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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0911.2897 | Lei Wang | Lei Wang, Fuqiang Xu, Jin Min Yang | Higgs boson production in photon-photon collision at ILC: a comparative
study in different little Higgs models | Version in JHEP (h-g-g & h-gamma-gamma expressions added) | JHEP 1001:107,2010 | 10.1007/JHEP01(2010)107 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the process \gamma\gamma->h->bb_bar at ILC as a probe of different
little Higgs models, including the simplest little Higgs model (SLH), the
littlest Higgs model (LH), and two types of littlest Higgs models with T-parity
(LHT-I, LHT-II). Compared with the Standard Model (SM) prediction, the
production rate is found to be sizably altered in these little Higgs models
and, more interestingly, different models give different predictions. We find
that the production rate can be possibly enhanced only in the LHT-II for some
part of the parameter space, while in all other cases the rate is suppressed.
The suppression can be 10% in the LH and as much as 60% in both the SLH and the
LHT-I/LHT-II. The severe suppression in the SLH happens for a large \tan\beta
and a small m_h, in which the new decay mode h->\eta\eta (\eta is a light
pseudo-scalar) is dominant; while for the LHT-I/LHT-II the large suppression
occurs when f and m_h are both small so that the new decay mode h->A_H A_H is
dominant. Therefore, the precision measurement of such a production process at
the ILC will allow for a test of these models and even distinguish between
different scenarios.
| [
{
"created": "Sun, 15 Nov 2009 17:55:27 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Jan 2010 07:47:11 GMT",
"version": "v2"
}
] | 2010-03-19 | [
[
"Wang",
"Lei",
""
],
[
"Xu",
"Fuqiang",
""
],
[
"Yang",
"Jin Min",
""
]
] | We study the process \gamma\gamma->h->bb_bar at ILC as a probe of different little Higgs models, including the simplest little Higgs model (SLH), the littlest Higgs model (LH), and two types of littlest Higgs models with T-parity (LHT-I, LHT-II). Compared with the Standard Model (SM) prediction, the production rate is found to be sizably altered in these little Higgs models and, more interestingly, different models give different predictions. We find that the production rate can be possibly enhanced only in the LHT-II for some part of the parameter space, while in all other cases the rate is suppressed. The suppression can be 10% in the LH and as much as 60% in both the SLH and the LHT-I/LHT-II. The severe suppression in the SLH happens for a large \tan\beta and a small m_h, in which the new decay mode h->\eta\eta (\eta is a light pseudo-scalar) is dominant; while for the LHT-I/LHT-II the large suppression occurs when f and m_h are both small so that the new decay mode h->A_H A_H is dominant. Therefore, the precision measurement of such a production process at the ILC will allow for a test of these models and even distinguish between different scenarios. |
hep-ph/9503270 | Marek Pawlowski | Marek Pawlowski and Ryszard Raczka | A HIGGS-FREE MODEL FOR FUNDAMENTAL INTERACTIONS. Part II: Predictions
for Electroweak Observables | 1+12 pages, uuencoded, compressed p2.ps file. Revised version: new
data included, improved presentation | null | null | null | hep-ph | null | The predictions for electroweak observables following from Higgs-Free Model
for Fundamental Interactions are derived. It is shown that these predictions
are close to the Standard Model predictions and they are in a surprising
agreement with the experimental data. The analysis of electroweak observables
at low and high energy suggests that the Higgs mass $m_H$ is just the
ultraviolet cutoff which increases if the process energy scale increases. We
propose several experimental tests which can discriminate between the Standard
and the Higgs-Free Models.
| [
{
"created": "Wed, 8 Mar 1995 20:00:35 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Jun 1995 14:55:07 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Pawlowski",
"Marek",
""
],
[
"Raczka",
"Ryszard",
""
]
] | The predictions for electroweak observables following from Higgs-Free Model for Fundamental Interactions are derived. It is shown that these predictions are close to the Standard Model predictions and they are in a surprising agreement with the experimental data. The analysis of electroweak observables at low and high energy suggests that the Higgs mass $m_H$ is just the ultraviolet cutoff which increases if the process energy scale increases. We propose several experimental tests which can discriminate between the Standard and the Higgs-Free Models. |
hep-ph/9807217 | Basim Kamal | Basim Kamal (Brookhaven) | Transversity and Mass Singularities in Dimensional Regularization | 11 pages with figures included, Latex, includes style files;
shortened somewhat | null | null | BNL-HET-98/24 | hep-ph | null | The proton's transversity distribution will be measured at BNL's Relativistic
Heavy Ion Collider in upcoming experiments using the transverse Drell-Yan
process. Understanding the one-loop corrections is therefore important. Here,
the collinear structure in transverse Drell-Yan is investigated in detail using
dimensional regularization and the correct behaviour is found, although the
mechanism is non-trivial. The resulting n-dimensional transversity splitting
function (and consequently the one-loop transversity distribution and its
two-loop evolution) is found to be the same in both the anticommuting-gamma_5
scheme and the HVBM scheme. Alternative schemes are considered.
| [
{
"created": "Thu, 2 Jul 1998 01:07:36 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Nov 1998 23:29:28 GMT",
"version": "v2"
}
] | 2009-09-25 | [
[
"Kamal",
"Basim",
"",
"Brookhaven"
]
] | The proton's transversity distribution will be measured at BNL's Relativistic Heavy Ion Collider in upcoming experiments using the transverse Drell-Yan process. Understanding the one-loop corrections is therefore important. Here, the collinear structure in transverse Drell-Yan is investigated in detail using dimensional regularization and the correct behaviour is found, although the mechanism is non-trivial. The resulting n-dimensional transversity splitting function (and consequently the one-loop transversity distribution and its two-loop evolution) is found to be the same in both the anticommuting-gamma_5 scheme and the HVBM scheme. Alternative schemes are considered. |
hep-ph/0508178 | Matthias Neubert | Bjorn O. Lange (MIT), Matthias Neubert (Cornell & Heidelberg
University), and Gil Paz (Cornell University) | A two-loop relation between inclusive radiative and semileptonic B-decay
spectra | 22 pages, 4 figures; few comments and one reference added; version to
appear in JHEP | JHEP 0510:084,2005 | 10.1088/1126-6708/2005/10/084 | CLNS-05/1922, MIT-CTP-3668 | hep-ph | null | A shape-function independent relation is derived between the partial
B->X_u+l+nu decay rate with a cut on P_+=E_X-P_X<Delta and a weighted integral
over the normalized B->X_s+gamma photon-energy spectrum. The leading-power
contribution to the weight function is calculated at next-to-next-to-leading
order in renormalization-group improved perturbation theory, including exact
two-loop matching corrections at the scale mu_i^2 ~ m_b*Lambda_{QCD}. The
overall normalization of the weight function is obtained up to yet unknown
corrections of order [alpha_s(m_b)]^2. Power corrections from phase-space
factors are included exactly, while the remaining subleading contributions are
included at first order in 1/m_b. At this level unavoidable hadronic
uncertainties enter, which are estimated in a conservative way. The combined
theoretical accuracy in the extraction of |V_{ub}| is at the level of 5% if a
value of Delta near the charm threshold can be achieved experimentally.
| [
{
"created": "Tue, 16 Aug 2005 16:47:26 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Oct 2005 09:32:21 GMT",
"version": "v2"
}
] | 2011-02-01 | [
[
"Lange",
"Bjorn O.",
"",
"MIT"
],
[
"Neubert",
"Matthias",
"",
"Cornell & Heidelberg\n University"
],
[
"Paz",
"Gil",
"",
"Cornell University"
]
] | A shape-function independent relation is derived between the partial B->X_u+l+nu decay rate with a cut on P_+=E_X-P_X<Delta and a weighted integral over the normalized B->X_s+gamma photon-energy spectrum. The leading-power contribution to the weight function is calculated at next-to-next-to-leading order in renormalization-group improved perturbation theory, including exact two-loop matching corrections at the scale mu_i^2 ~ m_b*Lambda_{QCD}. The overall normalization of the weight function is obtained up to yet unknown corrections of order [alpha_s(m_b)]^2. Power corrections from phase-space factors are included exactly, while the remaining subleading contributions are included at first order in 1/m_b. At this level unavoidable hadronic uncertainties enter, which are estimated in a conservative way. The combined theoretical accuracy in the extraction of |V_{ub}| is at the level of 5% if a value of Delta near the charm threshold can be achieved experimentally. |
hep-ph/9905238 | Erasmo Ferreira | Erasmo Ferreira (Universidade Federal do Rio de Janeiro), Uri Maor
(Tel Aviv University) | An Investigation of the Hard Contribution to phi Photoproduction | 14 pages including 5 postscript figures | Phys.Lett. B470 (1999) 200-208 | 10.1016/S0370-2693(99)01287-3 | null | hep-ph | null | We investigate the possibility that the process of phi photoproduction may
have a significant hard perturbative QCD component. This suggestion is based on
a study of the energy dependence of the forward phi photoproduction cross
section followed by a calculation where we show that a coherent sum of the pQCD
and conventional soft Pomeron contributions provides an excellent reproduction
of the experimental data. Our results suggest that the transition from the
predominantly soft photoproduction of light rho and omega vector mesons to the
predominantly hard photoproduction of heavy J/psi and upsilon is smooth and
gradual, similar to the transition observed in deep inelastic scattering
studies of the proton structure function in the small x limit. Our predictions
for higher HERA energies are presented.
| [
{
"created": "Tue, 4 May 1999 13:30:36 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Jun 1999 23:33:51 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Ferreira",
"Erasmo",
"",
"Universidade Federal do Rio de Janeiro"
],
[
"Maor",
"Uri",
"",
"Tel Aviv University"
]
] | We investigate the possibility that the process of phi photoproduction may have a significant hard perturbative QCD component. This suggestion is based on a study of the energy dependence of the forward phi photoproduction cross section followed by a calculation where we show that a coherent sum of the pQCD and conventional soft Pomeron contributions provides an excellent reproduction of the experimental data. Our results suggest that the transition from the predominantly soft photoproduction of light rho and omega vector mesons to the predominantly hard photoproduction of heavy J/psi and upsilon is smooth and gradual, similar to the transition observed in deep inelastic scattering studies of the proton structure function in the small x limit. Our predictions for higher HERA energies are presented. |
2101.06261 | Bin Yan | Bin Yan, C.-P. Yuan | The anomalous $Zb\bar{b}$ couplings: From LEP to LHC | 6 pages, 6 figurs, matches version published in PRL | Phys. Rev. Lett. 127, 051801 (2021) | 10.1103/PhysRevLett.127.051801 | MSUHEP-21-001,LA-UR-21-20373 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The bottom quark forward-backward asymmetry ($A_{FB}^b$) data at LEP exhibits
a long-standing discrepancy with the standard model prediction. We propose a
novel method to probe the $Zb\bar{b}$ interactions through $gg\to Zh$
production at the LHC, which is sensitive to the axial-vector component of the
$Zb\bar{b}$ couplings. We demonstrate that the $Zh$ data collected at the 13
TeV LHC can already resolve the apparent degeneracy of the anomalous
$Zb\bar{b}$ couplings implied by the LEP precision electroweak measurements,
with a strong dependence on the observed distribution of the $Z$ boson
transverse momentum. We also show the potential of the HL-LHC to either verify
or exclude the anomalous $Zb\bar{b}$ couplings observed at LEP through
measuring the $Zh$ production rate at the HL-LHC, and this conclusion is not
sensitive to possible new physics contribution induced by top quark or Higgs
boson anomalous couplings in the loop.
| [
{
"created": "Fri, 15 Jan 2021 18:51:00 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Jul 2021 05:54:52 GMT",
"version": "v2"
}
] | 2021-08-04 | [
[
"Yan",
"Bin",
""
],
[
"Yuan",
"C. -P.",
""
]
] | The bottom quark forward-backward asymmetry ($A_{FB}^b$) data at LEP exhibits a long-standing discrepancy with the standard model prediction. We propose a novel method to probe the $Zb\bar{b}$ interactions through $gg\to Zh$ production at the LHC, which is sensitive to the axial-vector component of the $Zb\bar{b}$ couplings. We demonstrate that the $Zh$ data collected at the 13 TeV LHC can already resolve the apparent degeneracy of the anomalous $Zb\bar{b}$ couplings implied by the LEP precision electroweak measurements, with a strong dependence on the observed distribution of the $Z$ boson transverse momentum. We also show the potential of the HL-LHC to either verify or exclude the anomalous $Zb\bar{b}$ couplings observed at LEP through measuring the $Zh$ production rate at the HL-LHC, and this conclusion is not sensitive to possible new physics contribution induced by top quark or Higgs boson anomalous couplings in the loop. |
hep-ph/9910206 | Ulrich Baur | U. Baur (SUNY Buffalo) and T. Stelzer (Urbana) | Two Photon Radiation in W and Z Boson Production at the Tevatron
Collider | Revtex, 28 pages, 3 figures | Phys.Rev.D61:073007,2000 | 10.1103/PhysRevD.61.073007 | ILL-(TH)-99-4, UB-HET-99-01 | hep-ph | null | We present a calculation of two photon radiation in W and Z boson production
in hadronic collisions, based on the complete matrix elements for the processes
q\bar q'\to\ell^\pm\nu\gamma\gamma and q\bar q\to\ell^+\ell^-\gamma\gamma,
including finite charged lepton masses. In order to achieve stable numerical
results over the full phase space, multiconfiguration Monte Carlo techniques
are used to map the peaks in the differential cross section. Numerical results
are presented for the Fermilab Tevatron.
| [
{
"created": "Fri, 1 Oct 1999 18:40:24 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Baur",
"U.",
"",
"SUNY Buffalo"
],
[
"Stelzer",
"T.",
"",
"Urbana"
]
] | We present a calculation of two photon radiation in W and Z boson production in hadronic collisions, based on the complete matrix elements for the processes q\bar q'\to\ell^\pm\nu\gamma\gamma and q\bar q\to\ell^+\ell^-\gamma\gamma, including finite charged lepton masses. In order to achieve stable numerical results over the full phase space, multiconfiguration Monte Carlo techniques are used to map the peaks in the differential cross section. Numerical results are presented for the Fermilab Tevatron. |
hep-ph/0612067 | Marcello Ciafaloni | Marcello Ciafaloni | Infrared Sensitive Physics in QCD and in Electroweak Theory | 8 pages, to be published in the volume "String Theory of Fundamental
Interactions", published on the 65-th birthday of Gabriele Veneziano, M.
Gasperini and J. Maharana editors (Springer, Berlin Heidelberg, 2007) | Lect.NotesPhys.737:151-158,2008 | null | null | hep-ph | null | I recall the main ideas about the treatment of QCD infrared physics, as
developed in the late seventies, and I outline some novel applications of those
ideas to Electroweak Theory.
| [
{
"created": "Wed, 6 Dec 2006 13:03:57 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ciafaloni",
"Marcello",
""
]
] | I recall the main ideas about the treatment of QCD infrared physics, as developed in the late seventies, and I outline some novel applications of those ideas to Electroweak Theory. |
hep-ph/0112157 | Bhaskar Dutta | R. Arnowitt and B. Dutta | Dark Matter Detection Rates In SUGRA Models | 14 pages, latex, 8 figures, talk at COSMO-01, Rovaniemi, Finland,
August 29 - September 4, 2001 | null | null | null | hep-ph | null | Direct detection of Milky Way wimps are discussed within the framework of
R-parity conserving SUGRA models with grand unification at M_G. Two questions
are discussed: what SUGRA models can account for the DAMA data if this data is
confirmed, and is the full SUGRA parameter space accessible to future planned
detectors. Experimental constraints of the Higgs mass bound, the b-> s\gamma
bound, relic density constraints (including all co-annihilation channels), etc.
are imposed. In addition, the effect of the possible muon g - 2 anomaly are
examined. For mSUGRA, we find that the Higgs mass and b\to s\gamma constraint
puts a lower bound m_{1/2} > (300 - 400) GeV (i.e. m_{\tilde\chi^0_1} > (120 -
160) GeV) for \tan\beta < 50, and thus the largest theoretical
neutralino-proton cross sections still lie significantly below the DAMA 3\sigma
lower bound. (Predictions for \tan\beta> 50 become sensitive to the precise
value of m_t and m_b.) If in addition one imposes the muon anomaly constraint,
\mu must be positive and an upper bound of m_{1/2}< 850 GeV for \tan\beta < 50
is obtained. More generally, if \mu >0 and m_{1/2} < 1 TeV, the cross sections
are >~ 10^{-10} pb, and hence this parameter space would be mostly accessible
to planned high sensitivity detectors. For non-minimal SUGRA models, the cross
sections can be considerably larger, and a simple SU(5) model with
non-universal soft breaking in the Higgs and third generation is seen to give
cross sections in the DAMA range for \tan\beta >~ 15 with m_{\tilde\chi^0_1} >
80 GeV, and minimum cross sections >~10^{-10} pb for \mu > 0.
| [
{
"created": "Tue, 11 Dec 2001 16:15:43 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Arnowitt",
"R.",
""
],
[
"Dutta",
"B.",
""
]
] | Direct detection of Milky Way wimps are discussed within the framework of R-parity conserving SUGRA models with grand unification at M_G. Two questions are discussed: what SUGRA models can account for the DAMA data if this data is confirmed, and is the full SUGRA parameter space accessible to future planned detectors. Experimental constraints of the Higgs mass bound, the b-> s\gamma bound, relic density constraints (including all co-annihilation channels), etc. are imposed. In addition, the effect of the possible muon g - 2 anomaly are examined. For mSUGRA, we find that the Higgs mass and b\to s\gamma constraint puts a lower bound m_{1/2} > (300 - 400) GeV (i.e. m_{\tilde\chi^0_1} > (120 - 160) GeV) for \tan\beta < 50, and thus the largest theoretical neutralino-proton cross sections still lie significantly below the DAMA 3\sigma lower bound. (Predictions for \tan\beta> 50 become sensitive to the precise value of m_t and m_b.) If in addition one imposes the muon anomaly constraint, \mu must be positive and an upper bound of m_{1/2}< 850 GeV for \tan\beta < 50 is obtained. More generally, if \mu >0 and m_{1/2} < 1 TeV, the cross sections are >~ 10^{-10} pb, and hence this parameter space would be mostly accessible to planned high sensitivity detectors. For non-minimal SUGRA models, the cross sections can be considerably larger, and a simple SU(5) model with non-universal soft breaking in the Higgs and third generation is seen to give cross sections in the DAMA range for \tan\beta >~ 15 with m_{\tilde\chi^0_1} > 80 GeV, and minimum cross sections >~10^{-10} pb for \mu > 0. |
hep-ph/0404236 | Elena Accomando | E. Accomando, A. Ballestrero and E. Maina | PHASE - An event generator for six fermion physics at the LHC | 4 pages, Latex, 1 figure. Talk given by E. Accomando at the IX
International Workshop on Advanced Computing and Analysis Techniques in
Physics Research (ACAT03), KEK, Tsukuba, December 1-5, 2003 | Nucl.Instrum.Meth.A534:265-268,2004 | 10.1016/j.nima.2004.07.098 | DFTT 9/2004 | hep-ph | null | PHASE is a Monte Carlo event generator, under construction, for all Standard
Model processes with six fermions in the final state at the LHC. It employs the
full set of tree level Feynman diagrams, taking into account fermion masses for
b quarks. The program can generate unweighted events for any subset of all six
fermion final states in a single run, by making use of dedicated pre-samples.
