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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1912.06619 | Ping Kwan Man Ellgan | Man Ping Kwan Ellgan | Double field inflation of generalized dilaton-axion models with a new
Fayet-Iliopoulos (FI) term | 36 pages. Questions and comments are welcomed | null | 10.1088/1361-6382/ab9bbc/meta | Classical and Quantum Gravity, Volume 37, Number 20 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the inflation dynamics of generalized dilaton-axion models with a
new Fayet-Iliopoulos (FI) term. In particular, we find the relationships
between the super-potential parameters and the coefficient of natural logarithm
of the real part of dilaton-axion fields stored in the K\"ahler potential based
on the vacuum conditions at the end of inflation. We also evaluate the feasible
initial field values, their corresponding SUSY breaking scales and the
iso-curvature parameters.
| [
{
"created": "Fri, 13 Dec 2019 17:32:14 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Dec 2019 09:52:07 GMT",
"version": "v2"
}
] | 2020-10-29 | [
[
"Ellgan",
"Man Ping Kwan",
""
]
] | We study the inflation dynamics of generalized dilaton-axion models with a new Fayet-Iliopoulos (FI) term. In particular, we find the relationships between the super-potential parameters and the coefficient of natural logarithm of the real part of dilaton-axion fields stored in the K\"ahler potential based on the vacuum conditions at the end of inflation. We also evaluate the feasible initial field values, their corresponding SUSY breaking scales and the iso-curvature parameters. |
1903.06926 | Francesco Giacosa | Francesco Giacosa, Milena Piotrowska, Susana Coito | $X(3872)$ as virtual companion pole of the charm-anticharm state
$\chi_{c1}(2P)$ | 23 pages, 5 figures, 8 tables. Accepted for publication in IJMPA | null | 10.1142/S0217751X19501732 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the spectral function of the axial-vector charmonium state
$\chi_{c1}(2P)$ coupled to $DD^{\ast}$ mesons, by employing a quantum field
theoretical approach: a pronounced enhancement close to the $D^{0}% D^{\ast0}$
threshold, to be identified with the $X(3872)$, emerges. In the complex plane
we find two poles: a pole for the broad seed state $\chi_{c1}(2P)$, and -- in
the easiest scenario -- a virtual pole for the $X(3872)$. Thus, our approach
describes both the seed state and the dynamically generated $X(3872)$
simultaneously. In particular, it explains the most prominent, both
molecular-like and quarkonium-like, features of the $X(3872)$: its very small
width (the decay into $D^{0}D^{\ast0}$ is predicted to be about 0.5 MeV), the
enhanced radiative decay into $\psi(2S)\gamma$ w.r.t. $\psi(1S)\gamma$, and the
isospin breaking decay into $J/\psi\rho$ (thanks to $DD^{\ast}$ loops mediating
this decay channel). At the same time, we aim to determine the pole position
and the properties of the charmonium seed state: quite interestingly, even if a
pole is always present, it is possible that there is no peak corresponding to
this state in the spectral function, thus potentially explaining why the
corresponding resonance could not yet be seen in experiments.
| [
{
"created": "Sat, 16 Mar 2019 14:02:17 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Oct 2019 13:05:51 GMT",
"version": "v2"
}
] | 2020-01-08 | [
[
"Giacosa",
"Francesco",
""
],
[
"Piotrowska",
"Milena",
""
],
[
"Coito",
"Susana",
""
]
] | We study the spectral function of the axial-vector charmonium state $\chi_{c1}(2P)$ coupled to $DD^{\ast}$ mesons, by employing a quantum field theoretical approach: a pronounced enhancement close to the $D^{0}% D^{\ast0}$ threshold, to be identified with the $X(3872)$, emerges. In the complex plane we find two poles: a pole for the broad seed state $\chi_{c1}(2P)$, and -- in the easiest scenario -- a virtual pole for the $X(3872)$. Thus, our approach describes both the seed state and the dynamically generated $X(3872)$ simultaneously. In particular, it explains the most prominent, both molecular-like and quarkonium-like, features of the $X(3872)$: its very small width (the decay into $D^{0}D^{\ast0}$ is predicted to be about 0.5 MeV), the enhanced radiative decay into $\psi(2S)\gamma$ w.r.t. $\psi(1S)\gamma$, and the isospin breaking decay into $J/\psi\rho$ (thanks to $DD^{\ast}$ loops mediating this decay channel). At the same time, we aim to determine the pole position and the properties of the charmonium seed state: quite interestingly, even if a pole is always present, it is possible that there is no peak corresponding to this state in the spectral function, thus potentially explaining why the corresponding resonance could not yet be seen in experiments. |
hep-ph/9604388 | Bryan Webber | M. Dasgupta and B.R. Webber (Cavendish Laboratory, University of
Cambridge, U.K.) | Power Corrections and Renormalons in Deep Inelastic Structure Functions | Latex 2e, 9 pages including 2 Postscript figures | Phys.Lett. B382 (1996) 273-281 | 10.1016/0370-2693(96)00674-0 | Cavendish-HEP-96/1 | hep-ph | null | We study the power corrections (infrared renormalon contributions) to the
coefficient functions for non-singlet deep inelastic structure functions due to
gluon vacuum polarization insertions in one-loop graphs. Remarkably, for all
the structure functions $F_1$, $F_2$, $F_3$ and $g_1$, there are only two such
contributions, corresponding to $1/Q^2$ and $1/Q^4$ power corrections. We
compute their dependence on Bjorken $x$. The results could be used to model the
dominant higher-twist contributions.
| [
{
"created": "Tue, 23 Apr 1996 14:58:25 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Dasgupta",
"M.",
"",
"Cavendish Laboratory, University of\n Cambridge, U.K."
],
[
"Webber",
"B. R.",
"",
"Cavendish Laboratory, University of\n Cambridge, U.K."
]
] | We study the power corrections (infrared renormalon contributions) to the coefficient functions for non-singlet deep inelastic structure functions due to gluon vacuum polarization insertions in one-loop graphs. Remarkably, for all the structure functions $F_1$, $F_2$, $F_3$ and $g_1$, there are only two such contributions, corresponding to $1/Q^2$ and $1/Q^4$ power corrections. We compute their dependence on Bjorken $x$. The results could be used to model the dominant higher-twist contributions. |
hep-ph/9404357 | Fred Cooper | Fred Cooper, Yuval Kluger, Emil Mottola, Juan Pablo Paz | Nonequilibrium Quantum Dynamics Of Disoriented Chiral Condensates | 49 pages, figures available by request | Phys.Rev. D51 (1995) 2377-2397 | 10.1103/PhysRevD.51.2377 | null | hep-ph | null | The nonequilibrium dynamics of the chiral phase transition expected during
the expansion of the quark-qluon plasma produced in a high energy hadron or
heavy ion collision is studied in the O(4) linear sigma model to leading order
in a large $N$ expansion. Starting from an approximate equilibrium
configuration at an initial proper time $\tau$ in the disordered phase we study
the transition to the ordered broken symmetry phase as the system expands and
cools. We give results for the proper time evolution of the effective pion
mass, the order parameter $<\sigma>$ as well as for the pion two point
correlation function expressed in terms of a time dependent phase space number
density and pair correlation density. We determine the phase space of initial
conditions that lead to instabilities (exponentially growing long wave length
modes) as the system evolves in time. These instabilities are what eventually
lead to disoriented chiral condensates. In our simulations,we found that
instabilities that are formed during the initial phases of the expansion exist
for proper times that are at most $3 fm/c$ and lead to condensate regions that
do not contain large numbers of particles. The damping of instabilities is a
consequence of strong coupling.
| [
{
"created": "Fri, 29 Apr 1994 22:34:04 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Cooper",
"Fred",
""
],
[
"Kluger",
"Yuval",
""
],
[
"Mottola",
"Emil",
""
],
[
"Paz",
"Juan Pablo",
""
]
] | The nonequilibrium dynamics of the chiral phase transition expected during the expansion of the quark-qluon plasma produced in a high energy hadron or heavy ion collision is studied in the O(4) linear sigma model to leading order in a large $N$ expansion. Starting from an approximate equilibrium configuration at an initial proper time $\tau$ in the disordered phase we study the transition to the ordered broken symmetry phase as the system expands and cools. We give results for the proper time evolution of the effective pion mass, the order parameter $<\sigma>$ as well as for the pion two point correlation function expressed in terms of a time dependent phase space number density and pair correlation density. We determine the phase space of initial conditions that lead to instabilities (exponentially growing long wave length modes) as the system evolves in time. These instabilities are what eventually lead to disoriented chiral condensates. In our simulations,we found that instabilities that are formed during the initial phases of the expansion exist for proper times that are at most $3 fm/c$ and lead to condensate regions that do not contain large numbers of particles. The damping of instabilities is a consequence of strong coupling. |
hep-ph/9611411 | Thomas Mannel | Thomas Mannel | Review of Heavy Quark Effective Theory | Talk presented at the workshop "Heavy Quarks at Fixed Target", St.
Goar, Germany, Oct. 3-6, 1996, 25 pages, LaTeX, 3 figures as ps-files, the
complete paper, including figures, is also available via anonymous ftp at
ftp://ttpux2.uni-karlsruhe.de, or via www at
http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/ | null | null | TTP 96-56 | hep-ph | null | A short review of a few selected topics in Heavy Quark Effective Theory is
given. Applications to exclusive decays are discussed.
| [
{
"created": "Mon, 25 Nov 1996 13:40:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Mannel",
"Thomas",
""
]
] | A short review of a few selected topics in Heavy Quark Effective Theory is given. Applications to exclusive decays are discussed. |
hep-ph/9701298 | Carlo Giunti | S.M. Bilenky, C. Giunti and M. Monteno | Constraints on neutrinoless double beta decay from neutrino oscillation
experiments | Latex2e file, 15 pages including 3 figures. The postscript file is
available at http://www.to.infn.it/teorici/giunti/papers.html | null | null | DFTT 3/97 | hep-ph | null | We show that, in the framework of a general model with mixing of three
Majorana neutrinos and a neutrino mass hierarchy, the results of the Bugey and
Krasnoyarsk reactor neutrino oscillation experiments imply strong limitations
for the effective Majorana mass |<m>| that characterizes the amplitude of
neutrinoless double beta decay. We obtain further limitations on |<m>| from the
data of the atmospheric neutrino experiments. We discuss the possible
implications of the results of the future long baseline neutrino oscillation
experiments for neutrinoless double beta decay.
| [
{
"created": "Wed, 15 Jan 1997 15:52:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bilenky",
"S. M.",
""
],
[
"Giunti",
"C.",
""
],
[
"Monteno",
"M.",
""
]
] | We show that, in the framework of a general model with mixing of three Majorana neutrinos and a neutrino mass hierarchy, the results of the Bugey and Krasnoyarsk reactor neutrino oscillation experiments imply strong limitations for the effective Majorana mass |<m>| that characterizes the amplitude of neutrinoless double beta decay. We obtain further limitations on |<m>| from the data of the atmospheric neutrino experiments. We discuss the possible implications of the results of the future long baseline neutrino oscillation experiments for neutrinoless double beta decay. |
1407.1879 | Andr\'es G\'omez A. G. Quinto | A. G. Dias, A. F. Ferrari, J. D. Gomez, A. A. Natale, A. G. Quinto | Non-perturbative fixed points and renormalization group improved
effective potential | 6 pages, 8 figures, References added. Matching the journal version | null | 10.1016/j.physletb.2014.10.017 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The stability conditions of a renormalization group improved effective
potential have been discussed in the case of scalar QED and QCD with a
colorless scalar. We calculate the same potential in these models assuming the
existence of non-perturbative fixed points associated to a conformal phase. In
the case of scalar QED the barrier of instability found previously is barely
displaced as we approach the fixed point, and in the case of QCD with a
colorless scalar not only the barrier is changed but the local minimum of the
potential is also changed.
| [
{
"created": "Mon, 7 Jul 2014 20:52:00 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Oct 2014 14:25:13 GMT",
"version": "v2"
}
] | 2015-06-22 | [
[
"Dias",
"A. G.",
""
],
[
"Ferrari",
"A. F.",
""
],
[
"Gomez",
"J. D.",
""
],
[
"Natale",
"A. A.",
""
],
[
"Quinto",
"A. G.",
""
]
] | The stability conditions of a renormalization group improved effective potential have been discussed in the case of scalar QED and QCD with a colorless scalar. We calculate the same potential in these models assuming the existence of non-perturbative fixed points associated to a conformal phase. In the case of scalar QED the barrier of instability found previously is barely displaced as we approach the fixed point, and in the case of QCD with a colorless scalar not only the barrier is changed but the local minimum of the potential is also changed. |
1903.08064 | Jacopo Ghiglieri | Alexander M. Eller, Jacopo Ghiglieri, Guy D. Moore | Thermal Heavy Quark Self-Energy from Euclidean Correlators | 5 pages, 1 figure. v2: very minor edits, matches journal version. v3:
Eqs. (11) and (17) of v2 fixed, title and abstract modified, conclusions
changed | Phys. Rev. D 99, 094042 (2019) | 10.1103/PhysRevD.99.094042 | CERN-TH-2019-025 | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Brambilla, Escobedo, Soto, and Vairo have derived an effective description of
quarkonium with two parameters; a momentum diffusion term and a real
self-energy term. We point out that there is a similar real self-energy term
for a single open heavy flavor and that it can be expressed directly in terms
of Euclidean electric field correlators along a Polyakov line. This quantity
can be directly studied on the lattice without the need for analytical
continuation. We show that Minkowski-space calculations of this correlator
correspond with the known NLO Euclidean value of the relevant electric field
two-point function and that it differs from the real self-energy term for
quarkonium.
| [
{
"created": "Tue, 19 Mar 2019 15:48:57 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Jun 2019 09:16:51 GMT",
"version": "v2"
},
{
"created": "Tue, 16 Jun 2020 14:49:04 GMT",
"version": "v3"
}
] | 2020-06-17 | [
[
"Eller",
"Alexander M.",
""
],
[
"Ghiglieri",
"Jacopo",
""
],
[
"Moore",
"Guy D.",
""
]
] | Brambilla, Escobedo, Soto, and Vairo have derived an effective description of quarkonium with two parameters; a momentum diffusion term and a real self-energy term. We point out that there is a similar real self-energy term for a single open heavy flavor and that it can be expressed directly in terms of Euclidean electric field correlators along a Polyakov line. This quantity can be directly studied on the lattice without the need for analytical continuation. We show that Minkowski-space calculations of this correlator correspond with the known NLO Euclidean value of the relevant electric field two-point function and that it differs from the real self-energy term for quarkonium. |
hep-ph/9806248 | Eef van Beveren | Eef van Beveren (University of Coimbra, Portugal) and George Rupp
(Instituto Superior Tecnico, Lisboa, Portugal) | Flavour symmetry of mesonic decay couplings | 29 pages, plain LaTeX, rewritten version | Eur.Phys.J.C11:717-728,1999 | 10.1007/s100520050668 | null | hep-ph | null | We present flavour-symmetric results for the couplings of quark-antiquark
systems to meson-meson channels in the harmonic-oscillator expansion. We
tabulate their values for all possible open and closed decay channels of
pseudo-scalar, vector and scalar mesons. We compare the predictions of a model
that employs these flavour-symmetric couplings, both with the results of a
model which uses explicitly flavour-dependent couplings, and with experiment.
| [
{
"created": "Wed, 3 Jun 1998 15:54:53 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Jun 1998 11:32:04 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Jan 1999 12:10:13 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"van Beveren",
"Eef",
"",
"University of Coimbra, Portugal"
],
[
"Rupp",
"George",
"",
"Instituto Superior Tecnico, Lisboa, Portugal"
]
] | We present flavour-symmetric results for the couplings of quark-antiquark systems to meson-meson channels in the harmonic-oscillator expansion. We tabulate their values for all possible open and closed decay channels of pseudo-scalar, vector and scalar mesons. We compare the predictions of a model that employs these flavour-symmetric couplings, both with the results of a model which uses explicitly flavour-dependent couplings, and with experiment. |
hep-ph/0411199 | Masaharu Iwasaki | Masaharu Iwasaki | First order phase transition in the quark matter | 6 pages, 7 figures | Phys.Rev. D70 (2004) 114031 | 10.1103/PhysRevD.70.114031 | null | hep-ph | null | We investigate chiral phase transition of the first order in the quark
matter. Using the Nambu-Jona-Lasinio model, an equation of state of the quark
matter which is similar to the van der Waals' one is obtained. Moreover the
specific heat and the compressibility are calculated. It is shown that they are
enhanced in the symmetry broken phase, in particular diverge near the
tricritical point.
| [
{
"created": "Tue, 16 Nov 2004 00:44:58 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Iwasaki",
"Masaharu",
""
]
] | We investigate chiral phase transition of the first order in the quark matter. Using the Nambu-Jona-Lasinio model, an equation of state of the quark matter which is similar to the van der Waals' one is obtained. Moreover the specific heat and the compressibility are calculated. It is shown that they are enhanced in the symmetry broken phase, in particular diverge near the tricritical point. |
hep-ph/0510324 | Tancredi Carli | Tancredi Carli, Gavin P. Salam, Frank Siegert | A posteriori inclusion of PDFs in NLO QCD final-state calculations | contribution to the CERN DESY workshop on "HERA and LHC" | null | null | null | hep-ph | null | Any NLO calculation of a QCD final-state observable involves Monte Carlo
integration over a large number of events. For DIS and hadron colliders this
must usually be repeated for each new PDF set, making it impractical to
consider many `error' PDF sets, or carry out PDF fits. Here we discuss ``a
posteriori'' inclusion of PDFs, whereby the Monte Carlo run calculates a grid
(in x and Q) of cross section weights that can subsequently be combined with an
arbitrary PDF. The procedure is numerically equivalent to using an interpolated
form of the PDF. The main novelty relative to prior work is the use of
higher-order interpolation, which substantially improves the tradeoff between
accuracy and memory use. An accuracy of about 0.01% has been reached for the
single inclusive cross-section in the central rapidity region |y|<0.5 for jet
transverse momenta from 100 to 5000 GeV. This method should facilitate the
consistent inclusion of final-state data from HERA, Tevatron and LHC in PDF
fits, thus helping to increase the sensitivity of LHC to deviations from
standard Model predictions.
| [
{
"created": "Tue, 25 Oct 2005 13:13:42 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Carli",
"Tancredi",
""
],
[
"Salam",
"Gavin P.",
""
],
[
"Siegert",
"Frank",
""
]
] | Any NLO calculation of a QCD final-state observable involves Monte Carlo integration over a large number of events. For DIS and hadron colliders this must usually be repeated for each new PDF set, making it impractical to consider many `error' PDF sets, or carry out PDF fits. Here we discuss ``a posteriori'' inclusion of PDFs, whereby the Monte Carlo run calculates a grid (in x and Q) of cross section weights that can subsequently be combined with an arbitrary PDF. The procedure is numerically equivalent to using an interpolated form of the PDF. The main novelty relative to prior work is the use of higher-order interpolation, which substantially improves the tradeoff between accuracy and memory use. An accuracy of about 0.01% has been reached for the single inclusive cross-section in the central rapidity region |y|<0.5 for jet transverse momenta from 100 to 5000 GeV. This method should facilitate the consistent inclusion of final-state data from HERA, Tevatron and LHC in PDF fits, thus helping to increase the sensitivity of LHC to deviations from standard Model predictions. |
1105.4944 | Shashank Bhatnagar Dr. | Elias Mengesha, Shashank Bhatnagar | Cross section for double charmonium production in electron-positron
annihilation at energy $\sqrt{s}$= 10.6 GeV | 14 pages, 2 figures. arXiv admin note: substantial text overlap with
arXiv:0912.3081 | Intl. J. Mod. Phys. E20, 2521-2533 (2011) | 10.1142/S0218301311030017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we study the process $e^{+}+e^{-}\longrightarrow J/\Psi+\eta_{c}
$ at energy $\sqrt{s}= 10.6 GeV$ observed recently at B-factories whose
measurements were made by Babar and Belle groups. We calculate the cross
section for this process in the Bethe-salpeter formalism under Covariant
Instantaneous Anstaz (CIA). To simplify our calculation, the heavy quark
approximation $(q<<M, P M)$ is employed in the quark and gluon propagators. In
the exclusive process of $e^{+}e^{-}$ annihilation into two heavy quarkonia,
the cross section calculated in this scenario is compatible with the
experimental data of Babar and Belle.
| [
{
"created": "Wed, 25 May 2011 07:24:06 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jan 2012 07:01:21 GMT",
"version": "v2"
}
] | 2012-01-05 | [
[
"Mengesha",
"Elias",
""
],
[
"Bhatnagar",
"Shashank",
""
]
] | In this work we study the process $e^{+}+e^{-}\longrightarrow J/\Psi+\eta_{c} $ at energy $\sqrt{s}= 10.6 GeV$ observed recently at B-factories whose measurements were made by Babar and Belle groups. We calculate the cross section for this process in the Bethe-salpeter formalism under Covariant Instantaneous Anstaz (CIA). To simplify our calculation, the heavy quark approximation $(q<<M, P M)$ is employed in the quark and gluon propagators. In the exclusive process of $e^{+}e^{-}$ annihilation into two heavy quarkonia, the cross section calculated in this scenario is compatible with the experimental data of Babar and Belle. |
0803.1720 | Eung Jin Chun | Eung Jin Chun, Probir Roy | Dirac Leptogenesis in extended nMSSM | 7 pages, references added, numbering corrected, to be published in
JHEP | JHEP 0806:089,2008 | 10.1088/1126-6708/2008/06/089 | KIAS-P08024 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that a version of the nearly Minimal Supersymmetric Standard Model
(nMSSM), extended only in the singlet sector to include the additional
superfields of right-handed neutrinos and very heavy Dirac particles conserving
$B-L$, admits a viable scenario for Dirac leptogenesis and naturally small
Dirac neutrino masses. The origin of the ($B-L$)-conserving high singlet
neutrino scale and the desired supersymmetry breaking terms is associated with
dynamical supersymmetry breaking in the hidden sector.
| [
{
"created": "Wed, 12 Mar 2008 08:27:41 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Mar 2008 02:41:07 GMT",
"version": "v2"
},
{
"created": "Wed, 18 Jun 2008 02:18:03 GMT",
"version": "v3"
}
] | 2009-11-18 | [
[
"Chun",
"Eung Jin",
""
],
[
"Roy",
"Probir",
""
]
] | We show that a version of the nearly Minimal Supersymmetric Standard Model (nMSSM), extended only in the singlet sector to include the additional superfields of right-handed neutrinos and very heavy Dirac particles conserving $B-L$, admits a viable scenario for Dirac leptogenesis and naturally small Dirac neutrino masses. The origin of the ($B-L$)-conserving high singlet neutrino scale and the desired supersymmetry breaking terms is associated with dynamical supersymmetry breaking in the hidden sector. |
2109.09722 | Ara Ioannisian Dr. | Ara Ioannisian | On the measurement of the muon anomalous magnetic moment | minor changes in the text, statistics is corrected | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The ideas and formulas presented in the article will help to bring together
the theoretical predictions for the anomalous magnetic moment of muon and the
results of the "Muon g-2" experiment. In doing so, we are discussing the new
effect exclusively within the Standard Model. In quantum physics a state with
spin perpendicular to a magnetic field can be expressed as a superposition of
energy eigenstates with spins parallel and antiparallel to the field: the
resultant spin precession is due to the energy difference between the two
eigenstates. If the state, like the muon, is unstable and can decay, it will
have a natural energy spread. As a result the frequency of the spin precession
can vary. For a constant magnetic field the measured spin precession velocity
will be spread according to the Lorentzian distribution with width
$\left(\gamma\tau\right)^{-1}$, for Lorentz gamma factor $\gamma=E/ m$, and
particle lifetime $\tau$. Although the true mean and variance of a Lorentzian
distribution is undefined, the latter can be estimated by the maximum
likelihood method to be ${2 \over N (\gamma \tau)^2}$, twice that of a normal
distribution. Thus, the statistical error on the anomalous magnetic moment in
reality should turn out to be wider than with $\chi^2$ analysis of the
experiment.
| [
{
"created": "Mon, 20 Sep 2021 17:55:34 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Sep 2021 17:40:58 GMT",
"version": "v2"
}
] | 2021-09-30 | [
[
"Ioannisian",
"Ara",
""
]
] | The ideas and formulas presented in the article will help to bring together the theoretical predictions for the anomalous magnetic moment of muon and the results of the "Muon g-2" experiment. In doing so, we are discussing the new effect exclusively within the Standard Model. In quantum physics a state with spin perpendicular to a magnetic field can be expressed as a superposition of energy eigenstates with spins parallel and antiparallel to the field: the resultant spin precession is due to the energy difference between the two eigenstates. If the state, like the muon, is unstable and can decay, it will have a natural energy spread. As a result the frequency of the spin precession can vary. For a constant magnetic field the measured spin precession velocity will be spread according to the Lorentzian distribution with width $\left(\gamma\tau\right)^{-1}$, for Lorentz gamma factor $\gamma=E/ m$, and particle lifetime $\tau$. Although the true mean and variance of a Lorentzian distribution is undefined, the latter can be estimated by the maximum likelihood method to be ${2 \over N (\gamma \tau)^2}$, twice that of a normal distribution. Thus, the statistical error on the anomalous magnetic moment in reality should turn out to be wider than with $\chi^2$ analysis of the experiment. |
1911.11213 | Gustavo H Guerrero Navarro | Gustavo H. Guerrero Navarro | $\Delta(1232)$ Contribution in the $\pi$-photoproduction on Nucleons in
Covariant Chiral Perturbation Theory | Conference proceedings of the XVIII International Conference on
Hadron Spectroscopy and Structure, HADRON 2019. August 16-21, Guilin, China | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of the $\Delta$(1232) resonance as an effective degree
of freedom for charged and neutral pion photo-production on nucleons. Different
observables have been calculated for these processes by using relativistic
chiral perturbation theory up to $\mathcal{O}(p^3)$ in the $ \delta$ counting,
thus, including pion loops. We compare our model with a large database
containing the available experimental data and constrain some unknown low
energy constants.
| [
{
"created": "Mon, 25 Nov 2019 20:27:40 GMT",
"version": "v1"
}
] | 2019-11-27 | [
[
"Navarro",
"Gustavo H. Guerrero",
""
]
] | We study the effects of the $\Delta$(1232) resonance as an effective degree of freedom for charged and neutral pion photo-production on nucleons. Different observables have been calculated for these processes by using relativistic chiral perturbation theory up to $\mathcal{O}(p^3)$ in the $ \delta$ counting, thus, including pion loops. We compare our model with a large database containing the available experimental data and constrain some unknown low energy constants. |
hep-ph/9910501 | Jake Lee | T. M. Aliev, C. S. Kim, Y. G. Kim | A Systematic Analysis of the Exclusive B -> K^* l^+ l^- Decay | To be published in PRD (2000) | Phys.Rev.D62:014026,2000 | 10.1103/PhysRevD.62.014026 | YUMS 99-024 | hep-ph | null | A model-independent analysis for the exclusive, rare B -> K^* l^+ l^- decay
is presented. Systematically studied are the experimentally measured
quantities, such as, branching ratio, forward-backward asymmetry, longitudinal
polarization of the final leptons, and the ratio $\Gamma_L/\Gamma_T$ of the
decay widths when $K^\ast$ meson is longitudinally and transversally polarized.
