonable time.
| [
{
"created": "Mon, 27 May 2002 09:43:49 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ammosov",
"V.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Garkusha",
"V.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Ivanilov",
"A.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Kabachenko",
"V.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Melnikov",
"E.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Novoskoltsev",
"F.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Soldatov",
"A.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
],
[
"Zaitsev",
"A.",
"",
"Institute for High Energy Physics,\n Protvino, Russia"
]
] | The concept of a very long baseline neutrino experiment with quasi monochromatic neutrino beam and very large area underground detector is discussed. The detector could be placed in the existing 20 km tunnel at IHEP, Protvino. The High Intensity Proton Accelerators (HIPA) which are planned to be built in Japan (JAERI-KEK, baseline of 7000 km) and Germany (GSI, baseline of 2000 km) as well as the Main Injector at Fermilab (7600 km) are considered as possible sources of neutrino beams. The oscillations are analysed in the three-neutrino scheme taking into account terrestrial matter effects. In the proposed experiment it is feasible to observe the oscillation pattern as an unique proof of the existence of neutrino oscillations. Precise measurements of disappearance oscillation parameters of the muon neutrinos and antineutrinos can be done within a reasonable time. |
2406.02419 | Hai-Bing Fu | Jia-Wei Zhang, Bo-Yan Cui, Xing-Gang Wu, Hai-Bing Fu, Ya-Hui Chen | Quasi-two-body decays $B\to P f_0(500)\to P\pi^+\pi^-$ in the
perturbative QCD approach | 15 pages, 3 figures, comments welcome | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this paper, we study the quasi-two-body decays $B\to P f_0(500)\to
P\pi^+\pi^-$ (with $P=(\pi, K, \eta, \eta^{\prime})$) within framework of
perturbative QCD (PQCD) factorization approach. With the help of $\pi$-$\pi$
distribution amplitude and scalar form factor $F_{\pi\pi}(\omega^2)$, we
calculate the CP averaged branching fraction and the CP asymmetry for the
quasi-two-body decays $B\to P f_0(500)\to P\pi^+\pi^-$. Taking the
quasi-two-body decay $B^+ \to \pi^+ f_0(500) \to \pi^+ \pi^+ \pi^-$ as an
explicit example, we present the behaviour of differential branching fraction
and direct CP violation versus the $\pi$-$\pi$ invariant mass. The total
branching fraction and direct CP violation are $\mathcal{B}(B^+\to \pi^+
[\sigma\to]\pi^+\pi^-) = (1.78 \pm 0.41\pm 0.51) \times 10^{-6}$ and
$\mathcal{A}_{\rm CP}(B^+\to \pi^+ [\sigma\to]\pi^+\pi^-) = (29.8\pm 11.1\pm
13.0)\%$ respectively. Our results could be tested by further experiments.
| [
{
"created": "Tue, 4 Jun 2024 15:37:12 GMT",
"version": "v1"
}
] | 2024-06-05 | [
[
"Zhang",
"Jia-Wei",
""
],
[
"Cui",
"Bo-Yan",
""
],
[
"Wu",
"Xing-Gang",
""
],
[
"Fu",
"Hai-Bing",
""
],
[
"Chen",
"Ya-Hui",
""
]
] | In this paper, we study the quasi-two-body decays $B\to P f_0(500)\to P\pi^+\pi^-$ (with $P=(\pi, K, \eta, \eta^{\prime})$) within framework of perturbative QCD (PQCD) factorization approach. With the help of $\pi$-$\pi$ distribution amplitude and scalar form factor $F_{\pi\pi}(\omega^2)$, we calculate the CP averaged branching fraction and the CP asymmetry for the quasi-two-body decays $B\to P f_0(500)\to P\pi^+\pi^-$. Taking the quasi-two-body decay $B^+ \to \pi^+ f_0(500) \to \pi^+ \pi^+ \pi^-$ as an explicit example, we present the behaviour of differential branching fraction and direct CP violation versus the $\pi$-$\pi$ invariant mass. The total branching fraction and direct CP violation are $\mathcal{B}(B^+\to \pi^+ [\sigma\to]\pi^+\pi^-) = (1.78 \pm 0.41\pm 0.51) \times 10^{-6}$ and $\mathcal{A}_{\rm CP}(B^+\to \pi^+ [\sigma\to]\pi^+\pi^-) = (29.8\pm 11.1\pm 13.0)\%$ respectively. Our results could be tested by further experiments. |
hep-ph/9708390 | Torbjorn Sjostrand | J. Andr\'e and T. Sj\"ostrand (Lund University) | A matching of matrix elements and parton showers | 1+8 pages, LaTeX2e, 5 postscript figures included | Phys.Rev.D57:5767-5772,1998 | 10.1103/PhysRevD.57.5767 | LU TP 97-18 | hep-ph | null | We propose a simple scheme to start a parton-shower evolution description
from a given jet configuration in $e^+ e^-$ annihilation events. This allows a
convenient combination of the full angular information content of matrix
elements with the detailed sub-jet structure of parton showers, and should give
a realistic overall description of event properties. Explicit studies with this
hybrid approach are presented for the four-jet case, as a simple testing ground
of the ideas.
| [
{
"created": "Mon, 18 Aug 1997 14:11:22 GMT",
"version": "v1"
}
] | 2011-01-13 | [
[
"André",
"J.",
"",
"Lund University"
],
[
"Sjöstrand",
"T.",
"",
"Lund University"
]
] | We propose a simple scheme to start a parton-shower evolution description from a given jet configuration in $e^+ e^-$ annihilation events. This allows a convenient combination of the full angular information content of matrix elements with the detailed sub-jet structure of parton showers, and should give a realistic overall description of event properties. Explicit studies with this hybrid approach are presented for the four-jet case, as a simple testing ground of the ideas. |
hep-ph/9406398 | Alexander Ignatiev | A.Yu.Ignatiev, G.C.Joshi and M.Matsuda | The Search for the Decay of Z Boson into Two Gammas as a Test of Bose
Statistics | 9 pages, in REVTEX, RCHEP-94/17, UM-P-94/63 | Mod.Phys.Lett.A11:871-876,1996 | 10.1142/S0217732396000874 | null | hep-ph quant-ph | null | We suggest that Bose statistics for photons can be tested by looking for
decays of spin-1 bosons into two photons. The experimental upper limit on the
decay $Z \rightarrow \gamma \gamma $ is used to establish for the first time
the quantitative measure of the validity of Bose symmetry for photons.
| [
{
"created": "Mon, 27 Jun 1994 03:09:50 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Ignatiev",
"A. Yu.",
""
],
[
"Joshi",
"G. C.",
""
],
[
"Matsuda",
"M.",
""
]
] | We suggest that Bose statistics for photons can be tested by looking for decays of spin-1 bosons into two photons. The experimental upper limit on the decay $Z \rightarrow \gamma \gamma $ is used to establish for the first time the quantitative measure of the validity of Bose symmetry for photons. |
hep-ph/9403407 | null | P. Ball, U. Nierste | The Mass Definition in Hqet and a New Determination of V$_{\text{cb}}$ | 21 p., 5 figs, all style files incl., TUM-T31-56/R (Sec. 2 revised,
phenomenological results unchanged) | Phys.Rev.D50:5841-5852,1994 | 10.1103/PhysRevD.50.5841 | null | hep-ph | null | Positive powers of the mass parameter in a physical quantity calculated with
the help of heavy quark effective theory originate from a Wilson coefficient in
the matching of QCD and HQET Green function. We show that this mass parameter
enters the calculation as a well--defined running current mass. We further
argue that the recently found ill--definition of the pole mass, which is the
natural expansion parameter of HQET, does not affect a phenomenological
analysis which uses truncated perturbative series. We reanalyse inclusive
semileptonic decays of heavy mesons and obtain the $c$ quark mass
$m_c^{\overline{\text{MS}}}(m_c) = (1.35\pm 0.20)\,\text{GeV}$ where the error
is almost entirely due to scale--uncertainties. We also obtain
$m_b^{\overline{\text{MS}}}(m_b) = (4.6\pm 0.3)\,\text{GeV}$ and
$|V_{cb}|(\tau_B/1.49\,\text{ps})^{1/2} = 0.036\pm 0.005$ where the errors come
from the uncertainty in the kinetic energy of the heavy quark inside the meson,
in the experimental branching ratios, in QCD input parameters, and
scale--uncertainties.
| [
{
"created": "Thu, 31 Mar 1994 16:22:07 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Apr 1994 17:29:10 GMT",
"version": "v2"
},
{
"created": "Sun, 24 Apr 1994 09:38:08 GMT",
"version": "v3"
}
] | 2010-11-01 | [
[
"Ball",
"P.",
""
],
[
"Nierste",
"U.",
""
]
] | Positive powers of the mass parameter in a physical quantity calculated with the help of heavy quark effective theory originate from a Wilson coefficient in the matching of QCD and HQET Green function. We show that this mass parameter enters the calculation as a well--defined running current mass. We further argue that the recently found ill--definition of the pole mass, which is the natural expansion parameter of HQET, does not affect a phenomenological analysis which uses truncated perturbative series. We reanalyse inclusive semileptonic decays of heavy mesons and obtain the $c$ quark mass $m_c^{\overline{\text{MS}}}(m_c) = (1.35\pm 0.20)\,\text{GeV}$ where the error is almost entirely due to scale--uncertainties. We also obtain $m_b^{\overline{\text{MS}}}(m_b) = (4.6\pm 0.3)\,\text{GeV}$ and $|V_{cb}|(\tau_B/1.49\,\text{ps})^{1/2} = 0.036\pm 0.005$ where the errors come from the uncertainty in the kinetic energy of the heavy quark inside the meson, in the experimental branching ratios, in QCD input parameters, and scale--uncertainties. |
2205.07902 | Xiaojun Yao | Xiaojun Yao | Quantum Simulation of Light-Front QCD for Jet Quenching in Nuclear
Environments | 56 pages, 9 figures; v2: add a section on the simulation of the LPM
effect in gluon radiation; v3: added more discussions in introduction,
modified discussions of simulation results | null | null | MIT-CTP 5435, IQuS@UW-21-037 | hep-ph hep-lat nucl-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a framework to simulate jet quenching in nuclear environments on a
quantum computer. The formulation is based on the light-front Hamiltonian
dynamics of QCD. The Hamiltonian consists of three parts relevant for jet
quenching studies: kinetic, diffusion and splitting terms. In the basis made up
of $n$-particle states in momentum space, the kinetic Hamiltonian is diagonal.
Matrices representing the diffusion and splitting parts are sparse. The
diffusion part of the Hamiltonian depends on classical background gauge fields,
which need to be sampled classically before constructing quantum circuits for
the time evolution. The cost of the sampling scales linearly with the time
length of the evolution and the momentum grid volume. The framework
automatically keeps track of quantum interference and thus it can be applied to
study the Landau-Pomeranchuk-Migdal effect in cases with more than two coherent
splittings, which is beyond the scope of state-of-the-art analyses, no matter
whether the medium is static or expanding, thin or thick, hot or cold. We apply
this framework to study a toy model and gluon in-medium radiation on a small
lattice. The essence of the Landau-Pomeranchuk-Migdal effect is observed in the
quantum simulation results of both the toy model and the gluon case, which is
quantum decoherence caused by medium interactions that suppresses the total
radiation probability.
| [
{
"created": "Mon, 16 May 2022 18:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Nov 2022 23:26:09 GMT",
"version": "v2"
},
{
"created": "Tue, 27 Dec 2022 07:54:36 GMT",
"version": "v3"
}
] | 2022-12-29 | [
[
"Yao",
"Xiaojun",
""
]
] | We develop a framework to simulate jet quenching in nuclear environments on a quantum computer. The formulation is based on the light-front Hamiltonian dynamics of QCD. The Hamiltonian consists of three parts relevant for jet quenching studies: kinetic, diffusion and splitting terms. In the basis made up of $n$-particle states in momentum space, the kinetic Hamiltonian is diagonal. Matrices representing the diffusion and splitting parts are sparse. The diffusion part of the Hamiltonian depends on classical background gauge fields, which need to be sampled classically before constructing quantum circuits for the time evolution. The cost of the sampling scales linearly with the time length of the evolution and the momentum grid volume. The framework automatically keeps track of quantum interference and thus it can be applied to study the Landau-Pomeranchuk-Migdal effect in cases with more than two coherent splittings, which is beyond the scope of state-of-the-art analyses, no matter whether the medium is static or expanding, thin or thick, hot or cold. We apply this framework to study a toy model and gluon in-medium radiation on a small lattice. The essence of the Landau-Pomeranchuk-Migdal effect is observed in the quantum simulation results of both the toy model and the gluon case, which is quantum decoherence caused by medium interactions that suppresses the total radiation probability. |
hep-ph/0412348 | Amon Ilakovac | Takeshi Fukuyama (Ritsumeikan U., Kusatsu), Amon Ilakovac (Zagreb U.),
Tatsuru Kikuchi (Ritsumeikan U., Kusatsu), Stjepan Meljanac (Ruder Boskovic
Institute, Zagreb) and Nobuchika Okada (KEK, Tsukuba) | Higgs Masses in the Minimal SUSY SO(10) GUT | 4 pages, revtex4, Changes in the paper : We agree with Ref.
hep-ph/0501025 that there there should exist equivalence mappings between
results of Higgs mass spectra calculated by three groups of authors. (in
three different approaches. However, in the Note added of the Ref.
hep-ph/0405074 v3 the wrong mapping was presented. The explicit construction
of equivalence mappings to other approches is given. Minor changes in the
text. Paper is beeing accepted for publication in Phys. Rev D | Phys.Rev. D72 (2005) 051701 | 10.1103/PhysRevD.72.051701 | null | hep-ph | null | We explicitly show that minimal SUSY SO(10) Higgs-Higgsino mass matrices
evaluated by various groups are mutually consistent and correct. We comment on
the corresponding results of other authors. We construct one-to-one mappings of
our approach to the approaches of other authors.
| [
{
"created": "Wed, 22 Dec 2004 18:28:05 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jan 2005 18:55:33 GMT",
"version": "v2"
},
{
"created": "Mon, 22 Aug 2005 17:21:16 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Fukuyama",
"Takeshi",
"",
"Ritsumeikan U., Kusatsu"
],
[
"Ilakovac",
"Amon",
"",
"Zagreb U."
],
[
"Kikuchi",
"Tatsuru",
"",
"Ritsumeikan U., Kusatsu"
],
[
"Meljanac",
"Stjepan",
"",
"Ruder Boskovic\n Institute, Zagreb"
],
[
"Okada",
"Nobuchika",
"",
"KEK, Tsukuba"
]
] | We explicitly show that minimal SUSY SO(10) Higgs-Higgsino mass matrices evaluated by various groups are mutually consistent and correct. We comment on the corresponding results of other authors. We construct one-to-one mappings of our approach to the approaches of other authors. |
1104.0170 | Tetsutaro Higaki | Tetsutaro Higaki, Ryuichiro Kitano | On Supersymmetric Effective Theories of Axion | 41 pages, 3 figures, 2 tables; v2 additional comments and references | null | 10.1103/PhysRevD.86.075027 | DESY 11-053, TU-881 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study effective theories of an axion in spontaneously broken
supersymmetric theories. We consider a system where the axion supermultiplet is
directly coupled to a supersymmetry breaking sector whereas the standard model
sector is communicated with those sectors through loops of messenger fields.
The gaugino masses and the axion-gluon coupling necessary for solving the
strong CP problem are both obtained by the same effective interaction. We
discuss cosmological constraints on this framework.
| [
{
"created": "Fri, 1 Apr 2011 13:44:14 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Apr 2011 06:48:48 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Higaki",
"Tetsutaro",
""
],
[
"Kitano",
"Ryuichiro",
""
]
] | We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. |
1505.00561 | Dominik Kara | Thomas Gehrmann, Sam Guns, Dominik Kara | The rare decay $H\to Z\gamma$ in perturbative QCD | 19 pages, 3 figures, 1 table; v2: derived analytical result for small
quark masses and demonstrated vanishing of double logarithms, accepted for
publication in JHEP | null | null | ZU-TH 10/15 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The rare Higgs boson decay $H\to Z\gamma$ is forbidden at tree-level. In the
Standard Model, it is loop-mediated through a $W$ boson or a heavy quark. We
analytically compute the QCD correction to the heavy quark loop, confirming
earlier purely numerical results, that were obtained for on-shell
renormalization. The small quark mass expansion of the decay matrix element
contains only single-logarithmic contributions at each perturbative order,
which is in contrast to the double logarithms observed in $H\to \gamma\gamma$.
We investigate the numerical interplay of bottom and top quark contributions,
and the dependence of the result on the renormalization scheme.
| [
{
"created": "Mon, 4 May 2015 09:00:26 GMT",
"version": "v1"
},
{
"created": "Fri, 21 Aug 2015 16:07:25 GMT",
"version": "v2"
}
] | 2015-08-24 | [
[
"Gehrmann",
"Thomas",
""
],
[
"Guns",
"Sam",
""
],
[
"Kara",
"Dominik",
""
]
] | The rare Higgs boson decay $H\to Z\gamma$ is forbidden at tree-level. In the Standard Model, it is loop-mediated through a $W$ boson or a heavy quark. We analytically compute the QCD correction to the heavy quark loop, confirming earlier purely numerical results, that were obtained for on-shell renormalization. The small quark mass expansion of the decay matrix element contains only single-logarithmic contributions at each perturbative order, which is in contrast to the double logarithms observed in $H\to \gamma\gamma$. We investigate the numerical interplay of bottom and top quark contributions, and the dependence of the result on the renormalization scheme. |
2207.01656 | Alvaro S. de Jesus | Guo-yuan Huang, Sudip Jana, Alvaro S. de Jesus, Farinaldo S. Queiroz
and Werner Rodejohann | Search for Leptophilic Dark Matter at the LHeC | 5 pages and 5 figures | null | 10.1088/1361-6471/accc4a | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The Large Hadron electron Collider (LHeC) has been designed to push the field
of deep inelastic scattering to the high energy and intensity frontier using an
intense electron beam with a proton beam from the High Luminosity-Large Hadron
Collider. However, LHeC is also a great laboratory for new physics. In this
work, we propose a search for dark matter that couples with leptons. This may
yield $ej$+ missing energy and $\mu j$ + missing energy signals that can be
potentially observed through simple missing-energy cuts that suppress the
Standard Model background. Considering direct dark matter detection and LHC
constraints, we show that LHeC can indeed discover a weak scale dark matter
fermion for masses up to 350 GeV, which reproduces the correct relic density,
and has interesting implications for lepton flavor violation.
| [
{
"created": "Mon, 4 Jul 2022 18:09:05 GMT",
"version": "v1"
}
] | 2023-05-17 | [
[
"Huang",
"Guo-yuan",
""
],
[
"Jana",
"Sudip",
""
],
[
"de Jesus",
"Alvaro S.",
""
],
[
"Queiroz",
"Farinaldo S.",
""
],
[
"Rodejohann",
"Werner",
""
]
] | The Large Hadron electron Collider (LHeC) has been designed to push the field of deep inelastic scattering to the high energy and intensity frontier using an intense electron beam with a proton beam from the High Luminosity-Large Hadron Collider. However, LHeC is also a great laboratory for new physics. In this work, we propose a search for dark matter that couples with leptons. This may yield $ej$+ missing energy and $\mu j$ + missing energy signals that can be potentially observed through simple missing-energy cuts that suppress the Standard Model background. Considering direct dark matter detection and LHC constraints, we show that LHeC can indeed discover a weak scale dark matter fermion for masses up to 350 GeV, which reproduces the correct relic density, and has interesting implications for lepton flavor violation. |
hep-ph/9904494 | Nathan Isgur | Nathan Isgur (Jefferson Lab) | Flux Tube Zero-Point Motion, Hadronic Charge Radii, and Hybrid Meson
Production Cross Sections | 16 pages, revised to clarify some points and to improve and correct
the notation for the flux tube wave functions | Phys.Rev.D60:114016,1999 | 10.1103/PhysRevD.60.114016 | JLAB-THY-99-09 | hep-ph nucl-th | null | Flux tube zero-point motion produces quark displacements transverse to the
flux tube which make significant contributions to hadronic charge radii. In
heavy quark systems, these contributions can be related by Bjorken's sum rule
to the rates for semileptonic decay to hybrid mesons. This connection can be
generalized to other leptoproduction processes, where transverse contributions
to elastic form factor slopes are related to the cross sections for the
production of the associated hybrid states. I identify the flux tube overlap
integral responsible for these effects as the strong QCD analogue of the
Sudakov form factor of perturbative QCD.
| [
{
"created": "Thu, 29 Apr 1999 17:43:07 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Jun 1999 20:10:06 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Isgur",
"Nathan",
"",
"Jefferson Lab"
]
] | Flux tube zero-point motion produces quark displacements transverse to the flux tube which make significant contributions to hadronic charge radii. In heavy quark systems, these contributions can be related by Bjorken's sum rule to the rates for semileptonic decay to hybrid mesons. This connection can be generalized to other leptoproduction processes, where transverse contributions to elastic form factor slopes are related to the cross sections for the production of the associated hybrid states. I identify the flux tube overlap integral responsible for these effects as the strong QCD analogue of the Sudakov form factor of perturbative QCD. |
hep-ph/0204289 | Rudolph C. Hwa | Rudolph C. Hwa and C. B. Yang | Inclusive Distributions for Hadronic Collisions in the
Valon-Recombination Model | 12 pages + 10 figures in eps | Phys.Rev.C66:025205,2002 | 10.1103/PhysRevC.66.025205 | OITS-716 | hep-ph | null | Inclusive distributions of soft production of mesons in hadronic collisions
are calculated in the valon-recombination model. The new determination of the
valon distributions from hard scattering data makes possible a tightly
interrelated treatment of pion and kaon production in the fragmentation regions
of proton, pion and kaon. Only one free parameter is used in the determination
of the valon distribution in the kaon. No other adjustable parameter is needed
to fit the $x$-distributions of the data on inclusive cross sections, except
for the normalizations since the data are at fixed $p_T$. The success of the
model in reproducing seven inclusive distributions suggests that there are two
important mechanisms at work in soft production. One is that the structure of
the hadron that fragments is highly relevant. The other is that the produced
particles are formed by the recombination of quarks and antiquarks. These two
aspects about hadrons in soft processes can be well described in the framework
of the valon-recombination model.
