id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1207.6066 | Michael Spannowsky | Kiran Joshi, Andrew D. Pilkington and Michael Spannowsky | The dependency of boosted tagging algorithms on the event colour
structure | 17 pages, 7 figures | null | 10.1103/PhysRevD.86.114016 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The impact of event colour structure on the performance of the Johns-Hopkins,
CMS, HEPToptagger and N-Subjettiness algorithms is investigated by studying
colour singlet and colour octet resonances decaying to top-quark pairs. Large
differences in top-tagging efficiency are observed due to the different colour
charge of each resonance. These differences are quantified as a function of the
algorithm parameters, the jet size parameter and the probability to misidentify
light quarks and gluons as top candidates. We suggest that future experimental
searches would benefit from optimising the choice of algorithm parameters in
order to minimise this source of model dependency.
| [
{
"created": "Wed, 25 Jul 2012 17:40:06 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"Joshi",
"Kiran",
""
],
[
"Pilkington",
"Andrew D.",
""
],
[
"Spannowsky",
"Michael",
""
]
] | The impact of event colour structure on the performance of the Johns-Hopkins, CMS, HEPToptagger and N-Subjettiness algorithms is investigated by studying colour singlet and colour octet resonances decaying to top-quark pairs. Large differences in top-tagging efficiency are observed due to the different colour charge of each resonance. These differences are quantified as a function of the algorithm parameters, the jet size parameter and the probability to misidentify light quarks and gluons as top candidates. We suggest that future experimental searches would benefit from optimising the choice of algorithm parameters in order to minimise this source of model dependency. |
hep-ph/0408351 | Peter Wienemann | Peter Wienemann | Experimental Tools for SPA | 5 pages, 1 figure, 2 tables, contribution to the proceedings of the
International Conference on Linear Colliders (LCWS 04), Paris, April 19-23,
2004 | null | null | null | hep-ph | null | Provided SUSY is realized in Nature, future colliders like the Large Hadron
Collider (LHC) and a future e+e- linear collider (LC) will provide a wealth of
data on SUSY phenomena. One important task will be to extract the Lagrangian
parameters at the electroweak scale from the numerous measured observables and
to extrapolate them to a high scale to check whether unification takes place or
to learn about the SUSY breaking mechanism. To accomplish such a task, two new
programs, SFITTER and Fittino, have recently been developed. This talk
introduces both programs and presents first results obtained with them.
| [
{
"created": "Tue, 31 Aug 2004 13:22:13 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Wienemann",
"Peter",
""
]
] | Provided SUSY is realized in Nature, future colliders like the Large Hadron Collider (LHC) and a future e+e- linear collider (LC) will provide a wealth of data on SUSY phenomena. One important task will be to extract the Lagrangian parameters at the electroweak scale from the numerous measured observables and to extrapolate them to a high scale to check whether unification takes place or to learn about the SUSY breaking mechanism. To accomplish such a task, two new programs, SFITTER and Fittino, have recently been developed. This talk introduces both programs and presents first results obtained with them. |
1510.01626 | Francesco Giovanni Celiberto | Francesco Giovanni Celiberto, Dmitry Yu. Ivanov, Beatrice Murdaca,
Alessandro Papa | Mueller-Navelet jets at LHC: discriminating BFKL from DGLAP by
asymmetric cuts | 6 pages, 5 figures, presented by F.G. Celiberto at the 16th
conference on Elastic and Diffractive Scattering, EDS Blois 2015, Borgo,
Corsica, France, June/July 2015 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Mueller-Navelet di-jet production process represents an ultimate
testfield of pQCD in the high-energy limit. Several experimental analyses
carried out so far are in good agreement with theoretical predictions, based on
collinear factorization and BFKL resummation of energy logarithms in the
next-to-leading approximation, with the CMS experimental data at center-of-mass
energy equal to 7 TeV. However, the question if the same data can be described
also by fixed-order perturbative approaches has not yet been fully answered. We
discuss how the use of partially asymmetric cuts in the transverse momenta of
the detected jets allows to discriminate between BFKL-resummed and fixed-order
predictions (the latter in the high-energy limit) in observables related with
this process at LHC.
| [
{
"created": "Tue, 6 Oct 2015 15:32:45 GMT",
"version": "v1"
}
] | 2015-10-07 | [
[
"Celiberto",
"Francesco Giovanni",
""
],
[
"Ivanov",
"Dmitry Yu.",
""
],
[
"Murdaca",
"Beatrice",
""
],
[
"Papa",
"Alessandro",
""
]
] | The Mueller-Navelet di-jet production process represents an ultimate testfield of pQCD in the high-energy limit. Several experimental analyses carried out so far are in good agreement with theoretical predictions, based on collinear factorization and BFKL resummation of energy logarithms in the next-to-leading approximation, with the CMS experimental data at center-of-mass energy equal to 7 TeV. However, the question if the same data can be described also by fixed-order perturbative approaches has not yet been fully answered. We discuss how the use of partially asymmetric cuts in the transverse momenta of the detected jets allows to discriminate between BFKL-resummed and fixed-order predictions (the latter in the high-energy limit) in observables related with this process at LHC. |
hep-ph/9508401 | Dirk Graudenz | D. Graudenz and G. Veneziano (CERN) | Estimating Diffractive Higgs Boson Production at LHC from HERA Data | 12 pages (LATEX); figures are included via epsfig; the corresponding
postscript files are uuencoded. A style file derived from the ``elsart.sty''
is included, as well as the ``elsart12.sty'' file. The AMSTEX fonts are
required. See http://surya11.cern.ch/users/graudenz/publications.html for a
complete postscript file | Phys.Lett. B365 (1996) 302-308 | 10.1016/0370-2693(95)01243-5 | CERN-TH/95-232 | hep-ph | null | Using a recently proposed factorization hypothesis for semi-inclusive hard
processes in QCD, one can study, in principle, the diffractive production of
the Standard Model Higgs boson at LHC using only, as input, $ep$ diffractive
hard-processes data of the type recently collected and analyzed by the H1 and
ZEUS collaborations at HERA. While waiting for a more precise and complete set
of data, we combine here the existing data with a simple Pomeron-exchange
picture and find a large spread in the Higgs boson production cross section,
depending on the input parametrization of the Pomeron's parton content. In
particular, if the Pomeron gluon density $f_{g/P}(\beta)$ is peaked at large
$\beta$ for small scales, single diffractive events will represent a sizeable
fraction of all produced Higgs bosons with an expected better-than-average
signal-to-background ratio.
| [
{
"created": "Wed, 30 Aug 1995 21:07:55 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Graudenz",
"D.",
"",
"CERN"
],
[
"Veneziano",
"G.",
"",
"CERN"
]
] | Using a recently proposed factorization hypothesis for semi-inclusive hard processes in QCD, one can study, in principle, the diffractive production of the Standard Model Higgs boson at LHC using only, as input, $ep$ diffractive hard-processes data of the type recently collected and analyzed by the H1 and ZEUS collaborations at HERA. While waiting for a more precise and complete set of data, we combine here the existing data with a simple Pomeron-exchange picture and find a large spread in the Higgs boson production cross section, depending on the input parametrization of the Pomeron's parton content. In particular, if the Pomeron gluon density $f_{g/P}(\beta)$ is peaked at large $\beta$ for small scales, single diffractive events will represent a sizeable fraction of all produced Higgs bosons with an expected better-than-average signal-to-background ratio. |
1910.01248 | Stefano Laporta | Stefano Laporta | High-precision calculation of the 4-loop QED contribution to the slope
of the Dirac form factor | 12 pages, 3 figures and 3 tables; v2: a few misprints corrected,
version formatted to be published on Physics Letters B | null | 10.1016/j.physletb.2019.135137 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have evaluated with 1100 digits of precision the contribution of all the
891 mass-independent four-loop Feynman diagrams contributing to the slope of
the Dirac form factor in QED. The total 4-loop contribution is $ m^2
F_1^{(4)'}(0) = 0.886545673946443145836821730610315359390424032660064745...
\left(\frac{\alpha}{\pi}\right)^4$. We have fit a semi-analytical expression to
the numerical value. The expression contains harmonic polylogarithms of
argument $e^{\frac{i\pi}{3}}$, $e^{\frac{2i\pi}{3}}$, $e^{\frac{i\pi}{2}}$,
one-dimensional integrals of products of complete elliptic integrals and six
finite parts of master integrals, evaluated up to 4800 digits. I show the
correction on the shift of the energy levels of the hydrogen atom due to the
slope.
| [
{
"created": "Wed, 2 Oct 2019 23:17:44 GMT",
"version": "v1"
},
{
"created": "Sun, 8 Dec 2019 16:58:17 GMT",
"version": "v2"
}
] | 2019-12-11 | [
[
"Laporta",
"Stefano",
""
]
] | We have evaluated with 1100 digits of precision the contribution of all the 891 mass-independent four-loop Feynman diagrams contributing to the slope of the Dirac form factor in QED. The total 4-loop contribution is $ m^2 F_1^{(4)'}(0) = 0.886545673946443145836821730610315359390424032660064745... \left(\frac{\alpha}{\pi}\right)^4$. We have fit a semi-analytical expression to the numerical value. The expression contains harmonic polylogarithms of argument $e^{\frac{i\pi}{3}}$, $e^{\frac{2i\pi}{3}}$, $e^{\frac{i\pi}{2}}$, one-dimensional integrals of products of complete elliptic integrals and six finite parts of master integrals, evaluated up to 4800 digits. I show the correction on the shift of the energy levels of the hydrogen atom due to the slope. |
hep-ph/9212312 | Isamu Watanabe | Y. Yasui, I. Watanabe, J. Kodaira and I. Endo | Measuring the Beam Polarizations and the Luminosity at Photon-Photon
Colliders | 16 pages and 7 figures attached as PostScript files, LaTeX, HUPD-9217
(Revised for 4 points: 2 are important, see the top of the file for details.) | Nucl.Instrum.Meth.A335:385-396,1993 | 10.1016/0168-9002(93)91222-9 | null | hep-ph | null | We present methods to measure the beam polarizations and the luminosity of
$\gamma \gamma$ colliders at TeV energy scale.
The beam polarizations of a $\gamma \gamma$ collider can easily be monitored
by comparing the numbers of events of the processes $\gamma \gamma$
$\rightarrow$ $\ell^+ \ell^-$ and $\gamma \gamma$ $\rightarrow$ $W^+ W^-$,
where $\ell$ means $e$ or $\mu$.
The luminosity of a $\gamma \gamma$ collider is also measurable by the event
rate of $W$ boson pair productions and the light lepton pair productions.
| [
{
"created": "Mon, 28 Dec 1992 17:16:34 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Feb 1993 16:45:39 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Yasui",
"Y.",
""
],
[
"Watanabe",
"I.",
""
],
[
"Kodaira",
"J.",
""
],
[
"Endo",
"I.",
""
]
] | We present methods to measure the beam polarizations and the luminosity of $\gamma \gamma$ colliders at TeV energy scale. The beam polarizations of a $\gamma \gamma$ collider can easily be monitored by comparing the numbers of events of the processes $\gamma \gamma$ $\rightarrow$ $\ell^+ \ell^-$ and $\gamma \gamma$ $\rightarrow$ $W^+ W^-$, where $\ell$ means $e$ or $\mu$. The luminosity of a $\gamma \gamma$ collider is also measurable by the event rate of $W$ boson pair productions and the light lepton pair productions. |
0904.1648 | Herv\'e Moutarde | H. Moutarde | Extraction of the Compton Form Factor H from DVCS measurements at
Jefferson Lab | 24 pages, 8 figures | Phys.Rev.D79:094021,2009 | 10.1103/PhysRevD.79.094021 | IRFU-09-32 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of Generalised Parton Distributions, we study the
helicity-dependent and independent cross sections measured in Hall A and the
beam spin asymmetries measured in Hall B at Jefferson Laboratory. We perform a
global fit of these data and fits on each kinematical bin. We extract the real
and imaginary parts of the Compton Form Factor $\mathcal{H}$ under the main
hypothesis of dominance of the Generalised Parton Distribution $H$ and twist 2
accuracy. We discuss our results and compare to previous extractions as well as
to the VGG model. We pay extra attention to the estimation of errors on the
extraction of $\mathcal{H}$.
| [
{
"created": "Fri, 10 Apr 2009 07:30:40 GMT",
"version": "v1"
}
] | 2009-07-30 | [
[
"Moutarde",
"H.",
""
]
] | In the framework of Generalised Parton Distributions, we study the helicity-dependent and independent cross sections measured in Hall A and the beam spin asymmetries measured in Hall B at Jefferson Laboratory. We perform a global fit of these data and fits on each kinematical bin. We extract the real and imaginary parts of the Compton Form Factor $\mathcal{H}$ under the main hypothesis of dominance of the Generalised Parton Distribution $H$ and twist 2 accuracy. We discuss our results and compare to previous extractions as well as to the VGG model. We pay extra attention to the estimation of errors on the extraction of $\mathcal{H}$. |
2006.06913 | Ning Chen | Ning Chen, Tong Li, Zhaolong Teng, Yongcheng Wu | Collapsing domain walls in the two-Higgs-doublet model and deep insights
from the EDM | 33 pages, 8 figures, matches the published version | null | 10.1007/JHEP10(2020)081 | null | hep-ph gr-qc physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the domain wall solutions in the general two-Higgs-doublet model
(2HDM) with a CP-violating phase. The 2HDM with the spontaneouse CP violation
is found to have domain wall solutions whose tensions are
$\mathcal{O}(10^6)\,{\rm GeV}^3$, which are excluded by the
Zel'dovich-Kobzarev-Okun bound. With the explicit CP-violating (CPV) terms as
the so-called biased term in the scalar potential, domain walls can collapse in
the early Universe. The sizes of the explicit CP violation can be constrained
from the Big Bang nucleosynthesis. This constraint is converted to the CPV
mixing of $\alpha_c$, and is mostly sensitive to the mass splittings between
two heavy neutral Higgs bosons. We estimate the possible gravitational wave
signals and the electric dipole moment (EDM) predictions due to the domain wall
collapsing. It turns out that the peak spectrum of the GW from the domain wall
collapsing cannot be probed in any future program. In contrast, the untenable
regions with very tiny explicit CPV parameter in the Higgs potential has been
partially excluded by the latest electron EDM measurements at the ACME-II and
will be further confirmed or excluded by the future ACME-III projection.
| [
{
"created": "Fri, 12 Jun 2020 02:32:48 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Jun 2020 02:38:53 GMT",
"version": "v2"
},
{
"created": "Mon, 2 Nov 2020 08:53:14 GMT",
"version": "v3"
}
] | 2020-11-03 | [
[
"Chen",
"Ning",
""
],
[
"Li",
"Tong",
""
],
[
"Teng",
"Zhaolong",
""
],
[
"Wu",
"Yongcheng",
""
]
] | We study the domain wall solutions in the general two-Higgs-doublet model (2HDM) with a CP-violating phase. The 2HDM with the spontaneouse CP violation is found to have domain wall solutions whose tensions are $\mathcal{O}(10^6)\,{\rm GeV}^3$, which are excluded by the Zel'dovich-Kobzarev-Okun bound. With the explicit CP-violating (CPV) terms as the so-called biased term in the scalar potential, domain walls can collapse in the early Universe. The sizes of the explicit CP violation can be constrained from the Big Bang nucleosynthesis. This constraint is converted to the CPV mixing of $\alpha_c$, and is mostly sensitive to the mass splittings between two heavy neutral Higgs bosons. We estimate the possible gravitational wave signals and the electric dipole moment (EDM) predictions due to the domain wall collapsing. It turns out that the peak spectrum of the GW from the domain wall collapsing cannot be probed in any future program. In contrast, the untenable regions with very tiny explicit CPV parameter in the Higgs potential has been partially excluded by the latest electron EDM measurements at the ACME-II and will be further confirmed or excluded by the future ACME-III projection. |
2105.14292 | Takahiro Yoshida | Hiroshi Okada, Yusuke Shimizu, Morimitsu Tanimoto, Takahiro Yoshida | Modulus $\tau$ linking leptonic CP violation to baryon asymmetry in
$A_4$ modular invariant flavor model | 30 pages, 14 figures, 7 tables, minor corrections | null | 10.1007/JHEP07(2021)184 | APCTP Pre 2021-009, HUPD-2103 | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose an $A_4$ modular invariant flavor model of leptons, in which both
CP and modular symmetries are broken spontaneously by the vacuum expectation
value of the modulus $\tau$. The value of the modulus $\tau$ is restricted by
the observed lepton mixing angles and lepton masses for the normal hierarchy of
neutrino masses at $3\sigma$ confidence level. The predictive Dirac CP phase
$\delta_{CP}$ is in the ranges $[0^\circ,50^\circ]$, $[170^\circ,175^\circ]$
and $[280^\circ,360^\circ]$ for ${\rm Re}\, [\tau]<0$, and
$[0^\circ,80^\circ]$, $[185^\circ,190^\circ]$ and $[310^\circ,360^\circ]$ for
${\rm Re}\,[\tau]>0$ at $3\sigma$ confidence level. The sum of three neutrino
masses is predicted in $[60, 84]$ meV, and the effective mass for the
$0\nu\beta\beta$ decay is in [0.003, 3] meV. On the other hand, there is no
allowed region of the modulus $\tau$ for the inverted hierarchy of neutrino
masses at $3\sigma$ confidence level. The modulus $\tau$ links the Dirac CP
phase to the cosmological baryon asymmetry (BAU) via the leptogenesis. Due to
the strong wash-out effect, the predictive baryon asymmetry $Y_B$ can be at
most the same order of the observed value. Then, the lightest right-handed
neutrino mass is restricted in the range of $M_1 =[1.5,\,6.5] \times 10^{13}$
GeV. We find the correlation between the predictive $Y_B$ and the Dirac CP
phase $\delta_{CP}$. Only two predictive $\delta_{CP}$ ranges,
$[5^\circ,40^\circ]$ (${\rm Re}\,[\tau]>0$) and $[320^\circ,355^\circ]$ (${\rm
Re}\,[\tau]<0$) are consistent with the BAU.
| [
{
"created": "Sat, 29 May 2021 13:06:49 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Jun 2021 06:54:41 GMT",
"version": "v2"
},
{
"created": "Fri, 16 Jul 2021 06:52:01 GMT",
"version": "v3"
}
] | 2021-08-18 | [
[
"Okada",
"Hiroshi",
""
],
[
"Shimizu",
"Yusuke",
""
],
[
"Tanimoto",
"Morimitsu",
""
],
[
"Yoshida",
"Takahiro",
""
]
] | We propose an $A_4$ modular invariant flavor model of leptons, in which both CP and modular symmetries are broken spontaneously by the vacuum expectation value of the modulus $\tau$. The value of the modulus $\tau$ is restricted by the observed lepton mixing angles and lepton masses for the normal hierarchy of neutrino masses at $3\sigma$ confidence level. The predictive Dirac CP phase $\delta_{CP}$ is in the ranges $[0^\circ,50^\circ]$, $[170^\circ,175^\circ]$ and $[280^\circ,360^\circ]$ for ${\rm Re}\, [\tau]<0$, and $[0^\circ,80^\circ]$, $[185^\circ,190^\circ]$ and $[310^\circ,360^\circ]$ for ${\rm Re}\,[\tau]>0$ at $3\sigma$ confidence level. The sum of three neutrino masses is predicted in $[60, 84]$ meV, and the effective mass for the $0\nu\beta\beta$ decay is in [0.003, 3] meV. On the other hand, there is no allowed region of the modulus $\tau$ for the inverted hierarchy of neutrino masses at $3\sigma$ confidence level. The modulus $\tau$ links the Dirac CP phase to the cosmological baryon asymmetry (BAU) via the leptogenesis. Due to the strong wash-out effect, the predictive baryon asymmetry $Y_B$ can be at most the same order of the observed value. Then, the lightest right-handed neutrino mass is restricted in the range of $M_1 =[1.5,\,6.5] \times 10^{13}$ GeV. We find the correlation between the predictive $Y_B$ and the Dirac CP phase $\delta_{CP}$. Only two predictive $\delta_{CP}$ ranges, $[5^\circ,40^\circ]$ (${\rm Re}\,[\tau]>0$) and $[320^\circ,355^\circ]$ (${\rm Re}\,[\tau]<0$) are consistent with the BAU. |
1704.07968 | Andrey Grozin | A. G. Grozin | Heavy quark form factors in the large $\beta_0$ limit | v2: the section on inversion relations extended; v3: 3 refs added,
discussion of the hypergeometric function expansion extended; v4: eq. (22)
and fig. 5 corrected | null | 10.1140/epjc/s10052-017-5021-4 | TTP17-022, MITP/17-026 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Heavy quark form factors are calculated at $\beta_0 \alpha_s \sim 1$ to all
orders in $\alpha_s$ at the first order in $1/\beta_0$. The $n_f^2 \alpha_s^3$
terms in the recent results [arXiv:1611.07535] for the vector form factors are
confirmed, and $n_f^{L-1} \alpha_s^L$ terms for higher $L$ are predicted.
| [
{
"created": "Wed, 26 Apr 2017 04:33:24 GMT",
"version": "v1"
},
{
"created": "Sat, 29 Apr 2017 06:39:23 GMT",
"version": "v2"
},
{
"created": "Sat, 6 May 2017 06:18:58 GMT",
"version": "v3"
},
{
"created": "Sun, 14 May 2017 06:25:03 GMT",
"version": "v4"
}
] | 2017-08-02 | [
[
"Grozin",
"A. G.",
""
]
] | Heavy quark form factors are calculated at $\beta_0 \alpha_s \sim 1$ to all orders in $\alpha_s$ at the first order in $1/\beta_0$. The $n_f^2 \alpha_s^3$ terms in the recent results [arXiv:1611.07535] for the vector form factors are confirmed, and $n_f^{L-1} \alpha_s^L$ terms for higher $L$ are predicted. |
hep-ph/0703126 | Brett D. Altschul | Brett Altschul | Bound on the Photon Charge from the Phase Coherence of Extragalactic
Radiation | 8 pages, new bound added, version appearing in Phys. Rev. Lett | Phys. Rev. Lett. 98, 261801 (2007) | 10.1103/PhysRevLett.98.261801 | IUHET-506 | hep-ph | null | If the photon possessed a nonzero charge, then electromagnetic waves
traveling along different paths would acquire Aharonov-Bohm phase differences.