The dependence of the asymmetry parameter $\alpha = 2 \Gamma_L/\Gamma_T -1$ on
the new Wilson coefficients is also studied in detail. It is found that the
afore-mentioned physical observables are quite sensitive to the new Wilson
coefficients. Therefore, once we have the experimental data with high
statistics and a deviation from the Standard Model, we can interpret the source
of such discrepancy.
| [
{
"created": "Wed, 27 Oct 1999 02:05:04 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Oct 1999 05:14:11 GMT",
"version": "v2"
},
{
"created": "Fri, 11 Feb 2000 02:45:17 GMT",
"version": "v3"
}
] | 2011-03-23 | [
[
"Aliev",
"T. M.",
""
],
[
"Kim",
"C. S.",
""
],
[
"Kim",
"Y. G.",
""
]
] | A model-independent analysis for the exclusive, rare B -> K^* l^+ l^- decay is presented. Systematically studied are the experimentally measured quantities, such as, branching ratio, forward-backward asymmetry, longitudinal polarization of the final leptons, and the ratio $\Gamma_L/\Gamma_T$ of the decay widths when $K^\ast$ meson is longitudinally and transversally polarized. The dependence of the asymmetry parameter $\alpha = 2 \Gamma_L/\Gamma_T -1$ on the new Wilson coefficients is also studied in detail. It is found that the afore-mentioned physical observables are quite sensitive to the new Wilson coefficients. Therefore, once we have the experimental data with high statistics and a deviation from the Standard Model, we can interpret the source of such discrepancy. |
2108.05816 | Christopher Schwan | Christopher Schwan | PineAPPL: NLO EW corrections for PDF processes | 7 pages, 2 figures. Contribution to the XXVIII International Workshop
on Deep-Inelastic Scattering and Related Subjects (DIS2021), April 12-16,
2021. Submission to SciPost Physics Proceedings | null | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | Modern parton distribution function (PDF) determinations either neglect
higher-order corrections in the electroweak (EW) coupling or implement them
approximately for a subset of PDF processes. We present a new tool, PineAPPL,
which supports perturbative correction in arbitrary powers of the EW and strong
coupling constant, and stores theoretical predictions independently of the used
PDFs in so-called interpolation grids. These are the foundation of any PDF
determination, and will allow us to perform a PDF fit taking into account EW
corrections for all processes consistently. Apart from PDF determinations
PineAPPL can also be used in precision phenomenology to study the impact of
different choices of PDF sets, without rerunning the time-consuming
computation. As an application of this tool we show Drell-Yan (DY) lepton-pair
production were larger effects of NLO EW corrections can be seen that will
potentially influence the PDF fit and comment about which observables are
particularly suited and NLO EW PDF fit and which are not.
| [
{
"created": "Thu, 12 Aug 2021 15:56:02 GMT",
"version": "v1"
}
] | 2021-08-13 | [
[
"Schwan",
"Christopher",
""
]
] | Modern parton distribution function (PDF) determinations either neglect higher-order corrections in the electroweak (EW) coupling or implement them approximately for a subset of PDF processes. We present a new tool, PineAPPL, which supports perturbative correction in arbitrary powers of the EW and strong coupling constant, and stores theoretical predictions independently of the used PDFs in so-called interpolation grids. These are the foundation of any PDF determination, and will allow us to perform a PDF fit taking into account EW corrections for all processes consistently. Apart from PDF determinations PineAPPL can also be used in precision phenomenology to study the impact of different choices of PDF sets, without rerunning the time-consuming computation. As an application of this tool we show Drell-Yan (DY) lepton-pair production were larger effects of NLO EW corrections can be seen that will potentially influence the PDF fit and comment about which observables are particularly suited and NLO EW PDF fit and which are not. |
1505.05183 | David Zaslavsky | Kazuhiro Watanabe, Bo-Wen Xiao, Feng Yuan, David Zaslavsky | Implementing the exact kinematical constraint in the saturation
formalism | 20 pages, 7 figures; v2 fixes some typos | Phys. Rev. D 92, 034026 (2015) | 10.1103/PhysRevD.92.034026 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the issue of the large negative next-to-leading order (NLO) cross
section for single inclusive hadron production in $pA$ collisions in the
saturation formalism. By implementing the exact kinematical constraint in the
modified dipole splitting functions, two additional positive NLO correction
terms are obtained. In the asymptotic large $k_\perp$ limit, we analytically
show that these two terms become as large as the negative NLO contributions
found in our previous calculation. Furthermore, the numerical results
demonstrate that the applicable regime of the saturation formalism can be
extended to a larger $k_\perp$ window, where the exact matching between the
saturation formalism (in the asymptotic $k_\perp$ regime) and the collinear
factorization calculations will have to be performed separately. In addition,
after significantly improving the numerical accuracy of the NLO correction, we
obtain excellent agreement with the LHC and RHIC data for forward hadron
productions.
| [
{
"created": "Tue, 19 May 2015 20:51:38 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Jun 2015 16:59:58 GMT",
"version": "v2"
}
] | 2015-09-02 | [
[
"Watanabe",
"Kazuhiro",
""
],
[
"Xiao",
"Bo-Wen",
""
],
[
"Yuan",
"Feng",
""
],
[
"Zaslavsky",
"David",
""
]
] | We revisit the issue of the large negative next-to-leading order (NLO) cross section for single inclusive hadron production in $pA$ collisions in the saturation formalism. By implementing the exact kinematical constraint in the modified dipole splitting functions, two additional positive NLO correction terms are obtained. In the asymptotic large $k_\perp$ limit, we analytically show that these two terms become as large as the negative NLO contributions found in our previous calculation. Furthermore, the numerical results demonstrate that the applicable regime of the saturation formalism can be extended to a larger $k_\perp$ window, where the exact matching between the saturation formalism (in the asymptotic $k_\perp$ regime) and the collinear factorization calculations will have to be performed separately. In addition, after significantly improving the numerical accuracy of the NLO correction, we obtain excellent agreement with the LHC and RHIC data for forward hadron productions. |
2008.02684 | Zhiguang Xiao | Zhi-Yong Zhou, Zhiguang Xiao | Relativistic Friedrichs-Lee model and quark-pair creation model | v3, figure 3 added, some discussions added, published version | EPJC 80, 1191(2020) | 10.1140/epjc/s10052-020-08752-8 | USTC-ICTS/PCFT-20-24 | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we present how the Friedrichs-Lee model could be extended to
the relativistic scenario and be combined with the relativistic quark pair
creation model in a consistent way. This scheme could be applied to study the
"unquenched" effect of the meson spectra. As an example, if the lowest
$J^{PC}=0^{++}$ $(u\bar u+d\bar d)/\sqrt{2}$ bound state in the potential model
is coupled to the $\pi\pi$ continuum, two resonance poles could be found from
the scattering amplitude for the continuum states. One of them could correspond
to the $f_0(500)/\sigma$ and the other probably $f_0(1370)$. This scheme might
shed more light on why extra states could appear in the hadron spectrum other
than the prediction of the quark potential model.
| [
{
"created": "Thu, 6 Aug 2020 14:34:42 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Aug 2020 17:13:14 GMT",
"version": "v2"
},
{
"created": "Fri, 25 Dec 2020 07:14:59 GMT",
"version": "v3"
}
] | 2020-12-29 | [
[
"Zhou",
"Zhi-Yong",
""
],
[
"Xiao",
"Zhiguang",
""
]
] | In this paper, we present how the Friedrichs-Lee model could be extended to the relativistic scenario and be combined with the relativistic quark pair creation model in a consistent way. This scheme could be applied to study the "unquenched" effect of the meson spectra. As an example, if the lowest $J^{PC}=0^{++}$ $(u\bar u+d\bar d)/\sqrt{2}$ bound state in the potential model is coupled to the $\pi\pi$ continuum, two resonance poles could be found from the scattering amplitude for the continuum states. One of them could correspond to the $f_0(500)/\sigma$ and the other probably $f_0(1370)$. This scheme might shed more light on why extra states could appear in the hadron spectrum other than the prediction of the quark potential model. |
1811.00554 | Georges Obied | Prateek Agrawal and Georges Obied | Dark Energy and the Refined de Sitter Conjecture | 7 pages, 4 figures; added references | null | null | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the phenomenology of quintessence models in light of the recently
refined version of the de Sitter Swampland conjecture, which includes the
possibility of unstable de Sitter critical points. We show that models of
quintessence can evade previously derived lower bounds on $(1+w)$, albeit with
very finely-tuned initial conditions. In the absence of such tuning or other
rolling quintessence fields, a field with mass close to Hubble is required,
which has a generic prediction for $(1+w)$. Slow-roll single field inflation
models remain in tension. Other phenomenological constraints arising from the
coupling of the quintessence field with the Higgs or the QCD axion are
significantly relaxed.
| [
{
"created": "Thu, 1 Nov 2018 18:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Nov 2018 11:56:41 GMT",
"version": "v2"
}
] | 2018-11-19 | [
[
"Agrawal",
"Prateek",
""
],
[
"Obied",
"Georges",
""
]
] | We revisit the phenomenology of quintessence models in light of the recently refined version of the de Sitter Swampland conjecture, which includes the possibility of unstable de Sitter critical points. We show that models of quintessence can evade previously derived lower bounds on $(1+w)$, albeit with very finely-tuned initial conditions. In the absence of such tuning or other rolling quintessence fields, a field with mass close to Hubble is required, which has a generic prediction for $(1+w)$. Slow-roll single field inflation models remain in tension. Other phenomenological constraints arising from the coupling of the quintessence field with the Higgs or the QCD axion are significantly relaxed. |
hep-ph/0208031 | Antonio Pineda | Antonio Pineda | The static potential: lattice versus perturbation theory in a
renormalon-based approach | 18 pages, 11 figures, lattice data of Necco and Sommer introduced,
references added, some lengthier explanations given, physical results
unchanged | J.Phys.G29:371-385,2003 | 10.1088/0954-3899/29/2/313 | UB-ECM-PF 02/11 | hep-ph hep-lat hep-th | null | We compare, for the static potential and at short distances, perturbation
theory with the results of lattice simulations. We show that a
renormalon-dominance picture explains why in the literature sometimes
agreement, and another disagreement, is found between lattice simulations and
perturbation theory depending on the different implementations of the latter.
We also show that, within a renormalon-based scheme, perturbation theory agrees
with lattice simulations.
| [
{
"created": "Sat, 3 Aug 2002 06:52:22 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Oct 2002 07:51:14 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Pineda",
"Antonio",
""
]
] | We compare, for the static potential and at short distances, perturbation theory with the results of lattice simulations. We show that a renormalon-dominance picture explains why in the literature sometimes agreement, and another disagreement, is found between lattice simulations and perturbation theory depending on the different implementations of the latter. We also show that, within a renormalon-based scheme, perturbation theory agrees with lattice simulations. |
1307.2322 | Glennys R. Farrar | Glennys R. Farrar and Jeffrey D. Allen | A new physical phenomenon in ultra-high energy collisions | Based on talk given Feb. 14, 2012 at UHECR 2012 - International
Symposium on Future Directions in UHECR Physics, CERN, Geneva | EPJ Web of Conferences, Volume 53, 2013 id.07007 | 10.1051/epjconf/20135307007 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that combining the published Pierre Auger Observatory measurements of
the longitudinal_and_ lateral properties of UHE atmospheric showers, points to
an unforeseen change in the nature of particle interactions at ultrahigh
energy. A "toy model" of UHE proton-air interactions is presented which
provides the first fully consistent description of air shower observations. It
demonstrates that the observed energy dependence of the depth-of-shower-maximum
distribution may not indicate a transition to a heavier composition, as
commonly assumed. While fundamentally phenomenological, the model is based on
considerations of how the normal vacuum of QCD might be vaporized and chiral
symmetry restored by the extreme energy densities produced in UHE collisions.
Whatever its origin, understanding this unexpected phenomenon opens exciting
directions in particle physics and may impact Early Universe cosmology.
| [
{
"created": "Tue, 9 Jul 2013 02:11:09 GMT",
"version": "v1"
}
] | 2013-07-10 | [
[
"Farrar",
"Glennys R.",
""
],
[
"Allen",
"Jeffrey D.",
""
]
] | We show that combining the published Pierre Auger Observatory measurements of the longitudinal_and_ lateral properties of UHE atmospheric showers, points to an unforeseen change in the nature of particle interactions at ultrahigh energy. A "toy model" of UHE proton-air interactions is presented which provides the first fully consistent description of air shower observations. It demonstrates that the observed energy dependence of the depth-of-shower-maximum distribution may not indicate a transition to a heavier composition, as commonly assumed. While fundamentally phenomenological, the model is based on considerations of how the normal vacuum of QCD might be vaporized and chiral symmetry restored by the extreme energy densities produced in UHE collisions. Whatever its origin, understanding this unexpected phenomenon opens exciting directions in particle physics and may impact Early Universe cosmology. |
1907.09036 | Wenchang Xiang | Yi Yang, Shaohong Cai, Yanbing Cai, and Wenchang Xiang | Inclusive diffractive heavy quarkonium photoproduction in pp, pA and AA
collisions | 10 pages | Nucl.Phys. A990 (2019) 17-28 | 10.1016/j.nuclphysa.2019.06.012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The inclusive $J/\Psi$ production by direct and resolved photoproduction in
the $\gamma$p scattering is calculated based on the nonrelativistic quantum
chromodynamics (NRQCD) factorization formalism, which is in good agreement with
the experimental data of total cross section distribution of heavy quarkonium
production at HERA. Then we extend the formalism including the direct and
resolved photoproduction processes to resolved pomeron model to study the heavy
quarkonium photoproduction at the LHC energies. We present the predictions of
rapidity and transverse momentum distributions of the inclusive diffractive
$J/\Psi$, $\Psi(2S)$ and $\Upsilon$ photoproduction in pp, pPb and PbPb
collisions at the LHC energies. Our numerical results indicate that the
resolved photoproduction processes play an important role in the heavy
quarkonium production. Especially for pp collisions, the contribution of
resolved photoproduction processes is the largest, which can reach to $28\%$,
$13\%$ and $44\%$ for the rapidity distributions of $J/\Psi$, $\Psi(2S)$ and
$\Upsilon$ inclusive diffractive photoproduction, respectively.
| [
{
"created": "Sun, 21 Jul 2019 21:10:56 GMT",
"version": "v1"
}
] | 2019-07-23 | [
[
"Yang",
"Yi",
""
],
[
"Cai",
"Shaohong",
""
],
[
"Cai",
"Yanbing",
""
],
[
"Xiang",
"Wenchang",
""
]
] | The inclusive $J/\Psi$ production by direct and resolved photoproduction in the $\gamma$p scattering is calculated based on the nonrelativistic quantum chromodynamics (NRQCD) factorization formalism, which is in good agreement with the experimental data of total cross section distribution of heavy quarkonium production at HERA. Then we extend the formalism including the direct and resolved photoproduction processes to resolved pomeron model to study the heavy quarkonium photoproduction at the LHC energies. We present the predictions of rapidity and transverse momentum distributions of the inclusive diffractive $J/\Psi$, $\Psi(2S)$ and $\Upsilon$ photoproduction in pp, pPb and PbPb collisions at the LHC energies. Our numerical results indicate that the resolved photoproduction processes play an important role in the heavy quarkonium production. Especially for pp collisions, the contribution of resolved photoproduction processes is the largest, which can reach to $28\%$, $13\%$ and $44\%$ for the rapidity distributions of $J/\Psi$, $\Psi(2S)$ and $\Upsilon$ inclusive diffractive photoproduction, respectively. |
2307.05654 | Choong Sun Kim | C. S. Kim | Practical Dirac Majorana confusion theorem: Issues and Applicability | Final version, published in European Physics Journal C (2023) | null | 10.1140/epjc/s10052-023-12156-9 | null | hep-ph hep-ex hep-th nucl-th | http://creativecommons.org/licenses/by/4.0/ | We inspect the model-independent study of practical Dirac Majorana confusion
theorem (pDMCT) -- a wide spread belief that the difference between Dirac and
Majorana neutrinos via any kinematical observable would be practically
impossible to determine because of the difference only being proportional to
the square of neutrino mass -- in context of processes that have at least a
neutrino antineutrino pair in their final state. We scrutinize the domain of
applicability of pDMCT and also highlight those aspects that are often
misunderstood. We try to clarify some of the frequently used concepts that are
used to assert pDMCT as a generic feature irrespective of the process, or
observable, such as the existence of any analytic continuity between Dirac and
Majorana neutrinos in the limit mass(neutrino) -> 0. In summary, we illustrate
that pDMCT is not any fundamental property of neutrinos, instead, it is a
phenomenological feature of neutrino non-observation, depending on models and
processes.
| [
{
"created": "Tue, 11 Jul 2023 15:09:25 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jul 2023 19:47:21 GMT",
"version": "v2"
},
{
"created": "Fri, 27 Oct 2023 15:12:26 GMT",
"version": "v3"
}
] | 2023-10-30 | [
[
"Kim",
"C. S.",
""
]
] | We inspect the model-independent study of practical Dirac Majorana confusion theorem (pDMCT) -- a wide spread belief that the difference between Dirac and Majorana neutrinos via any kinematical observable would be practically impossible to determine because of the difference only being proportional to the square of neutrino mass -- in context of processes that have at least a neutrino antineutrino pair in their final state. We scrutinize the domain of applicability of pDMCT and also highlight those aspects that are often misunderstood. We try to clarify some of the frequently used concepts that are used to assert pDMCT as a generic feature irrespective of the process, or observable, such as the existence of any analytic continuity between Dirac and Majorana neutrinos in the limit mass(neutrino) -> 0. In summary, we illustrate that pDMCT is not any fundamental property of neutrinos, instead, it is a phenomenological feature of neutrino non-observation, depending on models and processes. |
2102.13118 | Sany Willian Ponce Novelo | M. M. Guzzo, L. J. F. Leite, S. W. P. Novelo, O. L. G. Peres, V.
Pleitez | Hidden physics in pion and some other meson decays | 21 pages, 4 figures | Phys. Rev. D 107, 095037 (2023) | 10.1103/PhysRevD.107.095037 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | It has been commonly assumed that pseudoscalar contributions to the leptonic
decay of charged mesons, like pions and kaons, is strongly constrained due to
the helicity suppression present in the ratio $R_{l/l'} = \Gamma(P \rightarrow
l\nu[\gamma])/\Gamma(P \rightarrow l'\nu[\gamma])$, where $P$ are the charged
pseudoscalar meson and $l,l' = e,\mu,\tau$. Here we show that if the effective
couplings are proportional to the corresponding charged lepton masses (and also
the PMNS matrix), the constraints from $R_{l/l'}$ are entirely avoided, and a
rather new large allowed region is permitted in the parameter space. In the
case of the electron, we found a non-trivial region in the range
$10^{-4}\lesssim (G^\eta/G_F) \lesssim 10^{-3}$, where $G^\eta$ is the
effective pseudoscalar coupling associated with a novel charged scalar field,
$\eta$, and $G_F$ is the Fermi constant. Furthermore, we show that this
dependence of the pseudoscalar couplings on the charged lepton masses can
naturally be associated with a critical class beyond the standard model
physics, namely models without (leptonic) flavor-changing neutral currents in
the scalar sector. The most known examples are the models that satisfy the
so-called Glashow-Weinberg-Paschos theorem. Finally, we also point out that, in
those cases, the decay rate is degenerated with the Standard Model prediction,
possibly hiding the new physics effects in those decays.
| [
{
"created": "Thu, 25 Feb 2021 19:00:02 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Dec 2021 14:41:33 GMT",
"version": "v2"
},
{
"created": "Thu, 2 Dec 2021 15:31:11 GMT",
"version": "v3"
},
{
"created": "Wed, 15 Mar 2023 17:08:00 GMT",
"version": "v4"
}
] | 2023-09-14 | [
[
"Guzzo",
"M. M.",
""
],
[
"Leite",
"L. J. F.",
""
],
[
"Novelo",
"S. W. P.",
""
],
[
"Peres",
"O. L. G.",
""
],
[
"Pleitez",
"V.",
""
]
] | It has been commonly assumed that pseudoscalar contributions to the leptonic decay of charged mesons, like pions and kaons, is strongly constrained due to the helicity suppression present in the ratio $R_{l/l'} = \Gamma(P \rightarrow l\nu[\gamma])/\Gamma(P \rightarrow l'\nu[\gamma])$, where $P$ are the charged pseudoscalar meson and $l,l' = e,\mu,\tau$. Here we show that if the effective couplings are proportional to the corresponding charged lepton masses (and also the PMNS matrix), the constraints from $R_{l/l'}$ are entirely avoided, and a rather new large allowed region is permitted in the parameter space. In the case of the electron, we found a non-trivial region in the range $10^{-4}\lesssim (G^\eta/G_F) \lesssim 10^{-3}$, where $G^\eta$ is the effective pseudoscalar coupling associated with a novel charged scalar field, $\eta$, and $G_F$ is the Fermi constant. Furthermore, we show that this dependence of the pseudoscalar couplings on the charged lepton masses can naturally be associated with a critical class beyond the standard model physics, namely models without (leptonic) flavor-changing neutral currents in the scalar sector. The most known examples are the models that satisfy the so-called Glashow-Weinberg-Paschos theorem. Finally, we also point out that, in those cases, the decay rate is degenerated with the Standard Model prediction, possibly hiding the new physics effects in those decays. |
1803.04961 | Jonathan Cornell | James M. Cline and Jonathan M. Cornell | Dark decay of the neutron | 10 pages, 2 figures. v2: Clarifications and references added.