An interface to hadronization is provided.
| [
{
"created": "Tue, 27 Apr 2004 12:01:14 GMT",
"version": "v1"
}
] | 2011-01-27 | [
[
"Accomando",
"E.",
""
],
[
"Ballestrero",
"A.",
""
],
[
"Maina",
"E.",
""
]
] | PHASE is a Monte Carlo event generator, under construction, for all Standard Model processes with six fermions in the final state at the LHC. It employs the full set of tree level Feynman diagrams, taking into account fermion masses for b quarks. The program can generate unweighted events for any subset of all six fermion final states in a single run, by making use of dedicated pre-samples. An interface to hadronization is provided. |
hep-ph/0505134 | Seung-Il Nam | Seung-Il Nam (RCNP, Osaka Univ., Japan and Dept. of Phys. & NuRI,
Pusan Univ., Korea), Atsushi Hosaka (RCNP, Osaka Univ., Japan) and Hyun-Chul
Kim (Dept. of Phys. & NuRI, Pusan Univ., Korea) | Suppression of Theta^+(J^P=3/2^(+,-)) photoproduction from the proton | 4 pages, 11 figures | Phys.Lett. B633 (2006) 483-487 | 10.1016/j.physletb.2005.12.059 | PNU-NTG-09/2005 | hep-ph | null | We investigate the photoproduction of Theta^+ from the proton and neutron,
gamma N -> Kbar Theta^+. Assuming that spin and parity of Theta^+ are J^P =
3/2^(+,-), it is shown that the production from the proton is strongly
suppressed as compared with that from the neutron. This could provide a
possible explanation for the null results of the recent CLAS experiment in
finding Theta^+ via the reaction gamma p -> Kbar^0 Theta^+.
| [
{
"created": "Mon, 16 May 2005 07:04:26 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Jun 2005 03:46:08 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Nam",
"Seung-Il",
"",
"RCNP, Osaka Univ., Japan and Dept. of Phys. & NuRI,\n Pusan Univ., Korea"
],
[
"Hosaka",
"Atsushi",
"",
"RCNP, Osaka Univ., Japan"
],
[
"Kim",
"Hyun-Chul",
"",
"Dept. of Phys. & NuRI, Pusan Univ., Korea"
]
] | We investigate the photoproduction of Theta^+ from the proton and neutron, gamma N -> Kbar Theta^+. Assuming that spin and parity of Theta^+ are J^P = 3/2^(+,-), it is shown that the production from the proton is strongly suppressed as compared with that from the neutron. This could provide a possible explanation for the null results of the recent CLAS experiment in finding Theta^+ via the reaction gamma p -> Kbar^0 Theta^+. |
hep-ph/9809367 | Giovanni Ridolfi | S. Frixione (ETH Zurich), P. Nason (CERN) and G. Ridolfi (INFN Genova) | Problems in the resummation of soft-gluon effects in the
transverse-momentum distributions of massive vector bosons in hadronic
collisions | 21 pages, 1 figure, plain LaTex with epsfig | Nucl.Phys. B542 (1999) 311-328 | 10.1016/S0550-3213(98)00853-0 | CERN-TH/98-278,ETH-TH/98-24,GEF-TH-9/1998,IFUM 630/FT | hep-ph | null | We consider the resummation of soft-gluon emission in the transverse-momentum
distribution of vector mesons in hadronic collisions. We find that the resummed
expression in the impact-parameter formulation has an expansion in $\as$ with
factorially growing terms with oscillating signs. These diverging terms arise
from the small impact-parameter region of integration, and are of a subleading
nature. We also obtain a closed expression for the next-to-leading logarithm
resummation in $\qt$-space, and we study its analytic structure. We find in
this case that, although no factorially growing terms are present, there are
geometrical singularities that severely restrict the range of applicability of
the resummation formula.
| [
{
"created": "Mon, 14 Sep 1998 12:30:44 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Frixione",
"S.",
"",
"ETH Zurich"
],
[
"Nason",
"P.",
"",
"CERN"
],
[
"Ridolfi",
"G.",
"",
"INFN Genova"
]
] | We consider the resummation of soft-gluon emission in the transverse-momentum distribution of vector mesons in hadronic collisions. We find that the resummed expression in the impact-parameter formulation has an expansion in $\as$ with factorially growing terms with oscillating signs. These diverging terms arise from the small impact-parameter region of integration, and are of a subleading nature. We also obtain a closed expression for the next-to-leading logarithm resummation in $\qt$-space, and we study its analytic structure. We find in this case that, although no factorially growing terms are present, there are geometrical singularities that severely restrict the range of applicability of the resummation formula. |
1804.08797 | Peiwen Wu | Liangliang Shang, Yangle He, Jingwei Lian, Yusi Pan | Interpretations of galactic center gamma-ray excess confronting the
PandaX-II constraints on dark matter-neutron spin-dependent scatterings in
the NMSSM | 11 pages, 4 figures, meeting the published version by EPJC | null | 10.1140/epjc/s10052-018-5827-8 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Weakly Interacting Massive Particle (WIMP) has been one of the most
attractive candidates for Dark Matter (DM), and the lightest neutralino
($\widetilde{\chi}^0_1$) in the Next-to-Minimal Supersymmetric Standard Model
(NMSSM) is an interesting realization of WIMP. The Galactic Center Excess (GCE)
can be explained by WIMP DM annihilations in the sky. In this work we consider
the $Z_3$-NMSSM where the singlet $S$ and Singlino $\widetilde{S}^0$ components
play important roles in the Higgs and DM sector. Guided by our analytical
arguments, we perform a numerical scan over the NMSSM parameter space for the
GCE explanation by considering various observables such as the Standard Model
(SM) Higgs data measured by the ATLAS and CMS experiments, and the $B$-physics
observables $BR(B_s\rightarrow X_s\gamma)$ and $BR(B_s\rightarrow \mu^+\mu^-)$.
We find that the correlation between the coupling $C_{A_1 b\bar{b}}$ in
$\langle \sigma_{b\bar{b}} v \rangle _{0}$ and the coupling $C_{Z
\widetilde{\chi}^0_1 \widetilde{\chi}^0_1}$ in DM-neutron Spin Dependent (SD)
scattering rate $\sigma^{SD}_{\widetilde{\chi}^0_1-N}$ makes all samples we
obtain for GCE explanation get excluded by the PandaX-II results. Although the
DM resonant annihilation scenarios may be beyond the reach of our analytical
approximations and scan strategy, the aforementioned correlation can be a
reasonable motivation for future experiments such as PandaX-nT to further test
the NMSSM interpretation of GCE.
| [
{
"created": "Tue, 24 Apr 2018 01:23:07 GMT",
"version": "v1"
},
{
"created": "Wed, 23 May 2018 10:02:07 GMT",
"version": "v2"
}
] | 2018-06-13 | [
[
"Shang",
"Liangliang",
""
],
[
"He",
"Yangle",
""
],
[
"Lian",
"Jingwei",
""
],
[
"Pan",
"Yusi",
""
]
] | The Weakly Interacting Massive Particle (WIMP) has been one of the most attractive candidates for Dark Matter (DM), and the lightest neutralino ($\widetilde{\chi}^0_1$) in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) is an interesting realization of WIMP. The Galactic Center Excess (GCE) can be explained by WIMP DM annihilations in the sky. In this work we consider the $Z_3$-NMSSM where the singlet $S$ and Singlino $\widetilde{S}^0$ components play important roles in the Higgs and DM sector. Guided by our analytical arguments, we perform a numerical scan over the NMSSM parameter space for the GCE explanation by considering various observables such as the Standard Model (SM) Higgs data measured by the ATLAS and CMS experiments, and the $B$-physics observables $BR(B_s\rightarrow X_s\gamma)$ and $BR(B_s\rightarrow \mu^+\mu^-)$. We find that the correlation between the coupling $C_{A_1 b\bar{b}}$ in $\langle \sigma_{b\bar{b}} v \rangle _{0}$ and the coupling $C_{Z \widetilde{\chi}^0_1 \widetilde{\chi}^0_1}$ in DM-neutron Spin Dependent (SD) scattering rate $\sigma^{SD}_{\widetilde{\chi}^0_1-N}$ makes all samples we obtain for GCE explanation get excluded by the PandaX-II results. Although the DM resonant annihilation scenarios may be beyond the reach of our analytical approximations and scan strategy, the aforementioned correlation can be a reasonable motivation for future experiments such as PandaX-nT to further test the NMSSM interpretation of GCE. |
2207.03102 | Frederick Hiskens | Matthew J. Dolan, Frederick J. Hiskens and Raymond R. Volkas | Advancing Globular Cluster Constraints on the Axion-Photon Coupling | 11+13 pages, 3+1 figures, 1+2 tables. Matches published version.
Minor changes in Sections 1, 2 and 3 | JCAP 10 (2022) 096 | 10.1088/1475-7516/2022/10/096 | null | hep-ph astro-ph.SR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We improve the current upper bound on the axion-photon coupling derived from
stellar evolution using the $R_2$ parameter, the ratio of stellar populations
on the Asymptotic Giant Branch to Horizontal Branch in Globular Clusters. We
compare this with data from simulations using the stellar evolution code MESA
which include the effects of axion production. Particular attention is given to
quantifying in detail the effects of uncertainties on the $R$ and $R_2$
parameters due to the modelling of convective core boundaries. Using a
semiconvective mixing scheme we constrain the axion-photon coupling to be
$g_{a\gamma\gamma} < 0.47 \times 10^{-10}~\mathrm{GeV}^{-1}$. This rules out
new regions of QCD axion and axion-like particle parameter space. Complementary
evidence from asteroseismology suggests that this could improve to as much as
$g_{a\gamma\gamma} < 0.34 \times 10^{-10}~\mathrm{GeV}^{-1}$ as the
uncertainties surrounding mixing across convective boundaries are better
understood.
| [
{
"created": "Thu, 7 Jul 2022 05:50:49 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Nov 2022 05:49:07 GMT",
"version": "v2"
}
] | 2022-11-28 | [
[
"Dolan",
"Matthew J.",
""
],
[
"Hiskens",
"Frederick J.",
""
],
[
"Volkas",
"Raymond R.",
""
]
] | We improve the current upper bound on the axion-photon coupling derived from stellar evolution using the $R_2$ parameter, the ratio of stellar populations on the Asymptotic Giant Branch to Horizontal Branch in Globular Clusters. We compare this with data from simulations using the stellar evolution code MESA which include the effects of axion production. Particular attention is given to quantifying in detail the effects of uncertainties on the $R$ and $R_2$ parameters due to the modelling of convective core boundaries. Using a semiconvective mixing scheme we constrain the axion-photon coupling to be $g_{a\gamma\gamma} < 0.47 \times 10^{-10}~\mathrm{GeV}^{-1}$. This rules out new regions of QCD axion and axion-like particle parameter space. Complementary evidence from asteroseismology suggests that this could improve to as much as $g_{a\gamma\gamma} < 0.34 \times 10^{-10}~\mathrm{GeV}^{-1}$ as the uncertainties surrounding mixing across convective boundaries are better understood. |
1508.06512 | Qing-Hong Cao | Qing-Hong Cao, Bin Yan, Dong-Ming Zhang, Hao Zhang | Resolving the Degeneracy in Single Higgs Production with Higgs Pair
Production | null | null | 10.1016/j.physletb.2015.11.045 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Higgs boson production can be affected by several anomalous couplings,
e.g. $c_t$ and $c_g$ anomalous couplings. Precise measurement of $gg\to h$
production yields two degenerate parameter spaces of $c_t$ and $c_g$; one
parameter space exhibits the SM limit while the other does not. Such a
degeneracy could be resolved by Higgs boson pair production. In this work we
adapt the strategy suggested by the ATLAS collaboration to explore the
potential of distinguishing the degeneracy at the 14 TeV LHC. If the $c_t$
anomalous coupling is induced only by the operator $H^\dag H \bar Q_L \tilde{H}
t_R$, then the non-SM-like band could be excluded with an integrated luminosity
of $\sim 235~{\rm fb}^{-1}$. Making use of the fact that the Higgs boson pair
is mainly produced through an $s$-wave scattering, we propose an analytical
function to describe the fraction of signal events surviving a series of
experimental cuts for a given invariant mass of Higgs boson pair. The function
is model independent and can be applied to estimate the discovery potential of
various NP models.
| [
{
"created": "Wed, 26 Aug 2015 14:37:01 GMT",
"version": "v1"
}
] | 2015-12-02 | [
[
"Cao",
"Qing-Hong",
""
],
[
"Yan",
"Bin",
""
],
[
"Zhang",
"Dong-Ming",
""
],
[
"Zhang",
"Hao",
""
]
] | The Higgs boson production can be affected by several anomalous couplings, e.g. $c_t$ and $c_g$ anomalous couplings. Precise measurement of $gg\to h$ production yields two degenerate parameter spaces of $c_t$ and $c_g$; one parameter space exhibits the SM limit while the other does not. Such a degeneracy could be resolved by Higgs boson pair production. In this work we adapt the strategy suggested by the ATLAS collaboration to explore the potential of distinguishing the degeneracy at the 14 TeV LHC. If the $c_t$ anomalous coupling is induced only by the operator $H^\dag H \bar Q_L \tilde{H} t_R$, then the non-SM-like band could be excluded with an integrated luminosity of $\sim 235~{\rm fb}^{-1}$. Making use of the fact that the Higgs boson pair is mainly produced through an $s$-wave scattering, we propose an analytical function to describe the fraction of signal events surviving a series of experimental cuts for a given invariant mass of Higgs boson pair. The function is model independent and can be applied to estimate the discovery potential of various NP models. |
2402.18557 | Ngo Phuc Duc Loc | Rouzbeh Allahverdi, Ngo Phuc Duc Loc, Jacek K. Osi\'nski | Dark matter from mediator decay in early matter domination | 19 pages, 4 figures; published version | Phys. Rev. D 110, 023511 (2024) | 10.1103/PhysRevD.110.023511 | null | hep-ph astro-ph.CO hep-th | http://creativecommons.org/licenses/by/4.0/ | We study dark matter production from mediator decays in scenarios with an
epoch of early matter domination. Particles that mediate interactions between
dark matter and the standard model particles are kinematically accessible to
the thermal bath as long as their mass is below the reheating temperature of
the Universe after inflation. Decay of on-shell mediators can then lead to
copious production of dark matter during early matter domination or a preceding
radiation-dominated phase. In particular, for mediators that are charged under
the standard model, it can exceed the standard freeze-in channel due to inverse
annihilations at much lower temperatures (often by many orders of magnitude).