The fact that such an effect has not hindered interferometric astronomy places
a bound on the photon charge estimated to be at the 10^(-32) e level if all
photons have the same charge and 10^(-46) e if different photons can carry
different charges.
| [
{
"created": "Mon, 12 Mar 2007 16:32:10 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Mar 2007 17:33:48 GMT",
"version": "v2"
},
{
"created": "Fri, 29 Jun 2007 14:30:04 GMT",
"version": "v3"
}
] | 2011-11-10 | [
[
"Altschul",
"Brett",
""
]
] | If the photon possessed a nonzero charge, then electromagnetic waves traveling along different paths would acquire Aharonov-Bohm phase differences. The fact that such an effect has not hindered interferometric astronomy places a bound on the photon charge estimated to be at the 10^(-32) e level if all photons have the same charge and 10^(-46) e if different photons can carry different charges. |
2004.10628 | Nikolaos Mavromatos | Nick E. Mavromatos and Sarben Sarkar | Curvature and thermal corrections in tree-level CPT-Violating
Leptogenesis | 30 pages revtex, one pdf figure incorporated | null | 10.1140/epjc/s10052-020-8109-1 | KCL-PH-TH/2019-96 | hep-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a model for leptogenesis based on spontaneous breaking of Lorentz and CPT
symmetry [1-3], we examine the consistency of using the approximation of
plane-wave solutions for a free spin-(1/2) Dirac (or Majorana) fermion field
propagating in a Friedmann-Lemaitre-Robertson-Walker space time augmented with
a cosmic time-dependent (or, equivalently, a temperature-dependent) Kalb-Ramond
(KR) background. For the range of parameters relevant for leptogenesis, our
analysis fully justifies the use of plane-wave solutions in our study of
leptogenesis with Boltzmann equations; any corrections induced by
space-time-curvature are negligible. We also elaborate further on how the
lepton asymmetry is communicated to the Baryon sector. We demonstrate that the
KR background (KRB) does not contribute to the anomaly equations that determine
the baryon asymmetry a) through an explicit evaluation of a triangle Feynman
graph and b) indirectly, on topological grounds, by identifying the KRB as
torsion (in the effective string-inspired low energy gravitational field
theory).
| [
{
"created": "Wed, 22 Apr 2020 15:14:43 GMT",
"version": "v1"
}
] | 2020-07-15 | [
[
"Mavromatos",
"Nick E.",
""
],
[
"Sarkar",
"Sarben",
""
]
] | In a model for leptogenesis based on spontaneous breaking of Lorentz and CPT symmetry [1-3], we examine the consistency of using the approximation of plane-wave solutions for a free spin-(1/2) Dirac (or Majorana) fermion field propagating in a Friedmann-Lemaitre-Robertson-Walker space time augmented with a cosmic time-dependent (or, equivalently, a temperature-dependent) Kalb-Ramond (KR) background. For the range of parameters relevant for leptogenesis, our analysis fully justifies the use of plane-wave solutions in our study of leptogenesis with Boltzmann equations; any corrections induced by space-time-curvature are negligible. We also elaborate further on how the lepton asymmetry is communicated to the Baryon sector. We demonstrate that the KR background (KRB) does not contribute to the anomaly equations that determine the baryon asymmetry a) through an explicit evaluation of a triangle Feynman graph and b) indirectly, on topological grounds, by identifying the KRB as torsion (in the effective string-inspired low energy gravitational field theory). |
1809.03450 | Michael Trott | Ilaria Brivio and Michael Trott | Examining the neutrino option | 26 pages, 6 figures v2, typo corrections and refs added | null | 10.1007/JHEP02(2019)107 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The neutrino option is a scenario where the electroweak scale, and thereby
the Higgs mass, is generated simultaneously with neutrino masses in the seesaw
model. This occurs via the leading one loop and tree level diagrams matching
the seesaw model onto the Standard Model Effective Field Theory. We advance the
study of this scenario by determining one loop corrections to the leading order
matching results systematically, performing a detailed numerical analysis of
the consistency of this approach with Neutrino data and the Standard Model
particle masses, and by examining the embedding of this scenario into a more
ultraviolet complete model. We find that the neutrino option remains a viable
and intriguing scenario to explain the origin of observed particle masses.
| [
{
"created": "Mon, 10 Sep 2018 16:48:34 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Sep 2018 12:22:38 GMT",
"version": "v2"
}
] | 2019-03-27 | [
[
"Brivio",
"Ilaria",
""
],
[
"Trott",
"Michael",
""
]
] | The neutrino option is a scenario where the electroweak scale, and thereby the Higgs mass, is generated simultaneously with neutrino masses in the seesaw model. This occurs via the leading one loop and tree level diagrams matching the seesaw model onto the Standard Model Effective Field Theory. We advance the study of this scenario by determining one loop corrections to the leading order matching results systematically, performing a detailed numerical analysis of the consistency of this approach with Neutrino data and the Standard Model particle masses, and by examining the embedding of this scenario into a more ultraviolet complete model. We find that the neutrino option remains a viable and intriguing scenario to explain the origin of observed particle masses. |
hep-ph/0206143 | Chuan Hung Chen | Chuan-Hung Chen | Implication of scalar-pseudoscalar mixing on $\epsilon'/\epsilon$ in
SUSY models | 11 pages, 1 figure, one typo corrected, to appear in Phys. Lett. B | Phys.Lett.B541:155-160,2002 | 10.1016/S0370-2693(02)02215-3 | null | hep-ph | null | We study the effects of scalar-pseudoscalar mixing induced from quantum loop
on $\epsilon'/\epsilon$ in SUSY models with $\tan\beta\sim m_{t}/m_{b}$. We
find that even the non-universal soft ${\cal A}^{d}$ term and Yukawa matrix,
$Y^{d}$, are hermitian, the predicted value of $|\epsilon'/\epsilon|$ can be
consistent with the measured results of NA48 and KTeV. And also the EDMs are
compatible with experimental bounds.
| [
{
"created": "Mon, 17 Jun 2002 07:45:06 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Jun 2002 12:00:57 GMT",
"version": "v2"
}
] | 2011-02-03 | [
[
"Chen",
"Chuan-Hung",
""
]
] | We study the effects of scalar-pseudoscalar mixing induced from quantum loop on $\epsilon'/\epsilon$ in SUSY models with $\tan\beta\sim m_{t}/m_{b}$. We find that even the non-universal soft ${\cal A}^{d}$ term and Yukawa matrix, $Y^{d}$, are hermitian, the predicted value of $|\epsilon'/\epsilon|$ can be consistent with the measured results of NA48 and KTeV. And also the EDMs are compatible with experimental bounds. |
1610.04209 | Goran Senjanovic | Goran Senjanovic | Is Left-Right Symmetry the Key? | Added a reference, some phrasing changed (abstract and prologue) | null | 10.1142/S021773231730004X | null | hep-ph hep-ex physics.hist-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In collaboration with Jogesh Pati, Abdus Salam challenged the chiral gauge
nature of the Standard Model by paving the road towards the Left-Right
symmetric electro-weak theory. I describe here the logical and historical
construction of this theory, by emphasising the pioneering and key role it
played for neutrino mass. I show that it is a self-contained and predictive
model with the Higgs origin of Majorana neutrino mass, in complete analogy with
the SM situation regarding charged fermions.
| [
{
"created": "Thu, 13 Oct 2016 19:34:19 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Nov 2016 21:00:44 GMT",
"version": "v2"
}
] | 2017-03-08 | [
[
"Senjanovic",
"Goran",
""
]
] | In collaboration with Jogesh Pati, Abdus Salam challenged the chiral gauge nature of the Standard Model by paving the road towards the Left-Right symmetric electro-weak theory. I describe here the logical and historical construction of this theory, by emphasising the pioneering and key role it played for neutrino mass. I show that it is a self-contained and predictive model with the Higgs origin of Majorana neutrino mass, in complete analogy with the SM situation regarding charged fermions. |
0805.2521 | Antonio De Santis | KLOE collaboration: F. Ambrosino, A. Antonelli, M. Antonelli, F.
Archilli, C. Bacci, P. Beltrame, G. Bencivenni, S. Bertolucci, C. Bini, C.
Bloise, S. Bocchetta, F. Bossi, P. Branchini, R. Caloi, P. Campana, G. Capon,
T. Capussela, F. Ceradini, F. Cesario, S. Chi, G. Chiefari, P. Ciambrone, F.
Crucianelli, E. De Lucia, A. De Santis, P. De Simone, G. De Zorzi, A. Denig,
A. Di Domenico, C. Di Donato, B. Di Micco, A. Doria, M. Dreucci, G. Felici,
A. Ferrari, M. L. Ferrer, S. Fiore, C. Forti, P. Franzini, C. Gatti, P.
Gauzzi, S. Giovannella, E. Gorini, E. Graziani, W. Kluge, V. Kulikov, F.
Lacava, G. Lanfranchi, J. Lee-Franzini, D. Leone, M. Martini, P. Massarotti,
W. Mei, S. Meola, S. Miscetti, M. Moulson, S. M\"uller, F. Murtas, M.
Napolitano, F. Nguyen, M. Palutan, E. Pasqualucci, A. Passeri, V. Patera, F.
Perfetto, M. Primavera, P. Santangelo, G. Saracino, B. Sciascia, A. Sciubba,
A. Sibidanov, T. Spadaro, M. Testa, L. Tortora, P. Valente, G. Venanzoni,
R.Versaci, G. Xu | Recent results from KLOE experiment | Prepared for the XLIIrd Rencontres de Moriond QCD and High Energy
Interaction. 4 pages, 4 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report the newest results from the KLOE experiment on hadronic physics,
such as the parameters of scalars f0 and a0, the eta meson mass measurements
and dynamics, the first observation of the eta -> p+p-e+e- rare decay, and
study of e+e- -> omega p0 cross section around the phi resonance.
| [
{
"created": "Fri, 16 May 2008 13:11:45 GMT",
"version": "v1"
}
] | 2008-05-19 | [
[
"KLOE collaboration",
"",
""
],
[
"Ambrosino",
"F.",
""
],
[
"Antonelli",
"A.",
""
],
[
"Antonelli",
"M.",
""
],
[
"Archilli",
"F.",
""
],
[
"Bacci",
"C.",
""
],
[
"Beltrame",
"P.",
""
],
[
"Bencivenni",
"G.",
""
],
[
"Bertolucci",
"S.",
""
],
[
"Bini",
"C.",
""
],
[
"Bloise",
"C.",
""
],
[
"Bocchetta",
"S.",
""
],
[
"Bossi",
"F.",
""
],
[
"Branchini",
"P.",
""
],
[
"Caloi",
"R.",
""
],
[
"Campana",
"P.",
""
],
[
"Capon",
"G.",
""
],
[
"Capussela",
"T.",
""
],
[
"Ceradini",
"F.",
""
],
[
"Cesario",
"F.",
""
],
[
"Chi",
"S.",
""
],
[
"Chiefari",
"G.",
""
],
[
"Ciambrone",
"P.",
""
],
[
"Crucianelli",
"F.",
""
],
[
"De Lucia",
"E.",
""
],
[
"De Santis",
"A.",
""
],
[
"De Simone",
"P.",
""
],
[
"De Zorzi",
"G.",
""
],
[
"Denig",
"A.",
""
],
[
"Di Domenico",
"A.",
""
],
[
"Di Donato",
"C.",
""
],
[
"Di Micco",
"B.",
""
],
[
"Doria",
"A.",
""
],
[
"Dreucci",
"M.",
""
],
[
"Felici",
"G.",
""
],
[
"Ferrari",
"A.",
""
],
[
"Ferrer",
"M. L.",
""
],
[
"Fiore",
"S.",
""
],
[
"Forti",
"C.",
""
],
[
"Franzini",
"P.",
""
],
[
"Gatti",
"C.",
""
],
[
"Gauzzi",
"P.",
""
],
[
"Giovannella",
"S.",
""
],
[
"Gorini",
"E.",
""
],
[
"Graziani",
"E.",
""
],
[
"Kluge",
"W.",
""
],
[
"Kulikov",
"V.",
""
],
[
"Lacava",
"F.",
""
],
[
"Lanfranchi",
"G.",
""
],
[
"Lee-Franzini",
"J.",
""
],
[
"Leone",
"D.",
""
],
[
"Martini",
"M.",
""
],
[
"Massarotti",
"P.",
""
],
[
"Mei",
"W.",
""
],
[
"Meola",
"S.",
""
],
[
"Miscetti",
"S.",
""
],
[
"Moulson",
"M.",
""
],
[
"Müller",
"S.",
""
],
[
"Murtas",
"F.",
""
],
[
"Napolitano",
"M.",
""
],
[
"Nguyen",
"F.",
""
],
[
"Palutan",
"M.",
""
],
[
"Pasqualucci",
"E.",
""
],
[
"Passeri",
"A.",
""
],
[
"Patera",
"V.",
""
],
[
"Perfetto",
"F.",
""
],
[
"Primavera",
"M.",
""
],
[
"Santangelo",
"P.",
""
],
[
"Saracino",
"G.",
""
],
[
"Sciascia",
"B.",
""
],
[
"Sciubba",
"A.",
""
],
[
"Sibidanov",
"A.",
""
],
[
"Spadaro",
"T.",
""
],
[
"Testa",
"M.",
""
],
[
"Tortora",
"L.",
""
],
[
"Valente",
"P.",
""
],
[
"Venanzoni",
"G.",
""
],
[
"Versaci",
"R.",
""
],
[
"Xu",
"G.",
""
]
] | We report the newest results from the KLOE experiment on hadronic physics, such as the parameters of scalars f0 and a0, the eta meson mass measurements and dynamics, the first observation of the eta -> p+p-e+e- rare decay, and study of e+e- -> omega p0 cross section around the phi resonance. |
hep-ph/0111013 | P. Q. Hung | P. Q. Hung and M. Seco | Almost Pure Phase Mass Matrices from Six Dimensions | 36 pages, REVTEX4, minor changes | Nucl.Phys. B653 (2003) 123 | 10.1016/S0550-3213(03)00007-5 | INPP-UVA-01-15 | hep-ph | null | A model of quark masses and mixing angles is constructed within the framework
of two large extra compact dimensions. A ``democratic'' pure phase mass matrix
arises in a rather interesting way. This type of mass matrix has often been
used as a phenomenologically viable ansatz, albeit one which had very little
dynamical justification. It turns out that the idea of Large Extra Dimensions
provides a fresh look at this interesting phenomenological ansatz as presented
in this paper. Some possible interesting connections to the strong CP problem
will also be presented.
| [
{
"created": "Thu, 1 Nov 2001 16:37:19 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Nov 2001 15:07:17 GMT",
"version": "v2"
},
{
"created": "Fri, 9 Nov 2001 16:20:18 GMT",
"version": "v3"
},
{
"created": "Wed, 14 Nov 2001 20:42:49 GMT",
"version": "v4"
},
{
"created": "Fri, 16 Nov 2001 14:53:27 GMT",
"version": "v5"
},
{
"created": "Thu, 20 Dec 2001 15:46:16 GMT",
"version": "v6"
},
{
"created": "Wed, 29 May 2002 03:24:14 GMT",
"version": "v7"
},
{
"created": "Wed, 9 Oct 2002 16:02:32 GMT",
"version": "v8"
}
] | 2009-11-07 | [
[
"Hung",
"P. Q.",
""
],
[
"Seco",
"M.",
""
]
] | A model of quark masses and mixing angles is constructed within the framework of two large extra compact dimensions. A ``democratic'' pure phase mass matrix arises in a rather interesting way. This type of mass matrix has often been used as a phenomenologically viable ansatz, albeit one which had very little dynamical justification. It turns out that the idea of Large Extra Dimensions provides a fresh look at this interesting phenomenological ansatz as presented in this paper. Some possible interesting connections to the strong CP problem will also be presented. |
1211.5505 | Romulo Silva | L. M. Abreu, E. S. Nery and R. Rodrigues da Silva | Exotic Behavior of Heavy-Flavored Meson Matter | 13 pages, 11 figures | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we study the thermodynamic behavior of heavy-flavored meson
matter in the framework of $(\sigma,\omega)$-meson-exchange model in
relativistic mean field theory. We find a decreasing of the effective masses of
$D$ and $B$ mesons as the temperature increases. By using the effective mass
and maximum value of dissociation temperatures available from lattice QCD, the
masses of the bound states $D \bar{D}$ and $B \bar{B}$ are estimated in 2 MeV
for both molecules. For the $B$-meson matter, the pressure presents an exotic
behavior, being negative for temperatures above 6.6 times the deconfinement
transition temperature $T_c$. In addition, the ratio of pressure to energy
density is similar to the value predicted for systems that behave as dark
energy matter.
| [
{
"created": "Fri, 23 Nov 2012 13:48:23 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Dec 2012 09:34:41 GMT",
"version": "v2"
}
] | 2012-12-06 | [
[
"Abreu",
"L. M.",
""
],
[
"Nery",
"E. S.",
""
],
[
"da Silva",
"R. Rodrigues",
""
]
] | In this work, we study the thermodynamic behavior of heavy-flavored meson matter in the framework of $(\sigma,\omega)$-meson-exchange model in relativistic mean field theory. We find a decreasing of the effective masses of $D$ and $B$ mesons as the temperature increases. By using the effective mass and maximum value of dissociation temperatures available from lattice QCD, the masses of the bound states $D \bar{D}$ and $B \bar{B}$ are estimated in 2 MeV for both molecules. For the $B$-meson matter, the pressure presents an exotic behavior, being negative for temperatures above 6.6 times the deconfinement transition temperature $T_c$. In addition, the ratio of pressure to energy density is similar to the value predicted for systems that behave as dark energy matter. |
hep-ph/0611152 | Kazuharu Bamba | Kazuharu Bamba | Baryon asymmetry from hypermagnetic helicity in dilaton hypercharge
electromagnetism | 16 pages, 2 figures, a reference added, typos corrected | Phys.Rev.D74:123504,2006 | 10.1103/PhysRevD.74.123504 | YITP-06-47 | hep-ph astro-ph hep-th | null | The generation of the baryon asymmetry of the Universe (BAU) from the
hypermagnetic helicity, the physical interpretation of which is given in terms
of hypermagnetic knots, is studied in inflationary cosmology, taking into
account the breaking of the conformal invariance of hypercharge electromagnetic
fields through both a coupling with the dilaton and that with a pseudoscalar
field. It is shown that if the electroweak phase transition (EWPT) is strongly
first order and the present amplitude of the generated magnetic fields on the
horizon scale is sufficiently large, a baryon asymmetry with a sufficient
magnitude to account for the observed baryon to entropy ratio can be generated.
| [
{
"created": "Sat, 11 Nov 2006 04:42:30 GMT",
"version": "v1"
},
{
"created": "Sat, 23 Dec 2006 01:03:58 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Bamba",
"Kazuharu",
""
]
] | The generation of the baryon asymmetry of the Universe (BAU) from the hypermagnetic helicity, the physical interpretation of which is given in terms of hypermagnetic knots, is studied in inflationary cosmology, taking into account the breaking of the conformal invariance of hypercharge electromagnetic fields through both a coupling with the dilaton and that with a pseudoscalar field. It is shown that if the electroweak phase transition (EWPT) is strongly first order and the present amplitude of the generated magnetic fields on the horizon scale is sufficiently large, a baryon asymmetry with a sufficient magnitude to account for the observed baryon to entropy ratio can be generated. |
1302.0052 | Lei Guo | Liu Wen, Zhang Ren-You, Guo Lei, Ma Wen-Gan and Chen Liang-Wen | Precise QCD predictions on $W_HZ_H$ production in the littlest Higgs
Model with $T$ parity at the LHC | 27 pages, 14 figures and 3 tables, accepted for publication in Phys.
Rev. D | Phys. Rev. D 87, 034034 (2013) | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the effects of the littlest Higgs model with $T$ parity up to
the QCD next-to-leading order (NLO) on the $W_H^{\pm} Z_H$ productions at the
CERN Large Hadron Collider (LHC), and discuss the kinematic distributions of
final decay products and the theoretical dependence of the cross section on the
factorization/renormalization scale. We find the QCD NLO corrections reduce the
scale uncertainty of the leading order cross section in case of $\mu_F=\mu_R$.
By adopting the PROSPINO subtraction scheme (scheme (II)) in analysing the QCD
NLO contributions, we can obtain the numerical results which keep the
convergence of the perturbative QCD description. Our results by adopting scheme
(II) at the $14 {\rm TeV}$ ($8 {\rm TeV}$) LHC show that the $K$-factor for the
$W_H^+ Z_H$ production varies in the range of $1.01 \sim 1.10$ ($1.00 \sim
1.08$), while the $K$-factor for the $W_H^- Z_H$ production varies in the range
of $1.11 \sim 1.13$ ($1.11 \sim 1.12$), when the global symmetry breaking scale
$f$ goes from $400 {\rm GeV}$ to $1.5 {\rm TeV}$ ($1 {\rm TeV}$).
| [
{
"created": "Fri, 1 Feb 2013 01:28:33 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Feb 2013 06:37:34 GMT",
"version": "v2"
}
] | 2013-04-03 | [
[
"Wen",
"Liu",
""
],
[
"Ren-You",
"Zhang",
""
],
[
"Lei",
"Guo",
""
],
[
"Wen-Gan",
"Ma",
""
],
[
"Liang-Wen",
"Chen",
""
]
] | We investigate the effects of the littlest Higgs model with $T$ parity up to the QCD next-to-leading order (NLO) on the $W_H^{\pm} Z_H$ productions at the CERN Large Hadron Collider (LHC), and discuss the kinematic distributions of final decay products and the theoretical dependence of the cross section on the factorization/renormalization scale. We find the QCD NLO corrections reduce the scale uncertainty of the leading order cross section in case of $\mu_F=\mu_R$. By adopting the PROSPINO subtraction scheme (scheme (II)) in analysing the QCD NLO contributions, we can obtain the numerical results which keep the convergence of the perturbative QCD description. Our results by adopting scheme (II) at the $14 {\rm TeV}$ ($8 {\rm TeV}$) LHC show that the $K$-factor for the $W_H^+ Z_H$ production varies in the range of $1.01 \sim 1.10$ ($1.00 \sim 1.08$), while the $K$-factor for the $W_H^- Z_H$ production varies in the range of $1.11 \sim 1.13$ ($1.11 \sim 1.12$), when the global symmetry breaking scale $f$ goes from $400 {\rm GeV}$ to $1.5 {\rm TeV}$ ($1 {\rm TeV}$). |
hep-ph/9802298 | Dmitri Diakonov | Dmitri Diakonov (NORDITA and St.Petersburg NPI) | Chiral Quark-Soliton Model | 44 pages, 4 figures. Lectures at Advanced Summer School on
Non-Perturbative Field Theory, Peniscola, Spain, June 2-6 1997. To be
published by World Scientific in School proceedings | null | null | NORDITA-98/14 | hep-ph | null | The Chiral Quark-Soliton Model of nucleons is based on two ideas: 1) the
major role of spontaneous chiral symmetry breaking in hadron physics and 2) the
relevance of the large number of colours limit for the real world. In these
lectures I review the theoretical foundations of the model, the physics
involved, and some of applications.
Contents:
1. How do we know chiral symmetry is spontaneously broken?
2. Low-energy limit of QCD from instantons
2.1. Some of the results
2.2. Instanton-induced interactions
2.3. Bosonization
2.4. Chiral lagrangian
3. Properties of the chiral lagrangian
3.1. Derivative expansion and interpolation formula
3.2. The Wess-Zumino term and the baryon number
4. The nucleon
4.1. Physical motivations
4.2. Nucleon mass: a functional of the pion field
4.3. Nucleon profile
4.4. Quantum numbers of baryons
4.5. Some applications
4.6. Nucleon structure functions
5. Conclusions
| [
{
"created": "Wed, 11 Feb 1998 09:06:02 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Diakonov",
"Dmitri",
"",
"NORDITA and St.Petersburg NPI"
]
] | The Chiral Quark-Soliton Model of nucleons is based on two ideas: 1) the major role of spontaneous chiral symmetry breaking in hadron physics and 2) the relevance of the large number of colours limit for the real world. In these lectures I review the theoretical foundations of the model, the physics involved, and some of applications. Contents: 1. How do we know chiral symmetry is spontaneously broken? 2. Low-energy limit of QCD from instantons 2.1. Some of the results 2.2. Instanton-induced interactions 2.3. Bosonization 2.4. Chiral lagrangian 3. Properties of the chiral lagrangian 3.1. Derivative expansion and interpolation formula 3.2. The Wess-Zumino term and the baryon number 4. The nucleon 4.1. Physical motivations 4.2. Nucleon mass: a functional of the pion field 4.3. Nucleon profile 4.4. Quantum numbers of baryons 4.5. Some applications 4.6. Nucleon structure functions 5. Conclusions |
hep-ph/0101266 | Apostolos Pilaftsis | C. Panagiotakopoulos and A. Pilaftsis | Light Charged Higgs Boson and Supersymmetry | 12 pages, LaTeX file, one reference added | Phys.Lett. B505 (2001) 184-190 | 10.1016/S0370-2693(01)00347-1 | WUE-ITP-2001-004 | hep-ph hep-ex | null | A possible discovery of a relatively light charged Higgs boson H^+ in near
future experiments, with a mass M_{H+} ~< 110 GeV, together with the present
LEP2 direct limits on the chargino and neutral Higgs sectors, would disfavour
the minimal supersymmetric standard model as well as its frequently discussed
next-to-minimal supersymmetric extension. We show that a supersymmetric origin
can naturally be ascribed to the existence of such a light charged Higgs scalar
within the context of the recently introduced minimal nonminimal supersymmetric
standard model.
| [
{
"created": "Tue, 23 Jan 2001 21:11:11 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Feb 2001 12:08:58 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Feb 2001 18:21:27 GMT",
"version": "v3"
}
] | 2009-11-07 | [
[
"Panagiotakopoulos",
"C.",
""
],
[
"Pilaftsis",
"A.",
""
]
] | A possible discovery of a relatively light charged Higgs boson H^+ in near future experiments, with a mass M_{H+} ~< 110 GeV, together with the present LEP2 direct limits on the chargino and neutral Higgs sectors, would disfavour the minimal supersymmetric standard model as well as its frequently discussed next-to-minimal supersymmetric extension. We show that a supersymmetric origin can naturally be ascribed to the existence of such a light charged Higgs scalar within the context of the recently introduced minimal nonminimal supersymmetric standard model. |
hep-ph/0202172 | Baldicchi Massimiliano | M. Baldicchi, G.M. Prosperi | Infrared behavior of the running coupling constant and bound states in
QCD | 12 pages, 1 figure | Phys.Rev. D66 (2002) 074008 | 10.1103/PhysRevD.66.074008 | null | hep-ph | null | The perturbative expression of the running strong coupling constant
\alpha_{\rm s}(Q^{2}) has an unphysical singularity for Q^{2} =
\Lambda^{2}_{\rm QCD}. Various modification have been proposed for the infrared
region. The effect of some of such proposals on the quark-antiquark spectrum is
tested on a Bethe-Salpeter (second order) formalism which was successfully
applied in previous papers to an overall evaluation of the spectrum in the
light-light, light-heavy and heavy-heavy sectors (the only serious discrepancy
with data being for the light pseudoscalar meson masses). In this paper only
the {\rm c} \bar{\rm c}, {\rm b} \bar{\rm b} and {\rm q} \bar{\rm q} (q = u or
d) cases are considered and fine structure is neglected. It is found that in
the {\rm b} \bar{\rm b} and {\rm c} \bar{\rm c} cases the results are little
sensitive to the specific choice. In the light-light case the Dokshitzer et al.
prescription is again essentially equivalent to the truncation prescription
used in the previous calculation and it is consistent with the same a priori
fixing of the quark light masses on the typical current values m_{\rm u} =
m_{\rm d} = 10 MeV (only the pion mass resulting completely out of scale of
about 500 MeV). With the Shirkov-Solovtsov prescription, on the contrary, a
reasonable agreement with the data is obtained only at the price of using a
phenomenological momentum dependent effective mass for the quark. The use of
such an effective mass should amount to a correction of the free quark
propagator. It is remarkable that this has also the effect of bringing the pion
mass in the correct range.