| [
{
"created": "Wed, 24 Apr 2002 23:06:44 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hwa",
"Rudolph C.",
""
],
[
"Yang",
"C. B.",
""
]
] | Inclusive distributions of soft production of mesons in hadronic collisions are calculated in the valon-recombination model. The new determination of the valon distributions from hard scattering data makes possible a tightly interrelated treatment of pion and kaon production in the fragmentation regions of proton, pion and kaon. Only one free parameter is used in the determination of the valon distribution in the kaon. No other adjustable parameter is needed to fit the $x$-distributions of the data on inclusive cross sections, except for the normalizations since the data are at fixed $p_T$. The success of the model in reproducing seven inclusive distributions suggests that there are two important mechanisms at work in soft production. One is that the structure of the hadron that fragments is highly relevant. The other is that the produced particles are formed by the recombination of quarks and antiquarks. These two aspects about hadrons in soft processes can be well described in the framework of the valon-recombination model. |
1504.03817 | Naoki Yamatsu | Yutaka Hosotani and Naoki Yamatsu | Gauge-Higgs Grand Unification | 12 pages, 1 figure; the discussion about NG modes is changed | null | 10.1093/ptep/ptv153 | OU-HET 854 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | $SO(11)$ gauge-Higgs grand unification in the Randall-Sundrum warped space is
proposed. Orbifold boundary conditions and one brane scalar field reduce
$SO(11)$ to the standard model symmetry, which is further broken to $SU(3)_C
\times U(1)_{EM}$ by the Hosotani mechanism. In a minimal model quarks and
leptons are contained in a multiplet in ${\bf 32}$ of $SO(11)$ in each
generation. Proton decay is naturally suppressed by a conserved fermion number.
| [
{
"created": "Wed, 15 Apr 2015 08:25:11 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Apr 2015 10:42:40 GMT",
"version": "v2"
},
{
"created": "Wed, 10 Jun 2015 05:45:17 GMT",
"version": "v3"
},
{
"created": "Wed, 5 Aug 2015 08:19:37 GMT",
"version": "v4"
},
{
"created": "Thu, 20 Aug 2015 06:01:13 GMT",
"version": "v5"
}
] | 2015-11-18 | [
[
"Hosotani",
"Yutaka",
""
],
[
"Yamatsu",
"Naoki",
""
]
] | $SO(11)$ gauge-Higgs grand unification in the Randall-Sundrum warped space is proposed. Orbifold boundary conditions and one brane scalar field reduce $SO(11)$ to the standard model symmetry, which is further broken to $SU(3)_C \times U(1)_{EM}$ by the Hosotani mechanism. In a minimal model quarks and leptons are contained in a multiplet in ${\bf 32}$ of $SO(11)$ in each generation. Proton decay is naturally suppressed by a conserved fermion number. |
2008.04910 | Eric Metodiev | Eric M. Metodiev | Energy Flow in Particle Collisions | Ph.D. thesis, MIT, 2020, 229 pages, 34 figures | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this thesis, I introduce a new bottom-up approach to quantum field theory
and collider physics, beginning from the observable energy flow: the energy
distribution produced by particle collisions. First, I establish a metric space
for collision events by comparing their energy flows. I unify many ideas
spanning multiple decades, such as observables and jets, as simple geometric
objects in this new space. Second, I develop a basis of observables by
systematically expanding in particle energies and angles, encompassing many
existing observables and uncovering new analytic structures. I highlight how
the traditional criteria for theoretical calculability emerge as consistency
conditions, due to the redundancy of describing an event using particles rather
than its energy flow. Finally, I propose a definition of particle type, or
flavor, which makes use of only observable information. This definition
requires refining the notion of flavor from a per-event label to a statistical
category, and I showcase its direct experimental applicability at colliders.
Throughout, I synthesize concepts from particle physics with ideas from
statistics and computer science to expand the theoretical understanding of
particle interactions and enhance the experimental capabilities of collider
data analysis techniques.
| [
{
"created": "Tue, 11 Aug 2020 18:00:00 GMT",
"version": "v1"
}
] | 2020-08-13 | [
[
"Metodiev",
"Eric M.",
""
]
] | In this thesis, I introduce a new bottom-up approach to quantum field theory and collider physics, beginning from the observable energy flow: the energy distribution produced by particle collisions. First, I establish a metric space for collision events by comparing their energy flows. I unify many ideas spanning multiple decades, such as observables and jets, as simple geometric objects in this new space. Second, I develop a basis of observables by systematically expanding in particle energies and angles, encompassing many existing observables and uncovering new analytic structures. I highlight how the traditional criteria for theoretical calculability emerge as consistency conditions, due to the redundancy of describing an event using particles rather than its energy flow. Finally, I propose a definition of particle type, or flavor, which makes use of only observable information. This definition requires refining the notion of flavor from a per-event label to a statistical category, and I showcase its direct experimental applicability at colliders. Throughout, I synthesize concepts from particle physics with ideas from statistics and computer science to expand the theoretical understanding of particle interactions and enhance the experimental capabilities of collider data analysis techniques. |
1701.04334 | Jacob Noordmans Ph. D. | J. P. Noordmans | Gluonic Lorentz violation and chiral perturbation theory | 20 pages, 1 figure | Phys. Rev. D 95, 075030 (2017) | 10.1103/PhysRevD.95.075030 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By applying chiral-perturbation-theory methods to the QCD sector of the
Lorentz-violating Standard-Model Extension, we investigate Lorentz violation in
the strong interactions. In particular, we consider the CPT-even pure-gluon
operator of the minimal Standard-Model Extension. We construct the lowest-order
chiral effective Lagrangian for three as well as two light quark flavors. We
develop the power-counting rules and construct the heavy-baryon
chiral-perturbation-theory Lagrangian, which we use to calculate
Lorentz-violating contributions to the nucleon self energy. Using the
constructed effective operators, we derive the first stringent limits on many
of the components of the relevant Lorentz-violating parameter. We also obtain
the Lorentz-violating nucleon-nucleon potential. We suggest that this potential
may be used to obtain new limits from atomic-clock or deuteron storage-ring
experiments.
| [
{
"created": "Mon, 16 Jan 2017 15:43:48 GMT",
"version": "v1"
}
] | 2017-05-03 | [
[
"Noordmans",
"J. P.",
""
]
] | By applying chiral-perturbation-theory methods to the QCD sector of the Lorentz-violating Standard-Model Extension, we investigate Lorentz violation in the strong interactions. In particular, we consider the CPT-even pure-gluon operator of the minimal Standard-Model Extension. We construct the lowest-order chiral effective Lagrangian for three as well as two light quark flavors. We develop the power-counting rules and construct the heavy-baryon chiral-perturbation-theory Lagrangian, which we use to calculate Lorentz-violating contributions to the nucleon self energy. Using the constructed effective operators, we derive the first stringent limits on many of the components of the relevant Lorentz-violating parameter. We also obtain the Lorentz-violating nucleon-nucleon potential. We suggest that this potential may be used to obtain new limits from atomic-clock or deuteron storage-ring experiments. |
1310.4965 | Wilco J. den Dunnen | Wilco J. den Dunnen and Marc Schlegel | Determining the Higgs spin and parity in the di-photon decay channel
using gluon polarization | 7 pages, to appear in the proceedings of the XXI International
Workshop on Deep-Inelastic Scattering and Related Subjects, 22-26 April,
2013, Marseilles, France | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Gluons inside an unpolarized proton are in general linearly polarized. This
polarization can, in principle, be used to determine the spin and parity of the
newly found Higgs-like boson at the LHC. We focus here on the calculation of
the degree of polarization.
| [
{
"created": "Fri, 18 Oct 2013 10:10:33 GMT",
"version": "v1"
}
] | 2013-10-21 | [
[
"Dunnen",
"Wilco J. den",
""
],
[
"Schlegel",
"Marc",
""
]
] | Gluons inside an unpolarized proton are in general linearly polarized. This polarization can, in principle, be used to determine the spin and parity of the newly found Higgs-like boson at the LHC. We focus here on the calculation of the degree of polarization. |
1702.06679 | Sunando Patra | Zaineb Calcuttawala, Anirban Kundu, Soumitra Nandi, Sunando Kumar
Patra | Optimal observable analysis for the decay $b \to s$ plus missing energy | 14 pages, 9 captioned figures | Eur. Phys. J. C (2017) 77: 650 | 10.1140/epjc/s10052-017-5227-5 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The decay $b\to s\nu\bar\nu$ has been a neglected sibling of $b\to
s\ell^+\ell^-$ because neutrinos pass undetected and hence the process offers
less number of observables. We show how the decay $b\to s~+$~invisible(s) can
shed light, even with a limited number of observables, on possible new physics
beyond the Standard Model and also show, quantitatively, the reach of future
$B$ factories like SuperBelle to uncover such new physics. Depending on the
operator structure of new physics, different channels may act as the best
possible probe. We show, using the Optimal Observable technique, how almost the
entire parameter space allowed till now can successfully be probed at a high
luminosity $B$ factory.
| [
{
"created": "Wed, 22 Feb 2017 05:11:56 GMT",
"version": "v1"
}
] | 2017-09-28 | [
[
"Calcuttawala",
"Zaineb",
""
],
[
"Kundu",
"Anirban",
""
],
[
"Nandi",
"Soumitra",
""
],
[
"Patra",
"Sunando Kumar",
""
]
] | The decay $b\to s\nu\bar\nu$ has been a neglected sibling of $b\to s\ell^+\ell^-$ because neutrinos pass undetected and hence the process offers less number of observables. We show how the decay $b\to s~+$~invisible(s) can shed light, even with a limited number of observables, on possible new physics beyond the Standard Model and also show, quantitatively, the reach of future $B$ factories like SuperBelle to uncover such new physics. Depending on the operator structure of new physics, different channels may act as the best possible probe. We show, using the Optimal Observable technique, how almost the entire parameter space allowed till now can successfully be probed at a high luminosity $B$ factory. |
1002.4051 | HongWei Ke | Hong-Wei Ke, Guo-Li Wang, Xue-Qian Li and Chao-Hsi Chang | The magnetic dipole transitions in the $(c\bar{b})$ binding system | 10 pages, 2 figures, 1 table | Sci. China G53:2025-2030,2010 | 10.1007/s11433-010-4151-6 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The magnetic dipole transitions between the vector mesons $B_c^*$ and their
relevant pseudoscalar mesons $B_c$ ($B_c$, $B_c^*$, $B_c(2S)$, $B_c^*(2S)$,
$B_c(3S)$ and $B_c^*(3S)$ etc, the binding states of $(c\bar{b})$ system) of
the $B_c$ family are interesting. To see the `hyperfine' splitting due to
spin-spin interaction is an important topic for understanding the spin-spin
interaction and the spectrum of the the $(c\bar{b})$ binding system. The
knowledge about the magnetic dipole transitions is also very useful for
identifying the vector boson $B_c^*$ mesons experimentally, whose masses are
just slightly above the masses of their relevant pseudoscalar mesons $B_c$
accordingly. Considering the possibility to observe the vector mesons via the
transitions at $Z^0$ factory and the potentially usages of the theoretical
estimate on the transitions, we fucus our efforts on calculating the magnetic
dipole transitions, i.e. precisely to calculate the rates for the transitions
such as decays $B_c^*\to B_c\gamma$ and $B_c^*\to B_c e^+e^-$, and particularly
work in the Behte-Salpeter framework. In the estimate, as a typical example, we
carefully investigate the dependance of the rate $\Gamma(B_c^*\to B_c\gamma)$
on the mass difference $\Delta M=M_{B_c^*}-M_{B_c}$ as well.
| [
{
"created": "Mon, 22 Feb 2010 03:32:27 GMT",
"version": "v1"
}
] | 2011-01-28 | [
[
"Ke",
"Hong-Wei",
""
],
[
"Wang",
"Guo-Li",
""
],
[
"Li",
"Xue-Qian",
""
],
[
"Chang",
"Chao-Hsi",
""
]
] | The magnetic dipole transitions between the vector mesons $B_c^*$ and their relevant pseudoscalar mesons $B_c$ ($B_c$, $B_c^*$, $B_c(2S)$, $B_c^*(2S)$, $B_c(3S)$ and $B_c^*(3S)$ etc, the binding states of $(c\bar{b})$ system) of the $B_c$ family are interesting. To see the `hyperfine' splitting due to spin-spin interaction is an important topic for understanding the spin-spin interaction and the spectrum of the the $(c\bar{b})$ binding system. The knowledge about the magnetic dipole transitions is also very useful for identifying the vector boson $B_c^*$ mesons experimentally, whose masses are just slightly above the masses of their relevant pseudoscalar mesons $B_c$ accordingly. Considering the possibility to observe the vector mesons via the transitions at $Z^0$ factory and the potentially usages of the theoretical estimate on the transitions, we fucus our efforts on calculating the magnetic dipole transitions, i.e. precisely to calculate the rates for the transitions such as decays $B_c^*\to B_c\gamma$ and $B_c^*\to B_c e^+e^-$, and particularly work in the Behte-Salpeter framework. In the estimate, as a typical example, we carefully investigate the dependance of the rate $\Gamma(B_c^*\to B_c\gamma)$ on the mass difference $\Delta M=M_{B_c^*}-M_{B_c}$ as well. |
hep-ph/9703340 | null | Kacper Zalewski (Jagellonian University and Institute of Nuclear
Physics, Krak\'ow, Poland) | Elementary derivation of a recently proposed integral representation for
permanents | 5 pages, Latex file, to be published in Acta Phys. Pol. B | Acta Phys.Polon. B28 (1997) 1131-1136 | 10.1103/PhysRevD.56.2934 | TPJU - 5/97 | hep-ph | null | A recently proposed integral representation for permanents is rederived using
only elementary combinatorics. For this proof the assumption that the matrix,
for which the permanent is calculated, has an inverse is not necessary.
| [
{
"created": "Mon, 17 Mar 1997 11:40:00 GMT",
"version": "v1"
}
] | 2016-08-24 | [
[
"Zalewski",
"Kacper",
"",
"Jagellonian University and Institute of Nuclear\n Physics, Kraków, Poland"
]
] | A recently proposed integral representation for permanents is rederived using only elementary combinatorics. For this proof the assumption that the matrix, for which the permanent is calculated, has an inverse is not necessary. |
2212.08560 | Marius H\"ofer | Gerhard Buchalla, Marius H\"ofer, Christoph M\"uller-Salditt | $h\to gg$ and $h\to\gamma\gamma$ with Anomalous Couplings at
Next-to-Leading Order in QCD | Additional references included. 41 pages, 11 figures, 8 Tables | null | 10.1103/PhysRevD.107.076021 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We generalize the next-to-leading order QCD calculations for the decay rates
of $h\to gg$ and $h\to\gamma\gamma$ to the case of anomalous couplings of the
Higgs boson. We demonstrate how this computation can be done in a consistent
way within the framework of an electroweak chiral Lagrangian, based on a
systematic power counting. It turns out that no additional coupling parameters
arise at NLO in QCD beyond those already present at leading order. The impact
of QCD is large for $h\to gg$ and the uncertainties from QCD are significantly
reduced at NLO. $h\to\gamma\gamma$ is only mildly affected by QCD; here the NLO
treatment practically eliminates the uncertainties. Consequently, our results
will allow for an improved determination of anomalous Higgs couplings from
these processes. The relation of our framework to a treatment in Standard Model
effective field theory is also discussed.
| [
{
"created": "Fri, 16 Dec 2022 16:27:54 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Jan 2023 14:52:06 GMT",
"version": "v2"
}
] | 2023-05-03 | [
[
"Buchalla",
"Gerhard",
""
],
[
"Höfer",
"Marius",
""
],
[
"Müller-Salditt",
"Christoph",
""
]
] | We generalize the next-to-leading order QCD calculations for the decay rates of $h\to gg$ and $h\to\gamma\gamma$ to the case of anomalous couplings of the Higgs boson. We demonstrate how this computation can be done in a consistent way within the framework of an electroweak chiral Lagrangian, based on a systematic power counting. It turns out that no additional coupling parameters arise at NLO in QCD beyond those already present at leading order. The impact of QCD is large for $h\to gg$ and the uncertainties from QCD are significantly reduced at NLO. $h\to\gamma\gamma$ is only mildly affected by QCD; here the NLO treatment practically eliminates the uncertainties. Consequently, our results will allow for an improved determination of anomalous Higgs couplings from these processes. The relation of our framework to a treatment in Standard Model effective field theory is also discussed. |
0809.2869 | Urs Wiedemann A | Kazem Bitaghsir Fadafan, Hong Liu, Krishna Rajagopal, Urs Achim
Wiedemann | Stirring Strongly Coupled Plasma | 27 pages LaTex, 5 figures | Eur.Phys.J.C61:553-567,2009 | 10.1140/epjc/s10052-009-0885-6 | MIT-CTP-3979, CERN-PH-TH/2008-194 | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We determine the energy it takes to move a test quark along a circle of
radius L with angular frequency w through the strongly coupled plasma of N=4
supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w
the energy deposited by stirring the plasma in this way is governed either by
the drag force acting on a test quark moving through the plasma in a straight
line with speed v=Lw or by the energy radiated by a quark in circular motion in
the absence of any plasma, whichever is larger. There is a continuous crossover
from the drag-dominated regime to the radiation-dominated regime. In the
crossover regime we find evidence for significant destructive interference
between energy loss due to drag and that due to radiation as if in vacuum. The
rotating quark thus serves as a model system in which the relative strength of,
and interplay between, two different mechanisms of parton energy loss is
accessible via a controlled classical gravity calculation. We close by
speculating on the implications of our results for a quark that is moving
through the plasma in a straight line while decelerating, although in this case
the classical calculation breaks down at the same value of the deceleration at
which the radiation-dominated regime sets in.
| [
{
"created": "Wed, 17 Sep 2008 07:54:28 GMT",
"version": "v1"
}
] | 2010-04-15 | [
[
"Fadafan",
"Kazem Bitaghsir",
""
],
[
"Liu",
"Hong",
""
],
[
"Rajagopal",
"Krishna",
""
],
[
"Wiedemann",
"Urs Achim",
""
]
] | We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implications of our results for a quark that is moving through the plasma in a straight line while decelerating, although in this case the classical calculation breaks down at the same value of the deceleration at which the radiation-dominated regime sets in. |
0705.3152 | Xinjian Wen | X. J. Wen, G. X. Peng, Y. D. Chen | Charge, strangeness and radius of strangelets | 18 pages, 8 figures | J.Phys.G34:1697-1709,2007 | 10.1088/0954-3899/34/7/010 | null | hep-ph | null | We investigate, at both zero and finite temperature, the properties of
strangelets versus the electric charge Z and strangeness S. The strangelet
radius is not a monotonic function of either charge or strangeness, and a
minimum is reached in the (Z, S) plane. However, the thermodynamically stable
strangelets do not correspond to the radius minimum. The minimum radius always
appears at positive strangeness, while the stable radius may appear at negative
strangeness for very small baryon numbers. For large baryon numbers, the stable
radius is proportional to the cubic root of baryon numbers, but inversely
proportional to the square root of the confinement parameter in the present
model. If bulk strange quark matter is absolutely stable, the reduced size of
strangelets is about 1 fm, which may be relevant for the analysis of the
strangelet production and detection.
| [
{
"created": "Tue, 22 May 2007 14:23:40 GMT",
"version": "v1"
}
] | 2007-06-13 | [
[
"Wen",
"X. J.",
""
],
[
"Peng",
"G. X.",
""
],
[
"Chen",
"Y. D.",
""
]
] | We investigate, at both zero and finite temperature, the properties of strangelets versus the electric charge Z and strangeness S. The strangelet radius is not a monotonic function of either charge or strangeness, and a minimum is reached in the (Z, S) plane. However, the thermodynamically stable strangelets do not correspond to the radius minimum. The minimum radius always appears at positive strangeness, while the stable radius may appear at negative strangeness for very small baryon numbers. For large baryon numbers, the stable radius is proportional to the cubic root of baryon numbers, but inversely proportional to the square root of the confinement parameter in the present model. If bulk strange quark matter is absolutely stable, the reduced size of strangelets is about 1 fm, which may be relevant for the analysis of the strangelet production and detection. |
hep-ph/0111142 | Daniel Litim | Daniel F. Litim | Transport theory and low energy properties of colour superconductors | 5 pages, talk given at the International Conference on "Statistical
QCD", Bielefeld, August 26-30, 2001 | Nucl.Phys. A702 (2002) 201-205 | 10.1016/S0375-9474(02)00706-6 | CERN-TH 2001-315 | hep-ph | null | The one-loop polarisation tensor and the propagation of ``in-medium'' photons
of colour superconductors in the 2SC and CFL phase is discussed. For a study of
thermal corrections to the low energy effective theory in the 2SC phase, a
classical transport theory for fermionic quasiparticles is invoked.
| [
{
"created": "Mon, 12 Nov 2001 14:37:41 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Litim",
"Daniel F.",
""
]
] | The one-loop polarisation tensor and the propagation of ``in-medium'' photons of colour superconductors in the 2SC and CFL phase is discussed. For a study of thermal corrections to the low energy effective theory in the 2SC phase, a classical transport theory for fermionic quasiparticles is invoked. |
hep-ph/9410306 | Paul A. Griffin | L. Susskind and P. Griffin | Partons and Black Holes | 23 pages LaTeX + 10 figs. (epsf.sty needed for figs.). Based on
lectures given by L.S. at the `Theory of Hadrons and Light-front QCD'
workshop in Zakopane, Poland, August 1994 | null | null | Florida preprint ufift-hep-94-13 | hep-ph hep-th | null | A light-front renormalization group analysis is applied to study matter which
falls into massive black holes, and the related problem of matter with
transplankian energies. One finds that the rate of matter spreading over the
black hole's horizon unexpectedly saturates the causality bound. This is
related to the transverse growth behavior of transplankian particles as their
longitudinal momentum increases. This growth behavior suggests a natural
mechanism to impliment 'tHooft's scenario that the universe is an image of data
stored on a 2 + 1 dimensional hologram-like projection.
