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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9402227 | Hubert Simma | G. Kramer, W.F. Palmer, H. Simma | CP Violation and Strong Phases from Penguins in $\bf B^{\pm}\rightarrow
VV$ Decays | 24 pages, 3 figures (upon request), LaTeX, preprint DESY 93-192 | Nucl.Phys.B428:77-97,1994 | 10.1016/0550-3213(94)90192-9 | null | hep-ph | null | We calculate direct CP-violating observables in charged $B\to VV$ decays
arising from the interference of amplitudes with different strong and CKM
phases. The perturbative strong phases develop at order $\alpha_s$ from
absorptive parts of one-loop matrix elements of the next-to-leading logarithm
corrected effective Hamiltonian. CPT constraints are maintained. Based on this
model, we find that partial rate asymmetries between charge conjugate $B^{\pm}$
decays can be as high as 15-30\% for certain channels with branching ratios in
the $10^{-6}$ range. The small values of the coefficients of angular
correlations, which we calculated previously to be of order $10^{-2}$, are not
significantly degraded by the strong phases. The charge asymmetries of rates
and angular distributions would provide unambiguous evidence for direct CP
violation.
| [
{
"created": "Fri, 4 Feb 1994 13:49:43 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Kramer",
"G.",
""
],
[
"Palmer",
"W. F.",
""
],
[
"Simma",
"H.",
""
]
] | We calculate direct CP-violating observables in charged $B\to VV$ decays arising from the interference of amplitudes with different strong and CKM phases. The perturbative strong phases develop at order $\alpha_s$ from absorptive parts of one-loop matrix elements of the next-to-leading logarithm corrected effective Hamiltonian. CPT constraints are maintained. Based on this model, we find that partial rate asymmetries between charge conjugate $B^{\pm}$ decays can be as high as 15-30\% for certain channels with branching ratios in the $10^{-6}$ range. The small values of the coefficients of angular correlations, which we calculated previously to be of order $10^{-2}$, are not significantly degraded by the strong phases. The charge asymmetries of rates and angular distributions would provide unambiguous evidence for direct CP violation. |
1704.04711 | Danny Marfatia | Jiajun Liao, Danny Marfatia, Kerry Whisnant | Nonstandard interactions in solar neutrino oscillations with
Hyper-Kamiokande and JUNO | 8 pages, 11 figures | Phys. Lett. B 771 : 247-253 (2017) | 10.1016/j.physletb.2017.05.054 | null | hep-ph astro-ph.SR hep-ex nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Measurements of the solar neutrino mass-squared difference from KamLAND and
solar neutrino data are somewhat discrepant, perhaps due to nonstandard
neutrino interactions in matter. We show that the zenith angle distribution of
solar neutrinos at Hyper-Kamiokande and the energy spectrum of reactor
antineutrinos at JUNO can conclusively confirm the discrepancy and detect new
neutrino interactions.
| [
{
"created": "Sun, 16 Apr 2017 02:38:03 GMT",
"version": "v1"
}
] | 2017-05-30 | [
[
"Liao",
"Jiajun",
""
],
[
"Marfatia",
"Danny",
""
],
[
"Whisnant",
"Kerry",
""
]
] | Measurements of the solar neutrino mass-squared difference from KamLAND and solar neutrino data are somewhat discrepant, perhaps due to nonstandard neutrino interactions in matter. We show that the zenith angle distribution of solar neutrinos at Hyper-Kamiokande and the energy spectrum of reactor antineutrinos at JUNO can conclusively confirm the discrepancy and detect new neutrino interactions. |
hep-ph/0307394 | Carola F. Berger | Carola F. Berger (SUNY, Stony Brook and INFN, Turin), George Sterman
(SUNY, Stony Brook) | Scaling Rule for Nonperturbative Radiation in a Class of Event Shapes | 23 pages, 3 figures, uses JHEP3.cls (included); v2 - version to
appear in JHEP | JHEP 0309:058,2003 | 10.1088/1126-6708/2003/09/058 | YITP-SB-03-36 | hep-ph | null | We discuss nonperturbative radiation for a recently introduced class of
infrared safe event shape weights, which describe the narrow-jet limit.
Starting from next-to-leading logarithmic (NLL) resummation, we derive an
approximate scaling rule that relates the nonperturbative shape functions for
these weights to the shape function for the thrust. We argue that the scaling
reflects the boost invariance implicit in NLL resummation, and discuss its
limitations. In the absence of data analysis for the new event shapes, we
compare these predictions to the output of the event generator PYTHIA.
| [
{
"created": "Thu, 31 Jul 2003 17:14:40 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Sep 2003 13:12:02 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Berger",
"Carola F.",
"",
"SUNY, Stony Brook and INFN, Turin"
],
[
"Sterman",
"George",
"",
"SUNY, Stony Brook"
]
] | We discuss nonperturbative radiation for a recently introduced class of infrared safe event shape weights, which describe the narrow-jet limit. Starting from next-to-leading logarithmic (NLL) resummation, we derive an approximate scaling rule that relates the nonperturbative shape functions for these weights to the shape function for the thrust. We argue that the scaling reflects the boost invariance implicit in NLL resummation, and discuss its limitations. In the absence of data analysis for the new event shapes, we compare these predictions to the output of the event generator PYTHIA. |
1009.0476 | Stephen Parke | Rodrigo Alonso, Stefan Antusch, Mattias Blennow, Pilar Coloma, Andre
de Gouvea, Enrique Fernandez-Martinez, Belen Gavela, Concha Gonzalez-Garcia,
Sergio Hortner, Marco Laveder, Tracey Li, Jacobo Lopez-Pavon, Michele
Maltoni, Olga Mena, Pasquale Migliozzi, Toshihiko Ota, Sergio Palomares Ruiz,
Adam Para, Stephen J. Parke, Nuria Rius, Thomas Schwetz-Mangold, F. J. P.
Soler, Michel Sorel, Osamu Yasuda and Walter Winter | Summary report of MINSIS workshop in Madrid | Proceedings of the MINSIS Workshop, Dec 10-11, 2009 in Madrid. 15
pages latex | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent developments on tau detection technologies and the construction of
high intensity neutrino beams open the possibility of a high precision search
for non-standard {\mu} - {\tau} flavour transition with neutrinos at short
distances. The MINSIS - Main Injector Non-Standard Interaction Search- is a
proposal under discussion to realize such precision measurement. This document
contains the proceedings of the workshop which took place on 10-11 December
2009 in Madrid to discuss both the physics reach as well as the experimental
requirements for this proposal.
| [
{
"created": "Thu, 2 Sep 2010 17:02:51 GMT",
"version": "v1"
}
] | 2010-09-03 | [
[
"Alonso",
"Rodrigo",
""
],
[
"Antusch",
"Stefan",
""
],
[
"Blennow",
"Mattias",
""
],
[
"Coloma",
"Pilar",
""
],
[
"de Gouvea",
"Andre",
""
],
[
"Fernandez-Martinez",
"Enrique",
""
],
[
"Gavela",
"Belen",
""
],
[
"Gonzalez-Garcia",
"Concha",
""
],
[
"Hortner",
"Sergio",
""
],
[
"Laveder",
"Marco",
""
],
[
"Li",
"Tracey",
""
],
[
"Lopez-Pavon",
"Jacobo",
""
],
[
"Maltoni",
"Michele",
""
],
[
"Mena",
"Olga",
""
],
[
"Migliozzi",
"Pasquale",
""
],
[
"Ota",
"Toshihiko",
""
],
[
"Ruiz",
"Sergio Palomares",
""
],
[
"Para",
"Adam",
""
],
[
"Parke",
"Stephen J.",
""
],
[
"Rius",
"Nuria",
""
],
[
"Schwetz-Mangold",
"Thomas",
""
],
[
"Soler",
"F. J. P.",
""
],
[
"Sorel",
"Michel",
""
],
[
"Yasuda",
"Osamu",
""
],
[
"Winter",
"Walter",
""
]
] | Recent developments on tau detection technologies and the construction of high intensity neutrino beams open the possibility of a high precision search for non-standard {\mu} - {\tau} flavour transition with neutrinos at short distances. The MINSIS - Main Injector Non-Standard Interaction Search- is a proposal under discussion to realize such precision measurement. This document contains the proceedings of the workshop which took place on 10-11 December 2009 in Madrid to discuss both the physics reach as well as the experimental requirements for this proposal. |
hep-ph/0203205 | Roberto Ugoccioni | Alberto Giovannini, Sergio Lupia, Roberto Ugoccioni | Thermodynamics of Clan Production | 12 pages, revtex 4, 5 ps figures; to appear in Phys.Rev.D | Phys.Rev. D65 (2002) 094028 | 10.1103/PhysRevD.65.094028 | DFTT 37/2001 | hep-ph | null | Scenarios for particle production in the GeV and TeV regions are reviewed.
The expected increase with c.m. energy of the average number of clans for the
soft component and the decrease for the semihard one indicate possible
classical and quantum behaviour of gluons, respectively. Clan thermodynamics,
discussed in the paper, appears as the natural framework to deal with such
phenomena.
| [
{
"created": "Thu, 21 Mar 2002 13:52:02 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Giovannini",
"Alberto",
""
],
[
"Lupia",
"Sergio",
""
],
[
"Ugoccioni",
"Roberto",
""
]
] | Scenarios for particle production in the GeV and TeV regions are reviewed. The expected increase with c.m. energy of the average number of clans for the soft component and the decrease for the semihard one indicate possible classical and quantum behaviour of gluons, respectively. Clan thermodynamics, discussed in the paper, appears as the natural framework to deal with such phenomena. |
hep-ph/9903280 | Dmitri Kharzeev | R.L. Jaffe and D. Kharzeev | Chi_2 production in polarized pp collisions at RHIC: measuring \Delta G
and testing the color octet model | 7 pages | Phys.Lett.B455:306-310,1999 | 10.1016/S0370-2693(99)00448-7 | MIT-CTP-2838 | hep-ph hep-ex nucl-th | null | We consider the production and decay of the $\chi_2$ charmonium state in
polarized and unpolarized $pp$ collisions at RHIC in the framework of an
effective theory based on the QCD multipole expansion. We find that the angular
distribution in the decay of the produced charmonium, $\chi_2 \to J/\psi +
\gamma$, in the unpolarized case allows us to distinguish clearly between the
color singlet and color octet production mechanisms. Once the production
mechanism is known, the angular distribution in the polarized case can be used
to measure the polarized gluon distribution in the proton, $\Delta G(x)$.
| [
{
"created": "Mon, 8 Mar 1999 18:46:28 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Jaffe",
"R. L.",
""
],
[
"Kharzeev",
"D.",
""
]
] | We consider the production and decay of the $\chi_2$ charmonium state in polarized and unpolarized $pp$ collisions at RHIC in the framework of an effective theory based on the QCD multipole expansion. We find that the angular distribution in the decay of the produced charmonium, $\chi_2 \to J/\psi + \gamma$, in the unpolarized case allows us to distinguish clearly between the color singlet and color octet production mechanisms. Once the production mechanism is known, the angular distribution in the polarized case can be used to measure the polarized gluon distribution in the proton, $\Delta G(x)$. |
0901.3598 | Yosuke Takubo | Yosuke Takubo | Analysis of ZHH in the 4-jet mode | 4 pages, 5 figures, 1 table, proceedings of LCWS08 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Measurement of the cross-section of e+e- -> ZHH offers the information of the
trilinear Higgs self-coupling, which is important to confirm the mechanism of
the electro-weak symmetry breaking. Since there is huge background in the
signal region, background rejection is key point to identify ZHH events. In
this paper, we study the possibility to observe the ZHH events at ILC by using
ZHH -> nu nu HH, resulting 4 jets.
| [
{
"created": "Fri, 23 Jan 2009 04:12:55 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Jan 2009 06:28:15 GMT",
"version": "v2"
},
{
"created": "Thu, 29 Jan 2009 04:00:44 GMT",
"version": "v3"
}
] | 2009-01-29 | [
[
"Takubo",
"Yosuke",
""
]
] | Measurement of the cross-section of e+e- -> ZHH offers the information of the trilinear Higgs self-coupling, which is important to confirm the mechanism of the electro-weak symmetry breaking. Since there is huge background in the signal region, background rejection is key point to identify ZHH events. In this paper, we study the possibility to observe the ZHH events at ILC by using ZHH -> nu nu HH, resulting 4 jets. |
hep-ph/0203030 | Anna M. Stasto | J. Kwiecinski and A.M.Stasto | Geometric scaling and QCD evolution | 23 pages, 8 figures, new figures with illustration of the geometric
scaling, additional references added | Phys.Rev.D66:014013,2002 | 10.1103/PhysRevD.66.014013 | DFF 383/3/02 | hep-ph | null | We study the impact of the QCD DGLAP evolution on the geometric scaling of
the gluon distributions which is expected to hold at small x within the
saturation models. To this aim we solve the DGLAP evolution equations with the
initial conditions provided along the critical line Q^2=Q_s^2(x) where Q_s^2(x)
= Q_0^2 x^{-\lambda}and satisfying geometric scaling. Both fixed and running
coupling cases are studied. We show that in the fixed coupling case the
geometric scaling at low x is stable against the DGLAP evolution for
sufficiently large values of the parameter \lambda and in the double
logarithmic approximation of the DGLAP evolution this happens for \lambda >
4N_c\alpha_s/\pi. In the running coupling case geometric scaling is found to be
approximately preserved at very small x. The residual geometric scaling
violation in this case can be approximately factored out and the corresponding
form-factor controlling this violation is found.
| [
{
"created": "Mon, 4 Mar 2002 16:12:14 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Jun 2002 13:09:14 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Kwiecinski",
"J.",
""
],
[
"Stasto",
"A. M.",
""
]
] | We study the impact of the QCD DGLAP evolution on the geometric scaling of the gluon distributions which is expected to hold at small x within the saturation models. To this aim we solve the DGLAP evolution equations with the initial conditions provided along the critical line Q^2=Q_s^2(x) where Q_s^2(x) = Q_0^2 x^{-\lambda}and satisfying geometric scaling. Both fixed and running coupling cases are studied. We show that in the fixed coupling case the geometric scaling at low x is stable against the DGLAP evolution for sufficiently large values of the parameter \lambda and in the double logarithmic approximation of the DGLAP evolution this happens for \lambda > 4N_c\alpha_s/\pi. In the running coupling case geometric scaling is found to be approximately preserved at very small x. The residual geometric scaling violation in this case can be approximately factored out and the corresponding form-factor controlling this violation is found. |
0909.4163 | Dan Hooper | Dan Hooper and Kathryn M. Zurek | Pamela, FGST and Sub-Tev Dark Matter | 16 pages, 10 figures | Phys.Lett.B691:18-31,2010 | 10.1016/j.physletb.2010.06.014 | FERMILAB-PUB-09-441-A | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | PAMELA's observation that the cosmic ray positron fraction increases rapidly
with energy implies the presence of primary sources of energetic
electron-positron pairs. Of particular interest is the possibility that dark
matter annihilations in the halo of the Milky Way provide this anomalous flux
of antimatter. The recent measurement of the cosmic ray electron spectrum by
the Fermi Gamma Ray Space Telescope, however, can be used to constrain the
nature of any such dark matter particle. In particular, it has been argued that
in order to accommodate the observations of Fermi and provide the PAMELA
positron excess, annihilating dark matter particles must be as massive as ~1
TeV or heavier. In this article, we revisit Fermi's electron spectrum
measurement within the context of annihilating dark matter, focusing on masses
in the range of 100-1000 GeV, and considering effects such as variations in the
astrophysical backgrounds from the presence of local cosmic ray accelerators,
and the finite energy resolution of the Fermi Gamma Ray Space Telescope. When
these factors are taken into account, we find that dark matter particles as
light as ~300 GeV can be capable of generating the positron fraction observed
by PAMELA.
| [
{
"created": "Wed, 23 Sep 2009 13:38:49 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Hooper",
"Dan",
""
],
[
"Zurek",
"Kathryn M.",
""
]
] | PAMELA's observation that the cosmic ray positron fraction increases rapidly with energy implies the presence of primary sources of energetic electron-positron pairs. Of particular interest is the possibility that dark matter annihilations in the halo of the Milky Way provide this anomalous flux of antimatter. The recent measurement of the cosmic ray electron spectrum by the Fermi Gamma Ray Space Telescope, however, can be used to constrain the nature of any such dark matter particle. In particular, it has been argued that in order to accommodate the observations of Fermi and provide the PAMELA positron excess, annihilating dark matter particles must be as massive as ~1 TeV or heavier. In this article, we revisit Fermi's electron spectrum measurement within the context of annihilating dark matter, focusing on masses in the range of 100-1000 GeV, and considering effects such as variations in the astrophysical backgrounds from the presence of local cosmic ray accelerators, and the finite energy resolution of the Fermi Gamma Ray Space Telescope. When these factors are taken into account, we find that dark matter particles as light as ~300 GeV can be capable of generating the positron fraction observed by PAMELA. |
1706.00205 | Egle Tomasi-Gustafsson | Ying Wang, Yury M. Bystritskiy, Azad I. Ahmadov, Egle Tomasi
Gustafsson | Antiproton--proton annihilation into light neutral meson pairs within an
effective meson theory | 20 pages, 9 Figures | null | 10.1103/PhysRevC.96.025204 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Antiproton--proton annihilation into light neutral mesons in the few GeV
energy domain is investigated in view of a global description of the existing
data and predictions for future experiments at PANDA, FAIR. An effective meson
model earlier developed, with mesonic and baryonic degrees of freedom in $s$,
$t$, and $u$ channels, is applied here to $\pi^0\pi^0$ production. Form factors
with logarithmic $s$ and $t(u)$ dependencies are applied. A fair agreement with
the existing angular distributions is obtained. Applying SU(3) symmetry, it is
straightforward to recover the angular distributions for $ \pi^0\eta$, and
$\eta\eta$ production in the same energy range. A good agreement is generally
obtained with all existing data.
| [
{
"created": "Thu, 1 Jun 2017 08:34:33 GMT",
"version": "v1"
}
] | 2017-09-13 | [
[
"Wang",
"Ying",
""
],
[
"Bystritskiy",
"Yury M.",
""
],
[
"Ahmadov",
"Azad I.",
""
],
[
"Gustafsson",
"Egle Tomasi",
""
]
] | Antiproton--proton annihilation into light neutral mesons in the few GeV energy domain is investigated in view of a global description of the existing data and predictions for future experiments at PANDA, FAIR. An effective meson model earlier developed, with mesonic and baryonic degrees of freedom in $s$, $t$, and $u$ channels, is applied here to $\pi^0\pi^0$ production. Form factors with logarithmic $s$ and $t(u)$ dependencies are applied. A fair agreement with the existing angular distributions is obtained. Applying SU(3) symmetry, it is straightforward to recover the angular distributions for $ \pi^0\eta$, and $\eta\eta$ production in the same energy range. A good agreement is generally obtained with all existing data. |
hep-ph/0602091 | Jean-Philippe Lansberg | J.P. Lansberg | J/psi, psi' and Upsilon Production at Hadron Colliders: a review | 59 pages, 43 figures, LaTeX, uses ws-ijmpab.cls (included); v2:
Published version: a couple of typos corrected and a few references added | Int.J.Mod.Phys.A21:3857-3916,2006 | 10.1142/S0217751X06033180 | null | hep-ph hep-ex nucl-th | null | We give an overview of the present status of knowledge of the production of
J/psi, psi' and Upsilon in high-energy hadron collisions. We first present two
early models, namely the Colour-Singlet Model (CSM) and the Colour-Evaporation
Model (CEM). The first is the natural application of pQCD to quarkonium
production and has been shown to fail dramatically to describe data, the second
is its phenomenological counterpart and was introduced in the spirit of the
quark-hadron duality in the late seventies. Then, we expose the most recent
experimental measurements of J/psi, psi' and Upsilon prompt and direct
production at nonzero p_T from two high-energy hadron colliders, the Tevatron
and RHIC. In a third part, we review six contemporary models describing J/psi,
psi' and Upsilon production at nonzero p_T.
| [
{
"created": "Fri, 10 Feb 2006 14:20:51 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Aug 2006 17:01:34 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Lansberg",
"J. P.",
""
]
] | We give an overview of the present status of knowledge of the production of J/psi, psi' and Upsilon in high-energy hadron collisions. We first present two early models, namely the Colour-Singlet Model (CSM) and the Colour-Evaporation Model (CEM). The first is the natural application of pQCD to quarkonium production and has been shown to fail dramatically to describe data, the second is its phenomenological counterpart and was introduced in the spirit of the quark-hadron duality in the late seventies. Then, we expose the most recent experimental measurements of J/psi, psi' and Upsilon prompt and direct production at nonzero p_T from two high-energy hadron colliders, the Tevatron and RHIC. In a third part, we review six contemporary models describing J/psi, psi' and Upsilon production at nonzero p_T. |
1808.06618 | Francesco Capozzi | Francesco Capozzi (MPP Munich), Basudeb Dasgupta (TIFR, Mumbai),
Alessandro Mirizzi (Bari Univ., INFN Bari), Manibrata Sen (TIFR, Mumbai),
G\"unter Sigl (Hamburg Univ.) | Collisional triggering of fast flavor conversions of supernova neutrinos | 7 pages, 5 figures | Phys. Rev. Lett. 122, 091101 (2019) | 10.1103/PhysRevLett.122.091101 | MPP-2018-206, TIFR/TH/18-27 | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Fast flavor conversions of supernova neutrinos, possible near the
neutrinosphere, depends on an interesting interplay of collisions and neutrino
oscillations. Contrary to naive expectations, the rate of self-induced neutrino
oscillations, due to neutrino-neutrino forward scattering, comfortably exceeds
the rate of collisions even deep inside the supernova core. Consistently
accounting for collisions and oscillations, we present the first calculations
to show that collisions can create the conditions for fast flavor conversions
of neutrinos, but oscillations can continue without significant damping
thereafter. This may have interesting consequences for supernova explosions and
the nature of its associated neutrino emission.
| [
{
"created": "Mon, 20 Aug 2018 18:00:03 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Mar 2019 07:55:30 GMT",
"version": "v2"
}
] | 2019-03-13 | [
[
"Capozzi",
"Francesco",
"",
"MPP Munich"
],
[
"Dasgupta",
"Basudeb",
"",
"TIFR, Mumbai"
],
[
"Mirizzi",
"Alessandro",
"",
"Bari Univ., INFN Bari"
],
[
"Sen",
"Manibrata",
"",
"TIFR, Mumbai"
],
[
"Sigl",
"Günter",
"",
"Hamburg Univ."
]
] | Fast flavor conversions of supernova neutrinos, possible near the neutrinosphere, depends on an interesting interplay of collisions and neutrino oscillations. Contrary to naive expectations, the rate of self-induced neutrino oscillations, due to neutrino-neutrino forward scattering, comfortably exceeds the rate of collisions even deep inside the supernova core. Consistently accounting for collisions and oscillations, we present the first calculations to show that collisions can create the conditions for fast flavor conversions of neutrinos, but oscillations can continue without significant damping thereafter. This may have interesting consequences for supernova explosions and the nature of its associated neutrino emission. |
hep-ph/0301103 | Claudio Coriano | Alessandro Cafarella and Claudio Corian\'o | The Kinetic Interpretation of the DGLAP Equation, its Kramers-Moyal
Expansion and Positivity of Helicity Distributions | 38 pages, 27 figures, Dedicated to Prof. Pierre Ramond for his 60th
birthday | Int.J.Mod.Phys.A20:4863-4898,2005 | 10.1142/S0217751X05020951 | UFIFT-HEP-03-1 | hep-ph | null | According to a rederivation - due to Collins and Qiu - the DGLAP equation can
be reinterpreted (in leading order) in a probabilistic way. This form of the
equation has been used indirectly to prove the bound $|\Delta f(x,Q)| < f(x,Q)$
between polarized and unpolarized distributions, or positivity of the helicity
distributions, for any $Q$. We reanalize this issue by performing a detailed
numerical study of the positivity bounds of the helicity distributions. To
obtain the numerical solution we implement an x-space based algorithm for
polarized and unpolarized distributions to next-to-leading order in $\alpha_s$,
which we illustrate. We also elaborate on some of the formal properties of the
Collins-Qiu form and comment on the underlying regularization, introduce a
Kramers-Moyal expansion of the equation and briefly analize its Fokker-Planck
approximation. These follow quite naturally once the master version is given.