Submitted to JHEP. v3: Dark matter self scattering cross section and
constraints from direct detection corrected, additional constraints added.
v4: Typos corrected. Matches published version | JHEP 1807 (2018) 081 | 10.1007/JHEP07(2018)081 | null | hep-ph astro-ph.CO astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New decay channels for the neutron into dark matter plus other particles have
been suggested for explaining a long-standing discrepancy between the neutron
lifetime measured from trapped neutrons versus those decaying in flight. Many
such scenarios are already ruled out by their effects on neutron stars, and the
decay into dark matter plus photon has been experimentally excluded. Here we
explore the decay into a dark Dirac fermion $\chi$ and a dark photon $A'$,
which can be consistent with all constraints if $\chi$ is a subdominant
component of the dark matter. Neutron star constraints are evaded if the dark
photon mass to coupling ratio is $m_{A'}/g' \lesssim (45-60)\,$MeV, depending
upon the nuclear equation of state. $g'$ and the kinetic mixing between U(1)$'$
and electromagnetism are tightly constrained by direct and indirect dark matter
detection, supernova constraints, and cosmological limits.
| [
{
"created": "Tue, 13 Mar 2018 17:59:09 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Mar 2018 03:12:12 GMT",
"version": "v2"
},
{
"created": "Wed, 27 Jun 2018 15:25:39 GMT",
"version": "v3"
},
{
"created": "Thu, 12 Jul 2018 18:54:31 GMT",
"version": "v4"
}
] | 2018-07-16 | [
[
"Cline",
"James M.",
""
],
[
"Cornell",
"Jonathan M.",
""
]
] | New decay channels for the neutron into dark matter plus other particles have been suggested for explaining a long-standing discrepancy between the neutron lifetime measured from trapped neutrons versus those decaying in flight. Many such scenarios are already ruled out by their effects on neutron stars, and the decay into dark matter plus photon has been experimentally excluded. Here we explore the decay into a dark Dirac fermion $\chi$ and a dark photon $A'$, which can be consistent with all constraints if $\chi$ is a subdominant component of the dark matter. Neutron star constraints are evaded if the dark photon mass to coupling ratio is $m_{A'}/g' \lesssim (45-60)\,$MeV, depending upon the nuclear equation of state. $g'$ and the kinetic mixing between U(1)$'$ and electromagnetism are tightly constrained by direct and indirect dark matter detection, supernova constraints, and cosmological limits. |
hep-ph/0108241 | Marco Stratmann | M. Stratmann, W. Vogelsang | Next-to-leading order QCD evolution of transversity fragmentation
functions | 9 pages, LaTeX | Phys.Rev.D65:057502,2002 | 10.1103/PhysRevD.65.057502 | BNL-NT-01/20, RBRC-195 | hep-ph | null | We derive the next-to-leading order splitting kernels for the scale evolution
of fragmentation functions for transversely polarized quarks into transversely
polarized hadrons.
| [
{
"created": "Wed, 29 Aug 2001 13:07:25 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Stratmann",
"M.",
""
],
[
"Vogelsang",
"W.",
""
]
] | We derive the next-to-leading order splitting kernels for the scale evolution of fragmentation functions for transversely polarized quarks into transversely polarized hadrons. |
2003.07418 | Eugene Drukarev | E. G. Drukarev, A. I. Mikhailov, Kh. Yu. Rakhimov, and H. T. Yusupov | Relativistic photoeffect for $s$ states in a central field | null | null | 10.1140/epjd/e2020-10264-7 | null | hep-ph physics.atom-ph quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the photoionization of the $s$ states in the systems bound by
sufficiently weak central fields $V(r)$ for the large photon energies
corresponding to the relativistic photoelectrons. We demonstrate that the
energy dependence of the photoionization cross section can be obtained without
solving the wave equation. We show that the shape of the energy dependence of
the cross section is determined by analytical properties of the binding
potential $V(r)$. We find the cross sections for the potentials $V(r)$ which
have singularities in the origin, on the real axis and in the complex plane.
| [
{
"created": "Mon, 16 Mar 2020 19:22:44 GMT",
"version": "v1"
}
] | 2020-08-26 | [
[
"Drukarev",
"E. G.",
""
],
[
"Mikhailov",
"A. I.",
""
],
[
"Rakhimov",
"Kh. Yu.",
""
],
[
"Yusupov",
"H. T.",
""
]
] | We study the photoionization of the $s$ states in the systems bound by sufficiently weak central fields $V(r)$ for the large photon energies corresponding to the relativistic photoelectrons. We demonstrate that the energy dependence of the photoionization cross section can be obtained without solving the wave equation. We show that the shape of the energy dependence of the cross section is determined by analytical properties of the binding potential $V(r)$. We find the cross sections for the potentials $V(r)$ which have singularities in the origin, on the real axis and in the complex plane. |
hep-ph/0006178 | G. Valencia | G. Valencia | CP Violation in $\Lambda$ to p $\pi^-$: SM vs New Physics | 6 pages, Talk at Hyperon 99 Fermilab, and at Symmetries in Subatomic
Physics, Adelaide, 2000 | AIP Conf.Proc.539:80-85,2000 | 10.1063/1.1330905 | null | hep-ph | null | I discuss CP violation in $\Lambda$ to p $\pi^-$ comparing the standard model
expectations with what could happen in new physics scenarios. I point out that
Fermilab experiment E871 is sensitive to some of these scenarios.
| [
{
"created": "Thu, 15 Jun 2000 20:03:49 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Valencia",
"G.",
""
]
] | I discuss CP violation in $\Lambda$ to p $\pi^-$ comparing the standard model expectations with what could happen in new physics scenarios. I point out that Fermilab experiment E871 is sensitive to some of these scenarios. |
1208.3980 | Adam Szczepaniak | A.Ostrander, E.Santopinto, A.P.Szczepaniak, A.Vassallo | Gluon chain formation in presence of static charges | 10 pages, 9 figures | null | 10.1103/PhysRevD.86.114015 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the origins of the gluon chain model. The model serves as a
realization of the dynamics of the chromoelectric flux between static
quark-antiquark sources. The derivation is based on the large-N_C limit of the
Coulomb gauge Hamiltonian in the presence of a background field introduced to
model magnetic confinement.
| [
{
"created": "Mon, 20 Aug 2012 11:28:26 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Ostrander",
"A.",
""
],
[
"Santopinto",
"E.",
""
],
[
"Szczepaniak",
"A. P.",
""
],
[
"Vassallo",
"A.",
""
]
] | We consider the origins of the gluon chain model. The model serves as a realization of the dynamics of the chromoelectric flux between static quark-antiquark sources. The derivation is based on the large-N_C limit of the Coulomb gauge Hamiltonian in the presence of a background field introduced to model magnetic confinement. |
0808.2699 | Vinod Chandra | Vineet Agotiya, Vinod Chandra, Binoy Krishna Patra | Dissociation of quarkonium in hot QCD medium: Modification of the
inter-quark potential | Revised version, Revtex4, Accepted for publication in Physical Review
C | Phys.Rev.C80:025210,2009 | 10.1103/PhysRevC.80.025210 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have studied the dissociation of heavy quarkonium states in a hot QCD
medium by investigating the medium modifications to a heavy quark potential.
Our model shows that in-medium modification causes the screening of the charge
in contrast to the screening of the range of the potential. We have then
employed the medium-modified potential to estimate the dissociation pattern of
the charmonium and bottomonium states and also explore how the pattern changes
as we go from the perturbative to nonperturbative domain in the Debye mass. The
results are in good agreement with the other current theoretical works both
from the spectral function analysis and the potential model study.
| [
{
"created": "Wed, 20 Aug 2008 06:41:24 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Nov 2008 17:41:52 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Aug 2009 17:31:24 GMT",
"version": "v3"
}
] | 2009-09-11 | [
[
"Agotiya",
"Vineet",
""
],
[
"Chandra",
"Vinod",
""
],
[
"Patra",
"Binoy Krishna",
""
]
] | We have studied the dissociation of heavy quarkonium states in a hot QCD medium by investigating the medium modifications to a heavy quark potential. Our model shows that in-medium modification causes the screening of the charge in contrast to the screening of the range of the potential. We have then employed the medium-modified potential to estimate the dissociation pattern of the charmonium and bottomonium states and also explore how the pattern changes as we go from the perturbative to nonperturbative domain in the Debye mass. The results are in good agreement with the other current theoretical works both from the spectral function analysis and the potential model study. |
2111.04087 | Volodymyr Takhistov | Carlos Chichiri, Graciela B. Gelmini, Philip Lu, Volodymyr Takhistov | Cosmological Dependence of Sterile Neutrino Dark Matter With
Self-Interacting Neutrinos | 23 pages, 5 figures | null | 10.1088/1475-7516/2022/09/036 | IPMU21-0076 | hep-ph astro-ph.CO astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Unexplored interactions of neutrinos could be the key to understanding the
nature of the dark matter (DM). In particular, active neutrinos with new
self-interactions can produce keV-mass sterile neutrinos that account for the
whole of the DM through the Dodelson-Widrow mechanism for a large range of
active-sterile mixing values. This production typically occurs before Big-Bang
Nucleosynthesis (BBN) in a yet uncharted era of the Universe. We assess how the
mixing range for keV-mass sterile neutrino DM is affected by the uncertainty in
the early Universe pre-BBN cosmology. This is particularly relevant for
identifying the viable parameter space of sterile neutrino searches allowed by
all astrophysical limits, as well as for cosmology, since the detection of a
sterile neutrino could constitute the first observation of a particle providing
information about the pre-BBN epoch. We find that the combined uncertainties in
the early Universe cosmology and neutrino interactions significantly expand the
allowed parameter space for sterile neutrinos that can constitute the whole of
the DM.
| [
{
"created": "Sun, 7 Nov 2021 13:41:37 GMT",
"version": "v1"
}
] | 2022-09-21 | [
[
"Chichiri",
"Carlos",
""
],
[
"Gelmini",
"Graciela B.",
""
],
[
"Lu",
"Philip",
""
],
[
"Takhistov",
"Volodymyr",
""
]
] | Unexplored interactions of neutrinos could be the key to understanding the nature of the dark matter (DM). In particular, active neutrinos with new self-interactions can produce keV-mass sterile neutrinos that account for the whole of the DM through the Dodelson-Widrow mechanism for a large range of active-sterile mixing values. This production typically occurs before Big-Bang Nucleosynthesis (BBN) in a yet uncharted era of the Universe. We assess how the mixing range for keV-mass sterile neutrino DM is affected by the uncertainty in the early Universe pre-BBN cosmology. This is particularly relevant for identifying the viable parameter space of sterile neutrino searches allowed by all astrophysical limits, as well as for cosmology, since the detection of a sterile neutrino could constitute the first observation of a particle providing information about the pre-BBN epoch. We find that the combined uncertainties in the early Universe cosmology and neutrino interactions significantly expand the allowed parameter space for sterile neutrinos that can constitute the whole of the DM. |
hep-ph/0107331 | David Smith | Lawrence Hall, Yasunori Nomura and David Smith | Gauge-Higgs Unification in Higher Dimensions | 27 pages, latex, references added | Nucl.Phys.B639:307-330,2002 | 10.1016/S0550-3213(02)00539-4 | UCB-PTH-01/28, LBNL-48669 | hep-ph hep-th | null | The electroweak Higgs doublets are identified as components of a vector
multiplet in a higher dimensional supersymmetric field theory. We construct a
minimal model in 6D where the electroweak $SU(2) \otimes U(1)$ gauge group is
extended to SU(3), and unified 6D models with the unified SU(5) gauge symmetry
extended to SU(6). In these realistic theories the extended gauge group is
broken by orbifold boundary conditions, leaving Higgs doublet zero modes which
have Yukawa couplings to quarks and leptons on the orbifold fixed points. In
one SU(6) model the weak mixing angle receives power law corrections, while in
another the fixed point structure forbids such corrections. A 5D model is also
constructed in which the Higgs doublet contains the fifth component of the
gauge field. In this case Yukawa couplings are introduced as non-local
operators involving the Wilson line of this gauge field.
| [
{
"created": "Tue, 31 Jul 2001 21:01:06 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Sep 2001 20:48:22 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Hall",
"Lawrence",
""
],
[
"Nomura",
"Yasunori",
""
],
[
"Smith",
"David",
""
]
] | The electroweak Higgs doublets are identified as components of a vector multiplet in a higher dimensional supersymmetric field theory. We construct a minimal model in 6D where the electroweak $SU(2) \otimes U(1)$ gauge group is extended to SU(3), and unified 6D models with the unified SU(5) gauge symmetry extended to SU(6). In these realistic theories the extended gauge group is broken by orbifold boundary conditions, leaving Higgs doublet zero modes which have Yukawa couplings to quarks and leptons on the orbifold fixed points. In one SU(6) model the weak mixing angle receives power law corrections, while in another the fixed point structure forbids such corrections. A 5D model is also constructed in which the Higgs doublet contains the fifth component of the gauge field. In this case Yukawa couplings are introduced as non-local operators involving the Wilson line of this gauge field. |
1209.4808 | Dinh Nguyen Dinh | D. N. Dinh, S. T. Petcov, N. Sasao, M. Tanaka and M. Yoshimura | Observables in Neutrino Mass Spectroscopy Using Atoms | Typos corrected, a reference added; Version to be published in
Physics Letters B | null | 10.1016/j.physletb.2013.01.015 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The process of collective de-excitation of atoms in a metastable level into
emission mode of a single photon plus a neutrino pair, called radiative
emission of neutrino pair (RENP), is sensitive to the absolute neutrino mass
scale, to the neutrino mass hierarchy and to the nature (Dirac or Majorana) of
massive neutrinos. We investigate how the indicated neutrino mass and mixing
observables can be determined from the measurement of the corresponding
continuous photon spectrum taking the example of a transition between specific
levels of the Yb atom. The possibility of determining the nature of massive
neutrinos and, if neutrinos are Majorana fermions, of obtaining information
about the Majorana phases in the neutrino mixing matrix, is analyzed in the
cases of normal hierarchical, inverted hierarchical and quasi-degenerate types
of neutrino mass spectrum. We find, in particular, that the sensitivity to the
nature of massive neutrinos depends critically on the atomic level energy
difference relevant in the RENP.
| [
{
"created": "Fri, 21 Sep 2012 13:02:20 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Sep 2012 07:16:28 GMT",
"version": "v2"
},
{
"created": "Thu, 17 Jan 2013 13:31:43 GMT",
"version": "v3"
}
] | 2015-06-11 | [
[
"Dinh",
"D. N.",
""
],
[
"Petcov",
"S. T.",
""
],
[
"Sasao",
"N.",
""
],
[
"Tanaka",
"M.",
""
],
[
"Yoshimura",
"M.",
""
]
] | The process of collective de-excitation of atoms in a metastable level into emission mode of a single photon plus a neutrino pair, called radiative emission of neutrino pair (RENP), is sensitive to the absolute neutrino mass scale, to the neutrino mass hierarchy and to the nature (Dirac or Majorana) of massive neutrinos. We investigate how the indicated neutrino mass and mixing observables can be determined from the measurement of the corresponding continuous photon spectrum taking the example of a transition between specific levels of the Yb atom. The possibility of determining the nature of massive neutrinos and, if neutrinos are Majorana fermions, of obtaining information about the Majorana phases in the neutrino mixing matrix, is analyzed in the cases of normal hierarchical, inverted hierarchical and quasi-degenerate types of neutrino mass spectrum. We find, in particular, that the sensitivity to the nature of massive neutrinos depends critically on the atomic level energy difference relevant in the RENP. |
hep-ph/0110279 | Kai Schwenzer | J. Meyer, K. Schwenzer, H.-J. Pirner, A. Deandrea | Renormalization Group Flow in large N_c | 15 pages, 4 figures, submitted to Phys. Lett. B, added references | Phys.Lett. B526 (2002) 79-89 | 10.1016/S0370-2693(01)01482-4 | null | hep-ph | null | We calculate renormalization group flow equations for the linear sigma-model
in large N_c approximation. The flow equations decouple and can be solved
analytically. The solution is equal to a self consistent solution of the NJL
model in the same approximation, which shows that flow equations are a
promising method to extend the calculation to higher order in 1/N_c. Including
explicit chiral symmetry breaking, the large N_c approximation describes
physics reasonably well. We further compare the analytic solution to the
usually used polynomial truncation and find consistency.
| [
{
"created": "Mon, 22 Oct 2001 09:44:32 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Dec 2001 17:23:12 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Meyer",
"J.",
""
],
[
"Schwenzer",
"K.",
""
],
[
"Pirner",
"H. -J.",
""
],
[
"Deandrea",
"A.",
""
]
] | We calculate renormalization group flow equations for the linear sigma-model in large N_c approximation. The flow equations decouple and can be solved analytically. The solution is equal to a self consistent solution of the NJL model in the same approximation, which shows that flow equations are a promising method to extend the calculation to higher order in 1/N_c. Including explicit chiral symmetry breaking, the large N_c approximation describes physics reasonably well. We further compare the analytic solution to the usually used polynomial truncation and find consistency. |
hep-ph/9609447 | George Jikia | V. Borodulin (Institute for High Energy Physics, Protvino) and G.
Jikia (Albert-Ludwigs-Universit"at Freiburg) | Analytic evaluation of two-loop renormalization constants of enhanced
electroweak strength in the Higgs sector of the Standard Model | 8 pages, 3 Postscript figures, uses epsfig.sty | Phys.Lett.B391:434-440,1997 | 10.1016/S0370-2693(96)01546-8 | Freiburg-THEP 96/19 | hep-ph | null | We calculate renormalization constants Z_H, Z_w, the Higgs and W-boson mass
and tadpole counterterms in the on-mass-shell renormalization scheme to two
loops in the heavy-Higgs-boson limit m_H >> M_W. Explicit analytic formulae are
presented for the two-loop integrals with masses, which are not known in the
literature. As an application, the analytic expression for the two-loop leading
correction to the fermionic Higgs boson width is obtained.
| [
{
"created": "Tue, 24 Sep 1996 14:07:34 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Sep 1996 14:44:46 GMT",
"version": "v2"
},
{
"created": "Mon, 30 Sep 1996 12:37:39 GMT",
"version": "v3"
},
{
"created": "Mon, 18 Nov 1996 17:12:01 GMT",
"version": "v4"
}
] | 2014-11-17 | [
[
"Borodulin",
"V.",
"",
"Institute for High Energy Physics, Protvino"
],
[
"Jikia",
"G.",
"",
"Albert-Ludwigs-Universit\"at Freiburg"
]
] | We calculate renormalization constants Z_H, Z_w, the Higgs and W-boson mass and tadpole counterterms in the on-mass-shell renormalization scheme to two loops in the heavy-Higgs-boson limit m_H >> M_W. Explicit analytic formulae are presented for the two-loop integrals with masses, which are not known in the literature. As an application, the analytic expression for the two-loop leading correction to the fermionic Higgs boson width is obtained. |
1311.7155 | Joshua Sayre | Tao Han, Zhen Liu and Josh Sayre | Potential Precision on Higgs Couplings and Total Width at the ILC | 23 pages, 5 figures Ver.3 | Phys. Rev. D 89, 113006 (2014) | 10.1103/PhysRevD.89.113006 | PITT-PACC 1312 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We outline a systematic approach to the determination of the Standard
Model-like Higgs boson total width and measurable coupling parameters in a
model-independent manner at the International Linear Collider (ILC) and
illustrate the complementarity for operating the ILC at $250$ GeV near the $Zh$
threshold and at $500$ GeV and $1$ TeV utilizing the $WW, ZZ$ fusion processes.
We perform detailed simulations for an important contributing channel to the
coupling determination and for invisible decays. Without model assumptions, and
combining the information for the coupling ratios from the LHC, the total width
can be determined to an accuracy of about $6%$, and the couplings for the
observable channels can be measured to the $(3-5)%$ level at 250 GeV, reaching
$(1-3)%$ level including the 500 GeV results, with further improvements
possible with a $1$ TeV run. The best precision for the branching fraction
measurement of the Higgs to invisible modes can be reached at $0.5-0.7%$ around
the $Zh$ threshold. Further studies from $ZZ$ fusion at higher energies may
provide significant improvement for the measurements. With modest theory
assumptions, the width and coupling determinations can be further improved to
the percent or sub-percent level.
| [
{
"created": "Wed, 27 Nov 2013 21:09:12 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Jan 2014 22:27:08 GMT",
"version": "v2"
},
{
"created": "Sun, 20 Apr 2014 01:21:47 GMT",
"version": "v3"
}
] | 2014-07-09 | [
[
"Han",
"Tao",
""
],
[
"Liu",
"Zhen",
""
],
[
"Sayre",
"Josh",
""
]
] | We outline a systematic approach to the determination of the Standard Model-like Higgs boson total width and measurable coupling parameters in a model-independent manner at the International Linear Collider (ILC) and illustrate the complementarity for operating the ILC at $250$ GeV near the $Zh$ threshold and at $500$ GeV and $1$ TeV utilizing the $WW, ZZ$ fusion processes. We perform detailed simulations for an important contributing channel to the coupling determination and for invisible decays. Without model assumptions, and combining the information for the coupling ratios from the LHC, the total width can be determined to an accuracy of about $6%$, and the couplings for the observable channels can be measured to the $(3-5)%$ level at 250 GeV, reaching $(1-3)%$ level including the 500 GeV results, with further improvements possible with a $1$ TeV run. The best precision for the branching fraction measurement of the Higgs to invisible modes can be reached at $0.5-0.7%$ around the $Zh$ threshold. Further studies from $ZZ$ fusion at higher energies may provide significant improvement for the measurements. With modest theory assumptions, the width and coupling determinations can be further improved to the percent or sub-percent level. |
hep-ph/0311333 | Alexander Vereshagin | K. Semenov-Tian-Shanski (1), A. Vereshagin (1 and 2) and V.Vereshagin
(1) ((1) St.Petersburg State University, (2) University of Bergen) | Localizable Effective Theories, Bootstrap and the Parameters of Hadron
Resonances | 6 pages, Talk given at the X. International Conference On Hadron
spectroscopy (HADRON'03), August 31 - September 6, 2003, Aschaffenburg,
Germany; to appear in Proceedings | null | 10.1063/1.1799714 | null | hep-ph | null | We discuss the basic principles of constructing a meaningful perturbative
scheme for effective theory. The main goal of this talk is to explain the
approach and to present recent results obtained with the help of the method of
Cauchy forms in several complex variables.
| [
{
"created": "Wed, 26 Nov 2003 01:07:57 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Semenov-Tian-Shanski",
"K.",
"",
"St.Petersburg State University"
],
[
"Vereshagin",
"A.",
"",
"1 and 2"
],
[
"Vereshagin",
"V.",
"",
"St.Petersburg State University"
]
] | We discuss the basic principles of constructing a meaningful perturbative scheme for effective theory. The main goal of this talk is to explain the approach and to present recent results obtained with the help of the method of Cauchy forms in several complex variables. |
2303.02769 | Mohamed Miskaoui | M. Miskaoui | Neutrino model with broken $\mu -\tau $ Symmetry and Unflavored
Leptogenesis with Dihedral Flavor Symmetry | 30 pages, 20 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We propose a new neutrino flavor model based on a $D_{4}\times U(1)$ flavor
symmetry providing predictions for neutrino masses and mixing along with a
successful generation of the observed Baryon Asymmetry of the Universe (BAU).
After the spontaneous breaking of the flavor symmetry, the type I seesaw
mechanism leads to a light neutrino mass matrix with broken $\mu-\tau $
symmetry. By performing a numerical analysis, we find that the model favors a
normal mass hierarchy with the lightest neutrino mass lies in the range
$m_{1}\in \lbrack 2.516,21.351]$ m$\mathrm{eV}$. The phenomenological
implications of the neutrino sector are explored in detail and the results are
discussed. Moreover, the generation of BAU is addressed via the leptogenesis
mechanism from the decay of three right-handed neutrinos $N_{i}$. Through
analytical and numerical analysis of the baryon asymmetry parameter $Y_{B}$, a
successful unflavored leptogenesis takes place within the allowed parameter
space obtained from neutrino phenomenology. We also examine interesting
correlations between $Y_{B}$ and low energy observables and provide a
comprehensive discussion of the results.
| [
{
"created": "Sun, 5 Mar 2023 20:36:36 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Apr 2024 07:52:20 GMT",
"version": "v2"
}
] | 2024-04-26 | [
[
"Miskaoui",
"M.",
""
]
] | We propose a new neutrino flavor model based on a $D_{4}\times U(1)$ flavor symmetry providing predictions for neutrino masses and mixing along with a successful generation of the observed Baryon Asymmetry of the Universe (BAU). After the spontaneous breaking of the flavor symmetry, the type I seesaw mechanism leads to a light neutrino mass matrix with broken $\mu-\tau $ symmetry. By performing a numerical analysis, we find that the model favors a normal mass hierarchy with the lightest neutrino mass lies in the range $m_{1}\in \lbrack 2.516,21.351]$ m$\mathrm{eV}$. The phenomenological implications of the neutrino sector are explored in detail and the results are discussed. Moreover, the generation of BAU is addressed via the leptogenesis mechanism from the decay of three right-handed neutrinos $N_{i}$. Through analytical and numerical analysis of the baryon asymmetry parameter $Y_{B}$, a successful unflavored leptogenesis takes place within the allowed parameter space obtained from neutrino phenomenology. We also examine interesting correlations between $Y_{B}$ and low energy observables and provide a comprehensive discussion of the results. |
1303.6305 | Anton Poluektov | Alex Bondar, Alexander Dolgov, Anton Poluektov and Vitaly Vorobiev | Effect of direct CP violation in charm on gamma extraction from B->DK,
D->K0Spi+pi- Dalitz plot analysis | 5 pages, 2 figures. Accepted by Eur. Phys. Journal C. Replaced by
accepted version. Significant change after discussion with journal referee:
ambiguity in the CPV-allowed fit due to common CP-violating charm phase is
mentioned and way to account for it is proposed. Journal references added,
minor typos corrected | Eur. Phys. J C 73, 2476 (2013) | 10.1140/epjc/s10052-013-2476-9 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A possible effect of direct CP violation in D->K0Spipi decay on the gamma
measurement from B->DK, D->K0Spi+pi- Dalitz plot analysis is considered.