| [
{
"created": "Tue, 18 Oct 1994 00:02:35 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Susskind",
"L.",
""
],
[
"Griffin",
"P.",
""
]
] | A light-front renormalization group analysis is applied to study matter which falls into massive black holes, and the related problem of matter with transplankian energies. One finds that the rate of matter spreading over the black hole's horizon unexpectedly saturates the causality bound. This is related to the transverse growth behavior of transplankian particles as their longitudinal momentum increases. This growth behavior suggests a natural mechanism to impliment 'tHooft's scenario that the universe is an image of data stored on a 2 + 1 dimensional hologram-like projection. |
1012.3380 | Emanuele Re | Simone Alioli, Keith Hamilton, Paolo Nason, Carlo Oleari, Emanuele Re | Jet pair production in POWHEG | 40 pages, 27 figures | null | 10.1007/JHEP04(2011)081 | DESY-10-233, SFB/CPP-10-128, IPPP/10/100, DCPT/10/200, MCnet/10/23 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an implementation of the next-to-leading order dijet production
process in hadronic collisions in the framework of POWHEG, which is a method to
implement NLO calculations within a shower Monte Carlo context. In constructing
the simulation, we have made use of the POWHEG BOX toolkit, which makes light
of many of the most technical steps. The majority of this article is concerned
with the study of the predictions of the Monte Carlo simulation. In so doing,
we validate our program for use in experimental analyses, elaborating on some
of the more subtle features which arise from the interplay of the NLO and
resummed components of the calculation. We conclude our presentation by
comparing predictions from the simulation against a number of Tevatron and LHC
jet-production results.
| [
{
"created": "Wed, 15 Dec 2010 16:33:14 GMT",
"version": "v1"
}
] | 2015-05-20 | [
[
"Alioli",
"Simone",
""
],
[
"Hamilton",
"Keith",
""
],
[
"Nason",
"Paolo",
""
],
[
"Oleari",
"Carlo",
""
],
[
"Re",
"Emanuele",
""
]
] | We present an implementation of the next-to-leading order dijet production process in hadronic collisions in the framework of POWHEG, which is a method to implement NLO calculations within a shower Monte Carlo context. In constructing the simulation, we have made use of the POWHEG BOX toolkit, which makes light of many of the most technical steps. The majority of this article is concerned with the study of the predictions of the Monte Carlo simulation. In so doing, we validate our program for use in experimental analyses, elaborating on some of the more subtle features which arise from the interplay of the NLO and resummed components of the calculation. We conclude our presentation by comparing predictions from the simulation against a number of Tevatron and LHC jet-production results. |
1607.07271 | Matthew Frost | M.J. Frost | The NNbar Experiment at the European Spallation Source | Presented at the Seventh Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 20-24, 2016 | null | null | null | hep-ph physics.ins-det | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The observation of neutron to antineutron oscillation would be the first
experimental evidence to show that baryon number is not a conserved quantity.
It also provides an answer to the hypothesized post-sphaleron baryogenesis
mechanism shortly after the Big Bang. The free oscillation time
{\tau_{n\rightarrow\bar{n}} has a lower limit at 8.7 x 10^7 seconds determined
at ILL in 1994. Current beyond Standard Model theories of this oscillation time
estimate the value to be on the order of 10^{10} seconds. A new experiment is
proposed at the European Spallation Source that has 1000 times the sensitivity
of the previous experiment, and would confirm the viability of those beyond
Standard Model theories.
| [
{
"created": "Mon, 25 Jul 2016 13:53:32 GMT",
"version": "v1"
}
] | 2016-07-26 | [
[
"Frost",
"M. J.",
""
]
] | The observation of neutron to antineutron oscillation would be the first experimental evidence to show that baryon number is not a conserved quantity. It also provides an answer to the hypothesized post-sphaleron baryogenesis mechanism shortly after the Big Bang. The free oscillation time {\tau_{n\rightarrow\bar{n}} has a lower limit at 8.7 x 10^7 seconds determined at ILL in 1994. Current beyond Standard Model theories of this oscillation time estimate the value to be on the order of 10^{10} seconds. A new experiment is proposed at the European Spallation Source that has 1000 times the sensitivity of the previous experiment, and would confirm the viability of those beyond Standard Model theories. |
hep-ph/9406386 | null | D.P. Roy and K. Sridhar | Fragmentation contribution to quarkonium production in hadron collision | 9 pages + 4 figures (available upon request), Latex File,
CERN-TH.7329/94, TIFR/TH/94-21 | Phys.Lett. B339 (1994) 141-147 | 10.1016/0370-2693(94)91146-0 | null | hep-ph | null | We compute the contributions due to gluon and heavy-quark fragmentation to
quarkonium production at large transverse momentum in $\bar p p$ and $p p$
collisions. For inclusive $J/\psi$ production, there is a large contribution
from the $g \rightarrow \chi_c$ fragmentation. At large $p_T$, this is
comparable to the conventional charmonium model prediction via gluon fusion at
the ISR and dominates over the latter at the Tevatron energy. This may help to
explain, at least partly, the large $J/\psi$ production cross-section recently
observed by the CDF experiment. However, the fragmentation contribution to
$\psi^{\prime}$ production is not large enough to explain the corresponding CDF
data. We also present the results for $\Upsilon$ production at ISR and Tevatron
energies.
| [
{
"created": "Fri, 24 Jun 1994 12:59:18 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Roy",
"D. P.",
""
],
[
"Sridhar",
"K.",
""
]
] | We compute the contributions due to gluon and heavy-quark fragmentation to quarkonium production at large transverse momentum in $\bar p p$ and $p p$ collisions. For inclusive $J/\psi$ production, there is a large contribution from the $g \rightarrow \chi_c$ fragmentation. At large $p_T$, this is comparable to the conventional charmonium model prediction via gluon fusion at the ISR and dominates over the latter at the Tevatron energy. This may help to explain, at least partly, the large $J/\psi$ production cross-section recently observed by the CDF experiment. However, the fragmentation contribution to $\psi^{\prime}$ production is not large enough to explain the corresponding CDF data. We also present the results for $\Upsilon$ production at ISR and Tevatron energies. |
hep-ph/9510314 | Per Elmfors | Per Elmfors | Dispersion relations from the Hard Thermal Loop effective action in a
magnetic field | Latex+epsf with uuencoded ps-figures | null | null | CERN-TH/95-274 | hep-ph hep-th nucl-th | null | Dispersion relations for fermions at high temperature and in a background
magnetic field are calculated in two different ways. First from a
straightforward one-loop calculation where, in the weak field limit, we find an
expression closely related to the standard dispersion relations in the absence
of the magnetic field. Secondly, we derive the dispersion relations directly
from the Hard Thermal Loop effective action, which allows for an exact solution
(i.e. to all orders in the external field), up to the last numerical integrals.
| [
{
"created": "Tue, 17 Oct 1995 09:48:29 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Elmfors",
"Per",
""
]
] | Dispersion relations for fermions at high temperature and in a background magnetic field are calculated in two different ways. First from a straightforward one-loop calculation where, in the weak field limit, we find an expression closely related to the standard dispersion relations in the absence of the magnetic field. Secondly, we derive the dispersion relations directly from the Hard Thermal Loop effective action, which allows for an exact solution (i.e. to all orders in the external field), up to the last numerical integrals. |
hep-ph/9405290 | Gonzalo Parente Bermudez | A.V. Kotikov, V.G. Krivokhizhin and G. Parente | Next-to-Next-to-Leading Order QCD Analysis of DIS Structure Functions | Latex 12 pages, 2 figures available on request, preprint UCI-TR/94-4 | Phys.Lett. B333 (1994) 190-195 | 10.1016/0370-2693(94)91028-6 | null | hep-ph | null | It is performed for the first time a next-to-next-to-leading order analysis
of deep inelastic structure functions $F_2$ and $F_L$ using the recently
determined first moments of the non-singlet anomalous dimensions and the
corresponding Wilson coefficients. {}From a comparison to BCDMS data we found a
slight decrease in the energy scale of perturbative QCD with respect to the
next-to-leading order analysis, which brings the scale closer to the value
predicted from a scheme invariant approach.
| [
{
"created": "Sat, 14 May 1994 01:33:00 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Kotikov",
"A. V.",
""
],
[
"Krivokhizhin",
"V. G.",
""
],
[
"Parente",
"G.",
""
]
] | It is performed for the first time a next-to-next-to-leading order analysis of deep inelastic structure functions $F_2$ and $F_L$ using the recently determined first moments of the non-singlet anomalous dimensions and the corresponding Wilson coefficients. {}From a comparison to BCDMS data we found a slight decrease in the energy scale of perturbative QCD with respect to the next-to-leading order analysis, which brings the scale closer to the value predicted from a scheme invariant approach. |
hep-ph/9403232 | null | J. Mourad and H. Sazdjian | The two-fermion relativistic wave equations of Constraint Theory in the
Pauli-Schr\"odinger form | 49 pages, REVTEX, 2 figures (available from the authors), preprint
IPNO/TH 94-5 and LPTHE 94/16 | J.Math.Phys. 35 (1994) 6379-6406 | 10.1063/1.530681 | null | hep-ph | null | The two-fermion relativistic wave equations of Constraint Theory are reduced,
after expressing the components of the $4\times 4$ matrix wave function in
terms of one of the $2\times 2$ components, to a single equation of the
Pauli-Schr\"odinger type, valid for all sectors of quantum numbers. The
potentials that are present belong to the general classes of scalar,
pseudoscalar and vector interactions and are calculable in perturbation theory
from Feynman diagrams. In the limit when one of the masses becomes infinite,
the equation reduces to the two-component form of the one-particle Dirac
equation with external static potentials. The Hamiltonian, to order $1/c^2$,
reproduces most of the known theoretical results obtained by other methods. The
gauge invariance of the wave equation is checked, to that order, in the case of
QED. The role of the c.m. energy dependence of the relativistic interquark
confining potential is emphasized and the structure of the Hamiltonian, to
order $1/c^2$, corresponding to confining scalar potentials, is displayed.
| [
{
"created": "Mon, 7 Mar 1994 09:29:08 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Mourad",
"J.",
""
],
[
"Sazdjian",
"H.",
""
]
] | The two-fermion relativistic wave equations of Constraint Theory are reduced, after expressing the components of the $4\times 4$ matrix wave function in terms of one of the $2\times 2$ components, to a single equation of the Pauli-Schr\"odinger type, valid for all sectors of quantum numbers. The potentials that are present belong to the general classes of scalar, pseudoscalar and vector interactions and are calculable in perturbation theory from Feynman diagrams. In the limit when one of the masses becomes infinite, the equation reduces to the two-component form of the one-particle Dirac equation with external static potentials. The Hamiltonian, to order $1/c^2$, reproduces most of the known theoretical results obtained by other methods. The gauge invariance of the wave equation is checked, to that order, in the case of QED. The role of the c.m. energy dependence of the relativistic interquark confining potential is emphasized and the structure of the Hamiltonian, to order $1/c^2$, corresponding to confining scalar potentials, is displayed. |
1007.5053 | Natalia Radchenko | V. A. Abramovsky, N. V. Radchenko | Color Diagrams for Non Vacuum Reggeons in Hadron-Hadron Interactions | 9 pages, 13 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | One-to-one correspondence between dual diagrams of dual resonance model and
QCD based color diagrams describing non vacuum exchanges in pi+ pi-, pi+- p, p
anti p interactions is discussed. Both for dual and color diagrams there are
state with quark-antiquark in t channel and state, in which only coherent quark
string exists, in s channel. There are no such dual diagrams in pp interaction.
Color diagram for pp interaction was found basing on principle of conformity.
Secondary hadrons spectrum, obtained from this diagram, has nucleon in its
central region. This effect may lead to increase of baryon chemical potential
in nucleus-nucleus collisions in facilities NICA and FAIR.
| [
{
"created": "Wed, 28 Jul 2010 19:40:45 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Sep 2010 15:25:39 GMT",
"version": "v2"
}
] | 2010-09-16 | [
[
"Abramovsky",
"V. A.",
""
],
[
"Radchenko",
"N. V.",
""
]
] | One-to-one correspondence between dual diagrams of dual resonance model and QCD based color diagrams describing non vacuum exchanges in pi+ pi-, pi+- p, p anti p interactions is discussed. Both for dual and color diagrams there are state with quark-antiquark in t channel and state, in which only coherent quark string exists, in s channel. There are no such dual diagrams in pp interaction. Color diagram for pp interaction was found basing on principle of conformity. Secondary hadrons spectrum, obtained from this diagram, has nucleon in its central region. This effect may lead to increase of baryon chemical potential in nucleus-nucleus collisions in facilities NICA and FAIR. |
0908.1758 | Kazem Azizi | K. Azizi, M. Bayar, Y. Sarac, H. Sundu | Semileptonic $\Lambda_{b,c}$ to Nucleon Transitions in Full QCD at Light
Cone | 18 Pages and 16 Tables | null | 10.1103/PhysRevD.80.096007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The tree level semileptonic $\Lambda_{b}\to pl\nu$ and $\Lambda_{c}\to nl\nu$
transitions are investigated using the light cone QCD sum rules approach in
full theory. The spin--1/2, $\Lambda_{Q}$ baryon with $Q=b$ or $c$, is
considered by the most general form of its interpolating current. The time
ordering product of the initial and transition currents is expanded in terms of
the nucleon distribution amplitudes with different twists. Considering two sets
of independent input parameters entering to the nucleon wave functions, namely,
QCD sum rules and Lattice QCD parameters, the related form factors and their
heavy quark effective theory limits are calculated and compared with the
existing predictions of other approaches. It is shown that our results satisfy
the heavy quark symmetry relations for lattice input parameters and b case
exactly and the maximum violation is for charm case and QCD sum rules input
parameters. The obtained form factors are used to compute the transition rates
both in full theory and heavy quark effective theory. A comparison of the
results on decay rate of $\Lambda_{b}\to pl\nu$ with those predicted by other
phenomenological methods or the same method in heavy quark effective theory
with different interpolating current and distribution amplitudes of the
$\Lambda_{b}$ is also presented.
| [
{
"created": "Wed, 12 Aug 2009 17:37:46 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Nov 2009 12:15:22 GMT",
"version": "v2"
}
] | 2015-05-13 | [
[
"Azizi",
"K.",
""
],
[
"Bayar",
"M.",
""
],
[
"Sarac",
"Y.",
""
],
[
"Sundu",
"H.",
""
]
] | The tree level semileptonic $\Lambda_{b}\to pl\nu$ and $\Lambda_{c}\to nl\nu$ transitions are investigated using the light cone QCD sum rules approach in full theory. The spin--1/2, $\Lambda_{Q}$ baryon with $Q=b$ or $c$, is considered by the most general form of its interpolating current. The time ordering product of the initial and transition currents is expanded in terms of the nucleon distribution amplitudes with different twists. Considering two sets of independent input parameters entering to the nucleon wave functions, namely, QCD sum rules and Lattice QCD parameters, the related form factors and their heavy quark effective theory limits are calculated and compared with the existing predictions of other approaches. It is shown that our results satisfy the heavy quark symmetry relations for lattice input parameters and b case exactly and the maximum violation is for charm case and QCD sum rules input parameters. The obtained form factors are used to compute the transition rates both in full theory and heavy quark effective theory. A comparison of the results on decay rate of $\Lambda_{b}\to pl\nu$ with those predicted by other phenomenological methods or the same method in heavy quark effective theory with different interpolating current and distribution amplitudes of the $\Lambda_{b}$ is also presented. |
hep-ph/9701327 | Andrej Arbuzov | E.A. Kuraev (Dubna, JINR) | QED Radiative Corrections to the Pionium Life Time | 4 pages, LaTeX (considerable improvements) | null | null | null | hep-ph | null | The lowest order QED radiative corrections to the cross-section of the
recharged process of transition of two charged pions to two neutral ones and to
the pionium life time are calculated in frames of scalar QED. It is argued that
the ultraviolet cut--off of the loop momentum is to be chosen of order of
$\rho$ meson mass. This fact permits to perform the calculation in frames of
Effective Chiral Lagrangian theory with vector-meson dominance. The Coulomb
factor corresponding to interaction in the initial state, shown, is to be
removed to avoid the double counting. Resulting value of the radiative
correction to the pionium life time is -0.25%.
| [
{
"created": "Mon, 20 Jan 1997 08:32:47 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Feb 1997 10:14:37 GMT",
"version": "v2"
},
{
"created": "Mon, 17 Feb 1997 08:43:25 GMT",
"version": "v3"
}
] | 2008-02-03 | [
[
"Kuraev",
"E. A.",
"",
"Dubna, JINR"
]
] | The lowest order QED radiative corrections to the cross-section of the recharged process of transition of two charged pions to two neutral ones and to the pionium life time are calculated in frames of scalar QED. It is argued that the ultraviolet cut--off of the loop momentum is to be chosen of order of $\rho$ meson mass. This fact permits to perform the calculation in frames of Effective Chiral Lagrangian theory with vector-meson dominance. The Coulomb factor corresponding to interaction in the initial state, shown, is to be removed to avoid the double counting. Resulting value of the radiative correction to the pionium life time is -0.25%. |
1104.2737 | Juan Nieves Dr. | D. Gamermann, C. Garcia-Recio, J. Nieves and L.L. Salcedo | Odd Parity Light Baryon Resonances | New appendix and references added | Phys.Rev.D84: 056017, 2011 | 10.1103/PhysRevD.84.056017 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian
within a coupled channel unitary approach in order to calculate the T-matrix
for meson-baryon scattering in s-wave. The building blocks of the scheme are
the pion and nucleon octets, the rho nonet and the Delta decuplet. We identify
poles in this unitary T-matrix and interpret them as resonances. We study here
the non exotic sectors with strangeness S=0,-1,-2,-3 and spin J=1/2, 3/2 and
5/2. Many of the poles generated can be associated with known N, Delta, Sigma,
Lambda and Xi resonances with negative parity. We show that most of the
low-lying three and four star odd parity baryon resonances with spin 1/2 and
3/2 can be related to multiplets of the spin-flavor symmetry group SU(6). This
study allows us to predict the spin-parity of the Xi(1620), Xi(1690), Xi(1950),
Xi(2250), Omega(2250) and Omega(2380) resonances, which have not been
determined experimentally yet.
| [
{
"created": "Thu, 14 Apr 2011 12:08:14 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Sep 2011 14:18:39 GMT",
"version": "v2"
}
] | 2011-10-04 | [
[
"Gamermann",
"D.",
""
],
[
"Garcia-Recio",
"C.",
""
],
[
"Nieves",
"J.",
""
],
[
"Salcedo",
"L. L.",
""
]
] | We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T-matrix for meson-baryon scattering in s-wave. The building blocks of the scheme are the pion and nucleon octets, the rho nonet and the Delta decuplet. We identify poles in this unitary T-matrix and interpret them as resonances. We study here the non exotic sectors with strangeness S=0,-1,-2,-3 and spin J=1/2, 3/2 and 5/2. Many of the poles generated can be associated with known N, Delta, Sigma, Lambda and Xi resonances with negative parity. We show that most of the low-lying three and four star odd parity baryon resonances with spin 1/2 and 3/2 can be related to multiplets of the spin-flavor symmetry group SU(6). This study allows us to predict the spin-parity of the Xi(1620), Xi(1690), Xi(1950), Xi(2250), Omega(2250) and Omega(2380) resonances, which have not been determined experimentally yet. |
hep-ph/9901288 | Gerhard Buchalla | Gerhard Buchalla (CERN), Andrzej J. Buras (TU Munich) | The Rare Decays $K\to\pi\nu\bar\nu$, $B\to X\nu\bar\nu$ and $B\to
l^+l^-$ -- An Update | 19 pages, no figures | Nucl.Phys.B548:309-327,1999 | 10.1016/S0550-3213(99)00149-2 | CERN-TH/98-369, TUM-T31-337/98 | hep-ph | null | We update the Standard Model predictions for the rare decays
$K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$. In view of improved limits
on $B_s$--$\bar B_s$ mixing we derive a stringent and theoretically clean
Standard Model upper limit on $B(K^+\to\pi^+\nu\bar\nu)$, which is based on the
ratio of $B_d$--$\bar B_d$ to $B_s$--$\bar B_s$ mixing, $\Delta M_d/\Delta
M_s$, alone. This method avoids the large hadronic uncertainties present in the
usual analysis of the CKM matrix. We find $B(K^+\to\pi^+\nu\bar\nu)< 1.67\cdot
10^{-10}$, which can be further improved in the future. In addition we consider
the extraction of $|V_{td}|$ from a future measurement of
$B(K^+\to\pi^+\nu\bar\nu)$, discussing the various sources of uncertainties
involved. We also investigate theoretically clean constraints on
$B(K_L\to\pi^0\nu\bar\nu)$. We take the opportunity to review the
next-to-leading order (NLO) QCD corrections to $K\to\pi\nu\bar\nu$,
$K_L\to\mu^+\mu^-$, $B\to X\nu\bar\nu$ and $B\to l^+l^-$, including a small
additional term that had been missed in the original publications. The
phenomenological impact of this change is negligible, the corresponding
numerical shift being essentially within the small perturbative uncertainties
at the NLO level.
| [
{
"created": "Wed, 13 Jan 1999 10:25:39 GMT",
"version": "v1"
}
] | 2009-10-09 | [
[
"Buchalla",
"Gerhard",
"",
"CERN"
],
[
"Buras",
"Andrzej J.",
"",
"TU Munich"
]
] | We update the Standard Model predictions for the rare decays $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$. In view of improved limits on $B_s$--$\bar B_s$ mixing we derive a stringent and theoretically clean Standard Model upper limit on $B(K^+\to\pi^+\nu\bar\nu)$, which is based on the ratio of $B_d$--$\bar B_d$ to $B_s$--$\bar B_s$ mixing, $\Delta M_d/\Delta M_s$, alone. This method avoids the large hadronic uncertainties present in the usual analysis of the CKM matrix. We find $B(K^+\to\pi^+\nu\bar\nu)< 1.67\cdot 10^{-10}$, which can be further improved in the future. In addition we consider the extraction of $|V_{td}|$ from a future measurement of $B(K^+\to\pi^+\nu\bar\nu)$, discussing the various sources of uncertainties involved. We also investigate theoretically clean constraints on $B(K_L\to\pi^0\nu\bar\nu)$. We take the opportunity to review the next-to-leading order (NLO) QCD corrections to $K\to\pi\nu\bar\nu$, $K_L\to\mu^+\mu^-$, $B\to X\nu\bar\nu$ and $B\to l^+l^-$, including a small additional term that had been missed in the original publications. The phenomenological impact of this change is negligible, the corresponding numerical shift being essentially within the small perturbative uncertainties at the NLO level. |
hep-ph/0403045 | Stefano Frixione | M.A. Dobbs, S. Frixione, E. Laenen, K. Tollefson, H. Baer, E. Boos, B.
