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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2301.10757 | Wen Yin | Fuminobu Takahashi and Wen Yin | Hadrophobic Axion from GUT | v2: 51pages, 11figures, 4tables; version to appear in PRD, typos and
an error in axion-photon coupling corrected | null | null | TU-1179 | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new kind of axion model derived from the Grand Unified Theory
(GUT) based on $SU(5)\times U(1)_{\rm PQ}$. We demonstrate that, given a
certain charge assignment and potential flavor models, the axion is naturally
hadrophobic and provides a novel explanation for the required condition using
isospin symmetry. This axion can be the QCD axion that solves the strong CP
problem. Furthermore, to satisfy the limit on the axion-electron coupling from
the tip of the red giant branch, we impose the condition of electrophobia to
determine a possible PQ charge assignment consistent with GUT. We then discuss
the possibility that the hadrophobic and electrophobic axion serves as an
inflaton and dark matter, as in the ALP miracle scenario. Interestingly, in the
viable parameter region, the strong CP phase must be suppressed, providing
another solution to the strong CP problem. This scenario is intimately linked
to flavor physics, dark matter searches, and stellar cooling. Detecting such an
axion with peculiar couplings in various experiments would serve as a probe for
GUT and the origin of flavor.
| [
{
"created": "Wed, 25 Jan 2023 18:37:11 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Feb 2024 19:01:18 GMT",
"version": "v2"
}
] | 2024-02-16 | [
[
"Takahashi",
"Fuminobu",
""
],
[
"Yin",
"Wen",
""
]
] | We propose a new kind of axion model derived from the Grand Unified Theory (GUT) based on $SU(5)\times U(1)_{\rm PQ}$. We demonstrate that, given a certain charge assignment and potential flavor models, the axion is naturally hadrophobic and provides a novel explanation for the required condition using isospin symmetry. This axion can be the QCD axion that solves the strong CP problem. Furthermore, to satisfy the limit on the axion-electron coupling from the tip of the red giant branch, we impose the condition of electrophobia to determine a possible PQ charge assignment consistent with GUT. We then discuss the possibility that the hadrophobic and electrophobic axion serves as an inflaton and dark matter, as in the ALP miracle scenario. Interestingly, in the viable parameter region, the strong CP phase must be suppressed, providing another solution to the strong CP problem. This scenario is intimately linked to flavor physics, dark matter searches, and stellar cooling. Detecting such an axion with peculiar couplings in various experiments would serve as a probe for GUT and the origin of flavor. |
2003.04505 | Luis Hernandez | Alejandro Ayala, Saul Hernandez-Ortiz, Luis A. Hernandez, Victor
Knapp-Perez and Renato Zamora | Fluctuating temperature and baryon chemical potential in heavy-ion
collisions and the position of the critical end point in the effective QCD
phase diagram | 15 pages, 9 figures | Phys. Rev. D 101, 074023 (2020) | 10.1103/PhysRevD.101.074023 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use the linear sigma model with quarks to locate the critical end point in
the effective QCD phase diagram accounting for fluctuations in temperature and
quark chemical potential. For this purpose, we use the non-equilibrium
formalism provided by the superstatistics framework. We compute the effective
potential in the high- and low-temperature approximations up to sixth order and
include the contribution of ring diagrams to account for plasma screening
effects. We fix the model parameters from relations between the thermal sigma
and pion masses imposing a first order phase transition at zero temperature and
a finite critical value for the baryon chemical potential that we take of order
of the nucleon mass. We find that the CEP displacement due to fluctuations in
temperature and/or quark chemical potential is almost negligible.
| [
{
"created": "Tue, 10 Mar 2020 02:21:50 GMT",
"version": "v1"
}
] | 2020-04-29 | [
[
"Ayala",
"Alejandro",
""
],
[
"Hernandez-Ortiz",
"Saul",
""
],
[
"Hernandez",
"Luis A.",
""
],
[
"Knapp-Perez",
"Victor",
""
],
[
"Zamora",
"Renato",
""
]
] | We use the linear sigma model with quarks to locate the critical end point in the effective QCD phase diagram accounting for fluctuations in temperature and quark chemical potential. For this purpose, we use the non-equilibrium formalism provided by the superstatistics framework. We compute the effective potential in the high- and low-temperature approximations up to sixth order and include the contribution of ring diagrams to account for plasma screening effects. We fix the model parameters from relations between the thermal sigma and pion masses imposing a first order phase transition at zero temperature and a finite critical value for the baryon chemical potential that we take of order of the nucleon mass. We find that the CEP displacement due to fluctuations in temperature and/or quark chemical potential is almost negligible. |
1609.04783 | Christoph Bobeth | Christoph Bobeth, Andrzej J. Buras, Alejandro Celis and Martin Jung | Patterns of Flavour Violation in Models with Vector-Like Quarks | 50 + 24 pages, 12 figures; v3: added top-Yukawa RG evolution, details
on VLQ matching on G_SM^(')-EFT, one figure, references; revised numerics;
some changes in conclusions | null | 10.1007/JHEP04(2017)079 | FLAVOUR(267104)-ERC-120, LMU-ASC 01/16, TUM-HEP-1060/16 | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the patterns of flavour violation in renormalisable extensions of
the Standard Model (SM) that contain vector-like quarks (VLQs) in a single
complex representation of either the SM gauge group $G_{SM}$ or $G_{SM}' =
G_{SM} \times U(1)_{L_\mu - L_\tau}$. We first decouple VLQs in the $M=(1-10)$
TeV range and then at the electroweak scale also $Z, Z'$ gauge bosons and
additional scalars to study the resulting phenomenology that depends on the
relative size of $Z$- and $Z'$-induced flavour-changing neutral currents, as
well as the size of $\Delta F=2$ contributions including the effects of
renormalisation group Yukawa evolution from $M$ to the electroweak scale that
turn out to be very important for models with right-handed currents through the
generation of left-right operators. In addition to rare decays like $P\to
\ell\bar\ell$, $P\to P' \ell\bar\ell$, $P\to P'\nu\bar\nu$ with $P=K, B_s, B_d$
and $\Delta F=2$ observables we analyze the ratio $\varepsilon'/\varepsilon$
which appears in the SM to be significantly below the data. We study patterns
and correlations between these observables which taken together should in the
future allow for differentiating between VLQ models. In particular the patterns
in models with left-handed and right-handed currents are markedly different
from each other. Among the highlights are large $Z$-mediated new physics
effects in Kaon observables in some of the models and significant effects in
$B_{s,d}$-observables. $\varepsilon'/\varepsilon$ can easily be made consistent
with the data, implying then uniquely the suppression of $K_L\to \pi^0
\nu\bar\nu$. Significant enhancements of $Br(K^+\to \pi^+ \nu\bar\nu)$ are
still possible. We point out that the combination of $\Delta F=2$ and $\Delta
F=1$ observables in a given meson system generally allows to determine the
masses of VLQs independently of the size of VLQ couplings.
| [
{
"created": "Thu, 15 Sep 2016 19:18:38 GMT",
"version": "v1"
},
{
"created": "Sat, 15 Oct 2016 18:55:32 GMT",
"version": "v2"
},
{
"created": "Wed, 29 Mar 2017 15:59:17 GMT",
"version": "v3"
}
] | 2017-05-24 | [
[
"Bobeth",
"Christoph",
""
],
[
"Buras",
"Andrzej J.",
""
],
[
"Celis",
"Alejandro",
""
],
[
"Jung",
"Martin",
""
]
] | We study the patterns of flavour violation in renormalisable extensions of the Standard Model (SM) that contain vector-like quarks (VLQs) in a single complex representation of either the SM gauge group $G_{SM}$ or $G_{SM}' = G_{SM} \times U(1)_{L_\mu - L_\tau}$. We first decouple VLQs in the $M=(1-10)$ TeV range and then at the electroweak scale also $Z, Z'$ gauge bosons and additional scalars to study the resulting phenomenology that depends on the relative size of $Z$- and $Z'$-induced flavour-changing neutral currents, as well as the size of $\Delta F=2$ contributions including the effects of renormalisation group Yukawa evolution from $M$ to the electroweak scale that turn out to be very important for models with right-handed currents through the generation of left-right operators. In addition to rare decays like $P\to \ell\bar\ell$, $P\to P' \ell\bar\ell$, $P\to P'\nu\bar\nu$ with $P=K, B_s, B_d$ and $\Delta F=2$ observables we analyze the ratio $\varepsilon'/\varepsilon$ which appears in the SM to be significantly below the data. We study patterns and correlations between these observables which taken together should in the future allow for differentiating between VLQ models. In particular the patterns in models with left-handed and right-handed currents are markedly different from each other. Among the highlights are large $Z$-mediated new physics effects in Kaon observables in some of the models and significant effects in $B_{s,d}$-observables. $\varepsilon'/\varepsilon$ can easily be made consistent with the data, implying then uniquely the suppression of $K_L\to \pi^0 \nu\bar\nu$. Significant enhancements of $Br(K^+\to \pi^+ \nu\bar\nu)$ are still possible. We point out that the combination of $\Delta F=2$ and $\Delta F=1$ observables in a given meson system generally allows to determine the masses of VLQs independently of the size of VLQ couplings. |
1809.04517 | Can Kilic | Dipsikha Debnath, James S. Gainer, Can Kilic, Doojin Kim, Konstantin
T. Matchev, Yuan-Pao Yang | Enhancing the discovery prospects for SUSY-like decays with a forgotten
kinematic variable | 20 pages, 13 figures. v2: matches published version | null | 10.1007/JHEP05(2019)008 | UTTG-09-18, CERN-TH-2018-203, UH-511-2018-1295 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The lack of a new physics signal thus far at the Large Hadron Collider
motivates us to consider how to look for challenging final states, with large
Standard Model backgrounds and subtle kinematic features, such as cascade
decays with compressed spectra. Adopting a benchmark SUSY-like decay topology
with a four-body final state proceeding through a sequence of two-body decays
via intermediate resonances, we focus our attention on the kinematic variable
$\Delta_{4}$ which previously has been used to parameterize the boundary of the
allowed four-body phase space. We highlight the advantages of using
$\Delta_{4}$ as a discovery variable, and present an analysis suggesting that
the pairing of $\Delta_{4}$ with another invariant mass variable leads to a
significant improvement over more conventional variable choices and techniques.
| [
{
"created": "Wed, 12 Sep 2018 15:39:25 GMT",
"version": "v1"
},
{
"created": "Thu, 23 May 2019 16:27:32 GMT",
"version": "v2"
}
] | 2019-05-24 | [
[
"Debnath",
"Dipsikha",
""
],
[
"Gainer",
"James S.",
""
],
[
"Kilic",
"Can",
""
],
[
"Kim",
"Doojin",
""
],
[
"Matchev",
"Konstantin T.",
""
],
[
"Yang",
"Yuan-Pao",
""
]
] | The lack of a new physics signal thus far at the Large Hadron Collider motivates us to consider how to look for challenging final states, with large Standard Model backgrounds and subtle kinematic features, such as cascade decays with compressed spectra. Adopting a benchmark SUSY-like decay topology with a four-body final state proceeding through a sequence of two-body decays via intermediate resonances, we focus our attention on the kinematic variable $\Delta_{4}$ which previously has been used to parameterize the boundary of the allowed four-body phase space. We highlight the advantages of using $\Delta_{4}$ as a discovery variable, and present an analysis suggesting that the pairing of $\Delta_{4}$ with another invariant mass variable leads to a significant improvement over more conventional variable choices and techniques. |
1007.4052 | Falk Bruckmann | Falk Bruckmann | A random matrix-like model for the Polyakov loop and center symmetry | 5 pages, 3 figures | null | null | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We formulate a random matrix-like model for the Polyakov loop in SU(N)
Yang-Mills theories. It describes a simplified dynamics in terms of eigenvalue
differences. The deconfinement phase transition encoded in center symmetry
breaking is reproduced including its nature being first order for SU(3) and
second order for SU(2). Analytical arguments about the phases are presented and
a comparison to other approaches is made.
| [
{
"created": "Fri, 23 Jul 2010 06:49:48 GMT",
"version": "v1"
}
] | 2010-07-27 | [
[
"Bruckmann",
"Falk",
""
]
] | We formulate a random matrix-like model for the Polyakov loop in SU(N) Yang-Mills theories. It describes a simplified dynamics in terms of eigenvalue differences. The deconfinement phase transition encoded in center symmetry breaking is reproduced including its nature being first order for SU(3) and second order for SU(2). Analytical arguments about the phases are presented and a comparison to other approaches is made. |
1110.5830 | Jos\'e Daniel Madrigal | Grigorios Chachamics, Jos\'e Daniel Madrigal and Agust\'in Sabio Vera | High-Energy Dijets in N=4 SYM | 8 pages, presented at the Low-x Meeting 2011, Santiago de Compostela | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Ratios of azimuthal angle correlations for Mueller-Navelet jets are compared
in QCD and N = 4 SYM. Such observables are well suited to study the effects of
Moebius invariance in the Regge limit. The role of the renormalization
prescription and the size of conformal contributions is addressed, showing that
the BLM procedure best reproduces the N = 4 SYM results.
| [
{
"created": "Wed, 26 Oct 2011 16:02:06 GMT",
"version": "v1"
}
] | 2011-10-27 | [
[
"Chachamics",
"Grigorios",
""
],
[
"Madrigal",
"José Daniel",
""
],
[
"Vera",
"Agustín Sabio",
""
]
] | Ratios of azimuthal angle correlations for Mueller-Navelet jets are compared in QCD and N = 4 SYM. Such observables are well suited to study the effects of Moebius invariance in the Regge limit. The role of the renormalization prescription and the size of conformal contributions is addressed, showing that the BLM procedure best reproduces the N = 4 SYM results. |
1410.4824 | Farvah Mahmoudi | A. Arbey, J. Ellis, R. M. Godbole, F. Mahmoudi | Exploring CP Violation in the MSSM | 36 pages, 32 figures | Eur. Phys. J. C75 (2015) 2, 85 | 10.1140/epjc/s10052-015-3294-z | KCL-PH-TH/2014-40, LCTS/2014-40, CERN-PH-TH/2014-195 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the prospects for observing CP violation in the minimal
supersymmetric extension of the Standard Model (MSSM) with six CP-violating
parameters, three gaugino mass phases and three phases in trilinear soft
supersymmetry-breaking parameters, using the CPsuperH code combined with a
geometric approach to maximize CP-violating observables subject to the
experimental upper bounds on electric dipole moments. We also implement
CP-conserving constraints from Higgs physics, flavour physics and the upper
limits on the cosmological dark matter density and spin-independent scattering.
We study possible values of observables within the constrained MSSM (CMSSM),
the non-universal Higgs model (NUHM), the CPX scenario and a variant of the
phenomenological MSSM (pMSSM). We find values of the CP-violating asymmetry
A_CP in b -> s gamma decay that may be as large as 3%, so future measurements
of A_CP may provide independent information about CP violation in the MSSM. We
find that CP-violating MSSM contributions to the B_s meson mass mixing term
Delta M_Bs are in general below the present upper limit, which is dominated by
theoretical uncertainties. If these could be reduced, Delta M_Bs could also
provide an interesting and complementary constraint on the six CP-violating
MSSM phases, enabling them all to be determined experimentally, in principle.
We also find that CP violation in the h_{2,3} tau+ tau- and h_{2,3} tbar t
couplings can be quite large, and so may offer interesting prospects for future
pp, e+ e-, mu+ mu- and gamma gamma colliders.
| [
{
"created": "Fri, 17 Oct 2014 18:56:40 GMT",
"version": "v1"
},
{
"created": "Sat, 28 Feb 2015 18:22:38 GMT",
"version": "v2"
}
] | 2015-03-03 | [
[
"Arbey",
"A.",
""
],
[
"Ellis",
"J.",
""
],
[
"Godbole",
"R. M.",
""
],
[
"Mahmoudi",
"F.",
""
]
] | We explore the prospects for observing CP violation in the minimal supersymmetric extension of the Standard Model (MSSM) with six CP-violating parameters, three gaugino mass phases and three phases in trilinear soft supersymmetry-breaking parameters, using the CPsuperH code combined with a geometric approach to maximize CP-violating observables subject to the experimental upper bounds on electric dipole moments. We also implement CP-conserving constraints from Higgs physics, flavour physics and the upper limits on the cosmological dark matter density and spin-independent scattering. We study possible values of observables within the constrained MSSM (CMSSM), the non-universal Higgs model (NUHM), the CPX scenario and a variant of the phenomenological MSSM (pMSSM). We find values of the CP-violating asymmetry A_CP in b -> s gamma decay that may be as large as 3%, so future measurements of A_CP may provide independent information about CP violation in the MSSM. We find that CP-violating MSSM contributions to the B_s meson mass mixing term Delta M_Bs are in general below the present upper limit, which is dominated by theoretical uncertainties. If these could be reduced, Delta M_Bs could also provide an interesting and complementary constraint on the six CP-violating MSSM phases, enabling them all to be determined experimentally, in principle. We also find that CP violation in the h_{2,3} tau+ tau- and h_{2,3} tbar t couplings can be quite large, and so may offer interesting prospects for future pp, e+ e-, mu+ mu- and gamma gamma colliders. |
1008.4355 | Matthew Schwartz | Randall Kelley and Matthew D. Schwartz | Threshold Hadronic Event Shapes with Effective Field Theory | 38 pages, 2 figures; small typos corrected in v2 | Phys.Rev.D83:033001,2011 | 10.1103/PhysRevD.83.033001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Hadronic event shapes, that is, event shapes at hadron colliders, could
provide a great way to test both standard and non-standard theoretical models.
However, they are significantly more complicated than event shapes at e+e-
colliders, involving multiple hard directions, multiple channels and multiple
color structures. In this paper, hadronic event shapes are examined with
Soft-Collinear Effective Theory (SCET) by expanding around the dijet limit. A
simple event shape, threshold thrust, is defined. This observable is global and
has no free parameters, making it ideal for clarifying how resummation of
hadronic event shapes can be done in SCET. Threshold thrust is calculated at
next-to-leading fixed order (NLO) in SCET and resummed to
next-to-next-to-leading logarithmic accuracy (NNLL). The scale-dependent parts
of the soft function are shown to agree with what is expected from general
observations, and the factorization formula is explicitly shown to be
renormalization group invariant to 1-loop. Although threshold thrust is not
itself expected to be phenomenologically interesting, it can be modified into a
related observable which allows the jet pT distribution to be calculated and
resummed to NNLL+NLO accuracy. As in other processes, one expects resummation
to be important even for moderate jet momenta due to dynamical threshold
enhancement. A general discussion of threshold enhancement and non-global logs
in hadronic event shapes is also included.
| [
{
"created": "Wed, 25 Aug 2010 20:00:03 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Mar 2011 15:56:29 GMT",
"version": "v2"
}
] | 2011-03-28 | [
[
"Kelley",
"Randall",
""
],
[
"Schwartz",
"Matthew D.",
""
]
] | Hadronic event shapes, that is, event shapes at hadron colliders, could provide a great way to test both standard and non-standard theoretical models. However, they are significantly more complicated than event shapes at e+e- colliders, involving multiple hard directions, multiple channels and multiple color structures. In this paper, hadronic event shapes are examined with Soft-Collinear Effective Theory (SCET) by expanding around the dijet limit. A simple event shape, threshold thrust, is defined. This observable is global and has no free parameters, making it ideal for clarifying how resummation of hadronic event shapes can be done in SCET. Threshold thrust is calculated at next-to-leading fixed order (NLO) in SCET and resummed to next-to-next-to-leading logarithmic accuracy (NNLL). The scale-dependent parts of the soft function are shown to agree with what is expected from general observations, and the factorization formula is explicitly shown to be renormalization group invariant to 1-loop. Although threshold thrust is not itself expected to be phenomenologically interesting, it can be modified into a related observable which allows the jet pT distribution to be calculated and resummed to NNLL+NLO accuracy. As in other processes, one expects resummation to be important even for moderate jet momenta due to dynamical threshold enhancement. A general discussion of threshold enhancement and non-global logs in hadronic event shapes is also included. |
hep-ph/0511226 | D.N. Triantafyllopoulos | D.N. Triantafyllopoulos | Pomeron Loops in High Energy QCD | 76 pages, 18 Figures, 9 Appendices. Based on lectures given at the
XLV Course of the Cracow School of Theoretical Physics, Zakopane, Poland,
3-12 June 2005 | Acta Phys.Polon.B36:3593-3664,2005 | null | Saclay-T05/182, ECT*-05-18 | hep-ph | null | We discuss the QCD evolution equations governing the high energy behavior of
scattering amplitudes at the leading logarithmic level. This hierarchy of
equations accommodates normal BFKL dynamics, Pomeron mergings and Pomeron
splittings. Pomeron loops are built in the course of evolution and the
scattering amplitudes satisfy the unitarity bound.
| [
{
"created": "Fri, 18 Nov 2005 17:54:00 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Triantafyllopoulos",
"D. N.",
""
]
] | We discuss the QCD evolution equations governing the high energy behavior of scattering amplitudes at the leading logarithmic level. This hierarchy of equations accommodates normal BFKL dynamics, Pomeron mergings and Pomeron splittings. Pomeron loops are built in the course of evolution and the scattering amplitudes satisfy the unitarity bound. |
1511.00355 | Javier Fuentes-Mart\'in | Javier Fuentes-Martin | A class of Z' models with non-universal couplings and protected
flavor-changing interactions | 10 pages, 2 figures. Prepared for the proceedings of the EPS-HEP 2015
conference, 22-29 July 2015, Vienna, Austria. v2: references added | PoS(EPS-HEP2015)577 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the $b\to s\ell^+\ell^-$ anomalies recently reported by the LHCb
collaboration, I present a class of flavored U(1)' gauge extensions of the
Standard Model that naturally accommodates them and possesses a rich
phenomenology. This model is characterized by the presence of tree-level
flavor-changing interactions in the down-quark sector, protected by
off-diagonal quark-mixing matrix elements. Anomaly cancellation fixes the
extension of the symmetry to the lepton sector in a very specific way, giving
rise to flavor-conserving family-non-universal Z' couplings. The fermion
content of this model is the same as in the SM while the scalar sector is
extended with an extra Higgs doublet and a scalar singlet. The model will be
tested in the next run of LHC and presents specific correlations in certain
flavor observables that allow to clearly discriminate among them and from other
new physics signals.
| [
{
"created": "Mon, 2 Nov 2015 02:03:55 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Dec 2015 18:26:53 GMT",
"version": "v2"
}
] | 2015-12-22 | [
[
"Fuentes-Martin",
"Javier",
""
]
] | Motivated by the $b\to s\ell^+\ell^-$ anomalies recently reported by the LHCb collaboration, I present a class of flavored U(1)' gauge extensions of the Standard Model that naturally accommodates them and possesses a rich phenomenology. This model is characterized by the presence of tree-level flavor-changing interactions in the down-quark sector, protected by off-diagonal quark-mixing matrix elements. Anomaly cancellation fixes the extension of the symmetry to the lepton sector in a very specific way, giving rise to flavor-conserving family-non-universal Z' couplings. The fermion content of this model is the same as in the SM while the scalar sector is extended with an extra Higgs doublet and a scalar singlet. The model will be tested in the next run of LHC and presents specific correlations in certain flavor observables that allow to clearly discriminate among them and from other new physics signals. |
0801.1932 | Zhi-Gang Wang | Z. G. Wang | Strong decays $B_{s0} \to B_s \pi$ and $B_{s1} \to B^*_s \pi $ with
light-cone QCD sum rules | 15 pages, 2 figures, revised version | Eur.Phys.J.C56:181-187,2008 | 10.1140/epjc/s10052-008-0646-y | null | hep-ph | null | In this article, we calculate the strong coupling constants $g_{B_{s0} B_s
\eta}$ and $g_{B_{s1} B^*_s \eta}$ with the light-cone QCD sum rules. Then we
take into account the small $\eta-\pi^0$ transition matrix according to
Dashen's theorem, and obtain the small decay widths for the isospin violation
processes $B_{s0}\to B_s\eta\to B_s\pi^0$ and $B_{s1}\to B_s^*\eta\to
B_s^*\pi^0$. We can search the strange-bottomed $(0^+,1^+)$ mesons $B_{s0}$ and
$B_{s1}$ in the invariant $B_s \pi^0$ and $B^*_s \pi^0$ mass distributions
respectively.