| [
{
"created": "Mon, 18 Feb 2002 14:07:18 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Baldicchi",
"M.",
""
],
[
"Prosperi",
"G. M.",
""
]
] | The perturbative expression of the running strong coupling constant \alpha_{\rm s}(Q^{2}) has an unphysical singularity for Q^{2} = \Lambda^{2}_{\rm QCD}. Various modification have been proposed for the infrared region. The effect of some of such proposals on the quark-antiquark spectrum is tested on a Bethe-Salpeter (second order) formalism which was successfully applied in previous papers to an overall evaluation of the spectrum in the light-light, light-heavy and heavy-heavy sectors (the only serious discrepancy with data being for the light pseudoscalar meson masses). In this paper only the {\rm c} \bar{\rm c}, {\rm b} \bar{\rm b} and {\rm q} \bar{\rm q} (q = u or d) cases are considered and fine structure is neglected. It is found that in the {\rm b} \bar{\rm b} and {\rm c} \bar{\rm c} cases the results are little sensitive to the specific choice. In the light-light case the Dokshitzer et al. prescription is again essentially equivalent to the truncation prescription used in the previous calculation and it is consistent with the same a priori fixing of the quark light masses on the typical current values m_{\rm u} = m_{\rm d} = 10 MeV (only the pion mass resulting completely out of scale of about 500 MeV). With the Shirkov-Solovtsov prescription, on the contrary, a reasonable agreement with the data is obtained only at the price of using a phenomenological momentum dependent effective mass for the quark. The use of such an effective mass should amount to a correction of the free quark propagator. It is remarkable that this has also the effect of bringing the pion mass in the correct range. |
2311.18692 | Felix Tellander | Johan Rathsman and Felix Tellander | UV-complete Gauged Anomaly-free U(1) Froggatt-Nielsen Model | 13 pages, 2 figures | null | null | DESY 23-191 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the possibility of understanding all fermion masses and
mixings within a gauged Froggatt-Nielsen framework. Continuing the work from
[J. Rathsman and F. Tellander, Phys. Rev. D \textbf{100}, 055032 (2019)] we
especially focus on a UV completion of this type of models. Independent of the
UV completion, we construct an anomaly-free two Higgs doublet model with a
gauged $U(1)_F$ flavor symmetry and three right-handed neutrinos explaining all
observed masses and mixings in the fermion sector. We then investigate two
different UV completions: one through fermions and one through scalars. The
fermion completion has low lying Landau poles in the gague couplings while the
scalar completion is viable up to the gravity scale.
| [
{
"created": "Thu, 30 Nov 2023 16:38:32 GMT",
"version": "v1"
}
] | 2023-12-01 | [
[
"Rathsman",
"Johan",
""
],
[
"Tellander",
"Felix",
""
]
] | We investigate the possibility of understanding all fermion masses and mixings within a gauged Froggatt-Nielsen framework. Continuing the work from [J. Rathsman and F. Tellander, Phys. Rev. D \textbf{100}, 055032 (2019)] we especially focus on a UV completion of this type of models. Independent of the UV completion, we construct an anomaly-free two Higgs doublet model with a gauged $U(1)_F$ flavor symmetry and three right-handed neutrinos explaining all observed masses and mixings in the fermion sector. We then investigate two different UV completions: one through fermions and one through scalars. The fermion completion has low lying Landau poles in the gague couplings while the scalar completion is viable up to the gravity scale. |
hep-ph/0106282 | Jon Urrestilla | Jon Urrestilla, Ana Achucarro, Julian Borrill, Andrew R. Liddle | The evolution and persistence of dumbbells | 13 pages, 5 figures, uses JHEP3.cls. Colour images and movies can be
found at http://www.nersc.gov/~borrill/defects/electroweak.html . Replaced
with the version to appear in JHEP | JHEP 0208:033,2002 | 10.1088/1126-6708/2002/08/033 | null | hep-ph hep-th | null | We use large-scale numerical simulations to study the formation and evolution
of non-topological defects in a generalized electroweak phase transition
described by the Glashow-Salam-Weinberg model without fermions. Such defects
include dumbbells, comprising a pair of monopoles joined by a segment of
electroweak string. These exhibit complex dynamics, with some shrinking under
the string tension and others growing due to the monopole-antimonopole
attractions between near neighbours. We estimate the range of parameters where
the network of dumbbells persists, and show that this region is narrower than
the region within which infinite straight electroweak strings are
perturbatively stable.
| [
{
"created": "Mon, 25 Jun 2001 23:51:10 GMT",
"version": "v1"
},
{
"created": "Tue, 7 May 2002 11:55:11 GMT",
"version": "v2"
},
{
"created": "Tue, 3 Sep 2002 10:19:54 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Urrestilla",
"Jon",
""
],
[
"Achucarro",
"Ana",
""
],
[
"Borrill",
"Julian",
""
],
[
"Liddle",
"Andrew R.",
""
]
] | We use large-scale numerical simulations to study the formation and evolution of non-topological defects in a generalized electroweak phase transition described by the Glashow-Salam-Weinberg model without fermions. Such defects include dumbbells, comprising a pair of monopoles joined by a segment of electroweak string. These exhibit complex dynamics, with some shrinking under the string tension and others growing due to the monopole-antimonopole attractions between near neighbours. We estimate the range of parameters where the network of dumbbells persists, and show that this region is narrower than the region within which infinite straight electroweak strings are perturbatively stable. |
hep-ph/0309183 | Marc Sher | Marc Sher and Ismail Turan (Coll. of William and Mary) | Mu + N --> Tau + N at a Muon or Neutrino Factory | Paragraph on theoretical models added. Version to be published in
Phys. Rev. D | Phys.Rev. D69 (2004) 017302 | 10.1103/PhysRevD.69.017302 | WM-03-107 | hep-ph | null | The experimental discovery of large nu_mu-nu_tau mixing indicates that
analogous mixing in the charged lepton sector could be substantial. We consider
the possibility that if a high intensity muon beam, perhaps at the early stages
of a muon or neutrino factory, strikes a nuclear target, then conversion of
some of the muons into tau leptons could occur (similar to the conversion of
muons to electrons at MECO). Using current experimental limits on rare tau
decays to bound the size of the relevant operators, we find that a 50 GeV muon
beam, with 10^20 muons on target per year, could yield as many as 10^7 mu + N
--> tau + N events per year. Backgrounds could be substantial, and we comment
on the possibility of detection of this process.
| [
{
"created": "Tue, 16 Sep 2003 14:17:15 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Sep 2003 16:27:02 GMT",
"version": "v2"
},
{
"created": "Tue, 18 Nov 2003 18:51:57 GMT",
"version": "v3"
}
] | 2009-11-10 | [
[
"Sher",
"Marc",
"",
"Coll. of William and Mary"
],
[
"Turan",
"Ismail",
"",
"Coll. of William and Mary"
]
] | The experimental discovery of large nu_mu-nu_tau mixing indicates that analogous mixing in the charged lepton sector could be substantial. We consider the possibility that if a high intensity muon beam, perhaps at the early stages of a muon or neutrino factory, strikes a nuclear target, then conversion of some of the muons into tau leptons could occur (similar to the conversion of muons to electrons at MECO). Using current experimental limits on rare tau decays to bound the size of the relevant operators, we find that a 50 GeV muon beam, with 10^20 muons on target per year, could yield as many as 10^7 mu + N --> tau + N events per year. Backgrounds could be substantial, and we comment on the possibility of detection of this process. |
hep-ph/0507060 | Jean-Rene Cudell | J.P. Lansberg, J.R. Cudell and Yu. L. Kalinovsky | New contributions to heavy-quarkonium production | 16 pages, 12 figures, LaTeX. References updated, typo fixed,
discussion of the scale dependence, minor corrections to the text | Phys.Lett. B633 (2006) 301-308 | 10.1016/j.physletb.2005.11.073 | null | hep-ph | null | We reconsider quarkonium production in a field-theoretical setting and we
show that the lowest-order mechanism for heavy-quarkonium production receives
in general contributions from two different cuts. The first one corresponds to
the usual colour-singlet mechanism. The second one has not been considered so
far. We treat it in a gauge-invariant manner, and introduce new 4-point
vertices, suggestive of the colour-octet mechanism. These new objects enable us
to go beyond the static approximation. We show that the contribution of the new
cut can be as large as the usual colour-singlet mechanism at high transverse
momentum for J/psi. In the psi' case, theoretical uncertainties are shown to be
large and agreement with data is possible.
| [
{
"created": "Tue, 5 Jul 2005 15:42:59 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Sep 2005 15:47:10 GMT",
"version": "v2"
},
{
"created": "Mon, 21 Nov 2005 15:40:39 GMT",
"version": "v3"
}
] | 2009-11-11 | [
[
"Lansberg",
"J. P.",
""
],
[
"Cudell",
"J. R.",
""
],
[
"Kalinovsky",
"Yu. L.",
""
]
] | We reconsider quarkonium production in a field-theoretical setting and we show that the lowest-order mechanism for heavy-quarkonium production receives in general contributions from two different cuts. The first one corresponds to the usual colour-singlet mechanism. The second one has not been considered so far. We treat it in a gauge-invariant manner, and introduce new 4-point vertices, suggestive of the colour-octet mechanism. These new objects enable us to go beyond the static approximation. We show that the contribution of the new cut can be as large as the usual colour-singlet mechanism at high transverse momentum for J/psi. In the psi' case, theoretical uncertainties are shown to be large and agreement with data is possible. |
0801.3666 | Ben Allanach | B.C. Allanach, J.P. Conlon and C.G. Lester | Measuring Smuon-Selectron Mass Splitting at the LHC and Patterns of
Supersymmetry Breaking | 5 pages, 5 figs. v2 has minor changes: to appear in PRD Rapid Comm | Phys.Rev.D77:076006,2008 | 10.1103/PhysRevD.77.076006 | null | hep-ph hep-ex | null | With sufficient data, Large Hadron Collider (LHC) experiments can constrain
the selectron-smuon mass splitting through differences in the di-electron and
di-muon edges from supersymmetry (SUSY) cascade decays. We study the
sensitivity of the LHC to this mass splitting, which within mSUGRA may be
constrained down to O(10^{-4}) for 30 fb^{-1} of integrated luminosity. Over
substantial regions of SUSY breaking parameter space the fractional edge
splitting can be significantly enhanced over the fractional mass splitting.
Within models where the selectron and smuon are constrained to be universal at
a high scale, edge splittings up to a few percent may be induced by
renormalisation group effects and may be significantly discriminated from zero.
The edge splitting provides important information about high-scale SUSY
breaking terms and should be included in any fit of LHC data to high-scale
models.
| [
{
"created": "Wed, 23 Jan 2008 21:00:05 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Mar 2008 16:45:24 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Allanach",
"B. C.",
""
],
[
"Conlon",
"J. P.",
""
],
[
"Lester",
"C. G.",
""
]
] | With sufficient data, Large Hadron Collider (LHC) experiments can constrain the selectron-smuon mass splitting through differences in the di-electron and di-muon edges from supersymmetry (SUSY) cascade decays. We study the sensitivity of the LHC to this mass splitting, which within mSUGRA may be constrained down to O(10^{-4}) for 30 fb^{-1} of integrated luminosity. Over substantial regions of SUSY breaking parameter space the fractional edge splitting can be significantly enhanced over the fractional mass splitting. Within models where the selectron and smuon are constrained to be universal at a high scale, edge splittings up to a few percent may be induced by renormalisation group effects and may be significantly discriminated from zero. The edge splitting provides important information about high-scale SUSY breaking terms and should be included in any fit of LHC data to high-scale models. |
1411.4749 | Walaa Eshraim | Walaa I. Eshraim | Vacuum properties of open charmed mesons in a chiral symmetric model | 5 pages, 2 tables. Contribution to the workshop for young scientists
with research interests focused on physics at FAIR, 22-27 September 2014,
Vietri sul Mare, Italy. arXiv admin note: text overlap with arXiv:1411.2218 | null | 10.1088/1742-6596/599/1/012009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a $U(4)_R \times U(4)_L$ chirally symmetric model, which in
addition to scalar and pseudoscalar mesons also includes vector and
axial-vector mesons. A part from the three new parameters pertaining to the
charm degree of freedom, the parameters of the model are fixed from the $N_f=3$
flavor sector. We calculate open charmed meson masses and the weak decay
constants of nonstrange open charm $D$ and strange open charm $D_S$. We also
evaluate the (OZI-dominant) strong decays of open charmed mesons. The results
are turn out to be in quantitative agreement with experimental data.
| [
{
"created": "Tue, 18 Nov 2014 07:10:35 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Nov 2014 12:41:05 GMT",
"version": "v2"
}
] | 2015-06-23 | [
[
"Eshraim",
"Walaa I.",
""
]
] | We present a $U(4)_R \times U(4)_L$ chirally symmetric model, which in addition to scalar and pseudoscalar mesons also includes vector and axial-vector mesons. A part from the three new parameters pertaining to the charm degree of freedom, the parameters of the model are fixed from the $N_f=3$ flavor sector. We calculate open charmed meson masses and the weak decay constants of nonstrange open charm $D$ and strange open charm $D_S$. We also evaluate the (OZI-dominant) strong decays of open charmed mesons. The results are turn out to be in quantitative agreement with experimental data. |
0808.0707 | Paride Paradisi | W. Altmannshofer, A.J. Buras and P. Paradisi | Low Energy Probes of CP Violation in a Flavor Blind MSSM | 7 pages, 8 figures. v3: Eq.(6) corrected, definition (3) changed,
minor changes in the corresponding plots, conclusions unchanged | Phys.Lett.B669:239-245,2008 | 10.1016/j.physletb.2008.09.057 | TUM-HEP-694/08 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the low energy implications of a flavor blind supersymmetric
scenario (where the CKM matrix is the only source of flavor violation) in the
presence of new CP violating but flavor conserving phases in the soft sector.
We find that the best probes of this rather restricted scenario are i) the
electric dipole moments (EDMs) of the electron (d_e) and the neutron (d_n) and
ii) flavor changing and CP violating processes in B systems, like the CP
asymmetries in b->s gamma and B->phi(eta^')K_S, i.e. A_CP(b->s gamma) and
S_phi(eta^')K_S, respectively. The non-standard values for S_phi(eta^')K_S,
measured at the B factories, can find a natural explanation within our scenario
and this would unambiguously imply i) positive and often large (non-standard)
values for A_CP(b->s gamma) and ii) a lower bound for the electron and neutron
EDMs at the level of d_e,n > 10^-28 e cm. Moreover, we predict positive New
Physics (NP) contributions to epsilon_K which could be welcomed in view of the
recently lowered Standard Model value for epsilon_K. Interestingly, an
explanation for the non-standard values for S_phi(eta^')K_S can also naturally
lead to an explanation for the anomaly of the muon anomalous magnetic moment.
Finally, we outline the role and the interplay of the direct NP searches at the
LHC with the indirect searches performed by low energy flavor physics
observables.
| [
{
"created": "Tue, 5 Aug 2008 19:48:23 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Sep 2008 15:45:02 GMT",
"version": "v2"
},
{
"created": "Fri, 30 Oct 2009 16:31:52 GMT",
"version": "v3"
}
] | 2010-05-12 | [
[
"Altmannshofer",
"W.",
""
],
[
"Buras",
"A. J.",
""
],
[
"Paradisi",
"P.",
""
]
] | We analyze the low energy implications of a flavor blind supersymmetric scenario (where the CKM matrix is the only source of flavor violation) in the presence of new CP violating but flavor conserving phases in the soft sector. We find that the best probes of this rather restricted scenario are i) the electric dipole moments (EDMs) of the electron (d_e) and the neutron (d_n) and ii) flavor changing and CP violating processes in B systems, like the CP asymmetries in b->s gamma and B->phi(eta^')K_S, i.e. A_CP(b->s gamma) and S_phi(eta^')K_S, respectively. The non-standard values for S_phi(eta^')K_S, measured at the B factories, can find a natural explanation within our scenario and this would unambiguously imply i) positive and often large (non-standard) values for A_CP(b->s gamma) and ii) a lower bound for the electron and neutron EDMs at the level of d_e,n > 10^-28 e cm. Moreover, we predict positive New Physics (NP) contributions to epsilon_K which could be welcomed in view of the recently lowered Standard Model value for epsilon_K. Interestingly, an explanation for the non-standard values for S_phi(eta^')K_S can also naturally lead to an explanation for the anomaly of the muon anomalous magnetic moment. Finally, we outline the role and the interplay of the direct NP searches at the LHC with the indirect searches performed by low energy flavor physics observables. |
0806.2094 | Elliot Leader | Elliot Leader, Alexander Sidorov and Dimiter Stamenov | Gluon polarization and higher twist effects | 4 pages, 7 figures. Proceedings of DIS2008 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the influence of the recent CLAS and COMPASS experiments on our
understanding of higher twist (HT) effects and the gluon polarization, and show
how EIC could discriminate between negative and positive gluon polarizations.
We comment on the issue of HT and the recent DSSV analysis.
| [
{
"created": "Thu, 12 Jun 2008 15:08:05 GMT",
"version": "v1"
}
] | 2008-06-13 | [
[
"Leader",
"Elliot",
""
],
[
"Sidorov",
"Alexander",
""
],
[
"Stamenov",
"Dimiter",
""
]
] | We examine the influence of the recent CLAS and COMPASS experiments on our understanding of higher twist (HT) effects and the gluon polarization, and show how EIC could discriminate between negative and positive gluon polarizations. We comment on the issue of HT and the recent DSSV analysis. |
1804.06072 | Shayan Ghosh | B. Ananthanarayan, Johan Bijnens, Samuel Friot, Shayan Ghosh | Analytic representations of $m_K$, $F_K$, $m_\eta$ and $F_\eta$ in two
loop $SU(3)$ chiral perturbation theory | 50 pages, 4 figures; ancillary Mathematica file | Phys. Rev. D 97, 114004 (2018) | 10.1103/PhysRevD.97.114004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we consider expressions for the masses and decay constants of
the pseudoscalar mesons in $SU(3)$ chiral perturbation theory. These involve
sunset diagrams and their derivatives evaluated at $p^2=m_P^2$ ($P=\pi, K,
\eta$). Recalling that there are three mass scales in this theory, $m_\pi$,
$m_K$ and $m_\eta$, there are instances when the finite part of the sunset
diagrams do not admit an expression in terms of elementary functions, and have
therefore been evaluated numerically in the past. In a recent publication, an
expansion in the external momentum was performed to obtain approximate analytic
expressions for $m_\pi$ and $F_\pi$, the pion mass and decay constant. We
provide fully analytic exact expressions for $m_K$ and $m_\eta$, the kaon and
eta masses, and $F_K$ and $F_\eta$, the kaon and eta decay constants. These
expressions, calculated using Mellin-Barnes methods, are in the form of double
series in terms of two mass ratios. A numerical analysis of the results to
evaluate the relative size of contributions coming from loops, chiral
logarithms as well as phenomenological low-energy constants is presented. We
also present a set of approximate analytic expressions for $m_K$, $F_K$,
$m_\eta$ and $F_\eta$ that facilitate comparisons with lattice results.
Finally, we show how exact analytic expressions for $m_\pi$ and $F_\pi$ may be
obtained, the latter having been used in conjunction with the results for $F_K$
to produce a recently published analytic representation of $F_K/F_\pi$.
| [
{
"created": "Tue, 17 Apr 2018 06:55:19 GMT",
"version": "v1"
}
] | 2018-06-13 | [
[
"Ananthanarayan",
"B.",
""
],
[
"Bijnens",
"Johan",
""
],
[
"Friot",
"Samuel",
""
],
[
"Ghosh",
"Shayan",
""
]
] | In this work, we consider expressions for the masses and decay constants of the pseudoscalar mesons in $SU(3)$ chiral perturbation theory. These involve sunset diagrams and their derivatives evaluated at $p^2=m_P^2$ ($P=\pi, K, \eta$). Recalling that there are three mass scales in this theory, $m_\pi$, $m_K$ and $m_\eta$, there are instances when the finite part of the sunset diagrams do not admit an expression in terms of elementary functions, and have therefore been evaluated numerically in the past. In a recent publication, an expansion in the external momentum was performed to obtain approximate analytic expressions for $m_\pi$ and $F_\pi$, the pion mass and decay constant. We provide fully analytic exact expressions for $m_K$ and $m_\eta$, the kaon and eta masses, and $F_K$ and $F_\eta$, the kaon and eta decay constants. These expressions, calculated using Mellin-Barnes methods, are in the form of double series in terms of two mass ratios. A numerical analysis of the results to evaluate the relative size of contributions coming from loops, chiral logarithms as well as phenomenological low-energy constants is presented. We also present a set of approximate analytic expressions for $m_K$, $F_K$, $m_\eta$ and $F_\eta$ that facilitate comparisons with lattice results. Finally, we show how exact analytic expressions for $m_\pi$ and $F_\pi$ may be obtained, the latter having been used in conjunction with the results for $F_K$ to produce a recently published analytic representation of $F_K/F_\pi$. |
hep-ph/9906221 | Hrachia M. Asatrian | H. H. Asatryan, H. M. Asatrian (Yerevan Physics Institute) | CP Asymmetry for Inclusive Decay $B \to X_d + \gamma$ in the Minimal
Supersymmetric Standard Model | 15 pages, uses axodraw.sty | Phys.Lett. B460 (1999) 148-156 | 10.1016/S0370-2693(99)00778-9 | YERPHI-1534(8)-99 | hep-ph | null | We study the inclusive rare decay $B\to X_d+\gamma$ in the supergravity
inspired Minimal Supersymmetric Standard Model and compute the CP-asymmetry in
the decay rates. We show that there exist two phenomenologically acceptable
sets of SUSY parameters: for one set the CP-asymmetry has the same (positive)
sign as in the Standard Model and lies in the range (5-45)% while for the other
set it is negative with values within -(2-21)%.
| [
{
"created": "Wed, 2 Jun 1999 17:57:24 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Aug 1999 11:09:55 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Asatryan",
"H. H.",
"",
"Yerevan Physics Institute"
],
[
"Asatrian",
"H. M.",
"",
"Yerevan Physics Institute"
]
] | We study the inclusive rare decay $B\to X_d+\gamma$ in the supergravity inspired Minimal Supersymmetric Standard Model and compute the CP-asymmetry in the decay rates. We show that there exist two phenomenologically acceptable sets of SUSY parameters: for one set the CP-asymmetry has the same (positive) sign as in the Standard Model and lies in the range (5-45)% while for the other set it is negative with values within -(2-21)%. |
1612.09075 | Mustafa Savci | T. M. Aliev (1), T. Barakat (2), M. Savc{\i} (1) ((1) Middle East
Technical University/Ankara/Turkey, (2) King Saud University/Riyadh/Saudi
Arabia) | Magnetic dipole moments of the negative parity $J^{PC}=2^{--}$ mesons in
QCD | 15 pages, 2 figures, LaTeX formatted | null | null | metu-phys-hep-16-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Magnetic dipole moments of the negative parity light and heavy tensor mesons
are calculated within the light cone QCD sum rules method. The results are
compared with the positive parity counterparts of the corresponding tensor
mesons. The results of the analysis show that the magnetic dipole moments of
the negative parity light mesons are smaller compared to those of the positive
parity mesons. Contrary to the light meson case, magnetic dipole moments of the
negative parity heavy mesons are larger than the ones for the positive parity
mesons.
| [
{
"created": "Thu, 29 Dec 2016 08:48:09 GMT",
"version": "v1"
}
] | 2016-12-30 | [
[
"Aliev",
"T. M.",
""
],
[
"Barakat",
"T.",
""
],
[
"Savcı",
"M.",
""
]
] | Magnetic dipole moments of the negative parity light and heavy tensor mesons are calculated within the light cone QCD sum rules method. The results are compared with the positive parity counterparts of the corresponding tensor mesons. The results of the analysis show that the magnetic dipole moments of the negative parity light mesons are smaller compared to those of the positive parity mesons. Contrary to the light meson case, magnetic dipole moments of the negative parity heavy mesons are larger than the ones for the positive parity mesons. |
1511.08542 | Mohammadreza Hadizadeh | M. R. Hadizadeh and A. Khaledi-Nasab | Heavy Tetraquarks in the Diquark-Antidiquark Picture | null | Phys. Lett. B 753, 8 (2016) | 10.1016/j.physletb.2015.11.072 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The homogeneous Lippmann-Schwinger integral equation is solved in momentum
space to calculate the masses of heavy tetraquarks with hidden charm and
bottom. The tetraquark bound states are studied in the diquark-antidiquark
picture as a two-body problem. A regularized form of the diquark-antidiquark
potential is used to overcome the singularity of the confining potential at
large distances or small momenta. Our numerical results indicate that the
relativistic effect leads to a small reduction in the mass of heavy
tetraquarks, which is less than $2\,\%$ for charm and less than $0.2\,\%$ for
bottom tetraquarks. The calculated masses of heavy tetraquarks for $1s$, $1p$,
$2s$, $1d$ and $2p$ states are in good agreement with other theoretical
calculations and experimental data. Our numerical analysis predict the masses
of heavy tetraquarks for $3s$, $2d$ and $3p$ states for the first time, and we
are not aware of any other theoretical results or experimental data for these
states.
