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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1701.01267 | Phongpichit Channuie | Khamphee Karwan (Naresuan U.), Phongpichit Channuie (Walailak U.) | Preheating in an inflationary model with disformal coupling | v2: 17 pages, 2 figures, texts modified, more references added,
version accepted for publication by Physical Rev. D | Phys. Rev. D 96, 023524 (2017) | 10.1103/PhysRevD.96.023524 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we investigate the preheating mechanism in a
disformally-coupled inflationary model where the scalar field $\phi$ (which is
the inflaton field) naturally coupled to another matter field $\chi$ induced by
the disformal transformation. In the present scenario, novel derivative
interactions mixing the kinetic terms of the two fields emerge inherently. We
start by deriving the evolution of the background system when the back reaction
on the background field is neglected. We examine the particle production due to
parametric resonances in the models and find in Minkowski space that the stage
of parametric resonances can be described by the Mathieu equation.
Interestingly, we discover that broad resonances in our models can be typically
achieved. Finally, we compare our results with previously studied model with
derivative couplings.
| [
{
"created": "Thu, 5 Jan 2017 10:06:35 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Jul 2017 02:18:45 GMT",
"version": "v2"
}
] | 2017-07-26 | [
[
"Karwan",
"Khamphee",
"",
"Naresuan U."
],
[
"Channuie",
"Phongpichit",
"",
"Walailak U."
]
] | In this work, we investigate the preheating mechanism in a disformally-coupled inflationary model where the scalar field $\phi$ (which is the inflaton field) naturally coupled to another matter field $\chi$ induced by the disformal transformation. In the present scenario, novel derivative interactions mixing the kinetic terms of the two fields emerge inherently. We start by deriving the evolution of the background system when the back reaction on the background field is neglected. We examine the particle production due to parametric resonances in the models and find in Minkowski space that the stage of parametric resonances can be described by the Mathieu equation. Interestingly, we discover that broad resonances in our models can be typically achieved. Finally, we compare our results with previously studied model with derivative couplings. |
1901.07526 | Jian Liang | Jian Liang, Mingyang Sun, Yi-Bo Yang, Terrence Draper and Keh-Fei Liu | Ratio of strange to $u/d$ momentum fraction in disconnected insertions | 11 pages, 9 figures, matched to the version accepted by PRD | Phys. Rev. D 102, 034514 (2020) | 10.1103/PhysRevD.102.034514 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ratio of the strange quark momentum fraction $\langle
x\rangle_{s+\bar{s}}$ to that of light quark $u$ or $d$ in disconnected
insertions (DI) is calculated on the lattice with overlap fermions on four
domain wall fermion ensembles. These ensembles cover three lattice spacings,
three volumes and several pion masses including the physical one, from which a
global fitting is carried out. A complete nonperturbative renormalization and
the mixing between the quark and glue operators are taken into account. We find
the ratio to be $\langle x\rangle_{s+\bar{s}}/\langle x\rangle_{u+\bar{u}}
({\rm DI})=0.795(79)(77)$ at $\mu = 2$ GeV in the $\overline{{\rm MS}}$ scheme.
This ratio can be used as a constraint to better determine the strange parton
distribution especially in the small $x$ region in the global fittings of PDFs
when the connected and disconnected sea are fitted and evolved separately,
demonstrating a new way that connects lattice calculations with global
analyses.
| [
{
"created": "Tue, 22 Jan 2019 18:59:36 GMT",
"version": "v1"
},
{
"created": "Sun, 30 Aug 2020 00:00:04 GMT",
"version": "v2"
}
] | 2020-09-02 | [
[
"Liang",
"Jian",
""
],
[
"Sun",
"Mingyang",
""
],
[
"Yang",
"Yi-Bo",
""
],
[
"Draper",
"Terrence",
""
],
[
"Liu",
"Keh-Fei",
""
]
] | The ratio of the strange quark momentum fraction $\langle x\rangle_{s+\bar{s}}$ to that of light quark $u$ or $d$ in disconnected insertions (DI) is calculated on the lattice with overlap fermions on four domain wall fermion ensembles. These ensembles cover three lattice spacings, three volumes and several pion masses including the physical one, from which a global fitting is carried out. A complete nonperturbative renormalization and the mixing between the quark and glue operators are taken into account. We find the ratio to be $\langle x\rangle_{s+\bar{s}}/\langle x\rangle_{u+\bar{u}} ({\rm DI})=0.795(79)(77)$ at $\mu = 2$ GeV in the $\overline{{\rm MS}}$ scheme. This ratio can be used as a constraint to better determine the strange parton distribution especially in the small $x$ region in the global fittings of PDFs when the connected and disconnected sea are fitted and evolved separately, demonstrating a new way that connects lattice calculations with global analyses. |
hep-ph/9505435 | Juergen Baacke | J. Baacke, A. Suerig (University of Dortmund) | Fermionic fluctuation corrections to bubble nucleation | 22 pages LaTeX, 3 figures, epsfig.sty,a4.sty | Phys.Rev.D53:4499-4509,1996 | 10.1103/PhysRevD.53.4499 | DO-TH 95/08 | hep-ph astro-ph hep-th | null | We determine the fermionic corrections to the nucleation rate of bubbles at
the electroweak phase transition. The fermion determinant is evaluated exactly
and by using the gradient expansion. The gradient expansion is found to be a
reliable approximation and is used to extrapolate to the large values of $\nu_n
= (2n+1)\pi T$ needed in the Matsubara sum. The contribution to effective
action is found to be negative and to be given, essentially, by the gradient
terms, the finite part of the wave function renormalization. Only the top quark
contribution is evaluated, it is of the same order as the Higgs- and W-boson
contributions found previously, but of opposite sign.
| [
{
"created": "Wed, 31 May 1995 15:46:11 GMT",
"version": "v1"
}
] | 2011-01-13 | [
[
"Baacke",
"J.",
"",
"University of Dortmund"
],
[
"Suerig",
"A.",
"",
"University of Dortmund"
]
] | We determine the fermionic corrections to the nucleation rate of bubbles at the electroweak phase transition. The fermion determinant is evaluated exactly and by using the gradient expansion. The gradient expansion is found to be a reliable approximation and is used to extrapolate to the large values of $\nu_n = (2n+1)\pi T$ needed in the Matsubara sum. The contribution to effective action is found to be negative and to be given, essentially, by the gradient terms, the finite part of the wave function renormalization. Only the top quark contribution is evaluated, it is of the same order as the Higgs- and W-boson contributions found previously, but of opposite sign. |
2108.12959 | Stefan Evans | Stefan Evans and Johann Rafelski | Particle production at a finite potential step: Transition from
Euler-Heisenberg to Klein paradox | 10 pages, 6 figures | null | 10.1140/epja/s10050-021-00654-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Spontaneous pair production for spin-$1/2$ and spin-$0$ particles is explored
in a quantitative manner for a static $\tanh$-Sauter potential step (SS),
evaluating the imaginary part of the effective action. We provide finite-valued
per unit-surface results, including the exact sharp-edge Klein paradox (KP)
limit, which is the upper bound to pair production. At the vacuum instability
threshold the spin-$0$ particle production can surpass that for the spin-$1/2$
rate. Presenting the effect of two opposite sign Sauter potential steps
creating a well we show that spin-$0$ pair production, contrary to the case of
spin-$1/2$, requires a smoothly sloped wall.
| [
{
"created": "Mon, 30 Aug 2021 02:33:54 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Oct 2021 16:13:27 GMT",
"version": "v2"
}
] | 2022-01-19 | [
[
"Evans",
"Stefan",
""
],
[
"Rafelski",
"Johann",
""
]
] | Spontaneous pair production for spin-$1/2$ and spin-$0$ particles is explored in a quantitative manner for a static $\tanh$-Sauter potential step (SS), evaluating the imaginary part of the effective action. We provide finite-valued per unit-surface results, including the exact sharp-edge Klein paradox (KP) limit, which is the upper bound to pair production. At the vacuum instability threshold the spin-$0$ particle production can surpass that for the spin-$1/2$ rate. Presenting the effect of two opposite sign Sauter potential steps creating a well we show that spin-$0$ pair production, contrary to the case of spin-$1/2$, requires a smoothly sloped wall. |
1502.01581 | Alexandru Parvan | A.S. Parvan | Non-extensive statistics effects in transverse momentum spectra of
hadrons | 2 figures | PoS(Baldin ISHEPP XXII)077, 2014 | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Bose-Einstein and Fermi-Dirac statistics of the identified hadrons were
verified on the basis of the transverse momentum distributions of bosons and
fermions created in the $pp$ collisions at high energies using the
Tsallis-factorized statistics and the two-component distributions of the
Boltzmann-Gibbs statistics. The main differences between the parameters of the
Tsallis-factorized statistics and the Boltzmann-Gibbs statistics were
identified. The results of the Boltzmann-Gibbs statistics are reasonable and
suggest that the soft and hard hadrons may be produced from the two different
macroscopic states of the dynamical system. It was revealed that the volume of
the system obtained in the Tsallis-factorized statistics is unusually large in
comparison with the geometrical volume of two protons. The main formulas for
the Tsallis statistics in the grand canonical ensemble were formulated.
| [
{
"created": "Thu, 5 Feb 2015 15:07:35 GMT",
"version": "v1"
}
] | 2015-02-06 | [
[
"Parvan",
"A. S.",
""
]
] | The Bose-Einstein and Fermi-Dirac statistics of the identified hadrons were verified on the basis of the transverse momentum distributions of bosons and fermions created in the $pp$ collisions at high energies using the Tsallis-factorized statistics and the two-component distributions of the Boltzmann-Gibbs statistics. The main differences between the parameters of the Tsallis-factorized statistics and the Boltzmann-Gibbs statistics were identified. The results of the Boltzmann-Gibbs statistics are reasonable and suggest that the soft and hard hadrons may be produced from the two different macroscopic states of the dynamical system. It was revealed that the volume of the system obtained in the Tsallis-factorized statistics is unusually large in comparison with the geometrical volume of two protons. The main formulas for the Tsallis statistics in the grand canonical ensemble were formulated. |
2306.11575 | Ibrahim Sulai | Ibrahim A. Sulai, Saarik Kalia, Ariel Arza, Itay M. Bloch, Eduardo
Castro Mu\~noz, Christopher Fabian, Michael A. Fedderke, Madison Forseth,
Brian Garthwaite, Peter W. Graham, Will Griffith, Erik Helgren, Andres
Interiano-Alvarado, Brittany Karki, Abaz Kryemadhi, Andre Li, Ehsanullah
Nikfar, Jason E. Stalnaker, Yicheng Wang, Derek F. Jackson Kimball | A Hunt for Magnetic Signatures of Hidden-Photon and Axion Dark Matter in
the Wilderness | 22 pages, 12 figures. Accepted for publication in PRD. Minor changes
in text and updated / improved limits | Phys. Rev. D 108, 096026 (2023) | 10.1103/PhysRevD.108.096026 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | Earth can act as a transducer to convert ultralight bosonic dark matter
(axions and hidden photons) into an oscillating magnetic field with a
characteristic pattern across its surface. Here we describe the first results
of a dedicated experiment, the Search for Non-Interacting Particles
Experimental Hunt (SNIPE Hunt), that aims to detect such dark-matter-induced
magnetic-field patterns by performing correlated measurements with a network of
magnetometers in relatively quiet magnetic environments (in the wilderness far
from human-generated magnetic noise). Our experiment constrains parameter space
describing hidden-photon and axion dark matter with Compton frequencies in the
0.5-5.0 Hz range. Limits on the kinetic-mixing parameter for hidden-photon dark
matter represent the best experimental bounds to date in this frequency range.
| [
{
"created": "Tue, 20 Jun 2023 14:43:43 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Oct 2023 17:21:38 GMT",
"version": "v2"
}
] | 2024-01-11 | [
[
"Sulai",
"Ibrahim A.",
""
],
[
"Kalia",
"Saarik",
""
],
[
"Arza",
"Ariel",
""
],
[
"Bloch",
"Itay M.",
""
],
[
"Muñoz",
"Eduardo Castro",
""
],
[
"Fabian",
"Christopher",
""
],
[
"Fedderke",
"Michael A.",
"... | Earth can act as a transducer to convert ultralight bosonic dark matter (axions and hidden photons) into an oscillating magnetic field with a characteristic pattern across its surface. Here we describe the first results of a dedicated experiment, the Search for Non-Interacting Particles Experimental Hunt (SNIPE Hunt), that aims to detect such dark-matter-induced magnetic-field patterns by performing correlated measurements with a network of magnetometers in relatively quiet magnetic environments (in the wilderness far from human-generated magnetic noise). Our experiment constrains parameter space describing hidden-photon and axion dark matter with Compton frequencies in the 0.5-5.0 Hz range. Limits on the kinetic-mixing parameter for hidden-photon dark matter represent the best experimental bounds to date in this frequency range. |
hep-ph/0104059 | Rasche | A. Gashi, G.Rasche, W. S. Woolcock | The influence of the hadronic interaction on the pionium wave functions | 9 pages including 2 figures | Phys.Lett.B513:269-272,2001 | 10.1016/S0370-2693(01)00753-5 | ZU-TH 12/01 | hep-ph | null | The influence of the hadronic \pi\pi interaction on the wave functions of
pionium (the Coulomb bound \pi^+\pi^- system) at distances less than 10 fm is
calculated for s-states with principal quantum numbers n<5. Hadronic \pi\pi
potentials are used that reproduce the scattering phase shifts of two-loop
chiral perturbation theory. The pionium wave functions \psi_n (r) are obtained
by integrating the coupled Schr\"odinger equations for the
(\pi^+\pi^-,\pi^0\pi^0) system. We find that, for r<10 fm, n^{3/2} \psi_n (r)
is practically independent of n. From this we conclude that the production
rates of the s-states of pionium are proportional to n^{-3}, a result needed
for the interpretation of the DIRAC experiment currently running at CERN.
| [
{
"created": "Thu, 5 Apr 2001 14:11:46 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Gashi",
"A.",
""
],
[
"Rasche",
"G.",
""
],
[
"Woolcock",
"W. S.",
""
]
] | The influence of the hadronic \pi\pi interaction on the wave functions of pionium (the Coulomb bound \pi^+\pi^- system) at distances less than 10 fm is calculated for s-states with principal quantum numbers n<5. Hadronic \pi\pi potentials are used that reproduce the scattering phase shifts of two-loop chiral perturbation theory. The pionium wave functions \psi_n (r) are obtained by integrating the coupled Schr\"odinger equations for the (\pi^+\pi^-,\pi^0\pi^0) system. We find that, for r<10 fm, n^{3/2} \psi_n (r) is practically independent of n. From this we conclude that the production rates of the s-states of pionium are proportional to n^{-3}, a result needed for the interpretation of the DIRAC experiment currently running at CERN. |
0804.2802 | Francois Arleo | Francois Arleo (LAPTH) | Constraints on nuclear gluon densities from J/psi data | 7 pages, 1 figure | Phys.Lett.B666:31-33,2008 | 10.1016/j.physletb.2008.06.074 | LAPTH-1244/08 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The gluon density in nuclei, G^A(x), is poorly constrained at all x from the
current DIS and Drell-Yan data. In this paper, we point out that J/psi
production measured in proton-nucleus collisions at sqrt(s)=38.8 GeV by the
E866 collaboration puts stringent constraints on the x-dependence of the
G^W/G^Be ratio in the x=0.02-0.1 range. The E866 data suggest a rather mild
x-dependence of G^W/G^Be, and consequently tend to favour DS and HKM sets,
rather than the DSg, EKS, and EPS parametrizations which exhibit a large
shadowing and anti-shadowing.
| [
{
"created": "Thu, 17 Apr 2008 13:34:19 GMT",
"version": "v1"
}
] | 2008-12-18 | [
[
"Arleo",
"Francois",
"",
"LAPTH"
]
] | The gluon density in nuclei, G^A(x), is poorly constrained at all x from the current DIS and Drell-Yan data. In this paper, we point out that J/psi production measured in proton-nucleus collisions at sqrt(s)=38.8 GeV by the E866 collaboration puts stringent constraints on the x-dependence of the G^W/G^Be ratio in the x=0.02-0.1 range. The E866 data suggest a rather mild x-dependence of G^W/G^Be, and consequently tend to favour DS and HKM sets, rather than the DSg, EKS, and EPS parametrizations which exhibit a large shadowing and anti-shadowing. |
hep-ph/9903320 | James L. Carr | James L. Carr | A classical picture of lepton neutral current forces | 20 pages | null | null | null | hep-ph | null | When charged current weak interations are excluded, the neutral current weak
interaction is formally similar to ordinary electromagnetism with a massive
photon. In this spirit, the Maxwell equations for the fields of the Z-boson are
derived from the standard model. These describe the Z-boson scalar and vector
potentials, and the Z-boson electric and magnetic fields whose sources are
electron and neutrino distributions and currents. The Z-boson Maxwell equations
are solved for point sources representing classical point-like electrons and
neutrinos. The parity violation of the weak interation is manifest in the
structure of these solutions. As an application of this model, the neutral
current contribution to the muonium hyperfine structure is computed using
nonrelativistic perturbation theory.
| [
{
"created": "Thu, 11 Mar 1999 03:57:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Carr",
"James L.",
""
]
] | When charged current weak interations are excluded, the neutral current weak interaction is formally similar to ordinary electromagnetism with a massive photon. In this spirit, the Maxwell equations for the fields of the Z-boson are derived from the standard model. These describe the Z-boson scalar and vector potentials, and the Z-boson electric and magnetic fields whose sources are electron and neutrino distributions and currents. The Z-boson Maxwell equations are solved for point sources representing classical point-like electrons and neutrinos. The parity violation of the weak interation is manifest in the structure of these solutions. As an application of this model, the neutral current contribution to the muonium hyperfine structure is computed using nonrelativistic perturbation theory. |
hep-ph/9906407 | Christer Friberg | Christer Friberg and Torbj\"orn Sj\"ostrand (Lund university, Sweden) | Jet Production by Real and Virtual Photons | 1+13 pages, LaTeX2e, 16 eps figures, to appear in the Proceedings of
the DESY Workshop on "Monte Carlo Generators for HERA Physics" | null | null | LU TP 99-12 | hep-ph | null | The production of jets is studied in collisions of virtual photons,
specifically for applications at HERA. Photon flux factors are convoluted with
matrix elements involving either direct or resolved photons and, for the
latter, with parton distributions of the photon. Special emphasis is put on the
range of uncertainty in the modeling of the resolved component. The resulting
model is compared with existing data and further tests are proposed.
| [
{
"created": "Thu, 17 Jun 1999 09:10:38 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Friberg",
"Christer",
"",
"Lund university, Sweden"
],
[
"Sjöstrand",
"Torbjörn",
"",
"Lund university, Sweden"
]
] | The production of jets is studied in collisions of virtual photons, specifically for applications at HERA. Photon flux factors are convoluted with matrix elements involving either direct or resolved photons and, for the latter, with parton distributions of the photon. Special emphasis is put on the range of uncertainty in the modeling of the resolved component. The resulting model is compared with existing data and further tests are proposed. |
2310.02363 | Ranjeet Kumar | Ranjeet Kumar, Priya Mishra, Mitesh Kumar Behera, Rukmani Mohanta,
Rahul Srivastava | Predictions from scoto-seesaw with $A_4$ modular symmetry | 38 pages, 4 tables, 15 figures, V3 minor correction, results
unchanged, matches with published version in PLB | Phys. Lett. B 853 (2024) 138635 | 10.1016/j.physletb.2024.138635 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper's novelty lies in introducing a hybrid scoto-seesaw model rooted
in $A_4$ discrete modular symmetry leading to several interesting
phenomenological implications. The scoto-seesaw framework leads to generation
of one mass square difference $( \Delta m^2_{\rm atm}$) using the type-I seesaw
mechanism at the tree level. Additionally, the scotogenic contribution is vital
in obtaining the other mass square difference ($\Delta m^2 _{\rm sol}$) at the
loop level, thus providing a clear interpretation of the two different mass
square differences. The non-trivial transformation of Yukawa couplings under
the $A_4$ modular symmetry helps to explore neutrino phenomenology with a
specific flavor structure of the mass matrix. In addition to predictions for
neutrino mass ordering, mixing angles and CP phases, this setup leads to
precise predictions for $\sum m_i$ as well as $|m_{ee}|$. In particular, the
model predicts $\sum m_i \in (0.073,0.097)$ eV and $\left| m_{ee}\right| \in
(3.15,6.66)\times 10^{-3} $ eV range; within reach of upcoming experiments.
Furthermore, our model is also promising for addressing lepton flavor
violations, i.e., $\ell_\alpha \to \ell_\beta \gamma$, $\ell_\alpha \to
3\ell_\beta$ and $\mu - e $ conversion rates while staying within the realm of
current experimental limits.
| [
{
"created": "Tue, 3 Oct 2023 18:38:29 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Apr 2024 06:30:40 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Apr 2024 16:50:13 GMT",
"version": "v3"
}
] | 2024-04-25 | [
[
"Kumar",
"Ranjeet",
""
],
[
"Mishra",
"Priya",
""
],
[
"Behera",
"Mitesh Kumar",
""
],
[
"Mohanta",
"Rukmani",
""
],
[
"Srivastava",
"Rahul",
""
]
] | This paper's novelty lies in introducing a hybrid scoto-seesaw model rooted in $A_4$ discrete modular symmetry leading to several interesting phenomenological implications. The scoto-seesaw framework leads to generation of one mass square difference $( \Delta m^2_{\rm atm}$) using the type-I seesaw mechanism at the tree level. Additionally, the scotogenic contribution is vital in obtaining the other mass square difference ($\Delta m^2 _{\rm sol}$) at the loop level, thus providing a clear interpretation of the two different mass square differences. The non-trivial transformation of Yukawa couplings under the $A_4$ modular symmetry helps to explore neutrino phenomenology with a specific flavor structure of the mass matrix. In addition to predictions for neutrino mass ordering, mixing angles and CP phases, this setup leads to precise predictions for $\sum m_i$ as well as $|m_{ee}|$. In particular, the model predicts $\sum m_i \in (0.073,0.097)$ eV and $\left| m_{ee}\right| \in (3.15,6.66)\times 10^{-3} $ eV range; within reach of upcoming experiments. Furthermore, our model is also promising for addressing lepton flavor violations, i.e., $\ell_\alpha \to \ell_\beta \gamma$, $\ell_\alpha \to 3\ell_\beta$ and $\mu - e $ conversion rates while staying within the realm of current experimental limits. |
2404.13226 | XinYang Li | Chong-Xing Yue, Xin-Yang Li, Xiao-Chen Sun | Prospects for detecting the couplings of axion-like particle with
neutrinos at the CEPC | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We explore the possibility of detecting the couplings of axion-like particle
(ALP) with leptons from their loop-level impact on the ALP couplings to
electroweak (EW) gauge bosons via the signal process $e^+ e^- \to \gamma \gamma
/E$ at the Circular Electron Positron Collider (CEPC) and obtain prospective
sensitivities to the ALP-lepton couplings. Our numerical results show that the
CEPC with the center of mass energy $\sqrt{s}=240$ GeV and the integrated
luminosity $\mathcal{L}=$ $5.6$ ab$^{-1}$ might be sensitive for probing the
ALP-lepton couplings in the ALP mass range from $10$ GeV to $130$ GeV, where
the prospective sensitivities to the ALP-neutrino coupling
$Tr(g_{a\nu\nu})/f_a$ can be as low as $0.016$ GeV$^{-1}$ and $0.0031$
GeV$^{-1}$ for $c_{R}=0$ and $c_{R}=c_{L}$, and to the ALP-charged lepton
coupling $Tr(g_{a\ell\ell})/f_a$ can be as low as $0.035$ GeV$^{-1}$ for
$c_{L}=0$. We find that the prospective sensitivities given by the CEPC are not
covered by the current exclusion regions in some ALP mass intervals. The CEPC
has the potential for exploring the ALP-neutrino couplings via some promising
processes induced by the ALP-EW gauge boson couplings in the future.
| [
{
"created": "Sat, 20 Apr 2024 01:27:09 GMT",
"version": "v1"
}
] | 2024-04-23 | [
[
"Yue",
"Chong-Xing",
""
],
[
"Li",
"Xin-Yang",
""
],
[
"Sun",
"Xiao-Chen",
""
]
] | We explore the possibility of detecting the couplings of axion-like particle (ALP) with leptons from their loop-level impact on the ALP couplings to electroweak (EW) gauge bosons via the signal process $e^+ e^- \to \gamma \gamma /E$ at the Circular Electron Positron Collider (CEPC) and obtain prospective sensitivities to the ALP-lepton couplings. Our numerical results show that the CEPC with the center of mass energy $\sqrt{s}=240$ GeV and the integrated luminosity $\mathcal{L}=$ $5.6$ ab$^{-1}$ might be sensitive for probing the ALP-lepton couplings in the ALP mass range from $10$ GeV to $130$ GeV, where the prospective sensitivities to the ALP-neutrino coupling $Tr(g_{a\nu\nu})/f_a$ can be as low as $0.016$ GeV$^{-1}$ and $0.0031$ GeV$^{-1}$ for $c_{R}=0$ and $c_{R}=c_{L}$, and to the ALP-charged lepton coupling $Tr(g_{a\ell\ell})/f_a$ can be as low as $0.035$ GeV$^{-1}$ for $c_{L}=0$. We find that the prospective sensitivities given by the CEPC are not covered by the current exclusion regions in some ALP mass intervals. The CEPC has the potential for exploring the ALP-neutrino couplings via some promising processes induced by the ALP-EW gauge boson couplings in the future. |
1307.3299 | Amir Nawaz Khan | Amir N. Khan, Douglas W. McKay, and John P. Ralston | Optimizing the Determination of the Neutrino Mixing Angle $\theta_{13}$
from Reactor Data | New text, new figure and new references revise the thrust of the
paper to improve determination of the mixing angle. New title reflects this
improvement | International Journal of Modern Physics A, Vol. 29, No. 20 (2014)
1450109 (18 pages) | 10.1142/S0217751X14501097 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The technical breakthroughs of multiple detectors developed by Daya Bay and
RENO collaborations have gotten great attention. Yet the optimal determination
of neutrino mixing parameters from reactor data depends on the statistical
method and demands equal attention. We find that a straightforward method using
a minimal parameters will generally outperform a multi-parameter method by
delivering more reliable values with sharper resolution. We review standard
confidence levels and statistical penalties for models using extra parameters,
and apply those rules to our analysis. We find that the methods used in recent
work of the Daya Bay and RENO collaborations have several undesirable
properties. The existing work also uses non-standard measures of significance
which we are unable to explain. A central element of the current methods
consists of variationally fitting many more parameters than data points. As a
result the experimental resolution of $\sin ^{2}(2\theta _{13})$ is degraded.