| [
{
"created": "Sun, 13 Jan 2008 04:03:49 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Feb 2008 02:06:14 GMT",
"version": "v2"
},
{
"created": "Wed, 12 Mar 2008 08:54:58 GMT",
"version": "v3"
},
{
"created": "Wed, 19 Mar 2008 00:24:02 GMT",
"version": "v4"
}
] | 2008-08-15 | [
[
"Wang",
"Z. G.",
""
]
] | In this article, we calculate the strong coupling constants $g_{B_{s0} B_s \eta}$ and $g_{B_{s1} B^*_s \eta}$ with the light-cone QCD sum rules. Then we take into account the small $\eta-\pi^0$ transition matrix according to Dashen's theorem, and obtain the small decay widths for the isospin violation processes $B_{s0}\to B_s\eta\to B_s\pi^0$ and $B_{s1}\to B_s^*\eta\to B_s^*\pi^0$. We can search the strange-bottomed $(0^+,1^+)$ mesons $B_{s0}$ and $B_{s1}$ in the invariant $B_s \pi^0$ and $B^*_s \pi^0$ mass distributions respectively. |
2211.03401 | Yu-xin Liu | Yi Lu, Fei Gao, Xiaofeng Luo, Lei Chang and Yu-xin Liu | Revealing the Signal of QCD Phase Transition in Heavy-Ion Collisions | 7 pages, 4 figures | null | null | null | hep-ph nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | We propose a novel method to construct the Landau thermodynamic potential
directly from the fluctuations measured in heavy-ion collisions. The potential
is capable of revealing the signal of the critical end-point (CEP) and the
first order phase transition (FOPT) of QCD in the system even away from the
phase transition region. With the available experimental data, we show that the
criterion of the FOPT is negative for most of the collision energies which
indicates no signal of FOPT. The data at $\sqrt{s_\mathrm{NN}}=7.7$ GeV with
0-5% centrality shows a different behavior and the mean value of the data
satisfies the criterion. However, the uncertainty is still too large to make a
certain conclusion. The higher order fluctuations are also required for
confirming the signal. We emphasize therefore that new measurements with higher
precision for the $C_{1,...,6}$ within 0-5% centrality in the vicinity of
$\sqrt{s_\mathrm{NN}}=7.7$ GeV are in demand which may finally reveal the
signal of QCD phase transition.
| [
{
"created": "Mon, 7 Nov 2022 10:06:39 GMT",
"version": "v1"
}
] | 2022-11-09 | [
[
"Lu",
"Yi",
""
],
[
"Gao",
"Fei",
""
],
[
"Luo",
"Xiaofeng",
""
],
[
"Chang",
"Lei",
""
],
[
"Liu",
"Yu-xin",
""
]
] | We propose a novel method to construct the Landau thermodynamic potential directly from the fluctuations measured in heavy-ion collisions. The potential is capable of revealing the signal of the critical end-point (CEP) and the first order phase transition (FOPT) of QCD in the system even away from the phase transition region. With the available experimental data, we show that the criterion of the FOPT is negative for most of the collision energies which indicates no signal of FOPT. The data at $\sqrt{s_\mathrm{NN}}=7.7$ GeV with 0-5% centrality shows a different behavior and the mean value of the data satisfies the criterion. However, the uncertainty is still too large to make a certain conclusion. The higher order fluctuations are also required for confirming the signal. We emphasize therefore that new measurements with higher precision for the $C_{1,...,6}$ within 0-5% centrality in the vicinity of $\sqrt{s_\mathrm{NN}}=7.7$ GeV are in demand which may finally reveal the signal of QCD phase transition. |
1006.0818 | Stephane Peigne | Francois Arleo, Stephane Peigne, Taklit Sami | Revisiting scaling properties of medium-induced gluon radiation | 16 pages, 11 figures. One error corrected in equation (3.6). Slight
simplifications and minor additions in the text, one Figure added | Phys.Rev.D83:114036,2011 | 10.1103/PhysRevD.83.114036 | LAPTH-019/10, CERN-PH-TH/2010-116 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Discussing the general case of a hard partonic production process, we show
that the notion of parton energy loss is not always sufficient to fully address
medium-induced gluon radiation. The broader notion of gluon radiation
associated to a hard process has to be used, in particular when initial and
final state radiation amplitudes interfere, making the medium-induced radiated
energy different from the energy loss of any well-identified parton. Our
arguments are first presented in an abelian QED model, and then applied to
large-xF quarkonium hadroproduction. In this case, we show that the
medium-induced radiated energy is qualitatively similar (but not identical) to
the radiative energy loss of an "asymptotic massive parton" undergoing
transverse momentum broadening when travelling through the nucleus. In
particular, it scales as the incoming parton energy, which suggests to
reconsider gluon radiation as a possible explanation of large-xF quarkonium
suppression in p-A collisions. We expect a similar effect in open heavy-flavour
and possibly light-hadron hadroproduction at large xF, depending on the precise
definition of the nuclear suppression factor in the latter case.
| [
{
"created": "Fri, 4 Jun 2010 09:31:43 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Jan 2011 15:33:45 GMT",
"version": "v2"
}
] | 2011-07-05 | [
[
"Arleo",
"Francois",
""
],
[
"Peigne",
"Stephane",
""
],
[
"Sami",
"Taklit",
""
]
] | Discussing the general case of a hard partonic production process, we show that the notion of parton energy loss is not always sufficient to fully address medium-induced gluon radiation. The broader notion of gluon radiation associated to a hard process has to be used, in particular when initial and final state radiation amplitudes interfere, making the medium-induced radiated energy different from the energy loss of any well-identified parton. Our arguments are first presented in an abelian QED model, and then applied to large-xF quarkonium hadroproduction. In this case, we show that the medium-induced radiated energy is qualitatively similar (but not identical) to the radiative energy loss of an "asymptotic massive parton" undergoing transverse momentum broadening when travelling through the nucleus. In particular, it scales as the incoming parton energy, which suggests to reconsider gluon radiation as a possible explanation of large-xF quarkonium suppression in p-A collisions. We expect a similar effect in open heavy-flavour and possibly light-hadron hadroproduction at large xF, depending on the precise definition of the nuclear suppression factor in the latter case. |
1805.04540 | Gl\'auber Sampaio dos Santos | V. P. Goncalves, M. V. T. Machado, B. D. Moreira, F. S. Navarra, G.
Sampaio dos Santos | Investigating the exclusive vector meson photoproduction in nuclear
collisions at Run 2 LHC energies | 4 pages, 2 figures, 1 table. Poster presented by G. Sampaio dos
Santos at the XIV International Workshop on Hadron Physics, Florianopolis,
Brazil, March 2018 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the theoretical uncertainty on the predictions for the
photoproduction of $\rho$ and $J/\Psi$ states in nucleus-nucleus collisions at
Run 2 LHC energies using the Color Dipole formalism. The results for rapidity
distributions and total cross sections are presented. Moreover, we compare
directly the theoretical results to the recent preliminary data from ALICE
collaboration on $\rho$ production in $PbPb$ collisions at central rapidity.
| [
{
"created": "Fri, 11 May 2018 18:11:28 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Jun 2018 13:14:55 GMT",
"version": "v2"
}
] | 2018-06-13 | [
[
"Goncalves",
"V. P.",
""
],
[
"Machado",
"M. V. T.",
""
],
[
"Moreira",
"B. D.",
""
],
[
"Navarra",
"F. S.",
""
],
[
"Santos",
"G. Sampaio dos",
""
]
] | We investigate the theoretical uncertainty on the predictions for the photoproduction of $\rho$ and $J/\Psi$ states in nucleus-nucleus collisions at Run 2 LHC energies using the Color Dipole formalism. The results for rapidity distributions and total cross sections are presented. Moreover, we compare directly the theoretical results to the recent preliminary data from ALICE collaboration on $\rho$ production in $PbPb$ collisions at central rapidity. |
2302.00720 | Thomas Schaefer | Jingyi Chao, Thomas Schaefer | N-particle irreducible actions for stochastic fluids | 15 pages, 7 figures; revised version to appear in JHEP | null | 10.1007/JHEP06(2023)057 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct one- and two-particle irreducible (1PI and 2PI) effective
actions for the stochastic fluid dynamics of a conserved density undergoing
diffusive motion. We compute the 1PI action at one-loop order, and the 2PI
action in two-loop approximation. We derive a set of Schwinger-Dyson equations,
and regularize the resulting equations using Pauli-Villars fields. We
numerically solve the Schwinger-Dyson equations for a non-critical fluid. We
find that higher-loop effects summed by the Schwinger-Dyson renormalize the
non-linear coupling. We also find indications of a diffuson-cascade, the
appearance $n$-loop corrections with smaller and smaller exponential
suppression.
| [
{
"created": "Wed, 1 Feb 2023 19:29:55 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Feb 2023 18:55:49 GMT",
"version": "v2"
},
{
"created": "Wed, 31 May 2023 05:02:51 GMT",
"version": "v3"
}
] | 2023-06-28 | [
[
"Chao",
"Jingyi",
""
],
[
"Schaefer",
"Thomas",
""
]
] | We construct one- and two-particle irreducible (1PI and 2PI) effective actions for the stochastic fluid dynamics of a conserved density undergoing diffusive motion. We compute the 1PI action at one-loop order, and the 2PI action in two-loop approximation. We derive a set of Schwinger-Dyson equations, and regularize the resulting equations using Pauli-Villars fields. We numerically solve the Schwinger-Dyson equations for a non-critical fluid. We find that higher-loop effects summed by the Schwinger-Dyson renormalize the non-linear coupling. We also find indications of a diffuson-cascade, the appearance $n$-loop corrections with smaller and smaller exponential suppression. |
1508.07853 | Yury Bystritskiy | A.G. Aleksejevs, S.G. Barkanova, Yu.M. Bystritskiy, E.A. Kuraev, V.A.
Zykunov | Two-loop electroweak vertex corrections for polarized M{\o}ller
scattering | 9 pages, 1 figure. arXiv admin note: text overlap with
arXiv:1504.03560 | null | 10.1134/S1547477116030031 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The contributions to the electron-electron-photon vertex of two-loop
electroweak corrections are calculated. The relative correction to the
parity-violating asymmetry of M{\o}ller scattering for the case of 11 GeV
electron scattered off the electron at rest is found to be about -0.0034 and
should be taken into account at future experiment MOLLER at JLab.
| [
{
"created": "Mon, 31 Aug 2015 14:45:22 GMT",
"version": "v1"
}
] | 2016-06-22 | [
[
"Aleksejevs",
"A. G.",
""
],
[
"Barkanova",
"S. G.",
""
],
[
"Bystritskiy",
"Yu. M.",
""
],
[
"Kuraev",
"E. A.",
""
],
[
"Zykunov",
"V. A.",
""
]
] | The contributions to the electron-electron-photon vertex of two-loop electroweak corrections are calculated. The relative correction to the parity-violating asymmetry of M{\o}ller scattering for the case of 11 GeV electron scattered off the electron at rest is found to be about -0.0034 and should be taken into account at future experiment MOLLER at JLab. |
1504.05166 | Leonard Fister | Leonard Fister and Jan Martin Pawlowski | Functional renormalisation group in a finite volume | 20 pages, 20 figures | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a $\phi^4$-theory at finite temperature in a finite volume. Quantum,
thermal and volume fluctuations are treated with the functional renormalisation
group. Specifically, we focus on the interplay of temperature and length scales
driving the system. We find that thermodynamical observables at finite volume
such as the pressure approach the infinite volume limit similarly to that of
the vanishing temperature limit. We also advance the functional renormalisation
group method at finite volume. In particular, we identify requirements for
suitable regulators that admit the exponential thermal and finite volume decay
properties.
| [
{
"created": "Mon, 20 Apr 2015 19:40:24 GMT",
"version": "v1"
}
] | 2015-04-21 | [
[
"Fister",
"Leonard",
""
],
[
"Pawlowski",
"Jan Martin",
""
]
] | We study a $\phi^4$-theory at finite temperature in a finite volume. Quantum, thermal and volume fluctuations are treated with the functional renormalisation group. Specifically, we focus on the interplay of temperature and length scales driving the system. We find that thermodynamical observables at finite volume such as the pressure approach the infinite volume limit similarly to that of the vanishing temperature limit. We also advance the functional renormalisation group method at finite volume. In particular, we identify requirements for suitable regulators that admit the exponential thermal and finite volume decay properties. |
1206.2371 | Haipeng An | Haipeng An, Maxim Pospelov | Dark Resonance | 20 pages, 10 figures | null | 10.1088/1475-7516/2012/11/061 | PI-PARTPHYS-281 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We construct explicit models of particle dark matter where the attractive
force in the dark matter sector creates a narrow near-threshold resonance that
qualitatively changes the energy dependence of the annihilation cross section.
In these models, the resonant enhancement of the dark matter annihilation can
easily source the excess of energetic leptons observed by experiments on PAMELA
and FERMI satellites. The distinct feature of these models is that by
construction the enhancement of the annihilation cross section shuts off when
the dark matter velocity falls below the typical Milky Way values, thus
automatically satisfying constraints on dark matter annihilation imposed by the
CMB anisotropies and gamma ray constraints from satellite galaxies.
| [
{
"created": "Mon, 11 Jun 2012 20:21:52 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"An",
"Haipeng",
""
],
[
"Pospelov",
"Maxim",
""
]
] | We construct explicit models of particle dark matter where the attractive force in the dark matter sector creates a narrow near-threshold resonance that qualitatively changes the energy dependence of the annihilation cross section. In these models, the resonant enhancement of the dark matter annihilation can easily source the excess of energetic leptons observed by experiments on PAMELA and FERMI satellites. The distinct feature of these models is that by construction the enhancement of the annihilation cross section shuts off when the dark matter velocity falls below the typical Milky Way values, thus automatically satisfying constraints on dark matter annihilation imposed by the CMB anisotropies and gamma ray constraints from satellite galaxies. |
0801.4168 | Volker D. Burkert | Latifa Elouadrhiri | Deeply Virtual Compton Scattering with CLAS12 | 6 pages, 3 figures, talk presented at the Workshop on Deeply
Exclusive Processes, Jefferson Lab, 2007 | null | 10.1142/9789812796950_0018 | null | hep-ph | null | An overview is given about the capabilities provided by the JLab 12 GeV
Upgrade to measure deeply virtual exclusive processes with high statistics and
covering a large kinematics range in the parameters that are needed to allow
reconstruction of a spatial image of the nucleon's quark structure. The
measurements planned with CLAS12 will cross section asymmetries with polarized
beams and with longitudinally and transversely polarized proton targets in the
constrained kinematics $x = \pm \xi$. In addition, unpolarized DVCS cross
sections, and doubly polarized beam target asymmetries will be measured as
well. In this talk only the beam and target asymmetries will be discussed.
| [
{
"created": "Mon, 28 Jan 2008 00:08:17 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Elouadrhiri",
"Latifa",
""
]
] | An overview is given about the capabilities provided by the JLab 12 GeV Upgrade to measure deeply virtual exclusive processes with high statistics and covering a large kinematics range in the parameters that are needed to allow reconstruction of a spatial image of the nucleon's quark structure. The measurements planned with CLAS12 will cross section asymmetries with polarized beams and with longitudinally and transversely polarized proton targets in the constrained kinematics $x = \pm \xi$. In addition, unpolarized DVCS cross sections, and doubly polarized beam target asymmetries will be measured as well. In this talk only the beam and target asymmetries will be discussed. |
hep-ph/0608058 | Olga Lalakulich | O. Lalakulich, W. Melnitchouk, and E. A. Paschos | Quark-hadron duality in neutrino scattering | 28 pages, 6 figures | Phys.Rev.C75:015202,2007 | 10.1103/PhysRevC.75.015202 | DO-TH 05/09, JLAB-THY-06-515 | hep-ph nucl-th | null | We present a phenomenological model of the quark-hadron transition in
neutrino-nucleon scattering. Using recently extracted weak nucleon transition
form factors, we investigate the extent to which local and global quark-hadron
duality is applicable in the neutrino F_1, F_2 and F_3 structure functions, and
contrast this with duality in electron scattering. Our findings suggest that
duality works relatively well for neutrino-nucleon scattering for the F_2 and
F_3 structure functions, but not as well for F_1. We also calculate the
quasielastic, resonance and deep inelastic contributions to the Adler sum rule,
and find it to be satisfied to within 10% for 0.5 < Q^2 < 2 GeV^2.
| [
{
"created": "Fri, 4 Aug 2006 14:17:16 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Lalakulich",
"O.",
""
],
[
"Melnitchouk",
"W.",
""
],
[
"Paschos",
"E. A.",
""
]
] | We present a phenomenological model of the quark-hadron transition in neutrino-nucleon scattering. Using recently extracted weak nucleon transition form factors, we investigate the extent to which local and global quark-hadron duality is applicable in the neutrino F_1, F_2 and F_3 structure functions, and contrast this with duality in electron scattering. Our findings suggest that duality works relatively well for neutrino-nucleon scattering for the F_2 and F_3 structure functions, but not as well for F_1. We also calculate the quasielastic, resonance and deep inelastic contributions to the Adler sum rule, and find it to be satisfied to within 10% for 0.5 < Q^2 < 2 GeV^2. |
1605.08724 | Mikhail Zubkov Dr | M.A. Zubkov | Absence of equilibrium chiral magnetic effect | Latex, 18 pages, misprints corrected. arXiv admin note: text overlap
with arXiv:1603.03665 | Phys.Rev. D93 (2016) no.10, 105036 | 10.1103/PhysRevD.93.105036 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse the $3+1$ D equilibrium chiral magnetic effect (CME). We apply
derivative expansion to the Wigner transform of the two - point Green function.
This technique allows us to express the response of electric current to
external electromagnetic field strength through the momentum space topological
invariant. We consider the wide class of the lattice regularizations of quantum
field theory (that includes, in particular, the regularization with Wilson
fermions) and also certain lattice models of solid state physics (including
those of Dirac semimetals). It appears, that in these models the mentioned
topological invariant vanishes identically at nonzero chiral chemical
potential. That means, that the bulk equilibrium CME is absent in those
systems.
| [
{
"created": "Fri, 27 May 2016 17:37:01 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Apr 2021 17:57:04 GMT",
"version": "v2"
}
] | 2021-04-28 | [
[
"Zubkov",
"M. A.",
""
]
] | We analyse the $3+1$ D equilibrium chiral magnetic effect (CME). We apply derivative expansion to the Wigner transform of the two - point Green function. This technique allows us to express the response of electric current to external electromagnetic field strength through the momentum space topological invariant. We consider the wide class of the lattice regularizations of quantum field theory (that includes, in particular, the regularization with Wilson fermions) and also certain lattice models of solid state physics (including those of Dirac semimetals). It appears, that in these models the mentioned topological invariant vanishes identically at nonzero chiral chemical potential. That means, that the bulk equilibrium CME is absent in those systems. |
0706.1798 | Christophe Royon | O. Kepka, C. Royon | New QCD fits to HERA data and search for exclusive events at the
Tevatron | Proceedings for the DIS 2007 workshop, Munich, April 2007 | null | null | null | hep-ph | null | We describe new QCD fits to diffractive proton structure functions measured
at HERA, and we use these parton densities to predict the shape of the dijet
mass fraction at the Tevatron and look for the existence of exclusive events in
the dijet channel.
| [
{
"created": "Tue, 12 Jun 2007 22:27:42 GMT",
"version": "v1"
}
] | 2007-06-14 | [
[
"Kepka",
"O.",
""
],
[
"Royon",
"C.",
""
]
] | We describe new QCD fits to diffractive proton structure functions measured at HERA, and we use these parton densities to predict the shape of the dijet mass fraction at the Tevatron and look for the existence of exclusive events in the dijet channel. |
hep-ph/0009350 | Concha Gonzalez Garcia | M.C. Gonzalez-Garcia, M. Maltoni, C. Pe\~na-Garay, J.W.F. Valle | Global three-neutrino oscillation analysis of neutrino data | 56 pages, 21 postscript figures. Some misprints corrected and new
references added. Chooz limit included in Fig.21. Final version to appear in
Phys. Rev. D | Phys.Rev.D63:033005,2001 | 10.1103/PhysRevD.63.033005 | null | hep-ph | null | A global analysis of the solar, atmospheric and reactor neutrino data is
presented in terms of three-neutrino oscillations. We include the most recent
solar neutrino rates of Homestake, SAGE, GALLEX and GNO, as well as the recent
1117 day Super-Kamiokande data sample, including the recoil electron energy
spectrum both for day and night periods and we treat in a unified way the full
parameter space for oscillations, correctly accounting for the transition from
the matter enhanced (MSW) to the vacuum oscillations regime. Likewise, we
include in our description conversions with $\theta_{12} > \pi/4$. For the
atmospheric data we perform our analysis of the contained events and the
upward-going $\nu$-induced muon fluxes, including the previous data samples of
Frejus, IMB, Nusex, and Kamioka experiments as well as the full 71 kton-yr
(1144 days) Super-Kamiokande data set, the recent 5.1 kton-yr contained events
of Soudan2 and the results on upgoing muons from the MACRO detector. We first
present the allowed regions of solar and atmospheric oscillation parameters
$\theta_{12}$, $\Delta m^2_{21}$ and $\theta_{23}$, $\Delta m^2_{32}$,
respectively, as a function of $\theta_{13}$ and determine the constraints from
atmospheric and solar data on the mixing angle $\theta_{13}$, common to solar
and atmospheric analyses. We also obtain the allowed ranges of parameters from
the full five-dimensional combined analysis of the solar, atmospheric and
reactor data.
| [
{
"created": "Fri, 29 Sep 2000 14:02:37 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Nov 2000 16:16:20 GMT",
"version": "v2"
}
] | 2009-09-17 | [
[
"Gonzalez-Garcia",
"M. C.",
""
],
[
"Maltoni",
"M.",
""
],
[
"Peña-Garay",
"C.",
""
],
[
"Valle",
"J. W. F.",
""
]
] | A global analysis of the solar, atmospheric and reactor neutrino data is presented in terms of three-neutrino oscillations. We include the most recent solar neutrino rates of Homestake, SAGE, GALLEX and GNO, as well as the recent 1117 day Super-Kamiokande data sample, including the recoil electron energy spectrum both for day and night periods and we treat in a unified way the full parameter space for oscillations, correctly accounting for the transition from the matter enhanced (MSW) to the vacuum oscillations regime. Likewise, we include in our description conversions with $\theta_{12} > \pi/4$. For the atmospheric data we perform our analysis of the contained events and the upward-going $\nu$-induced muon fluxes, including the previous data samples of Frejus, IMB, Nusex, and Kamioka experiments as well as the full 71 kton-yr (1144 days) Super-Kamiokande data set, the recent 5.1 kton-yr contained events of Soudan2 and the results on upgoing muons from the MACRO detector. We first present the allowed regions of solar and atmospheric oscillation parameters $\theta_{12}$, $\Delta m^2_{21}$ and $\theta_{23}$, $\Delta m^2_{32}$, respectively, as a function of $\theta_{13}$ and determine the constraints from atmospheric and solar data on the mixing angle $\theta_{13}$, common to solar and atmospheric analyses. We also obtain the allowed ranges of parameters from the full five-dimensional combined analysis of the solar, atmospheric and reactor data. |
0708.3600 | Frank Daniel Steffen | Frank Daniel Steffen | Supersymmetric Candidates for Dark Matter (in German) | 14 pages, 4 figures, to appear in the Jahrbuch 2007 (German only) of
the Max Planck Society | null | null | MPP-2006-256 | hep-ph astro-ph hep-ex physics.pop-ph | null | The identity of dark matter is one of the greatest puzzles of our Universe.
