id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1512.07591 | Fernando Febres Cordero | F. Febres Cordero, P. Hofmann and H. Ita | $W^+W^-$ + 3 Jet Production at the Large Hadron Collider in NLO QCD | null | Phys. Rev. D 95, 034006 (2017) | 10.1103/PhysRevD.95.034006 | FR-PHENO-2015-005 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present next-to-leading order (NLO) QCD predictions to $W^+W^-$ production
in association with up to three jets at hadron colliders. We include
contributions from couplings of the $W$ bosons to light quarks as well as
trilinear vector couplings. These processes are used in vector-boson coupling
measurements, are background to Higgs signals and are needed to constrain many
new physics scenarios. For the first time NLO QCD predictions are shown for
electroweak di-vector boson production with three jets at a hadron collider. We
show total and differential cross sections for the LHC with proton
center-of-mass energies of 8 and 13 TeV. To perform the calculation we employ
on-shell and unitarity methods implemented in the BlackHat library along with
the SHERPA package. We have produced event files that can be accessed for
future dedicated studies.
| [
{
"created": "Wed, 23 Dec 2015 19:14:37 GMT",
"version": "v1"
}
] | 2017-02-15 | [
[
"Cordero",
"F. Febres",
""
],
[
"Hofmann",
"P.",
""
],
[
"Ita",
"H.",
""
]
] | We present next-to-leading order (NLO) QCD predictions to $W^+W^-$ production in association with up to three jets at hadron colliders. We include contributions from couplings of the $W$ bosons to light quarks as well as trilinear vector couplings. These processes are used in vector-boson coupling measurements, are background to Higgs signals and are needed to constrain many new physics scenarios. For the first time NLO QCD predictions are shown for electroweak di-vector boson production with three jets at a hadron collider. We show total and differential cross sections for the LHC with proton center-of-mass energies of 8 and 13 TeV. To perform the calculation we employ on-shell and unitarity methods implemented in the BlackHat library along with the SHERPA package. We have produced event files that can be accessed for future dedicated studies. |
1206.3815 | Li-Hua Song | Li-Hua Song, Chun-Gui Duan, Na Liu | Systematic analysis of the incoming quark energy loss in cold nuclear
matter | null | null | 10.1016/j.physletb.2012.01.019 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The investigation into the fast parton energy loss in cold nuclear matter is
crucial for a good understanding of the parton propagation in hot-dense medium.
By means of four typical sets of nuclear parton distributions and three
parametrizations of quark energy loss, the parameter values in quark energy
loss expressions are determined from a leading order statistical analysis of
the existing experimental data on nuclear Drell-Yan differential cross section
ratio as a function of the quark momentum fraction. It is found that with
independence on the nuclear modification of parton distributions, the available
experimental data from lower incident beam energy rule out the incident-parton
momentum fraction quark energy loss. Whether the quark energy loss is linear or
quadratic with the path length is not discriminated. The global fit of all
selected data gives the quark energy loss per unit path length {\alpha} =
1.21\pm0.09 GeV/fm by using nuclear parton distribution functions determined
only by means of the world data on nuclear structure function. Our result does
not support the theoretical prediction: the energy loss of an outgoing quark is
three times larger than that of an incoming quark approaching the nuclear
medium. It is desirable that the present work can provide useful reference for
the Fermilab E906/SeaQuest experiment.
| [
{
"created": "Mon, 18 Jun 2012 02:19:43 GMT",
"version": "v1"
}
] | 2012-06-19 | [
[
"Song",
"Li-Hua",
""
],
[
"Duan",
"Chun-Gui",
""
],
[
"Liu",
"Na",
""
]
] | The investigation into the fast parton energy loss in cold nuclear matter is crucial for a good understanding of the parton propagation in hot-dense medium. By means of four typical sets of nuclear parton distributions and three parametrizations of quark energy loss, the parameter values in quark energy loss expressions are determined from a leading order statistical analysis of the existing experimental data on nuclear Drell-Yan differential cross section ratio as a function of the quark momentum fraction. It is found that with independence on the nuclear modification of parton distributions, the available experimental data from lower incident beam energy rule out the incident-parton momentum fraction quark energy loss. Whether the quark energy loss is linear or quadratic with the path length is not discriminated. The global fit of all selected data gives the quark energy loss per unit path length {\alpha} = 1.21\pm0.09 GeV/fm by using nuclear parton distribution functions determined only by means of the world data on nuclear structure function. Our result does not support the theoretical prediction: the energy loss of an outgoing quark is three times larger than that of an incoming quark approaching the nuclear medium. It is desirable that the present work can provide useful reference for the Fermilab E906/SeaQuest experiment. |
1402.0975 | Xing-Gang Wu | Sheng-Quan Wang, Xing-Gang Wu, Jian-Ming Shen, Hua-Yong Han and Yang
Ma | The QCD improved electroweak parameter $\rho$ | 8 pages, 2 figures. Discussions improved. To be published in
Phys.Rev.D | Phys. Rev. D 89, 116001 (2014) | 10.1103/PhysRevD.89.116001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the present paper, we make a detailed analysis for the QCD corrections to
the electroweak $\rho$ parameter by applying the principle of maximum
conformality (PMC). As a comparison, we show that under the conventional scale
setting, we have $\Delta\rho|_{\rm N^3LO} =
\left(8.257^{+0.045}_{-0.012}\right) \times10^{-3}$ by varying the scale
$\mu_{r}\in[M_{t}/2$, $2M_{t}]$. By defining a ratio, $\Delta
R=\Delta\rho/3X_t-1$, which shows the relative importance of the QCD
corrections, it is found that its scale error is $\sim \pm9 \%$ at the two-loop
level, which changes to $\sim\pm4\%$ at the three-loop level and $\sim \pm
2.5\%$ at the four-loop level, respectively. These facts well explain why the
conventional scale uncertainty constitutes an important error for estimating
the $\rho$ parameter. On the other hand, by applying the PMC scale setting, the
four-loop estimation $\Delta\rho|_{\rm N^3LO}$ shall be almost fixed to
$8.228\times10^{-3}$, which indicates that the conventional scale error has
been eliminated. We observe the pQCD convergence for the $\rho$ parameter has
also been greatly improved due to the elimination of the divergent renormalon
terms. As applications of the present QCD improved $\rho$ parameter, we show
the shifts of the $W$-boson mass and the effective leptonic weak-mixing angle
due to $\Delta\rho$ can be reduced to $\delta M_{W}|_{\rm N^3LO} =0.7$ MeV and
$\delta \sin^2{\theta}_{\rm eff}|_{\rm N^3LO}=-0.4\times10^{-5}$.
| [
{
"created": "Wed, 5 Feb 2014 08:58:19 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Feb 2014 08:31:13 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Apr 2014 00:03:14 GMT",
"version": "v3"
},
{
"created": "Wed, 21 May 2014 00:41:16 GMT",
"version": "v4"
}
] | 2014-06-04 | [
[
"Wang",
"Sheng-Quan",
""
],
[
"Wu",
"Xing-Gang",
""
],
[
"Shen",
"Jian-Ming",
""
],
[
"Han",
"Hua-Yong",
""
],
[
"Ma",
"Yang",
""
]
] | In the present paper, we make a detailed analysis for the QCD corrections to the electroweak $\rho$ parameter by applying the principle of maximum conformality (PMC). As a comparison, we show that under the conventional scale setting, we have $\Delta\rho|_{\rm N^3LO} = \left(8.257^{+0.045}_{-0.012}\right) \times10^{-3}$ by varying the scale $\mu_{r}\in[M_{t}/2$, $2M_{t}]$. By defining a ratio, $\Delta R=\Delta\rho/3X_t-1$, which shows the relative importance of the QCD corrections, it is found that its scale error is $\sim \pm9 \%$ at the two-loop level, which changes to $\sim\pm4\%$ at the three-loop level and $\sim \pm 2.5\%$ at the four-loop level, respectively. These facts well explain why the conventional scale uncertainty constitutes an important error for estimating the $\rho$ parameter. On the other hand, by applying the PMC scale setting, the four-loop estimation $\Delta\rho|_{\rm N^3LO}$ shall be almost fixed to $8.228\times10^{-3}$, which indicates that the conventional scale error has been eliminated. We observe the pQCD convergence for the $\rho$ parameter has also been greatly improved due to the elimination of the divergent renormalon terms. As applications of the present QCD improved $\rho$ parameter, we show the shifts of the $W$-boson mass and the effective leptonic weak-mixing angle due to $\Delta\rho$ can be reduced to $\delta M_{W}|_{\rm N^3LO} =0.7$ MeV and $\delta \sin^2{\theta}_{\rm eff}|_{\rm N^3LO}=-0.4\times10^{-5}$. |
1907.12202 | Gang Li | Ju-Jun Xie, Gang Li, and Xiao-Hai Liu | Radiative decays of $f_1(1285)$ as the $ K^*\bar K$ molecular state | 5 pages, 3 figures | null | 10.1088/1674-1137/abae51 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within a picture of the $f_1(1285)$ being a dynamically generated resonance
from the $ K^*\bar K$ interactions, we estimate the rates for the radiative
transitions of the $f_1(1285)$ meson to the vector mesons $\rho^0$,$\omega$ and
$\phi$. These radiative decays proceed via the kaon loop diagrams. The
calculated results are in fair agreement with the experimental measurements.
Some predictions can be tested by experiments and their implementation and
comparison with these predictions will be valuable to decode the nature of the
$f_1(1285)$ state.
| [
{
"created": "Mon, 29 Jul 2019 03:55:40 GMT",
"version": "v1"
}
] | 2020-12-02 | [
[
"Xie",
"Ju-Jun",
""
],
[
"Li",
"Gang",
""
],
[
"Liu",
"Xiao-Hai",
""
]
] | Within a picture of the $f_1(1285)$ being a dynamically generated resonance from the $ K^*\bar K$ interactions, we estimate the rates for the radiative transitions of the $f_1(1285)$ meson to the vector mesons $\rho^0$,$\omega$ and $\phi$. These radiative decays proceed via the kaon loop diagrams. The calculated results are in fair agreement with the experimental measurements. Some predictions can be tested by experiments and their implementation and comparison with these predictions will be valuable to decode the nature of the $f_1(1285)$ state. |
2307.09460 | Gonzalo Herrera | Gonzalo Herrera, Kohta Murase | Probing Light Dark Matter through Cosmic-Ray Cooling in Active Galactic
Nuclei | Matches published version in PRD as a Letter. Extended discussion on
the adiabatic growth assumption of the SMBH of NGC 1068 and TXS 0506+056, and
on the uncertainties on the DM distribution. Extended discussion on the
parameter space of thermal and non-thermal light DM that we are able to
probe, and comparison of our constraints with complementary bounds on light
scalar mediators | Phys.Rev.D 110 (2024) L011701 | 10.1103/PhysRevD.110.L011701 | null | hep-ph astro-ph.GA astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent observations of high-energy neutrinos from active galactic nuclei
(AGN), NGC 1068 and TXS 0506+056, suggest that cosmic rays (CRs) are
accelerated in the vicinity of the central supermassive black hole and
high-energy protons and electrons can cool efficiently via interactions with
ambient photons and gas. The dark matter density may be significantly enhanced
near the central black hole, and CRs could lose energies predominantly due to
scatterings with the ambient dark matter particles. We propose CR cooling in
AGN as a new probe of dark matter-proton and dark matter-electron scatterings.
Under plausible astrophysical assumptions, our constraints on sub-GeV dark
matter can be the strongest derived to date. Some of the parameter space
favored by thermal light dark matter models might already be probed with
current multimessenger observations of AGN.
| [
{
"created": "Tue, 18 Jul 2023 17:43:09 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Jul 2024 10:50:18 GMT",
"version": "v2"
}
] | 2024-07-25 | [
[
"Herrera",
"Gonzalo",
""
],
[
"Murase",
"Kohta",
""
]
] | Recent observations of high-energy neutrinos from active galactic nuclei (AGN), NGC 1068 and TXS 0506+056, suggest that cosmic rays (CRs) are accelerated in the vicinity of the central supermassive black hole and high-energy protons and electrons can cool efficiently via interactions with ambient photons and gas. The dark matter density may be significantly enhanced near the central black hole, and CRs could lose energies predominantly due to scatterings with the ambient dark matter particles. We propose CR cooling in AGN as a new probe of dark matter-proton and dark matter-electron scatterings. Under plausible astrophysical assumptions, our constraints on sub-GeV dark matter can be the strongest derived to date. Some of the parameter space favored by thermal light dark matter models might already be probed with current multimessenger observations of AGN. |
0805.2623 | Ken Hsieh | Stefano Di Chiara, Ken Hsieh | Triplet Extended Supersymmetric Standard Model | 26 pages, 19 figures. Errors on the RGEs corrected and consequential
changes applied. Plots updated and discussion broadened. Version to appear in
PRD | Phys.Rev.D78:055016,2008 | 10.1103/PhysRevD.78.055016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit an extension of the MSSM by adding a hypercharge-neutral,
SU(2)-triplet chiral superfield. Similar to the NMSSM, the triplet gives an
additional contribution to the quartic coupling in the Higgs potential, and the
mass of the lightest CP-even Higgs boson can be greater than tne mass of the
Z-bosn at tree-level. In addition to discussing the perturbativity,
fine-tuning, and decoupling issues of this model, we compute the dominant
1-loop corrections to the mass of the lightest CP-even Higgs boson from the
triplet sector. When the Higgs-Higgs-Triplet coupling in the superpotential is
comparable to the top Yukawa coupling, we find that the Higgs mass can be as
heavy as 140 GeV even without the traditional contributions from the top--s-top
sector, and at the same time consistent with the precision electroweak
constraints. At the expense of having Landau poles before the GUT scale, this
opens up a previously forbidden region in the MSSM parameter space where both
s-tops are light. In addition to having relatively small fine-tuning (about one
part in 30), this leads to a gluo-philic Higgs boson whose production via
gluon-gluon fusion at the LHC can be twice as large as the SM prediction.
| [
{
"created": "Fri, 16 May 2008 21:20:59 GMT",
"version": "v1"
},
{
"created": "Fri, 30 May 2008 17:26:24 GMT",
"version": "v2"
},
{
"created": "Sun, 29 Jun 2008 21:11:12 GMT",
"version": "v3"
},
{
"created": "Mon, 8 Sep 2008 18:49:43 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Di Chiara",
"Stefano",
""
],
[
"Hsieh",
"Ken",
""
]
] | We revisit an extension of the MSSM by adding a hypercharge-neutral, SU(2)-triplet chiral superfield. Similar to the NMSSM, the triplet gives an additional contribution to the quartic coupling in the Higgs potential, and the mass of the lightest CP-even Higgs boson can be greater than tne mass of the Z-bosn at tree-level. In addition to discussing the perturbativity, fine-tuning, and decoupling issues of this model, we compute the dominant 1-loop corrections to the mass of the lightest CP-even Higgs boson from the triplet sector. When the Higgs-Higgs-Triplet coupling in the superpotential is comparable to the top Yukawa coupling, we find that the Higgs mass can be as heavy as 140 GeV even without the traditional contributions from the top--s-top sector, and at the same time consistent with the precision electroweak constraints. At the expense of having Landau poles before the GUT scale, this opens up a previously forbidden region in the MSSM parameter space where both s-tops are light. In addition to having relatively small fine-tuning (about one part in 30), this leads to a gluo-philic Higgs boson whose production via gluon-gluon fusion at the LHC can be twice as large as the SM prediction. |
1610.01996 | Wan-Zhe Feng | Wan-Zhe Feng, Pran Nath | Baryogenesis and Dark Matter in $U(1)$ Extensions | 10 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1312.1334 | Mod. Phys. Lett. A 32, 1740005 (2017) | 10.1142/S0217732317400053 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A brief review is given of some recent works where baryogenesis and dark
matter have a common origin within the $U(1)$ extensions of the standard model
and of the minimal supersymmetric standard model. The models considered
generate the desired baryon asymmetry and the dark matter to baryon ratio. In
one model all of the fundamental interactions do not violate lepton number, and
the total $B-L$ in the Universe vanishes. In addition, one may also generate a
normal hierarchy of neutrino masses and mixings in conformity with the current
data. Specifically one can accommodate $\theta_{13}\sim 9^{\circ}$ consistent
with the data from Daya Bay reactor neutrino experiment.
| [
{
"created": "Thu, 6 Oct 2016 19:09:00 GMT",
"version": "v1"
}
] | 2017-05-31 | [
[
"Feng",
"Wan-Zhe",
""
],
[
"Nath",
"Pran",
""
]
] | A brief review is given of some recent works where baryogenesis and dark matter have a common origin within the $U(1)$ extensions of the standard model and of the minimal supersymmetric standard model. The models considered generate the desired baryon asymmetry and the dark matter to baryon ratio. In one model all of the fundamental interactions do not violate lepton number, and the total $B-L$ in the Universe vanishes. In addition, one may also generate a normal hierarchy of neutrino masses and mixings in conformity with the current data. Specifically one can accommodate $\theta_{13}\sim 9^{\circ}$ consistent with the data from Daya Bay reactor neutrino experiment. |
1906.04389 | Heikki M\"antysaari | Heikki M\"antysaari and Niklas Mueller and Bj\"orn Schenke | Diffractive dijet production from the Color Glass Condensate and the
small-$x$ gluon distributions | 5 pages, 4 figures. Talk by H.M. at DIS2019 | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study exclusive dijet production in electron-proton deep inelastic
scattering at a future Electron Ion Collider. We predict the elliptic
modulation of the cross section as a function of the angle between the dijet
transverse momentum and the recoil momentum, and show that this modulation is
due to non-trivial angular correlations between the transverse coordinate and
transverse momentum in the Wigner (or Husimi) distribution. The small-$x$
evolution is shown to decrease the elliptic modulation in the EIC kinematics,
because of the growth of the proton with decreasing $x$.
| [
{
"created": "Tue, 11 Jun 2019 04:33:13 GMT",
"version": "v1"
}
] | 2019-06-12 | [
[
"Mäntysaari",
"Heikki",
""
],
[
"Mueller",
"Niklas",
""
],
[
"Schenke",
"Björn",
""
]
] | We study exclusive dijet production in electron-proton deep inelastic scattering at a future Electron Ion Collider. We predict the elliptic modulation of the cross section as a function of the angle between the dijet transverse momentum and the recoil momentum, and show that this modulation is due to non-trivial angular correlations between the transverse coordinate and transverse momentum in the Wigner (or Husimi) distribution. The small-$x$ evolution is shown to decrease the elliptic modulation in the EIC kinematics, because of the growth of the proton with decreasing $x$. |
1311.2078 | Gero von Gersdorff | Gero von Gersdorff | Flavor Physics in Warped Space | Invited review for IJMPA. 13 pages, 2 tables | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review constraints from quark and lepton flavor violation on extra
dimensional models with warped geometry, both in the minimal and the custodial
model. For both scenarios, KK masses that are large enough to suppress
constraints from electroweak precision tests also sufficiently suppress all
quark flavor and CP violation, with the exception of CP violation in $K\bar K$
mixing and (to a lesser extend) in $D\bar D$ mixing. In the lepton sector the
minimal scenario leads to excessively large contributions to $\mu\to e\gamma$
transitions, requiring KK masses of at least 20 TeV or larger.
| [
{
"created": "Fri, 8 Nov 2013 21:00:47 GMT",
"version": "v1"
}
] | 2013-11-12 | [
[
"von Gersdorff",
"Gero",
""
]
] | We review constraints from quark and lepton flavor violation on extra dimensional models with warped geometry, both in the minimal and the custodial model. For both scenarios, KK masses that are large enough to suppress constraints from electroweak precision tests also sufficiently suppress all quark flavor and CP violation, with the exception of CP violation in $K\bar K$ mixing and (to a lesser extend) in $D\bar D$ mixing. In the lepton sector the minimal scenario leads to excessively large contributions to $\mu\to e\gamma$ transitions, requiring KK masses of at least 20 TeV or larger. |
hep-ph/0202050 | Nobuhiro Maekawa | Nobuhiro Maekawa and Toshifumi Yamashita | E_6 Unification, Doublet-Triplet Splitting and Anomalous U(1)_A Symmetry | 36pages, 1 fugure, published version | Prog.Theor.Phys. 107 (2002) 1201-1233 | 10.1143/PTP.107.1201 | KUNS-1754 | hep-ph | null | We propose a natural Higgs sector in E_6 grand unified theory (GUT) with
anomalous U(1)_A gauge symmetry. In the scenario, the doublet-triplet splitting
can be realized while the proton decay via dimension 5 operator is suppressed.
The gauge coupling unification is also realized without finetuning. The GUT
scale is generally lower than the usual GUT scale 2\times 10^{16} GeV, the
proton decay via dimension 6 operator can be seen in near future experiment.
The lifetime of nucleon in the model is roughly estimated as \tau_p(p\to
e^+\pi^0)\sim 3\times 10^{33} years. It is shown that the Higgs sector is
compatible with the matter sector proposed by one of the authors, which
reproduces the realistic quark and lepton mass matrices including bi-large
neutrino mixing angle. Combining the Higgs sector and the matter sector, we can
obtain the totally consistent E_6 GUT. The input parameters are only 8 integer
anomalous U(1)_A charges (+3 for singlet Higgs) for the Higgs sector and 3
(half) integer charges for the matter sector.
| [
{
"created": "Wed, 6 Feb 2002 15:08:00 GMT",
"version": "v1"
},
{
"created": "Wed, 7 May 2003 03:13:00 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Maekawa",
"Nobuhiro",
""
],
[
"Yamashita",
"Toshifumi",
""
]
] | We propose a natural Higgs sector in E_6 grand unified theory (GUT) with anomalous U(1)_A gauge symmetry. In the scenario, the doublet-triplet splitting can be realized while the proton decay via dimension 5 operator is suppressed. The gauge coupling unification is also realized without finetuning. The GUT scale is generally lower than the usual GUT scale 2\times 10^{16} GeV, the proton decay via dimension 6 operator can be seen in near future experiment. The lifetime of nucleon in the model is roughly estimated as \tau_p(p\to e^+\pi^0)\sim 3\times 10^{33} years. It is shown that the Higgs sector is compatible with the matter sector proposed by one of the authors, which reproduces the realistic quark and lepton mass matrices including bi-large neutrino mixing angle. Combining the Higgs sector and the matter sector, we can obtain the totally consistent E_6 GUT. The input parameters are only 8 integer anomalous U(1)_A charges (+3 for singlet Higgs) for the Higgs sector and 3 (half) integer charges for the matter sector. |
hep-ph/9308371 | null | Michael Gronau (Department of Physics, Technion) and Jonathan L.
Rosner (Enrico Fermi Institute and Department of Physics, University of
Chicago) | Identification of Neutral B Mesons Using Correlated Hadrons | To be submitted to Phys. Rev. D. 26 pages, LaTeX, figures not
included (available upon request). Technion-PH-93-32 / EFI 93-41 | Phys.Rev.D49:254-264,1994 | 10.1103/PhysRevD.49.254 | null | hep-ph | null | The identification of the flavor of a neutral $B$ meson can make use of
hadrons produced nearby in phase space. Examples include the decay of
``$B^{**}$'' resonances or the production of hadrons as a result of the
fragmentation process. Some aspects of this method are discussed, including
time-dependent effects in neutral $B$ decays to flavor states, to eigenstates
of CP and to other states, and the effects of possible coherence between $B^0$
and $\overline{B}^0$ in the initial state. We study the behavior of the leading
hadrons in $b$-quark jets and the expected properties of $B^{**}$ resonances.
These are extrapolated from the corresponding $D^{**}$ resonances, of whose
properties we suggest further studies.
| [
{
"created": "Tue, 31 Aug 1993 18:01:37 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Gronau",
"Michael",
"",
"Department of Physics, Technion"
],
[
"Rosner",
"Jonathan L.",
"",
"Enrico Fermi Institute and Department of Physics, University of\n Chicago"
]
] | The identification of the flavor of a neutral $B$ meson can make use of hadrons produced nearby in phase space. Examples include the decay of ``$B^{**}$'' resonances or the production of hadrons as a result of the fragmentation process. Some aspects of this method are discussed, including time-dependent effects in neutral $B$ decays to flavor states, to eigenstates of CP and to other states, and the effects of possible coherence between $B^0$ and $\overline{B}^0$ in the initial state. We study the behavior of the leading hadrons in $b$-quark jets and the expected properties of $B^{**}$ resonances. These are extrapolated from the corresponding $D^{**}$ resonances, of whose properties we suggest further studies. |
0904.2169 | Peter Athron | P. Athron (1), S. F. King (2), D. J. Miller (3), S. Moretti (2 and 4)
and R. Nevzorov (3) ((1) TU Dresden, (2) University of Southampton, (3)
University of Glasgow, (4) Universita' degli Studi di Torino) | The Constrained Exceptional Supersymmetric Standard Model | Version accepted for publication in Phys. Rev. D | Phys.Rev.D80:035009,2009 | 10.1103/PhysRevD.80.035009 | DFTT 38/2009 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose and study a constrained version of the Exceptional Supersymmetric
Standard Model (E6SSM), which we call the cE6SSM, based on a universal high
energy scalar mass m_0, trilinear scalar coupling A_0 and gaugino mass M_{1/2}.