The results also become extremely sensitive to certain model parameters that
can be adjusted arbitrarily. The number of parameters to include in evaluating
significance is an important issue that has generally been overlooked. The
measures of significance applied previously would be consistent if and only if
all parameters but one were considered to have no physical relevance for the
experiment's hypothesis test. Simpler, more transparent methods can improve the
determination of the mixing angle $\theta _{13}$ from reactor data, and exploit
the advantages from superb hardware technique of the experiments. We anticipate
that future experimental analysis will fully exploit those advantages.
| [
{
"created": "Fri, 12 Jul 2013 00:23:48 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Jan 2014 15:54:41 GMT",
"version": "v2"
}
] | 2014-09-23 | [
[
"Khan",
"Amir N.",
""
],
[
"McKay",
"Douglas W.",
""
],
[
"Ralston",
"John P.",
""
]
] | The technical breakthroughs of multiple detectors developed by Daya Bay and RENO collaborations have gotten great attention. Yet the optimal determination of neutrino mixing parameters from reactor data depends on the statistical method and demands equal attention. We find that a straightforward method using a minimal parameters will generally outperform a multi-parameter method by delivering more reliable values with sharper resolution. We review standard confidence levels and statistical penalties for models using extra parameters, and apply those rules to our analysis. We find that the methods used in recent work of the Daya Bay and RENO collaborations have several undesirable properties. The existing work also uses non-standard measures of significance which we are unable to explain. A central element of the current methods consists of variationally fitting many more parameters than data points. As a result the experimental resolution of $\sin ^{2}(2\theta _{13})$ is degraded. The results also become extremely sensitive to certain model parameters that can be adjusted arbitrarily. The number of parameters to include in evaluating significance is an important issue that has generally been overlooked. The measures of significance applied previously would be consistent if and only if all parameters but one were considered to have no physical relevance for the experiment's hypothesis test. Simpler, more transparent methods can improve the determination of the mixing angle $\theta _{13}$ from reactor data, and exploit the advantages from superb hardware technique of the experiments. We anticipate that future experimental analysis will fully exploit those advantages. |
hep-ph/9512384 | null | T. Schaefer (INT, Seattle) and E.V. Shuryak (SUNY Stony Brook) | Hadronic Correlation Functions in the Interacting Instanton Liquid | 34 pages, Revtex, 7 postscript figures | Phys.Rev. D54 (1996) 1099-1111 | 10.1103/PhysRevD.54.1099 | SUNY-NTG-95-23, INT95-00-110 | hep-ph hep-lat | null | We study hadronic correlation functions in the interacting instanton liquid
model, both at zero and nonzero temperature $T$. At zero $T$ we investigate the
dependence of the correlators on the instanton ensemble, in particular the
effect of the fermionic determinant. We demonstrate that quark-induced
correlations between instantons are important, especially in the repulsive
$\eta'$ and $\delta$-meson channels. We also calculate a large number of
mesonic and baryonic correlation functions as a function of temperature. We
find three different types of behavior as $T\to T_c$. The vector channels
$\rho,a_1,\Delta$ show a gradual melting of the resonance contribution and
approach free quark behavior near the chiral phase transition. The light
pseudoscalars and scalars $\pi,\sigma$, as well as the nucleon show stable
resonance contributions, probably even surviving above $T_c$. Correlation
functions in the heavy scalar channels $\eta',\delta$ are enhanced as $T\to
T_c$.
| [
{
"created": "Wed, 20 Dec 1995 22:42:46 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Schaefer",
"T.",
"",
"INT, Seattle"
],
[
"Shuryak",
"E. V.",
"",
"SUNY Stony Brook"
]
] | We study hadronic correlation functions in the interacting instanton liquid model, both at zero and nonzero temperature $T$. At zero $T$ we investigate the dependence of the correlators on the instanton ensemble, in particular the effect of the fermionic determinant. We demonstrate that quark-induced correlations between instantons are important, especially in the repulsive $\eta'$ and $\delta$-meson channels. We also calculate a large number of mesonic and baryonic correlation functions as a function of temperature. We find three different types of behavior as $T\to T_c$. The vector channels $\rho,a_1,\Delta$ show a gradual melting of the resonance contribution and approach free quark behavior near the chiral phase transition. The light pseudoscalars and scalars $\pi,\sigma$, as well as the nucleon show stable resonance contributions, probably even surviving above $T_c$. Correlation functions in the heavy scalar channels $\eta',\delta$ are enhanced as $T\to T_c$. |
1502.02612 | Victor Goncalves | C. Brenner Mariotto, V. P. Goncalves | Double $J/\psi$ production in central diffractive processes at the LHC | 6 pages, 3 figures, 1 table. Version to be published in Physical
Review D. arXiv admin note: text overlap with arXiv:1309.2026 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we study the double $J/\psi$ production in central diffractive
processes considering the Resolved Pomeron model. Based on the nonrelativistic
QCD (NRQCD) factorization formalism for the quarkonium production mechanism we
estimate the rapidity and transverse momentum dependence of the cross section
for the double $J/\psi$ production in diffractive processes at LHC energies.
The contributions of the color-singlet and color-octet channels are estimated
and predictions for the total cross sections in the kinematical regions of the
LHC experiments are also presented. Our results demonstrate that the
contribution of central diffractive processes is not negligible and that its
study can be useful to test the Resolved Pomeron model.
| [
{
"created": "Mon, 9 Feb 2015 19:19:36 GMT",
"version": "v1"
},
{
"created": "Mon, 11 May 2015 18:48:19 GMT",
"version": "v2"
}
] | 2015-05-12 | [
[
"Mariotto",
"C. Brenner",
""
],
[
"Goncalves",
"V. P.",
""
]
] | In this paper we study the double $J/\psi$ production in central diffractive processes considering the Resolved Pomeron model. Based on the nonrelativistic QCD (NRQCD) factorization formalism for the quarkonium production mechanism we estimate the rapidity and transverse momentum dependence of the cross section for the double $J/\psi$ production in diffractive processes at LHC energies. The contributions of the color-singlet and color-octet channels are estimated and predictions for the total cross sections in the kinematical regions of the LHC experiments are also presented. Our results demonstrate that the contribution of central diffractive processes is not negligible and that its study can be useful to test the Resolved Pomeron model. |
1804.05691 | Dariusz Prorok | Dariusz Prorok | Centrality dependence of freeze-out temperature fluctuations in Pb-Pb
collisions at the LHC | 7 pages, 7 figures. arXiv admin note: substantial text overlap with
arXiv:1508.07922, matches the published version | Eur. Phys. J. A (2019) 55: 37 | 10.1140/epja/i2019-12709-3 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Many data in the High Energy Physics are, in fact, sample means. It is shown
that when this exact meaning of the data is taken into account and the most
weakly bound states are removed from the hadron resonance gas, the whole
spectra of pions, kaons and protons measured at midrapidity in Pb-Pb collisions
at $\sqrt{s_{NN}} = 2.76$ TeV can be fitted simultaneously. The invariant
distributions are predicted with the help of the single-freeze-out model in the
chemical equilibrium framework. The method is applied to the measurements in
centrality bins of Pb-Pb collisions and gives acceptable fits for all but
peripheral bins. The comparison with the results obtained in the framework of
the original single-freeze-out model is also presented. Some more general,
possible implications of this approach are pointed out.
| [
{
"created": "Fri, 13 Apr 2018 14:02:35 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Mar 2019 12:20:20 GMT",
"version": "v2"
}
] | 2019-03-18 | [
[
"Prorok",
"Dariusz",
""
]
] | Many data in the High Energy Physics are, in fact, sample means. It is shown that when this exact meaning of the data is taken into account and the most weakly bound states are removed from the hadron resonance gas, the whole spectra of pions, kaons and protons measured at midrapidity in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV can be fitted simultaneously. The invariant distributions are predicted with the help of the single-freeze-out model in the chemical equilibrium framework. The method is applied to the measurements in centrality bins of Pb-Pb collisions and gives acceptable fits for all but peripheral bins. The comparison with the results obtained in the framework of the original single-freeze-out model is also presented. Some more general, possible implications of this approach are pointed out. |
0909.2760 | Luca Merlo | Luca Merlo | Bimaximal neutrino mixing and weak complementarity with S4 discrete
symmetry | 4 pages, 1 figure; talk given at SUSY 2009 -- 17th International
Conference on Supersymmetry and the Unification of Fundamental Interactions,
June 2-4, Boston | AIP Conf.Proc.1200:948-951,2010 | 10.1063/1.3327771 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The neutrino oscillation data are well explained by the tri-bimaximal
pattern. Recently a paper appeared showing that also the bimaximal pattern
could be a very good starting point in order to describe the lepton mixing. In
this paper I review both the flavour structures and then I present an explicit
model based on the discrete symmetry group S4.
| [
{
"created": "Tue, 15 Sep 2009 10:30:54 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Sep 2009 21:16:34 GMT",
"version": "v2"
}
] | 2015-05-14 | [
[
"Merlo",
"Luca",
""
]
] | The neutrino oscillation data are well explained by the tri-bimaximal pattern. Recently a paper appeared showing that also the bimaximal pattern could be a very good starting point in order to describe the lepton mixing. In this paper I review both the flavour structures and then I present an explicit model based on the discrete symmetry group S4. |
1208.0551 | Sacha Davidson | Sacha Davidson and Martin Elmer | Similar Dark Matter and Baryon abundances with TeV-scale Leptogenesis | references added | null | 10.1007/JHEP10(2012)148 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We estimate the Baryon Asymmetry of the Universe (BAU) produced in an inverse
seesaw model containing extra light singlets, and with lepton number
conservation prior to the electroweak phase transition. An order one CP
asymmetry epsilon is required to obtain a large enough BAU. We discuss the
relation between the baryon and WIMP relic densities in baryogenesis scenarios
using the out-of-equilibrium decay of a baryon-parent of mass M: when baryon
number violation freezes out, the remaining density of baryon-parents is of
order M/m_W times the WIMP relic density. So the baryon/WIMP ratio is or order
epsilon M/m_W. A natural explanation of the similar WIMP and baryon densities
could be that CP violation is of order the ratio m_W/M.
| [
{
"created": "Thu, 2 Aug 2012 17:30:27 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Aug 2012 09:15:39 GMT",
"version": "v2"
}
] | 2015-06-11 | [
[
"Davidson",
"Sacha",
""
],
[
"Elmer",
"Martin",
""
]
] | We estimate the Baryon Asymmetry of the Universe (BAU) produced in an inverse seesaw model containing extra light singlets, and with lepton number conservation prior to the electroweak phase transition. An order one CP asymmetry epsilon is required to obtain a large enough BAU. We discuss the relation between the baryon and WIMP relic densities in baryogenesis scenarios using the out-of-equilibrium decay of a baryon-parent of mass M: when baryon number violation freezes out, the remaining density of baryon-parents is of order M/m_W times the WIMP relic density. So the baryon/WIMP ratio is or order epsilon M/m_W. A natural explanation of the similar WIMP and baryon densities could be that CP violation is of order the ratio m_W/M. |
0902.1678 | Christophe Royon | M. Boonekamp, F. Chevallier, C. Royon, L. Schoeffel | Understanding the structure of the proton: From HERA and Tevatron to LHC | 92 pages, review | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this review, we first discuss the perspectives concerning a better
determination of the proton structure in terms of quarks and gluons at LHC
after describing the results coming from HERA and Tevatron. In a second part of
the review, we describe the diffractive phenomena at HERA and Tevatron and the
consequences for LHC.
| [
{
"created": "Tue, 10 Feb 2009 16:00:06 GMT",
"version": "v1"
}
] | 2012-07-04 | [
[
"Boonekamp",
"M.",
""
],
[
"Chevallier",
"F.",
""
],
[
"Royon",
"C.",
""
],
[
"Schoeffel",
"L.",
""
]
] | In this review, we first discuss the perspectives concerning a better determination of the proton structure in terms of quarks and gluons at LHC after describing the results coming from HERA and Tevatron. In a second part of the review, we describe the diffractive phenomena at HERA and Tevatron and the consequences for LHC. |
1612.08090 | Yuichiro Nakai | Yuichiro Nakai and Matthew Reece | Electric Dipole Moments in Natural Supersymmetry | 37 pages plus appendices, 16 figures; v2: journal version | null | 10.1007/JHEP08(2017)031 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss electric dipole moments (EDMs) in the framework of CP-violating
natural supersymmetry (SUSY). Recent experimental results have significantly
tightened constraints on the EDMs of electrons and of mercury, and substantial
further progress is expected in the near future. We assess how these results
constrain the parameter space of natural SUSY. In addition to our discussion of
SUSY, we provide a set of general formulas for two-loop fermion EDMs, which can
be applied to a wide range of models of new physics. In the SUSY context, the
two-loop effects of stops and charginos respectively constrain the phases of
$A_t \mu$ and $M_2 \mu$ to be small in the natural part of parameter space. If
the Higgs mass is lifted to 125 GeV by a new tree-level superpotential
interaction and soft term with CP-violating phases, significant EDMs can arise
from the two-loop effects of $W$ bosons and tops. We compare the bounds arising
from EDMs to those from other probes of new physics including colliders, $b \to
s \gamma$, and dark matter searches. Importantly, improvements in reach not
only constrain higher masses, but require the phases to be significantly
smaller in the natural parameter space at low mass. The required smallness of
phases sharpens the CP problem of natural SUSY model building.
| [
{
"created": "Fri, 23 Dec 2016 21:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Aug 2017 13:42:56 GMT",
"version": "v2"
}
] | 2017-09-13 | [
[
"Nakai",
"Yuichiro",
""
],
[
"Reece",
"Matthew",
""
]
] | We discuss electric dipole moments (EDMs) in the framework of CP-violating natural supersymmetry (SUSY). Recent experimental results have significantly tightened constraints on the EDMs of electrons and of mercury, and substantial further progress is expected in the near future. We assess how these results constrain the parameter space of natural SUSY. In addition to our discussion of SUSY, we provide a set of general formulas for two-loop fermion EDMs, which can be applied to a wide range of models of new physics. In the SUSY context, the two-loop effects of stops and charginos respectively constrain the phases of $A_t \mu$ and $M_2 \mu$ to be small in the natural part of parameter space. If the Higgs mass is lifted to 125 GeV by a new tree-level superpotential interaction and soft term with CP-violating phases, significant EDMs can arise from the two-loop effects of $W$ bosons and tops. We compare the bounds arising from EDMs to those from other probes of new physics including colliders, $b \to s \gamma$, and dark matter searches. Importantly, improvements in reach not only constrain higher masses, but require the phases to be significantly smaller in the natural parameter space at low mass. The required smallness of phases sharpens the CP problem of natural SUSY model building. |
hep-ph/0703125 | Fred Jegerlehner | F. Jegerlehner | Essentials of the Muon g-2 | 39 pages, 21 figures,v2: comment on Ref. 82/83 corrected,some figures
replaced by colored version, Ref. 82 updated; v3: update using new result of
T. Aoyama, M. Hayakawa, T. Kinoshita, M. Nio,arXiv:0706.3496 [hep-ph]; final
result unchanged | Acta Phys.Polon.B38:3021,2007 | null | DESY 07-033 | hep-ph | null | The muon anomalous magnetic moment is one of the most precisely measured
quantities in particle physics. Recent high precision measurements (0.54ppm) at
Brookhaven reveal a ``discrepancy'' by 3 standard deviations from the
electroweak Standard Model which could be a hint for an unknown contribution
from physics beyond the Standard Model. This triggered numerous speculations
about the possible origin of the ``missing piece''. The remarkable 14-fold
improvement of the previous CERN experiment, actually animated a multitude of
new theoretical efforts which lead to a substantial improvement of the
prediction of a_mu. The dominating uncertainty of the prediction, caused by
strong interaction effects, could be reduced substantially, due to new hadronic
cross section measurements in electron-positron annihilation at low energies.
After an introduction and a brief description of the principle of the
experiment, I present a major update and review the status of the theoretical
prediction and discuss the role of the hadronic vacuum polarization effects and
the hadronic light--by--light scattering contribution. Prospects for the future
will be briefly discussed. As, in electroweak precision physics, the muon g-2
shows the largest established deviation between theory and experiment at
present, it will remain one of the hot topics for further investigations.
| [
{
"created": "Mon, 12 Mar 2007 13:10:55 GMT",
"version": "v1"
},
{
"created": "Fri, 11 May 2007 12:33:38 GMT",
"version": "v2"
},
{
"created": "Sun, 1 Jul 2007 16:45:24 GMT",
"version": "v3"
}
] | 2010-04-06 | [
[
"Jegerlehner",
"F.",
""
]
] | The muon anomalous magnetic moment is one of the most precisely measured quantities in particle physics. Recent high precision measurements (0.54ppm) at Brookhaven reveal a ``discrepancy'' by 3 standard deviations from the electroweak Standard Model which could be a hint for an unknown contribution from physics beyond the Standard Model. This triggered numerous speculations about the possible origin of the ``missing piece''. The remarkable 14-fold improvement of the previous CERN experiment, actually animated a multitude of new theoretical efforts which lead to a substantial improvement of the prediction of a_mu. The dominating uncertainty of the prediction, caused by strong interaction effects, could be reduced substantially, due to new hadronic cross section measurements in electron-positron annihilation at low energies. After an introduction and a brief description of the principle of the experiment, I present a major update and review the status of the theoretical prediction and discuss the role of the hadronic vacuum polarization effects and the hadronic light--by--light scattering contribution. Prospects for the future will be briefly discussed. As, in electroweak precision physics, the muon g-2 shows the largest established deviation between theory and experiment at present, it will remain one of the hot topics for further investigations. |
0907.4699 | Mohammed Mia | Mohammed Mia and Charles Gale | Jet quenching and the gravity dual | 4 pages, 2 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee | Nucl.Phys.A830:303c-306c,2009 | 10.1016/j.nuclphysa.2009.09.029 | null | hep-ph hep-th nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the momentum broadening of an energetic parton as it moves through
strongly interacting matter, using the gravity dual of a non conformal gauge
theory with matter in the fundamental representation. Our approach defines a
family of theories, all of which have logarithmic running of the couplings in
the far IR but becomes almost conformal in the far UV. For a given set of
degrees of freedom, we obtain average transverse momentum square of the parton
as a function of temperature and compare with results obtained from the AdS/CFT
correspondence.
| [
{
"created": "Mon, 27 Jul 2009 18:10:18 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Sep 2009 19:08:14 GMT",
"version": "v2"
}
] | 2009-11-18 | [
[
"Mia",
"Mohammed",
""
],
[
"Gale",
"Charles",
""
]
] | We compute the momentum broadening of an energetic parton as it moves through strongly interacting matter, using the gravity dual of a non conformal gauge theory with matter in the fundamental representation. Our approach defines a family of theories, all of which have logarithmic running of the couplings in the far IR but becomes almost conformal in the far UV. For a given set of degrees of freedom, we obtain average transverse momentum square of the parton as a function of temperature and compare with results obtained from the AdS/CFT correspondence. |
2112.14600 | Federico Lamagna | Leandro Da Rold (Centro At\'omico Bariloche, Instituto Balseiro and
CONICET) and Federico Lamagna (Centro At\'omico Bariloche, Instituto Balseiro
and CONICET) | A composite Froggatt-Nielsen model of flavor | 23 pages, 5 figures. All comments welcome. Updated references and
improved resolution of figures, and improved naming of sections. Definitions
of some operator bases added for clarity. Added a short discussion on mixing
between FN field and Higgs. Main results unchanged | null | 10.1103/PhysRevD.105.115020 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A natural composite Higgs demands the presence of light resonances at the TeV
scale, that in general are in conflict with bounds from flavor and CP
violation. We propose a composite model with a Froggatt-Nielsen mechanism, that
offers new possibilities for the origin of flavor. We analyse the interplay of
partial compositeness and the horizontal U(1) symmetry in achieving the quark
masses and mixing angles. We study the contributions to $\Delta F=2$ 4-fermion
operators, as well as to $\Delta F=1$ and neutron dipole operators. We find
scenarios in which the contribution to Left-Right and Right-handed operators
involving the first and second generations can be suppressed, in particular for
a region of parameter space it is possible to simultaneously suppress the
mixed-chirality contribution to $K^0-\bar K^0$ mixing by one power of the
Cabibbo angle, $\lambda_C$, and the dipole moments by $\lambda_C^2$ compared
with anarchic partial compositeness, possibly making the resonances accessible
at LHC. 4-fermion operators of $B_s$-meson mixing and Left-handed operators are
not suppressed.
| [
{
"created": "Wed, 29 Dec 2021 15:18:47 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Feb 2022 12:39:14 GMT",
"version": "v2"
},
{
"created": "Fri, 3 Jun 2022 13:26:44 GMT",
"version": "v3"
}
] | 2022-06-29 | [
[
"Da Rold",
"Leandro",
"",
"Centro Atómico Bariloche, Instituto Balseiro and\n CONICET"
],
[
"Lamagna",
"Federico",
"",
"Centro Atómico Bariloche, Instituto Balseiro\n and CONICET"
]
] | A natural composite Higgs demands the presence of light resonances at the TeV scale, that in general are in conflict with bounds from flavor and CP violation. We propose a composite model with a Froggatt-Nielsen mechanism, that offers new possibilities for the origin of flavor. We analyse the interplay of partial compositeness and the horizontal U(1) symmetry in achieving the quark masses and mixing angles. We study the contributions to $\Delta F=2$ 4-fermion operators, as well as to $\Delta F=1$ and neutron dipole operators. We find scenarios in which the contribution to Left-Right and Right-handed operators involving the first and second generations can be suppressed, in particular for a region of parameter space it is possible to simultaneously suppress the mixed-chirality contribution to $K^0-\bar K^0$ mixing by one power of the Cabibbo angle, $\lambda_C$, and the dipole moments by $\lambda_C^2$ compared with anarchic partial compositeness, possibly making the resonances accessible at LHC. 4-fermion operators of $B_s$-meson mixing and Left-handed operators are not suppressed. |
hep-ph/0511193 | Martin Schumacher | M.I. Levchuk, A.I. L'vov, A.I. Milstein, M. Schumacher | Structure of the $\sigma$-meson and diamagnetism of the nucleon | Contribution made by Martin Schumacher to the International Workshop
on the Physics of Excited Baryons, 12 - 15 Oct. 2005, Tallahasse, Florida USA | null | 10.1142/9789812773333_0057 | hep-ph/0511193 | hep-ph | null | The structure of the $\sigma$ meson and the diamagnetism of the nucleon are
shown to be topics which are closely related to each other. Arguments are found
that the $\sigma$ meson couples to two photons via its non-strange $q\bar{q}$
structure component. This ansatz leads to a quantitative explanation of the
$t$-channel component of the difference of electromagnetic polarizabilities,
(\alpha-\beta)^t$, containing the diamagnetism of the nucleon. The prediction
is $(\alpha-\beta)^t_{p,n}=(5\alpha_e g_{\pi MM})/(6\pi^2 m^2_\sigma
f_\pi)=15.3$ in units of $10^{-4}{\rm fm}^3$ to be compared with the
experimental value $(\alpha-\beta)^t_p=15.1\pm 1.3$ for the proton and
$(\alpha-\beta)^t_n=14.8\pm 2.7$ for the neutron. The equivalent approach to
exploit the $\pi\pi$ structure component of the $\sigma$ meson via the BEFT sum
rule leads to $(\alpha-\beta)^t_{p,n}=14\pm 2$, what also is in agreement with
the experimental results.