Its solution may be associated with supersymmetry which is a fundamental
space-time symmetry that has not been verified experimentally so far. In many
supersymmetric extensions of the Standard Model of particle physics, the
lightest supersymmetric particle cannot decay and is hence a promising dark
matter candidate. The lightest neutralino, which appears already in the minimal
supersymmetric model, can be identified as such a candidate in indirect and
direct dark matter searches and at future colliders. As the superpartner of the
graviton, the gravitino is another candidate for the lightest superparticle
that provides a compelling explanation of dark matter. While it will neither be
detected in indirect or direct searches nor be produced directly at
accelerators, the analysis of late-decaying charged particles can allow for an
experimental identification of the gravitino at future accelerators. In this
way, the upcoming experiments at the CERN Large Hadron Collider may become a
key to the understanding of our Universe.
| [
{
"created": "Mon, 27 Aug 2007 09:49:02 GMT",
"version": "v1"
}
] | 2007-08-28 | [
[
"Steffen",
"Frank Daniel",
""
]
] | The identity of dark matter is one of the greatest puzzles of our Universe. Its solution may be associated with supersymmetry which is a fundamental space-time symmetry that has not been verified experimentally so far. In many supersymmetric extensions of the Standard Model of particle physics, the lightest supersymmetric particle cannot decay and is hence a promising dark matter candidate. The lightest neutralino, which appears already in the minimal supersymmetric model, can be identified as such a candidate in indirect and direct dark matter searches and at future colliders. As the superpartner of the graviton, the gravitino is another candidate for the lightest superparticle that provides a compelling explanation of dark matter. While it will neither be detected in indirect or direct searches nor be produced directly at accelerators, the analysis of late-decaying charged particles can allow for an experimental identification of the gravitino at future accelerators. In this way, the upcoming experiments at the CERN Large Hadron Collider may become a key to the understanding of our Universe. |
hep-ph/9406296 | Jihn E. Kim | Jihn E. Kim and Hans Peter Nilles | Symmetry Principles toward Solutions of $\mu$ Problem | Latex file, 13 pages | Mod.Phys.Lett.A9:3575-3584,1994 | 10.1142/S0217732394003415 | null | hep-ph hep-th | null | We stress that a natural solution of the $\mu$ problem requires two
ingredients: a symmetry that would enforce $\mu = 0$ as well as the occurence
of a small breaking parameter that generates a nonzero $\mu$. It is suggested
that both the Peccei-Quinn symmetry and the spontaneously broken $R$ symmetry
may be the sources of the needed $\mu$ term in the minimal supersymmetric
standard model provided that they are spontaneously broken at a scale
$10^{10}-10^{12}$ GeV. To solve the strong CP problem with a hidden sector
confining group, both of these symmetries are needed in superstring models with
an anomalous $U(1)_A$.
| [
{
"created": "Mon, 13 Jun 1994 14:38:04 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Kim",
"Jihn E.",
""
],
[
"Nilles",
"Hans Peter",
""
]
] | We stress that a natural solution of the $\mu$ problem requires two ingredients: a symmetry that would enforce $\mu = 0$ as well as the occurence of a small breaking parameter that generates a nonzero $\mu$. It is suggested that both the Peccei-Quinn symmetry and the spontaneously broken $R$ symmetry may be the sources of the needed $\mu$ term in the minimal supersymmetric standard model provided that they are spontaneously broken at a scale $10^{10}-10^{12}$ GeV. To solve the strong CP problem with a hidden sector confining group, both of these symmetries are needed in superstring models with an anomalous $U(1)_A$. |
0710.2273 | George Rupp | M. D. Scadron, F. Kleefeld, G. Rupp | Constituent and current quark masses at low chiral energies | 5 pages, EPL style, accepted for publication in Europhys. Lett | Europhys.Lett.80:51001,2007 | 10.1209/0295-5075/80/51001 | null | hep-ph | null | Light constituent quark masses and the corresponding dynamical quark masses
are determined by data, the Quark-Level Linear $\sigma$ Model, and infrared
QCD. This allows to define effective nonstrange and strange current quark
masses which reproduce the experimental pion and kaon masses very accurately,
by simple additivity. Moreover, the masses of the light scalar mesons
$\sigma(600)$ and $\kappa(800)$ can be obtained straightforwardly from the
constituent quark masses. In contrast, the usual nonstrange and strange current
quark masses employed by Chiral Perturbation Theory do not allow a simple
quantitative explanation of the pion and kaon masses.
| [
{
"created": "Thu, 11 Oct 2007 15:23:48 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Scadron",
"M. D.",
""
],
[
"Kleefeld",
"F.",
""
],
[
"Rupp",
"G.",
""
]
] | Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the Quark-Level Linear $\sigma$ Model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses which reproduce the experimental pion and kaon masses very accurately, by simple additivity. Moreover, the masses of the light scalar mesons $\sigma(600)$ and $\kappa(800)$ can be obtained straightforwardly from the constituent quark masses. In contrast, the usual nonstrange and strange current quark masses employed by Chiral Perturbation Theory do not allow a simple quantitative explanation of the pion and kaon masses. |
hep-ph/9711383 | Johannes Ranft | R.Engel (University of Delaware, Bartol Research Institute, USA) and
J.Ranft (Siegen University, Germany) | Hard diffraction and central diffraction in hadron-hadron and
photon-hadron collisions | 13 pages, LATEX, 17 Figs. included as ps files | null | null | SI-97-17 | hep-ph | null | Hadron production in single and central diffraction dissociation is studied
in a model which includes soft hadron interaction as controlled by a
supercritical pomeron parametrization and hard diffraction. Within this model,
particle production in collisions with pomerons exhibit properties like
multiple soft interactions and multiple minijets, quite similar to hadron
production in non-diffractive hadronic collisions at high energies. However,
important differences occur in transverse momentum jet and hadron
distributions. It is shown that the model is able to describe data from the
CERN-SPS collider and from the HERA collider. Model predictions are presented
for single and central diffraction at TEVATRON.
| [
{
"created": "Wed, 19 Nov 1997 09:50:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Engel",
"R.",
"",
"University of Delaware, Bartol Research Institute, USA"
],
[
"Ranft",
"J.",
"",
"Siegen University, Germany"
]
] | Hadron production in single and central diffraction dissociation is studied in a model which includes soft hadron interaction as controlled by a supercritical pomeron parametrization and hard diffraction. Within this model, particle production in collisions with pomerons exhibit properties like multiple soft interactions and multiple minijets, quite similar to hadron production in non-diffractive hadronic collisions at high energies. However, important differences occur in transverse momentum jet and hadron distributions. It is shown that the model is able to describe data from the CERN-SPS collider and from the HERA collider. Model predictions are presented for single and central diffraction at TEVATRON. |
0712.3489 | Luis F. Urrutia | C. M. Reyes, L. Urrutia and J.D. Vergara | Quantization of the Myers-Pospelov model: a progress report | 13 pages, no figures, to be published in the Proceedings of the
Conference: From Quantum to Emergent Gravity: Theory and Phenomenology, June
11-15, Trieste, Italy | null | null | null | hep-ph | null | The Myers-Pospelov (MP) model is an effective field theory, including
dimension five operators, which describes the phenomenology of active Lorentz
invariance violation produced by a preferred reference frame. We concentrate
here in the case of the modified electrodynamics. The point of view taken in
this work is that the Lorentz violating part of the action in the MP model,
which includes higher order time derivative (HOTD) operators, is to be
considered as a perturbation over the dynamics described by standard
Electrodynamics, particularly in the quantum case. In order to cope with the
challenges posed by HOTD theories it will be necessary to deal with a modified
perturbation scheme which is well described in the literature. We apply such
methods to this specific model providing a quantization of the free sector of
the theory. The calculation of interacting processes, together with radiative
corrections, is beyond the scope of the present article.
| [
{
"created": "Thu, 20 Dec 2007 16:35:40 GMT",
"version": "v1"
}
] | 2007-12-21 | [
[
"Reyes",
"C. M.",
""
],
[
"Urrutia",
"L.",
""
],
[
"Vergara",
"J. D.",
""
]
] | The Myers-Pospelov (MP) model is an effective field theory, including dimension five operators, which describes the phenomenology of active Lorentz invariance violation produced by a preferred reference frame. We concentrate here in the case of the modified electrodynamics. The point of view taken in this work is that the Lorentz violating part of the action in the MP model, which includes higher order time derivative (HOTD) operators, is to be considered as a perturbation over the dynamics described by standard Electrodynamics, particularly in the quantum case. In order to cope with the challenges posed by HOTD theories it will be necessary to deal with a modified perturbation scheme which is well described in the literature. We apply such methods to this specific model providing a quantization of the free sector of the theory. The calculation of interacting processes, together with radiative corrections, is beyond the scope of the present article. |
2207.00478 | Giulia Zanderighi | Gavin P. Salam, Lian-Tao Wang, Giulia Zanderighi | The Higgs boson Turns Ten | 16 pages, 5 figures, invited Nature perspective article | null | 10.1038/s41586-022-04899-4 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The discovery of the Higgs boson, ten years ago, was a milestone that opened
the door to the study of a new sector of fundamental physical interactions. We
review the role of the Higgs field in the Standard Model of particle physics
and explain its impact on the world around us. We summarize the insights into
Higgs physics revealed so far by ten years of work, discuss what remains to be
determined, and outline potential connections of the Higgs sector with unsolved
mysteries of particle physics.
| [
{
"created": "Fri, 1 Jul 2022 15:01:14 GMT",
"version": "v1"
}
] | 2022-07-27 | [
[
"Salam",
"Gavin P.",
""
],
[
"Wang",
"Lian-Tao",
""
],
[
"Zanderighi",
"Giulia",
""
]
] | The discovery of the Higgs boson, ten years ago, was a milestone that opened the door to the study of a new sector of fundamental physical interactions. We review the role of the Higgs field in the Standard Model of particle physics and explain its impact on the world around us. We summarize the insights into Higgs physics revealed so far by ten years of work, discuss what remains to be determined, and outline potential connections of the Higgs sector with unsolved mysteries of particle physics. |
hep-ph/0008217 | Jes Madsen | Jes Madsen (University of Aarhus) | Intermediate mass strangelets are positively charged | Final version, slightly shortened. To appear in Phys.Rev.Lett.85,
p.4687 (27 Nov 2000) | Phys.Rev.Lett.85:4687-4690,2000 | 10.1103/PhysRevLett.85.4687 | null | hep-ph astro-ph hep-ex nucl-ex nucl-th | null | For a limited range of parameters, stable strange quark matter may be
negatively charged in bulk due to one gluon exchange interactions. However, the
reduction in strange quark occupation in the surface layer, which is
responsible for surface tension, more than compensates this for intermediate
mass strangelets, which therefore always have positive quark charge (e.g. for
baryon number between 10^2 and 10^{18} assuming alpha_S=0.9). While details are
sensitive to the choice of renormalisation, the general conclusion is not. This
rules out a scenario where negatively charged strangelets produced in
ultrarelativistic heavy ion colliders might grow indefinitely with potentially
disastrous consequences.
| [
{
"created": "Mon, 21 Aug 2000 08:25:53 GMT",
"version": "v1"
},
{
"created": "Tue, 31 Oct 2000 11:36:59 GMT",
"version": "v2"
},
{
"created": "Thu, 16 Nov 2000 09:44:43 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Madsen",
"Jes",
"",
"University of Aarhus"
]
] | For a limited range of parameters, stable strange quark matter may be negatively charged in bulk due to one gluon exchange interactions. However, the reduction in strange quark occupation in the surface layer, which is responsible for surface tension, more than compensates this for intermediate mass strangelets, which therefore always have positive quark charge (e.g. for baryon number between 10^2 and 10^{18} assuming alpha_S=0.9). While details are sensitive to the choice of renormalisation, the general conclusion is not. This rules out a scenario where negatively charged strangelets produced in ultrarelativistic heavy ion colliders might grow indefinitely with potentially disastrous consequences. |
1507.06349 | Avelino Vicente | Avelino Vicente | Computer tools in particle physics | 68 pages, 2 figures. Notes of the mini-course given at CINVESTAV,
Mexico, C\'atedra Augusto Garc\'ia Gonz\'alez, June 22nd-26th, 2015. v4:
several updates and improvements | null | null | IFIC/15-47 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The field of particle physics is living very exciting times with a plethora
of experiments looking for new physics in complementary ways. This has made
increasingly necessary to obtain precise predictions in new physics models in
order to be ready for a discovery that might be just around the corner.
However, analyzing new models and studying their phenomenology can be really
challenging. Computing mass matrices, interaction vertices and decay rates is
already a tremendous task. In addition, obtaining predictions for the dark
matter relic density and its detection prospects, computing flavor observables
or estimating the LHC reach in certain collider signals constitutes quite a
technical work due to the precision level that is currently required. For this
reason, computer tools such as SARAH, MicrOmegas, MadGraph, SPheno or FlavorKit
have become quite popular, and many physicists use them on a daily basis. In
this course we will learn how to use these computer tools to explore new
physics models and get robust numerical predictions to probe them in current
and future experiments.
| [
{
"created": "Wed, 22 Jul 2015 22:24:14 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Jul 2015 18:34:40 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Nov 2016 14:44:13 GMT",
"version": "v3"
},
{
"created": "Thu, 18 May 2017 16:22:13 GMT",
"version": "v4"
}
] | 2017-05-19 | [
[
"Vicente",
"Avelino",
""
]
] | The field of particle physics is living very exciting times with a plethora of experiments looking for new physics in complementary ways. This has made increasingly necessary to obtain precise predictions in new physics models in order to be ready for a discovery that might be just around the corner. However, analyzing new models and studying their phenomenology can be really challenging. Computing mass matrices, interaction vertices and decay rates is already a tremendous task. In addition, obtaining predictions for the dark matter relic density and its detection prospects, computing flavor observables or estimating the LHC reach in certain collider signals constitutes quite a technical work due to the precision level that is currently required. For this reason, computer tools such as SARAH, MicrOmegas, MadGraph, SPheno or FlavorKit have become quite popular, and many physicists use them on a daily basis. In this course we will learn how to use these computer tools to explore new physics models and get robust numerical predictions to probe them in current and future experiments. |
2408.04166 | Hyun-Chul Kim | Samson Clymton, Hyun-Chul Kim, Terry Mart | Production mechanism of the hidden charm pentaquark states
$P_{c\bar{c}}$ | 17 pages, 9 figures | null | null | INHA-NTG-05/2024 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate hidden-charm pentaquark states using an off-shell
coupled-channel formalism involving heavy meson and singly heavy baryon
scattering. Our approach utilizes an effective Lagrangian to construct the
kernel amplitudes, which respect both heavy quark symmetry and hidden local
symmetry. After solving the coupled integral equations, we obtain the
transition amplitudes for $J/\psi N$ scattering and various heavy meson and
singly heavy baryon scattering processes. We identify seven distinct peaks
related to molecular states of heavy mesons $\bar{D}$ ($\bar{D}^*$) and singly
heavy baryons $\Sigma_c$ ($\Sigma_c^*$). Four of these peaks can be associated
with the known $P_{c\bar{c}}$ states: $P_{c\bar{c}}(4312)$,
$P_{c\bar{c}}(4380)$, $P_{c\bar{c}}(4440)$, and $P_{c\bar{c}}(4457)$. We
predict two additional resonances with masses around 4.5 GeV, which we
interpret as $\overline{D}^* \Sigma_c^*$ molecular states, and identify one
cusp structure. Additionally, we predict two $P$-wave pentaquark states with
positive parity, which may be candidates for genuine pentaquark configurations.
Notably, these pentaquark states undergo significant modifications in the
$J/\psi N$ elastic channel, with some even disappearing due to interference
from the positive parity channel. The present investigation may provide insight
into the absence of pentaquark states in $J/\psi$ photoproduction observed by
the GlueX collaboration.
| [
{
"created": "Thu, 8 Aug 2024 02:25:50 GMT",
"version": "v1"
}
] | 2024-08-09 | [
[
"Clymton",
"Samson",
""
],
[
"Kim",
"Hyun-Chul",
""
],
[
"Mart",
"Terry",
""
]
] | We investigate hidden-charm pentaquark states using an off-shell coupled-channel formalism involving heavy meson and singly heavy baryon scattering. Our approach utilizes an effective Lagrangian to construct the kernel amplitudes, which respect both heavy quark symmetry and hidden local symmetry. After solving the coupled integral equations, we obtain the transition amplitudes for $J/\psi N$ scattering and various heavy meson and singly heavy baryon scattering processes. We identify seven distinct peaks related to molecular states of heavy mesons $\bar{D}$ ($\bar{D}^*$) and singly heavy baryons $\Sigma_c$ ($\Sigma_c^*$). Four of these peaks can be associated with the known $P_{c\bar{c}}$ states: $P_{c\bar{c}}(4312)$, $P_{c\bar{c}}(4380)$, $P_{c\bar{c}}(4440)$, and $P_{c\bar{c}}(4457)$. We predict two additional resonances with masses around 4.5 GeV, which we interpret as $\overline{D}^* \Sigma_c^*$ molecular states, and identify one cusp structure. Additionally, we predict two $P$-wave pentaquark states with positive parity, which may be candidates for genuine pentaquark configurations. Notably, these pentaquark states undergo significant modifications in the $J/\psi N$ elastic channel, with some even disappearing due to interference from the positive parity channel. The present investigation may provide insight into the absence of pentaquark states in $J/\psi$ photoproduction observed by the GlueX collaboration. |
2205.08131 | Salaheddin Zarrin | S. Zarrin and S. Dadfar (Department of Physics, University of Sistan
and Baluchestan, Zahedan, Iran) | Nonlinear corrections to the single differential cross section for
neutral current e-p scattering at the NLO approximation | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the effects of nonlinear corrections to the single differential
cross section d\sigma/dQ^2 and the reduced cross section \sigma_r (x,Q^2) for
the neutral current (NC) e-p scattering at the leading order (LO) and the
next-to-leading order (NLO) approximations in perturbative quantum chromo
dynamics (QCD). Technically, based on the double Laplace transform method, we
first derive the effects of the nonlinear corrections to the proton structure
functions F2(x,Q^2) and FL(x,Q^2) and consequently obtain the corresponding
single differential and reduced cross sections. Our results clearly indicate
the consistency of the nonlinear behavior of the quark and gluon distributions
at low x values. Our numerical results ( obtained in a range of the virtuality
8.5 < Q2 < 5000 GeV ^2 and the Bjorken scale 10^(-5)< x < 1) show that the
effects of these nonlinear corrections to the proton structure functions are
more noticeable at x < 0.001 and, to some extent, control the incremental trend
of these functions at low x values. Moreover, a comparison of our numerical
results of the single differential and reduced cross sections at the NLO
approximations with those of H1 collaboration data shows that the nonlinear
corrections increase the accuracy of calculations rather than the linear
calculations at low to moderate Q^2 values for low x values.
| [
{
"created": "Tue, 17 May 2022 07:00:42 GMT",
"version": "v1"
}
] | 2022-05-18 | [
[
"Zarrin",
"S.",
"",
"Department of Physics, University of Sistan\n and Baluchestan, Zahedan, Iran"
],
[
"Dadfar",
"S.",
"",
"Department of Physics, University of Sistan\n and Baluchestan, Zahedan, Iran"
]
] | We present the effects of nonlinear corrections to the single differential cross section d\sigma/dQ^2 and the reduced cross section \sigma_r (x,Q^2) for the neutral current (NC) e-p scattering at the leading order (LO) and the next-to-leading order (NLO) approximations in perturbative quantum chromo dynamics (QCD). Technically, based on the double Laplace transform method, we first derive the effects of the nonlinear corrections to the proton structure functions F2(x,Q^2) and FL(x,Q^2) and consequently obtain the corresponding single differential and reduced cross sections. Our results clearly indicate the consistency of the nonlinear behavior of the quark and gluon distributions at low x values. Our numerical results ( obtained in a range of the virtuality 8.5 < Q2 < 5000 GeV ^2 and the Bjorken scale 10^(-5)< x < 1) show that the effects of these nonlinear corrections to the proton structure functions are more noticeable at x < 0.001 and, to some extent, control the incremental trend of these functions at low x values. Moreover, a comparison of our numerical results of the single differential and reduced cross sections at the NLO approximations with those of H1 collaboration data shows that the nonlinear corrections increase the accuracy of calculations rather than the linear calculations at low to moderate Q^2 values for low x values. |
hep-ph/0207294 | Aleksander Filip Zarnecki | P. Niezurawski, A.F. Zarnecki, M. Krawczyk | Study of the Higgs-boson decays into WW and ZZ at the Photon Collider | 19 pages, 18 figures; updated version with improved precision of
estimates | JHEP 0211 (2002) 034 | 10.1088/1126-6708/2002/11/034 | CERN-TH/2002-165, IFT-28/2002 | hep-ph | null | Production of the Standard Model Higgs-boson at the Photon Collider at TESLA
is studied for the Higgs-boson masses above 150 GeV. Simulation of signal and
background processes takes into account realistic luminosity spectra and
detector effects. In the considered mass range, large interference effects are
expected in the W+W- decay channel. By reconstructing W+W- and ZZ final states,
not only the h->gamma gamma partial width can be measured, but also the
relative phase of the scattering amplitude. This opens a new window for the
precise determination of the Higgs-boson couplings. Models with heavy,
fourth-generation fermions and with enlarged Higgs sector (2HDM (II)) are
considered.
| [
{
"created": "Wed, 24 Jul 2002 11:31:40 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Aug 2002 11:14:11 GMT",
"version": "v2"
},
{
"created": "Fri, 22 Nov 2002 13:32:03 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Niezurawski",
"P.",
""
],
[
"Zarnecki",
"A. F.",
""
],
[
"Krawczyk",
"M.",
""
]
] | Production of the Standard Model Higgs-boson at the Photon Collider at TESLA is studied for the Higgs-boson masses above 150 GeV. Simulation of signal and background processes takes into account realistic luminosity spectra and detector effects. In the considered mass range, large interference effects are expected in the W+W- decay channel. By reconstructing W+W- and ZZ final states, not only the h->gamma gamma partial width can be measured, but also the relative phase of the scattering amplitude. This opens a new window for the precise determination of the Higgs-boson couplings. Models with heavy, fourth-generation fermions and with enlarged Higgs sector (2HDM (II)) are considered. |
1707.01725 | C\'edric Weiland | C. Weiland | Searching for heavy sterile neutrinos in kaon decays | 8 pages, 5 figures, Proceedings of the 52nd Rencontres de Moriond EW
2017 | null | null | IPPP/17/54 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present here a study of the impact of a heavy neutrino (or heavy neutral
lepton) on leptonic and semileptonic kaon decays. We used a simplified model
consisting of 3 light neutrinos responsible for neutrino oscillations and a
heavy sterile neutrino. We found that it can lead to large deviations from the
Standard Model predictions for leptonic decays, in conflict with experimental
measurements of $K_{e2}$ and the lepton universality test $R_K$. This allows to
derive new constraints on the leptonic mixing for heavy sterile neutrinos. No
tension was found when considering the semileptonic decays. Finally, we point
out the potential of the decay $K_L \rightarrow \nu \nu$ as a clear signature
of physics beyond the Standard Model.
| [
{
"created": "Thu, 6 Jul 2017 10:45:16 GMT",
"version": "v1"
}
] | 2017-07-07 | [
[
"Weiland",
"C.",
""
]
] | We present here a study of the impact of a heavy neutrino (or heavy neutral lepton) on leptonic and semileptonic kaon decays. We used a simplified model consisting of 3 light neutrinos responsible for neutrino oscillations and a heavy sterile neutrino. We found that it can lead to large deviations from the Standard Model predictions for leptonic decays, in conflict with experimental measurements of $K_{e2}$ and the lepton universality test $R_K$. This allows to derive new constraints on the leptonic mixing for heavy sterile neutrinos. No tension was found when considering the semileptonic decays. Finally, we point out the potential of the decay $K_L \rightarrow \nu \nu$ as a clear signature of physics beyond the Standard Model. |
1109.4980 | Giacomo Cacciapaglia | Giacomo Cacciapaglia, Aldo Deandrea, and Luca Panizzi | Superluminal neutrinos in long baseline experiments and SN1987a | 22 pages, 7 figures; comment on Cherenkov emission added, version
matching JHEP published paper | JHEP 11 (2011) 137 | 10.1007/JHEP11(2011)137 | LYCEN 2011-05; KCL-PH-TH/2011-16 | hep-ph hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Precise tests of Lorentz invariance in neutrinos can be performed using long
baseline experiments such as MINOS and OPERA or neutrinos from astrophysical
sources. The MINOS collaboration reported a measurement of the muonic neutrino
velocities that hints to super-luminal propagation, very recently confirmed at
6 sigma by OPERA. We consider a general parametrisation which goes beyond the
usual linear or quadratic violation considered in quantum-gravitational models.