The requirement to obtain the correct relic abundance severely constrains the
parameter space for dark matter masses above a few TeV.
| [
{
"created": "Wed, 28 Feb 2024 18:39:05 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Jul 2024 00:14:56 GMT",
"version": "v2"
}
] | 2024-07-10 | [
[
"Allahverdi",
"Rouzbeh",
""
],
[
"Loc",
"Ngo Phuc Duc",
""
],
[
"Osiński",
"Jacek K.",
""
]
] | We study dark matter production from mediator decays in scenarios with an epoch of early matter domination. Particles that mediate interactions between dark matter and the standard model particles are kinematically accessible to the thermal bath as long as their mass is below the reheating temperature of the Universe after inflation. Decay of on-shell mediators can then lead to copious production of dark matter during early matter domination or a preceding radiation-dominated phase. In particular, for mediators that are charged under the standard model, it can exceed the standard freeze-in channel due to inverse annihilations at much lower temperatures (often by many orders of magnitude). The requirement to obtain the correct relic abundance severely constrains the parameter space for dark matter masses above a few TeV. |
1511.02371 | Lei Wu | Archil Kobakhidze, Ning Liu, Lei Wu, Jin Min Yang, Mengchao Zhang | Closing up a light stop window in natural SUSY at LHC | Discussions added, version accepted by Phys. Lett. B | null | 10.1016/j.physletb.2016.02.003 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Top squark (stop) plays a key role in the radiative stability of the Higgs
boson mass in supersymmetry (SUSY). The LHC searches for stop have made a great
progress and tightly constrained the stop mass during Run-1. In this work, we
use the LHC Run-1 data to determine the lower mass limit of the right-handed
stop in a natural SUSY scenario, where the higgsinos $\tilde{\chi}^0_{1,2}$ and
$\tilde{\chi}^\pm_{1}$ are light and nearly degenerate. We find that the stop
mass has been excluded up to 430 GeV for $m_{\tilde{\chi}^0_1} \lesssim 250$
GeV and to 540 GeV for $m_{\tilde{\chi}^0_1} \simeq 100$ GeV by the Run-1 SUSY
searches for $2b+E^{miss}_T$ and $1\ell+jets+E^{miss}_T$, respectively. In a
small strip of parameter space with $m_{\tilde{\chi}^0_1} \gtrsim 190$ GeV, the
stop mass can still be as light as 210 GeV and compatible with the Higgs mass
measurement and the monojet bound. The 14 TeV LHC with a luminosity of 20
fb$^{-1}$ can further cover such a light stop window by monojet and
$2b+E^{miss}_T$ searches and push the lower bound of the stop mass to 710 GeV.
We also explore the potential to use the Higgs golden ratio,
$D_{\gamma\gamma}=\sigma(pp \to h \to \gamma\gamma)/\sigma(pp \to h \to ZZ^*
\to4\ell^\pm)$, as a complementary probe for the light and compressed stop. If
this golden ratio can be measured at percent level at the high luminosity LHC
(HL-LHC) or future $e^+e^-$ colliders, the light stop can be excluded for most
of the currently allowed parameter region.
| [
{
"created": "Sat, 7 Nov 2015 16:32:27 GMT",
"version": "v1"
},
{
"created": "Sat, 14 Nov 2015 15:22:19 GMT",
"version": "v2"
},
{
"created": "Wed, 2 Dec 2015 16:01:14 GMT",
"version": "v3"
},
{
"created": "Mon, 1 Feb 2016 23:34:08 GMT",
"version": "v4"
}
] | 2016-02-10 | [
[
"Kobakhidze",
"Archil",
""
],
[
"Liu",
"Ning",
""
],
[
"Wu",
"Lei",
""
],
[
"Yang",
"Jin Min",
""
],
[
"Zhang",
"Mengchao",
""
]
] | Top squark (stop) plays a key role in the radiative stability of the Higgs boson mass in supersymmetry (SUSY). The LHC searches for stop have made a great progress and tightly constrained the stop mass during Run-1. In this work, we use the LHC Run-1 data to determine the lower mass limit of the right-handed stop in a natural SUSY scenario, where the higgsinos $\tilde{\chi}^0_{1,2}$ and $\tilde{\chi}^\pm_{1}$ are light and nearly degenerate. We find that the stop mass has been excluded up to 430 GeV for $m_{\tilde{\chi}^0_1} \lesssim 250$ GeV and to 540 GeV for $m_{\tilde{\chi}^0_1} \simeq 100$ GeV by the Run-1 SUSY searches for $2b+E^{miss}_T$ and $1\ell+jets+E^{miss}_T$, respectively. In a small strip of parameter space with $m_{\tilde{\chi}^0_1} \gtrsim 190$ GeV, the stop mass can still be as light as 210 GeV and compatible with the Higgs mass measurement and the monojet bound. The 14 TeV LHC with a luminosity of 20 fb$^{-1}$ can further cover such a light stop window by monojet and $2b+E^{miss}_T$ searches and push the lower bound of the stop mass to 710 GeV. We also explore the potential to use the Higgs golden ratio, $D_{\gamma\gamma}=\sigma(pp \to h \to \gamma\gamma)/\sigma(pp \to h \to ZZ^* \to4\ell^\pm)$, as a complementary probe for the light and compressed stop. If this golden ratio can be measured at percent level at the high luminosity LHC (HL-LHC) or future $e^+e^-$ colliders, the light stop can be excluded for most of the currently allowed parameter region. |
1012.0067 | Ahmad Galea Mr | Nicole F. Bell, Ahmad J. Galea, Raymond R. Volkas | A Model For Late Dark Matter Decay | 10 pages, 8 figures; updated to match published version, minor
changes to text and figures | Phys.Rev.D83:063504,2011 | 10.1103/PhysRevD.83.063504 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The standard cold dark matter cosmological model, while successful in
explaining the observed large scale structure of the Universe, tends to
overpredict structure on small scales. It has been proposed this problem may be
alleviated in a class of late-decaying dark matter models, in which the parent
dark matter particle decays to an almost degenerate daughter, plus a
relativistic final state. We construct explicit particle physics models that
realize this goal while obeying observational constraints. To achieve this, we
introduce a pair of fermionic dark matter candidates and a new scalar field,
which obey either a Z4 or a U(1) symmetry. Through the spontaneous breaking of
these symmetries, and coupling of the new fields to standard model particles,
we demonstrate that the desired decay process may be obtained. We also discuss
the dark matter production processes in these models.
| [
{
"created": "Wed, 1 Dec 2010 00:08:29 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Mar 2011 03:24:37 GMT",
"version": "v2"
}
] | 2011-03-21 | [
[
"Bell",
"Nicole F.",
""
],
[
"Galea",
"Ahmad J.",
""
],
[
"Volkas",
"Raymond R.",
""
]
] | The standard cold dark matter cosmological model, while successful in explaining the observed large scale structure of the Universe, tends to overpredict structure on small scales. It has been proposed this problem may be alleviated in a class of late-decaying dark matter models, in which the parent dark matter particle decays to an almost degenerate daughter, plus a relativistic final state. We construct explicit particle physics models that realize this goal while obeying observational constraints. To achieve this, we introduce a pair of fermionic dark matter candidates and a new scalar field, which obey either a Z4 or a U(1) symmetry. Through the spontaneous breaking of these symmetries, and coupling of the new fields to standard model particles, we demonstrate that the desired decay process may be obtained. We also discuss the dark matter production processes in these models. |
2406.07477 | Shuoyu Xia | Ying-Ying Li, Yu-Feng Li and Shuo-Yu Xia | Neutrino magnetic dipole portal with low energy neutrino nucleus
scattering data | 8 pages, 2 figures | null | null | null | hep-ph hep-ex | http://creativecommons.org/publicdomain/zero/1.0/ | Sterile neutrinos that couple to the Standard Model via the neutrino magnetic
dipole portals have been extensively studied at various experiments. In this
work, we scrutinize these interactions for sterile neutrinos in the mass range
of $\unit[0.1]{}-\unit[50]{MeV}$ through the nuclear and electron recoils at
various neutrino scattering experiments. For the $e$-flavor specific dipole
portal, we demonstrate that Dresden-II can provide leading constraints for $m_N
\lesssim \unit[0.5]{MeV}$, setting aside currently unresolved theoretical
uncertainties. For the $\mu$-flavor case, we show that the COHERENT experiment
can probe a unique parameter region for $m_N$ in the range of
$\unit[10]{}-\unit[40]{MeV}$ with the full dataset collected by the CsI[Na]
scintillation detector, including both the energy and timing structure of the
neutrino beam. We also present limits on the parameter regions of the
$\tau$-flavor dipole portal using measurements of the solar neutrino flux from
dark matter direct detection experiments.
| [
{
"created": "Tue, 11 Jun 2024 17:23:05 GMT",
"version": "v1"
}
] | 2024-06-13 | [
[
"Li",
"Ying-Ying",
""
],
[
"Li",
"Yu-Feng",
""
],
[
"Xia",
"Shuo-Yu",
""
]
] | Sterile neutrinos that couple to the Standard Model via the neutrino magnetic dipole portals have been extensively studied at various experiments. In this work, we scrutinize these interactions for sterile neutrinos in the mass range of $\unit[0.1]{}-\unit[50]{MeV}$ through the nuclear and electron recoils at various neutrino scattering experiments. For the $e$-flavor specific dipole portal, we demonstrate that Dresden-II can provide leading constraints for $m_N \lesssim \unit[0.5]{MeV}$, setting aside currently unresolved theoretical uncertainties. For the $\mu$-flavor case, we show that the COHERENT experiment can probe a unique parameter region for $m_N$ in the range of $\unit[10]{}-\unit[40]{MeV}$ with the full dataset collected by the CsI[Na] scintillation detector, including both the energy and timing structure of the neutrino beam. We also present limits on the parameter regions of the $\tau$-flavor dipole portal using measurements of the solar neutrino flux from dark matter direct detection experiments. |
hep-ph/0506263 | Keitaro Nagata | Keitaro Nagata, Atsushi Hosaka | Path-integral approach in a chiral quark-diquark model to the nucleon
structure and interactions | 13 pages, 9 figures. To appear in the proceedings of Workshop on
Quark Nuclear Physics; Nuclear and Hadronic Systems and Quark Degrees of
Freedom, Pyoungchang, Kangwondo, Korea, 22-24 Feb 2005 | null | null | null | hep-ph nucl-th | null | We study the structure of the nuclear force by using a path-integral
hadronization approach in a chiral quark-diquark model. After the construction
of the chiral quark-diquark model, we hadronize it to obtain a meson-baryon
Lagrangian. The effective meson-baryon Lagrangian incorporates chiral symmetry
and the composite description of the mesons and baryons. Using the effective
meson-baryon Lagrangian we investigate the structure of the nuclear force in
the simple case of neglecting the axial-vector diquark. It is shown that the
meson-baryon Lagrangian contains two kinds of the nuclear force; the
meson-exchange interaction and a quark-diquark loop interaction. It is also
shown that the quark-diquark loop interaction consists of the scalar and vector
interactions. The properties of these interactions are discussed.
| [
{
"created": "Sat, 25 Jun 2005 09:24:38 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Nagata",
"Keitaro",
""
],
[
"Hosaka",
"Atsushi",
""
]
] | We study the structure of the nuclear force by using a path-integral hadronization approach in a chiral quark-diquark model. After the construction of the chiral quark-diquark model, we hadronize it to obtain a meson-baryon Lagrangian. The effective meson-baryon Lagrangian incorporates chiral symmetry and the composite description of the mesons and baryons. Using the effective meson-baryon Lagrangian we investigate the structure of the nuclear force in the simple case of neglecting the axial-vector diquark. It is shown that the meson-baryon Lagrangian contains two kinds of the nuclear force; the meson-exchange interaction and a quark-diquark loop interaction. It is also shown that the quark-diquark loop interaction consists of the scalar and vector interactions. The properties of these interactions are discussed. |
0805.2506 | Florian Bonnet | F.Bonnet | $\ell_1 \to \ell_2 \gamma$ in type III seesaw | o appear in the Proceedings of the 43rd Rencontres de Moriond EW
session, La Thuile, Italy, 1-8 March 2008 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the decay rates of the $\mu \to e \gamma$ and $\tau \to \ell \gamma$
transitions in the framework of the type III seesaw model, where fermionic
triplets are exchanged to generate neutrino masses. We show that the
observation of one of those decays in planned experiments would contradict
bounds arising from present experimental limits on the $\mu \to eee$ and $\tau
\to 3 l$ decay rates, and therefore imply that there exist other sources of
lepton flavour violation than those associated to triplet of fermions.
| [
{
"created": "Fri, 16 May 2008 11:47:06 GMT",
"version": "v1"
}
] | 2008-05-19 | [
[
"Bonnet",
"F.",
""
]
] | We study the decay rates of the $\mu \to e \gamma$ and $\tau \to \ell \gamma$ transitions in the framework of the type III seesaw model, where fermionic triplets are exchanged to generate neutrino masses. We show that the observation of one of those decays in planned experiments would contradict bounds arising from present experimental limits on the $\mu \to eee$ and $\tau \to 3 l$ decay rates, and therefore imply that there exist other sources of lepton flavour violation than those associated to triplet of fermions. |
1904.10145 | Sibo Zheng | Sibo Zheng | Minimal Vectorlike Model in Supersymmetric Unification | 18 pages, to match published version | Eur. Phys. J. C80 (2020) 273 | 10.1140/epjc/s10052-020-7843-8 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Compared to the minimal supersymmetric standard model, an extension by
vectorlike fermions is able to explain the Higgs mass while retains the grand
unification. We investigate the minimal vectorlike model by focusing on the
vectorlike electroweak sector. We firstly derive the mass spectrum in the
electroweak sector, then calculate the one-loop effects on the Higgs physics,
and finally explore either vectorlike or neutralino dark matter. Collider
constraints are briefly discussed.
| [
{
"created": "Tue, 23 Apr 2019 04:17:16 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Apr 2019 00:55:11 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Jul 2019 18:06:34 GMT",
"version": "v3"
},
{
"created": "Tue, 1 Oct 2019 14:24:18 GMT",
"version": "v4"
},
{
"created": "Thu, 12 Mar 2020 18:13:37 GMT",
"version": "v5"
}
] | 2020-03-30 | [
[
"Zheng",
"Sibo",
""
]
] | Compared to the minimal supersymmetric standard model, an extension by vectorlike fermions is able to explain the Higgs mass while retains the grand unification. We investigate the minimal vectorlike model by focusing on the vectorlike electroweak sector. We firstly derive the mass spectrum in the electroweak sector, then calculate the one-loop effects on the Higgs physics, and finally explore either vectorlike or neutralino dark matter. Collider constraints are briefly discussed. |
0705.4624 | Maxim Chernodub | M.N. Chernodub and I.E. Kozlov | Topological susceptibility in Yang-Mills theory in the vacuum correlator
method | 5 pages (JETP Letters style) | JETP Lett.86:1-5,2007 | 10.1134/S0021364007130012 | ITEP-LAT/2007-10 | hep-ph hep-lat | null | We calculate the topological susceptibility of the Yang-Mills vacuum using
the field correlator method. Our estimate for the SU(3) gauge group, \chi^{1/4}
= 196(7) MeV, is in a very good agreement with the results of recent numerical
simulations of the Yang-Mills theory on the lattice.
| [
{
"created": "Thu, 31 May 2007 15:18:55 GMT",
"version": "v1"
}
] | 2011-07-19 | [
[
"Chernodub",
"M. N.",
""
],
[
"Kozlov",
"I. E.",
""
]
] | We calculate the topological susceptibility of the Yang-Mills vacuum using the field correlator method. Our estimate for the SU(3) gauge group, \chi^{1/4} = 196(7) MeV, is in a very good agreement with the results of recent numerical simulations of the Yang-Mills theory on the lattice. |
1906.06535 | Javier Mazzitelli | Stefano Catani, Simone Devoto, Massimiliano Grazzini, Stefan Kallweit
and Javier Mazzitelli | Top-quark pair production at the LHC: Fully differential QCD predictions
at NNLO | 24 pages, 9 figures | null | 10.1007/JHEP07(2019)100 | ZU-TH 31/19 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on a new fully differential calculation of the
next-to-next-to-leading-order (NNLO) QCD radiative corrections to the
production of top-quark pairs at hadron colliders. The calculation is performed
by using the $q_T$ subtraction formalism to handle and cancel infrared
singularities in real and virtual contributions. The computation is implemented
in the Matrix framework, thereby allowing us to efficiently compute arbitrary
infrared-safe observables for stable top quarks. We present NNLO predictions
for several single- and double-differential kinematical distributions in $pp$
collisions at the centre-of-mass energy $\sqrt{s}=13$ TeV, and we compare them
with recent LHC data by the CMS collaboration.
| [
{
"created": "Sat, 15 Jun 2019 11:56:28 GMT",
"version": "v1"
}
] | 2019-09-04 | [
[
"Catani",
"Stefano",
""
],
[
"Devoto",
"Simone",
""
],
[
"Grazzini",
"Massimiliano",
""
],
[
"Kallweit",
"Stefan",
""
],
[
"Mazzitelli",
"Javier",
""
]
] | We report on a new fully differential calculation of the next-to-next-to-leading-order (NNLO) QCD radiative corrections to the production of top-quark pairs at hadron colliders. The calculation is performed by using the $q_T$ subtraction formalism to handle and cancel infrared singularities in real and virtual contributions. The computation is implemented in the Matrix framework, thereby allowing us to efficiently compute arbitrary infrared-safe observables for stable top quarks. We present NNLO predictions for several single- and double-differential kinematical distributions in $pp$ collisions at the centre-of-mass energy $\sqrt{s}=13$ TeV, and we compare them with recent LHC data by the CMS collaboration. |
hep-ph/0607105 | Fariborz | Amir H. Fariborz | Mass Uncertainties of f0(600) and f0(1370) and their Effects on
Determination of the Quark and Glueball Admixtures of the I=0 Scalar Mesons | placement of figures inside text improved. Content unchanged | Phys.Rev.D74:054030,2006 | 10.1103/PhysRevD.74.054030 | null | hep-ph hep-ex hep-lat | null | Within a nonlinear chiral Lagrangian framework the correlations between the
quark and glueball admixtures of the isosinglet scalar mesons below 2 GeV and
the current large uncertainties on the mass of the f0(600) and the f0(1370) are
studied. The framework is formulated in terms of two scalar meson nonets (a
two-quark nonet and a four-quark nonet) together with a scalar glueball. It is
shown that while some properties of these states are sensitive to the mass of
f0(600) and f0(1370), several relatively robust conclusions can be made: The
f0(600), the f0(980), and the f0(1370) are admixtures of two and four quark
components, with f0(600) being dominantly a non-strange four-quark state, and
f0(980) and f0(1370) having a dominant two-quark component. Similarly, the
f0(1500) and the f0(1710) have considerable two and four quark admixtures, but
in addition have a large glueball component. For each state, a detailed
analysis providing the numerical estimates of all components is given. It is
also shown that this framework clearly favors the experimental values:
m[f0(600)] < 700 MeV and m[f0(1370)] = 1300-1450 MeV. Moreover, an overall fit
to the available data shows a reciprocal substructure for the f0(600) and the
f0(1370), and a linear correlation between their masses of the form m
[f0(1370)] = 0.29 m[f0(600)] + 1.22 GeV. The scalar glueball mass of 1.5-1.7
GeV is found in this analysis.