| [
{
"created": "Wed, 16 Nov 2005 10:46:03 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Levchuk",
"M. I.",
""
],
[
"L'vov",
"A. I.",
""
],
[
"Milstein",
"A. I.",
""
],
[
"Schumacher",
"M.",
""
]
] | The structure of the $\sigma$ meson and the diamagnetism of the nucleon are shown to be topics which are closely related to each other. Arguments are found that the $\sigma$ meson couples to two photons via its non-strange $q\bar{q}$ structure component. This ansatz leads to a quantitative explanation of the $t$-channel component of the difference of electromagnetic polarizabilities, (\alpha-\beta)^t$, containing the diamagnetism of the nucleon. The prediction is $(\alpha-\beta)^t_{p,n}=(5\alpha_e g_{\pi MM})/(6\pi^2 m^2_\sigma f_\pi)=15.3$ in units of $10^{-4}{\rm fm}^3$ to be compared with the experimental value $(\alpha-\beta)^t_p=15.1\pm 1.3$ for the proton and $(\alpha-\beta)^t_n=14.8\pm 2.7$ for the neutron. The equivalent approach to exploit the $\pi\pi$ structure component of the $\sigma$ meson via the BEFT sum rule leads to $(\alpha-\beta)^t_{p,n}=14\pm 2$, what also is in agreement with the experimental results. |
0707.3785 | Harmen J. Warringa | Kenji Fukushima, Harmen J. Warringa | Color superconducting matter in a magnetic field | 5 pages, 3 figures | Phys.Rev.Lett.100:032007,2008 | 10.1103/PhysRevLett.100.032007 | BNL-NT-07/33; RBRC-679 | hep-ph | null | We investigate the effect of a magnetic field on cold dense three-flavor
quark matter using an effective model with four-Fermi interactions with
electric and color neutrality taken into account. The gap parameters Delta_1,
Delta_2, and Delta_3 representing respectively the predominant pairing between
down and strange (d-s) quarks, strange and up (s-u) quarks, and up and down
(u-d) quarks, show the de Haas-van Alphen effect, i.e. oscillatory behavior as
a function of the modified magnetic field B that can penetrate the color
superconducting medium. Without applying electric and color neutrality we find
Delta_2 \approx Delta_3 >> Delta_1 for 2 e B / mu_q^2, where e is the modified
electromagnetic coupling constant and mu_q is one third of the baryon chemical
potential. Because the average Fermi surface for each pairing is affected by
taking into account neutrality, the gap structure changes drastically in this
case; we find Delta_1 >> Delta_2 \approx Delta_3 for 2 e B > mu_q^2. We point
out that the magnetic fields as strong as presumably existing inside magnetars
might induce significant deviations from the gap structure Delta_1 \approx
Delta_2 \approx Delta_3 at zero magnetic field.
| [
{
"created": "Wed, 25 Jul 2007 17:28:13 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Fukushima",
"Kenji",
""
],
[
"Warringa",
"Harmen J.",
""
]
] | We investigate the effect of a magnetic field on cold dense three-flavor quark matter using an effective model with four-Fermi interactions with electric and color neutrality taken into account. The gap parameters Delta_1, Delta_2, and Delta_3 representing respectively the predominant pairing between down and strange (d-s) quarks, strange and up (s-u) quarks, and up and down (u-d) quarks, show the de Haas-van Alphen effect, i.e. oscillatory behavior as a function of the modified magnetic field B that can penetrate the color superconducting medium. Without applying electric and color neutrality we find Delta_2 \approx Delta_3 >> Delta_1 for 2 e B / mu_q^2, where e is the modified electromagnetic coupling constant and mu_q is one third of the baryon chemical potential. Because the average Fermi surface for each pairing is affected by taking into account neutrality, the gap structure changes drastically in this case; we find Delta_1 >> Delta_2 \approx Delta_3 for 2 e B > mu_q^2. We point out that the magnetic fields as strong as presumably existing inside magnetars might induce significant deviations from the gap structure Delta_1 \approx Delta_2 \approx Delta_3 at zero magnetic field. |
1712.06936 | Vicente Vento | Matteo Rinaldi, Vicente Vento | Comments on glueballs as gravitons | 3 pages , 3 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The graviton solutions for the glueball spectrum of ref.
\cite{Rinaldi:2017wdn} interpreted in a different manner lead to very
interesting results which we describe in this comment.
| [
{
"created": "Tue, 19 Dec 2017 14:10:19 GMT",
"version": "v1"
}
] | 2017-12-20 | [
[
"Rinaldi",
"Matteo",
""
],
[
"Vento",
"Vicente",
""
]
] | The graviton solutions for the glueball spectrum of ref. \cite{Rinaldi:2017wdn} interpreted in a different manner lead to very interesting results which we describe in this comment. |
1107.3150 | Seth Quackenbush | Edmond L. Berger, C. B. Jackson, Seth Quackenbush, Gabe Shaughnessy | Calculation of W b bbar Production via Double Parton Scattering at the
LHC | 21 pages, 9 figures; v2: improved presentation and figures, version
published in Phys. Rev. D | Phys. Rev. D 84 (2011), 074021 | 10.1103/PhysRevD.84.074021 | Preprint-nos: ANL-HEP-PR-11-45; NSF-KITP-11-125 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the potential to observe double parton scattering at the Large
Hadron Collider in p p -> W b bbar X -> l nu b bbar X at 7 TeV. Our analysis
tests the efficacy of several kinematic variables in isolating the double
parton process of interest from the single parton process and relevant
backgrounds for the first 10 inverse fb of integrated luminosity. These
variables are constructed to expose the independent nature of the two
subprocesses in double parton scattering, pp -> l nu X and pp -> b bbar X. We
use next-to-leading order perturbative predictions for the double parton and
single parton scattering components of W b bbar and for the pertinent
backgrounds. The next-to-leading order contributions are important for a proper
description of some of the observables we compute. We find that the double
parton process can be identified and measured with significance S/sqrt(B) ~ 10,
provided the double parton scattering effective cross section sigma_{eff} ~ 12
mb.
| [
{
"created": "Fri, 15 Jul 2011 20:00:04 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Oct 2011 15:07:35 GMT",
"version": "v2"
}
] | 2011-11-01 | [
[
"Berger",
"Edmond L.",
""
],
[
"Jackson",
"C. B.",
""
],
[
"Quackenbush",
"Seth",
""
],
[
"Shaughnessy",
"Gabe",
""
]
] | We investigate the potential to observe double parton scattering at the Large Hadron Collider in p p -> W b bbar X -> l nu b bbar X at 7 TeV. Our analysis tests the efficacy of several kinematic variables in isolating the double parton process of interest from the single parton process and relevant backgrounds for the first 10 inverse fb of integrated luminosity. These variables are constructed to expose the independent nature of the two subprocesses in double parton scattering, pp -> l nu X and pp -> b bbar X. We use next-to-leading order perturbative predictions for the double parton and single parton scattering components of W b bbar and for the pertinent backgrounds. The next-to-leading order contributions are important for a proper description of some of the observables we compute. We find that the double parton process can be identified and measured with significance S/sqrt(B) ~ 10, provided the double parton scattering effective cross section sigma_{eff} ~ 12 mb. |
2004.04611 | Nikolaos Mavromatos | Jean Alexandre, Nick E. Mavromatos and Alex Soto | Dynamical Majorana Neutrino Masses and Axions | 24 pages revtex, one eps figure incorporated; section IIIC contains
material related to arXiv:2004.03699 [hep-ph]. Minor restructuring on
sections, with section II added. Also discussion added, along with Figure 2
and ref. [25], on resummation of four-fermion loops, which justifies our
approximations. Minor typos corrected. No effects on conclusions. Version to
be published in Nuclear Physics B | Nucl. Phys. B 961 (2020) 115212 | 10.1016/j.nuclphysb.2020.115212 | KCL-PH-TH/2020-17 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss dynamical mass generation for fermions and pseudoscalar fields
(axion-like particles (ALP)), in the context of effective theories containing
Yukawa type interactions between the fermions and ALPs. We discuss both
Hermitian and non-Hermitian Yukawa interactions, which are motivated in the
context of some scenarios for radiative (anomalous) Majorana sterile neutrino
masses in some effective field theories. The latter contain shift-symmetry
breaking Yukawa interactions between sterile neutrinos and ALPs. We show that,
for a Hermitian Yukawa interaction, there is no (pseudo)scalar dynamical mass
generation, but there is fermion dynamical mass generation, provided one adds a
bare (pseudo)scalar mass. The situation is opposite for an anti-Hermitian
Yukawa model: there is (pseudo)scalar dynamical mass generation, but no fermion
dynamical mass generation.In the presence of additional attractive four-fermion
interactions, dynamical fermion mass generation can occur in these models,
under appropriate conditions and range of their couplings.
| [
{
"created": "Thu, 9 Apr 2020 15:47:21 GMT",
"version": "v1"
},
{
"created": "Tue, 5 May 2020 14:23:15 GMT",
"version": "v2"
},
{
"created": "Fri, 14 Aug 2020 09:11:43 GMT",
"version": "v3"
},
{
"created": "Tue, 6 Oct 2020 08:47:34 GMT",
"version": "v4"
}
] | 2020-12-16 | [
[
"Alexandre",
"Jean",
""
],
[
"Mavromatos",
"Nick E.",
""
],
[
"Soto",
"Alex",
""
]
] | We discuss dynamical mass generation for fermions and pseudoscalar fields (axion-like particles (ALP)), in the context of effective theories containing Yukawa type interactions between the fermions and ALPs. We discuss both Hermitian and non-Hermitian Yukawa interactions, which are motivated in the context of some scenarios for radiative (anomalous) Majorana sterile neutrino masses in some effective field theories. The latter contain shift-symmetry breaking Yukawa interactions between sterile neutrinos and ALPs. We show that, for a Hermitian Yukawa interaction, there is no (pseudo)scalar dynamical mass generation, but there is fermion dynamical mass generation, provided one adds a bare (pseudo)scalar mass. The situation is opposite for an anti-Hermitian Yukawa model: there is (pseudo)scalar dynamical mass generation, but no fermion dynamical mass generation.In the presence of additional attractive four-fermion interactions, dynamical fermion mass generation can occur in these models, under appropriate conditions and range of their couplings. |
1108.5187 | James Halverson | Mirjam Cveti\v{c}, James Halverson, Paul Langacker | Implications of String Constraints for Exotic Matter and Z' s Beyond the
Standard Model | 38 pages. v2: JHEP version, references added | null | 10.1007/JHEP11(2011)058 | UPR-1231-T | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Global consistency of string compactifications places constraints on the
chiral matter spectrum of a gauge theory which include those necessary for the
absence of cubic nonabelian anomalies, but also contain some additional
conditions. In the class of theories we study, some of these are present in a
field theory augmented by anomalous U(1)'s and Chern-Simons terms, but some are
genuinely not present in field theory. Their violation has phenomenological
implications, rendering inconsistent many quiver gauge theories with the chiral
matter spectrum of the MSSM. The inconsistent MSSM quivers often violate the
constraints in a particular way that is suggestive of what matter must be added
for consistency. The preferred matter additions are MSSM singlets with
anomalous U(1) charge, hyperchargeless SU(2) triplets, quasichiral Higgs or
lepton isodoublet pairs, quasichiral quark isosinglet pairs, and nonabelian
singlets with charge +-1. Smaller numbers of quark isodoublet pairs, lepton
pairs with charges (+- 1,+- 2), and chiral fourth families are also found. We
present the results of systematic analyses including multiplicity counts of
matter beyond the standard model and also study the possibility of using the
singlets for a dynamical perturbative \mu-term or for neutrino mass. We also
systematically study the appearance of additional non-anomalous U(1)'
symmetries in the low energy theory and find that family non-universality is
very common. These new physics effects may be observable at the LHC even for a
large string scale close to the Planck scale.
| [
{
"created": "Thu, 25 Aug 2011 20:14:16 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jun 2012 13:52:12 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Cvetič",
"Mirjam",
""
],
[
"Halverson",
"James",
""
],
[
"Langacker",
"Paul",
""
]
] | Global consistency of string compactifications places constraints on the chiral matter spectrum of a gauge theory which include those necessary for the absence of cubic nonabelian anomalies, but also contain some additional conditions. In the class of theories we study, some of these are present in a field theory augmented by anomalous U(1)'s and Chern-Simons terms, but some are genuinely not present in field theory. Their violation has phenomenological implications, rendering inconsistent many quiver gauge theories with the chiral matter spectrum of the MSSM. The inconsistent MSSM quivers often violate the constraints in a particular way that is suggestive of what matter must be added for consistency. The preferred matter additions are MSSM singlets with anomalous U(1) charge, hyperchargeless SU(2) triplets, quasichiral Higgs or lepton isodoublet pairs, quasichiral quark isosinglet pairs, and nonabelian singlets with charge +-1. Smaller numbers of quark isodoublet pairs, lepton pairs with charges (+- 1,+- 2), and chiral fourth families are also found. We present the results of systematic analyses including multiplicity counts of matter beyond the standard model and also study the possibility of using the singlets for a dynamical perturbative \mu-term or for neutrino mass. We also systematically study the appearance of additional non-anomalous U(1)' symmetries in the low energy theory and find that family non-universality is very common. These new physics effects may be observable at the LHC even for a large string scale close to the Planck scale. |
hep-ph/9403285 | Mit | Edward Farhi, Valentin V. Khoze, Krishna Rajagopal, and Robert
Singleton Jr | Spherical Shells of Classical Gauge Field and their Topological Charge
as a Perturbative Expansion | 18 pages in REVTEX | Phys.Rev.D50:4162-4174,1994 | 10.1103/PhysRevD.50.4162 | SLAC-PUB-6419(T), HUTP-94-A003, BUHEP-94-6, MIT-CTP-2287 | hep-ph hep-th | null | We consider the classical equations of motion of $SU(2)$ gauge theory,
without a Higgs field, in Minkowski space. We work in the spherical ansatz and
develop a perturbative expansion in the coupling constant $g$ for solutions
which in the far past look like freely propagating spherical shells. The
topological charge $Q$ of these solutions is typically non-integer. We then
show that $Q$ can be expressed as a power series expansion in $g$ which can be
nonzero at finite order. We give an explicit analytic calculation of the order
$g^5$ contribution to $Q$ for specific initial pulses. We discuss the relation
between our findings and anomalous fermion number violation, and speculate on
the physical implications of our results.
| [
{
"created": "Mon, 14 Mar 1994 13:43:19 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Mar 1994 23:03:18 GMT",
"version": "v2"
}
] | 2010-11-01 | [
[
"Farhi",
"Edward",
""
],
[
"Khoze",
"Valentin V.",
""
],
[
"Rajagopal",
"Krishna",
""
],
[
"Singleton",
"Robert",
"Jr"
]
] | We consider the classical equations of motion of $SU(2)$ gauge theory, without a Higgs field, in Minkowski space. We work in the spherical ansatz and develop a perturbative expansion in the coupling constant $g$ for solutions which in the far past look like freely propagating spherical shells. The topological charge $Q$ of these solutions is typically non-integer. We then show that $Q$ can be expressed as a power series expansion in $g$ which can be nonzero at finite order. We give an explicit analytic calculation of the order $g^5$ contribution to $Q$ for specific initial pulses. We discuss the relation between our findings and anomalous fermion number violation, and speculate on the physical implications of our results. |
0908.1363 | Deva O'Neil | Deva O'Neil | Phenomenology of the Basis-Independent CP-Violating Two-Higgs Doublet
Model [Dissertation] | 119 pages, 7 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Two-Higgs Doublet Model (2HDM) is a model of low-energy particle
interactions that is identical to the Standard Model except for the addition of
an extra Higgs doublet. This extended Higgs sector would appear in experiments
as the presence of multiple Higgs particles, both neutral and charged. The
neutral states may either be eigenstates of CP (in the CP-conserving 2HDM), or
be mixtures of CP eigenstates (in the CP-violating 2HDM). In order to
understand how to measure the couplings of these new particles, this document
presents the theory of the CP-violating 2HDM in a basis-independent formalism
and explicitly identifies the physical parameters of the model, including a
discussion of tan(beta)-like parameters. The CP-conserving limit, decoupling
limit, and the custodial limit of the model are presented.
In addition, phenomenological constraints from the oblique parameters (S, T,
and U) are discussed. A survey of the parameter space of this model shows that
the 2HDM is consistent with a large range of possible values for T. Our results
also suggest that the 2HDM favors a slightly positive value of S and a value of
U within .02 of zero, which is consistent with present data within the
statistical error. In a scenario in which the heaviest scalar particle is the
charged Higgs boson, we find that the measured value of T puts an upper limit
on the mass difference between the charged Higgs boson and the heaviest neutral
Higgs boson.
| [
{
"created": "Mon, 10 Aug 2009 17:59:40 GMT",
"version": "v1"
}
] | 2009-08-11 | [
[
"O'Neil",
"Deva",
""
]
] | The Two-Higgs Doublet Model (2HDM) is a model of low-energy particle interactions that is identical to the Standard Model except for the addition of an extra Higgs doublet. This extended Higgs sector would appear in experiments as the presence of multiple Higgs particles, both neutral and charged. The neutral states may either be eigenstates of CP (in the CP-conserving 2HDM), or be mixtures of CP eigenstates (in the CP-violating 2HDM). In order to understand how to measure the couplings of these new particles, this document presents the theory of the CP-violating 2HDM in a basis-independent formalism and explicitly identifies the physical parameters of the model, including a discussion of tan(beta)-like parameters. The CP-conserving limit, decoupling limit, and the custodial limit of the model are presented. In addition, phenomenological constraints from the oblique parameters (S, T, and U) are discussed. A survey of the parameter space of this model shows that the 2HDM is consistent with a large range of possible values for T. Our results also suggest that the 2HDM favors a slightly positive value of S and a value of U within .02 of zero, which is consistent with present data within the statistical error. In a scenario in which the heaviest scalar particle is the charged Higgs boson, we find that the measured value of T puts an upper limit on the mass difference between the charged Higgs boson and the heaviest neutral Higgs boson. |
2111.10833 | Paolo Cea | Paolo Cea | The Higgs condensate as a quantum liquid: Comparison with the ATLAS full
Run 2 data | 9 pages, 6 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, we proposed to picture the Higgs condensate of the Standard Model
as a quantum liquid analogous to the superfluid Helium II. In this scenario the
Higgs condensate excitations resemble closely two Standard Model Higgs bosons.
The lightest Higgs boson was already identified with the LHC narrow resonance
at 125 GeV. Concerning the heavy Higgs boson, we found preliminary evidence in
our previous phenomenological analysis in the so-called golden channel. In the
present note we compared our proposal to the full Run 2 data set released
recently by the ATLAS Collaboration. Even though we do not found a clear
statistical evidence for our Standard Model heavy Higgs, we found that our
theoretical proposal is still in accordance with the available observations.
| [
{
"created": "Sun, 21 Nov 2021 15:00:09 GMT",
"version": "v1"
}
] | 2021-11-24 | [
[
"Cea",
"Paolo",
""
]
] | Recently, we proposed to picture the Higgs condensate of the Standard Model as a quantum liquid analogous to the superfluid Helium II. In this scenario the Higgs condensate excitations resemble closely two Standard Model Higgs bosons. The lightest Higgs boson was already identified with the LHC narrow resonance at 125 GeV. Concerning the heavy Higgs boson, we found preliminary evidence in our previous phenomenological analysis in the so-called golden channel. In the present note we compared our proposal to the full Run 2 data set released recently by the ATLAS Collaboration. Even though we do not found a clear statistical evidence for our Standard Model heavy Higgs, we found that our theoretical proposal is still in accordance with the available observations. |
hep-ph/9608437 | N. Arbex | N.Arbex, U.Ornik, M.Pluemer, B.R.Schlei, R.M. Weiner | pi-/pi+ ratio in heavy ions collisions: Coulomb effect or chemical
equilibration? | 8 pages and 2 figures, submmited to Phys. Lett. B. This reviewed
version (Nov.29,1996) contains more details about the model simulated
efficiency considering the experimental detection conditions. Other small
modifications were made | Phys.Lett. B391 (1997) 465-468 | 10.1016/S0370-2693(96)01289-0 | null | hep-ph | null | We calculate the pi-/pi+ ratio for Pb+Pb at CERN/SPS energies and for Au+Au
at BNL/AGS energies using a (3+1) dimensional hydrodynamical model. Without
consideration of Coulomb effect an enhancement of this ratio at low mt is found
compatible with that observed in these experiments. Our calculations are based
on previous (3+1) dimensional hydrodynamical simulations (HYLANDER), which
described many other aspects of experimental data. In this model the observed
enhancement is a consequence of baryon and strangeness conservation and of
chemical equilibration of the system and is caused by the decay of produced
hyperons, which leads to a difference in the total number of positive and
negative pions as well. Based on the same approach, we also present results for
the pi-/pi+ ratio for S+S (CERN/SPS) collisions, where we find a similar
effect. The absence of the enhancement of the pi-/pi+ ratio in the S+S data
presented by the NA44 Collaboration, if confirmed, could indicate that chemical
equilibration has not yet been estabilished in this reaction.
| [
{
"created": "Mon, 26 Aug 1996 11:19:25 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Dec 1996 13:09:30 GMT",
"version": "v2"
}
] | 2009-10-28 | [
[
"Arbex",
"N.",
""
],
[
"Ornik",
"U.",
""
],
[
"Pluemer",
"M.",
""
],
[
"Schlei",
"B. R.",
""
],
[
"Weiner",
"R. M.",
""
]
] | We calculate the pi-/pi+ ratio for Pb+Pb at CERN/SPS energies and for Au+Au at BNL/AGS energies using a (3+1) dimensional hydrodynamical model. Without consideration of Coulomb effect an enhancement of this ratio at low mt is found compatible with that observed in these experiments. Our calculations are based on previous (3+1) dimensional hydrodynamical simulations (HYLANDER), which described many other aspects of experimental data. In this model the observed enhancement is a consequence of baryon and strangeness conservation and of chemical equilibration of the system and is caused by the decay of produced hyperons, which leads to a difference in the total number of positive and negative pions as well. Based on the same approach, we also present results for the pi-/pi+ ratio for S+S (CERN/SPS) collisions, where we find a similar effect. The absence of the enhancement of the pi-/pi+ ratio in the S+S data presented by the NA44 Collaboration, if confirmed, could indicate that chemical equilibration has not yet been estabilished in this reaction. |
1303.5522 | Jens Erler | Jens Erler and Shufang Su | The Weak Neutral Current | 43 pages, 10 figures | null | 10.1016/j.ppnp.2013.03.004 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is a review of electroweak precision physics with particular emphasis on
low-energy precision measurements in the neutral current sector of the
electroweak theory and includes future experimental prospects and the
theoretical challenges one faces to interpret these observables. Within the
minimal Standard Model they serve as determinations of the weak mixing angle
which are competitive with and complementary to those obtained near the
Z-resonance. In the context of new physics beyond the Standard Model these
measurements are crucial to discriminate between models and to reduce the
allowed parameter space within a given model. We illustrate this for the
minimal supersymmetric Standard Model with or without R-parity.