We illustrate this expansion both for the valence quark distribution $q_V$ and
for the transverse spin distribution $h_1$.
| [
{
"created": "Wed, 15 Jan 2003 18:14:03 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Feb 2003 13:52:17 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Cafarella",
"Alessandro",
""
],
[
"Corianó",
"Claudio",
""
]
] | According to a rederivation - due to Collins and Qiu - the DGLAP equation can be reinterpreted (in leading order) in a probabilistic way. This form of the equation has been used indirectly to prove the bound $|\Delta f(x,Q)| < f(x,Q)$ between polarized and unpolarized distributions, or positivity of the helicity distributions, for any $Q$. We reanalize this issue by performing a detailed numerical study of the positivity bounds of the helicity distributions. To obtain the numerical solution we implement an x-space based algorithm for polarized and unpolarized distributions to next-to-leading order in $\alpha_s$, which we illustrate. We also elaborate on some of the formal properties of the Collins-Qiu form and comment on the underlying regularization, introduce a Kramers-Moyal expansion of the equation and briefly analize its Fokker-Planck approximation. These follow quite naturally once the master version is given. We illustrate this expansion both for the valence quark distribution $q_V$ and for the transverse spin distribution $h_1$. |
2303.14805 | Abdulkadir Senol | A. Senol, H. Denizli and C. Helveci | Sensitivity of anomalous quartic gauge couplings via tri-photon
production at FCC-hh | 17 pages, 6 figures, some typos corrected and reference added | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A direct investigation of the self-couplings of gauge bosons, completely
described by the non-Abelian gauge symmetry of the Standard Model, is extremely
valuable in understanding the gauge structure of the SM. Any deviation from the
SM predictions on gauge boson self-coupling is to give a hint at the existence
of a new physics beyond the SM, which is defined with a modification of the
self-interactions using an effective field theory approach. In this paper, we
present a detailed Monte Carlo study searching for anomalous quartic gauge
dimension-8 couplings related to $\gamma\gamma\gamma\gamma$ and
$\gamma\gamma\gamma Z$ vertices at the future hadron-hadron collider (FCC-hh)
via tri-photon production at a 100 TeV center of mass energy with an integrated
luminosity L$_{int}$=30 ab$^{-1}$. Events that have been parton showered and
include detector effects are analyzed with a Toolkit for Multivariate Data
Analysis (TMVA) using a boosted decision tree to help distinguish between
signal and background events to achieve the best sensitivities on anomalous
quartic gauge couplings. Our obtained results reveal that the limits on
anomalous quartic gauge couplings $f_{T8}/\Lambda^{4}$ and $f_{T9}/\Lambda^{4}$
at 95\% C.L. without systematic errors are about three orders of magnitude
stronger compared to the best current experimental limits reported by the ATLAS
collaboration at the LHC. Considering a realistic systematic uncertainty such
as 10\% from possible experimental sources, our obtained limits of anomalous
quartic couplings get worse by about one order of magnitude compared to those
without systematic uncertainty but are still two orders of magnitude better
than those recently reported by ATLAS.
| [
{
"created": "Sun, 26 Mar 2023 20:11:47 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Mar 2023 07:31:28 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Apr 2023 10:09:25 GMT",
"version": "v3"
}
] | 2023-04-26 | [
[
"Senol",
"A.",
""
],
[
"Denizli",
"H.",
""
],
[
"Helveci",
"C.",
""
]
] | A direct investigation of the self-couplings of gauge bosons, completely described by the non-Abelian gauge symmetry of the Standard Model, is extremely valuable in understanding the gauge structure of the SM. Any deviation from the SM predictions on gauge boson self-coupling is to give a hint at the existence of a new physics beyond the SM, which is defined with a modification of the self-interactions using an effective field theory approach. In this paper, we present a detailed Monte Carlo study searching for anomalous quartic gauge dimension-8 couplings related to $\gamma\gamma\gamma\gamma$ and $\gamma\gamma\gamma Z$ vertices at the future hadron-hadron collider (FCC-hh) via tri-photon production at a 100 TeV center of mass energy with an integrated luminosity L$_{int}$=30 ab$^{-1}$. Events that have been parton showered and include detector effects are analyzed with a Toolkit for Multivariate Data Analysis (TMVA) using a boosted decision tree to help distinguish between signal and background events to achieve the best sensitivities on anomalous quartic gauge couplings. Our obtained results reveal that the limits on anomalous quartic gauge couplings $f_{T8}/\Lambda^{4}$ and $f_{T9}/\Lambda^{4}$ at 95\% C.L. without systematic errors are about three orders of magnitude stronger compared to the best current experimental limits reported by the ATLAS collaboration at the LHC. Considering a realistic systematic uncertainty such as 10\% from possible experimental sources, our obtained limits of anomalous quartic couplings get worse by about one order of magnitude compared to those without systematic uncertainty but are still two orders of magnitude better than those recently reported by ATLAS. |
hep-ph/0607275 | Andre Peshier | A. Peshier | Rethinking the QCD collisional energy loss | contribution to "Hot Quarks 2006", Villasimius, Italy, 15-20 May 2006 | Eur.Phys.J.C49:9-12,2007 | 10.1140/epjc/s10052-006-0063-z | null | hep-ph | null | It is shown that to leading order the collisional energy loss of an energetic
parton in the hot quark gluon plasma reads $dE/dx \sim \alpha(m_D^2)T^2$, where
the scale of the coupling is determined by the (parametrically soft) Debye
screening mass. Compared to previous expressions derived by Bjorken and other
authors, $dE^B/dx \sim \alpha^2 T^2 \ln(ET/m_D^2)$, the rectified result takes
into account the running of the coupling, as dictated by quantum corrections
beyond tree level. As one significant consequence, due to asymptotic freedom,
the QCD collisional energy loss becomes independent of the jet energy in the
limit $E \gg T$. It is advocated that this resummation improved perturbative
result might be useful to (re-)estimate the collisional energy loss for
temperatures relevant in heavy ion phenomenology.
| [
{
"created": "Tue, 25 Jul 2006 13:55:12 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Peshier",
"A.",
""
]
] | It is shown that to leading order the collisional energy loss of an energetic parton in the hot quark gluon plasma reads $dE/dx \sim \alpha(m_D^2)T^2$, where the scale of the coupling is determined by the (parametrically soft) Debye screening mass. Compared to previous expressions derived by Bjorken and other authors, $dE^B/dx \sim \alpha^2 T^2 \ln(ET/m_D^2)$, the rectified result takes into account the running of the coupling, as dictated by quantum corrections beyond tree level. As one significant consequence, due to asymptotic freedom, the QCD collisional energy loss becomes independent of the jet energy in the limit $E \gg T$. It is advocated that this resummation improved perturbative result might be useful to (re-)estimate the collisional energy loss for temperatures relevant in heavy ion phenomenology. |
1011.4024 | S. Mukherjee Dr. | S.Mukherjee and S.N.Banerjee | The dimensional properties of the hadron | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The statistical model of the hadron as a quarkonium system suggests the
dimensional dependence of some of the properties of the hadron like the scaling
in its probability density with the anomalous dimension as the exponent,the
universality, the power law scaling in transverse momentum in hadron
production.Recent experimental findings are found to be in agreement with the
corresponding predictions of the model.
| [
{
"created": "Wed, 17 Nov 2010 18:56:54 GMT",
"version": "v1"
}
] | 2010-11-18 | [
[
"Mukherjee",
"S.",
""
],
[
"Banerjee",
"S. N.",
""
]
] | The statistical model of the hadron as a quarkonium system suggests the dimensional dependence of some of the properties of the hadron like the scaling in its probability density with the anomalous dimension as the exponent,the universality, the power law scaling in transverse momentum in hadron production.Recent experimental findings are found to be in agreement with the corresponding predictions of the model. |
hep-ph/0604215 | Hyun Min Lee | Dumitru M. Ghilencea, Hyun Min Lee, Kai Schmidt-Hoberg | Higher derivatives and brane-localised kinetic terms in gauge theories
on orbifolds | 1+45 pages, 2 figures, JHEP style file, version to be published in
JHEP | JHEP 0608 (2006) 009 | 10.1088/1126-6708/2006/08/009 | DESY 06-028, DAMTP-2005-85 | hep-ph hep-th | null | We perform a detailed analysis of one-loop corrections to the self-energy of
the (off-shell) gauge bosons in six-dimensional N=1 supersymmetric gauge
theories on orbifolds. After discussing the Abelian case in the standard
Feynman diagram approach, we extend the analysis to the non-Abelian case by
employing the method of an orbifold-compatible one-loop effective action for a
classical background gauge field. We find that bulk higher derivative and
brane-localised gauge kinetic terms are required to cancel one-loop divergences
of the gauge boson self energy. After their renormalisation we study the
momentum dependence of both the higher derivative coupling h(k^2) and the {\it
effective} gauge coupling g_eff(k^2). For momenta smaller than the
compactification scales, we obtain the 4D logarithmic running of g_eff(k^2),
with suppressed power-like corrections, while the higher derivative coupling is
constant. We present in detail the threshold corrections to the low energy
gauge coupling, due to the massive bulk modes. At momentum scales above the
compactification scales, the higher derivative operator becomes important and
leads to a power-like running of g_eff(k^2) with respect to the momentum scale.
The coefficient of this running is at all scales equal to the renormalised
coupling of the higher derivative operator which ensures the quantum
consistency of the model. We discuss the relation to the similar one-loop
correction in the heterotic string, to show that the higher derivative
operators are relevant in that case too, since the field theory limit of the
one-loop string correction does not commute with the infrared regularisation of
the (on-shell) string result.
| [
{
"created": "Tue, 25 Apr 2006 15:18:42 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Apr 2006 12:37:06 GMT",
"version": "v2"
},
{
"created": "Mon, 24 Jul 2006 11:09:01 GMT",
"version": "v3"
}
] | 2009-11-11 | [
[
"Ghilencea",
"Dumitru M.",
""
],
[
"Lee",
"Hyun Min",
""
],
[
"Schmidt-Hoberg",
"Kai",
""
]
] | We perform a detailed analysis of one-loop corrections to the self-energy of the (off-shell) gauge bosons in six-dimensional N=1 supersymmetric gauge theories on orbifolds. After discussing the Abelian case in the standard Feynman diagram approach, we extend the analysis to the non-Abelian case by employing the method of an orbifold-compatible one-loop effective action for a classical background gauge field. We find that bulk higher derivative and brane-localised gauge kinetic terms are required to cancel one-loop divergences of the gauge boson self energy. After their renormalisation we study the momentum dependence of both the higher derivative coupling h(k^2) and the {\it effective} gauge coupling g_eff(k^2). For momenta smaller than the compactification scales, we obtain the 4D logarithmic running of g_eff(k^2), with suppressed power-like corrections, while the higher derivative coupling is constant. We present in detail the threshold corrections to the low energy gauge coupling, due to the massive bulk modes. At momentum scales above the compactification scales, the higher derivative operator becomes important and leads to a power-like running of g_eff(k^2) with respect to the momentum scale. The coefficient of this running is at all scales equal to the renormalised coupling of the higher derivative operator which ensures the quantum consistency of the model. We discuss the relation to the similar one-loop correction in the heterotic string, to show that the higher derivative operators are relevant in that case too, since the field theory limit of the one-loop string correction does not commute with the infrared regularisation of the (on-shell) string result. |
hep-ph/9604311 | Boris M. Kastening | Boris Kastening | Four-Loop Vacuum Energy Beta Function in O(N) Symmetric Scalar Theory | 16 pages, latex, no figures. Enlarged and updated reference list,
minor typographical changes | Phys. Rev. D 54, 3965 (1996) | 10.1103/PhysRevD.54.3965 | PURD-TH-96-03 | hep-ph cond-mat.stat-mech hep-th | null | The beta function of the vacuum energy density is computed at the four-loop
level in massive O(N) symmetric phi^4 theory. Dimensional regularization is
used in conjunction with the MSbar scheme and all calculations are in momentum
space in the massive theory. The result is
beta_v = g N/4+g^3 N(N+2)/96+g^4 N(N+2)(N+8)[12 zeta(3)-25]/1296+o(g^5).
| [
{
"created": "Fri, 12 Apr 1996 22:54:11 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Aug 1996 17:22:31 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Kastening",
"Boris",
""
]
] | The beta function of the vacuum energy density is computed at the four-loop level in massive O(N) symmetric phi^4 theory. Dimensional regularization is used in conjunction with the MSbar scheme and all calculations are in momentum space in the massive theory. The result is beta_v = g N/4+g^3 N(N+2)/96+g^4 N(N+2)(N+8)[12 zeta(3)-25]/1296+o(g^5). |
hep-ph/9912488 | Gavin Salam | Vito Antonelli, Mrinal Dasgupta, Gavin P. Salam | Resummation of thrust distributions in DIS | 25 pages | JHEP 0002:001,2000 | 10.1088/1126-6708/2000/02/001 | Bicocca-FT-99-32, CERN-TH/99-396 | hep-ph | null | We calculate the resummed distributions for the thrust in DIS in the limit
T->1. Two variants of the thrust are considered: that normalised to Q/2, and
that normalised to the energy in the current hemisphere. The results expanded
to second order are compared to predictions from the Monte Carlo programs
DISENT and DISASTER++. A prescription is given for matching the resummed
expressions with the full fixed order calculation.
| [
{
"created": "Thu, 23 Dec 1999 14:46:06 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Antonelli",
"Vito",
""
],
[
"Dasgupta",
"Mrinal",
""
],
[
"Salam",
"Gavin P.",
""
]
] | We calculate the resummed distributions for the thrust in DIS in the limit T->1. Two variants of the thrust are considered: that normalised to Q/2, and that normalised to the energy in the current hemisphere. The results expanded to second order are compared to predictions from the Monte Carlo programs DISENT and DISASTER++. A prescription is given for matching the resummed expressions with the full fixed order calculation. |
2110.11889 | Julien Froustey | Julien Froustey, Cyril Pitrou | Primordial neutrino asymmetry evolution with full mean-field effects and
collisions | 51 pages, 17 figures | JCAP 03 (2022), 065 | 10.1088/1475-7516/2022/03/065 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Neutrino oscillations and mean-field effects considerably enrich the
phenomenology of neutrino evolution in the early Universe. Taking into account
these effects, most notably the neutrino self-interaction mean-field
contribution, we revisit the problem of the evolution of primordial neutrino
asymmetries including for the first time the complete expression for
collisions, which describe scattering and annihilations with
electrons/positrons and reactions among (anti)neutrinos. We show that a
generalisation of the adiabatic transfer of averaged oscillations (ATAO)
scheme, a numerical method previously developed without neutrino degeneracy and
based on the large separation of time scales in this problem, is sufficient to
reach the same accuracy as the full quantum kinetic equation integration, but
is notably faster. This approximation highlights the physics of synchronous
oscillations at play in the evolution of neutrino chemical potentials,
especially in the particular case with only two-neutrino mixing. In particular,
it allows to understand what controls the beginning and the amplitude of
oscillations, but also why there is a subsequent regime of collective
oscillations with larger frequencies. We also find that it is very important to
use the full collision term instead of relying on damping-like approximations,
in order not to overestimate how collisions reduce these synchronous
oscillations. Finally we study qualitatively how mixing parameters affect the
final neutrino configuration, and in particular we show that the CP-violating
Dirac phase cannot substantially affect the final $N_{\rm eff}$ nor the final
electronic (anti)-neutrino spectrum, and thus should not affect cosmological
observables.
| [
{
"created": "Fri, 22 Oct 2021 16:16:24 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Mar 2022 16:04:13 GMT",
"version": "v2"
}
] | 2022-03-31 | [
[
"Froustey",
"Julien",
""
],
[
"Pitrou",
"Cyril",
""
]
] | Neutrino oscillations and mean-field effects considerably enrich the phenomenology of neutrino evolution in the early Universe. Taking into account these effects, most notably the neutrino self-interaction mean-field contribution, we revisit the problem of the evolution of primordial neutrino asymmetries including for the first time the complete expression for collisions, which describe scattering and annihilations with electrons/positrons and reactions among (anti)neutrinos. We show that a generalisation of the adiabatic transfer of averaged oscillations (ATAO) scheme, a numerical method previously developed without neutrino degeneracy and based on the large separation of time scales in this problem, is sufficient to reach the same accuracy as the full quantum kinetic equation integration, but is notably faster. This approximation highlights the physics of synchronous oscillations at play in the evolution of neutrino chemical potentials, especially in the particular case with only two-neutrino mixing. In particular, it allows to understand what controls the beginning and the amplitude of oscillations, but also why there is a subsequent regime of collective oscillations with larger frequencies. We also find that it is very important to use the full collision term instead of relying on damping-like approximations, in order not to overestimate how collisions reduce these synchronous oscillations. Finally we study qualitatively how mixing parameters affect the final neutrino configuration, and in particular we show that the CP-violating Dirac phase cannot substantially affect the final $N_{\rm eff}$ nor the final electronic (anti)-neutrino spectrum, and thus should not affect cosmological observables. |
hep-ph/9306269 | null | B.Brahmachari, U. Sarkar and K. Sridhar | Non-perturbative unification in the light of LEP results | Latex file 7 pages+1 fig. (ps file appended after the latex file),
CERN-TH.6913/93 | Mod.Phys.Lett. A8 (1993) 3349-3354 | 10.1142/S0217732393003779 | null | hep-ph | null | We consider an alternative to conventional GUTs originally proposed by
Maiani, Parisi and Petronzio, where owing to the existence of extra fermion
generations at some intermediate scale, the gauge couplings become large at
high energies. We first comment on how the non- supersymmetric version of this
scenario is ruled out; we then consider the two-loop evolution of the couplings
in the supersymmetric extension of this scenario, and check whether such a
scenario is feasible in the light of the precies values of couplings now
available from LEP.
| [
{
"created": "Mon, 14 Jun 1993 16:23:33 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Brahmachari",
"B.",
""
],
[
"Sarkar",
"U.",
""
],
[
"Sridhar",
"K.",
""
]
] | We consider an alternative to conventional GUTs originally proposed by Maiani, Parisi and Petronzio, where owing to the existence of extra fermion generations at some intermediate scale, the gauge couplings become large at high energies. We first comment on how the non- supersymmetric version of this scenario is ruled out; we then consider the two-loop evolution of the couplings in the supersymmetric extension of this scenario, and check whether such a scenario is feasible in the light of the precies values of couplings now available from LEP. |
1108.1196 | William Shepherd | Arvind Rajaraman, William Shepherd, Tim M.P. Tait and Alexander M.
Wijangco | LHC Bounds on Interactions of Dark Matter | 20 pages, 11 figures | null | 10.1103/PhysRevD.84.095013 | UCI-HEP-TR-2011-15 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive limits on the interactions of dark matter with quarks from ATLAS
null searches for jets + missing energy based on ~1 fb^-1 of integrated
luminosity, using a model-insensitive effective theory framework. We find that
the new limits from the LHC significantly extend limits previously derived from
CDF data at the Tevatron. Translated into the parameter space of direct
searches, these limits are particularly effective for ~GeV mass WIMPs. Our
limits indicate tension with isospin violating models satisfying minimal flavor
violation which attempt to reconcile the purported CoGeNT excess with
Xenon-100, indicating that either a light mediator or nontrivial flavor
structure for the dark sector is necessary for a viable reconciliation of
CoGeNT with Xenon.
| [
{
"created": "Thu, 4 Aug 2011 20:00:02 GMT",
"version": "v1"
}
] | 2013-05-29 | [
[
"Rajaraman",
"Arvind",
""
],
[
"Shepherd",
"William",
""
],
[
"Tait",
"Tim M. P.",
""
],
[
"Wijangco",
"Alexander M.",
""
]
] | We derive limits on the interactions of dark matter with quarks from ATLAS null searches for jets + missing energy based on ~1 fb^-1 of integrated luminosity, using a model-insensitive effective theory framework. We find that the new limits from the LHC significantly extend limits previously derived from CDF data at the Tevatron. Translated into the parameter space of direct searches, these limits are particularly effective for ~GeV mass WIMPs. Our limits indicate tension with isospin violating models satisfying minimal flavor violation which attempt to reconcile the purported CoGeNT excess with Xenon-100, indicating that either a light mediator or nontrivial flavor structure for the dark sector is necessary for a viable reconciliation of CoGeNT with Xenon. |
hep-ph/9908504 | Alan Kostelecky | Alan Kostelecky and Charles Lane | Constraints on Lorentz violation from clock-comparison experiments | accepted for publication in Physical Review D; scheduled for issue of
December 1, 1999 | Phys.Rev.D60:116010,1999 | 10.1103/PhysRevD.60.116010 | IUHET 403, March 1999 | hep-ph | null | Constraints from clock-comparison experiments on violations of Lorentz and
CPT symmetry are investigated in the context of a general Lorentz-violating
extension of the standard model. The experimental signals are shown to depend
on the atomic and ionic species used as clocks. Certain experiments usually
regarded as establishing comparable bounds are in this context sensitive to
different types of Lorentz violation. Some considerations relevant to possible
future measurements are presented. All these experiments are potentially
sensitive to Lorentz-violating physics at the Planck scale.
| [
{
"created": "Mon, 30 Aug 1999 14:21:54 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Kostelecky",
"Alan",
""
],
[
"Lane",
"Charles",
""
]
] | Constraints from clock-comparison experiments on violations of Lorentz and CPT symmetry are investigated in the context of a general Lorentz-violating extension of the standard model. The experimental signals are shown to depend on the atomic and ionic species used as clocks. Certain experiments usually regarded as establishing comparable bounds are in this context sensitive to different types of Lorentz violation. Some considerations relevant to possible future measurements are presented. All these experiments are potentially sensitive to Lorentz-violating physics at the Planck scale. |
hep-ph/0407068 | Gabriele Bodenmueller | Harald Fritzsch | Does the QCD Scale vary in time? | 5 pages, QCD International Conference Montpellier 2-9 July 2003 | null | 10.1016/j.nuclphysbps.2004.04.149 | LMU 20 / 03 | hep-ph | null | Last year I talked at this meeting about a possible time dependence of the
QCD coupling constant $\alpha_s$. This year I shall look into the problem once
more, without fully repeating the arguments given last year. Astrophysical
indications that the fine structure constant has undergone a small time
variation during the cosmological evolution are discussed within the framework
of the standard model of the electroweak and strong interactions and of grand
unification. A variation of the electromagnetic coupling constant could either
be generated by a corresponding time variation of the unified coupling constant
or by a time variation of the unification scale, or by both. The various
possibilities, differing substantially in their implications for the variation
of low energy physics parameters like the nuclear mass scale, are discussed.
