id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2002.07517 | Cem Salih Un | Mario Gomez, Qaisar Shafi and Cem Salih Un | Testing Yukawa Unification at LHC Run-3 and HL-LHC | null | null | 10.1007/JHEP07(2020)096 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore $t-b-\tau$ Yukawa unification (YU) in a supersymmetric $SU(4)_c
\times SU(2)_L \times SU(2)_R $ model without imposing a discrete left-right
(L-R) symmetry. A number of interesting solutions that are compatible with
$t-b-\tau$ YU, LSP neutralino dark matter (DM), and LHC and other experimental
constraints are identified. In particular, they include gluino-neutralino and
stau-neutralino co-annihilation scenarios, where the NLSP gluino mass can range
from 1-3 TeV. Higgsino-like dark matter solutions are also identified for which
gluino masses can approach 5 TeV or so. This scenario will be tested at LHC
Run-3 and its future upgrades.
| [
{
"created": "Tue, 18 Feb 2020 12:26:58 GMT",
"version": "v1"
}
] | 2020-08-26 | [
[
"Gomez",
"Mario",
""
],
[
"Shafi",
"Qaisar",
""
],
[
"Un",
"Cem Salih",
""
]
] | We explore $t-b-\tau$ Yukawa unification (YU) in a supersymmetric $SU(4)_c \times SU(2)_L \times SU(2)_R $ model without imposing a discrete left-right (L-R) symmetry. A number of interesting solutions that are compatible with $t-b-\tau$ YU, LSP neutralino dark matter (DM), and LHC and other experimental constraints are identified. In particular, they include gluino-neutralino and stau-neutralino co-annihilation scenarios, where the NLSP gluino mass can range from 1-3 TeV. Higgsino-like dark matter solutions are also identified for which gluino masses can approach 5 TeV or so. This scenario will be tested at LHC Run-3 and its future upgrades. |
1108.5662 | Christopher Coleman-Smith | C.E.Coleman-Smith, G-Y.Qin, S.A.Bass and B.Muller | Jet Modification in a Brick of QGP Matter | Presented at Panic 11 | null | 10.1063/1.3700711 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have implemented the LPM effect into a microscopic transport model with
partonic degrees of freedom by following the algorithm of Zapp & Wiedemann. The
Landau-Pomeranchuk-Migdal (LPM) effect is a quantum interference process that
modifies the emission of radiation in the presence of a dense medium. In QCD
this results in a quadratic length dependence for radiative energy loss. This
is an important effect for the modification of jets by their passage through
the QGP.
We verify the leading parton energy loss in the model against the leading
order Baier-Dokshitzer-Mueller-Peigne-Schiff-Zakharov (BDMPS-Z) result.
We apply our model to the recent observations of the modification of di-jets
at the LHC.
| [
{
"created": "Mon, 29 Aug 2011 17:22:28 GMT",
"version": "v1"
}
] | 2015-05-30 | [
[
"Coleman-Smith",
"C. E.",
""
],
[
"Qin",
"G-Y.",
""
],
[
"Bass",
"S. A.",
""
],
[
"Muller",
"B.",
""
]
] | We have implemented the LPM effect into a microscopic transport model with partonic degrees of freedom by following the algorithm of Zapp & Wiedemann. The Landau-Pomeranchuk-Migdal (LPM) effect is a quantum interference process that modifies the emission of radiation in the presence of a dense medium. In QCD this results in a quadratic length dependence for radiative energy loss. This is an important effect for the modification of jets by their passage through the QGP. We verify the leading parton energy loss in the model against the leading order Baier-Dokshitzer-Mueller-Peigne-Schiff-Zakharov (BDMPS-Z) result. We apply our model to the recent observations of the modification of di-jets at the LHC. |
hep-ph/0104181 | Ernest Ma | Ernest Ma (UC Riverside) | Quark Mass Matrices from a Softly Broken U(1) Symmetry | 10 pages, no figure | Phys.Lett.B516:165-170,2001 | 10.1016/S0370-2693(01)00910-8 | UCRHEP-T305 (April 2001) | hep-ph | null | Assigning U(1) charges to the quarks of the standard model, and allowing one
extra scalar doublet with m^2 > 0, the correct pattern of the up and down quark
mass matrices is obtained, together with their charged-current mixing matrix.
| [
{
"created": "Wed, 18 Apr 2001 16:08:26 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] | Assigning U(1) charges to the quarks of the standard model, and allowing one extra scalar doublet with m^2 > 0, the correct pattern of the up and down quark mass matrices is obtained, together with their charged-current mixing matrix. |
1408.4652 | Marco Frasca | Marco Frasca | Ground state of Yang-Mills theory in 2+1 dimensions | 16 pages, no figure. Added references | null | null | null | hep-ph hep-th math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Yang-Mills theory in 2+1 dimensions showed to be a research area yielding
firm results in theoretical physics when compared to lattice computations.
Recent analysis displayed astonishing agreement for the value of the string
tension and excellent comparison for the spectrum. This successful approach can
be put at test with a different theoretical framework that we devised in our
preceding work for the scalar field theory in the strong coupling limit. The
confirmations we get are really striking supporting it in full. As a by-product
we are also able to show how AdS/CFT approach, with a description using flux
tubes, is supported exactly as expected in the Isgur-Paton model with a
dimensionless correction factor for the ground state of the theory already
determined in lattice computations.
| [
{
"created": "Wed, 20 Aug 2014 13:42:36 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Aug 2014 15:01:36 GMT",
"version": "v2"
}
] | 2014-08-26 | [
[
"Frasca",
"Marco",
""
]
] | Yang-Mills theory in 2+1 dimensions showed to be a research area yielding firm results in theoretical physics when compared to lattice computations. Recent analysis displayed astonishing agreement for the value of the string tension and excellent comparison for the spectrum. This successful approach can be put at test with a different theoretical framework that we devised in our preceding work for the scalar field theory in the strong coupling limit. The confirmations we get are really striking supporting it in full. As a by-product we are also able to show how AdS/CFT approach, with a description using flux tubes, is supported exactly as expected in the Isgur-Paton model with a dimensionless correction factor for the ground state of the theory already determined in lattice computations. |
1306.2944 | Yang Bai | Yang Bai and Hsin-Chia Cheng | A Holographic Model of Heavy-light Mesons | 31 pages, 2 figures | null | 10.1007/JHEP08(2013)074 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct a holographic model of heavy-light mesons by extending the
AdS/QCD to incorporate the behavior of the heavy quark limit. In that limit,
the QCD dynamics is governed by the light quark and the heavy quark simply
plays the role of a static color source. The heavy quark spin symmetry can be
treated as a global symmetry in the AdS bulk. As a consequence, the heavy-light
mesons are mapped to "fermions" in the AdS theory. The light flavor chiral
symmetry is naturally built in by this construction, and its breaking produces
the splitting of the parity-doubled heavy-light meson states. The scaling
dependences of physical quantities on the heavy quark mass in the heavy quark
effective theory are reproduced. The mass spectra and decay constants of the B
and D mesons can be well fit by suitable choices of model parameters. The
couplings between the heavy-light mesons and the pions are also calculated. The
holographic model may capture the essence of the long distance effects of QCD
and can serve as a useful tool for studying the non-perturbative hadronic
matrix elements involving heavy-light mesons.
| [
{
"created": "Wed, 12 Jun 2013 20:00:02 GMT",
"version": "v1"
}
] | 2015-06-16 | [
[
"Bai",
"Yang",
""
],
[
"Cheng",
"Hsin-Chia",
""
]
] | We construct a holographic model of heavy-light mesons by extending the AdS/QCD to incorporate the behavior of the heavy quark limit. In that limit, the QCD dynamics is governed by the light quark and the heavy quark simply plays the role of a static color source. The heavy quark spin symmetry can be treated as a global symmetry in the AdS bulk. As a consequence, the heavy-light mesons are mapped to "fermions" in the AdS theory. The light flavor chiral symmetry is naturally built in by this construction, and its breaking produces the splitting of the parity-doubled heavy-light meson states. The scaling dependences of physical quantities on the heavy quark mass in the heavy quark effective theory are reproduced. The mass spectra and decay constants of the B and D mesons can be well fit by suitable choices of model parameters. The couplings between the heavy-light mesons and the pions are also calculated. The holographic model may capture the essence of the long distance effects of QCD and can serve as a useful tool for studying the non-perturbative hadronic matrix elements involving heavy-light mesons. |
hep-ph/0106113 | A. Khare | F. Cooper, A. Khare and H. Rose | Classical Limit of Time-Dependent Quantum Field Theory-a Schwinger-Dyson
Approach | 13 pages, no figures, minor modification in few equations | Phys.Lett. B515 (2001) 463-469 | 10.1016/S0370-2693(01)00872-3 | IP/BBSR/01-13 | hep-ph cond-mat hep-th | null | We rewrite the Martin-Siggia-Rose (MSR) formalism for the statistical
dynamics of classical fields in a covariant second order form appropriate for
the statistical dynamics of relativistic field theory. This second order
formalism is related to a rotation of Schwinger's closed time path (CTP)
formalism for quantum dynamics, with the main difference being that certain
vertices are absent in the classical theory. These vertices are higher order in
an $\hbar$ expansion. The structure of the second order formulation of the
Schwinger Dyson (S-D) equations is identical to that of the rotated CTP
formalism apart from initial conditions on the Green's functions and the
absence of these vertices. We then discuss self-consistent truncation schemes
based on keeping certain graphs in the two-particle irreducible effective
action made up of bare vertices and exact Green's functions.
| [
{
"created": "Mon, 11 Jun 2001 15:31:41 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Jun 2001 14:48:25 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Cooper",
"F.",
""
],
[
"Khare",
"A.",
""
],
[
"Rose",
"H.",
""
]
] | We rewrite the Martin-Siggia-Rose (MSR) formalism for the statistical dynamics of classical fields in a covariant second order form appropriate for the statistical dynamics of relativistic field theory. This second order formalism is related to a rotation of Schwinger's closed time path (CTP) formalism for quantum dynamics, with the main difference being that certain vertices are absent in the classical theory. These vertices are higher order in an $\hbar$ expansion. The structure of the second order formulation of the Schwinger Dyson (S-D) equations is identical to that of the rotated CTP formalism apart from initial conditions on the Green's functions and the absence of these vertices. We then discuss self-consistent truncation schemes based on keeping certain graphs in the two-particle irreducible effective action made up of bare vertices and exact Green's functions. |
2008.08434 | Kei Suzuki | Yasufumi Araki, Daiki Suenaga, Kei Suzuki, Shigehiro Yasui | Two relativistic Kondo effects: Classification with particle and
antiparticle impurities | 14 pages, 2 figures, 1 table; published version | Phys. Rev. Research 3, 013233 (2021) | 10.1103/PhysRevResearch.3.013233 | RIKEN-iTHEMS-Report-20 | hep-ph cond-mat.mes-hall cond-mat.str-el | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate two different types of relativistic Kondo effects,
distinguished by heavy-impurity degrees of freedom, by focusing on the
energy-momentum dispersion relations of the ground state with condensates
composed of a light Dirac fermion and a nonrelativistic impurity fermion. Heavy
fermion degrees of freedom are introduced in terms of two types of
heavy-fermion effective theories, in other words, two heavy-fermion limits for
the heavy Dirac fermion, which are known as the heavy-quark effective theories
(HQETs) in high-energy physics. While the first one includes only the
heavy-particle component, the second one contains both the heavy-particle and
heavy-antiparticle components, which are opposite in their parity. From these
theories, we obtain two types of Kondo effects, in which the dispersions near
the Fermi surface are very similar, but they differ in the structure at low
momentum. We also classify the possible forms of condensates in the two limits.
The two Kondo effects will be examined by experiments with Dirac/Weyl
semimetals or quark matter, lattice simulations, and cold-atom simulations.
| [
{
"created": "Wed, 19 Aug 2020 13:37:11 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Mar 2021 11:41:39 GMT",
"version": "v2"
}
] | 2021-03-17 | [
[
"Araki",
"Yasufumi",
""
],
[
"Suenaga",
"Daiki",
""
],
[
"Suzuki",
"Kei",
""
],
[
"Yasui",
"Shigehiro",
""
]
] | We investigate two different types of relativistic Kondo effects, distinguished by heavy-impurity degrees of freedom, by focusing on the energy-momentum dispersion relations of the ground state with condensates composed of a light Dirac fermion and a nonrelativistic impurity fermion. Heavy fermion degrees of freedom are introduced in terms of two types of heavy-fermion effective theories, in other words, two heavy-fermion limits for the heavy Dirac fermion, which are known as the heavy-quark effective theories (HQETs) in high-energy physics. While the first one includes only the heavy-particle component, the second one contains both the heavy-particle and heavy-antiparticle components, which are opposite in their parity. From these theories, we obtain two types of Kondo effects, in which the dispersions near the Fermi surface are very similar, but they differ in the structure at low momentum. We also classify the possible forms of condensates in the two limits. The two Kondo effects will be examined by experiments with Dirac/Weyl semimetals or quark matter, lattice simulations, and cold-atom simulations. |
1810.12432 | Laurent Forthomme | Marta {\L}uszczak, Laurent Forthomme, Wolfgang Sch\"afer, Antoni
Szczurek | Production of $t\bar t$ pairs via $\gamma\gamma$ fusion with photon
transverse momenta and proton dissociation | 12 pages, 11 figures | null | 10.1007/JHEP02(2019)100 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the production of $t\bar t$ quark-antiquark pairs in proton-proton
collisions via the $\gamma\gamma$ fusion mechanism. We include topologies in
which both protons stay intact or one or even both of them undergo
dissociation. The calculations are performed within the $k_{\rm
T}$-factorisation approach, including transverse momenta of intermediate
photons. Photon fluxes associated to inelastic (dissociative) processes are
calculated based on modern parameterisations of proton structure functions. We
find an integrated cross section of about 2.36 fb at $\sqrt{s}=$ 13 TeV for all
contributions. The cross section for the fully elastic process is the smallest.
Inelastic contributions are significantly reduced when a veto on outgoing jets
is imposed. We present several differential distributions in rapidity and
transverse momenta of single $t$ or $\bar t$ quarks/antiquarks as well as
distributions in invariant mass of both the $t\bar t$ and masses of dissociated
systems. A few two-dimensional distributions are presented in addition.
| [
{
"created": "Mon, 29 Oct 2018 22:10:03 GMT",
"version": "v1"
}
] | 2019-03-27 | [
[
"Łuszczak",
"Marta",
""
],
[
"Forthomme",
"Laurent",
""
],
[
"Schäfer",
"Wolfgang",
""
],
[
"Szczurek",
"Antoni",
""
]
] | We discuss the production of $t\bar t$ quark-antiquark pairs in proton-proton collisions via the $\gamma\gamma$ fusion mechanism. We include topologies in which both protons stay intact or one or even both of them undergo dissociation. The calculations are performed within the $k_{\rm T}$-factorisation approach, including transverse momenta of intermediate photons. Photon fluxes associated to inelastic (dissociative) processes are calculated based on modern parameterisations of proton structure functions. We find an integrated cross section of about 2.36 fb at $\sqrt{s}=$ 13 TeV for all contributions. The cross section for the fully elastic process is the smallest. Inelastic contributions are significantly reduced when a veto on outgoing jets is imposed. We present several differential distributions in rapidity and transverse momenta of single $t$ or $\bar t$ quarks/antiquarks as well as distributions in invariant mass of both the $t\bar t$ and masses of dissociated systems. A few two-dimensional distributions are presented in addition. |
2004.06727 | Seyda Ipek | Dillon Berger, Seyda Ipek, Tim M.P. Tait, Michael Waterbury | Dark Matter Freeze Out during an Early Cosmological Period of QCD
Confinement | null | JHEP 07 (2020) 192 | 10.1007/JHEP07(2020)192 | UCI-HEP-TR-2020-02 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Standard lore states that there is tension between the need to accommodate
the relic density of a weakly interacting massive particle and direct searches
for dark matter. However, the estimation of the relic density rests on an
extrapolation of the cosmology of the early Universe to the time of freeze out,
untethered by observations. We explore a nonstandard cosmology in which the
strong coupling constant evolves in the early Universe, triggering an early
period of QCD confinement at the time of freeze out. We find that depending on
the nature of the interactions between the dark matter and the Standard Model,
freeze out during an early period of confinement can lead to drastically
different expectations for the relic density, allowing for regions of parameter
space which realize the correct abundance but would otherwise be excluded by
direct searches.
| [
{
"created": "Tue, 14 Apr 2020 18:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Jul 2020 02:30:01 GMT",
"version": "v2"
}
] | 2020-08-03 | [
[
"Berger",
"Dillon",
""
],
[
"Ipek",
"Seyda",
""
],
[
"Tait",
"Tim M. P.",
""
],
[
"Waterbury",
"Michael",
""
]
] | Standard lore states that there is tension between the need to accommodate the relic density of a weakly interacting massive particle and direct searches for dark matter. However, the estimation of the relic density rests on an extrapolation of the cosmology of the early Universe to the time of freeze out, untethered by observations. We explore a nonstandard cosmology in which the strong coupling constant evolves in the early Universe, triggering an early period of QCD confinement at the time of freeze out. We find that depending on the nature of the interactions between the dark matter and the Standard Model, freeze out during an early period of confinement can lead to drastically different expectations for the relic density, allowing for regions of parameter space which realize the correct abundance but would otherwise be excluded by direct searches. |
0910.4872 | Clemens Kie{\ss}ig | Clemens P. Kiessig, Michael Plumacher | Thermal masses in leptogenesis | 4 pages, 2 figures, proceedings of SUSY 20y09 | AIP Conf.Proc.1200:999-1002,2010 | 10.1063/1.3327783 | MPP-2009-173 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the validity of using thermal masses in the kinematics of
final states in the decay rate of heavy neutrinos in leptogenesis calculations.
We find that using thermal masses this way is a reasonable approximation, but
corrections arise through quantum statistical distribution functions and
leptonic quasiparticles.
| [
{
"created": "Mon, 26 Oct 2009 13:27:29 GMT",
"version": "v1"
}
] | 2015-05-14 | [
[
"Kiessig",
"Clemens P.",
""
],
[
"Plumacher",
"Michael",
""
]
] | We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles. |
hep-ph/9402354 | Zpli | Leonard S. Kisslinger and Zhenping Li | The Isospin Splittings of Heavy-Light Quark Systems | 9 pages and 1 postscript figure file can be obtained from the author | null | null | null | hep-ph | null | The mass splittings of the pseudoscalar and vector D and B light-heavy quark
systems have been calculated using the method of QCD sum rules.
Electromagnetic, quark mass, and nonperturbative QCD effects are all included.
The results are in good agreement with experiment. A measurement of isospin
splitting for the vector B mesons would give valuable information about quark
mass splittings.
| [
{
"created": "Fri, 25 Feb 1994 19:49:22 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Kisslinger",
"Leonard S.",
""
],
[
"Li",
"Zhenping",
""
]
] | The mass splittings of the pseudoscalar and vector D and B light-heavy quark systems have been calculated using the method of QCD sum rules. Electromagnetic, quark mass, and nonperturbative QCD effects are all included. The results are in good agreement with experiment. A measurement of isospin splitting for the vector B mesons would give valuable information about quark mass splittings. |
0909.5257 | Junichi Kanzaki | K. Hagiwara, J. Kanzaki, N. Okamura, D. Rainwater, T. Stelzer | Calculation of HELAS amplitudes for QCD processes using graphics
processing unit (GPU) | null | Eur.Phys.J.C70:513-524,2010 | 10.1140/epjc/s10052-010-1465-5 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use a graphics processing unit (GPU) for fast calculations of helicity
amplitudes of quark and gluon scattering processes in massless QCD. New HEGET
({\bf H}ELAS {\bf E}valuation with {\bf G}PU {\bf E}nhanced {\bf T}echnology)
codes for gluon self-interactions are introduced, and a C++ program to convert
the MadGraph generated FORTRAN codes into HEGET codes in CUDA (a C-platform for
general purpose computing on GPU) is created. Because of the proliferation of
the number of Feynman diagrams and the number of independent color amplitudes,
the maximum number of final state jets we can evaluate on a GPU is limited to 4
for pure gluon processes ($gg\to 4g$), or 5 for processes with one or more
quark lines such as $q\bar{q}\to 5g$ and $qq\to qq+3g$. Compared with the usual
CPU-based programs, we obtain 60-100 times better performance on the GPU,
except for 5-jet production processes and the $gg\to 4g$ processes for which
the GPU gain over the CPU is about 20.
| [
{
"created": "Tue, 29 Sep 2009 03:34:54 GMT",
"version": "v1"
}
] | 2011-02-09 | [
[
"Hagiwara",
"K.",
""
],
[
"Kanzaki",
"J.",
""
],
[
"Okamura",
"N.",
""
],
[
"Rainwater",
"D.",
""
],
[
"Stelzer",
"T.",
""
]
] | We use a graphics processing unit (GPU) for fast calculations of helicity amplitudes of quark and gluon scattering processes in massless QCD. New HEGET ({\bf H}ELAS {\bf E}valuation with {\bf G}PU {\bf E}nhanced {\bf T}echnology) codes for gluon self-interactions are introduced, and a C++ program to convert the MadGraph generated FORTRAN codes into HEGET codes in CUDA (a C-platform for general purpose computing on GPU) is created. Because of the proliferation of the number of Feynman diagrams and the number of independent color amplitudes, the maximum number of final state jets we can evaluate on a GPU is limited to 4 for pure gluon processes ($gg\to 4g$), or 5 for processes with one or more quark lines such as $q\bar{q}\to 5g$ and $qq\to qq+3g$. Compared with the usual CPU-based programs, we obtain 60-100 times better performance on the GPU, except for 5-jet production processes and the $gg\to 4g$ processes for which the GPU gain over the CPU is about 20. |
2209.11670 | Umberto D'Alesio | Umberto D'Alesio, Leonard Gamberg, Francesco Murgia, and Marco
Zaccheddu | Transverse $\Lambda$ polarization in $e^+e^-$ processes within a TMD
factorization approach and the polarizing fragmentation function | 45 pages, 14 figures | null | 10.1007/JHEP12(2022)074 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We perform a re-analysis of Belle data for the transverse $\Lambda$ and
$\bar\Lambda$ polarization in $e^+ e^-$ annihilation processes within a
transverse momentum dependent (TMD) factorization approach. We consider two
data sets, one referring to the associated production of $\Lambda$'s with a
light unpolarized hadron in an almost back-to-back configuration, and one for
the inclusive $\Lambda$ production, with the reconstruction of the thrust axis.
We adopt the Collins-Soper-Sterman framework and employ the recent formulation
on the factorization of single-inclusive hadron production. This extends a
previous phenomenological study carried out in a more simplified TMD approach,
leading to a new extraction of the polarizing fragmentation function (FF).
While confirming several features of the previous analysis, here we include the
proper QCD scale dependence of this TMD FF and carefully exploit the role of
its nonperturbative component. The compatibility, within a unique TMD
factorization scheme, of double and single-inclusive hadron production is
discussed in detail. Moreover, we consider another data set for inclusive
$\Lambda$ production, at much larger energies, from the OPAL Collaboration, in
order to test the consistency of the entire approach. Finally, we elaborate on
some fundamental issues like the role of $SU(2)$ isospin symmetry and the heavy
quark contributions.
| [
{
"created": "Fri, 23 Sep 2022 15:57:34 GMT",
"version": "v1"
}
] | 2022-12-28 | [
[
"D'Alesio",
"Umberto",
""
],
[
"Gamberg",
"Leonard",
""
],
[
"Murgia",
"Francesco",
""
],
[
"Zaccheddu",
"Marco",
""
]
] | We perform a re-analysis of Belle data for the transverse $\Lambda$ and $\bar\Lambda$ polarization in $e^+ e^-$ annihilation processes within a transverse momentum dependent (TMD) factorization approach. We consider two data sets, one referring to the associated production of $\Lambda$'s with a light unpolarized hadron in an almost back-to-back configuration, and one for the inclusive $\Lambda$ production, with the reconstruction of the thrust axis. We adopt the Collins-Soper-Sterman framework and employ the recent formulation on the factorization of single-inclusive hadron production. This extends a previous phenomenological study carried out in a more simplified TMD approach, leading to a new extraction of the polarizing fragmentation function (FF). While confirming several features of the previous analysis, here we include the proper QCD scale dependence of this TMD FF and carefully exploit the role of its nonperturbative component. The compatibility, within a unique TMD factorization scheme, of double and single-inclusive hadron production is discussed in detail. Moreover, we consider another data set for inclusive $\Lambda$ production, at much larger energies, from the OPAL Collaboration, in order to test the consistency of the entire approach. Finally, we elaborate on some fundamental issues like the role of $SU(2)$ isospin symmetry and the heavy quark contributions. |
0908.0507 | Mairon Machado | M. B. Gay Ducati, M. M. Machado, M. V. T. Machado | Diffractive quarkonium production in association with a photon at the
LHC | 5 pages, 2 figures, 1 table | Phys.Lett.B683:150-153,2010 | 10.1016/j.physletb.2009.12.025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The rates for diffractive quarkonium plus prompt-photon associated production
at the LHC are estimated. The theoretical framework considered in the J/Psi (or
Upsilon) production associated with a direct photon at the hadron collider is
the non-relativistic QCD (NRQCD) factorization formalism. The corresponding
single diffractive cross section is computed based on the hard diffractive
scattering factorization supplemented by absorptive corrections. Such processes
are sensitive to the gluon content of the Pomeron at small Bjorken-x and they
may also be a good place to test the different available mechanisms for
quarkonium production at hadron colliders.
| [
{
"created": "Tue, 4 Aug 2009 18:12:16 GMT",
"version": "v1"
}
] | 2010-01-15 | [
[
"Ducati",
"M. B. Gay",
""
],
[
"Machado",
"M. M.",
""
],
[
"Machado",
"M. V. T.",
""
]
] | The rates for diffractive quarkonium plus prompt-photon associated production at the LHC are estimated. The theoretical framework considered in the J/Psi (or Upsilon) production associated with a direct photon at the hadron collider is the non-relativistic QCD (NRQCD) factorization formalism. The corresponding single diffractive cross section is computed based on the hard diffractive scattering factorization supplemented by absorptive corrections. Such processes are sensitive to the gluon content of the Pomeron at small Bjorken-x and they may also be a good place to test the different available mechanisms for quarkonium production at hadron colliders. |
hep-ph/9912461 | Shulyakovsky Roman | V.Kuvshinov and R.Shulyakovsky | Correlation analysis of the instanton-induced particle production in QCD | 5 pages, 5 figures. Talk presented by R.Shulyakovsky at the Int.