We also propose a toy model showing why Lorentz violation can be specific to
the neutrino sector and give rise to a generic energy behaviour E^alpha, where
alpha is not necessarily an integer number. Supernova bounds and the preferred
MINOS and OPERA regions show a tension, due to the absence of shape distortion
in the neutrino bunch in the far detector of MINOS. The energy independence of
the effect has also been pointed out by the OPERA results.
| [
{
"created": "Fri, 23 Sep 2011 00:45:00 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Jan 2012 15:07:36 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Cacciapaglia",
"Giacomo",
""
],
[
"Deandrea",
"Aldo",
""
],
[
"Panizzi",
"Luca",
""
]
] | Precise tests of Lorentz invariance in neutrinos can be performed using long baseline experiments such as MINOS and OPERA or neutrinos from astrophysical sources. The MINOS collaboration reported a measurement of the muonic neutrino velocities that hints to super-luminal propagation, very recently confirmed at 6 sigma by OPERA. We consider a general parametrisation which goes beyond the usual linear or quadratic violation considered in quantum-gravitational models. We also propose a toy model showing why Lorentz violation can be specific to the neutrino sector and give rise to a generic energy behaviour E^alpha, where alpha is not necessarily an integer number. Supernova bounds and the preferred MINOS and OPERA regions show a tension, due to the absence of shape distortion in the neutrino bunch in the far detector of MINOS. The energy independence of the effect has also been pointed out by the OPERA results. |
0909.2565 | Xiaohui Liu | Xiaohui Liu | Color-Octet $\jpsi$ Production in $\Upsilon$ Decay near the Kinematic
Limit | version to appear in plb. 13 pages, 6 figures, reference added | Phys.Lett.B685:151-157,2010 | 10.1016/j.physletb.2010.01.045 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent experiments by the CLEO III detector at CESR indicate that the $\jpsi$
spectrum produced in $\Upsilon$ decay is in conflict with Non-Relativistic QCD
(NRQCD) calculations. The measured $\jpsi$ momentum distribution is much softer
than predicted by the color-octet mechanisms. The expected peak at the
kinematic limit is not observed in the data. However it has recent been pointed
out that NRQCD calculations break down near the kinematic endpoint due to large
perturbative and non-perturbative corrections. In this paper we combine NRQCD
with soft collinear effective theory to study the color-octet contribution to
the $\Upsilon \to \jpsi + X$ decay in this region of phase space. We obtain a
spectrum that is significantly softened when including the correct degrees of
freedom in the endpoint region, giving better agreement with the data than
previous predictions.
| [
{
"created": "Mon, 14 Sep 2009 15:06:34 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Feb 2010 05:34:17 GMT",
"version": "v2"
}
] | 2010-02-23 | [
[
"Liu",
"Xiaohui",
""
]
] | Recent experiments by the CLEO III detector at CESR indicate that the $\jpsi$ spectrum produced in $\Upsilon$ decay is in conflict with Non-Relativistic QCD (NRQCD) calculations. The measured $\jpsi$ momentum distribution is much softer than predicted by the color-octet mechanisms. The expected peak at the kinematic limit is not observed in the data. However it has recent been pointed out that NRQCD calculations break down near the kinematic endpoint due to large perturbative and non-perturbative corrections. In this paper we combine NRQCD with soft collinear effective theory to study the color-octet contribution to the $\Upsilon \to \jpsi + X$ decay in this region of phase space. We obtain a spectrum that is significantly softened when including the correct degrees of freedom in the endpoint region, giving better agreement with the data than previous predictions. |
hep-ph/0110084 | Daniele Dominici | Daniele Dominici | Degenerate BESS model at future colliders | 3 pages, 2 Figs, Revtex4; to appear in the Proceedings of the
APS/DPF/DPB Summer Study on the Future of Particle Physics (Snowmass2001) | eConf C010630:P329,2001 | null | DFF-377/10/01 | hep-ph | null | A brief overview of the sensitivity of future colliders to new vector
particles from strongly interacting Higgs is presented. In particular the
capability of detecting almost degenerate resonances is reviewed.
| [
{
"created": "Fri, 5 Oct 2001 10:07:31 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Dominici",
"Daniele",
""
]
] | A brief overview of the sensitivity of future colliders to new vector particles from strongly interacting Higgs is presented. In particular the capability of detecting almost degenerate resonances is reviewed. |
hep-ph/9307263 | null | John F. Donoghue and Eugene Golowich | Anatomy of a Weak Matrix Element | Standard Latex file, 10 pgs (figure not included), UMHEP-390 | Phys.Lett. B315 (1993) 406-411 | 10.1016/0370-2693(93)91632-W | null | hep-ph | null | Although the weak nonleptonic amplitudes of the Standard Model are
notoriously difficult to calculate, we have produced a modified weak matrix
element which can be analyzed using reliable methods. This hypothetical
nonleptonic matrix element is expressible in terms of the isovector vector and
axialvector spectral functions $\rho_{\rm V}(s)$ and $\rho_{\rm A}(s)$, which
can be determined in terms of data from tau lepton decay and $e^+ e^-$
annihilation. Chiral symmetry and the operator product expansion are used to
constrain the spectral functions respectively in the low energy and the high
energy limits. The magnitude of the matrix element thus determined is compared
with its `vacuum saturation' estimate, and in the future may be accessible with
lattice calculations.
| [
{
"created": "Tue, 13 Jul 1993 15:37:14 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Donoghue",
"John F.",
""
],
[
"Golowich",
"Eugene",
""
]
] | Although the weak nonleptonic amplitudes of the Standard Model are notoriously difficult to calculate, we have produced a modified weak matrix element which can be analyzed using reliable methods. This hypothetical nonleptonic matrix element is expressible in terms of the isovector vector and axialvector spectral functions $\rho_{\rm V}(s)$ and $\rho_{\rm A}(s)$, which can be determined in terms of data from tau lepton decay and $e^+ e^-$ annihilation. Chiral symmetry and the operator product expansion are used to constrain the spectral functions respectively in the low energy and the high energy limits. The magnitude of the matrix element thus determined is compared with its `vacuum saturation' estimate, and in the future may be accessible with lattice calculations. |
1205.3781 | Kristjan Kannike | Kristjan Kannike | Vacuum Stability Conditions From Copositivity Criteria | 15 pages, 1 figure, complex singlet in polar form clarified | null | 10.1140/epjc/s10052-012-2093-z | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A scalar potential of the form $\lambda_{ab} \phi_a^2 \phi_b^2$ is bounded
from below if its matrix of quartic couplings $\lambda_{ab}$ is copositive --
positive on non-negative vectors. Scalar potentials of this form occur
naturally for scalar dark matter stabilised by a $\mathbb{Z}_2$ symmetry.
Copositivity criteria allow to derive analytic necessary and sufficient vacuum
stability conditions for the matrix $\lambda_{ab}$. We review the basic
properties of copositive matrices and analytic criteria for copositivity. To
illustrate these, we re-derive the vacuum stability conditions for the inert
doublet model in a simple way, and derive the vacuum stability conditions for
the $\mathbb{Z}_2$ complex singlet dark matter, and for the model with both a
complex singlet and an inert doublet invariant under a global U(1) symmetry.
| [
{
"created": "Wed, 16 May 2012 20:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Jun 2012 10:09:04 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Nov 2013 12:24:00 GMT",
"version": "v3"
}
] | 2015-06-05 | [
[
"Kannike",
"Kristjan",
""
]
] | A scalar potential of the form $\lambda_{ab} \phi_a^2 \phi_b^2$ is bounded from below if its matrix of quartic couplings $\lambda_{ab}$ is copositive -- positive on non-negative vectors. Scalar potentials of this form occur naturally for scalar dark matter stabilised by a $\mathbb{Z}_2$ symmetry. Copositivity criteria allow to derive analytic necessary and sufficient vacuum stability conditions for the matrix $\lambda_{ab}$. We review the basic properties of copositive matrices and analytic criteria for copositivity. To illustrate these, we re-derive the vacuum stability conditions for the inert doublet model in a simple way, and derive the vacuum stability conditions for the $\mathbb{Z}_2$ complex singlet dark matter, and for the model with both a complex singlet and an inert doublet invariant under a global U(1) symmetry. |
1707.03964 | Maarten F. L. Golterman | Diogo Boito, Maarten Golterman, Kim Maltman and Santiago Peris | Hadronic tau decays and the strong coupling | talk at Mini Workshop on Tau Physics, May 22-23, 2017, Mexico City,
12 pages | null | 10.1088/1742-6596/912/1/012003 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We provide an overview of recent determinations of the strong coupling,
$\alpha_s$, from hadronic $\tau$ decays. We contrast two analysis methods, the
"truncated-OPE approach" and the "DV-model approach," highlighting the
assumptions going into each of these. We argue that a detailed study based on
ALEPH data shows the truncated-OPE approach to be quantitatively unreliable,
while the DV-model approach passes all tests. New data for hadronic $\tau$
decays from Belle and Belle-II could provide more stringent tests of the
DV-model approach, and thus potentially lead to a more precise value of
$\alpha_s$ from hadronic $\tau$ decays.
| [
{
"created": "Thu, 13 Jul 2017 02:52:34 GMT",
"version": "v1"
}
] | 2017-11-22 | [
[
"Boito",
"Diogo",
""
],
[
"Golterman",
"Maarten",
""
],
[
"Maltman",
"Kim",
""
],
[
"Peris",
"Santiago",
""
]
] | We provide an overview of recent determinations of the strong coupling, $\alpha_s$, from hadronic $\tau$ decays. We contrast two analysis methods, the "truncated-OPE approach" and the "DV-model approach," highlighting the assumptions going into each of these. We argue that a detailed study based on ALEPH data shows the truncated-OPE approach to be quantitatively unreliable, while the DV-model approach passes all tests. New data for hadronic $\tau$ decays from Belle and Belle-II could provide more stringent tests of the DV-model approach, and thus potentially lead to a more precise value of $\alpha_s$ from hadronic $\tau$ decays. |
0802.0555 | Matthew Sudano | Elie Gorbatov, Matthew Sudano | Sparticle Masses in Higgsed Gauge Mediation | typos in formulas in the appendix corrected | JHEP 0810:066,2008 | 10.1088/1126-6708/2008/10/066 | UCSD-PTH-08-02 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We generalize the gauge sector of gauge-mediated supersymmetry breaking to
allow for an arbitrary gauge group with an arbitrary supersymmetric Higgsing.
The sparticle masses are computed to leading order in the gauge coupling. The
generic effect on the MSSM spectrum from additional Higgsed gauge structure is
to increase the sfermion masses relative to the gaugino masses.
| [
{
"created": "Tue, 5 Feb 2008 07:34:03 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Dec 2011 17:57:52 GMT",
"version": "v2"
}
] | 2011-12-22 | [
[
"Gorbatov",
"Elie",
""
],
[
"Sudano",
"Matthew",
""
]
] | We generalize the gauge sector of gauge-mediated supersymmetry breaking to allow for an arbitrary gauge group with an arbitrary supersymmetric Higgsing. The sparticle masses are computed to leading order in the gauge coupling. The generic effect on the MSSM spectrum from additional Higgsed gauge structure is to increase the sfermion masses relative to the gaugino masses. |
1506.07575 | Alejandro Gutierrez-Rodriguez | A. Gutierrez-Rodriguez and M. A. Hernandez-Ruiz | $Z'$ resonance and associated $Zh$ production at future Higgs boson
factory: ILC and CLIC | 21 pages, 11 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the prospects of the B-L model with an additional $Z'$ boson to be a
Higgs boson factory at high-energy and high-luminosity linear electron positron
colliders, such as the ILC and CLIC, through the Higgs-strahlung process
$e^{+}e^{-}\rightarrow (Z, Z') \to Zh$, including both the resonant and
non-resonant effects. We evaluate the total cross section of $Zh$ and we
calculate the total number of events for integrated luminosities of
500-2000\hspace{0.8mm}$fb^{-1}$ and center of mass energies between 500 and
3000\hspace{0.8mm}$GeV$. We find that the total number of expected $Zh$ events
can reach $10^6$, which is a very optimistic scenario and it would be possible
to perform precision measurements for both the $Z'$ and Higgs boson in future
high-energy $e^+e^-$ colliders experiments.
| [
{
"created": "Wed, 24 Jun 2015 22:26:46 GMT",
"version": "v1"
}
] | 2015-06-26 | [
[
"Gutierrez-Rodriguez",
"A.",
""
],
[
"Hernandez-Ruiz",
"M. A.",
""
]
] | We study the prospects of the B-L model with an additional $Z'$ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process $e^{+}e^{-}\rightarrow (Z, Z') \to Zh$, including both the resonant and non-resonant effects. We evaluate the total cross section of $Zh$ and we calculate the total number of events for integrated luminosities of 500-2000\hspace{0.8mm}$fb^{-1}$ and center of mass energies between 500 and 3000\hspace{0.8mm}$GeV$. We find that the total number of expected $Zh$ events can reach $10^6$, which is a very optimistic scenario and it would be possible to perform precision measurements for both the $Z'$ and Higgs boson in future high-energy $e^+e^-$ colliders experiments. |
1409.4567 | Moh'd Hussein | Moh'd A. Hussein | W Boson Kinematic Analysis at the Tevatron: A comparison of ResBos
resummation and Pythia generator | Resbos grids were not generated properly | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The kinematical features of the differential cross section distributions in
inclusive W boson production at the Tevatron (ppbar -> W X -> e \u{psion}_e X)
are presented using the resummation program ResBos, and the Monte Carlo event
generator Pythia, and are found to be in marginal agreement with each other.
While both programs reproduce the basic qualitative features of W boson, the
distributions validate that Pythia can't be used as a reliable substitute for
ResBos as far as the invariant mass of W boson and other electroweak precision
measurements are concerned.
| [
{
"created": "Tue, 16 Sep 2014 10:19:56 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Sep 2017 17:04:05 GMT",
"version": "v2"
}
] | 2017-09-04 | [
[
"Hussein",
"Moh'd A.",
""
]
] | The kinematical features of the differential cross section distributions in inclusive W boson production at the Tevatron (ppbar -> W X -> e \u{psion}_e X) are presented using the resummation program ResBos, and the Monte Carlo event generator Pythia, and are found to be in marginal agreement with each other. While both programs reproduce the basic qualitative features of W boson, the distributions validate that Pythia can't be used as a reliable substitute for ResBos as far as the invariant mass of W boson and other electroweak precision measurements are concerned. |
1312.4937 | Thomas Hahn | T. Hahn, S. Heinemeyer, W. Hollik, H. Rzehak, G. Weiglein | High-precision predictions for the light CP-even Higgs Boson Mass of the
MSSM | LaTeX, 4 pages | Phys. Rev. Lett. 112, 141801 (2014) | 10.1103/PhysRevLett.112.141801 | DESY 13-248, FR-PHENO-2013-018, MPP-2013-317 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For the interpretation of the signal discovered in the Higgs searches at the
LHC it will be crucial in particular to discriminate between the minimal Higgs
sector realised in the Standard Model (SM) and its most commonly studied
extension, the Minimal Supersymmetric SM (MSSM). The measured mass value,
having already reached the level of a precision observable with an experimental
accuracy of about 500 MeV, plays an important role in this context. In the MSSM
the mass of the light CP-even Higgs boson, M_h, can directly be predicted from
the other parameters of the model. The accuracy of this prediction should at
least match the one of the experimental result. The relatively high mass value
of about 126 GeV has led to many investigations where the scalar top quarks are
in the multi-TeV range. We improve the prediction for M_h in the MSSM by
combining the existing fixed-order result, comprising the full one-loop and
leading and subleading two-loop corrections, with a resummation of the leading
and subleading logarithmic contributions from the scalar top sector to all
orders. In this way for the first time a high-precision prediction for the mass
of the light CP-even Higgs boson in the MSSM is possible all the way up to the
multi-TeV region of the relevant supersymmetric particles. The results are
included in the code FeynHiggs.
| [
{
"created": "Tue, 17 Dec 2013 20:53:03 GMT",
"version": "v1"
}
] | 2014-04-23 | [
[
"Hahn",
"T.",
""
],
[
"Heinemeyer",
"S.",
""
],
[
"Hollik",
"W.",
""
],
[
"Rzehak",
"H.",
""
],
[
"Weiglein",
"G.",
""
]
] | For the interpretation of the signal discovered in the Higgs searches at the LHC it will be crucial in particular to discriminate between the minimal Higgs sector realised in the Standard Model (SM) and its most commonly studied extension, the Minimal Supersymmetric SM (MSSM). The measured mass value, having already reached the level of a precision observable with an experimental accuracy of about 500 MeV, plays an important role in this context. In the MSSM the mass of the light CP-even Higgs boson, M_h, can directly be predicted from the other parameters of the model. The accuracy of this prediction should at least match the one of the experimental result. The relatively high mass value of about 126 GeV has led to many investigations where the scalar top quarks are in the multi-TeV range. We improve the prediction for M_h in the MSSM by combining the existing fixed-order result, comprising the full one-loop and leading and subleading two-loop corrections, with a resummation of the leading and subleading logarithmic contributions from the scalar top sector to all orders. In this way for the first time a high-precision prediction for the mass of the light CP-even Higgs boson in the MSSM is possible all the way up to the multi-TeV region of the relevant supersymmetric particles. The results are included in the code FeynHiggs. |
hep-ph/0002166 | Florian Krajewski | J.G. Koerner, F. Krajewski, A.A. Pivovarov | Strong coupling constant from $\tau$ decay within renormalization scheme
invariant treatment | 8 pages | Phys.Rev. D63 (2001) 036001 | 10.1103/PhysRevD.63.036001 | MZ-TH/00-03 | hep-ph hep-ex | null | We extract a numerical value for the strong coupling constant \alpha_s from
the \tau-lepton decay rate into nonstrange particles. A new feature of our
procedure is the explicit use of renormalization scheme invariance in
analytical form in order to perform the actual analysis in a particular
renormalization scheme. For the reference coupling constant in the
\MSsch-scheme we obtain \alpha_s(M_\tau)= 0.3184 \pm 0.0060_{exp} which
corresponds to \al_s(M_Z)= 0.1184 \pm 0.0007_{exp} \pm 0.0006_{hq mass}. This
new numerical value is smaller than the standard value from $\tau$-data quoted
in the literature and is closer to \al_s(M_Z)-values obtained from high energy
experiments.
| [
{
"created": "Tue, 15 Feb 2000 12:57:00 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Nov 2000 14:13:31 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Koerner",
"J. G.",
""
],
[
"Krajewski",
"F.",
""
],
[
"Pivovarov",
"A. A.",
""
]
] | We extract a numerical value for the strong coupling constant \alpha_s from the \tau-lepton decay rate into nonstrange particles. A new feature of our procedure is the explicit use of renormalization scheme invariance in analytical form in order to perform the actual analysis in a particular renormalization scheme. For the reference coupling constant in the \MSsch-scheme we obtain \alpha_s(M_\tau)= 0.3184 \pm 0.0060_{exp} which corresponds to \al_s(M_Z)= 0.1184 \pm 0.0007_{exp} \pm 0.0006_{hq mass}. This new numerical value is smaller than the standard value from $\tau$-data quoted in the literature and is closer to \al_s(M_Z)-values obtained from high energy experiments. |
hep-ph/9510283 | Bryan Webber | B.R. Webber | Hadronic Final States | Plenary talk at the Workshop on Deep Inelastic Scattering and QCD,
Paris, April 1995. 12 pages, LaTeX, uses qcdparis_mod.sty (appended at end).