Cox, R. Engel, W. Giele, J. Huston, S. Ilyin, B. Kersevan, F. Krauss, Y.
Kurihara, L. Lonnblad, F. Maltoni, M. Mangano, S. Odaka, P. Richardson, A.
Ryd, T. Sjostrand, P. Skands, Z. Was, B.R. Webber, D. Zeppenfeld | Les Houches Guidebook to Monte Carlo Generators for Hadron Collider
Physics | 49 pages Latex. Compiled by the Working Group on Quantum
ChromoDynamics and the Standard Model for the Workshop ``Physics at TeV
Colliders'', Les Houches, France, May 2003. To appear in the proceedings | null | null | null | hep-ph | null | Recently the collider physics community has seen significant advances in the
formalisms and implementations of event generators. This review is a primer of
the methods commonly used for the simulation of high energy physics events at
particle colliders. We provide brief descriptions, references, and links to the
specific computer codes which implement the methods. The aim is to provide an
overview of the available tools, allowing the reader to ascertain which tool is
best for a particular application, but also making clear the limitations of
each tool.
| [
{
"created": "Thu, 4 Mar 2004 13:49:05 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Mar 2004 15:44:26 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Dobbs",
"M. A.",
""
],
[
"Frixione",
"S.",
""
],
[
"Laenen",
"E.",
""
],
[
"Tollefson",
"K.",
""
],
[
"Baer",
"H.",
""
],
[
"Boos",
"E.",
""
],
[
"Cox",
"B.",
""
],
[
"Engel",
"R.",
""
],
[
"Giele",
"W.",
""
],
[
"Huston",
"J.",
""
],
[
"Ilyin",
"S.",
""
],
[
"Kersevan",
"B.",
""
],
[
"Krauss",
"F.",
""
],
[
"Kurihara",
"Y.",
""
],
[
"Lonnblad",
"L.",
""
],
[
"Maltoni",
"F.",
""
],
[
"Mangano",
"M.",
""
],
[
"Odaka",
"S.",
""
],
[
"Richardson",
"P.",
""
],
[
"Ryd",
"A.",
""
],
[
"Sjostrand",
"T.",
""
],
[
"Skands",
"P.",
""
],
[
"Was",
"Z.",
""
],
[
"Webber",
"B. R.",
""
],
[
"Zeppenfeld",
"D.",
""
]
] | Recently the collider physics community has seen significant advances in the formalisms and implementations of event generators. This review is a primer of the methods commonly used for the simulation of high energy physics events at particle colliders. We provide brief descriptions, references, and links to the specific computer codes which implement the methods. The aim is to provide an overview of the available tools, allowing the reader to ascertain which tool is best for a particular application, but also making clear the limitations of each tool. |
1007.5414 | Pietro Falgari | Martin Beneke, Pietro Falgari, Christian Schwinn | Threshold resummation for pair production of coloured heavy (s)particles
at hadron colliders | 71 pages, LaTeX, 18 figures. v2 matches published version (minor
typos corrected, more references added) | Nucl.Phys.B842:414-474,2011 | 10.1016/j.nuclphysb.2010.09.009 | TTK-10-45, IPPP/10/61, DCPT/10/122, FR-PHENO-2010-026, SFB/CPP-10-65 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive a factorization formula for the production of pairs of heavy
coloured particles in hadronic collisions near the production threshold that
establishes factorization of soft and Coulomb effects. This forms the basis for
a combined resummation of Coulomb and soft corrections, including the
non-trivial interference of the two effects. We develop a resummation formalism
valid at NNLL accuracy using the momentum-space approach to soft gluon
resummation. We present numerical results for the NLL resummed
squark-antisquark production cross section at the LHC and Tevatron, including
also the contribution of squark-antisquark bound states below threshold. The
total correction on top of the next-to-leading order approximation is found to
be sizeable, and amounts to (4-20)% in the squark mass region 200 GeV-3 TeV at
the 14 TeV LHC. The scale dependence of the total cross section is also
reduced.
| [
{
"created": "Fri, 30 Jul 2010 11:02:30 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Oct 2010 15:33:53 GMT",
"version": "v2"
}
] | 2011-03-22 | [
[
"Beneke",
"Martin",
""
],
[
"Falgari",
"Pietro",
""
],
[
"Schwinn",
"Christian",
""
]
] | We derive a factorization formula for the production of pairs of heavy coloured particles in hadronic collisions near the production threshold that establishes factorization of soft and Coulomb effects. This forms the basis for a combined resummation of Coulomb and soft corrections, including the non-trivial interference of the two effects. We develop a resummation formalism valid at NNLL accuracy using the momentum-space approach to soft gluon resummation. We present numerical results for the NLL resummed squark-antisquark production cross section at the LHC and Tevatron, including also the contribution of squark-antisquark bound states below threshold. The total correction on top of the next-to-leading order approximation is found to be sizeable, and amounts to (4-20)% in the squark mass region 200 GeV-3 TeV at the 14 TeV LHC. The scale dependence of the total cross section is also reduced. |
hep-ph/9902249 | Petrus Pennanen | A.M. Green, J. Koponen and P. Pennanen | A variational fit to the lattice energy of two heavy-light mesons | 17 pages, 2 eps figures. Considerably revised version accepted for
publication | Phys.Rev. D61 (2000) 014014 | 10.1103/PhysRevD.61.014014 | HIP-1999-04/TH, NORDITA-99/7 | hep-ph hep-lat nucl-th | null | Recent lattice calculations on the interaction energy of two heavy-light
mesons (Q^2\bar{q}^2) are interpreted in terms of the potential of the
corresponding single heavy-light meson (Q\bar{q}). This model leads to a large
overestimate of the binding compared with the lattice data -- unless the basic
Q\bar{q} potential is modified to become a four-quark potential.
| [
{
"created": "Fri, 5 Feb 1999 15:19:13 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Sep 1999 11:01:46 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Green",
"A. M.",
""
],
[
"Koponen",
"J.",
""
],
[
"Pennanen",
"P.",
""
]
] | Recent lattice calculations on the interaction energy of two heavy-light mesons (Q^2\bar{q}^2) are interpreted in terms of the potential of the corresponding single heavy-light meson (Q\bar{q}). This model leads to a large overestimate of the binding compared with the lattice data -- unless the basic Q\bar{q} potential is modified to become a four-quark potential. |
1509.00809 | Natsumi Nagata | Natsumi Nagata, Keith A. Olive, and Jiaming Zheng | Weakly-Interacting Massive Particles in Non-supersymmetric SO(10) Grand
Unified Models | 43 pages, 3 figures | null | null | FTPI-MINN-15/40, UMN-TH-3501/15, IPMU15-0142 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Non-supersymmetric SO(10) grand unified theories provide a framework in which
the stability of dark matter is explained while gauge coupling unification is
realized. In this work, we systematically study this possibility by classifying
weakly interacting DM candidates in terms of their quantum numbers of
$\text{SU}(2)_L \otimes \text{U}(1)_Y$, $B-L$, and $\text{SU}(2)_R$. We
consider both scalar and fermion candidates. We show that the requirement of a
sufficiently high unification scale to ensure a proton lifetime compatible with
experimental constraints plays a strong role in selecting viable candidates.
Among the scalar candidates originating from either a 16 or 144 of SO(10), only
SU(2)$_L$ singlets with zero hypercharge or doublets with $Y=1/2$ satisfy all
constraints for $\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R$
and $\text{SU}(3)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R \otimes
\text{U}(1)_{B-L}$ intermediate scale gauge groups. Among fermion triplets with
zero hypercharge, only a triplet in the 45 with intermediate group
$\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R$ leads to
solutions with $M_{\rm GUT} > M_{\rm int}$ and a long proton lifetime. We find
three models with weak doublets and $Y=1/2$ as dark matter candidates for the
$\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R$ and
$\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{U}(1)_R$ intermediate
scale gauge groups assuming a minimal Higgs content. We also discuss how these
models may be tested at accelerators and in dark matter detection experiments.
| [
{
"created": "Wed, 2 Sep 2015 18:18:08 GMT",
"version": "v1"
}
] | 2015-09-03 | [
[
"Nagata",
"Natsumi",
""
],
[
"Olive",
"Keith A.",
""
],
[
"Zheng",
"Jiaming",
""
]
] | Non-supersymmetric SO(10) grand unified theories provide a framework in which the stability of dark matter is explained while gauge coupling unification is realized. In this work, we systematically study this possibility by classifying weakly interacting DM candidates in terms of their quantum numbers of $\text{SU}(2)_L \otimes \text{U}(1)_Y$, $B-L$, and $\text{SU}(2)_R$. We consider both scalar and fermion candidates. We show that the requirement of a sufficiently high unification scale to ensure a proton lifetime compatible with experimental constraints plays a strong role in selecting viable candidates. Among the scalar candidates originating from either a 16 or 144 of SO(10), only SU(2)$_L$ singlets with zero hypercharge or doublets with $Y=1/2$ satisfy all constraints for $\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R$ and $\text{SU}(3)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R \otimes \text{U}(1)_{B-L}$ intermediate scale gauge groups. Among fermion triplets with zero hypercharge, only a triplet in the 45 with intermediate group $\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R$ leads to solutions with $M_{\rm GUT} > M_{\rm int}$ and a long proton lifetime. We find three models with weak doublets and $Y=1/2$ as dark matter candidates for the $\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{SU}(2)_R$ and $\text{SU}(4)_C \otimes \text{SU}(2)_L \otimes \text{U}(1)_R$ intermediate scale gauge groups assuming a minimal Higgs content. We also discuss how these models may be tested at accelerators and in dark matter detection experiments. |
hep-ph/0609029 | Mikhail Zubkov | M. A. Zubkov | The observability of an additional discrete symmetry in the Standard
Model | Latex, 10 pages | Phys.Lett.B649:91-94,2007; Erratum-ibid.B655:91,2007 | 10.1016/j.physletb.2007.04.005; 10.1016/j.physletb.2007.09.026 | ITEP-LAT/2006-08 | hep-ph | null | Standard Model may be defined with the additional discrete symmetry, i.e.
with the gauge group $SU(3)\times SU(2) \times U(1)/{\cal Z}$ (${\cal Z} =
Z_6$, $Z_3$ or $Z_2$) instead of the usual $SU(3)\times SU(2) \times U(1)$. It
has the same perturbation expansion as the conventional one. However, it may
describe nature in a different way at the energies compared to the triviality
bound (of about 1 Tev). In this paper we present a possibility to observe this
difference assuming that the gauge group of the Standard Model is embedded into
the gauge group of an {\it a priory} unknown model, which describes physics at
a Tev scale. This difference is related to the monopole content of the theory.
We illustrate our results by consideration of the Petite Unification of quarks
and leptons.
| [
{
"created": "Mon, 4 Sep 2006 15:22:39 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Sep 2006 07:49:11 GMT",
"version": "v2"
},
{
"created": "Sat, 24 Mar 2007 17:16:09 GMT",
"version": "v3"
},
{
"created": "Sun, 6 May 2007 10:44:52 GMT",
"version": "v4"
},
{
"created": "Wed, 19 Sep 2007 13:10:32 GMT",
"version": "v5"
}
] | 2008-11-26 | [
[
"Zubkov",
"M. A.",
""
]
] | Standard Model may be defined with the additional discrete symmetry, i.e. with the gauge group $SU(3)\times SU(2) \times U(1)/{\cal Z}$ (${\cal Z} = Z_6$, $Z_3$ or $Z_2$) instead of the usual $SU(3)\times SU(2) \times U(1)$. It has the same perturbation expansion as the conventional one. However, it may describe nature in a different way at the energies compared to the triviality bound (of about 1 Tev). In this paper we present a possibility to observe this difference assuming that the gauge group of the Standard Model is embedded into the gauge group of an {\it a priory} unknown model, which describes physics at a Tev scale. This difference is related to the monopole content of the theory. We illustrate our results by consideration of the Petite Unification of quarks and leptons. |
0809.3545 | Radovan Dermisek | Radovan Dermisek | Light Charged and CP-odd Higgses in MSSM-like Models | 4 pages, 2 figures, talk presented at SUSY 2008 and ICHEP 2008 | AIP Conf.Proc.1078:226-228,2009 | 10.1063/1.3051917 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the Higgs sector of supersymmetric models containing two Higgs
doublets with a light MSSM-like CP odd Higgs, $m_A \lesssim 10$ GeV, and $\tan
\beta \lesssim 2.5$. In this scenario all Higgses resulting from two Higgs
doublets: light and heavy CP even Higgses, $h$ and $H$, the CP odd Higgs, $A$,
and the charged Higgs, $H^\pm$, could have been produced at LEP or the
Tevatron, but would have escaped detection because they decay in modes that
have not been searched for or the experiments are not sensitive to. Especially
$H \to ZA$ and $H^\pm \to W^{\pm \star} A$ with $A \to c \bar c, \tau^+ \tau^-$
present an opportunity to discover some of the Higgses at LEP, the Tevatron and
also at B factories. In addition, the $2.8 \sigma$ excess of the branching
ratio $W \to \tau \nu$ with respect to the other leptons measured at LEP
correlates well with the existence of the charged Higgs with properties typical
for this scenario. Dominant $\tau$- and $c$-rich decay products of all Higgses
require modified strategies for their discovery at the LHC.
| [
{
"created": "Sun, 21 Sep 2008 01:17:24 GMT",
"version": "v1"
},
{
"created": "Sun, 19 Oct 2008 20:31:26 GMT",
"version": "v2"
}
] | 2009-04-06 | [
[
"Dermisek",
"Radovan",
""
]
] | We study the Higgs sector of supersymmetric models containing two Higgs doublets with a light MSSM-like CP odd Higgs, $m_A \lesssim 10$ GeV, and $\tan \beta \lesssim 2.5$. In this scenario all Higgses resulting from two Higgs doublets: light and heavy CP even Higgses, $h$ and $H$, the CP odd Higgs, $A$, and the charged Higgs, $H^\pm$, could have been produced at LEP or the Tevatron, but would have escaped detection because they decay in modes that have not been searched for or the experiments are not sensitive to. Especially $H \to ZA$ and $H^\pm \to W^{\pm \star} A$ with $A \to c \bar c, \tau^+ \tau^-$ present an opportunity to discover some of the Higgses at LEP, the Tevatron and also at B factories. In addition, the $2.8 \sigma$ excess of the branching ratio $W \to \tau \nu$ with respect to the other leptons measured at LEP correlates well with the existence of the charged Higgs with properties typical for this scenario. Dominant $\tau$- and $c$-rich decay products of all Higgses require modified strategies for their discovery at the LHC. |
hep-ph/9909489 | Madina Penttinen | M. Penttinen, M.V. Polyakov and K. Goeke | Helicity skewed quark distributions of the nucleon and chiral symmetry | 22 pages, 5 figures | Phys.Rev.D62:014024,2000 | 10.1103/PhysRevD.62.014024 | RUB-TPII-19/98 | hep-ph | null | We compute the helicity skewed quark distributions $\widetilde{H}$ and
$\widetilde{E}$ in the chiral quark-soliton model of the nucleon. This model
emphasizes correctly the role of spontaneously broken chiral symmetry in
structure of nucleon. It is based on the large-N_c picture of the nucleon as a
soliton of the effective chiral lagrangian and allows to calculate the leading
twist quark- and antiquark distributions at a low normalization point. We
discuss the role of chiral symmetry in the helicity skewed quark distributions
$\widetilde{H}$ and $\widetilde{E}$. We show that generalization of soft pion
theorems, based on chiral Ward identities, leads in the region of -\xi < x <
\xi to the pion pole contribution to $\widetilde{E}$ which dominates at small
momentum transfer.
| [
{
"created": "Thu, 23 Sep 1999 15:19:12 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Penttinen",
"M.",
""
],
[
"Polyakov",
"M. V.",
""
],
[
"Goeke",
"K.",
""
]
] | We compute the helicity skewed quark distributions $\widetilde{H}$ and $\widetilde{E}$ in the chiral quark-soliton model of the nucleon. This model emphasizes correctly the role of spontaneously broken chiral symmetry in structure of nucleon. It is based on the large-N_c picture of the nucleon as a soliton of the effective chiral lagrangian and allows to calculate the leading twist quark- and antiquark distributions at a low normalization point. We discuss the role of chiral symmetry in the helicity skewed quark distributions $\widetilde{H}$ and $\widetilde{E}$. We show that generalization of soft pion theorems, based on chiral Ward identities, leads in the region of -\xi < x < \xi to the pion pole contribution to $\widetilde{E}$ which dominates at small momentum transfer. |
hep-ph/0405230 | Mikhail Tokarev V. | M.V.Tokarev (Joint Institute for Nuclear Research, Dubna, Russia) | z-Scaling and Prompt J/psi Production at High-pT in bar pp at Tevatron | 5 pages, LaTeX, 3 figures | null | null | null | hep-ph | null | New data on high-pT spectra of J/psi measured by the CDF Collaboration at the
Tevatron are analyzed in the framework of z-scaling. F-dependence of
z-presentation of the data is used to construct the scaling function of J/psi.
The energy independence of the scaling function is used to predict inclusive
cross section of prompt J/psi production in bar pp collisions at high-pT. The
concept of z-scaling is considered to reflect the general features of high-pT
particle production in hadron-hadron and hadron-nucleus collisions. Violation
of z-scaling is suggested to consider as a signature of new physics.
| [
{
"created": "Mon, 24 May 2004 13:18:00 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Tokarev",
"M. V.",
"",
"Joint Institute for Nuclear Research, Dubna, Russia"
]
] | New data on high-pT spectra of J/psi measured by the CDF Collaboration at the Tevatron are analyzed in the framework of z-scaling. F-dependence of z-presentation of the data is used to construct the scaling function of J/psi. The energy independence of the scaling function is used to predict inclusive cross section of prompt J/psi production in bar pp collisions at high-pT. The concept of z-scaling is considered to reflect the general features of high-pT particle production in hadron-hadron and hadron-nucleus collisions. Violation of z-scaling is suggested to consider as a signature of new physics. |
hep-ph/0609145 | James Cline | James M. Cline | Baryogenesis | 63 pages, many figures; lectures at Les Houches Summer School,
Session 86: Particle Physics and Cosmology: the Fabric of Spacetime, 7-11
Aug. 2006. Fixed more minor errors and omissions | null | null | null | hep-ph astro-ph | null | Pedagogical lectures on baryogenesis, with emphasis on the electroweak phase
transition and electroweak baryogenesis. Contents: (1) Observational evidence
for the BAU; (2) Sakharov's conditions for baryogenesis; (3) Example: GUT
baryogenesis; (4) B and CP violation in the standard model; (5) Electroweak
phase transition and electroweak baryogenesis; (6) A model of electroweak
baryogenesis: the two Higgs doublet model; (7) EWBG in the MSSM; (8)
Leptogenesis
| [
{
"created": "Fri, 15 Sep 2006 01:50:25 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Sep 2006 15:49:14 GMT",
"version": "v2"
},
{
"created": "Wed, 22 Nov 2006 19:51:12 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Cline",
"James M.",
""
]
] | Pedagogical lectures on baryogenesis, with emphasis on the electroweak phase transition and electroweak baryogenesis. Contents: (1) Observational evidence for the BAU; (2) Sakharov's conditions for baryogenesis; (3) Example: GUT baryogenesis; (4) B and CP violation in the standard model; (5) Electroweak phase transition and electroweak baryogenesis; (6) A model of electroweak baryogenesis: the two Higgs doublet model; (7) EWBG in the MSSM; (8) Leptogenesis |
1209.2703 | Peng-fei Yin | Xiao-Jun Bi, Qi-Shu Yan and Peng-Fei Yin | Light stop/sbottom pair production searches in the NMSSM | 43 pages, 18 figs | Phys. Rev. D 87, 035007 (2013) | 10.1103/PhysRevD.87.035007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we study the constraints on the scenario of light stops and
sbottoms in the next-to-minimal supersymmetric standard model (NMSSM),
especially by a 125 GeV Higgs boson discovery and the LHC bounds on
supersymmetry. The constraints from dark matter detections are also taken into
account. From the parameter scan, we find that the NMSSM can well accommodate a
light Higgs boson around 125 GeV and decay patterns. We would like to stress
that the LHC direct supersymmetry searches with b-tagging are very powerful and
can set strong bounds on many NMSSM parameter points with light stops and
sbottoms. We find $\tilde {t}\to b\tilde{\chi}^+_1$ is a very promising channel
for light stop detection if the mass splitting between $\tilde{\chi}^+_1$ and
$\tilde{\chi}^0_1$ is very small. It is also pointed out that in order to close
the parameter space of light stops and sbottoms, new search strategies for
signal channels such as $p p \to {\tilde t_1} {\tilde t_1} \to t {\bar t} h h
\tilde{\chi}^0_1 \tilde{\chi}^0_1$ and $p p \to {\tilde b_1} {\tilde b_1} \to t
{\bar t} W^+ W^- \tilde{\chi}^0_1 \tilde{\chi}^0_1$ may be necessary.