Summer School "Particle production spanning MeV and TeV energies" (August
8-20, 1999, Nijmegen, The Netherlands) | null | null | null | hep-ph | null | Factorial, cumulant and $H_q$-moments in dependence on their rank q for the
instanton-induced deep inelastic scattering (DIS) in the frameworks of QCD are
calculated and analysed. The obtained correlation moments behaviour has
specific form, which can be considered as a new criterion of the QCD-instantons
identification on experiment at HERA.
| [
{
"created": "Wed, 22 Dec 1999 12:14:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kuvshinov",
"V.",
""
],
[
"Shulyakovsky",
"R.",
""
]
] | Factorial, cumulant and $H_q$-moments in dependence on their rank q for the instanton-induced deep inelastic scattering (DIS) in the frameworks of QCD are calculated and analysed. The obtained correlation moments behaviour has specific form, which can be considered as a new criterion of the QCD-instantons identification on experiment at HERA. |
hep-ph/0101186 | Dean Lee | Bugra Borasoy (TU Muenchen), Dean Lee (UMass Amherst) | Study of relativistic bound states in a scalar model using
diagonalization/Monte Carlo methods | 19 pages, 11 figures, version to appear in Nucl. Phys. A | Nucl.Phys.A696:537-555,2001 | 10.1016/S0375-9474(01)01127-7 | null | hep-ph hep-lat nucl-th | null | We use a recently proposed diagonalization/Monte Carlo computational scheme
to study relativistic two-body and three-body bound states in 1+1 dimensional
phi^6-phi^4 theory. We find that the approach is well-suited for calculating
bound state energies and wavefunctions.
| [
{
"created": "Wed, 17 Jan 2001 22:35:22 GMT",
"version": "v1"
},
{
"created": "Mon, 28 May 2001 14:55:33 GMT",
"version": "v2"
}
] | 2010-11-19 | [
[
"Borasoy",
"Bugra",
"",
"TU Muenchen"
],
[
"Lee",
"Dean",
"",
"UMass Amherst"
]
] | We use a recently proposed diagonalization/Monte Carlo computational scheme to study relativistic two-body and three-body bound states in 1+1 dimensional phi^6-phi^4 theory. We find that the approach is well-suited for calculating bound state energies and wavefunctions. |
hep-ph/0506137 | Yang Bai | Thomas Appelquist, Yang Bai and Maurizio Piai (Yale U.) | Breaking Discrete Symmetries in Broken Gauge Theories | 9 pages, 1 figure, corrected typos, added a reference | Phys.Rev. D72 (2005) 036005 | 10.1103/PhysRevD.72.036005 | null | hep-ph | null | We study the spontaneous breaking of discrete symmetries in theories with
broken gauge symmetry. The intended application is to CP breaking in theories
with gauged flavor symmetries, but the analysis described here is preliminary.
We dispense with matter fields and take the gauge theory to be weakly coupled
and broken spontaneously by unspecified, short-distance forces. We develop an
effective-field-theory description of the resultant low energy theory, and ask
whether this theory by itself can describe the subsequent breaking of discrete
symmetries. We conclude that this can happen depending on the parameters of the
effective theory, and that the intrinsic violation is naturally of order unity.
| [
{
"created": "Tue, 14 Jun 2005 14:24:24 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Jul 2005 19:23:28 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Appelquist",
"Thomas",
"",
"Yale U."
],
[
"Bai",
"Yang",
"",
"Yale U."
],
[
"Piai",
"Maurizio",
"",
"Yale U."
]
] | We study the spontaneous breaking of discrete symmetries in theories with broken gauge symmetry. The intended application is to CP breaking in theories with gauged flavor symmetries, but the analysis described here is preliminary. We dispense with matter fields and take the gauge theory to be weakly coupled and broken spontaneously by unspecified, short-distance forces. We develop an effective-field-theory description of the resultant low energy theory, and ask whether this theory by itself can describe the subsequent breaking of discrete symmetries. We conclude that this can happen depending on the parameters of the effective theory, and that the intrinsic violation is naturally of order unity. |
hep-ph/9305331 | null | Marc Knecht | Experimental determination of Chiral Symmetry Breaking Parameters | 6 pages, preprint IPNO/TH 93-15, plain Latex | null | null | null | hep-ph | null | In the low energy domain, Chiral Perturbation Theory parametrizes the small
chiral symmetry breaking effects, produced by the quark masses $m_u$, $m_d$ and
$m_s$, in terms of order parameters of massless QCD. The latter can then, in
principle, be measured in high precision, low energy experiments. We discuss
several relevant processes and possible improvements at future high luminosity
tau/charm or K factories. (talk given at the XXVIIIth Rencontres de Moriond on
QCD and High Energy Hadronic Interactions, Les Arcs (France), March 20-27
1993.)
| [
{
"created": "Thu, 27 May 1993 13:56:20 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Knecht",
"Marc",
""
]
] | In the low energy domain, Chiral Perturbation Theory parametrizes the small chiral symmetry breaking effects, produced by the quark masses $m_u$, $m_d$ and $m_s$, in terms of order parameters of massless QCD. The latter can then, in principle, be measured in high precision, low energy experiments. We discuss several relevant processes and possible improvements at future high luminosity tau/charm or K factories. (talk given at the XXVIIIth Rencontres de Moriond on QCD and High Energy Hadronic Interactions, Les Arcs (France), March 20-27 1993.) |
0709.4650 | Covi Laura | Wilfried Buchmuller, Laura Covi, David Emmanuel-Costa and Soren
Wiesenfeldt | CP Violation and Neutrino Masses and Mixings from Quark Mass Hierarchies | v2: typos corrected, references updated. 42 pages, 1 figure, LaTeX
with JHEP3.cls | JHEP 0712:030,2007 | 10.1088/1126-6708/2007/12/030 | DESY 07-141 | hep-ph | null | We study the connection between quark and lepton mass matrices in a
supersymmetric SO(10) GUT model in six dimensions, compactified on an orbifold.
The physical quarks and leptons are mixtures of brane and bulk states. This
leads to a characteristic pattern of mass matrices and high-energy CP violating
phases. The hierarchy of up and down quark masses determines the CKM matrix and
most charged lepton and neutrino masses and mixings. The small hierarchy of
neutrino masses is a consequence of the mismatch of the up and down quark mass
hierarchies. The effective CP violating phases in the quark sector, neutrino
oscillations and leptogenesis are unrelated. In the neutrino sector we can
accomodate naturally $\sin \theta_{23} \sim 1$, $\sin \theta_{13} \lesssim 0.1$
and $m_1 \lesssim m_2 \sim \sqrt{\Delta m^2_\text{sol}} < m_3 \sim \sqrt{\Delta
m^2_\text{atm}}$.
| [
{
"created": "Fri, 28 Sep 2007 16:26:13 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Oct 2007 12:16:13 GMT",
"version": "v2"
}
] | 2009-01-06 | [
[
"Buchmuller",
"Wilfried",
""
],
[
"Covi",
"Laura",
""
],
[
"Emmanuel-Costa",
"David",
""
],
[
"Wiesenfeldt",
"Soren",
""
]
] | We study the connection between quark and lepton mass matrices in a supersymmetric SO(10) GUT model in six dimensions, compactified on an orbifold. The physical quarks and leptons are mixtures of brane and bulk states. This leads to a characteristic pattern of mass matrices and high-energy CP violating phases. The hierarchy of up and down quark masses determines the CKM matrix and most charged lepton and neutrino masses and mixings. The small hierarchy of neutrino masses is a consequence of the mismatch of the up and down quark mass hierarchies. The effective CP violating phases in the quark sector, neutrino oscillations and leptogenesis are unrelated. In the neutrino sector we can accomodate naturally $\sin \theta_{23} \sim 1$, $\sin \theta_{13} \lesssim 0.1$ and $m_1 \lesssim m_2 \sim \sqrt{\Delta m^2_\text{sol}} < m_3 \sim \sqrt{\Delta m^2_\text{atm}}$. |
hep-ph/9602379 | D. Indumathi | D. Indumathi (Dortmund University, Germany) | Nuclear Modifications of Double Spin Asymmetries | 9 pages LaTeX, with 2 postscript figures, to appear in Physics
Letters B | Phys.Lett. B374 (1996) 193-198 | 10.1016/0370-2693(96)00166-9 | DO-TH-95/21 | hep-ph | null | We compute nuclear spin dependent structure functions using a dynamical model
for bound nucleon densities and hence calculate nuclear modifications to
asymmetries observed in recent doubly polarised deep inelastic scattering
experiments. We conclude that while the individual densities are changed
substantially by nuclear effects, the asymmetries themselves are largely
insensitive to these changes.
| [
{
"created": "Fri, 23 Feb 1996 12:24:56 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Indumathi",
"D.",
"",
"Dortmund University, Germany"
]
] | We compute nuclear spin dependent structure functions using a dynamical model for bound nucleon densities and hence calculate nuclear modifications to asymmetries observed in recent doubly polarised deep inelastic scattering experiments. We conclude that while the individual densities are changed substantially by nuclear effects, the asymmetries themselves are largely insensitive to these changes. |
hep-ph/0702283 | W. Desmond Ramsay | W.D. Ramsay (for the Qweak Collaboration) | The Qweak Experiment -- A search for new physics at the TeV Scale by
measurement of the proton's weak charge | 7 pages, 4 figures, LaTeX, uses aipproc 8s style -- Invited talk at
XI Workshop on Nuclear Physics (WONP2007) Havana, Cuba, Feb 5-8, 2007 | null | null | TRI-PP-07-02 | hep-ph nucl-ex | null | From a distance, the proton's weak charge is seen through the distorting
effects of clouds of virtual particles. The effective weak charge can be
calculated by starting with the measured weak coupling at the Z-pole and
"running" the coupling to lower energy or, equivalently, longer distances.
Because the "electroweak radiative corrections" or "loop diagrams" which give
rise to the running depend not only on known particles, but on particles which
have not yet been discovered, a difference between the calculated and measured
weak charges may signal new physics. A measurement of Qweak to 4% will be
sensitive to new physics at the few TeV scale. The Qweak experiment is based on
the fact that the parity-violating longitudinal analyzing power, Az, in
electron-proton scattering at low momentum transfer and small scattering angle,
is proportional to the proton's weak charge. The experiment plans to measure
the predicted Az of -0.3 ppm with a combined statistical and systematic
uncertainty of 2.2%, corresponding to a total uncertainty of 4% of Qweak. This
requires a statistical precision of 5 x 10^-9, which can be achieved in 2200
hours with an 85% polarized, 180 microamp electron beam incident on a 0.35 m
liquid hydrogen target. A synchronous data acquisition system will integrate
the detector current signals over each spin state and extract the helicity
correlated, parity violating component.
| [
{
"created": "Wed, 28 Feb 2007 00:07:10 GMT",
"version": "v1"
}
] | 2019-08-14 | [
[
"Ramsay",
"W. D.",
"",
"for the Qweak Collaboration"
]
] | From a distance, the proton's weak charge is seen through the distorting effects of clouds of virtual particles. The effective weak charge can be calculated by starting with the measured weak coupling at the Z-pole and "running" the coupling to lower energy or, equivalently, longer distances. Because the "electroweak radiative corrections" or "loop diagrams" which give rise to the running depend not only on known particles, but on particles which have not yet been discovered, a difference between the calculated and measured weak charges may signal new physics. A measurement of Qweak to 4% will be sensitive to new physics at the few TeV scale. The Qweak experiment is based on the fact that the parity-violating longitudinal analyzing power, Az, in electron-proton scattering at low momentum transfer and small scattering angle, is proportional to the proton's weak charge. The experiment plans to measure the predicted Az of -0.3 ppm with a combined statistical and systematic uncertainty of 2.2%, corresponding to a total uncertainty of 4% of Qweak. This requires a statistical precision of 5 x 10^-9, which can be achieved in 2200 hours with an 85% polarized, 180 microamp electron beam incident on a 0.35 m liquid hydrogen target. A synchronous data acquisition system will integrate the detector current signals over each spin state and extract the helicity correlated, parity violating component. |
hep-ph/0301129 | Hans-Werner Hammer | H.-W. Hammer | Nucleon Strangeness in Dispersion Theory | Invited talk at PAVI02, Mainz, June 5-8 2002, 16 pages, 7 figures,
uses ws-procs9x6.cls | null | null | null | hep-ph nucl-th | null | Dispersion relations provide a powerful tool to describe the low-energy
structure of hadrons. We review the status of the strange vector form factors
of the nucleon in dispersion theory. We also comment on open questions and the
relation to chiral perturbation theory.
| [
{
"created": "Fri, 17 Jan 2003 10:12:07 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Hammer",
"H. -W.",
""
]
] | Dispersion relations provide a powerful tool to describe the low-energy structure of hadrons. We review the status of the strange vector form factors of the nucleon in dispersion theory. We also comment on open questions and the relation to chiral perturbation theory. |
1511.00767 | Na Liu | Na Liu, Wen-Dan Miao, Li-Hua Song, Chun-Gui Duan | Nuclear geometry effect and transport coefficient in semi-inclusive
lepton-production of hadrons off nuclei | 14 pages, 3 figures. arXiv admin note: text overlap with
arXiv:1310.5692 | Phys.Lett. B749 (2015) 88-93 | 10.1016/j.physletb.2015.07.048 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Hadron production in semi-inclusive deep-inelastic scattering of leptons from
nuclei is an ideal tool to determine and constrain the transport coefficient in
cold nuclear matter. The leading-order computations for hadron multiplicity
ratios are performed by means of the SW quenching weights and the analytic
parameterizations of quenching weights based on BDMPS formalism. The
theoretical results are compared to the HERMES positively charged pions
production data with the quarks hadronization occurring outside the nucleus.
With considering the nuclear geometry effect on hadron production, our
predictions are in good agreement with the experimental measurements. The
extracted transport parameter from the global fit is shown to be $\hat{q} =
0.74\pm0.03 GeV^2/fm$ for the SW quenching weight without the finite energy
corrections. As for the analytic parameterization of BDMPS quenching weight
without the quark energy E dependence, the computed transport coefficient is
$\hat{q} = 0.20\pm0.02 GeV^2/fm$. It is found that the nuclear geometry effect
has a significant impact on the transport coefficient in cold nuclear matter.
It is necessary to consider the detailed nuclear geometry in studying the
semi-inclusive hadron production in deep inelastic scattering on nuclear
targets.
| [
{
"created": "Tue, 3 Nov 2015 03:45:54 GMT",
"version": "v1"
}
] | 2015-11-20 | [
[
"Liu",
"Na",
""
],
[
"Miao",
"Wen-Dan",
""
],
[
"Song",
"Li-Hua",
""
],
[
"Duan",
"Chun-Gui",
""
]
] | Hadron production in semi-inclusive deep-inelastic scattering of leptons from nuclei is an ideal tool to determine and constrain the transport coefficient in cold nuclear matter. The leading-order computations for hadron multiplicity ratios are performed by means of the SW quenching weights and the analytic parameterizations of quenching weights based on BDMPS formalism. The theoretical results are compared to the HERMES positively charged pions production data with the quarks hadronization occurring outside the nucleus. With considering the nuclear geometry effect on hadron production, our predictions are in good agreement with the experimental measurements. The extracted transport parameter from the global fit is shown to be $\hat{q} = 0.74\pm0.03 GeV^2/fm$ for the SW quenching weight without the finite energy corrections. As for the analytic parameterization of BDMPS quenching weight without the quark energy E dependence, the computed transport coefficient is $\hat{q} = 0.20\pm0.02 GeV^2/fm$. It is found that the nuclear geometry effect has a significant impact on the transport coefficient in cold nuclear matter. It is necessary to consider the detailed nuclear geometry in studying the semi-inclusive hadron production in deep inelastic scattering on nuclear targets. |
1905.05246 | Emma Slade | Emma Slade | A Monte Carlo analysis of the SMEFT in the top quark sector | 5 pages, 3 figures. Based on 1901.05965. To appear in the proceedings
of the XXVII International Workshop on Deep-Inelastic Scattering and Related
Subjects, 8-12 April, 2019, Torino, Italy | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a framework for carrying out global analyses of the Standard Model
Effective Field Theory: SMEFiT. This approach is based on the Monte Carlo
replica method, widely used in the case of NNPDF fits of the proton structure,
for deriving a faithful estimate of the experimental and theoretical
uncertainties. As a proof of concept of the SMEFiT methodology, we present a
study of the constraints on the SMEFT provided by top quark production
measurements from the LHC. We derive bounds for the 34 degrees of freedom
relevant for the interpretation of the LHC top quark data and compare these
bounds with previously reported constraints.
| [
{
"created": "Mon, 13 May 2019 19:10:51 GMT",
"version": "v1"
}
] | 2019-05-15 | [
[
"Slade",
"Emma",
""
]
] | We present a framework for carrying out global analyses of the Standard Model Effective Field Theory: SMEFiT. This approach is based on the Monte Carlo replica method, widely used in the case of NNPDF fits of the proton structure, for deriving a faithful estimate of the experimental and theoretical uncertainties. As a proof of concept of the SMEFiT methodology, we present a study of the constraints on the SMEFT provided by top quark production measurements from the LHC. We derive bounds for the 34 degrees of freedom relevant for the interpretation of the LHC top quark data and compare these bounds with previously reported constraints. |
hep-ph/9810544 | Wolfgang Ochs | Wolfgang Ochs (MPI fuer Physik) | Multiparticle Production in the Soft Limit and QCD Coherence | Talk at 8th Int. Workshop on Multiparticle Production, Correlations
and Fluctuations, June 14-22, 1998, Matrahaza, Hungary. LaTex, 9 pages, 2
figures | null | null | MPI-PhT/98-81 | hep-ph | null | The production of gluons in a jet is considered in limited phase space,
either with a cut in transverse momentum with respect to the jet axis
$k_\perp<k_\perp^{cut}$ or with a cut in absolute momentum $|\vec{k} |
<k^{cut}$. It is shown in the perturbative QCD calculations that in the soft
limit $k_\perp^{cut} \to 0$ the multiplicity distribution becomes Poissonian,
whereas for $k^{cut} \to 0$ the distribution remains non-Poissonian. The
Poissonian limit is a consequence of the soft gluon coherence in the genuine
multiparticle correlations. We also investigate how incoherent hadronization
processes could possibly modify the predictions for small cut-off parameters.
| [
{
"created": "Fri, 30 Oct 1998 13:02:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ochs",
"Wolfgang",
"",
"MPI fuer Physik"
]
] | The production of gluons in a jet is considered in limited phase space, either with a cut in transverse momentum with respect to the jet axis $k_\perp<k_\perp^{cut}$ or with a cut in absolute momentum $|\vec{k} | <k^{cut}$. It is shown in the perturbative QCD calculations that in the soft limit $k_\perp^{cut} \to 0$ the multiplicity distribution becomes Poissonian, whereas for $k^{cut} \to 0$ the distribution remains non-Poissonian. The Poissonian limit is a consequence of the soft gluon coherence in the genuine multiparticle correlations. We also investigate how incoherent hadronization processes could possibly modify the predictions for small cut-off parameters. |
2401.02483 | Tyler Smith | Tyler B. Smith, Tim M. P. Tait | Conserved Currents are Not Anomaly-Safe | 19 pages, 4 figures, 1 table | null | null | UCI-HEP-TR-2023-12 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New vector bosons that are coupled to conserved currents in the Standard
Model exhibit enhanced rates below the electroweak scale from anomalous
triangle amplitudes, leading to (energy/vector mass)$^2$ enhancements to rare Z
decays and flavor-changing meson decays into the longitudinally polarized
vector boson. In the case of a vector boson gauging $U(1)_{B-L}$, the mass gap
between the top quark and the remaining SM fermions leads to (energy/vector
mass)$^2$ enhancements for processes with momentum transfer below the top mass.
In addition, we examine the case of an intergenerational $U(1)_{B_3 - L_2}$
that has been proposed to resolve the $(g-2)_\mu$ anomaly with an MeV scale DM
candidate, and we find that these enhanced processes constrain the entire
parameter space.
| [
{
"created": "Thu, 4 Jan 2024 19:00:04 GMT",
"version": "v1"
}
] | 2024-01-08 | [
[
"Smith",
"Tyler B.",
""
],
[
"Tait",
"Tim M. P.",
""
]
] | New vector bosons that are coupled to conserved currents in the Standard Model exhibit enhanced rates below the electroweak scale from anomalous triangle amplitudes, leading to (energy/vector mass)$^2$ enhancements to rare Z decays and flavor-changing meson decays into the longitudinally polarized vector boson. In the case of a vector boson gauging $U(1)_{B-L}$, the mass gap between the top quark and the remaining SM fermions leads to (energy/vector mass)$^2$ enhancements for processes with momentum transfer below the top mass. In addition, we examine the case of an intergenerational $U(1)_{B_3 - L_2}$ that has been proposed to resolve the $(g-2)_\mu$ anomaly with an MeV scale DM candidate, and we find that these enhanced processes constrain the entire parameter space. |
hep-ph/0310207 | Jambul Gegelia | M. R. Schindler, J. Gegelia, S. Scherer | Infrared and extended on-mass-shell renormalization of two-loop diagrams | 10 pages, 2 figures, REVTeX 4 | Nucl.Phys. B682 (2004) 367-376 | 10.1016/j.nuclphysb.2004.01.027 | MKPH-T-03-18 | hep-ph nucl-th | null | Using a toy model Lagrangian we demonstrate the application of both infrared
and extended on-mass-shell renormalization schemes to multiloop diagrams by
considering as an example a two-loop self-energy diagram. We show that in both
cases the renormalized diagrams satisfy a straightforward power counting.
| [
{
"created": "Fri, 17 Oct 2003 10:18:04 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Schindler",
"M. R.",
""
],
[
"Gegelia",
"J.",
""
],
[
"Scherer",
"S.",
""
]
] | Using a toy model Lagrangian we demonstrate the application of both infrared and extended on-mass-shell renormalization schemes to multiloop diagrams by considering as an example a two-loop self-energy diagram. We show that in both cases the renormalized diagrams satisfy a straightforward power counting. |
1512.00040 | Gustavo Burdman | Gustavo Burdman and Raffaele Tito D'Agnolo | Scalar Leptons in Folded Supersymmetry | 7 pages, 4 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Folded supersymmetry is a natural theory of the electroweak scale in which
the scalar top partner responsible for canceling the ultraviolet sensitivity of
the Higgs mass at one loop carries no color. As a result, bounds on naturalness
on these theories are more relaxed than in typical supersymmetric models, since
collider bounds on top partners are less stringent. Here we consider the lepton
sector of these theories. We show that a natural realization in a
five-dimensional completion requires the existence of scalar leptons with weak
scale masses and study their phenomenology. We derive bounds on the masses of
these sleptons from the LHC data at $\sqrt{s}=8~$TeV and study the sensitivity
of the $\sqrt{s}=13~$TeV run for various integrated luminosities. When
supersymmetry is broken exclusively by Scherk-Schwarz boundary conditions the
sleptons are stable on collider scales. This leads to bounds on the folded
sleptons that translate into masses above $1~$TeV for the folded stops
resulting in tuning. When additional sources of supersymmetry breaking, which
may be necessary to ensure electroweak symmetry breaking, are allowed the
bounds on stops are mostly avoided. On the other hand, these terms lead to
faster slepton decays resulting in interesting signals with highly displaced
vertices and multi-jet final states inside the detectors.
| [
{
"created": "Mon, 30 Nov 2015 21:12:53 GMT",
"version": "v1"
}
] | 2015-12-02 | [
[
"Burdman",
"Gustavo",
""
],
[
"D'Agnolo",
"Raffaele Tito",
""
]
] | Folded supersymmetry is a natural theory of the electroweak scale in which the scalar top partner responsible for canceling the ultraviolet sensitivity of the Higgs mass at one loop carries no color. As a result, bounds on naturalness on these theories are more relaxed than in typical supersymmetric models, since collider bounds on top partners are less stringent. Here we consider the lepton sector of these theories. We show that a natural realization in a five-dimensional completion requires the existence of scalar leptons with weak scale masses and study their phenomenology. We derive bounds on the masses of these sleptons from the LHC data at $\sqrt{s}=8~$TeV and study the sensitivity of the $\sqrt{s}=13~$TeV run for various integrated luminosities. When supersymmetry is broken exclusively by Scherk-Schwarz boundary conditions the sleptons are stable on collider scales. This leads to bounds on the folded sleptons that translate into masses above $1~$TeV for the folded stops resulting in tuning. When additional sources of supersymmetry breaking, which may be necessary to ensure electroweak symmetry breaking, are allowed the bounds on stops are mostly avoided. On the other hand, these terms lead to faster slepton decays resulting in interesting signals with highly displaced vertices and multi-jet final states inside the detectors. |
hep-ph/9609471 | null | D. Cocolicchio, L. Telesca | The Classical Analogue of CP-violation | 12 pages, Latex, 2 figures available by fax | Found.Phys.Lett. 11 (1998) 23-39 | 10.1023/A:1022402719468 | UNIBAS-TH 6/96 | hep-ph | null | The phenomenological features of the mixing in the neutral pseudoscalar
mesons K0-K0bar can be illustrated in the classical framework of mechanics and
by means of electromagnetic coupled circuits. The time-reversed not-invariant
processes and the related phenomenon of CP-nonconservation can be induced by
dissipative effects which yield a not vanishing imaginary part for the relevant
Hamiltonian. Thus, two coupled dissipative oscillators can resemble the
peculiar asymmetries which are so common in the realm of high energy particle
physics.