12 uuencoded postscript figures. Also available from
http://www.hep.phy.cam.ac.uk/theory/papers/index.html | null | null | Cavendish-HEP-95/11 | hep-ph | null | The following aspects of hadronic final states in deep inelastic lepton
scattering are reviewed: measuring $alpha_s$ from multi-jet production rates
and event shapes; alternative jet algorithms for DIS; power-suppressed
corrections to event shapes; comparing jet fragmentation in $e^+e^-$
annihilation and DIS; final states in the BFKL and CCFM formulations of
small-$x$ dynamics; exotic (instanton-induced) final states.
| [
{
"created": "Thu, 12 Oct 1995 17:04:34 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Webber",
"B. R.",
""
]
] | The following aspects of hadronic final states in deep inelastic lepton scattering are reviewed: measuring $alpha_s$ from multi-jet production rates and event shapes; alternative jet algorithms for DIS; power-suppressed corrections to event shapes; comparing jet fragmentation in $e^+e^-$ annihilation and DIS; final states in the BFKL and CCFM formulations of small-$x$ dynamics; exotic (instanton-induced) final states. |
1910.01205 | Kyohei Mukaida | Valerie Domcke, Yohei Ema, Kyohei Mukaida | Chiral Anomaly, Schwinger Effect, Euler-Heisenberg Lagrangian, and
application to axion inflation | 45 pages, 9 figures; v2: typos fixed, published version | JHEP 2002 (2020) 055 | 10.1007/JHEP02(2020)055 | DESY 19-166 | hep-ph astro-ph.CO cond-mat.mes-hall hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Particle production in strong electromagnetic fields is a recurring theme in
solid state physics, heavy ion collisions, early universe cosmology and formal
quantum field theory. In this paper we discuss the Dirac equation in a
background of parallel electric and magnetic fields. We review the Schwinger
particle production rate, clarify the emergence of the chiral anomaly equation
and compute the induced current of charged fermions. We distinguish the
contributions from non-perturbative particle production, from the running of
the gauge coupling constant and from non-linearities in the effective QED
Lagrangian, and clarify how these contributions arise within a single
framework. We apply these results to axion inflation. A Chern-Simons coupling
between the pseudoscalar particle driving cosmic inflaton and an abelian gauge
group induces a dual production of gauge fields and charged fermions. We show
that the resulting scalar and gravitational wave power spectra strongly depend
on the fermion mass.
| [
{
"created": "Wed, 2 Oct 2019 20:31:32 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Feb 2020 19:55:15 GMT",
"version": "v2"
}
] | 2020-03-03 | [
[
"Domcke",
"Valerie",
""
],
[
"Ema",
"Yohei",
""
],
[
"Mukaida",
"Kyohei",
""
]
] | Particle production in strong electromagnetic fields is a recurring theme in solid state physics, heavy ion collisions, early universe cosmology and formal quantum field theory. In this paper we discuss the Dirac equation in a background of parallel electric and magnetic fields. We review the Schwinger particle production rate, clarify the emergence of the chiral anomaly equation and compute the induced current of charged fermions. We distinguish the contributions from non-perturbative particle production, from the running of the gauge coupling constant and from non-linearities in the effective QED Lagrangian, and clarify how these contributions arise within a single framework. We apply these results to axion inflation. A Chern-Simons coupling between the pseudoscalar particle driving cosmic inflaton and an abelian gauge group induces a dual production of gauge fields and charged fermions. We show that the resulting scalar and gravitational wave power spectra strongly depend on the fermion mass. |
hep-ph/0101146 | Gwo-Guang Wong | Wei-Shu Hou, Ching-Shan Luo and Gwo-Guang Wong | Glueball States in a Constituent Gluon Model | Revtex, 7 pages with 7 eps figures | Phys.Rev. D64 (2001) 014028 | 10.1103/PhysRevD.64.014028 | null | hep-ph | null | In a model with dynamical gluon mass, we investigate the bound states of two
and three gluons via a Schr\"odinger equation. The short distance potential is
approximated by one-gluon-exchange while the long distance part is assumed to
be of a breakable string. We estimate the masses and in particular the {\it
sizes} of low-lying bound states with no orbital angular momentum. By
considering quantum-mechanical smearing of the gluon fields and normalizing to
lattice results on $M_{0^{++}}$ and $M_{2^{++}}$, we find that the $0^{++}$
glueball is rather small in size compared with the others. The fitted gluon
mass is of order 600 to 700 MeV, which is reasonable. The 3-gluon glueballs
$0^{-+}$, $1^{--}$ and $3^{--}$ states are nearly degenerate, and their mass
ratio with $2^{++}$ is largely independent of all parameters and consistent
with lattice calculations. We estimate the mass of $1^{--}$ glueball to be
$3.1-3.7$ GeV, which is close to the mass of $J/\psi$ and $\psi^\prime$.
| [
{
"created": "Mon, 15 Jan 2001 05:35:17 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Jan 2001 03:24:00 GMT",
"version": "v2"
},
{
"created": "Thu, 1 Mar 2001 15:43:21 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Hou",
"Wei-Shu",
""
],
[
"Luo",
"Ching-Shan",
""
],
[
"Wong",
"Gwo-Guang",
""
]
] | In a model with dynamical gluon mass, we investigate the bound states of two and three gluons via a Schr\"odinger equation. The short distance potential is approximated by one-gluon-exchange while the long distance part is assumed to be of a breakable string. We estimate the masses and in particular the {\it sizes} of low-lying bound states with no orbital angular momentum. By considering quantum-mechanical smearing of the gluon fields and normalizing to lattice results on $M_{0^{++}}$ and $M_{2^{++}}$, we find that the $0^{++}$ glueball is rather small in size compared with the others. The fitted gluon mass is of order 600 to 700 MeV, which is reasonable. The 3-gluon glueballs $0^{-+}$, $1^{--}$ and $3^{--}$ states are nearly degenerate, and their mass ratio with $2^{++}$ is largely independent of all parameters and consistent with lattice calculations. We estimate the mass of $1^{--}$ glueball to be $3.1-3.7$ GeV, which is close to the mass of $J/\psi$ and $\psi^\prime$. |
hep-ph/0006333 | Anton Ryzhov | Anton V. Ryzhov, Laurence G. Yaffe | Large N Quantum Time Evolution Beyond Leading Order | 36 pages, 2 eps figures, latex, uses revtex, epsfig, floats | Phys.Rev. D62 (2000) 125003 | 10.1103/PhysRevD.62.125003 | UW/PT-00-12, UCLA/00/TEP/21 | hep-ph hep-th | null | For quantum theories with a classical limit (which includes the large N
limits of typical field theories), we derive a hierarchy of evolution equations
for equal time correlators which systematically incorporate corrections to the
limiting classical evolution. Explicit expressions are given for
next-to-leading order, and next-to-next-to-leading order time evolution. The
large N limit of N-component vector models, and the usual semiclassical limit
of point particle quantum mechanics are used as concrete examples. Our
formulation directly exploits the appropriate group structure which underlies
the construction of suitable coherent states and generates the classical phase
space. We discuss the growth of truncation error with time, and argue that
truncations of the large-N evolution equations are generically expected to be
useful only for times short compared to a ``decoherence'' time which scales
like N^{1/2}.
| [
{
"created": "Thu, 29 Jun 2000 05:19:46 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Ryzhov",
"Anton V.",
""
],
[
"Yaffe",
"Laurence G.",
""
]
] | For quantum theories with a classical limit (which includes the large N limits of typical field theories), we derive a hierarchy of evolution equations for equal time correlators which systematically incorporate corrections to the limiting classical evolution. Explicit expressions are given for next-to-leading order, and next-to-next-to-leading order time evolution. The large N limit of N-component vector models, and the usual semiclassical limit of point particle quantum mechanics are used as concrete examples. Our formulation directly exploits the appropriate group structure which underlies the construction of suitable coherent states and generates the classical phase space. We discuss the growth of truncation error with time, and argue that truncations of the large-N evolution equations are generically expected to be useful only for times short compared to a ``decoherence'' time which scales like N^{1/2}. |
hep-ph/0505077 | Bachir Moussallam | Bachir Moussallam (IPNO), Sebastien Descotes-Genon (LPTO) | Radiative corrections in weak semi-leptoni processes at low energy: a
two-step matching determination | 28 pages, latex | Eur.Phys.J.C42:403-417,2005 | 10.1140/epjc/s2005-02316-8 | null | hep-ph | null | We focus on the chiral Lagrangian couplings describing radiative corrections
to weak semi-leptonic decays and relate them to the decay amplitude of a
lepton, computed by Braaten and Li at one loop in the Standard Model. For this
purpose, we follow a two-step procedure. A first matching, from the Standard
Model to Fermi theory, yields a relevant set of counterterms. The latter are
related to chiral couplings thanks to a second matching, from Fermi theory to
the chiral Lagrangian, which is performed using the spurion method. We show
that the chiral couplings of physical relevance obey integral representations
in a closed form, expressed in terms of QCD chiral correlators and vertex
functions. We deduce exact relations among the couplings, as well as numerical
estimates which go beyond the usual $\log(M\_Z/M\_\rho)$ approximation.
| [
{
"created": "Tue, 10 May 2005 11:49:44 GMT",
"version": "v1"
}
] | 2009-01-07 | [
[
"Moussallam",
"Bachir",
"",
"IPNO"
],
[
"Descotes-Genon",
"Sebastien",
"",
"LPTO"
]
] | We focus on the chiral Lagrangian couplings describing radiative corrections to weak semi-leptonic decays and relate them to the decay amplitude of a lepton, computed by Braaten and Li at one loop in the Standard Model. For this purpose, we follow a two-step procedure. A first matching, from the Standard Model to Fermi theory, yields a relevant set of counterterms. The latter are related to chiral couplings thanks to a second matching, from Fermi theory to the chiral Lagrangian, which is performed using the spurion method. We show that the chiral couplings of physical relevance obey integral representations in a closed form, expressed in terms of QCD chiral correlators and vertex functions. We deduce exact relations among the couplings, as well as numerical estimates which go beyond the usual $\log(M\_Z/M\_\rho)$ approximation. |
2211.04837 | Yair Mulian | Edmond Iancu, Yair Mulian | Dihadron production in DIS at NLO: the real corrections | 43 pages, 13 figures | null | 10.1007/JHEP07(2023)121 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | By using the formalism of the light-cone wave function along with the colour
glass condensate effective theory, we consider next-to-leading order (NLO)
corrections to the production of a pair of hadrons in electron-proton, or
electron-nucleus, collisions at small Bjorken $x$. To the order of interest,
the process involves the fluctuation of a virtual photon into a quark-antiquark
pair, followed by the emission of a gluon from either the quark, or the
antiquark. For the case of a virtual photon with transverse polarization, we
compute the real NLO corrections, where the emitted gluon is present in the
final state. We first compute the tree-level cross-section for the production
of the quark-antiquark-gluon system and then deduce the real NLO corrections to
dihadron production by integrating out the kinematics of the gluon. We verify
in detail that, in the limit where the gluon is soft, our calculation
reproduces the (real piece of the) B-JIMWLK evolution of the leading-order
cross-section for quark-antiquark production. Similarly, in the limit where the
gluon is collinear with its emitter, we recover the real terms in the DGLAP
evolution of the fragmentation function. The virtual NLO corrections to
dihadron production will be presented by one of us in a subsequent publication.
| [
{
"created": "Wed, 9 Nov 2022 12:23:25 GMT",
"version": "v1"
}
] | 2023-08-02 | [
[
"Iancu",
"Edmond",
""
],
[
"Mulian",
"Yair",
""
]
] | By using the formalism of the light-cone wave function along with the colour glass condensate effective theory, we consider next-to-leading order (NLO) corrections to the production of a pair of hadrons in electron-proton, or electron-nucleus, collisions at small Bjorken $x$. To the order of interest, the process involves the fluctuation of a virtual photon into a quark-antiquark pair, followed by the emission of a gluon from either the quark, or the antiquark. For the case of a virtual photon with transverse polarization, we compute the real NLO corrections, where the emitted gluon is present in the final state. We first compute the tree-level cross-section for the production of the quark-antiquark-gluon system and then deduce the real NLO corrections to dihadron production by integrating out the kinematics of the gluon. We verify in detail that, in the limit where the gluon is soft, our calculation reproduces the (real piece of the) B-JIMWLK evolution of the leading-order cross-section for quark-antiquark production. Similarly, in the limit where the gluon is collinear with its emitter, we recover the real terms in the DGLAP evolution of the fragmentation function. The virtual NLO corrections to dihadron production will be presented by one of us in a subsequent publication. |
1012.4165 | Khaled Abdel-Waged Khaled Abdel-Waged | Khaled Abdel-Waged, Nuha Felemban and V.V. Uzhinskii | Enabling comparison of UrQMD with Geant4 hadronic models | 17 pages, 5 Figures | CERN LCGAPP 2010-04 | 10.1103/PhysRevC.84.014905 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Geant4 has an abundant set of physics models that handle the diverse
interaction of particles with matter across a wide energy range. However, there
are also many well established reaction codes currently used in the same fields
where Geant4 is applied. One such code is the Ultra-relativistic Quantum
Molecular Dynamics (UrQMD) model. In order to take advantage of the UrQMD code,
we create a tool to enable comparisons among UrQMD and Geant4 hadronic models.
This tool allows a user to process the output file of UrQMD through Geant4
toolkit, while at the same time, can choose among different Geant4 hadronic
model generators. As an example, the UrQMD model is compared with the HARP-CDP
experimental data and with the Binary and FRITIOF generators, in the framework
of Geant4. It is shown that the UrQMD model can better reproduce charged pion
production for p+Cu and Pb interactions at 3, 8 and 15 GeV/c, and is a good
candidate for Geant4 hadronic models.
| [
{
"created": "Sun, 19 Dec 2010 13:00:35 GMT",
"version": "v1"
}
] | 2015-05-20 | [
[
"Abdel-Waged",
"Khaled",
""
],
[
"Felemban",
"Nuha",
""
],
[
"Uzhinskii",
"V. V.",
""
]
] | Geant4 has an abundant set of physics models that handle the diverse interaction of particles with matter across a wide energy range. However, there are also many well established reaction codes currently used in the same fields where Geant4 is applied. One such code is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. In order to take advantage of the UrQMD code, we create a tool to enable comparisons among UrQMD and Geant4 hadronic models. This tool allows a user to process the output file of UrQMD through Geant4 toolkit, while at the same time, can choose among different Geant4 hadronic model generators. As an example, the UrQMD model is compared with the HARP-CDP experimental data and with the Binary and FRITIOF generators, in the framework of Geant4. It is shown that the UrQMD model can better reproduce charged pion production for p+Cu and Pb interactions at 3, 8 and 15 GeV/c, and is a good candidate for Geant4 hadronic models. |
0706.2222 | Jae Sik Lee | Jae Sik Lee | LHC Signatures of MSSM Higgs-sector CP Violation | 6 pages, 3 figures, invited talk given at the CTP Symposium on
Supersymmetry at LHC: Theoretical and Experimental Perspectives, the British
University in Egypt, 11-14 March 2007 (to appear in the proceedings) | null | null | null | hep-ph | null | We discuss a few new characteristic features of the loop-induced MSSM
Higgs-sector CP violation at the LHC based on two scenarios: (i) CPX and (ii)
Trimixing.
| [
{
"created": "Fri, 15 Jun 2007 12:28:20 GMT",
"version": "v1"
}
] | 2007-06-18 | [
[
"Lee",
"Jae Sik",
""
]
] | We discuss a few new characteristic features of the loop-induced MSSM Higgs-sector CP violation at the LHC based on two scenarios: (i) CPX and (ii) Trimixing. |
hep-ph/0301236 | Pavel Pobylitsa | P.V. Pobylitsa | Transverse-momentum dependent parton distributions in large-Nc QCD | 19 pages | null | null | null | hep-ph | null | The transverse-momentum dependent quark distributions are studied in the
limit of the large number of colors Nc. The leading orders of Nc are determined
for all twist-2 distributions including the T-odd functions. The isospin
structure of the dominant contributions is found.
| [
{
"created": "Mon, 27 Jan 2003 20:54:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pobylitsa",
"P. V.",
""
]
] | The transverse-momentum dependent quark distributions are studied in the limit of the large number of colors Nc. The leading orders of Nc are determined for all twist-2 distributions including the T-odd functions. The isospin structure of the dominant contributions is found. |
hep-ph/0403178 | Mikhail Gorshteyn | M. Gorchtein, D. Drechsel, M.M. Giannini, and E. Santopinto | Generalized sum rules of the nucleon in the CQM | Talk given at IV International Conference on "Perspectives in
Hadronic Physics", May 12-16, 2003, Trieste (Italy) 3 pages, 4 figures | Eur.Phys.J.A19:77-79,2004 | 10.1140/epjad/s2004-03-013-1 | null | hep-ph | null | The sum rules serve a powerful tool to study the nucleon structure by
providing a bridge between the statical properties of the nucleon (such as
electrical charge, and magnetic moment) and the dynamical properties (e.g. the
transition amplitudes to excited states) in a wide range of energy and momentum
transfer $Q^2$. We study the generalized sum rules of the nucleon in the
framework of the constituent quark model. We use two different CQM, the one
with the hypercentral potential \cite{hccqm1}, \cite{hccqm2}, \cite{hccqm3},
and with the harmonic oscillator potential \cite{KI}, both with only few
parameters fixed to the baryonic spectrum. We confront our results to the model
independent sum rules and to the predictions of the phenomenological MAID
\cite{MAID} model and find that in all the cases considered, in the
intermediate $Q^2$ range (0.2-1.5 GeV$^2$), both CQM models provide a good
description of the sum rules on the neutron.
| [
{
"created": "Tue, 16 Mar 2004 15:02:30 GMT",
"version": "v1"
}
] | 2010-03-02 | [
[
"Gorchtein",
"M.",
""
],
[
"Drechsel",
"D.",
""
],
[
"Giannini",
"M. M.",
""
],
[
"Santopinto",
"E.",
""
]
] | The sum rules serve a powerful tool to study the nucleon structure by providing a bridge between the statical properties of the nucleon (such as electrical charge, and magnetic moment) and the dynamical properties (e.g. the transition amplitudes to excited states) in a wide range of energy and momentum transfer $Q^2$. We study the generalized sum rules of the nucleon in the framework of the constituent quark model. We use two different CQM, the one with the hypercentral potential \cite{hccqm1}, \cite{hccqm2}, \cite{hccqm3}, and with the harmonic oscillator potential \cite{KI}, both with only few parameters fixed to the baryonic spectrum. We confront our results to the model independent sum rules and to the predictions of the phenomenological MAID \cite{MAID} model and find that in all the cases considered, in the intermediate $Q^2$ range (0.2-1.5 GeV$^2$), both CQM models provide a good description of the sum rules on the neutron. |
1404.3374 | Monalisa Patra | Aarti Girdhar, Biswarup Mukhopadhyaya, Monalisa Patra | Distinguishing Signatures of top-and bottom-type heavy vectorlike quarks
at the LHC | 18 pages, 10 figures | Phys. Rev. D 91, 055015 (2015) | 10.1103/PhysRevD.91.055015 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An SU(2) vectorlike singlet quark with a charge either +2/3 (t') or -1/3 (b')
is predicted in many extensions of the Standard Model. The mixing of these
quarks with the top or bottom lead to Flavor Changing Yukawa Interactions and
Neutral Current. The decay modes of the heavier mass eigenstates are therefore
different from the Standard Model type chiral quarks. The Large Hadron Collider
(LHC) will provide an ideal environment to look for the signals of these exotic
quarks. Considering all decays, including those involving Z- and Yukawa
interactions, we show how one can distinguish between t' and b' from ratios of
event rates with different lepton multiplicities. The ability to reconstruct
the Higgs boson with a mass around 125.5 GeV plays an important role in such
differentiation.
| [
{
"created": "Sun, 13 Apr 2014 12:27:39 GMT",
"version": "v1"
}
] | 2015-03-18 | [
[
"Girdhar",
"Aarti",
""
],
[
"Mukhopadhyaya",
"Biswarup",
""
],
[
"Patra",
"Monalisa",
""
]
] | An SU(2) vectorlike singlet quark with a charge either +2/3 (t') or -1/3 (b') is predicted in many extensions of the Standard Model. The mixing of these quarks with the top or bottom lead to Flavor Changing Yukawa Interactions and Neutral Current. The decay modes of the heavier mass eigenstates are therefore different from the Standard Model type chiral quarks. The Large Hadron Collider (LHC) will provide an ideal environment to look for the signals of these exotic quarks. Considering all decays, including those involving Z- and Yukawa interactions, we show how one can distinguish between t' and b' from ratios of event rates with different lepton multiplicities. The ability to reconstruct the Higgs boson with a mass around 125.5 GeV plays an important role in such differentiation. |
hep-ph/0511324 | Alexander L. Bondarev | Alexander L. Bondarev (NC PHEP BSU) | Calculation of the scattering amplitudes | 12 pages, LaTeX2E, to appear in the proceedings of 9th Annual RDMS
CMS Collaboration Conference, Minsk, Belarus, November 28 – December 2,
2004 | null | null | null | hep-ph | null | General equations for the calculation of amplitudes are presented. As an
illustration of application of proposed formulae we calculate electron-electron
scattering amplitudes.
| [
{
"created": "Tue, 29 Nov 2005 14:53:07 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bondarev",
"Alexander L.",
"",
"NC PHEP BSU"
]
] | General equations for the calculation of amplitudes are presented. As an illustration of application of proposed formulae we calculate electron-electron scattering amplitudes. |
hep-ph/9502248 | Adam Falk | Adam F. Falk and Alexander Kyatkin | Instantons and the endpoint of the lepton energy spectrum in charmless
semileptonic $B$ decays | Slightly revised version, to appear in Phys. Rev. D. A few additional
comments have been added on the approximations which are used. 13 pages, 2
embedded uuencoded figures, uses REVTeX | Phys.Rev.D52:5049-5055,1995 | 10.1103/PhysRevD.52.5049 | JHU-TIPAC-950004 | hep-ph | null | A recent calculation by Chay and Rey has shown that instantons may make a
significant contribution to the lepton energy spectrum near its endpoint. Using
an ansatz borrowed from the study of high energy baryon number violating
processes, we investigate whether these corrections could spoil the relation
between the nonperturbative contributions to this spectrum and to the photon
energy spectrum in radiative $B$ decays. We find, in general, that this
universality may well fail unless the spectrum is smeared over a region which
is considerably larger than had previously been thought necessary. This result
affects the possibility of performing a reliable measurement of $V_{ub}$ using
inclusive decays.
| [
{
"created": "Tue, 7 Feb 1995 17:33:30 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Jun 1995 16:13:22 GMT",
"version": "v2"
}
] | 2010-11-01 | [
[
"Falk",
"Adam F.",
""
],
[
"Kyatkin",
"Alexander",
""
]
] | A recent calculation by Chay and Rey has shown that instantons may make a significant contribution to the lepton energy spectrum near its endpoint. Using an ansatz borrowed from the study of high energy baryon number violating processes, we investigate whether these corrections could spoil the relation between the nonperturbative contributions to this spectrum and to the photon energy spectrum in radiative $B$ decays. We find, in general, that this universality may well fail unless the spectrum is smeared over a region which is considerably larger than had previously been thought necessary. This result affects the possibility of performing a reliable measurement of $V_{ub}$ using inclusive decays. |
hep-ph/0408061 | Jonathan Butterworth | J. M. Butterworth and T. Carli | QCD uncertainties at the LHC and the implications of HERA | Contributed to the Proceedings of DIS04, Strbske Pleso, Slovakia | null | 10.1103/PhysRevD.71.024010 | null | hep-ph hep-ex | null | Strong interaction physics will be ubiquitous at the Large Hadron Collider
since the colliding beams consist of confined quarks and gluons. Although the
main purpose of the LHC is to study the mechanism of electroweak symmetry
breaking and to search for physics beyond the Standard Model, to maximise the
precision and sensitivity of such anaylses it is necessary to understand in
detail various perturbative, semi-perturbative and non-perturbative QCD
effects. Many of these effects have been extensively studied at HERA and will
be studied further at HERA II. We discuss the impact of the knowledge thus
gained on physics at the LHC.
| [
{
"created": "Wed, 4 Aug 2004 11:11:52 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Aug 2004 08:56:40 GMT",
"version": "v2"
}
] | 2013-05-29 | [
[
"Butterworth",
"J. M.",
""
],
[
"Carli",
"T.",
""
]
] | Strong interaction physics will be ubiquitous at the Large Hadron Collider since the colliding beams consist of confined quarks and gluons. Although the main purpose of the LHC is to study the mechanism of electroweak symmetry breaking and to search for physics beyond the Standard Model, to maximise the precision and sensitivity of such anaylses it is necessary to understand in detail various perturbative, semi-perturbative and non-perturbative QCD effects. Many of these effects have been extensively studied at HERA and will be studied further at HERA II. We discuss the impact of the knowledge thus gained on physics at the LHC. |
hep-ph/0112176 | Ismd31 | F. Tessarotto | The COMPASS Experiment and the measurement of the gluon polarisation | 6 pages, 3 figures in eps and 1 in jpg, talk given at XXXI
International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong
China. see http://ismd31.ccnu.edu.cn/ | null | 10.1142/9789812778048_0050 | null | hep-ph | null | COMPASS, a new fixed target experiment at CERN, aimed at the study of nucleon
spin structure and hadron spectroscopy, has started to collect physics data in
Autumn 2001. This paper describes the COMPASS apparatus and the measurement of
the gluon polarisation $\Delta G /G$. The apparatus consists in a solid state
polarised target and a two stage spectro-meter with high resolution tracking,
particle identification and calorimetry, capable of standing high event rates.
COMPASS measures the longitudinal spin asymmetry of open charm production in
polarised deep inelastic muon nucleon scattering: this asymmetry is directly
related to $\Delta G$ since at COMPASS energies open charm is essentially
produced by photon gluon fusion only. A second channel, used to access $\Delta
G$ with higher statistics, is the production of correlated high $p_T$ hadron
pairs.
| [
{
"created": "Thu, 13 Dec 2001 09:40:47 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Tessarotto",
"F.",
""
]
] | COMPASS, a new fixed target experiment at CERN, aimed at the study of nucleon spin structure and hadron spectroscopy, has started to collect physics data in Autumn 2001. This paper describes the COMPASS apparatus and the measurement of the gluon polarisation $\Delta G /G$. The apparatus consists in a solid state polarised target and a two stage spectro-meter with high resolution tracking, particle identification and calorimetry, capable of standing high event rates. COMPASS measures the longitudinal spin asymmetry of open charm production in polarised deep inelastic muon nucleon scattering: this asymmetry is directly related to $\Delta G$ since at COMPASS energies open charm is essentially produced by photon gluon fusion only. A second channel, used to access $\Delta G$ with higher statistics, is the production of correlated high $p_T$ hadron pairs. |
1104.0117 | Koichi Kanazawa | Koichi Kanazawa and Yuji Koike | A phenomenological study of single transverse-spin asymmetry for
inclusive light-hadron productions at RHIC | 12 pages, 8 figures, Final version published in Phys. Rev. D 83,
114024 (2011) | Phys.Rev.D83:114024,2011 | 10.1103/PhysRevD.83.114024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the single transverse-spin asymmetry for inclusive light-hadron
productions in the proton-proton collision, $\pphx$ ($h=\pi,K,\eta$), for the
RHIC kinematics based on the twist-3 mechanism in the collinear factorization.