| [
{
"created": "Fri, 27 Nov 2015 02:26:02 GMT",
"version": "v1"
}
] | 2015-12-11 | [
[
"Hadizadeh",
"M. R.",
""
],
[
"Khaledi-Nasab",
"A.",
""
]
] | The homogeneous Lippmann-Schwinger integral equation is solved in momentum space to calculate the masses of heavy tetraquarks with hidden charm and bottom. The tetraquark bound states are studied in the diquark-antidiquark picture as a two-body problem. A regularized form of the diquark-antidiquark potential is used to overcome the singularity of the confining potential at large distances or small momenta. Our numerical results indicate that the relativistic effect leads to a small reduction in the mass of heavy tetraquarks, which is less than $2\,\%$ for charm and less than $0.2\,\%$ for bottom tetraquarks. The calculated masses of heavy tetraquarks for $1s$, $1p$, $2s$, $1d$ and $2p$ states are in good agreement with other theoretical calculations and experimental data. Our numerical analysis predict the masses of heavy tetraquarks for $3s$, $2d$ and $3p$ states for the first time, and we are not aware of any other theoretical results or experimental data for these states. |
hep-ph/0209006 | Christoph Greub | H.M. Asatrian, K. Bieri, C. Greub and A. Hovhannisyan | NNLL corrections to the angular distribution and to the forward-backward
asymmetries in b -> X_s l+ l- | 26 pages including 11 postscript figures | Phys.Rev.D66:094013,2002 | 10.1103/PhysRevD.66.094013 | BUTP-02/11; comparison with literature modified in last section | hep-ph | null | We present NNLL results for the double differential decay width dGamma(b ->
X_s l+ l-)/(dsh dcos(theta)), where theta is the angle between the momenta of
the b-quark and the l+, measured in the rest-frame of the lepton pair. From
these results we also derive NNLL results for the lepton forward-backward
asymmetries. Genuinely new calculations for the combined virtual- and gluon
bremsstrahlung corrections associated with the operators O_7, O_9 and O_10 are
necessary. We find that the NNLL corrections drastically reduce the
renormalization scale dependence of the forward-backward asymmetries. In
particular, sh_0, the position at which the forward-backward asymmetries
vanish, is essentially free of uncertainties due to the renormalization scale
at NNLL precision. We find sh_0(NNLL)=0.162 +/- 0.005, where the error is
dominated by the uncertainty in (m_c/m_b). This is to be compared with
sh_0(NLL)=0.144 +/- 0.020, where the error is dominated by uncertainties due to
the choice of mu.
| [
{
"created": "Sat, 31 Aug 2002 15:18:15 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Sep 2002 01:44:56 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Asatrian",
"H. M.",
""
],
[
"Bieri",
"K.",
""
],
[
"Greub",
"C.",
""
],
[
"Hovhannisyan",
"A.",
""
]
] | We present NNLL results for the double differential decay width dGamma(b -> X_s l+ l-)/(dsh dcos(theta)), where theta is the angle between the momenta of the b-quark and the l+, measured in the rest-frame of the lepton pair. From these results we also derive NNLL results for the lepton forward-backward asymmetries. Genuinely new calculations for the combined virtual- and gluon bremsstrahlung corrections associated with the operators O_7, O_9 and O_10 are necessary. We find that the NNLL corrections drastically reduce the renormalization scale dependence of the forward-backward asymmetries. In particular, sh_0, the position at which the forward-backward asymmetries vanish, is essentially free of uncertainties due to the renormalization scale at NNLL precision. We find sh_0(NNLL)=0.162 +/- 0.005, where the error is dominated by the uncertainty in (m_c/m_b). This is to be compared with sh_0(NLL)=0.144 +/- 0.020, where the error is dominated by uncertainties due to the choice of mu. |
0910.5600 | Christian Fischer | Christian S. Fischer and Jens A. Mueller | Dual order parameters and the deconfinement transition | 8 pages, 4 figures, contributed to the proceedings of the EMMI
Workshop and XXVI Max Born Symposium at 09th-11th of July 2009 in Wroclaw,
Poland | Acta Phys.Polon.Supp.3:549-556,2010 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the chiral and the deconfinement transition within the
framework of Dyson-Schwinger equations using quenched lattice data for the
temperature dependent gluon propagator as input. We extract corresponding order
parameters from the Landau gauge quark propagator with U(1)-valued boundary
conditions. We study the chiral transition using the conventional quark
condensate, whereas for the deconfinement transition we determine the dual
condensate ('dressed Polyakov loop'). In addition we consider an alternative
order parameter for deconfinement, the dual scalar quark dressing function. As
a result we find almost the same transition temperatures for the chiral and
deconfinement transitions.
| [
{
"created": "Thu, 29 Oct 2009 10:02:46 GMT",
"version": "v1"
}
] | 2010-11-02 | [
[
"Fischer",
"Christian S.",
""
],
[
"Mueller",
"Jens A.",
""
]
] | We investigate the chiral and the deconfinement transition within the framework of Dyson-Schwinger equations using quenched lattice data for the temperature dependent gluon propagator as input. We extract corresponding order parameters from the Landau gauge quark propagator with U(1)-valued boundary conditions. We study the chiral transition using the conventional quark condensate, whereas for the deconfinement transition we determine the dual condensate ('dressed Polyakov loop'). In addition we consider an alternative order parameter for deconfinement, the dual scalar quark dressing function. As a result we find almost the same transition temperatures for the chiral and deconfinement transitions. |
1102.0172 | Johan Bijnens | Johan Bijnens and Jie Lu (Lund) | Meson-meson Scattering in QCD-like Theories | 61 pages | JHEP 1103:028,2011 | 10.1007/JHEP03(2011)028 | LU TP 11-07 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss meson-meson scattering at next-to-next-to-leading order in the
chiral expansion for QCD-like theories with general $n$ degenerate flavours for
the cases with a complex, real and pseudo-real representation. I.e. with global
symmetry and breaking pattern $SU(n)_L\times SU(n)_R\to SU(n)_V$, $SU(2n)\to
SO(2n)$ and $SU(2n)\to Sp(2n)$. We obtain fully analytical expressions for all
these cases. We discuss the general structure of the amplitude and the
structure of the possible intermediate channels for all three cases. We derive
the expressions for the lowest partial wave scattering length in each channel
and present some representative numerical results. We also show various
relations between the different cases in the limit of large $n$.
| [
{
"created": "Tue, 1 Feb 2011 14:52:26 GMT",
"version": "v1"
}
] | 2011-03-14 | [
[
"Bijnens",
"Johan",
"",
"Lund"
],
[
"Lu",
"Jie",
"",
"Lund"
]
] | We discuss meson-meson scattering at next-to-next-to-leading order in the chiral expansion for QCD-like theories with general $n$ degenerate flavours for the cases with a complex, real and pseudo-real representation. I.e. with global symmetry and breaking pattern $SU(n)_L\times SU(n)_R\to SU(n)_V$, $SU(2n)\to SO(2n)$ and $SU(2n)\to Sp(2n)$. We obtain fully analytical expressions for all these cases. We discuss the general structure of the amplitude and the structure of the possible intermediate channels for all three cases. We derive the expressions for the lowest partial wave scattering length in each channel and present some representative numerical results. We also show various relations between the different cases in the limit of large $n$. |
hep-ph/9404270 | C. Cavata | the SMC | Measurement of the Spin-Dependent Structure Function $g_1(x)$ of the
Proton | 11 pages, CERN-PPE/94-57 | Phys.Lett.B329:399-406,1994 | 10.1016/0370-2693(94)90793-5 | null | hep-ph hep-ex | null | We have measured the spin-dependent structure function $g_1^p$ of the proton
in deep inelastic scattering of polarized muons off polarized protons, in the
kinematic range $0.003<x<0.7$ and $1\,\mbox{GeV}^2<Q^2<60\,\mbox{GeV}^2$. Its
first moment, $\int_0^1 g_1^p(x) dx $, is found to be $0.136 \pm
0.011\,(\mbox{stat.})\pm 0.011\,(\mbox{syst.})$ at $Q^2=10\,\mbox{GeV}^2$. This
value is smaller than the prediction of the Ellis--Jaffe sum rule by two
standard deviations, and is consistent with previous measurements. A combined
analysis of all available proton, deuteron and neutron data confirms the
Bjorken sum rule to within $10\%$ of the theoretical value.
| [
{
"created": "Fri, 15 Apr 1994 08:56:12 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Apr 1994 10:24:13 GMT",
"version": "v2"
}
] | 2010-01-15 | [
[
"SMC",
"the",
""
]
] | We have measured the spin-dependent structure function $g_1^p$ of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003<x<0.7$ and $1\,\mbox{GeV}^2<Q^2<60\,\mbox{GeV}^2$. Its first moment, $\int_0^1 g_1^p(x) dx $, is found to be $0.136 \pm 0.011\,(\mbox{stat.})\pm 0.011\,(\mbox{syst.})$ at $Q^2=10\,\mbox{GeV}^2$. This value is smaller than the prediction of the Ellis--Jaffe sum rule by two standard deviations, and is consistent with previous measurements. A combined analysis of all available proton, deuteron and neutron data confirms the Bjorken sum rule to within $10\%$ of the theoretical value. |
0912.3534 | Carola F. Berger | Carola F. Berger (MIT, LNS), Darren Forde (CERN & NIKHEF, Amsterdam) | Multi-Parton Scattering Amplitudes via On-Shell Methods | Invited review, Annual Review of Nuclear and Particle Science; v2:
references added | null | 10.1146/annurev.nucl.012809.104538 | MIT-CTP 4092, CERN-PH-TH/2009-255, NIKHEF/2009-035 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an overview of recent developments, based on on-shell techniques,
in the calculation of multi-parton scattering amplitudes at one loop that are
relevant for phenomenological studies at hadron colliders. These new on-shell
methods make efficient use of the physical properties of the hard scattering,
such as unitarity and factorization.
| [
{
"created": "Fri, 18 Dec 2009 18:49:54 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Dec 2009 15:57:56 GMT",
"version": "v2"
}
] | 2015-05-14 | [
[
"Berger",
"Carola F.",
"",
"MIT, LNS"
],
[
"Forde",
"Darren",
"",
"CERN & NIKHEF, Amsterdam"
]
] | We present an overview of recent developments, based on on-shell techniques, in the calculation of multi-parton scattering amplitudes at one loop that are relevant for phenomenological studies at hadron colliders. These new on-shell methods make efficient use of the physical properties of the hard scattering, such as unitarity and factorization. |
1405.1622 | Vien Vo Van | H.N.Long and V.V.Vien | Neutrino Mixing With Non-Zero $\theta_{13}$ In Zee-Babu Model | 16 pages, 8 figures | Int. J. Mod. Phys. A 29 (2014) 1450072 | 10.1142/S0217751X14500729 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The exact solution for the neutrino mass matrix of the Zee-Babu model is
derived. Tribimaximal mixing imposes conditions on the Yukawa couplings, from
which the normal mass hierarchy is preferred. The derived conditions give a
possibility of Majorana maximal $\mathrm{CP}$ violation in the neutrino sector.
We have shown that non-zero $\theta_{13}$ is generated if Yukawa couplings
between leptons almost equal to each other. The model gives some regions of the
parameters where neutrino mixing angles and the normal neutrino mass hierarchy
obtained consistent with the recent experimental data.
| [
{
"created": "Wed, 7 May 2014 14:38:45 GMT",
"version": "v1"
}
] | 2014-05-08 | [
[
"Long",
"H. N.",
""
],
[
"Vien",
"V. V.",
""
]
] | The exact solution for the neutrino mass matrix of the Zee-Babu model is derived. Tribimaximal mixing imposes conditions on the Yukawa couplings, from which the normal mass hierarchy is preferred. The derived conditions give a possibility of Majorana maximal $\mathrm{CP}$ violation in the neutrino sector. We have shown that non-zero $\theta_{13}$ is generated if Yukawa couplings between leptons almost equal to each other. The model gives some regions of the parameters where neutrino mixing angles and the normal neutrino mass hierarchy obtained consistent with the recent experimental data. |
1801.10530 | Andrea Romanino | Y. Reyimuaji and A. Romanino | Can an unbroken flavour symmetry provide an approximate description of
lepton masses and mixing? | null | JHEP 03 (2018) 067 | 10.1007/JHEP03(2018)067 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We provide a complete answer to the following question: what are the flavour
groups and representations providing, in the symmetric limit, an approximate
description of lepton masses and mixings? We assume that neutrinos masses are
described by the Weinberg operator. We show that the pattern of lepton masses
and mixings only depends on the dimension, type (real, pseudoreal, complex),
and equivalence of the irreducible components of the flavour representation,
and we find only six viable cases. In all cases the neutrinos are either
anarchical or have an inverted hierarchical spectrum. In the context of SU(5)
unification, only the anarchical option is allowed. Therefore, if the hint of a
normal hierarchical spectrum were confirmed, we would conclude (under the above
assumption) that symmetry breaking effects must play a primary role in the
understanding of neutrino flavour observables. In order to obtain the above
results, we develop a simple algorithm to determine the form of the lepton
masses and mixings directly from the structure of the decomposition of the
flavour representation in irreducible components, without the need to specify
the form of the lepton mass matrices.
| [
{
"created": "Wed, 31 Jan 2018 16:30:20 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Apr 2018 12:18:31 GMT",
"version": "v2"
}
] | 2018-04-12 | [
[
"Reyimuaji",
"Y.",
""
],
[
"Romanino",
"A.",
""
]
] | We provide a complete answer to the following question: what are the flavour groups and representations providing, in the symmetric limit, an approximate description of lepton masses and mixings? We assume that neutrinos masses are described by the Weinberg operator. We show that the pattern of lepton masses and mixings only depends on the dimension, type (real, pseudoreal, complex), and equivalence of the irreducible components of the flavour representation, and we find only six viable cases. In all cases the neutrinos are either anarchical or have an inverted hierarchical spectrum. In the context of SU(5) unification, only the anarchical option is allowed. Therefore, if the hint of a normal hierarchical spectrum were confirmed, we would conclude (under the above assumption) that symmetry breaking effects must play a primary role in the understanding of neutrino flavour observables. In order to obtain the above results, we develop a simple algorithm to determine the form of the lepton masses and mixings directly from the structure of the decomposition of the flavour representation in irreducible components, without the need to specify the form of the lepton mass matrices. |
hep-ph/0408118 | Yudi Santoso | John Ellis, Keith A. Olive, Yudi Santoso and Vassilis C. Spanos | Prospects for Sparticle Discovery in Variants of the MSSM | 19 pages, 16 eps figures, as accepted in PLB | Phys.Lett.B603:51,2004 | 10.1016/j.physletb.2004.09.073 | CERN-PH-TH/2004-131, UMN-TH-2315/04, FTPI-MINN-04/27 | hep-ph astro-ph | null | We discuss the prospects for detecting supersymmetric particles in variants
of the minimal supersymmetric extension of the Standard Model (MSSM), in light
of laboratory and cosmological constraints. We first assume that the lightest
supersymmetric particle (LSP) is the lightest neutralino chi, and present
scatter plots of the masses of the two lightest visible supersymmetric
particles when the input scalar and gaugino masses are constrained to be
universal (CMSSM), when the input Higgs scalar masses are non-universal (NUHM),
and when the squark and slepton masses are also non-universal and the MSSM is
regarded as a low-energy effective field theory valid up to the GUT scale
(LEEST) or just up to 10 TeV (LEEST10). We then present similar plots in
various scenarios when the LSP is the gravitino. We compare the prospects for
detecting supersymmetry at linear colliders (LCs) of various energies, at the
LHC, and as astrophysical dark matter. We find that, whilst a LC with a
centre-of-mass energy E_{CM} <= 1000 GeV has some chance of discovering the
lightest and next-to-lightest visible supersymmetric particles, E_{CM} >= 3000
GeV would be required to `guarantee' finding supersymmetry in the neutralino
LSP scenarios studied, and an even higher E_{CM} might be required in certain
gravitino dark matter scenarios. Direct dark matter experiments could explore
part of the low-mass neutralino LSP region, but would not reveal all the models
accessible to a low-energy LC.
| [
{
"created": "Mon, 9 Aug 2004 20:02:19 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Oct 2004 19:33:46 GMT",
"version": "v2"
}
] | 2009-09-11 | [
[
"Ellis",
"John",
""
],
[
"Olive",
"Keith A.",
""
],
[
"Santoso",
"Yudi",
""
],
[
"Spanos",
"Vassilis C.",
""
]
] | We discuss the prospects for detecting supersymmetric particles in variants of the minimal supersymmetric extension of the Standard Model (MSSM), in light of laboratory and cosmological constraints. We first assume that the lightest supersymmetric particle (LSP) is the lightest neutralino chi, and present scatter plots of the masses of the two lightest visible supersymmetric particles when the input scalar and gaugino masses are constrained to be universal (CMSSM), when the input Higgs scalar masses are non-universal (NUHM), and when the squark and slepton masses are also non-universal and the MSSM is regarded as a low-energy effective field theory valid up to the GUT scale (LEEST) or just up to 10 TeV (LEEST10). We then present similar plots in various scenarios when the LSP is the gravitino. We compare the prospects for detecting supersymmetry at linear colliders (LCs) of various energies, at the LHC, and as astrophysical dark matter. We find that, whilst a LC with a centre-of-mass energy E_{CM} <= 1000 GeV has some chance of discovering the lightest and next-to-lightest visible supersymmetric particles, E_{CM} >= 3000 GeV would be required to `guarantee' finding supersymmetry in the neutralino LSP scenarios studied, and an even higher E_{CM} might be required in certain gravitino dark matter scenarios. Direct dark matter experiments could explore part of the low-mass neutralino LSP region, but would not reveal all the models accessible to a low-energy LC. |
hep-ph/9902230 | Renard Fernand Michel | G.J. Gounaris, P.I. Porfyriadis and F.M. Renard | The gamma gamma to gamma gamma process in the Standard and SUSY models
at high energies | 18 pages and 7 figures | Eur.Phys.J.C9:673-686,1999 | 10.1007/s100529900079 | PM/99-04, THES-TP 99-01 | hep-ph | null | We study the helicity amplitudes of the process \gamma \gamma \to \gamma
\gamma at high energy, which in the standard and SUSY models first arise at the
one-loop order. In the standard model (SM), the diagrams involve W and charged
quark and lepton loops, while in SUSY we also have contributions from chargino,
charged sfermion and Higgs loop diagrams. The SUSY contributions are most
important in the region above the threshold for producing the supersymmetric
partners; since there, they interfere most effectively with the primarily
imaginary SM amplitudes. Simple expressions for the relevant 1-loop functions
are given, which provide a direct overview of the behaviour of the helicity
amplitudes in the whole parameter space at high energies. The various
characteristics of a large set of observables are studied in detail.
| [
{
"created": "Wed, 3 Feb 1999 07:16:14 GMT",
"version": "v1"
}
] | 2011-09-13 | [
[
"Gounaris",
"G. J.",
""
],
[
"Porfyriadis",
"P. I.",
""
],
[
"Renard",
"F. M.",
""
]
] | We study the helicity amplitudes of the process \gamma \gamma \to \gamma \gamma at high energy, which in the standard and SUSY models first arise at the one-loop order. In the standard model (SM), the diagrams involve W and charged quark and lepton loops, while in SUSY we also have contributions from chargino, charged sfermion and Higgs loop diagrams. The SUSY contributions are most important in the region above the threshold for producing the supersymmetric partners; since there, they interfere most effectively with the primarily imaginary SM amplitudes. Simple expressions for the relevant 1-loop functions are given, which provide a direct overview of the behaviour of the helicity amplitudes in the whole parameter space at high energies. The various characteristics of a large set of observables are studied in detail. |
hep-ph/9609284 | Qiao Cong Feng | Cong-feng Qiao, Feng Yuan, and Kuang-Ta Chao (Peking University) | A Crucial Test for Color-Octet Production Mechanism in Z^0 Decays | 14 pages in LaTex (3 figures in PS-file) | Phys.Rev.D55:4001-4004,1997 | 10.1103/PhysRevD.55.4001 | PUTP-96-28 | hep-ph | null | The direct production rates of $D$-wave charmonia in the decays of $Z^0$ is
evaluated. The color-octet production processes $Z^0\rightarrow ^3D_J(c\bar c)
q\bar q$ are shown to have distinctively large branching ratios, the same order
of magnitude as that of $J/\psi$ prodution, as compared with other $D$-wave
charmonium production mechanisms. This may suggest a crucial channel to test
the color-octet mechanism as well as to observe the $D$-wave charmonium states
in $Z^0$ decays. In addition, a signal for the $^3D_J$ charmonium as strong as
$J/\psi$ or $\psi^\prime$ with large transverse momentum at the Tevatron should
also be observed.
| [
{
"created": "Sun, 8 Sep 1996 02:48:21 GMT",
"version": "v1"
}
] | 2019-08-17 | [
[
"Qiao",
"Cong-feng",
"",
"Peking University"
],
[
"Yuan",
"Feng",
"",
"Peking University"
],
[
"Chao",
"Kuang-Ta",
"",
"Peking University"
]
] | The direct production rates of $D$-wave charmonia in the decays of $Z^0$ is evaluated. The color-octet production processes $Z^0\rightarrow ^3D_J(c\bar c) q\bar q$ are shown to have distinctively large branching ratios, the same order of magnitude as that of $J/\psi$ prodution, as compared with other $D$-wave charmonium production mechanisms. This may suggest a crucial channel to test the color-octet mechanism as well as to observe the $D$-wave charmonium states in $Z^0$ decays. In addition, a signal for the $^3D_J$ charmonium as strong as $J/\psi$ or $\psi^\prime$ with large transverse momentum at the Tevatron should also be observed. |
2306.01918 | Maria Vittoria Garzelli | S. Alekhin, M. V. Garzelli, S. Kulagin, S.-O. Moch | Impact of SeaQuest data on PDF fits at large $x$ | 23 pages, 7 figures, 3 tables, v2: report number updated, references
added, typos corrected, discussion slightly revised and extended. Further
small modifications still to come in a next version | null | null | INR-TH-2023-012 | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | We evaluate the impact of recent SeaQuest (E906 experiment) data on dimuon
production in proton-deuteron and proton-proton collisions on parton
distribution functions (PDFs). We find these data in a good agreement with the
QCD predictions based on PDFs fitted to the Tevatron and LHC data on forward
production of $W$ and $Z$ bosons. As a basis for this study we use the ABMP16
PDF fits and show that they turn out to be compatible with the SeaQuest data,
and that these data have constraining power, allowing to reduce the
uncertainties on the isospin asymmetry of the light-sea-quark distribution at
large longitudinal momentum fraction $x$. We discuss the nuclear corrections
needed to describe the deuteron and show that they affect the theoretical
description of the proton-deuteron Drell-Yan cross section at the level of
$\mathcal{O}(0.5 - 1)$\%. We also comment on the compatibility of the SeaQuest
results with other state-of-the-art PDF fits and show that these data are in
clear disagreement with models proposing an SU(3)-flavor symmetric quark sea.
Finally, we perform a comparison between the second Mellin moments of the
light-quark PDFs and recent results from various lattice QCD computations,
which demonstrates good compatibility, albeit limited by the uncertainties
inherent in current lattice QCD simulations.
| [
{
"created": "Fri, 2 Jun 2023 21:15:43 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Jul 2023 15:54:58 GMT",
"version": "v2"
}
] | 2023-07-20 | [
[
"Alekhin",
"S.",
""
],
[
"Garzelli",
"M. V.",
""
],
[
"Kulagin",
"S.",
""
],
[
"Moch",
"S. -O.",
""
]
] | We evaluate the impact of recent SeaQuest (E906 experiment) data on dimuon production in proton-deuteron and proton-proton collisions on parton distribution functions (PDFs). We find these data in a good agreement with the QCD predictions based on PDFs fitted to the Tevatron and LHC data on forward production of $W$ and $Z$ bosons. As a basis for this study we use the ABMP16 PDF fits and show that they turn out to be compatible with the SeaQuest data, and that these data have constraining power, allowing to reduce the uncertainties on the isospin asymmetry of the light-sea-quark distribution at large longitudinal momentum fraction $x$. We discuss the nuclear corrections needed to describe the deuteron and show that they affect the theoretical description of the proton-deuteron Drell-Yan cross section at the level of $\mathcal{O}(0.5 - 1)$\%. We also comment on the compatibility of the SeaQuest results with other state-of-the-art PDF fits and show that these data are in clear disagreement with models proposing an SU(3)-flavor symmetric quark sea. Finally, we perform a comparison between the second Mellin moments of the light-quark PDFs and recent results from various lattice QCD computations, which demonstrates good compatibility, albeit limited by the uncertainties inherent in current lattice QCD simulations. |
2402.11240 | Xing-Xing Dong | Xing-Xing Dong, Shu-Min Zhao, Jia-Peng Huo, Tong-Tong Wang, Yi-Tong
Wang, Tai-Fu Feng | Search for charged lepton flavor violation of vector mesons in the
$\mathrm{U}(1)_{X} \mathrm{SSM}$ | null | null | null | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | Charged lepton flavor violation (CLFV) represents a clear new physics (NP)
signal beyond the standard model (SM). In this work, we investigate the CLFV
decays of vector mesons $V\rightarrow l_i^{\pm}l_j^{\mp}$ with $V\in\{\phi,
J/\Psi, \Upsilon(1S), \Upsilon(2S),\Upsilon(3S)\}$ in the $\mathrm{U}(1)_{X}
\mathrm{SSM}$. Considering the SM-like Higgs boson mass within $3\sigma$
region, we discuss the corresponding constraints on the relevant parameter
space of the model, which indicate this model can produce significant
contributions to such CLFV decays. From the numerical analyses, the main
sensitive parameters and CLFV sources originate from the non-diagonal elements
correspond to the initial and final generations of the leptons. And the
branching ratios to these CLFV processes can easily reach the present
experimental upper bounds. Therefore, searching for CLFV processes of vector
mesons may be an effective channel to study new physics.
| [
{
"created": "Sat, 17 Feb 2024 10:17:23 GMT",
"version": "v1"
}
] | 2024-02-20 | [
[
"Dong",
"Xing-Xing",
""
],
[
"Zhao",
"Shu-Min",
""
],
[
"Huo",
"Jia-Peng",
""
],
[
"Wang",
"Tong-Tong",
""
],
[
"Wang",
"Yi-Tong",
""
],
[
"Feng",
"Tai-Fu",
""
]
] | Charged lepton flavor violation (CLFV) represents a clear new physics (NP) signal beyond the standard model (SM). In this work, we investigate the CLFV decays of vector mesons $V\rightarrow l_i^{\pm}l_j^{\mp}$ with $V\in\{\phi, J/\Psi, \Upsilon(1S), \Upsilon(2S),\Upsilon(3S)\}$ in the $\mathrm{U}(1)_{X} \mathrm{SSM}$. Considering the SM-like Higgs boson mass within $3\sigma$ region, we discuss the corresponding constraints on the relevant parameter space of the model, which indicate this model can produce significant contributions to such CLFV decays. From the numerical analyses, the main sensitive parameters and CLFV sources originate from the non-diagonal elements correspond to the initial and final generations of the leptons. And the branching ratios to these CLFV processes can easily reach the present experimental upper bounds. Therefore, searching for CLFV processes of vector mesons may be an effective channel to study new physics. |
1512.05439 | Tathagata Ghosh | Bhaskar Dutta, Yu Gao, Tathagata Ghosh, Ilia Gogoladze, Tianjun Li | Interpretation of the diphoton excess at CMS and ATLAS | 8 pages, 6 figures, 3 tables; v2: typos corrected, references added | Phys. Rev. D 93, 055032 (2016) | 10.1103/PhysRevD.93.055032 | MI-TH-1546 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the diphoton resonance at the 13 TeV LHC in a consistent model
with new scalars and vector-like fermions added to the Standard Model (SM),
which can be constructed from orbifold grand unified theories and string
models. The gauge coupling unification can be achieved, neutrino masses can be
generated radiatively, and electroweak vacuum stability problem can be solved.