We derive the Renormalisation Group (RG) Equations for the cE6SSM, including
the extra U(1)_{N} gauge factor and the low energy matter content involving
three 27 representations of E6. We perform a numerical RG analysis for the
cE6SSM, imposing the usual low energy experimental constraints and successful
Electro-Weak Symmetry Breaking (EWSB). Our analysis reveals that the sparticle
spectrum of the cE6SSM involves a light gluino, two light neutralinos and a
light chargino. Furthermore, although the squarks, sleptons and Z' boson are
typically heavy, the exotic quarks and squarks can also be relatively light. We
finally specify a set of benchmark points which correspond to particle spectra,
production modes and decay patterns peculiar to the cE6SSM, altogether leading
to spectacular new physics signals at the Large Hadron Collider (LHC).
| [
{
"created": "Tue, 14 Apr 2009 18:22:20 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Apr 2009 09:29:56 GMT",
"version": "v2"
},
{
"created": "Tue, 28 Jul 2009 10:10:47 GMT",
"version": "v3"
}
] | 2009-12-10 | [
[
"Athron",
"P.",
"",
"2 and 4"
],
[
"King",
"S. F.",
"",
"2 and 4"
],
[
"Miller",
"D. J.",
"",
"2 and 4"
],
[
"Moretti",
"S.",
"",
"2 and 4"
],
[
"Nevzorov",
"R.",
""
]
] | We propose and study a constrained version of the Exceptional Supersymmetric Standard Model (E6SSM), which we call the cE6SSM, based on a universal high energy scalar mass m_0, trilinear scalar coupling A_0 and gaugino mass M_{1/2}. We derive the Renormalisation Group (RG) Equations for the cE6SSM, including the extra U(1)_{N} gauge factor and the low energy matter content involving three 27 representations of E6. We perform a numerical RG analysis for the cE6SSM, imposing the usual low energy experimental constraints and successful Electro-Weak Symmetry Breaking (EWSB). Our analysis reveals that the sparticle spectrum of the cE6SSM involves a light gluino, two light neutralinos and a light chargino. Furthermore, although the squarks, sleptons and Z' boson are typically heavy, the exotic quarks and squarks can also be relatively light. We finally specify a set of benchmark points which correspond to particle spectra, production modes and decay patterns peculiar to the cE6SSM, altogether leading to spectacular new physics signals at the Large Hadron Collider (LHC). |
hep-ph/9508209 | Mike Berger | M. S. Berger (Indiana University) | The ttbar threshold at a muon collider | 6 pages, 5 uuencoded figures. Presented at the Workshop on Particle
Theory and Phenomenology: Physics of the Top Quark, Iowa State University,
May 25-26, 1995. (200 MeV should have been 300 MeV) | null | null | IUHET-310 | hep-ph | null | The beam energy spread is a major issue in future attempts to study the
$t\overline{t}$ threshold at $e^+e^-$ colliders. Muon colliders are expected to
naturally have narrow band beams making them an ideal place to study the
excitation curve. We present the parameter determinations that are possible
from measuring the total cross section near threshold at a $\mu ^+\mu ^-$
collider.
| [
{
"created": "Tue, 1 Aug 1995 21:39:10 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Aug 1995 01:07:44 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Berger",
"M. S.",
"",
"Indiana University"
]
] | The beam energy spread is a major issue in future attempts to study the $t\overline{t}$ threshold at $e^+e^-$ colliders. Muon colliders are expected to naturally have narrow band beams making them an ideal place to study the excitation curve. We present the parameter determinations that are possible from measuring the total cross section near threshold at a $\mu ^+\mu ^-$ collider. |
hep-ph/0102337 | Greg Mahlon | C.S. Lam (McGill U.) and Gregory Mahlon (U. Arizona & McGill U.) | Non-Gaussian Correlations in the McLerran-Venugopalan Model | 21 pages with 4 figures (revtex) | Phys.Rev. D64 (2001) 016004 | 10.1103/PhysRevD.64.016004 | McGill/01-02 | hep-ph nucl-th | null | We argue that the statistical weight function W[rho] appearing in the
McLerran-Venugopalan model of a large nucleus is intrinsically non-Gaussian,
even if we neglect quantum corrections. Based on the picture where the nucleus
of radius R consists of a collection of color-neutral nucleons, each of radius
a<<R, we show that to leading order in alpha_s and a/R only the Gaussian part
of W[rho] enters into the final expression for the gluon number density. Thus,
the existing results in the literature which assume a Gaussian weight remain
valid.
| [
{
"created": "Wed, 28 Feb 2001 17:19:34 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Lam",
"C. S.",
"",
"McGill U."
],
[
"Mahlon",
"Gregory",
"",
"U. Arizona & McGill U."
]
] | We argue that the statistical weight function W[rho] appearing in the McLerran-Venugopalan model of a large nucleus is intrinsically non-Gaussian, even if we neglect quantum corrections. Based on the picture where the nucleus of radius R consists of a collection of color-neutral nucleons, each of radius a<<R, we show that to leading order in alpha_s and a/R only the Gaussian part of W[rho] enters into the final expression for the gluon number density. Thus, the existing results in the literature which assume a Gaussian weight remain valid. |
hep-ph/9411429 | null | Jan Louis, Yosef Nir | Some Phenomenological Implications of String Loop Effects | 27 pages, phyzzx, no figures | Nucl.Phys.B447:18-34,1995 | 10.1016/0550-3213(95)00155-L | LMU-TPW 94--17, WIS-94/50/Dec-PH | hep-ph hep-th | null | We investigate low energy implications of string loop corrections to
supergravity couplings which break a possible flavor universality of the tree
level. If Supersymmetry is broken by the dilaton $F$-term, universal soft
scalar masses arise at the leading order but string loop corrections
generically induce flavor-non-diagonal soft terms. Constraints from flavor
changing neutral currents (FCNC) and CP violation then require a large
supersymmtery breaking scale and thus heavy gluinos and squarks. If
Supersymmetry is broken by moduli $F$-terms, universality at the string tree
level can only be guaranteed by extra conditions on the K\"ahler potential. A
large hierarchy between the gluino and squark masses ensures that FCNC and CP
violation constraints are satisfied. If the soft scalar masses vanish at the
string tree level, the cosmological problems related to light moduli can be
evaded. However, generic string loop corrections violate FCNC bounds and
require very heavy squark masses ($\approx 100\, TeV$).
| [
{
"created": "Wed, 30 Nov 1994 04:24:15 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Louis",
"Jan",
""
],
[
"Nir",
"Yosef",
""
]
] | We investigate low energy implications of string loop corrections to supergravity couplings which break a possible flavor universality of the tree level. If Supersymmetry is broken by the dilaton $F$-term, universal soft scalar masses arise at the leading order but string loop corrections generically induce flavor-non-diagonal soft terms. Constraints from flavor changing neutral currents (FCNC) and CP violation then require a large supersymmtery breaking scale and thus heavy gluinos and squarks. If Supersymmetry is broken by moduli $F$-terms, universality at the string tree level can only be guaranteed by extra conditions on the K\"ahler potential. A large hierarchy between the gluino and squark masses ensures that FCNC and CP violation constraints are satisfied. If the soft scalar masses vanish at the string tree level, the cosmological problems related to light moduli can be evaded. However, generic string loop corrections violate FCNC bounds and require very heavy squark masses ($\approx 100\, TeV$). |
0711.3713 | Ian D. Lawrie | Javier Moreno Almeida and Ian D. Lawrie | Dissipation due to fermions in inflaton equations of motion | 9 pages, 4 figures | null | null | null | hep-ph | null | According to quantum field theory, the inflaton equation of motion does not
have the local form that is generally assumed for cosmological purposes. In
particular, earlier investigations of the nonequilibrium dynamics of an
inflaton that decays into scalar particles suggest that the loss of inflaton
energy is not well approximated by the local friction term derived from linear
response theory. We extend this analysis to the case of an inflaton that decays
into fermions, and reach broadly the same conclusion.
| [
{
"created": "Fri, 23 Nov 2007 11:37:16 GMT",
"version": "v1"
}
] | 2007-11-26 | [
[
"Almeida",
"Javier Moreno",
""
],
[
"Lawrie",
"Ian D.",
""
]
] | According to quantum field theory, the inflaton equation of motion does not have the local form that is generally assumed for cosmological purposes. In particular, earlier investigations of the nonequilibrium dynamics of an inflaton that decays into scalar particles suggest that the loss of inflaton energy is not well approximated by the local friction term derived from linear response theory. We extend this analysis to the case of an inflaton that decays into fermions, and reach broadly the same conclusion. |
1209.2797 | David Lopez-Val | David Lopez-Val, Dorival Goncalves, Kentarou Mawatari, Tilman Plehn,
Ioan Wigmore | MadGolem: automating NLO calculations for New Physics | Prepared for the proceedings to Loops and Legs in Quantum Field
Theory - 11th DESY Workshop on Elementary Particle Physics, April 15-20,
2012, Wernigerode, Germany | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | With the LHC close to complete its 8 TeV run, the experimental searches have
already started to probe the vast beyond-the-standard Model scenery. Providing
next-to-leading order (NLO) predictions for the major new physics discovery
channels is therefore a most pressing request to particle phenomenologists
these days. MadGolem is a new computational tool that automates NLO
calculations of generic 2->2 new physics processes in the MadGraph/Golem
framework. In this contribution we concisely describe the structure and
performance of the code, with particular focus on the generation of the
renormalized one-loop amplitudes and the automatized subtraction of infrared
and on-shell divergences. We briefly survey the many dedicated tests of all
these aspects and outline some applications to LHC phenomenology.
| [
{
"created": "Thu, 13 Sep 2012 07:26:59 GMT",
"version": "v1"
}
] | 2014-05-30 | [
[
"Lopez-Val",
"David",
""
],
[
"Goncalves",
"Dorival",
""
],
[
"Mawatari",
"Kentarou",
""
],
[
"Plehn",
"Tilman",
""
],
[
"Wigmore",
"Ioan",
""
]
] | With the LHC close to complete its 8 TeV run, the experimental searches have already started to probe the vast beyond-the-standard Model scenery. Providing next-to-leading order (NLO) predictions for the major new physics discovery channels is therefore a most pressing request to particle phenomenologists these days. MadGolem is a new computational tool that automates NLO calculations of generic 2->2 new physics processes in the MadGraph/Golem framework. In this contribution we concisely describe the structure and performance of the code, with particular focus on the generation of the renormalized one-loop amplitudes and the automatized subtraction of infrared and on-shell divergences. We briefly survey the many dedicated tests of all these aspects and outline some applications to LHC phenomenology. |
hep-ph/0207321 | Karmanov | V.A. Karmanov and A.E. Kudryavtsev | The Centauro events as a result of induced pions emission | 12 pages, 1 figure | null | null | Preprint ITEP-88, Moscow, 1983 | hep-ph hep-th | null | It is shown that only in the case of n pion production amplitude (at n > 10),
which is symmetric enough relative to the momenta permutations, there is
appreciable probability of events with nothing but charged or nothing but
neutral pions. Significant enhancement of the probability of these events in
comparison with that follows from Poisson distribution is caused by induced
pions emission, in complete analogy with the phenomenon of the induced photon
emission in QED.
| [
{
"created": "Fri, 26 Jul 2002 11:52:02 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Karmanov",
"V. A.",
""
],
[
"Kudryavtsev",
"A. E.",
""
]
] | It is shown that only in the case of n pion production amplitude (at n > 10), which is symmetric enough relative to the momenta permutations, there is appreciable probability of events with nothing but charged or nothing but neutral pions. Significant enhancement of the probability of these events in comparison with that follows from Poisson distribution is caused by induced pions emission, in complete analogy with the phenomenon of the induced photon emission in QED. |
1912.00637 | Takashi Shimomura | Tatsuo Kobayashi, Takaaki Nomura and Takashi Shimomura | Type II seesaw models with modular $A_4$ symmetry | 33pages, 16 figures, new figures added, some figures replaced and
major revision in text to the reflect changes | Phys. Rev. D 102, 035019 (2020) | 10.1103/PhysRevD.102.035019 | EPHOU-19-018, KIAS-P19068, UME-PP-011 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss type-II seesaw models adopting modular $A_4$ symmetry in
supersymmetric framework. In our approach, the models are classified by the
assignment of $A_4$ representations and modular weights for leptons and triplet
Higgs fields. Then neutrino mass matrix is characterized by modulus $\tau$ and
two free parameters. Carrying out numerical analysis, we find allowed parameter
sets which can fit the neutrino oscillation data. For the allowed parameter
sets, we obtain the predictions in neutrino sector such as CP violating phases
and the lightest neutrino mass. Finally we also show the predictions for the
branching ratios of doubly charged scalar boson focusing on the case where the
doubly charged scalar boson dominantly decays into charged leptons.
| [
{
"created": "Mon, 2 Dec 2019 08:59:02 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Aug 2020 07:59:26 GMT",
"version": "v2"
}
] | 2020-08-26 | [
[
"Kobayashi",
"Tatsuo",
""
],
[
"Nomura",
"Takaaki",
""
],
[
"Shimomura",
"Takashi",
""
]
] | We discuss type-II seesaw models adopting modular $A_4$ symmetry in supersymmetric framework. In our approach, the models are classified by the assignment of $A_4$ representations and modular weights for leptons and triplet Higgs fields. Then neutrino mass matrix is characterized by modulus $\tau$ and two free parameters. Carrying out numerical analysis, we find allowed parameter sets which can fit the neutrino oscillation data. For the allowed parameter sets, we obtain the predictions in neutrino sector such as CP violating phases and the lightest neutrino mass. Finally we also show the predictions for the branching ratios of doubly charged scalar boson focusing on the case where the doubly charged scalar boson dominantly decays into charged leptons. |
hep-ph/9606358 | Mikulas Blazek | Mikulaas Blazek (Institute of Physics, Slovak Acad. Sci., Bratislava,
Slovak Republic) | High energy density fluctuations in terms of factorial moments and
associated frequency moments | 20 pages | Int.J.Mod.Phys.A12:839-858,1997 | 10.1142/S0217751X97000645 | FUSAV-96/05 | hep-ph | null | We propose to verify relations between quantities which characterize scaling
properties of high energy density fluctuations in terms of factorial moments
and newly introduced associated frequency moments. Typical examples are
presented in frame of systematics developed in the present paper. It involves
also several sorts of moments applied so far in the search for intermittency
and multifractality. Our approach takes the advantage of relations in which a
linear combination of associated frequency moments reduces statistical
fluctuations to the same extent as it is done by corresponding factorial
moments.
| [
{
"created": "Tue, 18 Jun 1996 13:39:51 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Blazek",
"Mikulaas",
"",
"Institute of Physics, Slovak Acad. Sci., Bratislava,\n Slovak Republic"
]
] | We propose to verify relations between quantities which characterize scaling properties of high energy density fluctuations in terms of factorial moments and newly introduced associated frequency moments. Typical examples are presented in frame of systematics developed in the present paper. It involves also several sorts of moments applied so far in the search for intermittency and multifractality. Our approach takes the advantage of relations in which a linear combination of associated frequency moments reduces statistical fluctuations to the same extent as it is done by corresponding factorial moments. |
hep-ph/0104021 | Michael Kachelriess | M. Kachelriess and R. Tomas | Non-adiabatic level crossing in (non-) resonant neutrino oscillations | 4 pages, revtex, 3 eps figures | Phys.Rev. D64 (2001) 073002 | 10.1103/PhysRevD.64.073002 | CERN-TH/2001-098, IFIC/01-17 | hep-ph | null | We study neutrino oscillations and the level-crossing probability
$P_{LZ}=\exp(-\gamma_n\F_n\pi/2)$ in power-law like potential profiles
$A(r)\propto r^n$. After showing that the resonance point coincides only for a
linear profile with the point of maximal violation of adiabaticity, we point
out that the ``adiabaticity'' parameter $\gamma_n$ can be calculated at an
arbitrary point if the correction function $\F_n$ is rescaled appropriately. We
present a new representation for the level-crossing probability,
$P_{LZ}=\exp(-\kappa_n\G_n)$, which allows a simple numerical evaluation of
$P_{LZ}$ in both the resonant and non-resonant cases and where $\G_n$ contains
the full dependence of $P_{LZ}$ on the mixing angle $\theta$. As an application
we consider the case $n=-3$ important for oscillations of supernova neutrinos.
| [
{
"created": "Mon, 2 Apr 2001 16:20:44 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Kachelriess",
"M.",
""
],
[
"Tomas",
"R.",
""
]
] | We study neutrino oscillations and the level-crossing probability $P_{LZ}=\exp(-\gamma_n\F_n\pi/2)$ in power-law like potential profiles $A(r)\propto r^n$. After showing that the resonance point coincides only for a linear profile with the point of maximal violation of adiabaticity, we point out that the ``adiabaticity'' parameter $\gamma_n$ can be calculated at an arbitrary point if the correction function $\F_n$ is rescaled appropriately. We present a new representation for the level-crossing probability, $P_{LZ}=\exp(-\kappa_n\G_n)$, which allows a simple numerical evaluation of $P_{LZ}$ in both the resonant and non-resonant cases and where $\G_n$ contains the full dependence of $P_{LZ}$ on the mixing angle $\theta$. As an application we consider the case $n=-3$ important for oscillations of supernova neutrinos. |
1712.06675 | Yuber Ferney Perez Gonzalez | Yuber F. Perez-Gonzalez | Massive Neutrinos: Phenomenological and Cosmological Consequences | Ph.D. Thesis, based on arXiv:1507.07550 [hep-ph], arXiv:1510.04284
[hep-ph], arXiv:1701.07443 [hep-ph] and arXiv:1708.07841 [hep-ph] | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this thesis we will address three different phenomena related to neutrino
physics: mass models, detection of the cosmic neutrino background and the
neutrino background in Dark Matter searches, considering the different
characteristics in each case. In the study of neutrino mass models, we will
consider models for both Majorana and Dirac neutrinos; specifically, we will
probe the neutrinophilic two-Higgs-doublet model. Regarding the detection of
relic neutrinos, we will analyse the consequences of the existence of physics
beyond the Standard Model in the capture rate by tritium. Finally, we will
scrutinize the impact of neutrinos in Direct Detection searches of Weakly
Interacting Massive Particles (WIMP) including Standard Model plus additional
interactions in the form of simplified models.
| [
{
"created": "Mon, 18 Dec 2017 21:06:59 GMT",
"version": "v1"
}
] | 2017-12-20 | [
[
"Perez-Gonzalez",
"Yuber F.",
""
]
] | In this thesis we will address three different phenomena related to neutrino physics: mass models, detection of the cosmic neutrino background and the neutrino background in Dark Matter searches, considering the different characteristics in each case. In the study of neutrino mass models, we will consider models for both Majorana and Dirac neutrinos; specifically, we will probe the neutrinophilic two-Higgs-doublet model. Regarding the detection of relic neutrinos, we will analyse the consequences of the existence of physics beyond the Standard Model in the capture rate by tritium. Finally, we will scrutinize the impact of neutrinos in Direct Detection searches of Weakly Interacting Massive Particles (WIMP) including Standard Model plus additional interactions in the form of simplified models. |
2308.14629 | Hyun Min Lee | Seong-Sik Kim, Hyun Min Lee, Kimiko Yamashita | Positivity Bounds on Higgs-Portal Freeze-in Dark Matter | 20 pages, 4 figures, v2: expanded discussion on microscopic models
and freeze-in contribution from higher dimensional operators. Version to
appear in JHEP | null | null | null | hep-ph astro-ph.CO hep-th | http://creativecommons.org/licenses/by-nc-sa/4.0/ | We consider the relic density and positivity bounds for freeze-in scalar dark
matter with general Higgs-portal interactions up to dimension-8 operators. When
dimension-4 and dimension-6 Higgs-portal interactions are proportional to mass
squares for Higgs or scalar dark matter in certain microscopic models such as
massive graviton, radion or general metric couplings with conformal and
disformal modes, we can take the dimension-8 derivative Higgs-portal
interactions to be dominant for determining the relic density via the 2-to-2
thermal scattering of the Higgs fields after reheating. We discuss the
implications of positivity bounds for microscopic models. First, massive
graviton or radion mediates attractive forces between Higgs and scalar dark
matter and the resultant dimension-8 operators respect the positivity bounds.
Second, the disformal couplings in the general metric allow for the subluminal
propagation of graviton but violate the positivity bounds. We show that there
is a wide parameter space for explaining the correct relic density from the
freeze-in mechanism and the positivity bounds can curb out the dimension-8
derivative Higgs-portal interactions nontrivially in the presence of the
similar dimension-8 self-interactions for Higgs and dark matter.
| [
{
"created": "Mon, 28 Aug 2023 14:52:18 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Nov 2023 23:03:55 GMT",
"version": "v2"
}
] | 2023-11-08 | [
[
"Kim",
"Seong-Sik",
""
],
[
"Lee",
"Hyun Min",
""
],
[
"Yamashita",
"Kimiko",
""
]
] | We consider the relic density and positivity bounds for freeze-in scalar dark matter with general Higgs-portal interactions up to dimension-8 operators. When dimension-4 and dimension-6 Higgs-portal interactions are proportional to mass squares for Higgs or scalar dark matter in certain microscopic models such as massive graviton, radion or general metric couplings with conformal and disformal modes, we can take the dimension-8 derivative Higgs-portal interactions to be dominant for determining the relic density via the 2-to-2 thermal scattering of the Higgs fields after reheating. We discuss the implications of positivity bounds for microscopic models. First, massive graviton or radion mediates attractive forces between Higgs and scalar dark matter and the resultant dimension-8 operators respect the positivity bounds. Second, the disformal couplings in the general metric allow for the subluminal propagation of graviton but violate the positivity bounds. We show that there is a wide parameter space for explaining the correct relic density from the freeze-in mechanism and the positivity bounds can curb out the dimension-8 derivative Higgs-portal interactions nontrivially in the presence of the similar dimension-8 self-interactions for Higgs and dark matter. |
2106.06967 | Eugene Levin | Eugene Levin (Tel Aviv U./UTFSM) | Multiplicity distribution of dipoles in QCD from Le, Mueller and Munier
equation | 15pp. 1 figure. arXiv admin note: text overlap with arXiv:2006.11793,
arXiv:2008.10911 | Phys. Rev. D 104, 056025 (2021) | 10.1103/PhysRevD.104.056025 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this paper we derived in QCD the BFKL linear, inhomogeneous equation for
the factorial moments of multiplicity distribution($M_k$) from LMM equation. In
particular, the equation for the average multiplicity of the color-singlet
dipoles($N$) turns out to be the homogeneous BFKL while $M_k \propto N^k$ at
small $x$. Second, using the diffusion approximation for the BFKL kernel we
show that the factorial moments are equal to: $M_k=k!N( N-1)^{k-1}$ which leads
to the multiplicity distribution:$ \frac{\sigma_n}{\sigma_{in}}=\frac{1}{N} (
\frac{N\,-\,1}{N})^{n - 1}$. We also suggest a procedure for finding
corrections to this multiplicity distribution which will be useful for
descriptions of the experimental data.
| [
{
"created": "Sun, 13 Jun 2021 11:42:16 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Sep 2021 08:57:57 GMT",
"version": "v2"
}
] | 2021-10-04 | [
[
"Levin",
"Eugene",
"",
"Tel Aviv U./UTFSM"
]
] | In this paper we derived in QCD the BFKL linear, inhomogeneous equation for the factorial moments of multiplicity distribution($M_k$) from LMM equation. In particular, the equation for the average multiplicity of the color-singlet dipoles($N$) turns out to be the homogeneous BFKL while $M_k \propto N^k$ at small $x$. Second, using the diffusion approximation for the BFKL kernel we show that the factorial moments are equal to: $M_k=k!N( N-1)^{k-1}$ which leads to the multiplicity distribution:$ \frac{\sigma_n}{\sigma_{in}}=\frac{1}{N} ( \frac{N\,-\,1}{N})^{n - 1}$. We also suggest a procedure for finding corrections to this multiplicity distribution which will be useful for descriptions of the experimental data. |
hep-ph/0210264 | Jacques Soffer | Claude Bourrely, Jacques Soffer and Tai Tsun Wu | Impact-Picture Phenomenology for $\pi^{\pm}p, K^{\pm}p$ and $pp, \bar p
p$ | 28 pages, 18 eps figures | Eur.Phys.J.C28:97-105,2003 | 10.1140/epjc/s2003-01159-7 | CPT-2002/P.4429 | hep-ph | null | We present an extension to $\pi^{\pm} p$ and $K^{\pm} p$ elastic scattering
at high energies of the impact-picture phenomenology we first proposed more
than twenty years ago, for $p p$ and $\bar p p$ elastic scattering. We show, in
particular, that the analytic form of the opacity function for the proton
obtained previously is compatible with the experimental results on $\pi p$ and
$K p$ elastic scattering at high energies. It is proposed that $\pi^{\pm}$ and
$K^{\pm}$ external beams be provided from CERN-LHC, so that their elastic
scattering from protons can be studied at higher energies. Our phenomenology
for $p p$ and $\bar p p$ elastic scattering is updated by including new data
and we give predictions for future experiments at BNL-RHIC and CERN-LHC.
| [
{
"created": "Fri, 18 Oct 2002 16:39:59 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Bourrely",
"Claude",
""
],
[
"Soffer",
"Jacques",
""
],
[
"Wu",
"Tai Tsun",
""
]
] | We present an extension to $\pi^{\pm} p$ and $K^{\pm} p$ elastic scattering at high energies of the impact-picture phenomenology we first proposed more than twenty years ago, for $p p$ and $\bar p p$ elastic scattering. We show, in particular, that the analytic form of the opacity function for the proton obtained previously is compatible with the experimental results on $\pi p$ and $K p$ elastic scattering at high energies. It is proposed that $\pi^{\pm}$ and $K^{\pm}$ external beams be provided from CERN-LHC, so that their elastic scattering from protons can be studied at higher energies. Our phenomenology for $p p$ and $\bar p p$ elastic scattering is updated by including new data and we give predictions for future experiments at BNL-RHIC and CERN-LHC. |
hep-ph/0612173 | Yu Jia | Gang Hao, Yu Jia, Cong-Feng Qiao, and Peng Sun | Hunting eta_b through radiative decay into J/psi | 19 pages, 2 figures. References added/updated. Typo in Fig.1 fixed.