| [
{
"created": "Mon, 10 Jul 2006 19:43:28 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Jul 2006 20:49:50 GMT",
"version": "v2"
}
] | 2009-09-29 | [
[
"Fariborz",
"Amir H.",
""
]
] | Within a nonlinear chiral Lagrangian framework the correlations between the quark and glueball admixtures of the isosinglet scalar mesons below 2 GeV and the current large uncertainties on the mass of the f0(600) and the f0(1370) are studied. The framework is formulated in terms of two scalar meson nonets (a two-quark nonet and a four-quark nonet) together with a scalar glueball. It is shown that while some properties of these states are sensitive to the mass of f0(600) and f0(1370), several relatively robust conclusions can be made: The f0(600), the f0(980), and the f0(1370) are admixtures of two and four quark components, with f0(600) being dominantly a non-strange four-quark state, and f0(980) and f0(1370) having a dominant two-quark component. Similarly, the f0(1500) and the f0(1710) have considerable two and four quark admixtures, but in addition have a large glueball component. For each state, a detailed analysis providing the numerical estimates of all components is given. It is also shown that this framework clearly favors the experimental values: m[f0(600)] < 700 MeV and m[f0(1370)] = 1300-1450 MeV. Moreover, an overall fit to the available data shows a reciprocal substructure for the f0(600) and the f0(1370), and a linear correlation between their masses of the form m [f0(1370)] = 0.29 m[f0(600)] + 1.22 GeV. The scalar glueball mass of 1.5-1.7 GeV is found in this analysis. |
1306.1004 | Zhun Lu | Wenjuan Mao and Zhun Lu | Beam Spin Asymmetries of Charged and Neutral Pion Productions in
Semi-inclusive DIS | 9 pages, 8 figures | null | 10.1140/epjc/s10052-013-2557-9 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a study on the beam single spin asymmetries $A_{LU}^{\sin\phi_h}$
of $\pi^+$, $\pi^-$ and $\pi^0$ production in semi-inclusive deep inelastic
scattering process, by considering Collins effect and the $g^\perp D_1$ term
simultaneously. We calculate the twist-3 distributions $e(x, \bm k_T^2)$ and
$g^\perp(x,\bm k_T^2)$ for the valence quarks inside the proton in a spectator
model. We consider two different options for the form of diquark propagator, as
well as two different choices for the model parameters in the calculation.
Using the model results, we estimate the beam spin asymmetries
$A_{LU}^{\sin\phi_h}$ for the charged and neutral pions and compare the results
with the measurement from the HERMES Collaboration. We also make predictions on
the asymmetries at CLAS with a $5.5 \,\textrm{GeV}$ beam using the same model
results. It is found that different choices for the diquark propagator will not
only lead to different expressions for the distribution functions, but also
result in different sizes of the asymmetries. Our study also shows that,
although the spectator model calculation can describe the asymmetries for
certain pion production in some kinematic regions, it seems difficult to
explain the asymmetries of pion production for all three pions in a consistent
way from the current versions.
| [
{
"created": "Wed, 5 Jun 2013 07:21:55 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Sep 2013 10:44:45 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Mao",
"Wenjuan",
""
],
[
"Lu",
"Zhun",
""
]
] | We present a study on the beam single spin asymmetries $A_{LU}^{\sin\phi_h}$ of $\pi^+$, $\pi^-$ and $\pi^0$ production in semi-inclusive deep inelastic scattering process, by considering Collins effect and the $g^\perp D_1$ term simultaneously. We calculate the twist-3 distributions $e(x, \bm k_T^2)$ and $g^\perp(x,\bm k_T^2)$ for the valence quarks inside the proton in a spectator model. We consider two different options for the form of diquark propagator, as well as two different choices for the model parameters in the calculation. Using the model results, we estimate the beam spin asymmetries $A_{LU}^{\sin\phi_h}$ for the charged and neutral pions and compare the results with the measurement from the HERMES Collaboration. We also make predictions on the asymmetries at CLAS with a $5.5 \,\textrm{GeV}$ beam using the same model results. It is found that different choices for the diquark propagator will not only lead to different expressions for the distribution functions, but also result in different sizes of the asymmetries. Our study also shows that, although the spectator model calculation can describe the asymmetries for certain pion production in some kinematic regions, it seems difficult to explain the asymmetries of pion production for all three pions in a consistent way from the current versions. |
1901.10456 | Ashley Perko | Helene Gertov, Ann E. Nelson, Ashley Perko and Devin G. E. Walker | Lattice-Friendly Gauge Completion of a Composite Higgs with Top Partners | 12 pages; edited to clarify assumptions of model (conclusions
unchanged) | null | 10.1007/JHEP02(2019)181 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give an explicit example of a composite Higgs model with a
pseudo-Nambu-Goldstone Higgs in which the top Yukawa coupling is generated via
the partial compositeness mechanism. This mechanism requires composite top
partners which are relatively light compared to the typical mass scale of the
strongly coupled theory. While most studies of the phenomenology of such models
have focused on a bottom-up approach with a minimal effective theory, a
top-down approach suggests that that the theory should contain a limit in which
an unbroken global chiral symmetry protects the mass of the top partners, and
the spectrum of the partners satisfies `t Hooft matching conditions. We
therefore consider a model for the UV gauge group which could provide a
solution to the matching conditions, and note that the relatively light
fermions and pseudo-Goldstone bosons fall into complete multiplets of a large
approximate global symmetry. This implies that the spectrum of particles
lighter than a few TeV is non-minimal. Our example illustrates likely features
of a composite Higgs theory, and also serves as an example of a non-chiral
theory with no sign problem and a possible solution to `t Hooft matching
conditions. It would therefore be very interesting for a lattice exploration.
We find in this example that for some low-energy parameters in the effective
theory the top partners can decay into high multiplicity final states, which
could be difficult for the Large Hadron Collider (LHC) to constrain. This may
potentially allow for the top partners to be lighter than those in more minimal
models.
| [
{
"created": "Tue, 29 Jan 2019 18:58:24 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Feb 2019 20:57:16 GMT",
"version": "v2"
}
] | 2019-03-27 | [
[
"Gertov",
"Helene",
""
],
[
"Nelson",
"Ann E.",
""
],
[
"Perko",
"Ashley",
""
],
[
"Walker",
"Devin G. E.",
""
]
] | We give an explicit example of a composite Higgs model with a pseudo-Nambu-Goldstone Higgs in which the top Yukawa coupling is generated via the partial compositeness mechanism. This mechanism requires composite top partners which are relatively light compared to the typical mass scale of the strongly coupled theory. While most studies of the phenomenology of such models have focused on a bottom-up approach with a minimal effective theory, a top-down approach suggests that that the theory should contain a limit in which an unbroken global chiral symmetry protects the mass of the top partners, and the spectrum of the partners satisfies `t Hooft matching conditions. We therefore consider a model for the UV gauge group which could provide a solution to the matching conditions, and note that the relatively light fermions and pseudo-Goldstone bosons fall into complete multiplets of a large approximate global symmetry. This implies that the spectrum of particles lighter than a few TeV is non-minimal. Our example illustrates likely features of a composite Higgs theory, and also serves as an example of a non-chiral theory with no sign problem and a possible solution to `t Hooft matching conditions. It would therefore be very interesting for a lattice exploration. We find in this example that for some low-energy parameters in the effective theory the top partners can decay into high multiplicity final states, which could be difficult for the Large Hadron Collider (LHC) to constrain. This may potentially allow for the top partners to be lighter than those in more minimal models. |
hep-ph/0607052 | Ant\^onio Scarpelli | J. E. Ottoni, A. P. Baeta Scarpelli, Marcos Sampaio, M. C. Nemes | Supergravity corrections to the $(g-2)_l$ factor by Implicit
Regularization | 9 pages, 2 figures | Phys.Lett. B642 (2006) 253-262 | 10.1016/j.physletb.2006.09.025 | null | hep-ph | null | We apply Implicit regularization in the calculation of the one-loop graviton
and gravitino corrections to the anomalous magnetic moment of the lepton in
unbroken supergravity, which is known to be an important test for any
regularization method. We find a null result as it is expected from
supersymmetry. We compare our results with the ones obtained by using
Differential Regularization and Dimensional Reduction, which are known to
preserve supersymmetry at one-loop order.
| [
{
"created": "Wed, 5 Jul 2006 13:47:21 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Oct 2006 16:38:29 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Ottoni",
"J. E.",
""
],
[
"Scarpelli",
"A. P. Baeta",
""
],
[
"Sampaio",
"Marcos",
""
],
[
"Nemes",
"M. C.",
""
]
] | We apply Implicit regularization in the calculation of the one-loop graviton and gravitino corrections to the anomalous magnetic moment of the lepton in unbroken supergravity, which is known to be an important test for any regularization method. We find a null result as it is expected from supersymmetry. We compare our results with the ones obtained by using Differential Regularization and Dimensional Reduction, which are known to preserve supersymmetry at one-loop order. |
2204.11915 | Ryan E. Mitchell | N. H\"usken, R. E. Mitchell, E. S. Swanson | K-matrix Analysis of $e^+e^-$ Annihilation in the Bottomonium Region | 24 pages, 12 figures | null | 10.1103/PhysRevD.106.094013 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We perform the first global and unitary analysis of $e^+e^-\to b\bar{b}$
cross sections. We analyze exclusive cross sections in the $B\bar{B}$, $B^*
\bar{B}(+c.c.)$, $B^*\bar{B}^*$, $B_s^*\bar{B}_s^*$, $\Upsilon(nS)\pi^+\pi^-$
and $h_b(nP)\pi^+\pi^-$ channels as well as the total inclusive cross section
for $b\bar{b}$ production. Pole positions and residues are determined for four
vector states, which we associate with the $\Upsilon(4S)$, $\Upsilon(10750)$,
$\Upsilon(5S)$ (or $\Upsilon(10860)$), and $\Upsilon(6S)$ (or
$\Upsilon(11020)$). We find strong evidence for the new $\Upsilon(10750)$
recently claimed by Belle, although with parameters not well constrained by the
data. Results presented here cast doubt on the validity of branching ratios
reported earlier using Breit-Wigner parameterizations or ratios of cross
sections. We also compare our results with a selection of theoretical
calculations for the vector bottomonium spectrum.
| [
{
"created": "Mon, 25 Apr 2022 18:38:41 GMT",
"version": "v1"
}
] | 2022-11-23 | [
[
"Hüsken",
"N.",
""
],
[
"Mitchell",
"R. E.",
""
],
[
"Swanson",
"E. S.",
""
]
] | We perform the first global and unitary analysis of $e^+e^-\to b\bar{b}$ cross sections. We analyze exclusive cross sections in the $B\bar{B}$, $B^* \bar{B}(+c.c.)$, $B^*\bar{B}^*$, $B_s^*\bar{B}_s^*$, $\Upsilon(nS)\pi^+\pi^-$ and $h_b(nP)\pi^+\pi^-$ channels as well as the total inclusive cross section for $b\bar{b}$ production. Pole positions and residues are determined for four vector states, which we associate with the $\Upsilon(4S)$, $\Upsilon(10750)$, $\Upsilon(5S)$ (or $\Upsilon(10860)$), and $\Upsilon(6S)$ (or $\Upsilon(11020)$). We find strong evidence for the new $\Upsilon(10750)$ recently claimed by Belle, although with parameters not well constrained by the data. Results presented here cast doubt on the validity of branching ratios reported earlier using Breit-Wigner parameterizations or ratios of cross sections. We also compare our results with a selection of theoretical calculations for the vector bottomonium spectrum. |
hep-ph/0003176 | Gregers Neergaard | Gregers Neergaard and Jes Madsen | Does the quark-gluon plasma contain stable hadronic bubbles? | 12 pages including 8 figures. To appear in Phys. Rev. D | Phys.Rev. D62 (2000) 034005 | 10.1103/PhysRevD.62.034005 | null | hep-ph astro-ph nucl-th | null | We calculate the thermodynamic potential of bubbles of hadrons embedded in
quark-gluon plasma, and of droplets of quark-gluon plasma embedded in hadron
phase. This is a generalization of our previous results to the case of non-zero
chemical potentials. As in the zero chemical potential case, we find that a
quark-gluon plasma in thermodynamic equilibrium may contain stable bubbles of
hadrons of radius $R \simeq 1$ fm. The calculations are performed within the
MIT Bag model, using an improved multiple reflection expansion. The results are
of relevance for neutron star phenomenology and for ultrarelativistic heavy ion
collisions.
| [
{
"created": "Fri, 17 Mar 2000 12:27:35 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Neergaard",
"Gregers",
""
],
[
"Madsen",
"Jes",
""
]
] | We calculate the thermodynamic potential of bubbles of hadrons embedded in quark-gluon plasma, and of droplets of quark-gluon plasma embedded in hadron phase. This is a generalization of our previous results to the case of non-zero chemical potentials. As in the zero chemical potential case, we find that a quark-gluon plasma in thermodynamic equilibrium may contain stable bubbles of hadrons of radius $R \simeq 1$ fm. The calculations are performed within the MIT Bag model, using an improved multiple reflection expansion. The results are of relevance for neutron star phenomenology and for ultrarelativistic heavy ion collisions. |
hep-ph/0101122 | Jonathan Feng | Jonathan L. Feng (MIT) | Theoretical Overview: Motivations for Lepton Flavor Violation | 13 pages, references added. Invited talk presented at New Initiatives
in Lepton Flavor Violation and Neutrino Oscillations, 2-6 October 2000,
University of Hawaii, USA | null | 10.1142/9789812777003_0002 | MIT-CTP-3066 | hep-ph hep-ex | null | In the coming years, experiments underway will increase the sensitivity to
charged lepton flavor violation by four orders of magnitude. These experiments
will stringently probe weak scale physics. I review the status of global
symmetries in the standard model and present several well-motivated models that
predict observable lepton flavor violation. Finally, I describe what we might
learn from future experimental results, whether positive or null.
| [
{
"created": "Fri, 12 Jan 2001 00:01:50 GMT",
"version": "v1"
},
{
"created": "Sun, 21 Jan 2001 04:19:00 GMT",
"version": "v2"
}
] | 2017-08-23 | [
[
"Feng",
"Jonathan L.",
"",
"MIT"
]
] | In the coming years, experiments underway will increase the sensitivity to charged lepton flavor violation by four orders of magnitude. These experiments will stringently probe weak scale physics. I review the status of global symmetries in the standard model and present several well-motivated models that predict observable lepton flavor violation. Finally, I describe what we might learn from future experimental results, whether positive or null. |
hep-ph/0011140 | Leutwyler | H. Leutwyler (University of Bern) | Theoretical Chiral Dynamics | Talk given at Chiral 2000, Jefferson Laboratory, Newport News,
Virginia, July 2000, 15 pp | null | 10.1142/9789812810977_0001 | null | hep-ph | null | The reasons why a considerable effort is made to resolve the low energy
structure of QCD are discussed. The effective field theory used for this
purpose is illustrated with the recent progress made in the predictions for
pipi scattering and in understanding the low energy properties of the theory in
the large Nc limit.
| [
{
"created": "Thu, 9 Nov 2000 23:52:50 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Leutwyler",
"H.",
"",
"University of Bern"
]
] | The reasons why a considerable effort is made to resolve the low energy structure of QCD are discussed. The effective field theory used for this purpose is illustrated with the recent progress made in the predictions for pipi scattering and in understanding the low energy properties of the theory in the large Nc limit. |
1011.4468 | Walter Winter | Walter Winter | Performance Comparison: Superbeams, Beta Beams, Neutrino Factory | 5 pages, 2 figures. Plenary talk given at the 12th International
Workshop on Neutrino Factories, Superbeams and Beta Beams (NuFact10), October
20-25, 2010, Mumbai, India | null | 10.1063/1.3644263 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk, the performance comparison among superbeams (SB), beta beams
(BB), and the Neutrino Factory (NF) is discussed. The ingredients to such a
comparison are described, as well as we the optimization and status of BB and
NF are addressed. Finally, one example for the performance comparison is shown.
| [
{
"created": "Fri, 19 Nov 2010 16:42:07 GMT",
"version": "v1"
}
] | 2015-05-20 | [
[
"Winter",
"Walter",
""
]
] | In this talk, the performance comparison among superbeams (SB), beta beams (BB), and the Neutrino Factory (NF) is discussed. The ingredients to such a comparison are described, as well as we the optimization and status of BB and NF are addressed. Finally, one example for the performance comparison is shown. |
1511.03728 | Patrick Stengel | Nicolas Fernandez, Ilsoo Seong, Patrick Stengel | Constraints on Light Dark Matter from Single-Photon Decays of Heavy
Quarkonium | 24 pages, 4 figures, version to appear in PRD | Phys. Rev. D 93, 054023 (2016) | 10.1103/PhysRevD.93.054023 | UH-511-1252-2015; SCIPP-15/14 | hep-ph astro-ph.CO hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate constraints on the interactions of light dark matter with
Standard Model quarks in a framework with effective contact operators mediating
the decay of heavy flavor bound state quarkonium to dark matter and a photon.