Systematic uncertainty of gamma coming from the current limits on direct CP
violation in D->K0Spi+pi- is estimated, and a modified model-independent
procedure of B->DK, D->K0Spi+pi- Dalitz plot analysis is proposed that gives an
unbiased gamma measurement even in presence of direct CP violation in charm
decays. The technique is applicable to other three-body D decays such as
D->K0SK+K-, D->pi+pi-pi0, etc.
| [
{
"created": "Mon, 25 Mar 2013 20:36:17 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jun 2013 09:39:25 GMT",
"version": "v2"
}
] | 2013-06-25 | [
[
"Bondar",
"Alex",
""
],
[
"Dolgov",
"Alexander",
""
],
[
"Poluektov",
"Anton",
""
],
[
"Vorobiev",
"Vitaly",
""
]
] | A possible effect of direct CP violation in D->K0Spipi decay on the gamma measurement from B->DK, D->K0Spi+pi- Dalitz plot analysis is considered. Systematic uncertainty of gamma coming from the current limits on direct CP violation in D->K0Spi+pi- is estimated, and a modified model-independent procedure of B->DK, D->K0Spi+pi- Dalitz plot analysis is proposed that gives an unbiased gamma measurement even in presence of direct CP violation in charm decays. The technique is applicable to other three-body D decays such as D->K0SK+K-, D->pi+pi-pi0, etc. |
2006.05177 | Henry Day-Hall | Rachid Benbrik (1), Henry Day-Hall (2)(3), Stefano Moretti (2), Souad
Semlali (1) ((1) Laboratoire de Physique fondamentale et Appliq\'ee Safi,
Facult\'e Polydisciplinaire de Safi, Sidi Bouzid, Morocco, (2) School of
Physics and Astronomy, University of Southampton, United Kingdom, (3)
Particle Physics Department, Rutherford Appleton Laboratory, United Kingdom) | Mapping $pp\to A\to ZH\to l^+l^-b\bar b$ and $pp\to H\to ZA\to
l^+l^-b\bar b$ Current and Future Searches onto 2HDM Parameter Spaces | 16 pages, 4 figures | null | 10.1016/j.physletb.2020.135819 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By borrowing the results from a Large Hadron Collider (LHC) analysis
performed with $36.1~\text{fb}^{-1}$ of Run 2 data intended to search for $A$
production followed by $ZH$ decay in turn yielding $l^+l^-b\bar b$ ($l=e,\mu$)
final states in the context of the standard four Yukawa types of the 2-Higgs
Doublet Model (2HDM), we recast it in terms of sensitivity reaches for the
similar process $pp\to H\to ZA\to l^+l^-b\bar b$. This simple exercise across
the two processes, which is possible because the only kinematic difference
between these are different widths for the Higgs bosons, in turn affecting
minimally the efficiency of an experimental selection, enables us to expand the
region of parameter space that can be tested to the case when $m_H\ge m_A+m_Z$.
Furthermore, we extrapolate our results to full Run 3 data samples. We conclude
that, while the high energy and luminosity stage of the LHC can afford one with
increased sensitivity to the 2HDM in general, the recast analysis does not add
anything to what already probed through the actual one.
| [
{
"created": "Tue, 9 Jun 2020 10:49:04 GMT",
"version": "v1"
}
] | 2020-10-15 | [
[
"Benbrik",
"Rachid",
""
],
[
"Day-Hall",
"Henry",
""
],
[
"Moretti",
"Stefano",
""
],
[
"Semlali",
"Souad",
""
]
] | By borrowing the results from a Large Hadron Collider (LHC) analysis performed with $36.1~\text{fb}^{-1}$ of Run 2 data intended to search for $A$ production followed by $ZH$ decay in turn yielding $l^+l^-b\bar b$ ($l=e,\mu$) final states in the context of the standard four Yukawa types of the 2-Higgs Doublet Model (2HDM), we recast it in terms of sensitivity reaches for the similar process $pp\to H\to ZA\to l^+l^-b\bar b$. This simple exercise across the two processes, which is possible because the only kinematic difference between these are different widths for the Higgs bosons, in turn affecting minimally the efficiency of an experimental selection, enables us to expand the region of parameter space that can be tested to the case when $m_H\ge m_A+m_Z$. Furthermore, we extrapolate our results to full Run 3 data samples. We conclude that, while the high energy and luminosity stage of the LHC can afford one with increased sensitivity to the 2HDM in general, the recast analysis does not add anything to what already probed through the actual one. |
2205.05750 | Ted Rogers | J. O. Gonzalez-Hernandez, T. C. Rogers, N. Sato | Combining nonperturbative transverse momentum dependence with TMD
evolution | 41 pages, 12 figures | null | 10.1103/PhysRevD.106.034002 | null | hep-ph hep-ex nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | Central to understanding the nonpertubative, intrinsic partonic nature of
hadron structure are the concepts of transverse momentum dependent (TMD) parton
distribution and fragmentation functions. A TMD factorization approach to the
phenomenology of semi-inclusive processes that includes evolution, higher
orders, and matching to larger transverse momentum, is ultimately necessary for
reliably connecting with phenomenologically extracted nonperturbative
structures, especially when widely different scales are involved. In this
paper, we will address some of the difficulties that arise when
phenomenological techniques that were originally designed for very high energy
applications are extended to studies of hadron structures, and we will solidify
the connection between standard high energy TMD implementations and the more
intuitive, parton model based approaches to phenomenology that emphasize
nonperturbative hadron structure. In the process, we will elaborate on
differences between forward and backward TMD evolution, which in the context of
this paper we call "bottom-up" and "top-down" approaches, and we will explain
the advantages of a bottom-up strategy. We will also emphasize and clarify the
role of the integral relations that connect TMD and collinear correlation
functions. We will show explicitly how they constrain the nonperturbative
"$g$-functions" of standard Collins-Soper-Sterman (CSS) implementations of TMD
factorization. This paper is especially targeted toward phenomenologists and
model builders who are interested in merging specific nonperturbative models
and calculations (including lattice QCD) with TMD factorization at large $Q$.
Our main result is a recipe for incorporating nonperturbative models into TMD
factorization, and for constraining their parameters in a way that matches to
perturbative QCD and evolution.
| [
{
"created": "Wed, 11 May 2022 19:41:54 GMT",
"version": "v1"
}
] | 2022-08-17 | [
[
"Gonzalez-Hernandez",
"J. O.",
""
],
[
"Rogers",
"T. C.",
""
],
[
"Sato",
"N.",
""
]
] | Central to understanding the nonpertubative, intrinsic partonic nature of hadron structure are the concepts of transverse momentum dependent (TMD) parton distribution and fragmentation functions. A TMD factorization approach to the phenomenology of semi-inclusive processes that includes evolution, higher orders, and matching to larger transverse momentum, is ultimately necessary for reliably connecting with phenomenologically extracted nonperturbative structures, especially when widely different scales are involved. In this paper, we will address some of the difficulties that arise when phenomenological techniques that were originally designed for very high energy applications are extended to studies of hadron structures, and we will solidify the connection between standard high energy TMD implementations and the more intuitive, parton model based approaches to phenomenology that emphasize nonperturbative hadron structure. In the process, we will elaborate on differences between forward and backward TMD evolution, which in the context of this paper we call "bottom-up" and "top-down" approaches, and we will explain the advantages of a bottom-up strategy. We will also emphasize and clarify the role of the integral relations that connect TMD and collinear correlation functions. We will show explicitly how they constrain the nonperturbative "$g$-functions" of standard Collins-Soper-Sterman (CSS) implementations of TMD factorization. This paper is especially targeted toward phenomenologists and model builders who are interested in merging specific nonperturbative models and calculations (including lattice QCD) with TMD factorization at large $Q$. Our main result is a recipe for incorporating nonperturbative models into TMD factorization, and for constraining their parameters in a way that matches to perturbative QCD and evolution. |
hep-ph/9702264 | Boris Kayser | Boris Kayser | CP Violation in the K and B Systems | To appear in the Proceedings of the Summer School in High Energy
Physics and Cosmology, held at ICTP, Trieste, 1995. 47 pages. PS file | null | null | FERMILAB-CONF-96/429-T, NSF-PT-96-2 | hep-ph | null | Although CP violation was discovered more than thirty years ago, its origin
is still unknown. In these lectures, we describe the CP-violating effects which
have been seen in K decays, and explain how CP violation can be caused by the
Standard Model weak interaction. The hypothesis that this interaction is indeed
the origin of CP violation will be incisively tested by future experiments on B
and K decays. We explain what quantities these experiments will try to
determine, and how they will be able to determine them in a theoretically clean
way. To clarify the physics of the K system, we give a phase-convention-free
description of CP violation in this system. We conclude by briefly exploring
whether electric dipole moments actually violate CP even if CPT invariance is
not assumed.
| [
{
"created": "Wed, 5 Feb 1997 16:49:19 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kayser",
"Boris",
""
]
] | Although CP violation was discovered more than thirty years ago, its origin is still unknown. In these lectures, we describe the CP-violating effects which have been seen in K decays, and explain how CP violation can be caused by the Standard Model weak interaction. The hypothesis that this interaction is indeed the origin of CP violation will be incisively tested by future experiments on B and K decays. We explain what quantities these experiments will try to determine, and how they will be able to determine them in a theoretically clean way. To clarify the physics of the K system, we give a phase-convention-free description of CP violation in this system. We conclude by briefly exploring whether electric dipole moments actually violate CP even if CPT invariance is not assumed. |
1912.04457 | Shi Pu | Jun-Jie Zhang, Hong-Zhong Wu, Shi Pu, Guang-You Qin, Qun Wang | Towards a full solution of relativistic Boltzmann equation for
quark-gluon matter on GPUs | 32 pages, 12 figures | Phys. Rev. D 102, 074011 (2020) | 10.1103/PhysRevD.102.074011 | null | hep-ph hep-ex nucl-th physics.comp-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have developed a numerical framework for a full solution of the
relativistic Boltzmann equations for the quark-gluon matter using the multiple
Graphics Processing Units (GPUs) on distributed clusters. Including all the $2
\to 2$ scattering processes of 3-flavor quarks and gluons, we compute the time
evolution of distribution functions in both coordinate and momentum spaces for
the cases of pure gluons, quarks and the mixture of quarks and gluons. By
introducing a symmetrical sampling method on GPUs which ensures the particle
number conservation, our framework is able to perform the space-time evolution
of quark-gluon system towards thermal equilibrium with high performance. We
also observe that the gluons naturally accumulate in the soft region at the
early time, which may indicate the gluon condensation.
| [
{
"created": "Tue, 10 Dec 2019 02:24:13 GMT",
"version": "v1"
}
] | 2020-10-28 | [
[
"Zhang",
"Jun-Jie",
""
],
[
"Wu",
"Hong-Zhong",
""
],
[
"Pu",
"Shi",
""
],
[
"Qin",
"Guang-You",
""
],
[
"Wang",
"Qun",
""
]
] | We have developed a numerical framework for a full solution of the relativistic Boltzmann equations for the quark-gluon matter using the multiple Graphics Processing Units (GPUs) on distributed clusters. Including all the $2 \to 2$ scattering processes of 3-flavor quarks and gluons, we compute the time evolution of distribution functions in both coordinate and momentum spaces for the cases of pure gluons, quarks and the mixture of quarks and gluons. By introducing a symmetrical sampling method on GPUs which ensures the particle number conservation, our framework is able to perform the space-time evolution of quark-gluon system towards thermal equilibrium with high performance. We also observe that the gluons naturally accumulate in the soft region at the early time, which may indicate the gluon condensation. |
1506.04121 | Stefan Schacht | Sarah M\"uller, Ulrich Nierste, Stefan Schacht | Sum Rules of Charm CP Asymmetries beyond the SU(3)$_F$ Limit | Typos corrected, clarifying text added. Matches version published in
PRL | Phys. Rev. Lett. 115, 251802 (2015) | 10.1103/PhysRevLett.115.251802 | TTP15-020 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We find new sum rules between direct CP asymmetries in $D$ meson decays with
coefficients that can be determined from a global fit to branching ratio data.
Our sum rules eliminate the penguin topologies $P$ and $PA$, which cannot be
determined from branching ratios. In this way we can make predictions about
direct CP asymmetries in the standard model without ad hoc assumptions on the
sizes of penguin diagrams. We consistently include first-order SU(3)$_F$
breaking in the topological amplitudes extracted from the branching ratios. By
confronting our sum rules with future precise data from LHCb and Belle~II one
will identify or constrain new-physics contributions to $P$ or $PA$. The first
sum rule correlates the CP asymmetries $a_{CP}^{\mathrm{dir}}$ in $D^0\to
K^+K^-$, $D^0\to \pi^+\pi^-$, and $D^0\to \pi^0\pi^0$. We study the region of
the $a_{CP}^{\mathrm{dir}}(D^0\to \pi^+\pi^-)$--$a_{CP}^{\mathrm{dir}} (D^0\to
\pi^0\pi^0)$ plane allowed by current data and find that our sum rule excludes
more than half of the allowed region at 95\% C.L. Our second sum rule
correlates the direct CP asymmetries in $D^+\rightarrow \bar{K}^0 K^+$,
$D_s^+\rightarrow K^0 \pi^+$, and $D_s^+\rightarrow K^+\pi^0$.
| [
{
"created": "Fri, 12 Jun 2015 19:08:17 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Nov 2015 19:33:05 GMT",
"version": "v2"
}
] | 2015-12-18 | [
[
"Müller",
"Sarah",
""
],
[
"Nierste",
"Ulrich",
""
],
[
"Schacht",
"Stefan",
""
]
] | We find new sum rules between direct CP asymmetries in $D$ meson decays with coefficients that can be determined from a global fit to branching ratio data. Our sum rules eliminate the penguin topologies $P$ and $PA$, which cannot be determined from branching ratios. In this way we can make predictions about direct CP asymmetries in the standard model without ad hoc assumptions on the sizes of penguin diagrams. We consistently include first-order SU(3)$_F$ breaking in the topological amplitudes extracted from the branching ratios. By confronting our sum rules with future precise data from LHCb and Belle~II one will identify or constrain new-physics contributions to $P$ or $PA$. The first sum rule correlates the CP asymmetries $a_{CP}^{\mathrm{dir}}$ in $D^0\to K^+K^-$, $D^0\to \pi^+\pi^-$, and $D^0\to \pi^0\pi^0$. We study the region of the $a_{CP}^{\mathrm{dir}}(D^0\to \pi^+\pi^-)$--$a_{CP}^{\mathrm{dir}} (D^0\to \pi^0\pi^0)$ plane allowed by current data and find that our sum rule excludes more than half of the allowed region at 95\% C.L. Our second sum rule correlates the direct CP asymmetries in $D^+\rightarrow \bar{K}^0 K^+$, $D_s^+\rightarrow K^0 \pi^+$, and $D_s^+\rightarrow K^+\pi^0$. |
1704.08220 | Falko Dulat | Falko Dulat, Simone Lionetti, Bernhard Mistlberger, Andrea Pelloni,
Caterina Specchia | Higgs-differential cross section at NNLO in dimensional regularisation | 27 pages, 6 awesome figures | null | 10.1007/JHEP07(2017)017 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an analytic computation of the Higgs production cross section in
the gluon fusion channel, which is differential in the components of the Higgs
momentum and inclusive in the associated partonic radiation through NNLO in
perturbative QCD. Our computation includes the necessary higher order terms in
the dimensional regulator beyond the finite part that are required for
renormalisation and collinear factorisation at N$^3$LO. We outline in detail
the computational methods which we employ. We present numerical predictions for
realistic final state observables, specifically distributions for the decay
products of the Higgs boson in the $\gamma\gamma$ decay channel.
| [
{
"created": "Wed, 26 Apr 2017 17:12:16 GMT",
"version": "v1"
}
] | 2017-08-02 | [
[
"Dulat",
"Falko",
""
],
[
"Lionetti",
"Simone",
""
],
[
"Mistlberger",
"Bernhard",
""
],
[
"Pelloni",
"Andrea",
""
],
[
"Specchia",
"Caterina",
""
]
] | We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N$^3$LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the $\gamma\gamma$ decay channel. |
hep-ph/9804243 | Tianjun Li | Tianjun Li | Soft Terms in M-theory | 15 pages, latex, 4 figures | Phys. Rev. D 59, 107902 (1999) | 10.1103/PhysRevD.59.107902 | MADPH-98-1051 | hep-ph hep-th | null | We discuss dilaton and Moduli dominant SUSY breaking scenarios in M-theory.
In addition, for the nonperturbative superpotential from gaugino condensation,
we discuss the soft terms in the simplest model (only S and T moduli fields)
and in the $T^6/Z_{12}$ model from M-theory. From the phenomenology
consideration, we suggest massless scalar SUSY breaking scenario.
| [
{
"created": "Mon, 6 Apr 1998 18:39:18 GMT",
"version": "v1"
}
] | 2016-08-25 | [
[
"Li",
"Tianjun",
""
]
] | We discuss dilaton and Moduli dominant SUSY breaking scenarios in M-theory. In addition, for the nonperturbative superpotential from gaugino condensation, we discuss the soft terms in the simplest model (only S and T moduli fields) and in the $T^6/Z_{12}$ model from M-theory. From the phenomenology consideration, we suggest massless scalar SUSY breaking scenario. |
hep-ph/9711316 | Sergio Pastor | S. Pastor, V.B. Semikoz and J.W.F. Valle | Low-energy Anti-neutrinos from the Sun | LaTeX, 14 pages, 3 PS figures included, 3 references added | Phys. Lett. B423:118-125,1998 | 10.1016/S0370-2693(98)00122-1 | FTUV/97-43, IFIC/97-59 | hep-ph astro-ph | null | We consider the sensitivity of future neutrino experiments in the low energy
region, such as BOREXINO or HELLAZ, to a solar electron antineutrino signal. We
show that, if neutrino conversions within the Sun result in partial
polarization of initial solar neutrino fluxes, then a new opportunity arises to
observe the electron antineutrinos and thus to probe the Majorana nature of the
neutrinos. This is achieved by comparing the slopes of the energy dependence of
the differential neutrino electron scattering cross section for different
neutrino conversion scenarios. We also show how the \nu_e -> \bar{\nu}_e
conversions may take place for low energy solar neutrinos while being
unobservable at the Kamiokande and Super-Kamiokande experiments.
| [
{
"created": "Thu, 13 Nov 1997 15:14:38 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Mar 1998 19:55:15 GMT",
"version": "v2"
}
] | 2009-09-17 | [
[
"Pastor",
"S.",
""
],
[
"Semikoz",
"V. B.",
""
],
[
"Valle",
"J. W. F.",
""
]
] | We consider the sensitivity of future neutrino experiments in the low energy region, such as BOREXINO or HELLAZ, to a solar electron antineutrino signal. We show that, if neutrino conversions within the Sun result in partial polarization of initial solar neutrino fluxes, then a new opportunity arises to observe the electron antineutrinos and thus to probe the Majorana nature of the neutrinos. This is achieved by comparing the slopes of the energy dependence of the differential neutrino electron scattering cross section for different neutrino conversion scenarios. We also show how the \nu_e -> \bar{\nu}_e conversions may take place for low energy solar neutrinos while being unobservable at the Kamiokande and Super-Kamiokande experiments. |
0705.1121 | Robert Fleischer | Robert Fleischer (CERN) | $B_{s,d} \to \pi\pi,\pi K, KK$: Status and Prospects | 28 pages, 10 figures | Eur.Phys.J.C52:267-281,2007 | 10.1140/epjc/s10052-007-0391-7 | CERN-PH-TH/2007-080 | hep-ph hep-ex | null | Several years ago, it was pointed out that the U-spin-related decays
$B_d\to\pi^+\pi^-$, $B_s\to K^+K^-$ and $B_d\to\pi^\mp K^\pm$, $B_s\to \pi^\pm
K^\mp$ offer interesting strategies for the extraction of the angle gamma of
the unitarity triangle. Using the first results from the Tevatron on the $B_s$
decays and the B-factory data on $B_{u,d}$ modes, we compare the determinations
of gamma from both strategies, study the sensitivity on U-spin-breaking
effects, discuss the resolution of discrete ambiguities, predict observables
that were not yet measured but will be accessible at LHCb, explore the
extraction of the width difference $\Delta\Gamma_s$ from untagged $B_s\to
K^+K^-$ rates, and address the impact of new physics. The data for the
$B_d\to\pi^+\pi^-$, $B_s\to K^+K^-$ system favour the BaBar measurement of
direct CP violation in $B_d\to\pi^+\pi^-$, which will be used in the numerical
analysis, and result in a fortunate situation, yielding
$\gamma=(66.6^{+4.3+4.0}_{-5.0-3.0})^\circ$, where the latter errors correspond
to a generous estimate of U-spin-breaking effects. On the other hand, the
$B_d\to\pi^\mp K^\pm$, $B_s\to \pi^\pm K^\mp$ analysis leaves us with
$26^\circ\leq\gamma\leq70^\circ$, and points to a value of the $B_s\to \pi^\pm
K^\mp$ branching ratio that is larger than the current Tevatron result. An
important further step will be the measurement of mixing-induced CP violation
in $B_s\to K^+K^-$, which will also allow us to extract the $B^0_s$--$\bar
B^0_s$ mixing phase unambiguously with the help of $B_s\to J/\psi \phi$ at the
LHC. Finally, the measurement of direct CP violation in $B_s\to K^+K^-$ will
make the full exploitation of the physics potential of the $B_{s,d}\to \pi\pi,
\pi K, KK$ modes possible.
| [
{
"created": "Tue, 8 May 2007 16:15:31 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Fleischer",
"Robert",
"",
"CERN"
]
] | Several years ago, it was pointed out that the U-spin-related decays $B_d\to\pi^+\pi^-$, $B_s\to K^+K^-$ and $B_d\to\pi^\mp K^\pm$, $B_s\to \pi^\pm K^\mp$ offer interesting strategies for the extraction of the angle gamma of the unitarity triangle. Using the first results from the Tevatron on the $B_s$ decays and the B-factory data on $B_{u,d}$ modes, we compare the determinations of gamma from both strategies, study the sensitivity on U-spin-breaking effects, discuss the resolution of discrete ambiguities, predict observables that were not yet measured but will be accessible at LHCb, explore the extraction of the width difference $\Delta\Gamma_s$ from untagged $B_s\to K^+K^-$ rates, and address the impact of new physics. The data for the $B_d\to\pi^+\pi^-$, $B_s\to K^+K^-$ system favour the BaBar measurement of direct CP violation in $B_d\to\pi^+\pi^-$, which will be used in the numerical analysis, and result in a fortunate situation, yielding $\gamma=(66.6^{+4.3+4.0}_{-5.0-3.0})^\circ$, where the latter errors correspond to a generous estimate of U-spin-breaking effects. On the other hand, the $B_d\to\pi^\mp K^\pm$, $B_s\to \pi^\pm K^\mp$ analysis leaves us with $26^\circ\leq\gamma\leq70^\circ$, and points to a value of the $B_s\to \pi^\pm K^\mp$ branching ratio that is larger than the current Tevatron result. An important further step will be the measurement of mixing-induced CP violation in $B_s\to K^+K^-$, which will also allow us to extract the $B^0_s$--$\bar B^0_s$ mixing phase unambiguously with the help of $B_s\to J/\psi \phi$ at the LHC. Finally, the measurement of direct CP violation in $B_s\to K^+K^-$ will make the full exploitation of the physics potential of the $B_{s,d}\to \pi\pi, \pi K, KK$ modes possible. |
2109.08173 | Francesco Hautmann | A. Bermudez Martinez, F. Hautmann and M.L. Mangano | Multi-jet physics at high-energy colliders and TMD parton evolution | 9 pages, 4 figures. Contribution at the 2021 Rencontres de Physique
de la Vallee d'Aoste. arXiv admin note: substantial text overlap with
arXiv:2107.01224 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss implications of the evolution of transverse momentum dependent
(TMD) parton distributions on the structure of multi-jet states at high
energies. In particular we analyze the theoretical systematics associated with
multi-jet merging. We introduce a new merging methodology incorporating TMDs,
illustrate its main features and present a comparison of our theoretical
results with experimental measurements for Z-boson + jets production at the
Large Hadron Collider (LHC).