Presentation refined. Connection with NRQCD, the major QCD bacground and the
impact of NLO correction on the branching ratio are discussed | JHEP 0702:057,2007 | 10.1088/1126-6708/2007/02/057 | GUCAS-CPS-06-12 | hep-ph hep-ex | null | We propose that the radiative decay process, \eta_b\to J/\psi\gamma, may
serve as a clean searching mode for \eta_b in hadron collision facilities. By a
perturbative QCD calculation, we estimate the corresponding branching ratio to
be of order 10^{-7}. Though very suppressed, this radiative decay channel in
fact has larger branching ratio than the hadronic decay process \eta_b\to
J/\psi J/\psi, which was previously hoped to be a viable mode for ferreting out
\eta_b in Tevatron Run 2. The discovery potential of \eta_b through this
channel seems promising in the forthcoming LHC experiments and maybe even in
Tevatron Run 2, thanks to the huge statistics of \eta_b to be accumulated in
these experiments. The same calculational scheme is also used to estimate the
branching ratios for the processes \eta_b (\eta_c) \to \phi\gamma.
| [
{
"created": "Thu, 14 Dec 2006 18:39:50 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Jan 2007 14:20:50 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Hao",
"Gang",
""
],
[
"Jia",
"Yu",
""
],
[
"Qiao",
"Cong-Feng",
""
],
[
"Sun",
"Peng",
""
]
] | We propose that the radiative decay process, \eta_b\to J/\psi\gamma, may serve as a clean searching mode for \eta_b in hadron collision facilities. By a perturbative QCD calculation, we estimate the corresponding branching ratio to be of order 10^{-7}. Though very suppressed, this radiative decay channel in fact has larger branching ratio than the hadronic decay process \eta_b\to J/\psi J/\psi, which was previously hoped to be a viable mode for ferreting out \eta_b in Tevatron Run 2. The discovery potential of \eta_b through this channel seems promising in the forthcoming LHC experiments and maybe even in Tevatron Run 2, thanks to the huge statistics of \eta_b to be accumulated in these experiments. The same calculational scheme is also used to estimate the branching ratios for the processes \eta_b (\eta_c) \to \phi\gamma. |
1003.5612 | Igor Strakovsky | Y. Qiang (Duke/JLab), Ya.I. Azimov (PNPI), I.I. Strakovsky (GWU), W.J.
Briscoe (GWU), H. Gao (Duke), D.W. Higinbotham (JLab), V.V. Nelyubin (UVa) | Properties of the Lambda(1520) Resonance from High-Precision
Electroproduction Data | 7 pages, 3 figures; corresponds to the published version | Phys.Lett.B694:123-128,2010 | 10.1016/j.physletb.2010.09.052 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | High-resolution spectrometer measurements of the reaction H(e,e'K+)X at small
Q2 are used to extract the mass and width of the Lambda(1520). We investigate
the influence of various assumptions used in the extraction. The width appears
to be more sensitive to the assumptions than the mass. To reach a width
uncertainty about 1 MeV or better, one needs to know the structure of the
non-resonant background. Based on the new Jefferson Lab Hall A data, our final
values for the Breit-Wigner parameters are M = 1520.4 +- 0.6 (stat) +- 1.5
(syst) MeV, Gamma = 18.6 +- 1.9 (stat) +- 1 (syst) MeV. For the first time, we
also estimate the pole position for this resonance and find that both the pole
mass and width seem to be smaller than the Breit-Wigner values.
| [
{
"created": "Mon, 29 Mar 2010 17:19:47 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Oct 2010 01:13:13 GMT",
"version": "v2"
},
{
"created": "Mon, 17 Jan 2011 22:44:08 GMT",
"version": "v3"
}
] | 2011-01-19 | [
[
"Qiang",
"Y.",
"",
"Duke/JLab"
],
[
"Azimov",
"Ya. I.",
"",
"PNPI"
],
[
"Strakovsky",
"I. I.",
"",
"GWU"
],
[
"Briscoe",
"W. J.",
"",
"GWU"
],
[
"Gao",
"H.",
"",
"Duke"
],
[
"Higinbotham",
"D. W.",
"",
"JLab"
],
[
"Nelyubin",
"V. V.",
"",
"UVa"
]
] | High-resolution spectrometer measurements of the reaction H(e,e'K+)X at small Q2 are used to extract the mass and width of the Lambda(1520). We investigate the influence of various assumptions used in the extraction. The width appears to be more sensitive to the assumptions than the mass. To reach a width uncertainty about 1 MeV or better, one needs to know the structure of the non-resonant background. Based on the new Jefferson Lab Hall A data, our final values for the Breit-Wigner parameters are M = 1520.4 +- 0.6 (stat) +- 1.5 (syst) MeV, Gamma = 18.6 +- 1.9 (stat) +- 1 (syst) MeV. For the first time, we also estimate the pole position for this resonance and find that both the pole mass and width seem to be smaller than the Breit-Wigner values. |
1704.03862 | Alexey A. Petrov | Alexey A Petrov | Theory of rare charm decays into leptons | 7 pages + cover, one figure, one table. Invited talk at the 9th
International Workshop on the CKM Unitarity Triangle, 28 November - 3
December 2016, Tata Institute for Fundamental Research (TIFR), Mumbai (India) | null | null | WSU-HEP-1707 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Studies of rare decays of charmed mesons into the final states containing
leptons is an important vehicle in low-energy searches for new physics. I
review theoretical implications of those studies involving transitions with and
without lepton flavor conservation. I argue that lepton-flavor violation (LFV)
could be successfully studied in heavy quarkonium transitions yielding more
sensitive results than similar searches involving $D$ mesons.
| [
{
"created": "Wed, 12 Apr 2017 17:51:58 GMT",
"version": "v1"
}
] | 2017-04-13 | [
[
"Petrov",
"Alexey A",
""
]
] | Studies of rare decays of charmed mesons into the final states containing leptons is an important vehicle in low-energy searches for new physics. I review theoretical implications of those studies involving transitions with and without lepton flavor conservation. I argue that lepton-flavor violation (LFV) could be successfully studied in heavy quarkonium transitions yielding more sensitive results than similar searches involving $D$ mesons. |
hep-ph/0207204 | Andrea Piccione | Andrea Piccione | Aspects of QCD perturbative evolution | PhD. Thesis, 135 latex pages, 29 ps figures, 10 eps figures | null | null | GEF/TH-10-02 | hep-ph | null | This thesis is devoted to the study of some aspects of perturbative QCD, and
in particular to the development of high-precision techniques for the
extraction of physical parameters such as structure functions, parton
distributions, and the strong coupling from the analysis of deep inelastic
scattering data. First, we will discuss scaling violations of singlet and
nonsinglet truncated moments, and the use of truncated momets to solve the
Altarelli-Parisi equation. Then we will suggest an approach based on neural
networks to the parametrization and interpolation of experimental data, which
retains information on experimental errors and correlations. The method of
truncated moments can be combined with the neural network fit to extract
various quantities of phenomenological interest in a bias-free way. As an
example of such application, we will discuss the determination of the strong
coupling constant.
| [
{
"created": "Wed, 17 Jul 2002 10:53:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Piccione",
"Andrea",
""
]
] | This thesis is devoted to the study of some aspects of perturbative QCD, and in particular to the development of high-precision techniques for the extraction of physical parameters such as structure functions, parton distributions, and the strong coupling from the analysis of deep inelastic scattering data. First, we will discuss scaling violations of singlet and nonsinglet truncated moments, and the use of truncated momets to solve the Altarelli-Parisi equation. Then we will suggest an approach based on neural networks to the parametrization and interpolation of experimental data, which retains information on experimental errors and correlations. The method of truncated moments can be combined with the neural network fit to extract various quantities of phenomenological interest in a bias-free way. As an example of such application, we will discuss the determination of the strong coupling constant. |
1609.03408 | Tatiana Tarutina | C.A. Garc\`ia Canal, T. Tarutina and V. Vento | Deuteron structure in the deep inelastic regime | 10 pages, 4 figures | null | 10.1140/epja/i2017-12303-9 | IFIC/16-31 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study nuclear effects on the deuteron in the deep inelastic regime using
the newest available data analyzing their $Q^2$ dependence. We conclude that
precise EMC ratios for large $Q^2$ (> 30, GeV$^2$) cannot be obtained without
considering these nuclear effects. For this purpose we use a scheme which
parametrizes these effects in a simple manner and compare our results with
other recent proposals.
| [
{
"created": "Mon, 12 Sep 2016 14:05:22 GMT",
"version": "v1"
}
] | 2017-06-28 | [
[
"Canal",
"C. A. Garcìa",
""
],
[
"Tarutina",
"T.",
""
],
[
"Vento",
"V.",
""
]
] | We study nuclear effects on the deuteron in the deep inelastic regime using the newest available data analyzing their $Q^2$ dependence. We conclude that precise EMC ratios for large $Q^2$ (> 30, GeV$^2$) cannot be obtained without considering these nuclear effects. For this purpose we use a scheme which parametrizes these effects in a simple manner and compare our results with other recent proposals. |
1611.01316 | Jonathan Gaunt | Markus Diehl, Jonathan R. Gaunt | Double parton scattering in the ultraviolet: addressing the double
counting problem | 8 pages, 3 figures. To appear in the proceedings of the QCD Evolution
Workshop 2016, Amsterdam, the Netherlands, May 30 - June 3, 2016. v2: fixed a
typo in eq. 3.6 (values transposed between h_g and h_q), inserted missing
factor 2pi in all curves in figure 3 | null | null | DESY 16-208 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An important question in the theory of double parton scattering is how to
incorporate the possibility of the parton pairs being generated perturbatively
via $1 \to 2$ splitting into the theory, whilst avoiding double counting with
single parton scattering loop corrections. Here, we describe a consistent
approach for solving this problem, which retains the notion of double parton
distributions (DPDs) for individual hadrons. Further, we discuss the
construction of appropriate model DPDs in our framework, and the use of these
to compute the DPS part, presenting DPS 'luminosities' from our model DPDs for
a few sample cases.
| [
{
"created": "Fri, 4 Nov 2016 10:36:32 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Dec 2016 14:24:23 GMT",
"version": "v2"
}
] | 2016-12-12 | [
[
"Diehl",
"Markus",
""
],
[
"Gaunt",
"Jonathan R.",
""
]
] | An important question in the theory of double parton scattering is how to incorporate the possibility of the parton pairs being generated perturbatively via $1 \to 2$ splitting into the theory, whilst avoiding double counting with single parton scattering loop corrections. Here, we describe a consistent approach for solving this problem, which retains the notion of double parton distributions (DPDs) for individual hadrons. Further, we discuss the construction of appropriate model DPDs in our framework, and the use of these to compute the DPS part, presenting DPS 'luminosities' from our model DPDs for a few sample cases. |
1512.09353 | Bin Wu | Edmond Iancu and Bin Wu | Thermalization of mini-jets in a quark-gluon plasma | 4 pages, 4 figures, proceedings of Quark Matter 2015, Kobe, Japan.
arXiv admin note: text overlap with arXiv:1510.04464 | null | 10.1016/j.nuclphysa.2016.04.028 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the complete physical picture for the evolution of a high-energy
jet propagating through a weakly-coupled quark-gluon plasma (QGP) by analytical
and numerical investigation of thermalization of the soft components of the
jet. Our results support the following physical picture: the leading particle
emits a significant number of mini-jets which promptly evolve via multiple
branching and thus degrade into a myriad of soft gluons, with energies of the
order of the medium temperature $T$. Via elastic collisions with the medium
constituents, these soft gluons relax to local thermal equilibrium with the
plasma over a time scale which is considerably shorter than the typical
lifetime of the mini-jet. The thermalized gluons form a tail which lags behind
the hard components of the jet. Together with the background QGP, they behave
hydrodynamically.
| [
{
"created": "Thu, 31 Dec 2015 19:42:54 GMT",
"version": "v1"
}
] | 2016-11-23 | [
[
"Iancu",
"Edmond",
""
],
[
"Wu",
"Bin",
""
]
] | We present the complete physical picture for the evolution of a high-energy jet propagating through a weakly-coupled quark-gluon plasma (QGP) by analytical and numerical investigation of thermalization of the soft components of the jet. Our results support the following physical picture: the leading particle emits a significant number of mini-jets which promptly evolve via multiple branching and thus degrade into a myriad of soft gluons, with energies of the order of the medium temperature $T$. Via elastic collisions with the medium constituents, these soft gluons relax to local thermal equilibrium with the plasma over a time scale which is considerably shorter than the typical lifetime of the mini-jet. The thermalized gluons form a tail which lags behind the hard components of the jet. Together with the background QGP, they behave hydrodynamically. |
hep-ph/0109108 | Luis Bettencourt | Luis M. A. Bettencourt, Fred Cooper and Karen Pao | Hydrodynamic scaling from the dynamics of relativistic quantum field
theory | 4 pages, 4 color eps figures, uses RevTex, v2 some typos corrected
and references added | Phys.Rev.Lett. 89 (2002) 112301 | 10.1103/PhysRevLett.89.112301 | MIT--CTP-3179, LAUR-01-5183 | hep-ph hep-lat nlin.PS nucl-th | null | Hydrodynamic behavior is a general feature of interacting systems with many
degrees of freedom constrained by conservation laws. To date hydrodynamic
scaling in relativistic quantum systems has been observed in many high energy
settings, from cosmic ray detections to accelerators, with large particle
multiplicity final states. Here we show first evidence for the emergence of
hydrodynamic scaling in the dynamics of a relativistic quantum field theory. We
consider a simple scalar $\lambda \phi^4$ model in 1+1 dimensions in the
Hartree approximation and study the dynamics of two colliding kinks at
relativistic speeds as well as the decay of a localized high energy density
region. The evolution of the energy-momentum tensor determines the dynamical
local equation of state and allows the measurement of the speed of sound.
Hydrodynamic scaling emerges at high local energy densities.
| [
{
"created": "Wed, 12 Sep 2001 22:36:46 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Sep 2001 18:51:35 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Bettencourt",
"Luis M. A.",
""
],
[
"Cooper",
"Fred",
""
],
[
"Pao",
"Karen",
""
]
] | Hydrodynamic behavior is a general feature of interacting systems with many degrees of freedom constrained by conservation laws. To date hydrodynamic scaling in relativistic quantum systems has been observed in many high energy settings, from cosmic ray detections to accelerators, with large particle multiplicity final states. Here we show first evidence for the emergence of hydrodynamic scaling in the dynamics of a relativistic quantum field theory. We consider a simple scalar $\lambda \phi^4$ model in 1+1 dimensions in the Hartree approximation and study the dynamics of two colliding kinks at relativistic speeds as well as the decay of a localized high energy density region. The evolution of the energy-momentum tensor determines the dynamical local equation of state and allows the measurement of the speed of sound. Hydrodynamic scaling emerges at high local energy densities. |
2004.03699 | Jean Alexandre | Jean Alexandre and Nick E. Mavromatos | On the consistency of a non-Hermitian Yukawa interaction | 7 pages, comments added | null | 10.1016/j.physletb.2020.135562 | KCL-PH-TH/2020-16 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study different properties of an anti-Hermitian Yukawa interaction,
motivated by a scenario of radiative anomalous generation of masses for the
right-handed sterile neutrinos. The model, involving either a pseudo-scalar or
a scalar, is consistent both at the classical and quantum levels, and
particular attention is given to its properties under improper Lorentz
transformations. The path integral is consistently defined with a Euclidean
signature, and we discuss the energetics of the model, which show that no
dynamical mass generation can occur, unless extra interactions are considered.
| [
{
"created": "Tue, 7 Apr 2020 20:44:34 GMT",
"version": "v1"
},
{
"created": "Tue, 5 May 2020 10:09:19 GMT",
"version": "v2"
}
] | 2020-06-24 | [
[
"Alexandre",
"Jean",
""
],
[
"Mavromatos",
"Nick E.",
""
]
] | We study different properties of an anti-Hermitian Yukawa interaction, motivated by a scenario of radiative anomalous generation of masses for the right-handed sterile neutrinos. The model, involving either a pseudo-scalar or a scalar, is consistent both at the classical and quantum levels, and particular attention is given to its properties under improper Lorentz transformations. The path integral is consistently defined with a Euclidean signature, and we discuss the energetics of the model, which show that no dynamical mass generation can occur, unless extra interactions are considered. |
1806.10820 | Christian Bierlich | Christian Bierlich, G\"osta Gustafson, Leif L\"onnblad and Harsh Shah | The Angantyr model for Heavy-Ion Collisions in PYTHIA8 | 57 pages, 26 figures. Updated corresponding to published version | J. High Energ. Phys. (2018) 2018: 134 | 10.1007/JHEP10(2018)134 | LU-TP 18-19, MCnet-18-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new model for building up complete exclusive hadronic final
states in high energy nucleus collisions. It is a direct extrapolation of high
energy pp collisions (as described by PYTHIA), and thus bridges a large part of
the existing gap between heavy ion and high energy physics phenomenology. The
model is inspired by the old Fritiof model and the notion of wounded nucleons.
Two essential features are the treatment of multi-parton interactions and
diffractive excitation in each NN sub-collision. Diffractive excitation is
related to fluctuations in the nucleon partonic sub-structure, and fluctuations
in both projectile and target are here included for the first time. The model
is able to give a good description of general final-state properties such as
multiplicity and transverse momentum distributions, both in pA and AA
collisions. The model can therefore serve as a baseline for understanding the
non-collective background to observables sensitive to collective behaviour. As
PYTHIA does not include a mechanism to reproduce the collective effects seen in
pp collisions, such effects are also not reproduced by the present version of
Angantyr. Effects of high string density, shown to be able to reproduce e.g.
higher strangeness ratios and the ridge in pp, will be added in future studies
| [
{
"created": "Thu, 28 Jun 2018 08:23:59 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Oct 2018 07:58:11 GMT",
"version": "v2"
}
] | 2018-10-29 | [
[
"Bierlich",
"Christian",
""
],
[
"Gustafson",
"Gösta",
""
],
[
"Lönnblad",
"Leif",
""
],
[
"Shah",
"Harsh",
""
]
] | We present a new model for building up complete exclusive hadronic final states in high energy nucleus collisions. It is a direct extrapolation of high energy pp collisions (as described by PYTHIA), and thus bridges a large part of the existing gap between heavy ion and high energy physics phenomenology. The model is inspired by the old Fritiof model and the notion of wounded nucleons. Two essential features are the treatment of multi-parton interactions and diffractive excitation in each NN sub-collision. Diffractive excitation is related to fluctuations in the nucleon partonic sub-structure, and fluctuations in both projectile and target are here included for the first time. The model is able to give a good description of general final-state properties such as multiplicity and transverse momentum distributions, both in pA and AA collisions. The model can therefore serve as a baseline for understanding the non-collective background to observables sensitive to collective behaviour. As PYTHIA does not include a mechanism to reproduce the collective effects seen in pp collisions, such effects are also not reproduced by the present version of Angantyr. Effects of high string density, shown to be able to reproduce e.g. higher strangeness ratios and the ridge in pp, will be added in future studies |
hep-ph/0004109 | Anna M. Stasto | J. Kwiecinski, A.D. Martin, A.M. Stasto | Ultrahigh energy neutrino physics | Talk given at Cracow Epiphany Conference on neutrinos in physics and
astrophysics, 6-9 January 2000, Cracow,Poland; 14 pages, 7 figures | Acta Phys.Polon. B31 (2000) 1273-1285 | null | null | hep-ph astro-ph | null | We discuss a problem concerning the ultrahigh energy neutrino propagation
through the Earth. We present calculation of the neutrino-nucleon cross section
at high energies, based on the unifed evolution equation at small x.
We also show the solution of the transport equation for different neutrino
fluxes originating from active galactic nuclei, gamma ray bursts and top-down
model.
| [
{
"created": "Wed, 12 Apr 2000 10:26:49 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Kwiecinski",
"J.",
""
],
[
"Martin",
"A. D.",
""
],
[
"Stasto",
"A. M.",
""
]
] | We discuss a problem concerning the ultrahigh energy neutrino propagation through the Earth. We present calculation of the neutrino-nucleon cross section at high energies, based on the unifed evolution equation at small x. We also show the solution of the transport equation for different neutrino fluxes originating from active galactic nuclei, gamma ray bursts and top-down model. |
hep-ph/0112334 | John F. Gunion | J.F. Gunion, T. Han, J. Jiang, S. Mrenna, A. Sopczak | Determination of $\tan\beta$ at a Future $e^+e^-$ Linear Collider | 7 pages, 3 figures. Contribution to the Snowmass 2001 Workshop on
``The Future of Particle Physics'', Snowmass, CO, USA, July 2001. Revised to
include several improvements and additional references | eConf C010630:P120,2001 | null | null | hep-ph | null | It is widely stated that the ratio of neutral Higgs field vacuum expectation
values, $\tanb$, is one of the most difficult parameters to determine in either
the Minimal Supersymmetric Standard Model (MSSM) or a general type-II Two-Higgs
Doublet Model (2HDM). Assuming an energy and integrated luminosity of
$\rts=500\gev$ and $\call=2000\fbi$, we show that a very accurate determination
of $\tanb$ will often be possible using Higgs production rates and/or Higgs
decays. Based on a TESLA simulation, and assuming no other light Higgs bosons
and $100\leq m_A \leq 200\gev$, we find that the rate for the process $\epem\to
b\anti b A \to b\anti b b\anti b$ provides an excellent determination of
$\tanb$ at high $\tanb$. In the MSSM Higgs sector, the rate for $\epem\to
b\anti b A+ b\anti b H \to b\anti b b\anti b$ ($\epem\to HA \to b\anti b b\anti
b$) provides a good determination of $\tanb$ at high (low) $\tanb$,
respectively, at moderate $m_A$ values. We also show that direct measurement of
the average total width of the $H$ and $A$ in $\epem\to HA \to b\anti b b\anti
b$ events provides an excellent determination of $\tanb$ at large $\tanb$.
| [
{
"created": "Thu, 27 Dec 2001 01:39:34 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Jan 2002 02:04:05 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Gunion",
"J. F.",
""
],
[
"Han",
"T.",
""
],
[
"Jiang",
"J.",
""
],
[
"Mrenna",
"S.",
""
],
[
"Sopczak",
"A.",
""
]
] | It is widely stated that the ratio of neutral Higgs field vacuum expectation values, $\tanb$, is one of the most difficult parameters to determine in either the Minimal Supersymmetric Standard Model (MSSM) or a general type-II Two-Higgs Doublet Model (2HDM). Assuming an energy and integrated luminosity of $\rts=500\gev$ and $\call=2000\fbi$, we show that a very accurate determination of $\tanb$ will often be possible using Higgs production rates and/or Higgs decays. Based on a TESLA simulation, and assuming no other light Higgs bosons and $100\leq m_A \leq 200\gev$, we find that the rate for the process $\epem\to b\anti b A \to b\anti b b\anti b$ provides an excellent determination of $\tanb$ at high $\tanb$. In the MSSM Higgs sector, the rate for $\epem\to b\anti b A+ b\anti b H \to b\anti b b\anti b$ ($\epem\to HA \to b\anti b b\anti b$) provides a good determination of $\tanb$ at high (low) $\tanb$, respectively, at moderate $m_A$ values. We also show that direct measurement of the average total width of the $H$ and $A$ in $\epem\to HA \to b\anti b b\anti b$ events provides an excellent determination of $\tanb$ at large $\tanb$. |
hep-ph/0509178 | Stanislaw Jadach | S. Jadach and M. Skrzypek | Constrained non-Markovian Monte Carlo modelling of the evolution
equation in QCD | Contribution to HERA-LHC workshop | null | null | IFJPAN-V-05-09, CERN-PH-TH/2005-146 | hep-ph | null | A new class of the constrained Monte Carlo (CMC) algorithms for the QCD
evolution equation was recently discovered. The constraint is imposed on the
type and the total longitudinal energy of the parton exiting QCD evolution and
entering a hard process. The efficiency of the new CMCs is found to be
reasonable.