| [
{
"created": "Fri, 22 Mar 2013 05:51:18 GMT",
"version": "v1"
}
] | 2015-06-15 | [
[
"Erler",
"Jens",
""
],
[
"Su",
"Shufang",
""
]
] | This is a review of electroweak precision physics with particular emphasis on low-energy precision measurements in the neutral current sector of the electroweak theory and includes future experimental prospects and the theoretical challenges one faces to interpret these observables. Within the minimal Standard Model they serve as determinations of the weak mixing angle which are competitive with and complementary to those obtained near the Z-resonance. In the context of new physics beyond the Standard Model these measurements are crucial to discriminate between models and to reduce the allowed parameter space within a given model. We illustrate this for the minimal supersymmetric Standard Model with or without R-parity. |
hep-ph/0604111 | Guido Marandella | G. Cacciapaglia, C. Cs\'aki, G. Marandella, and A. Strumia | The Minimal Set of Electroweak Precision Parameters | 22 pages, 3 figures | Phys.Rev.D74:033011,2006 | 10.1103/PhysRevD.74.033011 | null | hep-ph | null | We present a simple method for analyzing the impact of precision electroweak
data above and below the Z-peak on flavour-conserving heavy new physics. We
find that experiments have probed about ten combinations of new physics
effects, which to a good approximation can be condensed into the effective
oblique parameters Shat, That, Uhat, V, X, W, Y (we prove positivity
constraints W, Y >= 0) and three combinations of quark couplings (including a
distinct parameter for the bottom). We apply our method to generic extra Z'
vectors.
| [
{
"created": "Wed, 12 Apr 2006 19:51:02 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Cacciapaglia",
"G.",
""
],
[
"Csáki",
"C.",
""
],
[
"Marandella",
"G.",
""
],
[
"Strumia",
"A.",
""
]
] | We present a simple method for analyzing the impact of precision electroweak data above and below the Z-peak on flavour-conserving heavy new physics. We find that experiments have probed about ten combinations of new physics effects, which to a good approximation can be condensed into the effective oblique parameters Shat, That, Uhat, V, X, W, Y (we prove positivity constraints W, Y >= 0) and three combinations of quark couplings (including a distinct parameter for the bottom). We apply our method to generic extra Z' vectors. |
2110.15692 | Andreas Maier | Jeppe R. Andersen, James Black, Helen Brooks, Bertrand Duclou\'e,
Marian Heil, Andreas Maier, Jennifer M. Smillie | HEJ 2.1: High-energy Resummation with Vector Bosons and Next-to-Leading
Logarithms | 16 pages, 4 figures | Comp. Phys. Commun. 278, (2022) 108404 | 10.1016/j.cpc.2022.108404 | DCPT/21/86, DESY-21-174, IPPP/21/43, MCNET-21-14, SAGEX-21-33 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present version 2.1 of the High Energy Jets (HEJ) event generator for
hadron colliders. HEJ is a Monte Carlo generator for processes at high energies
with multiple well-separated jets in the final state. To achieve accurate
predictions, conventional fixed-order perturbative QCD is supplemented with an
all-order resummation of large high-energy logarithms. The new version 2.1 now
supports processes with final-state leptons originating from a charged or
neutral vector boson together with multiple jets, in addition to processes
available in earlier versions. Furthermore, the all-order resummation is
extended to include an additional gauge-invariant class of subdominant
logarithmic corrections. HEJ 2.1 can be obtained from https://hej.hepforge.org.
| [
{
"created": "Fri, 29 Oct 2021 11:35:37 GMT",
"version": "v1"
},
{
"created": "Mon, 16 May 2022 14:50:45 GMT",
"version": "v2"
}
] | 2022-06-01 | [
[
"Andersen",
"Jeppe R.",
""
],
[
"Black",
"James",
""
],
[
"Brooks",
"Helen",
""
],
[
"Ducloué",
"Bertrand",
""
],
[
"Heil",
"Marian",
""
],
[
"Maier",
"Andreas",
""
],
[
"Smillie",
"Jennifer M.",
""
]
] | We present version 2.1 of the High Energy Jets (HEJ) event generator for hadron colliders. HEJ is a Monte Carlo generator for processes at high energies with multiple well-separated jets in the final state. To achieve accurate predictions, conventional fixed-order perturbative QCD is supplemented with an all-order resummation of large high-energy logarithms. The new version 2.1 now supports processes with final-state leptons originating from a charged or neutral vector boson together with multiple jets, in addition to processes available in earlier versions. Furthermore, the all-order resummation is extended to include an additional gauge-invariant class of subdominant logarithmic corrections. HEJ 2.1 can be obtained from https://hej.hepforge.org. |
hep-ph/0411171 | Matthias Neubert | M. Beneke (RWTH Aachen), G. Buchalla (LMU Munich), M. Neubert (Cornell
U. & IAS, Princeton), and C.T. Sachrajda (U. Southampton) | Comment on ``B->M_1 M_2: Factorization, charming penguins, strong
phases, and polarization'' | Comment on hep-ph/0401188 by Bauer, Pirjol, Rothstein and Stewart; 4
pages | Phys.Rev.D72:098501,2005 | 10.1103/PhysRevD.72.098501 | CLNS-04/1891, LMU-15/04, PITHA-04/17, SHEP-04/37 | hep-ph hep-ex | null | We show that the factorization formula for non-leptonic B decays to two light
flavor non-singlet mesons derived by Bauer et al. in the context of
soft-collinear effective theory is equivalent to the corresponding formula in
the QCD factorization approach. The apparent numerical differences in the
analysis of B->pi+pi data performed by these authors, as compared to previous
QCD factorization analyses, can largely be attributed to the neglect of known
perturbative and power corrections.
| [
{
"created": "Fri, 12 Nov 2004 15:53:00 GMT",
"version": "v1"
}
] | 2009-10-09 | [
[
"Beneke",
"M.",
"",
"RWTH Aachen"
],
[
"Buchalla",
"G.",
"",
"LMU Munich"
],
[
"Neubert",
"M.",
"",
"Cornell\n U. & IAS, Princeton"
],
[
"Sachrajda",
"C. T.",
"",
"U. Southampton"
]
] | We show that the factorization formula for non-leptonic B decays to two light flavor non-singlet mesons derived by Bauer et al. in the context of soft-collinear effective theory is equivalent to the corresponding formula in the QCD factorization approach. The apparent numerical differences in the analysis of B->pi+pi data performed by these authors, as compared to previous QCD factorization analyses, can largely be attributed to the neglect of known perturbative and power corrections. |
hep-ph/0410123 | Marco Battaglia | Marco Battaglia | Study of Dark Matter inspired cMSSM scenarios at a TeV-class Linear
Collider | 5 pages, 2 figures, to apper in the Proceedings of the Int. Workshop
on Linear Colliders, LCWS04, Paris 2004 | null | null | null | hep-ph | null | The accuracy in the measurement of the masses of sleptons and heavy Higgs
bosons in cMSSM scenarios, compatible with the WMAP result on cold dark matter,
has been re-analysed in view of the requirements for predicting this density to
a few percent level from SUSY measurements at the linear collider.
| [
{
"created": "Fri, 8 Oct 2004 01:03:46 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Battaglia",
"Marco",
""
]
] | The accuracy in the measurement of the masses of sleptons and heavy Higgs bosons in cMSSM scenarios, compatible with the WMAP result on cold dark matter, has been re-analysed in view of the requirements for predicting this density to a few percent level from SUSY measurements at the linear collider. |
hep-ph/9812449 | Kazuhiro Tanaka | Jiro Kodaira (Hiroshima Univ.), Kazuhiro Tanaka (Juntendo Univ.) | Polarized Structure Functions in QCD | 58 pages, PTPTEX, 4 Postscript figures, psfig.sty and here.sty are
required; typos fixed and minor changes in the text. Final version to be
published in Prog. Theor. Phys | Prog.Theor.Phys. 101 (1999) 191-242 | 10.1143/PTP.101.191 | HUPD-9819, JUPD-9825 | hep-ph | null | Hadron spin physics is now one of the most active fields of physics.
Especially in the last ten years, great progress has been made both
theoretically and experimentally that has considerably improved our knowledge
of the spin structure of nucleons. We review the nucleon's polarized structure
functions from the viewpoint of factorization theorems and the gauge invariant,
nonlocal light-cone operators in QCD. We discuss a systematic treatment of the
polarized structure functions and the corresponding parton distribution
functions, which are relevant to inclusive lepto- and hadro-production. We give
a detailed analysis of these spin-dependent distribution functions at the
twist-2 and twist-3 level, and present various properties and relations
satisfied by the parton distributions, which can be derived directly from QCD.
We emphasize unique features of higher twist distributions, and the role of the
QCD equations of motion to derive their sensitivity to the quark-gluon
correlation and their anomalous dimensions for Q^2-evolution.
| [
{
"created": "Sun, 20 Dec 1998 11:45:04 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Jan 1999 11:35:07 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Kodaira",
"Jiro",
"",
"Hiroshima Univ."
],
[
"Tanaka",
"Kazuhiro",
"",
"Juntendo Univ."
]
] | Hadron spin physics is now one of the most active fields of physics. Especially in the last ten years, great progress has been made both theoretically and experimentally that has considerably improved our knowledge of the spin structure of nucleons. We review the nucleon's polarized structure functions from the viewpoint of factorization theorems and the gauge invariant, nonlocal light-cone operators in QCD. We discuss a systematic treatment of the polarized structure functions and the corresponding parton distribution functions, which are relevant to inclusive lepto- and hadro-production. We give a detailed analysis of these spin-dependent distribution functions at the twist-2 and twist-3 level, and present various properties and relations satisfied by the parton distributions, which can be derived directly from QCD. We emphasize unique features of higher twist distributions, and the role of the QCD equations of motion to derive their sensitivity to the quark-gluon correlation and their anomalous dimensions for Q^2-evolution. |
1912.09639 | Cody B Duncan | Cody B Duncan and Peter Skands | Fragmentation of Two Repelling Lund Strings | 30 pages, 13 figures | SciPost Phys. 8, 080 (2020) | 10.21468/SciPostPhys.8.5.080 | CoEPP-MN-19-5, MCNET-19-30 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by recent discoveries of flow-like effects in pp collisions, and
noting that multiple string systems can form and hadronize simultaneously in
such collisions, we develop a simple model for the repulsive interaction
between two Lund strings with a positive (colour-oriented) overlap in rapidity.
The model is formulated in momentum space and is based on a postulate of a
constant net transverse momentum being acquired per unit of overlap along a
common rapidity direction. To conserve energy, the strings shrink in the
longitudinal direction, essentially converting a portion of the string
invariant mass $m^2$ into $p_{\perp}^2$ for constant $m_{\perp}^2 = m^2 +
p_{\perp}^2$ for each string. The reduction in string invariant mass implies a
reduced overall multiplicity of produced hadrons; the increase in $p_{\perp}^2$
is local and only affects hadrons in the overlapping region. Starting from the
simplest case of two symmetric and parallel strings with massless endpoints, we
generalize to progressively more complicated configurations. We present an
implementation of this model in the Pythia event generator and use it to
illustrate the effects on hadron $p_{\perp}$ distributions and dihadron
azimuthal correlations, contrasting it with the current version of the
"shoving" model implemented in the same generator.
| [
{
"created": "Fri, 20 Dec 2019 04:40:58 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Jan 2020 22:17:04 GMT",
"version": "v2"
},
{
"created": "Tue, 21 Apr 2020 06:36:45 GMT",
"version": "v3"
},
{
"created": "Tue, 16 Jun 2020 03:08:29 GMT",
"version": "v4"
}
] | 2020-06-17 | [
[
"Duncan",
"Cody B",
""
],
[
"Skands",
"Peter",
""
]
] | Motivated by recent discoveries of flow-like effects in pp collisions, and noting that multiple string systems can form and hadronize simultaneously in such collisions, we develop a simple model for the repulsive interaction between two Lund strings with a positive (colour-oriented) overlap in rapidity. The model is formulated in momentum space and is based on a postulate of a constant net transverse momentum being acquired per unit of overlap along a common rapidity direction. To conserve energy, the strings shrink in the longitudinal direction, essentially converting a portion of the string invariant mass $m^2$ into $p_{\perp}^2$ for constant $m_{\perp}^2 = m^2 + p_{\perp}^2$ for each string. The reduction in string invariant mass implies a reduced overall multiplicity of produced hadrons; the increase in $p_{\perp}^2$ is local and only affects hadrons in the overlapping region. Starting from the simplest case of two symmetric and parallel strings with massless endpoints, we generalize to progressively more complicated configurations. We present an implementation of this model in the Pythia event generator and use it to illustrate the effects on hadron $p_{\perp}$ distributions and dihadron azimuthal correlations, contrasting it with the current version of the "shoving" model implemented in the same generator. |
1001.4486 | Wolfgang Ochs | Wolfgang Ochs | No indication of f0(1370) in pi pi phase shift analyses | 5 pages, 3 figures. Conference on Hadron Spectroscopy (Hadron2009),
Tallahassee, Florida, Nov 29 - Dec 4, 2009 | null | 10.1063/1.3483327 | MPP-2010-9 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The scalar meson f_0(1370) - indicated in particular in the low energy p\bar
p \to 3 body reactions - is a crucial element in certain schemes of the scalar
meson spectroscopy including glueballs. The most definitive results can be
obtained from elastic and inelastic pi pi phase shift analyses using the
constraints from unitarity where the discrete ambiguities can be identified and
resolved. We reconsider the phase shift analyses for pi^+ pi^- \to pi+ \pi-,
pi^0 pi^0, K \bar K, eta eta. While a clear resonance signal for f_0(1500) in
the resp. Argand diagrams is seen in all channels above a large ``background''
from f_0(600) there is no clear signal of a second resonance ``f_0(1370)'' in
this mass range in any reaction, at the level of \sim 10% branching ratio into
pi-pi.
| [
{
"created": "Mon, 25 Jan 2010 17:17:47 GMT",
"version": "v1"
}
] | 2015-05-18 | [
[
"Ochs",
"Wolfgang",
""
]
] | The scalar meson f_0(1370) - indicated in particular in the low energy p\bar p \to 3 body reactions - is a crucial element in certain schemes of the scalar meson spectroscopy including glueballs. The most definitive results can be obtained from elastic and inelastic pi pi phase shift analyses using the constraints from unitarity where the discrete ambiguities can be identified and resolved. We reconsider the phase shift analyses for pi^+ pi^- \to pi+ \pi-, pi^0 pi^0, K \bar K, eta eta. While a clear resonance signal for f_0(1500) in the resp. Argand diagrams is seen in all channels above a large ``background'' from f_0(600) there is no clear signal of a second resonance ``f_0(1370)'' in this mass range in any reaction, at the level of \sim 10% branching ratio into pi-pi. |
hep-ph/0611384 | Nikolai Zotov | A.V. Lipatov, N.P. Zotov | Prompt photon production with $k_T-$factorization | 6 pages, 4 figs., to be published in Proceedings of ISHEPP'06, Dubna,
2006 | null | null | null | hep-ph | null | We consider the prompt photon production at modern high energy colliders in
the framework of $k_T-$factorization approach. We compare our theoretical
predictions with recent experimental data at HERA and Tevatron, empahasizing
the distinction between our theoretical predictions and the results of NLO QCD
calculations. Finally, we extrapolate our predictions to LHC energies.
| [
{
"created": "Thu, 30 Nov 2006 11:46:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Lipatov",
"A. V.",
""
],
[
"Zotov",
"N. P.",
""
]
] | We consider the prompt photon production at modern high energy colliders in the framework of $k_T-$factorization approach. We compare our theoretical predictions with recent experimental data at HERA and Tevatron, empahasizing the distinction between our theoretical predictions and the results of NLO QCD calculations. Finally, we extrapolate our predictions to LHC energies. |
1403.0521 | Susan Gardner | Susan Gardner, Brad Plaster | An overview of neV probes of PeV scale physics --- and of what's in
between | 6 pages, 2 figures, prepared for the proceedings of MENU 2013, the
13th International Conference on Meson-Nucleon Physics and the Structure of
the Nucleon, Rome, Sept. 30 - Oct. 4, 2013 | null | 10.1051/epjconf/20147301012 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Low-energy experiments which would identify departures from the Standard
Model (SM) rely either on the unexpected observation of symmetry breaking, such
as of CP or B, or on an observed significant deviation from a precise SM
prediction. We discuss examples of each search strategy, and show that
low-energy experiments can open windows on physics far beyond accessible
collider energies. We consider how the use of a frequentist analysis framework
can redress the impact of theoretical uncertainties in such searches --- and
how lattice QCD can help control them.
| [
{
"created": "Mon, 3 Mar 2014 18:48:47 GMT",
"version": "v1"
}
] | 2015-06-19 | [
[
"Gardner",
"Susan",
""
],
[
"Plaster",
"Brad",
""
]
] | Low-energy experiments which would identify departures from the Standard Model (SM) rely either on the unexpected observation of symmetry breaking, such as of CP or B, or on an observed significant deviation from a precise SM prediction. We discuss examples of each search strategy, and show that low-energy experiments can open windows on physics far beyond accessible collider energies. We consider how the use of a frequentist analysis framework can redress the impact of theoretical uncertainties in such searches --- and how lattice QCD can help control them. |
2109.04478 | Chee Sheng Fong | Chee Sheng Fong | Cosmic Evolution of Lepton Flavor Charges | 46 pages, 4 figures and 4 appendices. Appendix B is new. Update to
match the published version | null | 10.1103/PhysRevD.105.043004 | null | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | In the early Universe above the weak scale, both baryon $B$ and lepton $L$
numbers are violated by nonperturabive effects in the Standard Model while
$B-L$ remains conserved. Introducing new physics which violates perturbatively
$L$ and/or $B$, one can generate dynamically a nonzero $B-L$ charge and hence a
nonzero $B$ charge. In this work, we focus on the former scenario which is also
known as leptogenesis. We show how to describe the evolutions of lepton flavor
charges taking into account the complete Standard Model lepton flavor and
spectator effects in a unified and lepton flavor basis-independent way. The
recipe we develop can be applied to any leptogenesis model with arbitrary
number of new scalars carrying nonzero hypercharges and is valid for cosmic
temperature ranging from $10^{15}$ GeV down to the weak scale. We demonstrate
that in order to describe the physics in a basis-independent manner and to
include lepton flavor effect consistently it is necessary to describe both
left-handed and right-handed lepton charges in terms of density matrices. This
is a crucial point since physics should be basis independent. As examples, we
apply the formalism to type-I and type-II leptogenesis models where in the
latter case, a flavor-covariant formalism is indispensable.
| [
{
"created": "Thu, 9 Sep 2021 18:00:01 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Feb 2022 16:53:53 GMT",
"version": "v2"
}
] | 2022-02-09 | [
[
"Fong",
"Chee Sheng",
""
]
] | In the early Universe above the weak scale, both baryon $B$ and lepton $L$ numbers are violated by nonperturabive effects in the Standard Model while $B-L$ remains conserved. Introducing new physics which violates perturbatively $L$ and/or $B$, one can generate dynamically a nonzero $B-L$ charge and hence a nonzero $B$ charge. In this work, we focus on the former scenario which is also known as leptogenesis. We show how to describe the evolutions of lepton flavor charges taking into account the complete Standard Model lepton flavor and spectator effects in a unified and lepton flavor basis-independent way. The recipe we develop can be applied to any leptogenesis model with arbitrary number of new scalars carrying nonzero hypercharges and is valid for cosmic temperature ranging from $10^{15}$ GeV down to the weak scale. We demonstrate that in order to describe the physics in a basis-independent manner and to include lepton flavor effect consistently it is necessary to describe both left-handed and right-handed lepton charges in terms of density matrices. This is a crucial point since physics should be basis independent. As examples, we apply the formalism to type-I and type-II leptogenesis models where in the latter case, a flavor-covariant formalism is indispensable. |
hep-ph/9904348 | Genevieve Belanger | G.Belanger, F.Boudjema, K.Sridhar | SUSY Higgs at the LHC: Large stop mixing effects and associated
production | latex file, 48 pages, 24 figures | Nucl.Phys. B568 (2000) 3-39 | 10.1016/S0550-3213(00)00195-4 | LAPTH-730/99,TIFR/TH/99-17 | hep-ph | null | We revisit the effect of the large stop mixing on the decay and production of
the lightest SUSY Higgs at the LHC. We stress that whenever the inclusive
2-photon signature is substantially reduced, associated production, $Wh$ and
$t\bar t h$, with the subsequent decay of the Higgs into photons is enhanced
and becomes an even more important discovery channel. We also point out that
these reductions in the inclusive channel do not occur for the smallest Higgs
mass where the significance is known to be lowest. We show that in such
scenarios the Higgs can be produced in the decay of the heaviest stop. For not
too heavy masses of the pseudo-scalar Higgs where the inclusive channel is even
further reduced, we show that large stop mixing also allows the production of
the pseudo-scalar Higgs through stop decays. These large mixing scenarios
therefore offer much better prospects than previously thought. As a by-product
we have recalculated stop1-stop1-h production at the LHC and give a first
evaluation of stop1-stop1-Z.
| [
{
"created": "Thu, 15 Apr 1999 15:00:25 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Belanger",
"G.",
""
],
[
"Boudjema",
"F.",
""
],
[
"Sridhar",
"K.",
""
]
] | We revisit the effect of the large stop mixing on the decay and production of the lightest SUSY Higgs at the LHC. We stress that whenever the inclusive 2-photon signature is substantially reduced, associated production, $Wh$ and $t\bar t h$, with the subsequent decay of the Higgs into photons is enhanced and becomes an even more important discovery channel. We also point out that these reductions in the inclusive channel do not occur for the smallest Higgs mass where the significance is known to be lowest. We show that in such scenarios the Higgs can be produced in the decay of the heaviest stop. For not too heavy masses of the pseudo-scalar Higgs where the inclusive channel is even further reduced, we show that large stop mixing also allows the production of the pseudo-scalar Higgs through stop decays. These large mixing scenarios therefore offer much better prospects than previously thought. As a by-product we have recalculated stop1-stop1-h production at the LHC and give a first evaluation of stop1-stop1-Z. |
0907.4123 | Victor Goncalves | V.P. Goncalves, M.V.T. Machado | Photoproduction of $\rho^0$ mesons in ultraperipheral heavy ion
collisions at energies available at the BNL Relativistic Heavy Ion Collider
(RHIC) and CERN Large Hadron Collider (LHC) | 6 pages, 5 figures, 1 table. Improved version to be published in
Physical Review C | Phys.Rev.C80:054901,2009 | 10.1103/PhysRevC.80.054901 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the photoproduction of $\rho$ mesons in ultraperipheral heavy
ion collisions at RHIC and LHC energies in the dipole approach and within two
phenomenological models based on the the Color Glass Condensate (CGC)
formalism. We estimate the integrated cross section and rapidity distribution
for meson production and compare our predictions with the data from the STAR
collaboration. In particular, we demonstrate that the total cross section at
RHIC is strongly dependent on the energy behavior of the dipole-target cross
section at low energies, which is not well determined in the dipole approach.