The case in which the variation is caused by a time variation of the
unification scale is of special interest. It is supported in addition by recent
hints towards a time change of the proton-electron mass ratio.
| [
{
"created": "Tue, 6 Jul 2004 13:00:50 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Fritzsch",
"Harald",
""
]
] | Last year I talked at this meeting about a possible time dependence of the QCD coupling constant $\alpha_s$. This year I shall look into the problem once more, without fully repeating the arguments given last year. Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of grand unification. A variation of the electromagnetic coupling constant could either be generated by a corresponding time variation of the unified coupling constant or by a time variation of the unification scale, or by both. The various possibilities, differing substantially in their implications for the variation of low energy physics parameters like the nuclear mass scale, are discussed. The case in which the variation is caused by a time variation of the unification scale is of special interest. It is supported in addition by recent hints towards a time change of the proton-electron mass ratio. |
1304.1787 | Jeremie Quevillon | Abdelhak Djouadi and Jeremie Quevillon | The MSSM Higgs sector at a high $M_{SUSY}$: reopening the low tan$\beta$
regime and heavy Higgs searches | 36 pages, 11 figures, 1 table, pdflatex; v2: quality of figures
improved, typos corrected and references added | JHEP 1310 (2013) 028 | 10.1007/JHEP10(2013)028 | LPT Orsay 13-26 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | One of the main implications of the LHC discovery of a Higgs boson with a
mass $M_h \approx 126$ GeV is that the scale of supersymmetry-breaking in the
Minimal Supersymmetric Standard Model (MSSM) might be rather high, $M_S \gg
M_Z$. In this paper, we consider the high $M_S$ regime and study the spectrum
of the extended Higgs sector of the MSSM, including the LHC constraints on the
mass and the rates of the observed light $h$ state. In particular, we show that
in a simplified model that approximates the important radiative corrections,
the unknown scale $M_S$ (and some other leading SUSY parameters) can be traded
against the measured value of $M_h$. One would be then essentially left with
only two free parameters to describe the Higgs sector, tan$\beta$ and the
pseudoscalar Higgs mass $M_A$, even at higher orders. The main phenomenological
consequence of these high $M_S$ values is to reopen the low tan$\beta$ region,
tan$\beta \lsim 3-5$, which was for a long time buried under the LEP constraint
on the lightest $h$ mass when a low SUSY scale was assumed. We show that, in
this case, the heavier MSSM neutral $H/A$ and charged $H^\pm$ states can be
searched for in a variety of interesting final states such as decays into gauge
and lighter Higgs bosons (in pairs on in mixed states) and decays into heavy
top quarks. Examples of sensitivity on the $[tan\beta, M_A]$ parameter space at
the LHC in these channels are given.
| [
{
"created": "Fri, 5 Apr 2013 19:07:05 GMT",
"version": "v1"
},
{
"created": "Fri, 21 Jun 2013 15:13:42 GMT",
"version": "v2"
}
] | 2014-04-18 | [
[
"Djouadi",
"Abdelhak",
""
],
[
"Quevillon",
"Jeremie",
""
]
] | One of the main implications of the LHC discovery of a Higgs boson with a mass $M_h \approx 126$ GeV is that the scale of supersymmetry-breaking in the Minimal Supersymmetric Standard Model (MSSM) might be rather high, $M_S \gg M_Z$. In this paper, we consider the high $M_S$ regime and study the spectrum of the extended Higgs sector of the MSSM, including the LHC constraints on the mass and the rates of the observed light $h$ state. In particular, we show that in a simplified model that approximates the important radiative corrections, the unknown scale $M_S$ (and some other leading SUSY parameters) can be traded against the measured value of $M_h$. One would be then essentially left with only two free parameters to describe the Higgs sector, tan$\beta$ and the pseudoscalar Higgs mass $M_A$, even at higher orders. The main phenomenological consequence of these high $M_S$ values is to reopen the low tan$\beta$ region, tan$\beta \lsim 3-5$, which was for a long time buried under the LEP constraint on the lightest $h$ mass when a low SUSY scale was assumed. We show that, in this case, the heavier MSSM neutral $H/A$ and charged $H^\pm$ states can be searched for in a variety of interesting final states such as decays into gauge and lighter Higgs bosons (in pairs on in mixed states) and decays into heavy top quarks. Examples of sensitivity on the $[tan\beta, M_A]$ parameter space at the LHC in these channels are given. |
0906.4562 | Diego Becciolini | Diego Becciolini, Michele Redi and Andrea Wulzer | AdS/QCD: The Relevance of the Geometry | 25 pages + appendix. v2 minor changes and Refs. added | JHEP 1001:074,2010 | 10.1007/JHEP01(2010)074 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the relevance of the metric and of the geometry in
five-dimensional models of hadrons. Generically, the metric does not affect
strongly the results and even flat space agrees reasonably well with the data.
Nevertheless, we observe a preference for a decreasing warp factor, for example
AdS space. The Sakai-Sugimoto model reduces to one of these models and the
level of agreement is similar to the one of flat space. We also consider the
discrete version of the five-dimensional models, obtained by dimensional
deconstruction. We find that essentially all the relevant features of
"holographic" models of QCD can be reproduced with a simple 3-site model
describing only the states below the cut-off of the theory.
| [
{
"created": "Thu, 25 Jun 2009 09:22:34 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Oct 2009 09:24:52 GMT",
"version": "v2"
}
] | 2010-03-19 | [
[
"Becciolini",
"Diego",
""
],
[
"Redi",
"Michele",
""
],
[
"Wulzer",
"Andrea",
""
]
] | We investigate the relevance of the metric and of the geometry in five-dimensional models of hadrons. Generically, the metric does not affect strongly the results and even flat space agrees reasonably well with the data. Nevertheless, we observe a preference for a decreasing warp factor, for example AdS space. The Sakai-Sugimoto model reduces to one of these models and the level of agreement is similar to the one of flat space. We also consider the discrete version of the five-dimensional models, obtained by dimensional deconstruction. We find that essentially all the relevant features of "holographic" models of QCD can be reproduced with a simple 3-site model describing only the states below the cut-off of the theory. |
0903.3890 | Bastian Kubis | Martin Hoferichter, Bastian Kubis, Ulf-G. Mei{\ss}ner | Isospin breaking in the pion-nucleon scattering lengths | 7 pages, 1 figure | Phys.Lett.B678:65-71,2009 | 10.1016/j.physletb.2009.05.068 | HISKP-TH-09/11, FZJ-IKP-TH-2009-9 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze isospin breaking through quark mass differences and virtual
photons in the pion-nucleon scattering lengths in all physical channels in the
framework of covariant baryon chiral perturbation theory.
| [
{
"created": "Mon, 23 Mar 2009 16:50:00 GMT",
"version": "v1"
}
] | 2009-06-25 | [
[
"Hoferichter",
"Martin",
""
],
[
"Kubis",
"Bastian",
""
],
[
"Meißner",
"Ulf-G.",
""
]
] | We analyze isospin breaking through quark mass differences and virtual photons in the pion-nucleon scattering lengths in all physical channels in the framework of covariant baryon chiral perturbation theory. |
2003.07638 | Takaaki Nomura | Chuan-Hung Chen, Takaaki Nomura | Electron and muon $g-2$, radiative neutrino mass, and $\ell' \to \ell
\gamma$ in a $U(1)_{e-\mu}$ model | 24 pages, 7 figures, version accepted for publication in NPB | null | 10.1016/j.nuclphysb.2021.115314 | KIAS-P20012 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A nonconventional $U(1)_{e-\mu}$ gauge model is proposed to explain the
unexpected anomalous magnetic moments of the electron and muon (lepton $g-2$),
where only the right-handed electron and muon in the standard model carry the
$U(1)_{e-\mu}$ charge. Although the light lepton masses are suppressed when the
gauge symmetry is spontaneously broken, they can be generated through the
Yukawa couplings to newly introduced particles, such as vector-like lepton
doublets and singlet, and scalar singlets. It is found that the same Yukawa
couplings combined with the new scalar couplings to the Higgs can induce the
radiative lepton-flavor violation processes $\ell' \to \ell \gamma$ and lepton
$g-2$, where the lepton $g-2$ is proportional to $m_{\ell}$. When Majorana
fermions and a scalar singlet are further added into the model, the active
neutrinos can obtain masses via the radiative seesaw mechanism. When the bounds
from the $m_e$ and $m_\mu$ and the neutrino data are satisfied, we find that
the electron $g-2$ can reach an order of $-10^{-12}$, and the muon $g-2$ can be
an order of $10^{-9}$. In addition, when the $\mu\to e \gamma$ decay is
suppressed, the resulting branching ratio for $\tau\to e \gamma$ can be of
$O(10^{-8})$, and that for $\tau\to \mu \gamma$ can be as large as the current
upper limit.
| [
{
"created": "Tue, 17 Mar 2020 10:54:13 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Mar 2020 01:33:18 GMT",
"version": "v2"
},
{
"created": "Sat, 19 Dec 2020 13:35:12 GMT",
"version": "v3"
},
{
"created": "Mon, 25 Jan 2021 02:54:02 GMT",
"version": "v4"
}
] | 2021-02-24 | [
[
"Chen",
"Chuan-Hung",
""
],
[
"Nomura",
"Takaaki",
""
]
] | A nonconventional $U(1)_{e-\mu}$ gauge model is proposed to explain the unexpected anomalous magnetic moments of the electron and muon (lepton $g-2$), where only the right-handed electron and muon in the standard model carry the $U(1)_{e-\mu}$ charge. Although the light lepton masses are suppressed when the gauge symmetry is spontaneously broken, they can be generated through the Yukawa couplings to newly introduced particles, such as vector-like lepton doublets and singlet, and scalar singlets. It is found that the same Yukawa couplings combined with the new scalar couplings to the Higgs can induce the radiative lepton-flavor violation processes $\ell' \to \ell \gamma$ and lepton $g-2$, where the lepton $g-2$ is proportional to $m_{\ell}$. When Majorana fermions and a scalar singlet are further added into the model, the active neutrinos can obtain masses via the radiative seesaw mechanism. When the bounds from the $m_e$ and $m_\mu$ and the neutrino data are satisfied, we find that the electron $g-2$ can reach an order of $-10^{-12}$, and the muon $g-2$ can be an order of $10^{-9}$. In addition, when the $\mu\to e \gamma$ decay is suppressed, the resulting branching ratio for $\tau\to e \gamma$ can be of $O(10^{-8})$, and that for $\tau\to \mu \gamma$ can be as large as the current upper limit. |
1708.07802 | Estela A. Garces | E. A. Garc\'es, M. Hern\'andez Villanueva, G. L\'opez Castro, P. Roig | Effective-field theory analysis of the $\tau^- \to \eta^{(\prime)} \pi^-
\nu_\tau$ decays | 23 pages, 8 multiple figures and one table. Extended discussion of
the hadronization of the tensor current and improved presentation of the
plots. Accepted for publication in JHEP | J. High Energ. Phys. (2017) 2017: 27 | 10.1007/JHEP12(2017)027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The rare $\tau^- \to \eta^{(\prime)} \pi^- \nu_\tau$ decays, which are
suppressed by $G$-parity in the Standard Model (SM), can be sensitive to the
effects of new interactions. We study the sensitivity of different observables
of these decays in the framework of an effective field theory that includes the
most general interactions between SM fields up to dimension six, assuming
massless neutrinos. Owing to the strong suppression of the SM isospin breaking
amplitudes, we find that the different observables would allow to set
constraints on scalar interactions that are stronger than those coming from
other low-energy observables.
| [
{
"created": "Fri, 25 Aug 2017 16:33:38 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Nov 2017 03:58:43 GMT",
"version": "v2"
}
] | 2017-12-11 | [
[
"Garcés",
"E. A.",
""
],
[
"Villanueva",
"M. Hernández",
""
],
[
"Castro",
"G. López",
""
],
[
"Roig",
"P.",
""
]
] | The rare $\tau^- \to \eta^{(\prime)} \pi^- \nu_\tau$ decays, which are suppressed by $G$-parity in the Standard Model (SM), can be sensitive to the effects of new interactions. We study the sensitivity of different observables of these decays in the framework of an effective field theory that includes the most general interactions between SM fields up to dimension six, assuming massless neutrinos. Owing to the strong suppression of the SM isospin breaking amplitudes, we find that the different observables would allow to set constraints on scalar interactions that are stronger than those coming from other low-energy observables. |
hep-ph/0210310 | Artem V. Lipatov | A.V. Lipatov (Physical Department, Moscow State University), N.P.
Zotov (SINP, Moscow State University) | Inelastic J/psi production at HERA in the colour singlet model with
k_T-factorization | 14 pages, 10 figures | Eur.Phys.J.C27:87-99,2003 | 10.1140/epjc/s2002-01106-2 | null | hep-ph | null | In the framework of k_T-factorization QCD approach and the colour singlet
model we consider J/\psi inelastic photo- and leptoproduction processes at
HERA. We investigate the dependences of the single differential and double
differential cross section on different forms of the unintegrated gluon
distribution. The z and p_T dependences of the spin aligment parameter \alpha
are presented also. Our theoretical predictions agree well with recent data
taken by the H1 and ZEUS collaborations at HERA. It is shown that experimental
study of the polarization J/\psi mesons at low Q^2 < 1 GeV^2 is an additional
test of BFKL gluon dynamics.
| [
{
"created": "Wed, 23 Oct 2002 12:14:09 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Oct 2002 13:34:43 GMT",
"version": "v2"
}
] | 2009-01-07 | [
[
"Lipatov",
"A. V.",
"",
"Physical Department, Moscow State University"
],
[
"Zotov",
"N. P.",
"",
"SINP, Moscow State University"
]
] | In the framework of k_T-factorization QCD approach and the colour singlet model we consider J/\psi inelastic photo- and leptoproduction processes at HERA. We investigate the dependences of the single differential and double differential cross section on different forms of the unintegrated gluon distribution. The z and p_T dependences of the spin aligment parameter \alpha are presented also. Our theoretical predictions agree well with recent data taken by the H1 and ZEUS collaborations at HERA. It is shown that experimental study of the polarization J/\psi mesons at low Q^2 < 1 GeV^2 is an additional test of BFKL gluon dynamics. |
hep-ph/9906533 | Yulik Khriplovich | I.B. Khriplovich | Electric dipole moments, present and future | 9 pages, latex, no figures, plenary talk at PANIC99, Uppsala, June
1999 | Nucl.Phys. A663 (2000) 147-154 | 10.1016/S0375-9474(99)00582-5 | null | hep-ph nucl-th physics.acc-ph | null | Upper limits on the electric dipole moments (EDM) of elementary particles and
atoms are presented, and their physical implications are discussed. The bounds
following from the neutron and atomic experiments are comparable. In
particular, they strongly constrain P odd, T even interactions. The nuclear
EDMs can be studied at ion storage rings, with the expected sensitivity much
better than $10^{-24} e$ cm. It would be a serious progress in the studies of
the CP violation.
| [
{
"created": "Tue, 29 Jun 1999 10:57:02 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Khriplovich",
"I. B.",
""
]
] | Upper limits on the electric dipole moments (EDM) of elementary particles and atoms are presented, and their physical implications are discussed. The bounds following from the neutron and atomic experiments are comparable. In particular, they strongly constrain P odd, T even interactions. The nuclear EDMs can be studied at ion storage rings, with the expected sensitivity much better than $10^{-24} e$ cm. It would be a serious progress in the studies of the CP violation. |
1412.2938 | Alexander Kurilin | Alexander V. Kurilin | Chargino production via Z-Boson Decay in a Strong Electromagnetic Field | 7 pages, 2 figures | Chinese Physics Letters, 2016, Volume: 33, Issue: 03, Pages:
31301-1...31301-3 | 10.1088/0256-307X/33/3/031301 | MTI 0412-2014 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of MSSM the probability of $Z^0$-boson decay to charginos in
a strong electromagnetic field, $Z^0\rightarrow \chi ^{+} \chi ^{-}$, is
analyzed. The method of calculations employs exact solutions of relativistic
wave equations for charginos in a crossed electromagnetic field. Analytic
expression for the decay width $\Gamma(Z^{0}\rightarrow \chi ^{+} \chi ^{-})$
is obtained at an arbitrary value of the parameter $\varkappa=e
m_Z^{-3}\sqrt{-(F_{\mu\nu}q^\nu)^2}$, which characterizes the external-field
strength $F_{\mu\nu}$ and $Z^0$-boson momentum $q^{\nu}$. The process
$Z^0\rightarrow \chi ^{+} \chi ^{-}$ is forbidden in vacuum for the case of
relatively heavy charginos: $M_{\chi^{\pm}} > m_Z/2$. However in an intense
electromagnetic background this reaction could take place in the region of
superstrong fields ($\varkappa > 1$).
| [
{
"created": "Tue, 9 Dec 2014 12:28:10 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Feb 2015 20:47:22 GMT",
"version": "v2"
}
] | 2016-04-28 | [
[
"Kurilin",
"Alexander V.",
""
]
] | In the framework of MSSM the probability of $Z^0$-boson decay to charginos in a strong electromagnetic field, $Z^0\rightarrow \chi ^{+} \chi ^{-}$, is analyzed. The method of calculations employs exact solutions of relativistic wave equations for charginos in a crossed electromagnetic field. Analytic expression for the decay width $\Gamma(Z^{0}\rightarrow \chi ^{+} \chi ^{-})$ is obtained at an arbitrary value of the parameter $\varkappa=e m_Z^{-3}\sqrt{-(F_{\mu\nu}q^\nu)^2}$, which characterizes the external-field strength $F_{\mu\nu}$ and $Z^0$-boson momentum $q^{\nu}$. The process $Z^0\rightarrow \chi ^{+} \chi ^{-}$ is forbidden in vacuum for the case of relatively heavy charginos: $M_{\chi^{\pm}} > m_Z/2$. However in an intense electromagnetic background this reaction could take place in the region of superstrong fields ($\varkappa > 1$). |
hep-ph/0610113 | Alexandre Kisselev | A.V. Kisselev | RS model with a small curvature and gravity effects in e+e- annihilation
into leptons at the LC | 23 pages, 13 figures, Appendix and one reference are added | JHEP 0703:006,2007 | 10.1088/1126-6708/2007/03/006 | null | hep-ph hep-ex | null | The Randall-Sundrum (RS) model with a small curvature is considered. The mass
spectrum of Kaluza-Klein (KK) gravitons in such a scheme is similar (although
not equivalent) to that in a model with one extra dimension in a flat metric.
The gravity effects in the processes $e^+e^- \to e^+e^-$ and $e^+e^-
\to\mu^+\mu^-$ at the collision energy 1 TeV are presented. Our calculations
are based on the previously obtained formula for virtual graviton contributions
which takes into account both a discrete character of the mass spectrum and
nonzero widths of the KK gravitons.
| [
{
"created": "Tue, 10 Oct 2006 16:57:59 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Nov 2006 08:28:50 GMT",
"version": "v2"
},
{
"created": "Tue, 9 Jan 2007 09:57:29 GMT",
"version": "v3"
},
{
"created": "Wed, 7 Feb 2007 08:45:16 GMT",
"version": "v4"
}
] | 2010-10-27 | [
[
"Kisselev",
"A. V.",
""
]
] | The Randall-Sundrum (RS) model with a small curvature is considered. The mass spectrum of Kaluza-Klein (KK) gravitons in such a scheme is similar (although not equivalent) to that in a model with one extra dimension in a flat metric. The gravity effects in the processes $e^+e^- \to e^+e^-$ and $e^+e^- \to\mu^+\mu^-$ at the collision energy 1 TeV are presented. Our calculations are based on the previously obtained formula for virtual graviton contributions which takes into account both a discrete character of the mass spectrum and nonzero widths of the KK gravitons. |
0901.0233 | Wei-Min Yang | Wei-Min Yang and Hong-Huan Liu | The New Extended Left-Right Symmetric Grand Unified Model with SO(3)
Family Symmetry | 24 pages, 4 figures; to revise the old manuscript and add some new
contents | Nucl.Phys.B820:364-384,2009 | 10.1016/j.nuclphysb.2009.05.028 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We suggest a new left-right symmetric grand unified model by extending
Pati-Salam group to contain an isospin SU(2) and a flavor SO(3) subgroup, where
the superheavy fermions are introduced as a mirror to the low-energy standard
model fermions. The model undergoes three steps to break to the SM by means of
the specified Higgs multiplets. The model few parameters can elegantly
accommodate whole mass spectra for all the particles at the electroweak scale,
especially, two different flavor mixing for the quark and lepton sectors are
reproduced in agreement with the current experimental data very well. The
strong CP violation is excellently explained. The matter-antimatter asymmetry
in the universe is successfully implemented through the B-L violating decays of
the superheavy gauge bosons. The model also predicts that the lightest
right-handed Majorana neutrino, whose mass is about several hundred GeVs and
energy is about $10^{16}$ GeV, is possibly a candidate for the dark matter.
| [
{
"created": "Fri, 2 Jan 2009 11:42:00 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Jan 2009 06:10:19 GMT",
"version": "v2"
},
{
"created": "Wed, 22 Apr 2009 02:03:35 GMT",
"version": "v3"
}
] | 2009-07-22 | [
[
"Yang",
"Wei-Min",
""
],
[
"Liu",
"Hong-Huan",
""
]
] | We suggest a new left-right symmetric grand unified model by extending Pati-Salam group to contain an isospin SU(2) and a flavor SO(3) subgroup, where the superheavy fermions are introduced as a mirror to the low-energy standard model fermions. The model undergoes three steps to break to the SM by means of the specified Higgs multiplets. The model few parameters can elegantly accommodate whole mass spectra for all the particles at the electroweak scale, especially, two different flavor mixing for the quark and lepton sectors are reproduced in agreement with the current experimental data very well. The strong CP violation is excellently explained. The matter-antimatter asymmetry in the universe is successfully implemented through the B-L violating decays of the superheavy gauge bosons. The model also predicts that the lightest right-handed Majorana neutrino, whose mass is about several hundred GeVs and energy is about $10^{16}$ GeV, is possibly a candidate for the dark matter. |
1902.11288 | Yu Jia | Feng Feng, Yu Jia, Wen-Long Sang | Optimized predictions for $W \to B_c + \gamma$ by combining light-cone
and NRQCD approaches | 16 pages, 3 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The rare process of $W$ radiative decay into the $B_c$ meson can serve as an
interesting play ground for testing two influential perturbative QCD
approaches: non-relativistic quantum chromodynamics (NRQCD) and ligh-cone (LC)
factorization. Since the $B_c$ meson is a genuine heavy quarkonium which is
composed of two different species of heavy quarks, it is natural to employ
NRQCD factorization to tackle this exclusive quarkonium production process; on
the other hand, since the mass of the $W$ boson is much greater than that of
the $B_c$, the collinear factorization is also a viable approach. To fully
disentangle the contributions from several distinct scales $M_W$, $m_Q$, $m_Q
v$ ($v$ represents the typical velocity of the $c/\bar{b}$ quarks inside
$B_c$), and $\Lambda_{\rm QCD}$, we carry out a joint analysis that combines
both light-cone and NRQCD factorization approaches, and compute the
order-$\alpha_s$ correction to $W \to B_c+\gamma$. With the aid of the
celebrated Efremov-Radyushkin-Brodsky-Lepage (ERBL) evolution equation, we
resum the leading collinear logarithms $\alpha_s \ln\! {M_W\over m_Q}$ to all
orders in $\alpha_s$. We also explore some phenomenological implications of our
predictions.
| [
{
"created": "Thu, 28 Feb 2019 18:47:25 GMT",
"version": "v1"
}
] | 2019-03-01 | [
[
"Feng",
"Feng",
""
],
[
"Jia",
"Yu",
""
],
[
"Sang",
"Wen-Long",
""
]
] | The rare process of $W$ radiative decay into the $B_c$ meson can serve as an interesting play ground for testing two influential perturbative QCD approaches: non-relativistic quantum chromodynamics (NRQCD) and ligh-cone (LC) factorization. Since the $B_c$ meson is a genuine heavy quarkonium which is composed of two different species of heavy quarks, it is natural to employ NRQCD factorization to tackle this exclusive quarkonium production process; on the other hand, since the mass of the $W$ boson is much greater than that of the $B_c$, the collinear factorization is also a viable approach. To fully disentangle the contributions from several distinct scales $M_W$, $m_Q$, $m_Q v$ ($v$ represents the typical velocity of the $c/\bar{b}$ quarks inside $B_c$), and $\Lambda_{\rm QCD}$, we carry out a joint analysis that combines both light-cone and NRQCD factorization approaches, and compute the order-$\alpha_s$ correction to $W \to B_c+\gamma$. With the aid of the celebrated Efremov-Radyushkin-Brodsky-Lepage (ERBL) evolution equation, we resum the leading collinear logarithms $\alpha_s \ln\! {M_W\over m_Q}$ to all orders in $\alpha_s$. We also explore some phenomenological implications of our predictions. |
0709.4044 | Frank J. Petriello | Achilleas Lazopoulos, Kirill Melnikov, Frank Petriello | NLO QCD corrections to the production of t-tbar-Z in gluon fusion | 9 pages, 4 figures | Phys.Rev.D77:034021,2008 | 10.1103/PhysRevD.77.034021 | null | hep-ph hep-ex | null | We compute the O(alpha_s) QCD corrections to the partonic process gg ->
t-tbar-Z at the LHC. This partonic channel is the dominant component of the
scattering process pp -> t-tbar-Z, which will be important for measuring the
t-tbar-Z electroweak couplings. The O(alpha_s) corrections increase the total
cross section by up to 75% for reasonable choices of the renormalization and
factorization scales. Inclusion of these contributions descreases the residual
scale dependence of the cross section coming from uncalculated higher order
terms to +-5%.
| [
{
"created": "Tue, 25 Sep 2007 21:39:18 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Lazopoulos",
"Achilleas",
""
],
[
"Melnikov",
"Kirill",
""
],
[
"Petriello",
"Frank",
""
]
] | We compute the O(alpha_s) QCD corrections to the partonic process gg -> t-tbar-Z at the LHC. This partonic channel is the dominant component of the scattering process pp -> t-tbar-Z, which will be important for measuring the t-tbar-Z electroweak couplings. The O(alpha_s) corrections increase the total cross section by up to 75% for reasonable choices of the renormalization and factorization scales. Inclusion of these contributions descreases the residual scale dependence of the cross section coming from uncalculated higher order terms to +-5%. |
hep-ph/9712504 | Vladimir Anisovich | V. V. Anisovich | The lightest scalar glueball | 48 pages, LaTeX, 25 PostScript figures, epsfig.sty. Submitted to
Russian Journal Uspekhi Fiz. Nauk (Phys-Uspekhi) | Phys.Usp.41:419-439,1998; Usp.Fiz.Nauk 168:481-502,1998 | 10.1070/PU1998v041n05ABEH000390 | null | hep-ph | null | Recently performed investigations of meson spectra allow us to determine the
resonance structure for the waves $IJ^{PC}=00^{++}$, $10^{++}$, $02^{++}$,
$12^{++}$ = $IJ^P= 1/2 0^+$ in the mass region up to 1900 MeV, thus
establishing the meson multiplets $1^3P_0q\bar q$ and $2^3P_0q\bar q$.