| [
{
"created": "Wed, 25 Sep 1996 13:23:50 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Cocolicchio",
"D.",
""
],
[
"Telesca",
"L.",
""
]
] | The phenomenological features of the mixing in the neutral pseudoscalar mesons K0-K0bar can be illustrated in the classical framework of mechanics and by means of electromagnetic coupled circuits. The time-reversed not-invariant processes and the related phenomenon of CP-nonconservation can be induced by dissipative effects which yield a not vanishing imaginary part for the relevant Hamiltonian. Thus, two coupled dissipative oscillators can resemble the peculiar asymmetries which are so common in the realm of high energy particle physics. |
2309.06737 | Julian Bernhardt | Julian Bernhardt, Christian S. Fischer | QCD phase transitions in the light quark chiral limit | 14 pages, 9 figures, 4 tables; v3: version published in PRD; data for
plots in ancillary files | Phys. Rev. D 108, 114018 (2023) | 10.1103/PhysRevD.108.114018 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the order of the QCD chiral transition in the limit of
vanishing bare up/down quark masses and variations of the bare strange-quark
mass $0 \le m_{\mathrm{s}} \le \infty$. In this limit and due to universality
long range correlations with the quantum numbers of pseudoscalar and scalar
mesons may dominate the physics. In order to study the interplay between the
microscopic quark and gluon degrees of freedom and the long range correlations
we extend a combination of lattice Yang--Mills theory and a (truncated) version
of Dyson--Schwinger equations by also taking back-reactions of mesonic degrees
of freedom into account. Both this system and the meson backcoupling approach
have been studied extensively in the past but this is the first work in a full
$(2 + 1)$-flavor setup. Starting from the physical point, we determine the
chiral susceptibilities for decreasing up/down quark masses and find good
agreement with both lattice and functional renormalization group results. We
then proceed to determine the order of the chiral transition along the
left-hand side of the Columbia plot, for chemical potentials in the range $-(30
\,\textrm{MeV})^2 \le \mu_q^2 \le (30 \,\textrm{MeV})^2$. We find a
second-order phase transition throughout and no trace of a first-order region
in the $N_{f} = 3$ corner of the Columbia plot. This result remains unchanged
when an additional Goldstone boson due to a restored axial $\mathrm{U_A}(1)$ is
taken into account.
| [
{
"created": "Wed, 13 Sep 2023 06:00:48 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Oct 2023 14:51:08 GMT",
"version": "v2"
},
{
"created": "Fri, 12 Jan 2024 12:58:24 GMT",
"version": "v3"
}
] | 2024-01-15 | [
[
"Bernhardt",
"Julian",
""
],
[
"Fischer",
"Christian S.",
""
]
] | We investigate the order of the QCD chiral transition in the limit of vanishing bare up/down quark masses and variations of the bare strange-quark mass $0 \le m_{\mathrm{s}} \le \infty$. In this limit and due to universality long range correlations with the quantum numbers of pseudoscalar and scalar mesons may dominate the physics. In order to study the interplay between the microscopic quark and gluon degrees of freedom and the long range correlations we extend a combination of lattice Yang--Mills theory and a (truncated) version of Dyson--Schwinger equations by also taking back-reactions of mesonic degrees of freedom into account. Both this system and the meson backcoupling approach have been studied extensively in the past but this is the first work in a full $(2 + 1)$-flavor setup. Starting from the physical point, we determine the chiral susceptibilities for decreasing up/down quark masses and find good agreement with both lattice and functional renormalization group results. We then proceed to determine the order of the chiral transition along the left-hand side of the Columbia plot, for chemical potentials in the range $-(30 \,\textrm{MeV})^2 \le \mu_q^2 \le (30 \,\textrm{MeV})^2$. We find a second-order phase transition throughout and no trace of a first-order region in the $N_{f} = 3$ corner of the Columbia plot. This result remains unchanged when an additional Goldstone boson due to a restored axial $\mathrm{U_A}(1)$ is taken into account. |
hep-ph/9705204 | Alejandro Gangui | Alejandro Gangui, Patrick Peter and Celine Boehm | Could Electromagnetic Corrections Solve The Vorton Excess Problem ? | 10 pp RevTeX and 6 eps figures | Phys.Rev. D57 (1998) 2580-2589 | 10.1103/PhysRevD.57.2580 | null | hep-ph astro-ph | null | The modifications of circular cosmic string loop dynamics due to the
electromagnetic self-interaction are calculated and shown to reduce the
available phase space for reaching classical vorton states, thereby decreasing
their remnant abundance. Use is made of the duality between master-function and
Lagrangian formalisms on an explicit model.
| [
{
"created": "Thu, 1 May 1997 08:33:54 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Gangui",
"Alejandro",
""
],
[
"Peter",
"Patrick",
""
],
[
"Boehm",
"Celine",
""
]
] | The modifications of circular cosmic string loop dynamics due to the electromagnetic self-interaction are calculated and shown to reduce the available phase space for reaching classical vorton states, thereby decreasing their remnant abundance. Use is made of the duality between master-function and Lagrangian formalisms on an explicit model. |
hep-ph/0410393 | Kunihiko Terasaki | Arata Hayashigaki and Kunihiko Terasaki | Isospin quantum number of D_{s0}^+(2317) | 6 pages, no figure, RevTeX4, references added and clarification of
text | Prog.Theor.Phys.114:1191-1200,2006 | 10.1143/PTP.114.1191 | YITP-04-63 | hep-ph hep-ex nucl-th | null | The D_s^+ pi^0 and D_s^{*+} gamma decays of the D_{s0}^+(2317) are studied by
assigning it to various charmed strange scalar mesons. As a result, it is found
that its assignment to an iso-triplet four-quark meson is favored by the
severest experimental constraint on the ratio of the rates for these decays,
while assigning it to an I=0 state (a four-quark or a conventional {c\bar{s}})
is inconsistent with this constraint.
| [
{
"created": "Fri, 29 Oct 2004 05:27:49 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Dec 2005 03:15:27 GMT",
"version": "v2"
}
] | 2010-11-15 | [
[
"Hayashigaki",
"Arata",
""
],
[
"Terasaki",
"Kunihiko",
""
]
] | The D_s^+ pi^0 and D_s^{*+} gamma decays of the D_{s0}^+(2317) are studied by assigning it to various charmed strange scalar mesons. As a result, it is found that its assignment to an iso-triplet four-quark meson is favored by the severest experimental constraint on the ratio of the rates for these decays, while assigning it to an I=0 state (a four-quark or a conventional {c\bar{s}}) is inconsistent with this constraint. |
1311.6478 | Benjamin Fuks | Jean-Laurent Agram, Jeremy Andrea, Michael Buttignol, Eric Conte and
Benjamin Fuks | Monotop phenomenology at the Large Hadron Collider | 17 pages, 12 figures, 3 tables | Phys. Rev. D 89, 014028 (2014) | 10.1103/PhysRevD.89.014028 | CERN-PH-TH/2013-277 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate new physics scenarios where systems comprised of a single top
quark accompanied by missing transverse energy, dubbed monotops, can be
produced at the LHC. Following a simplified model approach, we describe all
possible monotop production modes via an effective theory and estimate the
sensitivity of the LHC, assuming 20 fb$^{-1}$ of collisions at a center-of-mass
energy of 8 TeV, to the observation of a monotop state. Considering both
leptonic and hadronic top quark decays, we show that large fractions of the
parameter space are reachable and that new physics particles with masses
ranging up to 1.5 TeV can leave hints within the 2012 LHC dataset, assuming
moderate new physics coupling strengths.
| [
{
"created": "Mon, 25 Nov 2013 21:00:31 GMT",
"version": "v1"
}
] | 2014-02-05 | [
[
"Agram",
"Jean-Laurent",
""
],
[
"Andrea",
"Jeremy",
""
],
[
"Buttignol",
"Michael",
""
],
[
"Conte",
"Eric",
""
],
[
"Fuks",
"Benjamin",
""
]
] | We investigate new physics scenarios where systems comprised of a single top quark accompanied by missing transverse energy, dubbed monotops, can be produced at the LHC. Following a simplified model approach, we describe all possible monotop production modes via an effective theory and estimate the sensitivity of the LHC, assuming 20 fb$^{-1}$ of collisions at a center-of-mass energy of 8 TeV, to the observation of a monotop state. Considering both leptonic and hadronic top quark decays, we show that large fractions of the parameter space are reachable and that new physics particles with masses ranging up to 1.5 TeV can leave hints within the 2012 LHC dataset, assuming moderate new physics coupling strengths. |
1910.06300 | Mikael Mieskolainen | Mikael Mieskolainen | GRANIITTI: A Monte Carlo Event Generator for High Energy Diffraction | 81 pages, 25 figures, v2: minor modifications | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe the physics and computational power of GRANIITTI Monte Carlo
event generator, a new fully multithreaded engine designed for high energy
diffraction, written in modern C++. The emphasis is especially on the low-mass
domain of central exclusive processes of the S-matrix, where exotic QCD
phenomena such as glueballs are expected and holographic dualities with gravity
may be tested. The generator includes photon-photon, photon-pomeron,
pomeron-pomeron, Durham QCD model and Tensor pomeron model type scattering
amplitudes and advanced spin analysis tools. The generator combines a full
parametric resonance spectrum with continuum interference and forward + central
spin correlations together with event-by-event eikonal screening loop and
forward proton excitation kinematics. We demonstrate the state-of-the-art
capabilities and show how the enigmatic `glueball filter' observable is driven
by spin polarization.
| [
{
"created": "Mon, 14 Oct 2019 17:28:23 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Oct 2019 14:13:17 GMT",
"version": "v2"
}
] | 2019-10-23 | [
[
"Mieskolainen",
"Mikael",
""
]
] | We describe the physics and computational power of GRANIITTI Monte Carlo event generator, a new fully multithreaded engine designed for high energy diffraction, written in modern C++. The emphasis is especially on the low-mass domain of central exclusive processes of the S-matrix, where exotic QCD phenomena such as glueballs are expected and holographic dualities with gravity may be tested. The generator includes photon-photon, photon-pomeron, pomeron-pomeron, Durham QCD model and Tensor pomeron model type scattering amplitudes and advanced spin analysis tools. The generator combines a full parametric resonance spectrum with continuum interference and forward + central spin correlations together with event-by-event eikonal screening loop and forward proton excitation kinematics. We demonstrate the state-of-the-art capabilities and show how the enigmatic `glueball filter' observable is driven by spin polarization. |
1406.0308 | Peter Ballett | Peter Ballett, Stephen F. King, Christoph Luhn, Silvia Pascoli and
Michael A. Schmidt | Precision measurements of {\theta}12 for testing models of discrete
leptonic flavour symmetries | 3 pages, 1 figure; contribution to conference proceedings for
NuPhys2013 | null | 10.1088/1742-6596/598/1/012014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Models of leptonic flavour with discrete symmetries can provide an attractive
explanation of the pattern of elements found in the leptonic mixing matrix. The
next generation of neutrino oscillation experiments will allow the mixing
parameters to be tested to a new level of precision, crucially measuring the CP
violating phase {\delta} for the first time. In this contribution, we present
results of a systematic survey of the predictions of a class of models based on
residual discrete symmetries and the prospects for excluding such models at
medium- and long-term oscillation experiments. We place particular emphasis on
the complementary role that a future circa 50 km reactor experiment, e.g. JUNO,
can play in constraining these models.
| [
{
"created": "Mon, 2 Jun 2014 09:45:50 GMT",
"version": "v1"
}
] | 2015-06-19 | [
[
"Ballett",
"Peter",
""
],
[
"King",
"Stephen F.",
""
],
[
"Luhn",
"Christoph",
""
],
[
"Pascoli",
"Silvia",
""
],
[
"Schmidt",
"Michael A.",
""
]
] | Models of leptonic flavour with discrete symmetries can provide an attractive explanation of the pattern of elements found in the leptonic mixing matrix. The next generation of neutrino oscillation experiments will allow the mixing parameters to be tested to a new level of precision, crucially measuring the CP violating phase {\delta} for the first time. In this contribution, we present results of a systematic survey of the predictions of a class of models based on residual discrete symmetries and the prospects for excluding such models at medium- and long-term oscillation experiments. We place particular emphasis on the complementary role that a future circa 50 km reactor experiment, e.g. JUNO, can play in constraining these models. |
1712.00729 | Katsuta Sakai | Kiyoharu Kawana, Katsuta Sakai | Hillclimbing saddle point inflation | 5 pages, 3 figures; Report number added (v2) | Phys.Lett. B778, 60 (2018) | 10.1016/j.physletb.2018.01.007 | KEK-TH-2019, KUNS-2711 | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently a new inflationary scenario was proposed in arXiv:1703.09020 which
can be applicable to an inflaton having multiple vacua. In this letter, we
consider a more general situation where the inflaton potential has a (UV)
saddle point around the Planck scale. This class of models can be regarded as a
natural generalization of the hillclimbing Higgs inflation (arXiv:1705.03696).
| [
{
"created": "Sun, 3 Dec 2017 07:42:39 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Jan 2018 04:54:54 GMT",
"version": "v2"
}
] | 2018-02-01 | [
[
"Kawana",
"Kiyoharu",
""
],
[
"Sakai",
"Katsuta",
""
]
] | Recently a new inflationary scenario was proposed in arXiv:1703.09020 which can be applicable to an inflaton having multiple vacua. In this letter, we consider a more general situation where the inflaton potential has a (UV) saddle point around the Planck scale. This class of models can be regarded as a natural generalization of the hillclimbing Higgs inflation (arXiv:1705.03696). |
0807.2514 | Sven Heinemeyer | S. Heinemeyer | Higgs Physics at the LHC: Some Theory Aspects | 20 pages, 8 figures, lecture given at the "Spanish Winter Meeting
2008", February 2008, Baeza, Spain | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these lecture notes we review some prospect for the upcoming LHC
experiments in view of the exploration of the Standard Model (SM) or its
minimal Supersymmetric extension (MSSM). We focus on some theoretical aspects
concerning the Higgs sector of the two models. We give results for the
precision observables M_W and m_t and their impact on the indirect
determination of the Higgs sector. We furthermore review some prospects for the
direct measurements in the SM and MSSM Higgs sector.
| [
{
"created": "Wed, 16 Jul 2008 08:30:33 GMT",
"version": "v1"
}
] | 2008-07-17 | [
[
"Heinemeyer",
"S.",
""
]
] | In these lecture notes we review some prospect for the upcoming LHC experiments in view of the exploration of the Standard Model (SM) or its minimal Supersymmetric extension (MSSM). We focus on some theoretical aspects concerning the Higgs sector of the two models. We give results for the precision observables M_W and m_t and their impact on the indirect determination of the Higgs sector. We furthermore review some prospects for the direct measurements in the SM and MSSM Higgs sector. |
1712.05105 | Gregory Soyez | Simone Marzani, Lais Schunk and Gregory Soyez | The jet mass distribution after Soft Drop | 5 pages, 2 figures | null | 10.1140/epjc/s10052-018-5579-5 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a first-principle computation of the mass distribution of jets
which have undergone the grooming procedure known as Soft Drop. This
calculation includes the resummation of the large logarithms of the jet mass
over its transverse momentum, up to next-to-logarithmic accuracy, matched to
exact fixed-order results at next-to-leading order. We also include
non-perturbative corrections obtained from Monte-Carlo simulations and discuss
analytic expressions for hadronisation and Underlying Event effects.
| [
{
"created": "Thu, 14 Dec 2017 07:03:19 GMT",
"version": "v1"
}
] | 2018-03-14 | [
[
"Marzani",
"Simone",
""
],
[
"Schunk",
"Lais",
""
],
[
"Soyez",
"Gregory",
""
]
] | We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects. |
1211.2229 | Jorge de Blas Mateo | J. de Blas, J. M. Lizana, M. Perez-Victoria | Combining searches of Z' and W' bosons | pdfLateX, 36 pages, 11 figures. Minor changes, version published in
Journal of High Energy Physics | null | 10.1007/JHEP01(2013)166 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study in a model-independent way new neutral and charged vector bosons
that could give observable signals with leptonic final states at the LHC. We
show, in particular, that a charged vector W' decaying into lepton plus
neutrino is accompanied by at least an extra neutral vector boson Z', nearly
degenerate with the charged one. Conversely, a Z' boson with significant
isospin violation cannot exist without a companion W'. To take advantage of
these generic correlations, we perform a combined analysis of LHC data in the
dilepton and lepton-plus-missing-energy channels, which allows us to improve
the limits from independent analyses. We also develop some tools to easily deal
with cases in which several heavy vector bosons with similar masses interfere.
Finally, we develop a theoretically consistent framework for the study of the
sequential Z' and W' benchmarks.
| [
{
"created": "Fri, 9 Nov 2012 20:51:11 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Feb 2013 22:11:24 GMT",
"version": "v2"
}
] | 2015-06-12 | [
[
"de Blas",
"J.",
""
],
[
"Lizana",
"J. M.",
""
],
[
"Perez-Victoria",
"M.",
""
]
] | We study in a model-independent way new neutral and charged vector bosons that could give observable signals with leptonic final states at the LHC. We show, in particular, that a charged vector W' decaying into lepton plus neutrino is accompanied by at least an extra neutral vector boson Z', nearly degenerate with the charged one. Conversely, a Z' boson with significant isospin violation cannot exist without a companion W'. To take advantage of these generic correlations, we perform a combined analysis of LHC data in the dilepton and lepton-plus-missing-energy channels, which allows us to improve the limits from independent analyses. We also develop some tools to easily deal with cases in which several heavy vector bosons with similar masses interfere. Finally, we develop a theoretically consistent framework for the study of the sequential Z' and W' benchmarks. |
hep-ph/9804417 | Bruno Machet | B. Machet | Indirect CP violation in an electroweak SU(2)left x U(1) gauge theory of
chiral mesons | 19 pages, Latex2e, 1 postscript logo | null | null | PAR-LPTHE 98/12 | hep-ph | null | Indirect CP violation is analyzed in the framework of the electroweak gauge
theory of J=0 mesons proposed in ref.[1], in which they transform like
composite fermion-antifermion operators by the chiral U(N)left x U(N)right
group and by the SU(2)left x U(1) gauge group of the Glashow-Salam-Weinberg
model. It is shown that, in this model where, in particular, mass terms can be
introduced for the mesons themselves, and unlike what happens in the standard
model for fermions: - electroweak mass eigenstates can differ from CP
eigenstates even in the case of two generations; - the existence of a complex
entry in the mixing matrix for the constituent fermions is no longer a
sufficient condition for indirect CP violation to occur at the mesonic level.
| [
{
"created": "Mon, 27 Apr 1998 14:11:47 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Machet",
"B.",
""
]
] | Indirect CP violation is analyzed in the framework of the electroweak gauge theory of J=0 mesons proposed in ref.[1], in which they transform like composite fermion-antifermion operators by the chiral U(N)left x U(N)right group and by the SU(2)left x U(1) gauge group of the Glashow-Salam-Weinberg model. It is shown that, in this model where, in particular, mass terms can be introduced for the mesons themselves, and unlike what happens in the standard model for fermions: - electroweak mass eigenstates can differ from CP eigenstates even in the case of two generations; - the existence of a complex entry in the mixing matrix for the constituent fermions is no longer a sufficient condition for indirect CP violation to occur at the mesonic level. |
1305.4727 | Antoni Szczurek | Marta Luszczak, Wolfgang Schafer and Antoni Szczurek | Diffractive dissociation of gluons into heavy quark-antiquark pairs in
proton-proton collisions | 17 pages, 12 figures | null | 10.1016/j.physletb.2013.12.050 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss diffractive dissociation of gluons into heavy quark pairs. The
particular mechanism is similar to the diffractive dissociation of virtual
photons into quarks, which drives diffractive deep inelastic production of
charm in the low-mass diffraction, or large $\beta$-region. There, it can be
understood, with some reservations, in terms of a valence heavy quark content
of the Pomeron. The amplitude for the $g p \to Q \bar Q p$ is derived in the
impact parameter and momentum space. The cross section for single diffractive
$p p \to Q \bar Q p X$ is calculated as a convolution of the elementary cross
section and gluon distribution in the proton. Integrated cross section and the
differential distributions in e.g. transverse momentum and rapidity of the
charm and bottom quark and antiquark, as well as the quark-antiquark invariant
mass are calculated for the nominal LHC energy for different unintegrated gluon
distributions from the literature. The ratio of the bottom-to-charm cross
sections are shown and discussed as a function of several kinematical
variables.
| [
{
"created": "Tue, 21 May 2013 06:33:57 GMT",
"version": "v1"
}
] | 2015-06-16 | [
[
"Luszczak",
"Marta",
""
],
[
"Schafer",
"Wolfgang",
""
],
[
"Szczurek",
"Antoni",
""
]
] | We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the low-mass diffraction, or large $\beta$-region. There, it can be understood, with some reservations, in terms of a valence heavy quark content of the Pomeron. The amplitude for the $g p \to Q \bar Q p$ is derived in the impact parameter and momentum space. The cross section for single diffractive $p p \to Q \bar Q p X$ is calculated as a convolution of the elementary cross section and gluon distribution in the proton. Integrated cross section and the differential distributions in e.g. transverse momentum and rapidity of the charm and bottom quark and antiquark, as well as the quark-antiquark invariant mass are calculated for the nominal LHC energy for different unintegrated gluon distributions from the literature. The ratio of the bottom-to-charm cross sections are shown and discussed as a function of several kinematical variables. |
hep-ph/0312137 | Jens D. Noritzsch | Jens D. Noritzsch | Heavy quarks in deeply virtual Compton scattering | 15 pages, 12 eps-figures, LaTeX2e; (V2) include correct figure 3b,
remove 'bottom' from figure caption 4 | Phys.Rev.D69:094016,2004 | 10.1103/PhysRevD.69.094016 | DO-TH 03/13 | hep-ph | null | A detailed study of the heavy quark h=c,b,... contributions to deeply virtual
Compton scattering is performed at both the amplitude and the cross section
level, and their phenomenological relevance is discussed. For this purpose I
calculate the lowest order off-forward photon-gluon scattering amplitude with a
massive quark loop and the corresponding hard scattering coefficients. In a
first numerical analysis these fixed order perturbation theory results are
compared with the conventional intrinsic "massless" parton approach considering
generalized parton distributions for the heavy quarks. The differences between
these two prescriptions can be quite significant, especially at small
skewedness where the massless approach largely overestimates the deeply virtual
Compton scattering cross section.
| [
{
"created": "Wed, 10 Dec 2003 13:23:36 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Dec 2003 18:06:41 GMT",
"version": "v2"
}
] | 2011-01-25 | [
[
"Noritzsch",
"Jens D.",
""
]
] | A detailed study of the heavy quark h=c,b,... contributions to deeply virtual Compton scattering is performed at both the amplitude and the cross section level, and their phenomenological relevance is discussed. For this purpose I calculate the lowest order off-forward photon-gluon scattering amplitude with a massive quark loop and the corresponding hard scattering coefficients. In a first numerical analysis these fixed order perturbation theory results are compared with the conventional intrinsic "massless" parton approach considering generalized parton distributions for the heavy quarks. The differences between these two prescriptions can be quite significant, especially at small skewedness where the massless approach largely overestimates the deeply virtual Compton scattering cross section. |
0810.1323 | Lance Labun | Lance Labun and Johann Rafelski | QED Energy-Momentum Trace as a Force in Astrophysics | 4 pages, 2 figures; Added discussion of the force induced by vacuum
fluctuations in presence of strong external magnetic field | Phys.Lett.B687:133-138,2010 | 10.1016/j.physletb.2010.02.083 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the properties of the trace $\Tmm$ of the QED energy-momentum tensor
in the presence of quasi-constant external electromagnetic fields. We exhibit
the origin of $\Tmm$ in the quantum nonlinearity of the electromagnetic theory.
We obtain the quantum vacuum fluctuation-induced interaction of a particle with
the field of a strongly magnetized compact stellar object.
| [
{
"created": "Wed, 8 Oct 2008 18:13:39 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Dec 2008 21:59:46 GMT",
"version": "v2"
},
{
"created": "Thu, 16 Jul 2009 17:44:28 GMT",
"version": "v3"
},
{
"created": "Sat, 27 Feb 2010 00:54:24 GMT",
"version": "v4"
}
] | 2010-04-12 | [
[
"Labun",
"Lance",
""
],
[
"Rafelski",
"Johann",
""
]
] | We study the properties of the trace $\Tmm$ of the QED energy-momentum tensor in the presence of quasi-constant external electromagnetic fields. We exhibit the origin of $\Tmm$ in the quantum nonlinearity of the electromagnetic theory. We obtain the quantum vacuum fluctuation-induced interaction of a particle with the field of a strongly magnetized compact stellar object. |
hep-ph/9906527 | Takeo Moroi | Takeo Moroi (IAS) and Lisa Randall (Princeton/MIT) | Wino Cold Dark Matter from Anomaly-Mediated SUSY Breaking | 19 pages, 4 figures | Nucl.Phys.B570:455-472,2000 | 10.1016/S0550-3213(99)00748-8 | IASSNS-HEP-99-54, PUPT-1873, MIT-CTP-2873 | hep-ph | null | The cosmological moduli problem is discussed in the framework of sequestered
sector/anomaly-mediated supersymmetry (SUSY) breaking. In this scheme, the
gravitino mass (corresponding to the moduli masses) is naturally 10 - 100 TeV,
and hence the lifetime of the moduli fields can be shorter than $\sim 1 sec$.