In contrast, the predictions at midrapidities at RHIC and in the full rapidity
at LHC are under theoretical control and can be used to test the QCD dynamics
at high energies.
| [
{
"created": "Thu, 23 Jul 2009 17:17:24 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Oct 2009 13:44:02 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Goncalves",
"V. P.",
""
],
[
"Machado",
"M. V. T.",
""
]
] | We investigate the photoproduction of $\rho$ mesons in ultraperipheral heavy ion collisions at RHIC and LHC energies in the dipole approach and within two phenomenological models based on the the Color Glass Condensate (CGC) formalism. We estimate the integrated cross section and rapidity distribution for meson production and compare our predictions with the data from the STAR collaboration. In particular, we demonstrate that the total cross section at RHIC is strongly dependent on the energy behavior of the dipole-target cross section at low energies, which is not well determined in the dipole approach. In contrast, the predictions at midrapidities at RHIC and in the full rapidity at LHC are under theoretical control and can be used to test the QCD dynamics at high energies. |
hep-ph/0407035 | Konstantin Goulianos | Konstantin Goulianos (The Rockefeller University) | Hadronic Diffraction: Where do we Stand? | 17 pages, Presented at Les Rencontres de Physique de la Valle
d'Aoste, La Thuile, Aosta Valley, Italy, February 29 - March 6, 2004 | null | null | null | hep-ph | null | Experimental results on hadronic soft and hard diffractive processes are
reviewed with emphasis on aspects of the data that point to the underlying QCD
mechanism for diffraction. Diffractive differential cross sections are shown to
be factorized into two terms, one representing the total cross section at the
reduced energy, corresponding to the rapidity region(s) in which there is
particle production, and another interpreted as the probability of formation of
the rapidity gap(s) characterizing diffraction. By (re)normalizing the term of
gap formation probability to unity, cross sections for single, central, and
multiple rapidity gap soft diffraction, as well as structure functions for hard
diffraction processes, are obtained from the underlying inclusive parton
distribution functions. A unified partonic picture emerges, in which
diffraction appears to be mediated by the exchange of low-x partons subject to
color constraints.
| [
{
"created": "Fri, 2 Jul 2004 20:16:25 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Goulianos",
"Konstantin",
"",
"The Rockefeller University"
]
] | Experimental results on hadronic soft and hard diffractive processes are reviewed with emphasis on aspects of the data that point to the underlying QCD mechanism for diffraction. Diffractive differential cross sections are shown to be factorized into two terms, one representing the total cross section at the reduced energy, corresponding to the rapidity region(s) in which there is particle production, and another interpreted as the probability of formation of the rapidity gap(s) characterizing diffraction. By (re)normalizing the term of gap formation probability to unity, cross sections for single, central, and multiple rapidity gap soft diffraction, as well as structure functions for hard diffraction processes, are obtained from the underlying inclusive parton distribution functions. A unified partonic picture emerges, in which diffraction appears to be mediated by the exchange of low-x partons subject to color constraints. |
1507.00437 | BingRan He | Bing-Ran He, Yong-Liang Ma, Masayasu Harada | Effects of scalar mesons in a Skyrme model with hidden local symmetry | 9 pages, 6 figures | Phys. Rev. D 92, 076007 (2015) | 10.1103/PhysRevD.92.076007 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of light scalar mesons on the skyrmion properties by
constructing and examining a mesonic model including pion, rho meson, and omega
meson fields as well as two-quark and four-quark scalar meson fields. In our
model, the physical scalar mesons are defined as mixing states of the two- and
four-quark fields. We first omit the four-quark scalar meson field from the
model and find that when there is no direct coupling between the two-quark
scalar meson and the vector mesons, the soliton mass is smaller and the soliton
size is larger for lighter scalar mesons; when direct coupling is switched on,
as the coupling strength increases, the soliton becomes heavy, and the radius
of the baryon number density becomes large, as the repulsive force arising from
the $\omega$ meson becomes strong. We then include the four-quark scalar meson
field in the model and find that mixing between the two-quark and four-quark
components of the scalar meson fields also affects the properties of the
soliton. When the two-quark component of the lighter scalar meson is increased,
the soliton mass decreases and the soliton size increases.
| [
{
"created": "Thu, 2 Jul 2015 06:34:47 GMT",
"version": "v1"
},
{
"created": "Sun, 25 Oct 2015 09:38:02 GMT",
"version": "v2"
}
] | 2015-10-28 | [
[
"He",
"Bing-Ran",
""
],
[
"Ma",
"Yong-Liang",
""
],
[
"Harada",
"Masayasu",
""
]
] | We study the effects of light scalar mesons on the skyrmion properties by constructing and examining a mesonic model including pion, rho meson, and omega meson fields as well as two-quark and four-quark scalar meson fields. In our model, the physical scalar mesons are defined as mixing states of the two- and four-quark fields. We first omit the four-quark scalar meson field from the model and find that when there is no direct coupling between the two-quark scalar meson and the vector mesons, the soliton mass is smaller and the soliton size is larger for lighter scalar mesons; when direct coupling is switched on, as the coupling strength increases, the soliton becomes heavy, and the radius of the baryon number density becomes large, as the repulsive force arising from the $\omega$ meson becomes strong. We then include the four-quark scalar meson field in the model and find that mixing between the two-quark and four-quark components of the scalar meson fields also affects the properties of the soliton. When the two-quark component of the lighter scalar meson is increased, the soliton mass decreases and the soliton size increases. |
hep-ph/0410290 | Kacper Zalewski | K. Zalewski | Quantum statistics in multiple particle production | Latex 12 pages no figures | Acta Phys.Polon. B36 (2005) 1869-1880 | null | TPJU 13/2004 | hep-ph | null | Effects of quantum statistics are clearly seen in the final states of
high-energy multiparticle production processes. These effects are being widely
used to obtain information about the regions where the final state hadrons are
produced. Here we briefly present and discuss the assumptions underlying most
of these analyses.
| [
{
"created": "Thu, 21 Oct 2004 11:41:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Zalewski",
"K.",
""
]
] | Effects of quantum statistics are clearly seen in the final states of high-energy multiparticle production processes. These effects are being widely used to obtain information about the regions where the final state hadrons are produced. Here we briefly present and discuss the assumptions underlying most of these analyses. |
hep-ph/0411395 | Martin Beneke | M. Beneke (RWTH Aachen), F. Campanario (U. Karlsruhe), T. Mannel, B.D.
Pecjak (U. Siegen) | Power corrections to B\to X_u l \nu (X_s\gamma) decay spectra in the
"shape-function" region | 34 pages, v2: journal version | JHEP 0506:071,2005 | 10.1088/1126-6708/2005/06/071 | PITHA 04/18 | hep-ph | null | Using soft-collinear effective theory (SCET), we examine the 1/m_b
corrections to the factorization formulas for inclusive semi-leptonic B decays
in the endpoint region, where the hadronic final state consists of a single
jet. At tree level, we find a new contribution from four-quark operators that
was previously assumed absent. Beyond tree level many sub-leading
shape-functions are needed to correctly describe the decay process.
| [
{
"created": "Tue, 30 Nov 2004 11:31:30 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Jun 2005 06:25:38 GMT",
"version": "v2"
}
] | 2011-01-27 | [
[
"Beneke",
"M.",
"",
"RWTH Aachen"
],
[
"Campanario",
"F.",
"",
"U. Karlsruhe"
],
[
"Mannel",
"T.",
"",
"U. Siegen"
],
[
"Pecjak",
"B. D.",
"",
"U. Siegen"
]
] | Using soft-collinear effective theory (SCET), we examine the 1/m_b corrections to the factorization formulas for inclusive semi-leptonic B decays in the endpoint region, where the hadronic final state consists of a single jet. At tree level, we find a new contribution from four-quark operators that was previously assumed absent. Beyond tree level many sub-leading shape-functions are needed to correctly describe the decay process. |
hep-ph/0104226 | Yoshio Koide | Yoshio Koide | Can the Zee Model Explain the Observed Neutrino Data? | Latex file, 10 pages, 1 figure, explanations and references added,
typos corrected, to be published in Phys.Rev.D | Phys.Rev. D64 (2001) 077301 | 10.1103/PhysRevD.64.077301 | US-01-02 | hep-ph | null | The eigenvalues and mixing angles in the Zee model are investigated
parameter-independently. When we require |\Delta m^2_{12}/\Delta m^2_{23}| \ll
1 in order to understand the solar and atmospheric data simultaneously, the
only solution is one which gives bi-maximal mixing. It is pointed out that the
observed values \sin^2 2\theta_{solar} \simeq 0.66 in the MSW LMA solution
cannot be explained within the framework of the Zee model, because we derive a
severe constraint on the value of \sin^2 2 \theta_{solar}, \sin^2 2
\theta_{solar} \geq 1 -(1/16)(\Delta m^2_{solar}/\Delta m^2_{atm})^2.
| [
{
"created": "Mon, 23 Apr 2001 11:24:22 GMT",
"version": "v1"
},
{
"created": "Wed, 2 May 2001 10:20:36 GMT",
"version": "v2"
},
{
"created": "Thu, 21 Jun 2001 11:35:47 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Koide",
"Yoshio",
""
]
] | The eigenvalues and mixing angles in the Zee model are investigated parameter-independently. When we require |\Delta m^2_{12}/\Delta m^2_{23}| \ll 1 in order to understand the solar and atmospheric data simultaneously, the only solution is one which gives bi-maximal mixing. It is pointed out that the observed values \sin^2 2\theta_{solar} \simeq 0.66 in the MSW LMA solution cannot be explained within the framework of the Zee model, because we derive a severe constraint on the value of \sin^2 2 \theta_{solar}, \sin^2 2 \theta_{solar} \geq 1 -(1/16)(\Delta m^2_{solar}/\Delta m^2_{atm})^2. |
1708.03482 | Anton Konrad Cyrol | Anton K. Cyrol, Mario Mitter, Jan M. Pawlowski, and Nils Strodthoff | Non-perturbative finite-temperature Yang-Mills theory | 13 pages + appendix | Phys. Rev. D 97, 054015 (2018) | 10.1103/PhysRevD.97.054015 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present non-perturbative correlation functions in Landau-gauge Yang-Mills
theory at finite temperature. The results are obtained from the functional
renormalisation group within a self-consistent approximation scheme. In
particular, we compute the magnetic and electric components of the gluon
propagator, and the three- and four-gluon vertices. We also show the ghost
propagator and the ghost-gluon vertex at finite temperature. Our results for
the propagators are confronted with lattice simulations and our Debye mass is
compared to hard thermal loop perturbation theory.
| [
{
"created": "Fri, 11 Aug 2017 09:26:51 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Mar 2018 16:11:41 GMT",
"version": "v2"
}
] | 2018-03-20 | [
[
"Cyrol",
"Anton K.",
""
],
[
"Mitter",
"Mario",
""
],
[
"Pawlowski",
"Jan M.",
""
],
[
"Strodthoff",
"Nils",
""
]
] | We present non-perturbative correlation functions in Landau-gauge Yang-Mills theory at finite temperature. The results are obtained from the functional renormalisation group within a self-consistent approximation scheme. In particular, we compute the magnetic and electric components of the gluon propagator, and the three- and four-gluon vertices. We also show the ghost propagator and the ghost-gluon vertex at finite temperature. Our results for the propagators are confronted with lattice simulations and our Debye mass is compared to hard thermal loop perturbation theory. |
1706.07235 | Wei-Min Yang | Wei-Min Yang | A Model of Dark Matter, Leptogenesis, and Neutrino Mass from the $B-L$
Violation just above the Electroweak Scale | 14 pages, 4 figures, make some revisions and add a few contents | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I suggest an extension of the SM by introducing a dark sector with the local
$U(1)_{D}$ symmetry. The particles in the dark sector bring about the new
physics beyond the SM. In particular the global $B-L$ symmetry is violated just
above the electroweak scale, this becomes a common origin of the tiny neutrino
mass, the cold dark mater and the baryon asymmetry. The model can not only
account for the tiny neutrino mass and the "WIMP Miracle", but also achieve the
leptogenesis around the electroweak scale. Finally, it is very possible that
the model predictions are tested in near future experiments.
| [
{
"created": "Thu, 22 Jun 2017 10:02:02 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Jul 2017 10:12:25 GMT",
"version": "v2"
},
{
"created": "Thu, 24 Aug 2017 11:32:52 GMT",
"version": "v3"
}
] | 2017-08-25 | [
[
"Yang",
"Wei-Min",
""
]
] | I suggest an extension of the SM by introducing a dark sector with the local $U(1)_{D}$ symmetry. The particles in the dark sector bring about the new physics beyond the SM. In particular the global $B-L$ symmetry is violated just above the electroweak scale, this becomes a common origin of the tiny neutrino mass, the cold dark mater and the baryon asymmetry. The model can not only account for the tiny neutrino mass and the "WIMP Miracle", but also achieve the leptogenesis around the electroweak scale. Finally, it is very possible that the model predictions are tested in near future experiments. |
hep-ph/9507286 | null | G. Degrassi, S. Fanchiotti, F. Feruglio, P. Gambino and A. Vicini | Two-loop Corrections for Electroweak Processes | presented at the XXX^th Rencontres de Moriond, "Electroweak
Interactions and Unified Theories, March 11-18, 1995, Les Arcs, Savoie,
France; 8 pages, LaTeX, 1 uuencoded postscript figure in additional file | null | null | null | hep-ph | null | Theoretical uncertainties affecting electroweak observables are reviewed and
the relevance of two-loop electroweak radiative corrections for the precision
tests of the Standard Model is discussed.
| [
{
"created": "Tue, 11 Jul 1995 10:58:29 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Jul 1995 07:57:39 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Degrassi",
"G.",
""
],
[
"Fanchiotti",
"S.",
""
],
[
"Feruglio",
"F.",
""
],
[
"Gambino",
"P.",
""
],
[
"Vicini",
"A.",
""
]
] | Theoretical uncertainties affecting electroweak observables are reviewed and the relevance of two-loop electroweak radiative corrections for the precision tests of the Standard Model is discussed. |
hep-ph/0304236 | Zong-Kuan Guo | Zong-Kuan Guo, Yun-Song Piao, Rong-Gen Cai and Yuan-Zhong Zhang | Inflationary Attractor from Tachyonic Matter | 4 pages, 2 figures, RevTeX | Phys.Rev. D68 (2003) 043508 | 10.1103/PhysRevD.68.043508 | null | hep-ph | null | We study the complete evolution of a flat and homogeneous universe dominated
by tachyonic matter. We demonstrate the attractor behaviour of the tachyonic
inflation using the Hamilton-Jacobi formalism. We else obtain analytical
approximations to the trajectories of the tachyon field in different regions.
The numerical calculation shows that an initial non-vanishing momentum does not
prevent the onset of inflation. The slow-rolling solution is an attractor.
| [
{
"created": "Thu, 24 Apr 2003 10:43:39 GMT",
"version": "v1"
},
{
"created": "Sat, 14 Jun 2003 07:12:20 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Guo",
"Zong-Kuan",
""
],
[
"Piao",
"Yun-Song",
""
],
[
"Cai",
"Rong-Gen",
""
],
[
"Zhang",
"Yuan-Zhong",
""
]
] | We study the complete evolution of a flat and homogeneous universe dominated by tachyonic matter. We demonstrate the attractor behaviour of the tachyonic inflation using the Hamilton-Jacobi formalism. We else obtain analytical approximations to the trajectories of the tachyon field in different regions. The numerical calculation shows that an initial non-vanishing momentum does not prevent the onset of inflation. The slow-rolling solution is an attractor. |
0806.4092 | Wolfgang Ochs | G. Mennessier, S. Narison and W. Ochs | Two-photon width and gluonic component of sigma/f_0(600) | 5 pages, 2 figures, Talk (W.O.) at the International Workshop on e+e-
collisions from phi to psi, Frascati, April 2008, to appear in Nucl. Phys. B
(Proc. suppl.) | Nucl.Phys.Proc.Suppl.181-182:238-242,2008 | 10.1016/j.nuclphysbps.2008.09.043 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse data on pi pi and gamma gamma scattering below 700 MeV within an
improved analytic K-matrix model. This model is based on an effective theory
with couplings between resonances, hadrons and photons. The two-photon decay of
a resonance can proceed through intermediate transition into charged hadrons
(here: pi^+ pi^-) and their subsequent annihilation or through a ``direct''
transition into photons. Our analysis confirms the rather large total radiative
width of the sigma/f_0(600) resonance which we find as (3.9 \pm 0.6) keV but
suggests its dominance by the pi pi rescattering process. This process is not
sensitive to the internal structure of the resonance contrary to the direct
component which we find small, (0.13 \pm 0.05) keV, and well consistent with
the expectations for an unmixed glueball according to the QCD sum rule
calculations.
| [
{
"created": "Wed, 25 Jun 2008 13:17:42 GMT",
"version": "v1"
}
] | 2008-11-07 | [
[
"Mennessier",
"G.",
""
],
[
"Narison",
"S.",
""
],
[
"Ochs",
"W.",
""
]
] | We analyse data on pi pi and gamma gamma scattering below 700 MeV within an improved analytic K-matrix model. This model is based on an effective theory with couplings between resonances, hadrons and photons. The two-photon decay of a resonance can proceed through intermediate transition into charged hadrons (here: pi^+ pi^-) and their subsequent annihilation or through a ``direct'' transition into photons. Our analysis confirms the rather large total radiative width of the sigma/f_0(600) resonance which we find as (3.9 \pm 0.6) keV but suggests its dominance by the pi pi rescattering process. This process is not sensitive to the internal structure of the resonance contrary to the direct component which we find small, (0.13 \pm 0.05) keV, and well consistent with the expectations for an unmixed glueball according to the QCD sum rule calculations. |
hep-ph/0106065 | Namit Mahajan | Abhinav Gupta, Namit Mahajan and Amitabha Mukherjee (Univ. of Delhi) | Neutrino Masses from Non-minimal Gravitational Interactions of Massive
Neutral Fermions | 7 page Latex 2e file, axodraw needed. Discussion and references
added. Version to appear in MPLA | Mod.Phys.Lett.A17:763-770,2002 | 10.1142/S0217732302006813 | null | hep-ph | null | A new mechanism is proposed for generating neutrino masses radiatively
through a non-minimal coupling to gravity of fermionic bilinears involving
massive neutral fermions. Such coupling terms can arise in theories where the
gravity sector is augmented by a scalar field. They necessarily violate the
principle of equivalence, but such violations are not ruled out by present
experiments. It is shown that the proposed mechanism is realised most
convincingly in theories of the Randall- Sundrum type, where gravity couples
strongly in the TeV range. The mechanism has the potential for solving both the
solar and atmospheric neutrino problems. The smallness of neutrino masses in
this scenario is due to the fact that the interaction of the massive neutral
fermions arises entirely from higher-dimensional operators in the effective
Lagrangian.
| [
{
"created": "Wed, 6 Jun 2001 12:27:25 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Jul 2001 08:41:14 GMT",
"version": "v2"
},
{
"created": "Mon, 24 Sep 2001 05:33:58 GMT",
"version": "v3"
},
{
"created": "Tue, 11 Jun 2002 08:37:32 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Gupta",
"Abhinav",
"",
"Univ. of Delhi"
],
[
"Mahajan",
"Namit",
"",
"Univ. of Delhi"
],
[
"Mukherjee",
"Amitabha",
"",
"Univ. of Delhi"
]
] | A new mechanism is proposed for generating neutrino masses radiatively through a non-minimal coupling to gravity of fermionic bilinears involving massive neutral fermions. Such coupling terms can arise in theories where the gravity sector is augmented by a scalar field. They necessarily violate the principle of equivalence, but such violations are not ruled out by present experiments. It is shown that the proposed mechanism is realised most convincingly in theories of the Randall- Sundrum type, where gravity couples strongly in the TeV range. The mechanism has the potential for solving both the solar and atmospheric neutrino problems. The smallness of neutrino masses in this scenario is due to the fact that the interaction of the massive neutral fermions arises entirely from higher-dimensional operators in the effective Lagrangian. |
1405.7564 | Kausik Pal | Kausik Pal | Correlation corrections to the thermodynamic properties of spin
asymmetric QGP matter | 18 pages, 17 eps figures. Abstract is modified, this new version is
published in Eur. Phys. J. Plus: 130, 23 (2015) | Eur. Phys. J. Plus: 130, 23 (2015) | 10.1140/epjp/i2015-15023-7 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the free energy, entropy and pressure of the Quark Gluon Plasma
(QGP) at finite temperature and density with a given fraction of spin-up and
spin-down quarks using a MIT bag model with corrections up to ${\cal O} (g^4
\ln g^2)$. The expressions for the specific heat and the spin susceptibility
are derived in terms of Fermi momentum and temperature. The effects of
interaction between the quarks on the properties of the QGP phase are also
investigated. Within our phenomenological model, we estimate the transition
temperature $T_c$ by constructing the phase boundary between the hadronic phase
and the QGP phase. Finally, we compute the equation of state of the QGP and its
dependence on the temperature and the density.
| [
{
"created": "Thu, 29 May 2014 14:28:56 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Feb 2015 14:44:21 GMT",
"version": "v2"
}
] | 2015-02-09 | [
[
"Pal",
"Kausik",
""
]
] | We calculate the free energy, entropy and pressure of the Quark Gluon Plasma (QGP) at finite temperature and density with a given fraction of spin-up and spin-down quarks using a MIT bag model with corrections up to ${\cal O} (g^4 \ln g^2)$. The expressions for the specific heat and the spin susceptibility are derived in terms of Fermi momentum and temperature. The effects of interaction between the quarks on the properties of the QGP phase are also investigated. Within our phenomenological model, we estimate the transition temperature $T_c$ by constructing the phase boundary between the hadronic phase and the QGP phase. Finally, we compute the equation of state of the QGP and its dependence on the temperature and the density. |
1504.08233 | Alessandro Papa | Francesco Giovanni Celiberto, Dmitry Yu. Ivanov, Beatrice Murdaca,
Alessandro Papa | Mueller-Navelet jets at LHC: BFKL versus high-energy DGLAP | 15 pages, 3 figures, 2 tables; slight change in the title; version to
appear on Eur. Phys. J. C. arXiv admin note: text overlap with
arXiv:1407.8431 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The production of forward jets separated by a large rapidity gap at LHC, the
so-called Mueller-Navelet jets, is a fundamental testfield for perturbative QCD
in the high-energy limit. Several analyses have already provided with evidence
about the compatibility of theoretical predictions, based on collinear
factorization and BFKL resummation of energy logarithms in the next-to-leading
approximation, with the CMS experimental data at 7 TeV of center-of-mass
energy. However, the question if the same data can be described also by
fixed-order perturbative approaches has not been yet fully answered. In this
paper we provide numerical evidence that the mere use of partially asymmetric
cuts in the transverse momenta of the detected jets allows a clear separation
between BFKL-resummed and fixed-order predictions in some observables related
with the Mueller-Navelet jet production process.
| [
{
"created": "Thu, 30 Apr 2015 13:56:01 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jun 2015 18:33:01 GMT",
"version": "v2"
}
] | 2015-06-23 | [
[
"Celiberto",
"Francesco Giovanni",
""
],
[
"Ivanov",
"Dmitry Yu.",
""
],
[
"Murdaca",
"Beatrice",
""
],
[
"Papa",
"Alessandro",
""
]
] | The production of forward jets separated by a large rapidity gap at LHC, the so-called Mueller-Navelet jets, is a fundamental testfield for perturbative QCD in the high-energy limit. Several analyses have already provided with evidence about the compatibility of theoretical predictions, based on collinear factorization and BFKL resummation of energy logarithms in the next-to-leading approximation, with the CMS experimental data at 7 TeV of center-of-mass energy. However, the question if the same data can be described also by fixed-order perturbative approaches has not been yet fully answered. In this paper we provide numerical evidence that the mere use of partially asymmetric cuts in the transverse momenta of the detected jets allows a clear separation between BFKL-resummed and fixed-order predictions in some observables related with the Mueller-Navelet jet production process. |
hep-ph/9312294 | Gregory Leptoukh | E.G.Gurvich and G.G.Leptoukh | Area Decay Law Implementation for Quark String Fragmentation | 5 pages (REVTEX) + 3 figures (available in ps format from
G.G.Leptoukh <visitor@pyrssc.physics.ncsu.edu>, IPGAS-HE/93-3, to be
published in Phys. Rev. D | Phys.Rev. D49 (1994) 2627-2630 | 10.1103/PhysRevD.49.2627 | null | hep-ph | null | We apply the Area Decay Law (ADL) straightforwardly to simulate a quark
string hadronization and compare the results with the explicit analytic
calculations. We show that the usual "inclusive" Monte--Carlo simulations do
not correspond to the ADL because of two mistakes: not proper simulation of
two--dimensional probability density and lack of an important combinatorial
factor in a binary tree simulation. We also show how to simulate area decay law
"inclusively" avoiding the above--mentioned mistakes.
| [
{
"created": "Thu, 16 Dec 1993 04:13:57 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Dec 1993 21:46:04 GMT",
"version": "v2"
}
] | 2009-10-22 | [
[
"Gurvich",
"E. G.",
""
],
[
"Leptoukh",
"G. G.",
""
]
] | We apply the Area Decay Law (ADL) straightforwardly to simulate a quark string hadronization and compare the results with the explicit analytic calculations. We show that the usual "inclusive" Monte--Carlo simulations do not correspond to the ADL because of two mistakes: not proper simulation of two--dimensional probability density and lack of an important combinatorial factor in a binary tree simulation. We also show how to simulate area decay law "inclusively" avoiding the above--mentioned mistakes. |
hep-ph/9809375 | Kari Enqvist | Kari Enqvist (University of Helsinki) | Dark Matter from Unstable B-balls | 11 pages, 3 ps figures. Invited talk at DARK98 conference,
Heidelberg, Germany, July 20-25 | null | null | HIP-1998-63/TH | hep-ph | null | The spectrum of MSSM admits solitons carrying baryonic charge, or B-balls. In
an inflationary universe they can be produced in significant numbers by a
break-up of a scalar condensate along the flat directions. It is shown that if
SUSY breaking is mediated to the observable sector by gravity, B-balls are
unstable but decay to baryons and LSPs typically well below the electroweak
phase transition. It is argued that B-balls could be the source of most baryons
and cold dark matter in the universe, with their number densities related by
$n_{LSP}\simeq 3n_{B}$. For B-balls to survive thermalization, the reheating
temperature after inflation should be less than about $10^{3}$ GeV.
| [
{
"created": "Mon, 14 Sep 1998 13:24:10 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Enqvist",
"Kari",
"",
"University of Helsinki"
]
] | The spectrum of MSSM admits solitons carrying baryonic charge, or B-balls. In an inflationary universe they can be produced in significant numbers by a break-up of a scalar condensate along the flat directions. It is shown that if SUSY breaking is mediated to the observable sector by gravity, B-balls are unstable but decay to baryons and LSPs typically well below the electroweak phase transition. It is argued that B-balls could be the source of most baryons and cold dark matter in the universe, with their number densities related by $n_{LSP}\simeq 3n_{B}$. For B-balls to survive thermalization, the reheating temperature after inflation should be less than about $10^{3}$ GeV. |
0706.3409 | Kyoungchul Kong | Bogdan A. Dobrescu, Dan Hooper, Kyoungchul Kong, Rakhi Mahbubani | Spinless photon dark matter from two universal extra dimensions | 22 pages. Figure 7 corrected, leading to improved prospects for
direct detection. Some clarifying remarks included | JCAP 0710:012,2007 | 10.1088/1475-7516/2007/10/012 | FERMILAB-PUB-07-274-A-T | hep-ph astro-ph | null | We explore the properties of dark matter in theories with two universal extra
dimensions, where the lightest Kaluza-Klein state is a spin-0 neutral particle,
representing a six-dimensional photon polarized along the extra dimensions.