Experimental data demonstrate that there are five scalar/isoscalar states in
this mass region. Four of them are $q\bar q$ states, that is, members of the
$1^3P_0q\bar q$ and $2^3P_0q\bar q$ nonets, while the fifth state is an extra
one not accomodated by $q \bar q$ systematics; it has the properties of the
lightest scalar glueball. Analysis of the $00^{++}$-wave performed within the
framework of the dispersion relation technique allows us to reconstruct the
mixing of a pure gluonium with neighbouring scalar $q \bar q$ states belonging
to $1^3P_0q\bar q$ and $2^3P_0q\bar q$ nonets: three scalar mesons share the
gluonium state between each other -- those are two comparatively narrow
resonances $f_0(1300)$ and $f_0(1500)$ and a broad resonance
$f_0(1530^{+90}_{-250})$. The broad state is a descendant of the gluonium,
keeping about 40-50% of its component.
| [
{
"created": "Tue, 23 Dec 1997 13:06:55 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Anisovich",
"V. V.",
""
]
] | Recently performed investigations of meson spectra allow us to determine the resonance structure for the waves $IJ^{PC}=00^{++}$, $10^{++}$, $02^{++}$, $12^{++}$ = $IJ^P= 1/2 0^+$ in the mass region up to 1900 MeV, thus establishing the meson multiplets $1^3P_0q\bar q$ and $2^3P_0q\bar q$. Experimental data demonstrate that there are five scalar/isoscalar states in this mass region. Four of them are $q\bar q$ states, that is, members of the $1^3P_0q\bar q$ and $2^3P_0q\bar q$ nonets, while the fifth state is an extra one not accomodated by $q \bar q$ systematics; it has the properties of the lightest scalar glueball. Analysis of the $00^{++}$-wave performed within the framework of the dispersion relation technique allows us to reconstruct the mixing of a pure gluonium with neighbouring scalar $q \bar q$ states belonging to $1^3P_0q\bar q$ and $2^3P_0q\bar q$ nonets: three scalar mesons share the gluonium state between each other -- those are two comparatively narrow resonances $f_0(1300)$ and $f_0(1500)$ and a broad resonance $f_0(1530^{+90}_{-250})$. The broad state is a descendant of the gluonium, keeping about 40-50% of its component. |
hep-ph/9307315 | null | Howard D. Trottier | $\Upsilon$ decay into charmonium and the color octet mechanism | 13 Pages (regular LaTeX document). Includes three postscript figures | Phys.Lett. B320 (1994) 145-151 | 10.1016/0370-2693(94)90838-9 | SFU HEP-104-93 | hep-ph | null | A factorization theorem for $P$-wave quarkonium production, recently derived
by Bodwin, Braaten, Yuan and Lepage, is applied to $\Upsilon \to \chi_{cJ} +
X$, where $\chi_{cJ}$ labels the ${}^3 P_J$ charmonium states. The widths for
$\chi_{cJ}$ production through color-singlet $P$-wave and color-octet $S$-wave
$c \bar c$ subprocesses are computed each to leading order in $\alpha_s$.
Experimental data on $\Upsilon \to J / \psi + X$ is used to obtain an upper
bound on a nonperturbative parameter (related to the probability for
color-octet $S$-wave $c \bar c$ hadronization into $P$-wave charmonium) that
enters into the factorization theorem. The bound obtained here adds to the
limited information so far available on the color-octet mechanism for $P$-wave
quarkonium production.
| [
{
"created": "Wed, 21 Jul 1993 22:35:20 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Trottier",
"Howard D.",
""
]
] | A factorization theorem for $P$-wave quarkonium production, recently derived by Bodwin, Braaten, Yuan and Lepage, is applied to $\Upsilon \to \chi_{cJ} + X$, where $\chi_{cJ}$ labels the ${}^3 P_J$ charmonium states. The widths for $\chi_{cJ}$ production through color-singlet $P$-wave and color-octet $S$-wave $c \bar c$ subprocesses are computed each to leading order in $\alpha_s$. Experimental data on $\Upsilon \to J / \psi + X$ is used to obtain an upper bound on a nonperturbative parameter (related to the probability for color-octet $S$-wave $c \bar c$ hadronization into $P$-wave charmonium) that enters into the factorization theorem. The bound obtained here adds to the limited information so far available on the color-octet mechanism for $P$-wave quarkonium production. |
1511.07604 | Shi Pi | Jinn-Ouk Gong, Chengcheng Han, and Shi Pi | Trail of the Higgs in the primordial spectrum | 17 pages, 2 figues | null | null | null | hep-ph astro-ph.CO gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of the Higgs directly coupled to the inflaton on the
primordial power spectrum. The quadratic coupling between the Higgs and the
inflaton stabilizes the Higgs in the electroweak vacuum during inflation by
inducing a large effective mass for the Higgs, which also leads to oscillatory
features in the primordial power spectrum due to the oscillating classical
background. Meanwhile, the features from quantum fluctuations exhibit simple
monotonic k-dependence and are subleading compared to the classical
contributions. We also comment on the collider searches.
| [
{
"created": "Tue, 24 Nov 2015 08:08:39 GMT",
"version": "v1"
}
] | 2015-12-04 | [
[
"Gong",
"Jinn-Ouk",
""
],
[
"Han",
"Chengcheng",
""
],
[
"Pi",
"Shi",
""
]
] | We study the effects of the Higgs directly coupled to the inflaton on the primordial power spectrum. The quadratic coupling between the Higgs and the inflaton stabilizes the Higgs in the electroweak vacuum during inflation by inducing a large effective mass for the Higgs, which also leads to oscillatory features in the primordial power spectrum due to the oscillating classical background. Meanwhile, the features from quantum fluctuations exhibit simple monotonic k-dependence and are subleading compared to the classical contributions. We also comment on the collider searches. |
2107.00016 | Yuber F. Perez-Gonzalez | Andrew Cheek, Lucien Heurtier, Yuber F. Perez-Gonzalez, Jessica Turner | Primordial Black Hole Evaporation and Dark Matter Production: II.
Interplay with the Freeze-In/Out Mechanism | 21 pages, 13 figures, code available at
https://github.com/earlyuniverse/ulysses Added clarifying comments. Matches
published version | Phys. Rev. D 105 (2022) 015023 | 10.1103/PhysRevD.105.015023 | FERMILAB-PUB-21-305-T, NUHEP-TH/21-07, CP3-21-42, IPPP/21/01 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We study how the evaporation of primordial black holes (PBHs) can affect the
production of dark matter (DM) particles through thermal processes. We consider
fermionic DM interacting with Standard Model particles via a spin-1 mediator in
the context of a Freeze-Out or Freeze-In mechanism. We show that when PBHs
evaporate after dominating the Universe's energy density, PBHs act as a source
of DM and continuously inject entropy into the visible sector that can affect
the thermal production in three qualitatively different ways. We compute the
annihilation cross-sections which account for the interactions between and
within the PBH produced and thermally produced DM populations, and establish a
set of Boltzmann equations which we solve to obtain the correct relic abundance
in those different regimes and confront the results with a set of different
cosmological constraints. We provide analytic formulae to calculate the relic
abundance for the Freeze-Out and Freeze-In mechanism in a PBH dominated early
Universe. We identify regions of the parameter space where the PBHs dilute the
relic density and thermalization occurs. Furthermore, we have made our code
that numerically solves the Boltzmann equations publicly available.
| [
{
"created": "Wed, 30 Jun 2021 18:00:01 GMT",
"version": "v1"
},
{
"created": "Sat, 29 Jan 2022 14:12:59 GMT",
"version": "v2"
}
] | 2022-02-01 | [
[
"Cheek",
"Andrew",
""
],
[
"Heurtier",
"Lucien",
""
],
[
"Perez-Gonzalez",
"Yuber F.",
""
],
[
"Turner",
"Jessica",
""
]
] | We study how the evaporation of primordial black holes (PBHs) can affect the production of dark matter (DM) particles through thermal processes. We consider fermionic DM interacting with Standard Model particles via a spin-1 mediator in the context of a Freeze-Out or Freeze-In mechanism. We show that when PBHs evaporate after dominating the Universe's energy density, PBHs act as a source of DM and continuously inject entropy into the visible sector that can affect the thermal production in three qualitatively different ways. We compute the annihilation cross-sections which account for the interactions between and within the PBH produced and thermally produced DM populations, and establish a set of Boltzmann equations which we solve to obtain the correct relic abundance in those different regimes and confront the results with a set of different cosmological constraints. We provide analytic formulae to calculate the relic abundance for the Freeze-Out and Freeze-In mechanism in a PBH dominated early Universe. We identify regions of the parameter space where the PBHs dilute the relic density and thermalization occurs. Furthermore, we have made our code that numerically solves the Boltzmann equations publicly available. |
hep-ph/0601155 | Mojtaba Mohammadi Najafabadi | Mojtaba Mohammadi Najafabadi | Secondary particles spectra in the decay of a polarized top quark with
anomalous $tWb$ coupling | 9 pages, 5 figures | J.Phys.G34:39-46,2007 | 10.1088/0954-3899/34/1/003 | null | hep-ph | null | Analytic expression for energy and angular dependence of a secondary charged
lepton in the decay of a polarized top quark with anomalous $tWb$ couplings in
the presence of all anomalous couplings are derived. The angular distribution
of the b-quark is derived as well. It is presented that the charged lepton spin
correlation coefficient is not very sensitive to the anomalous couplings.
However, the b-quark spin correlation coefficient is sensitive to anomalous
couplings and could be used as a powerful tool for searching of non-SM
coupling.
| [
{
"created": "Thu, 19 Jan 2006 11:23:39 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Jan 2006 15:41:55 GMT",
"version": "v2"
},
{
"created": "Tue, 22 Aug 2006 16:36:53 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Najafabadi",
"Mojtaba Mohammadi",
""
]
] | Analytic expression for energy and angular dependence of a secondary charged lepton in the decay of a polarized top quark with anomalous $tWb$ couplings in the presence of all anomalous couplings are derived. The angular distribution of the b-quark is derived as well. It is presented that the charged lepton spin correlation coefficient is not very sensitive to the anomalous couplings. However, the b-quark spin correlation coefficient is sensitive to anomalous couplings and could be used as a powerful tool for searching of non-SM coupling. |
2401.01639 | Pritam Das | Debasish Borah, Pritam Das, Satyabrata Mahapatra, Narendra Sahu | Light thermal dark matter via type-I seesaw portal | 39 pages, 18 figures | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a minimal scenario for light thermal dark matter (DM) in sub-GeV
to GeV ballpark by incorporating a scalar singlet DM in a type-I seesaw
scenario extended by an additional Higgs doublet $\phi_2$. The latter permits
efficient annihilation of light scalar DM into leptonic final states including
right-handed neutrinos (RHN). While DM annihilation into charged lepton final
states is kept either suppressed or in a kinematically forbidden ballpark to
avoid cosmic microwave background (CMB) bounds, the RHN, active neutrino final
states remain safe from such bounds even if they are allowed kinematically. We
discuss the interplay of forbidden and non-forbidden channels in generating
light thermal DM relic while incorporating constraints from cosmology as well
as laboratory experiments. The model can also explain the anomalous magnetic
moment of muon, W-mass anomaly and saturate experimental bounds on charged
lepton flavour violation and DM direct detection while offering tantalising
detection prospects of the lightest RHN, the mass of which is kept in the same
ballpark as DM.
| [
{
"created": "Wed, 3 Jan 2024 09:29:56 GMT",
"version": "v1"
}
] | 2024-01-04 | [
[
"Borah",
"Debasish",
""
],
[
"Das",
"Pritam",
""
],
[
"Mahapatra",
"Satyabrata",
""
],
[
"Sahu",
"Narendra",
""
]
] | We propose a minimal scenario for light thermal dark matter (DM) in sub-GeV to GeV ballpark by incorporating a scalar singlet DM in a type-I seesaw scenario extended by an additional Higgs doublet $\phi_2$. The latter permits efficient annihilation of light scalar DM into leptonic final states including right-handed neutrinos (RHN). While DM annihilation into charged lepton final states is kept either suppressed or in a kinematically forbidden ballpark to avoid cosmic microwave background (CMB) bounds, the RHN, active neutrino final states remain safe from such bounds even if they are allowed kinematically. We discuss the interplay of forbidden and non-forbidden channels in generating light thermal DM relic while incorporating constraints from cosmology as well as laboratory experiments. The model can also explain the anomalous magnetic moment of muon, W-mass anomaly and saturate experimental bounds on charged lepton flavour violation and DM direct detection while offering tantalising detection prospects of the lightest RHN, the mass of which is kept in the same ballpark as DM. |
1207.3343 | Howard Baer | Howard Baer, Vernon Barger, Peisi Huang, Azar Mustafayev and Xerxes
Tata | Radiative natural SUSY with a 125 GeV Higgs boson | 5 pages including 3 figures; minor typos/references added for version
2 | null | 10.1103/PhysRevLett.109.161802 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It has been argued that requiring low electroweak fine-tuning (EWFT) along
with a (partial) decoupling solution to the SUSY flavor and CP problems leads
to a sparticle mass spectra characterized by light Higgsinos at 100-300 GeV,
sub-TeV third generation scalars, gluinos at a few TeV and multi-TeV
first/second generation scalars (natural SUSY). We show that by starting with
multi-TeV first/second and third generation scalars and trilinear soft breaking
terms, the natural SUSY spectrum can be generated radiatively via
renormalization group running effects. Using the complete 1-loop effective
potential to calculate EWFT, significantly heavier third generation squarks can
be allowed even with low EWFT. The large negative trilinear term and heavier
top squarks allow for a light Higgs scalar in the ~125 GeV regime.
| [
{
"created": "Fri, 13 Jul 2012 19:56:10 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Sep 2012 19:47:29 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Baer",
"Howard",
""
],
[
"Barger",
"Vernon",
""
],
[
"Huang",
"Peisi",
""
],
[
"Mustafayev",
"Azar",
""
],
[
"Tata",
"Xerxes",
""
]
] | It has been argued that requiring low electroweak fine-tuning (EWFT) along with a (partial) decoupling solution to the SUSY flavor and CP problems leads to a sparticle mass spectra characterized by light Higgsinos at 100-300 GeV, sub-TeV third generation scalars, gluinos at a few TeV and multi-TeV first/second generation scalars (natural SUSY). We show that by starting with multi-TeV first/second and third generation scalars and trilinear soft breaking terms, the natural SUSY spectrum can be generated radiatively via renormalization group running effects. Using the complete 1-loop effective potential to calculate EWFT, significantly heavier third generation squarks can be allowed even with low EWFT. The large negative trilinear term and heavier top squarks allow for a light Higgs scalar in the ~125 GeV regime. |
1601.02934 | Marco Chianese Mr | Marco Chianese, Gennaro Miele, Stefano Morisi, Edoardo Vitagliano | Low energy IceCube data and a possible Dark Matter related excess | 6 pages, 4 figures. References added and clumpiness factor included
in case of dark matter annihilation | null | 10.1016/j.physletb.2016.03.084 | null | hep-ph astro-ph.CO astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this Letter we focus our attention on the IceCube events in the energy
range between 60 and 100 TeV, which show an order 2-sigma excess with respect
to a power-law with spectral index 2. We analyze the possible origin of such an
excess by comparing the distribution of the arrival directions of IceCube
events with the angular distributions of simply distributed astrophysical
galactic/extragalactic sources, as well as with the expected flux coming from
DM interactions (decay and annihilation) for different DM profiles. The
statistical analysis performed seems to disfavor the correlation with the
galactic plane, whereas rules out the DM annihilation scenario only in case of
small clumpiness effect. The small statistics till now collected does not allow
to scrutinize the cases of astrophysical isotropic distribution and DM decay
scenarios. For this reason we perform a forecast analysis in order to stress
the role of future Neutrino Telescopes.
| [
{
"created": "Tue, 12 Jan 2016 16:10:02 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Jan 2016 17:07:46 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Mar 2016 16:22:11 GMT",
"version": "v3"
}
] | 2016-05-04 | [
[
"Chianese",
"Marco",
""
],
[
"Miele",
"Gennaro",
""
],
[
"Morisi",
"Stefano",
""
],
[
"Vitagliano",
"Edoardo",
""
]
] | In this Letter we focus our attention on the IceCube events in the energy range between 60 and 100 TeV, which show an order 2-sigma excess with respect to a power-law with spectral index 2. We analyze the possible origin of such an excess by comparing the distribution of the arrival directions of IceCube events with the angular distributions of simply distributed astrophysical galactic/extragalactic sources, as well as with the expected flux coming from DM interactions (decay and annihilation) for different DM profiles. The statistical analysis performed seems to disfavor the correlation with the galactic plane, whereas rules out the DM annihilation scenario only in case of small clumpiness effect. The small statistics till now collected does not allow to scrutinize the cases of astrophysical isotropic distribution and DM decay scenarios. For this reason we perform a forecast analysis in order to stress the role of future Neutrino Telescopes. |
1708.08912 | Michael E. Peskin | Tim Barklow, Keisuke Fujii, Sunghoon Jung, Robert Karl, Jenny List,
Tomohisa Ogawa, Michael E. Peskin, and Junping Tian | Improved Formalism for Precision Higgs Coupling Fits | 34 pages, 4 figures; v4: clarifications and new references added; v5,
additional references added | Phys. Rev. D 97, 053003 (2018) | 10.1103/PhysRevD.97.053003 | DESY 17-120 / KEK preprint 2017-22 / SLAC-PUB-17129 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Future e+e- colliders give the promise of model-independent determinations of
the couplings of the Higgs boson. In this paper, we present an improved
formalism for extracting Higgs boson couplings from e+e- data, based on the
Effective Field Theory description of corrections to the Standard Model. We
apply this formalism to give projections of Higgs coupling accuracies for
stages of the International Linear Collider and for other proposed e+e-
colliders.
| [
{
"created": "Tue, 29 Aug 2017 17:58:35 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Aug 2017 00:41:48 GMT",
"version": "v2"
},
{
"created": "Wed, 6 Sep 2017 21:09:16 GMT",
"version": "v3"
},
{
"created": "Thu, 8 Feb 2018 01:21:42 GMT",
"version": "v4"
},
{
"created": "Tue, 13 Feb 2018 02:23:13 GMT",
"version": "v5"
}
] | 2018-03-28 | [
[
"Barklow",
"Tim",
""
],
[
"Fujii",
"Keisuke",
""
],
[
"Jung",
"Sunghoon",
""
],
[
"Karl",
"Robert",
""
],
[
"List",
"Jenny",
""
],
[
"Ogawa",
"Tomohisa",
""
],
[
"Peskin",
"Michael E.",
""
],
[
"Tian",
"Junping",
""
]
] | Future e+e- colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e+e- data, based on the Effective Field Theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e+e- colliders. |
0906.3745 | Tao Liu | Vernon Barger, Lisa L. Everett, Jing Jiang, Paul Langacker, Tao Liu
and Carlos E.M. Wagner | $b \to s$ Transitions in Family-dependent $U(1)^\prime$ Models | 36 pages, 11 figures | JHEP 0912:048,2009 | 10.1088/1126-6708/2009/12/048 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze flavor-changing-neutral-current (FCNC) effects in the $b\to s$
transitions that are induced by family non-universal $U(1)'$ gauge symmetries.
After systematically developing the necessary formalism, we present a
correlated analysis for the $\Delta B =1, 2$ processes. We adopt a
model-independent approach in which we only require family-universal charges
for the first and second generations and small fermion mixing angles. We
analyze the constraints on the resulting parameter space from $B_s - \bar B_s$
mixing and the time-dependent CP asymmetries of the penguin-dominated $B_d \to
(\pi, \phi, \eta', \rho, \omega, f_0)K_S$ decays. Our results indicate that the
currently observed discrepancies in some of these modes with respect to the
Standard Model predictions can be consistently accommodated within this general
class of models.
| [
{
"created": "Fri, 19 Jun 2009 20:57:32 GMT",
"version": "v1"
}
] | 2010-01-06 | [
[
"Barger",
"Vernon",
""
],
[
"Everett",
"Lisa L.",
""
],
[
"Jiang",
"Jing",
""
],
[
"Langacker",
"Paul",
""
],
[
"Liu",
"Tao",
""
],
[
"Wagner",
"Carlos E. M.",
""
]
] | We analyze flavor-changing-neutral-current (FCNC) effects in the $b\to s$ transitions that are induced by family non-universal $U(1)'$ gauge symmetries. After systematically developing the necessary formalism, we present a correlated analysis for the $\Delta B =1, 2$ processes. We adopt a model-independent approach in which we only require family-universal charges for the first and second generations and small fermion mixing angles. We analyze the constraints on the resulting parameter space from $B_s - \bar B_s$ mixing and the time-dependent CP asymmetries of the penguin-dominated $B_d \to (\pi, \phi, \eta', \rho, \omega, f_0)K_S$ decays. Our results indicate that the currently observed discrepancies in some of these modes with respect to the Standard Model predictions can be consistently accommodated within this general class of models. |
1512.05544 | Patrick Janot | Patrick Janot | Direct measurement of alpha_QED(mZ) at the FCC-ee | Version 4: Corrigendum added (2 pages). Accepted for publication in
JHEP | JHEP 1602 (2016) 053 | 10.1007/JHEP02(2016)053 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | When the measurements from the FCC-ee become available, an improved
determination of the standard-model "input" parameters will be needed to fully
exploit the new precision data towards either constraining or fitting the
parameters of beyond-the-standard-model theories. Among these input parameters
is the electromagnetic coupling constant estimated at the Z mass scale,
alpha_QED(mZ). The measurement of the muon forward-backward asymmetry at the
FCC-ee, just below and just above the Z pole, can be used to make a direct
determination of alpha_QED(mZ) with an accuracy deemed adequate for an optimal
use of the FCC-ee precision data.
| [
{
"created": "Thu, 17 Dec 2015 11:49:13 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Jan 2016 17:13:55 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Jan 2016 16:55:18 GMT",
"version": "v3"
},
{
"created": "Tue, 21 Nov 2017 12:02:24 GMT",
"version": "v4"
}
] | 2017-11-22 | [
[
"Janot",
"Patrick",
""
]
] | When the measurements from the FCC-ee become available, an improved determination of the standard-model "input" parameters will be needed to fully exploit the new precision data towards either constraining or fitting the parameters of beyond-the-standard-model theories. Among these input parameters is the electromagnetic coupling constant estimated at the Z mass scale, alpha_QED(mZ). The measurement of the muon forward-backward asymmetry at the FCC-ee, just below and just above the Z pole, can be used to make a direct determination of alpha_QED(mZ) with an accuracy deemed adequate for an optimal use of the FCC-ee precision data. |
1802.10509 | Adith Ramamurti | Adith Ramamurti, Edward Shuryak, Ismail Zahed | Are there monopoles in the quark-gluon plasma? | 8 pages, 1 figure | Phys. Rev. D 97, 114028 (2018) | 10.1103/PhysRevD.97.114028 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Monopole-like objects have been identified in multiple lattice studies, and
there is now a significant amount of literature on their importance in
phenomenology. Some analytic indications of their role, however, are still
missing. The 't Hooft-Polyakov monopoles, originally derived in the
Georgi-Glashow model, are an important dynamical ingredient in theories with
extended supersymmetry ${\cal N} = 2,\,4$, and help explain the issues related
with electric-magnetic duality. There is no such solution in QCD-like theories
without scalar fields. However, all of these theories have instantons and their
finite-$T$ constituents known as instanton-dyons (or instanton-monopoles). The
latter leads to semiclassical partition functions, which for ${\cal N} = 2,\,4$
theories were shown to be identical ("Poisson dual") to the partition function
for monopoles. We show how, in a pure gauge theory, the semiclassical
instanton-based partition function can also be Poisson-transformed into a
partition function, interpreted as the one of moving and rotating monopoles.