| [
{
"created": "Wed, 12 Sep 2012 19:53:38 GMT",
"version": "v1"
},
{
"created": "Wed, 8 May 2013 15:02:20 GMT",
"version": "v2"
}
] | 2013-05-09 | [
[
"Bi",
"Xiao-Jun",
""
],
[
"Yan",
"Qi-Shu",
""
],
[
"Yin",
"Peng-Fei",
""
]
] | In this work, we study the constraints on the scenario of light stops and sbottoms in the next-to-minimal supersymmetric standard model (NMSSM), especially by a 125 GeV Higgs boson discovery and the LHC bounds on supersymmetry. The constraints from dark matter detections are also taken into account. From the parameter scan, we find that the NMSSM can well accommodate a light Higgs boson around 125 GeV and decay patterns. We would like to stress that the LHC direct supersymmetry searches with b-tagging are very powerful and can set strong bounds on many NMSSM parameter points with light stops and sbottoms. We find $\tilde {t}\to b\tilde{\chi}^+_1$ is a very promising channel for light stop detection if the mass splitting between $\tilde{\chi}^+_1$ and $\tilde{\chi}^0_1$ is very small. It is also pointed out that in order to close the parameter space of light stops and sbottoms, new search strategies for signal channels such as $p p \to {\tilde t_1} {\tilde t_1} \to t {\bar t} h h \tilde{\chi}^0_1 \tilde{\chi}^0_1$ and $p p \to {\tilde b_1} {\tilde b_1} \to t {\bar t} W^+ W^- \tilde{\chi}^0_1 \tilde{\chi}^0_1$ may be necessary. |
1910.14152 | Raymond Co | Raymond T. Co, Lawrence J. Hall, and Keisuke Harigaya | Axion Kinetic Misalignment Mechanism | 7+4 pages, 2+2 figures; v2: Supplemental Material and references
added, matches journal version | Phys. Rev. Lett. 124, 251802 (2020) | 10.1103/PhysRevLett.124.251802 | LCTP-19-28 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the conventional misalignment mechanism, the axion field has a constant
initial field value in the early universe and later begins to oscillate. We
present an alternative scenario where the axion field has a nonzero initial
velocity, allowing an axion decay constant much below the conventional
prediction from axion dark matter. This axion velocity can be generated from
explicit breaking of the axion shift symmetry in the early universe, which may
occur as this symmetry is approximate.
| [
{
"created": "Wed, 30 Oct 2019 21:51:00 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Jul 2020 00:44:00 GMT",
"version": "v2"
}
] | 2020-07-21 | [
[
"Co",
"Raymond T.",
""
],
[
"Hall",
"Lawrence J.",
""
],
[
"Harigaya",
"Keisuke",
""
]
] | In the conventional misalignment mechanism, the axion field has a constant initial field value in the early universe and later begins to oscillate. We present an alternative scenario where the axion field has a nonzero initial velocity, allowing an axion decay constant much below the conventional prediction from axion dark matter. This axion velocity can be generated from explicit breaking of the axion shift symmetry in the early universe, which may occur as this symmetry is approximate. |
1601.07774 | Alan D. Martin | A.D. Martin and M.G. Ryskin | Advantages of exclusive \gamma\gamma production to probe high mass
systems | 5 pages, text added, version published in J.Phys.G. (Letters) | J. Phys. G: Nucl. Part. Phys. 43 (2016) 04LT02 | 10.1088/0954-3899/43/4/04LT02 | IPPP/16/07, DCPT/16/14 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We recall that the exclusive production of high mass objects via \gamma\gamma
fusion at the LHC is not strongly suppressed in comparison with inclusive
\gamma\gamma fusion. Therefore it may be promising to study new objects
produced by the \gamma\gamma subprocess in experiments with exclusive
kinematics. We list the main advantages of exclusive experiments. We discuss
the special advantage of observing $\gamma\gamma \to X \to \gamma Z$ exclusive
events.
| [
{
"created": "Thu, 28 Jan 2016 14:35:40 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Feb 2016 10:31:31 GMT",
"version": "v2"
}
] | 2016-03-23 | [
[
"Martin",
"A. D.",
""
],
[
"Ryskin",
"M. G.",
""
]
] | We recall that the exclusive production of high mass objects via \gamma\gamma fusion at the LHC is not strongly suppressed in comparison with inclusive \gamma\gamma fusion. Therefore it may be promising to study new objects produced by the \gamma\gamma subprocess in experiments with exclusive kinematics. We list the main advantages of exclusive experiments. We discuss the special advantage of observing $\gamma\gamma \to X \to \gamma Z$ exclusive events. |
1807.05350 | Ying Li | Faisal Munir Bhutta, Ying Li, Cai-Dian L\"u, Yue-Hong Xie | New Physics Search in the Doubly Weak Decay $\overline B^0 \to K^+ \pi^-
$ | 26 pages, 3 figures, 3 tables | null | 10.1088/1674-1137/43/7/073102 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The doubly weak transition $b\to dd{\bar s}$ is highly suppressed in the
standard model, which makes it a potential channel to explore new physics
signals. We present a study of the exclusive two body wrong sign weak decay
$\smash{\overline B}^0\to K^+\pi^-$ belonging to this class within the
perturbative QCD approach. We perform a model independent analysis for various
effective dimension-6 operators, in which large effects are possible. We
further analyze the considered process in example models such as
Randall-Sundrum model, including the custodially protected and the bulk-Higgs
Randall-Sundrum model. Exploring the experimentally favored parameter spaces of
these models leads to a large and significant enhancement of the decay rate,
compared to the standard model result, which might be accessible in future
experiments. We propose to look for the wrong sign decay $\smash{\overline
B}^0\to K^+\pi^-$ via flavour-tagged time-dependent analyses, which can be
performed at LHCb and Belle-II.
| [
{
"created": "Sat, 14 Jul 2018 07:53:12 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Jul 2018 07:26:23 GMT",
"version": "v2"
}
] | 2019-09-04 | [
[
"Bhutta",
"Faisal Munir",
""
],
[
"Li",
"Ying",
""
],
[
"Lü",
"Cai-Dian",
""
],
[
"Xie",
"Yue-Hong",
""
]
] | The doubly weak transition $b\to dd{\bar s}$ is highly suppressed in the standard model, which makes it a potential channel to explore new physics signals. We present a study of the exclusive two body wrong sign weak decay $\smash{\overline B}^0\to K^+\pi^-$ belonging to this class within the perturbative QCD approach. We perform a model independent analysis for various effective dimension-6 operators, in which large effects are possible. We further analyze the considered process in example models such as Randall-Sundrum model, including the custodially protected and the bulk-Higgs Randall-Sundrum model. Exploring the experimentally favored parameter spaces of these models leads to a large and significant enhancement of the decay rate, compared to the standard model result, which might be accessible in future experiments. We propose to look for the wrong sign decay $\smash{\overline B}^0\to K^+\pi^-$ via flavour-tagged time-dependent analyses, which can be performed at LHCb and Belle-II. |
hep-ph/9912317 | L. T. Handoko | Wilfried Buchmuller, David Delepine, Laksana Tri Handoko | Neutrino Mixing and Flavour Changing Processes | 25 pages, 6 figures | Nucl.Phys.B576:445-465,2000 | 10.1016/S0550-3213(00)00095-X | DESY 99-169 | hep-ph | null | We study the implications of a large nu_mu - nu_tau mixing angle on flavour
changing transitions of quarks and leptons in supersymmetric extensions of the
standard model. Two patterns of supersymmetry breaking are considered, models
with modular invariance and the standard scenario of universal soft breaking
terms at the GUT scale. The analysis is performed for two symmetry groups G x
U(1)_F, with G=SU(5) and G=SU(3)^3, where U(1)_F is a family symmetry. Models
with modular invariance are in agreement with observations only for restricted
scalar quark and gaugino masses, (M_squark^2)/(m_gluino^2) \simeq 7/9 and
m_bino > 350 GeV. A characteristic feature of models with large tan beta and
radiatively induced flavour mixing is a large branching ratio for mu -> e
gamma. For both symmetry groups and for the considered range of supersymmetry
breaking mass parameters we find BR(mu -> e gamma) > 10^(-14).
| [
{
"created": "Mon, 13 Dec 1999 10:38:17 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Buchmuller",
"Wilfried",
""
],
[
"Delepine",
"David",
""
],
[
"Handoko",
"Laksana Tri",
""
]
] | We study the implications of a large nu_mu - nu_tau mixing angle on flavour changing transitions of quarks and leptons in supersymmetric extensions of the standard model. Two patterns of supersymmetry breaking are considered, models with modular invariance and the standard scenario of universal soft breaking terms at the GUT scale. The analysis is performed for two symmetry groups G x U(1)_F, with G=SU(5) and G=SU(3)^3, where U(1)_F is a family symmetry. Models with modular invariance are in agreement with observations only for restricted scalar quark and gaugino masses, (M_squark^2)/(m_gluino^2) \simeq 7/9 and m_bino > 350 GeV. A characteristic feature of models with large tan beta and radiatively induced flavour mixing is a large branching ratio for mu -> e gamma. For both symmetry groups and for the considered range of supersymmetry breaking mass parameters we find BR(mu -> e gamma) > 10^(-14). |
hep-ph/0605028 | Guy Raz | Yuval Grossman, Yosef Nir and Guy Raz | Constraining the Phase of B_s - \bar{B}_s Mixing | V3: Following clarifications by D0, our range for A_{SL} (and
consequently for A_{SL}^s) has been modified, strengthening our conclusions.
A new figure has been added; 5 pages | Phys.Rev.Lett.97:151801,2006 | 10.1103/PhysRevLett.97.151801 | null | hep-ph hep-ex | null | New physics contributions to B_s-\bar{B}_s mixing can be parametrized by the
size (r_s^2) and the phase (2\theta_s) of the total mixing amplitude relative
to the Standard Model amplitude. The phase has so far been unconstrained. We
first use the D0 measurement of the semileptonic CP asymmetry A_SL to obtain
the first constraint on the semileptonic CP asymmetry in B_s decays,
A_SL^s=-0.008 \pm 0.011. Then we combine recent measurements by the CDF and D0
collaborations - the mass difference (\Delta M_s), the width difference
(\Delta\Gamma_s) and A_SL^s - to constrain 2\theta_s. The errors on
\Delta\Gamma_s and A_SL^s should still be reduced to have a sensitive probe of
the phase, yet the central values are such that the regions around 2\theta_s ~
3\pi/2 and, in particular, 2\theta_s ~ \pi/2, are disfavored.
| [
{
"created": "Tue, 2 May 2006 09:08:02 GMT",
"version": "v1"
},
{
"created": "Mon, 15 May 2006 12:38:46 GMT",
"version": "v2"
},
{
"created": "Thu, 27 Jul 2006 17:49:23 GMT",
"version": "v3"
}
] | 2011-03-23 | [
[
"Grossman",
"Yuval",
""
],
[
"Nir",
"Yosef",
""
],
[
"Raz",
"Guy",
""
]
] | New physics contributions to B_s-\bar{B}_s mixing can be parametrized by the size (r_s^2) and the phase (2\theta_s) of the total mixing amplitude relative to the Standard Model amplitude. The phase has so far been unconstrained. We first use the D0 measurement of the semileptonic CP asymmetry A_SL to obtain the first constraint on the semileptonic CP asymmetry in B_s decays, A_SL^s=-0.008 \pm 0.011. Then we combine recent measurements by the CDF and D0 collaborations - the mass difference (\Delta M_s), the width difference (\Delta\Gamma_s) and A_SL^s - to constrain 2\theta_s. The errors on \Delta\Gamma_s and A_SL^s should still be reduced to have a sensitive probe of the phase, yet the central values are such that the regions around 2\theta_s ~ 3\pi/2 and, in particular, 2\theta_s ~ \pi/2, are disfavored. |
1202.5244 | Ulrich Ellwanger | Debottam Das, Ulrich Ellwanger and Ana M. Teixeira | Modified Signals for Supersymmetry in the NMSSM with a Singlino-like LSP | 24 pages, 9 Figures, misprint in Table 1 correcred | null | 10.1007/JHEP04(2012)067 | LPT Orsay 12-21; PCCF RI 12-01 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of the NMSSM with a singlino-like LSP, we study
quantitatively the impact of the additional bino -> singlino cascade on the
efficiencies in several search channels for supersymmetry of the ATLAS and CMS
collaborations. Compared to the MSSM, the additional cascade reduces the
missing transverse energy, but leads to additional jets or leptons. For the
NMSSM benchmark lines which generalize cMSSM benchmark points, the efficiencies
in the most relevant 2/3 jet + missing energy search channels can drop by
factors ~1/3 to ~1/7, and can reduce the present lower bounds on M_{1/2} by as
much as ~0.9 - 0.75 in the NMSSM for large bino-singlino mass differences. The
larger efficiencies in multijet or multilepton search channels are not strong
enough to affect this conclusion. In the fully constrained cNMSSM, sparticle
decay cascades via the lightest stau can lead to signal cross sections in
multilepton and 2tau search channels which are potentially visible at the LHC
with 7 TeV center of mass energy.
| [
{
"created": "Thu, 23 Feb 2012 17:49:22 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Mar 2012 17:22:16 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Das",
"Debottam",
""
],
[
"Ellwanger",
"Ulrich",
""
],
[
"Teixeira",
"Ana M.",
""
]
] | In the framework of the NMSSM with a singlino-like LSP, we study quantitatively the impact of the additional bino -> singlino cascade on the efficiencies in several search channels for supersymmetry of the ATLAS and CMS collaborations. Compared to the MSSM, the additional cascade reduces the missing transverse energy, but leads to additional jets or leptons. For the NMSSM benchmark lines which generalize cMSSM benchmark points, the efficiencies in the most relevant 2/3 jet + missing energy search channels can drop by factors ~1/3 to ~1/7, and can reduce the present lower bounds on M_{1/2} by as much as ~0.9 - 0.75 in the NMSSM for large bino-singlino mass differences. The larger efficiencies in multijet or multilepton search channels are not strong enough to affect this conclusion. In the fully constrained cNMSSM, sparticle decay cascades via the lightest stau can lead to signal cross sections in multilepton and 2tau search channels which are potentially visible at the LHC with 7 TeV center of mass energy. |
hep-ph/9911341 | Neal Weiner | Lawrence Hall, Hitoshi Murayama, and Neal Weiner (UC Berkeley, LBNL) | Neutrino Mass Anarchy | 4 pages, 3 figures, RevTeX. Minor changes, reference added | Phys.Rev.Lett.84:2572-2575,2000 | 10.1103/PhysRevLett.84.2572 | UCB-PTH-99/51, LBNL-44551 | hep-ph | null | What is the form of the neutrino mass matrix which governs the oscillations
of the atmospheric and solar neutrinos? Features of the data have led to a
dominant viewpoint where the mass matrix has an ordered, regulated pattern,
perhaps dictated by a flavor symmetry. We challenge this viewpoint, and
demonstrate that the data are well accounted for by a neutrino mass matrix
which appears to have random entries.
| [
{
"created": "Mon, 15 Nov 1999 22:43:23 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Nov 1999 19:34:01 GMT",
"version": "v2"
}
] | 2009-09-29 | [
[
"Hall",
"Lawrence",
"",
"UC Berkeley, LBNL"
],
[
"Murayama",
"Hitoshi",
"",
"UC Berkeley, LBNL"
],
[
"Weiner",
"Neal",
"",
"UC Berkeley, LBNL"
]
] | What is the form of the neutrino mass matrix which governs the oscillations of the atmospheric and solar neutrinos? Features of the data have led to a dominant viewpoint where the mass matrix has an ordered, regulated pattern, perhaps dictated by a flavor symmetry. We challenge this viewpoint, and demonstrate that the data are well accounted for by a neutrino mass matrix which appears to have random entries. |
hep-ph/0107025 | Mihail Chizhov | M. V. Chizhov | A new mass relation among the hadron vector resonances | LaTex 6 pages, 1 eps figure, contributed to Lepton-Photon 2001 | null | null | MIH-2001-02 | hep-ph | null | We show that the hadron vector resonances are described by fields
transforming according to different inequivalent representations of the Lorentz
group: (1/2,1/2) and (1,0)+(0,1). The vector representation (1/2,1/2) is well
studied and corresponds to the gauge fields. On the other hand, the chiral
representations (1,0) and (0,1) are described by the second rank antisymmetric
tensor fields, for which interaction theory has not yet been constructed. In
the framework of the phenomenological Nambu - Jona-Lasinio approach we have
introduced and used all these fields for a description of the vector
resonances. A new mass relation between low-lying hadron vector and
axial-vector resonances is obtained. This relation is in agreement with the
present experimental data.
| [
{
"created": "Tue, 3 Jul 2001 16:20:04 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Chizhov",
"M. V.",
""
]
] | We show that the hadron vector resonances are described by fields transforming according to different inequivalent representations of the Lorentz group: (1/2,1/2) and (1,0)+(0,1). The vector representation (1/2,1/2) is well studied and corresponds to the gauge fields. On the other hand, the chiral representations (1,0) and (0,1) are described by the second rank antisymmetric tensor fields, for which interaction theory has not yet been constructed. In the framework of the phenomenological Nambu - Jona-Lasinio approach we have introduced and used all these fields for a description of the vector resonances. A new mass relation between low-lying hadron vector and axial-vector resonances is obtained. This relation is in agreement with the present experimental data. |
hep-ph/0008216 | Guohuai Zhu | Dongsheng Du, Deshan Yang and Guohuai Zhu | QCD Factorization For B Decays To Two Light Pseudoscalars Including
Chirally Enhanced Corrections | A revised version | null | null | null | hep-ph | null | Since b quark mass is not asymptotically large, chirally enhanced corrections
which arise from twist-3 wave functions may be important in B decays. We thus
evaluate the hadronic matrix elements with the emitted meson described by
leading twist and twist-3 distribution amplitudes $\Phi_p(x)$. After summing
over the four "vertex correction" diagrams, we obtain the results with infrared
finiteness which shows that chirally enhanced corrections arise from
$\Phi_p(x)$ can be consistently included in QCD factorization. We also briefly
discuss the contributions from "hard spectator" diagrams.
| [
{
"created": "Mon, 21 Aug 2000 04:59:25 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Aug 2000 06:52:28 GMT",
"version": "v2"
},
{
"created": "Fri, 22 Dec 2000 08:03:32 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Du",
"Dongsheng",
""
],
[
"Yang",
"Deshan",
""
],
[
"Zhu",
"Guohuai",
""
]
] | Since b quark mass is not asymptotically large, chirally enhanced corrections which arise from twist-3 wave functions may be important in B decays. We thus evaluate the hadronic matrix elements with the emitted meson described by leading twist and twist-3 distribution amplitudes $\Phi_p(x)$. After summing over the four "vertex correction" diagrams, we obtain the results with infrared finiteness which shows that chirally enhanced corrections arise from $\Phi_p(x)$ can be consistently included in QCD factorization. We also briefly discuss the contributions from "hard spectator" diagrams. |
hep-ph/9501300 | Stefano Moretti | Stefano Moretti | Heavy Higgs production and decay via $e^+e^-\to Z^0 H^0 \to b\bar
bZ^0Z^0$ and irreducible backgrounds at Next Linear Colliders | 24 pages, LaTeX (uses Feynman), 7 figures (.ps files or hardcopies of
figs.2-7 available upon request) | Phys.Rev. D52 (1995) 6316-6326 | 10.1103/PhysRevD.52.6316 | DFTT 69/94, DTP/95/02 | hep-ph | null | The complete matrix element for $e^+e^-\ar b\bar bZ^0Z^0$ has been computed
at tree--level and applied to $Z^0H^0$--production followed by $Z^0\ar b\bar b$
and $H^0\ar Z^0Z^0$, including all the irreducible background, at Next Linear
Colliders. We find that, assuming flavour identification of the $Z^0$--decay
products, this channel, together with $e^+e^-\ar b\bar bW^+W^-$ in which
$Z^0H^0\ar (b\bar b)(W^+W^-$), can be important for the study of the parameters
of the Standard Model Higgs boson over the heavy mass range $2M_{Z^0}\Ord
M_{H^0}\Ord 2{m_t}$.
| [
{
"created": "Sat, 14 Jan 1995 16:14:08 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Moretti",
"Stefano",
""
]
] | The complete matrix element for $e^+e^-\ar b\bar bZ^0Z^0$ has been computed at tree--level and applied to $Z^0H^0$--production followed by $Z^0\ar b\bar b$ and $H^0\ar Z^0Z^0$, including all the irreducible background, at Next Linear Colliders. We find that, assuming flavour identification of the $Z^0$--decay products, this channel, together with $e^+e^-\ar b\bar bW^+W^-$ in which $Z^0H^0\ar (b\bar b)(W^+W^-$), can be important for the study of the parameters of the Standard Model Higgs boson over the heavy mass range $2M_{Z^0}\Ord M_{H^0}\Ord 2{m_t}$. |
2303.01915 | Reinaldo Francener | R. Francener, D.R. Gratieri and G. Torrieri | Investigating the impact of spin effects at the high-energy
neutrino-nucleon interactions while it crosses the Earth's core | null | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | In this work, we investigate the impact of assuming the polarization of the
Earth's outer core on the propagation of neutrinos that cross the all the
Earth. We taking into account the spin-dependent structure functions to
describe the polarized neutrino-nucleon cross-section, and also on the neutrino
absorption while it crosses all of the Earth. We found that adding spin
information and simultaneously assuming polarization of Earth's outer core
impacts the probability of neutrino absorption in the energy range of 10 - 100
TeV and for upward neutrino direction. However, the magnitude of the effect is
small and should be comparable with the magnitude of the errors associated with
the IceCube neutrino data.
| [
{
"created": "Fri, 3 Mar 2023 13:36:47 GMT",
"version": "v1"
}
] | 2023-03-07 | [
[
"Francener",
"R.",
""
],
[
"Gratieri",
"D. R.",
""
],
[
"Torrieri",
"G.",
""
]
] | In this work, we investigate the impact of assuming the polarization of the Earth's outer core on the propagation of neutrinos that cross the all the Earth. We taking into account the spin-dependent structure functions to describe the polarized neutrino-nucleon cross-section, and also on the neutrino absorption while it crosses all of the Earth. We found that adding spin information and simultaneously assuming polarization of Earth's outer core impacts the probability of neutrino absorption in the energy range of 10 - 100 TeV and for upward neutrino direction. However, the magnitude of the effect is small and should be comparable with the magnitude of the errors associated with the IceCube neutrino data. |
hep-ph/0602162 | Zbigniew Was | Johann H. Kuhn, Z. Was | tau Decays to Five Mesons in TAUOLA | 10 pages | ActaPhys.Polon.B39:147-158,2008 | null | CERN-PH-TH/2006-025, TTP06-01, IFJPAN-IV-2006-1 | hep-ph | null | The tau-decay library TAUOLA has gained popularity over the last decade.