As a result, the cosmological moduli fields should decay before big-bang
nucleosynthesis starts. Furthermore, in the anomaly-mediated scenario, the
lightest superparticle (LSP) is the Wino-like neutralino. Although the large
annihilation cross section means the thermal relic density of the Wino LSP is
too small to be the dominant component of cold dark matter (CDM), moduli decays
can produce Winos in sufficient abundance to constitute CDM. If Winos are
indeed the dark matter, it will be highly advantageous from the point of view
of detection. If the halo density is dominated by the Wino-like LSP, the
detection rate of Wino CDM in Ge detectors can be as large as $0.1 - 0.01$
event/kg/day, which is within the reach of the future CDM detection with Ge
detector. Furthermore, there is a significant positron signal from pair
annihilation of Winos in our galaxy which should give a spectacular signal at
AMS.
| [
{
"created": "Tue, 29 Jun 1999 14:07:32 GMT",
"version": "v1"
}
] | 2009-09-15 | [
[
"Moroi",
"Takeo",
"",
"IAS"
],
[
"Randall",
"Lisa",
"",
"Princeton/MIT"
]
] | The cosmological moduli problem is discussed in the framework of sequestered sector/anomaly-mediated supersymmetry (SUSY) breaking. In this scheme, the gravitino mass (corresponding to the moduli masses) is naturally 10 - 100 TeV, and hence the lifetime of the moduli fields can be shorter than $\sim 1 sec$. As a result, the cosmological moduli fields should decay before big-bang nucleosynthesis starts. Furthermore, in the anomaly-mediated scenario, the lightest superparticle (LSP) is the Wino-like neutralino. Although the large annihilation cross section means the thermal relic density of the Wino LSP is too small to be the dominant component of cold dark matter (CDM), moduli decays can produce Winos in sufficient abundance to constitute CDM. If Winos are indeed the dark matter, it will be highly advantageous from the point of view of detection. If the halo density is dominated by the Wino-like LSP, the detection rate of Wino CDM in Ge detectors can be as large as $0.1 - 0.01$ event/kg/day, which is within the reach of the future CDM detection with Ge detector. Furthermore, there is a significant positron signal from pair annihilation of Winos in our galaxy which should give a spectacular signal at AMS. |
2003.03997 | Paolo Ciafaloni | Fabio Bossi and Paolo Ciafaloni | Lepton Flavor Violation at muon-electron colliders | 9 pages, 4 figures. Final version published on JHEP | null | 10.1007/JHEP10(2020)033 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Lepton Flavor Violating (LFV) processes are clear signals of physics beyond
the Standard Model. We investigate the possibility of measuring this kind of
processes at present and foreseeable future muon-electron colliders, taking
into account present day bounds from existing experiments. As a model of new
physics we consider a Z' boson with a $U'(1)$ gauge symmetry and generic
couplings. Processes that violate lepton flavor by two units seem to be
particularly promising.
| [
{
"created": "Mon, 9 Mar 2020 09:36:25 GMT",
"version": "v1"
},
{
"created": "Sat, 12 Dec 2020 09:04:39 GMT",
"version": "v2"
}
] | 2020-12-15 | [
[
"Bossi",
"Fabio",
""
],
[
"Ciafaloni",
"Paolo",
""
]
] | Lepton Flavor Violating (LFV) processes are clear signals of physics beyond the Standard Model. We investigate the possibility of measuring this kind of processes at present and foreseeable future muon-electron colliders, taking into account present day bounds from existing experiments. As a model of new physics we consider a Z' boson with a $U'(1)$ gauge symmetry and generic couplings. Processes that violate lepton flavor by two units seem to be particularly promising. |
1309.0020 | Stephen Barr | S.M. Barr and Heng-Yu Chen | Cogeneration of Dark Matter and Baryons by Non-Standard-Model Sphalerons
in Unified Models | 13 pages. Revised introduction and references, changed title | null | 10.1007/JHEP10(2013)129 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Sphalerons of a new gauge interaction can convert a primordial asymmetry in B
or L into a dark matter asymmetry. From the equilibrium conditions for the
sphalerons of both the electroweak and the new interactions, one can compute
the ratios of B, L, and X, where X is the dark matter number, thus determining
the mass of the dark matter particle fairly precisely. Such a scenario can
arise naturally in the context of unification with larger groups. An
illustrative model embeddable in $SU(6) \times SU(2) \subset E_6$ is described
as well as an equally simple model based on SU(7).
| [
{
"created": "Fri, 30 Aug 2013 20:22:04 GMT",
"version": "v1"
},
{
"created": "Tue, 17 Sep 2013 18:37:19 GMT",
"version": "v2"
}
] | 2015-06-17 | [
[
"Barr",
"S. M.",
""
],
[
"Chen",
"Heng-Yu",
""
]
] | Sphalerons of a new gauge interaction can convert a primordial asymmetry in B or L into a dark matter asymmetry. From the equilibrium conditions for the sphalerons of both the electroweak and the new interactions, one can compute the ratios of B, L, and X, where X is the dark matter number, thus determining the mass of the dark matter particle fairly precisely. Such a scenario can arise naturally in the context of unification with larger groups. An illustrative model embeddable in $SU(6) \times SU(2) \subset E_6$ is described as well as an equally simple model based on SU(7). |
hep-ph/9401239 | Axel de la Macorra P. | A. de la Macorra | Unification Scale in String Theory | 12 pages (LaTeX) | Phys.Lett. B341 (1994) 31-37 | 10.1016/0370-2693(94)01275-X | Oxford preprint OUTP-93-33P | hep-ph | null | We study the unification scale and gauge coupling constant in 4D string
theory. We show that the fine structure constant is determined by the dimension
of the hidden gauge group and only $SU(6)$ and $SO(9)$ are consistent with
minimal string unification while the unification scale can be of order of
$10^{16}\,GeV$.
| [
{
"created": "Wed, 12 Jan 1994 00:45:25 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Jan 1994 23:25:42 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Feb 1994 00:24:03 GMT",
"version": "v3"
}
] | 2009-10-28 | [
[
"de la Macorra",
"A.",
""
]
] | We study the unification scale and gauge coupling constant in 4D string theory. We show that the fine structure constant is determined by the dimension of the hidden gauge group and only $SU(6)$ and $SO(9)$ are consistent with minimal string unification while the unification scale can be of order of $10^{16}\,GeV$. |
hep-ph/9711248 | Mark Wise | Zoltan Ligeti, Iain W. Stewart, Mark B. Wise | Comment on $V_{ub}$ from Exclusive Semileptonic B and D Decays | 14 pages, 3 figs, minor typos corrected, to appear in Phys. Lett. B | Phys.Lett.B420:359-366,1998 | 10.1016/S0370-2693(97)01518-9 | CALT-68-2141, UCSD/PTH 97-34 | hep-ph | null | The prospects for determining $|V_{ub}|$ from exclusive B semileptonic decay
are discussed. The double ratio of form factors $(f^{B\to\rho}/f^{B\to K^*})/
(f^{D\to\rho}/f^{D\to K^*})$ is calculated using chiral perturbation theory.
Its deviation from unity due to contributions that are non-analytic in the
symmetry breaking parameters is very small. Combining experimental data
obtainable from (B->rho l nu), (B->K* l l) and (D->rho l nu) can lead to a
model independent determination of $|V_{ub}|$ with an uncertainty from theory
of about 10%.
| [
{
"created": "Thu, 6 Nov 1997 06:04:20 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Mar 1998 22:03:54 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Ligeti",
"Zoltan",
""
],
[
"Stewart",
"Iain W.",
""
],
[
"Wise",
"Mark B.",
""
]
] | The prospects for determining $|V_{ub}|$ from exclusive B semileptonic decay are discussed. The double ratio of form factors $(f^{B\to\rho}/f^{B\to K^*})/ (f^{D\to\rho}/f^{D\to K^*})$ is calculated using chiral perturbation theory. Its deviation from unity due to contributions that are non-analytic in the symmetry breaking parameters is very small. Combining experimental data obtainable from (B->rho l nu), (B->K* l l) and (D->rho l nu) can lead to a model independent determination of $|V_{ub}|$ with an uncertainty from theory of about 10%. |
2112.01389 | Sven Heinemeyer | Manimala Chakraborti, Sven Heinemeyer, Ipsita Saha, Christian
Schappacher | $(g-2)_\mu$ and SUSY Dark Matter: Direct Detection and Collider Search
Complementarity | 32 pages, 9 figures. arXiv admin note: text overlap with
arXiv:2103.13403 | null | 10.1140/epjc/s10052-022-10414-w | IFT-UAM/CSIC-21-138, IPMU21-0083 | hep-ph | http://creativecommons.org/licenses/by-nc-sa/4.0/ | The electroweak (EW) sector of the Minimal Supersymmetric Standard Model
(MSSM) can account for variety of experimental data. The EW particles with
masses of a few hundred GeV evade the LHC searches owing to their small
production cross sections. Such a light EW sector can in particular explain the
reinforced $4.2\,\sigma$ discrepancy between the experimental result for the
anomalous magnetic moment of the muon, \gmin2, and its Standard Model (SM)
prediction. The lightest supersymmetric particle (LSP), assumed to be the
lightest neutralino, $\tilde{\chi}_1^0$, as a Dark Matter (DM) candidate is
furthermore in agreement with the observed limits on the DM content of the
universe. Here the Next-to LSP (NLSP) serves as a coannihilation partner and is
naturally close in mass to the LSP. Such scenarios are also to a large extent
in agreement with negative results from Direct Detection (DD) experiments. The
DM relic density can fully be explained by a nearly pure bino or a mixed
bino/wino LSP. Relatively light wino and higgsino DM, on the other hand,
remains easily below the DM relic density upper bound. Using the improved
limits on $(g-2)_\mu$, we explore the mass ranges of the LSP and the NLSP in
their correlation with the DM relic density for bino, bino/wino, wino and
higgsino DM. In particular analyze the sensitivity of future DM DD experiments
to these DM scenarios. We find that higgsino, wino and one type of bino
scenario can be covered by future DD experiments. Mixed bino/wino and another
type of bino DM can reach DD cross sections below the neutrino floor. In these
cases we analyze the complementarity with the (HL-)LHC and future $e^+e^-$
linear colliders. We find that while the prospects for the HL-LHC are
interesting, but not conclusive, an $e^+e^-$ collider with $\sqrt{s} \le 1$ TeV
can cover effectively all points of the MSSM that may be missed by DD
experiments.
| [
{
"created": "Thu, 2 Dec 2021 16:20:44 GMT",
"version": "v1"
}
] | 2022-06-08 | [
[
"Chakraborti",
"Manimala",
""
],
[
"Heinemeyer",
"Sven",
""
],
[
"Saha",
"Ipsita",
""
],
[
"Schappacher",
"Christian",
""
]
] | The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for variety of experimental data. The EW particles with masses of a few hundred GeV evade the LHC searches owing to their small production cross sections. Such a light EW sector can in particular explain the reinforced $4.2\,\sigma$ discrepancy between the experimental result for the anomalous magnetic moment of the muon, \gmin2, and its Standard Model (SM) prediction. The lightest supersymmetric particle (LSP), assumed to be the lightest neutralino, $\tilde{\chi}_1^0$, as a Dark Matter (DM) candidate is furthermore in agreement with the observed limits on the DM content of the universe. Here the Next-to LSP (NLSP) serves as a coannihilation partner and is naturally close in mass to the LSP. Such scenarios are also to a large extent in agreement with negative results from Direct Detection (DD) experiments. The DM relic density can fully be explained by a nearly pure bino or a mixed bino/wino LSP. Relatively light wino and higgsino DM, on the other hand, remains easily below the DM relic density upper bound. Using the improved limits on $(g-2)_\mu$, we explore the mass ranges of the LSP and the NLSP in their correlation with the DM relic density for bino, bino/wino, wino and higgsino DM. In particular analyze the sensitivity of future DM DD experiments to these DM scenarios. We find that higgsino, wino and one type of bino scenario can be covered by future DD experiments. Mixed bino/wino and another type of bino DM can reach DD cross sections below the neutrino floor. In these cases we analyze the complementarity with the (HL-)LHC and future $e^+e^-$ linear colliders. We find that while the prospects for the HL-LHC are interesting, but not conclusive, an $e^+e^-$ collider with $\sqrt{s} \le 1$ TeV can cover effectively all points of the MSSM that may be missed by DD experiments. |
2002.07137 | Amit Adhikary | Amit Adhikary, Biplob Bhattacherjee, Rohini M. Godbole, Najimuddin
Khan, Suchita Kulkarni | Searching for heavy Higgs in supersymmetric final states at the LHC | Version 2; Accepted for publication in JHEP | JHEP 2104 (2021) 284 | 10.1007/JHEP04(2021)284 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we analyse and demonstrate possible strategies to explore
extended Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). In
particular we concentrate on heavy Higgs decays to electroweakinos. We analyse
the Higgs to electroweakino decays in the allowed MSSM parameter space after
taking into account 13 TeV LHC searches for supersymmetric particles and
phenomenological constraints such as flavour physics, Higgs measurements and
dark matter constraints. We explore some novel aspects of these Higgs decays.
The final states resulting from Higgs to electroweakino decays will have
backgrounds arising from the Standard Model as well as direct electroweakino
production at the LHC. We demonstrate explicit kinematical differences between
Higgs to electroweakino decays and associated backgrounds. Furthermore, we
demonstrate for a few specific example points, optimised analysis search
strategies at the high luminosity LHC (HL-LHC) run. Finally, we comment on
possible search strategies for heavy Higgs decays to exotic final states, where
the lightest chargino is long lived and leads to a disappearing track at the
LHC.
| [
{
"created": "Mon, 17 Feb 2020 18:54:42 GMT",
"version": "v1"
},
{
"created": "Wed, 5 May 2021 16:31:10 GMT",
"version": "v2"
}
] | 2021-05-06 | [
[
"Adhikary",
"Amit",
""
],
[
"Bhattacherjee",
"Biplob",
""
],
[
"Godbole",
"Rohini M.",
""
],
[
"Khan",
"Najimuddin",
""
],
[
"Kulkarni",
"Suchita",
""
]
] | In this work, we analyse and demonstrate possible strategies to explore extended Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). In particular we concentrate on heavy Higgs decays to electroweakinos. We analyse the Higgs to electroweakino decays in the allowed MSSM parameter space after taking into account 13 TeV LHC searches for supersymmetric particles and phenomenological constraints such as flavour physics, Higgs measurements and dark matter constraints. We explore some novel aspects of these Higgs decays. The final states resulting from Higgs to electroweakino decays will have backgrounds arising from the Standard Model as well as direct electroweakino production at the LHC. We demonstrate explicit kinematical differences between Higgs to electroweakino decays and associated backgrounds. Furthermore, we demonstrate for a few specific example points, optimised analysis search strategies at the high luminosity LHC (HL-LHC) run. Finally, we comment on possible search strategies for heavy Higgs decays to exotic final states, where the lightest chargino is long lived and leads to a disappearing track at the LHC. |
2004.06740 | Cristian Pisano | Dani\"el Boer, Umberto D'Alesio, Francesco Murgia, Cristian Pisano,
Pieter Taels | $J/\psi$ meson production in SIDIS: matching high and low transverse
momentum | 17 pages, 1 figure; final version to appear in JHEP | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the transverse momentum spectrum and the $\cos 2\phi$ azimuthal
distribution of $J/\psi$ mesons produced in semi-inclusive, deep-inelastic
electron-proton scattering, where the electron and the proton are unpolarized.
At low transverse momentum, we propose factorized expressions in terms of
transverse momentum dependent gluon distributions and shape functions. We show
that our formulae, at the order $\alpha_s,$ correctly match with the collinear
factorization results at high transverse momentum. The latter are computed at
the order $\alpha_s^2$ in the framework of nonrelativistic QCD (NRQCD), with
the inclusion of the intermediate $^3S_1^{[1]}$ color-singlet Fock state, as
well as the subleading color-octet ones that are relatively suppressed by a
factor $v^4$ in the NRQCD velocity parameter $v$. We show that the
$^1\!S_0^{[8]}$ and $^3\!P_J^{[8]}$ ($J = 0,1,2$) contributions diverge in the
small transverse momentum region and allow us to determine the perturbative
tails of the shape functions, which carry the same quantum numbers. These turn
out to be identical, except for the overall magnitude given by the appropriate
NRQCD long distance matrix element.
| [
{
"created": "Tue, 14 Apr 2020 18:01:25 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Sep 2020 21:29:48 GMT",
"version": "v2"
}
] | 2020-09-07 | [
[
"Boer",
"Daniël",
""
],
[
"D'Alesio",
"Umberto",
""
],
[
"Murgia",
"Francesco",
""
],
[
"Pisano",
"Cristian",
""
],
[
"Taels",
"Pieter",
""
]
] | We consider the transverse momentum spectrum and the $\cos 2\phi$ azimuthal distribution of $J/\psi$ mesons produced in semi-inclusive, deep-inelastic electron-proton scattering, where the electron and the proton are unpolarized. At low transverse momentum, we propose factorized expressions in terms of transverse momentum dependent gluon distributions and shape functions. We show that our formulae, at the order $\alpha_s,$ correctly match with the collinear factorization results at high transverse momentum. The latter are computed at the order $\alpha_s^2$ in the framework of nonrelativistic QCD (NRQCD), with the inclusion of the intermediate $^3S_1^{[1]}$ color-singlet Fock state, as well as the subleading color-octet ones that are relatively suppressed by a factor $v^4$ in the NRQCD velocity parameter $v$. We show that the $^1\!S_0^{[8]}$ and $^3\!P_J^{[8]}$ ($J = 0,1,2$) contributions diverge in the small transverse momentum region and allow us to determine the perturbative tails of the shape functions, which carry the same quantum numbers. These turn out to be identical, except for the overall magnitude given by the appropriate NRQCD long distance matrix element. |
1101.4177 | Mihail Chizhov | D. Kirilova | BBN with Late Electron-Sterile Neutrino Oscillations - The Finest
Leptometer | 13 pages, 6 figs | null | 10.1088/1475-7516/2012/06/007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A relic lepton asymmetry orders of magnitude bigger than the baryon one may
hide in the relic neutrino background. No direct theoretical or experimental
limitations on its magnitude and sign are known. Indirect cosmological
constraints exist ranging from $|L|<0.01$ to $L<10$. We discuss a BBN model
with late electron-sterile neutrino oscillations which is a fine leptometer -
it is capable of feeling extremely small relic lepton asymmetry -
$|L|>10^{-8}$. This sensitivity is achieved through the influence of such small
$L$ on the neutrino oscillations, suppressing or enhancing them, and thus
changing the primordially produced $^4He$. The influence of $L$ on nucleons
freezing in pre-BBN epoch is numerically analyzed in the full range of the
oscillation parameters of the model and for $ L \ge 10^{-10}$. The case of
oscillations generated asymmetry by late electron-sterile oscillations and its
effect on primordial $^4He$ is also briefly discussed.
| [
{
"created": "Fri, 21 Jan 2011 16:38:47 GMT",
"version": "v1"
}
] | 2015-05-27 | [
[
"Kirilova",
"D.",
""
]
] | A relic lepton asymmetry orders of magnitude bigger than the baryon one may hide in the relic neutrino background. No direct theoretical or experimental limitations on its magnitude and sign are known. Indirect cosmological constraints exist ranging from $|L|<0.01$ to $L<10$. We discuss a BBN model with late electron-sterile neutrino oscillations which is a fine leptometer - it is capable of feeling extremely small relic lepton asymmetry - $|L|>10^{-8}$. This sensitivity is achieved through the influence of such small $L$ on the neutrino oscillations, suppressing or enhancing them, and thus changing the primordially produced $^4He$. The influence of $L$ on nucleons freezing in pre-BBN epoch is numerically analyzed in the full range of the oscillation parameters of the model and for $ L \ge 10^{-10}$. The case of oscillations generated asymmetry by late electron-sterile oscillations and its effect on primordial $^4He$ is also briefly discussed. |
hep-ph/9805354 | Yan Mu-Lin | Mu-Lin Yan (ICTP, Trieste; USTC, Hefei) Yi Wei and Ting-Liang Zhuang
(USTC, Hefei) | Comment on the hadronic decay of excited heavy quarkonia | 7 pages, no figures, LaTeX file, To appear in The European Physical
Journal (1998) | Eur.Phys.J.C7:61-63,1999 | 10.1007/s100520050384 | null | hep-ph | null | We make comments on ref.[Z.Phys. C73, 541 (1997)], and provide partial wave
analysis to the decays of excited heavy S-wave $1^-$ quarkonia into the basic
$1^-$ quarkonia state plus $\pi\pi$. It is revealed that there exist
contributions of D-wave transition in $\psi'\longrightarrow J/\psi\pi\pi$,
$\Upsilon(2S)\longrightarrow \Upsilon(1S) \pi \pi$ and
$\Upsilon(3S)\longrightarrow \Upsilon(1S) \pi \pi$ by using the data-fitting
results in ref.[Z.Phys C73, 541 (1997)]. A possible experimental method to
measure the D-wave directly is discussed.
| [
{
"created": "Mon, 18 May 1998 11:33:37 GMT",
"version": "v1"
},
{
"created": "Sun, 26 Jul 1998 16:06:09 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Yan",
"Mu-Lin",
"",
"ICTP, Trieste; USTC, Hefei"
],
[
"Wei",
"Yi",
"",
"USTC, Hefei"
],
[
"Zhuang",
"Ting-Liang",
"",
"USTC, Hefei"
]
] | We make comments on ref.[Z.Phys. C73, 541 (1997)], and provide partial wave analysis to the decays of excited heavy S-wave $1^-$ quarkonia into the basic $1^-$ quarkonia state plus $\pi\pi$. It is revealed that there exist contributions of D-wave transition in $\psi'\longrightarrow J/\psi\pi\pi$, $\Upsilon(2S)\longrightarrow \Upsilon(1S) \pi \pi$ and $\Upsilon(3S)\longrightarrow \Upsilon(1S) \pi \pi$ by using the data-fitting results in ref.[Z.Phys C73, 541 (1997)]. A possible experimental method to measure the D-wave directly is discussed. |
1206.0352 | Manmohan Gupta | Gulsheen Ahuja | Exploring the likelihood of CP violation in neutrino oscillations | 8 pages, 2 figures | Modern Physics Letters A, Vol.26, No.34 (2011) 2597-2603 | 10.1142/S0217732311036905 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In view of the latest T2K and MINOS observations regarding the mixing angle
s_{13}, we have explored the possibility of existence of CP violation in the
leptonic sector. Using hints from the construction of the 'db' unitarity
triangle in the quark sector, we have made an attempt to construct the
'\nu_1.\nu_3' leptonic unitarity triangle, suggesting a good possibility of
having non zero CP violation.
| [
{
"created": "Sat, 2 Jun 2012 07:30:56 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"Ahuja",
"Gulsheen",
""
]
] | In view of the latest T2K and MINOS observations regarding the mixing angle s_{13}, we have explored the possibility of existence of CP violation in the leptonic sector. Using hints from the construction of the 'db' unitarity triangle in the quark sector, we have made an attempt to construct the '\nu_1.\nu_3' leptonic unitarity triangle, suggesting a good possibility of having non zero CP violation. |
2204.08266 | Dibyendu Nanda | Debasish Borah, Satyabrata Mahapatra, Dibyendu Nanda, Narendra Sahu | Type II Dirac Seesaw with Observable $\Delta N_{\rm eff}$ in the light
of W-mass Anomaly | 10 pages, 9 figures, version accepted for publication in Phys. Lett.
B | null | 10.1016/j.physletb.2022.137297 | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a type II seesaw model for light Dirac neutrinos to provide an
explanation for the recently reported anomaly in W boson mass by the CDF
collaboration with $7\sigma$ statistical significance. In the minimal model,
the required enhancement in W boson mass is obtained at tree level due to the
vacuum expectation value of a real scalar triplet, which also plays a role in
generating light Dirac neutrino mass. Depending upon the couplings and masses
of newly introduced particles, we can have thermally or non-thermally generated
relativistic degrees of freedom $\Delta N_{\rm eff}$ in the form of right
handed neutrinos which can be observed at future cosmology experiments.
Extending the model to a radiative Dirac seesaw scenario can also accommodate
dark matter and lepton anomalous magnetic moment.
| [
{
"created": "Mon, 18 Apr 2022 11:49:42 GMT",
"version": "v1"
},
{
"created": "Sat, 9 Jul 2022 10:29:24 GMT",
"version": "v2"
}
] | 2022-08-10 | [
[
"Borah",
"Debasish",
""
],
[
"Mahapatra",
"Satyabrata",
""
],
[
"Nanda",
"Dibyendu",
""
],
[
"Sahu",
"Narendra",
""
]
] | We propose a type II seesaw model for light Dirac neutrinos to provide an explanation for the recently reported anomaly in W boson mass by the CDF collaboration with $7\sigma$ statistical significance. In the minimal model, the required enhancement in W boson mass is obtained at tree level due to the vacuum expectation value of a real scalar triplet, which also plays a role in generating light Dirac neutrino mass. Depending upon the couplings and masses of newly introduced particles, we can have thermally or non-thermally generated relativistic degrees of freedom $\Delta N_{\rm eff}$ in the form of right handed neutrinos which can be observed at future cosmology experiments. Extending the model to a radiative Dirac seesaw scenario can also accommodate dark matter and lepton anomalous magnetic moment. |
1808.03252 | Tommi Alanne | Tommi Alanne, Simone Blasi | The abelian gauge-Yukawa $\beta$-functions at large $N_f$ | 13 pages, 6 figures. v3 matches the published version | Phys. Rev. D 98, 116004 (2018) | 10.1103/PhysRevD.98.116004 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the impact of the Yukawa interaction in the large-$N_f$ limit to the
abelian gauge theory. We compute the coupled $\beta$-functions for the system
in a closed form at $\mathcal{O}(1/N_f)$.
| [
{
"created": "Thu, 9 Aug 2018 17:34:05 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Sep 2018 12:34:40 GMT",
"version": "v2"
},
{
"created": "Wed, 19 Dec 2018 10:31:35 GMT",
"version": "v3"
}
] | 2018-12-26 | [
[
"Alanne",
"Tommi",
""
],
[
"Blasi",
"Simone",
""
]
] | We study the impact of the Yukawa interaction in the large-$N_f$ limit to the abelian gauge theory. We compute the coupled $\beta$-functions for the system in a closed form at $\mathcal{O}(1/N_f)$. |
1105.2699 | Xiao-Gang He | Tsedenbaljir Enkhbat, Xiao-Gang He, Yukihiro Mimura, and Hiroshi
Yokoya | Colored Scalars And The CDF $W+$dijet Excess | RevTex, 17 pages and 4 figures. Some minor corrections | JHEP 1202 (2012) 058 | 10.1007/JHEP02(2012)058 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recent data on $W+$dijet excess reported by CDF may be interpreted as the
associated production of a $W$ and a new particle of mass about 150 GeV which
subsequently decays into two hadron jets. We study the possibility of
explaining the $W+$dijet excess by colored scalar bosons. There are several
colored scalars which can have tree level renormalizable Yukawa couplings with
two quarks, $({\bf 8}, {\bf 2},1/2)$, $(\bar{\bf 6}({\bf 3}), {\bf 3}({\bf 1}),
-1/3)$, $(\bar {\bf 6}({\bf 3}), {\bf 1}, -4/3(2/3))$. If one of these scalars
has a mass about 150 GeV, being colored it can naturally explain why the excess
only shows up in the form of two hadron jets. Although the required production
cross section and mass put constraints on model parameters and rule out some
possible scenarios when confronted with other existing data, in particular FCNC
data, we find that there are strong constraints on the Yukawa couplings of
these scalars. Without forcing the couplings to be some special texture forms
most of the scalars, except the $({\bf 3}, {\bf 3}, -1/3)$, are in trouble with
FCNC data. We also study some features for search of these new particles at the
RHIC and the LHC and find that related information can help further to
distinguish different models.
| [
{
"created": "Fri, 13 May 2011 12:04:49 GMT",
"version": "v1"
},
{
"created": "Thu, 19 May 2011 02:32:32 GMT",
"version": "v2"
},
{
"created": "Fri, 20 May 2011 02:56:50 GMT",
"version": "v3"
},
{
"created": "Wed, 24 Aug 2011 02:22:21 GMT",
"version": "v4"
},
{
"created": "Fri, 16 Dec 2011 16:21:40 GMT",
"version": "v5"
},
{
"created": "Wed, 11 Jan 2012 06:03:21 GMT",
"version": "v6"
}
] | 2012-02-24 | [
[
"Enkhbat",
"Tsedenbaljir",
""
],
[
"He",
"Xiao-Gang",
""
],
[
"Mimura",
"Yukihiro",
""
],
[
"Yokoya",
"Hiroshi",
""
]
] | The recent data on $W+$dijet excess reported by CDF may be interpreted as the associated production of a $W$ and a new particle of mass about 150 GeV which subsequently decays into two hadron jets. We study the possibility of explaining the $W+$dijet excess by colored scalar bosons. There are several colored scalars which can have tree level renormalizable Yukawa couplings with two quarks, $({\bf 8}, {\bf 2},1/2)$, $(\bar{\bf 6}({\bf 3}), {\bf 3}({\bf 1}), -1/3)$, $(\bar {\bf 6}({\bf 3}), {\bf 1}, -4/3(2/3))$. If one of these scalars has a mass about 150 GeV, being colored it can naturally explain why the excess only shows up in the form of two hadron jets. Although the required production cross section and mass put constraints on model parameters and rule out some possible scenarios when confronted with other existing data, in particular FCNC data, we find that there are strong constraints on the Yukawa couplings of these scalars. Without forcing the couplings to be some special texture forms most of the scalars, except the $({\bf 3}, {\bf 3}, -1/3)$, are in trouble with FCNC data. We also study some features for search of these new particles at the RHIC and the LHC and find that related information can help further to distinguish different models. |
2209.12191 | Moha Ouali | M. Ouhammou, M. Ouali, S. Taj, R. Benbrik, and B. Manaut | Laser-induced proton decay | 10 pages, 2 figures | null | 10.1007/s00340-023-08035-6 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this research paper, we investigate the decay of the proton into neutron,
positron and electron neutrino in the presence of an external electromagnetic
field with circular polarization. Different physical quantities related to this
decay process, such as proton's decay rate and its lifetime, are calculated
based on the S-matrix approach. The proton and positron are treated as
Dirac-Volkov states, while the neutron and electron neutrino are free-states.