| [
{
"created": "Wed, 28 Feb 2018 16:19:47 GMT",
"version": "v1"
}
] | 2018-07-04 | [
[
"Ramamurti",
"Adith",
""
],
[
"Shuryak",
"Edward",
""
],
[
"Zahed",
"Ismail",
""
]
] | Monopole-like objects have been identified in multiple lattice studies, and there is now a significant amount of literature on their importance in phenomenology. Some analytic indications of their role, however, are still missing. The 't Hooft-Polyakov monopoles, originally derived in the Georgi-Glashow model, are an important dynamical ingredient in theories with extended supersymmetry ${\cal N} = 2,\,4$, and help explain the issues related with electric-magnetic duality. There is no such solution in QCD-like theories without scalar fields. However, all of these theories have instantons and their finite-$T$ constituents known as instanton-dyons (or instanton-monopoles). The latter leads to semiclassical partition functions, which for ${\cal N} = 2,\,4$ theories were shown to be identical ("Poisson dual") to the partition function for monopoles. We show how, in a pure gauge theory, the semiclassical instanton-based partition function can also be Poisson-transformed into a partition function, interpreted as the one of moving and rotating monopoles. |
1808.03102 | Pok Man Lo | Anton Andronic, Peter Braun-Munzinger, Bengt Friman, Pok Man Lo,
Krzysztof Redlich, Johanna Stachel | The thermal proton yield anomaly in Pb-Pb collisions at the LHC and its
resolution | 7 pages, 3 figures, submitted to PLB | null | 10.1016/j.physletb.2019.03.052 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a resolution of the discrepancy between the proton yield predicted
by the statistical hadronization approach and data on hadron production in
ultra-relativistic nuclear collisions at the LHC. Applying the S-matrix
formulation of statistical mechanics to include pion-nucleon interactions, we
reexamine their contribution to the proton yield, taking resonance widths and
the presence of nonresonant correlations into account. The effect of
multi-pion-nucleon interactions is estimated using lattice QCD results on the
baryon-charge susceptibility. We show that a consistent implementation of these
features in the statistical hadronization model, leads to a reduction of the
predicted proton yield, which then quantitatively matches data of the ALICE
collaboration for Pb-Pb collisions at the LHC.
| [
{
"created": "Thu, 9 Aug 2018 11:49:59 GMT",
"version": "v1"
},
{
"created": "Sun, 27 Jan 2019 14:32:46 GMT",
"version": "v2"
}
] | 2019-04-03 | [
[
"Andronic",
"Anton",
""
],
[
"Braun-Munzinger",
"Peter",
""
],
[
"Friman",
"Bengt",
""
],
[
"Lo",
"Pok Man",
""
],
[
"Redlich",
"Krzysztof",
""
],
[
"Stachel",
"Johanna",
""
]
] | We propose a resolution of the discrepancy between the proton yield predicted by the statistical hadronization approach and data on hadron production in ultra-relativistic nuclear collisions at the LHC. Applying the S-matrix formulation of statistical mechanics to include pion-nucleon interactions, we reexamine their contribution to the proton yield, taking resonance widths and the presence of nonresonant correlations into account. The effect of multi-pion-nucleon interactions is estimated using lattice QCD results on the baryon-charge susceptibility. We show that a consistent implementation of these features in the statistical hadronization model, leads to a reduction of the predicted proton yield, which then quantitatively matches data of the ALICE collaboration for Pb-Pb collisions at the LHC. |
hep-ph/9710422 | Borut Bajc | B. Bajc, S. Fajfer, R.J. Oakes and T.N. Pham | Resonant and nonresonant D+ -> K- pi+ l+ nu(l) semileptonic decays | 17 pages, 3 Postscript figures, standard Latex, extended revision,
title, abstract and text (especially Sec. IV) changed, results unchanged | Phys.Rev. D58 (1998) 054009 | 10.1103/PhysRevD.58.054009 | IJS-TP-97/14, DTP/97/88, NUHEP-TH-97-15, CPT-S565.1097 | hep-ph | null | We analyse the semileptonic decay D+ -> K- pi+ l+ nu(l) using an effective
Lagrangian developed previously to describe the decays D -> P l nu(l) and D ->
V l nu(l). Light vector mesons are included in the model which combines the
heavy quark effective Lagrangian and chiral perturbation theory approach. The
nonresonant and resonant contributions are compared. With no new parameters the
model correctly reproduces the measured ratio Gamma(nres)/Gamma(nres + res). We
also present useful nonresonant decay distributions. Finally, a similar model,
but with a modified current which satisfies the soft pion theorems at the
expense of introducing another parameter, is analyzed and the results of the
models are compared.
| [
{
"created": "Tue, 21 Oct 1997 09:24:35 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Apr 1998 14:10:45 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Bajc",
"B.",
""
],
[
"Fajfer",
"S.",
""
],
[
"Oakes",
"R. J.",
""
],
[
"Pham",
"T. N.",
""
]
] | We analyse the semileptonic decay D+ -> K- pi+ l+ nu(l) using an effective Lagrangian developed previously to describe the decays D -> P l nu(l) and D -> V l nu(l). Light vector mesons are included in the model which combines the heavy quark effective Lagrangian and chiral perturbation theory approach. The nonresonant and resonant contributions are compared. With no new parameters the model correctly reproduces the measured ratio Gamma(nres)/Gamma(nres + res). We also present useful nonresonant decay distributions. Finally, a similar model, but with a modified current which satisfies the soft pion theorems at the expense of introducing another parameter, is analyzed and the results of the models are compared. |
1410.6107 | Alma D. Rojas | Alma D. Rojas | Non-diagonal charged lepton mass matrix, the TBM and non-zero
$\theta_{13}$ | 6 pages, 2 figures. Contribution to the proceedings of the 37th
International Conference on High Energy Physics (ICHEP 2014), 2-9 July 2014,
Valencia, Spain | null | null | IFIC/14-71 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Assuming that the neutrino mass matrix is diagonalized by the TBM, we looked
for the charged lepton mass matrix textures which render a lepton mixing matrix
consistent with data. We were interested in the textures with the maximum
number of zeros, so, we explored the cases of real matrices with three (and
also four zeros) and found which of them provide solutions in agreement with
data. We present the successful Yukawa textures and obtained the relative sizes
of their non-zero entries. We found some interesting relations among the
entries of these textures in terms of the charged lepton masses.
| [
{
"created": "Wed, 22 Oct 2014 16:59:26 GMT",
"version": "v1"
}
] | 2014-10-23 | [
[
"Rojas",
"Alma D.",
""
]
] | Assuming that the neutrino mass matrix is diagonalized by the TBM, we looked for the charged lepton mass matrix textures which render a lepton mixing matrix consistent with data. We were interested in the textures with the maximum number of zeros, so, we explored the cases of real matrices with three (and also four zeros) and found which of them provide solutions in agreement with data. We present the successful Yukawa textures and obtained the relative sizes of their non-zero entries. We found some interesting relations among the entries of these textures in terms of the charged lepton masses. |
1202.5444 | Mustafa Savci | T. M. Aliev, M. Savci (Physics Department, Middle East Technical
University-Ankara-Turkey) | Lepton polarization effects in "Lambda_b -> Lambda l+l-" decay in family
non-universal Z' model | 15 pages, 3 figures, LaTeX formatted | null | 10.1016/j.physletb.2012.11.013 | metu-phys-hep-010-14 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Possible manifestation of the family non-universal Z' boson effects in lepton
polarization in rare, exclusive baryonic "Lambda_b -> Lambda l+l-" decay is
examined. It is observed that the double lepton polarizations P_TT and P_NN are
sensitive to the Z' contribution. Moreover, it is found that the zero position
of the polarized forward-backward asymmetry A_FB^LL is shifted to the left
compared to the standard model prediction. Therefore, determination of the zero
value of A_FB^LL is quite an efficient tool for establishing new Z' boson, but
also in discriminating various scenarios of the considered family non-universal
Z' model.
| [
{
"created": "Fri, 24 Feb 2012 13:18:34 GMT",
"version": "v1"
}
] | 2015-06-04 | [
[
"Aliev",
"T. M.",
"",
"Physics Department, Middle East Technical\n University-Ankara-Turkey"
],
[
"Savci",
"M.",
"",
"Physics Department, Middle East Technical\n University-Ankara-Turkey"
]
] | Possible manifestation of the family non-universal Z' boson effects in lepton polarization in rare, exclusive baryonic "Lambda_b -> Lambda l+l-" decay is examined. It is observed that the double lepton polarizations P_TT and P_NN are sensitive to the Z' contribution. Moreover, it is found that the zero position of the polarized forward-backward asymmetry A_FB^LL is shifted to the left compared to the standard model prediction. Therefore, determination of the zero value of A_FB^LL is quite an efficient tool for establishing new Z' boson, but also in discriminating various scenarios of the considered family non-universal Z' model. |
1901.08844 | M.I. Vyazovsky | M.A. Braun and M.I. Vyazovsky (Saint-Petersburg State University,
Russia) | Gluon emission at small longitudinal momenta in the QCD effective action
approach | 20 pages, 13 figures; to be published in Eur.Phys.Jour. C | null | 10.1140/epjc/s10052-019-6897-y | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of the QCD effective action the vertices of gluon emission
in interaction of reggeons are studied in the limit of small longitudinal
momenta of the emitted gluon. It is found that the vertices drastically
simplify in this limit so that the gluon becomes emitted from a single reggeon
coupled to the projectile and target via multireggeon vertices. Contribution
from this kinematical region is studied for double and 2x2 elementary
collisions inside the composite projectile and target.
| [
{
"created": "Fri, 25 Jan 2019 11:54:13 GMT",
"version": "v1"
},
{
"created": "Sun, 10 Mar 2019 21:21:35 GMT",
"version": "v2"
},
{
"created": "Sun, 5 May 2019 08:05:32 GMT",
"version": "v3"
}
] | 2019-05-22 | [
[
"Braun",
"M. A.",
"",
"Saint-Petersburg State University,\n Russia"
],
[
"Vyazovsky",
"M. I.",
"",
"Saint-Petersburg State University,\n Russia"
]
] | In the framework of the QCD effective action the vertices of gluon emission in interaction of reggeons are studied in the limit of small longitudinal momenta of the emitted gluon. It is found that the vertices drastically simplify in this limit so that the gluon becomes emitted from a single reggeon coupled to the projectile and target via multireggeon vertices. Contribution from this kinematical region is studied for double and 2x2 elementary collisions inside the composite projectile and target. |
hep-ph/9610527 | Nils A. Tornqvist | Nils A. Tornqvist and Matts Roos (University of Helsinki) | Reply to the Comment by Harada, Sannino and Schechter on "Confirmation
of the Sigma Meson" | 2 pages, RevTeX, No Figures | Phys.Rev.Lett. 77 (1996) 2333 | 10.1103/PhysRevLett.77.2333 | null | hep-ph | null | We reply to the comment of Harada, Sannino and Schechter (hep-ph/9609428) on
our recent paper in the Phys. Rev. Letters on the sigma meson. This concerns
the question, raised by Isgur and Speth in another comment, of whether a
detailed crossing symmetric form is necessary to understand the data. The
discussion gives further support on the existence of the broad sigma near 500
MeV.
| [
{
"created": "Tue, 29 Oct 1996 16:01:16 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Tornqvist",
"Nils A.",
"",
"University of Helsinki"
],
[
"Roos",
"Matts",
"",
"University of Helsinki"
]
] | We reply to the comment of Harada, Sannino and Schechter (hep-ph/9609428) on our recent paper in the Phys. Rev. Letters on the sigma meson. This concerns the question, raised by Isgur and Speth in another comment, of whether a detailed crossing symmetric form is necessary to understand the data. The discussion gives further support on the existence of the broad sigma near 500 MeV. |
1607.04235 | Michal Praszalowicz | Michal Praszalowicz | Saturation and geometrical scaling in small systems | 6 pages, 4 figures, talk presented at Excited QCD, Costa da Caparica,
Portugal, March 6-12, 2016 | null | null | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | Saturation and geometrical scaling (GS) of gluon distributions are a
consequence of the non-linear evolution equations of QCD. We argue that in pp
GS holds for the inelastic cross-section rather than for the multiplicity
distributions. We also discuss possible fluctuations of the proton saturation
scale in pA collisions at the LHC.
| [
{
"created": "Thu, 14 Jul 2016 18:28:37 GMT",
"version": "v1"
}
] | 2016-07-15 | [
[
"Praszalowicz",
"Michal",
""
]
] | Saturation and geometrical scaling (GS) of gluon distributions are a consequence of the non-linear evolution equations of QCD. We argue that in pp GS holds for the inelastic cross-section rather than for the multiplicity distributions. We also discuss possible fluctuations of the proton saturation scale in pA collisions at the LHC. |
0712.2442 | Marc Schumann | M. Schumann, M. Kreuz, M. Deissenroth, F. Glueck, J. Krempel, B.
Maerkisch, D. Mund, A. Petoukhov, T. Soldner, H. Abele | Measurement of the Proton Asymmetry Parameter C in Neutron Beta Decay | 4 pages, 2 figures | Phys.Rev.Lett.100:151801,2008 | 10.1103/PhysRevLett.100.151801 | null | hep-ph | null | The proton asymmetry parameter C in neutron decay describes the correlation
between neutron spin and proton momentum. In this Letter, the first measurement
of this quantity is presented. The result C=-0.2377(26) agrees with the
Standard Model expectation. The coefficient C provides an additional parameter
for new and improved Standard Model tests. From a differential analysis of the
same data (assuming the Standard Model), we obtain lambda=-1.275(16) as ratio
of axial-vector and vector coupling constant.
| [
{
"created": "Fri, 14 Dec 2007 20:13:12 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Schumann",
"M.",
""
],
[
"Kreuz",
"M.",
""
],
[
"Deissenroth",
"M.",
""
],
[
"Glueck",
"F.",
""
],
[
"Krempel",
"J.",
""
],
[
"Maerkisch",
"B.",
""
],
[
"Mund",
"D.",
""
],
[
"Petoukhov",
"A.",
""
],
[
"Soldner",
"T.",
""
],
[
"Abele",
"H.",
""
]
] | The proton asymmetry parameter C in neutron decay describes the correlation between neutron spin and proton momentum. In this Letter, the first measurement of this quantity is presented. The result C=-0.2377(26) agrees with the Standard Model expectation. The coefficient C provides an additional parameter for new and improved Standard Model tests. From a differential analysis of the same data (assuming the Standard Model), we obtain lambda=-1.275(16) as ratio of axial-vector and vector coupling constant. |
hep-ph/0611342 | Alex Bernardini | Alex E. Bernardini | The construction of Dirac wave packets for a fermionic particle
non-minimally coupling with an external magnetic field | 10 pages | Int. J. Theor. Phys. 46 (2007) 1562-1569 | 10.1007/s10773-006-9292-z | null | hep-ph | null | We shall proceed with the construction of normalizable Dirac wave packets for
{\em fermionic} particles (neutrinos) with dynamics governed by a ``modified''
Dirac equation with a non-minimal coupling with an external magnetic field. We
are not only interested on the analytic solutions of the ``modified'' Dirac
wave equation but also on the construction of Dirac wave packets which can be
used for describing the dynamics of some observable physical quantities which
are relevant in the context of the quantum oscillation phenomena. To conclude,
we discuss qualitatively the applicability of this formal construction in the
treatment of chiral (and flavor) oscillations in the theoretical context of
neutrino physics.
| [
{
"created": "Tue, 28 Nov 2006 00:55:35 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Bernardini",
"Alex E.",
""
]
] | We shall proceed with the construction of normalizable Dirac wave packets for {\em fermionic} particles (neutrinos) with dynamics governed by a ``modified'' Dirac equation with a non-minimal coupling with an external magnetic field. We are not only interested on the analytic solutions of the ``modified'' Dirac wave equation but also on the construction of Dirac wave packets which can be used for describing the dynamics of some observable physical quantities which are relevant in the context of the quantum oscillation phenomena. To conclude, we discuss qualitatively the applicability of this formal construction in the treatment of chiral (and flavor) oscillations in the theoretical context of neutrino physics. |
hep-ph/0503080 | C. Pallis | C. Pallis | Quintessential Kination and Cold Dark Matter Abundance | Published version | JCAP 0510:015,2005 | 10.1088/1475-7516/2005/10/015 | null | hep-ph astro-ph | null | The generation of a kination-dominated phase by a quintessential exponential
model is investigated and the parameters of the model are restricted so that a
number of observational constraints (originating from nucleosynthesis, the
present acceleration of the universe and the dark-energy-density parameter) are
satisfied. The decoupling of a thermal cold dark matter particle during the
period of kination is analyzed, the relic density is calculated both
numerically and semi-analytically and the results are compared with each other.
It is argued that the enhancement, with respect to the standard paradigm, of
the cold dark matter abundance can be expressed as a function of the
quintessential density parameter at the onset of nucleosynthesis. We find that
values of the latter quantity close to its upper bound require the
thermal-averaged cross section times the velocity of the cold relic to be
almost three orders of magnitude larger than this needed in the standard
scenario so as compatibility with the cold dark matter constraint is achieved.
| [
{
"created": "Tue, 8 Mar 2005 20:36:15 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Oct 2005 18:03:53 GMT",
"version": "v2"
},
{
"created": "Thu, 27 Oct 2005 15:44:33 GMT",
"version": "v3"
}
] | 2011-07-19 | [
[
"Pallis",
"C.",
""
]
] | The generation of a kination-dominated phase by a quintessential exponential model is investigated and the parameters of the model are restricted so that a number of observational constraints (originating from nucleosynthesis, the present acceleration of the universe and the dark-energy-density parameter) are satisfied. The decoupling of a thermal cold dark matter particle during the period of kination is analyzed, the relic density is calculated both numerically and semi-analytically and the results are compared with each other. It is argued that the enhancement, with respect to the standard paradigm, of the cold dark matter abundance can be expressed as a function of the quintessential density parameter at the onset of nucleosynthesis. We find that values of the latter quantity close to its upper bound require the thermal-averaged cross section times the velocity of the cold relic to be almost three orders of magnitude larger than this needed in the standard scenario so as compatibility with the cold dark matter constraint is achieved. |
hep-ph/0107305 | null | Yasuhiro Daikoku | Muon anomalous magnetic dipole moment in the $\mu$-problem solvable
extra U(1) models | 22 pages, latex, 14 figures | null | null | KANAZAWA-01-08 | hep-ph | null | The recent measurement of the muon anomalous magnetic dipole moment shows
2.6$\sigma$ deviation of $a_\mu$ from the standard model prediction which can
be explained by a chargino-sneutrino loop correction in the supersymmetric
models. In this paper we consider extra U(1) models where the $\mu$ parameter
is radiatively generated. This model predicts the sign of $\mu$ is positive in
wide parameter regions. But even the 2$\sigma$ constraint causes a serious
contradiction to the experimental bound of the extra neutral gauge boson mass.
Although a minimal supergravity scenario is ruled out, a very small window is
remained as an allowed region for a no-scale model with non-universal gaugino
masses.
| [
{
"created": "Mon, 30 Jul 2001 15:27:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Daikoku",
"Yasuhiro",
""
]
] | The recent measurement of the muon anomalous magnetic dipole moment shows 2.6$\sigma$ deviation of $a_\mu$ from the standard model prediction which can be explained by a chargino-sneutrino loop correction in the supersymmetric models. In this paper we consider extra U(1) models where the $\mu$ parameter is radiatively generated. This model predicts the sign of $\mu$ is positive in wide parameter regions. But even the 2$\sigma$ constraint causes a serious contradiction to the experimental bound of the extra neutral gauge boson mass. Although a minimal supergravity scenario is ruled out, a very small window is remained as an allowed region for a no-scale model with non-universal gaugino masses. |
2402.15847 | Jingwei Lian | Junjie Cao, Xinglong Jia, Jingwei Lian | Unified Interpretation of Muon g-2 anomaly, 95 GeV Diphoton, and
$b\bar{b}$ Excesses in the General Next-to-Minimal Supersymmetric Standard
Model | 38 pages, 7 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate three intriguing anomalies within the framework of the General
Next-to-Minimal Supersymmetric Standard Model. These anomalies include a
significant deviation of the experimental results for the muon anomalous
magnetic moment from its Standard Model prediction, with a confidence level of
$5.1\sigma$; a joint observation by the CMS and ATLAS collaborations of a
diphoton excess with a local significance of $3.1 \sigma$ in the invariant mass
distribution around 95.4 GeV; and a reported excess in the $b\bar{b}$
production at LEP with a local significance of $2.3 \sigma$. Through analytical
and numerical analyses, we provide unified interpretations across an extensive
parameter space that remain consistent with current experimental restrictions
from data on the Higgs boson at 125 GeV, B-physics measurements, dark matter
observables, as well as existing searches for supersymmetry and extra Higgs
bosons. We attribute the muon anomaly to loops involving muon-smuon-neutralino
and muon-sneutrino-chargino interactions, while attributing the diphoton and $b
\bar{b}$ excesses to the resonant production of a singlet-dominated scalar.
These proposed solutions are poised for experimental tests at the
high-luminosity LHC and future linear colliders.
| [
{
"created": "Sat, 24 Feb 2024 16:30:03 GMT",
"version": "v1"
}
] | 2024-02-27 | [
[
"Cao",
"Junjie",
""
],
[
"Jia",
"Xinglong",
""
],
[
"Lian",
"Jingwei",
""
]
] | We investigate three intriguing anomalies within the framework of the General Next-to-Minimal Supersymmetric Standard Model. These anomalies include a significant deviation of the experimental results for the muon anomalous magnetic moment from its Standard Model prediction, with a confidence level of $5.1\sigma$; a joint observation by the CMS and ATLAS collaborations of a diphoton excess with a local significance of $3.1 \sigma$ in the invariant mass distribution around 95.4 GeV; and a reported excess in the $b\bar{b}$ production at LEP with a local significance of $2.3 \sigma$. Through analytical and numerical analyses, we provide unified interpretations across an extensive parameter space that remain consistent with current experimental restrictions from data on the Higgs boson at 125 GeV, B-physics measurements, dark matter observables, as well as existing searches for supersymmetry and extra Higgs bosons. We attribute the muon anomaly to loops involving muon-smuon-neutralino and muon-sneutrino-chargino interactions, while attributing the diphoton and $b \bar{b}$ excesses to the resonant production of a singlet-dominated scalar. These proposed solutions are poised for experimental tests at the high-luminosity LHC and future linear colliders. |
hep-ph/0408324 | Seung Woo Ham | S. W. Ham and S. K. Oh | Electroweak phase transition in the standard model with a dimension-six
Higgs operator at one-loop level | 12 pages, 1 table, 4 figures | Phys.Rev. D70 (2004) 093007 | 10.1103/PhysRevD.70.093007 | null | hep-ph | null | The possibility of a strongly first-order electroweak phase transition by
means of a dimension-six Higgs operator in the Higgs potential of the standard
model is studied at finite temperature at the one-loop level. Exact calculation
of the one-loop effective Higgs potential at finite temperature suggests that
for the Higgs boson with its mass between 115 and 132 GeV the strongly
first-order electroweak phase transition is possible if a dimension-six
operator is present.
| [
{
"created": "Sun, 29 Aug 2004 03:08:58 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Oct 2004 01:54:05 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Ham",
"S. W.",
""
],
[
"Oh",
"S. K.",
""
]
] | The possibility of a strongly first-order electroweak phase transition by means of a dimension-six Higgs operator in the Higgs potential of the standard model is studied at finite temperature at the one-loop level. Exact calculation of the one-loop effective Higgs potential at finite temperature suggests that for the Higgs boson with its mass between 115 and 132 GeV the strongly first-order electroweak phase transition is possible if a dimension-six operator is present. |
1307.1349 | Matteo Fael | Matteo Fael, Thomas Gehrmann | Probing top quark electromagnetic dipole moments in
single-top-plus-photon production | 11 pages, 3 figures, 2 tables. v2: version published in PRD,
references added and 1 figure updated | Phys.Rev. D88 (2013) 033003 | 10.1103/PhysRevD.88.033003 | ZU-TH 14/13, DFPD-13-TH-13, LPN13-040 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The production of a single top quark in association with an isolated photon
probes the electromagnetic coupling structure of the top quark. We investigate
the sensitivity of kinematical distributions at the LHC in
single-top-plus-photon production in view of a detection of anomalous electric
and magnetic dipole moments of the top quark.
| [
{
"created": "Thu, 4 Jul 2013 14:30:01 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Aug 2013 12:21:38 GMT",
"version": "v2"
}
] | 2013-08-27 | [
[
"Fael",
"Matteo",
""
],
[
"Gehrmann",
"Thomas",
""
]
] | The production of a single top quark in association with an isolated photon probes the electromagnetic coupling structure of the top quark. We investigate the sensitivity of kinematical distributions at the LHC in single-top-plus-photon production in view of a detection of anomalous electric and magnetic dipole moments of the top quark. |
1307.2280 | Vitaliy D. Rusov | N.O. Chudak, K.K. Merkotan, D.A. Ptashynskyy, O.S. Potiyenko, M.A.