To explain the diphoton resonance, we study a spin-0 particle, and discuss
various associated final states.
| [
{
"created": "Thu, 17 Dec 2015 02:13:38 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Feb 2016 07:08:26 GMT",
"version": "v2"
}
] | 2016-03-30 | [
[
"Dutta",
"Bhaskar",
""
],
[
"Gao",
"Yu",
""
],
[
"Ghosh",
"Tathagata",
""
],
[
"Gogoladze",
"Ilia",
""
],
[
"Li",
"Tianjun",
""
]
] | We consider the diphoton resonance at the 13 TeV LHC in a consistent model with new scalars and vector-like fermions added to the Standard Model (SM), which can be constructed from orbifold grand unified theories and string models. The gauge coupling unification can be achieved, neutrino masses can be generated radiatively, and electroweak vacuum stability problem can be solved. To explain the diphoton resonance, we study a spin-0 particle, and discuss various associated final states. |
1608.07791 | Sergey Ostapchenko | S. Ostapchenko, M. Bleicher, T. Pierog and K. Werner | Constraining high energy interaction mechanisms by studying forward
hadron production at the LHC | null | Phys. Rev. D 94, 114026 (2016) | 10.1103/PhysRevD.94.114026 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We demonstrate that underlying assumptions concerning the structure of
constituent parton Fock states in hadrons make a strong impact on the
predictions of hadronic interaction models for forward hadron spectra and for
long-range correlations between central and forward hadron production. Our
analysis shows that combined studies of proton-proton collisions at the Large
Hadron Collider by central and forward-looking detectors have a rich potential
for discriminating between the main model approaches.
| [
{
"created": "Sun, 28 Aug 2016 09:21:49 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Dec 2016 12:37:05 GMT",
"version": "v2"
}
] | 2016-12-28 | [
[
"Ostapchenko",
"S.",
""
],
[
"Bleicher",
"M.",
""
],
[
"Pierog",
"T.",
""
],
[
"Werner",
"K.",
""
]
] | We demonstrate that underlying assumptions concerning the structure of constituent parton Fock states in hadrons make a strong impact on the predictions of hadronic interaction models for forward hadron spectra and for long-range correlations between central and forward hadron production. Our analysis shows that combined studies of proton-proton collisions at the Large Hadron Collider by central and forward-looking detectors have a rich potential for discriminating between the main model approaches. |
hep-ph/0306087 | Palash Baran Pal | Jose F. Nieves, Palash B. Pal | Generalized Fierz identities | 18 pages, Latex | Am.J.Phys. 72 (2004) 1100-1108 | 10.1119/1.1757445 | SINP/TNP/03-16 | hep-ph | null | Low energy weak interactions calculations with fermions frequently involve a
superposition of quartic products of Dirac spinors, in which the order of the
spinors is not the same in all the contributing terms. A common trick that is
used to bring them to a uniform ordering is the Fierz transformation. We show
that the standard Fierz rearrangement formula quoted in textbooks is one
element of a class of transformations of a quartic product amplitude, under
which the spinors are rearranged with different orderings and, in the general
case, some or all of the spinors are transformed to their Lorentz-invariant
complex conjugate form. We give a pedagogical derivation of the explicit forms
of all such transformation matrices. In addition to the usual Lorentz scalar
quartic products, we consider pseudoscalar ones as well. Such manipulations and
formulas are useful, in particular, when some of the fermions involved are
Majorana particles.
| [
{
"created": "Wed, 11 Jun 2003 04:43:55 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Nieves",
"Jose F.",
""
],
[
"Pal",
"Palash B.",
""
]
] | Low energy weak interactions calculations with fermions frequently involve a superposition of quartic products of Dirac spinors, in which the order of the spinors is not the same in all the contributing terms. A common trick that is used to bring them to a uniform ordering is the Fierz transformation. We show that the standard Fierz rearrangement formula quoted in textbooks is one element of a class of transformations of a quartic product amplitude, under which the spinors are rearranged with different orderings and, in the general case, some or all of the spinors are transformed to their Lorentz-invariant complex conjugate form. We give a pedagogical derivation of the explicit forms of all such transformation matrices. In addition to the usual Lorentz scalar quartic products, we consider pseudoscalar ones as well. Such manipulations and formulas are useful, in particular, when some of the fermions involved are Majorana particles. |
2105.01842 | Jihn E. Kim | Junu Jeong, Jihn E. Kim, and Sungwoo Youn | Electromagnetic properties of neutrinos from scattering on bound
electrons in atom | 12 pages, 4 figures | IJMPA 36 (2021) 2150182 | 10.1142/S0217751X21501827 | null | hep-ph astro-ph.SR hep-ex | http://creativecommons.org/publicdomain/zero/1.0/ | We consider the effects of bound atomic electrons scattered by solar
neutrinos due to the electromagnetic properties of neutrinos. This necessiate
considering the recoil of atomic nucleus, which should be considered in the
momentum conservation, but that effect to the energy conservation is
negligible. This effect changes the kinematic behavior of the scattered
electron compared to that scattered on free electrons. We apply this effect to
the recent XENON1T data, but the bounds obtained from this is not very
restrictive. We obtained the bounds: the (transition) magnetic moment
$|f_{\alpha\beta}|\le 0.86\times 10^{-7}$ (times the electron Bohr magneton)
and the charge radius $|\tilde{r}|< 4.30\times 10^{-17\,}{\rm cm}$. For a
non-vanishing millicharge ($\varepsilon$), the allowed bound is shown in the
$\tilde{r}^2-\varepsilon$ plane.
| [
{
"created": "Wed, 5 May 2021 02:34:05 GMT",
"version": "v1"
}
] | 2021-12-09 | [
[
"Jeong",
"Junu",
""
],
[
"Kim",
"Jihn E.",
""
],
[
"Youn",
"Sungwoo",
""
]
] | We consider the effects of bound atomic electrons scattered by solar neutrinos due to the electromagnetic properties of neutrinos. This necessiate considering the recoil of atomic nucleus, which should be considered in the momentum conservation, but that effect to the energy conservation is negligible. This effect changes the kinematic behavior of the scattered electron compared to that scattered on free electrons. We apply this effect to the recent XENON1T data, but the bounds obtained from this is not very restrictive. We obtained the bounds: the (transition) magnetic moment $|f_{\alpha\beta}|\le 0.86\times 10^{-7}$ (times the electron Bohr magneton) and the charge radius $|\tilde{r}|< 4.30\times 10^{-17\,}{\rm cm}$. For a non-vanishing millicharge ($\varepsilon$), the allowed bound is shown in the $\tilde{r}^2-\varepsilon$ plane. |
1606.00524 | Paride Paradisi | Ferruccio Feruglio, Paride Paradisi, Andrea Pattori | Revisiting Lepton Flavour Universality in B Decays | 5 pages, 2 figures. V2: Minor text improvements. Published PRL
version | Phys. Rev. Lett. 118, 011801 (2017) | 10.1103/PhysRevLett.118.011801 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Lepton flavour universality (LFU) in B-decays is revisited by considering a
class of semileptonic operators defined at a scale Lambda above the electroweak
scale v. The importance of quantum effects, so far neglected in the literature,
is emphasised. We construct the low-energy effective Lagrangian taking into
account the running effects from Lambda down to v through the one-loop
renormalization group equations (RGE) in the limit of exact electroweak
symmetry and QED RGEs from v down to the 1 GeV scale. The most important
quantum effects turn out to be the modification of the leptonic couplings of
the vector boson Z and the generation of a purely leptonic effective
Lagrangian. Large LFU breaking effects in Z and tau decays and visible lepton
flavour violating (LFV) effects in the processes tau -> mu ll, tau -> mu rho,
tau -> mu pi and tau -> mu eta^(') are induced.
| [
{
"created": "Thu, 2 Jun 2016 02:29:26 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Dec 2016 17:06:31 GMT",
"version": "v2"
}
] | 2017-01-11 | [
[
"Feruglio",
"Ferruccio",
""
],
[
"Paradisi",
"Paride",
""
],
[
"Pattori",
"Andrea",
""
]
] | Lepton flavour universality (LFU) in B-decays is revisited by considering a class of semileptonic operators defined at a scale Lambda above the electroweak scale v. The importance of quantum effects, so far neglected in the literature, is emphasised. We construct the low-energy effective Lagrangian taking into account the running effects from Lambda down to v through the one-loop renormalization group equations (RGE) in the limit of exact electroweak symmetry and QED RGEs from v down to the 1 GeV scale. The most important quantum effects turn out to be the modification of the leptonic couplings of the vector boson Z and the generation of a purely leptonic effective Lagrangian. Large LFU breaking effects in Z and tau decays and visible lepton flavour violating (LFV) effects in the processes tau -> mu ll, tau -> mu rho, tau -> mu pi and tau -> mu eta^(') are induced. |
2001.04085 | Zhi-Long Han | Ang Liu, Zhi-Long Han, Yi Jin and Fa-Xin Yang | Leptogenesis and Dark Matter from Low Scale Seesaw | 17 pages, 6 figures | Phys. Rev. D 101, 095005 (2020) | 10.1103/PhysRevD.101.095005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we perform a detail analysis on leptogenesis and dark matter
form low scale seesaw. In the framework of $\nu$2HDM, we further introduce one
scalar singlet $\phi$ and one Dirac fermion singlet $\chi$, which are charged
under a $Z_2$ symmetry. Assuming the coupling of $\chi$ is extremely small, it
serves as a FIMP dark matter. The heavy right hand neutrinos $N$ provide a
common origin for tiny neutrino mass (via seesaw mechanism), leptogenesis (via
$N\to \ell_L \Phi_\nu^*,\bar{\ell}_L \Phi_\nu$) and dark matter (via $N\to
\chi\phi$). With hierarchical right hand neutrino masses, the explicit
calculation shows that success thermal leptogenesis is viable even for TeV
scale $N_1$ with $0.4 \lesssim v_\nu\lesssim1$ GeV and lightest neutrino mass
$m_1\lesssim 10^{-11}$ eV. In such scenario, light FIMP dark matter in the keV
to MeV range is naturally expected. The common parameter space for neutrino
mass, natural leptogenesis and FIMP DM is also obtained in this paper.
| [
{
"created": "Mon, 13 Jan 2020 07:21:06 GMT",
"version": "v1"
}
] | 2020-05-13 | [
[
"Liu",
"Ang",
""
],
[
"Han",
"Zhi-Long",
""
],
[
"Jin",
"Yi",
""
],
[
"Yang",
"Fa-Xin",
""
]
] | In this paper, we perform a detail analysis on leptogenesis and dark matter form low scale seesaw. In the framework of $\nu$2HDM, we further introduce one scalar singlet $\phi$ and one Dirac fermion singlet $\chi$, which are charged under a $Z_2$ symmetry. Assuming the coupling of $\chi$ is extremely small, it serves as a FIMP dark matter. The heavy right hand neutrinos $N$ provide a common origin for tiny neutrino mass (via seesaw mechanism), leptogenesis (via $N\to \ell_L \Phi_\nu^*,\bar{\ell}_L \Phi_\nu$) and dark matter (via $N\to \chi\phi$). With hierarchical right hand neutrino masses, the explicit calculation shows that success thermal leptogenesis is viable even for TeV scale $N_1$ with $0.4 \lesssim v_\nu\lesssim1$ GeV and lightest neutrino mass $m_1\lesssim 10^{-11}$ eV. In such scenario, light FIMP dark matter in the keV to MeV range is naturally expected. The common parameter space for neutrino mass, natural leptogenesis and FIMP DM is also obtained in this paper. |
hep-ph/9606432 | Huabin Tang | Hua-Bin Tang and Paul J. Ellis | Redundance of $\Delta$-isobar Parameters in Effective Field Theories | 11 pages, RevTex, no figures, a minor error corrected, to appear in
PLB | Phys.Lett. B387 (1996) 9-13 | 10.1016/0370-2693(96)00862-3 | NUC-MINN-96/4-T | hep-ph nucl-th | null | It is shown that the off-shell parameters in the interaction Lagrangian of
pions, nucleons, and $\Delta$-isobars are redundant in the framework of
effective field theories. Our results also suggest the necessity of including
the $\Delta$ as an explicit dynamical degree of freedom.
| [
{
"created": "Tue, 25 Jun 1996 17:38:49 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Sep 1996 21:44:10 GMT",
"version": "v2"
}
] | 2015-06-25 | [
[
"Tang",
"Hua-Bin",
""
],
[
"Ellis",
"Paul J.",
""
]
] | It is shown that the off-shell parameters in the interaction Lagrangian of pions, nucleons, and $\Delta$-isobars are redundant in the framework of effective field theories. Our results also suggest the necessity of including the $\Delta$ as an explicit dynamical degree of freedom. |
hep-ph/0605245 | Thomas Schietinger | Federica Legger and Thomas Schietinger | Photon helicity in Lambda_b --> p K gamma decays | elsart, 17 pages, 4 figures; corrected sensitivity estimates | Phys.Lett.B645:204-212,2007; Erratum-ibid.B647:527-528,2007 | 10.1016/j.physletb.2006.12.011 10.1016/j.physletb.2007.02.044 | LPHE/2006-08 | hep-ph | null | Radiative decays of polarized Lambda_b baryons represent an attractive
possibility to measure the helicity of the photon emitted in the b --> s gamma
quark transition and thus to subject the Standard Model to a stringent test at
existing and future hadron colliders. The most abundant mode, Lambda(1116)
gamma, is experimentally very challenging because of the long decay length of
the Lambda(1116). We show that the experimentally more accessible Lambda_b -->
p K gamma decays proceeding via Lambda resonances may be used to extract the
photon helicity for sufficient Lambda_b polarization, if the resonance spin
does not exceed 3/2. A direct comparison of the potential of such resonance
decays to assess the photon polarization at a hadron collider with respect to
the decay to Lambda(1116) is given.
| [
{
"created": "Tue, 23 May 2006 15:02:18 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Jan 2007 11:17:24 GMT",
"version": "v2"
},
{
"created": "Wed, 14 Feb 2007 13:18:43 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Legger",
"Federica",
""
],
[
"Schietinger",
"Thomas",
""
]
] | Radiative decays of polarized Lambda_b baryons represent an attractive possibility to measure the helicity of the photon emitted in the b --> s gamma quark transition and thus to subject the Standard Model to a stringent test at existing and future hadron colliders. The most abundant mode, Lambda(1116) gamma, is experimentally very challenging because of the long decay length of the Lambda(1116). We show that the experimentally more accessible Lambda_b --> p K gamma decays proceeding via Lambda resonances may be used to extract the photon helicity for sufficient Lambda_b polarization, if the resonance spin does not exceed 3/2. A direct comparison of the potential of such resonance decays to assess the photon polarization at a hadron collider with respect to the decay to Lambda(1116) is given. |
hep-ph/9902371 | Apostolos Pilaftsis | Apostolos Pilaftsis and Carlos E.M. Wagner | Higgs Bosons in the Minimal Supersymmetric Standard Model with Explicit
CP Violation | null | Nucl.Phys.B553:3-42,1999 | 10.1016/S0550-3213(99)00261-8 | null | hep-ph astro-ph hep-ex | null | We study the Higgs-boson mass spectrum of the minimal supersymmetric standard
model, in which the tree-level CP invariance of the Higgs potential is broken
explicitly by loop effects of soft-CP-violating Yukawa interactions related to
scalar quarks of the third generation. The analysis is performed by considering
the CP-non-invariant renormalization-group improved effective potential through
next-to-leading order that includes leading logarithms due to two-loop Yukawa
and QCD corrections. We find that the three neutral Higgs particles predicted
by the theory may strongly mix with one another, thereby significantly
modifying their tree-level couplings to fermions and to the $W^\pm$ and Z
bosons. We analyze the phenomenological consequences of such a minimal
supersymmetric scenario of explicit CP violation on the production rates of the
lightest Higgs particle, and discuss strategies for its potential discovery at
high-energy colliders.
| [
{
"created": "Tue, 16 Feb 1999 20:08:51 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Feb 1999 17:52:46 GMT",
"version": "v2"
},
{
"created": "Fri, 16 Apr 1999 19:35:52 GMT",
"version": "v3"
},
{
"created": "Wed, 18 Aug 1999 11:48:06 GMT",
"version": "v4"
}
] | 2009-10-07 | [
[
"Pilaftsis",
"Apostolos",
""
],
[
"Wagner",
"Carlos E. M.",
""
]
] | We study the Higgs-boson mass spectrum of the minimal supersymmetric standard model, in which the tree-level CP invariance of the Higgs potential is broken explicitly by loop effects of soft-CP-violating Yukawa interactions related to scalar quarks of the third generation. The analysis is performed by considering the CP-non-invariant renormalization-group improved effective potential through next-to-leading order that includes leading logarithms due to two-loop Yukawa and QCD corrections. We find that the three neutral Higgs particles predicted by the theory may strongly mix with one another, thereby significantly modifying their tree-level couplings to fermions and to the $W^\pm$ and Z bosons. We analyze the phenomenological consequences of such a minimal supersymmetric scenario of explicit CP violation on the production rates of the lightest Higgs particle, and discuss strategies for its potential discovery at high-energy colliders. |
2108.06521 | Ajay Kumar Rai | Rohit Tiwari, D. P. Rathaud and Ajay Kumar Rai | Mass-Spectroscopy of [$bb][\bar{b}\bar{b}$] and [$bq][\bar{b}\bar{q}$]
tetraquark states in a diquark-antidiquark formalism | 12 pages, accepted for the publication in EPJ A | Eur. Phys. J. A (2021) 57:289 | 10.1140/epja/s10050-021-00601-w | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this article, we utilise the non-relativistic potential model to calculate
the mass-spectra of all bottom [$bb][\bar{b}\bar{b}$] and heavy-light bottom
[$bq][\bar{b}\bar{q}$] (q=u,d) tetraquark states in diquark-antidiquark
approximation. The four-body problem is reduced into two-body problems by
numerically solving the $Schr\ddot{o}dinger$ equation using a cornell-inspired
potential along with relativistic correction term. The splitting structure of
the tetraquark spectrum is described using spin-dependent terms (spin-spin,
spin-orbit, and tensor). We have successfully calculated and predicted the
masses of bottom mesons, diquarks and tetraquarks. The masses of S and P-wave
tetraquark states [$bb][\bar{b}\bar{b}$] and [$bq][\bar{b}\bar{q}$],
respectively, are found to be between 18.7-19.4 GeV and 10.4-11.3 GeV, in which
the masses of S-wave [$bb][\bar{b}\bar{b}$] states are less than the
2$\eta_{b}$, $\eta_{b}\Upsilon$, and 2$\Upsilon$ threshold. Additionally, we
investigated the $Z_b(10610)$ and $Z_ b(10650)$ states in the current model and
found that they are 150 MeV below the $BB^{*}$ and $B^{*}B^{*}$ thresholds.
| [
{
"created": "Sat, 14 Aug 2021 11:58:49 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Oct 2021 06:21:10 GMT",
"version": "v2"
}
] | 2021-10-22 | [
[
"Tiwari",
"Rohit",
""
],
[
"Rathaud",
"D. P.",
""
],
[
"Rai",
"Ajay Kumar",
""
]
] | In this article, we utilise the non-relativistic potential model to calculate the mass-spectra of all bottom [$bb][\bar{b}\bar{b}$] and heavy-light bottom [$bq][\bar{b}\bar{q}$] (q=u,d) tetraquark states in diquark-antidiquark approximation. The four-body problem is reduced into two-body problems by numerically solving the $Schr\ddot{o}dinger$ equation using a cornell-inspired potential along with relativistic correction term. The splitting structure of the tetraquark spectrum is described using spin-dependent terms (spin-spin, spin-orbit, and tensor). We have successfully calculated and predicted the masses of bottom mesons, diquarks and tetraquarks. The masses of S and P-wave tetraquark states [$bb][\bar{b}\bar{b}$] and [$bq][\bar{b}\bar{q}$], respectively, are found to be between 18.7-19.4 GeV and 10.4-11.3 GeV, in which the masses of S-wave [$bb][\bar{b}\bar{b}$] states are less than the 2$\eta_{b}$, $\eta_{b}\Upsilon$, and 2$\Upsilon$ threshold. Additionally, we investigated the $Z_b(10610)$ and $Z_ b(10650)$ states in the current model and found that they are 150 MeV below the $BB^{*}$ and $B^{*}B^{*}$ thresholds. |
1005.2105 | Alvin Kiswandhi | Alvin Kiswandhi, Ju-Jun Xie, Shin Nan Yang | Is the nonmonotonic behavior in the cross section of phi photoproduction
near threshold a signature of a resonance? | null | Phys.Lett.B691:214-218,2010 | 10.1016/j.physletb.2010.06.029 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study whether the nonmonotonic behavior found in the differential cross
section of the phi-meson photoproduction near threshold can be described by a
resonance. Namely, we add a resonance to a model consisting of Pomeron and
(pi,eta) exchange by fiat and see if, with a suitable assignment of spin and
parity, mass and width, as well as the coupling constants, one would be able to
obtain a good description to all the data reported by the LEPS collaboration in
the low-energy region. The resonant contribution is evaluated by using an
effective Lagrangian approach. We find that, with the assumption of a J^P=3/2^-
resonance with mass of 2.10 +- 0.03 GeV and width of 0.465 +- 0.141 GeV, LEPS
data can indeed be well described. The ratio of the helicity amplitudes
A_(1/2)/A_(3/2) calculated from the resulting coupling constants differs in
sign from that of the known D13(2080). We further find that the addition of
this postulated resonance can substantially improve the agreement between the
existing theoretical predictions and the recent omega photoproduction data if a
large value of the OZI evading parameter x_OZI = 12 is assumed for the
resonance.
| [
{
"created": "Wed, 12 May 2010 13:59:53 GMT",
"version": "v1"
},
{
"created": "Thu, 13 May 2010 09:21:11 GMT",
"version": "v2"
}
] | 2014-11-21 | [
[
"Kiswandhi",
"Alvin",
""
],
[
"Xie",
"Ju-Jun",
""
],
[
"Yang",
"Shin Nan",
""
]
] | We study whether the nonmonotonic behavior found in the differential cross section of the phi-meson photoproduction near threshold can be described by a resonance. Namely, we add a resonance to a model consisting of Pomeron and (pi,eta) exchange by fiat and see if, with a suitable assignment of spin and parity, mass and width, as well as the coupling constants, one would be able to obtain a good description to all the data reported by the LEPS collaboration in the low-energy region. The resonant contribution is evaluated by using an effective Lagrangian approach. We find that, with the assumption of a J^P=3/2^- resonance with mass of 2.10 +- 0.03 GeV and width of 0.465 +- 0.141 GeV, LEPS data can indeed be well described. The ratio of the helicity amplitudes A_(1/2)/A_(3/2) calculated from the resulting coupling constants differs in sign from that of the known D13(2080). We further find that the addition of this postulated resonance can substantially improve the agreement between the existing theoretical predictions and the recent omega photoproduction data if a large value of the OZI evading parameter x_OZI = 12 is assumed for the resonance. |
1401.1547 | Marat Siddikov Ilfatovich | B. Z.Kopeliovich, Ivan Schmidt and M. Siddikov | Higher-twist contributions to neutrino-production of pions | 10 pages, 3 figures | Phys. Rev. D 89, 053001 (2014) | 10.1103/PhysRevD.89.053001 | USM-TH-318 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we estimate the size of twist-3 corrections to the deeply
virtual meson production in neutrino interactions due to the chiral odd
transversity Generalized Parton Distribution (GPD). We conclude that in
contrast to pion electroproduction, in neutrino-induced reactions these
corrections are small. This happens due to large contribution of unpolarized
GPDs H, E to the leading-twist amplitude in neutrinoproduction. We provide a
computational code, which can be used for evaluation of the cross-sections
accounting for these twist-3 corrections with various GPD models. Our results
are particularly relevant for analyses of the pion and kaon production in the
Minerva experiment at FERMILAB.