| [
{
"created": "Thu, 16 Sep 2021 18:13:52 GMT",
"version": "v1"
}
] | 2021-09-20 | [
[
"Martinez",
"A. Bermudez",
""
],
[
"Hautmann",
"F.",
""
],
[
"Mangano",
"M. L.",
""
]
] | We discuss implications of the evolution of transverse momentum dependent (TMD) parton distributions on the structure of multi-jet states at high energies. In particular we analyze the theoretical systematics associated with multi-jet merging. We introduce a new merging methodology incorporating TMDs, illustrate its main features and present a comparison of our theoretical results with experimental measurements for Z-boson + jets production at the Large Hadron Collider (LHC). |
hep-ph/0112322 | Pavel Pobylitsa | P.V. Pobylitsa | Inequalities for generalized parton distributions H and E | 4 pages, references added, typos corrected | Phys.Rev. D65 (2002) 077504 | 10.1103/PhysRevD.65.077504 | null | hep-ph | null | New positivity bounds are derived for quark and gluon generalized parton
distributions $H$ and $E$ in spin 1/2 hadrons.
| [
{
"created": "Mon, 24 Dec 2001 21:35:40 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Jan 2002 00:24:42 GMT",
"version": "v2"
},
{
"created": "Fri, 15 Feb 2002 17:44:36 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Pobylitsa",
"P. V.",
""
]
] | New positivity bounds are derived for quark and gluon generalized parton distributions $H$ and $E$ in spin 1/2 hadrons. |
1110.1127 | Maarten F. L. Golterman | Diogo Boito, Oscar Cata, Maarten Golterman, Matthias Jamin, Kim
Maltman, James Osborne, Santiago Peris | A new determination of \alpha_s from hadronic \tau\ decays | 31 pages, 7 figures, revtex, version accepted for publication, minor
changes, reference added | null | 10.1103/PhysRevD.84.113006 | null | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new framework for the extraction of the strong coupling from
hadronic \tau decays through finite-energy sum rules. Our focus is on the
small, but still significant non-perturbative effects that, in principle,
affect both the central value and the systematic error. We employ a
quantitative model in order to accommodate violations of quark-hadron duality,
and enforce a consistent treatment of the higher-dimensional contributions of
the Operator Product Expansion to our sum rules. Using 1998 OPAL data for the
non-strange isovector vector and axial-vector spectral functions, we find the
n_f=3 values \alpha_s(m_\tau^2)=0.307+-0.019 in fixed-order perturbation
theory, and 0.322+-0.026 in contour-improved perturbation theory. For
comparison, the original OPAL analysis of the same data led to the values
0.324+-0.014 (fixed-order) and 0.348+-0.021 (contour-improved).
| [
{
"created": "Thu, 6 Oct 2011 01:19:17 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Nov 2011 23:44:14 GMT",
"version": "v2"
}
] | 2013-05-29 | [
[
"Boito",
"Diogo",
""
],
[
"Cata",
"Oscar",
""
],
[
"Golterman",
"Maarten",
""
],
[
"Jamin",
"Matthias",
""
],
[
"Maltman",
"Kim",
""
],
[
"Osborne",
"James",
""
],
[
"Peris",
"Santiago",
""
]
] | We present a new framework for the extraction of the strong coupling from hadronic \tau decays through finite-energy sum rules. Our focus is on the small, but still significant non-perturbative effects that, in principle, affect both the central value and the systematic error. We employ a quantitative model in order to accommodate violations of quark-hadron duality, and enforce a consistent treatment of the higher-dimensional contributions of the Operator Product Expansion to our sum rules. Using 1998 OPAL data for the non-strange isovector vector and axial-vector spectral functions, we find the n_f=3 values \alpha_s(m_\tau^2)=0.307+-0.019 in fixed-order perturbation theory, and 0.322+-0.026 in contour-improved perturbation theory. For comparison, the original OPAL analysis of the same data led to the values 0.324+-0.014 (fixed-order) and 0.348+-0.021 (contour-improved). |
2006.12488 | Manuel A. Buen-Abad | Jatan Buch, Manuel A. Buen-Abad, JiJi Fan, John Shing Chau Leung | Galactic Origin of Relativistic Bosons and XENON1T Excess | 12 pages, 1 figure. Version accepted for publication | null | 10.1088/1475-7516/2020/10/051 | null | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We entertain the exotic possibility that dark matter (DM) decays or
annihilations taking place in our galaxy may produce a flux of relativistic
very weakly-coupled bosons, axions or dark photons. We show that there exist
several upper bounds for this flux on Earth assuming generic minimal
requirements for DM, such as a lifetime longer than the age of the Universe or
an annihilation rate that leaves unaffected the background evolution during
matter domination. These bounds do not depend on the identity or the couplings
of the bosons. We then show that this new flux cannot be large enough to
explain the recent XENON1T excess, while assuming that the bosons' couplings to
the Standard Model are consistent with all current experimental and
observational constraints. We also discuss a possible caveat to these bounds
and a route to explain the excess.
| [
{
"created": "Mon, 22 Jun 2020 17:59:51 GMT",
"version": "v1"
},
{
"created": "Fri, 11 Sep 2020 13:17:35 GMT",
"version": "v2"
}
] | 2020-11-11 | [
[
"Buch",
"Jatan",
""
],
[
"Buen-Abad",
"Manuel A.",
""
],
[
"Fan",
"JiJi",
""
],
[
"Leung",
"John Shing Chau",
""
]
] | We entertain the exotic possibility that dark matter (DM) decays or annihilations taking place in our galaxy may produce a flux of relativistic very weakly-coupled bosons, axions or dark photons. We show that there exist several upper bounds for this flux on Earth assuming generic minimal requirements for DM, such as a lifetime longer than the age of the Universe or an annihilation rate that leaves unaffected the background evolution during matter domination. These bounds do not depend on the identity or the couplings of the bosons. We then show that this new flux cannot be large enough to explain the recent XENON1T excess, while assuming that the bosons' couplings to the Standard Model are consistent with all current experimental and observational constraints. We also discuss a possible caveat to these bounds and a route to explain the excess. |
1906.09174 | Michal Malinsk\'y | Michal Malinsk\'y | Lepton non-universality in $B$-decays in the minimal leptoquark gauge
model | 3 pages; contribution to the proceedings of the 17th Conference on
Flavor Physics and CP Violation (FPCP 2019) | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The anomalies in semileptonic $B$-decays are often attributed to new physics
scenarios featuring leptoquark degrees of freedom. Attempts to accommodate all
the deviations at once usually result in an elaborate model building way beyond
the minimal scenarios containing the desired degrees of freedom. However, as it
is far from clear whether all these signals (if any) survives the future
experimental scrutiny, in this contribution we decided to take the opposite
standpoint and review the actual room available for various $B$-decay anomalies
within the very minimal low-energy leptoquark gauge model based on the
$SU(4)_{C}\otimes SU(2)_{L}\otimes U(1)_{R}$ symmetry group.
| [
{
"created": "Fri, 21 Jun 2019 14:53:11 GMT",
"version": "v1"
}
] | 2019-06-24 | [
[
"Malinský",
"Michal",
""
]
] | The anomalies in semileptonic $B$-decays are often attributed to new physics scenarios featuring leptoquark degrees of freedom. Attempts to accommodate all the deviations at once usually result in an elaborate model building way beyond the minimal scenarios containing the desired degrees of freedom. However, as it is far from clear whether all these signals (if any) survives the future experimental scrutiny, in this contribution we decided to take the opposite standpoint and review the actual room available for various $B$-decay anomalies within the very minimal low-energy leptoquark gauge model based on the $SU(4)_{C}\otimes SU(2)_{L}\otimes U(1)_{R}$ symmetry group. |
hep-ph/0211194 | David Broadhurst | D.J. Broadhurst | Where do the tedious products of zetas come from? | 5 pages, LaTeX, uses npb.sty, talk given at "RadCor 2002 - Loops and
Legs 2002", Kloster Banz, Germany, Sep 8-13, 2002 | Nucl.Phys.Proc.Suppl. 116 (2003) 432-436 | 10.1016/S0920-5632(03)80214-1 | OUT-4102-90 | hep-ph | null | Lamentably, the full analytical content of the epsilon-expansion of the
master two-loop two-point function, with arbitrary self-energy insertions in
4-2epsilon dimensions, is still unknown. Here we show that multiple zeta values
(MZVs) of weights up to 12 suffice through O(epsilon^9). Products of primitive
MZVs are generated by a processes of "pseudo-exponentiation"" whose
combinatorics faithfully accord with expectations based on Kreimer's modified
shuffle product and on the Drinfeld-Deligne conjecture. The existence of such a
mechanism, relating thousands of complicated rational numbers, enables us to
identify precise and simple combinations of MZVs specific to quantum field
theories in even numbers of spacetime dimensions.
| [
{
"created": "Wed, 13 Nov 2002 09:07:46 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Broadhurst",
"D. J.",
""
]
] | Lamentably, the full analytical content of the epsilon-expansion of the master two-loop two-point function, with arbitrary self-energy insertions in 4-2epsilon dimensions, is still unknown. Here we show that multiple zeta values (MZVs) of weights up to 12 suffice through O(epsilon^9). Products of primitive MZVs are generated by a processes of "pseudo-exponentiation"" whose combinatorics faithfully accord with expectations based on Kreimer's modified shuffle product and on the Drinfeld-Deligne conjecture. The existence of such a mechanism, relating thousands of complicated rational numbers, enables us to identify precise and simple combinations of MZVs specific to quantum field theories in even numbers of spacetime dimensions. |
hep-ph/9806252 | Mikhail Kalmykov | M.Yu.Kalmykov | Manifestation of metric renormalization in quantum $R^2$--gravity | LaTeX, 8 pages | null | null | null | hep-ph gr-qc hep-th | null | The renormalization group method in $R^2$-gravity without matter fields is
discussed. A criterion for the existence of the renormalization constant for
the metric has been found, two-loop higher order poles have been calculated, a
relation which allows us to find the one-loop renormalization constant of the
Newtonian constant has been suggested.
| [
{
"created": "Thu, 4 Jun 1998 09:42:46 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kalmykov",
"M. Yu.",
""
]
] | The renormalization group method in $R^2$-gravity without matter fields is discussed. A criterion for the existence of the renormalization constant for the metric has been found, two-loop higher order poles have been calculated, a relation which allows us to find the one-loop renormalization constant of the Newtonian constant has been suggested. |
1812.09371 | Katarzyna Mazurek | K. Mazurek, A. Rybicki, A. Szczurek, V. Ozvenchuk, P.N. Nadtochy, A.
Kelic, A. Marcinek | Role of the spectator system in electromagnetic effects | 7 pages, 4 figures | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The electromagnetic effects on charged pion ($\pi^+,\pi^-$) spectra provide
new, independent information on the space-time evolution of the
ultrarelativistic heavy ion collision. The spectator life time and its
excitation energy may also be of importance for the understanding of the
space-time evolution of the participant zone. This paper gives an overview of
our coordinated effort to understand the interplay between electromagnetic
phenomena and processes related to the fragmentation of the spectator system at
forward rapidity in peripheral $Pb$+$Pb$ collisions at top CERN SPS energies.
Our study includes on one hand the experimental analysis of electromagnetic
effects and corresponding phenomenological Monte Carlo simulations, and on the
other hand dedicated theoretical calculations based on the Abrasion-Ablation
model ABRABLA and the 4D Langevin approach.
| [
{
"created": "Fri, 21 Dec 2018 21:08:29 GMT",
"version": "v1"
}
] | 2018-12-27 | [
[
"Mazurek",
"K.",
""
],
[
"Rybicki",
"A.",
""
],
[
"Szczurek",
"A.",
""
],
[
"Ozvenchuk",
"V.",
""
],
[
"Nadtochy",
"P. N.",
""
],
[
"Kelic",
"A.",
""
],
[
"Marcinek",
"A.",
""
]
] | The electromagnetic effects on charged pion ($\pi^+,\pi^-$) spectra provide new, independent information on the space-time evolution of the ultrarelativistic heavy ion collision. The spectator life time and its excitation energy may also be of importance for the understanding of the space-time evolution of the participant zone. This paper gives an overview of our coordinated effort to understand the interplay between electromagnetic phenomena and processes related to the fragmentation of the spectator system at forward rapidity in peripheral $Pb$+$Pb$ collisions at top CERN SPS energies. Our study includes on one hand the experimental analysis of electromagnetic effects and corresponding phenomenological Monte Carlo simulations, and on the other hand dedicated theoretical calculations based on the Abrasion-Ablation model ABRABLA and the 4D Langevin approach. |
hep-ph/0202167 | Sven Heinemeyer | M. Carena, S. Heinemeyer, C.E.M. Wagner, G. Weiglein | Suggestions for Benchmark Scenarios for MSSM Higgs Boson Searches at
Hadron Colliders | 8 pages, 4 figures, extended version of the contribution to the
workshop "Physics at TeV Colliders", Les Houches, France, May 2001 | Eur.Phys.J.C26:601-607,2003 | 10.1140/epjc/s2002-01084-3 | ANL-HEP-CP-02-017, BNL-HET-02/7, DCPT/02/24, EFI-02-64,
FERMILAB-Pub-02/024-T, IPPP/02/11 | hep-ph | null | The Higgs boson search has shifted from LEP2 to the Tevatron and will
subsequently move to the LHC. Due to the different initial states, the Higgs
production and decay channels relevant for Higgs boson searches were different
at LEP2 to what they are at hadron colliders. We suggest new benchmark
scenarios for the MSSM Higgs boson search at hadron colliders that exemplify
the phenomenology of different parts of the MSSM parameter space. Besides the
m_h^max scenario and the no-mixing scenario used in the LEP2 Higgs boson
searches, we propose two new scenarios. In one the main production channel at
the LHC, gg -> h, is suppressed. In the other, important Higgs decay channels
at the Tevatron and at the LHC, h -> b \bar b and h -> tau^+ tau^-, are
suppressed. All scenarios evade the LEP2 constraints for nearly the whole
M_A-tan beta-plane.
| [
{
"created": "Sat, 16 Feb 2002 22:09:30 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Carena",
"M.",
""
],
[
"Heinemeyer",
"S.",
""
],
[
"Wagner",
"C. E. M.",
""
],
[
"Weiglein",
"G.",
""
]
] | The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. Due to the different initial states, the Higgs production and decay channels relevant for Higgs boson searches were different at LEP2 to what they are at hadron colliders. We suggest new benchmark scenarios for the MSSM Higgs boson search at hadron colliders that exemplify the phenomenology of different parts of the MSSM parameter space. Besides the m_h^max scenario and the no-mixing scenario used in the LEP2 Higgs boson searches, we propose two new scenarios. In one the main production channel at the LHC, gg -> h, is suppressed. In the other, important Higgs decay channels at the Tevatron and at the LHC, h -> b \bar b and h -> tau^+ tau^-, are suppressed. All scenarios evade the LEP2 constraints for nearly the whole M_A-tan beta-plane. |
1902.08844 | Gilberto Ramalho | G. Ramalho, J.P.B.C. de Melo and K. Tsushima | Octet baryon electromagnetic form factor double ratios
$(G_E^\ast/G_M^\ast)/(G_E/G_M)$ in a nuclear medium | Version published in Phys. Rev. D. The discussions are extended. 11
pages, 6 figures | Phys. Rev. D 100, 014030 (2019) | 10.1103/PhysRevD.100.014030 | LFTC-19-6/44 | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ratios of the baryon electric ($G_E$) to magnetic ($G_M$) form factors,
$G_E/G_M$, can provide us with important information on the structure of
baryons in vacuum as demonstrated in recent studies for the proton and neutron
systems. It has been argued that the corresponding in-medium ratios,
$G_E^\ast/G_M^\ast$, can also provide useful information on the electromagnetic
structure of baryons in a nuclear medium. Although the ratios may not be
measured directly in experiments except for the proton at present, the double
ratios $(G_E^\ast/G_M^\ast)/(G_E/G_M)$ can be directly related to the
polarization-transfer measurements of bound baryons. In the present work we
estimate, for the first time, the double ratios $(G_E^\ast/G_M^\ast)/(G_E/G_M)$
for all the members of octet baryons in symmetric nuclear matter in the range
$Q^2=0$--3 GeV$^2$, where $Q^2=- q^2$ with $q$ being the four-momentum
transfer.
| [
{
"created": "Sat, 23 Feb 2019 20:32:31 GMT",
"version": "v1"
},
{
"created": "Wed, 31 Jul 2019 01:18:06 GMT",
"version": "v2"
}
] | 2019-08-01 | [
[
"Ramalho",
"G.",
""
],
[
"de Melo",
"J. P. B. C.",
""
],
[
"Tsushima",
"K.",
""
]
] | The ratios of the baryon electric ($G_E$) to magnetic ($G_M$) form factors, $G_E/G_M$, can provide us with important information on the structure of baryons in vacuum as demonstrated in recent studies for the proton and neutron systems. It has been argued that the corresponding in-medium ratios, $G_E^\ast/G_M^\ast$, can also provide useful information on the electromagnetic structure of baryons in a nuclear medium. Although the ratios may not be measured directly in experiments except for the proton at present, the double ratios $(G_E^\ast/G_M^\ast)/(G_E/G_M)$ can be directly related to the polarization-transfer measurements of bound baryons. In the present work we estimate, for the first time, the double ratios $(G_E^\ast/G_M^\ast)/(G_E/G_M)$ for all the members of octet baryons in symmetric nuclear matter in the range $Q^2=0$--3 GeV$^2$, where $Q^2=- q^2$ with $q$ being the four-momentum transfer. |
hep-ph/0610247 | Jose W. F. Valle | J. W. F. Valle | Neutrinos in astroparticle physics | 16 pages, 9 figures. Contribution to the Proceedings of the
International Workshop The Dark Side of the Universe, Madrid, June 20-24,
2006. Proceedings to be published in AIP | AIP Conf.Proc.878:369-384,2006 | 10.1063/1.2409109 | IFIC/06-34 | hep-ph | null | I briefly discuss the role of neutrinos as probes in astroparticle physics
and review the status of neutrino oscillation parameters as of June 2006,
including recent fluxes, and latest SNO, K2K and MINOS results. I comment on
the origin of neutrino masses in seesaw-type and low-scale models and mention
some of their experimental signals.
| [
{
"created": "Thu, 19 Oct 2006 10:35:41 GMT",
"version": "v1"
}
] | 2009-09-17 | [
[
"Valle",
"J. W. F.",
""
]
] | I briefly discuss the role of neutrinos as probes in astroparticle physics and review the status of neutrino oscillation parameters as of June 2006, including recent fluxes, and latest SNO, K2K and MINOS results. I comment on the origin of neutrino masses in seesaw-type and low-scale models and mention some of their experimental signals. |
1601.08063 | Pritibhajan Byakti | Pritibhajan Byakti and Palash B. Pal | Coxeter groups and the PMNS matrix | 31 pages, 1 figure and 4 table, minor changes. Matches with publish
version | null | 10.1140/epjc/s10052-017-5305-8 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the symmetries of the Lagrangian of the leptonic sector. We
consider the case when this symmetry group is a Coxeter group. The number of
elements of the PMNS matrix predicted by this group structure would depend on
the number of generators of this group. We analyze finite Coxeter groups with 2
to 4 generators and even finite subgroups of infinite Coxeter groups with 4
generators and show which of them can give results that are consistent with
experimental data.
| [
{
"created": "Fri, 29 Jan 2016 11:48:33 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Feb 2016 07:23:51 GMT",
"version": "v2"
},
{
"created": "Tue, 17 May 2016 06:12:34 GMT",
"version": "v3"
},
{
"created": "Sun, 12 Nov 2017 09:46:53 GMT",
"version": "v4"
}
] | 2017-12-06 | [
[
"Byakti",
"Pritibhajan",
""
],
[
"Pal",
"Palash B.",
""
]
] | We discuss the symmetries of the Lagrangian of the leptonic sector. We consider the case when this symmetry group is a Coxeter group. The number of elements of the PMNS matrix predicted by this group structure would depend on the number of generators of this group. We analyze finite Coxeter groups with 2 to 4 generators and even finite subgroups of infinite Coxeter groups with 4 generators and show which of them can give results that are consistent with experimental data. |
2105.04765 | Yunheng Ma | Ying Chen, Yunheng Ma, Shun Zhou | Quantum Simulations of the Non-Unitary Time Evolution and Applications
to Neutral-Kaon Oscillations | 20 pages, 5 figures | null | null | null | hep-ph hep-ex quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In light of recent exciting progress in building up quantum computing
facilities based on both optical and cold-atom techniques, the algorithms for
quantum simulations of particle-physics systems are in rapid progress. In this
paper, we propose an efficient algorithm for simulating the non-unitary time
evolution of neutral-kaon oscillations $K^0 \leftrightarrow \overline{K}^0$,
with or without CP conservation, on the quantum computers provided by the IBM
company. The essential strategy is to realize the time-evolution operator with
basic quantum gates and an extra qubit corresponding to some external
environment. The final results are well consistent with theoretical
expectations, and the algorithm can also be applied to open systems beyond
elementary particles.
| [
{
"created": "Tue, 11 May 2021 03:16:20 GMT",
"version": "v1"
}
] | 2021-05-12 | [
[
"Chen",
"Ying",
""
],
[
"Ma",
"Yunheng",
""
],
[
"Zhou",
"Shun",
""
]
] | In light of recent exciting progress in building up quantum computing facilities based on both optical and cold-atom techniques, the algorithms for quantum simulations of particle-physics systems are in rapid progress. In this paper, we propose an efficient algorithm for simulating the non-unitary time evolution of neutral-kaon oscillations $K^0 \leftrightarrow \overline{K}^0$, with or without CP conservation, on the quantum computers provided by the IBM company. The essential strategy is to realize the time-evolution operator with basic quantum gates and an extra qubit corresponding to some external environment. The final results are well consistent with theoretical expectations, and the algorithm can also be applied to open systems beyond elementary particles. |
2312.07143 | Irinel Caprini | Irinel Caprini | Revisiting the convergence of the perturbative QCD expansions based on
conformal mapping of the Borel plane | Accepted for publication at Physical Review D | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The difference between fixed-order (FO) and contour-improved (CI)
formulations of QCD perturbation theory limits the precision of the strong
coupling determined from the hadronic decay of the $\tau$ lepton. Recently,
several attempts to understand the mathematical origin of the difference and to
solve it by subtracting the dominant infrared renormalon divergence have been
made. Motivated by these studies, we review in this paper an improved
perturbative QCD expansion, defined some time ago, which also exploits the
renormalons by means of a suitable conformal mapping of the Borel plane. In
particular, we revisit the convergence of the new expansion, by completing the
proof presented in a previous paper and showing that the domain of convergence
is larger than stated before. We also check the validity of the convergence
conditions for the Adler function and the CI and FO expansions of the $\tau$
hadronic spectral function moments, and compare the approach based on conformal
mapping with recent solutions to the CIPT-FOPT discrepancy proposed in the
literature.
| [
{
"created": "Tue, 12 Dec 2023 10:25:27 GMT",
"version": "v1"
}
] | 2023-12-13 | [
[
"Caprini",
"Irinel",
""
]
] | The difference between fixed-order (FO) and contour-improved (CI) formulations of QCD perturbation theory limits the precision of the strong coupling determined from the hadronic decay of the $\tau$ lepton. Recently, several attempts to understand the mathematical origin of the difference and to solve it by subtracting the dominant infrared renormalon divergence have been made. Motivated by these studies, we review in this paper an improved perturbative QCD expansion, defined some time ago, which also exploits the renormalons by means of a suitable conformal mapping of the Borel plane. In particular, we revisit the convergence of the new expansion, by completing the proof presented in a previous paper and showing that the domain of convergence is larger than stated before. We also check the validity of the convergence conditions for the Adler function and the CI and FO expansions of the $\tau$ hadronic spectral function moments, and compare the approach based on conformal mapping with recent solutions to the CIPT-FOPT discrepancy proposed in the literature. |
hep-ph/0302176 | Yukihiro Mimura | Ilia Gogoladze, Yukihiro Mimura and S. Nandi | Unification of Gauge, Higgs and Matter in Extra Dimensions | 13 pages and 1 figure, some minor corrections and references added | Phys.Lett.B562:307-315,2003 | 10.1016/S0370-2693(03)00564-1 | OSU-HEP-03-4 | hep-ph hep-th | null | We consider the unification of gauge, Higgs as well as the matter fields in a
6D N=2 supersymmetric SU(8) gauge theory. The gauge symmetry SU(8) is broken
down to SU(4) x SU(2)_L x SU(2)_R x U(1)^2 in 4D through T^2/Z_6 orbifold
compactification, and the theory is reduced to 4D N=1 supersymmetric Pati-Salam
model. The electroweak Higgs fields as well as the third family of fermions are
unified in the 6D N=2 gauge multiplet. The 6D bulk gauge interaction provides
both gauge and Yukawa interactions for the third family predicting \alpha_1 =
\alpha_2 = \alpha_3 = \alpha_t = \alpha_b = \alpha_tau at the unification
scale, in good agreement with experiment. Incorporation of the first and second
family as well as other orbifolds are also briefly discussed.