| [
{
"created": "Sun, 18 Sep 2005 19:51:25 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Jadach",
"S.",
""
],
[
"Skrzypek",
"M.",
""
]
] | A new class of the constrained Monte Carlo (CMC) algorithms for the QCD evolution equation was recently discovered. The constraint is imposed on the type and the total longitudinal energy of the parton exiting QCD evolution and entering a hard process. The efficiency of the new CMCs is found to be reasonable. |
1305.3272 | Stefan Berge | Stefan Berge and Susanne Westhoff | Top-Quark Charge Asymmetry Goes Forward: Two New Observables for Hadron
Colliders | 32 pages, 12 figures, 5 tables | JHEP07(2013)179 | 10.1007/JHEP07(2013)179 | MITP/13-005, PITT-PACC-1304 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose two new observables to measure the charge asymmetry in hadronic
top-quark pair production in association with a hard jet. The incline
asymmetry, based on the inclination between the planes of initial- and
final-state momenta, probes the charge asymmetry in the quark-antiquark
channel. Compared to the hitherto investigated rapidity asymmetries, the
incline asymmetry provides improved access to the partonic charge asymmetry at
both the Tevatron and the LHC. The energy asymmetry, based on the energy
difference between top and antitop quarks, for the first time allows us to
probe the charge asymmetry in the quark-gluon channel at the LHC. In quantum
chromodynamics, asymmetries of up to -12% at the leading order are achievable
with appropriate cuts. Top-pair plus jet production thus has the potential to
become the discovery channel of the charge asymmetry in proton-proton
collisions.
| [
{
"created": "Tue, 14 May 2013 20:00:01 GMT",
"version": "v1"
}
] | 2013-09-27 | [
[
"Berge",
"Stefan",
""
],
[
"Westhoff",
"Susanne",
""
]
] | We propose two new observables to measure the charge asymmetry in hadronic top-quark pair production in association with a hard jet. The incline asymmetry, based on the inclination between the planes of initial- and final-state momenta, probes the charge asymmetry in the quark-antiquark channel. Compared to the hitherto investigated rapidity asymmetries, the incline asymmetry provides improved access to the partonic charge asymmetry at both the Tevatron and the LHC. The energy asymmetry, based on the energy difference between top and antitop quarks, for the first time allows us to probe the charge asymmetry in the quark-gluon channel at the LHC. In quantum chromodynamics, asymmetries of up to -12% at the leading order are achievable with appropriate cuts. Top-pair plus jet production thus has the potential to become the discovery channel of the charge asymmetry in proton-proton collisions. |
1104.1283 | Boris A. Arbuzov | B.A. Arbuzov, E.E. Boos and V.I. Savrin | CMS ridge effect at LHC as a manifestation of bremstralung of gluons due
to the quark-anti-quark string formation | 5 pages, 3 figures | null | 10.1140/epjc/s10052-011-1730-2 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recently reported effect of long-range near-side angular correlations at
LHC occurs for large multiplicities of particles with
$1\,GeV\,<p_T\,<\,3\,GeV$. To understand the effect several possibilities have
been discussed. In the letter we propose a simple qualitative mechanism which
corresponds to gluon bremstralung of quarks moving with acceleration
appropriate to the quark--anti-quark string. The smallness of azimuthal angle
difference $\Delta \phi$ along with large $\Delta \eta$ at large multiplicities
in this interval of $p_T$ are natural in the mechanism. The mechanism predicts
also bremstralung photons with mean values of $p_T \approx 2.9$ and
$0.72\,GeV$.
| [
{
"created": "Thu, 7 Apr 2011 09:45:18 GMT",
"version": "v1"
}
] | 2015-05-27 | [
[
"Arbuzov",
"B. A.",
""
],
[
"Boos",
"E. E.",
""
],
[
"Savrin",
"V. I.",
""
]
] | The recently reported effect of long-range near-side angular correlations at LHC occurs for large multiplicities of particles with $1\,GeV\,<p_T\,<\,3\,GeV$. To understand the effect several possibilities have been discussed. In the letter we propose a simple qualitative mechanism which corresponds to gluon bremstralung of quarks moving with acceleration appropriate to the quark--anti-quark string. The smallness of azimuthal angle difference $\Delta \phi$ along with large $\Delta \eta$ at large multiplicities in this interval of $p_T$ are natural in the mechanism. The mechanism predicts also bremstralung photons with mean values of $p_T \approx 2.9$ and $0.72\,GeV$. |
1705.00982 | Stefan H\"oche | Stefan H\"oche, Frank Krauss, Stefan Prestel | Implementing NLO DGLAP evolution in Parton Showers | 11 pages, 4 figures | null | 10.1007/JHEP10(2017)093 | SLAC-PUB-16965, FERMILAB-PUB-17-134-T, IPPP/17/34, DCPT/17/68,
MCNET-17-06 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a parton shower which implements the DGLAP evolution of parton
densities and fragmentation functions at next-to-leading order precision up to
effects stemming from local four-momentum conservation. The Monte-Carlo
simulation is based on including next-to-leading order collinear splitting
functions in an existing parton shower and combining their soft enhanced
contributions with the corresponding terms at leading order. Soft double
counting is avoided by matching to the soft eikonal. Example results from two
independent realizations of the algorithm, implemented in the two event
generation frameworks Pythia and Sherpa, illustrate the improved precision of
the new formalism.
| [
{
"created": "Tue, 2 May 2017 14:04:11 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Oct 2017 19:11:09 GMT",
"version": "v2"
}
] | 2017-11-01 | [
[
"Höche",
"Stefan",
""
],
[
"Krauss",
"Frank",
""
],
[
"Prestel",
"Stefan",
""
]
] | We present a parton shower which implements the DGLAP evolution of parton densities and fragmentation functions at next-to-leading order precision up to effects stemming from local four-momentum conservation. The Monte-Carlo simulation is based on including next-to-leading order collinear splitting functions in an existing parton shower and combining their soft enhanced contributions with the corresponding terms at leading order. Soft double counting is avoided by matching to the soft eikonal. Example results from two independent realizations of the algorithm, implemented in the two event generation frameworks Pythia and Sherpa, illustrate the improved precision of the new formalism. |
0710.4479 | Gareth Jones | Gareth Warren Jones | Meson distribution amplitudes - applications to weak radiative B decays
and B transition form factors | 160 pages, 52 figures. A version with high resolution figures can be
found at http://www.ippp.dur.ac.uk/Research/Theses/jones.pdf | null | null | null | hep-ph | null | This thesis examines the applications and determinations of meson light-cone
distribution amplitudes. The investigation of such processes, in the context of
$B$ physics, provides one with a rich and extensive way of determining the
Standard Model parameters of the CKM matrix, which are essential in describing
CP violation, and searching for tell-tale signs of new physics beyond the
Standard Model. We investigate the twist-2 and twist-3 distribution amplitudes
of light vector mesons and fully examine $\rm SU(3)_F$-breaking effects and
include leading G-parity violating terms. Numerical values of the leading
non-perturbative hadronic parameters are determined from QCD sum rules. The
distribution amplitude results find direct application in the radiative $B$
decays to light vector mesons $B \to V \gamma$. We examine the
phenomenologically most important observables in this decay mode using the
formalism of QCD factorisation. We also include long-distance photon emission
and soft quark loop effects, which formally lie outside the QCD factorisation
formalism. The analysis encompasses all the modes $B_{u,d} \to \rho, \omega,
K^*$ and $B_{s} \to \phi, \bar{K}^*$. We also calculate the $B \to \etapb$
transition form factor using QCD sum rules on the light-cone. We include the
singlet contribution originating from the $\rm U(1)_A$ anomaly and bring the
calculation consistently within the $\eta$-$\etap$ mixing framework.
| [
{
"created": "Wed, 24 Oct 2007 14:42:39 GMT",
"version": "v1"
}
] | 2007-10-25 | [
[
"Jones",
"Gareth Warren",
""
]
] | This thesis examines the applications and determinations of meson light-cone distribution amplitudes. The investigation of such processes, in the context of $B$ physics, provides one with a rich and extensive way of determining the Standard Model parameters of the CKM matrix, which are essential in describing CP violation, and searching for tell-tale signs of new physics beyond the Standard Model. We investigate the twist-2 and twist-3 distribution amplitudes of light vector mesons and fully examine $\rm SU(3)_F$-breaking effects and include leading G-parity violating terms. Numerical values of the leading non-perturbative hadronic parameters are determined from QCD sum rules. The distribution amplitude results find direct application in the radiative $B$ decays to light vector mesons $B \to V \gamma$. We examine the phenomenologically most important observables in this decay mode using the formalism of QCD factorisation. We also include long-distance photon emission and soft quark loop effects, which formally lie outside the QCD factorisation formalism. The analysis encompasses all the modes $B_{u,d} \to \rho, \omega, K^*$ and $B_{s} \to \phi, \bar{K}^*$. We also calculate the $B \to \etapb$ transition form factor using QCD sum rules on the light-cone. We include the singlet contribution originating from the $\rm U(1)_A$ anomaly and bring the calculation consistently within the $\eta$-$\etap$ mixing framework. |
0704.0174 | Miguel Nebot | Francisco J. Botella (Valencia U. & Valencia U., IFIC), Miguel Nebot
(Lisbon, IST) | Reparametrization Invariance, the controversial extraction of $\alpha$
from $B\to\pi\pi$ and New Physics | 25 pages, 40 figures | null | null | IFIC/07-17, FTUV-07-0402 | hep-ph hep-ex | null | The extraction of the weak phase $\alpha$ from $B\to\pi\pi$ decays has been
controversial from a statistical point of view, as the frequentist vs. bayesian
confrontation shows. We analyse several relevant questions which have not
deserved full attention and pervade the extraction of $\alpha$.
Reparametrization Invariance proves appropriate to understand those issues. We
show that some Standard Model inspired parametrizations can be senseless or
inadequate if they go beyond the minimal Gronau and London assumptions: the
single weak phase $\alpha$ just in the $\Delta I=3/2$ amplitudes, the isospin
relations and experimental data. Beside those analyses, we extract $\alpha$
through the use of several adequate parametrizations, showing that there is no
relevant discrepancy between frequentist and bayesian results. The most
relevant information, in terms of $\alpha$, is the exclusion of values around
$\alpha\sim \pi/4$; this result is valid in the presence of arbitrary New
Physics contributions to the $\Delta I=1/2$ piece.
| [
{
"created": "Mon, 2 Apr 2007 11:36:35 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Botella",
"Francisco J.",
"",
"Valencia U. & Valencia U., IFIC"
],
[
"Nebot",
"Miguel",
"",
"Lisbon, IST"
]
] | The extraction of the weak phase $\alpha$ from $B\to\pi\pi$ decays has been controversial from a statistical point of view, as the frequentist vs. bayesian confrontation shows. We analyse several relevant questions which have not deserved full attention and pervade the extraction of $\alpha$. Reparametrization Invariance proves appropriate to understand those issues. We show that some Standard Model inspired parametrizations can be senseless or inadequate if they go beyond the minimal Gronau and London assumptions: the single weak phase $\alpha$ just in the $\Delta I=3/2$ amplitudes, the isospin relations and experimental data. Beside those analyses, we extract $\alpha$ through the use of several adequate parametrizations, showing that there is no relevant discrepancy between frequentist and bayesian results. The most relevant information, in terms of $\alpha$, is the exclusion of values around $\alpha\sim \pi/4$; this result is valid in the presence of arbitrary New Physics contributions to the $\Delta I=1/2$ piece. |
hep-ph/9711307 | Marco Aurelio Diaz | Marco A. Diaz (Valencia), Steve F. King (CERN, Southampton), and
Douglas A. Ross (Southampton) | Radiative Corrections to Chargino Production in Electron-Positron
Collisions | 44 pages including 22 figures, Latex | Nucl.Phys. B529 (1998) 23-61 | 10.1016/S0550-3213(98)00611-7 | CERN-TH/97-313, SHEP--97/23, FTUV/97--47, IFIC/97--78 | hep-ph hep-ex | null | We discuss the one-loop radiative corrections to the reaction e^+ e^- ->
X^+_a X^-_b, for a,b=1,2 where X^+_{1,2} are the charginos of the minimal
supersymmetric standard model. We calculate the leading one loop radiative
corrections involving loops of top, stop, bottom and sbottom quarks, working in
the MS-bar scheme. At LEP2 we find positive radiative corrections typically of
10% to 15% and with a maximum value of approximately 30% if the squark mass
parameters are of the order of 1 TeV. If \sqrt{s}=500 GeV we find smaller
corrections but they can be also negative, with extreme values of 13% and -4%.
For a center of mass given by \sqrt{s}=2 TeV we find larger corrections, with
typical values between 20% and -20%.
| [
{
"created": "Wed, 12 Nov 1997 17:51:09 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Diaz",
"Marco A.",
"",
"Valencia"
],
[
"King",
"Steve F.",
"",
"CERN, Southampton"
],
[
"Ross",
"Douglas A.",
"",
"Southampton"
]
] | We discuss the one-loop radiative corrections to the reaction e^+ e^- -> X^+_a X^-_b, for a,b=1,2 where X^+_{1,2} are the charginos of the minimal supersymmetric standard model. We calculate the leading one loop radiative corrections involving loops of top, stop, bottom and sbottom quarks, working in the MS-bar scheme. At LEP2 we find positive radiative corrections typically of 10% to 15% and with a maximum value of approximately 30% if the squark mass parameters are of the order of 1 TeV. If \sqrt{s}=500 GeV we find smaller corrections but they can be also negative, with extreme values of 13% and -4%. For a center of mass given by \sqrt{s}=2 TeV we find larger corrections, with typical values between 20% and -20%. |
0903.5305 | JiJi Fan | Andrea De Simone, JiJi Fan, Veronica Sanz, Witold Skiba | Leptogenic Supersymmetry | 25 pages, 16 figures; Figure 7,8,11,13 and Table 2 revised | Phys.Rev.D 80:035010,2009 | 10.1103/PhysRevD.80.035010 | MIT-CTP-4024 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Leptogenic supersymmetry is a scenario characterized by cascade decays with
copious lepton production. Leptogenic models have striking signatures that can
be probed by the LHC even in the 10 TeV run with as little as 200 pb^-1 of
data, provided the squark masses are about 1 TeV. Leptogenic supersymmetry
spectrum arises in several well-motivated models and its signatures are
long-lived sleptons, numerous isolated leptons, abundant Higgs production,
rather energetic jets, and no missing energy. The Higgs can be discovered in
the h->b bbar mode via the 4 leptons+4 jets channel because the leptons
accompanying Higgs production suppress the background. The superparticle masses
in leptogenic supersymmetry can be measured efficiently due to lack of missing
energy and high lepton multiplicity. We estimate that 1 fb^-1 of integrated
luminosity is sufficient to determine the light Higgs, neutralinos, charginos,
slepton, sneutrino and squark masses in a 14 TeV run.
| [
{
"created": "Mon, 30 Mar 2009 20:36:57 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Apr 2009 00:15:13 GMT",
"version": "v2"
}
] | 2009-09-17 | [
[
"De Simone",
"Andrea",
""
],
[
"Fan",
"JiJi",
""
],
[
"Sanz",
"Veronica",
""
],
[
"Skiba",
"Witold",
""
]
] | Leptogenic supersymmetry is a scenario characterized by cascade decays with copious lepton production. Leptogenic models have striking signatures that can be probed by the LHC even in the 10 TeV run with as little as 200 pb^-1 of data, provided the squark masses are about 1 TeV. Leptogenic supersymmetry spectrum arises in several well-motivated models and its signatures are long-lived sleptons, numerous isolated leptons, abundant Higgs production, rather energetic jets, and no missing energy. The Higgs can be discovered in the h->b bbar mode via the 4 leptons+4 jets channel because the leptons accompanying Higgs production suppress the background. The superparticle masses in leptogenic supersymmetry can be measured efficiently due to lack of missing energy and high lepton multiplicity. We estimate that 1 fb^-1 of integrated luminosity is sufficient to determine the light Higgs, neutralinos, charginos, slepton, sneutrino and squark masses in a 14 TeV run. |
hep-ph/9705226 | Zhang Wei-Ming | Wei-Min Zhang (Institute of Physics, Academia Sinica, Taipei) | A Weak-Coupling Treatment of Nonperturbative QCD Dynamics to Heavy
Hadrons | 35 pages, Revtex, 3 figs. (A shortened and impoved version of
hep-ph/9510428 that will be published in Phys. Rev. D) | Phys.Rev.D56:1528-1548,1997 | 10.1103/PhysRevD.56.1528 | null | hep-ph | null | Based on the recently developed light-front similarity renormalization group
approach and the light-front heavy quark effective theory, we derive
analytically from first-principles QCD a heavy quark light-front Hamiltonian
which contains explicitly a confinement interaction at long distances and a
Coulomb-type interaction at short distances. With this light-front QCD
Hamiltonian, we further demonstrate that the nonperturbative QCD dynamics of
the strongly interacting heavy hadron bound states can be treated as a
weak-coupling problem.
| [
{
"created": "Sun, 4 May 1997 16:04:09 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Zhang",
"Wei-Min",
"",
"Institute of Physics, Academia Sinica, Taipei"
]
] | Based on the recently developed light-front similarity renormalization group approach and the light-front heavy quark effective theory, we derive analytically from first-principles QCD a heavy quark light-front Hamiltonian which contains explicitly a confinement interaction at long distances and a Coulomb-type interaction at short distances. With this light-front QCD Hamiltonian, we further demonstrate that the nonperturbative QCD dynamics of the strongly interacting heavy hadron bound states can be treated as a weak-coupling problem. |
hep-ph/0006094 | Parvez Anandam | Parvez Anandam | Leading logarithm calculation of the e^+ e^- -> e^+ \nu_e \bar{u} d
cross section | 10 pages including 9 figures | Phys.Rev. D63 (2001) 074015 | 10.1103/PhysRevD.63.074015 | null | hep-ph | null | We analytically evaluate in the leading logarithm approximation the
differential cross section for e^+ e^- -> e^+ \nu_e \bar{u} d. We compare our
order \alpha^4 \alpha_s^0 leading-log result to the order \alpha^4 \alpha_s^0
exact result obtained from the GRC4F Monte Carlo program. Finally we use the
Gluck, Reya, Schienbien distribution of partons in a virtual photon, which
incorporates both evolution and nonperturbative strong interaction
contributions, to obtain better estimates of the differential cross section.
| [
{
"created": "Sat, 10 Jun 2000 05:13:47 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Anandam",
"Parvez",
""
]
] | We analytically evaluate in the leading logarithm approximation the differential cross section for e^+ e^- -> e^+ \nu_e \bar{u} d. We compare our order \alpha^4 \alpha_s^0 leading-log result to the order \alpha^4 \alpha_s^0 exact result obtained from the GRC4F Monte Carlo program. Finally we use the Gluck, Reya, Schienbien distribution of partons in a virtual photon, which incorporates both evolution and nonperturbative strong interaction contributions, to obtain better estimates of the differential cross section. |
2211.11272 | Fabian Zierler | Fabian Zierler, Suchita Kulkarni, Axel Maas, Se\'an Mee, Marco
Nikolic, Josef Pradler | Strongly Interacting Dark Matter from $Sp(4)$ Gauge Theory | 7 pages, 2 figures, Contribution to the proceedings of the 15th Quark
Confinement and the Hadron Spectrum conference (ConfXV), 1st-6th August 2022,
Stavanger, Norway | null | 10.1051/epjconf/202227408014 | null | hep-ph hep-lat | http://creativecommons.org/licenses/by/4.0/ | The stable hadronic bound states in a hidden new non-Abelian gauge sector
provide interesting candidates for strongly-interacting Dark Matter (DM). A
particular example are theories in which DM is made up of dark pions which set
the DM relic abundance through self-annihilation. One of the simplest
realizations is $Sp(4)_c$ gauge theory with two Dirac fermions. We discuss its
mesonic multiplets for degenerate and non-degenerate fermions, construct a
low-energy effective theory and present lattice results for the pseudoscalar
mesons and vector mesons.
| [
{
"created": "Mon, 21 Nov 2022 09:07:30 GMT",
"version": "v1"
}
] | 2023-01-11 | [
[
"Zierler",
"Fabian",
""
],
[
"Kulkarni",
"Suchita",
""
],
[
"Maas",
"Axel",
""
],
[
"Mee",
"Seán",
""
],
[
"Nikolic",
"Marco",
""
],
[
"Pradler",
"Josef",
""
]
] | The stable hadronic bound states in a hidden new non-Abelian gauge sector provide interesting candidates for strongly-interacting Dark Matter (DM). A particular example are theories in which DM is made up of dark pions which set the DM relic abundance through self-annihilation. One of the simplest realizations is $Sp(4)_c$ gauge theory with two Dirac fermions. We discuss its mesonic multiplets for degenerate and non-degenerate fermions, construct a low-energy effective theory and present lattice results for the pseudoscalar mesons and vector mesons. |
hep-ph/0007063 | Cheng-Wei Chiang | Cheng-Wei Chiang and Frederick J. Gilman | K_{L,S} \to \pi \pi \nu \bar{\nu} Decays Within and Beyond the Standard
Model | 12 pages and no figure | Phys.Rev. D62 (2000) 094026 | 10.1103/PhysRevD.62.094026 | null | hep-ph | null | The decays K_{L,S} -> \pi^o \pi^o \nu \bar{\nu} and K_{L,S} -> \pi^+ \pi^-
\nu \bar{\nu} involve the weak transition from a strange to a non-strange
quark. Although they have considerably smaller branching ratios than those for
the corresponding rare processes involving single pions, some may be more
distinguishable experimentally from background processes and thus could provide
another probe of the s -> d \nu \bar{\nu} transition. Using recent knowledge of
the CKM matrix elements and measurements of related processes, we give improved
predictions for their branching ratios both within and beyond the Standard
Model.
| [
{
"created": "Fri, 7 Jul 2000 00:42:56 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Chiang",
"Cheng-Wei",
""
],
[
"Gilman",
"Frederick J.",
""
]
] | The decays K_{L,S} -> \pi^o \pi^o \nu \bar{\nu} and K_{L,S} -> \pi^+ \pi^- \nu \bar{\nu} involve the weak transition from a strange to a non-strange quark. Although they have considerably smaller branching ratios than those for the corresponding rare processes involving single pions, some may be more distinguishable experimentally from background processes and thus could provide another probe of the s -> d \nu \bar{\nu} transition. Using recent knowledge of the CKM matrix elements and measurements of related processes, we give improved predictions for their branching ratios both within and beyond the Standard Model. |
hep-ph/9706317 | Gabriela Grunfeld | A. G. Grunfeld and M. C. Rocca | Quarkonium spectra with a Klein-Gordon Oscillator as a confining
potential | 11 pages, Revtex | null | null | La Plata-Th 97/09 | hep-ph | null | A quantum relativistic model is proposed to represent the confining potential
of $c \bar{c}$ and $b \bar{b}$ mesons by using the Klein Gordon oscillator. We
have solved the two-body problem obtaining the eigenvalues and the
corresponding mass spectra, which fit very well with experimental data. We
compare the results of our model with others obtained from different quark
binding potentials.
| [
{
"created": "Tue, 10 Jun 1997 17:27:13 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Grunfeld",
"A. G.",
""
],
[
"Rocca",
"M. C.",
""
]
] | A quantum relativistic model is proposed to represent the confining potential of $c \bar{c}$ and $b \bar{b}$ mesons by using the Klein Gordon oscillator. We have solved the two-body problem obtaining the eigenvalues and the corresponding mass spectra, which fit very well with experimental data. We compare the results of our model with others obtained from different quark binding potentials. |
2007.07917 | Jacek Ksawery Osi\'nski | Michael L. Graesser, Jacek K. Osi\'nski | Hidden Sector Monopole Dark Matter with Matter Domination | 42 pages, 8 figures - references added to v2 | null | 10.1007/JHEP11(2020)133 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The thermal freeze-out mechanism for relic dark matter heavier than $O(10-100
$ TeV$)$ requires cross-sections that violate perturbative unitarity. Yet the
existence of dark matter heavier than these scales is certainly plausible from
a particle physics perspective, pointing to the need for a non-thermal
cosmological history for such theories. Topological dark matter is a
well-motivated scenario of this kind. Here the hidden-sector dark matter can be
produced in abundance through the Kibble-Zurek mechanism describing the
non-equilibrium dynamics of defects produced in a second order phase
transition. We revisit the original topological dark matter scenario, focusing
on hidden-sector magnetic monopoles, and consider more general cosmological
histories. We find that a monopole mass of order ($1-10^5$) PeV is generic for
the thermal histories considered here, if monopoles are to entirely reproduce
the current abundance of dark matter. In particular, in a scenario involving an
early era of matter domination, the monopole number density is always less than
or equal to that in a pure radiation dominated equivalent provided a certain
condition on critical exponents is satisfied. This results in a larger monopole
mass needed to account for a fixed relic abundance in such cosmologies.