| [
{
"created": "Wed, 8 Jan 2014 00:03:42 GMT",
"version": "v1"
}
] | 2014-03-12 | [
[
"Kopeliovich",
"B. Z.",
""
],
[
"Schmidt",
"Ivan",
""
],
[
"Siddikov",
"M.",
""
]
] | In this paper we estimate the size of twist-3 corrections to the deeply virtual meson production in neutrino interactions due to the chiral odd transversity Generalized Parton Distribution (GPD). We conclude that in contrast to pion electroproduction, in neutrino-induced reactions these corrections are small. This happens due to large contribution of unpolarized GPDs H, E to the leading-twist amplitude in neutrinoproduction. We provide a computational code, which can be used for evaluation of the cross-sections accounting for these twist-3 corrections with various GPD models. Our results are particularly relevant for analyses of the pion and kaon production in the Minerva experiment at FERMILAB. |
hep-ph/9909352 | Tim M. P. Tait | Tim M.P. Tait (Argonne National Lab) | The t W- Mode of Single Top Production | 16 pages, 4 figures | Phys.Rev.D61:034001,2000 | 10.1103/PhysRevD.61.034001 | ANL-HEP-PR-99-98 | hep-ph hep-ex | null | The t W- mode of single top production is proposed as an important means to
study the weak interactions of the top quark. While the rate of this mode is
most likely too small to be observed at Run II of the Fermilab Tevatron, it is
expected to be considerably larger at the CERN LHC. In this article the
inclusive t W- rate is computed, including O(1 / log (m_t^2 / m_b^2))
corrections, and when combined with detailed Monte Carlo simulations including
the top and W decay products, indicate that the t W- single top process may be
extracted from the considerable t tbar and W+ W- j backgrounds at low
luminosity runs of the LHC.
| [
{
"created": "Mon, 13 Sep 1999 23:40:25 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Tait",
"Tim M. P.",
"",
"Argonne National Lab"
]
] | The t W- mode of single top production is proposed as an important means to study the weak interactions of the top quark. While the rate of this mode is most likely too small to be observed at Run II of the Fermilab Tevatron, it is expected to be considerably larger at the CERN LHC. In this article the inclusive t W- rate is computed, including O(1 / log (m_t^2 / m_b^2)) corrections, and when combined with detailed Monte Carlo simulations including the top and W decay products, indicate that the t W- single top process may be extracted from the considerable t tbar and W+ W- j backgrounds at low luminosity runs of the LHC. |
hep-ph/0412350 | Konstantin Chetyrkin G. | P.A. Baikov, K.G. Chetyrkin and J.H. K\"uhn | Strange Quark Mass from Tau Lepton Decays with O(alpha_s^3) Accuracy | 4 pages. References updated. The final version accepted for
publication in Physical Review Letters. The complete paper is also available
via the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/ | Phys.Rev.Lett.95:012003,2005 | 10.1103/PhysRevLett.95.012003 | SFB/CPP-04-72, TTPTTP04-28 | hep-ph | null | The first complete calculation of the quadratic quark mass correction to the
correlator of the two currents relevant for the strangeness-changing
semihadronic tau-decay rate is presented including its real part at the
four-loop level. This allows to perform the extraction of the strange quark
mass m_s from the decay width of the tau-lepton with full O(alpha_s^3)
accuracy. In agreement with previous estimates the newly computed alpha_s^3
term proves to be rather large. This justifies inclusion of the similarly
estimated alpha_s^4 term in phenomenological analysis. Combined with an updated
value of V_{us} and an ``'improved'' version of the renormalization group
improvement of the perturbative series this leads to an increase of the central
value of m_s by about 20 % and a partial reduction of the theoretical
uncertainty by about 50 %.
| [
{
"created": "Wed, 22 Dec 2004 19:09:53 GMT",
"version": "v1"
},
{
"created": "Wed, 18 May 2005 19:23:46 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Baikov",
"P. A.",
""
],
[
"Chetyrkin",
"K. G.",
""
],
[
"Kühn",
"J. H.",
""
]
] | The first complete calculation of the quadratic quark mass correction to the correlator of the two currents relevant for the strangeness-changing semihadronic tau-decay rate is presented including its real part at the four-loop level. This allows to perform the extraction of the strange quark mass m_s from the decay width of the tau-lepton with full O(alpha_s^3) accuracy. In agreement with previous estimates the newly computed alpha_s^3 term proves to be rather large. This justifies inclusion of the similarly estimated alpha_s^4 term in phenomenological analysis. Combined with an updated value of V_{us} and an ``'improved'' version of the renormalization group improvement of the perturbative series this leads to an increase of the central value of m_s by about 20 % and a partial reduction of the theoretical uncertainty by about 50 %. |
hep-ph/9309321 | Masashi Hayakawa | M.Hayakawa, T.Kurimoto and A.I.Sanda | Chiral Lagrangian with higher resonances and flavour $ SU(3) $ breaking | 29 pages, REVTEX(ver.3), DPNU-93-34 | Prog.Theor.Phys. 92 (1994) 377-396 | 10.1143/ptp/92.2.377 | null | hep-ph | null | A chiral Lagrangian with $ SU(3) $ breaking and higher resonances is
proposed. In this model, the $ SU(3) $ breaking structure in
vector-pseudoscalar sector is realized with the decay constants of pseudoscalar
mesons and the masses of vector mesons used as inputs. We examine whether the
resulting $ SU(3) $ breaking effect in the charge radii of pseudoscalar mesons
is consistent with the experimental facts.
| [
{
"created": "Fri, 24 Sep 1993 05:41:27 GMT",
"version": "v1"
}
] | 2017-02-01 | [
[
"Hayakawa",
"M.",
""
],
[
"Kurimoto",
"T.",
""
],
[
"Sanda",
"A. I.",
""
]
] | A chiral Lagrangian with $ SU(3) $ breaking and higher resonances is proposed. In this model, the $ SU(3) $ breaking structure in vector-pseudoscalar sector is realized with the decay constants of pseudoscalar mesons and the masses of vector mesons used as inputs. We examine whether the resulting $ SU(3) $ breaking effect in the charge radii of pseudoscalar mesons is consistent with the experimental facts. |
hep-ph/9310299 | null | J. Stern, N. H. Fuchs and M. Knecht | Light Quark Masses from Exclusive Tau Decays: An Experimental Proposal | 18 pages, 13 figures not included, available upon request, IPNO-TH
93-38 | null | null | null | hep-ph | null | A method of indirect measurement of the light quark running mass $\hat{m} =
(m_d + m_u)/2$ is elaborated in detail. It is based on measuring 1\%-level
azimuthal angular asymmetries in the decay $\tau \rightarrow \nu_\tau + 3\pi$.
The latter are then used in QCD sum rules to obtain experimental lower bounds
for $\hat{m}$. For a sample of $2.5 \times 10^5$ $\tau \rightarrow \nu_\tau +
3\pi$ decays free of background, the resulting statistical error in the bound
for $\hat{m}$ is estimated to be 1 MeV, i.e., comparable to the systematic
error due to the use of QCD sum rules. Contribution to the Third Workshop on
the $\tau$ Charm Factory 1-6 June 1993, Marbella, Spain.
| [
{
"created": "Fri, 15 Oct 1993 15:26:12 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Stern",
"J.",
""
],
[
"Fuchs",
"N. H.",
""
],
[
"Knecht",
"M.",
""
]
] | A method of indirect measurement of the light quark running mass $\hat{m} = (m_d + m_u)/2$ is elaborated in detail. It is based on measuring 1\%-level azimuthal angular asymmetries in the decay $\tau \rightarrow \nu_\tau + 3\pi$. The latter are then used in QCD sum rules to obtain experimental lower bounds for $\hat{m}$. For a sample of $2.5 \times 10^5$ $\tau \rightarrow \nu_\tau + 3\pi$ decays free of background, the resulting statistical error in the bound for $\hat{m}$ is estimated to be 1 MeV, i.e., comparable to the systematic error due to the use of QCD sum rules. Contribution to the Third Workshop on the $\tau$ Charm Factory 1-6 June 1993, Marbella, Spain. |
hep-ph/0002182 | E. Reya | M. Gluck, E. Reya (Dortmund U.) | Phenomenology of the Flavor-Asymmetry in the Light-Quark Sea of the
Nucleon | 5 pages, LaTeX, 2 figures, uses epsfig | Mod.Phys.Lett. A15 (2000) 883 | 10.1142/S0217732300000888 | DO-TH 2000/03 | hep-ph | null | A phenomenological ansatz for the flavor-asymmetry of the light sea
distributions of the nucleon, based on the Pauli exclusion principle, is
proposed. This ansatz is compatible with the measured flavor-asymmetry of the
unpolarized sea distributions, $\bar{d}>\bar{u}$, of the nucleon. A prediction
for the corresponding polarized flavor-asymmetry is presented and shown to
agree with predictions of (chiral quark--soliton) models which successfully
reproduced the flavor-asymmetry of the unpolarized sea.
| [
{
"created": "Thu, 17 Feb 2000 13:19:34 GMT",
"version": "v1"
},
{
"created": "Wed, 17 May 2000 15:44:07 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Gluck",
"M.",
"",
"Dortmund U."
],
[
"Reya",
"E.",
"",
"Dortmund U."
]
] | A phenomenological ansatz for the flavor-asymmetry of the light sea distributions of the nucleon, based on the Pauli exclusion principle, is proposed. This ansatz is compatible with the measured flavor-asymmetry of the unpolarized sea distributions, $\bar{d}>\bar{u}$, of the nucleon. A prediction for the corresponding polarized flavor-asymmetry is presented and shown to agree with predictions of (chiral quark--soliton) models which successfully reproduced the flavor-asymmetry of the unpolarized sea. |
hep-ph/0012060 | German A. Luna-Acosta | R.L. Ingraham, G.A.Luna-Acosta, and J.M. Wilkes | An explanation of the "negative neutrino mass squared" anomaly in
tritium $ \beta$-decay based on a theory of mass | 5 pages, 1 Figure. Submitted to Physics Letters B (Dec. 2000) | null | null | null | hep-ph | null | A proposed solution of the anomalous behavior of the electron spectrum near
the endpoint of tritium $\beta$-decay is offered. It is based on a new theory
of mass in which mass becomes a dynamical variable, and the electron in the
tritium $\beta$-decay has a narrow mass distribution. The predicted Kurie plots
explain the main feature (``$m_{\nu}^2 < 0 $'') of this anomalous behavior.
| [
{
"created": "Wed, 6 Dec 2000 00:07:39 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ingraham",
"R. L.",
""
],
[
"Luna-Acosta",
"G. A.",
""
],
[
"Wilkes",
"J. M.",
""
]
] | A proposed solution of the anomalous behavior of the electron spectrum near the endpoint of tritium $\beta$-decay is offered. It is based on a new theory of mass in which mass becomes a dynamical variable, and the electron in the tritium $\beta$-decay has a narrow mass distribution. The predicted Kurie plots explain the main feature (``$m_{\nu}^2 < 0 $'') of this anomalous behavior. |
hep-ph/9210252 | Zurab Berezhiani | Zurab Berezhiani and Riccardo Rattazzi | Radiative Origin of the Fermion Mass Hierarchy: A Realistic and
Predictive Approach | 8 pages, LATEX, LMU-08/92 | null | null | null | hep-ph | null | The up-down splitting within quark families increases with the family number:
m_u ~ m_d, m_c > m_s, m_t >> m_b. We show an approach that realizes this
feature of the spectrum in a natural way. We suggest that the mass hierarchy is
first generated by radiative effects in a sector of heavy isosinglet fermions,
and then projected to the ordinary light fermions by means of a seesaw mixing.
The hierarchy appears then inverted in the light fermion sector. We present a
simple left-right symmetric gauge model in which the P- and CP-parities and an
isotopical "up-down" symmetry are softly (or spontaneously) broken in the Higgs
potential. Experimentally consistent predictions are obtained. The Cabibbo
angle is automatically in the needed range: Theta_C ~ 0.2. The top quark is
naturally heavy, but not too heavy: m_t < 150 GeV.
| [
{
"created": "Tue, 20 Oct 1992 18:57:22 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Oct 1992 18:46:47 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Berezhiani",
"Zurab",
""
],
[
"Rattazzi",
"Riccardo",
""
]
] | The up-down splitting within quark families increases with the family number: m_u ~ m_d, m_c > m_s, m_t >> m_b. We show an approach that realizes this feature of the spectrum in a natural way. We suggest that the mass hierarchy is first generated by radiative effects in a sector of heavy isosinglet fermions, and then projected to the ordinary light fermions by means of a seesaw mixing. The hierarchy appears then inverted in the light fermion sector. We present a simple left-right symmetric gauge model in which the P- and CP-parities and an isotopical "up-down" symmetry are softly (or spontaneously) broken in the Higgs potential. Experimentally consistent predictions are obtained. The Cabibbo angle is automatically in the needed range: Theta_C ~ 0.2. The top quark is naturally heavy, but not too heavy: m_t < 150 GeV. |
hep-ph/9901299 | Maxim Pospelov | Alon E. Faraggi and Maxim Pospelov | Phenomenological Issues in TeV scale Gravity with Light Neutrino Masses | 12 pages. Standard Latex. 2 eps figures. Minor changes, to appear in
Physics Letters B | Phys.Lett.B458:237-244,1999 | 10.1016/S0370-2693(99)00557-2 | TPI-MINN-99/4; UMN-TH-1740-99 | hep-ph | null | The possible existence of bulk singlet neutrinos in the scenario with large
compactified dimensions and low string scale $M_*$ has important consequences
for low-energy observables. We demonstrate that intergenerational mass
splitting and mixing lead to the effective violation of the lepton universality
and flavor changing processes in charged lepton sector. Current experimental
constraints push $M_*$ to the scale of 10 TeV over most of the interesting
range for neutrino mass splitting.
| [
{
"created": "Wed, 13 Jan 1999 22:11:57 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Jan 1999 19:36:40 GMT",
"version": "v2"
},
{
"created": "Thu, 6 May 1999 18:53:35 GMT",
"version": "v3"
}
] | 2010-04-06 | [
[
"Faraggi",
"Alon E.",
""
],
[
"Pospelov",
"Maxim",
""
]
] | The possible existence of bulk singlet neutrinos in the scenario with large compactified dimensions and low string scale $M_*$ has important consequences for low-energy observables. We demonstrate that intergenerational mass splitting and mixing lead to the effective violation of the lepton universality and flavor changing processes in charged lepton sector. Current experimental constraints push $M_*$ to the scale of 10 TeV over most of the interesting range for neutrino mass splitting. |
1812.02556 | Jihn E. Kim | Junu Jeong, Jihn E. Kim, Se-Jin Kim | Flavor mixing inspired by flipped SU(5) GUT | 9 pages of LaTeX file. arXiv admin note: substantial text overlap
with arXiv:1810.10796 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We obtain a phenomenologically acceptable Cabibbo-Kobayashi-Maskawa matrix in
a flipped SU(5) model inspired by the compactification of heterotic string
$E_8\times E_8'$.
| [
{
"created": "Thu, 6 Dec 2018 14:38:59 GMT",
"version": "v1"
}
] | 2019-02-12 | [
[
"Jeong",
"Junu",
""
],
[
"Kim",
"Jihn E.",
""
],
[
"Kim",
"Se-Jin",
""
]
] | We obtain a phenomenologically acceptable Cabibbo-Kobayashi-Maskawa matrix in a flipped SU(5) model inspired by the compactification of heterotic string $E_8\times E_8'$. |
0810.3803 | Daniel Seipt | D. Seipt, M. Bluhm (Forschungszentrum Dresden-Rossendorf), B. Kampfer
(Forschungszentrum Dresden-Rossendorf & Dresden, Tech. U.) | Quark mass dependence of thermal excitations in QCD in one-loop
approximation | Oct 2008. 25 pp | J.Phys.G36:045003,2009 | 10.1088/0954-3899/36/4/045003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A comprehensive determination of the quark mass dependence in the dispersion
relations of thermal excitations of gluons and quarks in non-Abelian gauge
theory (QCD) is presented for the one-loop approximation in Feynman gauge.
Larger values of the coupling are admitted, and the gauge dependence is
discussed. In a Dyson-Schwinger type approach, the effect of higher orders is
estimated for asymptotic thermal masses.
| [
{
"created": "Tue, 21 Oct 2008 13:52:37 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Seipt",
"D.",
"",
"Forschungszentrum Dresden-Rossendorf"
],
[
"Bluhm",
"M.",
"",
"Forschungszentrum Dresden-Rossendorf"
],
[
"Kampfer",
"B.",
"",
"Forschungszentrum Dresden-Rossendorf & Dresden, Tech. U."
]
] | A comprehensive determination of the quark mass dependence in the dispersion relations of thermal excitations of gluons and quarks in non-Abelian gauge theory (QCD) is presented for the one-loop approximation in Feynman gauge. Larger values of the coupling are admitted, and the gauge dependence is discussed. In a Dyson-Schwinger type approach, the effect of higher orders is estimated for asymptotic thermal masses. |
hep-ph/0311262 | Arttu Rajantie | A. Rajantie | Phase Transitions in the Early Universe and Defect Formation | 11 pages, 6 figures, revtex. To appear in the proceedings of
"Cosmological Phase Transitions and Topological Defects", 22-24 May 2003,
Porto, Portugal | null | null | DAMTP-2003-129 | hep-ph | null | In the first one of these two lectures, I give an introductory review of
phase transitions in finite temperature field theories. I highlight the
differences between theories with global and local symmetries, and the
similarities between cosmological phase transitions and phase transitions in
superconductors. In the second one, I review the theory of defect formation in
finite temperature phase transitions, emphasising the differences between
systems with broken global and local symmetries. These same principles apply to
relativistic and condensed matter systems alike.
| [
{
"created": "Thu, 20 Nov 2003 15:50:57 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Rajantie",
"A.",
""
]
] | In the first one of these two lectures, I give an introductory review of phase transitions in finite temperature field theories. I highlight the differences between theories with global and local symmetries, and the similarities between cosmological phase transitions and phase transitions in superconductors. In the second one, I review the theory of defect formation in finite temperature phase transitions, emphasising the differences between systems with broken global and local symmetries. These same principles apply to relativistic and condensed matter systems alike. |
hep-ph/0211195 | Gursevil Turan | Berin Sirvanli and Gursevil Turan | Rare B_s -> \gamma \nu \bar{\nu} decay with polarized photon and new
physics effects | 9 pages, 5 figures | Mod.Phys.Lett. A18 (2003) 47-56 | 10.1142/S0217732303009460 | null | hep-ph | null | Using the most general, model independent effective Hamiltonian, the rare B_s
->\gamma \nu \bar{\nu} decay with polarized photon is studied. The sensitivity
of the branching ratio and photon polarization to the new Wilson coefficients
are investigated. It is shown that these physical observables are sensitive to
the vector and tensor type interactions, which would be useful in search of new
physics.
| [
{
"created": "Wed, 13 Nov 2002 09:29:54 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Sirvanli",
"Berin",
""
],
[
"Turan",
"Gursevil",
""
]
] | Using the most general, model independent effective Hamiltonian, the rare B_s ->\gamma \nu \bar{\nu} decay with polarized photon is studied. The sensitivity of the branching ratio and photon polarization to the new Wilson coefficients are investigated. It is shown that these physical observables are sensitive to the vector and tensor type interactions, which would be useful in search of new physics. |
2010.11190 | Ryan Plestid | Roni Harnik, Ryan Plestid, Maxim Pospelov, Harikrishnan Ramani | Millicharged Cosmic Rays and Low Recoil Detectors | 12 pages + 4 pages appendix, 12 figures| matches journal version | Phys. Rev. D 103, 075029 (2021) | 10.1103/PhysRevD.103.075029 | FERMILAB-PUB-20-523-T | hep-ph astro-ph.CO astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the production of a "fast flux" of hypothetical millicharged
particles (mCPs) in the interstellar medium (ISM). We consider two possible
sources induced by cosmic rays: (a) $pp\rightarrow$(meson)$\rightarrow$(mCP)
which adds to atmospheric production of mCPs, and (b) cosmic-ray up-scattering
on a millicharged component of dark matter. We notice that the galactic
magnetic fields retain mCPs for a long time, leading to an enhancement of the
fast flux by many orders of magnitude. In both scenarios, we calculate the
expected signal for direct dark matter detection aimed at electron recoil. We
observe that in Scenario (a) neutrino detectors (ArgoNeuT and Super-Kamiokande)
still provide superior sensitivity compared to dark matter detectors (XENON1T).
However, in scenarios with a boosted dark matter component, the dark matter
detectors perform better, given the enhancement of the upscattered flux at low
velocities. Given the uncertainties, both in the flux generation model and in
the actual atomic physics leading to electron recoil, it is still possible that
the XENON1T-reported excess may come from a fast mCP flux, which will be
decisively tested with future experiments.
| [
{
"created": "Wed, 21 Oct 2020 18:00:00 GMT",
"version": "v1"
},
{
"created": "Tue, 18 May 2021 12:56:39 GMT",
"version": "v2"
}
] | 2021-05-19 | [
[
"Harnik",
"Roni",
""
],
[
"Plestid",
"Ryan",
""
],
[
"Pospelov",
"Maxim",
""
],
[
"Ramani",
"Harikrishnan",
""
]
] | We consider the production of a "fast flux" of hypothetical millicharged particles (mCPs) in the interstellar medium (ISM). We consider two possible sources induced by cosmic rays: (a) $pp\rightarrow$(meson)$\rightarrow$(mCP) which adds to atmospheric production of mCPs, and (b) cosmic-ray up-scattering on a millicharged component of dark matter. We notice that the galactic magnetic fields retain mCPs for a long time, leading to an enhancement of the fast flux by many orders of magnitude. In both scenarios, we calculate the expected signal for direct dark matter detection aimed at electron recoil. We observe that in Scenario (a) neutrino detectors (ArgoNeuT and Super-Kamiokande) still provide superior sensitivity compared to dark matter detectors (XENON1T). However, in scenarios with a boosted dark matter component, the dark matter detectors perform better, given the enhancement of the upscattered flux at low velocities. Given the uncertainties, both in the flux generation model and in the actual atomic physics leading to electron recoil, it is still possible that the XENON1T-reported excess may come from a fast mCP flux, which will be decisively tested with future experiments. |
2406.03950 | Matthias Saimpert | Henning Bahl, Alberto Carnelli, Fr\'ed\'eric D\'eliot, Elina Fuchs,
Anastasia Kotsokechagia, Tanguy Lucas Marsault, Marco Menen, Laurent
Schoeffel, Matthias Saimpert | $\cal{CP}$-sensitive simplified template cross-sections for $t\bar t H$ | 45 pages, 20 figures | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The $\cal{CP}$ structure of the Higgs boson is a fundamental property which
has not yet been constrained with high precision. $\cal{CP}$ violation in the
Yukawa coupling between the Higgs boson and top quark pair can be probed
directly at the Large Hadron Collider by measuring top-quark-associated Higgs
production. Multivariate analysis techniques commonly developed so far by the
experiments are designed for a specific signal model and, therefore, complicate
reinterpretations and statistical combinations. With this motivation in mind,
we propose a $\cal{CP}$-sensitive extension of the simplified template
cross-section (STXS) framework. Considering multiple Higgs decay channels, we
perform an in-depth comparison of $\cal{CP}$-sensitive observables and
combinations thereof. Our resulting proposal is to extend the existing binning
in the transverse momentum of the Higgs boson $p_{T,H}$ by either the
pseudorapidity difference of the two top-quarks $\Delta \eta_{t\bar t}$, or a
variable that is based on the top quark momenta, namely $b_2$ or the
Collins-Soper angle $|\cos\theta^*|$. We demonstrate that this variable
selection provides close to optimal sensitivity to the $\cal{CP}$ mixture in
the top Yukawa coupling for an integrated luminosity of $300\mathrm{fb}^{-1}$,
by comparing it to the results of a multivariate analysis. Our results also
suggest a benefit of the two-dimensional STXS extension at
3000$\mathrm{fb}^{-1}$.
| [
{
"created": "Thu, 6 Jun 2024 10:51:30 GMT",
"version": "v1"
}
] | 2024-06-07 | [
[
"Bahl",
"Henning",
""
],
[
"Carnelli",
"Alberto",
""
],
[
"Déliot",
"Frédéric",
""
],
[
"Fuchs",
"Elina",
""
],
[
"Kotsokechagia",
"Anastasia",
""
],
[
"Marsault",
"Tanguy Lucas",
""
],
[
"Menen",
"Marco",
""
],
[
"Schoeffel",
"Laurent",
""
],
[
"Saimpert",
"Matthias",
""
]
] | The $\cal{CP}$ structure of the Higgs boson is a fundamental property which has not yet been constrained with high precision. $\cal{CP}$ violation in the Yukawa coupling between the Higgs boson and top quark pair can be probed directly at the Large Hadron Collider by measuring top-quark-associated Higgs production. Multivariate analysis techniques commonly developed so far by the experiments are designed for a specific signal model and, therefore, complicate reinterpretations and statistical combinations. With this motivation in mind, we propose a $\cal{CP}$-sensitive extension of the simplified template cross-section (STXS) framework. Considering multiple Higgs decay channels, we perform an in-depth comparison of $\cal{CP}$-sensitive observables and combinations thereof. Our resulting proposal is to extend the existing binning in the transverse momentum of the Higgs boson $p_{T,H}$ by either the pseudorapidity difference of the two top-quarks $\Delta \eta_{t\bar t}$, or a variable that is based on the top quark momenta, namely $b_2$ or the Collins-Soper angle $|\cos\theta^*|$. We demonstrate that this variable selection provides close to optimal sensitivity to the $\cal{CP}$ mixture in the top Yukawa coupling for an integrated luminosity of $300\mathrm{fb}^{-1}$, by comparing it to the results of a multivariate analysis. Our results also suggest a benefit of the two-dimensional STXS extension at 3000$\mathrm{fb}^{-1}$. |
0709.2884 | Hendrik van Hees | H. van Hees, M. Mannarelli, V.Greco and R. Rapp | Nonperturbative Heavy-Quark Diffusion in the Quark-Gluon Plasma | 4 pages, 4 figures, v2: version to appear in Phys. Rev. Lett | Phys.Rev.Lett.100:192301,2008 | 10.1103/PhysRevLett.100.192301 | null | hep-ph nucl-ex nucl-th | null | We evaluate heavy-quark (HQ) transport properties in a Quark-Gluon Plasma
(QGP) employing interaction potentials extracted from thermal lattice QCD.