| [
{
"created": "Wed, 19 Feb 2003 20:42:58 GMT",
"version": "v1"
},
{
"created": "Tue, 20 May 2003 20:28:34 GMT",
"version": "v2"
}
] | 2010-11-19 | [
[
"Gogoladze",
"Ilia",
""
],
[
"Mimura",
"Yukihiro",
""
],
[
"Nandi",
"S.",
""
]
] | We consider the unification of gauge, Higgs as well as the matter fields in a 6D N=2 supersymmetric SU(8) gauge theory. The gauge symmetry SU(8) is broken down to SU(4) x SU(2)_L x SU(2)_R x U(1)^2 in 4D through T^2/Z_6 orbifold compactification, and the theory is reduced to 4D N=1 supersymmetric Pati-Salam model. The electroweak Higgs fields as well as the third family of fermions are unified in the 6D N=2 gauge multiplet. The 6D bulk gauge interaction provides both gauge and Yukawa interactions for the third family predicting \alpha_1 = \alpha_2 = \alpha_3 = \alpha_t = \alpha_b = \alpha_tau at the unification scale, in good agreement with experiment. Incorporation of the first and second family as well as other orbifolds are also briefly discussed. |
1812.09360 | Stephan Narison | Stephan Narison (LUPM-CNRS/IN2P3, Montpellier-FR) | $\alpha_s(\mu)$ from $M_{\chi_{0c(0b)}}-M_{\eta_{c(b)}}$@N2LO | 3 pages, 2 figures, to appear in IJMPA, presented at QCD18 (2-6 july
2018, Montpellier-FR) and at HEPMAD18 (6-11 september 2018, Antananarivo-MG).
arXiv admin note: substantial text overlap with arXiv:1801.00592 | null | null | null | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This note complements and clarifies the results obtained in the original
paper {\it QCD Parameters Correlations from Heavy Quarkonia} [1] where, here,
we present a more detailed discussion of the \alpha_s-results obtained @ N2LO
at two different subtraction scales \mu=2.85 and 9.50 GeV from the
(pseudo)scalar heavy quarkonia mass-spliitings
M_{\chi_{0c(0b)}}-M_{\eta_{c(b)}}. We obtain from the
M_{\chi_{0c}}-M_{\eta_{c}} sum rule: \alpha_s(2.85)=0.262(9) -->
\alpha_s(M_\tau)=0.318(15) --> \alpha_s(M_Z)=0.1183(19)(3) and from the
M_{\chi_{0b}}-M_{\eta_{b}} one: \alpha_s(9.50)=0.180(8) -->
\alpha_s(M_\tau)=0.312(27) --> \alpha_s(M_Z)=0.1175(32)(3), in complete
agreement with the world average: \alpha_s(M_Z)=0.1181(11).
| [
{
"created": "Wed, 19 Dec 2018 07:31:21 GMT",
"version": "v1"
}
] | 2018-12-27 | [
[
"Narison",
"Stephan",
"",
"LUPM-CNRS/IN2P3, Montpellier-FR"
]
] | This note complements and clarifies the results obtained in the original paper {\it QCD Parameters Correlations from Heavy Quarkonia} [1] where, here, we present a more detailed discussion of the \alpha_s-results obtained @ N2LO at two different subtraction scales \mu=2.85 and 9.50 GeV from the (pseudo)scalar heavy quarkonia mass-spliitings M_{\chi_{0c(0b)}}-M_{\eta_{c(b)}}. We obtain from the M_{\chi_{0c}}-M_{\eta_{c}} sum rule: \alpha_s(2.85)=0.262(9) --> \alpha_s(M_\tau)=0.318(15) --> \alpha_s(M_Z)=0.1183(19)(3) and from the M_{\chi_{0b}}-M_{\eta_{b}} one: \alpha_s(9.50)=0.180(8) --> \alpha_s(M_\tau)=0.312(27) --> \alpha_s(M_Z)=0.1175(32)(3), in complete agreement with the world average: \alpha_s(M_Z)=0.1181(11). |
hep-ph/9808444 | Myckola Schwetz | Nick Evans, Stephen D.H. Hsu and Myckola Schwetz | An Effective Field Theory Approach to Color Superconductivity at High
Quark Density | LaTEX, 16 pages, 2 eps figures, minor corrections | Nucl.Phys. B551 (1999) 275-289 | 10.1016/S0550-3213(99)00175-3 | null | hep-ph hep-th nucl-th | null | We investigate the Fermi Liquid theory of high density QCD. Using the
renormalization group (RG), we determine the behavior of effective fermion
interactions near the Fermi surface. At sufficiently high densities the
matching between the Fermi Liquid theory and QCD can be accomplished in
perturbation theory and a reliable calculation of Cooper pair formation
performed, modulo the existence of a magnetic screening mass for the gluon. The
presence of a chemical potential leads to different RG flows for sub-components
of the effective interactions which would ordinarily be linked by Lorentz
invariance. We also study instanton-induced operators and find that near the
Fermi surface they are likely to be subdominant relative to operators induced
by perturbative gluon exchange. We discuss the implications of our results for
the phase structure of QCD at finite baryon density and temperature.
| [
{
"created": "Thu, 27 Aug 1998 20:39:53 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Sep 1998 18:30:03 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Evans",
"Nick",
""
],
[
"Hsu",
"Stephen D. H.",
""
],
[
"Schwetz",
"Myckola",
""
]
] | We investigate the Fermi Liquid theory of high density QCD. Using the renormalization group (RG), we determine the behavior of effective fermion interactions near the Fermi surface. At sufficiently high densities the matching between the Fermi Liquid theory and QCD can be accomplished in perturbation theory and a reliable calculation of Cooper pair formation performed, modulo the existence of a magnetic screening mass for the gluon. The presence of a chemical potential leads to different RG flows for sub-components of the effective interactions which would ordinarily be linked by Lorentz invariance. We also study instanton-induced operators and find that near the Fermi surface they are likely to be subdominant relative to operators induced by perturbative gluon exchange. We discuss the implications of our results for the phase structure of QCD at finite baryon density and temperature. |
hep-ph/9911516 | Fridger Schrempp | A. Ringwald (DESY) and F. Schrempp (DESY) | QCDINS 2.0 - A Monte Carlo generator for instanton-induced processes in
deep-inelastic scattering | 51 pages, 3 figures | Comput.Phys.Commun. 132 (2000) 267-305 | 10.1016/S0010-4655(00)00148-X | DESY 99-180 | hep-ph hep-ex | null | We describe a Monte Carlo event generator for the simulation of QCD-instanton
induced processes in deep-inelastic scattering (HERA). The QCDINS package is
designed as an ``add-on'' hard process generator interfaced to the general
hadronic event simulation package HERWIG. It incorporates the theoretically
predicted production rate for instanton-induced events as well as the essential
characteristics that have been derived theoretically for the partonic final
state of instanton-induced processes: notably, the flavour democratic and
isotropic production of the partonic final state, energy weight factors
different for gluons and quarks, and a high average multiplicity O(10) of
produced partons with a Poisson distribution of the gluon multiplicity. While
the subsequent perturbative evolution of the generated partons is always
handled by the HERWIG package, the final hadronization step may optionally be
performed also by means of the general hadronic event simulation package
JETSET.
| [
{
"created": "Mon, 29 Nov 1999 14:01:14 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Ringwald",
"A.",
"",
"DESY"
],
[
"Schrempp",
"F.",
"",
"DESY"
]
] | We describe a Monte Carlo event generator for the simulation of QCD-instanton induced processes in deep-inelastic scattering (HERA). The QCDINS package is designed as an ``add-on'' hard process generator interfaced to the general hadronic event simulation package HERWIG. It incorporates the theoretically predicted production rate for instanton-induced events as well as the essential characteristics that have been derived theoretically for the partonic final state of instanton-induced processes: notably, the flavour democratic and isotropic production of the partonic final state, energy weight factors different for gluons and quarks, and a high average multiplicity O(10) of produced partons with a Poisson distribution of the gluon multiplicity. While the subsequent perturbative evolution of the generated partons is always handled by the HERWIG package, the final hadronization step may optionally be performed also by means of the general hadronic event simulation package JETSET. |
hep-ph/0005258 | Jon Rosner | Jonathan L. Rosner | CP Violation - A Brief Review | 22 pages, LaTeX, 2 figures, invited talk presented at 2nd Tropical
Workshop in Particle Physics and Cosmology, San Juan, Puerto Rico, May 1-6,
2000, procs. to be published by American Institute of Physics, minor
corrections and additions | null | 10.1063/1.1328890 | EFI 2000-16 | hep-ph | null | Some past, present, and future aspects of CP violation are reviewed. The
discrete symmetries C, P, and T are introduced with an example drawn from
Maxwell's Equations. The history of the discovery of CP violation in the kaon
system is described briefly, and brought up-to-date with a review of recent
results on kaon decays. The candidate theory of CP violation, based on phases
in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, will be tested by studies of $B$
mesons, both in decays to CP eigenstates and in ``direct'' decays; we will soon
learn a great deal more about whether the CKM picture is self-consistent.
Future measurements are noted and some brief remarks are made about the
``other'' manifestation of CP violation, the baryon asymmetry of the Universe.
| [
{
"created": "Thu, 25 May 2000 16:01:33 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Jun 2000 14:34:58 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Rosner",
"Jonathan L.",
""
]
] | Some past, present, and future aspects of CP violation are reviewed. The discrete symmetries C, P, and T are introduced with an example drawn from Maxwell's Equations. The history of the discovery of CP violation in the kaon system is described briefly, and brought up-to-date with a review of recent results on kaon decays. The candidate theory of CP violation, based on phases in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, will be tested by studies of $B$ mesons, both in decays to CP eigenstates and in ``direct'' decays; we will soon learn a great deal more about whether the CKM picture is self-consistent. Future measurements are noted and some brief remarks are made about the ``other'' manifestation of CP violation, the baryon asymmetry of the Universe. |
hep-ph/9405418 | Adrian Ghinculov | A. Ghinculov and J.J. van der Bij | Massive two--loop diagrams: The Higgs propagator | 21 pages, Freiburg-THEP 94/05 | Nucl.Phys. B436 (1995) 30-48 | 10.1016/0550-3213(94)00522-G | null | hep-ph | null | Formulae are provided to express any two-loop scalar integral with arbitrary
masses and arbitrary external momenta in terms of an integral of one fairly
simple function or of its derivatives. Such integrals can be calculated
numerically with high precision. Good agreement is found with known analytical
expressions of specific two--loop diagrams. To prove the effectiveness of these
techniques, the two--loop selfenergy of the Higgs boson to order $(g^{2}
\frac{m_{H}^{2}}{m_{W}^{2}})^{2}$ is calculated, and the correctness of the
result is checked by using the unitarity of the S matrix. This result allows
one to disentangle the leading corrections to the shape of the Higgs resonance,
and to derive a perturbative bound of $\sim$1.2 TeV on the mass of the Higgs
boson.
| [
{
"created": "Mon, 30 May 1994 13:28:41 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Ghinculov",
"A.",
""
],
[
"van der Bij",
"J. J.",
""
]
] | Formulae are provided to express any two-loop scalar integral with arbitrary masses and arbitrary external momenta in terms of an integral of one fairly simple function or of its derivatives. Such integrals can be calculated numerically with high precision. Good agreement is found with known analytical expressions of specific two--loop diagrams. To prove the effectiveness of these techniques, the two--loop selfenergy of the Higgs boson to order $(g^{2} \frac{m_{H}^{2}}{m_{W}^{2}})^{2}$ is calculated, and the correctness of the result is checked by using the unitarity of the S matrix. This result allows one to disentangle the leading corrections to the shape of the Higgs resonance, and to derive a perturbative bound of $\sim$1.2 TeV on the mass of the Higgs boson. |
hep-ph/0506282 | Yuri Markov Adolfovich | Yu.A. Markov, M.A. Markova | Problem of the noise-noise correlation function in hot non-Abelian
plasma | 3 pages, REVTeX4 | Phys.Rev. D71 (2005) 117501 | 10.1103/PhysRevD.71.117501 | ISDCT-05-2 | hep-ph | null | In this work on the basis of Kadomtsev's kinetic fluctuation theory we
present the more general expression for noise-noise correlation function in
effective theory for ultrasoft field modes.
| [
{
"created": "Tue, 28 Jun 2005 02:08:01 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Markov",
"Yu. A.",
""
],
[
"Markova",
"M. A.",
""
]
] | In this work on the basis of Kadomtsev's kinetic fluctuation theory we present the more general expression for noise-noise correlation function in effective theory for ultrasoft field modes. |
hep-ph/9610221 | null | Rathin Adhikari and Utpal Sarkar | Baryogenesis in a supersymmetric model without R-parity | 12 pages latex (including 2 eps files) | Phys.Lett.B427:59-64,1998 | 10.1016/S0370-2693(98)00305-0 | null | hep-ph | null | We propose a simple scenario for baryogenesis in supersymmetric models where
baryon number is broken alongwith R-parity. The lightest supersymmetric
particle (neutralino) decays to three quarks and $CP-$ violation comes from
interference of tree and one loop box diagrams. The bounds on the $R-$parity
breaking couplings from the out-of-equilibrium condition are considerably
relaxed in this scenario.
| [
{
"created": "Wed, 2 Oct 1996 19:30:40 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Adhikari",
"Rathin",
""
],
[
"Sarkar",
"Utpal",
""
]
] | We propose a simple scenario for baryogenesis in supersymmetric models where baryon number is broken alongwith R-parity. The lightest supersymmetric particle (neutralino) decays to three quarks and $CP-$ violation comes from interference of tree and one loop box diagrams. The bounds on the $R-$parity breaking couplings from the out-of-equilibrium condition are considerably relaxed in this scenario. |
1407.6882 | Yoshitaro Takaesu | Motoi Endo and Yoshitaro Takaesu | Heavy WIMP through Higgs portal at the LHC | 14 pages, 3 figures | null | 10.1016/j.physletb.2015.02.042 | UT--14--33 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | LHC constraints on Higgs-portal WIMPs are studied. Scalar, vector and
anti-symmetric tensor fields are considered. They are assumed to be heavier
than a half of the Higgs boson mass. We investigate 8 TeV LHC results on
signatures of the vector boson fusion, mono-jet and associated production of
the $Z$ boson, which proceed via virtual exchange of the Higgs boson. We show
that Higgs-portal interactions of the vector and tensor WIMPs are constrained
to be less than 0.43 and 0.16, respectively, while those for the scalar are
very weak. Prospects of the 14 TeV LHC are also discussed.
| [
{
"created": "Fri, 25 Jul 2014 13:16:13 GMT",
"version": "v1"
}
] | 2015-06-22 | [
[
"Endo",
"Motoi",
""
],
[
"Takaesu",
"Yoshitaro",
""
]
] | LHC constraints on Higgs-portal WIMPs are studied. Scalar, vector and anti-symmetric tensor fields are considered. They are assumed to be heavier than a half of the Higgs boson mass. We investigate 8 TeV LHC results on signatures of the vector boson fusion, mono-jet and associated production of the $Z$ boson, which proceed via virtual exchange of the Higgs boson. We show that Higgs-portal interactions of the vector and tensor WIMPs are constrained to be less than 0.43 and 0.16, respectively, while those for the scalar are very weak. Prospects of the 14 TeV LHC are also discussed. |
hep-ph/0006163 | Ralf Hofmann | Ralf Hofmann | Deconfining by Winding: The Magnetic Monopole Vacua at High Temperatures | 8 papes, 3 figures | Phys.Rev.D62:105021,2000; Erratum-ibid.D63:049901,2001 | 10.1103/PhysRevD.62.105021 10.1103/PhysRevD.63.049901 | null | hep-ph | null | Characterizing the vacuum of a thermalized SU(3) Yang-Mills theory in the
dual Ginzburg-Landau description, the possibility of topologically nontrivial,
classical monopole fields in the deconfining phase is explored. These fields
are assumed to be Bogomoln'yi-Prasad-Sommerfield (BPS) saturated solutions
along the compact, euclidean time dimension. A corresponding, gauge invariant
monopole interaction is constructed. The model passes first tests. In
particular, a reasonable value for the critical temperature is obtained, and
the partial persistence of nonperturbative features in the deconfining phase of
SU(3) Yang-Mills theory, as it is measured on the lattice, follows naturally.
| [
{
"created": "Thu, 15 Jun 2000 04:25:11 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Jul 2000 20:51:23 GMT",
"version": "v2"
},
{
"created": "Thu, 5 Oct 2000 03:04:07 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Hofmann",
"Ralf",
""
]
] | Characterizing the vacuum of a thermalized SU(3) Yang-Mills theory in the dual Ginzburg-Landau description, the possibility of topologically nontrivial, classical monopole fields in the deconfining phase is explored. These fields are assumed to be Bogomoln'yi-Prasad-Sommerfield (BPS) saturated solutions along the compact, euclidean time dimension. A corresponding, gauge invariant monopole interaction is constructed. The model passes first tests. In particular, a reasonable value for the critical temperature is obtained, and the partial persistence of nonperturbative features in the deconfining phase of SU(3) Yang-Mills theory, as it is measured on the lattice, follows naturally. |
hep-ph/9905445 | Colin Froggatt | C.D. Froggatt and H. B. Nielsen | Masses and mixing angles and going beyond the Standard Model | 19 page LaTeX file; updated version of invited talk published in the
Proceedings of the International Workshop on "What comes beyond the Standard
Model", Bled, Slovenia, 29 June - 9 July 1998 (DMFA - zalo\u{z}ni\u{s}tvo,
Ljubljana) | null | null | GUTPA/99/05/1 | hep-ph | null | The idea, following Michel and O'Raifeartaigh, of assigning meaning to the
(gauge) \underline{group} and not only the Lie algebra for a Yang Mills theory
is reviewed. Hints from the group and the fermion spectrum of the Standard
Model are used to suggest the putting forward of our AGUT-model, which gives a
very good fit to the orders of magnitudes of the quark and lepton masses and
the mixing angles including the CP-breaking phase. But for neutrino
oscillations modifications of the model are needed. Baryogenesis is not in
conflict with the model.
| [
{
"created": "Fri, 21 May 1999 16:40:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Froggatt",
"C. D.",
""
],
[
"Nielsen",
"H. B.",
""
]
] | The idea, following Michel and O'Raifeartaigh, of assigning meaning to the (gauge) \underline{group} and not only the Lie algebra for a Yang Mills theory is reviewed. Hints from the group and the fermion spectrum of the Standard Model are used to suggest the putting forward of our AGUT-model, which gives a very good fit to the orders of magnitudes of the quark and lepton masses and the mixing angles including the CP-breaking phase. But for neutrino oscillations modifications of the model are needed. Baryogenesis is not in conflict with the model. |
hep-ph/9305250 | null | Pankaj Jain and John P. Ralston | Measuring Chirally Odd Wave Functions with Helicity Flip Form Factors | 6 pages, 1 figure (not included), hard copy available upon request,
report # KU-HEP-93-27 | null | null | null | hep-ph | null | We consider the role of chirally odd wave functions in hard exclusive
reactions. Such wave functions have the quarks oriented in the opposite
helicity configuration from those assumed in the short-distance limit and are
generally associated with non-zero orbital angular momentum. Calculations in
the impulse approximation allow for non-zero helicity flip amplitudes while the
conventional factorization prescription for exclusive processes does not. By
introducing a new approach, we show how helicity flip form factors are
nevertheless calculable in QCD.
| [
{
"created": "Wed, 12 May 1993 02:31:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Jain",
"Pankaj",
""
],
[
"Ralston",
"John P.",
""
]
] | We consider the role of chirally odd wave functions in hard exclusive reactions. Such wave functions have the quarks oriented in the opposite helicity configuration from those assumed in the short-distance limit and are generally associated with non-zero orbital angular momentum. Calculations in the impulse approximation allow for non-zero helicity flip amplitudes while the conventional factorization prescription for exclusive processes does not. By introducing a new approach, we show how helicity flip form factors are nevertheless calculable in QCD. |
1910.05497 | June-Haak Ee | Geoffrey T. Bodwin, Hee Sok Chung, June-Haak Ee, U-Rae Kim, and Jungil
Lee | Covariant calculation of a two-loop test of nonrelativistic QCD
factorization | 74 pages, 9 figures, minor reorganization and clarifications, typos
corrected, published version | Phys. Rev. D 101, 096011 (2020) | 10.1103/PhysRevD.101.096011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We test the nonrelativistic QCD factorization conjecture for inclusive
quarkonium production at two loops by carrying out a covariant calculation of
the nonrelativistic quantum chromodynamics (NRQCD) long-distance matrix element
(LDME) for a heavy-quark pair in an $S$-wave, color-octet state to fragment
into a heavy-quark pair in a color-singlet state of arbitrary orbital angular
momentum. The NRQCD factorization conjecture for the universality of the LDME
requires that infrared divergences that it contains be independent of the
direction of the Wilson line that appears in its definition. We find this to be
the case in our calculation. The results of our calculation differ in some
respects from those of a previous calculation that was carried out by Nayak,
Qiu, and Sterman using light-cone methods. We have identified the sources of
some of these differences. The results of both calculations are consistent with
the NRQCD factorization conjecture. However, the general principle that
underlies this confirmation of NRQCD factorization at two-loop order has yet to
be revealed.
| [
{
"created": "Sat, 12 Oct 2019 05:19:32 GMT",
"version": "v1"
},
{
"created": "Thu, 21 May 2020 15:07:00 GMT",
"version": "v2"
}
] | 2020-05-27 | [
[
"Bodwin",
"Geoffrey T.",
""
],
[
"Chung",
"Hee Sok",
""
],
[
"Ee",
"June-Haak",
""
],
[
"Kim",
"U-Rae",
""
],
[
"Lee",
"Jungil",
""
]
] | We test the nonrelativistic QCD factorization conjecture for inclusive quarkonium production at two loops by carrying out a covariant calculation of the nonrelativistic quantum chromodynamics (NRQCD) long-distance matrix element (LDME) for a heavy-quark pair in an $S$-wave, color-octet state to fragment into a heavy-quark pair in a color-singlet state of arbitrary orbital angular momentum. The NRQCD factorization conjecture for the universality of the LDME requires that infrared divergences that it contains be independent of the direction of the Wilson line that appears in its definition. We find this to be the case in our calculation. The results of our calculation differ in some respects from those of a previous calculation that was carried out by Nayak, Qiu, and Sterman using light-cone methods. We have identified the sources of some of these differences. The results of both calculations are consistent with the NRQCD factorization conjecture. However, the general principle that underlies this confirmation of NRQCD factorization at two-loop order has yet to be revealed. |
1701.07068 | York Schroder | Thomas Luthe, Andreas Maier, Peter Marquard, York Schroder | Complete renormalization of QCD at five loops | 14 pages, 2 ancillary files available with the source | null | 10.1007/JHEP03(2017)020 | BI-TP 2017/01, DESY 17-011, IPPP/17/7 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present new analytical five-loop Feynman-gauge results for the anomalous
dimensions of ghost field and -vertex, generalizing the known values for SU(3)
to a general gauge group. Together with previously published results on the
quark mass and -field anomalous dimensions and the Beta function, this
completes the 5-loop renormalization program of gauge theories in that gauge.