| [
{
"created": "Wed, 15 Jul 2020 18:02:06 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Aug 2020 04:31:01 GMT",
"version": "v2"
}
] | 2020-12-30 | [
[
"Graesser",
"Michael L.",
""
],
[
"Osiński",
"Jacek K.",
""
]
] | The thermal freeze-out mechanism for relic dark matter heavier than $O(10-100 $ TeV$)$ requires cross-sections that violate perturbative unitarity. Yet the existence of dark matter heavier than these scales is certainly plausible from a particle physics perspective, pointing to the need for a non-thermal cosmological history for such theories. Topological dark matter is a well-motivated scenario of this kind. Here the hidden-sector dark matter can be produced in abundance through the Kibble-Zurek mechanism describing the non-equilibrium dynamics of defects produced in a second order phase transition. We revisit the original topological dark matter scenario, focusing on hidden-sector magnetic monopoles, and consider more general cosmological histories. We find that a monopole mass of order ($1-10^5$) PeV is generic for the thermal histories considered here, if monopoles are to entirely reproduce the current abundance of dark matter. In particular, in a scenario involving an early era of matter domination, the monopole number density is always less than or equal to that in a pure radiation dominated equivalent provided a certain condition on critical exponents is satisfied. This results in a larger monopole mass needed to account for a fixed relic abundance in such cosmologies. |
hep-ph/9507208 | Hans-Guenter Kohrs | Hans-G. Kohrs (II. Institut fuer Theoretische Physik, Universitaet
Hamburg, Germany) | Direct and resolved pomeron | talk at Workshop on DIS and QCD, Paris, April 1995, 3 pages LaTeX,
uses qcdparis.sty, 4 Postscript figures (uuencoded) | null | null | null | hep-ph | null | We investigate the effect of a direct pomeron coupling to quarks in DIS and
photoproduction of jets. The direct pomeron coupling generates a point-like
contribution to the diffractive part of the structure function $F_2$, which is
analysed on the basis of the latest H1 data. Our model assumptions for the
pomeron structure are consistent with the measured data.
| [
{
"created": "Mon, 3 Jul 1995 16:37:42 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kohrs",
"Hans-G.",
"",
"II. Institut fuer Theoretische Physik, Universitaet\n Hamburg, Germany"
]
] | We investigate the effect of a direct pomeron coupling to quarks in DIS and photoproduction of jets. The direct pomeron coupling generates a point-like contribution to the diffractive part of the structure function $F_2$, which is analysed on the basis of the latest H1 data. Our model assumptions for the pomeron structure are consistent with the measured data. |
1308.0222 | Enrico De Micheli | Enrico De Micheli, Giovanni Alberto Viano | Transition from resonances to surface waves in pi^+-p elastic scattering | 35 pages, 8 figures | Annals of Physics 323, 1817-1843, 2008 | 10.1016/j.aop.2008.04.001 | null | hep-ph math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article we study resonances and surface waves in $\pi^+$--p
scattering. We focus on the sequence whose spin-parity values are given by $J^p
= {3/2}^+,{7/2}^+, {11/2}^+, {15/2}^+,{19/2}^+$. A widely-held belief takes for
granted that this sequence can be connected by a moving pole in the complex
angular momentum (CAM) plane, which gives rise to a linear trajectory of the
form $J = \alpha_0+\alpha' m^2$, $\alpha'\sim 1/(\mathrm{GeV})^2$, which is the
standard expression of the Regge pole trajectory. But the phenomenology shows
that only the first few resonances lie on a trajectory of this type. For higher
$J^p$ this rule is violated and is substituted by the relation $J\sim kR$,
where $k$ is the pion--nucleon c.m.s.-momentum, and $R\sim 1$ fm. In this
article we prove: (a) Starting from a non-relativistic model of the proton,
regarded as composed by three quarks confined by harmonic potentials, we prove
that the first three members of this $\pi^+$-p resonance sequence can be
associated with a vibrational spectrum of the proton generated by an algebra
$Sp(3,R)$. Accordingly, these first three members of the sequence can be
described by Regge poles and lie on a standard linear trajectory. (b) At higher
energies the amplitudes are dominated by diffractive scattering, and the
creeping waves play a dominant role. They can be described by a second class of
poles, which can be called Sommerfeld's poles, and lie on a line nearly
parallel to the imaginary axis of the CAM-plane. (c) The Sommerfeld pole which
is closest to the real axis of the CAM-plane is dominant at large angles, and
describes in a proper way the backward diffractive peak in both the following
cases: at fixed $k$, as a function of the scattering angle, and at fixed
scattering angle $\theta=\pi$, as a function of $k$. (d) The evolution of this
pole, as a function of $k$, is given in first approximation by $J\simeq kR$.
| [
{
"created": "Thu, 1 Aug 2013 14:33:00 GMT",
"version": "v1"
}
] | 2013-08-02 | [
[
"De Micheli",
"Enrico",
""
],
[
"Viano",
"Giovanni Alberto",
""
]
] | In this article we study resonances and surface waves in $\pi^+$--p scattering. We focus on the sequence whose spin-parity values are given by $J^p = {3/2}^+,{7/2}^+, {11/2}^+, {15/2}^+,{19/2}^+$. A widely-held belief takes for granted that this sequence can be connected by a moving pole in the complex angular momentum (CAM) plane, which gives rise to a linear trajectory of the form $J = \alpha_0+\alpha' m^2$, $\alpha'\sim 1/(\mathrm{GeV})^2$, which is the standard expression of the Regge pole trajectory. But the phenomenology shows that only the first few resonances lie on a trajectory of this type. For higher $J^p$ this rule is violated and is substituted by the relation $J\sim kR$, where $k$ is the pion--nucleon c.m.s.-momentum, and $R\sim 1$ fm. In this article we prove: (a) Starting from a non-relativistic model of the proton, regarded as composed by three quarks confined by harmonic potentials, we prove that the first three members of this $\pi^+$-p resonance sequence can be associated with a vibrational spectrum of the proton generated by an algebra $Sp(3,R)$. Accordingly, these first three members of the sequence can be described by Regge poles and lie on a standard linear trajectory. (b) At higher energies the amplitudes are dominated by diffractive scattering, and the creeping waves play a dominant role. They can be described by a second class of poles, which can be called Sommerfeld's poles, and lie on a line nearly parallel to the imaginary axis of the CAM-plane. (c) The Sommerfeld pole which is closest to the real axis of the CAM-plane is dominant at large angles, and describes in a proper way the backward diffractive peak in both the following cases: at fixed $k$, as a function of the scattering angle, and at fixed scattering angle $\theta=\pi$, as a function of $k$. (d) The evolution of this pole, as a function of $k$, is given in first approximation by $J\simeq kR$. |
hep-ph/0210071 | Maurizio Lusignoli | M. Lusignoli and A. Pugliese | A comment on hadronic charm decays | 8 pages, 4 tables. A few changes in the text, following revised
version of ref. 6. New reference added, no change in the numerical results | null | null | ROMA1-1342/2002 | hep-ph | null | We give arguments in favor of the compatibility with standard physics of some
large nonleptonic branching fractions in Cabibbo--forbidden $D^+$ decays,
contrary to a recent claim in the literature.
| [
{
"created": "Fri, 4 Oct 2002 09:16:48 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Nov 2002 17:39:48 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Lusignoli",
"M.",
""
],
[
"Pugliese",
"A.",
""
]
] | We give arguments in favor of the compatibility with standard physics of some large nonleptonic branching fractions in Cabibbo--forbidden $D^+$ decays, contrary to a recent claim in the literature. |
hep-ph/9608255 | null | Michael C. Birse (U. of Manchester), Thomas D. Cohen (U. of Maryland)
and Judith A. McGovern (U. of Manchester) | U(1) Axial Symmetry and Correlation Functions in the High Temperature
Phase of QCD | 3 pages, RevTeX | Phys.Lett. B388 (1996) 137-140 | 10.1016/0370-2693(96)01151-3 | U of Md PP#97-014, MC/TH 96/24 | hep-ph | null | Simple group-theoretical arguments are used to demonstrated that in the high
temperature (chirally restored) phase of QCD with N massless flavours, all
n-point correlation functions of quark bilinears are invariant under U(1) axial
transformations provided n < N. In particular this implies that the two-point
correlation function in the eta' channel is identical to that in the pion
channel for N > 2. Unlike previous work, this result does not depend on the
topological properties of QCD and can be formulated without explicit reference
to functional integrals.
| [
{
"created": "Wed, 7 Aug 1996 19:39:03 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Birse",
"Michael C.",
"",
"U. of Manchester"
],
[
"Cohen",
"Thomas D.",
"",
"U. of Maryland"
],
[
"McGovern",
"Judith A.",
"",
"U. of Manchester"
]
] | Simple group-theoretical arguments are used to demonstrated that in the high temperature (chirally restored) phase of QCD with N massless flavours, all n-point correlation functions of quark bilinears are invariant under U(1) axial transformations provided n < N. In particular this implies that the two-point correlation function in the eta' channel is identical to that in the pion channel for N > 2. Unlike previous work, this result does not depend on the topological properties of QCD and can be formulated without explicit reference to functional integrals. |
hep-ph/9503449 | Jin | Jin Dai, J.F. Gunion and R. Vega | SEARCHING FOR HIGGS BOSONS ON LHC USING $b$-TAGGING | Talk presented at BEYOUND THE STANDARD MODEL IV conference; Taho
City, 12/19/94, 3 pages. | null | null | null | hep-ph | null | We demonstrate that the detection of the SM and MSSM Higgs bosons will be
possible at the LHC via $t\anti t b\anti b$ and $b\anti b b\anti b$ final
state, provided $b$-tagging can be performed with good efficiency and purity.
| [
{
"created": "Mon, 27 Mar 1995 21:16:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Dai",
"Jin",
""
],
[
"Gunion",
"J. F.",
""
],
[
"Vega",
"R.",
""
]
] | We demonstrate that the detection of the SM and MSSM Higgs bosons will be possible at the LHC via $t\anti t b\anti b$ and $b\anti b b\anti b$ final state, provided $b$-tagging can be performed with good efficiency and purity. |
2306.07788 | Mira Varma | Mira Varma, O.K. Baker | Quantum Entanglement in Top Quark Pair Production | 10 pages, 5 figures | Nuclear Physics A, Volume 1042, February 2024, 122795 | 10.1016/j.nuclphysa.2023.122795 | NPA-D-23-00260 | hep-ph quant-ph | http://creativecommons.org/licenses/by/4.0/ | Top quarks, the most massive particles in the standard model, attract
considerable attention since they decay before hadronizing. This presents
physicists with a unique opportunity to directly investigate their properties.
In this letter, we expand upon the work of G. Iskander, J. Pan, M. Tyler, C.
Weber and O. K. Baker to demonstrate that even with the most massive
fundamental particle, we see the same manifestation of entanglement observed in
both electroweak and electromagnetic interactions. We propose that the thermal
component resulting from protons colliding into two top quarks emerges from
entanglement within the two-proton wave function. The presence of entanglement
implies the coexistence of both thermal and hard scattering components in the
transverse momentum distribution. We use published ATLAS and CMS results to
show that the data exhibits the expected behavior.
| [
{
"created": "Tue, 13 Jun 2023 14:08:47 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Jun 2023 16:19:09 GMT",
"version": "v2"
},
{
"created": "Fri, 29 Sep 2023 13:56:43 GMT",
"version": "v3"
}
] | 2024-06-14 | [
[
"Varma",
"Mira",
""
],
[
"Baker",
"O. K.",
""
]
] | Top quarks, the most massive particles in the standard model, attract considerable attention since they decay before hadronizing. This presents physicists with a unique opportunity to directly investigate their properties. In this letter, we expand upon the work of G. Iskander, J. Pan, M. Tyler, C. Weber and O. K. Baker to demonstrate that even with the most massive fundamental particle, we see the same manifestation of entanglement observed in both electroweak and electromagnetic interactions. We propose that the thermal component resulting from protons colliding into two top quarks emerges from entanglement within the two-proton wave function. The presence of entanglement implies the coexistence of both thermal and hard scattering components in the transverse momentum distribution. We use published ATLAS and CMS results to show that the data exhibits the expected behavior. |
2012.09653 | Rohan Pramanick | Rohan Pramanick, Swarup Sangiri, Utpal Sarkar | Bargmann Invariants, Geometric Phases and Recursive Parametrization with
Majorana Fermions | 16 pages | null | 10.1016/j.nuclphysb.2021.115315 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A generalized connection between the quantum mechanical Bargmann invariants
and the geometric phases was established for the Dirac fermions. We extend that
formalism for the Majorana fermions by defining proper quantum mechanical ray
and Hilbert spaces. We then relate both the Dirac and Majorana type Bargmann
invariants to the rephasing invariant measures of CP violation with the
Majorana neutrinos, assuming that the neutrinos have lepton number violating
Majorana masses. We then generalize the recursive parametrization for studying
any unitary matrices to include the Majorana fermions, which could be useful
for studying the neutrino mixing matrix.
| [
{
"created": "Thu, 17 Dec 2020 15:04:23 GMT",
"version": "v1"
}
] | 2021-02-24 | [
[
"Pramanick",
"Rohan",
""
],
[
"Sangiri",
"Swarup",
""
],
[
"Sarkar",
"Utpal",
""
]
] | A generalized connection between the quantum mechanical Bargmann invariants and the geometric phases was established for the Dirac fermions. We extend that formalism for the Majorana fermions by defining proper quantum mechanical ray and Hilbert spaces. We then relate both the Dirac and Majorana type Bargmann invariants to the rephasing invariant measures of CP violation with the Majorana neutrinos, assuming that the neutrinos have lepton number violating Majorana masses. We then generalize the recursive parametrization for studying any unitary matrices to include the Majorana fermions, which could be useful for studying the neutrino mixing matrix. |
hep-ph/0201098 | Jeff Forshaw | J.M. Butterworth, B.E. Cox and J.R. Forshaw | WW scattering at the LHC | 29 pages | Phys.Rev.D65:096014,2002 | 10.1103/PhysRevD.65.096014 | MC-TH-01/13, MAN/HEP/01/05, UCL/HEP 2001-06 | hep-ph | null | A detailed study is presented of elastic WW scattering in the scenario that
there are no new particles discovered prior to the commissioning of the LHC. We
work within the framework of the electroweak chiral lagrangian and two
different unitarisation protocols are investigated. Signals and backgrounds are
simulated to the final-state-particle level. A new technique for identifying
the hadronically decaying W is developed, which is more generally applicable to
massive particles which decay to jets where the separation of the jets is
small. The effect of different assumptions about the underlying event is also
studied. We conclude that the channel WW -> jj+l+nu may contain scalar and/or
vector resonances which could be measurable after 100 fb^(-1) of LHC data.
| [
{
"created": "Fri, 11 Jan 2002 17:00:39 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Butterworth",
"J. M.",
""
],
[
"Cox",
"B. E.",
""
],
[
"Forshaw",
"J. R.",
""
]
] | A detailed study is presented of elastic WW scattering in the scenario that there are no new particles discovered prior to the commissioning of the LHC. We work within the framework of the electroweak chiral lagrangian and two different unitarisation protocols are investigated. Signals and backgrounds are simulated to the final-state-particle level. A new technique for identifying the hadronically decaying W is developed, which is more generally applicable to massive particles which decay to jets where the separation of the jets is small. The effect of different assumptions about the underlying event is also studied. We conclude that the channel WW -> jj+l+nu may contain scalar and/or vector resonances which could be measurable after 100 fb^(-1) of LHC data. |
1707.03990 | Victor Martin Lozano | David G. Cerdeno, Valentina De Romeri, Victor Martin-Lozano, Keith A.
Olive, Osamu Seto | The Constrained NMSSM with right-handed neutrinos | 21 pages, 4 figures | null | 10.1140/epjc/s10052-018-5689-0 | IPPP/17/56; DCTP/17/112; IFT-UAM/CSIC-17-064; BONN-TH-2017-06;
EPHOU-17-011; UMN-TH-3631/17; FTPI-MINN-17/13 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article, we study the renormalization group equations of the
Next-to-Minimal Supersymmetric Standard Model, and investigate universality
conditions on the soft supersymmetry-breaking parameters at the Grand
Unification scale. We demonstrate that the inclusion of right-handed neutrino
superfields can have a substantial effect on the running of the soft terms
(greatly contributing to driving the singlet Higgs mass- squared parameter
negative), which makes it considerably easier to satisfy the conditions for
radiative electroweak symmetry-breaking. The new fields also lead to larger
values of the Standard Model Higgs mass, thus making it easier to reproduce the
measured value. We investigate the phenomenology of this constrained scenario,
and focus on two viable benchmark points, which feature a neutral lightest
supersymmetric particle (either the lightest neutralino or the right-handed
sneutrino). We show that all bounds from colliders and low-energy observables
can be fulfilled in wide areas of the parameter space. However, the relic
density in these regions is generally too high requiring some form of late
entropy production to dilute the density of the lightest supersymmetric
particle.
| [
{
"created": "Thu, 13 Jul 2017 06:56:25 GMT",
"version": "v1"
}
] | 2022-10-19 | [
[
"Cerdeno",
"David G.",
""
],
[
"De Romeri",
"Valentina",
""
],
[
"Martin-Lozano",
"Victor",
""
],
[
"Olive",
"Keith A.",
""
],
[
"Seto",
"Osamu",
""
]
] | In this article, we study the renormalization group equations of the Next-to-Minimal Supersymmetric Standard Model, and investigate universality conditions on the soft supersymmetry-breaking parameters at the Grand Unification scale. We demonstrate that the inclusion of right-handed neutrino superfields can have a substantial effect on the running of the soft terms (greatly contributing to driving the singlet Higgs mass- squared parameter negative), which makes it considerably easier to satisfy the conditions for radiative electroweak symmetry-breaking. The new fields also lead to larger values of the Standard Model Higgs mass, thus making it easier to reproduce the measured value. We investigate the phenomenology of this constrained scenario, and focus on two viable benchmark points, which feature a neutral lightest supersymmetric particle (either the lightest neutralino or the right-handed sneutrino). We show that all bounds from colliders and low-energy observables can be fulfilled in wide areas of the parameter space. However, the relic density in these regions is generally too high requiring some form of late entropy production to dilute the density of the lightest supersymmetric particle. |
1603.03288 | Francesco Capozzi | Francesco Capozzi (Padua Univ. & INFN Padua), Basudeb Dasgupta (TIFR,
Mumbai), Alessandro Mirizzi (Bari Univ. & INFN Bari) | Self-induced temporal instability from a neutrino antenna | v2: revised version, 15 pages, 6 figures. Minor changes. Typos
removed, figures improved. Matches the version accepted on JCAP | JCAP 1604 (2016) no.04, 043 | 10.1088/1475-7516/2016/04/043 | TIFR/TH/16-06 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It has been recently shown that the flavor composition of a self-interacting
neutrino gas can spontaneously acquire a time-dependent pulsating component
during its flavor evolution. In this work, we perform a more detailed study of
this effect in a model where neutrinos are assumed to be emitted in a
two-dimensional plane from an infinite line that acts as a neutrino antenna. We
consider several examples with varying matter and neutrino densities and find
that temporal instabilities with various frequencies are excited in a cascade.
We compare the numerical calculations of the flavor evolution with the
predictions of linearized stability analysis of the equations of motion. The
results obtained with these two approaches are in good agreement in the linear
regime, while a dramatic speed-up of the flavor conversions occurs in the
non-linear regime due to the interactions among the different pulsating modes.
We show that large flavor conversions can take place if some of the temporal
modes are unstable for long enough, and that this can happen even if the matter
and neutrino densities are changing, as long as they vary slowly.
| [
{
"created": "Thu, 10 Mar 2016 14:48:38 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Apr 2016 09:33:39 GMT",
"version": "v2"
}
] | 2016-04-26 | [
[
"Capozzi",
"Francesco",
"",
"Padua Univ. & INFN Padua"
],
[
"Dasgupta",
"Basudeb",
"",
"TIFR,\n Mumbai"
],
[
"Mirizzi",
"Alessandro",
"",
"Bari Univ. & INFN Bari"
]
] | It has been recently shown that the flavor composition of a self-interacting neutrino gas can spontaneously acquire a time-dependent pulsating component during its flavor evolution. In this work, we perform a more detailed study of this effect in a model where neutrinos are assumed to be emitted in a two-dimensional plane from an infinite line that acts as a neutrino antenna. We consider several examples with varying matter and neutrino densities and find that temporal instabilities with various frequencies are excited in a cascade. We compare the numerical calculations of the flavor evolution with the predictions of linearized stability analysis of the equations of motion. The results obtained with these two approaches are in good agreement in the linear regime, while a dramatic speed-up of the flavor conversions occurs in the non-linear regime due to the interactions among the different pulsating modes. We show that large flavor conversions can take place if some of the temporal modes are unstable for long enough, and that this can happen even if the matter and neutrino densities are changing, as long as they vary slowly. |
1607.07318 | Takahiro Ueda | T. Ueda, B. Ruijl and J.A.M. Vermaseren | Forcer: a FORM program for 4-loop massless propagators | 10 pages, 2 figures, to appear in the proceedings of Loops and Legs
in Quantum Field Theory, 24-29 April 2016, Leipzig, Germany | null | null | NIKHEF-2016-036 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new FORM program for analytically evaluating four-loop massless
propagator-type Feynman integrals in an efficient way. Our program Forcer
implements parametric reductions of the aforementioned class of Feynman
integrals into a set of master integrals and can be considered as a four-loop
extension of the three-loop Mincer program. Since the program structure at the
four-loop level is highly complicated and the equations easily become lengthy,
most of the code was generated in an automatic way or with computer-assisted
derivations. We have checked correctness of the program by recomputing
already-known quantities in the literature.
| [
{
"created": "Mon, 25 Jul 2016 15:31:53 GMT",
"version": "v1"
}
] | 2016-07-26 | [
[
"Ueda",
"T.",
""
],
[
"Ruijl",
"B.",
""
],
[
"Vermaseren",
"J. A. M.",
""
]
] | We present a new FORM program for analytically evaluating four-loop massless propagator-type Feynman integrals in an efficient way. Our program Forcer implements parametric reductions of the aforementioned class of Feynman integrals into a set of master integrals and can be considered as a four-loop extension of the three-loop Mincer program. Since the program structure at the four-loop level is highly complicated and the equations easily become lengthy, most of the code was generated in an automatic way or with computer-assisted derivations. We have checked correctness of the program by recomputing already-known quantities in the literature. |
1207.1445 | Dan Hooper | Matthew R. Buckley and Dan Hooper | Are There Hints of Light Stops in Recent Higgs Search Results? | 6 pages, 5 figures | null | 10.1103/PhysRevD.86.075008 | FERMILAB-PUB-12-315-A | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recent discovery at the LHC by the CMS and ATLAS collaborations of the
Higgs boson presents, at long last, direct probes of the mechanism for
electroweak symmetry breaking. While it is clear from the observations that the
new particle plays some role in this process, it is not yet apparent whether
the couplings and widths of the observed particle match those predicted by the
Standard Model. In this paper, we perform a global fit of the Higgs results
from the LHC and Tevatron. While these results could be subject to
as-yet-unknown systematics, we find that the data are significantly better fit
by a Higgs with a suppressed width to gluon-gluon and an enhanced width to
gamma gamma, relative to the predictions of the Standard Model. After
considering a variety of new physics scenarios which could potenially modify
these widths, we find that the most promising possibility is the addition of a
new colored, charged particle, with a large coupling to the Higgs. Of
particular interest is a light, and highly mixed, stop, which we show can
provide the required alterations to the combination of gg and gamma gamma
widths.
| [
{
"created": "Thu, 5 Jul 2012 20:02:08 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Sep 2012 14:38:09 GMT",
"version": "v2"
}
] | 2015-06-05 | [
[
"Buckley",
"Matthew R.",
""
],
[
"Hooper",
"Dan",
""
]
] | The recent discovery at the LHC by the CMS and ATLAS collaborations of the Higgs boson presents, at long last, direct probes of the mechanism for electroweak symmetry breaking. While it is clear from the observations that the new particle plays some role in this process, it is not yet apparent whether the couplings and widths of the observed particle match those predicted by the Standard Model. In this paper, we perform a global fit of the Higgs results from the LHC and Tevatron. While these results could be subject to as-yet-unknown systematics, we find that the data are significantly better fit by a Higgs with a suppressed width to gluon-gluon and an enhanced width to gamma gamma, relative to the predictions of the Standard Model. After considering a variety of new physics scenarios which could potenially modify these widths, we find that the most promising possibility is the addition of a new colored, charged particle, with a large coupling to the Higgs. Of particular interest is a light, and highly mixed, stop, which we show can provide the required alterations to the combination of gg and gamma gamma widths. |
hep-ph/0211030 | Sergey Troshin | S. M. Troshin, N. E. Tyurin | Multiparticle production in the model with antishadowing | 11 pages, 3 figures, extended version of the talk at the XXXII
International Symposium on Multiparticle Dynamics September 7-13, 2002
Alushta, Crimea, Ukraine | J.Phys.G29:1061-1068,2003 | 10.1088/0954-3899/29/6/309 | null | hep-ph | null | We discuss the role of absorbtion and antishadowing in particle production.