Within a Brueckner many-body scheme we calculate in-medium T-matrices for
charm- and bottom-quark scattering off light quarks in the QGP. The
interactions are dominated by attractive meson and diquark channels which
support bound and resonance states up to temperatures of ~1.5 T_c. We apply
pertinent drag and diffusion coefficients (supplemented by perturbative
scattering off gluons) in Langevin simulations in an expanding fireball to
compute HQ spectra and elliptic flow in \sqrt{s_{NN}}=200 GeV Au-Au collisions.
We find good agreement with semileptonic electron-decay spectra which supports
our nonperturbative computation of the HQ diffusion coefficient, suggestive for
a strongly coupled QGP.
| [
{
"created": "Tue, 18 Sep 2007 17:18:12 GMT",
"version": "v1"
},
{
"created": "Sun, 4 May 2008 13:11:22 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"van Hees",
"H.",
""
],
[
"Mannarelli",
"M.",
""
],
[
"Greco",
"V.",
""
],
[
"Rapp",
"R.",
""
]
] | We evaluate heavy-quark (HQ) transport properties in a Quark-Gluon Plasma (QGP) employing interaction potentials extracted from thermal lattice QCD. Within a Brueckner many-body scheme we calculate in-medium T-matrices for charm- and bottom-quark scattering off light quarks in the QGP. The interactions are dominated by attractive meson and diquark channels which support bound and resonance states up to temperatures of ~1.5 T_c. We apply pertinent drag and diffusion coefficients (supplemented by perturbative scattering off gluons) in Langevin simulations in an expanding fireball to compute HQ spectra and elliptic flow in \sqrt{s_{NN}}=200 GeV Au-Au collisions. We find good agreement with semileptonic electron-decay spectra which supports our nonperturbative computation of the HQ diffusion coefficient, suggestive for a strongly coupled QGP. |
1512.01599 | Thomas A. Trainor | Thomas A. Trainor and Duncan J. Prindle | CCharge-multiplicity dependence of single-particle transverse-rapidity
$\bf y_t$ and pseudorapidity $\bf \eta$ densities and 2D angular correlations
from 200 GeV $p$-$p$ collisions | 21 pages, 14 figures | null | 10.1103/PhysRevD.93.014031 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An established phenomenology and theoretical interpretation of $p$-$p$
collision data at lower collision energies should provide a reference for
$p$-$p$ and other collision systems at higher energies, against which claims of
novel physics may be tested. The description of $p$-$p$ collisions at the
relativistic heavy ion collider (RHIC) has remained incomplete even as claims
for collectivity and other novelties in data from smaller systems at the large
hadron collider (LHC) have emerged recently. In this study we report the
charge-multiplicity dependence of two-dimensional (2D) angular correlations and
of single-particle (SP) densities on transverse rapidity $y_t$ and
pseudorapidity $\eta$ from 200 GeV $p$-$p$ collisions. We define a
comprehensive and self-consistent two-component (soft + hard) model (TCM) for
hadron production and report a significant $p$-$p$ nonjet (NJ) quadrupole
component as a third (angular-correlation) component. Our results have
implications for $p$-$p$ centrality, the underlying event (UE), collectivity in
small systems and the existence of flows in high-energy nuclear collisions.
| [
{
"created": "Sat, 5 Dec 2015 00:24:43 GMT",
"version": "v1"
}
] | 2016-02-17 | [
[
"Trainor",
"Thomas A.",
""
],
[
"Prindle",
"Duncan J.",
""
]
] | An established phenomenology and theoretical interpretation of $p$-$p$ collision data at lower collision energies should provide a reference for $p$-$p$ and other collision systems at higher energies, against which claims of novel physics may be tested. The description of $p$-$p$ collisions at the relativistic heavy ion collider (RHIC) has remained incomplete even as claims for collectivity and other novelties in data from smaller systems at the large hadron collider (LHC) have emerged recently. In this study we report the charge-multiplicity dependence of two-dimensional (2D) angular correlations and of single-particle (SP) densities on transverse rapidity $y_t$ and pseudorapidity $\eta$ from 200 GeV $p$-$p$ collisions. We define a comprehensive and self-consistent two-component (soft + hard) model (TCM) for hadron production and report a significant $p$-$p$ nonjet (NJ) quadrupole component as a third (angular-correlation) component. Our results have implications for $p$-$p$ centrality, the underlying event (UE), collectivity in small systems and the existence of flows in high-energy nuclear collisions. |
2012.08269 | Poonam Mehta | Jogesh Rout, Sheeba Shafaq, Mary Bishai and Poonam Mehta | Physics prospects with the second oscillation maximum at Deep
Underground Neutrino Experiment | to appear in Phys. Rev. D | Phys. Rev. D 103, 116003 (2021) | 10.1103/PhysRevD.103.116003 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Current long-baseline neutrino-oscillation experiments such as NO$\nu$A and
T2K are mainly sensitive to physics in the neighbourhood of the first
oscillation maximum of the $\nu_\mu \to \nu_e$ oscillation probability. The
future Deep Underground Neutrino Experiment (DUNE) utilizes a wide-band beam
tune optimized for CP violation sensitivity that fully covers the region of the
first maxima and part of the second. In the present study, we elucidate the
role of second oscillation maximum in addressing issues pertaining to unknowns
in the standard three flavour paradigm. We consider a new DUNE beam tune
optimized for coverage of the region of the second oscillation maxima which
could be realized using proposed accelerator upgrades that provide multi-MW of
power at proton energies of 8 GeV. We find that addition of the multi-MW 8 GeV
beam to DUNE wide-band running leads to modest improvement in sensitivity to CP
violation, mass hierarchy, the octant of $\theta_{23}$ as well as the
resolution of $\delta$ and the Jarlskog invariant. Significant improvements to
the DUNE neutrino energy resolution yield a much larger improvement in
performance. We conclude that the standard DUNE wide-band beam when coupled
with excellent detector resolution capabilities is sufficient to resolve
$\delta$ to better than $\sim 12^\circ$ for all values of $\delta$ in a decade
of running. For second maxima (8 GeV 3MW) beam running concurrently with the
standard wide-band (80 GeV 2.2 MW) beam for 5 of the 10 years, it is found that
$\delta$ can be further resolved better than $\sim 10^\circ$ for all values of
$\delta$.
| [
{
"created": "Tue, 15 Dec 2020 13:08:42 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Feb 2021 17:34:44 GMT",
"version": "v2"
},
{
"created": "Fri, 16 Apr 2021 13:26:50 GMT",
"version": "v3"
}
] | 2021-06-04 | [
[
"Rout",
"Jogesh",
""
],
[
"Shafaq",
"Sheeba",
""
],
[
"Bishai",
"Mary",
""
],
[
"Mehta",
"Poonam",
""
]
] | Current long-baseline neutrino-oscillation experiments such as NO$\nu$A and T2K are mainly sensitive to physics in the neighbourhood of the first oscillation maximum of the $\nu_\mu \to \nu_e$ oscillation probability. The future Deep Underground Neutrino Experiment (DUNE) utilizes a wide-band beam tune optimized for CP violation sensitivity that fully covers the region of the first maxima and part of the second. In the present study, we elucidate the role of second oscillation maximum in addressing issues pertaining to unknowns in the standard three flavour paradigm. We consider a new DUNE beam tune optimized for coverage of the region of the second oscillation maxima which could be realized using proposed accelerator upgrades that provide multi-MW of power at proton energies of 8 GeV. We find that addition of the multi-MW 8 GeV beam to DUNE wide-band running leads to modest improvement in sensitivity to CP violation, mass hierarchy, the octant of $\theta_{23}$ as well as the resolution of $\delta$ and the Jarlskog invariant. Significant improvements to the DUNE neutrino energy resolution yield a much larger improvement in performance. We conclude that the standard DUNE wide-band beam when coupled with excellent detector resolution capabilities is sufficient to resolve $\delta$ to better than $\sim 12^\circ$ for all values of $\delta$ in a decade of running. For second maxima (8 GeV 3MW) beam running concurrently with the standard wide-band (80 GeV 2.2 MW) beam for 5 of the 10 years, it is found that $\delta$ can be further resolved better than $\sim 10^\circ$ for all values of $\delta$. |
2407.07203 | Lisa L. Everett | George N. Wojcik, Shu Tian Eu, Lisa L. Everett | Graph Reinforcement Learning for Exploring BSM Model Spaces | 57 pages, 14 figures, 15 tables | null | null | null | hep-ph hep-ex hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a methodology for performing scans of BSM parameter spaces with
reinforcement learning (RL). We identify a novel procedure using graph neural
networks that is capable of exploring spaces of models without the user
specifying a fixed particle content, allowing broad classes of BSM models to be
explored. In theory, the technique is applicable to nearly any model space with
a pre-specified gauge group. We provide a generic procedure by which a suitable
graph grammar can be developed for any BSM model which features user-specified
symmetry groups and a finite number of different possible particle species. As
a proof of concept, we construct the graph grammar for theories with
vector-like leptons that may or may not be charged under a dark U(1) group,
inspired by portal matter extensions of the sub-GeV vector portal/kinetic
mixing simplified dark matter models. We then use this graph grammar to create
a RL environment tasked with creating models with these vector-like leptons
that are consistent with a list of a variety of precision observables. The RL
agent succeeds in developing models that can address the observed muon
anomalous magnetic moment discrepancy while remaining consistent with flavor
violation and electroweak precision observables, including both constructions
that have previously been studied as well as new models which have not, to our
knowledge, previously been identified. By inspecting the resulting ensembles of
models that the agent produces and experimenting with different configurations
for our RL environment and graph grammar, we also infer various lessons about
the development of these environments that can be transferable to RL scans of
more complicated model spaces, and comment on future directions for the
development of this technique into a more mature tool.
| [
{
"created": "Tue, 9 Jul 2024 19:44:59 GMT",
"version": "v1"
}
] | 2024-07-11 | [
[
"Wojcik",
"George N.",
""
],
[
"Eu",
"Shu Tian",
""
],
[
"Everett",
"Lisa L.",
""
]
] | We present a methodology for performing scans of BSM parameter spaces with reinforcement learning (RL). We identify a novel procedure using graph neural networks that is capable of exploring spaces of models without the user specifying a fixed particle content, allowing broad classes of BSM models to be explored. In theory, the technique is applicable to nearly any model space with a pre-specified gauge group. We provide a generic procedure by which a suitable graph grammar can be developed for any BSM model which features user-specified symmetry groups and a finite number of different possible particle species. As a proof of concept, we construct the graph grammar for theories with vector-like leptons that may or may not be charged under a dark U(1) group, inspired by portal matter extensions of the sub-GeV vector portal/kinetic mixing simplified dark matter models. We then use this graph grammar to create a RL environment tasked with creating models with these vector-like leptons that are consistent with a list of a variety of precision observables. The RL agent succeeds in developing models that can address the observed muon anomalous magnetic moment discrepancy while remaining consistent with flavor violation and electroweak precision observables, including both constructions that have previously been studied as well as new models which have not, to our knowledge, previously been identified. By inspecting the resulting ensembles of models that the agent produces and experimenting with different configurations for our RL environment and graph grammar, we also infer various lessons about the development of these environments that can be transferable to RL scans of more complicated model spaces, and comment on future directions for the development of this technique into a more mature tool. |
2011.10891 | Yuki Fujimoto | Yuki Fujimoto, Kenji Fukushima | Equation of state of cold and dense QCD matter in resummed perturbation
theory | 9 pages, 6 figures; Figs. 5 and 6 are updated, results unchanged | Phys. Rev. D 105, 014025 (2022) | 10.1103/PhysRevD.105.014025 | null | hep-ph astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the Hard Dense Loop resummation at finite quark mass and evaluate
the equation of state (EoS) of cold and dense QCD matter in $\beta$
equilibrium. The resummation in the quark sector has an effect of lowering the
baryon number density and the EoS turns out to have much smaller uncertainty
than the perturbative QCD estimate. Our numerical results favor smooth matching
between the EoS from the resummed QCD calculation at high density and the
extrapolated EoS from the nuclear matter density region. We also point out that
the speed of sound in our EoS slightly exceeds the conformal limit.
| [
{
"created": "Sat, 21 Nov 2020 23:11:54 GMT",
"version": "v1"
},
{
"created": "Sun, 5 Dec 2021 17:51:10 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Mar 2022 04:21:20 GMT",
"version": "v3"
}
] | 2022-03-15 | [
[
"Fujimoto",
"Yuki",
""
],
[
"Fukushima",
"Kenji",
""
]
] | We discuss the Hard Dense Loop resummation at finite quark mass and evaluate the equation of state (EoS) of cold and dense QCD matter in $\beta$ equilibrium. The resummation in the quark sector has an effect of lowering the baryon number density and the EoS turns out to have much smaller uncertainty than the perturbative QCD estimate. Our numerical results favor smooth matching between the EoS from the resummed QCD calculation at high density and the extrapolated EoS from the nuclear matter density region. We also point out that the speed of sound in our EoS slightly exceeds the conformal limit. |
hep-ph/9910342 | Valery Lyubovitskij | M. A. Ivanov (JINR, Dubna), J. G. Korner (Mainz University), V. E.
Lyubovitskij (JINR, Dubna and Tomsk University), A. G. Rusetsky (Bern
University, JINR, Dubna and Tbilisi University) | Lambda_b and Lambda_c baryon decays at finite values of heavy quark
masses | 12 pages, LaTeX-file, 1 Figure | Phys.Lett.B476:58-64,2000 | 10.1016/S0370-2693(00)00111-8 | Preprint Mainz Univ. MZ-TH/99-45 | hep-ph | null | Semileptonic decays of Lambda_b and Lambda_c baryons are studied within the
Relativistic Three-Quark Model using finite heavy quark mass values. Employing
the same parameters as have been used previously for the description of
exclusive decays of heavy baryons in the heavy quark limit we calculate the six
form factors of the process and the corresponding decay rates. Our calculation
shows that the ``finite mass'' corrections are important in heavy-to-light
transitions and are not negligible in heavy-to-heavy transitions.
| [
{
"created": "Thu, 14 Oct 1999 16:02:25 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Ivanov",
"M. A.",
"",
"JINR, Dubna"
],
[
"Korner",
"J. G.",
"",
"Mainz University"
],
[
"Lyubovitskij",
"V. E.",
"",
"JINR, Dubna and Tomsk University"
],
[
"Rusetsky",
"A. G.",
"",
"Bern\n University, JINR, Dubna and Tbilisi University"
]
] | Semileptonic decays of Lambda_b and Lambda_c baryons are studied within the Relativistic Three-Quark Model using finite heavy quark mass values. Employing the same parameters as have been used previously for the description of exclusive decays of heavy baryons in the heavy quark limit we calculate the six form factors of the process and the corresponding decay rates. Our calculation shows that the ``finite mass'' corrections are important in heavy-to-light transitions and are not negligible in heavy-to-heavy transitions. |
hep-ph/0107163 | Satoshi Mishima | S. Mishima | B -> phi K decays in perturbative QCD approach | 15 pages, 5 figures, RevTeX, Minor changes, a reference added | null | null | DPNU-01-13 | hep-ph | null | We calculate the branching ratios and CP asymmetries of the $B\to \phi K$
decays using perturbative QCD approach, which includes $k_T$ and threshold
resummations. Our results of branching ratios are consistent with the
experimental data and larger than those obtained from the naive factorization
assumption and the QCD-improved factorization approach.
| [
{
"created": "Sun, 15 Jul 2001 12:18:17 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Jul 2001 16:12:01 GMT",
"version": "v2"
},
{
"created": "Tue, 31 Jul 2001 08:36:55 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Mishima",
"S.",
""
]
] | We calculate the branching ratios and CP asymmetries of the $B\to \phi K$ decays using perturbative QCD approach, which includes $k_T$ and threshold resummations. Our results of branching ratios are consistent with the experimental data and larger than those obtained from the naive factorization assumption and the QCD-improved factorization approach. |
hep-ph/0504143 | Nikolaos Mavromatos | Nick E. Mavromatos (King's College London) | CPT Violation: Theory and Phenomenology | 11 pages latex, no figures. Invited talk at International Conf. on
Exotic Atoms 2005, Vienna, Academy of Sciences, February 21-25 2005, to be
published by Austrian Academy of Sciences | null | null | null | hep-ph | null | Invariance under the combined transformations of CPT (in any order) is
guaranteed in Quantum Field Theory in flat space times due to a basic theorem
(CPT Theorem). The currently used formalism of particle physics phenomenology
is based on this theorem. However, there may be violations of the basic
underlying assumptions of this theorem in models of quantum gravity, namely
Lorentz covariance, unitarity and/or locality of interactions. This may lead to
observable (in principle) effects of CPT violation. Since there is no single
figure of merit for this potential violation,the respective phenomenology is
rather complex. In this review I classify the possible ways of CPT violation,
and I describe briefly their phenomenology, in both terrestrial and
astrophysical experiments, including antimatter factories, neutral mesons and
neutrinos, and discuss the various sensitivities.
| [
{
"created": "Sun, 17 Apr 2005 20:30:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Mavromatos",
"Nick E.",
"",
"King's College London"
]
] | Invariance under the combined transformations of CPT (in any order) is guaranteed in Quantum Field Theory in flat space times due to a basic theorem (CPT Theorem). The currently used formalism of particle physics phenomenology is based on this theorem. However, there may be violations of the basic underlying assumptions of this theorem in models of quantum gravity, namely Lorentz covariance, unitarity and/or locality of interactions. This may lead to observable (in principle) effects of CPT violation. Since there is no single figure of merit for this potential violation,the respective phenomenology is rather complex. In this review I classify the possible ways of CPT violation, and I describe briefly their phenomenology, in both terrestrial and astrophysical experiments, including antimatter factories, neutral mesons and neutrinos, and discuss the various sensitivities. |
hep-ph/9311327 | Mannel Thomas | Guey-Lin Lin and Thomas Mannel | Subleading Corrections to Semileptonic Lambda_c Decays | 13 pages, no figures, LaTeX, CERN-TH.7086/93, IP-ASTP-30-93 | Phys.Lett. B321 (1994) 417-424 | 10.1016/0370-2693(94)90269-0 | null | hep-ph | null | The semileptonic decay $\Lambda_c \to \Lambda \ell \nu$ is considered in the
framework of heavy quark effective theory beyond the leading order in the
$1/m_c$ expansion. According to our estimate the polarization variable will
receive only very small corrections such that $\alpha_{\Lambda_c} \le -0.95$.
| [
{
"created": "Mon, 22 Nov 1993 09:20:04 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Lin",
"Guey-Lin",
""
],
[
"Mannel",
"Thomas",
""
]
] | The semileptonic decay $\Lambda_c \to \Lambda \ell \nu$ is considered in the framework of heavy quark effective theory beyond the leading order in the $1/m_c$ expansion. According to our estimate the polarization variable will receive only very small corrections such that $\alpha_{\Lambda_c} \le -0.95$. |
2103.15617 | Ghazaal Ghaffari | Manuel Drees and Ghazaal Ghaffari | Impact of the Bounds on the Direct Search for Neutralino Dark Matter on
Naturalness | 15 Pages,6 figures | null | 10.1103/PhysRevD.104.075031 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the Minimal Supersymmetric Extension of the Standard Model (MSSM) the
higgsino mass parameter $\mu$ appears both in the masses of the Higgs bosons
and in the neutralino mass matrix. Electroweak finetuning therefore prefers
small values of $|\mu|$. On the other hand, bino--like neutralinos make a good
dark matter candidate. We show that current direct search limits then impose a
strong lower bound on $|\mu|$, in particular for $\mu > 0$ or if the masses of
the heavy Higgs bosons of the MSSM are near their current limit from LHC
searches. There is therefore some tension between finetuning and neutralino
dark matter in the MSSM. We also provide simple analytical expressions which in
most cases closely reproduce the numerical results.
| [
{
"created": "Mon, 29 Mar 2021 13:58:38 GMT",
"version": "v1"
}
] | 2021-11-03 | [
[
"Drees",
"Manuel",
""
],
[
"Ghaffari",
"Ghazaal",
""
]
] | In the Minimal Supersymmetric Extension of the Standard Model (MSSM) the higgsino mass parameter $\mu$ appears both in the masses of the Higgs bosons and in the neutralino mass matrix. Electroweak finetuning therefore prefers small values of $|\mu|$. On the other hand, bino--like neutralinos make a good dark matter candidate. We show that current direct search limits then impose a strong lower bound on $|\mu|$, in particular for $\mu > 0$ or if the masses of the heavy Higgs bosons of the MSSM are near their current limit from LHC searches. There is therefore some tension between finetuning and neutralino dark matter in the MSSM. We also provide simple analytical expressions which in most cases closely reproduce the numerical results. |
1810.11455 | Binoy Patra Krishna | Jitendra Pal and Binoy Krishna Patra | S-Matrix approach to Compton scattering at the tree level in a strong
magnetic field | 43 pages, 3 figures | null | null | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have studied the Compton scattering ($\gamma e^- \longrightarrow \gamma
e^-$) at the tree level in a homogeneous background of strong magnetic field
($|eB| \gg { m }^{ 2 },~\text{m is the mass of electron}$) through the S-matrix
approach. For that purpose, using the Schwinger propagator for the electron, we
have first calculated the square of the S-matrix element in the Landau gauge by
summing over the final states of electron and photon and averaging over the
initial states of the same. In the strong magnetic field, only the lowest
Landau level for electron is considered. Finally we have computed the
crosssection for Compton scattering as a function of initial photon energy for
the different strengths of strong magnetic fields, where we have found that the
crosssection in vacuum gets decreased due to the presence of strong magnetic
field. However, for a fixed initial photon energy, the crosssection increases
linearly with the magnetic field.
| [
{
"created": "Wed, 24 Oct 2018 13:37:18 GMT",
"version": "v1"
}
] | 2018-10-30 | [
[
"Pal",
"Jitendra",
""
],
[
"Patra",
"Binoy Krishna",
""
]
] | We have studied the Compton scattering ($\gamma e^- \longrightarrow \gamma e^-$) at the tree level in a homogeneous background of strong magnetic field ($|eB| \gg { m }^{ 2 },~\text{m is the mass of electron}$) through the S-matrix approach. For that purpose, using the Schwinger propagator for the electron, we have first calculated the square of the S-matrix element in the Landau gauge by summing over the final states of electron and photon and averaging over the initial states of the same. In the strong magnetic field, only the lowest Landau level for electron is considered. Finally we have computed the crosssection for Compton scattering as a function of initial photon energy for the different strengths of strong magnetic fields, where we have found that the crosssection in vacuum gets decreased due to the presence of strong magnetic field. However, for a fixed initial photon energy, the crosssection increases linearly with the magnetic field. |
hep-ph/0406026 | Dan Hooper | Dan Hooper and Graham D. Kribs | Kaluza-Klein Dark Matter and the Positron Excess | 5 pages, 3 figures, REVTeX 4 | Phys.Rev. D70 (2004) 115004 | 10.1103/PhysRevD.70.115004 | null | hep-ph astro-ph | null | The excess of cosmic positrons observed by the HEAT experiment may be the
result of Kaluza-Klein dark matter annihilating in the galactic halo.
Kaluza-Klein dark matter annihilates dominantly into charged leptons that yield
a large number and hard spectrum of positrons per annihilation. Given a
Kaluza-Klein dark matter particle with a mass in the range of 300-400 GeV, no
exceptional substructure or clumping is needed in the local distribution of
dark matter to generate a positron flux that explains the HEAT observations.
This is in contrast to supersymmetric dark matter that requires unnaturally
large amounts of dark substructure to produce the observed positron excess.