| [
{
"created": "Tue, 24 Jan 2017 20:07:01 GMT",
"version": "v1"
}
] | 2017-04-05 | [
[
"Luthe",
"Thomas",
""
],
[
"Maier",
"Andreas",
""
],
[
"Marquard",
"Peter",
""
],
[
"Schroder",
"York",
""
]
] | We present new analytical five-loop Feynman-gauge results for the anomalous dimensions of ghost field and -vertex, generalizing the known values for SU(3) to a general gauge group. Together with previously published results on the quark mass and -field anomalous dimensions and the Beta function, this completes the 5-loop renormalization program of gauge theories in that gauge. |
hep-ph/0011123 | Carlos Quimbay Fisica Unalcol | Carlos Quimbay, John Morales, and Rafael Hurtado (Universidad Nacional
de Colombia) | Can large fermion chemical potentials suppress the electroweak phase
transition ? | LaTex File, 11 pages, 1 Postscript figure | null | null | FIUN-CP-00/1 | hep-ph | null | We calculate the critical temperature $(T_c$) of the electroweak phase
transition in the minimal standard model considering simultaneously temperature
($T$) and fermion chemical potential ($\mu_f$) effects over the effective
potential. The calculation is performed in the one-loop approximation to the
effective potential at non-zero temperature using the real time formalism of
the thermal field theory. We show that it exists a fermion chemical potential
critical value ($\mu_f^c$) for which the Higgs boson condensate vanishes at
T=0. If $T$ and $\mu_f$ effects are considered simultaneously, it is shown that
for $\mu_f \geq \mu_f^c$ then $T_c^2 \leq 0$, implying that the electroweak
phase transition might not take place.
| [
{
"created": "Thu, 9 Nov 2000 21:22:49 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Quimbay",
"Carlos",
"",
"Universidad Nacional\n de Colombia"
],
[
"Morales",
"John",
"",
"Universidad Nacional\n de Colombia"
],
[
"Hurtado",
"Rafael",
"",
"Universidad Nacional\n de Colombia"
]
] | We calculate the critical temperature $(T_c$) of the electroweak phase transition in the minimal standard model considering simultaneously temperature ($T$) and fermion chemical potential ($\mu_f$) effects over the effective potential. The calculation is performed in the one-loop approximation to the effective potential at non-zero temperature using the real time formalism of the thermal field theory. We show that it exists a fermion chemical potential critical value ($\mu_f^c$) for which the Higgs boson condensate vanishes at T=0. If $T$ and $\mu_f$ effects are considered simultaneously, it is shown that for $\mu_f \geq \mu_f^c$ then $T_c^2 \leq 0$, implying that the electroweak phase transition might not take place. |
1605.01169 | Larisa Laperashvili | B.G. Sidharth, A. Das, C.R. Das, L.V. Laperashvili and H.B. Nielsen | Topological Structure of the Vacuum, Cosmological Constant and Dark
Energy | 37 pages and 7 figures. arXiv admin note: text overlap with
arXiv:1601.03231; text overlap with arXiv:1302.2716 by other authors | Int.J.Mod.Phys. A31 (2016) no.34, 1630051 | 10.1142/S0217751X16300519 | null | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this review we present a theory of cosmological constant and Dark Energy
(DE), based on the topological structure of the vacuum. The Multiple Point
Principle (MPP) is reviewed. It demonstrates the existence of the two vacua
into the SM. The Froggatt-Nielsen's prediction of the top-quark and Higgs
masses is given in the assumption that there exist two degenerate vacua in the
SM. This prediction was improved by the next order calculations. We also
considered B.G. Sidharth's theory of cosmological constant based on the
non-commutative geometry of the Planck scale space-time, what gives an
extremely small DE density providing the accelerating expansion of the
Universe. Theory of two degenerate vacua - the Planck scale phase and
Electroweak (EW) phase - also is reviewed, topological defects in these vacua
are investigated, also the Compton wavelength phase suggested by B.G. Sidharth
was discussed. A general theory of the phase transition and the problem of the
vacuum stability in the SM is reviewed. Assuming that the recently discovered
at the LHC new resonance with mass $m_S \simeq 750$ GeV is a new scalar $S$
bound state $6t + 6\bar t$, earlier predicted by C.D. Froggatt, H.B. Nielsen
and L.V. Laperashvili, we try to provide the vacuum stability in the SM and
exact accuracy of the MPP.
| [
{
"created": "Wed, 4 May 2016 07:37:22 GMT",
"version": "v1"
}
] | 2017-03-16 | [
[
"Sidharth",
"B. G.",
""
],
[
"Das",
"A.",
""
],
[
"Das",
"C. R.",
""
],
[
"Laperashvili",
"L. V.",
""
],
[
"Nielsen",
"H. B.",
""
]
] | In this review we present a theory of cosmological constant and Dark Energy (DE), based on the topological structure of the vacuum. The Multiple Point Principle (MPP) is reviewed. It demonstrates the existence of the two vacua into the SM. The Froggatt-Nielsen's prediction of the top-quark and Higgs masses is given in the assumption that there exist two degenerate vacua in the SM. This prediction was improved by the next order calculations. We also considered B.G. Sidharth's theory of cosmological constant based on the non-commutative geometry of the Planck scale space-time, what gives an extremely small DE density providing the accelerating expansion of the Universe. Theory of two degenerate vacua - the Planck scale phase and Electroweak (EW) phase - also is reviewed, topological defects in these vacua are investigated, also the Compton wavelength phase suggested by B.G. Sidharth was discussed. A general theory of the phase transition and the problem of the vacuum stability in the SM is reviewed. Assuming that the recently discovered at the LHC new resonance with mass $m_S \simeq 750$ GeV is a new scalar $S$ bound state $6t + 6\bar t$, earlier predicted by C.D. Froggatt, H.B. Nielsen and L.V. Laperashvili, we try to provide the vacuum stability in the SM and exact accuracy of the MPP. |
0811.3206 | Tuhin Roy | Gilad Perez, Tuhin S. Roy and Martin Schmaltz | Phenomenology of SUSY with scalar sequestering | 16 pages and 3 figures | Phys.Rev.D79:095016,2009 | 10.1103/PhysRevD.79.095016 | WIS/20/08-NOV-DPP | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The defining feature of scalar sequestering is that the MSSM squark and
slepton masses as well as all entries of the scalar Higgs mass matrix vanish at
some high scale. This ultraviolet boundary condition - scalar masses vanish
while gaugino and Higgsino masses are unsuppressed - is independent of the
supersymmetry breaking mediation mechanism. It is the result of renormalization
group scaling from approximately conformal strong dynamics in the hidden
sector. We review the mechanism of scalar sequestering and prove that the same
dynamics which suppresses scalar soft masses and the B_mu term also drives the
Higgs soft masses to -|mu|^2. Thus the supersymmetric contribution to the Higgs
mass matrix from the mu-term is exactly canceled by the soft masses. Scalar
sequestering has two tell-tale predictions for the superpartner spectrum in
addition to the usual gaugino mediation predictions: Higgsinos are much heavier
(mu > TeV) than scalar Higgses (m_A ~ few hundred GeV), and third generation
scalar masses are enhanced because of new positive contributions from Higgs
loops.
| [
{
"created": "Thu, 20 Nov 2008 02:25:19 GMT",
"version": "v1"
}
] | 2009-07-30 | [
[
"Perez",
"Gilad",
""
],
[
"Roy",
"Tuhin S.",
""
],
[
"Schmaltz",
"Martin",
""
]
] | The defining feature of scalar sequestering is that the MSSM squark and slepton masses as well as all entries of the scalar Higgs mass matrix vanish at some high scale. This ultraviolet boundary condition - scalar masses vanish while gaugino and Higgsino masses are unsuppressed - is independent of the supersymmetry breaking mediation mechanism. It is the result of renormalization group scaling from approximately conformal strong dynamics in the hidden sector. We review the mechanism of scalar sequestering and prove that the same dynamics which suppresses scalar soft masses and the B_mu term also drives the Higgs soft masses to -|mu|^2. Thus the supersymmetric contribution to the Higgs mass matrix from the mu-term is exactly canceled by the soft masses. Scalar sequestering has two tell-tale predictions for the superpartner spectrum in addition to the usual gaugino mediation predictions: Higgsinos are much heavier (mu > TeV) than scalar Higgses (m_A ~ few hundred GeV), and third generation scalar masses are enhanced because of new positive contributions from Higgs loops. |
2001.07140 | U. J. Salda\~na-Salazar | Antonio E. C\'arcamo Hern\'andez, Claudio O. Dib, Ulises J.
Salda\~na-Salazar | When $\tan \beta$ meets all the mixing angles | Major improvement to the overall content of the paper; 15 pages, 8
figures, new sections, appendices and references; Matches published version
in PLB | null | 10.1016/j.physletb.2020.135750 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Models with two-Higgs-doublets and natural flavour conservation contain $\tan
\beta = v_2 / v_1$ as a physical parameter. We offer here a generalization of a
recently proposed idea where only the Cabibbo angle, $\theta_\text{c} \simeq
0.22$, was related to $\tan \beta$ by virtue of the $\mathbb{D}_{4}$ dihedral
symmetry group. The original proposal consisted of a massless first generation
of quarks and no mixing with the third generation. In our case, through the
addition of a third Higgs doublet with a small vacuum-expectation-value but
very large masses, thus later decoupling, all quarks become massive and quark
mixing is fully reproduced. In fact, all quark mixing angles are expressed in
terms of $\tan \beta$ and one recovers trivial mixing in the limit $\beta
\rightarrow 0$. We also explore the consequences in lepton mixing by adopting a
type I seesaw mechanism with three heavy right-handed neutrinos.
| [
{
"created": "Mon, 20 Jan 2020 15:27:21 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Aug 2020 18:02:15 GMT",
"version": "v2"
}
] | 2020-09-02 | [
[
"Hernández",
"Antonio E. Cárcamo",
""
],
[
"Dib",
"Claudio O.",
""
],
[
"Saldaña-Salazar",
"Ulises J.",
""
]
] | Models with two-Higgs-doublets and natural flavour conservation contain $\tan \beta = v_2 / v_1$ as a physical parameter. We offer here a generalization of a recently proposed idea where only the Cabibbo angle, $\theta_\text{c} \simeq 0.22$, was related to $\tan \beta$ by virtue of the $\mathbb{D}_{4}$ dihedral symmetry group. The original proposal consisted of a massless first generation of quarks and no mixing with the third generation. In our case, through the addition of a third Higgs doublet with a small vacuum-expectation-value but very large masses, thus later decoupling, all quarks become massive and quark mixing is fully reproduced. In fact, all quark mixing angles are expressed in terms of $\tan \beta$ and one recovers trivial mixing in the limit $\beta \rightarrow 0$. We also explore the consequences in lepton mixing by adopting a type I seesaw mechanism with three heavy right-handed neutrinos. |
hep-ph/0009278 | Brandon Carter | B. Carter, R. Brandenberger, A.-C. Davis, G. Sigl | Prolongation of Friction Dominated Evolution for Superconducting Cosmic
Strings | 10 pages Latex | JHEP 0011 (2000) 019 | 10.1088/1126-6708/2000/11/019 | null | hep-ph astro-ph | null | This investigation is concerned with cosmological scenarios based on particle
physics theories that give rise to superconducting cosmic strings (whose
subsequent evolution may produce stable loop configurations known as vortons).
Cases in which electromagnetic coupling of the string current is absent or
unimportant have been dealt with in previous work. The purpose of the present
work is to provide quantitative estimates for cases in which electromagnetic
interaction with the surrounding plasma significantly affects the string
dynamics. In particular it will be shown that the current can become
sufficiently strong for the initial period of friction dominated string motion
to be substantially prolonged, which would entail a reinforcement of the short
length scale end of the spectrum of the string distribution, with potentially
observable cosmological implications if the friction dominated scenario lasts
until the time of plasma recombination.
| [
{
"created": "Sat, 23 Sep 2000 15:55:18 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Carter",
"B.",
""
],
[
"Brandenberger",
"R.",
""
],
[
"Davis",
"A. -C.",
""
],
[
"Sigl",
"G.",
""
]
] | This investigation is concerned with cosmological scenarios based on particle physics theories that give rise to superconducting cosmic strings (whose subsequent evolution may produce stable loop configurations known as vortons). Cases in which electromagnetic coupling of the string current is absent or unimportant have been dealt with in previous work. The purpose of the present work is to provide quantitative estimates for cases in which electromagnetic interaction with the surrounding plasma significantly affects the string dynamics. In particular it will be shown that the current can become sufficiently strong for the initial period of friction dominated string motion to be substantially prolonged, which would entail a reinforcement of the short length scale end of the spectrum of the string distribution, with potentially observable cosmological implications if the friction dominated scenario lasts until the time of plasma recombination. |
2312.01173 | Chengrong Deng | Zu-Hang Lin, Chun-Sheng An, and Cheng-Rong Deng | $P$-wave states $T^-_{bb}$ from diquarks | 7 pages, 1 figures, 4 tables, to be published in Phys. Rev. D | Phys. Rev. D 109, 056005 (2024) | 10.1103/PhysRevD.109.056005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the $P$-wave states $T^-_{bb}$ in the isospin singlet and
three excited modes [excitation occurring in the diquark $[bb]^{s_1}_{c_1}$
($\rho $-mode), antidiquark $[\bar{u}\bar{d}]^{s_2}_{c_2}$ ($r$-mode) or
between them ($\lambda$-mode)] from diquarks in a quark model. We analyze the
dynamical behaviors of the diquark $[bb]^{s_1}_{c_1}$, antidiquark
$[\bar{u}\bar{d}]^{s_2}_{c_2}$ and their correlations in the states $T^-_{bb}$
by decomposing the interactions from various sources in the model. The absolute
dominant color-spin configuration, more than $99\%$, in the $\rho$-mode with
$1^1P_1$ is $[bb]^0_{\bar{\mathbf{3}}}[\bar{u}\bar{d}]^0_{\mathbf{3}}$. Its
energy is lower by about $18$ MeV than the threshold $\bar{B}\bar{B}$ so that
it can establish a compact bound state. The chromomagnetic and meson-exchange
interactions in the antidiquark $[\bar{u}\bar{d}]^0_{\mathbf{3}}$ are
responsible for its binding mechanism. Two other excited modes are higher than
their respective threshold. The color configuration
$\mathbf{6}\otimes\bar{\mathbf{6}}$ need to be handled discreetly in the
tetraquark states.
| [
{
"created": "Sat, 2 Dec 2023 16:29:40 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Feb 2024 13:02:51 GMT",
"version": "v2"
}
] | 2024-03-08 | [
[
"Lin",
"Zu-Hang",
""
],
[
"An",
"Chun-Sheng",
""
],
[
"Deng",
"Cheng-Rong",
""
]
] | We investigate the $P$-wave states $T^-_{bb}$ in the isospin singlet and three excited modes [excitation occurring in the diquark $[bb]^{s_1}_{c_1}$ ($\rho $-mode), antidiquark $[\bar{u}\bar{d}]^{s_2}_{c_2}$ ($r$-mode) or between them ($\lambda$-mode)] from diquarks in a quark model. We analyze the dynamical behaviors of the diquark $[bb]^{s_1}_{c_1}$, antidiquark $[\bar{u}\bar{d}]^{s_2}_{c_2}$ and their correlations in the states $T^-_{bb}$ by decomposing the interactions from various sources in the model. The absolute dominant color-spin configuration, more than $99\%$, in the $\rho$-mode with $1^1P_1$ is $[bb]^0_{\bar{\mathbf{3}}}[\bar{u}\bar{d}]^0_{\mathbf{3}}$. Its energy is lower by about $18$ MeV than the threshold $\bar{B}\bar{B}$ so that it can establish a compact bound state. The chromomagnetic and meson-exchange interactions in the antidiquark $[\bar{u}\bar{d}]^0_{\mathbf{3}}$ are responsible for its binding mechanism. Two other excited modes are higher than their respective threshold. The color configuration $\mathbf{6}\otimes\bar{\mathbf{6}}$ need to be handled discreetly in the tetraquark states. |
1607.05236 | Francesco Riva Dr | Aleksandr Azatov, Roberto Contino, Camila S. Machado, Francesco Riva | Helicity Selection Rules and Non-Interference for BSM Amplitudes | 12 pages, 2 figures | Phys. Rev. D 95, 065014 (2017) | 10.1103/PhysRevD.95.065014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Precision studies of scattering processes at colliders provide powerful
indirect constraints on new physics. We study the helicity structure of
scattering amplitudes in the SM and in the context of an effective Lagrangian
description of BSM dynamics. Our analysis reveals a novel set of helicity
selection rules according to which, in the majority of 2 to 2 scattering
processes at high energy, the SM and the leading BSM effects do not interfere.
In such situations, the naive expectation that dimension-6 operators represent
the leading BSM contribution is compromised, as corrections from dimension-8
operators can become equally (if not more) important well within the validity
of the effective field theory approach.
| [
{
"created": "Mon, 18 Jul 2016 18:45:52 GMT",
"version": "v1"
}
] | 2017-03-29 | [
[
"Azatov",
"Aleksandr",
""
],
[
"Contino",
"Roberto",
""
],
[
"Machado",
"Camila S.",
""
],
[
"Riva",
"Francesco",
""
]
] | Precision studies of scattering processes at colliders provide powerful indirect constraints on new physics. We study the helicity structure of scattering amplitudes in the SM and in the context of an effective Lagrangian description of BSM dynamics. Our analysis reveals a novel set of helicity selection rules according to which, in the majority of 2 to 2 scattering processes at high energy, the SM and the leading BSM effects do not interfere. In such situations, the naive expectation that dimension-6 operators represent the leading BSM contribution is compromised, as corrections from dimension-8 operators can become equally (if not more) important well within the validity of the effective field theory approach. |
1810.00607 | Stefano Scopel | Sunghyun Kang, Stefano Scopel, Gaurav Tomar, Jong-Hyun Yoon (Sogang
U.) | On the sensitivity of present direct detection experiments to WIMP-quark
and WIMP-gluon effective interactions: a systematic assessment and new
model-independent approaches | 23 pages, 11 figures, 2 tables. Updated to published version. The
companion code can be downloaded from
https://github.com/NRDD-constraints/NRDD | null | 10.1016/j.astropartphys.2019.07.001 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Assuming for Weakly Interacting Massive Particles (WIMPs) a Maxwellian
velocity distribution in the Galaxy we provide an assessment of the sensitivity
of existing Dark Matter (DM) direct detection (DD) experiments to operators up
to dimension 7 of the relativistic effective field theory describing dark
matter interactions with quarks and gluons . In particular we focus on a
systematic approach, including an extensive set of experiments and large number
of couplings, both exceeding for completeness similar analyses in the
literature. The relativistic effective theory requires to fix one coupling for
each quark flavor, so in principle for each different combination the bounds
should be recalculated starting from direct detection experimental data. To
address this problem we propose an approximate model-independent procedure that
allows to directly calculate the bounds for any combination of couplings in
terms of model-independent limits on the Wilson coefficients of the
non-relativistic theory expressed in terms of the WIMP mass and of the
neutron-to-proton coupling ratio $c^n/c^p$. We test the result of the
approximate procedure against that of a full calculation, and discuss its
possible pitfalls and limitations. We also provide a simple interpolating
interface in Python that allows to apply our method quantitatively.
| [
{
"created": "Mon, 1 Oct 2018 10:25:40 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Aug 2019 05:48:18 GMT",
"version": "v2"
}
] | 2019-08-07 | [
[
"Kang",
"Sunghyun",
"",
"Sogang\n U."
],
[
"Scopel",
"Stefano",
"",
"Sogang\n U."
],
[
"Tomar",
"Gaurav",
"",
"Sogang\n U."
],
[
"Yoon",
"Jong-Hyun",
"",
"Sogang\n U."
]
] | Assuming for Weakly Interacting Massive Particles (WIMPs) a Maxwellian velocity distribution in the Galaxy we provide an assessment of the sensitivity of existing Dark Matter (DM) direct detection (DD) experiments to operators up to dimension 7 of the relativistic effective field theory describing dark matter interactions with quarks and gluons . In particular we focus on a systematic approach, including an extensive set of experiments and large number of couplings, both exceeding for completeness similar analyses in the literature. The relativistic effective theory requires to fix one coupling for each quark flavor, so in principle for each different combination the bounds should be recalculated starting from direct detection experimental data. To address this problem we propose an approximate model-independent procedure that allows to directly calculate the bounds for any combination of couplings in terms of model-independent limits on the Wilson coefficients of the non-relativistic theory expressed in terms of the WIMP mass and of the neutron-to-proton coupling ratio $c^n/c^p$. We test the result of the approximate procedure against that of a full calculation, and discuss its possible pitfalls and limitations. We also provide a simple interpolating interface in Python that allows to apply our method quantitatively. |
hep-ph/9807266 | Chikage Habe | K. Fujii (Hokkaido Univ.), C. Habe (Hokkaido Univ.), T. Yabuki
(Rakunou Gakuen Univ.) | Note on the field theory of neutrino mixing | 21 pages, revtex, no figure | Phys.Rev.D59:113003,1999; Erratum-ibid.D60:099903,1999 | 10.1103/PhysRevD.59.113003 10.1103/PhysRevD.60.099903 | EPHOU-98-008 | hep-ph | null | The problem of the diagonalization of the flavor-neutrino propagator mat rix
is investigated in the theory with flavor-mixing mass terms in Lagrangian. For
this purpose we examine one-pole structures of flavor-neutrino propa gators,
leading to physical neutrino masses, and discuss the relation of the pro
pagator diagonalizaion to the diagonalizaion of the mass matrix in Lagrangian.
In connection with the paper by Blasone et al., it is pointed out that t here
is no compelling reason for fixing the mass parameters, althought this fixi ng
is necessary in order to construct the flavor Hilbert space.
| [
{
"created": "Tue, 7 Jul 1998 03:02:50 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Fujii",
"K.",
"",
"Hokkaido Univ."
],
[
"Habe",
"C.",
"",
"Hokkaido Univ."
],
[
"Yabuki",
"T.",
"",
"Rakunou Gakuen Univ."
]
] | The problem of the diagonalization of the flavor-neutrino propagator mat rix is investigated in the theory with flavor-mixing mass terms in Lagrangian. For this purpose we examine one-pole structures of flavor-neutrino propa gators, leading to physical neutrino masses, and discuss the relation of the pro pagator diagonalizaion to the diagonalizaion of the mass matrix in Lagrangian. In connection with the paper by Blasone et al., it is pointed out that t here is no compelling reason for fixing the mass parameters, althought this fixi ng is necessary in order to construct the flavor Hilbert space. |
hep-ph/9906244 | Kevin S. McFarland | Peter Fisher, Boris Kayser and Kevin S. McFarland | Neutrino Mass and Oscillation | 43 pages, 8 figures, to appear in the Annual Review of Nuclear and
Particle Science, Vol. 49 (1999) | Ann.Rev.Nucl.Part.Sci.49:481-528,1999 | 10.1146/annurev.nucl.49.1.481 | LNS-99-288, NSF-PT-99-1, UR-1569 | hep-ph hep-ex | null | The question of neutrino mass is one of the major riddles in particle
physics. Recently, strong evidence that neutrinos have nonzero masses has been
found. While tiny, these masses could be large enough to contribute
significantly to the mass density of the universe. The evidence for
nonvanishing neutrino masses is based on the apparent observation of neutrino
oscillation -- the transformation of a neutrino of one type or "flavor" into
one of another. We explain the physics of neutrino oscillation, and review and
weigh the evidence that it actually occurs in nature. We also discuss the
constraints on neutrino mass from cosmology and from experiments with negative
results. After presenting illustrative neutrino mass spectra suggested by the
present data, we consider how near- and far-future experiments can further
illuminate the nature of neutrinos and their masses.
| [
{
"created": "Fri, 4 Jun 1999 00:58:25 GMT",
"version": "v1"
}
] | 2008-12-18 | [
[
"Fisher",
"Peter",
""
],
[
"Kayser",
"Boris",
""
],
[
"McFarland",
"Kevin S.",
""
]
] | The question of neutrino mass is one of the major riddles in particle physics. Recently, strong evidence that neutrinos have nonzero masses has been found. While tiny, these masses could be large enough to contribute significantly to the mass density of the universe. The evidence for nonvanishing neutrino masses is based on the apparent observation of neutrino oscillation -- the transformation of a neutrino of one type or "flavor" into one of another. We explain the physics of neutrino oscillation, and review and weigh the evidence that it actually occurs in nature. We also discuss the constraints on neutrino mass from cosmology and from experiments with negative results. After presenting illustrative neutrino mass spectra suggested by the present data, we consider how near- and far-future experiments can further illuminate the nature of neutrinos and their masses. |
hep-ph/0403126 | Xiaofei Zhang | George Fai (Kent State University), Jianwei Qiu (Iowa State
University), and Xiaofei Zhang (Kent State University) | Probing small-x gluons by low-mass Drell-Yan pairs at RHIC and LHC | To appear in the proceedings of the seventeenth international
conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter
2004), 5 pages and 3 figures | J.Phys. G30 (2004) S1037-S1042 | 10.1088/0954-3899/30/8/054 | null | hep-ph | null | We calculate the transverse momentum distribution of low-mass Drell-Yan pairs
in QCD perturbation theory with all-order resummation. We demonstrate that the
transverse momentum distribution of low-mass Drell-Yan pairs is an advantageous
source of constraints on the gluon distribution and its nuclear dependence.