When considered in combination with decays to purely invisible final states,
constraints from heavy quarkonium decays at high intensity electron-positron
colliders can complement missing energy searches at high energy colliders and
provide sensitivity to dark matter masses difficult to probe at direct and
indirect detection experiments. We calculate the approximate limits on the
branching fraction for $\Upsilon (1 S)$ decays to dark matter and a photon.
Given the approximate limits on the branching fractions for all dimension 6 or
lower contact operators, we present the corresponding limits on the interaction
strength for each operator and the inferred limits on dark matter-nucleon
scattering. Complementary constraints on dark matter annihilation from
gamma-ray searches from dwarf spheroidal galaxies are also considered.
| [
{
"created": "Wed, 11 Nov 2015 23:19:13 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Apr 2016 04:35:20 GMT",
"version": "v2"
}
] | 2016-04-05 | [
[
"Fernandez",
"Nicolas",
""
],
[
"Seong",
"Ilsoo",
""
],
[
"Stengel",
"Patrick",
""
]
] | We investigate constraints on the interactions of light dark matter with Standard Model quarks in a framework with effective contact operators mediating the decay of heavy flavor bound state quarkonium to dark matter and a photon. When considered in combination with decays to purely invisible final states, constraints from heavy quarkonium decays at high intensity electron-positron colliders can complement missing energy searches at high energy colliders and provide sensitivity to dark matter masses difficult to probe at direct and indirect detection experiments. We calculate the approximate limits on the branching fraction for $\Upsilon (1 S)$ decays to dark matter and a photon. Given the approximate limits on the branching fractions for all dimension 6 or lower contact operators, we present the corresponding limits on the interaction strength for each operator and the inferred limits on dark matter-nucleon scattering. Complementary constraints on dark matter annihilation from gamma-ray searches from dwarf spheroidal galaxies are also considered. |
hep-ph/0508013 | Gennaro Corcella | Gennaro Corcella (CERN), Volker Drollinger (Padua) | Bottom-quark fragmentation: comparing results from tuned event
generators and resummed calculations | 22 pages, 11 colour figures. Minor changes in the text, published
version | Nucl.Phys.B730:82-102,2005 | 10.1016/j.nuclphysb.2005.09.030 | CERN-PH-TH/2005-144 | hep-ph | null | We study bottom-quark fragmentation in e+e- annihilation, top and Higgs decay
H -> b bbar, using Monte Carlo event generators, as well as calculations, based
on the formalism of perturbative fragmentation functions, which resum soft- and
collinear-radiation effects in the next-to-leading logarithmic approximation.
We consider the PYTHIA and HERWIG generators, and implement matrix-element
corrections to the parton shower simulation of the H -> b bbar process in
HERWIG. We tune the Kartvelishvili, string and cluster models to B-hadron data
from LEP and SLD, and present results in both x_B and moment spaces. The
B-hadron spectra yielded by HERWIG, PYTHIA and resummed calculations show small
discrepancies, which are due to the different approaches and models employed
and to the quality of the fits to the e+e- data.
| [
{
"created": "Sun, 31 Jul 2005 19:02:58 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Aug 2005 14:41:02 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Nov 2005 09:46:03 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Corcella",
"Gennaro",
"",
"CERN"
],
[
"Drollinger",
"Volker",
"",
"Padua"
]
] | We study bottom-quark fragmentation in e+e- annihilation, top and Higgs decay H -> b bbar, using Monte Carlo event generators, as well as calculations, based on the formalism of perturbative fragmentation functions, which resum soft- and collinear-radiation effects in the next-to-leading logarithmic approximation. We consider the PYTHIA and HERWIG generators, and implement matrix-element corrections to the parton shower simulation of the H -> b bbar process in HERWIG. We tune the Kartvelishvili, string and cluster models to B-hadron data from LEP and SLD, and present results in both x_B and moment spaces. The B-hadron spectra yielded by HERWIG, PYTHIA and resummed calculations show small discrepancies, which are due to the different approaches and models employed and to the quality of the fits to the e+e- data. |
hep-ph/0401116 | Vyacheslav Rychkov | Vyacheslav S. Rychkov | Black Hole Production in Particle Collisions and Higher Curvature
Gravity | 36 pp, v2: quantum wavelength limit on particle size and shock width
included; curvature estimate lowered but still well above Planck value; small
modifications throughout; conclusions unchanged | Phys.Rev. D70 (2004) 044003 | 10.1103/PhysRevD.70.044003 | ITFA-2004-02 | hep-ph gr-qc hep-th | null | The problem of black hole production in transplanckian particle collisions is
revisited, in the context of large extra dimensions scenarios of TeV-scale
gravity. The validity of the standard description of this process (two
colliding Aichelburg-Sexl shock waves in classical Einstein gravity) is
questioned. It is observed that the classical spacetime has large curvature
along the transverse collision plane, as signaled by the curvature invariant
(R_ijkl)^2. Thus quantum gravity effects, and in particular higher curvature
corrections to the Einstein gravity, cannot be ignored. To give a specific
example of what may happen, the collision is re-analyzed in the
Einstein-Lanczos-Lovelock gravity theory, which modifies the Einstein-Hilbert
Lagrangian by adding a particular `Gauss-Bonnet' combination of curvature
squared terms. The analysis uses a series of approximations, which reduce the
field equations to a tractable second order nonlinear PDE of the Monge-Ampere
type. It is found that the resulting spacetime is significantly different from
the pure Einstein case in the future of the transverse collision plane. These
considerations cast serious doubts on the geometric cross section estimate,
which is based on the classical Einstein gravity description of the black hole
production process.
| [
{
"created": "Thu, 15 Jan 2004 21:00:13 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Apr 2004 20:39:09 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Rychkov",
"Vyacheslav S.",
""
]
] | The problem of black hole production in transplanckian particle collisions is revisited, in the context of large extra dimensions scenarios of TeV-scale gravity. The validity of the standard description of this process (two colliding Aichelburg-Sexl shock waves in classical Einstein gravity) is questioned. It is observed that the classical spacetime has large curvature along the transverse collision plane, as signaled by the curvature invariant (R_ijkl)^2. Thus quantum gravity effects, and in particular higher curvature corrections to the Einstein gravity, cannot be ignored. To give a specific example of what may happen, the collision is re-analyzed in the Einstein-Lanczos-Lovelock gravity theory, which modifies the Einstein-Hilbert Lagrangian by adding a particular `Gauss-Bonnet' combination of curvature squared terms. The analysis uses a series of approximations, which reduce the field equations to a tractable second order nonlinear PDE of the Monge-Ampere type. It is found that the resulting spacetime is significantly different from the pure Einstein case in the future of the transverse collision plane. These considerations cast serious doubts on the geometric cross section estimate, which is based on the classical Einstein gravity description of the black hole production process. |
hep-ph/9811225 | Anatoly Radyushkin | A.V. Radyushkin | QCD sum rules and soft-hard interplay for hadronic form factors | 9 pages, Latex, 1 figure; Contribution to proceedings of the Joint
ECT* / TJNAF Workshop on N* Physics and Nonperturbative QCD, Trento, Italy,
18-29 May 1998 | Few Body Syst.Suppl.11:57-65,1999 | null | JLAB-THY-98-44 | hep-ph | null | We discuss two types of contributions to hadronic form factors in QCD: hard
gluon exchange and soft wave function overlap. Within the QCD sum rule
approach, the hard contribution has strong numeric suppression by factor
(\alpha_s/\pi) ~ 0.1 for each exchange. For this reason, the soft contribution
dominates at accessible momentum transfers. The ``humpy'' distribution
amplitudes used to enhance hard terms cannot be derived from QCD sum rules in a
self-consistent way. The estimates of soft terms obtained within the local
quark-hadronic duality approach in all cases are close to existing data,
providing an experimental evidence that hard terms are small.
| [
{
"created": "Mon, 2 Nov 1998 22:12:20 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Radyushkin",
"A. V.",
""
]
] | We discuss two types of contributions to hadronic form factors in QCD: hard gluon exchange and soft wave function overlap. Within the QCD sum rule approach, the hard contribution has strong numeric suppression by factor (\alpha_s/\pi) ~ 0.1 for each exchange. For this reason, the soft contribution dominates at accessible momentum transfers. The ``humpy'' distribution amplitudes used to enhance hard terms cannot be derived from QCD sum rules in a self-consistent way. The estimates of soft terms obtained within the local quark-hadronic duality approach in all cases are close to existing data, providing an experimental evidence that hard terms are small. |
0911.3622 | Kumar Rao | Rohini M Godbole, Saurabh D Rindani, Kumar Rao, Ritesh K Singh | Top polarization as a probe of new physics | 5 pages, 4 figures (slightly modified), fixed typos, added
acknowledgement | AIP Conf.Proc.1200:682-685,2010 | 10.1063/1.3327703 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the effects of new physics scenarios containing a high mass
vector resonance on top pair production at the LHC, using the polarization of
the produced top. In particular we use kinematic distributions of the secondary
lepton coming from top decay, which depends on top polarization, as it has been
shown that the angular distribution of the decay lepton is insensitive to the
anomalous tbW vertex and hence is a pure probe of new physics in top quark
production. Spin sensitive variables involving the decay lepton are used to
probe top polarization. Some sensitivity is found for the new couplings of the
top.
| [
{
"created": "Wed, 18 Nov 2009 18:33:47 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Apr 2010 18:30:12 GMT",
"version": "v2"
}
] | 2010-04-20 | [
[
"Godbole",
"Rohini M",
""
],
[
"Rindani",
"Saurabh D",
""
],
[
"Rao",
"Kumar",
""
],
[
"Singh",
"Ritesh K",
""
]
] | We investigate the effects of new physics scenarios containing a high mass vector resonance on top pair production at the LHC, using the polarization of the produced top. In particular we use kinematic distributions of the secondary lepton coming from top decay, which depends on top polarization, as it has been shown that the angular distribution of the decay lepton is insensitive to the anomalous tbW vertex and hence is a pure probe of new physics in top quark production. Spin sensitive variables involving the decay lepton are used to probe top polarization. Some sensitivity is found for the new couplings of the top. |
hep-ph/9505420 | Rey Soo Jong | Chueng-Ryong Ji and Soo-Jong REY | Light-Front View of The Axial Anomaly | 12 pages, REVTEX, one figure postscript file encoded | Phys.Rev. D53 (1996) 5815-5820 | 10.1103/PhysRevD.53.5815 | SNUTP 94-134 | hep-ph hep-th nucl-th | null | Motivated by an apparent puzzle of the light-front vacua incompatible with
the axial anomaly, we have considered the two-dimensional massless Schwinger
model for an arbitrary interpolating angle of the quantization surface. By
examining spectral deformation of the Dirac sea under an external electric
field semiclassically, we have found that the axial anomaly is quantization
angle independent. This indicates an intricate nontrivial vacuum structure
present even in the light-front limit.
| [
{
"created": "Tue, 30 May 1995 15:09:18 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Ji",
"Chueng-Ryong",
""
],
[
"REY",
"Soo-Jong",
""
]
] | Motivated by an apparent puzzle of the light-front vacua incompatible with the axial anomaly, we have considered the two-dimensional massless Schwinger model for an arbitrary interpolating angle of the quantization surface. By examining spectral deformation of the Dirac sea under an external electric field semiclassically, we have found that the axial anomaly is quantization angle independent. This indicates an intricate nontrivial vacuum structure present even in the light-front limit. |
2407.01354 | Marius Wiesemann | Marco Niggetiedt and Marius Wiesemann | Higgs-boson production in the full theory at NNLO+PS | 19 pages, 6 figures, 2 tables | null | null | MPP-2024-120 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the production of a Standard-Model (SM) Higgs boson in gluon
fusion in hadronic collisions and compute the QCD corrections up to
next-to-next-to-leading order (NNLO) and match them to parton showers
(NNLO+PS). The complete dependence on the top-quark mass is taken into account
without making any approximations to the top quark loops mediating the coupling
between the gluons and the Higgs boson. To this end, we have included the
$gg\to H$ amplitudes up to three loops and the $pp\to H$+jet amplitudes up to
two loops in the full SM theory. This is the first fully differential
calculation of the top-quark mass effects up to NNLO in QCD, and we study their
impact on relevant observables for the LHC.
| [
{
"created": "Mon, 1 Jul 2024 15:10:25 GMT",
"version": "v1"
}
] | 2024-07-02 | [
[
"Niggetiedt",
"Marco",
""
],
[
"Wiesemann",
"Marius",
""
]
] | We consider the production of a Standard-Model (SM) Higgs boson in gluon fusion in hadronic collisions and compute the QCD corrections up to next-to-next-to-leading order (NNLO) and match them to parton showers (NNLO+PS). The complete dependence on the top-quark mass is taken into account without making any approximations to the top quark loops mediating the coupling between the gluons and the Higgs boson. To this end, we have included the $gg\to H$ amplitudes up to three loops and the $pp\to H$+jet amplitudes up to two loops in the full SM theory. This is the first fully differential calculation of the top-quark mass effects up to NNLO in QCD, and we study their impact on relevant observables for the LHC. |
1410.1485 | Brandon Murakami | Brandon Murakami and Tim M.P. Tait | Searching for Lepton Flavor Violation at a Future High Energy
Electron-Positron Collider | 5 pages | Phys. Rev. D 91, 015002 (2015) | 10.1103/PhysRevD.91.015002 | UCI-HEP-TR-2014-07 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider theories where lepton flavor is violated, in particular
concentrating on the four fermion operator consisting of three electrons and a
tau. Strong constraints are available from existing searches for tau -> eee,
requiring the scale of the contact interaction to be less than ~(9 TeV)^-2. We
reexamine this type of physics, assuming that the particles responsible are
heavy (with masses greater than ~TeV) such that a contact interaction
description continues to be applicable at the energies for a future e+e-
collider. We find that the process e+e- -> e tau can be a very sensitive probe
of this kind of physics (even for very conservative assumptions about the
detector performance), already improving upon the tau decay bounds to less than
~(11 TeV)^-2 at collider energy sqrt(s) 500 GeV, or reaching beyond ~(35
TeV)^-2 for sqrt(s) = 3 TeV. Even stronger bounds are possible at e-e-
colliders in the same energy range.
| [
{
"created": "Mon, 6 Oct 2014 18:29:11 GMT",
"version": "v1"
}
] | 2015-01-14 | [
[
"Murakami",
"Brandon",
""
],
[
"Tait",
"Tim M. P.",
""
]
] | We consider theories where lepton flavor is violated, in particular concentrating on the four fermion operator consisting of three electrons and a tau. Strong constraints are available from existing searches for tau -> eee, requiring the scale of the contact interaction to be less than ~(9 TeV)^-2. We reexamine this type of physics, assuming that the particles responsible are heavy (with masses greater than ~TeV) such that a contact interaction description continues to be applicable at the energies for a future e+e- collider. We find that the process e+e- -> e tau can be a very sensitive probe of this kind of physics (even for very conservative assumptions about the detector performance), already improving upon the tau decay bounds to less than ~(11 TeV)^-2 at collider energy sqrt(s) 500 GeV, or reaching beyond ~(35 TeV)^-2 for sqrt(s) = 3 TeV. Even stronger bounds are possible at e-e- colliders in the same energy range. |
hep-ph/9909572 | F. Krauss | F. Krauss, R. Kuhn, G. Soff | APACIC++, A Parton Cascade in C++ | 23 pages, 5 Figures, Talk presented at the 39. Cracow Summer School
of Theoretical Physics, submitted to Acta Physica Polonica | Acta Phys.Polon.B30:3875-3894,1999 | null | null | hep-ph | null | In this talk the newly developped Monte-Carlo event generator {\tt APACIC++}
suitable to describe multijet-events in high-energetic electron-positron
annihilations is presented. A new ansatz to match the corresponding matrix
elements for the production of jets via the strong and electroweak interactions
to the subsequent parton shower modelling the inner-jet evolution is discussed
in some detail. Results obtained with {\tt APACIC++} are compared to other QCD
event generators and to some representative experimental data.
| [
{
"created": "Thu, 30 Sep 1999 17:21:40 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Krauss",
"F.",
""
],
[
"Kuhn",
"R.",
""
],
[
"Soff",
"G.",
""
]
] | In this talk the newly developped Monte-Carlo event generator {\tt APACIC++} suitable to describe multijet-events in high-energetic electron-positron annihilations is presented. A new ansatz to match the corresponding matrix elements for the production of jets via the strong and electroweak interactions to the subsequent parton shower modelling the inner-jet evolution is discussed in some detail. Results obtained with {\tt APACIC++} are compared to other QCD event generators and to some representative experimental data. |
2311.02902 | Alberto Salvio | Alberto Salvio | Inflation and Reheating through an Independent Affine Connection | 8 pages, 2 figures; contribution to the proceedings of the XI
International Conference on New Frontiers in Physics (ICNFP 2022) | null | null | null | hep-ph astro-ph.CO gr-qc hep-th | http://creativecommons.org/licenses/by/4.0/ | This paper is based on a talk in which I discussed how a component of the
dynamical affine connection, that is independent of the metric, can drive
inflation in agreement with observations. This provides a geometrical origin
for the inflaton. I also illustrated how the decays of this field, which has
spin 0 and odd parity, into Higgs bosons can reheat the universe to a
sufficiently high temperature.