We reproduce power-like energy behavior of the mean multiplicity in the model
with antishadowing and discuss physical implications of such behavior for the
hadron structure.
| [
{
"created": "Mon, 4 Nov 2002 07:23:52 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Troshin",
"S. M.",
""
],
[
"Tyurin",
"N. E.",
""
]
] | We discuss the role of absorbtion and antishadowing in particle production. We reproduce power-like energy behavior of the mean multiplicity in the model with antishadowing and discuss physical implications of such behavior for the hadron structure. |
hep-ph/0201281 | Stefano Frixione | S. Frixione and P. Nason | Phenomenological study of charm photoproduction at HERA | 15 pages Latex; 25 figures included | JHEP 0203 (2002) 053 | 10.1088/1126-6708/2002/03/053 | Bicocca-FT-02-1, LAPTH-897/02, GEF-th-1/2002 | hep-ph | null | We present predictions for single inclusive distributions of charmed mesons,
relevant to the HERA experiments. Our results are based upon a computation that
correctly incorporates mass effects up to the next-to-leading order level, and
the resummation of transverse momentum logarithms up to
next-to-leading-logarithmic level. We apply the same acceptance cuts as the H1
and Zeus experiments, and compare our results to their data. We perform a study
of the sensitivity of our predictions on the charm mass, $\LambdaQCD$,
factorization scale, renormalization scale, and fragmentation parameters.
| [
{
"created": "Wed, 30 Jan 2002 09:10:43 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Frixione",
"S.",
""
],
[
"Nason",
"P.",
""
]
] | We present predictions for single inclusive distributions of charmed mesons, relevant to the HERA experiments. Our results are based upon a computation that correctly incorporates mass effects up to the next-to-leading order level, and the resummation of transverse momentum logarithms up to next-to-leading-logarithmic level. We apply the same acceptance cuts as the H1 and Zeus experiments, and compare our results to their data. We perform a study of the sensitivity of our predictions on the charm mass, $\LambdaQCD$, factorization scale, renormalization scale, and fragmentation parameters. |
hep-ph/0510055 | Herbert Weigel | H. Walliser, H. Weigel | Bound State versus Collective Coordinate Approaches in Chiral Soliton
Models and the Width of the $\Theta^+$ Pentaquark | minor language changes, version to be published in Eur. Phys. J. A | Eur.Phys.J. A26 (2005) 361-382 | 10.1140/epja/i2005-10180-5 | null | hep-ph hep-ex hep-th nucl-ex nucl-th | null | We thoroughly compare the bound state and rigid rotator approaches to
three--flavored chiral solitons. We establish that these two approaches yield
identical results for the baryon spectrum and kaon--nucleon $S$--matrix in the
limit that the number of colors ($N_C$) tends to infinity. After proper
subtraction of the background phase shift the bound state approach indeed
exhibits a clear resonance behavior in the strangeness $S=+1$ channel. We
present a first dynamical calculation of the widths of the $\Theta^+$ and
$\Theta^*$ pentaquarks for finite $N_C$ in a chiral soliton model.
| [
{
"created": "Wed, 5 Oct 2005 08:07:57 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Dec 2005 14:08:50 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Walliser",
"H.",
""
],
[
"Weigel",
"H.",
""
]
] | We thoroughly compare the bound state and rigid rotator approaches to three--flavored chiral solitons. We establish that these two approaches yield identical results for the baryon spectrum and kaon--nucleon $S$--matrix in the limit that the number of colors ($N_C$) tends to infinity. After proper subtraction of the background phase shift the bound state approach indeed exhibits a clear resonance behavior in the strangeness $S=+1$ channel. We present a first dynamical calculation of the widths of the $\Theta^+$ and $\Theta^*$ pentaquarks for finite $N_C$ in a chiral soliton model. |
1103.3501 | Moira Gresham | Moira I. Gresham, Ian-Woo Kim and Kathryn M. Zurek | On Models of New Physics for the Tevatron Top A_FB | 29 pages, 14 figures, 2 tables | Phys.Rev.D83:114027,2011 | 10.1103/PhysRevD.83.114027 | MCTP-11-13 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | CDF has observed a top forward-backward asymmetry discrepant with the
Standard Model prediction at 3.4 \sigma. We analyze models that could generate
the asymmetry, including flavor-violating W's, horizontal Z'_Hs, triplet and
sextet diquarks, and axigluons. We consider the detailed predictions of these
models for the invariant mass and rapidity distributions of the asymmetry at
the parton level, comparing against the unfolded parton-level CDF results.
While all models can reproduce the asymmetry with the appropriate choice of
mass and couplings, it appears at first examination that the extracted
parton-level invariant mass distribution for all models are in conflict with
Tevatron observations. We show on closer examination, however, that t tbar
events in Z'_H and W' models have considerably lower selection efficiencies in
high invariant mass bins as compared to the Standard Model, so that W', Z'_H,
and axigluon models can generate the observed asymmetry while being consistent
with the total cross-section and invariant mass spectrum. Triplet and sextet
models have greater difficulty producing the observed asymmetry while remaining
consistent with the total cross-section and invariant mass distribution. To
more directly match the models and the CDF results, we proceed to decay and
reconstruct the tops, comparing our results against the "raw" CDF asymmetry and
invariant mass distributions. We find that the models that successfully
generate the corrected CDF asymmetry at the parton level reproduce very well
the more finely binned uncorrected asymmetry. Finally, we discuss the early LHC
reach for discovery of these models, based on our previous analysis
[arXiv:1102.0018].
| [
{
"created": "Thu, 17 Mar 2011 20:00:01 GMT",
"version": "v1"
}
] | 2015-03-19 | [
[
"Gresham",
"Moira I.",
""
],
[
"Kim",
"Ian-Woo",
""
],
[
"Zurek",
"Kathryn M.",
""
]
] | CDF has observed a top forward-backward asymmetry discrepant with the Standard Model prediction at 3.4 \sigma. We analyze models that could generate the asymmetry, including flavor-violating W's, horizontal Z'_Hs, triplet and sextet diquarks, and axigluons. We consider the detailed predictions of these models for the invariant mass and rapidity distributions of the asymmetry at the parton level, comparing against the unfolded parton-level CDF results. While all models can reproduce the asymmetry with the appropriate choice of mass and couplings, it appears at first examination that the extracted parton-level invariant mass distribution for all models are in conflict with Tevatron observations. We show on closer examination, however, that t tbar events in Z'_H and W' models have considerably lower selection efficiencies in high invariant mass bins as compared to the Standard Model, so that W', Z'_H, and axigluon models can generate the observed asymmetry while being consistent with the total cross-section and invariant mass spectrum. Triplet and sextet models have greater difficulty producing the observed asymmetry while remaining consistent with the total cross-section and invariant mass distribution. To more directly match the models and the CDF results, we proceed to decay and reconstruct the tops, comparing our results against the "raw" CDF asymmetry and invariant mass distributions. We find that the models that successfully generate the corrected CDF asymmetry at the parton level reproduce very well the more finely binned uncorrected asymmetry. Finally, we discuss the early LHC reach for discovery of these models, based on our previous analysis [arXiv:1102.0018]. |
0708.4314 | Sergey Goloskokov | S.V. Goloskokov | Vector meson electroproduction within GPD approach | 7pages, 4 figures, Talk at 12th International Conference on Elastic
and Diffractive Scattering, DESY, Hamburg May 2007 | null | null | null | hep-ph | null | We analyze electroproduction of light vector meson at small Bjorken $x$
within the generalized parton distribution (GPD) approach. Calculation is based
on the modified perturbative approach, where the quark transverse degrees of
freedom in the hard subprocess are considered. Our results on the cross section
are in fair agreement with experiment from HERMES to HERA energies.
| [
{
"created": "Fri, 31 Aug 2007 11:23:50 GMT",
"version": "v1"
}
] | 2007-09-03 | [
[
"Goloskokov",
"S. V.",
""
]
] | We analyze electroproduction of light vector meson at small Bjorken $x$ within the generalized parton distribution (GPD) approach. Calculation is based on the modified perturbative approach, where the quark transverse degrees of freedom in the hard subprocess are considered. Our results on the cross section are in fair agreement with experiment from HERMES to HERA energies. |
2403.13160 | Sunny Kumar Singh | Sunny Kumar Singh, Manu Kurian, Vinod Chandra | Revisiting shear stress tensor evolution: Non-resistive
magnetohydrodynamics with momentum-dependent relaxation time | 25 pages, 3 figures, 1 table, version accepted in Physical Review D | null | 10.1103/PhysRevD.110.014004 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This study aims to develop second-order relativistic viscous
magnetohydrodynamics (MHD) derived from kinetic theory within an extended
relaxation time approximation (momentum/energy dependent) for the collision
kernel. The investigation involves a detailed examination of shear stress
tensor evolution equations and associated transport coefficients. The Boltzmann
equation is solved using a Chapman-Enskog-like gradient expansion for a
charge-conserved conformal system, incorporating a momentum-dependent
relaxation time. The derived relativistic non-resistive, viscous second-order
MHD equations for the shear stress tensor reveal significant modifications in
the coupling with dissipative charge current and magnetic field due to the
momentum dependence of the relaxation time. By utilizing a power law
parametrization to quantify the momentum dependence of the relaxation time, the
anisotropic magnetic field-dependent shear coefficients in the Navier-Stokes
limit have been investigated. The resulting viscous coefficients are seen to be
sensitive to the momentum dependence of the relaxation time.
| [
{
"created": "Tue, 19 Mar 2024 21:24:57 GMT",
"version": "v1"
},
{
"created": "Fri, 24 May 2024 20:32:14 GMT",
"version": "v2"
}
] | 2024-07-24 | [
[
"Singh",
"Sunny Kumar",
""
],
[
"Kurian",
"Manu",
""
],
[
"Chandra",
"Vinod",
""
]
] | This study aims to develop second-order relativistic viscous magnetohydrodynamics (MHD) derived from kinetic theory within an extended relaxation time approximation (momentum/energy dependent) for the collision kernel. The investigation involves a detailed examination of shear stress tensor evolution equations and associated transport coefficients. The Boltzmann equation is solved using a Chapman-Enskog-like gradient expansion for a charge-conserved conformal system, incorporating a momentum-dependent relaxation time. The derived relativistic non-resistive, viscous second-order MHD equations for the shear stress tensor reveal significant modifications in the coupling with dissipative charge current and magnetic field due to the momentum dependence of the relaxation time. By utilizing a power law parametrization to quantify the momentum dependence of the relaxation time, the anisotropic magnetic field-dependent shear coefficients in the Navier-Stokes limit have been investigated. The resulting viscous coefficients are seen to be sensitive to the momentum dependence of the relaxation time. |
hep-ph/0310013 | A. H. Rezaeian | Amir H. Rezaeian, Niels R. Walet, Michael C. Birse | Relativistic Faddeev approach to a non-local NJL model | 5 pages (AIP style), 3 figures, Talk presented at the " Xth
International Conference on Hadron Spectroscopy (HADRON '03) ", August
31-September 6, 2003, Aschaffenburg, Germany | AIP Conf.Proc. 717 (2004) 690-694 | 10.1063/1.1799781 | null | hep-ph nucl-th | null | The diquark and nucleon are studied in a non-local NJL model. We solve the
relativistic Faddeev equation and compare the results with the ordinary NJL
model. Although the model is quark confining, it is not diquark confining in
the rainbow-ladder approximation. We show that the off-shell contribution to
the diquark $T$ matrix is crucial for the structure of the nucleon: without its
inclusion the attraction in the scalar channel is too weak to form a three-body
bound state.
| [
{
"created": "Wed, 1 Oct 2003 10:26:39 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Rezaeian",
"Amir H.",
""
],
[
"Walet",
"Niels R.",
""
],
[
"Birse",
"Michael C.",
""
]
] | The diquark and nucleon are studied in a non-local NJL model. We solve the relativistic Faddeev equation and compare the results with the ordinary NJL model. Although the model is quark confining, it is not diquark confining in the rainbow-ladder approximation. We show that the off-shell contribution to the diquark $T$ matrix is crucial for the structure of the nucleon: without its inclusion the attraction in the scalar channel is too weak to form a three-body bound state. |
1203.1267 | Dmitry Kirpichnikov | D. V. Kirpichnikov | LHC signatures of vector boson emission from brane to bulk | null | Phys. Rev. D. 85. 115008 (2012) | 10.1103/PhysRevD.85.115008 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of the RSII-n model with n compact and one infinite extra
dimensions, we study the production of Z-bosons and photons, which escape into
the bulk, in association with a jet in pp collisions at the LHC energies. This
would show up as the process pp -> jet+bulk. We calculate the distributions in
the jet transverse momentum and rapidity and compare them with the Standard
Model background pp->jet +\nu\bar{\nu}.We find that the models with n>3 can be
probed at the collision energy 14 TeV, while searches at 7 TeV are sensitive to
models with n>5 only.
| [
{
"created": "Tue, 6 Mar 2012 18:06:59 GMT",
"version": "v1"
}
] | 2013-12-16 | [
[
"Kirpichnikov",
"D. V.",
""
]
] | In the framework of the RSII-n model with n compact and one infinite extra dimensions, we study the production of Z-bosons and photons, which escape into the bulk, in association with a jet in pp collisions at the LHC energies. This would show up as the process pp -> jet+bulk. We calculate the distributions in the jet transverse momentum and rapidity and compare them with the Standard Model background pp->jet +\nu\bar{\nu}.We find that the models with n>3 can be probed at the collision energy 14 TeV, while searches at 7 TeV are sensitive to models with n>5 only. |
hep-ph/9411388 | Seiji Matsumoto | Seiji Matsumoto | Constraints on the electroweak universal parameters and the top and
Higgs masses from updated LEP/SLC data | 19 pages, uuencoded compressed tar file of LaTeX file and 7 EPS files
(uses cite.sty and psfig.sty), PostScript version of complete paper available
at ftp://ftp.kek.jp/kek/preprints/TH/TH-418/kekth418.ps.gz | Mod.Phys.Lett.A10:2553-2570,1995 | 10.1142/S0217732395002696 | KEK-TH-418, KEK preprint 94-147, KANAZAWA-94-24 | hep-ph | null | A global analysis is performed using the latest data from LEP and SLC.
Constraints on the electroweak universal parameters ($S,T,U$) and on the masses
of the top quark and Higgs boson within the Standard Model (SM) are
investigated. The uncertainties due to the QCD and QED effective couplings,
$\alpha_s(\mz)$ and $\bar{\alpha}(\mmz)$, are examined in detail. Even though
the mean value of $S$ is increased to be consistent with zero, the naive
Technicolor models are still disfavored due to its reduced error. Within the
SM, we find the 90\,\%CL constraints; $133\gev<m_t<190\gev$ and
$10\gev<\mh<440\gev$ for $\alpha_s(\mz)=0.116$ and $1/\bar{\alpha}(\mmz)
=128.72$. The experimental constraints on the $\zbb$ vertex form-factor,
$\delb(\mmz)$, play an important role in disfavoring the region of large
$m_t(m_t \sim 200\gev)$ and large $\mh(\mh \sim 1000\gev)$. If $m_t$ is
precisely known, the present electroweak data give a rather strict upper bound
on the Higgs mass, $\mh<140\,(300)\gev\,$ at 95\%~CL, for $m_t=160\, (175)\gev$
and for the above $\alpha_s(\mz)$ and $\bar{\alpha}(\mmz)$.
| [
{
"created": "Thu, 24 Nov 1994 17:06:29 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Matsumoto",
"Seiji",
""
]
] | A global analysis is performed using the latest data from LEP and SLC. Constraints on the electroweak universal parameters ($S,T,U$) and on the masses of the top quark and Higgs boson within the Standard Model (SM) are investigated. The uncertainties due to the QCD and QED effective couplings, $\alpha_s(\mz)$ and $\bar{\alpha}(\mmz)$, are examined in detail. Even though the mean value of $S$ is increased to be consistent with zero, the naive Technicolor models are still disfavored due to its reduced error. Within the SM, we find the 90\,\%CL constraints; $133\gev<m_t<190\gev$ and $10\gev<\mh<440\gev$ for $\alpha_s(\mz)=0.116$ and $1/\bar{\alpha}(\mmz) =128.72$. The experimental constraints on the $\zbb$ vertex form-factor, $\delb(\mmz)$, play an important role in disfavoring the region of large $m_t(m_t \sim 200\gev)$ and large $\mh(\mh \sim 1000\gev)$. If $m_t$ is precisely known, the present electroweak data give a rather strict upper bound on the Higgs mass, $\mh<140\,(300)\gev\,$ at 95\%~CL, for $m_t=160\, (175)\gev$ and for the above $\alpha_s(\mz)$ and $\bar{\alpha}(\mmz)$. |
1306.6618 | Igor Strakovsky | V.E. Tarasov (ITEP), W.J. Briscoe (GWU), W. Gradl (Mainz U.), A.E.
Kudryavtsev (ITEP/GWU), I.I. Strakovsky (GWU) | Photoproduction and mixing effects of scalar a0 and f0 mesons | 18 pages, 9 figures, 1 table; v2: added some refs | null | 10.1103/PhysRevC.88.035207 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The photoproduction processes gp-->a0(980)p and gp-->f0(980)p at energies
close to threshold are considered. These reactions are studied in the \pi\pi p,
\pi\eta p, and K-barK p channels. Production cross sections are estimated in
different models. The role of the a0^0-f0 mixing is examined in the invariant
\pi\pi-,\pi\eta-, and K-barK-mass spectra.
| [
{
"created": "Thu, 27 Jun 2013 19:39:43 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Jul 2013 22:06:23 GMT",
"version": "v2"
}
] | 2013-10-02 | [
[
"Tarasov",
"V. E.",
"",
"ITEP"
],
[
"Briscoe",
"W. J.",
"",
"GWU"
],
[
"Gradl",
"W.",
"",
"Mainz U."
],
[
"Kudryavtsev",
"A. E.",
"",
"ITEP/GWU"
],
[
"Strakovsky",
"I. I.",
"",
"GWU"
]
] | The photoproduction processes gp-->a0(980)p and gp-->f0(980)p at energies close to threshold are considered. These reactions are studied in the \pi\pi p, \pi\eta p, and K-barK p channels. Production cross sections are estimated in different models. The role of the a0^0-f0 mixing is examined in the invariant \pi\pi-,\pi\eta-, and K-barK-mass spectra. |
1404.5632 | A. H. Rezaeian | Alex Kovner, Amir H. Rezaeian | Diphoton production in high-energy p+A collisions | 17 pages, 8 figures; v2: results unchanged, a clarifying footnote
added. The version to appear in PRD | Phys. Rev. D 90, 014031 (2014) | 10.1103/PhysRevD.90.014031 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider semi-inclusive diphoton+jet and inclusive diphoton production in
high-energy proton-nucleus collisions, treating the target nucleus as a
Color-Glass-Condensate and the projectile proton in the parton model. We obtain
the prompt diphoton production cross-section in terms of fragmentation and
direct contributions. The fragmentation part is given in terms of single-photon
and double-photon fragmentation functions. We study prompt, direct and
fragmentation diphoton correlations in p+p and p+A collisions at the LHC, and
show that at low values of transverse momenta of the produced photon pair,
these correlations are sensitive to saturation effects. We show that
back-to-back (de)-correlations in prompt diphoton production are stronger in
fragmentation part than in the direct one.
| [
{
"created": "Tue, 22 Apr 2014 20:00:50 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Jul 2014 20:03:48 GMT",
"version": "v2"
}
] | 2014-07-23 | [
[
"Kovner",
"Alex",
""
],
[
"Rezaeian",
"Amir H.",
""
]
] | We consider semi-inclusive diphoton+jet and inclusive diphoton production in high-energy proton-nucleus collisions, treating the target nucleus as a Color-Glass-Condensate and the projectile proton in the parton model. We obtain the prompt diphoton production cross-section in terms of fragmentation and direct contributions. The fragmentation part is given in terms of single-photon and double-photon fragmentation functions. We study prompt, direct and fragmentation diphoton correlations in p+p and p+A collisions at the LHC, and show that at low values of transverse momenta of the produced photon pair, these correlations are sensitive to saturation effects. We show that back-to-back (de)-correlations in prompt diphoton production are stronger in fragmentation part than in the direct one. |
hep-ph/0407092 | Osamu Seto | Nobuchika Okada and Osamu Seto | Relic density of dark matter in brane world cosmology | 8 pages, no figure, the version accepted for publication in
Phys.Rev.D | Phys.Rev. D70 (2004) 083531 | 10.1103/PhysRevD.70.083531 | KEK-TH-969 | hep-ph astro-ph | null | We investigate the thermal relic density of the cold dark matter in the
context of the brane world cosmology. Since the expansion law in a high energy
regime is modified from the one in the standard cosmology, if the dark matter
decouples in such a high energy regime its relic number density is affected by
this modified expansion law. We derive analytic formulas for the number density
of the dark matter. It is found that the resultant relic density is
characterized by the ``transition temperature'' at which the modified expansion
law in the brane world cosmology is connecting with the standard one, and can
be considerably enhanced compared to that in the standard cosmology, if the
transition temperature is low enough.
| [
{
"created": "Thu, 8 Jul 2004 01:14:52 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Sep 2004 16:02:24 GMT",
"version": "v2"
}
] | 2016-09-06 | [
[
"Okada",
"Nobuchika",
""
],
[
"Seto",
"Osamu",
""
]
] | We investigate the thermal relic density of the cold dark matter in the context of the brane world cosmology. Since the expansion law in a high energy regime is modified from the one in the standard cosmology, if the dark matter decouples in such a high energy regime its relic number density is affected by this modified expansion law. We derive analytic formulas for the number density of the dark matter. It is found that the resultant relic density is characterized by the ``transition temperature'' at which the modified expansion law in the brane world cosmology is connecting with the standard one, and can be considerably enhanced compared to that in the standard cosmology, if the transition temperature is low enough. |
2010.03730 | Lei Wang | Xiao-Fang Han, Lei Wang, Yang Zhang | Dark matter, electroweak phase transition and gravitational wave in the
type-II two-Higgs-doublet model with a singlet scalar field | 30 pages, 8 figures, 3 tables; references added in v2 | Phys. Rev. D 103, 035012 (2021) | 10.1103/PhysRevD.103.035012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of type-II two-Higgs-doublet model with a singlet scalar
dark matter $S$, we study the dark matter observables, the electroweak phase
transition, and the gravitational wave signals by such strongly first order
phase transition after imposing the constraints of the LHC Higgs data. We take
the heavy CP-even Higgs $H$ as the only portal between the dark matter and SM
sectors, and find the LHC Higgs data and dark matter observables require $m_S$
and $m_H$ to be larger than 130 GeV and 360 GeV for $m_A=600$ GeV in the case
of the 125 GeV Higgs with the SM-like coupling. Next, we carve out some
parameter space where a strongly first order electroweak phase transition can
be achieved, and find benchmark points for which the amplitudes of
gravitational wave spectra reach the sensitivities of the future gravitational
wave detectors.
| [
{
"created": "Thu, 8 Oct 2020 02:13:38 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Oct 2020 13:37:10 GMT",
"version": "v2"
}
] | 2021-02-24 | [
[
"Han",
"Xiao-Fang",
""
],
[
"Wang",
"Lei",
""
],
[
"Zhang",
"Yang",
""
]
] | In the framework of type-II two-Higgs-doublet model with a singlet scalar dark matter $S$, we study the dark matter observables, the electroweak phase transition, and the gravitational wave signals by such strongly first order phase transition after imposing the constraints of the LHC Higgs data. We take the heavy CP-even Higgs $H$ as the only portal between the dark matter and SM sectors, and find the LHC Higgs data and dark matter observables require $m_S$ and $m_H$ to be larger than 130 GeV and 360 GeV for $m_A=600$ GeV in the case of the 125 GeV Higgs with the SM-like coupling. Next, we carve out some parameter space where a strongly first order electroweak phase transition can be achieved, and find benchmark points for which the amplitudes of gravitational wave spectra reach the sensitivities of the future gravitational wave detectors. |
0802.0032 | Stefano Forte | Guido Altarelli, Richard D. Ball, Stefano Forte | Small x Resummation with Quarks: Deep-Inelastic Scattering | 45 pages, 16 figures, plain TeX with harvmac | Nucl.Phys.B799:199-240,2008 | 10.1016/j.nuclphysb.2008.03.003 | IFUM-905-FT, CERN-PH-TH/2008-014, Edinburgh 2007/49, RM3-TH/08-1 | hep-ph | null | We extend our previous results on small-x resummation in the pure Yang--Mills
theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of
resummed quark and gluon splitting functions. We also construct the
corresponding deep-inelastic coefficient functions, and show how these can be
combined with parton densities to give fully resummed deep-inelastic structure
functions F_2 and F_L at the next-to-leading logarithmic level. We discuss how
this resummation can be performed in different factorization schemes, including
the commonly used MSbar scheme. We study the importance of the resummation
effects by comparison with fixed-order perturbative results, and we discuss the
corresponding renormalization and factorization scale variation uncertainties.