Annihilation of this 'spinless photon' proceeds predominantly through Higgs
boson exchange, and is largely independent of other Kaluza-Klein particles. The
measured relic abundance sets an upper limit on the spinless photon mass of 500
GeV, which decreases to almost 200 GeV if the Higgs boson is light. The
phenomenology of this dark matter candidate is strikingly different from
Kaluza-Klein dark matter in theories with one universal extra dimension.
Elastic scattering of the spinless photon with quarks is helicity suppressed,
making its direct detection challenging, although possible at upcoming
experiments. The prospects for indirect detection with gamma rays and
antimatter are similar to those of neutralinos. The rates predicted at neutrino
telescopes are below the sensitivity of next-generation experiments.
| [
{
"created": "Mon, 25 Jun 2007 19:52:46 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Oct 2007 15:17:21 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Dobrescu",
"Bogdan A.",
""
],
[
"Hooper",
"Dan",
""
],
[
"Kong",
"Kyoungchul",
""
],
[
"Mahbubani",
"Rakhi",
""
]
] | We explore the properties of dark matter in theories with two universal extra dimensions, where the lightest Kaluza-Klein state is a spin-0 neutral particle, representing a six-dimensional photon polarized along the extra dimensions. Annihilation of this 'spinless photon' proceeds predominantly through Higgs boson exchange, and is largely independent of other Kaluza-Klein particles. The measured relic abundance sets an upper limit on the spinless photon mass of 500 GeV, which decreases to almost 200 GeV if the Higgs boson is light. The phenomenology of this dark matter candidate is strikingly different from Kaluza-Klein dark matter in theories with one universal extra dimension. Elastic scattering of the spinless photon with quarks is helicity suppressed, making its direct detection challenging, although possible at upcoming experiments. The prospects for indirect detection with gamma rays and antimatter are similar to those of neutralinos. The rates predicted at neutrino telescopes are below the sensitivity of next-generation experiments. |
hep-ph/9608352 | Sreerup Raychaudhuri | Dilip Kumar Ghosh (Bombay U.), Sreerup Raychaudhuri and K. Sridhar
(Tata Inst.) | Bounds from $t \bar t$ production on R-parity violating models of
supersymmetry | 12 pages, Latex, 3 postscript figures | Phys.Lett. B396 (1997) 177-182 | 10.1016/S0370-2693(97)00117-2 | TIFR-TH/96-44, BU-TH/96-3 | hep-ph | null | We study $t \bar t$ production in R-parity violating supersymmetry. The
annihilation channel $q \bar q \rightarrow t \bar t$ gets new contributions
from $t$-channel exchange of squarks or sleptons. With the data from Tevatron
on $t \bar t$ production, we find that the squark- or slepton-exchange
processes constrain the $B$-violating $\lambda''$ couplings or the
$L$-violating $\lambda'$ couplings, respectively. Our bounds are already
comparable to the few existing constraints on third-generation $R$-parity
violating couplings, and will improve when more precise measurements of the $t
\bar t$ production cross-section become available. We also discuss the effects
of these couplings for top production at the LHC.
| [
{
"created": "Sat, 17 Aug 1996 07:00:13 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Ghosh",
"Dilip Kumar",
"",
"Bombay U."
],
[
"Raychaudhuri",
"Sreerup",
"",
"Tata Inst."
],
[
"Sridhar",
"K.",
"",
"Tata Inst."
]
] | We study $t \bar t$ production in R-parity violating supersymmetry. The annihilation channel $q \bar q \rightarrow t \bar t$ gets new contributions from $t$-channel exchange of squarks or sleptons. With the data from Tevatron on $t \bar t$ production, we find that the squark- or slepton-exchange processes constrain the $B$-violating $\lambda''$ couplings or the $L$-violating $\lambda'$ couplings, respectively. Our bounds are already comparable to the few existing constraints on third-generation $R$-parity violating couplings, and will improve when more precise measurements of the $t \bar t$ production cross-section become available. We also discuss the effects of these couplings for top production at the LHC. |
1708.02446 | Boris Ermolaev | B.I. Ermolaev, S.I. Troyan | Light-by-light scattering in Double-Logarithmic Approximation | 16 pages, 4 figures. Multiple errors are corrected, 2 figs are added,
comparizon to BFKL is done in more detail | null | 10.1140/epjc/s10052-018-5998-3 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the present paper we consider the elastic 2 -> 2 -scattering of virtual
photons at high energies in the forward kinematics at zero and non-zero values
of t. Accounting for both gluon and quark double-logarithmic (DL) contributions
to all orders in the QCD coupling, we obtain explicit expressions for
amplitudes of this process in Double-Logarithmic Approximation (DLA). First we
keep the QCD coupling fixed and then account for running coupling effects.
Applying the saddle-point method to the obtained expressions for the scattering
amplitude, we calculate the high-energy asymptotics of the amplitude, which
proved to be of the Regge form. The Reggeon bears the vacuum quantum numbers
and therefore it is a new, DL contribution to Pomeron. Comparison of the DL
Pomeron to the BFKL Pomeron shows that contribution of the DL Pomeron to the
high-energy asymptotics is of the same order as contribution of the BFKL
Pomeron, so the DL Pomeron should be taken into account together with the BFKL
Pomeron. We estimate the applicability region for the asymptotics of the
light-by-light scattering amplitude, where the the DL Pomeron can reliably
represent the parent amplitude.
| [
{
"created": "Tue, 8 Aug 2017 11:12:56 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Aug 2017 10:00:18 GMT",
"version": "v2"
},
{
"created": "Tue, 19 Jun 2018 10:27:28 GMT",
"version": "v3"
}
] | 2018-08-01 | [
[
"Ermolaev",
"B. I.",
""
],
[
"Troyan",
"S. I.",
""
]
] | In the present paper we consider the elastic 2 -> 2 -scattering of virtual photons at high energies in the forward kinematics at zero and non-zero values of t. Accounting for both gluon and quark double-logarithmic (DL) contributions to all orders in the QCD coupling, we obtain explicit expressions for amplitudes of this process in Double-Logarithmic Approximation (DLA). First we keep the QCD coupling fixed and then account for running coupling effects. Applying the saddle-point method to the obtained expressions for the scattering amplitude, we calculate the high-energy asymptotics of the amplitude, which proved to be of the Regge form. The Reggeon bears the vacuum quantum numbers and therefore it is a new, DL contribution to Pomeron. Comparison of the DL Pomeron to the BFKL Pomeron shows that contribution of the DL Pomeron to the high-energy asymptotics is of the same order as contribution of the BFKL Pomeron, so the DL Pomeron should be taken into account together with the BFKL Pomeron. We estimate the applicability region for the asymptotics of the light-by-light scattering amplitude, where the the DL Pomeron can reliably represent the parent amplitude. |
1205.5267 | Ezequiel Alvarez | Ezequiel Alvarez | Enhancing the sensitivity to New Physics in the top-antitop invariant
mass distribution | 9 pages, 2 figures. Typo in numbers of Fig. 1 corrected, references
added and minor changes to agree with PRD published version | null | 10.1103/PhysRevD.86.037501 | SLAC-PUB-15035 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose selection cuts on the LHC top-antitop production sample which
should enhance the sensitivity to New Physics signals in the study of the
top-antitop invariant mass distribution. We show that selecting events in which
the top-antitop object has little transverse and large longitudinal momentum
enlarges the quark-fusion fraction of the sample and therefore increases its
sensitivity to New Physics which couples to quarks and not to gluons. We find
that systematic error bars play a fundamental role and assume a simple model
for them. We check how a non-visible new particle would become visible after
the selection cuts enhance its resonance bump. A final realistic analysis
should be done by the experimental groups with a correct evaluation of the
systematic error bars.
| [
{
"created": "Wed, 23 May 2012 20:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Oct 2012 04:09:56 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Alvarez",
"Ezequiel",
""
]
] | We propose selection cuts on the LHC top-antitop production sample which should enhance the sensitivity to New Physics signals in the study of the top-antitop invariant mass distribution. We show that selecting events in which the top-antitop object has little transverse and large longitudinal momentum enlarges the quark-fusion fraction of the sample and therefore increases its sensitivity to New Physics which couples to quarks and not to gluons. We find that systematic error bars play a fundamental role and assume a simple model for them. We check how a non-visible new particle would become visible after the selection cuts enhance its resonance bump. A final realistic analysis should be done by the experimental groups with a correct evaluation of the systematic error bars. |
hep-ph/9910264 | Rajen Kundu | Rajen Kundu (Saha Institute of Nuclear Physics) | Complete Set of Splitting Functions Relevant in the Evolution of
Nucleonic Helicity Distributions | null | null | null | null | hep-ph | null | In this work, we show how the complete set of splitting functions relevant
for the evolution of various distribution functions describing nucleonic
helicity structure can be obtained in the light front Hamiltonian perturbation
theory using completely fixed light front gauge, $A^+=0$.
| [
{
"created": "Thu, 7 Oct 1999 12:16:20 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kundu",
"Rajen",
"",
"Saha Institute of Nuclear Physics"
]
] | In this work, we show how the complete set of splitting functions relevant for the evolution of various distribution functions describing nucleonic helicity structure can be obtained in the light front Hamiltonian perturbation theory using completely fixed light front gauge, $A^+=0$. |
0910.5192 | Lisheng Geng | L.S. Geng, F.K. Guo, C. Hanhart, R. Molina, E. Oset, and B.S. Zou | Study of the $f_2(1270)$, $f_2'(1525)$, $f_0(1370)$ and $f_0(1710)$ in
the $J/\psi$ radiative decays | The large Nc argument improved; version published in EPJA. | Eur. Phys. J. A44:305-311,2010 | 10.1140/epja/i2010-10971-5 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we present an approach to study the radiative decay modes of
the $J/\psi$ into a photon and one of the tensor mesons $f_2(1270)$,
$f'_2(1525)$, as well as the scalar ones $f_0(1370)$ and $f_0(1710)$.
Especially we compare predictions that emerge from a scheme where the states
appear dynamically in the solution of vector meson--vector meson scattering
amplitudes to those from a (admittedly naive) quark model. We provide evidence
that it might be possible to distinguish amongst the two scenarios, once
improved data are available.
| [
{
"created": "Tue, 27 Oct 2009 18:02:31 GMT",
"version": "v1"
},
{
"created": "Sat, 24 Apr 2010 06:29:12 GMT",
"version": "v2"
}
] | 2010-04-30 | [
[
"Geng",
"L. S.",
""
],
[
"Guo",
"F. K.",
""
],
[
"Hanhart",
"C.",
""
],
[
"Molina",
"R.",
""
],
[
"Oset",
"E.",
""
],
[
"Zou",
"B. S.",
""
]
] | In this paper we present an approach to study the radiative decay modes of the $J/\psi$ into a photon and one of the tensor mesons $f_2(1270)$, $f'_2(1525)$, as well as the scalar ones $f_0(1370)$ and $f_0(1710)$. Especially we compare predictions that emerge from a scheme where the states appear dynamically in the solution of vector meson--vector meson scattering amplitudes to those from a (admittedly naive) quark model. We provide evidence that it might be possible to distinguish amongst the two scenarios, once improved data are available. |
1307.2370 | Norma Susana Mankoc Borstnik | Norma Susana Mankoc Borstnik | How can the Standard model Higgs and also the extensions of the Higgs to
Yukawa's scalars be interpreted in the spin-charge-family theory and to what
predictions about the Higgs does this theory lead? | 10 pages. This is the discussion presented at Bled 14^th Workshop
"What comes beyond the standard models", Bled, July 11-21, 2011 and published
in the Proceedings to this 14^th workshop. It appears two years later at
arxiv because of the change of the arXiv policy.Bled Workshop in Physics | Bled Workshop in Physics, Vol. 12. No.2, DMFA-Zaloznistvo,
Ljubljana, December 2011, ISSN 1580-4992 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This contribution is to show how does the spin-charge-family theory interpret
the assumptions of the standard model, and those extensions of this model,
which are trying to see the Yukawa couplings as scalar fields with the family
(flavour) charges in the fundamental representations of the group. The purpose
of these contribution is i.) to try to understand why the standard model works
so well, although its assumptions look quite artificial, and ii.) how do
predictions of the spin-charge-family theory about the measurements of the
scalar fields differ from predictions of the {\em standard model}, which has
only one scalar field - the Higgs - and also from its more or less direct
extensions with Yukawas as the scalar dynamical fields with the family charge
in the fundamental or anti-fundamental representation of group.
| [
{
"created": "Tue, 9 Jul 2013 08:54:40 GMT",
"version": "v1"
}
] | 2013-07-10 | [
[
"Borstnik",
"Norma Susana Mankoc",
""
]
] | This contribution is to show how does the spin-charge-family theory interpret the assumptions of the standard model, and those extensions of this model, which are trying to see the Yukawa couplings as scalar fields with the family (flavour) charges in the fundamental representations of the group. The purpose of these contribution is i.) to try to understand why the standard model works so well, although its assumptions look quite artificial, and ii.) how do predictions of the spin-charge-family theory about the measurements of the scalar fields differ from predictions of the {\em standard model}, which has only one scalar field - the Higgs - and also from its more or less direct extensions with Yukawas as the scalar dynamical fields with the family charge in the fundamental or anti-fundamental representation of group. |
hep-ph/9710242 | Fyodor V. Tkachov | A.V. Stepanova (Moscow State University) and F.V. Tkachov (Institute
for Nuclear Research, Russ. Acad. Sci., Moscow) | Algebraic algorithm for next-to-leading order calculations in the
large-s/small-x regime | PS 3p. in: QFTHEP'97 (Proc. XII Int. Workshop, Samara, 4-10 Sept.
1997); 7-11-98: maintenance | null | null | F5T-97/02 | hep-ph hep-th | null | We present an algebraic algorithm for analytical calculation of arbitrary
dimensionally regulated massless two-loop forward-scattering diagrams that
constitute the most cumbersome part of next-to-leading order calculations in
the large-s/small-x regime.
| [
{
"created": "Sun, 5 Oct 1997 13:28:33 GMT",
"version": "v1"
},
{
"created": "Sat, 7 Nov 1998 06:54:12 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Stepanova",
"A. V.",
"",
"Moscow State University"
],
[
"Tkachov",
"F. V.",
"",
"Institute\n for Nuclear Research, Russ. Acad. Sci., Moscow"
]
] | We present an algebraic algorithm for analytical calculation of arbitrary dimensionally regulated massless two-loop forward-scattering diagrams that constitute the most cumbersome part of next-to-leading order calculations in the large-s/small-x regime. |
2003.03230 | Soumia Lebbal | Soumia Lebbal, Noureddine Mebarki and Jamal Mimouni | Lepton Flavor Universality Violation in a 331 Model in $b\rightarrow s
l^+ l^-$ Processes | 9 pages, 1 figure, to be published in IOP Conference Series | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Lepton Flavor Universality Violation (LFUV) in $b\rightarrow s l^+ l^-$
processes is investigated in the context of a 331 model. It is shown that in
order to explain the experimentally observed deviations from the Standard Model
in these FCNC transitions, a non-minimal version of the model has to be
considered. We investigate the ability of this model in accomodating the
model-independant scenarios currently favored by global fits.
| [
{
"created": "Fri, 6 Mar 2020 14:13:06 GMT",
"version": "v1"
}
] | 2020-03-09 | [
[
"Lebbal",
"Soumia",
""
],
[
"Mebarki",
"Noureddine",
""
],
[
"Mimouni",
"Jamal",
""
]
] | Lepton Flavor Universality Violation (LFUV) in $b\rightarrow s l^+ l^-$ processes is investigated in the context of a 331 model. It is shown that in order to explain the experimentally observed deviations from the Standard Model in these FCNC transitions, a non-minimal version of the model has to be considered. We investigate the ability of this model in accomodating the model-independant scenarios currently favored by global fits. |
1308.4473 | Daekyoung Kang | Daekyoung Kang, Christopher Lee, and Iain W. Stewart | 1-Jettiness in DIS: Measuring 2 Jets in 3 Ways | 7 pages, 2 figures, to appear in the proceedings of the XXI
International Workshop on Deep-Inelastic Scattering and Related Subjects
(DIS2013), Marseille, 22-26 April 2013 | null | null | LA-UR-13-26573, MIT-CTP 4488 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute cross sections for two-jet production in deep inelastic scattering
(DIS), with one jet from initial state radiation (ISR) and the other from final
state radiation, with a summation of large logarithms up to
next-to-next-to-leading logarithmic (NNLL) accuracy. Use of the DIS event shape
1-jettiness ensures that events have two well-collimated jets. We calculate
distributions for three versions of 1-jettiness that have different sensitivity
to the transverse momentum of the ISR, and derive factorization theorems for
each of them using the soft collinear effective theory (SCET). The structure of
the transverse momentum dependence in the factorization theorems is different
for each 1-jettiness. We present numerical results for these three observables
with parameters for the HERA collider.
| [
{
"created": "Wed, 21 Aug 2013 03:16:08 GMT",
"version": "v1"
}
] | 2013-08-22 | [
[
"Kang",
"Daekyoung",
""
],
[
"Lee",
"Christopher",
""
],
[
"Stewart",
"Iain W.",
""
]
] | We compute cross sections for two-jet production in deep inelastic scattering (DIS), with one jet from initial state radiation (ISR) and the other from final state radiation, with a summation of large logarithms up to next-to-next-to-leading logarithmic (NNLL) accuracy. Use of the DIS event shape 1-jettiness ensures that events have two well-collimated jets. We calculate distributions for three versions of 1-jettiness that have different sensitivity to the transverse momentum of the ISR, and derive factorization theorems for each of them using the soft collinear effective theory (SCET). The structure of the transverse momentum dependence in the factorization theorems is different for each 1-jettiness. We present numerical results for these three observables with parameters for the HERA collider. |
hep-ph/0509109 | Robert Shrock | Neil D. Christensen and Robert Shrock | Technifermion Representations and Precision Electroweak Constraints | 8 pages, latex | Phys.Lett.B632:92-98,2006 | 10.1016/j.physletb.2005.10.022 | null | hep-ph | null | We discuss the selection of fermion representations in technicolor models
with a view toward minimizing technicolor contributions to the precision
electroweak $S$ parameter. We present and analyze models that involve one
technifermion SU(2)$_L$ doublet with standard-model singlet technifermion
sectors that lead to walking behavior, which further reduces $S$. We also
consider models that have technifermions in higher-dimensional representations
and study embeddings in extended technicolor theories.
| [
{
"created": "Mon, 12 Sep 2005 13:54:13 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Nov 2005 20:51:37 GMT",
"version": "v2"
}
] | 2011-09-29 | [
[
"Christensen",
"Neil D.",
""
],
[
"Shrock",
"Robert",
""
]
] | We discuss the selection of fermion representations in technicolor models with a view toward minimizing technicolor contributions to the precision electroweak $S$ parameter. We present and analyze models that involve one technifermion SU(2)$_L$ doublet with standard-model singlet technifermion sectors that lead to walking behavior, which further reduces $S$. We also consider models that have technifermions in higher-dimensional representations and study embeddings in extended technicolor theories. |
1802.01832 | Jens O. Andersen | Jens O. Andersen and Patrick Kneschke | Chiral density wave versus pion condensation at finite density | 14 pages and 11 figs. v2: Minor changes, matches published version in
PRD | Phys. Rev. D 97, 076005 (2018) | 10.1103/PhysRevD.97.076005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The quark-meson model is often used as an effective low-energy model for QCD
to study the chiral transition at finite temperature $T$, baryon chemical
potential $\mu_B$, and isospin chemical potential $\mu_I$. The parameters of
the model are determined by matching the meson and quark masses, as well as the
pion decay constant to their physical values using the on-shell and modified
minimal subtraction schemes. In this paper, we study the possibility of
different phases at zero temperature. In particular, we investigate the
competition between an inhomogeneous chiral condensate and a pion condensate.