However, with the continuously increasing precision of the data, some of its
functionality has become insufficient. One of the requirements is the
implementation of decays into five mesons plus a neutrino with a realistic
decay amplitude. This note describes a step into this direction. For the 2pi-
pi+ 2pi0 mode the three decay chains tau- --> a_1- nu --> rho- (--> pi- pi0)
omega (--> pi- pi+ pi0) nu, tau- --> a_1- nu --> a_1- (--> 2pi- pi+) f_0 (-->
2pi0) nu, and tau- --> a_1- nu --> a_1- (--> pi- 2pi0) f_0 (--> pi + pi-) nu
are introduced with simple assumptions about the couplings and propagators of
the various resonances. Similar amplitudes (without the rho omega
contributions) are adopted for the pi- 4pi0 and 3pi- 2pi+ modes.
The five-pion amplitude is thus based on a simple model, which, however, can
be considered as a first realistic example. Phase-space generation includes the
possibility of presampling the omega and a_1 resonances, in one channel only,
however. This is probably sufficient for the time being, both for physics
applications and for tests.
The technical test of the new part of the generator is performed by comparing
Monte Carlo and analytical results. To this end a non-realistic, but easy to
calculate, purely scalar amplitude for the decay into five massless pions was
used.
| [
{
"created": "Fri, 17 Feb 2006 12:13:32 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Kuhn",
"Johann H.",
""
],
[
"Was",
"Z.",
""
]
] | The tau-decay library TAUOLA has gained popularity over the last decade. However, with the continuously increasing precision of the data, some of its functionality has become insufficient. One of the requirements is the implementation of decays into five mesons plus a neutrino with a realistic decay amplitude. This note describes a step into this direction. For the 2pi- pi+ 2pi0 mode the three decay chains tau- --> a_1- nu --> rho- (--> pi- pi0) omega (--> pi- pi+ pi0) nu, tau- --> a_1- nu --> a_1- (--> 2pi- pi+) f_0 (--> 2pi0) nu, and tau- --> a_1- nu --> a_1- (--> pi- 2pi0) f_0 (--> pi + pi-) nu are introduced with simple assumptions about the couplings and propagators of the various resonances. Similar amplitudes (without the rho omega contributions) are adopted for the pi- 4pi0 and 3pi- 2pi+ modes. The five-pion amplitude is thus based on a simple model, which, however, can be considered as a first realistic example. Phase-space generation includes the possibility of presampling the omega and a_1 resonances, in one channel only, however. This is probably sufficient for the time being, both for physics applications and for tests. The technical test of the new part of the generator is performed by comparing Monte Carlo and analytical results. To this end a non-realistic, but easy to calculate, purely scalar amplitude for the decay into five massless pions was used. |
2401.07933 | Ahmad Jafar Arifi | Ahmad Jafar Arifi, Lucas Happ, Shuhei Ohno, Makoto Oka | Structure of Heavy Mesons in the Light-Front Quark Model | 17 pages, 11 figures, and 6 tables. We add more results and
discussion | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | We investigate the structure of ground-state heavy mesons within the
light-front quark model, utilizing wave functions derived from the Single
Gaussian Ansatz (SGA) and the Gaussian Expansion Method (GEM). By performing a
$\chi^2$ fit to static properties such as mass spectra and decay constants, we
determine the model parameters for each approach. We then compare the impacts
of both methods on the light-front wave functions and structural observables.
Our analysis reveals significant differences in the distribution amplitudes
(DAs) $\phi_{2;M}(x)$ near the endpoints, with GEM showing enhanced amplitudes
and correct asymptotic behavior $\phi_{2;M}(x \to 1) \propto (1-x)$, consistent
with perturbative QCD. This endpoint behavior is linked to the short-range
(high-momentum) wave function governed by color Coulomb interaction and
relativistic kinematics. GEM accurately reproduces a power-law damping
$\psi_0(k \to \infty) \propto 1/k_\perp^2$, aligning with perturbative QCD
predictions. Furthermore, the electromagnetic form factors of pseudoscalar
mesons in the low-$Q^2$ region fall off faster with GEM than with SGA. Overall,
while both methods adequately describe static properties, GEM provides a more
accurate description of structural properties, being more sensitive to details
and asymptotic behaviors.
| [
{
"created": "Mon, 15 Jan 2024 19:50:17 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Jun 2024 23:01:34 GMT",
"version": "v2"
}
] | 2024-06-24 | [
[
"Arifi",
"Ahmad Jafar",
""
],
[
"Happ",
"Lucas",
""
],
[
"Ohno",
"Shuhei",
""
],
[
"Oka",
"Makoto",
""
]
] | We investigate the structure of ground-state heavy mesons within the light-front quark model, utilizing wave functions derived from the Single Gaussian Ansatz (SGA) and the Gaussian Expansion Method (GEM). By performing a $\chi^2$ fit to static properties such as mass spectra and decay constants, we determine the model parameters for each approach. We then compare the impacts of both methods on the light-front wave functions and structural observables. Our analysis reveals significant differences in the distribution amplitudes (DAs) $\phi_{2;M}(x)$ near the endpoints, with GEM showing enhanced amplitudes and correct asymptotic behavior $\phi_{2;M}(x \to 1) \propto (1-x)$, consistent with perturbative QCD. This endpoint behavior is linked to the short-range (high-momentum) wave function governed by color Coulomb interaction and relativistic kinematics. GEM accurately reproduces a power-law damping $\psi_0(k \to \infty) \propto 1/k_\perp^2$, aligning with perturbative QCD predictions. Furthermore, the electromagnetic form factors of pseudoscalar mesons in the low-$Q^2$ region fall off faster with GEM than with SGA. Overall, while both methods adequately describe static properties, GEM provides a more accurate description of structural properties, being more sensitive to details and asymptotic behaviors. |
1108.6063 | Nikolaos Kidonakis | Nikolaos Kidonakis and Ben D. Pecjak | Top-quark production and QCD | 35 pages, 10 figures; invited review for a special "Top and flavor
physics in the LHC era" issue of the European Physical Journal C | Eur.Phys.J.C72:2084,2012 | 10.1140/epjc/s10052-012-2084-0 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review theoretical calculations for top-quark production that include
complete next-to-leading-order QCD corrections as well as higher-order
soft-gluon corrections from threshold resummation. We discuss in detail the
differences between various approaches that have appeared in the literature and
review results for top-quark total cross sections and differential
distributions at the Tevatron and the LHC.
| [
{
"created": "Tue, 30 Aug 2011 20:02:13 GMT",
"version": "v1"
}
] | 2015-05-30 | [
[
"Kidonakis",
"Nikolaos",
""
],
[
"Pecjak",
"Ben D.",
""
]
] | We review theoretical calculations for top-quark production that include complete next-to-leading-order QCD corrections as well as higher-order soft-gluon corrections from threshold resummation. We discuss in detail the differences between various approaches that have appeared in the literature and review results for top-quark total cross sections and differential distributions at the Tevatron and the LHC. |
2110.06869 | Dario Kermanschah | Dario Kermanschah | Numerical integration of loop integrals through local cancellation of
threshold singularities | 57 pages, 9 figures | null | 10.1007/JHEP01(2022)151 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new approach that allows for the separate numerical calculation
of the real and imaginary parts of finite loop integrals. We find that at
one-loop the real part is given by the Loop-Tree Duality integral supplemented
with suitable counterterms and the imaginary part is a sum of two-body phase
space integrals, constituting a locally finite representation of the
generalised optical theorem. These expressions are integrals in momentum space,
whose integrands were specially designed to feature local cancellations of
threshold singularities. Such a representation is well suited for Monte Carlo
integration and avoids the drawbacks of a numerical contour deformation around
remaining singularities. Our method is directly applicable to a range integrals
with certain geometric properties but not yet fully generalised for arbitrary
one-loop integrals. We demonstrate the computational performance with examples
of one-loop integrals with various kinematic configurations, which gives
promising prospects for an extension to multi-loop integrals.
| [
{
"created": "Wed, 13 Oct 2021 17:03:56 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Jan 2022 17:27:09 GMT",
"version": "v2"
}
] | 2022-02-01 | [
[
"Kermanschah",
"Dario",
""
]
] | We propose a new approach that allows for the separate numerical calculation of the real and imaginary parts of finite loop integrals. We find that at one-loop the real part is given by the Loop-Tree Duality integral supplemented with suitable counterterms and the imaginary part is a sum of two-body phase space integrals, constituting a locally finite representation of the generalised optical theorem. These expressions are integrals in momentum space, whose integrands were specially designed to feature local cancellations of threshold singularities. Such a representation is well suited for Monte Carlo integration and avoids the drawbacks of a numerical contour deformation around remaining singularities. Our method is directly applicable to a range integrals with certain geometric properties but not yet fully generalised for arbitrary one-loop integrals. We demonstrate the computational performance with examples of one-loop integrals with various kinematic configurations, which gives promising prospects for an extension to multi-loop integrals. |
hep-ph/0602085 | Piotr R\cczka | Piotr A. Raczka | Improving reliability of perturbative QCD predictions at moderate
energies | 92 pages, 20 figures; reformatted, expanded presentation, corrected
misprints, additional references | null | null | IFT-16-2005 | hep-ph | null | The problem of precise evaluation of the perturbative QCD predictions at
moderate energies is considered. Substantial renormalization scheme dependence
of the perturbative predictions obtained with the conventional renormalization
group improved perturbative approximants is discussed, using as an example the
QCD effective charge appearing in the static interquark potential and the QCD
corrections to the Gross-Llewellyn-Smith sum rule in the deep inelastic
neutrino-nucleon scattering. A new method for evaluating the QCD predictions at
moderate energies is proposed, based on a modified couplant, which is
constructed to be free from Landau singularity and less renormalization scheme
dependent than the conventional couplant. The modified couplant contains an
adjustable parameter, which may be used to improve the modified perturbative
predictions in low orders by utilizing some information outside of perturbation
theory. This parameter is fixed by matching the modified predictions to the
phenomenological expression for the effective charge in the interquark
potential. The renormalization scheme dependence of the perturbative
predictions in the modified expansion is then discussed in detail, including
the predictions selected by the Principle of Minimal Sensitivity applied to the
modified expansion. It is shown that the predictions obtained in the modified
expansion are much more stable with respect to change of the renormalization
scheme parameters than the predictions obtained in the conventional approach.
It is also found that the modified predictions display somewhat weaker energy
dependence then the predictions obtained with the conventional expansion, which
may help accommodate in a consistent way some low values of the strong coupling
parameter measured at low energies with the values measured at high energies.
| [
{
"created": "Thu, 9 Feb 2006 19:19:52 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Feb 2006 09:45:09 GMT",
"version": "v2"
},
{
"created": "Fri, 19 May 2006 16:24:12 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Raczka",
"Piotr A.",
""
]
] | The problem of precise evaluation of the perturbative QCD predictions at moderate energies is considered. Substantial renormalization scheme dependence of the perturbative predictions obtained with the conventional renormalization group improved perturbative approximants is discussed, using as an example the QCD effective charge appearing in the static interquark potential and the QCD corrections to the Gross-Llewellyn-Smith sum rule in the deep inelastic neutrino-nucleon scattering. A new method for evaluating the QCD predictions at moderate energies is proposed, based on a modified couplant, which is constructed to be free from Landau singularity and less renormalization scheme dependent than the conventional couplant. The modified couplant contains an adjustable parameter, which may be used to improve the modified perturbative predictions in low orders by utilizing some information outside of perturbation theory. This parameter is fixed by matching the modified predictions to the phenomenological expression for the effective charge in the interquark potential. The renormalization scheme dependence of the perturbative predictions in the modified expansion is then discussed in detail, including the predictions selected by the Principle of Minimal Sensitivity applied to the modified expansion. It is shown that the predictions obtained in the modified expansion are much more stable with respect to change of the renormalization scheme parameters than the predictions obtained in the conventional approach. It is also found that the modified predictions display somewhat weaker energy dependence then the predictions obtained with the conventional expansion, which may help accommodate in a consistent way some low values of the strong coupling parameter measured at low energies with the values measured at high energies. |
2110.05084 | Shaoqi Hou | Shaoqi Hou, Shuxun Tian, Shuo Cao, Zong-Hong Zhu | Dark photon bursts from compact binary systems and constraints | 11 pages, 2 figures. Modified according to Referee's suggestions | Phys. Rev. D 105, 064022 (2022) | 10.1103/PhysRevD.105.064022 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we consider the burst signal of the dark photon, the
hypothetical vector boson of the $U(1)_B$ or $U(1)_{B-L}$ gauge group,
generated by a compact binary star system. The absence of the signal in the
laser interferometer puts bounds on the coupling constant $\epsilon$ to the
ordinary matter. It turns out that if the dark photon is massless, $\epsilon^2$
is on the order of $10^{-37}-10^{-33}$ at most; in the massive case, the upper
bound of $\epsilon^2$ is about $10^{-38}-10^{-31}$ in the mass range from
$10^{-19}$ eV to $10^{-11}$ eV. These are the first bounds derived from the
interferometer observations independent of the assumption of dark photons being
dark matter.
| [
{
"created": "Mon, 11 Oct 2021 08:38:38 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Jan 2022 01:46:51 GMT",
"version": "v2"
}
] | 2022-03-16 | [
[
"Hou",
"Shaoqi",
""
],
[
"Tian",
"Shuxun",
""
],
[
"Cao",
"Shuo",
""
],
[
"Zhu",
"Zong-Hong",
""
]
] | In this work, we consider the burst signal of the dark photon, the hypothetical vector boson of the $U(1)_B$ or $U(1)_{B-L}$ gauge group, generated by a compact binary star system. The absence of the signal in the laser interferometer puts bounds on the coupling constant $\epsilon$ to the ordinary matter. It turns out that if the dark photon is massless, $\epsilon^2$ is on the order of $10^{-37}-10^{-33}$ at most; in the massive case, the upper bound of $\epsilon^2$ is about $10^{-38}-10^{-31}$ in the mass range from $10^{-19}$ eV to $10^{-11}$ eV. These are the first bounds derived from the interferometer observations independent of the assumption of dark photons being dark matter. |
1207.4267 | Andrew Casey | Andrew Casey, Ian C. Clo\"et, Hrayr H. Matevosyan, Anthony W. Thomas | Dihadron Fragmentation Functions from the NJL-jet model and their QCD
Evolution | 13 pages, 7 figures | null | 10.1103/PhysRevD.86.114018 | ADP-12-13/T780 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present results for dihadron fragmentation functions from the NJL-jet
model evolved from the model scale to a typical experimental scale of $4
\mathrm{GeV}^2$. The numerical method used in this evolution is discussed in
detail. The effect of evolution on the shapes of the dihadron fragmentation
functions is discussed for a doubly favored process ($u \to \pi^+\pi^-$), as
well as a singly favored ($u \to \pi^+K^-$) process involving light quarks.
Finally, we explore the production of $K^+ K^-$ pairs from an initial $u$, $d$
or $s$ quark.
| [
{
"created": "Wed, 18 Jul 2012 05:03:37 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Casey",
"Andrew",
""
],
[
"Cloët",
"Ian C.",
""
],
[
"Matevosyan",
"Hrayr H.",
""
],
[
"Thomas",
"Anthony W.",
""
]
] | We present results for dihadron fragmentation functions from the NJL-jet model evolved from the model scale to a typical experimental scale of $4 \mathrm{GeV}^2$. The numerical method used in this evolution is discussed in detail. The effect of evolution on the shapes of the dihadron fragmentation functions is discussed for a doubly favored process ($u \to \pi^+\pi^-$), as well as a singly favored ($u \to \pi^+K^-$) process involving light quarks. Finally, we explore the production of $K^+ K^-$ pairs from an initial $u$, $d$ or $s$ quark. |
1802.06320 | Sebasti\'an Felipe Mantilla Serrano | R. Martinez, S. F. Mantilla | Mass problem in the Standard Model | Conference proceedings from 6th International Conference on New
Frontiers in Physics (ICNFP 2017) from August 17th to 29th of 2017 at the
Conference Center of the Orthodox Academy of Creta (OAC) in Kolymbari
(Crete), Greece | null | 10.1051/epjconf/201818202084 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new $\mathrm{SU}(3)_C \otimes \mathrm{SU}(2)_{L}\otimes
\mathrm{U}(1)_{Y}\otimes \mathrm{U}(1)_{X}$ gauge model which is non universal
respect to the three fermion families of the Standard Model. We introduce
additional one top-like quark, two bottom-like quarks and three right handed
neutrinos in order to have an anomaly free theory. We also consider additional
three right handed neutrinos which are singlets respect to the gauge symmetry
of the model to implement see saw mechanism and give masses to the light
neutrinos according to the neutrino oscillation phenomenology. In the context
of this horizontal gauge symmetry we find mass ansatz for leptons and quarks.
In particular, from the analysis of solar, atmospheric, reactor and accelerator
neutrino oscillation experiments, we get the allow region for the Yukawa
couplings for the charge and neutral lepton sectors according with the mass
squared differences and mixing angles for the two neutrino hierarchy schemes,
normal and inverted.
| [
{
"created": "Sun, 18 Feb 2018 02:19:23 GMT",
"version": "v1"
}
] | 2018-08-22 | [
[
"Martinez",
"R.",
""
],
[
"Mantilla",
"S. F.",
""
]
] | We propose a new $\mathrm{SU}(3)_C \otimes \mathrm{SU}(2)_{L}\otimes \mathrm{U}(1)_{Y}\otimes \mathrm{U}(1)_{X}$ gauge model which is non universal respect to the three fermion families of the Standard Model. We introduce additional one top-like quark, two bottom-like quarks and three right handed neutrinos in order to have an anomaly free theory. We also consider additional three right handed neutrinos which are singlets respect to the gauge symmetry of the model to implement see saw mechanism and give masses to the light neutrinos according to the neutrino oscillation phenomenology. In the context of this horizontal gauge symmetry we find mass ansatz for leptons and quarks. In particular, from the analysis of solar, atmospheric, reactor and accelerator neutrino oscillation experiments, we get the allow region for the Yukawa couplings for the charge and neutral lepton sectors according with the mass squared differences and mixing angles for the two neutrino hierarchy schemes, normal and inverted. |
hep-ph/9803298 | Alexander Bakulev | A.P. Bakulev, S.V. Mikhailov | The $\rho$-meson and related meson wave functions in QCD sum rules with
nonlocal condensates | 10 pages, LATEX, 2 Tables, 4 figures are enclosed as ps-file, Last
version: improved figures (added figure captions) | Phys.Lett. B436 (1998) 351-362 | 10.1016/S0370-2693(98)00868-5 | E2-97-419 JINR, Dubna | hep-ph | null | We apply the nonlocal condensate formalism to construct generalized sum rules
(including $O(\as)$-radiative corrections) for $\pi$-, $\rho$- and
$\rho'$-meson wave functions of twist 2. Besides, we predict the lepton decay
constant $f_{\rho'}$ and estimate the mass of $\rho'$-meson. For all these
mesons we obtain the first 10 moments of longitudinal wave functions, suggest
the models for them and discuss their properties. We consider the peculiarities
of the QCD sum rules with nonlocal condensates for transverse $\rho$- and
$b_1$-meson wave functions. These results are compared with those found by Ball
and Braun and by Chernyak and Zhitnitsky.