The analysis includes all the contributions from the soft-gluon pole and the
soft-fermion pole for the twist-3 quark-gluon correlation functions in the
transversely polarized proton. After discussing the flavor decomposition and
the $P_T$-dependence of the asymmetry obtained in the previous analysis at the
center-of-mass energy $\sqrt{S}=62.4$ and 200 GeV, we will give a prediction
for the asymmetry at $\sqrt{S}=500$ GeV and also for the $\eta$-meson
production. We found slightly smaller asymmetry at $\sqrt{S}=500$ GeV for
$\pi^{\pm,0}$ and $K^+$ compared with those at the lower energies. The
asymmetry for the $\eta$-meson turned out to be significantly larger than that
for $\pi^0$.
| [
{
"created": "Fri, 1 Apr 2011 09:35:10 GMT",
"version": "v1"
},
{
"created": "Sat, 11 Jun 2011 05:21:16 GMT",
"version": "v2"
}
] | 2011-06-24 | [
[
"Kanazawa",
"Koichi",
""
],
[
"Koike",
"Yuji",
""
]
] | We study the single transverse-spin asymmetry for inclusive light-hadron productions in the proton-proton collision, $\pphx$ ($h=\pi,K,\eta$), for the RHIC kinematics based on the twist-3 mechanism in the collinear factorization. The analysis includes all the contributions from the soft-gluon pole and the soft-fermion pole for the twist-3 quark-gluon correlation functions in the transversely polarized proton. After discussing the flavor decomposition and the $P_T$-dependence of the asymmetry obtained in the previous analysis at the center-of-mass energy $\sqrt{S}=62.4$ and 200 GeV, we will give a prediction for the asymmetry at $\sqrt{S}=500$ GeV and also for the $\eta$-meson production. We found slightly smaller asymmetry at $\sqrt{S}=500$ GeV for $\pi^{\pm,0}$ and $K^+$ compared with those at the lower energies. The asymmetry for the $\eta$-meson turned out to be significantly larger than that for $\pi^0$. |
hep-ph/0111461 | Ismd31 | O.V.Utyuzh, G.Wilk and Z.Wlodarczyk | Numerical modelling of correlations | 4 pages, 1 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL
http://202.114.35.18/ | null | 10.1142/9789812778048_0056 | null | hep-ph | null | We demonstrate algorithm for numerical modelling of Bose-Einstein
correlations (BEC) formulated on quantum statistical level for a single event
and exploring the property that identical particles subjected to Bose
statistics do bunch themselves in a maximal possible way in the same cells in
phase-space.
| [
{
"created": "Fri, 30 Nov 2001 11:54:57 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Utyuzh",
"O. V.",
""
],
[
"Wilk",
"G.",
""
],
[
"Wlodarczyk",
"Z.",
""
]
] | We demonstrate algorithm for numerical modelling of Bose-Einstein correlations (BEC) formulated on quantum statistical level for a single event and exploring the property that identical particles subjected to Bose statistics do bunch themselves in a maximal possible way in the same cells in phase-space. |
hep-ph/9612450 | Andreas Laser | H.G. Dosch, J. Kripfganz, A. Laser, M.G. Schmidt | Non-perturbative correlation masses in the hot electroweak phase | 25 pages, 5 figures; needs epsf.sty, a4.sty and cite.sty Some
sentences moved from section 5 to section 6 | Nucl.Phys.B507:519-546,1997 | 10.1016/S0550-3213(97)00439-2 | HD-THEP-96-53, DO-TH 96/26 | hep-ph | null | The effective action describing the long range fluctuations in the high
temperature phase of the electroweak standard theory is a strongly coupled
SU(2)-Higgs-model in three dimensions. We outline in detail a model in which
the spatial correlation scales in this phase are calculated as inverse
relativistic bound state masses. Selection rules for these states are derived.
The correlation masses are calculated by evaluating the bound state Green's
function. The scalar-scalar-potential and its influence on the masses is
investigated. The predictions for the correlation masses agree very well with
the lattice data available now.
| [
{
"created": "Mon, 23 Dec 1996 14:47:18 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Dec 1996 12:59:56 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Dosch",
"H. G.",
""
],
[
"Kripfganz",
"J.",
""
],
[
"Laser",
"A.",
""
],
[
"Schmidt",
"M. G.",
""
]
] | The effective action describing the long range fluctuations in the high temperature phase of the electroweak standard theory is a strongly coupled SU(2)-Higgs-model in three dimensions. We outline in detail a model in which the spatial correlation scales in this phase are calculated as inverse relativistic bound state masses. Selection rules for these states are derived. The correlation masses are calculated by evaluating the bound state Green's function. The scalar-scalar-potential and its influence on the masses is investigated. The predictions for the correlation masses agree very well with the lattice data available now. |
2011.10058 | Timothy Trott | Timothy Trott | Causality, Unitarity and Symmetry in Effective Field Theory | ~50 pages v2: Improved discussion and use of discrete symmetries,
some corrections and clarifications, some other minor improvements. v3:
Corrected sign error in isospin projectors and resulting bounds (no
qualitative changes to the extent investigated), minor improvements in
exposition and typing errors corrected | null | 10.1007/JHEP07(2021)143 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | Sum rules in effective field theories, predicated upon causality, place
restrictions on scattering amplitudes mediated by effective contact
interactions. Through unitarity of the $S$-matrix, these imply that the size of
higher dimensional corrections to transition amplitudes between different
states is bounded by the strength of their contributions to elastic forward
scattering processes. This places fundamental limits on the extent to which
hypothetical symmetries can be broken by effective interactions. All analysis
is for dimension $8$ operators in the forward limit. Included is a thorough
derivation of all positivity bounds for a chiral fermion in $SU(2)$ and $SU(3)$
global symmetry representations resembling those of the Standard Model, general
bounds on flavour violation, new bounds for interactions between particles of
different spin, inclusion of loops of dimension $6$ operators and illustration
of the resulting strengthening of positivity bounds over tree-level
expectations, a catalogue of supersymmetric effective interactions up to mass
dimension $8$ and $4$ legs and the demonstration that supersymmetry unifies the
positivity theorems as well as the new bounds.
| [
{
"created": "Thu, 19 Nov 2020 19:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jan 2021 06:26:24 GMT",
"version": "v2"
},
{
"created": "Sat, 2 Oct 2021 22:32:49 GMT",
"version": "v3"
}
] | 2021-10-05 | [
[
"Trott",
"Timothy",
""
]
] | Sum rules in effective field theories, predicated upon causality, place restrictions on scattering amplitudes mediated by effective contact interactions. Through unitarity of the $S$-matrix, these imply that the size of higher dimensional corrections to transition amplitudes between different states is bounded by the strength of their contributions to elastic forward scattering processes. This places fundamental limits on the extent to which hypothetical symmetries can be broken by effective interactions. All analysis is for dimension $8$ operators in the forward limit. Included is a thorough derivation of all positivity bounds for a chiral fermion in $SU(2)$ and $SU(3)$ global symmetry representations resembling those of the Standard Model, general bounds on flavour violation, new bounds for interactions between particles of different spin, inclusion of loops of dimension $6$ operators and illustration of the resulting strengthening of positivity bounds over tree-level expectations, a catalogue of supersymmetric effective interactions up to mass dimension $8$ and $4$ legs and the demonstration that supersymmetry unifies the positivity theorems as well as the new bounds. |
hep-ph/9706505 | Mikhail Ryskin | M.G. Ryskin (PNPI St. Petersbug) | Diffractive rho-meson Leptoproduction on Polarized Nucleon as a Way to
Measure the Polarized Gluon Distribution | 13 pages, LaTeX, 2 figures | null | 10.1016/S0370-2693(97)00547-9 | null | hep-ph | null | The amplitude of diffractive $\rho$ (and open quark) leptoproduction on a
polarized target is calculated in the leading log approximation of pQCD using
the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in
terms of the spin dependent gluon and quark structure functions in the small
$x$ region. Therefore the $\gamma^*+p\to \rho +p$ reaction provides a promising
tool to study the spin dependent gluon distribution $\Delta G(x,q^2)$.
| [
{
"created": "Wed, 25 Jun 1997 13:24:42 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Ryskin",
"M. G.",
"",
"PNPI St. Petersbug"
]
] | The amplitude of diffractive $\rho$ (and open quark) leptoproduction on a polarized target is calculated in the leading log approximation of pQCD using the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in terms of the spin dependent gluon and quark structure functions in the small $x$ region. Therefore the $\gamma^*+p\to \rho +p$ reaction provides a promising tool to study the spin dependent gluon distribution $\Delta G(x,q^2)$. |
1205.6776 | Joachim Brod | Joachim Brod | Direct CP violation in D-meson decays | 4 pages, 1 figure. To appear in the proceedings of the 47th
Rencontres de Moriond on QCD and High-Energy Interactions, 2012 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, the LHCb and CDF collaborations reported a surprisingly large
difference between the direct CP asymmetries, Delta A_CP, in the D0 -> K+ K-
and D0 -> pi+ pi- decay modes. An interesting question is whether this
measurement can be explained within the standard model. In this review, I would
like to convey two messages: First, large penguin contractions can plausibly
account for this measurement and lead to a consistent picture, also explaining
the difference between the decay rates of the two modes. Second, "new physics"
contributions are by no means excluded; viable models exist and can possibly be
tested.
| [
{
"created": "Wed, 30 May 2012 18:48:09 GMT",
"version": "v1"
}
] | 2012-05-31 | [
[
"Brod",
"Joachim",
""
]
] | Recently, the LHCb and CDF collaborations reported a surprisingly large difference between the direct CP asymmetries, Delta A_CP, in the D0 -> K+ K- and D0 -> pi+ pi- decay modes. An interesting question is whether this measurement can be explained within the standard model. In this review, I would like to convey two messages: First, large penguin contractions can plausibly account for this measurement and lead to a consistent picture, also explaining the difference between the decay rates of the two modes. Second, "new physics" contributions are by no means excluded; viable models exist and can possibly be tested. |
hep-ph/0405047 | Takeo Moroi | Takeo Moroi | Curvaton mechanism and its implications to sneutrino cosmology | 11 pages. Invited Talk at the Fujihara Seminar ``SEESAW 1979 - 2004:
Neutrino Mass and Seesaw Mechanism'' (Feb 23 - 25, 2004, KEK, Japan). To be
published in Nucl. Phys B (Proceedings Supplement) | Nucl.Phys.Proc.Suppl. 137 (2004) 259-268 | 10.1016/j.nuclphysbps.2004.10.075 | TU-719 | hep-ph | null | I describe basic features of the curvaton scenario where the primordial
fluctuation of a late-decaying scalar field, called ``curvaton,'' becomes the
dominant source of the cosmic density fluctuations. I also discuss its
implications to sneutrino cosmology.
| [
{
"created": "Thu, 6 May 2004 12:16:41 GMT",
"version": "v1"
},
{
"created": "Tue, 11 May 2004 01:52:21 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Moroi",
"Takeo",
""
]
] | I describe basic features of the curvaton scenario where the primordial fluctuation of a late-decaying scalar field, called ``curvaton,'' becomes the dominant source of the cosmic density fluctuations. I also discuss its implications to sneutrino cosmology. |
hep-ph/9308320 | Ronald Kleiss | Ronald Kleiss | The matrix element for radiative Bhabha scattering in the forward
direction | 8 pages, preprint number NIKHEF-93-19 (August 1993) | Phys.Lett. B318 (1993) 217-220 | 10.1016/0370-2693(93)91809-2 | null | hep-ph | null | We present an approximation to the matrix element for the process e+e- -->
e+e-gamma, appropriate to the situation where one or both of the fermions are
scattered over very small angles. The leading terms in the situation where all
scattering angles are small contains not only terms quadratic in the electron
mass, but also quartic and even sextic terms must be included. Special
attention is devoted to the numerical stability of the resultant expression.
Its relation to several existing formulae is discussed.
| [
{
"created": "Mon, 23 Aug 1993 16:58:55 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Kleiss",
"Ronald",
""
]
] | We present an approximation to the matrix element for the process e+e- --> e+e-gamma, appropriate to the situation where one or both of the fermions are scattered over very small angles. The leading terms in the situation where all scattering angles are small contains not only terms quadratic in the electron mass, but also quartic and even sextic terms must be included. Special attention is devoted to the numerical stability of the resultant expression. Its relation to several existing formulae is discussed. |
hep-ph/0307320 | Fabio Siringo | Fabio Siringo | A Truly Minimal Left-Right Symmetric Extension of the Standard Model | 1 figure in a separate ps file | Eur.Phys.J.C32:555,2004 | 10.1140/epjc/s2003-01442-7 | null | hep-ph | null | By invoking the existence of a general custodial O(2) symmetry, a minimal
Left-Right symmetric model based on the gauge group G=SU(2)L SU(2)R U(1)BL is
shown to require the existence of only two physical Higgs bosons. The lighter
Higgs is predicted to have a small mass which could be evaluated by standard
perturbation theory. The fermionic mass matrices are recovered by insertion of
ad hoc fermion-Higgs interactions. The model is shown to be undistinguishable
from the standard model at the currently reachable energies.
| [
{
"created": "Fri, 25 Jul 2003 17:17:20 GMT",
"version": "v1"
}
] | 2009-01-07 | [
[
"Siringo",
"Fabio",
""
]
] | By invoking the existence of a general custodial O(2) symmetry, a minimal Left-Right symmetric model based on the gauge group G=SU(2)L SU(2)R U(1)BL is shown to require the existence of only two physical Higgs bosons. The lighter Higgs is predicted to have a small mass which could be evaluated by standard perturbation theory. The fermionic mass matrices are recovered by insertion of ad hoc fermion-Higgs interactions. The model is shown to be undistinguishable from the standard model at the currently reachable energies. |
1209.6627 | Andrew Kobach | Andre de Gouvea, Andrew C. Kobach | The Lightest Massive Invisible Particles at the LHC | 12 pages, 20 figures | Nuclear Physics B 874 (2013), pp. 399-412 | 10.1016/j.nuclphysb.2013.06.001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The observation of new physics events with large missing transverse energy at
the LHC would potentially serve as evidence for the direct production of dark
matter. A crucial step toward verifying such evidence is the measurement of the
would-be dark matter mass. If, for example, the invisible particles are found
to have masses consistent with zero, it may prove very challenging to ascertain
whether light dark matter or neutrinos are being observed. We assume that new
invisible particles are pair-produced in a ttbar-like topology and use two
MT2-based methods to measure the masses of the particles associated with the
missing energy. Instead of simulating events and backgrounds, we estimate the
uncertainty associated with measuring the mass of the invisible particle by
assuming a fixed value of the uncertainty associated with the location of the
MT2 endpoint. We find that if this uncertainty associated with measuring the
MT2 endpoints is, quite optimistically, O(1 GeV), the invisible particles must
have masses greater than O(10 GeV) so they can be distinguished from massless
ones at 95% CL. If the results from the CoGeNT, DAMA/LIBRA, and CRESST
experiments have indeed revealed the existence of light dark matter with mass
O(10 GeV), our results suggest that it may be difficult for the LHC to
distinguish dark matter from neutrinos solely via mass measurements.
| [
{
"created": "Fri, 28 Sep 2012 19:52:07 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Jun 2013 20:02:59 GMT",
"version": "v2"
}
] | 2013-07-02 | [
[
"de Gouvea",
"Andre",
""
],
[
"Kobach",
"Andrew C.",
""
]
] | The observation of new physics events with large missing transverse energy at the LHC would potentially serve as evidence for the direct production of dark matter. A crucial step toward verifying such evidence is the measurement of the would-be dark matter mass. If, for example, the invisible particles are found to have masses consistent with zero, it may prove very challenging to ascertain whether light dark matter or neutrinos are being observed. We assume that new invisible particles are pair-produced in a ttbar-like topology and use two MT2-based methods to measure the masses of the particles associated with the missing energy. Instead of simulating events and backgrounds, we estimate the uncertainty associated with measuring the mass of the invisible particle by assuming a fixed value of the uncertainty associated with the location of the MT2 endpoint. We find that if this uncertainty associated with measuring the MT2 endpoints is, quite optimistically, O(1 GeV), the invisible particles must have masses greater than O(10 GeV) so they can be distinguished from massless ones at 95% CL. If the results from the CoGeNT, DAMA/LIBRA, and CRESST experiments have indeed revealed the existence of light dark matter with mass O(10 GeV), our results suggest that it may be difficult for the LHC to distinguish dark matter from neutrinos solely via mass measurements. |
0707.4058 | Florian Bonnet | A. Abada, C.Biggio, F. Bonnet, M.B. Gavela, T. Hambye | Low energy effects of neutrino masses | modifications: couplings in appendix B, formulas (121)-(122) on rare
leptons decays (to match with published version) and consequently bounds in
table 8 | JHEP 0712:061,2007 | 10.1088/1126-6708/2007/12/061 | FTUAM-07-12, IFT-UAM/CSIC-07-41, LPT-Orsay 07-34, ULB-TH/07-27 | hep-ph | null | While all models of Majorana neutrino masses lead to the same dimension five
effective operator, which does not conserve lepton number, the dimension six
operators induced at low energies conserve lepton number and differ depending
on the high energy model of new physics. We derive the low-energy dimension six
operators which are characteristic of generic Seesaw models, in which neutrino
masses result from the exchange of heavy fields which may be either fermionic
singlets, fermionic triplets or scalar triplets. The resulting operators may
lead to effects observable in the near future, if the coefficients of the
dimension five and six operators are decoupled along a certain pattern, which
turns out to be common to all models. The phenomenological consequences are
explored as well, including their contributions to $\mu \to e \gamma$ and new
bounds on the Yukawa couplings for each model.
| [
{
"created": "Fri, 27 Jul 2007 07:55:16 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Oct 2007 09:48:36 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Apr 2008 14:30:58 GMT",
"version": "v3"
}
] | 2009-01-06 | [
[
"Abada",
"A.",
""
],
[
"Biggio",
"C.",
""
],
[
"Bonnet",
"F.",
""
],
[
"Gavela",
"M. B.",
""
],
[
"Hambye",
"T.",
""
]
] | While all models of Majorana neutrino masses lead to the same dimension five effective operator, which does not conserve lepton number, the dimension six operators induced at low energies conserve lepton number and differ depending on the high energy model of new physics. We derive the low-energy dimension six operators which are characteristic of generic Seesaw models, in which neutrino masses result from the exchange of heavy fields which may be either fermionic singlets, fermionic triplets or scalar triplets. The resulting operators may lead to effects observable in the near future, if the coefficients of the dimension five and six operators are decoupled along a certain pattern, which turns out to be common to all models. The phenomenological consequences are explored as well, including their contributions to $\mu \to e \gamma$ and new bounds on the Yukawa couplings for each model. |
hep-ph/0506233 | Kacper Zalewski | A. Bialas, W. Czyz and K. Zalewski | Coincidence probability as a measure of the average phase-space density
at freeze-out | LateX, 9 pages, no figures | Phys.Lett. B633 (2006) 479-482 | 10.1016/j.physletb.2005.12.044 | null | hep-ph | null | It is pointed out that the average semi-inclusive particle phase-space
density at freeze-out can be determined from the coincidence probability of the
events observed in multiparticle production. The method of measurement is
described and its accuracy examined.
| [
{
"created": "Thu, 23 Jun 2005 13:56:04 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Feb 2006 14:49:37 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Bialas",
"A.",
""
],
[
"Czyz",
"W.",
""
],
[
"Zalewski",
"K.",
""
]
] | It is pointed out that the average semi-inclusive particle phase-space density at freeze-out can be determined from the coincidence probability of the events observed in multiparticle production. The method of measurement is described and its accuracy examined. |
1612.02543 | Suchismita Sahoo | Suchismita Sahoo, Rukmani Mohanta | Study of the rare decays $B_{s,d}^* \to \mu^+ \mu^-$ | 19 pages, 1 figure | null | 10.1088/1361-6471/aa577e | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the effect of scalar leptoquarks and family non-universal
$Z^\prime$ boson on the rare leptonic decays of $B_{s, d}^*$ mesons, mediated
by the FCNC transitions $b \to (d, s) l^+ l^-$. They are sensitive to a variety
of new physics operators as opposed to the $B_{s,d}$ leptonic modes and hence,
can provide an ideal testing ground to look for new physics beyond the standard
model. We work out the constraint on new physics parameter space using the
measured branching ratios of $B_{d, s} \to \mu^+ \mu^-$ processes and the $B_q
- \bar B_q$ mixing data. Using the constrained parameters we estimate the
branching ratios of $B_{d,s} \to \mu^+ \mu^-~(e^+ e^-)$ processes. We find that
the branching ratios are reasonably enhanced from their corresponding standard
model values in the $X(3,2,1/6)$ leptoquark model and are expected to be within
the reach of Run II/III of LHC experiments.
| [
{
"created": "Thu, 8 Dec 2016 06:38:29 GMT",
"version": "v1"
}
] | 2017-03-08 | [
[
"Sahoo",
"Suchismita",
""
],
[
"Mohanta",
"Rukmani",
""
]
] | We investigate the effect of scalar leptoquarks and family non-universal $Z^\prime$ boson on the rare leptonic decays of $B_{s, d}^*$ mesons, mediated by the FCNC transitions $b \to (d, s) l^+ l^-$. They are sensitive to a variety of new physics operators as opposed to the $B_{s,d}$ leptonic modes and hence, can provide an ideal testing ground to look for new physics beyond the standard model. We work out the constraint on new physics parameter space using the measured branching ratios of $B_{d, s} \to \mu^+ \mu^-$ processes and the $B_q - \bar B_q$ mixing data. Using the constrained parameters we estimate the branching ratios of $B_{d,s} \to \mu^+ \mu^-~(e^+ e^-)$ processes. We find that the branching ratios are reasonably enhanced from their corresponding standard model values in the $X(3,2,1/6)$ leptoquark model and are expected to be within the reach of Run II/III of LHC experiments. |
hep-ph/9705309 | Wim deBoer | W. de Boer | In Search of SUSY | latex + 12 eps figs, 22 pages | Acta Phys.Polon.B28:1395-1418,1997 | null | IEKP-KA/97-03 | hep-ph | null | Electroweak precision tests of the SM and MSSM as well as searches for
Supersymmetric Particles and Higgs bosons at LEP II and their significance
within the MSSM are discussed. Invited talk presented at the EPIPHANY Conf. in
Cracow, Jan. 3-7, 1997.
| [
{
"created": "Tue, 13 May 1997 23:30:30 GMT",
"version": "v1"
},
{
"created": "Wed, 14 May 1997 14:25:45 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"de Boer",
"W.",
""
]
] | Electroweak precision tests of the SM and MSSM as well as searches for Supersymmetric Particles and Higgs bosons at LEP II and their significance within the MSSM are discussed. Invited talk presented at the EPIPHANY Conf. in Cracow, Jan. 3-7, 1997. |
hep-ph/9704414 | James V. Steele | James V. Steele, Hidenaga Yamagishi, and Ismail Zahed | Dilepton and Photon Emission Rates from a Hadronic Gas II | 12 pages revTeX, 7 figures, uses feynmp | Phys.Rev.D56:5605-5617,1997 | 10.1103/PhysRevD.56.5605 | null | hep-ph nucl-th | null | We extend our recent analysis of the dilepton and photon emission rates to
the case of finite temperature and baryon density, within the context of a
density expansion. To leading order, the effects of the baryon density are
assessed using data (photon emission) or constraints from broken chiral
symmetry (dilepton emission). Next to leading order effects are worked out, and
their contribution qualitatively assessed. The opening of the $\pi N$ cut
causes the photon rate to saturate the empirical photon yield of WA80, but may
not be enough to fully account for the excess low mass dileptons seen at CERES.
| [
{
"created": "Mon, 28 Apr 1997 04:23:23 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Apr 1997 02:48:59 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Steele",
"James V.",
""
],
[
"Yamagishi",
"Hidenaga",
""
],
[
"Zahed",
"Ismail",
""
]
] | We extend our recent analysis of the dilepton and photon emission rates to the case of finite temperature and baryon density, within the context of a density expansion. To leading order, the effects of the baryon density are assessed using data (photon emission) or constraints from broken chiral symmetry (dilepton emission). Next to leading order effects are worked out, and their contribution qualitatively assessed. The opening of the $\pi N$ cut causes the photon rate to saturate the empirical photon yield of WA80, but may not be enough to fully account for the excess low mass dileptons seen at CERES. |
hep-ph/0403265 | Thomas Kernreiter | A. Bartl, K. Hohenwarter-Sodek, T. Kernreiter, H. Rud | CP sensitive observables in chargino production with transverse
$e^{\pm}$ beam polarization | 19 pages, 6 figures | Eur.Phys.J. C36 (2004) 515-522 | 10.1140/epjc/s2004-01973-3 | null | hep-ph | null | We consider the process $e^+e^-\to\ti\chi^+_i\ti\chi^-_j$ at a linear
collider with transverse $e^{\pm}$ beam polarization. We investigate the
influence of the CP phases on azimuthal asymmetries in
$e^+e^-\to\ti\chi^+_i\ti\chi^-_j$ with subsequent two-body decays
$\ti\chi^-_j\to \ti\nu_{\ell}\ell^-$ and $\ti\chi^-_j\to W^-\ti\chi^0_1$. We
show that triple product correlations involving the transverse $e^{\pm}$ beam
polarization vanish if at least one subsequent chargino decay is not observed.