Deliyergiyev, A.V. Tykhonov, G.O. Sokhrannyi, O.V. Zharova, O.D.
Berezovs'kyi, V.V. Voitenko, Yu.V. Volkotrub, I.V. Sharph, V.D. Rusov | Internal States of Hadrons in Relativistic Reference Frames | 14 pages (v2: minor corrections in the References; v3: list of
authors fixed; v4: a number of text improvements; v5: a revised version of
the paper; v6: paper was reconfigured, appendix added) | Ukr. J. Phys. 2016, Vol. 61, N 12, p.1033-1047 | 10.15407/ujpe61.12.1033 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The internal state of a composite particle and its transformation, when
changing from the reference frame, where this composite particle is at rest, to
a reference frame, where it moves relativistically, have been considered. It is
supposed that the internal state of the composite particle in its rest frame
can be considered in the non-relativistic approximation. This internal state is
shown to remain the same, when changing from one inertial reference frame to
another one. In other words, a particle that is spherically symmetric in its
rest frame does not change its form in any other reference frame and does not
undergo the Lorentz contraction in the direction of motion of any reference
frame with respect to the rest one. A possible application of the results
obtained to describe the scattering of hadrons considered as bound states of
quarks has been discussed.
| [
{
"created": "Mon, 8 Jul 2013 21:32:26 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Jul 2013 17:28:05 GMT",
"version": "v2"
},
{
"created": "Thu, 1 Aug 2013 15:02:39 GMT",
"version": "v3"
},
{
"created": "Sun, 1 Sep 2013 08:11:47 GMT",
"version": "v4"
},
{
"created": "Tue, 11 Mar 2014 17:17:36 GMT",
"version": "v5"
},
{
"created": "Tue, 21 Mar 2017 07:28:13 GMT",
"version": "v6"
}
] | 2017-03-22 | [
[
"Chudak",
"N. O.",
""
],
[
"Merkotan",
"K. K.",
""
],
[
"Ptashynskyy",
"D. A.",
""
],
[
"Potiyenko",
"O. S.",
""
],
[
"Deliyergiyev",
"M. A.",
""
],
[
"Tykhonov",
"A. V.",
""
],
[
"Sokhrannyi",
"G. O.",
""
],
[
"Zharova",
"O. V.",
""
],
[
"Berezovs'kyi",
"O. D.",
""
],
[
"Voitenko",
"V. V.",
""
],
[
"Volkotrub",
"Yu. V.",
""
],
[
"Sharph",
"I. V.",
""
],
[
"Rusov",
"V. D.",
""
]
] | The internal state of a composite particle and its transformation, when changing from the reference frame, where this composite particle is at rest, to a reference frame, where it moves relativistically, have been considered. It is supposed that the internal state of the composite particle in its rest frame can be considered in the non-relativistic approximation. This internal state is shown to remain the same, when changing from one inertial reference frame to another one. In other words, a particle that is spherically symmetric in its rest frame does not change its form in any other reference frame and does not undergo the Lorentz contraction in the direction of motion of any reference frame with respect to the rest one. A possible application of the results obtained to describe the scattering of hadrons considered as bound states of quarks has been discussed. |
2007.15001 | Nicholas Rodd Dr | Christian W. Bauer, Nicholas L. Rodd, Bryan R. Webber | Dark Matter Spectra from the Electroweak to the Planck Scale | 8+24 pages, 3+12 figures, updated to published version. Spectra
available at https://github.com/nickrodd/HDMSpectra | null | 10.1007/JHEP06(2021)121 | null | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the decay spectrum for dark matter (DM) with masses above the
scale of electroweak symmetry breaking, all the way to the Planck scale. For an
arbitrary hard process involving a decay to the unbroken standard model, we
determine the prompt distribution of stable states including photons,
neutrinos, positrons, and antiprotons. These spectra are a crucial ingredient
in the search for DM via indirect detection at the highest energies as being
probed in current and upcoming experiments including IceCube, HAWC, CTA, and
LHAASO. Our approach improves considerably on existing methods. For example, we
include all relevant electroweak interactions. The importance of these effects
grow with DM mass, and by an EeV our spectra can differ by orders of magnitude
from existing results.
| [
{
"created": "Wed, 29 Jul 2020 18:00:00 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Jun 2021 00:36:52 GMT",
"version": "v2"
}
] | 2021-07-07 | [
[
"Bauer",
"Christian W.",
""
],
[
"Rodd",
"Nicholas L.",
""
],
[
"Webber",
"Bryan R.",
""
]
] | We compute the decay spectrum for dark matter (DM) with masses above the scale of electroweak symmetry breaking, all the way to the Planck scale. For an arbitrary hard process involving a decay to the unbroken standard model, we determine the prompt distribution of stable states including photons, neutrinos, positrons, and antiprotons. These spectra are a crucial ingredient in the search for DM via indirect detection at the highest energies as being probed in current and upcoming experiments including IceCube, HAWC, CTA, and LHAASO. Our approach improves considerably on existing methods. For example, we include all relevant electroweak interactions. The importance of these effects grow with DM mass, and by an EeV our spectra can differ by orders of magnitude from existing results. |
1510.03392 | Patrick Draper | Abdelhamid Albaid, Michael Dine, and Patrick Draper | Strong CP and SUZ$_2$ | 18 pp, v2: refs added | null | 10.1007/JHEP12(2015)046 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Solutions to the strong CP problem typically introduce new scales associated
with the spontaneous breaking of symmetries. Absent any anthropic argument for
small $\bar\theta$, these scales require stabilization against ultraviolet
corrections. Supersymmetry offers a tempting stabilization mechanism, since it
can solve the "big" electroweak hierarchy problem at the same time. One family
of solutions to strong CP, including generalized parity models, heavy axion
models, and heavy $\eta^\prime$ models, introduces $\mathbb{Z}_2$ copies of
(part of) the Standard Model and an associated scale of
$\mathbb{Z}_2$-breaking. We review why, without additional structure such as
supersymmetry, the $\mathbb{Z}_2$-breaking scale is unacceptably tuned. We then
study "SUZ$_2$" models, supersymmetric theories with $\mathbb{Z}_2$ copies of
the MSSM. We find that the addition of SUSY typically destroys the
$\mathbb{Z}_2$ protection of $\bar\theta=0$, even at tree level, once SUSY and
$\mathbb{Z}_2$ are broken. In theories like supersymmetric completions of the
twin Higgs, where $\mathbb{Z}_2$ addresses the little hierarchy problem but not
strong CP, two axions can be used to relax $\bar\theta$.
| [
{
"created": "Mon, 12 Oct 2015 18:53:13 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Oct 2015 05:46:45 GMT",
"version": "v2"
}
] | 2016-01-27 | [
[
"Albaid",
"Abdelhamid",
""
],
[
"Dine",
"Michael",
""
],
[
"Draper",
"Patrick",
""
]
] | Solutions to the strong CP problem typically introduce new scales associated with the spontaneous breaking of symmetries. Absent any anthropic argument for small $\bar\theta$, these scales require stabilization against ultraviolet corrections. Supersymmetry offers a tempting stabilization mechanism, since it can solve the "big" electroweak hierarchy problem at the same time. One family of solutions to strong CP, including generalized parity models, heavy axion models, and heavy $\eta^\prime$ models, introduces $\mathbb{Z}_2$ copies of (part of) the Standard Model and an associated scale of $\mathbb{Z}_2$-breaking. We review why, without additional structure such as supersymmetry, the $\mathbb{Z}_2$-breaking scale is unacceptably tuned. We then study "SUZ$_2$" models, supersymmetric theories with $\mathbb{Z}_2$ copies of the MSSM. We find that the addition of SUSY typically destroys the $\mathbb{Z}_2$ protection of $\bar\theta=0$, even at tree level, once SUSY and $\mathbb{Z}_2$ are broken. In theories like supersymmetric completions of the twin Higgs, where $\mathbb{Z}_2$ addresses the little hierarchy problem but not strong CP, two axions can be used to relax $\bar\theta$. |
2302.10215 | Peter Arnold | Peter Arnold, Omar Elgedawy, and Shahin Iqbal | The LPM effect in sequential bremsstrahlung: gluon shower development | [65 pages, 21 figures] | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give details of our study of whether high-energy gluon showers inside a
QCD medium can be treated as a sequence of individual splitting processes $g
\to gg$, or whether there is significant quantum overlap between where one
splitting ends and the next begins (neglecting effects that can be absorbed
into an effective value of the jet quenching parameter $\hat q$ that
characterizes the medium). The study is carried out by imagining in-medium
gluon shower development in the simplest theoretical situation, which includes
imagining a very large, static, homogeneous medium and taking the large $N_{\rm
c}$ limit. Along the way, we also show how in-medium shower evolution can be
written in terms of a "net" splitting rate $[d\Gamma/dx]_{\rm net}$, and we
provide a moderately simple analytic fit to our numerical results for the
overlap effects included in that rate, which we hope may be of use to others
wishing to study possible consequences of overlapping splittings.
| [
{
"created": "Mon, 20 Feb 2023 19:00:08 GMT",
"version": "v1"
}
] | 2023-02-23 | [
[
"Arnold",
"Peter",
""
],
[
"Elgedawy",
"Omar",
""
],
[
"Iqbal",
"Shahin",
""
]
] | We give details of our study of whether high-energy gluon showers inside a QCD medium can be treated as a sequence of individual splitting processes $g \to gg$, or whether there is significant quantum overlap between where one splitting ends and the next begins (neglecting effects that can be absorbed into an effective value of the jet quenching parameter $\hat q$ that characterizes the medium). The study is carried out by imagining in-medium gluon shower development in the simplest theoretical situation, which includes imagining a very large, static, homogeneous medium and taking the large $N_{\rm c}$ limit. Along the way, we also show how in-medium shower evolution can be written in terms of a "net" splitting rate $[d\Gamma/dx]_{\rm net}$, and we provide a moderately simple analytic fit to our numerical results for the overlap effects included in that rate, which we hope may be of use to others wishing to study possible consequences of overlapping splittings. |
hep-ph/0604270 | Rachel Jeannerot | Rachel Jeannerot (Leiden U.) | Grand unified models and cosmology | Ph.D.Thesis (Cambridge U., 1996). 97 pages | null | null | null | hep-ph | null | The cosmological consequences of particle physics grand unified theories
(GUTs) are studied. Cosmological models are implemented in realistic particle
physics models. Models consistent from both particle physics and cosmological
considerations are selected. (...)
| [
{
"created": "Fri, 28 Apr 2006 16:18:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Jeannerot",
"Rachel",
"",
"Leiden U."
]
] | The cosmological consequences of particle physics grand unified theories (GUTs) are studied. Cosmological models are implemented in realistic particle physics models. Models consistent from both particle physics and cosmological considerations are selected. (...) |
hep-ph/0302190 | Gabrijela | Glennys R. Farrar and Gabrijela Zaharijas | Non-binding of Flavor-Singlet Hadrons to Nuclei | 10 pages, 2 figures | Phys.Lett. B559 (2003) 223-228; Erratum-ibid. B575 (2003) 349-357 | 10.1016/S0370-2693(03)00331-9 | null | hep-ph | null | Strongly attractive color forces in the flavor singlet channel may lead to a
stable H dibaryon. Here we show that an H or other compact, flavor singlet
hadron is unlikely to bind to nuclei, so that bounds on exotic isotopes do not
exclude their stability. Remarkably, a stable H appears to evade other
experimental constraints as well, when account is taken of its expected compact
spatial wavefunction.
| [
{
"created": "Thu, 20 Feb 2003 19:27:31 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Farrar",
"Glennys R.",
""
],
[
"Zaharijas",
"Gabrijela",
""
]
] | Strongly attractive color forces in the flavor singlet channel may lead to a stable H dibaryon. Here we show that an H or other compact, flavor singlet hadron is unlikely to bind to nuclei, so that bounds on exotic isotopes do not exclude their stability. Remarkably, a stable H appears to evade other experimental constraints as well, when account is taken of its expected compact spatial wavefunction. |
1601.06598 | Heikki M\"antysaari | T. Lappi and H. M\"antysaari | Next-to-leading order Balitsky-Kovchegov equation with resummation | 10 pages, 8 figures. RevTex. v2: small clarifications to text,
published in Phys. Rev. D | Phys. Rev. D 93, 094004 (2016) | 10.1103/PhysRevD.93.094004 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We solve the Balitsky-Kovchegov evolution equation at next-to-leading order
accuracy including a resummation of large single and double transverse momentum
logarithms to all orders. We numerically determine an optimal value for the
constant under the large transverse momentum logarithm that enables including a
maximal amount of the full NLO result in the resummation. When this value is
used the contribution from the $\alpha_s^2$ terms without large logarithms is
found to be small at large saturation scales and at small dipoles. Close to
initial conditions relevant for phenomenological applications these fixed order
corrections are shown to be numerically important.
| [
{
"created": "Mon, 25 Jan 2016 13:29:01 GMT",
"version": "v1"
},
{
"created": "Thu, 5 May 2016 16:02:59 GMT",
"version": "v2"
}
] | 2016-05-06 | [
[
"Lappi",
"T.",
""
],
[
"Mäntysaari",
"H.",
""
]
] | We solve the Balitsky-Kovchegov evolution equation at next-to-leading order accuracy including a resummation of large single and double transverse momentum logarithms to all orders. We numerically determine an optimal value for the constant under the large transverse momentum logarithm that enables including a maximal amount of the full NLO result in the resummation. When this value is used the contribution from the $\alpha_s^2$ terms without large logarithms is found to be small at large saturation scales and at small dipoles. Close to initial conditions relevant for phenomenological applications these fixed order corrections are shown to be numerically important. |
2306.03138 | Oleksandr Tomalak | Vincenzo Cirigliano, Wouter Dekens, Emanuele Mereghetti, Oleksandr
Tomalak | Effective field theory for radiative corrections to charged-current
processes I: Vector coupling | 40 pages, 3 figures | Phys. Rev. D 108 (2023) 053003 | 10.1103/PhysRevD.108.053003 | LA-UR-22-21034, INT-PUB-23-015 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | We study radiative corrections to low-energy charged-current processes
involving nucleons, such as neutron beta decay and (anti)neutrino-nucleon
scattering within a top-down effective-field-theory approach. We first match
the Standard Model to the low-energy effective theory valid below the weak
scale and, using renormalization group equations with anomalous dimensions of
$\mathcal{O}(\alpha, \alpha \alpha_s, \alpha^2)$, evolve the resulting
effective coupling down to the hadronic scale. Here, we first match to
heavy-baryon chiral perturbation theory and subsequently, below the pion-mass
scale, to a pionless effective theory, evolving the effective vector coupling
with anomalous dimensions of $\mathcal{O}(\alpha, \alpha^2)$ all the way down
to the scale of the electron mass, relevant for beta decays. We thus provide a
new evaluation of the ``inner" radiative corrections to the vector coupling
constant and to the neutron decay rate, discussing differences with the
previous literature. Using our new result for the radiative corrections, we
update the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ud}$
from the neutron decay.
| [
{
"created": "Mon, 5 Jun 2023 18:00:05 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Sep 2023 21:27:32 GMT",
"version": "v2"
}
] | 2023-09-08 | [
[
"Cirigliano",
"Vincenzo",
""
],
[
"Dekens",
"Wouter",
""
],
[
"Mereghetti",
"Emanuele",
""
],
[
"Tomalak",
"Oleksandr",
""
]
] | We study radiative corrections to low-energy charged-current processes involving nucleons, such as neutron beta decay and (anti)neutrino-nucleon scattering within a top-down effective-field-theory approach. We first match the Standard Model to the low-energy effective theory valid below the weak scale and, using renormalization group equations with anomalous dimensions of $\mathcal{O}(\alpha, \alpha \alpha_s, \alpha^2)$, evolve the resulting effective coupling down to the hadronic scale. Here, we first match to heavy-baryon chiral perturbation theory and subsequently, below the pion-mass scale, to a pionless effective theory, evolving the effective vector coupling with anomalous dimensions of $\mathcal{O}(\alpha, \alpha^2)$ all the way down to the scale of the electron mass, relevant for beta decays. We thus provide a new evaluation of the ``inner" radiative corrections to the vector coupling constant and to the neutron decay rate, discussing differences with the previous literature. Using our new result for the radiative corrections, we update the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ud}$ from the neutron decay. |
2104.06958 | Andrey Pikelner | Andrey Pikelner | Three-loop vertex integrals at symmetric point | 14 pages, many figures | null | 10.1007/JHEP06(2021)083 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | This paper provides details of the massless three-loop three-point integrals
calculation at the symmetric point. Our work aimed to extend known two-loop
results for such integrals to the three-loop level. Obtained results can find
their application in regularization-invariant symmetric point
momentum-subtraction (RI/SMOM) scheme QCD calculations of renormalization group
functions and various composite operator matrix elements. To calculate
integrals, we solve differential equations for auxiliary integrals by
transforming the system to the $\varepsilon$-form. Calculated integrals are
expressed through the basis of functions with uniform transcendental weight. We
provide expansion up to the transcendental weight six for the basis functions
in terms of harmonic polylogarithms with six-root of unity argument.
| [
{
"created": "Wed, 14 Apr 2021 16:33:52 GMT",
"version": "v1"
}
] | 2021-06-17 | [
[
"Pikelner",
"Andrey",
""
]
] | This paper provides details of the massless three-loop three-point integrals calculation at the symmetric point. Our work aimed to extend known two-loop results for such integrals to the three-loop level. Obtained results can find their application in regularization-invariant symmetric point momentum-subtraction (RI/SMOM) scheme QCD calculations of renormalization group functions and various composite operator matrix elements. To calculate integrals, we solve differential equations for auxiliary integrals by transforming the system to the $\varepsilon$-form. Calculated integrals are expressed through the basis of functions with uniform transcendental weight. We provide expansion up to the transcendental weight six for the basis functions in terms of harmonic polylogarithms with six-root of unity argument. |
hep-ph/9905553 | Alexander Yelkhovsky | Gregory Adkins, Kirill Melnikov and Alexander Yelkhovsky | Virtual annihilation contribution to orthopositronium decay rate | 2 pages, no figures | null | 10.1103/PhysRevA.60.3306 | TTP-99-24 | hep-ph | null | Order alpha^2 contribution to the orthopositronium decay rate due to
one-photon virtual annihilation is found to be
delta Gamma = (alpha/pi)^2 (pi^2 ln(alpha) - 0.8622(9))Gamma_LO.
| [
{
"created": "Mon, 31 May 1999 04:15:29 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Adkins",
"Gregory",
""
],
[
"Melnikov",
"Kirill",
""
],
[
"Yelkhovsky",
"Alexander",
""
]
] | Order alpha^2 contribution to the orthopositronium decay rate due to one-photon virtual annihilation is found to be delta Gamma = (alpha/pi)^2 (pi^2 ln(alpha) - 0.8622(9))Gamma_LO. |
0911.1465 | Daniel G. Figueroa | Daniel G. Figueroa | Preheating the Universe from the Standard Model Higgs | 10 pages, 1 figure. Proceedings of the "Invisible Universe
International Conference", Paris 2009 | AIP Conf.Proc.1241:578-587,2010 | 10.1063/1.3462688 | IFT-UAM/CSIC-09-54 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss Preheating after an inflationary stage driven by the Standard
Model (SM) Higgs field non-minimally coupled to gravity. We find that
Preheating is driven by a complex process in which perturbative and
non-perturbative effects occur simultaneously. The Higgs field, initially an
oscillating coherent condensate, produces non-perturbatively W and Z gauge
fields. These decay very rapidly into fermions, thus preventing gauge bosons to
accumulate and, consequently, blocking the usual parametric resonance. The
energy transferred into the fermionic species is, nevertheless, not enough to
reheat the Universe, and resonant effects are eventually developed. Soon after
resonance becomes effective, also backreaction from the gauge bosons into the
Higgs condensate becomes relevant. We have determined the time evolution of the
energy distribution among the remnant Higgs condensate and the non-thermal
distribution of the SM fermions and gauge fields, until the moment in which
backreaction becomes important. Beyond backreaction our approximations break
down and numerical simulations and theoretical considerations beyond this work
are required, in order to study the evolution of the system until
thermalization.
| [
{
"created": "Sat, 7 Nov 2009 21:22:41 GMT",
"version": "v1"
}
] | 2014-11-20 | [
[
"Figueroa",
"Daniel G.",
""
]
] | We discuss Preheating after an inflationary stage driven by the Standard Model (SM) Higgs field non-minimally coupled to gravity. We find that Preheating is driven by a complex process in which perturbative and non-perturbative effects occur simultaneously. The Higgs field, initially an oscillating coherent condensate, produces non-perturbatively W and Z gauge fields. These decay very rapidly into fermions, thus preventing gauge bosons to accumulate and, consequently, blocking the usual parametric resonance. The energy transferred into the fermionic species is, nevertheless, not enough to reheat the Universe, and resonant effects are eventually developed. Soon after resonance becomes effective, also backreaction from the gauge bosons into the Higgs condensate becomes relevant. We have determined the time evolution of the energy distribution among the remnant Higgs condensate and the non-thermal distribution of the SM fermions and gauge fields, until the moment in which backreaction becomes important. Beyond backreaction our approximations break down and numerical simulations and theoretical considerations beyond this work are required, in order to study the evolution of the system until thermalization. |
1010.3883 | Dario Schalla | Alexander Lenz, Heinrich P\"as and Dario Schalla | Constraints on fourth generation Majorana neutrinos | 6 pages, Proceedings of the 16th International Symposium on
Particles, Strings and Cosmology (PASCOS2010), Valencia (Spain), July 19th -
23rd, 2010 | J.Phys.Conf.Ser.259:012096,2010 | 10.1088/1742-6596/259/1/012096 | DO-TH-10/13 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the possibility of a fourth sequential generation in the
lepton sector. Assuming neutrinos to be Majorana particles and starting from a
recent - albeit weak - evidence for a non-zero admixture of a fourth generation
neutrino from fits to weak lepton and meson decays we discuss constraints from
neutrinoless double beta decay, radiative lepton decay and like-sign di-lepton
production at hadron colliders.
| [
{
"created": "Tue, 19 Oct 2010 12:42:29 GMT",
"version": "v1"
}
] | 2011-01-27 | [
[
"Lenz",
"Alexander",
""
],
[
"Päs",
"Heinrich",
""
],
[
"Schalla",
"Dario",
""
]
] | We investigate the possibility of a fourth sequential generation in the lepton sector. Assuming neutrinos to be Majorana particles and starting from a recent - albeit weak - evidence for a non-zero admixture of a fourth generation neutrino from fits to weak lepton and meson decays we discuss constraints from neutrinoless double beta decay, radiative lepton decay and like-sign di-lepton production at hadron colliders. |
2102.02313 | Prolay Krishna Chanda | Prolay Chanda and James Unwin | Decoupling of Asymmetric Dark Matter During an Early Matter Dominated
Era | 24 pages, 7 figures v2: Matches version published in JCAP | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In models of Asymmetric Dark Matter (ADM) the relic density is set by a
particle asymmetry in an analogous manner to the baryons. Here we explore the
scenario in which ADM decouples from the Standard Model thermal bath during an
early period of matter domination. We first present a model independent
analysis for a generic ADM candidate with s-wave annihilation cross section
with fairly general assumptions regarding the origin of the early matter
dominated period. We contrast our results to those from conventional ADM models
which assume radiation domination during decoupling. Subsequently, we examine
an explicit example of this scenario in the context of an elegant SO(10)
implementation of ADM in which the matter dominated era is due to a long lived
heavy right-handed neutrino. In the concluding remarks we discuss the prospects
for superheavy ADM in this setting.