We find that for x below 0.01 the resummation effects are comparable in size to
the fixed order NNLO corrections, but differ in shape. We finally discuss the
phenomenological impact of the small-x resummation, specifically in the
extraction of parton distribution from present day experiments and their
extrapolation to the kinematics relevant for future colliders such as the LHC
| [
{
"created": "Thu, 31 Jan 2008 23:15:54 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Altarelli",
"Guido",
""
],
[
"Ball",
"Richard D.",
""
],
[
"Forte",
"Stefano",
""
]
] | We extend our previous results on small-x resummation in the pure Yang--Mills theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of resummed quark and gluon splitting functions. We also construct the corresponding deep-inelastic coefficient functions, and show how these can be combined with parton densities to give fully resummed deep-inelastic structure functions F_2 and F_L at the next-to-leading logarithmic level. We discuss how this resummation can be performed in different factorization schemes, including the commonly used MSbar scheme. We study the importance of the resummation effects by comparison with fixed-order perturbative results, and we discuss the corresponding renormalization and factorization scale variation uncertainties. We find that for x below 0.01 the resummation effects are comparable in size to the fixed order NNLO corrections, but differ in shape. We finally discuss the phenomenological impact of the small-x resummation, specifically in the extraction of parton distribution from present day experiments and their extrapolation to the kinematics relevant for future colliders such as the LHC |
2012.05662 | Arpan Das | Arpan Das, Wojciech Florkowski, Radoslaw Ryblewski, Rajeev Singh | Quantum fluctuations of energy in subsystems of a hot relativistic gas | 11 pages, 4 figures, Matches with the published version, Published in
Acta Physica Polonica B, Vol. 52 (2021), page no: 1395-1404 | Acta Physica Polonica B Vol. 52 (2021), page no: 1395-1404 | 10.5506/APhysPolB.52.1395 | null | hep-ph hep-th nucl-th | http://creativecommons.org/licenses/by/4.0/ | We derive a formula that defines quantum fluctuations of energy in subsystems
of a hot relativistic gas. For small subsystem sizes we find substantial
increase of fluctuations compared to those known from standard thermodynamic
considerations. However, if the size of the subsystem is sufficiently large, we
reproduce the result for energy fluctuations in the canonical ensemble. Our
results are subsequently used in the context of relativistic heavy-ion
collisions to introduce limitations of the concepts such as classical energy
density or fluid element. In the straightforward way, our formula can be
applied in other fields of physics, wherever one deals with hot and
relativistic matter.
| [
{
"created": "Thu, 10 Dec 2020 13:36:38 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Dec 2021 16:36:08 GMT",
"version": "v2"
}
] | 2021-12-15 | [
[
"Das",
"Arpan",
""
],
[
"Florkowski",
"Wojciech",
""
],
[
"Ryblewski",
"Radoslaw",
""
],
[
"Singh",
"Rajeev",
""
]
] | We derive a formula that defines quantum fluctuations of energy in subsystems of a hot relativistic gas. For small subsystem sizes we find substantial increase of fluctuations compared to those known from standard thermodynamic considerations. However, if the size of the subsystem is sufficiently large, we reproduce the result for energy fluctuations in the canonical ensemble. Our results are subsequently used in the context of relativistic heavy-ion collisions to introduce limitations of the concepts such as classical energy density or fluid element. In the straightforward way, our formula can be applied in other fields of physics, wherever one deals with hot and relativistic matter. |
1104.4124 | Anibal Medina | Anibal D. Medina and Eduardo Ponton | Warped Radion Dark Matter | 43 pages, 16 figures; added references | JHEP 1109:016,2011 | 10.1007/JHEP09(2011)016 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Warped scenarios offer an appealing solution to the hierarchy problem. We
consider a non-trivial deformation of the basic Randall-Sundrum framework that
has a KK-parity symmetry. This leads to a stable particle beyond the Standard
Model, that is generically expected to be the first KK-parity odd excitation of
the radion field. We consider the viability of the KK-radion as a DM candidate
in the context of thermal and non-thermal production in the early universe. In
the thermal case, the KK-radion can account for the observed DM density when
the radion decay constant is in the natural multi-TeV range. We also explore
the effects of coannihilations with the first KK excitation of the RH top, as
well as the effects of radion-Higgs mixing, which imply mixing between the
KK-radion and a KK-Higgs (both being KK-parity odd). The non-thermal scenario,
with a high radion decay constant, can also lead to a viable scenario provided
the reheat temperature and the radion decay constant take appropriate values,
although the reheat temperature should not be much higher than the TeV scale.
Direct detection is found to be feasible if the DM has a small (KK-parity odd)
Higgs admixture. Indirect detection via a photon signal from the galactic
center is an interesting possibility, while the positron and neutrino fluxes
from KK-radion annihilations are expected to be rather small. Colliders can
probe characteristic aspects of the DM sector of warped scenarios with
KK-parity, such as the degeneracy between the radion and the KK-radion (DM)
modes.
| [
{
"created": "Wed, 20 Apr 2011 20:11:44 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Jun 2011 20:08:43 GMT",
"version": "v2"
}
] | 2011-09-20 | [
[
"Medina",
"Anibal D.",
""
],
[
"Ponton",
"Eduardo",
""
]
] | Warped scenarios offer an appealing solution to the hierarchy problem. We consider a non-trivial deformation of the basic Randall-Sundrum framework that has a KK-parity symmetry. This leads to a stable particle beyond the Standard Model, that is generically expected to be the first KK-parity odd excitation of the radion field. We consider the viability of the KK-radion as a DM candidate in the context of thermal and non-thermal production in the early universe. In the thermal case, the KK-radion can account for the observed DM density when the radion decay constant is in the natural multi-TeV range. We also explore the effects of coannihilations with the first KK excitation of the RH top, as well as the effects of radion-Higgs mixing, which imply mixing between the KK-radion and a KK-Higgs (both being KK-parity odd). The non-thermal scenario, with a high radion decay constant, can also lead to a viable scenario provided the reheat temperature and the radion decay constant take appropriate values, although the reheat temperature should not be much higher than the TeV scale. Direct detection is found to be feasible if the DM has a small (KK-parity odd) Higgs admixture. Indirect detection via a photon signal from the galactic center is an interesting possibility, while the positron and neutrino fluxes from KK-radion annihilations are expected to be rather small. Colliders can probe characteristic aspects of the DM sector of warped scenarios with KK-parity, such as the degeneracy between the radion and the KK-radion (DM) modes. |
1306.0452 | Giulia Pancheri Dr. | Daniel A. Fagundes, Agnes Grau, Simone Pacetti, Giulia Pancheri,
Yogendra N. Srivastava | Elastic pp scattering from the optical point to past the dip: an
empirical parametrization from ISR to LHC | 19 pages, 26 figures, v2 with minor changes | Phys. Rev. D 88, 094019 (2013) | 10.1103/PhysRevD.88.094019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe the main features of recent LHC data on elastic pp scattering
through a simple parametrization to the amplitude, inspired by a model proposed
by Barger and Phillips in 1973, comprising of two exponentials with a relative
phase. Despite its simplicity, this parameterization reproduces two essential
aspects of the elastic differential cross section, the well known precipitous
descent in the forward direction and a sharp `dip' structure. To include a
complete description of data sets near -t=0, we correct the original
parametrization. We examine two possibilities, the presence of the two-pion
threshold singularity or a multiplicative factor reflecting the proton form
factor. We find good descriptions of LHC7 and ISR data in either case. The form
factor model allows simple predictions for higher energies through asymptotic
theorems and asymptotic sum rules in impact parameter space. We present
predictions for this model at higher LHC energies, which can be used to test
whether asymptotia is reached. The black disk limit in this model is seen to be
reached only for energies near 10^6 TeV.
| [
{
"created": "Mon, 3 Jun 2013 15:11:45 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Jun 2013 13:15:13 GMT",
"version": "v2"
}
] | 2013-12-04 | [
[
"Fagundes",
"Daniel A.",
""
],
[
"Grau",
"Agnes",
""
],
[
"Pacetti",
"Simone",
""
],
[
"Pancheri",
"Giulia",
""
],
[
"Srivastava",
"Yogendra N.",
""
]
] | We describe the main features of recent LHC data on elastic pp scattering through a simple parametrization to the amplitude, inspired by a model proposed by Barger and Phillips in 1973, comprising of two exponentials with a relative phase. Despite its simplicity, this parameterization reproduces two essential aspects of the elastic differential cross section, the well known precipitous descent in the forward direction and a sharp `dip' structure. To include a complete description of data sets near -t=0, we correct the original parametrization. We examine two possibilities, the presence of the two-pion threshold singularity or a multiplicative factor reflecting the proton form factor. We find good descriptions of LHC7 and ISR data in either case. The form factor model allows simple predictions for higher energies through asymptotic theorems and asymptotic sum rules in impact parameter space. We present predictions for this model at higher LHC energies, which can be used to test whether asymptotia is reached. The black disk limit in this model is seen to be reached only for energies near 10^6 TeV. |
hep-ph/9809434 | Tarasov A. V. | L. Afanasyev and O. Voskresenskaya (JINR, Dubna) | The eikonal approach to calculation of the multiphoton exchange
contributions to the total cross sections of \pi^+pi^- atom interaction with
ordinary atoms | 5 pages, LaTeX2e, 4 PostScript figure | null | null | null | hep-ph | null | The total cross sections of interaction of relativistic \pi^+\pi^- atom with
ordinary atoms are obtained in the eikonal approach, which takes into
consideration all multiphoton exchange processes. Contribution of these
processes strongly depends on the atom nucleus charge Z and varies from 1.5%
for Titanium (Z=22) to 14% for Tantalum (Z=73)
| [
{
"created": "Thu, 17 Sep 1998 14:17:52 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Sep 1998 14:27:04 GMT",
"version": "v2"
},
{
"created": "Mon, 11 Jan 1999 09:32:58 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Afanasyev",
"L.",
"",
"JINR, Dubna"
],
[
"Voskresenskaya",
"O.",
"",
"JINR, Dubna"
]
] | The total cross sections of interaction of relativistic \pi^+\pi^- atom with ordinary atoms are obtained in the eikonal approach, which takes into consideration all multiphoton exchange processes. Contribution of these processes strongly depends on the atom nucleus charge Z and varies from 1.5% for Titanium (Z=22) to 14% for Tantalum (Z=73) |
hep-ph/0608232 | Vishnu Bannur M | Vishnu M. Bannur | Comments on quasiparticle models of quark-gluon plasma | 7 pages, 2 figure, article (revised) | Phys.Lett.B647:271-274,2007 | 10.1016/j.physletb.2007.02.030 | null | hep-ph | null | Here we comment on the thermodynamic inconsistency problem and the
reformulation of statistical mechanics of widely studied quasiparticle models
of quark-gluon plasma. Their starting relation, the expression for pressure
itself is a wrong choice and lead to thermodynamic inconsistency and the
requirements of the reformulation of statistical mechanics. Hence we revise the
model using the standard statistical mechanics and is thermodynamically
consistent. We also show that the other quasiparticle models may be obtained
from our general formalism as a special case under certain restrictive
condition. Further, as an example, we applied our model to explain the nonideal
behaviour of gluon plasma and obtained a remarkable good fit to the lattice
results by adjusting just a single parameter.
| [
{
"created": "Mon, 21 Aug 2006 09:54:42 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Nov 2006 05:21:29 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Mar 2007 09:47:16 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Bannur",
"Vishnu M.",
""
]
] | Here we comment on the thermodynamic inconsistency problem and the reformulation of statistical mechanics of widely studied quasiparticle models of quark-gluon plasma. Their starting relation, the expression for pressure itself is a wrong choice and lead to thermodynamic inconsistency and the requirements of the reformulation of statistical mechanics. Hence we revise the model using the standard statistical mechanics and is thermodynamically consistent. We also show that the other quasiparticle models may be obtained from our general formalism as a special case under certain restrictive condition. Further, as an example, we applied our model to explain the nonideal behaviour of gluon plasma and obtained a remarkable good fit to the lattice results by adjusting just a single parameter. |
2310.06642 | Rui Santos | Gabriel Louren\c{c}o, Andr\'e Milagre, Rui Santos, Jo\~ao P. Silva | Precision Muon-Related Observables as a Tool to Constrain New Physics
Models | 16 pages, 12 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We propose a set of precision muon-related observables that serve as a tool
to constrain new physics models. Using LEP's precision measurements on the
$Z$-boson pole, we derive bounds on the new physics quantum contributions to
the decay $Z \to \mu^+ \mu^-$. We show that the new precision observables have
a real impact on two specific models that solve the $g-2$ anomaly and provide a
sound dark matter candidate.
| [
{
"created": "Tue, 10 Oct 2023 14:05:52 GMT",
"version": "v1"
}
] | 2023-10-11 | [
[
"Lourenço",
"Gabriel",
""
],
[
"Milagre",
"André",
""
],
[
"Santos",
"Rui",
""
],
[
"Silva",
"João P.",
""
]
] | We propose a set of precision muon-related observables that serve as a tool to constrain new physics models. Using LEP's precision measurements on the $Z$-boson pole, we derive bounds on the new physics quantum contributions to the decay $Z \to \mu^+ \mu^-$. We show that the new precision observables have a real impact on two specific models that solve the $g-2$ anomaly and provide a sound dark matter candidate. |
2405.07273 | Ulas Ozdem | U. \"Ozdem | Investigation on the electromagnetic properties of the $ D^{(*)}
\Sigma_c^{(*)}$ molecules | 11 pages, 4 tables, 1 figure | null | null | null | hep-ph hep-ex hep-lat | http://creativecommons.org/licenses/by/4.0/ | We systematically explore their electromagnetic characteristics to improve
our understanding of the quark-gluon dynamics underlying the complex and
controversial nature of multiquark systems. In this study, the magnetic dipole
moments of $ D \Sigma_c$, $ D \Sigma_c^{*}$ and $ D^{*} \Sigma_c$
doubly-charmed pentaquarks are extracted, which are directly related to the
inner organization of the relevant states. The magnetic dipole moments of these
states have been evaluated employing the QCD light-cone sum rules technique
with isospin spin-parity $\rm{I(J^P)} = \frac{1}{2}(\frac{1}{2}^-)$,
$\rm{I(J^P)} = \frac{1}{2}(\frac{3}{2}^-)$ and $\rm{I(J^P)} =
\frac{1}{2}(\frac{3}{2}^-)$, for $ D \Sigma_c$, $ D \Sigma_c^{*}$ and $ D^{*}
\Sigma_c$ doubly-charmed pentaquarks respectively. Our predictions for the
magnetic dipole moment $\mu_{D\Sigma_c} = 2.98^{+0.76}_{-0.54}~\mu_N$ for the $
D \Sigma_c$ pentaquark, $\mu_{D\Sigma_c^*} = 1.65^{+0.45}_{-0.34}~\mu_N$ for
the $D\Sigma_c^*$ pentaquark, and $\mu_{D^*\Sigma_c} =
-3.63^{+0.79}_{-0.60}~\mu_N$ for the $D^*\Sigma_c$ pentaquark. Furthermore, we
have also extracted the electric quadrupole and the magnetic octupole moments
of the $ D \Sigma_c^{*}$ and $ D^{*} \Sigma_c$ doubly-charmed pentaquarks.
These values show a non-spherical charge distribution. We hope that our
predictions of the magnetic dipole moments of the doubly-charmed pentaquarks,
in conjunction with the results of other theoretical investigations of the
spectroscopic parameters and decay widths of these intriguing pentaquarks, will
prove valuable in the search for these states in future experiments and in
elucidating the internal structure of these pentaquarks.
| [
{
"created": "Sun, 12 May 2024 12:39:21 GMT",
"version": "v1"
},
{
"created": "Sun, 28 Jul 2024 16:47:36 GMT",
"version": "v2"
}
] | 2024-07-30 | [
[
"Özdem",
"U.",
""
]
] | We systematically explore their electromagnetic characteristics to improve our understanding of the quark-gluon dynamics underlying the complex and controversial nature of multiquark systems. In this study, the magnetic dipole moments of $ D \Sigma_c$, $ D \Sigma_c^{*}$ and $ D^{*} \Sigma_c$ doubly-charmed pentaquarks are extracted, which are directly related to the inner organization of the relevant states. The magnetic dipole moments of these states have been evaluated employing the QCD light-cone sum rules technique with isospin spin-parity $\rm{I(J^P)} = \frac{1}{2}(\frac{1}{2}^-)$, $\rm{I(J^P)} = \frac{1}{2}(\frac{3}{2}^-)$ and $\rm{I(J^P)} = \frac{1}{2}(\frac{3}{2}^-)$, for $ D \Sigma_c$, $ D \Sigma_c^{*}$ and $ D^{*} \Sigma_c$ doubly-charmed pentaquarks respectively. Our predictions for the magnetic dipole moment $\mu_{D\Sigma_c} = 2.98^{+0.76}_{-0.54}~\mu_N$ for the $ D \Sigma_c$ pentaquark, $\mu_{D\Sigma_c^*} = 1.65^{+0.45}_{-0.34}~\mu_N$ for the $D\Sigma_c^*$ pentaquark, and $\mu_{D^*\Sigma_c} = -3.63^{+0.79}_{-0.60}~\mu_N$ for the $D^*\Sigma_c$ pentaquark. Furthermore, we have also extracted the electric quadrupole and the magnetic octupole moments of the $ D \Sigma_c^{*}$ and $ D^{*} \Sigma_c$ doubly-charmed pentaquarks. These values show a non-spherical charge distribution. We hope that our predictions of the magnetic dipole moments of the doubly-charmed pentaquarks, in conjunction with the results of other theoretical investigations of the spectroscopic parameters and decay widths of these intriguing pentaquarks, will prove valuable in the search for these states in future experiments and in elucidating the internal structure of these pentaquarks. |
hep-ph/9609245 | W. James Stirling | Z. Kunszt (ETH, Zurich), W. J. Stirling (Durham) | Hard diffractive scattering: partons and QCD | 6 pages (LaTeX), including 1 embedded figure, uses epsfig.sty. Based
on talks presented at the Workshop on HERA Physics (Durham, September 1995)
and the DIS96 Workshop (Rome, April 1996) | null | null | ETH-TH/96-27, DTP/96/74 | hep-ph | null | The HERA diffractive structure function data are interpreted in terms of
`diffractive parton distributions' which satisfy DGLAP evolution. These
distributions are modeled assuming that the scattering takes place off a colour
singlet `pomeron' target. A quantitative test of the universality of
diffractive parton distributions is proposed.
| [
{
"created": "Wed, 4 Sep 1996 20:11:40 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kunszt",
"Z.",
"",
"ETH, Zurich"
],
[
"Stirling",
"W. J.",
"",
"Durham"
]
] | The HERA diffractive structure function data are interpreted in terms of `diffractive parton distributions' which satisfy DGLAP evolution. These distributions are modeled assuming that the scattering takes place off a colour singlet `pomeron' target. A quantitative test of the universality of diffractive parton distributions is proposed. |
hep-ph/9708465 | sergei Gninenko | S.N.Gninenko | Limits on leptonic photon interactions from SN1987a | 6 pages, AmSTex, LaTex. The limits are revised for neutrino chemical
potential $\mu$ = 0. The new limits do not differ significantly from the
original one. To be published in Phys.Lett.B | Phys.Lett. B413 (1997) 365-368 | 10.1016/S0370-2693(97)01129-5 | INR-0951/97 | hep-ph | null | If massless leptonic photons associated to electron, muon or tau leptonic
number exist they would have been emitted from supernova 1987a via the
annihilation process $\nu\bar{\nu}\to\gamma_{l}\gamma_{l}$. By requiring that
this process does not carry away most of the energy that can be radiated by the
supernova we obtain an upper limit on the leptonic photon coupling constants,
$\alpha_{l} < 5.4 \times 10^{-11}$. Under certain assumptions about
$\gamma_{l}$ - trapping conditions we find that the region of $\alpha_{l} =
10^{-8} - 10^{-7}$ might be of interest for an experimental search for leptonic
photons.
| [
{
"created": "Tue, 26 Aug 1997 16:13:48 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Aug 1997 07:51:02 GMT",
"version": "v2"
},
{
"created": "Thu, 11 Sep 1997 17:06:08 GMT",
"version": "v3"
},
{
"created": "Thu, 13 Nov 1997 19:17:42 GMT",
"version": "v4"
}
] | 2009-10-30 | [
[
"Gninenko",
"S. N.",
""
]
] | If massless leptonic photons associated to electron, muon or tau leptonic number exist they would have been emitted from supernova 1987a via the annihilation process $\nu\bar{\nu}\to\gamma_{l}\gamma_{l}$. By requiring that this process does not carry away most of the energy that can be radiated by the supernova we obtain an upper limit on the leptonic photon coupling constants, $\alpha_{l} < 5.4 \times 10^{-11}$. Under certain assumptions about $\gamma_{l}$ - trapping conditions we find that the region of $\alpha_{l} = 10^{-8} - 10^{-7}$ might be of interest for an experimental search for leptonic photons. |
1101.1642 | David Bugg | D.V. Bugg (Queen Mary, University of London, UK) | An interesting feature of BESIII data for J/Psi ->
gamma-(etaprime-pi-pi) | 3 pages, 2 figures | Phys. Lett. B697 (2011) 364 | 10.1016/j.physletb.2011.02.027 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The eta(1835) is confirmed clearly in new BESIII data for J/Psi -> gamma
(eta'-pi-pi); the angular distribution of the photon is consistent with a
pseudoscalar. This makes it a candidate for an s-sbar radial excitation of eta'
and eta(1440) (or one or both of eta(1405) and eta(1475)). However, a
conspicuous feature of the BES III data is the absence of evidence for
eta(1440) -> eta'-pi-pi while it is well known that eta(1440) appears in
eta-pi-pi. Can these facts be reconciled? There is in fact a simple
explanation. The channel eta(1440) -> eta-pi-pi may be explained by the
two-step process eta(1440) -> [K*K]_{L=1} and [kappa K ]_{L=0}, followed by KK
-> a0(980) -> eta-pi. This process does not produce any significant eta'-pi
signal because of the Adler zero close to the eta'-pi threshold.
| [
{
"created": "Sun, 9 Jan 2011 14:52:44 GMT",
"version": "v1"
}
] | 2015-05-27 | [
[
"Bugg",
"D. V.",
"",
"Queen Mary, University of London, UK"
]
] | The eta(1835) is confirmed clearly in new BESIII data for J/Psi -> gamma (eta'-pi-pi); the angular distribution of the photon is consistent with a pseudoscalar. This makes it a candidate for an s-sbar radial excitation of eta' and eta(1440) (or one or both of eta(1405) and eta(1475)). However, a conspicuous feature of the BES III data is the absence of evidence for eta(1440) -> eta'-pi-pi while it is well known that eta(1440) appears in eta-pi-pi. Can these facts be reconciled? There is in fact a simple explanation. The channel eta(1440) -> eta-pi-pi may be explained by the two-step process eta(1440) -> [K*K]_{L=1} and [kappa K ]_{L=0}, followed by KK -> a0(980) -> eta-pi. This process does not produce any significant eta'-pi signal because of the Adler zero close to the eta'-pi threshold. |
2201.01903 | David-Francisco Renter\'ia-Estrada | David F. Renter\'ia-Estrada, Roger J. Hern\'andez-Pinto and German F.