| [
{
"created": "Mon, 6 Nov 2023 06:27:40 GMT",
"version": "v1"
}
] | 2023-11-07 | [
[
"Salvio",
"Alberto",
""
]
] | This paper is based on a talk in which I discussed how a component of the dynamical affine connection, that is independent of the metric, can drive inflation in agreement with observations. This provides a geometrical origin for the inflaton. I also illustrated how the decays of this field, which has spin 0 and odd parity, into Higgs bosons can reheat the universe to a sufficiently high temperature. |
1310.6864 | Hyun-Chul Kim | Hyun-Chul Kim, Hui-Young Ryu, Alexander Titov, Atsushi Hosaka | $\phi N$ photoproduction coupled with the $K\Lambda^*$ channel | 4 pages, 3 figures. A talk presented at The 22nd European Conference
on Few-Body Problems in Physics (EFB22) held in Krakow, Poland, 9 - 13
September 2013 | null | 10.1007/s00601-014-0883-6 | INHA-NTG-06/2013 | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present in this talk a recent investigation on $\phi$ photoproduction,
emphasizing the rescattering effects of the $K\Lambda^*$ channel near the
threshold region. We discuss the results of the differential cross section and
the angular distributions.
| [
{
"created": "Fri, 25 Oct 2013 09:44:04 GMT",
"version": "v1"
}
] | 2015-06-17 | [
[
"Kim",
"Hyun-Chul",
""
],
[
"Ryu",
"Hui-Young",
""
],
[
"Titov",
"Alexander",
""
],
[
"Hosaka",
"Atsushi",
""
]
] | We present in this talk a recent investigation on $\phi$ photoproduction, emphasizing the rescattering effects of the $K\Lambda^*$ channel near the threshold region. We discuss the results of the differential cross section and the angular distributions. |
hep-ph/9808382 | Tim | T.S.Evans | Derivative expansions of Euclidean thermal effective actions | RevTeX, 4 pages, no figures | null | null | Imperial/TP/97-98/21 | hep-ph | null | I compute the derivative expansion of an effective action at finite
temperature using the imaginary time approach. I show that it is a well behaved
expansion giving a unique seriers contrary to previous results. This disparity
is shown to originate in the choice of thermal Green functions used in the
calculations.
| [
{
"created": "Fri, 21 Aug 1998 16:36:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Evans",
"T. S.",
""
]
] | I compute the derivative expansion of an effective action at finite temperature using the imaginary time approach. I show that it is a well behaved expansion giving a unique seriers contrary to previous results. This disparity is shown to originate in the choice of thermal Green functions used in the calculations. |
0709.1031 | Mike Bisset | Mike Bisset (Tsinghua U., Beijing), Nick Kersting (Sichuan U.), Jun Li
(Tsinghua U., Beijing) | How to Detect `Decoupled' Heavy Supersymmetric Higgs Bosons | 4 pages, 3 figures; uses revtex.cls, revtex.sty, aps.sty, aps10.sty,
prabib.sty | null | null | TUHEP-TH-07160, SCUPHY-07001 | hep-ph | null | Heretofore neglected decay modes of heavy MSSM Higgs bosons into a variety of
neutralino pairs may push the LHC discovery reach for these crucial elements of
an extended Higgs sector to nearly the TeV-scale -- if sparticle-sector MSSM
input parameters are favorable. This is well into the so-called decoupling
region, including moderate to low tan(beta) values, where no known signals
exist for said heavy Higgs bosons via decays involving solely SM daughter
particles, and the lighter h^0 mimics the lone SM Higgs boson. While the
expanse of the Higgs to sparticle discovery region is sensitive to a number of
MSSM parameters, including in particular those for the sleptons, its presence
is primarily linked to the gaugino inputs -- in fact, to just one parameter,
M_2, if gaugino unification is invoked. Thus consideration of high vs. low M_2
realms in the MSSM should be placed on a par with the extensive consideration
already given to high vs. low tan(beta) regimes.
| [
{
"created": "Fri, 7 Sep 2007 09:42:53 GMT",
"version": "v1"
}
] | 2007-09-10 | [
[
"Bisset",
"Mike",
"",
"Tsinghua U., Beijing"
],
[
"Kersting",
"Nick",
"",
"Sichuan U."
],
[
"Li",
"Jun",
"",
"Tsinghua U., Beijing"
]
] | Heretofore neglected decay modes of heavy MSSM Higgs bosons into a variety of neutralino pairs may push the LHC discovery reach for these crucial elements of an extended Higgs sector to nearly the TeV-scale -- if sparticle-sector MSSM input parameters are favorable. This is well into the so-called decoupling region, including moderate to low tan(beta) values, where no known signals exist for said heavy Higgs bosons via decays involving solely SM daughter particles, and the lighter h^0 mimics the lone SM Higgs boson. While the expanse of the Higgs to sparticle discovery region is sensitive to a number of MSSM parameters, including in particular those for the sleptons, its presence is primarily linked to the gaugino inputs -- in fact, to just one parameter, M_2, if gaugino unification is invoked. Thus consideration of high vs. low M_2 realms in the MSSM should be placed on a par with the extensive consideration already given to high vs. low tan(beta) regimes. |
hep-ph/9806412 | Claude Bernard | MILC Collaboration: C. Bernard, T. DeGrand, C. DeTar, Steven Gottlieb,
Urs M. Heller, J. E. Hetrick, N. Ishizuka, C. McNeile, R. Sugar, D.
Toussaint, M. Wingate | Lattice Determination of Heavy-Light Decay Constants | 4 pages, 2 included figures. We adjust the perturbative correction
calculated by Kuramashi to take into account the fact that we match to the
continuum at the kinetic mass of the heavy meson, not the pole mass. This
produces a 2 to 4 MeV change in final results for decay constants, and has
negligible effect on decay constant ratios. We also include further
explanation of various features of the analysis | Phys.Rev.Lett.81:4812-4815,1998 | 10.1103/PhysRevLett.81.4812 | null | hep-ph hep-lat | null | We report on the MILC collaboration's calculation of $f_B$, $f_{B_s}$, $f_D$,
$f_{D_s}$, and their ratios. Our central values come from the quenched
approximation, but the quenching error is estimated from $N_F=2$ dynamical
staggered lattices. We use Wilson light valence quarks and Wilson and static
heavy quarks. We find, for example, $f_B=157 \pm 11 {}^{+25}_{-9} {}^{+23}_{-0}
\MeV$, $f_{B_s}/f_B = 1.11 \pm 0.02 {}^{+0.04}_{-0.03} \pm 0.03$, $f_{D_s} =
210 \pm 9 {}^{+25}_{-9} {}^{+17}_{-1} \MeV$ and $f_{B}/f_{D_s} = 0.75 \pm 0.03
{}^{+0.04}_{-0.02} {}^{+0.08}_{-0.00}$, where the errors are statistical,
systematic (within the quenched approximation), and systematic (of quenching),
respectively.
| [
{
"created": "Thu, 18 Jun 1998 20:03:15 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Oct 1998 17:05:31 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"MILC Collaboration",
"",
""
],
[
"Bernard",
"C.",
""
],
[
"DeGrand",
"T.",
""
],
[
"DeTar",
"C.",
""
],
[
"Gottlieb",
"Steven",
""
],
[
"Heller",
"Urs M.",
""
],
[
"Hetrick",
"J. E.",
""
],
[
"Ishizuka",
"N.",
""
],
[
"McNeile",
"C.",
""
],
[
"Sugar",
"R.",
""
],
[
"Toussaint",
"D.",
""
],
[
"Wingate",
"M.",
""
]
] | We report on the MILC collaboration's calculation of $f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$, and their ratios. Our central values come from the quenched approximation, but the quenching error is estimated from $N_F=2$ dynamical staggered lattices. We use Wilson light valence quarks and Wilson and static heavy quarks. We find, for example, $f_B=157 \pm 11 {}^{+25}_{-9} {}^{+23}_{-0} \MeV$, $f_{B_s}/f_B = 1.11 \pm 0.02 {}^{+0.04}_{-0.03} \pm 0.03$, $f_{D_s} = 210 \pm 9 {}^{+25}_{-9} {}^{+17}_{-1} \MeV$ and $f_{B}/f_{D_s} = 0.75 \pm 0.03 {}^{+0.04}_{-0.02} {}^{+0.08}_{-0.00}$, where the errors are statistical, systematic (within the quenched approximation), and systematic (of quenching), respectively. |
2006.15767 | Patrick Huber | Pilar Coloma, Patrick Huber, Jonathan M. Link | Telling Solar Neutrinos from Solar Axions When You Can't Shut Off the
Sun | 2 pages, 2 figures | null | null | null | hep-ph hep-ex nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The XENON1T experiment recently reported an excess of events at low electron
recoil energies, which may be due to interactions of solar neutrinos inside the
detector via a large neutrino magnetic moment. We point out that a $^{51}$Cr
neutrino source placed close to the detector can directly test this hypothesis.
| [
{
"created": "Mon, 29 Jun 2020 01:17:11 GMT",
"version": "v1"
}
] | 2020-06-30 | [
[
"Coloma",
"Pilar",
""
],
[
"Huber",
"Patrick",
""
],
[
"Link",
"Jonathan M.",
""
]
] | The XENON1T experiment recently reported an excess of events at low electron recoil energies, which may be due to interactions of solar neutrinos inside the detector via a large neutrino magnetic moment. We point out that a $^{51}$Cr neutrino source placed close to the detector can directly test this hypothesis. |
1701.09167 | Tevong You | Tevong You | A Dynamical Weak Scale from Inflation | 20 pages, 2 figures. v2: typos and discussion in subsection 3.2
corrected, version accepted for publication in JCAP | null | 10.1088/1475-7516/2017/09/019 | Cavendish-HEP-17/02, DAMTP-2017-5 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dynamical scanning of the Higgs mass by an axion-like particle during
inflation may provide a cosmological component to explaining part of the
hierarchy problem. We propose a novel interplay of this cosmological relaxation
mechanism with inflation, whereby the backreaction of the Higgs vacuum
expectation value near the weak scale causes inflation to end. As Hubble drops,
the relaxion's dissipative friction increases relative to Hubble and slows it
down enough to be trapped by the barriers of its periodic potential. Such a
scenario raises the natural cut-off of the theory up to $\sim 10^{10}$ GeV,
while maintaining a minimal relaxion sector without having to introduce
additional scanning scalars or new physics coincidentally close to the weak
scale.
| [
{
"created": "Tue, 31 Jan 2017 18:25:11 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Aug 2017 13:00:29 GMT",
"version": "v2"
}
] | 2017-09-20 | [
[
"You",
"Tevong",
""
]
] | Dynamical scanning of the Higgs mass by an axion-like particle during inflation may provide a cosmological component to explaining part of the hierarchy problem. We propose a novel interplay of this cosmological relaxation mechanism with inflation, whereby the backreaction of the Higgs vacuum expectation value near the weak scale causes inflation to end. As Hubble drops, the relaxion's dissipative friction increases relative to Hubble and slows it down enough to be trapped by the barriers of its periodic potential. Such a scenario raises the natural cut-off of the theory up to $\sim 10^{10}$ GeV, while maintaining a minimal relaxion sector without having to introduce additional scanning scalars or new physics coincidentally close to the weak scale. |
2112.00762 | Evangelos Sfakianakis | Yanou Cui, Evangelos I. Sfakianakis | Detectable Gravitational Wave Signals from Inflationary Preheating | 10 pages, 3 figures | null | null | null | hep-ph astro-ph.CO gr-qc hep-th | http://creativecommons.org/licenses/by/4.0/ | We consider gravitational wave (GW) production during preheating in hybrid
inflation models where an axion-like waterfall field couples to Abelian gauge
fields. Based on a linear analysis, we find that the GW signal from such models
can be within the reach of a variety of foreseeable GW experiments such as
LISA, AEDGE, ET and CE, and is close to that of LIGO A+, both in terms of
frequency range and signal strength. Furthermore, the resultant GW signal is
helically polarized and thus may distinguish itself from other sources of
stochastic GW background. Finally, such models can produce primordial black
holes that can compose dark matter and lead to merger events detectable by GW
detectors.
| [
{
"created": "Wed, 1 Dec 2021 19:00:04 GMT",
"version": "v1"
}
] | 2021-12-03 | [
[
"Cui",
"Yanou",
""
],
[
"Sfakianakis",
"Evangelos I.",
""
]
] | We consider gravitational wave (GW) production during preheating in hybrid inflation models where an axion-like waterfall field couples to Abelian gauge fields. Based on a linear analysis, we find that the GW signal from such models can be within the reach of a variety of foreseeable GW experiments such as LISA, AEDGE, ET and CE, and is close to that of LIGO A+, both in terms of frequency range and signal strength. Furthermore, the resultant GW signal is helically polarized and thus may distinguish itself from other sources of stochastic GW background. Finally, such models can produce primordial black holes that can compose dark matter and lead to merger events detectable by GW detectors. |
2212.02539 | Yu-Chen Ding | Yu-Chen Ding, Nan Li, Yu-Feng Zhou | Enhanced cosmic-ray antihelium production from dark matter annihilation
through light mediators | 20 pages, 5 figures, 3 tables | JCAP03(2023)051 | 10.1088/1475-7516/2023/03/051 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Cosmic-ray (CR) antihelium is an important probe for the indirect search of
dark matter (DM) annihilation in the Galaxy. However, due to stringent
constraints from the measurements of CR antiprotons and $\gamma$-rays, the flux
of CR antihelium from the conventional DM direct annihilation into Standard
Model final states is expected to be far below the sensitivity of the current
experiments. We show that the production of antihelium can be significantly
enhanced if the DM particles annihilate through light mediator particles with a
mass $m_\phi \approx 8$ GeV close to the antihelium production threshold. After
taking into account the constraints from the AMS-02 antiproton data and the
Fermi-LAT $\gamma$-ray data on the spheroidal dwarf galaxies, we find that in
this scenario the CR antihelium flux can be enhanced by three orders of
magnitude, which makes it within the sensitivity of the ongoing AMS-02
experiment.
| [
{
"created": "Mon, 5 Dec 2022 19:02:14 GMT",
"version": "v1"
}
] | 2023-03-28 | [
[
"Ding",
"Yu-Chen",
""
],
[
"Li",
"Nan",
""
],
[
"Zhou",
"Yu-Feng",
""
]
] | Cosmic-ray (CR) antihelium is an important probe for the indirect search of dark matter (DM) annihilation in the Galaxy. However, due to stringent constraints from the measurements of CR antiprotons and $\gamma$-rays, the flux of CR antihelium from the conventional DM direct annihilation into Standard Model final states is expected to be far below the sensitivity of the current experiments. We show that the production of antihelium can be significantly enhanced if the DM particles annihilate through light mediator particles with a mass $m_\phi \approx 8$ GeV close to the antihelium production threshold. After taking into account the constraints from the AMS-02 antiproton data and the Fermi-LAT $\gamma$-ray data on the spheroidal dwarf galaxies, we find that in this scenario the CR antihelium flux can be enhanced by three orders of magnitude, which makes it within the sensitivity of the ongoing AMS-02 experiment. |
0912.2031 | Zhun Lu | Zhun Lu, Ivan Schmidt | Updating Boer-Mulders functions from unpolarized pd and pp Drell-Yan
data | High q_t data excluded in the fit; uncertainty of the fitted
parameters given; figures renewed; references added; matches ther version
published in Physical Review D. | Phys.Rev.D81:034023,2010 | 10.1103/PhysRevD.81.034023 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We extract the Boer-Mulders functions for the proton by combining the
unpolarized pd and pp Drell-Yan data measured by the E866/NuSea Collaboration
by the assumption that the $\cos 2\phi$ asymmetry is from the Boer-Mulders
function. Using the extracted Boer-Mulders functions, we present the
predictions for the $\cos 2 \phi$ asymmetries in future pp experiments at
J-PARC and $p \bar{p}$ experiments at PANDA and PAX.
| [
{
"created": "Thu, 10 Dec 2009 16:07:10 GMT",
"version": "v1"
},
{
"created": "Sat, 6 Mar 2010 06:19:21 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Lu",
"Zhun",
""
],
[
"Schmidt",
"Ivan",
""
]
] | We extract the Boer-Mulders functions for the proton by combining the unpolarized pd and pp Drell-Yan data measured by the E866/NuSea Collaboration by the assumption that the $\cos 2\phi$ asymmetry is from the Boer-Mulders function. Using the extracted Boer-Mulders functions, we present the predictions for the $\cos 2 \phi$ asymmetries in future pp experiments at J-PARC and $p \bar{p}$ experiments at PANDA and PAX. |
hep-ph/0511212 | Michael Strickland | Michael Strickland | Visualizing Color Plasma Instabilities | 10 pages, 5 figures. Contribution to Proceedings of Workshop on
Quark-Gluon-Plasma Thermalization, Vienna, Austria, Aug 10-12. For full
resolution images see
http://www.fias.uni-frankfurt.de/home/strickland/instability/ | Eur.Phys.J. A29 (2006) 59-63 | 10.1140/epja/i2005-10299-3 | null | hep-ph | null | I discuss recent advances in the understanding of non-equilibrium gauge field
dynamics in plasmas which have particle distributions which are locally
anisotropic in momentum space. In contrast to locally isotropic plasmas such
anisotropic plasmas have a spectrum of soft unstable modes which are
characterized by exponential growth of transverse (chromo)-magnetic fields at
short times. The long-time behavior of such instabilities depends on whether or
not the gauge group is abelian or non-abelian. I will report on recent
numerical simulations which attempt to determine the long-time behavior of an
anisotropic non-abelian plasma within hard-loop effective theory. For novelty I
will present an interesting method for visualizing the time-dependence of SU(2)
gauge field configurations produced during our numerical simulations.