For the inhomogeneity, we use a chiral-density wave ansatz. For a sigma mass of
$600$ MeV, we find that an inhomogeneous chiral condensate exist only for pion
masses below approximately 37 MeV. We also show that due to our parameter
fixing, the onset of pion condensation takes place exactly at
$\mu_I={1\over2}m_{\pi}$ in accordance with exact results.
| [
{
"created": "Tue, 6 Feb 2018 07:48:45 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Apr 2018 15:47:00 GMT",
"version": "v2"
}
] | 2018-04-18 | [
[
"Andersen",
"Jens O.",
""
],
[
"Kneschke",
"Patrick",
""
]
] | The quark-meson model is often used as an effective low-energy model for QCD to study the chiral transition at finite temperature $T$, baryon chemical potential $\mu_B$, and isospin chemical potential $\mu_I$. The parameters of the model are determined by matching the meson and quark masses, as well as the pion decay constant to their physical values using the on-shell and modified minimal subtraction schemes. In this paper, we study the possibility of different phases at zero temperature. In particular, we investigate the competition between an inhomogeneous chiral condensate and a pion condensate. For the inhomogeneity, we use a chiral-density wave ansatz. For a sigma mass of $600$ MeV, we find that an inhomogeneous chiral condensate exist only for pion masses below approximately 37 MeV. We also show that due to our parameter fixing, the onset of pion condensation takes place exactly at $\mu_I={1\over2}m_{\pi}$ in accordance with exact results. |
1209.1306 | Yuhei Iwata | Yuhei Iwata, Hiroaki Abuki and Katsuhiko Suzuki | Chiral multicritical points driven by isospin density in the
Ginzburg-Landau approach | 4 pages, 2 eps figures. Presented at QCD@Work 2012: International
Workshop on QCD - Theory and Experiment, June 18-21, Lecce (Italy) | null | 10.1063/1.4763534 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study how a chiral tricritical point (TCP) on QCD phase diagram is
affected by the imbalance of up and down quark densities (isospin density),
using the generalized Ginzburg-Landau (GL) approach. The resulting phase
diagram near TCP shows a rich fine structure which includes inhomogeneities of
both the chiral and the charged pion condensations. It turns out that the TCP
splits into multicritical points.
| [
{
"created": "Thu, 6 Sep 2012 14:55:52 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Iwata",
"Yuhei",
""
],
[
"Abuki",
"Hiroaki",
""
],
[
"Suzuki",
"Katsuhiko",
""
]
] | We study how a chiral tricritical point (TCP) on QCD phase diagram is affected by the imbalance of up and down quark densities (isospin density), using the generalized Ginzburg-Landau (GL) approach. The resulting phase diagram near TCP shows a rich fine structure which includes inhomogeneities of both the chiral and the charged pion condensations. It turns out that the TCP splits into multicritical points. |
hep-ph/9601372 | Ananthanarayan "b." | B. Ananthanarayan and P. N. Pandita | The Non-Minimal Supersymmetric Standard Model at Large $\tan\beta$ | 30 pages plain LaTeX, to be run twice, 4 figures | Int.J.Mod.Phys.A12:2321-2342,1997 | 10.1142/S0217751X97001353 | BUTP-96/6, KL-TH~96/4 | hep-ph | null | We present a comprehensive analysis of the Non-Minimal Supersymmetric
Standard Model (NMSSM) for large values of $\tan\beta$, the ratio of the vacuum
expectation values of the two Higgs doublets, which arise when we impose the
constraint of the unification of Yukawa couplings in the model. In this limit
we show that the vacuum expectation value of the singlet is forced to be large,
of the order of $10$ TeV. The singlet decouples from the lightest CP-even
neutral Higgs boson and the neutralinos. We compare our results with the
corresponding particle spectrum of the Minimal Supersymmetric Standard Model in
the same limit. With the exception of the lightest Higgs boson, the particle
spectrum in the model turns out to be heavy. The Higgs boson mass, after the
inclusion of radiative corrections, is found to be in the neighbourhood of
$\sim 130$ GeV.
| [
{
"created": "Tue, 30 Jan 1996 15:00:56 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Ananthanarayan",
"B.",
""
],
[
"Pandita",
"P. N.",
""
]
] | We present a comprehensive analysis of the Non-Minimal Supersymmetric Standard Model (NMSSM) for large values of $\tan\beta$, the ratio of the vacuum expectation values of the two Higgs doublets, which arise when we impose the constraint of the unification of Yukawa couplings in the model. In this limit we show that the vacuum expectation value of the singlet is forced to be large, of the order of $10$ TeV. The singlet decouples from the lightest CP-even neutral Higgs boson and the neutralinos. We compare our results with the corresponding particle spectrum of the Minimal Supersymmetric Standard Model in the same limit. With the exception of the lightest Higgs boson, the particle spectrum in the model turns out to be heavy. The Higgs boson mass, after the inclusion of radiative corrections, is found to be in the neighbourhood of $\sim 130$ GeV. |
0711.0216 | Peter A. Sturrock | P.A. Sturrock | Analysis of bimodality in histograms formed from GALLEX and GNO solar
neutrino data | 14 pages, 8 figures | null | 10.1007/s11207-008-9170-3 | null | hep-ph astro-ph | null | A histogram display of the solar neutrino capture-rate measurements made by
the GALLEX experiment appears to be bimodal, but that of the follow-on GNO
experiment does not. To assess the significance of these results, we introduce
a "bimodality index" based on the probability-transform procedure. This
confirms that the GALLEX measurements are indeed bimodal (at the 99.98 percent
confidence level), and that the GNO measurements are not. Tracking the
bimodality index as a function of time shows that the strongest contribution to
bimodality comes from runs 42 to 62, i.e. from the time interval 1995.1 to
1996.9. The bimodality index for the first half (runs 1 through 33) is 2.56,
whereas that for the second half (runs 33 through 65) is 7.05. Power-spectrum
analysis shows a similar distinction: the peaks in the power spectrum formed
from the second half are stronger than those in the power spectrum formed from
the first half, suggesting that bimodality and rotational modulation are
related.
| [
{
"created": "Thu, 1 Nov 2007 20:41:47 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Sturrock",
"P. A.",
""
]
] | A histogram display of the solar neutrino capture-rate measurements made by the GALLEX experiment appears to be bimodal, but that of the follow-on GNO experiment does not. To assess the significance of these results, we introduce a "bimodality index" based on the probability-transform procedure. This confirms that the GALLEX measurements are indeed bimodal (at the 99.98 percent confidence level), and that the GNO measurements are not. Tracking the bimodality index as a function of time shows that the strongest contribution to bimodality comes from runs 42 to 62, i.e. from the time interval 1995.1 to 1996.9. The bimodality index for the first half (runs 1 through 33) is 2.56, whereas that for the second half (runs 33 through 65) is 7.05. Power-spectrum analysis shows a similar distinction: the peaks in the power spectrum formed from the second half are stronger than those in the power spectrum formed from the first half, suggesting that bimodality and rotational modulation are related. |
1310.0718 | A. Tawfik | A. Tawfik (WLCAPP, Cairo and Egyptian Ctr. Theor. Phys., Cairo) | Some Intensive and Extensive Quantities in High-Energy Collisions | 10 pages, 4 figures, 5 eps graphs, Invited Talk at XXXI Max Born
Symposium and HIC for FAIR Workshop, Three Days of Critical Behaviour in hot
and dense QCD, Wroclaw-Poland, 14 - 16 JUNE 2013 | null | null | ECTP-2012-14, WLCAPP-2013-11 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the evolution of some statistical and thermodynamical quantities
measured in difference sizes of high-energy collisions at different energies.
We differentiate between intensive and extensive quantities and discuss the
importance of their distinguishability in characterizing possible critical
phenomena of nuclear collisions at various energies with different initial
conditions.
| [
{
"created": "Wed, 2 Oct 2013 14:42:01 GMT",
"version": "v1"
}
] | 2013-10-03 | [
[
"Tawfik",
"A.",
"",
"WLCAPP, Cairo and Egyptian Ctr. Theor. Phys., Cairo"
]
] | We review the evolution of some statistical and thermodynamical quantities measured in difference sizes of high-energy collisions at different energies. We differentiate between intensive and extensive quantities and discuss the importance of their distinguishability in characterizing possible critical phenomena of nuclear collisions at various energies with different initial conditions. |
2206.08211 | Evgeny Gelfer | E.G. Gelfer, A.M. Fedotov, A.A. Mironov, S. Weber | Nonlinear Compton scattering in time-dependent electric fields: LCFA and
beyond | null | null | 10.1103/PhysRevD.106.056013 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Locally constant crossed field approximation (LCFA) is a powerful tool for
theoretical and numerical studies of various strong field quantum
electrodynamical effects. We explore this approximation in detail for photon
emission by a spinless particle in a strong time-dependent electric field. This
kind of electromagnetic fields is of particular interest, because, in contrast
to the comprehensively studied case of a plane wave, they are not crossed. We
develop an approach for calculating photon emission probability in a generic
time-dependent electric field, establish the range of applicability of LCFA,
and calculate the corrections to it.
| [
{
"created": "Thu, 16 Jun 2022 14:30:53 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Aug 2022 10:36:37 GMT",
"version": "v2"
}
] | 2023-07-19 | [
[
"Gelfer",
"E. G.",
""
],
[
"Fedotov",
"A. M.",
""
],
[
"Mironov",
"A. A.",
""
],
[
"Weber",
"S.",
""
]
] | Locally constant crossed field approximation (LCFA) is a powerful tool for theoretical and numerical studies of various strong field quantum electrodynamical effects. We explore this approximation in detail for photon emission by a spinless particle in a strong time-dependent electric field. This kind of electromagnetic fields is of particular interest, because, in contrast to the comprehensively studied case of a plane wave, they are not crossed. We develop an approach for calculating photon emission probability in a generic time-dependent electric field, establish the range of applicability of LCFA, and calculate the corrections to it. |
1912.08873 | Gernot Eichmann | Gernot Eichmann | Towards resonance properties in the Dyson-Schwinger approach | 7 pages, 5 figures. Proceedings for Light Cone 2019, September 16-20,
2019, Ecole Polytechnique, Palaiseau, France | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give a brief summary of the Dyson-Schwinger and Bethe-Salpeter approach to
hadron spectroscopy and report on recent progress in determining resonance
properties in this framework. We exemplify the extraction of resonances using a
scalar model, where we solve the scattering equation for the four-point
scattering amplitude and extract the pole locations on the second Riemann sheet
as well as the phase shifts.
| [
{
"created": "Wed, 18 Dec 2019 20:20:55 GMT",
"version": "v1"
}
] | 2019-12-20 | [
[
"Eichmann",
"Gernot",
""
]
] | We give a brief summary of the Dyson-Schwinger and Bethe-Salpeter approach to hadron spectroscopy and report on recent progress in determining resonance properties in this framework. We exemplify the extraction of resonances using a scalar model, where we solve the scattering equation for the four-point scattering amplitude and extract the pole locations on the second Riemann sheet as well as the phase shifts. |
1802.09492 | Mikhail Voloshin | M.B. Voloshin | $S$ wave hidden charm - hidden strangeness production in $e^+e^-$
annihilation | 6 pages, 3 figures | null | 10.1016/j.physletb.2018.06.058 | FTPI-MINN-18/03, UMN-TH-3711/18 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is suggested that the recently observed enhancement of the relative yield
in $e^+e^-$ annihilation of states with hidden charm and hidden strangeness
above 4.43\,GeV is associated with the $S$ wave production of the charmed
strange meson pairs $D_{s0}(2317) \bar D_s^* + {\rm c.c.}$ and $D_{s1}^*(2460)
\bar D_s+ {\rm c.c.}$. This mechanism implies a pattern of breaking of the
Heavy Quark Spin Symmetry (HQSS) that can be tested in the final channels such
as $\eta_c(1S) \phi$, $h_c(1P) \eta $, $h_c(1P) \eta' $ produced in the same
energy range.
| [
{
"created": "Mon, 26 Feb 2018 18:16:12 GMT",
"version": "v1"
}
] | 2018-07-04 | [
[
"Voloshin",
"M. B.",
""
]
] | It is suggested that the recently observed enhancement of the relative yield in $e^+e^-$ annihilation of states with hidden charm and hidden strangeness above 4.43\,GeV is associated with the $S$ wave production of the charmed strange meson pairs $D_{s0}(2317) \bar D_s^* + {\rm c.c.}$ and $D_{s1}^*(2460) \bar D_s+ {\rm c.c.}$. This mechanism implies a pattern of breaking of the Heavy Quark Spin Symmetry (HQSS) that can be tested in the final channels such as $\eta_c(1S) \phi$, $h_c(1P) \eta $, $h_c(1P) \eta' $ produced in the same energy range. |
1006.2099 | Tentyukov Mikhail | M. Tentyukov, J.A.M. Vermaseren, J. Vollinga | Parallel versions of the symbolic manipulation system FORM | null | PoS ACAT2010:072,2010 | null | null | hep-ph cs.SC | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The symbolic manipulation program FORM is specialized to handle very large
algebraic expressions. Some specific features of its internal structure make
FORM very well suited for parallelization.
We have now two parallel versions of FORM, one is based on POSIX threads and
is optimal for modern multicore computers while another one uses MPI and can be
used to parallelize FORM on clusters and Massive Parallel Processing systems.
Most existing FORM programs will be able to take advantage of the parallel
execution without the need for modifications.
| [
{
"created": "Thu, 10 Jun 2010 18:07:15 GMT",
"version": "v1"
}
] | 2011-04-20 | [
[
"Tentyukov",
"M.",
""
],
[
"Vermaseren",
"J. A. M.",
""
],
[
"Vollinga",
"J.",
""
]
] | The symbolic manipulation program FORM is specialized to handle very large algebraic expressions. Some specific features of its internal structure make FORM very well suited for parallelization. We have now two parallel versions of FORM, one is based on POSIX threads and is optimal for modern multicore computers while another one uses MPI and can be used to parallelize FORM on clusters and Massive Parallel Processing systems. Most existing FORM programs will be able to take advantage of the parallel execution without the need for modifications. |
2405.10101 | Riccardo Bartocci | Riccardo Bartocci | Global analysis of the $U(3)^5$ symmetric SMEFT | 4 pages, 2 figures, contribution to the 2024 Electroweak session of
the 58th Rencontres de Moriond | null | null | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | The $U(3)^5$ symmetry within the SMEFT framework restricts the inclusion of
only fully flavor-conserving operators at dimension six. This proceeding
presents a global analysis of the SMEFT under this assumption. We provide
global constraints on all 41 Wilson coefficients, utilizing leading-order and
next-to-leading-order SMEFT predictions for various experiments including
parity-violating experiments, Electroweak Precision Observables (EWPO), Higgs
physics, top quark interactions, flavor observables, dijet production, and
lepton scatterings. We address issues concerning the constraints of specific
four-quark operators, investigate correlations between observables at different
energy scales, and assess the impact of next-to-leading-order contributions on
the global fit.
| [
{
"created": "Thu, 16 May 2024 13:55:27 GMT",
"version": "v1"
}
] | 2024-05-17 | [
[
"Bartocci",
"Riccardo",
""
]
] | The $U(3)^5$ symmetry within the SMEFT framework restricts the inclusion of only fully flavor-conserving operators at dimension six. This proceeding presents a global analysis of the SMEFT under this assumption. We provide global constraints on all 41 Wilson coefficients, utilizing leading-order and next-to-leading-order SMEFT predictions for various experiments including parity-violating experiments, Electroweak Precision Observables (EWPO), Higgs physics, top quark interactions, flavor observables, dijet production, and lepton scatterings. We address issues concerning the constraints of specific four-quark operators, investigate correlations between observables at different energy scales, and assess the impact of next-to-leading-order contributions on the global fit. |
0904.3073 | Jens Pruschke | J. Berges, J. Pruschke, A. Rothkopf | Instability-induced fermion production in quantum field theory | 19 pages, 16 figures, Phys.Rev.D version, minor corrections | Phys.Rev.D80:023522,2009 | 10.1103/PhysRevD.80.023522 | null | hep-ph astro-ph.CO hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Nonequilibrium instabilities are known to lead to exponential amplification
of boson occupation numbers for low momentum modes on time scales much shorter
than the asymptotic thermal equilibration time. We show for Yukawa-type
interactions that this growth induces very efficient fermion production, which
proceeds with the maximum primary boson growth rate. The description is based
on a 1/N expansion of the 2PI effective action to NLO including boson-fermion
loops, which are crucial to observe this phenomenon. For long enough
amplification in the boson sector, fermion production terminates when the
thermal occupancy is reached in the infrared. At higher momenta, where boson
occupation numbers are low, the fermion modes exhibit a power-law regime with
exponent two.
| [
{
"created": "Mon, 20 Apr 2009 18:19:44 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Aug 2009 11:41:51 GMT",
"version": "v2"
}
] | 2009-09-02 | [
[
"Berges",
"J.",
""
],
[
"Pruschke",
"J.",
""
],
[
"Rothkopf",
"A.",
""
]
] | Nonequilibrium instabilities are known to lead to exponential amplification of boson occupation numbers for low momentum modes on time scales much shorter than the asymptotic thermal equilibration time. We show for Yukawa-type interactions that this growth induces very efficient fermion production, which proceeds with the maximum primary boson growth rate. The description is based on a 1/N expansion of the 2PI effective action to NLO including boson-fermion loops, which are crucial to observe this phenomenon. For long enough amplification in the boson sector, fermion production terminates when the thermal occupancy is reached in the infrared. At higher momenta, where boson occupation numbers are low, the fermion modes exhibit a power-law regime with exponent two. |
0906.2327 | Toru Sato | V. Dmitrasinovic, T. Sato, M. Suvakov | Low-lying spectrum of the Y-string three-quark potential using
hyper-spherical coordinates | 19 pages, 6 figures | Eur.Phys.J.C62:383-397,2009 | 10.1140/epjc/s10052-009-1050-y | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the energies of three-quark states with definite permutation
symmetry (i.e. of SU(6) multiplets) in the N=0,1,2 shells, confined by the
Y-string three-quark potential. The exact Y-string potential consists of one,
so-called three-string term, and three angle-dependent two-string terms. Due to
this technical complication we treat the problem at three increasingly accurate
levels of approximation: 1) the (approximate) three-string potential expanded
to first order in trigonometric functions of hyper-spherical angles; 2) the
(approximate) three-string potential to all orders in the power expansion in
hyper-spherical harmonics, but without taking into account the transition(s) to
two-string potentials; 3) the exact minimal-length string potential to all
orders in power expansion in hyper-spherical harmonics, and taking into account
the transition(s) to two-string potentials. We show the general trend of
improvement %convergence of these approximations: The exact non-perturbative
corrections to the total energy are of the order of one per cent, as compared
with approximation 2), yet the exact energy differences between the
$[20,1^{+}], [70,2^{+}], [56,2^{+}], [70,0^{+}]$-plets are shifted to 2:2:0.9,
from the Bowler and Tynemouth separation rule 2:2:1, which is obeyed by
approximation 2) at the one per cent level. The precise value of the energy
separation of the first radial excitation ("Roper") $[56^{\prime},0^{+}]$-plet
from the $[70,1^{-}]$-plet depends on the approximation, but does not become
negative, i.e. the "Roper" remains heavier than the odd-parity
$[70,1^{-}]$-plet in all of our approximations.
| [
{
"created": "Fri, 12 Jun 2009 13:51:30 GMT",
"version": "v1"
}
] | 2009-08-13 | [
[
"Dmitrasinovic",
"V.",
""
],
[
"Sato",
"T.",
""
],
[
"Suvakov",
"M.",
""
]
] | We calculate the energies of three-quark states with definite permutation symmetry (i.e. of SU(6) multiplets) in the N=0,1,2 shells, confined by the Y-string three-quark potential. The exact Y-string potential consists of one, so-called three-string term, and three angle-dependent two-string terms. Due to this technical complication we treat the problem at three increasingly accurate levels of approximation: 1) the (approximate) three-string potential expanded to first order in trigonometric functions of hyper-spherical angles; 2) the (approximate) three-string potential to all orders in the power expansion in hyper-spherical harmonics, but without taking into account the transition(s) to two-string potentials; 3) the exact minimal-length string potential to all orders in power expansion in hyper-spherical harmonics, and taking into account the transition(s) to two-string potentials. We show the general trend of improvement %convergence of these approximations: The exact non-perturbative corrections to the total energy are of the order of one per cent, as compared with approximation 2), yet the exact energy differences between the $[20,1^{+}], [70,2^{+}], [56,2^{+}], [70,0^{+}]$-plets are shifted to 2:2:0.9, from the Bowler and Tynemouth separation rule 2:2:1, which is obeyed by approximation 2) at the one per cent level. The precise value of the energy separation of the first radial excitation ("Roper") $[56^{\prime},0^{+}]$-plet from the $[70,1^{-}]$-plet depends on the approximation, but does not become negative, i.e. the "Roper" remains heavier than the odd-parity $[70,1^{-}]$-plet in all of our approximations. |
1305.3985 | German Sharov | G. S. Sharov | String Models, Stability and Regge Trajectories for Hadron States | 8 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1004.1518 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Various string models of mesons and baryons include a string carrying 2 or 3
massive points (quarks or antiquarks). Rotational states (planar uniform
rotations) of these systems generate quasilinear Regge trajectories and may be
used for describing excited hadron states on these trajectories. For different
string models of baryon we are to solve the problem of choice between them and
the stability problem for their rotational states. An unexpected result is that
for the Y string baryon model these rotations are unstable with respect to
small disturbances on the classical level. This instability has specific
feature, disturbances grow linearly, whereas for the linear string baryon model
they grow exponentially and may increase predictions for baryon's width
$\Gamma$. The classical instability of rotational states and nonstandard Regge
slope are the arguments in favor of the stable simplest model of string with
massive ends both for baryons and mesons. Rotational states of this model with
two types of spin-orbit correction are used to describe Regge trajectories for
light, strange, charmed, bottom mesons and for $N$, $\Delta$, $\Sigma$,
$\Lambda$ and $\Lambda_c$ baryons.
| [
{
"created": "Fri, 17 May 2013 05:31:14 GMT",
"version": "v1"
}
] | 2013-05-20 | [
[
"Sharov",
"G. S.",
""
]
] | Various string models of mesons and baryons include a string carrying 2 or 3 massive points (quarks or antiquarks). Rotational states (planar uniform rotations) of these systems generate quasilinear Regge trajectories and may be used for describing excited hadron states on these trajectories. For different string models of baryon we are to solve the problem of choice between them and the stability problem for their rotational states. An unexpected result is that for the Y string baryon model these rotations are unstable with respect to small disturbances on the classical level. This instability has specific feature, disturbances grow linearly, whereas for the linear string baryon model they grow exponentially and may increase predictions for baryon's width $\Gamma$. The classical instability of rotational states and nonstandard Regge slope are the arguments in favor of the stable simplest model of string with massive ends both for baryons and mesons. Rotational states of this model with two types of spin-orbit correction are used to describe Regge trajectories for light, strange, charmed, bottom mesons and for $N$, $\Delta$, $\Sigma$, $\Lambda$ and $\Lambda_c$ baryons. |
2208.01068 | Rafael Boto | Rafael Boto, Jorge C. Rom\~ao and Jo\~ao P. Silva | BFB conditions on a class of symmetry constrained 3HDM | 41 pages, 15 Figures, revtex. arXiv admin note: text overlap with
arXiv:2106.11977 | null | 10.1103/PhysRevD.106.115010 | CFTP/22-004 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the bounded from below (BFB) conditions on a class of three Higgs
doublet models (3HDM) constrained by the symmetry groups U(1)xU(1), U(1)xZ2 and
Z2xZ2. These constraints must be implemented on both the neutral (BFB-n) and
charged (BFB-c) directions. The exact necessary and sufficient BFB conditions
are unknown in the Z2xZ2 case. We develop a general strategy using lower bounds
to find sufficient conditions for BFB-n and BFB-c and apply it to these
symmetries. In addition, we investigate the concern that the use of safe
sufficient conditions can ignore valid points which would yield distinct
physical consequences. This is done by performing a full phenomenological
simulation of the U(1)xU(1) and U(1)xZ2 models, where exact necessary and
sufficient BFB conditions are possible. We look specifically at the points
allowed by exact solutions but precluded by safe lower bounds. We found no
evidence of remarkable new effects, partly reassuring the use of the lower
bounds we propose here, for those potentials where no exact necessary and
sufficient BFB conditions are known.
| [
{
"created": "Mon, 1 Aug 2022 18:09:49 GMT",
"version": "v1"
}
] | 2022-12-28 | [
[
"Boto",
"Rafael",
""
],
[
"Romão",
"Jorge C.",
""
],
[
"Silva",
"João P.",
""
]
] | We study the bounded from below (BFB) conditions on a class of three Higgs doublet models (3HDM) constrained by the symmetry groups U(1)xU(1), U(1)xZ2 and Z2xZ2. These constraints must be implemented on both the neutral (BFB-n) and charged (BFB-c) directions. The exact necessary and sufficient BFB conditions are unknown in the Z2xZ2 case. We develop a general strategy using lower bounds to find sufficient conditions for BFB-n and BFB-c and apply it to these symmetries. In addition, we investigate the concern that the use of safe sufficient conditions can ignore valid points which would yield distinct physical consequences. This is done by performing a full phenomenological simulation of the U(1)xU(1) and U(1)xZ2 models, where exact necessary and sufficient BFB conditions are possible. We look specifically at the points allowed by exact solutions but precluded by safe lower bounds. We found no evidence of remarkable new effects, partly reassuring the use of the lower bounds we propose here, for those potentials where no exact necessary and sufficient BFB conditions are known. |
1402.2129 | Gian Francesco Giudice | Gian F. Giudice and Hyun Min Lee | Starobinsky-like inflation from induced gravity | 13 pages; some references added; version published in PLB | null | 10.1016/j.physletb.2014.04.020 | CERN-PH-TH/2014-025 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive a general criterion that defines all single-field models leading to
Starobinsky-like inflation and to universal predictions for the spectral index
and tensor-to-scalar ratio, which are in agreement with Planck data. Out of all
the theories that satisfy this criterion, we single out a special class of
models with the interesting property of retaining perturbative unitarity up to
the Planck scale. These models are based on induced gravity, with the Planck
mass determined by the vacuum expectation value of the inflaton.
| [
{
"created": "Mon, 10 Feb 2014 12:45:55 GMT",
"version": "v1"
},
{
"created": "Sat, 12 Apr 2014 15:38:00 GMT",
"version": "v2"
}
] | 2015-06-18 | [
[
"Giudice",
"Gian F.",
""
],
[
"Lee",
"Hyun Min",
""
]
] | We derive a general criterion that defines all single-field models leading to Starobinsky-like inflation and to universal predictions for the spectral index and tensor-to-scalar ratio, which are in agreement with Planck data. Out of all the theories that satisfy this criterion, we single out a special class of models with the interesting property of retaining perturbative unitarity up to the Planck scale. These models are based on induced gravity, with the Planck mass determined by the vacuum expectation value of the inflaton. |
hep-ph/0205092 | Daisuke Nomura | Kaoru Hagiwara, Stephan Narison, and Daisuke Nomura | B^0_{d,s} - \bar{B}^0_{d,s} mass-differences from QCD spectral sum rules | 7 pages with 2 figures, uses espcrc2.sty. Version to appear in Phys.
Lett. B | Phys.Lett.B540:233-240,2002 | 10.1016/S0370-2693(02)02133-0 | null | hep-ph hep-ex hep-lat | null | We present the first QCD spectral sum rules analysis of the SU(3) breaking
parameter \xi and an improved estimate of the renormalization group invariant
(RGI) bag constant \hat{B}_{B_q} both entering into the B^0_{d,s} -
\bar{B}^0_{d,s} mass-differences. The averages of the results from the Laplace
and moment sum rules to order \alpha_s are f_B\sqrt{\hat B_B} \simeq (247 \pm
59) MeV and \xi \equiv f_{B_s} \sqrt{\hat B_{B_s}} / f_{B} \sqrt{\hat B_{B}}
\simeq (1.18\pm 0.03), in units where f_\pi=130.7 MeV. Combined with the
experimental data on the mass-differences \Delta M_{d,s}, one obtains the
constraint on the CKM weak mixing angle |V_{ts}/V_{td}|^2 > 20.0 (1.1).