| [
{
"created": "Tue, 10 Mar 1998 16:45:20 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Mar 1998 16:26:12 GMT",
"version": "v2"
},
{
"created": "Wed, 10 Jun 1998 19:04:11 GMT",
"version": "v3"
},
{
"created": "Wed, 1 Jul 1998 17:21:20 GMT",
"version": "v4"
},
{
"created": "Fri, 11 Dec 1998 22:06:10 GMT",
"version": "v5"
}
] | 2009-10-31 | [
[
"Bakulev",
"A. P.",
""
],
[
"Mikhailov",
"S. V.",
""
]
] | We apply the nonlocal condensate formalism to construct generalized sum rules (including $O(\as)$-radiative corrections) for $\pi$-, $\rho$- and $\rho'$-meson wave functions of twist 2. Besides, we predict the lepton decay constant $f_{\rho'}$ and estimate the mass of $\rho'$-meson. For all these mesons we obtain the first 10 moments of longitudinal wave functions, suggest the models for them and discuss their properties. We consider the peculiarities of the QCD sum rules with nonlocal condensates for transverse $\rho$- and $b_1$-meson wave functions. These results are compared with those found by Ball and Braun and by Chernyak and Zhitnitsky. |
2004.03773 | Fu-Hu Liu | Muhammad Waqas, Fu-Hu Liu, Zafar Wazir | Dependence of temperatures and kinetic freeze-out volume on centrality
in Au-Au and Pb-Pb collisions at high energy | 15 pages, 9 figures. Advances in High Energy Physics, accepted | Advances in High Energy Physics 2020, 8198126 (2020) (15 pages) | 10.1155/2020/8198126 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Centrality-dependent double-differential transverse momentum spectra of
negatively charged particles ($\pi^-$, $K^-$ and $\bar p$) at
mid-(pseudo)rapidity interval in nuclear collisions are analyzed by the
standard distribution in terms of multi-component. The experimental data
measured in gold-gold (Au-Au) collisions by the PHENIX Collaboration at the
Relativistic Heavy Ion Collider (RHIC) and in lead-lead (Pb-Pb) collisions by
the ALICE Collaboration at the Large Hadron Collider (LHC) are studied. The
effective temperature, initial temperature, kinetic freeze-out temperature,
transverse flow velocity and kinetic freeze-out volume are extracted from the
fitting to transverse momentum spectra. We observed, that the mentioned five
quantities increase with the increase of event centrality due to the fact that
the average transverse momentum increases with the increase of event
centrality. This renders that larger momentum (energy) transfer and further
multiple-scattering had happened in central centrality.
| [
{
"created": "Wed, 8 Apr 2020 01:56:42 GMT",
"version": "v1"
},
{
"created": "Mon, 11 May 2020 09:18:55 GMT",
"version": "v2"
}
] | 2020-05-28 | [
[
"Waqas",
"Muhammad",
""
],
[
"Liu",
"Fu-Hu",
""
],
[
"Wazir",
"Zafar",
""
]
] | Centrality-dependent double-differential transverse momentum spectra of negatively charged particles ($\pi^-$, $K^-$ and $\bar p$) at mid-(pseudo)rapidity interval in nuclear collisions are analyzed by the standard distribution in terms of multi-component. The experimental data measured in gold-gold (Au-Au) collisions by the PHENIX Collaboration at the Relativistic Heavy Ion Collider (RHIC) and in lead-lead (Pb-Pb) collisions by the ALICE Collaboration at the Large Hadron Collider (LHC) are studied. The effective temperature, initial temperature, kinetic freeze-out temperature, transverse flow velocity and kinetic freeze-out volume are extracted from the fitting to transverse momentum spectra. We observed, that the mentioned five quantities increase with the increase of event centrality due to the fact that the average transverse momentum increases with the increase of event centrality. This renders that larger momentum (energy) transfer and further multiple-scattering had happened in central centrality. |
1212.1288 | Kingman Cheung | Kingman Cheung, Chih-Ting Lu, and Tzu-Chiang Yuan | Diphoton Rate of the Standard-Model-Like Higgs Boson in the Extra U(1)
Extended MSSM | 22 pages, 6 figures; 2 new figures on the b-bbar and invisible
branching ratios; references added; match the published version. arXiv admin
note: text overlap with arXiv:1202.0054 | null | 10.1103/PhysRevD.87.075001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the excess in the diphoton production rate of the Higgs boson at
the Large Hadron Collider (LHC), we investigate the possibility that one of the
CP-even Higgs bosons of the extra U(1) extended minimal supersymmetric standard
model can give a consistent result. We scan the parameter space for a
standard-model-like Higgs boson such that the mass is in the range of 124-127
GeV and the production rate \sigma xB of the WW*, ZZ* modes are consistent with
the standard model (SM) values while that of \gamma\gamma is enhanced relative
to the SM value. We find that the SM-like Higgs boson is mostly the lightest
CP-even Higgs boson and it has a strong mixing with the second lightest one,
which is largely singlet-like. The implications on Z\gamma production rate and
properties of the other Higgs bosons are also studied.
| [
{
"created": "Thu, 6 Dec 2012 11:04:42 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Dec 2012 05:26:27 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Mar 2013 02:24:07 GMT",
"version": "v3"
}
] | 2013-04-10 | [
[
"Cheung",
"Kingman",
""
],
[
"Lu",
"Chih-Ting",
""
],
[
"Yuan",
"Tzu-Chiang",
""
]
] | Motivated by the excess in the diphoton production rate of the Higgs boson at the Large Hadron Collider (LHC), we investigate the possibility that one of the CP-even Higgs bosons of the extra U(1) extended minimal supersymmetric standard model can give a consistent result. We scan the parameter space for a standard-model-like Higgs boson such that the mass is in the range of 124-127 GeV and the production rate \sigma xB of the WW*, ZZ* modes are consistent with the standard model (SM) values while that of \gamma\gamma is enhanced relative to the SM value. We find that the SM-like Higgs boson is mostly the lightest CP-even Higgs boson and it has a strong mixing with the second lightest one, which is largely singlet-like. The implications on Z\gamma production rate and properties of the other Higgs bosons are also studied. |
1207.7068 | Muhammad Adeel Ajaib | M. Adeel Ajaib, Ilia Gogoladze, Qaisar Shafi | Higgs Boson Production and Decay: Effects from Light Third Generation
and Vectorlike Matter | 28 pages, 12 figures | null | 10.1103/PhysRevD.86.095028 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the implications of light third generation sparticles on the
production cross section and decay widths of a light CP-even Higgs boson. For
simplicity, we consider scenarios in which only one of the sfermions from the
third generation is light. For each case, we attempt to explain the apparently
large enhancement in the Higgs production and decay in the diphoton channel
with small deviations in the ZZ channel. In the MSSM framework we find that
only a light stau can explain these observations while keeping the lightest
CP-even Higgs boson mass in the interval 123 GeV \lesssim m_h \lesssim 127 GeV.
For the light stop scenario, the observations related to the diphoton and ZZ
channel can be accommodated but, in order to satisfy the Higgs mass bound, one
needs to go beyond the MSSM. In particular, we invoke vector like particles
with masses around a TeV. These new particles preserve gauge coupling
unification and provide additional contributions to the Higgs mass. With these
new contributions a 126 GeV Higgs mass is easily achieved. We also find that
with only a light sbottom quark, the above mentioned excess is hard to
accommodate.
| [
{
"created": "Mon, 30 Jul 2012 05:17:50 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Ajaib",
"M. Adeel",
""
],
[
"Gogoladze",
"Ilia",
""
],
[
"Shafi",
"Qaisar",
""
]
] | We study the implications of light third generation sparticles on the production cross section and decay widths of a light CP-even Higgs boson. For simplicity, we consider scenarios in which only one of the sfermions from the third generation is light. For each case, we attempt to explain the apparently large enhancement in the Higgs production and decay in the diphoton channel with small deviations in the ZZ channel. In the MSSM framework we find that only a light stau can explain these observations while keeping the lightest CP-even Higgs boson mass in the interval 123 GeV \lesssim m_h \lesssim 127 GeV. For the light stop scenario, the observations related to the diphoton and ZZ channel can be accommodated but, in order to satisfy the Higgs mass bound, one needs to go beyond the MSSM. In particular, we invoke vector like particles with masses around a TeV. These new particles preserve gauge coupling unification and provide additional contributions to the Higgs mass. With these new contributions a 126 GeV Higgs mass is easily achieved. We also find that with only a light sbottom quark, the above mentioned excess is hard to accommodate. |
hep-ph/0403308 | Sergei Dubovsky L. | S.L.Dubovsky | Star tracks in the ghost condensate | 20 pages, 2 figures, final version published in JCAP | JCAP 0407 (2004) 009 | 10.1088/1475-7516/2004/07/009 | null | hep-ph astro-ph hep-th | null | We consider the infrared modification of gravity by ghost condensate.
Naively, in this scenario one expects sizeable modification of gravity at
distances of order 1000 km, provided that the characteristic time scale of the
theory is of the order of the Hubble time. However, we argue that this is not
the case. The main physical reason for the conspiracy is a simple fact that the
Earth (and any other object in the Universe) has velocity of at least of order
10^{-3}c with respect to the rest frame of ghost condensate. Combined with
strong retardation effects present in the ghost sector, this fact implies that
no observable modification of the gravitational field of nearby objects occurs.
Instead, the physical manifestation of ghost condensate is the presence of
``star tracks'' -- narrow regions of space with growing gravitational and ghost
fields inside -- along the trajectory of any massive object. We briefly discuss
the possibilities to observe these tracks.
| [
{
"created": "Wed, 31 Mar 2004 20:01:56 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jul 2004 14:10:09 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Dubovsky",
"S. L.",
""
]
] | We consider the infrared modification of gravity by ghost condensate. Naively, in this scenario one expects sizeable modification of gravity at distances of order 1000 km, provided that the characteristic time scale of the theory is of the order of the Hubble time. However, we argue that this is not the case. The main physical reason for the conspiracy is a simple fact that the Earth (and any other object in the Universe) has velocity of at least of order 10^{-3}c with respect to the rest frame of ghost condensate. Combined with strong retardation effects present in the ghost sector, this fact implies that no observable modification of the gravitational field of nearby objects occurs. Instead, the physical manifestation of ghost condensate is the presence of ``star tracks'' -- narrow regions of space with growing gravitational and ghost fields inside -- along the trajectory of any massive object. We briefly discuss the possibilities to observe these tracks. |
2206.05811 | Divya Sachdeva | Priyotosh Bandyopadhyay, Debajyoti Choudhury, Divya Sachdeva | Semi-Annihilation of Fermionic Dark Matter | 22 pages, 7 figures | null | 10.1103/PhysRevD.107.015020 | null | hep-ph | http://creativecommons.org/licenses/by-sa/4.0/ | The continued non-observation of events emanating from dark matter (DM)
annihilations in various direct and indirect detection experiments calls into
question the mechanism for determining the relic density of a weakly
interacting massive particle. However, if the relic density is determined
primarily by a semi-annihilation process, as opposed to the usual annihilation,
this tension can be ameliorated. Here, we investigate a Z3 symmetric effective
field theory incorporating a fermionic dark matter that semi-annihilates to
right-handed neutrinos (RHN). The dynamics of the RHN and the impact of its
late decays are also scrutinised while obtaining the correct DM relic. Finally,
indirect detection bounds on the semi-annihilation cross-sections are drawn
from the gamma-ray observations in the direction of Dwarf Spheroidal Galaxies
(Fermi-LAT), and including the projections obtained for the H.E.S.S. and the
CTA detectors.
| [
{
"created": "Sun, 12 Jun 2022 18:28:24 GMT",
"version": "v1"
}
] | 2023-02-08 | [
[
"Bandyopadhyay",
"Priyotosh",
""
],
[
"Choudhury",
"Debajyoti",
""
],
[
"Sachdeva",
"Divya",
""
]
] | The continued non-observation of events emanating from dark matter (DM) annihilations in various direct and indirect detection experiments calls into question the mechanism for determining the relic density of a weakly interacting massive particle. However, if the relic density is determined primarily by a semi-annihilation process, as opposed to the usual annihilation, this tension can be ameliorated. Here, we investigate a Z3 symmetric effective field theory incorporating a fermionic dark matter that semi-annihilates to right-handed neutrinos (RHN). The dynamics of the RHN and the impact of its late decays are also scrutinised while obtaining the correct DM relic. Finally, indirect detection bounds on the semi-annihilation cross-sections are drawn from the gamma-ray observations in the direction of Dwarf Spheroidal Galaxies (Fermi-LAT), and including the projections obtained for the H.E.S.S. and the CTA detectors. |
1302.3656 | Igor Ivanov | I. P. Ivanov, L. Lavoura | Geometrical CP violation in the N-Higgs-doublet model | 17 pages, no figures; v2: more comments on symmetries, minor
corrections, matches the published version | Eur. Phys. J. C 73, 2416 (2013) | 10.1140/epjc/s10052-013-2416-8 | CFTP/13-004 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Geometrical CP violation is a particular type of spontaneous CP violation in
which the vacuum expectation values have phases which are calculable, i.e.
stable against the variation of the free parameters of the scalar potential.
Although originally suggested within a specific version of the
three-Higgs-doublet model, it is a generic phenomenon. We investigate its
viability and characteristic features in models with several Higgs doublets.
Our work contains both general results and illustrative examples.
| [
{
"created": "Fri, 15 Feb 2013 01:11:46 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Apr 2013 18:21:02 GMT",
"version": "v2"
}
] | 2013-04-30 | [
[
"Ivanov",
"I. P.",
""
],
[
"Lavoura",
"L.",
""
]
] | Geometrical CP violation is a particular type of spontaneous CP violation in which the vacuum expectation values have phases which are calculable, i.e. stable against the variation of the free parameters of the scalar potential. Although originally suggested within a specific version of the three-Higgs-doublet model, it is a generic phenomenon. We investigate its viability and characteristic features in models with several Higgs doublets. Our work contains both general results and illustrative examples. |
2012.12211 | Peter Stangl | Peter Stangl | smelli -- the SMEFT Likelihood | 17 pages, 1 figure. To be published in the proceedings of "Tools for
High Energy Physics and Cosmology - TOOLS2020", Lyon, France. Repository at
https://github.com/smelli/smelli | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I present the Python package smelli that implements a global likelihood
function in the space of dimension-six Wilson coefficients in the Standard
Model Effective Field Theory (SMEFT). The likelihood includes contributions
from a large number of flavor and other precision observables, currently 399 in
total.
| [
{
"created": "Tue, 22 Dec 2020 17:54:31 GMT",
"version": "v1"
}
] | 2020-12-23 | [
[
"Stangl",
"Peter",
""
]
] | I present the Python package smelli that implements a global likelihood function in the space of dimension-six Wilson coefficients in the Standard Model Effective Field Theory (SMEFT). The likelihood includes contributions from a large number of flavor and other precision observables, currently 399 in total. |
hep-ph/9409458 | Mariano Quiros | J.A. Casas, J.R. Espinosa and M. Quiros | Improved Higgs Mass Stability Bound in the Standard Model and
Implications for Supersymmetry | 11 pages + 7 postscript figures appended at the end, Latex,
IEM-FT-93/94 | Phys.Lett. B342 (1995) 171-179 | 10.1016/0370-2693(94)01404-Z | null | hep-ph | null | We re-examine the lower bound on the mass of the Higgs boson, $M_H$, from
Standard Model vacuum stability including next-to-leading-log radiative
corrections. This amounts to work with the full one-loop effective potential,
$V(\phi)$, improved by two-loop RGE, and allows to keep control of the scale
invariance of $V$ in a wide range of the $\phi$-field. Our results show that
the bound is ${\cal O}\ (10\ GeV)$ less stringent than in previous estimates.
In addition we perform a detailed comparison between the SM lower bounds on
$M_H$ and the supersymmetric upper bounds on it. It turns out that depending on
the actual value of the top mass, $M_t$, the eventually measured Higgs mass can
discard the pure SM, the Minimal Supersymmetric Standard Model or both.
| [
{
"created": "Fri, 30 Sep 1994 15:54:28 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Casas",
"J. A.",
""
],
[
"Espinosa",
"J. R.",
""
],
[
"Quiros",
"M.",
""
]
] | We re-examine the lower bound on the mass of the Higgs boson, $M_H$, from Standard Model vacuum stability including next-to-leading-log radiative corrections. This amounts to work with the full one-loop effective potential, $V(\phi)$, improved by two-loop RGE, and allows to keep control of the scale invariance of $V$ in a wide range of the $\phi$-field. Our results show that the bound is ${\cal O}\ (10\ GeV)$ less stringent than in previous estimates. In addition we perform a detailed comparison between the SM lower bounds on $M_H$ and the supersymmetric upper bounds on it. It turns out that depending on the actual value of the top mass, $M_t$, the eventually measured Higgs mass can discard the pure SM, the Minimal Supersymmetric Standard Model or both. |
hep-ph/9806425 | Francois Gelis | Francois Gelis | Ambiguities in the zero momentum limit of the thermal
$\pi^o\gamma\gamma$ triangle diagram | LaTeX2e file (makes use of the graphics package, 25 pages), 5
postscript figures | Phys.Rev. D59 (1999) 076004 | 10.1103/PhysRevD.59.076004 | LAPTH-689/98 | hep-ph | null | Modifications of the $\pi^o\to 2\gamma$ decay amplitude by thermal effects
have already been considered by several authors, leading to quite different
results. I consider in this paper the triangle diagram connecting a neutral
pion to two photons in a constituent quark model, within the real-time
formulation of thermal field theory and study the zero external momentum limit
of this diagram. It appears that this limit is not unique and depends strongly
on the kinematical configuration of the external particles. This non-uniqueness
is shown to explain the contradiction between existing results. I end with some
considerations suggesting that this decay amplitude may be significantly
modified by the resummation of hard thermal loops, due to infrared
singularities.
| [
{
"created": "Fri, 19 Jun 1998 17:16:04 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Gelis",
"Francois",
""
]
] | Modifications of the $\pi^o\to 2\gamma$ decay amplitude by thermal effects have already been considered by several authors, leading to quite different results. I consider in this paper the triangle diagram connecting a neutral pion to two photons in a constituent quark model, within the real-time formulation of thermal field theory and study the zero external momentum limit of this diagram. It appears that this limit is not unique and depends strongly on the kinematical configuration of the external particles. This non-uniqueness is shown to explain the contradiction between existing results. I end with some considerations suggesting that this decay amplitude may be significantly modified by the resummation of hard thermal loops, due to infrared singularities. |
2402.10239 | Xiangyang Ju | Andris Huang, Yash Melkani, Paolo Calafiura, Alina Lazar, Daniel
Thomas Murnane, Minh-Tuan Pham, Xiangyang Ju | A Language Model for Particle Tracking | 7 pages, 3 figures, A Proceeding of the Connecting the Dots Workshop
(CTD 2023) | null | null | PROC-CTD2023-33 | hep-ph cs.LG hep-ex | http://creativecommons.org/licenses/by-nc-sa/4.0/ | Particle tracking is crucial for almost all physics analysis programs at the
Large Hadron Collider. Deep learning models are pervasively used in particle
tracking related tasks. However, the current practice is to design and train
one deep learning model for one task with supervised learning techniques. The
trained models work well for tasks they are trained on but show no or little
generalization capabilities. We propose to unify these models with a language
model. In this paper, we present a tokenized detector representation that
allows us to train a BERT model for particle tracking. The trained BERT model,
namely TrackingBERT, offers latent detector module embedding that can be used
for other tasks. This work represents the first step towards developing a
foundational model for particle detector understanding.
| [
{
"created": "Wed, 14 Feb 2024 18:24:49 GMT",
"version": "v1"
}
] | 2024-02-19 | [
[
"Huang",
"Andris",
""
],
[
"Melkani",
"Yash",
""
],
[
"Calafiura",
"Paolo",
""
],
[
"Lazar",
"Alina",
""
],
[
"Murnane",
"Daniel Thomas",
""
],
[
"Pham",
"Minh-Tuan",
""
],
[
"Ju",
"Xiangyang",
""
]
] | Particle tracking is crucial for almost all physics analysis programs at the Large Hadron Collider. Deep learning models are pervasively used in particle tracking related tasks. However, the current practice is to design and train one deep learning model for one task with supervised learning techniques. The trained models work well for tasks they are trained on but show no or little generalization capabilities. We propose to unify these models with a language model. In this paper, we present a tokenized detector representation that allows us to train a BERT model for particle tracking. The trained BERT model, namely TrackingBERT, offers latent detector module embedding that can be used for other tasks. This work represents the first step towards developing a foundational model for particle detector understanding. |
2005.03933 | Motoi Endo | Motoi Endo, Satoshi Mishima | Muon $g-2$ and CKM Unitarity in Extra Lepton Models | 25 pages, 4 figures; version published in JHEP | null | 10.1007/JHEP08(2020)004 | KEK-TH-2215 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the impact of extra leptons on observed tensions in the muon
$g-2$ and the first-row CKM unitarity. By introducing a new SU(2)$_L$ doublet
lepton and a SU(2)$_L$ triplet lepton, we find that both of the tensions can be
explained simultaneously under constraints from electroweak precision
observables and Higgs-boson decays. Our model could be tested by measurements
of $h\to\mu\mu$ at future collider experiments.
| [
{
"created": "Fri, 8 May 2020 09:55:03 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Jul 2020 06:35:16 GMT",
"version": "v2"
}
] | 2020-08-26 | [
[
"Endo",
"Motoi",
""
],
[
"Mishima",
"Satoshi",
""
]
] | We investigate the impact of extra leptons on observed tensions in the muon $g-2$ and the first-row CKM unitarity. By introducing a new SU(2)$_L$ doublet lepton and a SU(2)$_L$ triplet lepton, we find that both of the tensions can be explained simultaneously under constraints from electroweak precision observables and Higgs-boson decays. Our model could be tested by measurements of $h\to\mu\mu$ at future collider experiments. |
1111.0857 | Takayuki Matsuki | Takayuki Matsuki and Koichi Seo | Chiral Particle Decay of Heavy-Light Mesons in a Relativistic Potential
Model | 14pages, 6tables | PhysRevD 85, 014036 (2012) | 10.1103/PhysRevD.85.014036 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Partial decay widths of the heavy-light mesons, $D, D_s, B,$ and $B_s$,
emitting one chiral particle ($\pi$ or $K$) are evaluated in the framework of a
relativistic potential model. Decay amplitudes are calculated by keeping the
Lorentz invariance as far as possible and use has been made of the
Lorentz-boosted relativistic wave functions of the heavy-light mesons. One of
predictions of our calculation is very narrow widths of a few keV for yet
undsicovered $B_s(0^+, 1^+)$ mesons corresponding to ${^{2S+1}L_J}={^3P_0}$ and
$"{^3P_1}"$ assuming their masses to be 5617 and 5682 MeV, respectively, as
calculated in our former paper. In the course of our calculation, new sum rules
are discovered on the decay widths in the limit of $m_Q\to \infty$. Among these
rules, $ \Gamma(D_{s0}^*(2317)\to D_s+\pi)=\Gamma (D_{s1}(2460)\to D_s^*+\pi) $
and $ \Gamma(B_{s0}^*(5615)\to B_s+\pi)=\Gamma (B_{s1}(5679)\to B_s^*+\pi) $
are predicted to hold with a good accuracy.