We have found that, though it can not occur in vacuum, the proton's decay
process into neutron, positron and electron neutrino becomes possible in the
presence of laser field with high intensities near or close to the Schwinger
limit. In addition, near this limit and for some frequencies, the proton's
lifetime can be comparable to that of the neutron, and the required laser
strength, from which this decay becomes possible, depends on the chosen laser
source.
| [
{
"created": "Sun, 25 Sep 2022 10:13:54 GMT",
"version": "v1"
}
] | 2023-06-21 | [
[
"Ouhammou",
"M.",
""
],
[
"Ouali",
"M.",
""
],
[
"Taj",
"S.",
""
],
[
"Benbrik",
"R.",
""
],
[
"Manaut",
"B.",
""
]
] | In this research paper, we investigate the decay of the proton into neutron, positron and electron neutrino in the presence of an external electromagnetic field with circular polarization. Different physical quantities related to this decay process, such as proton's decay rate and its lifetime, are calculated based on the S-matrix approach. The proton and positron are treated as Dirac-Volkov states, while the neutron and electron neutrino are free-states. We have found that, though it can not occur in vacuum, the proton's decay process into neutron, positron and electron neutrino becomes possible in the presence of laser field with high intensities near or close to the Schwinger limit. In addition, near this limit and for some frequencies, the proton's lifetime can be comparable to that of the neutron, and the required laser strength, from which this decay becomes possible, depends on the chosen laser source. |
hep-ph/0105248 | Ho-Meoyng Choi | Chueng-Ryong Ji (North Carolina State Univ.), Ho-Meoyng Choi (Carnegie
Mellon Univ.) | New Progress in Time-Like Exclusive Processes | Invited talk(ID No. T23) given at ``e^+e^- Physics at Intermediate
Energies Workshop", Stanford, CA, April 30-May 2, 2001; 6 pages including 5
figures; typo corrected in Eq. (14) | eConf C010430 (2001) T23 | null | null | hep-ph | null | We discuss a necessary nonvalence contribution in timelike exclusive
processes. Following a Schwinger-Dyson type of approach, we relate the
nonvalence contribution to an ordinary light-front wave function that has been
extensively tested in the spacelike exclusive processes. A complicate
multi-body energy denominator is exactly cancelled in summing the light-front
time-ordered amplitudes. Applying our method to $K_{\ell3}$ and $D^0\to K^-
\ell^+ \nu_l$ where a rather substantial nonvalence contribution is expected,
we find not only an improvement in comparing with the experimental data but
also a covariance(i.e. frame-indepndence) of existing light-front constituent
quark model.
| [
{
"created": "Wed, 23 May 2001 17:38:54 GMT",
"version": "v1"
},
{
"created": "Sat, 9 Jun 2001 22:51:40 GMT",
"version": "v2"
},
{
"created": "Thu, 5 Jul 2001 17:51:14 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Ji",
"Chueng-Ryong",
"",
"North Carolina State Univ."
],
[
"Choi",
"Ho-Meoyng",
"",
"Carnegie\n Mellon Univ."
]
] | We discuss a necessary nonvalence contribution in timelike exclusive processes. Following a Schwinger-Dyson type of approach, we relate the nonvalence contribution to an ordinary light-front wave function that has been extensively tested in the spacelike exclusive processes. A complicate multi-body energy denominator is exactly cancelled in summing the light-front time-ordered amplitudes. Applying our method to $K_{\ell3}$ and $D^0\to K^- \ell^+ \nu_l$ where a rather substantial nonvalence contribution is expected, we find not only an improvement in comparing with the experimental data but also a covariance(i.e. frame-indepndence) of existing light-front constituent quark model. |
1508.06424 | Jakub Zaremba | Zbigniew Was and Jakub Zaremba | Study of variants for Monte Carlo generators of $\tau\to 3\pi\nu$ decays | null | null | null | IFJPAN-IV-2015-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Low energy QCD (below 2 GeV) is a region of resonance dynamics, sometimes
lacking satisfactory description as compared to precision of available
experimental data. Hadronic $\tau$ decays offer a probe for such energy regime.
In general, predictions for decays are model dependent, with parameters fitted
to experimental results. Parameterizations differ by amount of assumptions and
theoretical requirements taken into account. Both model distributions and
acquired data samples used for fits are results of complex effort.
In this paper, we investigate main parameterizations of $\tau$ decay matrix
elements for the one- and three-prong channels of three-pion $\tau$ decays.
Differences in analytical forms of the currents and resulting distributions
used for comparison with the experimental data are studied. We use invariant
mass spectra of all possible pion pairs and the whole three-pion system. Also
three-dimensional histograms spanned over all distinct squared invariant masses
are used to represent results of models and experimental data.
We present distributions from {\tt TAUOLA} Monte Carlo generation and
semi-analytical calculation. These are necessary steps in development for
fitting in as model-independent way as possible, and to explore multi-million
event experimental data samples. This includes response of distributions to
model variants, and/or numerical values of parameters. Interference effects of
currents parts are also studied.
For technical purposes, weighted events are introduced. Even though we focus
on $3\pi\nu_\tau$ modes, technical aspects of our study are relevant for all
$\tau$ decay modes into three hadrons.
| [
{
"created": "Wed, 26 Aug 2015 09:42:38 GMT",
"version": "v1"
}
] | 2015-08-27 | [
[
"Was",
"Zbigniew",
""
],
[
"Zaremba",
"Jakub",
""
]
] | Low energy QCD (below 2 GeV) is a region of resonance dynamics, sometimes lacking satisfactory description as compared to precision of available experimental data. Hadronic $\tau$ decays offer a probe for such energy regime. In general, predictions for decays are model dependent, with parameters fitted to experimental results. Parameterizations differ by amount of assumptions and theoretical requirements taken into account. Both model distributions and acquired data samples used for fits are results of complex effort. In this paper, we investigate main parameterizations of $\tau$ decay matrix elements for the one- and three-prong channels of three-pion $\tau$ decays. Differences in analytical forms of the currents and resulting distributions used for comparison with the experimental data are studied. We use invariant mass spectra of all possible pion pairs and the whole three-pion system. Also three-dimensional histograms spanned over all distinct squared invariant masses are used to represent results of models and experimental data. We present distributions from {\tt TAUOLA} Monte Carlo generation and semi-analytical calculation. These are necessary steps in development for fitting in as model-independent way as possible, and to explore multi-million event experimental data samples. This includes response of distributions to model variants, and/or numerical values of parameters. Interference effects of currents parts are also studied. For technical purposes, weighted events are introduced. Even though we focus on $3\pi\nu_\tau$ modes, technical aspects of our study are relevant for all $\tau$ decay modes into three hadrons. |
2202.06886 | Ivan Aleksandrov | I. A. Aleksandrov, A. Di Piazza, G. Plunien, V. M. Shabaev | Stimulated vacuum emission and photon absorption in strong
electromagnetic fields | 11 pages, 6 figures | null | 10.1103/PhysRevD.105.116005 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | According to quantum electrodynamics (QED), a strong external field can make
the vacuum state decay producing electron-positron pairs. Here we investigate
emission of soft photons which accompanies a nonperturbative process of pair
production. Our analysis is carried out within the Furry picture to first order
in the fine-structure constant. It is shown that the presence of photons in the
initial state gives rise to an additional (stimulated) channel of photon
emission besides the pure vacuum one. On the other hand, the number of final
(signal) photons includes also a negative contribution due to photon absorption
within the pair production process. These contributions are evaluated and
compared. To obtain quantitative predictions in the domain of realistic field
parameters, we employ the WKB approach. We propose to use an optical probe
photon beam, whose intensity changes as it traverses a spatial region where a
strong electric component of a background laser field is present. It is
demonstrated that relative intensity changes on the level of $1 \%$ can be
experimentally observed once the intensity of the strong background field
exceeds $10^{27}~\text{W/cm}^2$ within a large laser wavelength interval. This
finding is expected to significantly support possible experimental
investigations of nonlinear QED phenomena in the nonperturbative regime.
| [
{
"created": "Mon, 14 Feb 2022 17:20:08 GMT",
"version": "v1"
}
] | 2022-06-22 | [
[
"Aleksandrov",
"I. A.",
""
],
[
"Di Piazza",
"A.",
""
],
[
"Plunien",
"G.",
""
],
[
"Shabaev",
"V. M.",
""
]
] | According to quantum electrodynamics (QED), a strong external field can make the vacuum state decay producing electron-positron pairs. Here we investigate emission of soft photons which accompanies a nonperturbative process of pair production. Our analysis is carried out within the Furry picture to first order in the fine-structure constant. It is shown that the presence of photons in the initial state gives rise to an additional (stimulated) channel of photon emission besides the pure vacuum one. On the other hand, the number of final (signal) photons includes also a negative contribution due to photon absorption within the pair production process. These contributions are evaluated and compared. To obtain quantitative predictions in the domain of realistic field parameters, we employ the WKB approach. We propose to use an optical probe photon beam, whose intensity changes as it traverses a spatial region where a strong electric component of a background laser field is present. It is demonstrated that relative intensity changes on the level of $1 \%$ can be experimentally observed once the intensity of the strong background field exceeds $10^{27}~\text{W/cm}^2$ within a large laser wavelength interval. This finding is expected to significantly support possible experimental investigations of nonlinear QED phenomena in the nonperturbative regime. |
1209.4579 | Peihong Gu | Pei-Hong Gu | From Dirac neutrino masses to baryonic and dark matter asymmetries | 15 pages, 6 figures. More discussions and references. To appear in
NPB | null | 10.1016/j.nuclphysb.2013.03.014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider an SU(3)'_c\times SU(2)'_L\times U(1)'_Y dark sector, parallel to
the SU(3)_c\times SU(2)_L\times U(1)_Y ordinary sector. The hypercharges,
baryon numbers and lepton numbers in the dark sector are opposite to those in
the ordinary sector. We further introduce three types of messenger sectors: (i)
two or more gauge-singlet Dirac fermions, (ii) two or more [SU(2)_L\times
SU(2)'_L]-bidoublet Higgs scalars, (iii) at least one gauge-singlet Dirac
fermion and at least one [SU(2)_L\times SU(2)'_L]-bidoublet Higgs scalar. The
lepton number conserving decays of the heavy fermion singlet(s) and/or Higgs
bidoublet(s) can simultaneously generate a lepton asymmetry in the
[SU(2)_L]-doublet leptons and an opposite lepton asymmetry in the
[SU(2)'_L]-doublet leptons to account for the cosmological baryon asymmetry and
dark matter relic density, respectively. The lightest dark nucleon as the dark
matter particle should have a mass about 5 GeV. By integrating out the heavy
fermion singlet(s) and/or Higgs bidoublet(s), we can obtain three light Dirac
neutrinos composed of the ordinary and dark neutrinos. If a mirror discrete
symmetry is further imposed, our models will not require more unknown
parameters than the traditional type-I, type-II or type-I+II seesaw models.
| [
{
"created": "Thu, 20 Sep 2012 16:34:56 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Mar 2013 16:18:48 GMT",
"version": "v2"
}
] | 2015-06-11 | [
[
"Gu",
"Pei-Hong",
""
]
] | We consider an SU(3)'_c\times SU(2)'_L\times U(1)'_Y dark sector, parallel to the SU(3)_c\times SU(2)_L\times U(1)_Y ordinary sector. The hypercharges, baryon numbers and lepton numbers in the dark sector are opposite to those in the ordinary sector. We further introduce three types of messenger sectors: (i) two or more gauge-singlet Dirac fermions, (ii) two or more [SU(2)_L\times SU(2)'_L]-bidoublet Higgs scalars, (iii) at least one gauge-singlet Dirac fermion and at least one [SU(2)_L\times SU(2)'_L]-bidoublet Higgs scalar. The lepton number conserving decays of the heavy fermion singlet(s) and/or Higgs bidoublet(s) can simultaneously generate a lepton asymmetry in the [SU(2)_L]-doublet leptons and an opposite lepton asymmetry in the [SU(2)'_L]-doublet leptons to account for the cosmological baryon asymmetry and dark matter relic density, respectively. The lightest dark nucleon as the dark matter particle should have a mass about 5 GeV. By integrating out the heavy fermion singlet(s) and/or Higgs bidoublet(s), we can obtain three light Dirac neutrinos composed of the ordinary and dark neutrinos. If a mirror discrete symmetry is further imposed, our models will not require more unknown parameters than the traditional type-I, type-II or type-I+II seesaw models. |
hep-ph/9610490 | Roland Hoepker | W. Beenakker (Leiden), R. H"opker (DESY), M. Spira (CERN) and P.M.
Zerwas (DESY) | Squark and Gluino Production at Hadron Colliders | 60 pages, Latex2e, 24 figures (uses epsfig.sty) | Nucl.Phys.B492:51-103,1997 | 10.1016/S0550-3213(97)00084-9 | DESY96-150 and CERN96-215 | hep-ph | null | We have determined the theoretical predictions for the cross-sections of
squark and gluino production at $\ppb$ and $pp$ colliders (Tevatron and LHC) in
next-to-leading order of supersymmetric QCD. By reducing the dependence on the
renormalization/factorization scale considerably, the theoretically predicted
values for the cross-sections are much more stable if these higher-order
corrections are implemented. If squarks and gluinos are discovered, this
improved stability translates into a reduced error on the masses, as extracted
experimentally from the size of the production cross-sections. The
cross-sections increase significantly if the next-to-leading order corrections
are included at a renormalization/factorization scale near the average mass of
the produced massive particles. This rise results in improved lower bounds on
squark and gluino masses. By contrast, the shape of the transverse-momentum and
rapidity distributions remains nearly unchanged when the next-to-leading order
corrections are included.
| [
{
"created": "Fri, 25 Oct 1996 14:43:31 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Beenakker",
"W.",
"",
"Leiden"
],
[
"H\"opker",
"R.",
"",
"DESY"
],
[
"Spira",
"M.",
"",
"CERN"
],
[
"Zerwas",
"P. M.",
"",
"DESY"
]
] | We have determined the theoretical predictions for the cross-sections of squark and gluino production at $\ppb$ and $pp$ colliders (Tevatron and LHC) in next-to-leading order of supersymmetric QCD. By reducing the dependence on the renormalization/factorization scale considerably, the theoretically predicted values for the cross-sections are much more stable if these higher-order corrections are implemented. If squarks and gluinos are discovered, this improved stability translates into a reduced error on the masses, as extracted experimentally from the size of the production cross-sections. The cross-sections increase significantly if the next-to-leading order corrections are included at a renormalization/factorization scale near the average mass of the produced massive particles. This rise results in improved lower bounds on squark and gluino masses. By contrast, the shape of the transverse-momentum and rapidity distributions remains nearly unchanged when the next-to-leading order corrections are included. |
1303.6180 | Gui-Jun Ding | Gui-Jun Ding, Stephen F. King, Christoph Luhn, Alexander J. Stuart | Spontaneous CP violation from vacuum alignment in $S_4$ models of
leptons | 34 pages, 2 figures | null | 10.1007/JHEP05(2013)084 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct models of leptons based on $S_4$ family symmetry combined with a
generalised CP symmetry $H_{CP}$. We show how the flavon potential can
spontaneously break the symmetry $S_4 \rtimes H_{CP}$ down to $Z_2 \times
H^{\nu}_{CP}$ in the neutrino sector, where the choice of preserved CP symmetry
$H^{\nu}_{CP}$ is controlled by free (real) parameters in the flavon potential.
We propose two realistic models of this kind, one at the effective level and
one at the renormalisable level. Both models predict trimaximal lepton mixing
with CP being either fully preserved or maximally broken, with the intermediate
possibility forbidden by the structure of the models.
| [
{
"created": "Mon, 25 Mar 2013 15:50:42 GMT",
"version": "v1"
},
{
"created": "Sun, 23 Mar 2014 08:48:13 GMT",
"version": "v2"
}
] | 2015-06-15 | [
[
"Ding",
"Gui-Jun",
""
],
[
"King",
"Stephen F.",
""
],
[
"Luhn",
"Christoph",
""
],
[
"Stuart",
"Alexander J.",
""
]
] | We construct models of leptons based on $S_4$ family symmetry combined with a generalised CP symmetry $H_{CP}$. We show how the flavon potential can spontaneously break the symmetry $S_4 \rtimes H_{CP}$ down to $Z_2 \times H^{\nu}_{CP}$ in the neutrino sector, where the choice of preserved CP symmetry $H^{\nu}_{CP}$ is controlled by free (real) parameters in the flavon potential. We propose two realistic models of this kind, one at the effective level and one at the renormalisable level. Both models predict trimaximal lepton mixing with CP being either fully preserved or maximally broken, with the intermediate possibility forbidden by the structure of the models. |
2405.02104 | Mar\'ia Olalla Olea-Romacho | Pierre Fayet, Mar\'ia Olalla Olea-Romacho | Searching for a new light gauge boson with axial couplings in muon beam
dump experiments | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a formalism for new $U(1)$ interactions involving weak
hypercharge, baryon, and lepton numbers, and a possible axial symmetry
generator $F_A$ in the presence of a second Brout-Englert-Higgs doublet. The
resulting $U$ boson, after mixing with the $Z$, interpolates between a
generalised dark photon, a dark $Z$, and an axially coupled gauge boson. We
especially focus on the axial couplings originating from $F_A$ or from mixing
with the $Z$, determined by the scalar sector via parameters like $\tan\beta$
and the v.e.v. of an extra dark singlet. We explore the distinctive features of
axially coupled interactions, especially in the ultrarelativistic limit, where
the $U$ boson behaves much as an axion-like particle, with enhanced
interactions to quarks and leptons. This enhancement is particularly relevant
for future muon beam dump experiments, since the muon mass considerably
increases the effective coupling, proportional to $2m_\mu/m_U$, compared to
analogous experiments with electrons. We also analyse the shape of the expected
beam dump exclusion or discovery regions, influenced by $U$ boson interactions
and the experiment geometry. Different situations are considered, limited in
particular by cases for which the $U$ decays before reaching the detector, or
has too small couplings to produce detectable events. We also compare to
vectorially coupled bosons and axion-like pseudoscalars, highlighting the
importance of understanding the parameter space for future experiment design
and optimisation.
| [
{
"created": "Fri, 3 May 2024 14:00:54 GMT",
"version": "v1"
}
] | 2024-05-06 | [
[
"Fayet",
"Pierre",
""
],
[
"Olea-Romacho",
"María Olalla",
""
]
] | We present a formalism for new $U(1)$ interactions involving weak hypercharge, baryon, and lepton numbers, and a possible axial symmetry generator $F_A$ in the presence of a second Brout-Englert-Higgs doublet. The resulting $U$ boson, after mixing with the $Z$, interpolates between a generalised dark photon, a dark $Z$, and an axially coupled gauge boson. We especially focus on the axial couplings originating from $F_A$ or from mixing with the $Z$, determined by the scalar sector via parameters like $\tan\beta$ and the v.e.v. of an extra dark singlet. We explore the distinctive features of axially coupled interactions, especially in the ultrarelativistic limit, where the $U$ boson behaves much as an axion-like particle, with enhanced interactions to quarks and leptons. This enhancement is particularly relevant for future muon beam dump experiments, since the muon mass considerably increases the effective coupling, proportional to $2m_\mu/m_U$, compared to analogous experiments with electrons. We also analyse the shape of the expected beam dump exclusion or discovery regions, influenced by $U$ boson interactions and the experiment geometry. Different situations are considered, limited in particular by cases for which the $U$ decays before reaching the detector, or has too small couplings to produce detectable events. We also compare to vectorially coupled bosons and axion-like pseudoscalars, highlighting the importance of understanding the parameter space for future experiment design and optimisation. |
1806.09154 | Takashi Toma | Mayumi Aoki, Takashi Toma | Boosted Self-interacting Dark Matter in a Multi-component Dark Matter
Model | 25 pages, 10 figures, 4 tables, version to appear in JCAP | JCAP 1810 (2018) 020 | 10.1088/1475-7516/2018/10/020 | KANAZAWA-18-02, TUM-HEP/1142/18 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In models of multi-component dark matter, the lighter component of dark
matter can be boosted by annihilations of the heavier state if mass splitting
is large enough. Such relativistic dark matter can be detectable via large
neutrino detectors such as Super-Kamiokande and IceCube. Moreover, if the
process is inelastic scattering and decay length of the produced particle is
short enough, another signature coming from the decay can also be detectable.