| [
{
"created": "Wed, 3 Feb 2021 22:27:01 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Jun 2021 21:47:38 GMT",
"version": "v2"
}
] | 2021-06-24 | [
[
"Chanda",
"Prolay",
""
],
[
"Unwin",
"James",
""
]
] | In models of Asymmetric Dark Matter (ADM) the relic density is set by a particle asymmetry in an analogous manner to the baryons. Here we explore the scenario in which ADM decouples from the Standard Model thermal bath during an early period of matter domination. We first present a model independent analysis for a generic ADM candidate with s-wave annihilation cross section with fairly general assumptions regarding the origin of the early matter dominated period. We contrast our results to those from conventional ADM models which assume radiation domination during decoupling. Subsequently, we examine an explicit example of this scenario in the context of an elegant SO(10) implementation of ADM in which the matter dominated era is due to a long lived heavy right-handed neutrino. In the concluding remarks we discuss the prospects for superheavy ADM in this setting. |
0805.4393 | Monika Blanke | Monika Blanke, Andrzej J. Buras, Stefan Recksiegel, Cecilia Tarantino | The Littlest Higgs Model with T-Parity Facing CP-Violation in B_s -
anti-B_s Mixing | 21 pages, 9 figures, 1 table. Version with full resolution plots
available at http://users.physik.tu-muenchen.de/mblanke/LHT-2008.pdf. Note
added on the omitted term in Z-penguin contribution. For an updated analysis
see arXiv:0906.5454 | null | null | TUM-HEP-689/08, MPP-2008-50, RM3-TH/08-1 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The non-minimal flavour violating interactions of mirror quarks and new heavy
gauge bosons in the Littlest Higgs model with T-parity (LHT) give rise to
naturally large CP-violating effects in the B_s system. In view of a large new
CP phase in B_s - anti-B_s mixing hinted by the CDF and D0 data and the recent
UTfit analysis, we update our 2006 analysis of particle-antiparticle mixing and
rare K and B decays in the LHT model, using the most recent values of a number
of input parameters and performing a more careful error analysis. We find that
the CP-asymmetry S_{psi phi} can easily reach values ~ 0.15-0.20, compared to
the SM value ~ 0.04, while higher values are rather unlikely though not
excluded. Large enhancements are also possible in the branching ratios for K_L
-> pi0 nu anti-nu, K+ -> pi+ nu anti-nu and K_L -> pi0 l+ l- with much more
modest effects in B_{s,d} -> mu+ mu-. We perform a detailed study of
correlations between the latter decays and S_{psi phi} as well as of the
correlation between S_{psi phi} and S_{psi K_S}. We also point out that the
possible tension between epsilon_K and the tree level CKM determination
recently hinted by various analyses can easily be resolved in the LHT model.
| [
{
"created": "Wed, 28 May 2008 17:37:20 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Jan 2010 17:08:13 GMT",
"version": "v2"
}
] | 2010-01-15 | [
[
"Blanke",
"Monika",
""
],
[
"Buras",
"Andrzej J.",
""
],
[
"Recksiegel",
"Stefan",
""
],
[
"Tarantino",
"Cecilia",
""
]
] | The non-minimal flavour violating interactions of mirror quarks and new heavy gauge bosons in the Littlest Higgs model with T-parity (LHT) give rise to naturally large CP-violating effects in the B_s system. In view of a large new CP phase in B_s - anti-B_s mixing hinted by the CDF and D0 data and the recent UTfit analysis, we update our 2006 analysis of particle-antiparticle mixing and rare K and B decays in the LHT model, using the most recent values of a number of input parameters and performing a more careful error analysis. We find that the CP-asymmetry S_{psi phi} can easily reach values ~ 0.15-0.20, compared to the SM value ~ 0.04, while higher values are rather unlikely though not excluded. Large enhancements are also possible in the branching ratios for K_L -> pi0 nu anti-nu, K+ -> pi+ nu anti-nu and K_L -> pi0 l+ l- with much more modest effects in B_{s,d} -> mu+ mu-. We perform a detailed study of correlations between the latter decays and S_{psi phi} as well as of the correlation between S_{psi phi} and S_{psi K_S}. We also point out that the possible tension between epsilon_K and the tree level CKM determination recently hinted by various analyses can easily be resolved in the LHT model. |
1402.1426 | Ana M. Teixeira | A.M. Teixeira, A. Abada, A. J. R. Figueiredo and J. C. Romao | Lepton flavour violation at high energies: the LHC and a Linear Collider | 6 pages, 6 figures. To appear in the proceedings of the "Linear
Collider Workshop - LC13", ECT* Trento, 16 - 20 September 2013 | Nuovo Cim. C037 (2014) 02, 19-24 | 10.1393/ncc/i2014-11731-5 | PCCF RI 14-02, LPT Orsay 14-08, CFTP/14-001 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss several manifestations of charged lepton flavour violation at high
energies. Focusing on a supersymmetric type I seesaw, considering constrained
and semi-constrained supersymmetry breaking scenarios, we analyse different
observables, both at the LHC and at a future Linear Collider. We further
discuss how the synergy between low- and high-energy observables can shed some
light on the underlying mechanism of lepton flavour violation.
| [
{
"created": "Thu, 6 Feb 2014 17:36:19 GMT",
"version": "v1"
}
] | 2015-03-03 | [
[
"Teixeira",
"A. M.",
""
],
[
"Abada",
"A.",
""
],
[
"Figueiredo",
"A. J. R.",
""
],
[
"Romao",
"J. C.",
""
]
] | We discuss several manifestations of charged lepton flavour violation at high energies. Focusing on a supersymmetric type I seesaw, considering constrained and semi-constrained supersymmetry breaking scenarios, we analyse different observables, both at the LHC and at a future Linear Collider. We further discuss how the synergy between low- and high-energy observables can shed some light on the underlying mechanism of lepton flavour violation. |
1012.1114 | Georgios Gounaris | G.J. Gounaris, J. Layssac and F.M. Renard | The processes of gluon fusion producing chargino or neutralino pairs at
high energies | Extended version to appear in International Journal of Modern Physics
A 21 pages | Int.J.Mod.Phys.A26:1253-1272,2011 | 10.1142/S0217751X11052888 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | According to the helicity conservation (HCns) theorem, the sum of the
helicities should be conserved, in any 2-to-2 processes in MSSM with R-parity
conservation, at high energies; i.e. all amplitudes violating this rule, must
vanish asymptotically. The realization of HCns in gluon-fusion to charginos or
neutralinos is studied, at the one loop electroweak order (EW), and simple high
energy expressions are derived for the non-vanishing helicity conserving (HC)
amplitudes. These are very similar to the corresponding expressions for $gg \to
W^+W^-, ZZ, \gamma Z, \gamma\gamma $ derived before. Asymptotic relations among
observable unpolarized cross sections for many such processes are then
obtained, some of which may hold at LHC-type energies.
| [
{
"created": "Mon, 6 Dec 2010 10:16:20 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Feb 2011 08:20:40 GMT",
"version": "v2"
}
] | 2011-09-23 | [
[
"Gounaris",
"G. J.",
""
],
[
"Layssac",
"J.",
""
],
[
"Renard",
"F. M.",
""
]
] | According to the helicity conservation (HCns) theorem, the sum of the helicities should be conserved, in any 2-to-2 processes in MSSM with R-parity conservation, at high energies; i.e. all amplitudes violating this rule, must vanish asymptotically. The realization of HCns in gluon-fusion to charginos or neutralinos is studied, at the one loop electroweak order (EW), and simple high energy expressions are derived for the non-vanishing helicity conserving (HC) amplitudes. These are very similar to the corresponding expressions for $gg \to W^+W^-, ZZ, \gamma Z, \gamma\gamma $ derived before. Asymptotic relations among observable unpolarized cross sections for many such processes are then obtained, some of which may hold at LHC-type energies. |
hep-ph/0409325 | Namit Mahajan | S. Dev and Sanjeev Kumar | Constraints on the Neutrino Parameters from the `Rise-up' in the Boron
Neutrino Spectrum at Low Energies | Latex 10pages including 3 postscript figures | Mod.Phys.Lett. A20 (2005) 2083 | 10.1142/S0217732305017032 | null | hep-ph | null | The rise-up in boron neutrino spectrum at low energies has been studied
within the framework of `pure LMA' scenario. Indirect bounds on the spectral
`upturn' have been obtained from the available solar neutrino data. These
bounds have been used to demonstrate the efficacy of the precision measurements
of the `upturn' for further constraining the neutrino parameter space allowed
by SNO salt phase data. The sterile neutrino flux has been constrained in the
light of the recent 766.3 Ty KamLAND spectral data.
| [
{
"created": "Tue, 28 Sep 2004 16:40:35 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Dev",
"S.",
""
],
[
"Kumar",
"Sanjeev",
""
]
] | The rise-up in boron neutrino spectrum at low energies has been studied within the framework of `pure LMA' scenario. Indirect bounds on the spectral `upturn' have been obtained from the available solar neutrino data. These bounds have been used to demonstrate the efficacy of the precision measurements of the `upturn' for further constraining the neutrino parameter space allowed by SNO salt phase data. The sterile neutrino flux has been constrained in the light of the recent 766.3 Ty KamLAND spectral data. |
0912.1437 | Kenji Maeda | Tetsuo Hatsuda, Kenji Maeda | Quantum Phase Transitions in Dense QCD | 32 pages, 10 figures. To appear as Chapter 25 in "Developments in
Quantum Phase Transitions" ed. L. D. Carr (Taylor and Francis, 2010) | null | 10.1201/b10273-31 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Quantum chromodynamics (QCD) at finite temperature, $T$, and quark chemical
potential, $\mu$, has a rich phase structure: at low $T$ and low $\mu$, the
Nambu-Goldstone (NG) phase with nearly massless pions is realized by the
dynamical breaking of chiral symmetry through condensation of quark-anti-quark
pairs, while, at low $T$ and high $\mu$, a Fermi liquid of deconfined quarks is
expected to appear as a consequence of asymptotic freedom. Furthermore, in such
a cold quark matter, condensation of quark-quark pairs leads to the color
superconductivity (CSC). At high $T$ for arbitrary $\mu$, all the condensates
melt away and a quark-gluon plasma (QGP) is realized. The experimental
exploration of thermal phase transition from the NG phase to QGP is being
actively pursued in ultrarelativistic heavy ion collisions at RHIC
(Relativistic Heavy Ion Collider), and will be continued in the future at LHC
(Large Hadron Collider). The quantum phase transition from the NG phase to the
CSC at low $T$ is also relevant to heavy-ion collisions at moderate energies,
and is of interest in the interiors of neutron stars and possible quark stars.
In this Chapter, after a brief introduction to the basic properties of QCD, the
current status of the QCD phase structure and associated quantum phase
transitions will be summarized with particular emphasis on the symmetry
realization of each phase. Possible connection between the physics of QCD and
that of ultracold atoms is also discussed.
| [
{
"created": "Tue, 8 Dec 2009 09:07:18 GMT",
"version": "v1"
}
] | 2015-05-14 | [
[
"Hatsuda",
"Tetsuo",
""
],
[
"Maeda",
"Kenji",
""
]
] | Quantum chromodynamics (QCD) at finite temperature, $T$, and quark chemical potential, $\mu$, has a rich phase structure: at low $T$ and low $\mu$, the Nambu-Goldstone (NG) phase with nearly massless pions is realized by the dynamical breaking of chiral symmetry through condensation of quark-anti-quark pairs, while, at low $T$ and high $\mu$, a Fermi liquid of deconfined quarks is expected to appear as a consequence of asymptotic freedom. Furthermore, in such a cold quark matter, condensation of quark-quark pairs leads to the color superconductivity (CSC). At high $T$ for arbitrary $\mu$, all the condensates melt away and a quark-gluon plasma (QGP) is realized. The experimental exploration of thermal phase transition from the NG phase to QGP is being actively pursued in ultrarelativistic heavy ion collisions at RHIC (Relativistic Heavy Ion Collider), and will be continued in the future at LHC (Large Hadron Collider). The quantum phase transition from the NG phase to the CSC at low $T$ is also relevant to heavy-ion collisions at moderate energies, and is of interest in the interiors of neutron stars and possible quark stars. In this Chapter, after a brief introduction to the basic properties of QCD, the current status of the QCD phase structure and associated quantum phase transitions will be summarized with particular emphasis on the symmetry realization of each phase. Possible connection between the physics of QCD and that of ultracold atoms is also discussed. |
1804.08437 | Juan Herrero-Garcia | Juan Herrero-Garcia, Andre Scaffidi, Martin White and Anthony G.
Williams | Time-dependent rate of multicomponent dark matter: Reproducing the
DAMA/LIBRA phase-2 results | 8 pages, 2 figures, 2 tables. Title and abstract changed, matches
published version in PRD | Phys. Rev. D 98, 123007 (2018) | 10.1103/PhysRevD.98.123007 | ADP-18-12/T1060 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The current paradigm for dark matter direct detection is to assume that the
dark sector is solely composed of a single particle species. In this short
paper, we make the observation that dark matter comprising both a light and a
heavy component that modulate out of phase leads to interesting phenomenology
in annual modulation experiments. For an illustrative example, we use the
recently released DAMA/LIBRA phase-2 results with a lower energy threshold.
Immediately after, it was argued that a one-component spin-independent dark
matter explanation of the observed annual modulation is strongly disfavored or
excluded unless isospin-violating couplings are invoked. We show that a simple
two-component extension can reproduce the observed spectrum without the need to
invoke fine-tuned couplings. Using the publicly available DAMA/LIBRA data, we
perform a fit of the DAMA/LIBRA energy spectrum of the annual modulation
amplitude to a scenario with two dark matter components. We also take into
account how gravitational focusing affects the phases of the light and a heavy
components differently, which leads to nontrivial effects in the total
time-dependent rate. Our results show that there exists a unique solution in
agreement with the data in the simplest case of isospin-conserving couplings
with equal cross sections. The distinctive features found in this work are
crucial for a dark matter interpretation of any observed annual modulation.
| [
{
"created": "Mon, 23 Apr 2018 13:54:46 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Apr 2018 17:40:05 GMT",
"version": "v2"
},
{
"created": "Mon, 24 Sep 2018 08:04:22 GMT",
"version": "v3"
},
{
"created": "Wed, 16 Jan 2019 12:49:23 GMT",
"version": "v4"
}
] | 2019-01-17 | [
[
"Herrero-Garcia",
"Juan",
""
],
[
"Scaffidi",
"Andre",
""
],
[
"White",
"Martin",
""
],
[
"Williams",
"Anthony G.",
""
]
] | The current paradigm for dark matter direct detection is to assume that the dark sector is solely composed of a single particle species. In this short paper, we make the observation that dark matter comprising both a light and a heavy component that modulate out of phase leads to interesting phenomenology in annual modulation experiments. For an illustrative example, we use the recently released DAMA/LIBRA phase-2 results with a lower energy threshold. Immediately after, it was argued that a one-component spin-independent dark matter explanation of the observed annual modulation is strongly disfavored or excluded unless isospin-violating couplings are invoked. We show that a simple two-component extension can reproduce the observed spectrum without the need to invoke fine-tuned couplings. Using the publicly available DAMA/LIBRA data, we perform a fit of the DAMA/LIBRA energy spectrum of the annual modulation amplitude to a scenario with two dark matter components. We also take into account how gravitational focusing affects the phases of the light and a heavy components differently, which leads to nontrivial effects in the total time-dependent rate. Our results show that there exists a unique solution in agreement with the data in the simplest case of isospin-conserving couplings with equal cross sections. The distinctive features found in this work are crucial for a dark matter interpretation of any observed annual modulation. |
hep-ph/9606349 | James M. Johnson | Suraj N. Gupta, James M. Johnson and Wayne W. Repko | Relativistic two-photon and two-gluon decay rates of heavy quarkonia | 15 pages, RevTeX, PostScript available at
http://gluon.physics.wayne.edu/wsuhep/jim/predecay.ps | Phys.Rev. D54 (1996) 2075-2080 | 10.1103/PhysRevD.54.2075 | null | hep-ph | null | The decay rates of $c\bar{c}$ and $b\bar{b}$ through two-photon or two-gluon
annihilations are obtained by using totally relativistic decay amplitudes and a
sophisticated quantum-chromodynamic potential model for heavy quarkonia. Our
results for the photonic and gluonic widths of the 1S0, 3P0, and the 3P2 states
are in excellent agreement with the available experimental data. The procedures
and mathematical techniques used by us for the treatment of the
fermion-antifermion bound states are also applicable to other decay processes.
| [
{
"created": "Mon, 17 Jun 1996 17:42:31 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Gupta",
"Suraj N.",
""
],
[
"Johnson",
"James M.",
""
],
[
"Repko",
"Wayne W.",
""
]
] | The decay rates of $c\bar{c}$ and $b\bar{b}$ through two-photon or two-gluon annihilations are obtained by using totally relativistic decay amplitudes and a sophisticated quantum-chromodynamic potential model for heavy quarkonia. Our results for the photonic and gluonic widths of the 1S0, 3P0, and the 3P2 states are in excellent agreement with the available experimental data. The procedures and mathematical techniques used by us for the treatment of the fermion-antifermion bound states are also applicable to other decay processes. |
hep-ph/9303241 | null | Lawrence Hall and Steven Weinberg | Flavor Changing Scalar Interactions | 18 pages. UTTG-22-92; LBL 33016; UCB 92/36 | Phys.Rev.D48:979-983,1993 | 10.1103/PhysRevD.48.R979 | null | hep-ph | null | The smallness of fermion masses and mixing angles has recently been been
attributed to approximate global $U(1)$ symmetries, one for each fermion type.
The parameters associated with these symmetry breakings are estimated here
directly from observed masses and mixing angles. It turns out that although
flavor changing reaction rates may be acceptably small in electroweak theories
with several scalar doublets without imposing any special symmetries on the
scalars themselves, such theories generically yield too much CP violation in
the neutral kaon mass matrix. Hence in these theories CP must also be a good
approximate symmetry. Such models provide an alternative mechanism for CP
violation and have various interesting phenomenological features.
| [
{
"created": "Thu, 11 Mar 1993 01:47:27 GMT",
"version": "v1"
}
] | 2009-12-30 | [
[
"Hall",
"Lawrence",
""
],
[
"Weinberg",
"Steven",
""
]
] | The smallness of fermion masses and mixing angles has recently been been attributed to approximate global $U(1)$ symmetries, one for each fermion type. The parameters associated with these symmetry breakings are estimated here directly from observed masses and mixing angles. It turns out that although flavor changing reaction rates may be acceptably small in electroweak theories with several scalar doublets without imposing any special symmetries on the scalars themselves, such theories generically yield too much CP violation in the neutral kaon mass matrix. Hence in these theories CP must also be a good approximate symmetry. Such models provide an alternative mechanism for CP violation and have various interesting phenomenological features. |
hep-ph/0508051 | Rodolfo A. Diaz | Rodolfo A. Diaz, R. Martinez, F. Ochoa | 331 vector-like models with mirror fermions as a possible solution for
the discrepancy in the b-quark asymmetries, and for the neutrino mass and
mixing pattern | 12 pages, 6 tables, LaTeX2e | null | null | null | hep-ph | null | A general study of the fermionic structure of the 331 models with \beta
arbitrary shows the possibility of obtaining 331 vector-like models with mirror
fermions. On one hand, the existence of mirror fermions gives a possible way to
fit the discrepancy in the bottom quark asymmetries from the prediction of the
standard model. On the other hand, the vector-like nature of the model permits
to address the problem of the fermion mass hierarchy, and in particular the
problem of the neutrino mass and mixing pattern. Specifically, we consider a
model with four families and \beta =-1/\sqrt{3} where the additional family
corresponds to a mirror fermion of the third generation of the Standard Model.
We also show how to generate ansatzs about the mass matrices of the fermions
according to the phenomenology. In particular, it is possible to get a natural
fit for the neutrino hierarchical masses and mixing angles. Moreover, by means
of the mixing between the third quark family and its mirror fermion, a possible
solution for the A_{FB}^{b} discrepancy is obtained.
| [
{
"created": "Wed, 3 Aug 2005 22:01:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Diaz",
"Rodolfo A.",
""
],
[
"Martinez",
"R.",
""
],
[
"Ochoa",
"F.",
""
]
] | A general study of the fermionic structure of the 331 models with \beta arbitrary shows the possibility of obtaining 331 vector-like models with mirror fermions. On one hand, the existence of mirror fermions gives a possible way to fit the discrepancy in the bottom quark asymmetries from the prediction of the standard model. On the other hand, the vector-like nature of the model permits to address the problem of the fermion mass hierarchy, and in particular the problem of the neutrino mass and mixing pattern. Specifically, we consider a model with four families and \beta =-1/\sqrt{3} where the additional family corresponds to a mirror fermion of the third generation of the Standard Model. We also show how to generate ansatzs about the mass matrices of the fermions according to the phenomenology. In particular, it is possible to get a natural fit for the neutrino hierarchical masses and mixing angles. Moreover, by means of the mixing between the third quark family and its mirror fermion, a possible solution for the A_{FB}^{b} discrepancy is obtained. |
hep-ph/0312017 | Gilberto Colangelo | Gilberto Colangelo | Hadronic contributions to a_\mu below one GeV | 7 pages, 3 figures, talk given at the SIGHAD 03 Workshop in Pisa,
8-10 October 2003 | null | 10.1016/S0920-5632(04)00027-1 | null | hep-ph | null | I present a method for evaluating the hadronic vacuum polarization
contribution below 1 GeV to a_\mu which relies on analyticity, unitarity and
chiral symmetry, as well as on data. The main advantage is that in the region
just above threshold, where data are either scarce or have large errors, these
theoretical constraints are particularly strong, and therefore allow us to
reduce the uncertainties with respect to a purely data-based evaluation. Some
preliminary numerical results are presented as illustration of the method.
| [
{
"created": "Mon, 1 Dec 2003 13:02:45 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Colangelo",
"Gilberto",
""
]
] | I present a method for evaluating the hadronic vacuum polarization contribution below 1 GeV to a_\mu which relies on analyticity, unitarity and chiral symmetry, as well as on data. The main advantage is that in the region just above threshold, where data are either scarce or have large errors, these theoretical constraints are particularly strong, and therefore allow us to reduce the uncertainties with respect to a purely data-based evaluation. Some preliminary numerical results are presented as illustration of the method. |
2307.10282 | Philipp Schreiner | Axel Maas, Philipp Schreiner | The manifestly gauge-invariant spectrum of the Minimal Supersymmetric
Standard Model | 11 pages | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Formal field theory requires, even in the presence of a Brout-Englert-Higgs
effect, to maintain manifest non-perturbative gauge invariance. The
Fr\"ohlich-Morchio-Strocchi mechanism allows nonetheless an augmented
perturbative treatment. We perform such an augmented tree-level analysis for
the minimal supersymmetric standard model. We find that, as for the standard
model, corrections to standard perturbation theory are only sub-leading.
| [
{
"created": "Tue, 18 Jul 2023 11:01:32 GMT",
"version": "v1"
}
] | 2023-07-21 | [
[
"Maas",
"Axel",
""
],
[
"Schreiner",
"Philipp",
""
]
] | Formal field theory requires, even in the presence of a Brout-Englert-Higgs effect, to maintain manifest non-perturbative gauge invariance. The Fr\"ohlich-Morchio-Strocchi mechanism allows nonetheless an augmented perturbative treatment. We perform such an augmented tree-level analysis for the minimal supersymmetric standard model. We find that, as for the standard model, corrections to standard perturbation theory are only sub-leading. |
1212.5560 | Lorenzo Basso Dr | L. Basso, O. Fischer and J. J. van der Bij | A singlet-triplet extension for the Higgs search at LEP and LHC | 12 pages, 2 figures | null | 10.1209/0295-5075/101/51004 | FR-PHENO-2012-39 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe a simple extension of the standard model, containing a scalar
singlet and a triplet fermion. The model can explain the possible enhancement
in the decay $H \rightarrow \gamma \gamma$ at the LHC together with the excess
found in the Higgs boson search at LEP2. The structure of the model is
motivated by a recent argument, that was used to explain the number of fermion
generations. For the sake of completenes we also considered the contributions
from higher multiplets.
| [
{
"created": "Fri, 21 Dec 2012 19:05:55 GMT",
"version": "v1"
}
] | 2015-06-12 | [
[
"Basso",
"L.",
""
],
[
"Fischer",
"O.",
""
],
[
"van der Bij",
"J. J.",
""
]
] | We describe a simple extension of the standard model, containing a scalar singlet and a triplet fermion. The model can explain the possible enhancement in the decay $H \rightarrow \gamma \gamma$ at the LHC together with the excess found in the Higgs boson search at LEP2. The structure of the model is motivated by a recent argument, that was used to explain the number of fermion generations. For the sake of completenes we also considered the contributions from higher multiplets. |
2308.01550 | Mariola Klusek-Gawenda | P. Jucha, M. Klusek-Gawenda and A. Szczurek | Light-by-light scattering in ultraperipheral collisions of heavy ions
with future FoCal and ALICE 3 detectors | 20 pages, 19 Figures, 3 Tables; misprint corrected, 2 figures added | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We discuss possible future studies of photon-photon (light-by-light)
scattering using a planned FoCal and ALICE 3 detectors. We include different
mechanisms of $\gamma\gamma\to\gamma\gamma$ scattering, such as double-hadronic
photon fluctuations, $t/u$-channel neutral pion exchange or resonance
excitations ($\gamma \gamma \to R$) and deexcitation ($R \to \gamma \gamma$).