We derive this result within the Minimal Supersymmetric Standard Model (MSSM)
with complex parameters, however, it holds also in the general MSSM with SUSY
flavour violation.
| [
{
"created": "Thu, 25 Mar 2004 13:15:41 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Jul 2004 10:29:27 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Bartl",
"A.",
""
],
[
"Hohenwarter-Sodek",
"K.",
""
],
[
"Kernreiter",
"T.",
""
],
[
"Rud",
"H.",
""
]
] | We consider the process $e^+e^-\to\ti\chi^+_i\ti\chi^-_j$ at a linear collider with transverse $e^{\pm}$ beam polarization. We investigate the influence of the CP phases on azimuthal asymmetries in $e^+e^-\to\ti\chi^+_i\ti\chi^-_j$ with subsequent two-body decays $\ti\chi^-_j\to \ti\nu_{\ell}\ell^-$ and $\ti\chi^-_j\to W^-\ti\chi^0_1$. We show that triple product correlations involving the transverse $e^{\pm}$ beam polarization vanish if at least one subsequent chargino decay is not observed. We derive this result within the Minimal Supersymmetric Standard Model (MSSM) with complex parameters, however, it holds also in the general MSSM with SUSY flavour violation. |
0910.4058 | Luca Merlo | Ferruccio Feruglio, Claudia Hagedorn, Luca Merlo | Vacuum Alignment in SUSY A4 Models | 23 pages; added a new section on the relation to Supergravity;
version accepted for publication in JHEP | JHEP 1003:084,2010 | 10.1007/JHEP03(2010)084 | DFPF-09/TH/18, SISSA 66/2009/EP | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note we discuss the vacuum alignment in supersymmetric models with
spontaneously broken flavour symmetries in the presence of soft supersymmetry
(SUSY) breaking terms. We show that the inclusion of soft SUSY breaking terms
can give rise to non-vanishing vacuum expectation values (VEVs) for the
auxiliary components of the flavon fields. These non-zero VEVs can have an
important impact on the phenomenology of this class of models, since they can
induce an additional flavour violating contribution to the sfermion soft mass
matrix of right-left (RL) type. We carry out an explicit computation in a class
of SUSY A4 models predicting tri-bimaximal mixing in the lepton sector. The
flavour symmetry breaking sector is described in terms of flavon and driving
supermultiplets. We find non-vanishing VEVs for the auxiliary components of the
flavon fields and for the scalar components of the driving fields which are of
order m_{SUSY} x <phi> and m_{SUSY}, respectively. Thereby, m_{SUSY} is the
generic soft SUSY breaking scale which is expected to be around 1 TeV and <phi>
is the VEV of scalar components of the flavon fields. Another effect of these
VEVs can be the generation of a mu term.
| [
{
"created": "Wed, 21 Oct 2009 11:42:23 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Mar 2010 16:12:20 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Feruglio",
"Ferruccio",
""
],
[
"Hagedorn",
"Claudia",
""
],
[
"Merlo",
"Luca",
""
]
] | In this note we discuss the vacuum alignment in supersymmetric models with spontaneously broken flavour symmetries in the presence of soft supersymmetry (SUSY) breaking terms. We show that the inclusion of soft SUSY breaking terms can give rise to non-vanishing vacuum expectation values (VEVs) for the auxiliary components of the flavon fields. These non-zero VEVs can have an important impact on the phenomenology of this class of models, since they can induce an additional flavour violating contribution to the sfermion soft mass matrix of right-left (RL) type. We carry out an explicit computation in a class of SUSY A4 models predicting tri-bimaximal mixing in the lepton sector. The flavour symmetry breaking sector is described in terms of flavon and driving supermultiplets. We find non-vanishing VEVs for the auxiliary components of the flavon fields and for the scalar components of the driving fields which are of order m_{SUSY} x <phi> and m_{SUSY}, respectively. Thereby, m_{SUSY} is the generic soft SUSY breaking scale which is expected to be around 1 TeV and <phi> is the VEV of scalar components of the flavon fields. Another effect of these VEVs can be the generation of a mu term. |
1508.01112 | Michele Redi | Oleg Antipin and Michele Redi | The Half-composite Two Higgs Doublet Model and the Relaxion | 16 pages. v2 minor changes; v3 typos fixed | null | 10.1007/JHEP12(2015)031 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a new confining gauge theory with fermions in a vectorial
representation under the SM gauge group that allows for Yukawa interactions
with the Higgs. If the fermion masses are smaller than the confinement scale
this realizes a type I two Higgs doublet model where a composite Higgs mixes
with the elementary Higgs. This class of models interpolates between an
elementary and a composite Higgs and has interesting phenomenology with
potentially observables effects in collider physics, EDMs and SM couplings but
very weak bounds from indirect searches. The very same framework can be used to
realize the cosmological relaxation of the electro-weak scale recently
discussed in the literature.
| [
{
"created": "Wed, 5 Aug 2015 15:53:46 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Oct 2015 16:08:50 GMT",
"version": "v2"
},
{
"created": "Fri, 8 Jun 2018 13:38:18 GMT",
"version": "v3"
}
] | 2018-06-11 | [
[
"Antipin",
"Oleg",
""
],
[
"Redi",
"Michele",
""
]
] | We study a new confining gauge theory with fermions in a vectorial representation under the SM gauge group that allows for Yukawa interactions with the Higgs. If the fermion masses are smaller than the confinement scale this realizes a type I two Higgs doublet model where a composite Higgs mixes with the elementary Higgs. This class of models interpolates between an elementary and a composite Higgs and has interesting phenomenology with potentially observables effects in collider physics, EDMs and SM couplings but very weak bounds from indirect searches. The very same framework can be used to realize the cosmological relaxation of the electro-weak scale recently discussed in the literature. |
1204.1700 | LiPing Sun | Cong-Feng Qiao, Li-Ping Sun | $J/\psi$ Pair Production at the Tevatron with
$\sqrt{s}=1.96~\mathrm{TeV} | 5 pages, 3 figures, to appear in Chinese Physics C | null | 10.1088/1674-1137/37/3/033105 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the $J/\psi$ pair production issue at the Fermilab Tevatron Run II
with the center-of-mass energy $\sqrt{s}=1.96 \mathrm{TeV}$. Both color-singlet
and -octet production mechanisms are considered. Our result shows that the
transverse momentum($p_T$) scaling behaviors of double $J/\psi$ differential
cross sections in color-singlet and -octet deviate distinctively from each
other while $p_T$ is larger than $8 \mathrm{GeV}$, and with the luminosity of
${5 \mathrm{fb^{-1}}}$ the $J/\psi$ pair events from color-singlet scheme are
substantially measurable in Tevatron experiments, even with certain lower
transverse momentum cut. Hence the Tevatron is still possibly a platform to
check the heavy quarkonium production mechanism.
| [
{
"created": "Sun, 8 Apr 2012 02:48:32 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Jun 2012 07:20:47 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Qiao",
"Cong-Feng",
""
],
[
"Sun",
"Li-Ping",
""
]
] | We revisit the $J/\psi$ pair production issue at the Fermilab Tevatron Run II with the center-of-mass energy $\sqrt{s}=1.96 \mathrm{TeV}$. Both color-singlet and -octet production mechanisms are considered. Our result shows that the transverse momentum($p_T$) scaling behaviors of double $J/\psi$ differential cross sections in color-singlet and -octet deviate distinctively from each other while $p_T$ is larger than $8 \mathrm{GeV}$, and with the luminosity of ${5 \mathrm{fb^{-1}}}$ the $J/\psi$ pair events from color-singlet scheme are substantially measurable in Tevatron experiments, even with certain lower transverse momentum cut. Hence the Tevatron is still possibly a platform to check the heavy quarkonium production mechanism. |
hep-ph/0505027 | Fredy Ochoa | Fredy Ochoa and R. Martinez | Family Dependence in SU(3)_C X SU(3)_L X U(1)_X models | 14 pages, 2 figures, LaTeX2e; added references, added equations with
electroweak corrections for section 4. Version to appear in Phys. Rev. D | Phys.Rev.D72:035010,2005 | 10.1103/PhysRevD.72.035010 | null | hep-ph | null | Using experimental results at the Z-pole and atomic parity violation, we
perform a chi-squared fit at 95% CL to obtain family-dependent bounds to Z_2
mass and Z-Z' mixing angle in the framework of SU(3)_C X SU(3)_L X U(1)_X
models. The allowed regions depend on the assignment of the quark families in
mass eigenstates into the three different families in weak eigenstates that
cancel anomalies
| [
{
"created": "Wed, 4 May 2005 21:32:13 GMT",
"version": "v1"
},
{
"created": "Sat, 6 Aug 2005 19:39:25 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Ochoa",
"Fredy",
""
],
[
"Martinez",
"R.",
""
]
] | Using experimental results at the Z-pole and atomic parity violation, we perform a chi-squared fit at 95% CL to obtain family-dependent bounds to Z_2 mass and Z-Z' mixing angle in the framework of SU(3)_C X SU(3)_L X U(1)_X models. The allowed regions depend on the assignment of the quark families in mass eigenstates into the three different families in weak eigenstates that cancel anomalies |
1003.5663 | Kentaro Hanaki | Kentaro Hanaki and Yutaka Ookouchi | Light Gauginos and Conformal Sequestering | 17 pages, 1 figure. References added | Phys.Rev.D83:125010,2011 | 10.1103/PhysRevD.83.125010 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a wide class of direct and semi-direct gauge mediation models, it has been
observed that the gaugino masses vanish at leading order. It implies that there
is a hierarchy between the gaugino and sfermion masses, invoking a fine-tuning
problem in the Higgs sector via radiative corrections. In this paper, we
explore the possibility of solving this anomalously light gaugino problem
exploiting strong conformal dynamics in the hidden sector. With a mild
assumption on the anomalous dimensions of the hidden sector operators, we show
that the next to leading order contributions to the gaugino masses can
naturally be in the same order as the sfermion masses. \mu/B_\mu problem is
also discussed.
| [
{
"created": "Mon, 29 Mar 2010 20:04:18 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Apr 2010 21:37:10 GMT",
"version": "v2"
}
] | 2011-06-21 | [
[
"Hanaki",
"Kentaro",
""
],
[
"Ookouchi",
"Yutaka",
""
]
] | In a wide class of direct and semi-direct gauge mediation models, it has been observed that the gaugino masses vanish at leading order. It implies that there is a hierarchy between the gaugino and sfermion masses, invoking a fine-tuning problem in the Higgs sector via radiative corrections. In this paper, we explore the possibility of solving this anomalously light gaugino problem exploiting strong conformal dynamics in the hidden sector. With a mild assumption on the anomalous dimensions of the hidden sector operators, we show that the next to leading order contributions to the gaugino masses can naturally be in the same order as the sfermion masses. \mu/B_\mu problem is also discussed. |
2001.08153 | Arkaitz Rodas | J.R. Pel\'aez, A. Rodas | Determination of the lightest strange resonance $K_0^*(700)$ or
$\kappa$, from a dispersive data analysis | 6 pages, 3 figures, 2 tables. References, comments, clarifications
and 1 table added. Minor typos corrected. Version to appear on Phys.Rev.Lett | Phys. Rev. Lett. 124, 172001 (2020) | 10.1103/PhysRevLett.124.172001 | JLAB-THY-20-3166 | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we present a precise and model-independent dispersive
determination from data of the existence and parameters of the lightest strange
resonance $\kappa/K_0^*(700)$. We use both subtracted and unsubtracted
partial-wave hyperbolic and fixed-$t$ dispersion relations as constraints on
combined fits to $\pi K\rightarrow\pi K$ and $\pi\pi\rightarrow K\bar K$ data.
We then use the hyperbolic equations for the analytic continuation of the
isospin $I=1/2$ scalar partial wave to the complex plane, in order to determine
the $\kappa/K_0^*(700)$ and $K^*(892)$ associated pole parameters and residues.
| [
{
"created": "Wed, 22 Jan 2020 17:25:30 GMT",
"version": "v1"
},
{
"created": "Fri, 1 May 2020 18:19:37 GMT",
"version": "v2"
}
] | 2020-05-05 | [
[
"Peláez",
"J. R.",
""
],
[
"Rodas",
"A.",
""
]
] | In this work we present a precise and model-independent dispersive determination from data of the existence and parameters of the lightest strange resonance $\kappa/K_0^*(700)$. We use both subtracted and unsubtracted partial-wave hyperbolic and fixed-$t$ dispersion relations as constraints on combined fits to $\pi K\rightarrow\pi K$ and $\pi\pi\rightarrow K\bar K$ data. We then use the hyperbolic equations for the analytic continuation of the isospin $I=1/2$ scalar partial wave to the complex plane, in order to determine the $\kappa/K_0^*(700)$ and $K^*(892)$ associated pole parameters and residues. |
1601.08094 | Max Zoller | Max F. Zoller | On the renormalization of operator products: the scalar gluonic case | v2: this is the version accepted by JHEP; more detailed discussion of
phenomenological applications | JHEP 1604 (2016) 165 | 10.1007/JHEP04(2016)165 | ZU-TH-4/16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we study the renormalization of the product of two operators
$O_1=-\frac{1}{4} G^{\mu \nu}G_{\mu \nu}$ in QCD. An insertion of two such
operators $O_1(x)O_1(0)$ into a Greens function produces divergent contact
terms for $x\rightarrow 0$.
In the course of the computation of the operator product expansion (OPE) of
the correlator of two such operators $i\int\!\mathrm{d}^4x\,e^{iqx}
T\{\,O_1(x)O_1(0)\}$ to three-loop order we discovered that divergent contact
terms remain not only in the leading Wilson coefficient $C_0$, which is just
the VEV of the correlator, but also in the Wilson coefficient $C_1$ in front of
$O_1$. As this correlator plays an important role for example in QCD sum rules
a full understanding of its renormalization is desireable.
This work explains how the divergences encountered in higher orders of an OPE
of this correlator should be absorbed in counterterms and derives an additive
renormalization constant for $C_1$ from first principles and to all orders in
perturnbation theory. The method to derive the renormalization of this operator
product is an extension of the ideas of a paper by Spiridonov and can be
generalized to other cases.
| [
{
"created": "Fri, 29 Jan 2016 13:25:33 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Apr 2016 10:49:48 GMT",
"version": "v2"
}
] | 2017-07-25 | [
[
"Zoller",
"Max F.",
""
]
] | In this paper we study the renormalization of the product of two operators $O_1=-\frac{1}{4} G^{\mu \nu}G_{\mu \nu}$ in QCD. An insertion of two such operators $O_1(x)O_1(0)$ into a Greens function produces divergent contact terms for $x\rightarrow 0$. In the course of the computation of the operator product expansion (OPE) of the correlator of two such operators $i\int\!\mathrm{d}^4x\,e^{iqx} T\{\,O_1(x)O_1(0)\}$ to three-loop order we discovered that divergent contact terms remain not only in the leading Wilson coefficient $C_0$, which is just the VEV of the correlator, but also in the Wilson coefficient $C_1$ in front of $O_1$. As this correlator plays an important role for example in QCD sum rules a full understanding of its renormalization is desireable. This work explains how the divergences encountered in higher orders of an OPE of this correlator should be absorbed in counterterms and derives an additive renormalization constant for $C_1$ from first principles and to all orders in perturnbation theory. The method to derive the renormalization of this operator product is an extension of the ideas of a paper by Spiridonov and can be generalized to other cases. |
hep-ph/0302156 | Olivier Leitner | Z.J. Ajaltouni (LPC), O. Leitner (CSSM, LPC), P. Perret (LPC), C.
Rimbault (LPC), A.W. Thomas (CSSM) | Direct CP Violation In B --> pi^+ pi^- V With rho^0--omega Mixing
Effects: Phenomenological Approach | 39 pages, 11 figures, 7 tables. Misprints corrected and comments
added in pages 5, 17 and 19 | Eur.Phys.J.C29:215-233,2003 | 10.1140/epjc/s2003-01219-0 | ADP-03-111/T549, PCCF-RI-03-03 | hep-ph | null | We present a detailed study of direct CP violation and branching ratios in
the channels $B^{0,\pm} \to \pi^{+}\pi^{-} V^{0,\pm}$, where $V$ is a vector
meson ($K^{*
0,\pm}$ or $\rho^{\pm}$). Emphasis is placed upon the important role played
by ${{\rho}^{0}}-{\omega}$ mixing effects in the estimation of the CP-violating
asymmetry parameter, $a_{cp}$, associated with the difference of $B$ and $\bar
B$ decay amplitudes. A thorough study of the helicity amplitudes is presented
as a function of the pion-pion invariant mass. All of the calculations and
simulations considered correspond to channels which will be analyzed at the
LHCb facility.
| [
{
"created": "Tue, 18 Feb 2003 11:26:40 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Jul 2003 09:43:26 GMT",
"version": "v2"
}
] | 2009-01-07 | [
[
"Ajaltouni",
"Z. J.",
"",
"LPC"
],
[
"Leitner",
"O.",
"",
"CSSM, LPC"
],
[
"Perret",
"P.",
"",
"LPC"
],
[
"Rimbault",
"C.",
"",
"LPC"
],
[
"Thomas",
"A. W.",
"",
"CSSM"
]
] | We present a detailed study of direct CP violation and branching ratios in the channels $B^{0,\pm} \to \pi^{+}\pi^{-} V^{0,\pm}$, where $V$ is a vector meson ($K^{* 0,\pm}$ or $\rho^{\pm}$). Emphasis is placed upon the important role played by ${{\rho}^{0}}-{\omega}$ mixing effects in the estimation of the CP-violating asymmetry parameter, $a_{cp}$, associated with the difference of $B$ and $\bar B$ decay amplitudes. A thorough study of the helicity amplitudes is presented as a function of the pion-pion invariant mass. All of the calculations and simulations considered correspond to channels which will be analyzed at the LHCb facility. |
2307.11148 | \'Alvaro Pastor Guti\'errez | Florian Goertz, \'Alvaro Pastor-Guti\'errez and Jan M. Pawlowski | Flavour hierarchies from emergent fundamental partial compositeness | 16 pages, 4 figures | null | null | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | Composite Higgs extensions of the Standard Model provide an explanation for
the large hierarchies between the Yukawa couplings. We study their realisation
in the context of fundamental partial compositeness where the Standard Model
fermions mix linearly with bound states of the new sector, consisting of a
fermion and a scalar. The properties of this composite are unravelled with the
functional renormalisation group approach using dynamically emergent
composites. Specifically, we extract the scaling of correlation functions and
provide indicative estimates for the minimal incarnation of the theory.
| [
{
"created": "Thu, 20 Jul 2023 18:00:01 GMT",
"version": "v1"
}
] | 2023-07-24 | [
[
"Goertz",
"Florian",
""
],
[
"Pastor-Gutiérrez",
"Álvaro",
""
],
[
"Pawlowski",
"Jan M.",
""
]
] | Composite Higgs extensions of the Standard Model provide an explanation for the large hierarchies between the Yukawa couplings. We study their realisation in the context of fundamental partial compositeness where the Standard Model fermions mix linearly with bound states of the new sector, consisting of a fermion and a scalar. The properties of this composite are unravelled with the functional renormalisation group approach using dynamically emergent composites. Specifically, we extract the scaling of correlation functions and provide indicative estimates for the minimal incarnation of the theory. |
hep-ph/9305269 | Vladimir Braun | I.I. Balitsky and V.M. Braun | Instanton-induced contributions to structure functions of deep inelastic
scattering | MPI-Ph/92-89 , LATEX, 15 pages, 3 figures incl. as uu-encoded file | Phys.Lett. B314 (1993) 237-245 | 10.1016/0370-2693(93)90455-Q | null | hep-ph | null | We identify and calculate the instanton-induced contributions to deep
inelastic scattering which correspond to nonperturbative exponential
corrections to the coefficient functions in front of parton distributions of
the leading twist.
| [
{
"created": "Fri, 14 May 1993 17:02:51 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Balitsky",
"I. I.",
""
],
[
"Braun",
"V. M.",
""
]
] | We identify and calculate the instanton-induced contributions to deep inelastic scattering which correspond to nonperturbative exponential corrections to the coefficient functions in front of parton distributions of the leading twist. |
2306.16804 | Azad Inshalla oglu Ahmadov | Azad I. Ahmadov | Total cross section of the process $e^+ + e^- \to \Sigma^0 +
\bar{\Sigma}^0$ in the vicinity of charmonium $\psi (3770)$ including the
$D$-meson loop and three gluon contributions | 25 pages, 10 figures, 1 table | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For the study of the structure of baryons it is necessary to investigate the
production of a baryon pair in $e^+e^-$ annihilation. The baryon-antibaryon
pair production at the electron-positron linear collider makes it possible to
investigate in detail the basic structure of the Standard Model. The creation
of baryon-antibaryon pairs in electron-positron annihilation provides an
increasingly powerful tool at higher c.m. energies. We present phenomenological
results for $\Sigma^0 \bar {\Sigma}^0$ production in $e^+e^-$ interaction at
the BESIII and BABAR Colliders. In the present work, we investigate a hyperon
pair produced in the reaction $e^+e^- \to \Sigma^0 \bar{\Sigma}^0$. We
calculate the total cross section of the process $e^+e^- \to \Sigma^0 \bar
{\Sigma}^0$ taking into account the contributions of the $D$-meson loop and
three gluon loops as well as the interference of all diagrams to the Born
approximation. For these contributions large relative phases are generated with
respect to the pure electromagnetic mechanism. For the large momentum
transferred region we obtain as a byproduct a fit of the electromagnetic form
factor of the $\Sigma$ hyperon.