In this paper, we construct a simple two-component dark matter model with a
hidden U(1)_D gauge symmetry where the lighter component of dark matter has a
potential to improve the so-called small scale structure problems with large
self-interacting cross section. We estimate number of multi-Cherenkov ring
events due to both of the boosted dark matter and subsequent decay of the
particle produced by inelastic scattering at Hyper-Kamiokande future
experiment. Some relevant constraints, such as dark matter direct detection and
cosmological observations, are also taken into account. The numerical analysis
shows that some parameter space which can induce large self-interacting cross
section can give a few multi-Cherenkov ring events per year at
Hyper-Kamiokande.
| [
{
"created": "Sun, 24 Jun 2018 14:28:41 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Oct 2018 16:35:50 GMT",
"version": "v2"
}
] | 2018-10-16 | [
[
"Aoki",
"Mayumi",
""
],
[
"Toma",
"Takashi",
""
]
] | In models of multi-component dark matter, the lighter component of dark matter can be boosted by annihilations of the heavier state if mass splitting is large enough. Such relativistic dark matter can be detectable via large neutrino detectors such as Super-Kamiokande and IceCube. Moreover, if the process is inelastic scattering and decay length of the produced particle is short enough, another signature coming from the decay can also be detectable. In this paper, we construct a simple two-component dark matter model with a hidden U(1)_D gauge symmetry where the lighter component of dark matter has a potential to improve the so-called small scale structure problems with large self-interacting cross section. We estimate number of multi-Cherenkov ring events due to both of the boosted dark matter and subsequent decay of the particle produced by inelastic scattering at Hyper-Kamiokande future experiment. Some relevant constraints, such as dark matter direct detection and cosmological observations, are also taken into account. The numerical analysis shows that some parameter space which can induce large self-interacting cross section can give a few multi-Cherenkov ring events per year at Hyper-Kamiokande. |
1009.3963 | Tao Liu | Patrick Draper, Tao Liu, Carlos E.M. Wagner, Lian-Tao Wang, Hao Zhang | Dark Light Higgs | 4 pages, 4 figures, final version for Phys. Rev. Lett | Phys.Rev.Lett.106:121805,2011 | 10.1103/PhysRevLett.106.121805 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a limit of the nearly-Peccei-Quinn-symmetric Next-to-Minimal
Supersymmetric Standard Model possessing novel Higgs and dark matter (DM)
properties. In this scenario, there naturally co-exist three light singlet-like
particles: a scalar, a pseudoscalar, and a singlino-like DM candidate, all with
masses of order 0.1-10 GeV. The decay of a Standard Model-like Higgs boson to
pairs of the light scalars or pseudoscalars is generically suppressed, avoiding
constraints from collider searches for these channels. For a certain parameter
window annihilation into the light pseudoscalar and exchange of the light
scalar with nucleons allow the singlino to achieve the correct relic density
and a large direct detection cross section consistent with the CoGeNT and
DAMA/LIBRA preferred region simultaneously. This parameter space is consistent
with experimental constraints from LEP, the Tevatron, and Upsilon- and flavor
physics.
| [
{
"created": "Mon, 20 Sep 2010 23:02:06 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Nov 2011 02:40:55 GMT",
"version": "v2"
}
] | 2011-11-14 | [
[
"Draper",
"Patrick",
""
],
[
"Liu",
"Tao",
""
],
[
"Wagner",
"Carlos E. M.",
""
],
[
"Wang",
"Lian-Tao",
""
],
[
"Zhang",
"Hao",
""
]
] | We study a limit of the nearly-Peccei-Quinn-symmetric Next-to-Minimal Supersymmetric Standard Model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally co-exist three light singlet-like particles: a scalar, a pseudoscalar, and a singlino-like DM candidate, all with masses of order 0.1-10 GeV. The decay of a Standard Model-like Higgs boson to pairs of the light scalars or pseudoscalars is generically suppressed, avoiding constraints from collider searches for these channels. For a certain parameter window annihilation into the light pseudoscalar and exchange of the light scalar with nucleons allow the singlino to achieve the correct relic density and a large direct detection cross section consistent with the CoGeNT and DAMA/LIBRA preferred region simultaneously. This parameter space is consistent with experimental constraints from LEP, the Tevatron, and Upsilon- and flavor physics. |
hep-ph/0312222 | Fran\c{c}ois Gelis | E. Fraga (UFRJ, Rio de Janeiro), F. Gelis (SPhT, Saclay), D. Schiff
(LPT, Orsay) | Remarks on transient photon production in heavy ion collisions | 13 pages | Phys.Rev. D71 (2005) 085015 | 10.1103/PhysRevD.71.085015 | null | hep-ph | null | In this note, we discuss the derivation of a formula that has been used in
the literature in order to compute the number of photons emitted by a hot or
dense system during a finite time. Our derivation is based on a variation of
the standard operator-based $S$-matrix approach. The shortcomings of this
formula are then emphasized, which leads to a negative conclusion concerning
the possibility of using it to predict transient effects for the photon rate.
| [
{
"created": "Tue, 16 Dec 2003 20:17:26 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Fraga",
"E.",
"",
"UFRJ, Rio de Janeiro"
],
[
"Gelis",
"F.",
"",
"SPhT, Saclay"
],
[
"Schiff",
"D.",
"",
"LPT, Orsay"
]
] | In this note, we discuss the derivation of a formula that has been used in the literature in order to compute the number of photons emitted by a hot or dense system during a finite time. Our derivation is based on a variation of the standard operator-based $S$-matrix approach. The shortcomings of this formula are then emphasized, which leads to a negative conclusion concerning the possibility of using it to predict transient effects for the photon rate. |
1006.0653 | Konstantin Matchev | Partha Konar, Kyoungchul Kong, Konstantin T. Matchev and Myeonghun
Park | RECO level \sqrt{s}_{min} and subsystem \sqrt{s}_{min}: improved global
inclusive variables for measuring the new physics mass scale in missing
energy events at hadron colliders | 41 pages, 26 figures | JHEP 1106:041,2011 | 10.1007/JHEP06(2011)041 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The variable \sqrt{s}_{min} was originally proposed in arXiv:0812.1042 as a
model-independent, global and fully inclusive measure of the new physics mass
scale in missing energy events at hadron colliders. In the original incarnation
of \sqrt{s}_{min}, however, the connection to the new physics mass scale was
blurred by the effects of the underlying event, most notably initial state
radiation and multiple parton interactions. In this paper we advertize two
improved variants of the \sqrt{s}_{min} variable, which overcome this problem.
First we show that by evaluating the \sqrt{s}_{min} variable at the RECO level,
in terms of the reconstructed objects in the event, the effects from the
underlying event are significantly diminished and the nice correlation between
the peak in the \sqrt{s}_{min}^{(reco)} distribution and the new physics mass
scale is restored. Secondly, the underlying event problem can be avoided
altogether when the \sqrt{s}_{min} concept is applied to a subsystem of the
event which does not involve any QCD jets. We supply an analytic formula for
the resulting subsystem \sqrt{s}_{min}^{(sub)} variable and show that its peak
exhibits the usual correlation with the mass scale of the particles produced in
the subsystem. Finally, we contrast \sqrt{s}_{min} to other popular inclusive
variables such as H_T, M_{Tgen} and M_{TTgen}. We illustrate our discussion
with several examples from supersymmetry, and with dilepton events from top
quark pair production.
| [
{
"created": "Thu, 3 Jun 2010 13:56:57 GMT",
"version": "v1"
}
] | 2011-06-20 | [
[
"Konar",
"Partha",
""
],
[
"Kong",
"Kyoungchul",
""
],
[
"Matchev",
"Konstantin T.",
""
],
[
"Park",
"Myeonghun",
""
]
] | The variable \sqrt{s}_{min} was originally proposed in arXiv:0812.1042 as a model-independent, global and fully inclusive measure of the new physics mass scale in missing energy events at hadron colliders. In the original incarnation of \sqrt{s}_{min}, however, the connection to the new physics mass scale was blurred by the effects of the underlying event, most notably initial state radiation and multiple parton interactions. In this paper we advertize two improved variants of the \sqrt{s}_{min} variable, which overcome this problem. First we show that by evaluating the \sqrt{s}_{min} variable at the RECO level, in terms of the reconstructed objects in the event, the effects from the underlying event are significantly diminished and the nice correlation between the peak in the \sqrt{s}_{min}^{(reco)} distribution and the new physics mass scale is restored. Secondly, the underlying event problem can be avoided altogether when the \sqrt{s}_{min} concept is applied to a subsystem of the event which does not involve any QCD jets. We supply an analytic formula for the resulting subsystem \sqrt{s}_{min}^{(sub)} variable and show that its peak exhibits the usual correlation with the mass scale of the particles produced in the subsystem. Finally, we contrast \sqrt{s}_{min} to other popular inclusive variables such as H_T, M_{Tgen} and M_{TTgen}. We illustrate our discussion with several examples from supersymmetry, and with dilepton events from top quark pair production. |
hep-ph/9509283 | Hyun-Chul Kim | Hyun-Chul Kim, Maxim V. Polyakov and Klaus Goeke | Nucleon Tensor Charges in the SU(2) Chiral Quark--Soliton Model | 4 pages. RevTex is used. 1 postscrip figure. The final version to be
published in Phys. Rev. D | Phys.Rev.D53:4715-4718,1996 | 10.1103/PhysRevD.53.4715 | RUB-TPII-26/95 | hep-ph | null | We investigate the singlet $g_T^{(0)}$ and isovector $g_T^{(3)}$ tensor
charges of the nucleon, which are deeply related to the first moment of the
leading twist transversity quark distribution $h_1(x)$, in the SU(2) chiral
quark-soliton model. With rotational $O(1/N_c)$ corrections taken into account,
we obtain $g_T^{(0)}=0.69$ and $g_T^{(3)}=1.45$ at a low normalization point of
several hundreds MeV.
Within the same approximation and parameters the model yields
$g_A^{(0)}=0.36$, $g_A^{(3)}=1.21$ for axial charges and correct
octet--decuplet mass splitting. We show how the chiral quark-soliton model
interpolates between the nonrelativistic quark model and the Skyrme model.
| [
{
"created": "Wed, 13 Sep 1995 12:01:54 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Sep 1995 13:16:23 GMT",
"version": "v2"
},
{
"created": "Wed, 27 Sep 1995 15:51:39 GMT",
"version": "v3"
},
{
"created": "Tue, 5 Dec 1995 16:19:05 GMT",
"version": "v4"
},
{
"created": "Wed, 27 Mar 1996 10:26:06 GMT",
"version": "v5"
}
] | 2016-09-01 | [
[
"Kim",
"Hyun-Chul",
""
],
[
"Polyakov",
"Maxim V.",
""
],
[
"Goeke",
"Klaus",
""
]
] | We investigate the singlet $g_T^{(0)}$ and isovector $g_T^{(3)}$ tensor charges of the nucleon, which are deeply related to the first moment of the leading twist transversity quark distribution $h_1(x)$, in the SU(2) chiral quark-soliton model. With rotational $O(1/N_c)$ corrections taken into account, we obtain $g_T^{(0)}=0.69$ and $g_T^{(3)}=1.45$ at a low normalization point of several hundreds MeV. Within the same approximation and parameters the model yields $g_A^{(0)}=0.36$, $g_A^{(3)}=1.21$ for axial charges and correct octet--decuplet mass splitting. We show how the chiral quark-soliton model interpolates between the nonrelativistic quark model and the Skyrme model. |
1712.07013 | Huaiyu Duan | Sajad Abbar and Huaiyu Duan (UNM) | Fast neutrino flavor conversion: roles of dense matter and spectrum
crossing | 11 pages, 4 figures. Updated with editorial changes and
clarifications | Phys. Rev. D 98, 043014 (2018) | 10.1103/PhysRevD.98.043014 | null | hep-ph astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The flavor conversion of a neutrino usually occurs at densities $\lesssim
G_F^{-1} \omega$, whether in the ordinary matter or the neutrino medium, and on
time/distance scales of order $\omega^{-1}$, where $G_F$ is the Fermi weak
coupling constant and $\omega$ is the vacuum oscillation frequency of the
neutrino. In 2005 Sawyer and more recently both he and other groups have shown
that neutrino flavor conversions can occur on scales much shorter than
$\omega^{-1}$ in a very dense, anisotropic neutrino gas such as that in a
core-collapse supernova or a binary neutron star merger. It has also been
suggested that the fast neutrino flavor conversion require a crossing in the
electron lepton number (ELN) angular distribution or spectrum. We study a few
simple analytical models with which we elucidate the roles of the dense matter
and the ELN spectrum crossing in neutrino fast flavor conversions. We show that
a large matter density can induce fast neutrino flavor conversions in certain
astrophysical scenarios such as at the early epoch of a core-collapse
supernova.
| [
{
"created": "Tue, 19 Dec 2017 16:00:09 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Aug 2018 14:24:24 GMT",
"version": "v2"
}
] | 2018-08-22 | [
[
"Abbar",
"Sajad",
"",
"UNM"
],
[
"Duan",
"Huaiyu",
"",
"UNM"
]
] | The flavor conversion of a neutrino usually occurs at densities $\lesssim G_F^{-1} \omega$, whether in the ordinary matter or the neutrino medium, and on time/distance scales of order $\omega^{-1}$, where $G_F$ is the Fermi weak coupling constant and $\omega$ is the vacuum oscillation frequency of the neutrino. In 2005 Sawyer and more recently both he and other groups have shown that neutrino flavor conversions can occur on scales much shorter than $\omega^{-1}$ in a very dense, anisotropic neutrino gas such as that in a core-collapse supernova or a binary neutron star merger. It has also been suggested that the fast neutrino flavor conversion require a crossing in the electron lepton number (ELN) angular distribution or spectrum. We study a few simple analytical models with which we elucidate the roles of the dense matter and the ELN spectrum crossing in neutrino fast flavor conversions. We show that a large matter density can induce fast neutrino flavor conversions in certain astrophysical scenarios such as at the early epoch of a core-collapse supernova. |
1603.03157 | Shahin Atashbar Tehrani | F. Taghavi Shahri, Hamzeh Khanpour, S. Atashbar Tehrani, Z. Alizadeh
Yazdi | Next-to-next-to-leading order QCD analysis of spin-dependent parton
distribution functions and their uncertainties: Jacobi polynomials approach | 17 Pages, 15 Figures, 8 Tables | Phys. Rev. D 93, 114024 (2016) | 10.1103/PhysRevD.93.114024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a first QCD analysis of next-to-next-leading-order (NNLO)
contributions of the spin-dependent parton distribution functions (PPDFs) in
the nucleon and their uncertainties using the Jacobi polynomial approach.
Having the NNLO contributions of the quark-quark and gluon-quark splitting
functions in perturbative QCD (Nucl. Phys. B 889 (2014) 351-400), one can
obtain the evolution of longitudinally polarized parton densities of hadrons up
to NNLO accuracy of QCD. A very large sets of recent and up-to-date
experimental data of spin structure functions of the proton $g_1^p$, neutron
$g_1^n$, and deuteron $g_1^d$ have been used in this analysis. The predictions
for the NNLO calculations of the polarized parton distribution functions as
well as the proton, neutron and deuteron polarized structure functions are
compared with the corresponding results of the NLO approximation. We form a
mutually consistent set of polarized PDFs due to the inclusion of the most
available experimental data including the recently high-precision measurements
from {\tt COMPASS16} experiments (Phys. Lett. B 753 (2016) 18-28). We have
performed a careful estimation of the uncertainties using the most common and
practical method, the Hessian method, for the polarized PDFs originating from
the experimental errors. The proton, neutron and deuteron structure functions
and also their first moments, $\Gamma^{\rm p, n, d}$, are in good agreement
with the experimental data at small and large momentum fraction of $x$. We will
discuss how our knowledge of spin-dependence structure functions can improve at
small and large value of $x$ by the recent {\tt COMPASS16} measurements at
CERN, the {\tt PHENIX} and {\tt STAR} measurements at RHIC, and at the future
proposed colliders such as Electron-Ion collider (EIC).
| [
{
"created": "Thu, 10 Mar 2016 06:43:20 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Jun 2016 15:58:34 GMT",
"version": "v2"
}
] | 2016-06-24 | [
[
"Shahri",
"F. Taghavi",
""
],
[
"Khanpour",
"Hamzeh",
""
],
[
"Tehrani",
"S. Atashbar",
""
],
[
"Yazdi",
"Z. Alizadeh",
""
]
] | We present a first QCD analysis of next-to-next-leading-order (NNLO) contributions of the spin-dependent parton distribution functions (PPDFs) in the nucleon and their uncertainties using the Jacobi polynomial approach. Having the NNLO contributions of the quark-quark and gluon-quark splitting functions in perturbative QCD (Nucl. Phys. B 889 (2014) 351-400), one can obtain the evolution of longitudinally polarized parton densities of hadrons up to NNLO accuracy of QCD. A very large sets of recent and up-to-date experimental data of spin structure functions of the proton $g_1^p$, neutron $g_1^n$, and deuteron $g_1^d$ have been used in this analysis. The predictions for the NNLO calculations of the polarized parton distribution functions as well as the proton, neutron and deuteron polarized structure functions are compared with the corresponding results of the NLO approximation. We form a mutually consistent set of polarized PDFs due to the inclusion of the most available experimental data including the recently high-precision measurements from {\tt COMPASS16} experiments (Phys. Lett. B 753 (2016) 18-28). We have performed a careful estimation of the uncertainties using the most common and practical method, the Hessian method, for the polarized PDFs originating from the experimental errors. The proton, neutron and deuteron structure functions and also their first moments, $\Gamma^{\rm p, n, d}$, are in good agreement with the experimental data at small and large momentum fraction of $x$. We will discuss how our knowledge of spin-dependence structure functions can improve at small and large value of $x$ by the recent {\tt COMPASS16} measurements at CERN, the {\tt PHENIX} and {\tt STAR} measurements at RHIC, and at the future proposed colliders such as Electron-Ion collider (EIC). |
1210.1197 | Akin Wingerter | Christoph Luhn and Krishna Mohan Parattu and Ak{\i}n Wingerter | A Minimal Model of Neutrino Flavor | null | JHEP 1212 (2012) 096 | 10.1007/JHEP12(2012)096 | LPSC-12250; IPPP-12-61; DCPT-12-122 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Models of neutrino mass which attempt to describe the observed lepton mixing
pattern are typically based on discrete family symmetries with a non-Abelian
and one or more Abelian factors. The latter so-called shaping symmetries are
imposed in order to yield a realistic phenomenology by forbidding unwanted
operators. Here we propose a supersymmetric model of neutrino flavor which is
based on the group T7 and does not require extra Z_N or U(1) factors, which
makes it the smallest realistic family symmetry that has been considered so
far. At leading order, the model predicts tribimaximal mixing which arises
completely accidentally from a combination of the T7 Clebsch-Gordan
coefficients and suitable flavon alignments. Next-to-leading order (NLO)
operators break the simple tribimaximal structure and render the model
compatible with the recent results of the Daya Bay and Reno collaborations
which have measured a reactor angle of around 9 degrees. Problematic NLO
deviations of the other two mixing angles can be controlled in an ultraviolet
completion of the model.
| [
{
"created": "Wed, 3 Oct 2012 19:32:52 GMT",
"version": "v1"
}
] | 2015-01-26 | [
[
"Luhn",
"Christoph",
""
],
[
"Parattu",
"Krishna Mohan",
""
],
[
"Wingerter",
"Akın",
""
]
] | Models of neutrino mass which attempt to describe the observed lepton mixing pattern are typically based on discrete family symmetries with a non-Abelian and one or more Abelian factors. The latter so-called shaping symmetries are imposed in order to yield a realistic phenomenology by forbidding unwanted operators. Here we propose a supersymmetric model of neutrino flavor which is based on the group T7 and does not require extra Z_N or U(1) factors, which makes it the smallest realistic family symmetry that has been considered so far. At leading order, the model predicts tribimaximal mixing which arises completely accidentally from a combination of the T7 Clebsch-Gordan coefficients and suitable flavon alignments. Next-to-leading order (NLO) operators break the simple tribimaximal structure and render the model compatible with the recent results of the Daya Bay and Reno collaborations which have measured a reactor angle of around 9 degrees. Problematic NLO deviations of the other two mixing angles can be controlled in an ultraviolet completion of the model. |
0907.1878 | Douglas Gingrich Mr. | Douglas M. Gingrich | Signatures of Singlet Neutrinos in Large Extra Dimensions at the LHC | Addressed comments by reviewer | Int.J.Mod.Phys.A24:5173-5215,2009 | 10.1142/S0217751X09047636 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is a challenge to explain why neutrinos are so light compared to other
leptons. Small neutrino masses can be explained if right-handed fermions
propagate in large extra dimensions. Fermions propagating in the bulk would
have implications on Higgs boson decays. If the Higgs boson is discovered at
the Large Hadron Collider (LHC), a detailed analysis may reveal the presence of
large extra dimensions. This paper reviews the status of large
extra-dimensional models in the context of the current limits on Higgs boson
masses and the fundamental Planck scale in extra dimensions.
| [
{
"created": "Fri, 10 Jul 2009 17:45:01 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Aug 2009 17:20:24 GMT",
"version": "v2"
}
] | 2009-11-30 | [
[
"Gingrich",
"Douglas M.",
""
]
] | It is a challenge to explain why neutrinos are so light compared to other leptons. Small neutrino masses can be explained if right-handed fermions propagate in large extra dimensions. Fermions propagating in the bulk would have implications on Higgs boson decays. If the Higgs boson is discovered at the Large Hadron Collider (LHC), a detailed analysis may reveal the presence of large extra dimensions. This paper reviews the status of large extra-dimensional models in the context of the current limits on Higgs boson masses and the fundamental Planck scale in extra dimensions. |
hep-ph/9905497 | Nikolai Kochelev | N.I. Kochelev | A New Mechanism for Single Spin Asymmetries in Strong Interactions | 8 pages, 3 figures, Latex; final version to appear in JETP Lett | JETP Lett.72:481-485,2000; Pisma Zh.Eksp.Teor.Fiz.72:691-697,2000 | 10.1134/1.1343147 | null | hep-ph | null | It is shown that the contribution of the instantons to the fragmentation of
quarks leads to the appearance of a imaginary part in diagrams of quark-quark
scattering at large transfer momentum. The imaginary part comes from the
analytical continuation of the instanton amplitudes from Euclidean to Minkowsky
space-time and reflects quasiclassical origin of instanton solution of QCD
equations of motion. This phenomenon and instanton--induced quark spin-flip
give a new nonperturbative mechanism for the observed anomalous single-spin
asymmetries in hadron-hadron and lepton-hadron interactions.
| [
{
"created": "Wed, 26 May 1999 19:04:08 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Sep 1999 12:04:45 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Oct 1999 07:31:09 GMT",
"version": "v3"
},
{
"created": "Tue, 16 Nov 1999 09:54:16 GMT",
"version": "v4"
},
{
"created": "Sun, 4 Feb 2001 12:31:48 GMT",
"version": "v5"
}
] | 2011-04-15 | [
[
"Kochelev",
"N. I.",
""
]
] | It is shown that the contribution of the instantons to the fragmentation of quarks leads to the appearance of a imaginary part in diagrams of quark-quark scattering at large transfer momentum. The imaginary part comes from the analytical continuation of the instanton amplitudes from Euclidean to Minkowsky space-time and reflects quasiclassical origin of instanton solution of QCD equations of motion. This phenomenon and instanton--induced quark spin-flip give a new nonperturbative mechanism for the observed anomalous single-spin asymmetries in hadron-hadron and lepton-hadron interactions. |
1105.3481 | Nikolaos Kidonakis | Nikolaos Kidonakis | Top quark cross sections and differential distributions | 7 pages, 8 figures; presented at XIX International Workshop on
Deep-Inelastic Scattering and Related Subjects (DIS 2011), Newport News,
Virginia, USA, April 11-15, 2011 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I present results for the top quark pair total cross section and the top
quark transverse momentum distribution at Tevatron and LHC energies. I also
present results for single top quark production. All calculations include NNLO
corrections from NNLL threshold resummation.
| [
{
"created": "Tue, 17 May 2011 20:01:37 GMT",
"version": "v1"
}
] | 2011-05-19 | [
[
"Kidonakis",
"Nikolaos",
""
]
] | I present results for the top quark pair total cross section and the top quark transverse momentum distribution at Tevatron and LHC energies. I also present results for single top quark production. All calculations include NNLO corrections from NNLL threshold resummation. |
1503.04159 | Asmaa Abada | Asmaa Abada, Damir Becirevic, Michele Lucente and Olcyr Sumensari | Lepton flavor violating decays of vector quarkonia and of the $Z$ boson | 23 pages, 7 figures, (published version) | Phys. Rev. D 91, 113013 (2015) | 10.1103/PhysRevD.91.113013 | LPT 15-10, SISSA 09/2015/FISI | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We address the impact of sterile fermions on the lepton flavor violating
decays of quarkonia as well as of the $Z$ boson. We compute the relevant Wilson
coefficients and show that the ${\rm B}(V\to\ell_\alpha\ell_\beta)$, where
$V=\phi,\psi^{(n)}$, $\Upsilon^{(n)},Z$ can be significantly enhanced in the
case of large sterile fermion masses and a non-negligible active-sterile
mixing. We illustrate that feature in a specific minimal realization of the
inverse seesaw mechanism, known as $(2,3)$-ISS, and in an effective model in
which the presence of non-standard sterile fermions is parameterized by means
of one heavy sterile (Majorana) neutrino.
| [
{
"created": "Fri, 13 Mar 2015 17:37:11 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Jun 2015 16:33:59 GMT",
"version": "v2"
}
] | 2015-06-29 | [
[
"Abada",
"Asmaa",
""
],
[
"Becirevic",
"Damir",
""
],
[
"Lucente",
"Michele",
""
],
[
"Sumensari",
"Olcyr",
""
]
] | We address the impact of sterile fermions on the lepton flavor violating decays of quarkonia as well as of the $Z$ boson. We compute the relevant Wilson coefficients and show that the ${\rm B}(V\to\ell_\alpha\ell_\beta)$, where $V=\phi,\psi^{(n)}$, $\Upsilon^{(n)},Z$ can be significantly enhanced in the case of large sterile fermion masses and a non-negligible active-sterile mixing. We illustrate that feature in a specific minimal realization of the inverse seesaw mechanism, known as $(2,3)$-ISS, and in an effective model in which the presence of non-standard sterile fermions is parameterized by means of one heavy sterile (Majorana) neutrino. |
1007.0382 | Nick Kersting | Z. Kang, N. Kersting, and M. White | Mass Estimation without using MET in early LHC data | 4 pages, 3 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Many techniques exist to reconstruct New Physics masses from LHC data, though
these tend to either require high luminosity O(100) fb^-1, or an accurate
measurement of missing transverse energy (MET) which may not be available in
the early running of the LHC. Since in popular models such as SUSY a fairly
sharp, triangular dilepton invariant mass spectrum can emerge already at low
luminosity O(1) fb^-1, a Decay Kinematics (DK) technique can be used on events
near the dilepton mass endpoint to estimate squark, slepton, and neutralino
masses without relying on MET. With the first 2 fb^-1 of 7 TeV LHC data SPS1a
masses can thus be found to 20% or better accuracy, at least several times
better than what has been taken to be achievable.
| [
{
"created": "Fri, 2 Jul 2010 15:14:16 GMT",
"version": "v1"
}
] | 2010-07-05 | [
[
"Kang",
"Z.",
""
],
[
"Kersting",
"N.",
""
],
[
"White",
"M.",
""
]
] | Many techniques exist to reconstruct New Physics masses from LHC data, though these tend to either require high luminosity O(100) fb^-1, or an accurate measurement of missing transverse energy (MET) which may not be available in the early running of the LHC. Since in popular models such as SUSY a fairly sharp, triangular dilepton invariant mass spectrum can emerge already at low luminosity O(1) fb^-1, a Decay Kinematics (DK) technique can be used on events near the dilepton mass endpoint to estimate squark, slepton, and neutralino masses without relying on MET. With the first 2 fb^-1 of 7 TeV LHC data SPS1a masses can thus be found to 20% or better accuracy, at least several times better than what has been taken to be achievable. |
hep-ph/9810523 | Daniel Gomez Dumm | D. Gomez Dumm, A. Pich | Short- and long-distance contributions to the rare decay K_L-->mu+ mu- | 4 pages, 1 figure, talk given at the Euroconference QCD 98,
Montpellier, France, July 1998 | Nucl.Phys.Proc.Suppl. 74 (1999) 186-189 | 10.1016/S0920-5632(99)00159-0 | FTUV/98-83, IFIC/98-84 | hep-ph | null | The interplay between short- and long-distance contributions to the K_L-->mu+
mu- decay amplitude is analyzed. The long-distance piece is estimated using
chiral perturbation theory techniques and large-N_C considerations, leading to
a consistent description of the pi^0-->e+ e-, eta-->mu+ mu- and K_L-->mu+ mu-
branching ratios.
| [
{
"created": "Thu, 29 Oct 1998 14:12:38 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Dumm",
"D. Gomez",
""
],
[
"Pich",
"A.",
""
]
] | The interplay between short- and long-distance contributions to the K_L-->mu+ mu- decay amplitude is analyzed. The long-distance piece is estimated using chiral perturbation theory techniques and large-N_C considerations, leading to a consistent description of the pi^0-->e+ e-, eta-->mu+ mu- and K_L-->mu+ mu- branching ratios. |
1307.1703 | Markos Maniatis | Markos Maniatis and Dhagash Mehta | On exact minimization of Higgs potentials | 7 pages, 3 tables | Eur. Phys. J. Plus (2014) 129 | 10.1140/epjp/i2014-14109-0 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Minimizing the Higgs potential is an essential task in any model involving
Higgs bosons. Exact minimization methods proposed in the literature are based
on the polynomial form of the potential. These methods will in general no
longer work if loop contributions to the potential are taken into account. We
present a method to keep the tree level global minimum unchanged in passing to
the effective potential. We illustrate the method for the case of the Minimal
Supersymmetric Model (MSSM).
| [
{
"created": "Fri, 5 Jul 2013 20:00:01 GMT",
"version": "v1"
},
{
"created": "Thu, 29 May 2014 20:17:58 GMT",
"version": "v2"
}
] | 2014-06-02 | [
[
"Maniatis",
"Markos",
""
],
[
"Mehta",
"Dhagash",
""
]
] | Minimizing the Higgs potential is an essential task in any model involving Higgs bosons. Exact minimization methods proposed in the literature are based on the polynomial form of the potential. These methods will in general no longer work if loop contributions to the potential are taken into account. We present a method to keep the tree level global minimum unchanged in passing to the effective potential. We illustrate the method for the case of the Minimal Supersymmetric Model (MSSM). |
1212.2175 | Andreas Windisch | Andreas Windisch, Markus Q. Huber and Reinhard Alkofer | On the analytic structure of scalar glueball operators at Born level | 10 pages, 15 figures | Phys.Rev.D87:065005,2013 | 10.1103/PhysRevD.87.065005 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the analytic structure of the two-point function of the operator F2
which is expected to describe a scalar glueball. The calculation of the
involved integrals is complicated by nonanalytic structures in the integrands,
which we take into account properly by identifying cuts generated by angular
integrals and deforming the contours for the radial integration accordingly.