With the reduction in background, we argue that low-mass Drell-Yan pairs in the
forward region provide a good and clean probe of small-x gluons at RHIC and
LHC.
| [
{
"created": "Thu, 11 Mar 2004 20:45:38 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Fai",
"George",
"",
"Kent State University"
],
[
"Qiu",
"Jianwei",
"",
"Iowa State\n University"
],
[
"Zhang",
"Xiaofei",
"",
"Kent State University"
]
] | We calculate the transverse momentum distribution of low-mass Drell-Yan pairs in QCD perturbation theory with all-order resummation. We demonstrate that the transverse momentum distribution of low-mass Drell-Yan pairs is an advantageous source of constraints on the gluon distribution and its nuclear dependence. With the reduction in background, we argue that low-mass Drell-Yan pairs in the forward region provide a good and clean probe of small-x gluons at RHIC and LHC. |
hep-ph/9807493 | Andrei Linde | Andrei Linde | A Toy Model for Open Inflation | 7 pages, 4 figures, revtex, a discussion of density perturbations is
extended | Phys.Rev.D59:023503,1999 | 10.1103/PhysRevD.59.023503 | SU-ITP-98-45 | hep-ph astro-ph gr-qc hep-th | null | The open inflation scenario based on the theory of bubble formation in the
models of a single scalar field suffered from a fatal defect. In all the
versions of this scenario known so far, the Coleman-De Luccia instantons
describing the creation of an open universe did not exist. We propose a simple
one-field model where the CDL instanton does exist and the open inflation
scenario can be realized.
| [
{
"created": "Mon, 27 Jul 1998 21:11:29 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Jul 1998 03:42:53 GMT",
"version": "v2"
},
{
"created": "Fri, 14 Aug 1998 04:53:26 GMT",
"version": "v3"
}
] | 2009-09-29 | [
[
"Linde",
"Andrei",
""
]
] | The open inflation scenario based on the theory of bubble formation in the models of a single scalar field suffered from a fatal defect. In all the versions of this scenario known so far, the Coleman-De Luccia instantons describing the creation of an open universe did not exist. We propose a simple one-field model where the CDL instanton does exist and the open inflation scenario can be realized. |
hep-ph/0306139 | Adam K. Leibovich | Sean Fleming, Adam K. Leibovich, Thomas Mehen | Resumming the color-octet contribution to e+ e- -> J/psi + X | 27 pages, 7 figures | Phys.Rev.D68:094011,2003 | 10.1103/PhysRevD.68.094011 | CMU-HEP-03-06 and FERMILAB-Pub-03/069-T | hep-ph hep-ex | null | Recent observations of the spectrum of J/psi produced in e+ e- collisions at
the Upsilon(4S) resonance are in conflict with fixed-order calculations using
the Non-Relativistic QCD (NRQCD) effective field theory. One problem is that
leading order color-octet mechanisms predict an enhancement of the cross
section for J/psi with maximal energy that is not observed in the data.
However, in this region of phase space large perturbative corrections (Sudakov
logarithms) as well as enhanced nonperturbative effects are important. In this
paper we use the newly developed Soft-Collinear Effective Theory (SCET) to
systematically include these effects. We find that these corrections
significantly broaden the color-octet contribution to the J/psi spectrum. Our
calculation employs a one-stage renormalization group evolution rather than the
two-stage evolution used in previous SCET calculations. We give a simple
argument for why the two methods yield identical results to lowest order in the
SCET power counting.
| [
{
"created": "Tue, 17 Jun 2003 16:43:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Fleming",
"Sean",
""
],
[
"Leibovich",
"Adam K.",
""
],
[
"Mehen",
"Thomas",
""
]
] | Recent observations of the spectrum of J/psi produced in e+ e- collisions at the Upsilon(4S) resonance are in conflict with fixed-order calculations using the Non-Relativistic QCD (NRQCD) effective field theory. One problem is that leading order color-octet mechanisms predict an enhancement of the cross section for J/psi with maximal energy that is not observed in the data. However, in this region of phase space large perturbative corrections (Sudakov logarithms) as well as enhanced nonperturbative effects are important. In this paper we use the newly developed Soft-Collinear Effective Theory (SCET) to systematically include these effects. We find that these corrections significantly broaden the color-octet contribution to the J/psi spectrum. Our calculation employs a one-stage renormalization group evolution rather than the two-stage evolution used in previous SCET calculations. We give a simple argument for why the two methods yield identical results to lowest order in the SCET power counting. |
2004.04138 | Pok Man Lo | Pok Man Lo (Wroclaw U.), Michal Szymanski (Wroclaw U.), Chihiro Sasaki
(Wroclaw U.), Krzysztof Redlich (Wroclaw U. and CERN-TH) | Deconfinement in the presence of a strong magnetic field | 17 pages, 13 figures, version in Phys. Rev. D | Phys. Rev. D 102, 034024 (2020) | 10.1103/PhysRevD.102.034024 | CERN-TH-2020-057 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the impact of a finite magnetic field on the deconfinement phase
transition for heavy quarks by computing the fluctuations of the Polyakov
loops. It is demonstrated that the explicit Z(3) breaking field increases with
the magnetic field, leading to a decrease in the (pseudo) critical temperatures
and a shrinking first-order region in the phase diagram. Phenomenological
equations that capture the behaviors of the Z(3) breaking field at strong and
weak magnetic fields for massive and massless quarks are given. Lastly, we
explore the case of dynamical light quarks and demonstrate how an improved
constituent quark mass function can enforce the correct magnetic field
dependence of the deconfinement temperature in an effective model, as observed
in Lattice QCD calculations.
| [
{
"created": "Wed, 8 Apr 2020 17:48:45 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Aug 2020 15:30:13 GMT",
"version": "v2"
}
] | 2020-08-27 | [
[
"Lo",
"Pok Man",
"",
"Wroclaw U."
],
[
"Szymanski",
"Michal",
"",
"Wroclaw U."
],
[
"Sasaki",
"Chihiro",
"",
"Wroclaw U."
],
[
"Redlich",
"Krzysztof",
"",
"Wroclaw U. and CERN-TH"
]
] | We study the impact of a finite magnetic field on the deconfinement phase transition for heavy quarks by computing the fluctuations of the Polyakov loops. It is demonstrated that the explicit Z(3) breaking field increases with the magnetic field, leading to a decrease in the (pseudo) critical temperatures and a shrinking first-order region in the phase diagram. Phenomenological equations that capture the behaviors of the Z(3) breaking field at strong and weak magnetic fields for massive and massless quarks are given. Lastly, we explore the case of dynamical light quarks and demonstrate how an improved constituent quark mass function can enforce the correct magnetic field dependence of the deconfinement temperature in an effective model, as observed in Lattice QCD calculations. |
1808.02539 | Daniel Boyanovsky | Nathan Herring, Brian Pardo, Daniel Boyanovsky, Andrew R. Zentner | Particle decay in post inflationary cosmology | more comments. published version | Phys. Rev. D 98, 083503 (2018) | 10.1103/PhysRevD.98.083503 | null | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study scalar particle decay during the radiation and matter dominated
epochs of a standard cosmological model. An adiabatic approximation is
introduced that is valid for degrees of freedom with typical wavelengths much
smaller than the particle horizon ($\propto$~Hubble radius) at a given time. We
implement a non-perturbative method that includes the cosmological expansion
and obtain a cosmological Fermi's Golden Rule that enables one to compute the
decay law of a parent particle of mass $m_1$, along with the build up of the
population of daughter particles of mass $m_2$. The survival probability of the
decaying particle is $P(t)=e^{-\widetilde{\Gamma}_k(t)\,t}$ with
$\widetilde{\Gamma}_k(t)$ being an \emph{effective momentum and time dependent
decay rate}. It features a transition time scale $t_{nr}$ between the
relativistic and non-relativistic regimes and for $k \neq 0$ is always smaller
than the analogous rate in Minkowski spacetime, as a consequence of (local)
time dilation and the cosmological redshift. For $t \ll t_{nr}$ the decay law
is a "stretched exponential" $P(t) = e^{-(t/t^*)^{3/2}}$, whereas for the
non-relativistic stage with $t \gg t_{nr}$, we find $P(t) = e^{-\Gamma_0
t}\,(t/t_{nr})^{\Gamma_0\,t_{nr}/2}$. The Hubble time scale $\propto 1/H(t)$
introduces an energy uncertainty $\Delta E \sim H(t)$ which relaxes the
constraints of kinematic thresholds. This opens new decay channels into heavier
particles for $2\pi E_k(t) H(t) \gg 4m^2_2-m^2_1$, with $E_k(t)$ the (local)
comoving energy of the decaying particle. As the expansion proceeds this
channel closes and the usual two particle thresholds restrict the decay
kinematics.
| [
{
"created": "Tue, 7 Aug 2018 20:20:52 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Oct 2018 13:38:21 GMT",
"version": "v2"
}
] | 2018-10-03 | [
[
"Herring",
"Nathan",
""
],
[
"Pardo",
"Brian",
""
],
[
"Boyanovsky",
"Daniel",
""
],
[
"Zentner",
"Andrew R.",
""
]
] | We study scalar particle decay during the radiation and matter dominated epochs of a standard cosmological model. An adiabatic approximation is introduced that is valid for degrees of freedom with typical wavelengths much smaller than the particle horizon ($\propto$~Hubble radius) at a given time. We implement a non-perturbative method that includes the cosmological expansion and obtain a cosmological Fermi's Golden Rule that enables one to compute the decay law of a parent particle of mass $m_1$, along with the build up of the population of daughter particles of mass $m_2$. The survival probability of the decaying particle is $P(t)=e^{-\widetilde{\Gamma}_k(t)\,t}$ with $\widetilde{\Gamma}_k(t)$ being an \emph{effective momentum and time dependent decay rate}. It features a transition time scale $t_{nr}$ between the relativistic and non-relativistic regimes and for $k \neq 0$ is always smaller than the analogous rate in Minkowski spacetime, as a consequence of (local) time dilation and the cosmological redshift. For $t \ll t_{nr}$ the decay law is a "stretched exponential" $P(t) = e^{-(t/t^*)^{3/2}}$, whereas for the non-relativistic stage with $t \gg t_{nr}$, we find $P(t) = e^{-\Gamma_0 t}\,(t/t_{nr})^{\Gamma_0\,t_{nr}/2}$. The Hubble time scale $\propto 1/H(t)$ introduces an energy uncertainty $\Delta E \sim H(t)$ which relaxes the constraints of kinematic thresholds. This opens new decay channels into heavier particles for $2\pi E_k(t) H(t) \gg 4m^2_2-m^2_1$, with $E_k(t)$ the (local) comoving energy of the decaying particle. As the expansion proceeds this channel closes and the usual two particle thresholds restrict the decay kinematics. |
0706.4269 | Poulose Poulose Dr. | S. Hesselbach (1), S. Moretti (1 and 2), S. Munir (1), P. Poulose (1)
((1)University of Southampton, (2) Orsay, LPT) | Exploring the Di-Photon Decay of a Light Higgs Boson in the MSSM With
Explicit CP Violation | 27 pages; LaTeX; minor changes in text; reference added; corrected
version to appear in EPJC | Eur.Phys.J.C54:129-147,2008 | 10.1140/epjc/s10052-007-0503-4 | SHEP-07-14, LPT-Orsay-07-129 | hep-ph | null | The di-photon decay channel of the lightest Higgs boson is considerd as a
probe to explore CP violation in the Minimal Supersymmetric Standard Model
(MSSM). The scalar/pseudo-scalar mixing is considered along with CP violation
entering through the Higgs-sfermion-sfermion couplings, with and without light
sparticles. The impact of a light stop on the decay width and Branching Ratio
(BR) is established through a detailed study of the amplitude of the process H1
--> gamma.gamma. The other sparticles have little influence even when they are
light. With a suitable combination of other MSSM parameters, a light stop can
change the BR by more than 50 % with a CP-violating phase phi_mu ~ 90 deg.,
while the change is almost nil with a heavy stop.
| [
{
"created": "Thu, 28 Jun 2007 17:14:34 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Jul 2007 13:03:19 GMT",
"version": "v2"
},
{
"created": "Wed, 5 Dec 2007 13:38:45 GMT",
"version": "v3"
},
{
"created": "Fri, 7 Dec 2007 14:15:46 GMT",
"version": "v4"
}
] | 2008-11-26 | [
[
"Hesselbach",
"S.",
"",
"University of Southampton"
],
[
"Moretti",
"S.",
"",
"1 and 2"
],
[
"Munir",
"S.",
"",
"University of Southampton"
],
[
"Poulose",
"P.",
"",
"University of Southampton"
]
] | The di-photon decay channel of the lightest Higgs boson is considerd as a probe to explore CP violation in the Minimal Supersymmetric Standard Model (MSSM). The scalar/pseudo-scalar mixing is considered along with CP violation entering through the Higgs-sfermion-sfermion couplings, with and without light sparticles. The impact of a light stop on the decay width and Branching Ratio (BR) is established through a detailed study of the amplitude of the process H1 --> gamma.gamma. The other sparticles have little influence even when they are light. With a suitable combination of other MSSM parameters, a light stop can change the BR by more than 50 % with a CP-violating phase phi_mu ~ 90 deg., while the change is almost nil with a heavy stop. |
hep-ph/0402241 | Martin Beneke | M. Beneke, Y. Kiyo and D. s. Yang | Loop corrections to sub-leading heavy quark currents in SCET | 17 pages | Nucl.Phys. B692 (2004) 232-248 | 10.1016/j.nuclphysb.2004.05.018 | PITHA 04/05 | hep-ph | null | We compute the one-loop (hard) matching correction to heavy-to-light
transition currents in soft-collinear effective theory (SCET) to sub-leading
power in the SCET expansion parameter for an arbitrary Dirac structure of the
QCD weak current.
| [
{
"created": "Mon, 23 Feb 2004 16:08:31 GMT",
"version": "v1"
}
] | 2010-04-05 | [
[
"Beneke",
"M.",
""
],
[
"Kiyo",
"Y.",
""
],
[
"Yang",
"D. s.",
""
]
] | We compute the one-loop (hard) matching correction to heavy-to-light transition currents in soft-collinear effective theory (SCET) to sub-leading power in the SCET expansion parameter for an arbitrary Dirac structure of the QCD weak current. |
hep-ph/9708449 | Finn Ravndal | Finn Ravndal | Applications of Effective Lagrangians | 10 pages, Latex with 8 figures | null | 10.1063/1.54471 | OSLO-TP 10-97 | hep-ph | null | Effective Lagrangians were originally used only at the tree level as
so-called phenomenological Lagrangians since they were in general
non-renormalizable. Today they are treated as effective field theories valid
below a characteristic energy scale. Quantum corrections can then be calculated
in a consistent way as for any renormalizable theory. A few applications of the
Euler-Heisenberg Lagrangian for interacting photons at low energies are
presented together with recent developments in the use of QED for
non-relativistic systems. Finally, the ingredients of an effective theory for
the electroweak sector of the Standard Model are discussed in the case of a
non-linear realization of the Higgs mechanism using the Stuckelberg formalism.
[Invited talk at "Beyond the Standard Model V", Balholm, Norway, April 29 - May
4, 1997]
| [
{
"created": "Mon, 25 Aug 1997 13:35:44 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Ravndal",
"Finn",
""
]
] | Effective Lagrangians were originally used only at the tree level as so-called phenomenological Lagrangians since they were in general non-renormalizable. Today they are treated as effective field theories valid below a characteristic energy scale. Quantum corrections can then be calculated in a consistent way as for any renormalizable theory. A few applications of the Euler-Heisenberg Lagrangian for interacting photons at low energies are presented together with recent developments in the use of QED for non-relativistic systems. Finally, the ingredients of an effective theory for the electroweak sector of the Standard Model are discussed in the case of a non-linear realization of the Higgs mechanism using the Stuckelberg formalism. [Invited talk at "Beyond the Standard Model V", Balholm, Norway, April 29 - May 4, 1997] |
2006.15743 | Gustavo Gil da Silveira | G. Sampaio dos Santos, G. Gil da Silveira, M. V. T. Machado | Prompt photon production in high-energy $pA$ collisions at forward
rapidity | 17 pages, 10 figures | Phys. Rev. C 102, 054901 (2020) | 10.1103/PhysRevC.102.054901 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Prompt photon production in hadronic collisions at the RHIC and the LHC
energies is investigated within the QCD color dipole approach. Predictions for
the nuclear modification factor in $pA$ collisions are evaluated based on
parton saturation framework and the results are compared to the experimental
measurements as a function of the photon transverse momentum at different
rapidity bins. The reliability of the models is performed with the data from
PHENIX, ATLAS, and ALICE Collaborations. Moreover, we show that the observed
$x_T$-scaling of prompt photon production in $pp$ and $pA$ collisions can
positively be addressed in the QCD color dipole formalism.
| [
{
"created": "Sun, 28 Jun 2020 23:17:03 GMT",
"version": "v1"
}
] | 2020-11-11 | [
[
"Santos",
"G. Sampaio dos",
""
],
[
"da Silveira",
"G. Gil",
""
],
[
"Machado",
"M. V. T.",
""
]
] | Prompt photon production in hadronic collisions at the RHIC and the LHC energies is investigated within the QCD color dipole approach. Predictions for the nuclear modification factor in $pA$ collisions are evaluated based on parton saturation framework and the results are compared to the experimental measurements as a function of the photon transverse momentum at different rapidity bins. The reliability of the models is performed with the data from PHENIX, ATLAS, and ALICE Collaborations. Moreover, we show that the observed $x_T$-scaling of prompt photon production in $pp$ and $pA$ collisions can positively be addressed in the QCD color dipole formalism. |
1606.04213 | Dong-Jing Yang | Dong-Jing Yang, Hsiang-nan Li | Gluon fragmentation functions in the Nambu-Jona-Lasinio model | 26 pages, 23 figures | Phys. Rev. D 94, 054041 (2016) | 10.1103/PhysRevD.94.054041 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive gluon fragmentation functions in the Nambu-Jona-Lasinio (NJL) model
by treating a gluon as a pair of color lines formed by fictitious quark and
anti-quark ($q\bar q$). Gluon elementary fragmentation functions are obtained
from the quark and anti-quark elementary fragmentation functions for emitting
specific mesons in the NJL model under the requirement that the $q\bar q$ pair
maintains in the flavor-singlet state after meson emissions. An integral
equation, which iterates the gluon elementary fragmentation functions to all
orders, is then solved to yield the gluon fragmentation functions at a model
scale. It is observed that these solutions are stable with respect to variation
of relevant model parameters, especially after QCD evolution to a higher scale
is implemented. We show that the inclusion of the gluon fragmentation functions
into the theoretical predictions from only the quark fragmentation functions
greatly improves the agreement with the SLD data for the pion and kaon
productions in $e^+e^-$ annihilation. Our proposal provides a plausible
construct for the gluon fragmentation functions, which are supposed to be null
in the NJL model.
| [
{
"created": "Tue, 14 Jun 2016 06:50:07 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jul 2016 17:25:33 GMT",
"version": "v2"
}
] | 2016-10-05 | [
[
"Yang",
"Dong-Jing",
""
],
[
"Li",
"Hsiang-nan",
""
]
] | We derive gluon fragmentation functions in the Nambu-Jona-Lasinio (NJL) model by treating a gluon as a pair of color lines formed by fictitious quark and anti-quark ($q\bar q$). Gluon elementary fragmentation functions are obtained from the quark and anti-quark elementary fragmentation functions for emitting specific mesons in the NJL model under the requirement that the $q\bar q$ pair maintains in the flavor-singlet state after meson emissions. An integral equation, which iterates the gluon elementary fragmentation functions to all orders, is then solved to yield the gluon fragmentation functions at a model scale. It is observed that these solutions are stable with respect to variation of relevant model parameters, especially after QCD evolution to a higher scale is implemented. We show that the inclusion of the gluon fragmentation functions into the theoretical predictions from only the quark fragmentation functions greatly improves the agreement with the SLD data for the pion and kaon productions in $e^+e^-$ annihilation. Our proposal provides a plausible construct for the gluon fragmentation functions, which are supposed to be null in the NJL model. |
1412.6283 | Yasaman Farzan | Yasaman Farzan | Two-loop snail diagrams: relating neutrino masses to dark matter | 14 pages, 3 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Various mechanisms have been developed to explain the origin of Majorana
neutrino masses. One of them is radiative mass generation. Two-loop mass
generation is of particular interest because the masses and couplings of new
particles propagating in the loop can be in the range testable by other
experiments and observations. In order for the radiative mass suppression to be
reliable, it should be guaranteed that lower loop contributions are suppressed.
Based on loop topology and the form of electroweak presentation of the
particles propagating in the loop, one can determine whether a lower---and
therefore dominant---loop contribution is possible. We present a model based on
these general considerations which leads to neutrino masses via a two-loop
diagram which we dub as "snail-diagram". The model has two natural candidates
for dark matter one of them being a neutral Dirac fermion which can satisfy the
conditions of the thermal freeze-out scenario by annihilation to lepton pairs.
We comment on the possibility of explaining the GeV gamma ray excess observed
by Fermi-LAT from the region close to the Galaxy Center. We also discuss
possible signals at the LHC and at experiments searching for lepton flavor
violating rare decays.
| [
{
"created": "Fri, 19 Dec 2014 10:46:06 GMT",
"version": "v1"
}
] | 2014-12-22 | [
[
"Farzan",
"Yasaman",
""
]
] | Various mechanisms have been developed to explain the origin of Majorana neutrino masses. One of them is radiative mass generation. Two-loop mass generation is of particular interest because the masses and couplings of new particles propagating in the loop can be in the range testable by other experiments and observations. In order for the radiative mass suppression to be reliable, it should be guaranteed that lower loop contributions are suppressed. Based on loop topology and the form of electroweak presentation of the particles propagating in the loop, one can determine whether a lower---and therefore dominant---loop contribution is possible. We present a model based on these general considerations which leads to neutrino masses via a two-loop diagram which we dub as "snail-diagram". The model has two natural candidates for dark matter one of them being a neutral Dirac fermion which can satisfy the conditions of the thermal freeze-out scenario by annihilation to lepton pairs. We comment on the possibility of explaining the GeV gamma ray excess observed by Fermi-LAT from the region close to the Galaxy Center. We also discuss possible signals at the LHC and at experiments searching for lepton flavor violating rare decays. |
hep-ph/9701403 | Ian Chapman | Ian Chapman (Texas at Austin) | Finite Temperature Wave-Function Renormalization, A Comparative Analysis | 12 pages, 3 figures. LaTeX | Phys.Rev.D55:6287-6291,1997 | 10.1103/PhysRevD.55.6287 | UTEXAS-HEP-97-3, DOE-ER40757-094 | hep-ph | null | We compare two competing theories regarding finite temperature wave-function
corrections for the process $H \to e^+e^-$ and for $n+\nu \to p+e^-$ and
related processes of interest for primordial nucleosynthesis. Although the two
methods are distinct (as shown in $H \to e^+e^-$) they yield the same finite
temperature correction for all $n\to p$ and $p \to n$ processes. Both methods
yield an increase in the He/H ratio of .01% due to finite temperature
renormalization rather than a decrease of .16% as previously predicted.
| [
{
"created": "Tue, 28 Jan 1997 21:32:36 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Chapman",
"Ian",
"",
"Texas at Austin"
]
] | We compare two competing theories regarding finite temperature wave-function corrections for the process $H \to e^+e^-$ and for $n+\nu \to p+e^-$ and related processes of interest for primordial nucleosynthesis. Although the two methods are distinct (as shown in $H \to e^+e^-$) they yield the same finite temperature correction for all $n\to p$ and $p \to n$ processes. Both methods yield an increase in the He/H ratio of .01% due to finite temperature renormalization rather than a decrease of .16% as previously predicted. |
1210.0925 | Vladimir Karmanov | V. A. Karmanov and J. Carbonell | Solving Bethe-Salpeter equation for scattering states | 4 pages, 2 figures. Presented at the 20th International IUPAP
Conference on Few-Body Problems in Physics, 20 - 25 August, 2012, Fukuoka,
Japan. Submitted in Few-Body Systems | null | 10.1007/s00601-013-0610-8 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the Minkowski space solutions of the inhomogeneous Bethe-Salpeter
equation for spinless particles with a ladder kernel. The off-mass shell
scattering amplitude is first obtained.
| [
{
"created": "Tue, 2 Oct 2012 21:04:03 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Karmanov",
"V. A.",
""
],
[
"Carbonell",
"J.",
""
]
] | We present the Minkowski space solutions of the inhomogeneous Bethe-Salpeter equation for spinless particles with a ladder kernel. The off-mass shell scattering amplitude is first obtained. |
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