The broad range of (pseudo)rapidities and lower cuts on transverse momenta open
a necessity to consider not only dominant box contributions but also other
subleading contributions. Here we include low mass resonant $R = \pi^0$,
$\eta$, $\eta'$ contributions. The resonance contributions give intermediate
photon transverse momenta. However, these contributions can be eliminated by
imposing windows on di-photon invariant mass. We study and quantify individual
box contributions (leptonic, quarkish). The electron/positron boxes dominate at
low $M_{\gamma \gamma}<1$ GeV di-photon invariant masses. The
PbPb$\to$PbPb$\gamma \gamma$ cross section is calculated within equivalent
photon approximation in the impact parameter space. Several differential
distributions are presented and discussed. We consider four different kinematic
regions. We predict cross section in the (mb-b) range for typical ALICE 3 cuts,
a few orders of magnitude larger than for the current ATLAS or CMS experiments.
We also consider the two-$\pi^0$ background which can, in principle, be
eliminated at the new kinematical range for the ALICE 3 measurements by
imposing dedicated cuts on di-photon transverse momentum and\or so-called
vector asymmetry.
| [
{
"created": "Thu, 3 Aug 2023 06:18:43 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Aug 2023 09:37:23 GMT",
"version": "v2"
},
{
"created": "Wed, 16 Aug 2023 15:29:09 GMT",
"version": "v3"
},
{
"created": "Fri, 18 Aug 2023 19:26:45 GMT",
"version": "v4"
}
] | 2023-08-22 | [
[
"Jucha",
"P.",
""
],
[
"Klusek-Gawenda",
"M.",
""
],
[
"Szczurek",
"A.",
""
]
] | We discuss possible future studies of photon-photon (light-by-light) scattering using a planned FoCal and ALICE 3 detectors. We include different mechanisms of $\gamma\gamma\to\gamma\gamma$ scattering, such as double-hadronic photon fluctuations, $t/u$-channel neutral pion exchange or resonance excitations ($\gamma \gamma \to R$) and deexcitation ($R \to \gamma \gamma$). The broad range of (pseudo)rapidities and lower cuts on transverse momenta open a necessity to consider not only dominant box contributions but also other subleading contributions. Here we include low mass resonant $R = \pi^0$, $\eta$, $\eta'$ contributions. The resonance contributions give intermediate photon transverse momenta. However, these contributions can be eliminated by imposing windows on di-photon invariant mass. We study and quantify individual box contributions (leptonic, quarkish). The electron/positron boxes dominate at low $M_{\gamma \gamma}<1$ GeV di-photon invariant masses. The PbPb$\to$PbPb$\gamma \gamma$ cross section is calculated within equivalent photon approximation in the impact parameter space. Several differential distributions are presented and discussed. We consider four different kinematic regions. We predict cross section in the (mb-b) range for typical ALICE 3 cuts, a few orders of magnitude larger than for the current ATLAS or CMS experiments. We also consider the two-$\pi^0$ background which can, in principle, be eliminated at the new kinematical range for the ALICE 3 measurements by imposing dedicated cuts on di-photon transverse momentum and\or so-called vector asymmetry. |
0908.2158 | D. Delepine | David Delepine, Vannia Gonzalez Macias (Departamento de fisica,
Universitad de Guanajuato), Shaaban Khalil (Centre for Theoretical Physics,
The British University in Egypt), Gabriel Lopez Castro (CINVESTAV) | A new strategy for probing the Majorana neutrino CP violating phases and
masses | 4 pages, 1 figure | AIP Conf.Proc.1361:395-397,2011 | 10.1063/1.3622737 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a new strategy for detecting the CP-violating phases and the
effective mass of muon Majorana neutrinos by measuring observables associated
with neutrino-antineutrino oscillations in $\pi^{\pm}$ decays. Within the
generic framework of quantum field theory, we compute the non-factorizable
probability for producing a pair of same-charged muons in $\pi^{\pm}$ decays as
a distinctive signature of $\nu_{\mu}-\bar{\nu_{\mu}}$ oscillations. We show
that an intense neutrino beam through a long baseline experiment is favored for
probing the Majorana phases. Using the neutrino-antineutrino oscillation
probability reported by MINOS collaboration, a new stringent bound on the
effective muon-neutrino mass is derived.
| [
{
"created": "Sat, 15 Aug 2009 04:19:22 GMT",
"version": "v1"
}
] | 2011-09-28 | [
[
"Delepine",
"David",
"",
"Departamento de fisica,\n Universitad de Guanajuato"
],
[
"Macias",
"Vannia Gonzalez",
"",
"Departamento de fisica,\n Universitad de Guanajuato"
],
[
"Khalil",
"Shaaban",
"",
"Centre for Theoretical Physics,\n The British University in Egypt"
],
[
"Castro",
"Gabriel Lopez",
"",
"CINVESTAV"
]
] | We propose a new strategy for detecting the CP-violating phases and the effective mass of muon Majorana neutrinos by measuring observables associated with neutrino-antineutrino oscillations in $\pi^{\pm}$ decays. Within the generic framework of quantum field theory, we compute the non-factorizable probability for producing a pair of same-charged muons in $\pi^{\pm}$ decays as a distinctive signature of $\nu_{\mu}-\bar{\nu_{\mu}}$ oscillations. We show that an intense neutrino beam through a long baseline experiment is favored for probing the Majorana phases. Using the neutrino-antineutrino oscillation probability reported by MINOS collaboration, a new stringent bound on the effective muon-neutrino mass is derived. |
1911.03919 | Clemens Heuson | Clemens Heuson | Relations for Massive Spinors | 8 pages, no figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently introduced massive spinors are written as 2-vectors consisting of
two massless spinors with opposite helicities. With this notation a couple of
relations between them can be derived easily, entirely avoiding the spinor
indices. The high energy limit of three point amplitudes is discussed shortly.
Finally we add some comments on recursion relations with massive particles.
| [
{
"created": "Sun, 10 Nov 2019 12:20:21 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Oct 2020 15:36:31 GMT",
"version": "v2"
}
] | 2020-10-29 | [
[
"Heuson",
"Clemens",
""
]
] | Recently introduced massive spinors are written as 2-vectors consisting of two massless spinors with opposite helicities. With this notation a couple of relations between them can be derived easily, entirely avoiding the spinor indices. The high energy limit of three point amplitudes is discussed shortly. Finally we add some comments on recursion relations with massive particles. |
2405.10419 | Emilse Cabrera Capera | Emilse Cabrera, Arman Esmaili and Alexander A. Quiroga | Limits on the parameter space of (3+2) sterile neutrino scenario by
IceCube data | 18 pages, 8 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | The neutrino sector of the standard model of particles can contain more than
one sterile neutrino states. Generally, existence of more sterile states leads
to better, or at least equally good, fit to the short baseline anomalous data
due to the larger number of parameters and interferences which create features
in the oscillation pattern. However, for experiments like IceCube, where the
sterile states distort the oscillation pattern of high energy atmospheric
neutrinos through parametric and MSW resonances, addition of more sterile
states leads to a more intense effect. Although the limits on one additional
sterile neutrino state by IceCube data have been studied in the literature,
bounds on the models with more sterile states are lacking. We analyze the
one-year data set of atmospheric neutrinos collected by IceCube during the
2011-2012 and derive the limits on the parameter space of (3+2) scenario with
two sterile neutrino states, taking into account the relevant systematic and
statistical uncertainties and atmospheric neutrino flux variants. To facilitate
the joint analysis of IceCube and short baseline data, we provide the table of
$\chi^2$ values from IceCube's data analysis as function of the parameters.
| [
{
"created": "Thu, 16 May 2024 19:44:30 GMT",
"version": "v1"
}
] | 2024-05-20 | [
[
"Cabrera",
"Emilse",
""
],
[
"Esmaili",
"Arman",
""
],
[
"Quiroga",
"Alexander A.",
""
]
] | The neutrino sector of the standard model of particles can contain more than one sterile neutrino states. Generally, existence of more sterile states leads to better, or at least equally good, fit to the short baseline anomalous data due to the larger number of parameters and interferences which create features in the oscillation pattern. However, for experiments like IceCube, where the sterile states distort the oscillation pattern of high energy atmospheric neutrinos through parametric and MSW resonances, addition of more sterile states leads to a more intense effect. Although the limits on one additional sterile neutrino state by IceCube data have been studied in the literature, bounds on the models with more sterile states are lacking. We analyze the one-year data set of atmospheric neutrinos collected by IceCube during the 2011-2012 and derive the limits on the parameter space of (3+2) scenario with two sterile neutrino states, taking into account the relevant systematic and statistical uncertainties and atmospheric neutrino flux variants. To facilitate the joint analysis of IceCube and short baseline data, we provide the table of $\chi^2$ values from IceCube's data analysis as function of the parameters. |
hep-ph/0311143 | C. Boehm | C. Boehm, P. Fayet, J. Silk | Light and Heavy Dark Matter Particles | 5 pages | Phys.Rev.D69:101302,2004 | 10.1103/PhysRevD.69.101302 | null | hep-ph | null | It has recently been pointed out that the 511 keV emission line detected by
Integral/SPI from the bulge of our galaxy could be explained by annihilations
of light Dark Matter particles into e^+ e^-. If such a signature is confirmed,
then one might expect a conflict with the interpretation of very high energy
gamma rays if they also turn out to be due to Dark Matter annihilations. Here,
we propose a way to accomodate the existence of both signals being produced by
Dark Matter annihilations through the existence of two stable (neutral) Dark
Matter particles, as is possible in theories inspired from N=2 supersymmetry.
| [
{
"created": "Tue, 11 Nov 2003 17:41:53 GMT",
"version": "v1"
}
] | 2009-02-20 | [
[
"Boehm",
"C.",
""
],
[
"Fayet",
"P.",
""
],
[
"Silk",
"J.",
""
]
] | It has recently been pointed out that the 511 keV emission line detected by Integral/SPI from the bulge of our galaxy could be explained by annihilations of light Dark Matter particles into e^+ e^-. If such a signature is confirmed, then one might expect a conflict with the interpretation of very high energy gamma rays if they also turn out to be due to Dark Matter annihilations. Here, we propose a way to accomodate the existence of both signals being produced by Dark Matter annihilations through the existence of two stable (neutral) Dark Matter particles, as is possible in theories inspired from N=2 supersymmetry. |
hep-ph/9801328 | Sean Fleming | Sean Fleming (U. Toronto) and Thomas Mehen (Cal. Tech.) | Photoproduction of h_c | Revtex file 8 pages, 1 figure. Macros needed: epsf,floats,rotate
Minor typos changed, and reference added. Version to be published in
Phys.Rev.D | Phys.Rev. D58 (1998) 037503 | 10.1103/PhysRevD.58.037503 | CALT-68-2154, UTPT-97-24 | hep-ph | null | Using the NRQCD factorization formalism, we calculate the total cross section
for the photoproduction of h_c mesons. We include color-octet and color-singlet
mechanisms as well as next-to-leading order perturbative QCD corrections. The
theoretical prediction depends on two nonperturbative matrix elements that are
not well determined from existing data on charmonium production. For reasonable
values of these matrix elements, the cross section is large enough that the h_c
may be observable at the E831 experiment and at the HERA experiments.
| [
{
"created": "Fri, 16 Jan 1998 15:36:59 GMT",
"version": "v1"
},
{
"created": "Fri, 1 May 1998 18:25:37 GMT",
"version": "v2"
},
{
"created": "Mon, 4 May 1998 15:41:12 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Fleming",
"Sean",
"",
"U. Toronto"
],
[
"Mehen",
"Thomas",
"",
"Cal. Tech."
]
] | Using the NRQCD factorization formalism, we calculate the total cross section for the photoproduction of h_c mesons. We include color-octet and color-singlet mechanisms as well as next-to-leading order perturbative QCD corrections. The theoretical prediction depends on two nonperturbative matrix elements that are not well determined from existing data on charmonium production. For reasonable values of these matrix elements, the cross section is large enough that the h_c may be observable at the E831 experiment and at the HERA experiments. |
hep-ph/0202268 | Antonio O. Bouzas | Antonio O. Bouzas, Ruben Flores-Mendieta | One-loop vertex integrals in heavy-particle effective theories | 10 pages, Latex, to appear in J. Phys. G | J.Phys.G28:1179-1190,2002 | 10.1088/0954-3899/28/6/302 | null | hep-ph | null | We give a complete analytical computation of three-point one-loop integrals
with one heavy propagator, up to the third tensor rank, for arbitrary values of
external momenta and masses.
| [
{
"created": "Wed, 27 Feb 2002 18:32:58 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Bouzas",
"Antonio O.",
""
],
[
"Flores-Mendieta",
"Ruben",
""
]
] | We give a complete analytical computation of three-point one-loop integrals with one heavy propagator, up to the third tensor rank, for arbitrary values of external momenta and masses. |
hep-ph/0703254 | Cecilia Tarantino | Monika Blanke, Andrzej J. Buras, Stefan Recksiegel, Cecilia Tarantino
and Selma Uhlig | Littlest Higgs Model with T-Parity Confronting the New Data on D^0-\bar
D^0 Mixing | 13 pages, 5 figures, 1 table. Note added on the omitted term in
Z-penguin contribution. For an updated analysis see arXiv:0906.5454 | Phys.Lett.B657:81-86,2007 | 10.1016/j.physletb.2007.10.008 | TUM-HEP-666/07, MPP-2007-33 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by the first experimental evidence of meson oscillations in the D
system, we study D^0 - \bar D^0 mixing in the Littlest Higgs model with
T-parity, we investigate its role in constraining the model parameters and its
impact on the most interesting flavour observables. We find that the
experimental data are potentially strongly constraining but at present limited
by large theoretical uncertainties in the long-distance Standard Model
contribution to D^0 - \bar D^0 mixing.
| [
{
"created": "Fri, 23 Mar 2007 16:13:03 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Jul 2007 13:25:26 GMT",
"version": "v2"
},
{
"created": "Fri, 15 Jan 2010 17:01:00 GMT",
"version": "v3"
}
] | 2010-01-15 | [
[
"Blanke",
"Monika",
""
],
[
"Buras",
"Andrzej J.",
""
],
[
"Recksiegel",
"Stefan",
""
],
[
"Tarantino",
"Cecilia",
""
],
[
"Uhlig",
"Selma",
""
]
] | Motivated by the first experimental evidence of meson oscillations in the D system, we study D^0 - \bar D^0 mixing in the Littlest Higgs model with T-parity, we investigate its role in constraining the model parameters and its impact on the most interesting flavour observables. We find that the experimental data are potentially strongly constraining but at present limited by large theoretical uncertainties in the long-distance Standard Model contribution to D^0 - \bar D^0 mixing. |
hep-ph/9310248 | JiangLiu | Jiang Liu and Gino Segr\`e | Unstable particle mixing and CP violation in weak decays | 16 pages in LaTeX, UPR-0582T | Phys.Rev.D49:1342-1349,1994 | 10.1103/PhysRevD.49.1342 | null | hep-ph | null | We discuss unstable particle mixing in CP-violating weak decays. It is shown
that for a completely degenerate system unstable particle mixing does not
introduce a CP-violating partial rate difference, and that when the mixings are
small only the off-diagonal mixings are relevant. Also, in the absence of
mixing, unstable particle wave function renormalization does not introduce any
additional effect. An illustrative example is given to heavy scalar decays with
arbitrary mixing.
| [
{
"created": "Fri, 8 Oct 1993 13:45:24 GMT",
"version": "v1"
}
] | 2010-11-01 | [
[
"Liu",
"Jiang",
""
],
[
"Segrè",
"Gino",
""
]
] | We discuss unstable particle mixing in CP-violating weak decays. It is shown that for a completely degenerate system unstable particle mixing does not introduce a CP-violating partial rate difference, and that when the mixings are small only the off-diagonal mixings are relevant. Also, in the absence of mixing, unstable particle wave function renormalization does not introduce any additional effect. An illustrative example is given to heavy scalar decays with arbitrary mixing. |
hep-ph/0410311 | Denis A. Suprun | Denis A. Suprun | Phenomenology of charmless hadronic B decays | Talk presented at the Sixth International Conference on Hyperons,
Charm and Beauty Hadrons, IIT, Chicago, June 27 - July 3, 2004 | null | 10.1016/j.nuclphysbps.2005.01.035 | null | hep-ph | null | The decays of $B$ mesons to a pair of charmless pseudoscalar mesons ($PP$
decays) or to a vector and pseudoscalar meson ($VP$ decays) have been analyzed
within the framework of flavor SU(3) symmetry and the Kobayashi-Maskawa
mechanism of CP violation. Separate $PP$ and $VP$ fits proved to be successful
in describing the experimental data (branching ratios, CP asymmetries and
time-dependent parameters). Decay magnitudes and relative weak and strong
phases have been extracted from the fits. Values of the weak phase $\gamma$
were found to be consistent with the current indirect bounds from other
analyses of CKM parameters.
| [
{
"created": "Fri, 22 Oct 2004 19:10:17 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Suprun",
"Denis A.",
""
]
] | The decays of $B$ mesons to a pair of charmless pseudoscalar mesons ($PP$ decays) or to a vector and pseudoscalar meson ($VP$ decays) have been analyzed within the framework of flavor SU(3) symmetry and the Kobayashi-Maskawa mechanism of CP violation. Separate $PP$ and $VP$ fits proved to be successful in describing the experimental data (branching ratios, CP asymmetries and time-dependent parameters). Decay magnitudes and relative weak and strong phases have been extracted from the fits. Values of the weak phase $\gamma$ were found to be consistent with the current indirect bounds from other analyses of CKM parameters. |
hep-ph/0007001 | Neal Weiner | Nima Arkani-Hamed, Lawrence Hall, Hitoshi Murayama, David Smith, Neal
Weiner | Neutrino Masses at v^{3/2} | Minor revisions, 4 pages, RevTeX | null | null | UCB-PTH-00/19,LBNL-46181 | hep-ph | null | Theories in which neutrino masses are generated by a conventional see-saw
mechanism generically yield masses which are O(v^2) in units where M_{Pl}=1,
which is naively too small to explain the results from SuperKamiokande. In
supersymmetric theories with gravity mediated supersymmetry breaking, the
fundamental small parameter is not v/M_{Pl}, but m_I/M_{Pl}, where m_I is the
scale of supersymmetry breaking in the hidden sector. We note that
m_I^3/M_{Pl}^2 is only slightly too large to explain SuperKamiokande, and
present two models that achieve neutrino masses at this order in m_I, one of
which has an additional suppression lambda_tau^2, while the other has
additional suppression arising from a loop factor. The latter model shares a
great deal of phenomenology with a class of models previously explored,
including the possibility of viable sneutrino dark matter.
| [
{
"created": "Sat, 1 Jul 2000 17:31:31 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Oct 2000 16:18:01 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Arkani-Hamed",
"Nima",
""
],
[
"Hall",
"Lawrence",
""
],
[
"Murayama",
"Hitoshi",
""
],
[
"Smith",
"David",
""
],
[
"Weiner",
"Neal",
""
]
] | Theories in which neutrino masses are generated by a conventional see-saw mechanism generically yield masses which are O(v^2) in units where M_{Pl}=1, which is naively too small to explain the results from SuperKamiokande. In supersymmetric theories with gravity mediated supersymmetry breaking, the fundamental small parameter is not v/M_{Pl}, but m_I/M_{Pl}, where m_I is the scale of supersymmetry breaking in the hidden sector. We note that m_I^3/M_{Pl}^2 is only slightly too large to explain SuperKamiokande, and present two models that achieve neutrino masses at this order in m_I, one of which has an additional suppression lambda_tau^2, while the other has additional suppression arising from a loop factor. The latter model shares a great deal of phenomenology with a class of models previously explored, including the possibility of viable sneutrino dark matter. |
1603.01028 | St\'ephane Peign\'e | St\'ephane Munier, St\'ephane Peign\'e, Elena Petreska | Medium-induced gluon radiation in hard forward parton scattering in the
saturation formalism | 25 pages, 2 figures | Phys. Rev. D 95, 014014 (2017) | 10.1103/PhysRevD.95.014014 | CPHT-RR009.032016 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We derive the medium-induced, coherent gluon radiation spectrum associated
with the hard forward scattering of an energetic parton off a nucleus, in the
saturation formalism and within the Gaussian approximation for the relevant
correlators of Wilson lines. The calculation reproduces the simple expression
for the spectrum previously obtained in the opacity expansion formalism, and
rigorously specifies its validity range. The connection between the
calculations in the opacity expansion and saturation formalisms is made
apparent. This study may serve as a first step in order to implement
consistently induced coherent energy loss and gluon shadowing in
`saturation-based models' of hadron nuclear suppression in proton-nucleus
collisions.
| [
{
"created": "Thu, 3 Mar 2016 08:55:30 GMT",
"version": "v1"
}
] | 2017-01-18 | [
[
"Munier",
"Stéphane",
""
],
[
"Peigné",
"Stéphane",
""
],
[
"Petreska",
"Elena",
""
]
] | We derive the medium-induced, coherent gluon radiation spectrum associated with the hard forward scattering of an energetic parton off a nucleus, in the saturation formalism and within the Gaussian approximation for the relevant correlators of Wilson lines. The calculation reproduces the simple expression for the spectrum previously obtained in the opacity expansion formalism, and rigorously specifies its validity range. The connection between the calculations in the opacity expansion and saturation formalisms is made apparent. This study may serve as a first step in order to implement consistently induced coherent energy loss and gluon shadowing in `saturation-based models' of hadron nuclear suppression in proton-nucleus collisions. |
hep-ph/0111420 | Ismd31 | Georgios D. Stavropoulos | QCD Processes at the LHC | 4 pages, 4 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL
http://ismd31.ccnu.edu.cn/ | null | 10.1142/9789812778048_0049 | null | hep-ph | null | The study of QCD processes at the LHC will serve two main goals. First the
predictions of QCD will be tested and precision measurements will be performed.
Second QCD processes represent a major part of the background to other Standard
Model processes and signals of new physics at the LHC and thus need to be
understood precisely in the new kinematic region available here. Furthermore,
the production cross-sections for almost all processes are controlled by QCD.
| [
{
"created": "Thu, 29 Nov 2001 13:31:27 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Stavropoulos",
"Georgios D.",
""
]
] | The study of QCD processes at the LHC will serve two main goals. First the predictions of QCD will be tested and precision measurements will be performed. Second QCD processes represent a major part of the background to other Standard Model processes and signals of new physics at the LHC and thus need to be understood precisely in the new kinematic region available here. Furthermore, the production cross-sections for almost all processes are controlled by QCD. |
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