| [
{
"created": "Thu, 17 Nov 2005 17:50:01 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Dec 2005 10:20:35 GMT",
"version": "v2"
}
] | 2008-10-18 | [
[
"Strickland",
"Michael",
""
]
] | I discuss recent advances in the understanding of non-equilibrium gauge field dynamics in plasmas which have particle distributions which are locally anisotropic in momentum space. In contrast to locally isotropic plasmas such anisotropic plasmas have a spectrum of soft unstable modes which are characterized by exponential growth of transverse (chromo)-magnetic fields at short times. The long-time behavior of such instabilities depends on whether or not the gauge group is abelian or non-abelian. I will report on recent numerical simulations which attempt to determine the long-time behavior of an anisotropic non-abelian plasma within hard-loop effective theory. For novelty I will present an interesting method for visualizing the time-dependence of SU(2) gauge field configurations produced during our numerical simulations. |
hep-ph/9307294 | Dudas | E.A.Dudas | Composite Supersymmetric Axion-Dilaton-Dilatino System and the breaking
of Supersymmetry | 20 pages, LPTHE 93/23 | Phys.Rev. D49 (1994) 1109-1116 | 10.1103/PhysRevD.49.1109 | null | hep-ph | null | The spontaneous breakdown of the scale, the chiral and the superconformal
symmetries for a hidden $SU(N)$ gauge group is studied in an effective
lagrangean approach. The relevant low-energy degrees of freedom are taken to be
the composite Goldstone particles associated with these three broken
symmetries. Supersymmetry is spontaneously broken in the large $N$ limit and
soft breaking terms in the observable sector are generated, together with
nonrenormalisable Nambu-Jona-Lasinio type interactions.
| [
{
"created": "Mon, 19 Jul 1993 15:43:11 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Dudas",
"E. A.",
""
]
] | The spontaneous breakdown of the scale, the chiral and the superconformal symmetries for a hidden $SU(N)$ gauge group is studied in an effective lagrangean approach. The relevant low-energy degrees of freedom are taken to be the composite Goldstone particles associated with these three broken symmetries. Supersymmetry is spontaneously broken in the large $N$ limit and soft breaking terms in the observable sector are generated, together with nonrenormalisable Nambu-Jona-Lasinio type interactions. |
1911.06788 | Mathias Becker | Mathias Becker, Wei-Chih Huang | Two-component asymmetric dark matter via bound states and freeze-in
decay | 19 pages plus appendices, 6 Figures | null | null | DO-TH 19/27, CP3-Origins-2019-43 DNRF90 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a novel mechanism to realize two-component asymmetric dark matter
of very different mass scales through bound state formation and late freeze-in
decay. Assuming a particle-antiparticle asymmetry is initially shared by SM
baryons and two dark matter components, we demonstrate that the existence of
bound states formed by the heavy component can efficiently transfer the
asymmetry from the heavy to the light component via late decay. In this case,
the energy densities of the two components can be comparable, and the correct
relic density is reproduced.
| [
{
"created": "Fri, 15 Nov 2019 18:10:07 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Apr 2020 17:13:48 GMT",
"version": "v2"
}
] | 2020-04-30 | [
[
"Becker",
"Mathias",
""
],
[
"Huang",
"Wei-Chih",
""
]
] | We propose a novel mechanism to realize two-component asymmetric dark matter of very different mass scales through bound state formation and late freeze-in decay. Assuming a particle-antiparticle asymmetry is initially shared by SM baryons and two dark matter components, we demonstrate that the existence of bound states formed by the heavy component can efficiently transfer the asymmetry from the heavy to the light component via late decay. In this case, the energy densities of the two components can be comparable, and the correct relic density is reproduced. |
hep-ph/0409103 | Tetsuya Shinozaki | Tetsuya Shinozaki, Makoto Oka and Sachiko Takeuchi | Effects of Instanton Induced Interaction on the Pentaquarks | 11 pages, 3 figures | Phys.Rev.D71:074025,2005 | 10.1103/PhysRevD.71.074025 | null | hep-ph | null | Roles of instanton induced interactions (III) in the masses of pentaquark
baryons, Theta^+ (J=1/2 and 3/2) and Xi^{--}, and a dibaryon, H, are discussed
using the MIT bag model in the negative parity case. It is shown that the
two-body terms in III give a strong attraction mainly due to the increase of
the number of pairs in multi-quark systems. In contrast, the three-body u-d-s
interaction is repulsive. It is found that III lowers the mass of Theta^+ as
much as 100 MeV from the mass predicted by the bag model without III.
| [
{
"created": "Thu, 9 Sep 2004 03:49:45 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Shinozaki",
"Tetsuya",
""
],
[
"Oka",
"Makoto",
""
],
[
"Takeuchi",
"Sachiko",
""
]
] | Roles of instanton induced interactions (III) in the masses of pentaquark baryons, Theta^+ (J=1/2 and 3/2) and Xi^{--}, and a dibaryon, H, are discussed using the MIT bag model in the negative parity case. It is shown that the two-body terms in III give a strong attraction mainly due to the increase of the number of pairs in multi-quark systems. In contrast, the three-body u-d-s interaction is repulsive. It is found that III lowers the mass of Theta^+ as much as 100 MeV from the mass predicted by the bag model without III. |
hep-ph/0510338 | Patricia Ball | Patricia Ball and Roman Zwicky | SU(3) Breaking of Leading--Twist K and K* Distribution Amplitudes - a
Reprise | 12 pages, 6 figures | Phys.Lett.B633:289-297,2006 | 10.1016/j.physletb.2005.11.068 | IPPP/05/57 | hep-ph | null | We review the status of the leptonic decay constants f_K and
f_K^{\parallel,\perp} of the K and K*, respectively, and the SU(3) breaking
quantities a_1(K) and a_{1}^{\parallel,\perp}(K*), the first Gegenbauer-moments
of the leading-twist distribution amplitudes of K and K*. We obtain new
predictions from QCD sum rules which are relevant for the calculation of K and
K* form factors, for instance T_1^{B->K*}, which determines the decay B -> K*
gamma, and for QCD factorisation calculations of nonleptonic B decays into
strange mesons, for instance B -> K pi.
| [
{
"created": "Wed, 26 Oct 2005 08:53:51 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ball",
"Patricia",
""
],
[
"Zwicky",
"Roman",
""
]
] | We review the status of the leptonic decay constants f_K and f_K^{\parallel,\perp} of the K and K*, respectively, and the SU(3) breaking quantities a_1(K) and a_{1}^{\parallel,\perp}(K*), the first Gegenbauer-moments of the leading-twist distribution amplitudes of K and K*. We obtain new predictions from QCD sum rules which are relevant for the calculation of K and K* form factors, for instance T_1^{B->K*}, which determines the decay B -> K* gamma, and for QCD factorisation calculations of nonleptonic B decays into strange mesons, for instance B -> K pi. |
1305.2606 | Gilberto Tavares-Velasco | I. Cort\'es-Maldonado, G. Hern\'andez-Tom\'e, G. Tavares-Velasco | Decay $t-> c\gamma$ in models with SU_L(3)XU_X(1) gauge symmetry | Revised version with minor modifications an some typos corrected | Phys.Rev.D 88 (2013) 014011 | 10.1103/PhysRevD.88.014011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The one-loop level mediated $t-> c \gamma$ decay is analyzed in the framework
of 331 models, which induce three-level flavor-changing neutral currents
mediated by an extra neutral gauge boson, Z', and a neutral scalar boson, \phi.
These models also predict new charged gauge and scalar bosons, together with
three new quarks, which can be exotic (with electric charges of -4/3e and 5/3e)
or standard model like. Apart from the contribution of the W boson, the $t\to
c\gamma$ decay receives contributions induced by the extra gauge boson and the
neutral scalar boson, which are generic for 331 models. In the so-called
minimal 331 model, there are additional contributions from the new charged
gauge and scalar bosons accompanied by the exotic quarks. We present analytical
results for the most general $t-> c\gamma$ amplitude in terms of transcendental
functions. For the numerical analysis we focus on the minimal 331 model: the
current bounds on the model parameters are examined and a particular scenario
is discussed in which the corresponding branching ratio could be of the order
of 10^{-6}, with the dominant contributions arising from the charged gauge
bosons and a relatively light neutral scalar boson with flavor-changing
couplings, whereas the Z' contribution would be of the order of 10^{-9} for
m_{Z'}>2 TeV. However, a further suppression could be expected due to a
potential suppression of the values of the flavor-changing coupling constants.
Under the same assumptions, in 331 models without exotic quarks, the $t->
c\gamma$ branching ratio would receive the dominant contribution from the
neutral scalar boson, which could be of the order of 10^{-7} for a Higgs mass
of a few hundreds of GeVs.
| [
{
"created": "Sun, 12 May 2013 17:11:46 GMT",
"version": "v1"
},
{
"created": "Mon, 20 May 2013 14:56:47 GMT",
"version": "v2"
},
{
"created": "Fri, 21 Jun 2013 15:28:52 GMT",
"version": "v3"
}
] | 2013-07-15 | [
[
"Cortés-Maldonado",
"I.",
""
],
[
"Hernández-Tomé",
"G.",
""
],
[
"Tavares-Velasco",
"G.",
""
]
] | The one-loop level mediated $t-> c \gamma$ decay is analyzed in the framework of 331 models, which induce three-level flavor-changing neutral currents mediated by an extra neutral gauge boson, Z', and a neutral scalar boson, \phi. These models also predict new charged gauge and scalar bosons, together with three new quarks, which can be exotic (with electric charges of -4/3e and 5/3e) or standard model like. Apart from the contribution of the W boson, the $t\to c\gamma$ decay receives contributions induced by the extra gauge boson and the neutral scalar boson, which are generic for 331 models. In the so-called minimal 331 model, there are additional contributions from the new charged gauge and scalar bosons accompanied by the exotic quarks. We present analytical results for the most general $t-> c\gamma$ amplitude in terms of transcendental functions. For the numerical analysis we focus on the minimal 331 model: the current bounds on the model parameters are examined and a particular scenario is discussed in which the corresponding branching ratio could be of the order of 10^{-6}, with the dominant contributions arising from the charged gauge bosons and a relatively light neutral scalar boson with flavor-changing couplings, whereas the Z' contribution would be of the order of 10^{-9} for m_{Z'}>2 TeV. However, a further suppression could be expected due to a potential suppression of the values of the flavor-changing coupling constants. Under the same assumptions, in 331 models without exotic quarks, the $t-> c\gamma$ branching ratio would receive the dominant contribution from the neutral scalar boson, which could be of the order of 10^{-7} for a Higgs mass of a few hundreds of GeVs. |
hep-ph/0207086 | Piotr Chankowski | Wojciech Krolikowski (IFT, Warsaw Univ.) | Explicit seesaw with nearly bimaximal neutrino mixing and no LSND effect | Some improvements introduced | null | null | IFT-02/23 | hep-ph | null | An explicit model of neutrino texture is presented, where in the 6 times 6
mass matrix the Majorana lefthanded component is zero, the Majorana righthanded
component - diagonal with equal entries, and the Dirac component gets a
hierarchical structure, deformed by nearly bimaximal mixing. If the Majorana
righthanded component dominates over the Dirac component, the familiar seesaw
mechanism leads effectively to the popular, nearly bimaximal oscillations of
active neutrinos. The Dirac component, before its deformation, may be similar
in shape to the charged-lepton and quark mass matrices. Then, parameters for
solar and atmospheric neutrinos may be related to each other, predicting from
the SuperKamiokande value of Delta m_{32}^2 a tiny Delta m_{21}^2, typical for
MSW LOW solar solution (rather than for MSW Large Mixing Angle solution).
| [
{
"created": "Fri, 5 Jul 2002 11:17:52 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Aug 2002 12:38:07 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Krolikowski",
"Wojciech",
"",
"IFT, Warsaw Univ."
]
] | An explicit model of neutrino texture is presented, where in the 6 times 6 mass matrix the Majorana lefthanded component is zero, the Majorana righthanded component - diagonal with equal entries, and the Dirac component gets a hierarchical structure, deformed by nearly bimaximal mixing. If the Majorana righthanded component dominates over the Dirac component, the familiar seesaw mechanism leads effectively to the popular, nearly bimaximal oscillations of active neutrinos. The Dirac component, before its deformation, may be similar in shape to the charged-lepton and quark mass matrices. Then, parameters for solar and atmospheric neutrinos may be related to each other, predicting from the SuperKamiokande value of Delta m_{32}^2 a tiny Delta m_{21}^2, typical for MSW LOW solar solution (rather than for MSW Large Mixing Angle solution). |
hep-ph/0002090 | Francesca Rosati | Francesca Rosati | Can the Inflaton and the Quintessence scalar be the same field? | 4 pages. Talk given at COSMO99, Trieste, Italy, September 1999. To
appear in the Proceedings | In 'COSMO-99 Proceedings of the 3^ Intern. Workshop on Particle
Physics and the Early Universe', pag. 126, World Scientific (2000) | null | null | hep-ph astro-ph gr-qc | null | The most recent cosmological data point in the direction of a cosmological
constant dominated universe. A suitable candidate for providing the required
acceleration is a rolling scalar field named ``quintessence''. We address the
issue of building a particle physics model for quintessence in the context of
Susy QCD. We then go on to ask if the quintessence scalar can be identified
with the inflaton field and give two examples in which this is indeed the case.
| [
{
"created": "Tue, 8 Feb 2000 17:48:11 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Rosati",
"Francesca",
""
]
] | The most recent cosmological data point in the direction of a cosmological constant dominated universe. A suitable candidate for providing the required acceleration is a rolling scalar field named ``quintessence''. We address the issue of building a particle physics model for quintessence in the context of Susy QCD. We then go on to ask if the quintessence scalar can be identified with the inflaton field and give two examples in which this is indeed the case. |
1410.4450 | Peter Kroll | P. Kroll | Status of DVMP, DVCS and GPDs | 12 pages, 17 figures, invited talk presented at Transversity 2014,
Chia (Italy), June 2014 | null | 10.1051/epjconf/20158501005 | WU B 14-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The analysis of exclusive meson leptoproduction (DVMP) within the handbag
approach is reviewed and the parametrization of the generalized parton
distributions (GPDs) is discussed in some detail with the main interest focused
of the GPDs H and E. Applications of the GPDs extracted from DVMP to other hard
exclusive processes as for instance deeply virtual Compton scattering (DVCS)
and an evaluation of Ji's sum rule are also presented.
| [
{
"created": "Thu, 16 Oct 2014 14:40:19 GMT",
"version": "v1"
}
] | 2015-06-23 | [
[
"Kroll",
"P.",
""
]
] | The analysis of exclusive meson leptoproduction (DVMP) within the handbag approach is reviewed and the parametrization of the generalized parton distributions (GPDs) is discussed in some detail with the main interest focused of the GPDs H and E. Applications of the GPDs extracted from DVMP to other hard exclusive processes as for instance deeply virtual Compton scattering (DVCS) and an evaluation of Ji's sum rule are also presented. |
hep-ph/9810442 | Hitoshi Murayama | Gian F. Giudice (CERN), Markus A. Luty (U. Maryland), Hitoshi Murayama
(UC Berkeley/LBNL), and Riccardo Rattazzi (CERN) | Gaugino Mass without Singlets | 25 pages, references added, typos and grammar corrected | JHEP 9812:027,1998 | 10.1088/1126-6708/1998/12/027 | CERN-TH/98-337, LBNL-42419, UCB-PTH-98/50, UMD-PP99-037 | hep-ph hep-th | null | In models with dynamical supersymmetry breaking in the hidden sector, the
gaugino masses in the observable sector have been believed to be extremely
suppressed (below 1 keV), unless there is a gauge singlet in the hidden sector
with specific couplings to the observable sector gauge multiplets. We point out
that there is a pure supergravity contribution to gaugino masses at the quantum
level arising from the superconformal anomaly. Our results are valid to all
orders in perturbation theory and are related to the `exact' beta functions for
soft terms. There is also an anomaly contribution to the A terms proportional
to the beta function of the corresponding Yukawa coupling. The gaugino masses
are proportional to the corresponding gauge beta functions, and so do not
satisfy the usual GUT relations.
| [
{
"created": "Wed, 21 Oct 1998 23:58:05 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Oct 1998 00:01:30 GMT",
"version": "v2"
},
{
"created": "Mon, 21 Dec 1998 17:55:06 GMT",
"version": "v3"
}
] | 2009-10-31 | [
[
"Giudice",
"Gian F.",
"",
"CERN"
],
[
"Luty",
"Markus A.",
"",
"U. Maryland"
],
[
"Murayama",
"Hitoshi",
"",
"UC Berkeley/LBNL"
],
[
"Rattazzi",
"Riccardo",
"",
"CERN"
]
] | In models with dynamical supersymmetry breaking in the hidden sector, the gaugino masses in the observable sector have been believed to be extremely suppressed (below 1 keV), unless there is a gauge singlet in the hidden sector with specific couplings to the observable sector gauge multiplets. We point out that there is a pure supergravity contribution to gaugino masses at the quantum level arising from the superconformal anomaly. Our results are valid to all orders in perturbation theory and are related to the `exact' beta functions for soft terms. There is also an anomaly contribution to the A terms proportional to the beta function of the corresponding Yukawa coupling. The gaugino masses are proportional to the corresponding gauge beta functions, and so do not satisfy the usual GUT relations. |
hep-ph/9512310 | Ralph Engel | R.Engel, A.Schiller and V.G.Serbo | A new possibility to monitor collisions of relativistic heavy ions at
LHC and RHIC | 9 pages + 4 figures, latex with poscript figures uuencoded | Part.Accel. 56 (1996) 1 | null | UL-NTZ 30/95 | hep-ph | null | We consider the radiation of particles of one bunch in the collective field
of the oncoming bunch, called coherent bremsstrahlung (CBS). The main
characteristics of CBS for LHC (in the Pb-Pb mode) and for RHIC are calculated.