Alternatively, using the weak mixing angle from the analysis of the unitarity
triangle and the data on \Delta M_d, one predicts \Delta M_s=18.6 (2.2) ps^{-1}
in agreement with the present experimental lower bound and within the reach of
Tevatron 2.
| [
{
"created": "Fri, 10 May 2002 01:33:53 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Jun 2002 23:30:51 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Hagiwara",
"Kaoru",
""
],
[
"Narison",
"Stephan",
""
],
[
"Nomura",
"Daisuke",
""
]
] | We present the first QCD spectral sum rules analysis of the SU(3) breaking parameter \xi and an improved estimate of the renormalization group invariant (RGI) bag constant \hat{B}_{B_q} both entering into the B^0_{d,s} - \bar{B}^0_{d,s} mass-differences. The averages of the results from the Laplace and moment sum rules to order \alpha_s are f_B\sqrt{\hat B_B} \simeq (247 \pm 59) MeV and \xi \equiv f_{B_s} \sqrt{\hat B_{B_s}} / f_{B} \sqrt{\hat B_{B}} \simeq (1.18\pm 0.03), in units where f_\pi=130.7 MeV. Combined with the experimental data on the mass-differences \Delta M_{d,s}, one obtains the constraint on the CKM weak mixing angle |V_{ts}/V_{td}|^2 > 20.0 (1.1). Alternatively, using the weak mixing angle from the analysis of the unitarity triangle and the data on \Delta M_d, one predicts \Delta M_s=18.6 (2.2) ps^{-1} in agreement with the present experimental lower bound and within the reach of Tevatron 2. |
hep-ph/0607295 | Carlos A. Salgado | Antonio D. Polosa and Carlos A. Salgado | Jet Shapes in Opaque Media | 4 pages, 2 ps figures | Phys.Rev.C75:041901,2007 | 10.1103/PhysRevC.75.041901 | ROMA1-1435/2006 | hep-ph | null | We present general arguments, based on medium-induced radiative energy loss,
which reproduce the non-gaussian shapes of away-side di-jet azimuthal
correlations found in nucleus-nucleus collisions at RHIC. A rather simple
generalization of the Sudakov form factors to opaque media allowing an
effective description of the experimental data is proposed.
| [
{
"created": "Wed, 26 Jul 2006 17:48:28 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Polosa",
"Antonio D.",
""
],
[
"Salgado",
"Carlos A.",
""
]
] | We present general arguments, based on medium-induced radiative energy loss, which reproduce the non-gaussian shapes of away-side di-jet azimuthal correlations found in nucleus-nucleus collisions at RHIC. A rather simple generalization of the Sudakov form factors to opaque media allowing an effective description of the experimental data is proposed. |
hep-ph/9405373 | null | M. Herrmann and G.F. Bertsch | Source Dimensions in Ultrarelativistic Heavy Ion Collisions | RevTeX 3.0, 28 pages, 6 figures, not included, revised version, major
change is an additional discussion of the classical two-body collision
algorithm, a (compressed) postscript file of the complete paper including
figures can be obtained from Authors or via anonymous ftp at
ftp://ftp_int.phys.washington.edu/pub/herrmann/pisource.ps.Z | Phys.Rev.C51:328-338,1995 | 10.1103/PhysRevC.51.328 | DOE/ER/40561-141-INT94-00-57 | hep-ph nucl-th | null | Recent experiments on pion correlations, interpreted as interferometric
measurements of the collision zone, are compared with models that distinguish a
prehadronic phase and a hadronic phase. The models include prehadronic
longitudinal expansion, conversion to hadrons in local kinetic equilibrium, and
rescattering of the produced hadrons. We find that the longitudinal and outward
radii are surprisingly sensitive to the algorithm used for two-body collisions.
The longitudinal radius measured in collisions of 200 GeV/u sulfur nuclei on a
heavy target requires the existence of a prehadronic phase which converts to
the hadronic phase at densities around 0.8-1.0 GeV/fm$^3$. The transverse radii
cannot be reproduced without introducing more complex dynamics into the
transverse expansion.
| [
{
"created": "Tue, 24 May 1994 21:20:01 GMT",
"version": "v1"
},
{
"created": "Sat, 19 Nov 1994 00:22:01 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Herrmann",
"M.",
""
],
[
"Bertsch",
"G. F.",
""
]
] | Recent experiments on pion correlations, interpreted as interferometric measurements of the collision zone, are compared with models that distinguish a prehadronic phase and a hadronic phase. The models include prehadronic longitudinal expansion, conversion to hadrons in local kinetic equilibrium, and rescattering of the produced hadrons. We find that the longitudinal and outward radii are surprisingly sensitive to the algorithm used for two-body collisions. The longitudinal radius measured in collisions of 200 GeV/u sulfur nuclei on a heavy target requires the existence of a prehadronic phase which converts to the hadronic phase at densities around 0.8-1.0 GeV/fm$^3$. The transverse radii cannot be reproduced without introducing more complex dynamics into the transverse expansion. |
hep-ph/9902247 | Jing Wang | M. Cveti\v{c}, L. Everett, P. Langacker and J. Wang | Physics Implications of a Perturbative Superstring Construction | 11 pages, two figures. Proceedings, contribution to the BTMSSM
subgroup for the Physics at Run II: Supersymmetry/Higgs Summary Meeting,
Fermilab, November 1998 | null | null | null | hep-ph | null | We investigate the low energy physics implications of a prototype
quasi-realistic superstring model with an anomalous U(1). First, we present the
techniques utilized to compute the mass spectrum and superpotential couplings
at the string scale, and demonstrate the results for the effective theory along
a particular flat direction/"restabilized vacuum" of the model. We then analyze
the gauge symmetry breaking patterns and renormalization group equations to
determine the mass spectrum at the electroweak scale for a particular numerical
example with a realistic Z-Z' hierarchy. Although the model considered is not
fully realistic, the results demonstrate general features of quasi-realistic
string models, such as extra matter (e.g. Z' gauge bosons and an extended Higgs
sector) at the electroweak/TeV scale, and noncanonical couplings (such as
R-parity violating terms).
| [
{
"created": "Fri, 5 Feb 1999 14:42:11 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Cvetič",
"M.",
""
],
[
"Everett",
"L.",
""
],
[
"Langacker",
"P.",
""
],
[
"Wang",
"J.",
""
]
] | We investigate the low energy physics implications of a prototype quasi-realistic superstring model with an anomalous U(1). First, we present the techniques utilized to compute the mass spectrum and superpotential couplings at the string scale, and demonstrate the results for the effective theory along a particular flat direction/"restabilized vacuum" of the model. We then analyze the gauge symmetry breaking patterns and renormalization group equations to determine the mass spectrum at the electroweak scale for a particular numerical example with a realistic Z-Z' hierarchy. Although the model considered is not fully realistic, the results demonstrate general features of quasi-realistic string models, such as extra matter (e.g. Z' gauge bosons and an extended Higgs sector) at the electroweak/TeV scale, and noncanonical couplings (such as R-parity violating terms). |
hep-ph/0311099 | Victor Abramovsky | V.A. Abramovsky, N.V. Prikhod'ko | Energy dependence of Cronin momentum in saturation model for $p+A$ and
$A+A$ collisions | LaTeX2e, 12 pages, 8 figures | Eur.Phys.J.C35:359-364,2004 | 10.1140/epjc/s2004-01822-5 | null | hep-ph | null | We calculate $\sqrt{s}$ dependence of Cronin momentum for $p+A$ and $A+A$
collisions in saturation model. We show that this dependence is consistent with
expectation from formula which was obtained using simple dimentional
consideration. This can be used to test validity of saturation model (and
distinguish among its variants) and measure $x$ dependence of saturation
momentum from experimental data.
| [
{
"created": "Fri, 7 Nov 2003 16:30:16 GMT",
"version": "v1"
}
] | 2011-10-11 | [
[
"Abramovsky",
"V. A.",
""
],
[
"Prikhod'ko",
"N. V.",
""
]
] | We calculate $\sqrt{s}$ dependence of Cronin momentum for $p+A$ and $A+A$ collisions in saturation model. We show that this dependence is consistent with expectation from formula which was obtained using simple dimentional consideration. This can be used to test validity of saturation model (and distinguish among its variants) and measure $x$ dependence of saturation momentum from experimental data. |
2111.04932 | Yinghua Tan | Yinghua Tan, Zhenyu Zhang and Xiang Zhou | Electromagnetic Dalitz Decays of $D_{(s)}^\ast$ Mesons | 9 pages, 12 figures | null | 10.1142/S0217751X22500750 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Rare electromagnetic decays of charmed mesons are useful laboratories to
explore the structure of hadronic states and the interactions between photon
and charmed mesons, to test the chiral perturbation theory in flavor sector and
to search for new physics including dark photons. In this paper, we calculate
the relative branching ratios of electromagnetic Dalitz decays $D_{(s)}^\ast\to
D_{(s)}\ell^+\ell^-$ to their corresponding radiative decays $D_{(s)}^\ast\to
D_{(s)}\gamma$, the dileptonic invariant mass spectra and the leptonic angular
distributions with transition form factor in Vector-Meson Dominance model,
where $D_{(s)}^\ast$ represents $D^\ast(2007)^0$, $D^\ast(2010)^\pm$,
$D^\ast(2640)^\pm$, $D_s^{\ast\pm}$, $D_{s1}^\ast(2700)^\pm$ and
$D_{s1}^\ast(2860)^\pm$.
| [
{
"created": "Tue, 9 Nov 2021 03:29:28 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Nov 2021 08:38:47 GMT",
"version": "v2"
},
{
"created": "Thu, 29 Dec 2022 15:11:47 GMT",
"version": "v3"
}
] | 2023-01-02 | [
[
"Tan",
"Yinghua",
""
],
[
"Zhang",
"Zhenyu",
""
],
[
"Zhou",
"Xiang",
""
]
] | Rare electromagnetic decays of charmed mesons are useful laboratories to explore the structure of hadronic states and the interactions between photon and charmed mesons, to test the chiral perturbation theory in flavor sector and to search for new physics including dark photons. In this paper, we calculate the relative branching ratios of electromagnetic Dalitz decays $D_{(s)}^\ast\to D_{(s)}\ell^+\ell^-$ to their corresponding radiative decays $D_{(s)}^\ast\to D_{(s)}\gamma$, the dileptonic invariant mass spectra and the leptonic angular distributions with transition form factor in Vector-Meson Dominance model, where $D_{(s)}^\ast$ represents $D^\ast(2007)^0$, $D^\ast(2010)^\pm$, $D^\ast(2640)^\pm$, $D_s^{\ast\pm}$, $D_{s1}^\ast(2700)^\pm$ and $D_{s1}^\ast(2860)^\pm$. |
hep-ph/0509143 | Vali Bashiry | V. Bashiry | B^-_c->\eta' \ell^- \bar{\nu} decay and lepton polarization asymmetry | 12 pages, 8 figures | Eur.Phys.J.C47:423-428,2006 | 10.1140/epjc/s2006-02598-2 | null | hep-ph | null | In this paper we study the lepton polarization asymmetry for the simileptonic
OZI-forbidden annihilation B^-_c->\eta' \ell^- \bar{\nu} decay where \ell=\mu,
\tau. Our results show that the branching ratio turn out to be of order
10^{-4}. Beside, we find that longitudinal, transversal and normal components
of lepton polarizations can be measured for both \mu and \tau decay modes in
the future experiments at the LHC.
| [
{
"created": "Wed, 14 Sep 2005 11:01:18 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Feb 2007 10:45:25 GMT",
"version": "v2"
}
] | 2009-01-07 | [
[
"Bashiry",
"V.",
""
]
] | In this paper we study the lepton polarization asymmetry for the simileptonic OZI-forbidden annihilation B^-_c->\eta' \ell^- \bar{\nu} decay where \ell=\mu, \tau. Our results show that the branching ratio turn out to be of order 10^{-4}. Beside, we find that longitudinal, transversal and normal components of lepton polarizations can be measured for both \mu and \tau decay modes in the future experiments at the LHC. |
2406.02281 | Chaja Baruch | C. Baruch, P. B. Changala, Y. Shagam, and Y. Soreq | Constraining P and T Violating Forces with Chiral Molecules | 12 pages, 5 figures | null | null | null | hep-ph hep-ex physics.atom-ph physics.chem-ph | http://creativecommons.org/licenses/by/4.0/ | New sources of parity and time reversal violation are predicted by well
motivated extensions of the Standard Model and can be effectively probed by
precision spectroscopy of atoms and molecules. Chiral molecules have
distinguished enantiomers which are related by parity transformation. Thus,
they are promising candidates to search for parity violation at molecular
scales, yet to be observed. In this work, we show that precision spectroscopy
of the hyperfine structure of chiral molecules is sensitive to new physics
sources of parity and time reversal violation. In particular, such a study can
be sensitive to regions unexplored by terrestial experiments of a new chiral
spin-1 particle that couples to nucleons. We explore the potential to hunt for
time reversal violation in chiral molecules and show that it can be a
complementary measurement to other probes. We assess the feasibility of such
hyperfine metrology and project the sensitivity in CHDBrI$^+$.
| [
{
"created": "Tue, 4 Jun 2024 12:54:34 GMT",
"version": "v1"
}
] | 2024-06-05 | [
[
"Baruch",
"C.",
""
],
[
"Changala",
"P. B.",
""
],
[
"Shagam",
"Y.",
""
],
[
"Soreq",
"Y.",
""
]
] | New sources of parity and time reversal violation are predicted by well motivated extensions of the Standard Model and can be effectively probed by precision spectroscopy of atoms and molecules. Chiral molecules have distinguished enantiomers which are related by parity transformation. Thus, they are promising candidates to search for parity violation at molecular scales, yet to be observed. In this work, we show that precision spectroscopy of the hyperfine structure of chiral molecules is sensitive to new physics sources of parity and time reversal violation. In particular, such a study can be sensitive to regions unexplored by terrestial experiments of a new chiral spin-1 particle that couples to nucleons. We explore the potential to hunt for time reversal violation in chiral molecules and show that it can be a complementary measurement to other probes. We assess the feasibility of such hyperfine metrology and project the sensitivity in CHDBrI$^+$. |
0812.3297 | Oluseyi Latunde-Dada | Oluseyi Latunde-Dada | The POWHEG method applied to top pair production and decays at the ILC | 6 pages, 3 figures | null | null | Cavendish-HEP-08/18 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of gluon radiation in top pair production and their
decays for e+e- annihilation at the ILC. To achieve this we apply the POWHEG
method and interface our results to the Monte Carlo event generator Herwig++.
We consider a center-of-mass energy of 500GeV and compare decay correlations
and bottom quark distributions before hadronization.
| [
{
"created": "Wed, 17 Dec 2008 14:00:24 GMT",
"version": "v1"
}
] | 2008-12-18 | [
[
"Latunde-Dada",
"Oluseyi",
""
]
] | We study the effects of gluon radiation in top pair production and their decays for e+e- annihilation at the ILC. To achieve this we apply the POWHEG method and interface our results to the Monte Carlo event generator Herwig++. We consider a center-of-mass energy of 500GeV and compare decay correlations and bottom quark distributions before hadronization. |
2107.13580 | Keping Xie | Keping Xie, T. J. Hobbs, Tie-Jiun Hou, Carl Schmidt, Mengshi Yan, and
C.-P. Yuan | The photon content of the proton in the CT18 global analysis | Submission to SciPost | null | null | MSUHEP-21-015, PITT-PACC-2116, SMU-HEP-21-11 | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, two photon PDF sets based on implementations of the LUX ansatz into
the CT18 global analysis were released. In CT18lux, the photon PDF is
calculated directly using the LUX master formula for all scales, $\mu$. In an
alternative realization, CT18qed, the photon PDF is initialized at the starting
scale, $\mu_0$, using the LUX formulation and evolved to higher scales
$\mu(>\mu_0)$ with a combined QED+QCD kernel at
$\mathcal{O}(\alpha),~\mathcal{O}(\alpha\alpha_s)$ and $\mathcal{O}(\alpha^2)$.
In the small-$x$ region, the photon PDF uncertainty is mainly induced by the
quark and gluon PDFs, through the perturbative DIS structure functions. In
comparison, the large-$x$ photon uncertainty comes from various low-energy,
nonperturbative contributions, including variations of the inelastic structure
functions in the resonance and continuum regions, higher-twist and target-mass
corrections, and elastic electromagnetic form factors of the proton. We take
the production of doubly-charged Higgs pairs, $(H^{++}H^{--})$, as an example
of scenarios beyond the Standard Model to illustrate the phenomenological
implications of these photon PDFs at the LHC.
| [
{
"created": "Wed, 28 Jul 2021 18:03:03 GMT",
"version": "v1"
}
] | 2021-07-30 | [
[
"Xie",
"Keping",
""
],
[
"Hobbs",
"T. J.",
""
],
[
"Hou",
"Tie-Jiun",
""
],
[
"Schmidt",
"Carl",
""
],
[
"Yan",
"Mengshi",
""
],
[
"Yuan",
"C. -P.",
""
]
] | Recently, two photon PDF sets based on implementations of the LUX ansatz into the CT18 global analysis were released. In CT18lux, the photon PDF is calculated directly using the LUX master formula for all scales, $\mu$. In an alternative realization, CT18qed, the photon PDF is initialized at the starting scale, $\mu_0$, using the LUX formulation and evolved to higher scales $\mu(>\mu_0)$ with a combined QED+QCD kernel at $\mathcal{O}(\alpha),~\mathcal{O}(\alpha\alpha_s)$ and $\mathcal{O}(\alpha^2)$. In the small-$x$ region, the photon PDF uncertainty is mainly induced by the quark and gluon PDFs, through the perturbative DIS structure functions. In comparison, the large-$x$ photon uncertainty comes from various low-energy, nonperturbative contributions, including variations of the inelastic structure functions in the resonance and continuum regions, higher-twist and target-mass corrections, and elastic electromagnetic form factors of the proton. We take the production of doubly-charged Higgs pairs, $(H^{++}H^{--})$, as an example of scenarios beyond the Standard Model to illustrate the phenomenological implications of these photon PDFs at the LHC. |
hep-ph/0203103 | Nicos Stefanis | N. G. Stefanis (U. of Bochum) | Perturbative logarithms and power corrections in QCD hadronic functions.
A unifying approach | 14 pages; 2 figures containing 3 EPS files; RevTex style; to appear
by Springer Verlag as Lecture Notes in Physics. V2: The following equations
have been corrected: second line of (26), (34), (39), (44), (45); values of
a_0, a_1, a_2 below (40) corrected; Conclusions unchanged. See also
hep-ph/0101031 | Lect.Notes Phys. 616 (2003) 153-166 | null | RUB-TPII-01/02 | hep-ph | null | I present a unifying scheme for hadronic functions that comprises logarithmic
corrections due to gluon emission in perturbative QCD, as well as power-behaved
corrections of nonperturbative origin. The latter are derived by demanding that
perturbatively resummed partonic observables should be analytic in the whole
$Q^2$-plane if they are to be related to physical observables measured in
experiments. I also show phenomenological consequences of this approach. The
focus is on the electromagnetic pion form factor to illustrate both effects,
Sudakov logarithms and power corrections in leading order of
$\Lambda_{\rm{QCD}}^2/Q^2$. The same approach applied to the inclusive
Drell-Yan cross section enables us to perform an absolutely normalized
calculation of the leading power correction in $b^2\Lambda_{\rm{QCD}}^2$ (b
being the impact parameter), which after exponentiation, gives rise to a
nonperturbative Sudakov-type contribution that provides enhancement rather than
suppression, hence partly counteracting the perturbative Sudakov suppression.
| [
{
"created": "Mon, 11 Mar 2002 18:29:08 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Mar 2006 12:23:08 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Stefanis",
"N. G.",
"",
"U. of Bochum"
]
] | I present a unifying scheme for hadronic functions that comprises logarithmic corrections due to gluon emission in perturbative QCD, as well as power-behaved corrections of nonperturbative origin. The latter are derived by demanding that perturbatively resummed partonic observables should be analytic in the whole $Q^2$-plane if they are to be related to physical observables measured in experiments. I also show phenomenological consequences of this approach. The focus is on the electromagnetic pion form factor to illustrate both effects, Sudakov logarithms and power corrections in leading order of $\Lambda_{\rm{QCD}}^2/Q^2$. The same approach applied to the inclusive Drell-Yan cross section enables us to perform an absolutely normalized calculation of the leading power correction in $b^2\Lambda_{\rm{QCD}}^2$ (b being the impact parameter), which after exponentiation, gives rise to a nonperturbative Sudakov-type contribution that provides enhancement rather than suppression, hence partly counteracting the perturbative Sudakov suppression. |
1006.1276 | Ma Yong-Liang | Yong-Liang Ma | Estimates for X(4350) Decays from the Effective Lagrangian Approach | 15 pages, 4 eps figures | Phys.Rev.D82:015013,2010 | 10.1103/PhysRevD.82.015013 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The strong and electromagnetic decays of $X(4350)$ with quantum numbers $J^P
=0^{++}$ and $2^{++}$ have been studied by using the effective Lagrangian
approach. The coupling constant between $X(4350)$ and $D_s^{\ast}D_{s0}^{\ast}$
is determined with the help of the compositeness condition which means that
$X(4350)$ is a bound state of $D_s^{\ast}D_{s0}^{\ast}$. Other coupling
constants applied in the calculation are determined phenomenologically. Our
numerical results show that, using the present data within the present model,
the possibility that $X(4350)$ is a $D_s^{\ast}D_{s0}^{\ast}$ molecule can not
be ruled out.
| [
{
"created": "Mon, 7 Jun 2010 15:24:28 GMT",
"version": "v1"
}
] | 2014-11-21 | [
[
"Ma",
"Yong-Liang",
""
]
] | The strong and electromagnetic decays of $X(4350)$ with quantum numbers $J^P =0^{++}$ and $2^{++}$ have been studied by using the effective Lagrangian approach. The coupling constant between $X(4350)$ and $D_s^{\ast}D_{s0}^{\ast}$ is determined with the help of the compositeness condition which means that $X(4350)$ is a bound state of $D_s^{\ast}D_{s0}^{\ast}$. Other coupling constants applied in the calculation are determined phenomenologically. Our numerical results show that, using the present data within the present model, the possibility that $X(4350)$ is a $D_s^{\ast}D_{s0}^{\ast}$ molecule can not be ruled out. |
1003.0986 | Thomas Gehrmann | Ansgar Denner, Stefan Dittmaier, Thomas Gehrmann, Christian Kurz | Electroweak corrections to hadronic event shapes and jet production in
e+e- annihilation | 47 pages, 20 figures | Nucl.Phys.B836:37-90,2010 | 10.1016/j.nuclphysb.2010.04.009 | FR-PHENO-2010-15, PSI-PR-10-06, ZU-TH 04/10 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a complete calculation of the electroweak O(alpha^3 alpha_s)
corrections to three-jet production and related event-shape observables at
electron--positron colliders. The Z-boson resonance is described within the
complex-mass scheme, rendering the calculation valid both in the resonance and
off-shell regions. Higher-order initial-state radiation is included in the
leading-logarithmic approximation. We properly account for the corrections to
the total hadronic cross section and for the experimental photon isolation
criteria. To this end we implement contributions of the quark-to-photon
fragmentation function both in the slicing and subtraction formalism. The
effects of the electroweak corrections on various event-shape distributions and
on the three-jet rate are studied. They are typically at the few-per-cent
level, and remnants of the radiative return are found even after inclusion of
appropriate cuts.
| [
{
"created": "Thu, 4 Mar 2010 13:50:17 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Denner",
"Ansgar",
""
],
[
"Dittmaier",
"Stefan",
""
],
[
"Gehrmann",
"Thomas",
""
],
[
"Kurz",
"Christian",
""
]
] | We present a complete calculation of the electroweak O(alpha^3 alpha_s) corrections to three-jet production and related event-shape observables at electron--positron colliders. The Z-boson resonance is described within the complex-mass scheme, rendering the calculation valid both in the resonance and off-shell regions. Higher-order initial-state radiation is included in the leading-logarithmic approximation. We properly account for the corrections to the total hadronic cross section and for the experimental photon isolation criteria. To this end we implement contributions of the quark-to-photon fragmentation function both in the slicing and subtraction formalism. The effects of the electroweak corrections on various event-shape distributions and on the three-jet rate are studied. They are typically at the few-per-cent level, and remnants of the radiative return are found even after inclusion of appropriate cuts. |
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