R. Sborlini | Parton distribution effects in the direct photon production at hadron
collisions | 5 pages, 3 figures, talk presented at "XIX Mexican School on
Particles and Fields". arXiv admin note: text overlap with arXiv:2104.14663 | null | null | DESY-22-001 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Parton distribution functions are crucial to understand the internal
kinematics of hadrons. There are currently a large number of distribution
functions on the market, and thanks to today's technology, performing
computational analysis of the differential cross-sections has become more
accessible. Despite technological advances, accurately accessing to the
internal structure of hadrons remains a difficult task from a theoretical point
of view. In this work, we analyze the impact on the differential cross-sections
when updating the sets of parton distribution and fragmentation functions, for
the production of one hadron plus a direct photon at the energy scale of RHIC
and LHC experiments.
| [
{
"created": "Thu, 6 Jan 2022 03:07:17 GMT",
"version": "v1"
}
] | 2022-01-07 | [
[
"Rentería-Estrada",
"David F.",
""
],
[
"Hernández-Pinto",
"Roger J.",
""
],
[
"Sborlini",
"German F. R.",
""
]
] | Parton distribution functions are crucial to understand the internal kinematics of hadrons. There are currently a large number of distribution functions on the market, and thanks to today's technology, performing computational analysis of the differential cross-sections has become more accessible. Despite technological advances, accurately accessing to the internal structure of hadrons remains a difficult task from a theoretical point of view. In this work, we analyze the impact on the differential cross-sections when updating the sets of parton distribution and fragmentation functions, for the production of one hadron plus a direct photon at the energy scale of RHIC and LHC experiments. |
1211.6559 | Matthias Steinhauser | Maik H\"oschele, Jens Hoff, Alexey Pak, Matthias Steinhauser, Takahiro
Ueda | Higgs boson production at the LHC: NNLO partonic cross sections through
order $\epsilon$ and convolutions with splitting functions to N$^3$LO | 14 pages, 1 figure | null | 10.1016/j.physletb.2013.03.003 | SFB/CPP-12-93; TTP12-45; LPN12-127 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider Higgs boson production at hadron colliders in the gluon fusion
channel and compute higher order terms in the regularization parameter
$\epsilon$. In particular, the next-to-next-to-leading order cross section is
evaluated including order $\epsilon$ terms. These results are used to compute
all convolutions with the splitting functions entering the
next-to-next-to-next-to-leading order cross section.
| [
{
"created": "Wed, 28 Nov 2012 09:55:20 GMT",
"version": "v1"
}
] | 2015-06-12 | [
[
"Höschele",
"Maik",
""
],
[
"Hoff",
"Jens",
""
],
[
"Pak",
"Alexey",
""
],
[
"Steinhauser",
"Matthias",
""
],
[
"Ueda",
"Takahiro",
""
]
] | We consider Higgs boson production at hadron colliders in the gluon fusion channel and compute higher order terms in the regularization parameter $\epsilon$. In particular, the next-to-next-to-leading order cross section is evaluated including order $\epsilon$ terms. These results are used to compute all convolutions with the splitting functions entering the next-to-next-to-next-to-leading order cross section. |
2004.01012 | Zhan Sun | Zhan Sun, Xing-Gang Wu | The production of the doubly charmed baryon in deeply inelastic $ep$
scattering at the Large Hadron Electron Collider | 22 pages, 5 figures, and 1 table; accepted for publication in JHEP | JHEP07(2020)034 | 10.1007/JHEP07(2020)034 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we carry out a detailed study on the production of the doubly
charmed baryon in deeply inelastic $ep$ scattering (DIS) for $Q^2\in[2,
100]~\textrm{GeV}^2$, at the Large Hadron Electron Collider (LHeC) with
$E_e=60(140)$ GeV and $E_p=7000$ GeV. To exclude the contributions from the
diffractive productions and the $b$ hadron decays, we impose the kinematic cuts
$0.3<z<0.9$, and $p_{t,\textrm{baryon}}^{\star2}>1~\textrm{GeV}^2$ in the
center-of-mass (CM) frame of $\gamma^{*}p$. Based on the designed LHeC
luminosity, by detecting the decay channel $\Xi^{+}_{cc}(\Xi^{++}_{cc}) \to
\Lambda_c^{+}$ with the subsequent decay $\Lambda_c^{+} \to pK^{-}\pi^{+}$, we
predict that about 1880 (2700) $\Xi^{+}_{cc}$ events and 3750 (5400)
$\Xi^{++}_{cc}$ events can be accumulated per year, which signifies the
prospect of observing them via the DIS at the forthcoming LHeC. In addition, we
also predict the distributions of a rich variety of physical observables in the
laboratory frame and the $\gamma^{*}p$ CM frame, including $Q^2$, $p_t^{2}$,
$Y$(rapidity), $p_t^{\star2}$, $Y^{\star}$, $W$, and $z$ distributions,
respectively, which can provide helpful references for studying the doubly
charmed baryon. In conclusion, we think that in addition to the LHC, the LHeC
is also a helpful platform for studying the properties of the doubly charmed
baryon.
| [
{
"created": "Thu, 2 Apr 2020 14:06:33 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Jun 2020 10:36:58 GMT",
"version": "v2"
}
] | 2020-07-07 | [
[
"Sun",
"Zhan",
""
],
[
"Wu",
"Xing-Gang",
""
]
] | In this paper, we carry out a detailed study on the production of the doubly charmed baryon in deeply inelastic $ep$ scattering (DIS) for $Q^2\in[2, 100]~\textrm{GeV}^2$, at the Large Hadron Electron Collider (LHeC) with $E_e=60(140)$ GeV and $E_p=7000$ GeV. To exclude the contributions from the diffractive productions and the $b$ hadron decays, we impose the kinematic cuts $0.3<z<0.9$, and $p_{t,\textrm{baryon}}^{\star2}>1~\textrm{GeV}^2$ in the center-of-mass (CM) frame of $\gamma^{*}p$. Based on the designed LHeC luminosity, by detecting the decay channel $\Xi^{+}_{cc}(\Xi^{++}_{cc}) \to \Lambda_c^{+}$ with the subsequent decay $\Lambda_c^{+} \to pK^{-}\pi^{+}$, we predict that about 1880 (2700) $\Xi^{+}_{cc}$ events and 3750 (5400) $\Xi^{++}_{cc}$ events can be accumulated per year, which signifies the prospect of observing them via the DIS at the forthcoming LHeC. In addition, we also predict the distributions of a rich variety of physical observables in the laboratory frame and the $\gamma^{*}p$ CM frame, including $Q^2$, $p_t^{2}$, $Y$(rapidity), $p_t^{\star2}$, $Y^{\star}$, $W$, and $z$ distributions, respectively, which can provide helpful references for studying the doubly charmed baryon. In conclusion, we think that in addition to the LHC, the LHeC is also a helpful platform for studying the properties of the doubly charmed baryon. |
1308.0792 | Kohsaku Tobioka | Xiaochuan Lu, Hitoshi Murayama, Joshua T. Ruderman and Kohsaku Tobioka | A Natural Higgs Mass in Supersymmetry from Non-Decoupling Effects | Version published in PRL, plus two additional figures. 6 pages, 4
figures | Phys. Rev. Lett. 112, 191803 (2014) | 10.1103/PhysRevLett.112.191803 | IPMU13-0140, UCB-PTH-13/06 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Higgs mass implies fine-tuning for minimal theories of weak scale
supersymmetry (SUSY). Non-decoupling effects can boost the Higgs mass when new
states interact with the Higgs, but new sources of SUSY breaking that accompany
such extensions threaten naturalness. We show that two singlets with a Dirac
mass can increase the Higgs mass while maintaining naturalness in the presence
of large SUSY breaking in the singlet sector. We explore the modified Higgs
phenomenology of this scenario, which we call the "Dirac NMSSM."
| [
{
"created": "Sun, 4 Aug 2013 09:29:48 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Aug 2013 19:47:42 GMT",
"version": "v2"
},
{
"created": "Mon, 26 May 2014 11:54:35 GMT",
"version": "v3"
}
] | 2014-05-27 | [
[
"Lu",
"Xiaochuan",
""
],
[
"Murayama",
"Hitoshi",
""
],
[
"Ruderman",
"Joshua T.",
""
],
[
"Tobioka",
"Kohsaku",
""
]
] | The Higgs mass implies fine-tuning for minimal theories of weak scale supersymmetry (SUSY). Non-decoupling effects can boost the Higgs mass when new states interact with the Higgs, but new sources of SUSY breaking that accompany such extensions threaten naturalness. We show that two singlets with a Dirac mass can increase the Higgs mass while maintaining naturalness in the presence of large SUSY breaking in the singlet sector. We explore the modified Higgs phenomenology of this scenario, which we call the "Dirac NMSSM." |
2003.11091 | Ahmed Rashed Dr | Stefan Antusch, A. Hammad and Ahmed Rashed | Probing $Z^\prime$ Mediated Charged Lepton Flavor Violation with Taus at
the LHeC | 6 pages, 5 figures | null | 10.1016/j.physletb.2020.135796 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | While charged lepton flavor violation (cLFV) with taus is often expected to
be largest in many extensions of the Standard Model (SM), it is currently much
less constrained than cLFV with electrons and muons. We study the sensitivity
of the LHeC to $e$-$\tau$ (and $e$-$\mu$) conversion processes $p e^- \to
\tau^- + j$ (and $p e^- \to \mu^- + j$) mediated by a $Z'$ with
flavor-violating couplings to charged leptons in the $t$-channel. Compared to
current tests at the LHC, where cLFV decays of the $Z'$ (produced in the
s-channel) are searched for, the LHeC has sensitivity to much higher $Z'$
masses, up to O(10) TeV. For cLFV with taus, we find that the LHeC sensitivity
from the process $p e^- \to \tau^- + j$ can exceed the current limits from
collider and non-collider experiments in the whole considered $Z'$ mass range
(above $500$ GeV) by more than two orders of magnitude. In particular for
extensions of the SM with a heavy $Z'$, where direct production at colliders is
kinematically suppressed, $e-\tau$ conversion at LHeC provides an exciting new
discovery channel for this type of new physics.
| [
{
"created": "Tue, 24 Mar 2020 19:49:15 GMT",
"version": "v1"
}
] | 2020-09-23 | [
[
"Antusch",
"Stefan",
""
],
[
"Hammad",
"A.",
""
],
[
"Rashed",
"Ahmed",
""
]
] | While charged lepton flavor violation (cLFV) with taus is often expected to be largest in many extensions of the Standard Model (SM), it is currently much less constrained than cLFV with electrons and muons. We study the sensitivity of the LHeC to $e$-$\tau$ (and $e$-$\mu$) conversion processes $p e^- \to \tau^- + j$ (and $p e^- \to \mu^- + j$) mediated by a $Z'$ with flavor-violating couplings to charged leptons in the $t$-channel. Compared to current tests at the LHC, where cLFV decays of the $Z'$ (produced in the s-channel) are searched for, the LHeC has sensitivity to much higher $Z'$ masses, up to O(10) TeV. For cLFV with taus, we find that the LHeC sensitivity from the process $p e^- \to \tau^- + j$ can exceed the current limits from collider and non-collider experiments in the whole considered $Z'$ mass range (above $500$ GeV) by more than two orders of magnitude. In particular for extensions of the SM with a heavy $Z'$, where direct production at colliders is kinematically suppressed, $e-\tau$ conversion at LHeC provides an exciting new discovery channel for this type of new physics. |
hep-ph/0112355 | Atsushi Hosaka | A. Hosaka, D. Jido and M. Oka | Determination of the axial coupling constant $g_{A}$ in the linear
representations of chiral symmetry | 7 pages, proceedings for EMI int. conf. at RCNP, Dec. 2001 | null | 10.1142/9789812777218_0063 | null | hep-ph | null | If a baryon field belongs to a certain linear representation of chiral
symmetry of $SU(2) \otimes SU(2)$, the axial coupling constant $g_{A}$ can be
determined algebraically from the commutation relations derived from the
superconvergence property of pion-nucleon scattering amplitudes. This
establishes an algebraic explanation for the values of $g_{A}$ of such as the
non-relativistic quark model, large-$N_{c}$ limit and the mirror assignment for
two chiral partner nucleons. For the mirror assignment, the axial charges of
the positive and negative parity nucleons have opposite signs. Experiments of
eta and pion productions are proposed in which the sign difference of the axial
charges can be observed.
| [
{
"created": "Sat, 29 Dec 2001 02:00:16 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Jan 2002 00:30:52 GMT",
"version": "v2"
}
] | 2017-08-23 | [
[
"Hosaka",
"A.",
""
],
[
"Jido",
"D.",
""
],
[
"Oka",
"M.",
""
]
] | If a baryon field belongs to a certain linear representation of chiral symmetry of $SU(2) \otimes SU(2)$, the axial coupling constant $g_{A}$ can be determined algebraically from the commutation relations derived from the superconvergence property of pion-nucleon scattering amplitudes. This establishes an algebraic explanation for the values of $g_{A}$ of such as the non-relativistic quark model, large-$N_{c}$ limit and the mirror assignment for two chiral partner nucleons. For the mirror assignment, the axial charges of the positive and negative parity nucleons have opposite signs. Experiments of eta and pion productions are proposed in which the sign difference of the axial charges can be observed. |
hep-ph/9504294 | Holger Bech Nielsen | D.L.Bennett (Royal Danish Academy of Farmacy and Niels Bohr
Institute), C.D.Froggatt (Department of Physics and Astronomy, University of
Glasgow), and H.B.Nielsen (Niels Bohr Institute) | Nonlocality as an Explanation for Finetuning and Field replication in
Nature | Slight improvement of citations and a strangely placed sectionheading | null | null | NBI-95-15, GUTPA/95/04/1 | hep-ph hep-th | null | Constants of Nature that have nongeneric values pose a riddle often referred
to as the finetuning problem. The conspicuous values assumed by many physical
constants (e.g., the vanishing effective cosmological constant, the smallness
of the Higgs mass compared to the Planck scale, the finestructure constants,
$\Theta_{QCD}$) seem to coincide with values that are obtained if one assumes
that Nature in general seeks out multiple point values for intensive
parameters. Multiple point values would occur in the presence of many
coexisting phases. Such coexistence could be enforced by having fixed but not
finetuned amounts of extensive quantities. We show that universally fixed
amounts of extensive quantities is tantamount to having long range nonlocal
interactions of a special type: these interactions are identical between fields
at all pairs of spacetime points regardless of the spacetime distance between
them. Such omnipresent nonlocal interactions, which can be described by a very
general form of a reparameterization invariant action, would not be perceived
as ``action at a distance'' but rather most likely incorporated into our theory
as constants of Nature. Hence one can speculate that this mild form of
nonlocality is the underlying explanation of Nature's affinity for the multiple
point. We also speculate that nonlocal effects, described by fields depending
on two spacetime points, may be responsible for the replication of the fields
in three generations. Such a nonlocal mechanism would also triple the number of
boson fields, as in the antigrand unification model. We briefly review the
multiple point predictions for the three fine structure constants and the
resolution of the quark-lepton mass hierarchy problem in this antigrand unified
extension of the Standard Model.
| [
{
"created": "Wed, 12 Apr 1995 15:24:33 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Apr 1995 23:38:11 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Bennett",
"D. L.",
"",
"Royal Danish Academy of Farmacy and Niels Bohr\n Institute"
],
[
"Froggatt",
"C. D.",
"",
"Department of Physics and Astronomy, University of\n Glasgow"
],
[
"Nielsen",
"H. B.",
"",
"Niels Bohr Institute"
]
] | Constants of Nature that have nongeneric values pose a riddle often referred to as the finetuning problem. The conspicuous values assumed by many physical constants (e.g., the vanishing effective cosmological constant, the smallness of the Higgs mass compared to the Planck scale, the finestructure constants, $\Theta_{QCD}$) seem to coincide with values that are obtained if one assumes that Nature in general seeks out multiple point values for intensive parameters. Multiple point values would occur in the presence of many coexisting phases. Such coexistence could be enforced by having fixed but not finetuned amounts of extensive quantities. We show that universally fixed amounts of extensive quantities is tantamount to having long range nonlocal interactions of a special type: these interactions are identical between fields at all pairs of spacetime points regardless of the spacetime distance between them. Such omnipresent nonlocal interactions, which can be described by a very general form of a reparameterization invariant action, would not be perceived as ``action at a distance'' but rather most likely incorporated into our theory as constants of Nature. Hence one can speculate that this mild form of nonlocality is the underlying explanation of Nature's affinity for the multiple point. We also speculate that nonlocal effects, described by fields depending on two spacetime points, may be responsible for the replication of the fields in three generations. Such a nonlocal mechanism would also triple the number of boson fields, as in the antigrand unification model. We briefly review the multiple point predictions for the three fine structure constants and the resolution of the quark-lepton mass hierarchy problem in this antigrand unified extension of the Standard Model. |
hep-ph/9803330 | Nikolai Kochelev | N.I.Kochelev and A. De Roeck | Instantons in the Large Q^2, x Region at HERA | 13 pages, Latex, 3 figures | null | null | null | hep-ph | null | A new mechanism for an increased event production in the large $Q^2$, $x$
region at HERA is suggested. This mechanism results from a new type of
instanton-induced quark-quark interaction, which is related to non-zero quark
modes in the instanton field. We estimate the contribution of this interaction
to the valence quark structure function $F_2^v$ using the gas instanton model
approximation for the QCD vacuum. It is shown that this interaction can give a
large contribution to $F_2^v$, especially at large values of $Q^2$. The strong
dependence of this contribution on the quark masses and $Q^2$ is discussed, and
it is concluded that a large charm quark contribution to events at high $Q^2$
can result from charm pair creation in the instanton field. We also obtain a
sizeable contribution to the valence quark longitudinal structure function
$F_L^v$ at high $Q^2$. Experimental observables which can check this instanton
mechanism in the high $Q^2$ region at HERA are suggested.
| [
{
"created": "Thu, 12 Mar 1998 19:28:01 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Apr 1998 13:16:44 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Kochelev",
"N. I.",
""
],
[
"De Roeck",
"A.",
""
]
] | A new mechanism for an increased event production in the large $Q^2$, $x$ region at HERA is suggested. This mechanism results from a new type of instanton-induced quark-quark interaction, which is related to non-zero quark modes in the instanton field. We estimate the contribution of this interaction to the valence quark structure function $F_2^v$ using the gas instanton model approximation for the QCD vacuum. It is shown that this interaction can give a large contribution to $F_2^v$, especially at large values of $Q^2$. The strong dependence of this contribution on the quark masses and $Q^2$ is discussed, and it is concluded that a large charm quark contribution to events at high $Q^2$ can result from charm pair creation in the instanton field. We also obtain a sizeable contribution to the valence quark longitudinal structure function $F_L^v$ at high $Q^2$. Experimental observables which can check this instanton mechanism in the high $Q^2$ region at HERA are suggested. |
hep-ph/0201306 | Goran Duplancic | G. Duplancic, B. Nizic | IR finite one-loop box scalar integral with massless internal lines | 7 pages, 2 figures | Eur.Phys.J.C24:385-391,2002 | 10.1007/s100520200943 | null | hep-ph | null | The IR finite one-loop box scalar integral with massless internal lines has
been recalculated. The result is very compact, simple and valid for arbitrary
values of the relevant kinematic variables. It is given in terms of only two
dilogarithms and a few logarithms, all of very simple arguments.
| [
{
"created": "Thu, 31 Jan 2002 16:17:35 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Duplancic",
"G.",
""
],
[
"Nizic",
"B.",
""
]
] | The IR finite one-loop box scalar integral with massless internal lines has been recalculated. The result is very compact, simple and valid for arbitrary values of the relevant kinematic variables. It is given in terms of only two dilogarithms and a few logarithms, all of very simple arguments. |
1212.4652 | Anirban Kundu | Debajyoti Choudhury, Rashidul Islam, Anirban Kundu | Anomalous Higgs Couplings as a Window to New Physics | 15 pages, 6 figures. Discussion on recent results of ATLAS and CMS.
Conclusions unchanged. Author list modified. Version accepted in Physical
Review D | Phys. Rev. D88 (2013) 013014 | 10.1103/PhysRevD.88.013014 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The initial data on the production and decay of the Higgs boson reported
significant deviations from the Standard Model (SM) expectations, prompting
much speculation about its couplings to the other particles. Although the
latest data has veered towards conformity with the SM, there is yet room for a
sizable deviation from the SM values of the coupling of the Higgs boson with
$t\bar{t}$, and to a smaller extent, of that with $W^+W^-$ and $ZZ$. Keeping
the fluid nature of the data in mind, this opens up an interesting avenue to
explore regarding unitarity of gauge boson scattering and the stability of the
electroweak vacuum in the presence of anomalous couplings. We show that, for
some typical benchmark points, unitarity in gauge boson scattering breaks down
between 1 and 10 TeV. We also show that if there are no new light degrees of
freedom, the Higgs quartic coupling becomes negative at around the same point,
making the electroweak vacuum unstable. Thus, some new ultraviolet completing
new physics is demanded at that scale to cancel both these anomalous behaviours
if such deviations from the SM couplings are indeed established.
| [
{
"created": "Wed, 19 Dec 2012 13:16:48 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Jul 2013 17:41:04 GMT",
"version": "v2"
}
] | 2013-11-20 | [
[
"Choudhury",
"Debajyoti",
""
],
[
"Islam",
"Rashidul",
""
],
[
"Kundu",
"Anirban",
""
]
] | The initial data on the production and decay of the Higgs boson reported significant deviations from the Standard Model (SM) expectations, prompting much speculation about its couplings to the other particles. Although the latest data has veered towards conformity with the SM, there is yet room for a sizable deviation from the SM values of the coupling of the Higgs boson with $t\bar{t}$, and to a smaller extent, of that with $W^+W^-$ and $ZZ$. Keeping the fluid nature of the data in mind, this opens up an interesting avenue to explore regarding unitarity of gauge boson scattering and the stability of the electroweak vacuum in the presence of anomalous couplings. We show that, for some typical benchmark points, unitarity in gauge boson scattering breaks down between 1 and 10 TeV. We also show that if there are no new light degrees of freedom, the Higgs quartic coupling becomes negative at around the same point, making the electroweak vacuum unstable. Thus, some new ultraviolet completing new physics is demanded at that scale to cancel both these anomalous behaviours if such deviations from the SM couplings are indeed established. |
1104.0243 | Felix Yu | Felix Yu | A Z' Model for the CDF Dijet Anomaly | 16 pages, 3 figures; v2, added references; v3, fixed references | Phys.Rev.D83:094028,2011 | 10.1103/PhysRevD.83.094028 | UCI-TR-2011-06 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We adopt a bottom-up approach to constructing a new physics model to explain
the CDF excess seen in dijets with an associated lepton and missing transverse
energy. We find that the 145 GeV broad feature seen by CDF in the dijet
invariant mass distribution can be explained by a Z' boson with a mass of 145
GeV that couples only to first generation quarks. After dijet resonance
constraints are considered, a sizeable region of the parameter space favored by
the CDF anomaly remains viable.
| [
{
"created": "Fri, 1 Apr 2011 19:59:04 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Apr 2011 01:56:26 GMT",
"version": "v2"
},
{
"created": "Mon, 18 Apr 2011 01:24:59 GMT",
"version": "v3"
}
] | 2011-06-07 | [
[
"Yu",
"Felix",
""
]
] | We adopt a bottom-up approach to constructing a new physics model to explain the CDF excess seen in dijets with an associated lepton and missing transverse energy. We find that the 145 GeV broad feature seen by CDF in the dijet invariant mass distribution can be explained by a Z' boson with a mass of 145 GeV that couples only to first generation quarks. After dijet resonance constraints are considered, a sizeable region of the parameter space favored by the CDF anomaly remains viable. |
2306.00982 | Krzysztof Jod{\l}owski | Krzysztof Jod{\l}owski | Looking forward to photon-coupled long-lived particles IV:
neutralino-ALPino/gravitino | 12 pages, 3 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Various supersymmetric (SUSY) scenarios predict a sub-GeV neutralino decaying
into a single photon and an invisible state. This signature has recently been
studied in a number of intensity frontier experiments, finding constraints
complementary to the usual collider searches. In this work, we study the
prospects of searches for long-lived neutralinos coupled to an ALPino or
gravitino, where each can act as the lightest SUSY particle (LSP). In addition
to the neutralino decays into a LSP and a photon, we also consider three-body
decays into a pair of charged leptons, and signatures related to scattering
with electrons and secondary neutralino production. For both models, we find
that the searches at FASER2 will allow to overcome the current bounds, while
SHIP will extend these limits by more than an order of magnitude in the value
of the coupling constant.
| [
{
"created": "Thu, 1 Jun 2023 17:59:49 GMT",
"version": "v1"
}
] | 2023-06-02 | [
[
"Jodłowski",
"Krzysztof",
""
]
] | Various supersymmetric (SUSY) scenarios predict a sub-GeV neutralino decaying into a single photon and an invisible state. This signature has recently been studied in a number of intensity frontier experiments, finding constraints complementary to the usual collider searches. In this work, we study the prospects of searches for long-lived neutralinos coupled to an ALPino or gravitino, where each can act as the lightest SUSY particle (LSP). In addition to the neutralino decays into a LSP and a photon, we also consider three-body decays into a pair of charged leptons, and signatures related to scattering with electrons and secondary neutralino production. For both models, we find that the searches at FASER2 will allow to overcome the current bounds, while SHIP will extend these limits by more than an order of magnitude in the value of the coupling constant. |
0903.2941 | Dremin | I.M. Dremin | QCD in the nuclear medium and effects due to Cherenkov gluons | 29 p., 4 figs; for "Phys. Atom. Nucl." volume dedicated to 80th
birthday of L.B. Okun; minor corrections on pp. 11 and 13 in v2 | Phys.Atom.Nucl.73:657-671,2010 | 10.1134/S1063778810040125 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The equations of in-medium gluodynamics are proposed. Their classical lowest
order solution is explicitly shown for a color charge moving with constant
speed. For nuclear permittivity larger than 1 it describes emission of
Cherenkov gluons resembling results of classical electrodynamics. The values of
the real and imaginary parts of the nuclear permittivity are obtained from the
fits to experimental data on the double-humped structure around the away-side
jet obtained at RHIC. The dispersion of the nuclear permittivity is predicted
by comparing the RHIC, SPS and cosmic ray data. This is important for LHC
experiments. Cherenkov gluons may be responsible for the asymmetry of dilepton
mass spectra near rho-meson, observed in the SPS experiment with excess in the
low-mass wing of the resonance. This feature is predicted to be common for all
resonances. The "color rainbow" quantum effect might appear according to higher
order terms of in-medium QCD if the nuclear permittivity depends on color.
| [
{
"created": "Tue, 17 Mar 2009 19:56:21 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Mar 2009 09:56:08 GMT",
"version": "v2"
}
] | 2010-04-30 | [
[
"Dremin",
"I. M.",
""
]
] | The equations of in-medium gluodynamics are proposed. Their classical lowest order solution is explicitly shown for a color charge moving with constant speed. For nuclear permittivity larger than 1 it describes emission of Cherenkov gluons resembling results of classical electrodynamics. The values of the real and imaginary parts of the nuclear permittivity are obtained from the fits to experimental data on the double-humped structure around the away-side jet obtained at RHIC. The dispersion of the nuclear permittivity is predicted by comparing the RHIC, SPS and cosmic ray data. This is important for LHC experiments. Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near rho-meson, observed in the SPS experiment with excess in the low-mass wing of the resonance. This feature is predicted to be common for all resonances. The "color rainbow" quantum effect might appear according to higher order terms of in-medium QCD if the nuclear permittivity depends on color. |
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