| [
{
"created": "Thu, 3 Nov 2011 14:43:14 GMT",
"version": "v1"
},
{
"created": "Sat, 24 Dec 2011 03:08:45 GMT",
"version": "v2"
}
] | 2012-02-16 | [
[
"Matsuki",
"Takayuki",
""
],
[
"Seo",
"Koichi",
""
]
] | Partial decay widths of the heavy-light mesons, $D, D_s, B,$ and $B_s$, emitting one chiral particle ($\pi$ or $K$) are evaluated in the framework of a relativistic potential model. Decay amplitudes are calculated by keeping the Lorentz invariance as far as possible and use has been made of the Lorentz-boosted relativistic wave functions of the heavy-light mesons. One of predictions of our calculation is very narrow widths of a few keV for yet undsicovered $B_s(0^+, 1^+)$ mesons corresponding to ${^{2S+1}L_J}={^3P_0}$ and $"{^3P_1}"$ assuming their masses to be 5617 and 5682 MeV, respectively, as calculated in our former paper. In the course of our calculation, new sum rules are discovered on the decay widths in the limit of $m_Q\to \infty$. Among these rules, $ \Gamma(D_{s0}^*(2317)\to D_s+\pi)=\Gamma (D_{s1}(2460)\to D_s^*+\pi) $ and $ \Gamma(B_{s0}^*(5615)\to B_s+\pi)=\Gamma (B_{s1}(5679)\to B_s^*+\pi) $ are predicted to hold with a good accuracy. |
hep-ph/9506201 | Zoltan Ligeti | Anton Kapustin and Zoltan Ligeti | Moments of the photon spectrum in the inclusive $B\to X_s\gamma$ decay | 13 pages, revtex | Phys.Lett. B355 (1995) 318-324 | 10.1016/0370-2693(95)00762-A | CALT-68-1996 | hep-ph | null | The moments of the photon spectrum in the inclusive $B\to X_s\,\gamma$ decay
can be calculated to order $\alpha_s$ accuracy at present, without knowing the
$\alpha_s$ corrections to the effective Hamiltonian. We discuss the standard
model predictions, and how the moments of the photon spectrum are related to
certain matrix elements of the heavy quark effective theory. The sensitivity of
these moments to new physics is small, and they provide a model-independent
determination of the $b$ quark pole mass (at order $\alpha_s$), or
equivalently, the matrix elements $\bar\Lambda$ and $\lambda_1$ of the
effective theory.
| [
{
"created": "Fri, 2 Jun 1995 03:50:46 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Kapustin",
"Anton",
""
],
[
"Ligeti",
"Zoltan",
""
]
] | The moments of the photon spectrum in the inclusive $B\to X_s\,\gamma$ decay can be calculated to order $\alpha_s$ accuracy at present, without knowing the $\alpha_s$ corrections to the effective Hamiltonian. We discuss the standard model predictions, and how the moments of the photon spectrum are related to certain matrix elements of the heavy quark effective theory. The sensitivity of these moments to new physics is small, and they provide a model-independent determination of the $b$ quark pole mass (at order $\alpha_s$), or equivalently, the matrix elements $\bar\Lambda$ and $\lambda_1$ of the effective theory. |
hep-ph/0508221 | Hyun Min Lee | D. M. Ghilencea, Hyun Min Lee | Higher Derivative Operators from Scherk-Schwarz Supersymmetry Breaking
on T^2/Z_2 | 23 pages, LaTeX, one figure, published version in JHEP | JHEP 0512 (2005) 039 | 10.1088/1126-6708/2005/12/039 | DAMTP-2005-71, DESY-05-144 | hep-ph | null | In orbifold compactifications on T^2/Z_2 with Scherk-Schwarz supersymmetry
breaking, it is shown that (brane-localised) superpotential interactions and
(bulk) gauge interactions generate at one-loop higher derivative counterterms
to the mass of the brane (or zero-mode of the bulk) scalar field. These
brane-localised operators are generated by integrating out the bulk modes of
the initial theory which, although supersymmetric, is nevertheless
non-renormalisable. It is argued that such operators, of non-perturbative
origin and not protected by non-renormalisation theorems, are generic in
orbifold compactifications and play a crucial role in the UV behaviour of the
two-point Green function of the scalar field self-energy. Their presence in the
action with unknown coefficients prevents one from making predictions about
physics at (momentum) scales close to/above the compactification scale(s). Our
results extend to the case of two dimensional orbifolds, previous findings for
S^1/Z_2 and S^1/(Z_2 x Z_2') compactifications where brane-localised higher
derivative operators are also dynamically generated at loop level, regardless
of the details of the supersymmetry breaking mechanism. We stress the
importance of these operators for the hierarchy and the cosmological constant
problems in compactified theories.
| [
{
"created": "Sat, 20 Aug 2005 20:31:50 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Dec 2005 14:45:16 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Ghilencea",
"D. M.",
""
],
[
"Lee",
"Hyun Min",
""
]
] | In orbifold compactifications on T^2/Z_2 with Scherk-Schwarz supersymmetry breaking, it is shown that (brane-localised) superpotential interactions and (bulk) gauge interactions generate at one-loop higher derivative counterterms to the mass of the brane (or zero-mode of the bulk) scalar field. These brane-localised operators are generated by integrating out the bulk modes of the initial theory which, although supersymmetric, is nevertheless non-renormalisable. It is argued that such operators, of non-perturbative origin and not protected by non-renormalisation theorems, are generic in orbifold compactifications and play a crucial role in the UV behaviour of the two-point Green function of the scalar field self-energy. Their presence in the action with unknown coefficients prevents one from making predictions about physics at (momentum) scales close to/above the compactification scale(s). Our results extend to the case of two dimensional orbifolds, previous findings for S^1/Z_2 and S^1/(Z_2 x Z_2') compactifications where brane-localised higher derivative operators are also dynamically generated at loop level, regardless of the details of the supersymmetry breaking mechanism. We stress the importance of these operators for the hierarchy and the cosmological constant problems in compactified theories. |
1005.3209 | Dalibor Kekez | R. Horvat, D. Kekez, J. Trampetic | Spacetime noncommutativity and ultra-high energy cosmic ray experiments | v2: 5 pages, 2 eps figures; discussion expanded, some errors
corrected; to appear in Phys.Rev. D | Phys.Rev.D83:065013,2011 | 10.1103/PhysRevD.83.065013 | null | hep-ph astro-ph.HE hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If new physics were capable to push the neutrino-nucleon inelastic cross
section three orders of magnitude beyond the standard-model (SM) prediction,
then ultra-high energy (UHE) neutrinos would have already been observed at
neutrino observatories. We use such a constraint to reveal information on the
scale of noncommutativity (NC) Lambda_NC in noncommutative gauge field theories
(NCGFT) where neutrinos possess a tree-level coupling to photons in a
generation-independent manner. In the energy range of interest (10^10 to 10^11
GeV) the theta-expansion (|theta| ~ 1/Lambda_NC^2) and therefore the
perturbative expansion in terms of Lambda_NC retains no longer its meaningful
character, forcing us to resort to those NC field-theoretical frameworks
involving the full theta-resummation. Our numerical analysis of the
contribution to the process coming from the photon exchange, pins impeccably
down a lower bound on Lambda_NC to be as high as around up to 900 (450) TeV,
depending on the estimates for the cosmogenic neutrino flux. If, on the other
hand, one considers a surprising recent result occurred in Pierre Auger
Observatory (PAO) data, that UHE cosmic rays are mainly composed of
highly-ionized Fe nuclei, then our bounds get weaker, due to the diminished
cosmic neutrino flux. Nevertheless, we show that even for the very high
fraction of heavy nuclei in primary UHE cosmic rays, our method may still yield
remarkable bounds on Lambda_NC, typically always above 200 TeV. Albeit, in this
case one encounters a maximal value for the Fe fraction from which any useful
information on Lambda_NC can be drawn, delimiting thus the applicability of our
method.
| [
{
"created": "Tue, 18 May 2010 14:33:06 GMT",
"version": "v1"
},
{
"created": "Sun, 13 Feb 2011 17:12:40 GMT",
"version": "v2"
}
] | 2011-03-22 | [
[
"Horvat",
"R.",
""
],
[
"Kekez",
"D.",
""
],
[
"Trampetic",
"J.",
""
]
] | If new physics were capable to push the neutrino-nucleon inelastic cross section three orders of magnitude beyond the standard-model (SM) prediction, then ultra-high energy (UHE) neutrinos would have already been observed at neutrino observatories. We use such a constraint to reveal information on the scale of noncommutativity (NC) Lambda_NC in noncommutative gauge field theories (NCGFT) where neutrinos possess a tree-level coupling to photons in a generation-independent manner. In the energy range of interest (10^10 to 10^11 GeV) the theta-expansion (|theta| ~ 1/Lambda_NC^2) and therefore the perturbative expansion in terms of Lambda_NC retains no longer its meaningful character, forcing us to resort to those NC field-theoretical frameworks involving the full theta-resummation. Our numerical analysis of the contribution to the process coming from the photon exchange, pins impeccably down a lower bound on Lambda_NC to be as high as around up to 900 (450) TeV, depending on the estimates for the cosmogenic neutrino flux. If, on the other hand, one considers a surprising recent result occurred in Pierre Auger Observatory (PAO) data, that UHE cosmic rays are mainly composed of highly-ionized Fe nuclei, then our bounds get weaker, due to the diminished cosmic neutrino flux. Nevertheless, we show that even for the very high fraction of heavy nuclei in primary UHE cosmic rays, our method may still yield remarkable bounds on Lambda_NC, typically always above 200 TeV. Albeit, in this case one encounters a maximal value for the Fe fraction from which any useful information on Lambda_NC can be drawn, delimiting thus the applicability of our method. |
hep-ph/0510116 | Valery Lyubovitskij | J. Kuckei, Claudio Dib, Amand Faessler, Th. Gutsche, Sergey Kovalenko,
V.E. Lyubovitskij, K. Pumsa-ard | Strong CP violation and the neutron electric dipole form factor | 18 pages, 2 figures, accepted for publication in Phys. Atom. Nucl | Phys.Atom.Nucl. 70 (2007) 349-357 | 10.1134/S1063778807020160 | null | hep-ph | null | We calculate the neutron electric dipole form factor induced by the CP
violating theta-term of QCD, within a perturbative chiral quark model which
includes pion and kaon clouds. On this basis we derive the neutron electric
dipole moment and the electron-neutron Schiff moment. From the existing
experimental upper limits on the neutron electric dipole moment we extract
constraints on the theta-parameter and compare our results with other
approaches.
| [
{
"created": "Mon, 10 Oct 2005 13:00:13 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Jun 2006 06:47:14 GMT",
"version": "v2"
}
] | 2015-06-25 | [
[
"Kuckei",
"J.",
""
],
[
"Dib",
"Claudio",
""
],
[
"Faessler",
"Amand",
""
],
[
"Gutsche",
"Th.",
""
],
[
"Kovalenko",
"Sergey",
""
],
[
"Lyubovitskij",
"V. E.",
""
],
[
"Pumsa-ard",
"K.",
""
]
] | We calculate the neutron electric dipole form factor induced by the CP violating theta-term of QCD, within a perturbative chiral quark model which includes pion and kaon clouds. On this basis we derive the neutron electric dipole moment and the electron-neutron Schiff moment. From the existing experimental upper limits on the neutron electric dipole moment we extract constraints on the theta-parameter and compare our results with other approaches. |
hep-ph/0504094 | Javier Ferrandis | J. Lorenzo Diaz-Cruz, Javier Ferrandis | Solving the SUSY CP problem with flavor breaking F-terms | 21 pages, RevTex4 | Phys.Rev.D72:035003,2005 | 10.1103/PhysRevD.72.035003 | LBNL-57358, CAPCyR-FCFM-BUAP-01-05 | hep-ph | null | Supersymmetric flavor models for the radiative generation of fermion masses
offer an alternative way to solve the SUSY-CP problem. We assume that the
supersymmetric theory is flavor and CP conserving. CP violating phases are
associated to the vacuum expectation values of flavor violating susy-breaking
fields. As a consequence, phases appear at tree level only in the soft
supersymmetry breaking matrices. Using a U(2) flavor model as an example we
show that it is possible to generate radiatively the first and second
generation of quark masses and mixings as well as the CKM CP phase. The
one-loop supersymmetric contributions to EDMs are automatically zero since all
the relevant parameters in the lagrangian are flavor conserving and as a
consequence real. The size of the flavor and CP mixing in the susy breaking
sector is mostly determined by the fermion mass ratios and CKM elements. We
calculate the contributions to epsilon, epsilon^{prime} and to the CP
asymmetries in the B decays to psi Ks, phi Ks, eta^{\prime} Ks and Xs gamma. We
analyze a case study with maximal predictivity in the fermion sector. For this
worst case scenario the measurements of Delta mK, Delta mB and epsilon
constrain the model requiring extremely heavy squark spectra.
| [
{
"created": "Wed, 13 Apr 2005 02:07:23 GMT",
"version": "v1"
},
{
"created": "Wed, 11 May 2005 23:51:23 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Diaz-Cruz",
"J. Lorenzo",
""
],
[
"Ferrandis",
"Javier",
""
]
] | Supersymmetric flavor models for the radiative generation of fermion masses offer an alternative way to solve the SUSY-CP problem. We assume that the supersymmetric theory is flavor and CP conserving. CP violating phases are associated to the vacuum expectation values of flavor violating susy-breaking fields. As a consequence, phases appear at tree level only in the soft supersymmetry breaking matrices. Using a U(2) flavor model as an example we show that it is possible to generate radiatively the first and second generation of quark masses and mixings as well as the CKM CP phase. The one-loop supersymmetric contributions to EDMs are automatically zero since all the relevant parameters in the lagrangian are flavor conserving and as a consequence real. The size of the flavor and CP mixing in the susy breaking sector is mostly determined by the fermion mass ratios and CKM elements. We calculate the contributions to epsilon, epsilon^{prime} and to the CP asymmetries in the B decays to psi Ks, phi Ks, eta^{\prime} Ks and Xs gamma. We analyze a case study with maximal predictivity in the fermion sector. For this worst case scenario the measurements of Delta mK, Delta mB and epsilon constrain the model requiring extremely heavy squark spectra. |
hep-ph/0103270 | Moultaka Gilbert | Y. Mambrini, G. Moultaka | Comment on ``Infrared Fixed Point Structure in Minimal Supersymmetric
Standard Model with Baryon and Lepton Number Violation" | Latex, 5 pages, 1 figure | Phys.Rev. D65 (2002) 058901 | 10.1103/PhysRevD.65.058901 | PM/01-14 | hep-ph | null | We reconsider the Infrared Quasi Fixed Points which were studied recently in
the literature in the context of the Baryon and Lepton number violating Minimal
Supersymmetric Standard Model (hep-ph/0011274). The complete analysis requires
further care and reveals more structure than what was previously shown. The
formalism we develop here is quite general, and can be readily applied to a
large class of models.
| [
{
"created": "Sun, 25 Mar 2001 19:37:08 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Mambrini",
"Y.",
""
],
[
"Moultaka",
"G.",
""
]
] | We reconsider the Infrared Quasi Fixed Points which were studied recently in the literature in the context of the Baryon and Lepton number violating Minimal Supersymmetric Standard Model (hep-ph/0011274). The complete analysis requires further care and reveals more structure than what was previously shown. The formalism we develop here is quite general, and can be readily applied to a large class of models. |
1211.1503 | I.V. Danilkin | I. V. Danilkin, M. F. M. Lutz, S. Leupold, C. Terschlusen | Photon-fusion reactions from the chiral Lagrangian with dynamical light
vector mesons | 17 pages, 10 figures, all assumptions used in our method are
clarified | null | 10.1140/epjc/s10052-013-2358-1 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the reactions $\gamma\gamma\rightarrow \pi^0\pi^0$, $\pi^+\pi^-$,
$K^0\bar{K}^0$, $K^+K^-$, $\eta \eta$ and $\pi^0\eta$ based on a chiral
Lagrangian with dynamical light vector mesons as formulated within the
hadrogenesis conjecture. At present our chiral Lagrangian contains 5 unknown
parameters that are relevant for the photon fusion reactions. They parameterize
the strength of interaction terms involving two vector meson fields. These
parameters are fitted to photon fusion data $\gamma\gamma\rightarrow
\pi^0\pi^0$, $\pi^+\pi^-, \pi^0\eta$ and to the decay
$\eta\rightarrow\pi^0\gamma\gamma$. In order to derive gauge invariant reaction
amplitudes in the resonance region constraints from micro-causality and exact
coupled-channel unitarity are used. Our results are in good agreement with the
existing experimental data from threshold up to about 0.9 GeV for the two-pion
final states. The $a_0$ meson in the $\pi^0\eta$ channel is dynamically
generated and an accurate reproduction of the $\gamma\gamma\rightarrow
\pi^0\eta$ data is achieved up to 1.2 GeV. Based on our parameter sets we
predict the $\gamma\gamma\rightarrow $ $K^0\bar{K}^0$, $K^+K^-$, $\eta \eta$
cross sections.
| [
{
"created": "Wed, 7 Nov 2012 10:17:51 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Mar 2013 13:53:28 GMT",
"version": "v2"
}
] | 2015-06-12 | [
[
"Danilkin",
"I. V.",
""
],
[
"Lutz",
"M. F. M.",
""
],
[
"Leupold",
"S.",
""
],
[
"Terschlusen",
"C.",
""
]
] | We study the reactions $\gamma\gamma\rightarrow \pi^0\pi^0$, $\pi^+\pi^-$, $K^0\bar{K}^0$, $K^+K^-$, $\eta \eta$ and $\pi^0\eta$ based on a chiral Lagrangian with dynamical light vector mesons as formulated within the hadrogenesis conjecture. At present our chiral Lagrangian contains 5 unknown parameters that are relevant for the photon fusion reactions. They parameterize the strength of interaction terms involving two vector meson fields. These parameters are fitted to photon fusion data $\gamma\gamma\rightarrow \pi^0\pi^0$, $\pi^+\pi^-, \pi^0\eta$ and to the decay $\eta\rightarrow\pi^0\gamma\gamma$. In order to derive gauge invariant reaction amplitudes in the resonance region constraints from micro-causality and exact coupled-channel unitarity are used. Our results are in good agreement with the existing experimental data from threshold up to about 0.9 GeV for the two-pion final states. The $a_0$ meson in the $\pi^0\eta$ channel is dynamically generated and an accurate reproduction of the $\gamma\gamma\rightarrow \pi^0\eta$ data is achieved up to 1.2 GeV. Based on our parameter sets we predict the $\gamma\gamma\rightarrow $ $K^0\bar{K}^0$, $K^+K^-$, $\eta \eta$ cross sections. |
hep-ph/0401192 | Jozef Dudek | F.E. Close and J.J. Dudek | Pentaquark Symmetries, Selection Rules and another potentially Narrow
State | Revised version, corrects PDF margin problems, minor changes to text | Phys.Lett. B586 (2004) 75-82 | 10.1016/j.physletb.2004.02.023 | null | hep-ph | null | We identify essential differences between the pentaquark and chiral soliton
models of \10bar$_5$ and {\bf 8}$_5$ pentaquarks and conventional {\bf 8}$_3$
states, which are experimentally measurable. We show how the decays of $\Xi_5$
states in particular can test models of the pentaquarks, recommend study of the
relative branching ratios of e.g. $\Xi^{-}_5 \to \Xi^-\pi^0:\Xi^0\pi^-$, and
predict that the decay amplitude $\Xi_5 \to \Xi^*\pi$ is zero at leading order
in pentaquark models for any mixture of \10bar and the associated {\bf 8}$_5$.
We also include a pedagogic discussion of wavefunctions in the pentaquark
picture and show that pentaquark models have this {\bf 8}$_5$ with $F/D=1/3$,
in leading order forbidding $\Xi_5 \to \Lambda K$. The role of Fermi-Dirac
symmetry in the $qqqq$ wavefunction and its implications for the width of
pentaquarks are briefly discussed. The relative couplings $g^2(\Theta_Q N
K_Q^*)/g^2(\Theta_Q N K_Q) = 3$ for $Q \equiv s,c,b$. A further potentially
narrow state $\Lambda$ in {\bf 8}$_5$ with $J^P = 3/2^+$ is predicted around
1650 MeV.
| [
{
"created": "Sat, 24 Jan 2004 13:41:07 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jan 2004 17:14:46 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Close",
"F. E.",
""
],
[
"Dudek",
"J. J.",
""
]
] | We identify essential differences between the pentaquark and chiral soliton models of \10bar$_5$ and {\bf 8}$_5$ pentaquarks and conventional {\bf 8}$_3$ states, which are experimentally measurable. We show how the decays of $\Xi_5$ states in particular can test models of the pentaquarks, recommend study of the relative branching ratios of e.g. $\Xi^{-}_5 \to \Xi^-\pi^0:\Xi^0\pi^-$, and predict that the decay amplitude $\Xi_5 \to \Xi^*\pi$ is zero at leading order in pentaquark models for any mixture of \10bar and the associated {\bf 8}$_5$. We also include a pedagogic discussion of wavefunctions in the pentaquark picture and show that pentaquark models have this {\bf 8}$_5$ with $F/D=1/3$, in leading order forbidding $\Xi_5 \to \Lambda K$. The role of Fermi-Dirac symmetry in the $qqqq$ wavefunction and its implications for the width of pentaquarks are briefly discussed. The relative couplings $g^2(\Theta_Q N K_Q^*)/g^2(\Theta_Q N K_Q) = 3$ for $Q \equiv s,c,b$. A further potentially narrow state $\Lambda$ in {\bf 8}$_5$ with $J^P = 3/2^+$ is predicted around 1650 MeV. |
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