Future astrophysical and collider tests are outlined that will confirm or rule
out this explanation of the HEAT data.
| [
{
"created": "Wed, 2 Jun 2004 15:28:25 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Hooper",
"Dan",
""
],
[
"Kribs",
"Graham D.",
""
]
] | The excess of cosmic positrons observed by the HEAT experiment may be the result of Kaluza-Klein dark matter annihilating in the galactic halo. Kaluza-Klein dark matter annihilates dominantly into charged leptons that yield a large number and hard spectrum of positrons per annihilation. Given a Kaluza-Klein dark matter particle with a mass in the range of 300-400 GeV, no exceptional substructure or clumping is needed in the local distribution of dark matter to generate a positron flux that explains the HEAT observations. This is in contrast to supersymmetric dark matter that requires unnaturally large amounts of dark substructure to produce the observed positron excess. Future astrophysical and collider tests are outlined that will confirm or rule out this explanation of the HEAT data. |
hep-ph/9903225 | Akram | N.F. Nasrallah (Lebanese University, Faculty of Science) | On the Spin content of the Nucleon | 7 pages, two (eps) figure, minor corrections and one figure added | Phys.Rev. D61 (2000) 056002 | 10.1103/PhysRevD.61.056002 | null | hep-ph | null | A QCD sum rule calculation of Balistky and Ji on the spin content of the
nucleon is done with a different approach to the evaluation of the bilocal
contributions and to the extraction of the nucleon pole residues. The result
obtained is much more numerically stable which puts their conclusion that about
half of the nucleon spin is carried by gluons on firmer ground.
| [
{
"created": "Tue, 2 Mar 1999 03:08:12 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Mar 1999 13:31:35 GMT",
"version": "v2"
},
{
"created": "Sun, 30 May 1999 20:38:01 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Nasrallah",
"N. F.",
"",
"Lebanese University, Faculty of Science"
]
] | A QCD sum rule calculation of Balistky and Ji on the spin content of the nucleon is done with a different approach to the evaluation of the bilocal contributions and to the extraction of the nucleon pole residues. The result obtained is much more numerically stable which puts their conclusion that about half of the nucleon spin is carried by gluons on firmer ground. |
2407.20329 | Kierthika Chathirathas | Kierthika Chathirathas, Torben Ferber, Felix Kahlhoefer and Alessandro
Morandini | Finding excesses in model parameter space | 20 pages, 12 figures, code available at
https://github.com/amorandini/param_hunt | null | null | TTP24-027, P3H-24-051 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Simulation-based inference (SBI) makes it possible to infer the parameters of
a model from high-dimensional low-level features of the observed events. In
this work we show how this method can be used to establish the presence of a
weak signal on top of an unknown background, to discard background events and
to determine the signal properties. The key idea is to use SBI methods to
identify events that are similar to each other in the sense that they agree on
the inferred model parameters. We illustrate this method for the case of
axion-like particles decaying to photons at beam-dump experiments. For poor
detector resolution the diphoton mass cannot be reliably reconstructed, so
there is no simple high-level observable that can be used to perform a bump
hunt. Since the SBI methods do not require explicit high-level observables,
they offer a promising alternative to increase the sensitivity to new physics.
| [
{
"created": "Mon, 29 Jul 2024 18:00:04 GMT",
"version": "v1"
}
] | 2024-07-31 | [
[
"Chathirathas",
"Kierthika",
""
],
[
"Ferber",
"Torben",
""
],
[
"Kahlhoefer",
"Felix",
""
],
[
"Morandini",
"Alessandro",
""
]
] | Simulation-based inference (SBI) makes it possible to infer the parameters of a model from high-dimensional low-level features of the observed events. In this work we show how this method can be used to establish the presence of a weak signal on top of an unknown background, to discard background events and to determine the signal properties. The key idea is to use SBI methods to identify events that are similar to each other in the sense that they agree on the inferred model parameters. We illustrate this method for the case of axion-like particles decaying to photons at beam-dump experiments. For poor detector resolution the diphoton mass cannot be reliably reconstructed, so there is no simple high-level observable that can be used to perform a bump hunt. Since the SBI methods do not require explicit high-level observables, they offer a promising alternative to increase the sensitivity to new physics. |
hep-ph/9403408 | Klaus Kinder-Geiger | K. Geiger | Comment on Transverse Mass Dependence of Partonic Dilepton Production in
Ultra-Relativistic Heavy Ion Collisions | 6 pages, RevTex | Phys.Rev.Lett. 74 (1995) 1487 | 10.1103/PhysRevLett.74.1487 | null | hep-ph | null | Comment on scale breaking effects in dilepton emission from partons during
the early stage of ultra-relativistic heavy ion collisions
| [
{
"created": "Thu, 31 Mar 1994 17:04:09 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Geiger",
"K.",
""
]
] | Comment on scale breaking effects in dilepton emission from partons during the early stage of ultra-relativistic heavy ion collisions |
1201.4252 | Takeshi Fukuyama | Takeshi Fukuyama | Searching for New Physics beyond the Standard Model in Electric Dipole
Moment | 95pages. References are added. Appendix K is revised | null | 10.1142/S0217751X12300153 | MISC-2012-03 | hep-ph nucl-ex nucl-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is a theoretical review of exploration of new physics beyond the
Standard Model (SM) in electric dipole moment (EDM) in elementary particles,
atoms, and molecule. EDM is a very important CP violating phenomenon and
sensitive to new physics. Starting with the estimations of EDM of
quarks-leptons in the SM, we explore the new signals beyond the SM. However,
these works drive us to more wide fronteers where we serach fundamental physics
using atoms and molecules and vice versa. Paramagnetic atoms and molecules have
great enhancement factor on electron EDM. Diamagnetic atoms and molecules are
very sensitive to nuclear P and T odd processes. Thus the EDM becomes the key
word not only of New Physics but also of unprecedented fruitful collaboration
among particle, atomic. molecular physics. This review intends to help such
collaboration over the wide range of physicists.
| [
{
"created": "Fri, 20 Jan 2012 10:29:14 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Jan 2012 06:09:47 GMT",
"version": "v2"
},
{
"created": "Mon, 4 Jun 2012 00:27:26 GMT",
"version": "v3"
},
{
"created": "Wed, 18 Jul 2012 04:59:32 GMT",
"version": "v4"
},
{
"created": "Wed, 17 Oct 2012 06:57:43 GMT",
"version": "v5"
},
{
"created": "Tue, 18 Jun 2013 08:15:57 GMT",
"version": "v6"
},
{
"created": "Mon, 15 Jul 2013 23:21:32 GMT",
"version": "v7"
}
] | 2015-06-03 | [
[
"Fukuyama",
"Takeshi",
""
]
] | This is a theoretical review of exploration of new physics beyond the Standard Model (SM) in electric dipole moment (EDM) in elementary particles, atoms, and molecule. EDM is a very important CP violating phenomenon and sensitive to new physics. Starting with the estimations of EDM of quarks-leptons in the SM, we explore the new signals beyond the SM. However, these works drive us to more wide fronteers where we serach fundamental physics using atoms and molecules and vice versa. Paramagnetic atoms and molecules have great enhancement factor on electron EDM. Diamagnetic atoms and molecules are very sensitive to nuclear P and T odd processes. Thus the EDM becomes the key word not only of New Physics but also of unprecedented fruitful collaboration among particle, atomic. molecular physics. This review intends to help such collaboration over the wide range of physicists. |
1207.3730 | C. Pallis | C. Pallis and N. Toumbas | Leptogenesis and Neutrino Masses in an Inflationary SUSY Pati-Salam
Model | Prepared for the edited collection "Open Questions in Cosmology"
(InTech, ISBN 980-953-307-658-9) edited by Dr. Gonzalo J. Olmo | null | 10.5772/51888 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We implement the mechanism of non-thermal leptogenesis in the framework of an
inflationary model based on a supersymmetric (SUSY) Pati-Salam Grand Unified
Theory (GUT). In particular, we show that inflation is driven by a quartic
potential associated with the Higgs fields involved in the spontaneous GUT
symmetry breaking, in the presence of a non-minimal coupling of the inflaton
field to gravity. The inflationary model relies on renormalizable
superpotential terms and does not lead to overproduction of magnetic monopoles.
It is largely independent of one-loop radiative corrections, and it can be
consistent with current observational data on the inflationary observables,
with the GUT symmetry breaking scale assuming its SUSY value. Non-thermal
leptogenesis is realized by the out-of-equilibrium decay of the two lightest
right-handed (RH) neutrinos, which are produced by the inflaton decay.
Confronting our scenario with the current observational data on light
neutrinos, the GUT prediction for the heaviest Dirac neutrino mass, the baryon
asymmetry of the universe and the gravitino limit on the reheating temperature,
we constrain the masses of the RH neutrinos in the range (10^10-10^15) GeV and
the Dirac neutrino masses of the two first generations to values between 0.1
and 20 GeV.
| [
{
"created": "Mon, 16 Jul 2012 17:04:09 GMT",
"version": "v1"
}
] | 2013-02-01 | [
[
"Pallis",
"C.",
""
],
[
"Toumbas",
"N.",
""
]
] | We implement the mechanism of non-thermal leptogenesis in the framework of an inflationary model based on a supersymmetric (SUSY) Pati-Salam Grand Unified Theory (GUT). In particular, we show that inflation is driven by a quartic potential associated with the Higgs fields involved in the spontaneous GUT symmetry breaking, in the presence of a non-minimal coupling of the inflaton field to gravity. The inflationary model relies on renormalizable superpotential terms and does not lead to overproduction of magnetic monopoles. It is largely independent of one-loop radiative corrections, and it can be consistent with current observational data on the inflationary observables, with the GUT symmetry breaking scale assuming its SUSY value. Non-thermal leptogenesis is realized by the out-of-equilibrium decay of the two lightest right-handed (RH) neutrinos, which are produced by the inflaton decay. Confronting our scenario with the current observational data on light neutrinos, the GUT prediction for the heaviest Dirac neutrino mass, the baryon asymmetry of the universe and the gravitino limit on the reheating temperature, we constrain the masses of the RH neutrinos in the range (10^10-10^15) GeV and the Dirac neutrino masses of the two first generations to values between 0.1 and 20 GeV. |
1904.05617 | Camilo Alejandro Rojas Pacheco Mr | Camilo A. Rojas, F. Ochoa and R. Martinez | CP symmetry violation in the scalar sector of 331 models | null | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In order to understand some frameworks for CP Violation scenarios in the
scalar sector, a 331 model was considered which its main property is the
incorporation of a local group symmetry SU(3) in the electroweak sector. In
particular, a 331 model with a particular choice of free parameter. CP
Violation scenarios were obtained by introducing a discrete symmetry in the
scalar triplets, which exhibit a spontaneous CP Violation frame with just one
independent CP phase associated. Mass state rotations were obtained.
| [
{
"created": "Thu, 11 Apr 2019 10:34:21 GMT",
"version": "v1"
}
] | 2019-04-12 | [
[
"Rojas",
"Camilo A.",
""
],
[
"Ochoa",
"F.",
""
],
[
"Martinez",
"R.",
""
]
] | In order to understand some frameworks for CP Violation scenarios in the scalar sector, a 331 model was considered which its main property is the incorporation of a local group symmetry SU(3) in the electroweak sector. In particular, a 331 model with a particular choice of free parameter. CP Violation scenarios were obtained by introducing a discrete symmetry in the scalar triplets, which exhibit a spontaneous CP Violation frame with just one independent CP phase associated. Mass state rotations were obtained. |
hep-ph/9204216 | Rajesh Parwani | Rajesh R. Parwani | Resummation in a Hot Scalar Field Theory | 26 pages (figures not included) | Phys.Rev.D45:4695,1992; Erratum-ibid.D48:5965,1993;
Phys.Rev.D48:5965,1993 | 10.1103/PhysRevD.45.4695 10.1103/PhysRevD.48.5965 | null | hep-ph | null | A resummed perturbative expansion is used to obtain the self-energy in the
high-temperature \(g^2\phi^4\) field theory model up to order $g^4$. From this
the zero momentum pole of the effective propagator is evaluated to determine
the induced thermal mass and damping rate for the bosons in the plasma to order
$g^3$. The calculations are performed in the imaginary time formalism and a
simple diagrammatic analysis is used to identify the relevant diagrams at each
order. Results are compared with similar real-time calculations found in the
literature.
| [
{
"created": "Fri, 10 Apr 1992 04:03:55 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Parwani",
"Rajesh R.",
""
]
] | A resummed perturbative expansion is used to obtain the self-energy in the high-temperature \(g^2\phi^4\) field theory model up to order $g^4$. From this the zero momentum pole of the effective propagator is evaluated to determine the induced thermal mass and damping rate for the bosons in the plasma to order $g^3$. The calculations are performed in the imaginary time formalism and a simple diagrammatic analysis is used to identify the relevant diagrams at each order. Results are compared with similar real-time calculations found in the literature. |
2309.16570 | Shota Nakagawa | Kwang Sik Jeong, Shota Nakagawa, Fuminobu Takahashi, and Masaki Yamada | Dissipation of axion energy via the Schwinger and Witten effects | 22 pages, 9 figures | null | null | TU-1211 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the presence of an anomalous CP phase in a U(1) gauge theory, a monopole
becomes a dyon via the Witten effect. When the anomalous CP phase is promoted
to a dynamical field, the axion, the electric charge of the dyon changes
according to the coherent motion of the axion oscillation. Once the electric
charge exceeds a certain threshold, the Schwinger pair production of charged
particles becomes efficient near the surface of the dyon. These
non-perturbative effects lead to the back reaction of the axion dynamics by
causing the dissipation of the axion oscillation energy and the change of the
effective potential due to the Witten effect. Taking these effects into
account, we consider the dynamics of the whole system, including the axion,
monopole, and charged heavy vector bosons, and discuss to what extent the axion
abundance is modified. We also discuss the electric dipole radiation from a
bound state of a monopole-anti-monopole pair due to the axion coherent
oscillations.
| [
{
"created": "Thu, 28 Sep 2023 16:26:43 GMT",
"version": "v1"
}
] | 2023-09-29 | [
[
"Jeong",
"Kwang Sik",
""
],
[
"Nakagawa",
"Shota",
""
],
[
"Takahashi",
"Fuminobu",
""
],
[
"Yamada",
"Masaki",
""
]
] | In the presence of an anomalous CP phase in a U(1) gauge theory, a monopole becomes a dyon via the Witten effect. When the anomalous CP phase is promoted to a dynamical field, the axion, the electric charge of the dyon changes according to the coherent motion of the axion oscillation. Once the electric charge exceeds a certain threshold, the Schwinger pair production of charged particles becomes efficient near the surface of the dyon. These non-perturbative effects lead to the back reaction of the axion dynamics by causing the dissipation of the axion oscillation energy and the change of the effective potential due to the Witten effect. Taking these effects into account, we consider the dynamics of the whole system, including the axion, monopole, and charged heavy vector bosons, and discuss to what extent the axion abundance is modified. We also discuss the electric dipole radiation from a bound state of a monopole-anti-monopole pair due to the axion coherent oscillations. |
hep-ph/0005032 | Boris Arbuzov | B.A. Arbuzov | Higgs Model without Elementary Scalars | 6 pages, latex, no figures | null | null | null | hep-ph | null | A model of interaction of massless vector and spinor fields is considered.
With the use of Bogolyubov quasi-average method we study a possibility of a
dynamical breaking of the initial symmetry. Assuming the existence of effective
cut-off $\Lambda$, we show, that there exists a solution, which breaks gauge
symmetry of the theory. Instead of Higgs scalars fermion-antifermion tachion
bound states are present here. As a result we have a theory with a massive
vector field, a massive spinor and a composite scalar.
| [
{
"created": "Thu, 4 May 2000 10:23:19 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Arbuzov",
"B. A.",
""
]
] | A model of interaction of massless vector and spinor fields is considered. With the use of Bogolyubov quasi-average method we study a possibility of a dynamical breaking of the initial symmetry. Assuming the existence of effective cut-off $\Lambda$, we show, that there exists a solution, which breaks gauge symmetry of the theory. Instead of Higgs scalars fermion-antifermion tachion bound states are present here. As a result we have a theory with a massive vector field, a massive spinor and a composite scalar. |
hep-ph/0512295 | Konstantin Chetyrkin G. | K.G. Chetyrkin and A. Khodjamirian | Strange Quark Mass from Pseudoscalar Sum Rule with O(alpha_s^4) Accuracy | Few misprints corrected, version to appear in European Physics
Journal C. 15 pages, the complete paper is also available via the www at
http://www-ttp.physik.uni-karlsruhe.de/Preprints/ | Eur.Phys.J.C46:721-728,2006 | 10.1140/epjc/s2006-02508-8 | SFB/CPP-05-84, TTP05-29, SI-HEP-2005-15 | hep-ph | null | We include the new, five-loop, O(alpha_s^4) correction into the QCD sum rule
used for the s-quark mass determination. The pseudoscalar Borel sum rule is
taken as a study case. The OPE for the correlation function with N^4LO,
O(alpha_s^4) accuracy in the perturbative part, and with dimension <= 6
operators reveals a good convergence. We observe a significant improvement of
stability of the sum rule with respect to the variation of the renormalization
scale after including the O(alpha_s^4) correction. We obtain the interval m_s(2
GeV)=105 \pm 6 \pm 7 MeV, which exhibits about 2 MeV increase of the central
value, if the O(alpha_s^4) terms are removed.
| [
{
"created": "Thu, 22 Dec 2005 12:08:05 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Feb 2006 17:52:13 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Chetyrkin",
"K. G.",
""
],
[
"Khodjamirian",
"A.",
""
]
] | We include the new, five-loop, O(alpha_s^4) correction into the QCD sum rule used for the s-quark mass determination. The pseudoscalar Borel sum rule is taken as a study case. The OPE for the correlation function with N^4LO, O(alpha_s^4) accuracy in the perturbative part, and with dimension <= 6 operators reveals a good convergence. We observe a significant improvement of stability of the sum rule with respect to the variation of the renormalization scale after including the O(alpha_s^4) correction. We obtain the interval m_s(2 GeV)=105 \pm 6 \pm 7 MeV, which exhibits about 2 MeV increase of the central value, if the O(alpha_s^4) terms are removed. |
hep-ph/0407063 | Tamar Kashti | Yuval Grossman, Tamar Kashti, Yosef Nir, Esteban Roulet | New Ways to Soft Leptogenesis | 18 pages, 3 figures | JHEP0411:080,2004 | 10.1088/1126-6708/2004/11/080 | SLAC-PUB-10519, WIS/18/04-July-DPP | hep-ph | null | Soft supersymmetry breaking terms involving heavy singlet sneutrinos provide
new sources of lepton number violation and of CP violation. In addition to the
CP violation in mixing, investigated previously, we find that `soft
leptogenesis' can be generated by CP violation in decay and in the interference
of mixing and decay. These additional ways to leptogenesis can be significant
for a singlet neutrino Majorana mass that is not much larger than the
supersymmetry breaking scale, $M < 100 m_{SUSY}$. In contrast to CP violation
in mixing, for some of these new contributions the sneutrino oscillation rate
can be much faster than the decay rate, so that the bilinear scalar term need
not be smaller than its natural scale.
| [
{
"created": "Tue, 6 Jul 2004 07:45:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Grossman",
"Yuval",
""
],
[
"Kashti",
"Tamar",
""
],
[
"Nir",
"Yosef",
""
],
[
"Roulet",
"Esteban",
""
]
] | Soft supersymmetry breaking terms involving heavy singlet sneutrinos provide new sources of lepton number violation and of CP violation. In addition to the CP violation in mixing, investigated previously, we find that `soft leptogenesis' can be generated by CP violation in decay and in the interference of mixing and decay. These additional ways to leptogenesis can be significant for a singlet neutrino Majorana mass that is not much larger than the supersymmetry breaking scale, $M < 100 m_{SUSY}$. In contrast to CP violation in mixing, for some of these new contributions the sneutrino oscillation rate can be much faster than the decay rate, so that the bilinear scalar term need not be smaller than its natural scale. |
hep-ph/0207148 | Anna Kulesza | A. Kulesza, G. Sterman, W. Vogelsang | Electroweak vector boson production in joint resummation | 5 pages, 2 figures. Talk presented by A. Kulesza at the XXXVIIth
Rencontres de Moriond `QCD and high energy hadronic interactions', Les Arcs,
France | null | null | BNL-HET-02/13, BNL-NT-02/16, RBRC-249, YITP-SB-02-36 | hep-ph | null | We study the application of the joint resummation to electroweak boson
production at hadron colliders. The joint resummation formalism resums both
threshold and transverse momentum corrections to the transverse momentum
distribution at next-to-leading logarithmic accuracy. We obtain a good
description of the transverse momentum distribution of Z bosons produced at the
Tevatron collider.
| [
{
"created": "Thu, 11 Jul 2002 19:13:47 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kulesza",
"A.",
""
],
[
"Sterman",
"G.",
""
],
[
"Vogelsang",
"W.",
""
]
] | We study the application of the joint resummation to electroweak boson production at hadron colliders. The joint resummation formalism resums both threshold and transverse momentum corrections to the transverse momentum distribution at next-to-leading logarithmic accuracy. We obtain a good description of the transverse momentum distribution of Z bosons produced at the Tevatron collider. |
1512.05085 | Xinyi Zhang | Xinyi Zhang | An $S_4$ model inspired from self-complementary neutrino mixing | updated analysis using the latest global analysis; references added;
matches version accepted for publication in J. Phys. G: Nucl. Part. Phys | null | 10.1088/1361-6471/aaa81b | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We build an $S_4$ model for neutrino masses and mixings based on the
self-complementary (SC) neutrino mixing pattern. The SC mixing is constructed
from the self-complementarity relation plus $\delta_{\rm CP}=-\frac{\pi}{2}$.
We elaborately construct the model at a percent level of accuracy to reproduce
the structure given by the SC mixing. After performing a numerical study on the
model's parameter space, we find that in the case of normal ordering, the model
can give predictions on the observables that are compatible with their
$3\sigma$ ranges, and give predictions for the not-yet observed quantities like
the lightest neutrino mass $m_1\in [0.003,0.010]$ eV and the Dirac CP violating
phase $\delta_{\rm CP}\in[256.72^\circ,283.33^\circ]$.
| [
{
"created": "Wed, 16 Dec 2015 08:25:18 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Jun 2016 11:02:33 GMT",
"version": "v2"
},
{
"created": "Wed, 31 Jan 2018 07:40:48 GMT",
"version": "v3"
}
] | 2018-02-01 | [
[
"Zhang",
"Xinyi",
""
]
] | We build an $S_4$ model for neutrino masses and mixings based on the self-complementary (SC) neutrino mixing pattern. The SC mixing is constructed from the self-complementarity relation plus $\delta_{\rm CP}=-\frac{\pi}{2}$. We elaborately construct the model at a percent level of accuracy to reproduce the structure given by the SC mixing. After performing a numerical study on the model's parameter space, we find that in the case of normal ordering, the model can give predictions on the observables that are compatible with their $3\sigma$ ranges, and give predictions for the not-yet observed quantities like the lightest neutrino mass $m_1\in [0.003,0.010]$ eV and the Dirac CP violating phase $\delta_{\rm CP}\in[256.72^\circ,283.33^\circ]$. |
1309.6597 | Mikulas Gintner | Mikulas Gintner, Josef Juran | The vector resonance triplet with the direct coupling to the third quark
generation | 17 pages, 10 figures, to be published in The European Physical
Journal C. arXiv admin note: text overlap with arXiv:1301.2124 | Eur. Phys. J. C 73 (2013) 2577 | 10.1140/epjc/s10052-013-2577-5 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The effective Lagrangian with scalar and vector resonances that might result
from new strong physics beyond the SM is formulated and studied. In particular,
the scalar resonance representing the recently discovered 125-GeV boson is
complemented with the SU(2)_{L+R} triplet of hypothetical vector resonances.
Motivated by experimental and theoretical considerations, the vector resonance
is allowed to couple directly to the third quark generation only. The coupling
is chiral-dependent and the interaction of the right top quark can differ from
that of the right bottom quark. To estimate the applicability range of the
effective Lagrangian the unitarity of the gauge boson scattering amplitudes is
analyzed. The experimental fits and limits on the free parameters of the vector
resonance triplet are investigated.
| [
{
"created": "Wed, 25 Sep 2013 18:16:08 GMT",
"version": "v1"
}
] | 2013-10-08 | [
[
"Gintner",
"Mikulas",
""
],
[
"Juran",
"Josef",
""
]
] | The effective Lagrangian with scalar and vector resonances that might result from new strong physics beyond the SM is formulated and studied. In particular, the scalar resonance representing the recently discovered 125-GeV boson is complemented with the SU(2)_{L+R} triplet of hypothetical vector resonances. Motivated by experimental and theoretical considerations, the vector resonance is allowed to couple directly to the third quark generation only. The coupling is chiral-dependent and the interaction of the right top quark can differ from that of the right bottom quark. To estimate the applicability range of the effective Lagrangian the unitarity of the gauge boson scattering amplitudes is analyzed. The experimental fits and limits on the free parameters of the vector resonance triplet are investigated. |
1804.10139 | Evgenij Martynov | E. Martynov, B. Nicolescu | Evidence for maximality of strong interactions from LHC forward data | Section 5 is extended, one reference is replaced, none of results is
changed | null | 10.1016/j.physletb.2018.09.049 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is important to check if the Froissaron-Maximal Odderon (FMO) approach is
the only model in agreement with the LHC data. We therefore generalized the FMO
approach by relaxing the $\ln^2s$ constraints both in the even-and
odd-under-crossing amplitude. We show that, in spite of a considerable freedom
of a large class of amplitudes, the best fits bring us back to the maximality
of strong interaction. Moreover, if we leave Odderon Regge pole intercept
$\alpha_O(0)$ completely free we find a very good solution for $\alpha_O(0)$
near -1 in agreement with the result of oddballs spectroscopy in QCD based on
AdS/CFT correspondence.
| [
{
"created": "Thu, 26 Apr 2018 16:09:16 GMT",
"version": "v1"
},
{
"created": "Mon, 7 May 2018 21:54:01 GMT",
"version": "v2"
},
{
"created": "Thu, 26 Jul 2018 10:42:50 GMT",
"version": "v3"
}
] | 2018-10-03 | [
[
"Martynov",
"E.",
""
],
[
"Nicolescu",
"B.",
""
]
] | It is important to check if the Froissaron-Maximal Odderon (FMO) approach is the only model in agreement with the LHC data. We therefore generalized the FMO approach by relaxing the $\ln^2s$ constraints both in the even-and odd-under-crossing amplitude. We show that, in spite of a considerable freedom of a large class of amplitudes, the best fits bring us back to the maximality of strong interaction. Moreover, if we leave Odderon Regge pole intercept $\alpha_O(0)$ completely free we find a very good solution for $\alpha_O(0)$ near -1 in agreement with the result of oddballs spectroscopy in QCD based on AdS/CFT correspondence. |
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