The obtained locations of the branch points agree with Cutkosky's cut rules. As
input we use different nonperturbative Landau gauge gluon propagators with
different analytic properties as obtained from lattice and functional
calculations. All of them violate positivity and describe thus gluons absent
from the asymptotic physical space. The resulting spectral densities for the
glueball candidate show a cut but no poles for lightlike momenta, which can be
attributed to the employed Born approximation.
| [
{
"created": "Mon, 10 Dec 2012 19:33:02 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Mar 2013 18:22:34 GMT",
"version": "v2"
}
] | 2013-03-14 | [
[
"Windisch",
"Andreas",
""
],
[
"Huber",
"Markus Q.",
""
],
[
"Alkofer",
"Reinhard",
""
]
] | We study the analytic structure of the two-point function of the operator F2 which is expected to describe a scalar glueball. The calculation of the involved integrals is complicated by nonanalytic structures in the integrands, which we take into account properly by identifying cuts generated by angular integrals and deforming the contours for the radial integration accordingly. The obtained locations of the branch points agree with Cutkosky's cut rules. As input we use different nonperturbative Landau gauge gluon propagators with different analytic properties as obtained from lattice and functional calculations. All of them violate positivity and describe thus gluons absent from the asymptotic physical space. The resulting spectral densities for the glueball candidate show a cut but no poles for lightlike momenta, which can be attributed to the employed Born approximation. |
1907.07973 | Anirban Biswas | Anirban Biswas, Sougata Ganguly, Sourov Roy | Fermionic dark matter via UV and IR freeze-in and its possible X-ray
signature | 40 pages, 7 figures, 1 table, additional production channels are
added, three new appendices are added, new references are included, minor
modifications in results and conclusions, version published in JCAP | JCAP03 (2020) 043 | 10.1088/1475-7516/2020/03/043 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Non-observation of any dark matter signature at various direct detection
experiments over the last decade keeps indicating that immensely popular WIMP
paradigm may not be the actual theory of particle dark matter. Non-thermal dark
matter produced through freeze-in is an attractive proposal, naturally
explaining null results by virtue of its feeble couplings with the Standard
Model (SM) particles. We consider a minimal extension of the SM by two gauge
singlet fields namely, a $\mathbb{Z}_2$-odd fermion $\chi$ and a pseudo scalar
$\tilde{\phi}$, where the former has interactions with the SM particles only at
dimension five level and beyond. This introduces natural suppression in the
interactions of $\chi$ by a heavy new physics scale $\Lambda$ and forces $\chi$
to be a non-thermal dark matter candidate. We have studied production of $\chi$
in detail taking into account both ultra-violate (UV), infra-red (IR) as well
as mixed UV-IR freeze-in and found that for $10^{10}{\rm GeV}\leq\Lambda\leq
10^{15}{\rm GeV}$, $\chi$ is dominantly produced via UV and mixed UV-IR
freeze-in when reheat temperature $T_{RH}\gtrsim 10^4$ GeV and below which the
production is dominated by IR and mixed freeze-in. Furthermore, we have
considered the cascade annihilation $\chi\bar{\chi} \rightarrow
\tilde{\phi}\tilde{\phi}\rightarrow 4\gamma$ to address the longstanding
$\sim3.5$ keV X-ray line observed from various galaxies and galaxy clusters. We
have found that the long-lived intermediate state $\tilde{\phi}$ modifies dark
matter density around the galactic centre to an effective density $\rho_{eff}$
which strongly depends on the decay length of $\tilde{\phi}$. Finally, the
allowed parameter space in $\Lambda-g$ plane ($g$ is the coupling between
$\chi\bar{\chi}$ and $\tilde{\phi}$) is obtained by comparing our result with
the XMM Newton observed X-ray flux from the centre of Milky Way galaxy in
$2\sigma$ range.
| [
{
"created": "Thu, 18 Jul 2019 10:37:24 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Mar 2020 10:08:42 GMT",
"version": "v2"
}
] | 2020-03-20 | [
[
"Biswas",
"Anirban",
""
],
[
"Ganguly",
"Sougata",
""
],
[
"Roy",
"Sourov",
""
]
] | Non-observation of any dark matter signature at various direct detection experiments over the last decade keeps indicating that immensely popular WIMP paradigm may not be the actual theory of particle dark matter. Non-thermal dark matter produced through freeze-in is an attractive proposal, naturally explaining null results by virtue of its feeble couplings with the Standard Model (SM) particles. We consider a minimal extension of the SM by two gauge singlet fields namely, a $\mathbb{Z}_2$-odd fermion $\chi$ and a pseudo scalar $\tilde{\phi}$, where the former has interactions with the SM particles only at dimension five level and beyond. This introduces natural suppression in the interactions of $\chi$ by a heavy new physics scale $\Lambda$ and forces $\chi$ to be a non-thermal dark matter candidate. We have studied production of $\chi$ in detail taking into account both ultra-violate (UV), infra-red (IR) as well as mixed UV-IR freeze-in and found that for $10^{10}{\rm GeV}\leq\Lambda\leq 10^{15}{\rm GeV}$, $\chi$ is dominantly produced via UV and mixed UV-IR freeze-in when reheat temperature $T_{RH}\gtrsim 10^4$ GeV and below which the production is dominated by IR and mixed freeze-in. Furthermore, we have considered the cascade annihilation $\chi\bar{\chi} \rightarrow \tilde{\phi}\tilde{\phi}\rightarrow 4\gamma$ to address the longstanding $\sim3.5$ keV X-ray line observed from various galaxies and galaxy clusters. We have found that the long-lived intermediate state $\tilde{\phi}$ modifies dark matter density around the galactic centre to an effective density $\rho_{eff}$ which strongly depends on the decay length of $\tilde{\phi}$. Finally, the allowed parameter space in $\Lambda-g$ plane ($g$ is the coupling between $\chi\bar{\chi}$ and $\tilde{\phi}$) is obtained by comparing our result with the XMM Newton observed X-ray flux from the centre of Milky Way galaxy in $2\sigma$ range. |
1603.09354 | Ian Shoemaker | Mads T. Frandsen and Ian M. Shoemaker | Asymmetric Dark Matter Models and the LHC Diphoton Excess | 33 pages, 5 figures | null | 10.1088/1475-7516/2016/05/064 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The existence of dark matter (DM) and the origin of the baryon asymmetry are
persistent indications that the SM is incomplete. More recently, the ATLAS and
CMS experiments have observed an excess of diphoton events with invariant mass
of about 750 GeV. One interpretation of this excess is decays of a new spin-0
particle with a sizable diphoton partial width, e.g. induced by new heavy
weakly charged particles. These are also key ingredients in models cogenerating
asymmetric DM and baryons via sphaleron interactions and an initial particle
asymmetry. We explore what consequences the new scalar may have for models of
asymmetric DM that attempt to account for the similarity of the dark and
visible matter abundances.
| [
{
"created": "Wed, 30 Mar 2016 20:01:41 GMT",
"version": "v1"
}
] | 2016-06-08 | [
[
"Frandsen",
"Mads T.",
""
],
[
"Shoemaker",
"Ian M.",
""
]
] | The existence of dark matter (DM) and the origin of the baryon asymmetry are persistent indications that the SM is incomplete. More recently, the ATLAS and CMS experiments have observed an excess of diphoton events with invariant mass of about 750 GeV. One interpretation of this excess is decays of a new spin-0 particle with a sizable diphoton partial width, e.g. induced by new heavy weakly charged particles. These are also key ingredients in models cogenerating asymmetric DM and baryons via sphaleron interactions and an initial particle asymmetry. We explore what consequences the new scalar may have for models of asymmetric DM that attempt to account for the similarity of the dark and visible matter abundances. |
1107.3829 | Ryo Takahasi | Adisorn Adulpravitchai, Ryo Takahashi | A4 Flavor Models in Split Seesaw Mechanism | 21 pages, 1 figure, version to appear in JHEP | JHEP 1109:127,2011 | 10.1007/JHEP09(2011)127 | null | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A seesaw mechanism in an extra-dimension, known as the split seesaw
mechanism, provides a natural way to realize a splitting mass spectrum of
right-handed neutrinos. It leads to one keV sterile neutrino as a dark matter
candidate and two heavy right-handed neutrinos being responsible for
leptogenesis to explain the observed baryon asymmetry of the Universe. We study
models based on $A_4$ flavor symmetry in the context of the split seesaw
mechanism. It is pointed out that most of known $A_4$ flavor models with three
right-handed neutrinos being $A_4$ triplet suffer from a degeneracy problem for
the bulk mass terms, which disturbs the split mechanism for right-handed
neutrino mass spectrum. Then we construct a new $A_4$ flavor model to work in
the split seesaw mechanism. In the model, the experimentally observed neutrino
masses and mixing angles can be realized from both type I+II seesaw
contributions. The model predicts the $\mu-\tau$ symmetry in the neutrino mass
matrix at the leading order, resulting in the vanishing $\theta_{13}$ and
maximal $\theta_{23}$. The flavor symmetry $A_4$ is broken via the flavon
vacuum alignment which can be obtained from the orbifold compactification. The
model can be consistent with all data of neutrino oscillation experiments,
cosmological discussions of dark matter abundance, leptogenesis, and recent
astrophysical data.
| [
{
"created": "Tue, 19 Jul 2011 19:47:40 GMT",
"version": "v1"
},
{
"created": "Sun, 9 Oct 2011 07:56:00 GMT",
"version": "v2"
}
] | 2011-10-11 | [
[
"Adulpravitchai",
"Adisorn",
""
],
[
"Takahashi",
"Ryo",
""
]
] | A seesaw mechanism in an extra-dimension, known as the split seesaw mechanism, provides a natural way to realize a splitting mass spectrum of right-handed neutrinos. It leads to one keV sterile neutrino as a dark matter candidate and two heavy right-handed neutrinos being responsible for leptogenesis to explain the observed baryon asymmetry of the Universe. We study models based on $A_4$ flavor symmetry in the context of the split seesaw mechanism. It is pointed out that most of known $A_4$ flavor models with three right-handed neutrinos being $A_4$ triplet suffer from a degeneracy problem for the bulk mass terms, which disturbs the split mechanism for right-handed neutrino mass spectrum. Then we construct a new $A_4$ flavor model to work in the split seesaw mechanism. In the model, the experimentally observed neutrino masses and mixing angles can be realized from both type I+II seesaw contributions. The model predicts the $\mu-\tau$ symmetry in the neutrino mass matrix at the leading order, resulting in the vanishing $\theta_{13}$ and maximal $\theta_{23}$. The flavor symmetry $A_4$ is broken via the flavon vacuum alignment which can be obtained from the orbifold compactification. The model can be consistent with all data of neutrino oscillation experiments, cosmological discussions of dark matter abundance, leptogenesis, and recent astrophysical data. |
1609.06781 | Yu-Sheng Liu | Yu-Sheng Liu, David McKeen, and Gerald A. Miller | The Validity of the Weizsacker-Williams Approximation and the Analysis
of Beam Dump Experiments: Production of a New Scalar Boson | 21 pages, 8 figures | Phys. Rev. D 95, 036010 (2017) | 10.1103/PhysRevD.95.036010 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Beam dump experiments have been used to search for new particles with null
results interpreted in terms of limits on masses $m_\phi$ and coupling
constants $\epsilon$. However these limits have been obtained by using
approximations [including the Weizs\"{a}cker-Williams (WW) approximation] or
Monte-Carlo simulations. We display methods, using a new scalar boson as an
example, to obtain the cross section and the resulting particle production
numbers without using approximations or Monte-Carlo simulations. We show that
the approximations cannot be used to obtain accurate values of cross sections.
The corresponding exclusion plots differ by substantial amounts when seen on a
linear scale. In the event of a discovery, we generate pseudodata (assuming
given values of $m_\phi$ and $\epsilon$) in the currently allowed regions of
parameter space. The use of approximations to analyze the pseudodata for the
future experiments is shown to lead to considerable errors in determining the
parameters. Furthermore, a new region of parameter space can be explored
without using one of the common approximations, $m_\phi\gg m_e$. Our method can
be used as a consistency check for Monte-Carlo simulations.
| [
{
"created": "Thu, 22 Sep 2016 00:02:08 GMT",
"version": "v1"
},
{
"created": "Sat, 8 Oct 2016 01:09:14 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Feb 2017 22:54:21 GMT",
"version": "v3"
}
] | 2017-02-22 | [
[
"Liu",
"Yu-Sheng",
""
],
[
"McKeen",
"David",
""
],
[
"Miller",
"Gerald A.",
""
]
] | Beam dump experiments have been used to search for new particles with null results interpreted in terms of limits on masses $m_\phi$ and coupling constants $\epsilon$. However these limits have been obtained by using approximations [including the Weizs\"{a}cker-Williams (WW) approximation] or Monte-Carlo simulations. We display methods, using a new scalar boson as an example, to obtain the cross section and the resulting particle production numbers without using approximations or Monte-Carlo simulations. We show that the approximations cannot be used to obtain accurate values of cross sections. The corresponding exclusion plots differ by substantial amounts when seen on a linear scale. In the event of a discovery, we generate pseudodata (assuming given values of $m_\phi$ and $\epsilon$) in the currently allowed regions of parameter space. The use of approximations to analyze the pseudodata for the future experiments is shown to lead to considerable errors in determining the parameters. Furthermore, a new region of parameter space can be explored without using one of the common approximations, $m_\phi\gg m_e$. Our method can be used as a consistency check for Monte-Carlo simulations. |
2107.01159 | Mary Hall Reno | Mary Hall Reno, Luis A. Anchordoqui, Atri Bhattacharya, Austin
Cummings, Johannes Eser, Claire Gu\'epin, John F. Krizmanic, Angela V.
Olinto, Thomas Paul, Ina Sarcevic and Tonia M. Venters | Neutrino constraints on long-lived heavy dark sector particle decays in
the Earth | 12 pages, 9 figures, matching version accepted for publication in
Physical Review D | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Recent theoretical work has explored dark matter accumulation in the Earth
and its drift towards the center of the Earth that, for the current age of the
Earth, does not necessarily result in a concentration of dark matter ($\chi$)
in the Earth's core. We consider a scenario of long-lived ($\tau_\chi\sim
10^{28}$ s), super heavy ($m_\chi=10^7-10^{10}$ GeV) dark matter that decays
via $\chi\to \nu_\tau \bar{\nu}_\tau$ or $\chi\to \nu_\mu \bar{\nu}_\mu$. We
show that an IceCube-like detector over 10 years can constrain a dark matter
density that mirrors the Earth's density or has a uniform density with density
fraction $\epsilon_\rho$ combined with the partial decay width $B_{\chi\to
\nu_\tau \bar{\nu}_\tau}\Gamma_\chi$ in the range of $(\epsilon_\rho/10^{-10})
B_{\chi\to \nu_\tau}\Gamma_\chi \lesssim 1.5\times 10^{-29}-1.5\times 10^{-28}$
s$^{-1}$. For $\chi\to \nu_\mu \bar{\nu}_\mu$, $m_\chi = 10^8-10^{10}$ GeV and
$E_\mu>10^7$ GeV, the range of constraints is $(\epsilon_\rho/10^{-10})
B_{\chi\to \nu_\mu}\Gamma_\chi \lesssim 3\times 10^{-29}-7\times 10^{-28}$
s$^{-1}$.
| [
{
"created": "Fri, 2 Jul 2021 16:00:36 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Feb 2022 18:13:02 GMT",
"version": "v2"
}
] | 2022-03-01 | [
[
"Reno",
"Mary Hall",
""
],
[
"Anchordoqui",
"Luis A.",
""
],
[
"Bhattacharya",
"Atri",
""
],
[
"Cummings",
"Austin",
""
],
[
"Eser",
"Johannes",
""
],
[
"Guépin",
"Claire",
""
],
[
"Krizmanic",
"John F.",
""
],
[
"Olinto",
"Angela V.",
""
],
[
"Paul",
"Thomas",
""
],
[
"Sarcevic",
"Ina",
""
],
[
"Venters",
"Tonia M.",
""
]
] | Recent theoretical work has explored dark matter accumulation in the Earth and its drift towards the center of the Earth that, for the current age of the Earth, does not necessarily result in a concentration of dark matter ($\chi$) in the Earth's core. We consider a scenario of long-lived ($\tau_\chi\sim 10^{28}$ s), super heavy ($m_\chi=10^7-10^{10}$ GeV) dark matter that decays via $\chi\to \nu_\tau \bar{\nu}_\tau$ or $\chi\to \nu_\mu \bar{\nu}_\mu$. We show that an IceCube-like detector over 10 years can constrain a dark matter density that mirrors the Earth's density or has a uniform density with density fraction $\epsilon_\rho$ combined with the partial decay width $B_{\chi\to \nu_\tau \bar{\nu}_\tau}\Gamma_\chi$ in the range of $(\epsilon_\rho/10^{-10}) B_{\chi\to \nu_\tau}\Gamma_\chi \lesssim 1.5\times 10^{-29}-1.5\times 10^{-28}$ s$^{-1}$. For $\chi\to \nu_\mu \bar{\nu}_\mu$, $m_\chi = 10^8-10^{10}$ GeV and $E_\mu>10^7$ GeV, the range of constraints is $(\epsilon_\rho/10^{-10}) B_{\chi\to \nu_\mu}\Gamma_\chi \lesssim 3\times 10^{-29}-7\times 10^{-28}$ s$^{-1}$. |
hep-ph/9403215 | Robert Brandenberger | R. Brandenberger (Brown), A.-C. Davis (DAMTP, Cambridge) and M.
Trodden (Brown) | Cosmic Strings and Electroweak Baryogenesis | BROWN-HET-935 (February 1994), 17 pages, 1 figure (available as
postscript file from the authors), uses phyzzx | Phys.Lett.B335:123-130,1994 | 10.1016/0370-2693(94)91402-8 | null | hep-ph astro-ph | null | The electroweak symmetry is unbroken in the core of cosmic strings
originating from a symmetry breaking at an energy higher than the electroweak
scale $\eta_{EW}$. The dynamics of such strings may generate a baryon asymmetry
below the electroweak symmetry breaking scale. This mechanism for electroweak
baryogenesis is most efficient if the scale of string formation is only
slightly higher than $\eta_{EW}$ \eg \ in theories of dynamical symmetry
breaking) and if the strings are superconducting. The mechanism is also
effective if the electroweak phase transition is second order.
| [
{
"created": "Thu, 3 Mar 1994 03:49:19 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Brandenberger",
"R.",
"",
"Brown"
],
[
"Davis",
"A. -C.",
"",
"DAMTP, Cambridge"
],
[
"Trodden",
"M.",
"",
"Brown"
]
] | The electroweak symmetry is unbroken in the core of cosmic strings originating from a symmetry breaking at an energy higher than the electroweak scale $\eta_{EW}$. The dynamics of such strings may generate a baryon asymmetry below the electroweak symmetry breaking scale. This mechanism for electroweak baryogenesis is most efficient if the scale of string formation is only slightly higher than $\eta_{EW}$ \eg \ in theories of dynamical symmetry breaking) and if the strings are superconducting. The mechanism is also effective if the electroweak phase transition is second order. |
0907.1984 | David A. Kosower | C. F. Berger, Z. Bern, L. J. Dixon, F. Febres Cordero, D. Forde, T.
Gleisberg, H. Ita, D. A. Kosower and D. Maitre | Next-to-Leading Order QCD Predictions for W+3-Jet Distributions at
Hadron Colliders | 64 pages, 37 figures, v2 minor changes in table X, cross sections and
distributions unaffected; other minor corrections to text, references added | Phys.Rev.D80:074036,2009 | 10.1103/PhysRevD.80.074036 | SLAC-PUB-13680, UCLA/09/TEP/53, MIT-CTP 4047, Saclay-IPhT-T09/078,
IPPP/09/46 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present next-to-leading order QCD predictions for a variety of
distributions in W+3-jet production at both the Tevatron and the Large Hadron
Collider. We include all subprocesses and incorporate the decay of the W boson
into leptons. Our results are in excellent agreement with existing Tevatron
data and provide the first quantitatively precise next-to-leading order
predictions for the LHC. We include all terms in an expansion in the number of
colors, confirming that the specific leading-color approximation used in our
previous study is accurate to within three percent. The dependence of the cross
section on renormalization and factorization scales is reduced significantly
with respect to a leading-order calculation. We study different dynamical scale
choices, and find that the total transverse energy is significantly better than
choices used in previous phenomenological studies. We compute the one-loop
matrix elements using on-shell methods, as numerically implemented in the
BlackHat code. The remaining parts of the calculation, including generation of
the real-emission contributions and integration over phase space, are handled
by the SHERPA package.
| [
{
"created": "Sat, 11 Jul 2009 19:23:48 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Oct 2009 16:53:07 GMT",
"version": "v2"
}
] | 2009-11-05 | [
[
"Berger",
"C. F.",
""
],
[
"Bern",
"Z.",
""
],
[
"Dixon",
"L. J.",
""
],
[
"Cordero",
"F. Febres",
""
],
[
"Forde",
"D.",
""
],
[
"Gleisberg",
"T.",
""
],
[
"Ita",
"H.",
""
],
[
"Kosower",
"D. A.",
""
],
[
"Maitre",
"D.",
""
]
] | We present next-to-leading order QCD predictions for a variety of distributions in W+3-jet production at both the Tevatron and the Large Hadron Collider. We include all subprocesses and incorporate the decay of the W boson into leptons. Our results are in excellent agreement with existing Tevatron data and provide the first quantitatively precise next-to-leading order predictions for the LHC. We include all terms in an expansion in the number of colors, confirming that the specific leading-color approximation used in our previous study is accurate to within three percent. The dependence of the cross section on renormalization and factorization scales is reduced significantly with respect to a leading-order calculation. We study different dynamical scale choices, and find that the total transverse energy is significantly better than choices used in previous phenomenological studies. We compute the one-loop matrix elements using on-shell methods, as numerically implemented in the BlackHat code. The remaining parts of the calculation, including generation of the real-emission contributions and integration over phase space, are handled by the SHERPA package. |
1808.05062 | Newton Nath | Newton Nath | $ \mu-\tau $ Reflection Symmetry and Its Explicit Breaking for
Leptogenesis in a Minimal Seesaw Model | 13 pages, 4 figures, some more discussion added. Version accepted for
publication in MPLA | null | 10.1142/S0217732319503292 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The minimal seesaw framework, embroiling the Dirac neutrino mass matrix $ M_D
$ and the Majorana neutrino mass matrix $ M_R $, is quite successful to explain
the current global-fit results of neutrino oscillation data. In this context,
we consider most predictive forms of $ M_D $ and $ M_R $ with two simple
parameters, respectively.
Considering these matrices, we obtain the low energy neutrino mass matrix
under type-I seesaw formalism which obeys $ \mu-\tau $ reflection symmetry and
predicts $ \theta_{23} = \pi/4$ and $ \delta = \pm \pi/2 $. In the given
set-up, we also evaluate the Baryon Asymmetry of the Universe (BAU) through
successful leptogenesis and find that perturbation of $ \mathcal{O}(10^{-2}) $
leads to the observed BAU and breaks exactness of the symmetry. Moreover, we
also perform various correlation studies among different parameters in the
framework of broken symmetry.
| [
{
"created": "Wed, 15 Aug 2018 13:10:27 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Nov 2019 03:20:53 GMT",
"version": "v2"
}
] | 2019-11-04 | [
[
"Nath",
"Newton",
""
]
] | The minimal seesaw framework, embroiling the Dirac neutrino mass matrix $ M_D $ and the Majorana neutrino mass matrix $ M_R $, is quite successful to explain the current global-fit results of neutrino oscillation data. In this context, we consider most predictive forms of $ M_D $ and $ M_R $ with two simple parameters, respectively. Considering these matrices, we obtain the low energy neutrino mass matrix under type-I seesaw formalism which obeys $ \mu-\tau $ reflection symmetry and predicts $ \theta_{23} = \pi/4$ and $ \delta = \pm \pi/2 $. In the given set-up, we also evaluate the Baryon Asymmetry of the Universe (BAU) through successful leptogenesis and find that perturbation of $ \mathcal{O}(10^{-2}) $ leads to the observed BAU and breaks exactness of the symmetry. Moreover, we also perform various correlation studies among different parameters in the framework of broken symmetry. |
1312.2869 | Toshitaka Uchino | M. Bayar, W. H. Liang, T. Uchino, C. W. Xiao | Description of $\rho (1700)$ as a $\rho K \bar{K}$ system with the fixed
center approximation | null | null | 10.1140/epja/i2014-14067-0 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the $\rho K\bar{K}$ system with an aim to describe the $\rho (1700)$
resonance. The chiral unitary approach has achieved success in a description of
systems of the light hadron sector. With this method, the $K \bar{K}$ system in
the isospin sector $I=0$, is found to be a dominant component of the $f_0
(980)$ resonance. Therefore, by regarding the $K\bar{K}$ system as a cluster,
the $f_0 (980)$ resonance, we evaluate the $\rho K\bar{K}$ system applying the
fixed center approximation to the Faddeev equations. We construct the $\rho K$
unitarized amplitude using the chiral unitary approach. As a result, we find a
peak in the three-body amplitude around 1739 MeV and a width of about 227 MeV.