| [
{
"created": "Thu, 29 Jun 2023 09:30:15 GMT",
"version": "v1"
},
{
"created": "Tue, 28 May 2024 12:45:45 GMT",
"version": "v2"
}
] | 2024-05-29 | [
[
"Ahmadov",
"Azad I.",
""
]
] | For the study of the structure of baryons it is necessary to investigate the production of a baryon pair in $e^+e^-$ annihilation. The baryon-antibaryon pair production at the electron-positron linear collider makes it possible to investigate in detail the basic structure of the Standard Model. The creation of baryon-antibaryon pairs in electron-positron annihilation provides an increasingly powerful tool at higher c.m. energies. We present phenomenological results for $\Sigma^0 \bar {\Sigma}^0$ production in $e^+e^-$ interaction at the BESIII and BABAR Colliders. In the present work, we investigate a hyperon pair produced in the reaction $e^+e^- \to \Sigma^0 \bar{\Sigma}^0$. We calculate the total cross section of the process $e^+e^- \to \Sigma^0 \bar {\Sigma}^0$ taking into account the contributions of the $D$-meson loop and three gluon loops as well as the interference of all diagrams to the Born approximation. For these contributions large relative phases are generated with respect to the pure electromagnetic mechanism. For the large momentum transferred region we obtain as a byproduct a fit of the electromagnetic form factor of the $\Sigma$ hyperon. |
1607.07324 | Aaron Higuera | A. Higuera | Results and Prospects from the Daya Bay Reactor Neutrino Experiment | Presented at the Seventh Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 20-24, 2016 | null | null | null | hep-ph physics.ins-det | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Daya Bay reactor experiment has reported the most precise measurement of
sin$^{2}2\theta_{13}$ and $\Delta m^{2}_{ee}$ by using a data set with the
fully constructed design of 8 antineutrino detectors (ADs). We also report on a
new independent measurement of sin$^{2}2\theta_{13}$ from neutron capture on
hydrogen, which confirms the results using gadolinium caputres. Several other
analyses are also performed, including a measurements on the absolute reactor
antineutrino flux and a search for light sterile neutrinos. Prospects for new
analyses such as searching for CPT/LI violation at Daya Bay are ongoing.
| [
{
"created": "Mon, 25 Jul 2016 15:48:56 GMT",
"version": "v1"
}
] | 2016-07-26 | [
[
"Higuera",
"A.",
""
]
] | The Daya Bay reactor experiment has reported the most precise measurement of sin$^{2}2\theta_{13}$ and $\Delta m^{2}_{ee}$ by using a data set with the fully constructed design of 8 antineutrino detectors (ADs). We also report on a new independent measurement of sin$^{2}2\theta_{13}$ from neutron capture on hydrogen, which confirms the results using gadolinium caputres. Several other analyses are also performed, including a measurements on the absolute reactor antineutrino flux and a search for light sterile neutrinos. Prospects for new analyses such as searching for CPT/LI violation at Daya Bay are ongoing. |
hep-ph/9409203 | Frank Close | Frank Close | New Metastable Charmonium and the $\psi '$ Anomaly at CDF | 11 pages, no figures. RAL-94-093 | Phys.Lett. B342 (1995) 369-374 | 10.1016/0370-2693(94)01360-O | null | hep-ph | null | Production of metastable charmonium states more massive than the $\psi(3685)$
is expected in models and could be the source of up to $50\%$ of the $\psi$
observed at large $p_T$ at the Tevatron.Narrow $2^{-+},2^{--} c\bar{c}$ are
predicted at around 3.8GeV and radially excited $2^3P_{1,2}$ may also have
suppressed hadronic widths making these states potentially extra sources of
$\psi(3685)$. Colour octet components are believed to dominate $\psi$
production at the Tevatron which suggests that hybrid charmonium production may
also be prominent. Estimates of hybrid production rates and branching ratios
into charmonium suggest that metastable hybrids with mass $\approx$ 4GeV may
play an important role in generating the observed $\psi(3685),\psi(3095)$
| [
{
"created": "Thu, 1 Sep 1994 16:54:00 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Close",
"Frank",
""
]
] | Production of metastable charmonium states more massive than the $\psi(3685)$ is expected in models and could be the source of up to $50\%$ of the $\psi$ observed at large $p_T$ at the Tevatron.Narrow $2^{-+},2^{--} c\bar{c}$ are predicted at around 3.8GeV and radially excited $2^3P_{1,2}$ may also have suppressed hadronic widths making these states potentially extra sources of $\psi(3685)$. Colour octet components are believed to dominate $\psi$ production at the Tevatron which suggests that hybrid charmonium production may also be prominent. Estimates of hybrid production rates and branching ratios into charmonium suggest that metastable hybrids with mass $\approx$ 4GeV may play an important role in generating the observed $\psi(3685),\psi(3095)$ |
hep-ph/0604009 | Biswajit Adhikary | Biswajit Adhikary | Soft breaking of $L_\mu-L_\tau$ symmetry: Light neutrino spectrum and
Leptogenesis | 21 pages, no figure, Revised with the comments on RG effect | Phys.Rev. D74 (2006) 033002 | 10.1103/PhysRevD.74.033002 | SINP/TNP/06-12 | hep-ph | null | Continuous $U(1)_{L_\mu-L_\tau}$ symmetry can generate quasi degenerate mass
spectrum for both left handed light and right handed heavy Majorana neutrinos
assuming that the symmetry preserving non zero parameters are nearly same.
There is an accidental $\mu\tau$ exchange symmetry in the light and heavy
neutrino Majorana mass terms. This implies $\theta_{13}=0$ and
$\theta_{23}=\frac{\pi}{4}$. In addition it generates another zero mixing angle
and one zero mass difference. We restrict ourselves to type-I See-Saw mechanism
for generation of light neutrino mass. We have found that under
$U(1)_{L_\mu-L_\tau}$ symmetry cosmological lepton asymmetry vanishes. We break
$U(1)_{L_\mu-L_\tau}$ such a way that the $\mu\tau$ exchange symmetry preserves
in the neutrino sector. We have seen that light neutrino phenomenology can be
explained under soft breaking of this symmetry. We have observed that softness
of this symmetry breaking depends on the degeneracy of the light neutrino mass
spectrum. Quasi-degeneracy of right handed neutrino mass spectrum opens an
option for resonant leptogenesis. The degeneracy of the right handed neutrino
mass spectrum is restricted through light neutrino data. We observed that for
generation of right sized baryon asymmetry common neutrino mass scale $m_0$
have to be of the order of $\sqrt{\Delta m^2_{\rm atm}}$ and corresponding
right handed neutrino mass scale have to be nearly $10^{13}$ GeV. We also have
discussed the effect of RG evolution on light neutrino spectrum and also on
baryon asymmetry.
| [
{
"created": "Mon, 3 Apr 2006 15:32:25 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Jul 2006 13:15:01 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Adhikary",
"Biswajit",
""
]
] | Continuous $U(1)_{L_\mu-L_\tau}$ symmetry can generate quasi degenerate mass spectrum for both left handed light and right handed heavy Majorana neutrinos assuming that the symmetry preserving non zero parameters are nearly same. There is an accidental $\mu\tau$ exchange symmetry in the light and heavy neutrino Majorana mass terms. This implies $\theta_{13}=0$ and $\theta_{23}=\frac{\pi}{4}$. In addition it generates another zero mixing angle and one zero mass difference. We restrict ourselves to type-I See-Saw mechanism for generation of light neutrino mass. We have found that under $U(1)_{L_\mu-L_\tau}$ symmetry cosmological lepton asymmetry vanishes. We break $U(1)_{L_\mu-L_\tau}$ such a way that the $\mu\tau$ exchange symmetry preserves in the neutrino sector. We have seen that light neutrino phenomenology can be explained under soft breaking of this symmetry. We have observed that softness of this symmetry breaking depends on the degeneracy of the light neutrino mass spectrum. Quasi-degeneracy of right handed neutrino mass spectrum opens an option for resonant leptogenesis. The degeneracy of the right handed neutrino mass spectrum is restricted through light neutrino data. We observed that for generation of right sized baryon asymmetry common neutrino mass scale $m_0$ have to be of the order of $\sqrt{\Delta m^2_{\rm atm}}$ and corresponding right handed neutrino mass scale have to be nearly $10^{13}$ GeV. We also have discussed the effect of RG evolution on light neutrino spectrum and also on baryon asymmetry. |
hep-ph/9704203 | Leonard Haakman | L.P.A. Haakman (NIKHEF), A.B. Kaidalov (ITEP), J.H. Koch (NIKHEF) | Charm production in deep inelastic and diffractive scattering | 14 pages REVTEX and 24 figures included | Eur.Phys.J.C1:547-561,1998 | 10.1007/s100520050104 | NIKHEF 97-015 | hep-ph | null | We consider the production of charm by real and virtual photons. Special
attention is paid to diffractive charm production, which provides information
on the gluonic content of the Pomeron. Our calculations are based on the gluon
distributions of the CKMT-model, which is shown to lead to agreement with the
data on open charm production in deep inelastic scattering. We compare
predictions for diffractive charm production of different models for the
distribution of gluons in the Pomeron. Experiments at HERA should be able to
discriminate between them. Predictions for beauty production in diffractive and
non-diffractive interactions of photons are also given.
| [
{
"created": "Tue, 1 Apr 1997 10:25:29 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Haakman",
"L. P. A.",
"",
"NIKHEF"
],
[
"Kaidalov",
"A. B.",
"",
"ITEP"
],
[
"Koch",
"J. H.",
"",
"NIKHEF"
]
] | We consider the production of charm by real and virtual photons. Special attention is paid to diffractive charm production, which provides information on the gluonic content of the Pomeron. Our calculations are based on the gluon distributions of the CKMT-model, which is shown to lead to agreement with the data on open charm production in deep inelastic scattering. We compare predictions for diffractive charm production of different models for the distribution of gluons in the Pomeron. Experiments at HERA should be able to discriminate between them. Predictions for beauty production in diffractive and non-diffractive interactions of photons are also given. |
2004.11990 | Xiaohui Liu | Hao-Yu Liu, Zhong-Bo Kang, Xiaohui Liu | Threshold Resummation for Hadron Production in the Small-$x$ Region | 6 pages, 3 figures, add comments on resummation and scale
independence. Published in PRD as a rapid communication | Phys. Rev. D 102, 051502 (2020) | 10.1103/PhysRevD.102.051502 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the single hadron inclusive production in the forward rapidity
region in proton-nucleus collisions. We find the long-standing negative cross
section at next-to-leading-order (NLO) is driven by the large negative
threshold logarithmic contributions. We established a factorization theorem for
resumming these logarithms with systematically improvable accuracy within the
color glass condensate formalism. We demonstrate how the threshold leading
logarithmic accuracy can be realized by a suitable scale choice in the NLO
results. The NLO spectrums with the threshold logarithms resummed remain
positive and impressive agreements with experimental data are observed.
| [
{
"created": "Fri, 24 Apr 2020 21:03:30 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Nov 2020 01:09:32 GMT",
"version": "v2"
}
] | 2020-12-01 | [
[
"Liu",
"Hao-Yu",
""
],
[
"Kang",
"Zhong-Bo",
""
],
[
"Liu",
"Xiaohui",
""
]
] | We study the single hadron inclusive production in the forward rapidity region in proton-nucleus collisions. We find the long-standing negative cross section at next-to-leading-order (NLO) is driven by the large negative threshold logarithmic contributions. We established a factorization theorem for resumming these logarithms with systematically improvable accuracy within the color glass condensate formalism. We demonstrate how the threshold leading logarithmic accuracy can be realized by a suitable scale choice in the NLO results. The NLO spectrums with the threshold logarithms resummed remain positive and impressive agreements with experimental data are observed. |
1209.0408 | Dmitri Antonov | Dmitri Antonov and Jose Emilio F. T. Ribeiro | Quark condensate for various heavy flavors | 12 pages, 2 figures, to appear in Eur. Phys. J. C | Eur.Phys.J. C72 (2012) 2179 | 10.1140/epjc/s10052-012-2179-7 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The quark condensate is calculated within the world-line effective-action
formalism, by using for the Wilson loop an ansatz provided by the stochastic
vacuum model. Starting with the relation between the quark and the gluon
condensates in the heavy-quark limit, we diminish the current quark mass down
to the value of the inverse vacuum correlation length, finding in this way a
64%-decrease in the absolute value of the quark condensate. In particular, we
find that the conventional formula for the heavy-quark condensate cannot be
applied to the c-quark, and that the corrections to this formula can reach 23%
even in the case of the b-quark. We also demonstrate that, for an exponential
parametrization of the two-point correlation function of gluonic field
strengths, the quark condensate does not depend on the non-confining
non-perturbative interactions of the stochastic background Yang-Mills fields.
| [
{
"created": "Mon, 3 Sep 2012 17:10:56 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Oct 2012 18:14:07 GMT",
"version": "v2"
}
] | 2012-10-16 | [
[
"Antonov",
"Dmitri",
""
],
[
"Ribeiro",
"Jose Emilio F. T.",
""
]
] | The quark condensate is calculated within the world-line effective-action formalism, by using for the Wilson loop an ansatz provided by the stochastic vacuum model. Starting with the relation between the quark and the gluon condensates in the heavy-quark limit, we diminish the current quark mass down to the value of the inverse vacuum correlation length, finding in this way a 64%-decrease in the absolute value of the quark condensate. In particular, we find that the conventional formula for the heavy-quark condensate cannot be applied to the c-quark, and that the corrections to this formula can reach 23% even in the case of the b-quark. We also demonstrate that, for an exponential parametrization of the two-point correlation function of gluonic field strengths, the quark condensate does not depend on the non-confining non-perturbative interactions of the stochastic background Yang-Mills fields. |
1109.5391 | David Blaschke | D. Blaschke, J. Berdermann, J. Cleymans, K. Redlich | Chiral condensate and Mott-Anderson freeze-out | 10 pages, 3 figures, presented at the workshop "30 years of strong
interactions", Spa, Belgium, 6-8 April 2011 | Few Body Syst. 53 (2012) 99-109 | 10.1007/s00601-011-0261-6 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the idea of a Mott-Anderson freeze-out that suggests a key role of
the localization of the hadron wave functions when traversing the hadronization
transition. The extension of hadron wave functions in dense matter is governed
by the behavior of the chiral quark condensate such that its melting at finite
temperatures and chemical potentials entails an increase of the size of hadrons
and thus their geometrical strong interaction cross sections. It is
demonstrated within a schematic resonance gas model, that a kinetic freeze-out
condition reveals a correlation with the reduction of the chiral condensate in
the phase diagram up to 50 % of its vacuum value. Generalizing the description
of the chiral condensate by taking into account a full hadron resonance gas
such correlation gets distorted. We discuss, that this may be due to our
approximations in calculating the chiral condensate which disregard both,
in-medium effects on hadron masses and hadron-hadron interactions. The latter,
in particular due to quark exchange reactions, could lead to a delocalization
of the hadron wave functions in accordance with the picture of a Mott-Anderson
transition.
| [
{
"created": "Sun, 25 Sep 2011 20:02:08 GMT",
"version": "v1"
}
] | 2012-09-20 | [
[
"Blaschke",
"D.",
""
],
[
"Berdermann",
"J.",
""
],
[
"Cleymans",
"J.",
""
],
[
"Redlich",
"K.",
""
]
] | We present the idea of a Mott-Anderson freeze-out that suggests a key role of the localization of the hadron wave functions when traversing the hadronization transition. The extension of hadron wave functions in dense matter is governed by the behavior of the chiral quark condensate such that its melting at finite temperatures and chemical potentials entails an increase of the size of hadrons and thus their geometrical strong interaction cross sections. It is demonstrated within a schematic resonance gas model, that a kinetic freeze-out condition reveals a correlation with the reduction of the chiral condensate in the phase diagram up to 50 % of its vacuum value. Generalizing the description of the chiral condensate by taking into account a full hadron resonance gas such correlation gets distorted. We discuss, that this may be due to our approximations in calculating the chiral condensate which disregard both, in-medium effects on hadron masses and hadron-hadron interactions. The latter, in particular due to quark exchange reactions, could lead to a delocalization of the hadron wave functions in accordance with the picture of a Mott-Anderson transition. |
hep-ph/0703039 | Christopher Smith | Christopher Smith | Rare K decays in the Standard Model | Talk given at 4th International Workshop on the CKM Unitarity
Triangle (CKM 2006), Nagoya, Japan, 12-16 Dec 2006 | null | null | null | hep-ph | null | The very clean theoretical predictions for the rare decays K --> pi nu nu_bar
and KL --> pi0 l+ l- are reviewed, and their various theoretical inputs
summarized. The less favorable situation for KL --> mu+ mu- is also commented.
| [
{
"created": "Sun, 4 Mar 2007 16:50:08 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Smith",
"Christopher",
""
]
] | The very clean theoretical predictions for the rare decays K --> pi nu nu_bar and KL --> pi0 l+ l- are reviewed, and their various theoretical inputs summarized. The less favorable situation for KL --> mu+ mu- is also commented. |
hep-ph/9905215 | Michal Brhlik | M. Brhlik, L. Everett, G. L. Kane, and J. Lykken | A Resolution to the Supersymmetric CP Problem with Large Soft Phases via
D-branes | 11 pages, 2 eps figures; revised references and updated text | Phys.Rev.Lett.83:2124-2127,1999 | 10.1103/PhysRevLett.83.2124 | FERMILAB-Pub-99/136-T | hep-ph hep-th | null | We examine the soft supersymmetry breaking parameters that result from
various ways of embedding the Standard Model (SM) on D-branes within the Type I
string picture, allowing the gaugino masses and $\mu$ to have large CP-
violating phases. One embedding naturally provides the relations among soft
parameters to satisfy the electron and neutron electric dipole moment
constraints even with large phases, while with other embeddings large phases
are not allowed. The string models provide some motivation for large phases in
the soft breaking parameters. The results generally suggest how low energy data
might teach us about Planck scale physics.
| [
{
"created": "Mon, 3 May 1999 20:44:14 GMT",
"version": "v1"
},
{
"created": "Mon, 10 May 1999 18:56:18 GMT",
"version": "v2"
},
{
"created": "Wed, 4 Aug 1999 20:27:59 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Brhlik",
"M.",
""
],
[
"Everett",
"L.",
""
],
[
"Kane",
"G. L.",
""
],
[
"Lykken",
"J.",
""
]
] | We examine the soft supersymmetry breaking parameters that result from various ways of embedding the Standard Model (SM) on D-branes within the Type I string picture, allowing the gaugino masses and $\mu$ to have large CP- violating phases. One embedding naturally provides the relations among soft parameters to satisfy the electron and neutron electric dipole moment constraints even with large phases, while with other embeddings large phases are not allowed. The string models provide some motivation for large phases in the soft breaking parameters. The results generally suggest how low energy data might teach us about Planck scale physics. |
1903.06269 | Eduardo Folco Capossoli | Eduardo Folco Capossoli, Miguel Angel Mart\'in Contreras, Danning Li,
Alfredo Vega, Henrique Boschi-Filho | Hadronic Spectra from Deformed AdS Backgrounds | 36 pages, 11 figures, 10 tables. V3: Abstract changed, Text improved,
Results unchanged, References added, Tables included | Chinese Physics C Vol. 44, No. 6 (2020) 064104 | 10.1088/1674-1137/44/6/064104 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Because of the presence of modified warp factors in metric tensors, we use
deformed AdS$_5$ spaces to apply the AdS/CFT correspondence to calculate the
spectra for even and odd glueballs, scalar and vector mesons, and baryons with
different spins. For the glueball cases, we derive their Regge trajectories and
compare them with those related to the pomeron and the odderon. For the scalar
and vector mesons as well as baryons the determined masses are compatible with
the PDG. In particular for these hadrons we found Regge trajectories compatible
with another holographic approach as well as with the hadronic spectroscopy,
which present an universal Regge slope of approximately 1.1 GeV$^2$.
| [
{
"created": "Thu, 14 Mar 2019 21:30:26 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Jul 2019 21:23:45 GMT",
"version": "v2"
},
{
"created": "Thu, 4 Jun 2020 03:21:53 GMT",
"version": "v3"
}
] | 2020-06-05 | [
[
"Capossoli",
"Eduardo Folco",
""
],
[
"Contreras",
"Miguel Angel Martín",
""
],
[
"Li",
"Danning",
""
],
[
"Vega",
"Alfredo",
""
],
[
"Boschi-Filho",
"Henrique",
""
]
] | Because of the presence of modified warp factors in metric tensors, we use deformed AdS$_5$ spaces to apply the AdS/CFT correspondence to calculate the spectra for even and odd glueballs, scalar and vector mesons, and baryons with different spins. For the glueball cases, we derive their Regge trajectories and compare them with those related to the pomeron and the odderon. For the scalar and vector mesons as well as baryons the determined masses are compatible with the PDG. In particular for these hadrons we found Regge trajectories compatible with another holographic approach as well as with the hadronic spectroscopy, which present an universal Regge slope of approximately 1.1 GeV$^2$. |
1508.07731 | Juan Rojo | Juan Rojo | Progress in the NNPDF global analysis and the impact of the legacy HERA
combination | 9 pages, 8 figures, to appear in the proceedings of the European
Physical Society Conference on High Energy Physics 2015 (EPS-HEP 2015),
Vienna, Austria, 22nd to 29th of July 2015 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The H1 and ZEUS collaborations have recently presented their final results
for the combination of inclusive cross-section measurements taken during Run I
and Run II at the HERA collider. In this contribution, following an overview of
recent progress in the NNPDF framework, we quantify the impact of the legacy
HERA dataset on the NNPDF3.0 analysis, finding that it has a very moderate
effect in the global fit. On the other hand, we also find that a HERA-only fit
using the legacy dataset leads to a rather more accurate determination of PDFs
as compared to a fit including only the HERA-I data. We also explore the
sensitivity of the fit with respect to kinematical cuts in the small-x and
small-Q region, finding hints of a possible tension between data and theory.
| [
{
"created": "Mon, 31 Aug 2015 09:23:59 GMT",
"version": "v1"
}
] | 2015-09-01 | [
[
"Rojo",
"Juan",
""
]
] | The H1 and ZEUS collaborations have recently presented their final results for the combination of inclusive cross-section measurements taken during Run I and Run II at the HERA collider. In this contribution, following an overview of recent progress in the NNPDF framework, we quantify the impact of the legacy HERA dataset on the NNPDF3.0 analysis, finding that it has a very moderate effect in the global fit. On the other hand, we also find that a HERA-only fit using the legacy dataset leads to a rather more accurate determination of PDFs as compared to a fit including only the HERA-I data. We also explore the sensitivity of the fit with respect to kinematical cuts in the small-x and small-Q region, finding hints of a possible tension between data and theory. |
1106.4020 | Shamayita Ray | Yuval Grossman and Shamayita Ray | Minimal Lepton Flavor Violation and Renormalization Group Evolution of
Lepton Masses and Mixing | 36 pages, 7 figures | null | 10.1007/JHEP10(2011)019 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the renormalization group equations (RGEs) of the neutrino
parameters in models of Minimal Lepton Flavor Violation. In such models, the
RGEs can be described in terms of flavor spurions, such that only the
coefficients depend on the specific model. We explicitly demonstrate this
method for the SM and MSSM for both Type-I and Type-III seesaw models. For that
purpose, the RGEs of neutrino parameters in the MSSM Type-III seesaw have been
computed. We have extended this method to get the evolution equations at second
order. The implications for leptogenesis are also discussed.
| [
{
"created": "Mon, 20 Jun 2011 20:01:11 GMT",
"version": "v1"
}
] | 2015-05-28 | [
[
"Grossman",
"Yuval",
""
],
[
"Ray",
"Shamayita",
""
]
] | We study the renormalization group equations (RGEs) of the neutrino parameters in models of Minimal Lepton Flavor Violation. In such models, the RGEs can be described in terms of flavor spurions, such that only the coefficients depend on the specific model. We explicitly demonstrate this method for the SM and MSSM for both Type-I and Type-III seesaw models. For that purpose, the RGEs of neutrino parameters in the MSSM Type-III seesaw have been computed. We have extended this method to get the evolution equations at second order. The implications for leptogenesis are also discussed. |
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