The effect of the width of $\rho$ and $f_0 (980)$ is also discussed. We
associate this peak to the $\rho (1700)$ which has a mass of $1720 \pm 20$ MeV
and a width of $250 \pm 100$ MeV.
| [
{
"created": "Tue, 10 Dec 2013 16:46:33 GMT",
"version": "v1"
}
] | 2015-06-18 | [
[
"Bayar",
"M.",
""
],
[
"Liang",
"W. H.",
""
],
[
"Uchino",
"T.",
""
],
[
"Xiao",
"C. W.",
""
]
] | We study the $\rho K\bar{K}$ system with an aim to describe the $\rho (1700)$ resonance. The chiral unitary approach has achieved success in a description of systems of the light hadron sector. With this method, the $K \bar{K}$ system in the isospin sector $I=0$, is found to be a dominant component of the $f_0 (980)$ resonance. Therefore, by regarding the $K\bar{K}$ system as a cluster, the $f_0 (980)$ resonance, we evaluate the $\rho K\bar{K}$ system applying the fixed center approximation to the Faddeev equations. We construct the $\rho K$ unitarized amplitude using the chiral unitary approach. As a result, we find a peak in the three-body amplitude around 1739 MeV and a width of about 227 MeV. The effect of the width of $\rho$ and $f_0 (980)$ is also discussed. We associate this peak to the $\rho (1700)$ which has a mass of $1720 \pm 20$ MeV and a width of $250 \pm 100$ MeV. |
hep-ph/0507104 | Jean-Pierre Leroy | Ph. Boucaud, J.P. Leroy, A. Le Yaouanc, A.Y. Lokhov, J. Micheli, O.
Pene, J. Rodriguez-Quintero and C. Roiesnel | The Infrared Behaviour of the Pure Yang-Mills Green Functions | 25 pages, 7 figures; replaced version with some references adde and
an enlarged discussion of the non-renormalization theorem; second replacement
with improved figures and added references | null | null | UHU-FP/05-12 CPHT RR 038.0605 LPT-Orsay/05-38 | hep-ph hep-lat | null | We study the infrared behaviour of the pure Yang-Mills correlators using
relations that are well defined in the non-perturbative domain. These are the
Slavnov-Taylor identity for three-gluon vertex and the Schwinger-Dyson equation
for ghost propagator in the Landau gauge. We also use several inputs from
lattice simulations. We show that lattice data are in serious conflict with a
widely spread analytical relation between the gluon and ghost infrared critical
exponents. We conjecture that this is explained by a singular behaviour of the
ghost-ghost-gluon vertex function in the infrared. We show that, anyhow, this
discrepancy is not due to some lattice artefact since lattice Green functions
satisfy the ghost propagator Schwinger-Dyson equation. We also report on a
puzzle concerning the infrared gluon propagator: lattice data seem to favor a
constant non vanishing zero momentum gluon propagator, while the Slavnov-Taylor
identity (complemented with some regularity hypothesis of scalar functions)
implies that it should diverge.
| [
{
"created": "Fri, 8 Jul 2005 10:44:08 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Jul 2005 07:37:15 GMT",
"version": "v2"
},
{
"created": "Fri, 28 Oct 2005 17:33:29 GMT",
"version": "v3"
},
{
"created": "Thu, 11 May 2006 10:09:41 GMT",
"version": "v4"
}
] | 2007-05-23 | [
[
"Boucaud",
"Ph.",
""
],
[
"Leroy",
"J. P.",
""
],
[
"Yaouanc",
"A. Le",
""
],
[
"Lokhov",
"A. Y.",
""
],
[
"Micheli",
"J.",
""
],
[
"Pene",
"O.",
""
],
[
"Rodriguez-Quintero",
"J.",
""
],
[
"Roiesnel",
"C.",
""
]
] | We study the infrared behaviour of the pure Yang-Mills correlators using relations that are well defined in the non-perturbative domain. These are the Slavnov-Taylor identity for three-gluon vertex and the Schwinger-Dyson equation for ghost propagator in the Landau gauge. We also use several inputs from lattice simulations. We show that lattice data are in serious conflict with a widely spread analytical relation between the gluon and ghost infrared critical exponents. We conjecture that this is explained by a singular behaviour of the ghost-ghost-gluon vertex function in the infrared. We show that, anyhow, this discrepancy is not due to some lattice artefact since lattice Green functions satisfy the ghost propagator Schwinger-Dyson equation. We also report on a puzzle concerning the infrared gluon propagator: lattice data seem to favor a constant non vanishing zero momentum gluon propagator, while the Slavnov-Taylor identity (complemented with some regularity hypothesis of scalar functions) implies that it should diverge. |
0808.2201 | Dmitri Antonov | D. Antonov, H.-J. Pirner, M.G. Schmidt | Pressure and interaction measure of the gluon plasma | 20 pages, 5 figures. Final version. To appear in Nucl. Phys. A | Nucl.Phys.A832:314-329,2010 | 10.1016/j.nuclphysa.2009.11.001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the thermodynamics of the gluon plasma in SU(3) Yang-Mills theory
emerging from the non-trivial spatial dynamics of valence gluons. The lattice
data suggest that these gluons interact with each other linearly at large
spatial separations. At high temperatures, valence gluons should reproduce the
pressure of the non-interacting Stefan-Boltzmann plasma along with the leading
perturbative correction. These properties of valence gluons can be modeled in
terms of the integral over their trajectories. We calculate such a world-line
integral analytically and obtain the pressure and the interaction measure
$(\varepsilon-3p)/T^4$ of the gluon plasma. Additionally, we account for the
contributions of stochastic background fields to these thermodynamic
quantities. The results turn out to be in a good agreement with the
corresponding lattice data. In particular, the lattice-simulated peak of the
interaction measure near the deconfinement critical temperature is reproduced.
| [
{
"created": "Fri, 15 Aug 2008 20:52:04 GMT",
"version": "v1"
},
{
"created": "Wed, 15 Apr 2009 15:09:06 GMT",
"version": "v2"
},
{
"created": "Fri, 24 Jul 2009 10:51:41 GMT",
"version": "v3"
},
{
"created": "Mon, 2 Nov 2009 14:30:50 GMT",
"version": "v4"
}
] | 2010-01-06 | [
[
"Antonov",
"D.",
""
],
[
"Pirner",
"H. -J.",
""
],
[
"Schmidt",
"M. G.",
""
]
] | We explore the thermodynamics of the gluon plasma in SU(3) Yang-Mills theory emerging from the non-trivial spatial dynamics of valence gluons. The lattice data suggest that these gluons interact with each other linearly at large spatial separations. At high temperatures, valence gluons should reproduce the pressure of the non-interacting Stefan-Boltzmann plasma along with the leading perturbative correction. These properties of valence gluons can be modeled in terms of the integral over their trajectories. We calculate such a world-line integral analytically and obtain the pressure and the interaction measure $(\varepsilon-3p)/T^4$ of the gluon plasma. Additionally, we account for the contributions of stochastic background fields to these thermodynamic quantities. The results turn out to be in a good agreement with the corresponding lattice data. In particular, the lattice-simulated peak of the interaction measure near the deconfinement critical temperature is reproduced. |
hep-ph/0511060 | Eran Naftali | E. Gotsman, E. Levin, U. Maor, E. Naftali, A. Prygarin | Survival Probability of Large Rapidity Gaps | Prepared for the HERA and the LHC CERN/DESY workshop 2004/2005 | null | null | null | hep-ph | null | Our presentation centers on the consequences of s-channel unitarity,
manifested by soft re-scatterings of the spectator partons in a high energy
diffractive process, focusing on the calculations of gap survival
probabilities. Our emphasis is on recent estimates relevant to exclusive
diffractive Higgs production at the LHC. To this end, we critically re-examine
the comparison of the theoretical estimates of large rapidity gap hard di-jets
with the measured data, and remark on the difficulties in the interpretation of
HERA hard di-jet photoproduction.
| [
{
"created": "Sun, 6 Nov 2005 17:50:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Gotsman",
"E.",
""
],
[
"Levin",
"E.",
""
],
[
"Maor",
"U.",
""
],
[
"Naftali",
"E.",
""
],
[
"Prygarin",
"A.",
""
]
] | Our presentation centers on the consequences of s-channel unitarity, manifested by soft re-scatterings of the spectator partons in a high energy diffractive process, focusing on the calculations of gap survival probabilities. Our emphasis is on recent estimates relevant to exclusive diffractive Higgs production at the LHC. To this end, we critically re-examine the comparison of the theoretical estimates of large rapidity gap hard di-jets with the measured data, and remark on the difficulties in the interpretation of HERA hard di-jet photoproduction. |
hep-ph/0202151 | Corrado Appignani | Corrado Appignani (Dipartimento di Fisica - Universita' di Bologna -
Bologna - Italy) | QCD Universality recovered via the Total Available Quadri-Scalar: Atot | V1: 24 pages, 4 figures; V2: reduced to 18 pages, layout and
presentation improved, content unchanged; V3: definitive published version,
adp latex style, a comparison to GPDs added, content unchanged | Ann. Phys. (Leipzig) 13, No. 6, 307-327 (2004) | 10.1002/andp.200310095 | null | hep-ph | null | After presenting a brief review of the phenomenology of the Leading Effect,
we define a new variable, the ``Total Available Quadri-Scalar'' (Atot), and
propose it as the invariant quantity effectively available for the production
of the multihadronic final states. The introduction and the definition of this
new variable are justified by means of simple geometrical-kinematical
considerations and we show that Atot reduces to the so-called Effective Energy
in the single specific situation where the use of the latter applies. Using
Atot to re-plot existing data, the quantity <Nch> is shown to be a
``Universality Feature'' - that is, independent from the process under exam,
the collider nominal energy, and even from the hadronic invariant mass - as
imposed by QCD Universality.
| [
{
"created": "Fri, 15 Feb 2002 17:01:49 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jun 2003 10:38:55 GMT",
"version": "v2"
},
{
"created": "Wed, 28 Jul 2004 17:14:19 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Appignani",
"Corrado",
"",
"Dipartimento di Fisica - Universita' di Bologna -\n Bologna - Italy"
]
] | After presenting a brief review of the phenomenology of the Leading Effect, we define a new variable, the ``Total Available Quadri-Scalar'' (Atot), and propose it as the invariant quantity effectively available for the production of the multihadronic final states. The introduction and the definition of this new variable are justified by means of simple geometrical-kinematical considerations and we show that Atot reduces to the so-called Effective Energy in the single specific situation where the use of the latter applies. Using Atot to re-plot existing data, the quantity <Nch> is shown to be a ``Universality Feature'' - that is, independent from the process under exam, the collider nominal energy, and even from the hadronic invariant mass - as imposed by QCD Universality. |
hep-ph/0412067 | Irina V. Titkova | V.A. Bednyakov, F. Simkovic, I.V. Titkova | Nuclear Spin in Direct Dark Matter Search | Talk was given on XVII International Baldin Seminar "Relativistic
Nuclear Physics and Quantum Chromodynamics" (JINR,Dubna, Russia, 2004) | null | null | null | hep-ph | null | The Weakly Interacting Massive Particles (WIMPs) are among the main
candidates for the relic dark matter (DM). The idea of the direct DM detection
relies on elastic in-dependent (SD) and spin-independent (SI) interaction of
WIMPs with target nuclei. The importance of the SD WIMP-nucleus interaction for
reliable DM detection is argued. The absolute lower bound for the detection
rate can naturally be due to SD interaction. An experiment aimed at detecting
DM with sensitivity higher than 10^{-5} event/day/kg should have a
non-zero-spin target.
| [
{
"created": "Sun, 5 Dec 2004 21:10:54 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bednyakov",
"V. A.",
""
],
[
"Simkovic",
"F.",
""
],
[
"Titkova",
"I. V.",
""
]
] | The Weakly Interacting Massive Particles (WIMPs) are among the main candidates for the relic dark matter (DM). The idea of the direct DM detection relies on elastic in-dependent (SD) and spin-independent (SI) interaction of WIMPs with target nuclei. The importance of the SD WIMP-nucleus interaction for reliable DM detection is argued. The absolute lower bound for the detection rate can naturally be due to SD interaction. An experiment aimed at detecting DM with sensitivity higher than 10^{-5} event/day/kg should have a non-zero-spin target. |
hep-ph/9709462 | Harald W. Griesshammer | Harald W. Griesshammer (U Erlangen, U of Washington) | Magnetic Defects Signal Failure of Abelian Projection Gauges in QCD | 20 pages, LaTeX2e, uses package fontenc | null | null | FAU-TP3-97/6, DOE/ER/41014-35-N97 | hep-ph hep-th | null | Magnetically charged Abelian defects are shown to arise on most compact base
manifolds and in most Abelian projection gauges. They obey the Dirac
quantisation condition and give rise to homogeneous magnetic background fields.
The reasons for their occurrence are global failures of the procedure with
which gauge covariant operators are diagonalised or their eigenphases
extracted. Defects related to the former case are string-like; for the latter
case they resemble domain walls. Either configuration forms the generic case
and indicates a failure of gauge fixing as continuity and periodicity
properties of the functional space are changed. These results are first
obtained in canonically quantised QCD_{3+1} and path integral QCD_{2+1} on the
torus for the modified axial gauge which keeps only the eigenphases as
dynamical variables of the Wilson line in the x_3-direction. In the end, they
are extended to other gauges, dimensions and standard manifolds.
| [
{
"created": "Thu, 25 Sep 1997 23:09:51 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Griesshammer",
"Harald W.",
"",
"U Erlangen, U of Washington"
]
] | Magnetically charged Abelian defects are shown to arise on most compact base manifolds and in most Abelian projection gauges. They obey the Dirac quantisation condition and give rise to homogeneous magnetic background fields. The reasons for their occurrence are global failures of the procedure with which gauge covariant operators are diagonalised or their eigenphases extracted. Defects related to the former case are string-like; for the latter case they resemble domain walls. Either configuration forms the generic case and indicates a failure of gauge fixing as continuity and periodicity properties of the functional space are changed. These results are first obtained in canonically quantised QCD_{3+1} and path integral QCD_{2+1} on the torus for the modified axial gauge which keeps only the eigenphases as dynamical variables of the Wilson line in the x_3-direction. In the end, they are extended to other gauges, dimensions and standard manifolds. |
2107.04860 | Zhi Yang | Zhi Yang, Guang-Juan Wang, Jia-Jun Wu, Makoto Oka and Shi-Lin Zhu | Novel coupled channel framework connecting quark model and lattice QCD:
an investigation on near-threshold $D_s$ states | 7 pages, 3 figures; accepted for publication in Physical Review
Letters | Phys.Rev.Lett. 128 (2022) 11, 112001 | 10.1103/PhysRevLett.128.112001 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A novel framework is proposed to extract near-threshold resonant states from
finite-volume energy levels of lattice QCD and is applied to elucidate
structures of the positive parity $D_s$. The quark model, the
quark-pair-creation mechanism and $D^{(*)}K$ interaction are incorporated into
the Hamiltonian effective field theory. The bare $1^+$ $c\bar s$ states are
almost purely given by the states with heavy-quark spin bases. The physical
$D^*_{s0}(2317)$ and $D^*_{s1}(2460)$ are the mixtures of bare $c\bar s$ core
and $D^{(*)}K$ component, while the $D^*_{s1}(2536)$ and $D^*_{s2}(2573)$ are
almost dominated by bare $c\bar{s}$. Furthermore, our model reproduces the
clear level crossing of the $D^*_{s1}(2536)$ with the scattering state at a
finite volume.
| [
{
"created": "Sat, 10 Jul 2021 15:22:28 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Aug 2021 07:12:03 GMT",
"version": "v2"
},
{
"created": "Sat, 19 Feb 2022 03:35:24 GMT",
"version": "v3"
}
] | 2022-04-20 | [
[
"Yang",
"Zhi",
""
],
[
"Wang",
"Guang-Juan",
""
],
[
"Wu",
"Jia-Jun",
""
],
[
"Oka",
"Makoto",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | A novel framework is proposed to extract near-threshold resonant states from finite-volume energy levels of lattice QCD and is applied to elucidate structures of the positive parity $D_s$. The quark model, the quark-pair-creation mechanism and $D^{(*)}K$ interaction are incorporated into the Hamiltonian effective field theory. The bare $1^+$ $c\bar s$ states are almost purely given by the states with heavy-quark spin bases. The physical $D^*_{s0}(2317)$ and $D^*_{s1}(2460)$ are the mixtures of bare $c\bar s$ core and $D^{(*)}K$ component, while the $D^*_{s1}(2536)$ and $D^*_{s2}(2573)$ are almost dominated by bare $c\bar{s}$. Furthermore, our model reproduces the clear level crossing of the $D^*_{s1}(2536)$ with the scattering state at a finite volume. |
2308.04773 | Gilberto Ramalho | G. Ramalho and K. Tsushima | Meson cloud contributions to the Dalitz decays of decuplet to octet
baryons | Published at Phys. Rev. D. 28 pages, 8 figures, 11 tables. More
compacted version. Appendix removed. Updated bibliography | Phys. Rev. D 108, 074019 (2023) | 10.1103/PhysRevD.108.074019 | LFTC-23-5/78 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the role of the meson cloud on the electromagnetic transitions from
decuplet ($B'$) to octet ($B$) baryons in terms of the squared four-momentum
transfer $q^2$. In the quark model framework, the meson cloud dressing of the
quark cores gives important contributions to the $\gamma^\ast N \to
\Delta(1232)$ transition form factors. In the present work, we estimate the
meson cloud contributions of all decuplet to octet baryon transitions
($\gamma^\ast B \to B'$ or $B' \to \gamma^\ast B$). Models that combine valence
quark effects with pion and kaon cloud dressing provide a fair description of
the radiative decays of decuplet to octet baryons, namely the $\Sigma^0(1385)
\to \gamma \Lambda (1116)$ and $\Sigma^+(1385) \to \gamma \Sigma^+ (1193)$
decays. Previous studies indicated the relevance of the pion cloud effects on
the $B^\prime \to \gamma^\ast B$ transition, but also suggested that the kaon
cloud contributions may be important in the timelike region. We combine then
the contributions of the bare core, estimated by a covariant quark model, with
$q^2$-dependent contributions of pion and kaon clouds. We use the framework to
calculate the Dalitz decay rates and the Dalitz decay widths of decuplet
baryons in octet baryons with di-electrons ($B' \to e^+ e^- B$) or di-muons
($B' \to \mu^+ \mu^- B$). We conclude, based on the magnitude of our results,
that most estimates of the $B' \to e^+ e^- B$ Dalitz decay widths may be tested
at HADES and PANDA (GSI) in a near future. We discuss also the possibility of
measuring the $\Delta (1232) \to \mu^+ \mu^- N$ and $\Sigma^0 (1385) \to \mu^+
\mu^- \Lambda (1116)$ decay widths in some facilities, based on the estimated
branching ratios.
| [
{
"created": "Wed, 9 Aug 2023 08:01:51 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Dec 2023 09:29:13 GMT",
"version": "v2"
}
] | 2023-12-25 | [
[
"Ramalho",
"G.",
""
],
[
"Tsushima",
"K.",
""
]
] | We study the role of the meson cloud on the electromagnetic transitions from decuplet ($B'$) to octet ($B$) baryons in terms of the squared four-momentum transfer $q^2$. In the quark model framework, the meson cloud dressing of the quark cores gives important contributions to the $\gamma^\ast N \to \Delta(1232)$ transition form factors. In the present work, we estimate the meson cloud contributions of all decuplet to octet baryon transitions ($\gamma^\ast B \to B'$ or $B' \to \gamma^\ast B$). Models that combine valence quark effects with pion and kaon cloud dressing provide a fair description of the radiative decays of decuplet to octet baryons, namely the $\Sigma^0(1385) \to \gamma \Lambda (1116)$ and $\Sigma^+(1385) \to \gamma \Sigma^+ (1193)$ decays. Previous studies indicated the relevance of the pion cloud effects on the $B^\prime \to \gamma^\ast B$ transition, but also suggested that the kaon cloud contributions may be important in the timelike region. We combine then the contributions of the bare core, estimated by a covariant quark model, with $q^2$-dependent contributions of pion and kaon clouds. We use the framework to calculate the Dalitz decay rates and the Dalitz decay widths of decuplet baryons in octet baryons with di-electrons ($B' \to e^+ e^- B$) or di-muons ($B' \to \mu^+ \mu^- B$). We conclude, based on the magnitude of our results, that most estimates of the $B' \to e^+ e^- B$ Dalitz decay widths may be tested at HADES and PANDA (GSI) in a near future. We discuss also the possibility of measuring the $\Delta (1232) \to \mu^+ \mu^- N$ and $\Sigma^0 (1385) \to \mu^+ \mu^- \Lambda (1116)$ decay widths in some facilities, based on the estimated branching ratios. |
2204.02218 | Guang-You Qin | Xiang-Yu Wu, Cong Yi, Guang-You Qin, Shi Pu | Local and global polarization of $\Lambda$ hyperons across RHIC-BES
energies: the roles of spin hall effect, initial condition and baryon
diffusion | 13 pages, 8 figures | Phys. Rev. C 105, 064909 (2022) | 10.1103/PhysRevC.105.064909 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a systematic study on the local and global spin polarization of
$\Lambda$ and $\overline{\Lambda}$ hyperons in relativistic heavy-ion
collisions at beam energy scan energies via the (3+1)-dimensional CLVisc
hydrodynamics model with AMPT and SMASH initial conditions. Following the
quantum kinetic theory, we decompose the polarization vector as the parts
induced by thermal vorticity, shear tensor and the spin Hall effect (SHE). We
find that the polarization induced by SHE and the total polarization strongly
depends on the initial conditions. At $7.7$GeV, SHE gives a sizeable
contribution and even flips the sign of the local polarization along the beam
direction for AMPT initial condition, which is not observed for SMASH initial
condition. Meanwhile, the local polarization along the out-of-plane direction
induced by SHE with AMPT initial condition does not always increase with
decreasing collision energies. Next, we find that the polarization along the
beam direction is sensitive to the baryon diffusion coefficient, but the local
polarization along the out-of-plane direction is not. Our results for the
global polarization of $\Lambda$ and $\overline{\Lambda}$ agree well with the
STAR data. Interestingly, the global polarization of $\overline{\Lambda}$ is
not always larger than that of $\Lambda$ due to various competing effects. Our
findings are helpful for understanding the polarization phenomenon and the
detailed structure of quark-gluon plasma in relativistic heavy-ion collisions.
| [
{
"created": "Tue, 5 Apr 2022 13:49:25 GMT",
"version": "v1"
}
] | 2022-06-28 | [
[
"Wu",
"Xiang-Yu",
""
],
[
"Yi",
"Cong",
""
],
[
"Qin",
"Guang-You",
""
],
[
"Pu",
"Shi",
""
]
] | We perform a systematic study on the local and global spin polarization of $\Lambda$ and $\overline{\Lambda}$ hyperons in relativistic heavy-ion collisions at beam energy scan energies via the (3+1)-dimensional CLVisc hydrodynamics model with AMPT and SMASH initial conditions. Following the quantum kinetic theory, we decompose the polarization vector as the parts induced by thermal vorticity, shear tensor and the spin Hall effect (SHE). We find that the polarization induced by SHE and the total polarization strongly depends on the initial conditions. At $7.7$GeV, SHE gives a sizeable contribution and even flips the sign of the local polarization along the beam direction for AMPT initial condition, which is not observed for SMASH initial condition. Meanwhile, the local polarization along the out-of-plane direction induced by SHE with AMPT initial condition does not always increase with decreasing collision energies. Next, we find that the polarization along the beam direction is sensitive to the baryon diffusion coefficient, but the local polarization along the out-of-plane direction is not. Our results for the global polarization of $\Lambda$ and $\overline{\Lambda}$ agree well with the STAR data. Interestingly, the global polarization of $\overline{\Lambda}$ is not always larger than that of $\Lambda$ due to various competing effects. Our findings are helpful for understanding the polarization phenomenon and the detailed structure of quark-gluon plasma in relativistic heavy-ion collisions. |
hep-ph/9210207 | David Gross | David J. Gross | Asymptotic Freedom and the Emergence of QCD | Talk delivered at the Third International Symposium on the History of
Particle Physics, June 26, 1992, 35 pages | null | null | PUPT 1329 | hep-ph hep-th | null | I describe our understanding of the strong interactions at the end of the
1960's and the impact of the experiments on deep inelastic scattering. I recall
the steps that lead from the attempts to understand these experiments to the
discovery of asymptotic freedom in 1973 and the subsequent rapid emergence,
development and acceptance of the non-Abelian gauge theory of color (QCD) as
the theory of the strong interactions.
| [
{
"created": "Fri, 2 Oct 1992 22:23:39 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Gross",
"David J.",
""
]
] | I describe our understanding of the strong interactions at the end of the 1960's and the impact of the experiments on deep inelastic scattering. I recall the steps that lead from the attempts to understand these experiments to the discovery of asymptotic freedom in 1973 and the subsequent rapid emergence, development and acceptance of the non-Abelian gauge theory of color (QCD) as the theory of the strong interactions. |
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