At LHC about $3.9 10^8 dE_\gamma/E_\gamma$ photons per second are expected for
photon energies $E_\gamma \stackrel{<} {\sim} E_c= 93 $ eV. It seems that CBS
can be a potential tool for optimizing collisions and for measuring beam
parameters. The bunch length can be found from the critical energy of the CBS
spectrum; the transverse bunch size is related to the photon rate. A specific
dependence of photon rate on the impact parameter between the beams allows for
a fast control over the beam displacement.
| [
{
"created": "Thu, 14 Dec 1995 16:46:49 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Engel",
"R.",
""
],
[
"Schiller",
"A.",
""
],
[
"Serbo",
"V. G.",
""
]
] | We consider the radiation of particles of one bunch in the collective field of the oncoming bunch, called coherent bremsstrahlung (CBS). The main characteristics of CBS for LHC (in the Pb-Pb mode) and for RHIC are calculated. At LHC about $3.9 10^8 dE_\gamma/E_\gamma$ photons per second are expected for photon energies $E_\gamma \stackrel{<} {\sim} E_c= 93 $ eV. It seems that CBS can be a potential tool for optimizing collisions and for measuring beam parameters. The bunch length can be found from the critical energy of the CBS spectrum; the transverse bunch size is related to the photon rate. A specific dependence of photon rate on the impact parameter between the beams allows for a fast control over the beam displacement. |
hep-ph/9907422 | Stephen Mrenna | M. Carena (1), S. Mrenna (2), C.E.M. Wagner (3) ((1) Fermi National
Accelerator Laboratory, (2) University of California at Davis, (3) Argonne
National Laboratory) | The complementarity of LEP, the Tevatron and the LHC in the search for a
light MSSM Higgs boson | 35 pages, including 11 Postscript figures, using JHEP.cls | Phys.Rev.D62:055008,2000 | 10.1103/PhysRevD.62.055008 | CERN--TH/99--203, FERMILAB--PUB--98/250--T | hep-ph | null | We study the properties of the Higgs boson sector in the MSSM, putting
special emphasis on radiative effects which can affect the discovery potential
of the LHC, Tevatron and/or LEP colliders. We concentrate on the V b b-bar
channel, with V=Z or W, and on the channels with diphoton final states, which
are the dominant ones for the search for a light Standard Model Higgs boson at
LEP/Tevatron and LHC, respectively. By analyzing the regions of parameter space
for which the searches in at least one of these colliders can be particularly
difficult, we demonstrate the complementarity of these three colliders in the
search for a light Higgs boson which couples in a relevant way to the W and Z
gauge bosons (and hence plays a relevant role in the mechanism of electroweak
symmetry breaking).
| [
{
"created": "Mon, 19 Jul 1999 22:08:01 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Carena",
"M.",
""
],
[
"Mrenna",
"S.",
""
],
[
"Wagner",
"C. E. M.",
""
]
] | We study the properties of the Higgs boson sector in the MSSM, putting special emphasis on radiative effects which can affect the discovery potential of the LHC, Tevatron and/or LEP colliders. We concentrate on the V b b-bar channel, with V=Z or W, and on the channels with diphoton final states, which are the dominant ones for the search for a light Standard Model Higgs boson at LEP/Tevatron and LHC, respectively. By analyzing the regions of parameter space for which the searches in at least one of these colliders can be particularly difficult, we demonstrate the complementarity of these three colliders in the search for a light Higgs boson which couples in a relevant way to the W and Z gauge bosons (and hence plays a relevant role in the mechanism of electroweak symmetry breaking). |
hep-ph/9309268 | G. Ecker | G. Ecker | The standard model at low energies | Lectures given at the 6th Indian-Summer School on Intermediate Energy
Physics, Prague, Aug. 1993, Latex, 26 pages (with a4.sty), UWThPh-1993-31 | Czech.J.Phys.44:405-430,1995 | 10.1007/BF01689769 | null | hep-ph | null | The hadronic sector of the standard model at low energies is described by a
non--decoupling effective field theory, chiral perturbation theory. An
introduction is given to the construction of effective chiral Lagrangians, both
in the purely mesonic sector and with inclusion of baryons. The connection
between the relativistic formulation and the heavy baryon approach to chiral
perturbation theory with baryons is reviewed.
| [
{
"created": "Wed, 15 Sep 1993 16:31:11 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Ecker",
"G.",
""
]
] | The hadronic sector of the standard model at low energies is described by a non--decoupling effective field theory, chiral perturbation theory. An introduction is given to the construction of effective chiral Lagrangians, both in the purely mesonic sector and with inclusion of baryons. The connection between the relativistic formulation and the heavy baryon approach to chiral perturbation theory with baryons is reviewed. |
2310.01486 | Andrew Larkoski | Andrew J. Larkoski and Duff Neill | Flavor Fragmentation Function Factorization | 38 pages + appendices, 1 figure; v2: JHEP version, some minor
expansions of explanations | null | null | LA-UR-23-31203 | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A definition of partonic jet flavor that is both theoretically well-defined
and experimentally robust would have profound implications for measurements and
predictions especially for heavy flavor applications. Recently, a definition of
jet flavor was introduced as the net flavor flowing along the direction of the
Winner-Take-All axis of a jet which is soft safe to all orders, but not
collinear safe. Here, we exploit the lack of collinear safety and propose a
factorization theorem of perturbative flavor fragmentation functions that resum
collinear divergences and describe the evolution of flavor from the short
distance of jet production to the long distance at which hadronization occurs.
Collinear flavor evolution is governed by a small modification of the DGLAP
equations. We present a detailed all-orders analysis and identify exact
relations that must hold amongst the various anomalous dimensions by
probability conservation and the existence of fixed points of the
renormalization group flow. We explicitly validate the factorization theorem at
one-loop order, and demonstrate its consistency at two loops in particular
flavor channels. Starting at two-loops, constraints on phase space imposed by
flavor measurements potentially allow for non-trivial soft contributions, but
we demonstrate that they are scaleless and so explicitly vanish, ensuring that
soft particles are summed inclusively and all divergences are exclusively
collinear in nature. This factorization theorem opens the door to precision
calculations with identified flavor in the infrared.
| [
{
"created": "Mon, 2 Oct 2023 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Jan 2024 23:11:00 GMT",
"version": "v2"
}
] | 2024-01-05 | [
[
"Larkoski",
"Andrew J.",
""
],
[
"Neill",
"Duff",
""
]
] | A definition of partonic jet flavor that is both theoretically well-defined and experimentally robust would have profound implications for measurements and predictions especially for heavy flavor applications. Recently, a definition of jet flavor was introduced as the net flavor flowing along the direction of the Winner-Take-All axis of a jet which is soft safe to all orders, but not collinear safe. Here, we exploit the lack of collinear safety and propose a factorization theorem of perturbative flavor fragmentation functions that resum collinear divergences and describe the evolution of flavor from the short distance of jet production to the long distance at which hadronization occurs. Collinear flavor evolution is governed by a small modification of the DGLAP equations. We present a detailed all-orders analysis and identify exact relations that must hold amongst the various anomalous dimensions by probability conservation and the existence of fixed points of the renormalization group flow. We explicitly validate the factorization theorem at one-loop order, and demonstrate its consistency at two loops in particular flavor channels. Starting at two-loops, constraints on phase space imposed by flavor measurements potentially allow for non-trivial soft contributions, but we demonstrate that they are scaleless and so explicitly vanish, ensuring that soft particles are summed inclusively and all divergences are exclusively collinear in nature. This factorization theorem opens the door to precision calculations with identified flavor in the infrared. |
1510.07288 | Antonio Capolupo Dr | A. Capolupo, G. Lambiase and G. Vitiello | Probing mixing of photons and axion-like particles by geometric phase | 7 pages, to be published on Advances in High Energy Physics | Advances in High Energy Physics Volume 2015, Article ID 826051, 7
pages | 10.1155/2015/826051 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We find that a geometric phase characterizes the phenomenon of mixing of
photons with axion-like particles (ALPs). The laboratory observation of such a
phase may provide a novel tool able to detect such a mixing phenomenon. We show
that the geometric phase is dependent on the axion-like particle mass and
coupling constant. We discuss an interferometric experiment able to detect the
geometric phase associated to the ALPs-photon mixing.
| [
{
"created": "Sun, 25 Oct 2015 19:04:16 GMT",
"version": "v1"
}
] | 2019-05-23 | [
[
"Capolupo",
"A.",
""
],
[
"Lambiase",
"G.",
""
],
[
"Vitiello",
"G.",
""
]
] | We find that a geometric phase characterizes the phenomenon of mixing of photons with axion-like particles (ALPs). The laboratory observation of such a phase may provide a novel tool able to detect such a mixing phenomenon. We show that the geometric phase is dependent on the axion-like particle mass and coupling constant. We discuss an interferometric experiment able to detect the geometric phase associated to the ALPs-photon mixing. |
2309.00681 | Yohan Mauricio Oviedo Torres | A.Alves, G. Gil da Silveira, V. P. Gon\c{c}alves, F. S. Queiroz, Y. M.
Oviedo-Torres, J. Zamora-Saa | Searching for a Leptophilic Z' and a 3-3-1 symmetry at CLIC | 8 pages, 4 figures | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We derive the discovery potential of a leptophilic Z', and a Z' rising from a
$SU(3) \times SU(3)_L \times U(1)_N$ symmetry at the Compact Linear Collider
(CLIC), which is planned to host $e^+e^-$ collisions with 3 TeV center-of-mass
energy. We perform an optimized selection cut strategy on the transverse
momentum, pseudorapidity, and invariant mass of the dileptons in order to
enhance the collider sensitivity. We find that CLIC can potentially reach a
$5\sigma$ signal of a $1-3$~TeV leptophilic Z' with less than $1fb^{-1}$ of
integrated luminosity. As for the Z' belonging to a 3-3-1 symmetry, CLIC will
offer a complementary probe with the potential to impose $M_{Z^\prime} > 3$~TeV
with $\mathcal{L}=2fb^{-1}$.
| [
{
"created": "Fri, 1 Sep 2023 18:00:50 GMT",
"version": "v1"
}
] | 2023-09-06 | [
[
"Alves",
"A.",
""
],
[
"da Silveira",
"G. Gil",
""
],
[
"Gonçalves",
"V. P.",
""
],
[
"Queiroz",
"F. S.",
""
],
[
"Oviedo-Torres",
"Y. M.",
""
],
[
"Zamora-Saa",
"J.",
""
]
] | We derive the discovery potential of a leptophilic Z', and a Z' rising from a $SU(3) \times SU(3)_L \times U(1)_N$ symmetry at the Compact Linear Collider (CLIC), which is planned to host $e^+e^-$ collisions with 3 TeV center-of-mass energy. We perform an optimized selection cut strategy on the transverse momentum, pseudorapidity, and invariant mass of the dileptons in order to enhance the collider sensitivity. We find that CLIC can potentially reach a $5\sigma$ signal of a $1-3$~TeV leptophilic Z' with less than $1fb^{-1}$ of integrated luminosity. As for the Z' belonging to a 3-3-1 symmetry, CLIC will offer a complementary probe with the potential to impose $M_{Z^\prime} > 3$~TeV with $\mathcal{L}=2fb^{-1}$. |
hep-ph/0006305 | Dr. B. Krippa | B. Krippa | Effective Field Theory at Moderate Nuclear Density | 17 pages, Latex | null | null | VUTH 00-17 | hep-ph | null | Effective field theory of the in-medium nucleon-nucleon interaction is
considered. The effective range parameters are found to be of a natural scale.
The low density limit is discussed both in perturbative and nonperturbative
situations. In the nonperturbative case the attractive character of the
nucleon-nucleon interactions in the $^{1}S_0$ channel leads to the nuclear
superfluidity which is analyzed in the framework of the renormalization group.
The numerical values of the corresponding energy gap are in agreement with
results obtained by more more traditional many-body techniques. The S-wave part
of potential energy per particle is calculated for different values of nuclear
density. The role of pion and many-body effects is discussed. Problems and
challenges in constructing the chiral theory of nuclear matter are outlined.
| [
{
"created": "Tue, 27 Jun 2000 14:44:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Krippa",
"B.",
""
]
] | Effective field theory of the in-medium nucleon-nucleon interaction is considered. The effective range parameters are found to be of a natural scale. The low density limit is discussed both in perturbative and nonperturbative situations. In the nonperturbative case the attractive character of the nucleon-nucleon interactions in the $^{1}S_0$ channel leads to the nuclear superfluidity which is analyzed in the framework of the renormalization group. The numerical values of the corresponding energy gap are in agreement with results obtained by more more traditional many-body techniques. The S-wave part of potential energy per particle is calculated for different values of nuclear density. The role of pion and many-body effects is discussed. Problems and challenges in constructing the chiral theory of nuclear matter are outlined. |
hep-ph/0210282 | Eulogio Oset | E. Oset, J. R. Pelaez and L. Roca | $\eta \to \pi^0 \gamma \gamma$ decay within unitarized chiral
perturbation theory | 15 pages, 10 figures, published version | Phys.Rev. D67 (2003) 073013 | 10.1103/PhysRevD.67.073013 | FTUV-02-1021, IFIC-02-1021 | hep-ph nucl-th | null | We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay
within the context of meson chiral lagrangians. We use a chiral unitary
approach for the meson-meson interaction, thus generating the $a_0(980)$
resonance and fixing the longstanding sign ambiguity on its contribution. This
also allows us to calculate the loops with one vector meson exchange, thus
removing a former source of uncertainty. In addition we ensure the consistency
of the approach with other processes. First, by using vector meson dominance
couplings normalized to agree with radiative vector meson decays. And, second,
by checking the consistency of the calculations with the related $\gamma \gamma
\to \pi^0 \eta$ reaction. We find an $\eta \to \pi^0 \gamma \gamma$ decay width
of $0.47\pm 0.10$ eV, in clear disagreement with published data but in
remarkable agreement with the most recent measurement.
| [
{
"created": "Mon, 21 Oct 2002 14:23:56 GMT",
"version": "v1"
},
{
"created": "Fri, 2 May 2003 16:11:35 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Oset",
"E.",
""
],
[
"Pelaez",
"J. R.",
""
],
[
"Roca",
"L.",
""
]
] | We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the $a_0(980)$ resonance and fixing the longstanding sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes. First, by using vector meson dominance couplings normalized to agree with radiative vector meson decays. And, second, by checking the consistency of the calculations with the related $\gamma \gamma \to \pi^0 \eta$ reaction. We find an $\eta \to \pi^0 \gamma \gamma$ decay width of $0.47\pm 0.10$ eV, in clear disagreement with published data but in remarkable agreement with the most recent measurement. |
1810.05403 | Andrew Akeroyd | A.G. Akeroyd, Stefano Moretti, Muyuan Song | Light charged Higgs boson with dominant decay to quarks and its search
at LHC and future colliders | 25 pages, 17 figures | Phys. Rev. D 98, 115024 (2018) | 10.1103/PhysRevD.98.115024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The possibility of a light charged Higgs boson $H^\pm$ that decays
predominantly to quarks ($cs$ and/or $cb$) and with a mass in the range 80 GeV
$\le m_{H^\pm} \le 90$ GeV is studied in the context of Three-Higgs-Doublet
Models (3HDMs). At present the Large Hadron Collider (LHC) has little
sensitivity to this scenario, and currently the best constraints are from LEP2
and Tevatron searches. The branching ratio of $H^\pm\to cb$ can be dominant in
two of the five types of 3HDM, and we determine the parameter space where this
occurs. The decay $H^\pm\to cb$ has recently been searched for at the LHC for
the first time, and with increased integrated luminosity one would expect
sensitivity to the region 80 GeV $\le m_{H^\pm} \le 90$ GeV due to the smaller
backgrounds with respect to $H^\pm\to cs$ decays.
| [
{
"created": "Fri, 12 Oct 2018 08:32:29 GMT",
"version": "v1"
}
] | 2018-12-26 | [
[
"Akeroyd",
"A. G.",
""
],
[
"Moretti",
"Stefano",
""
],
[
"Song",
"Muyuan",
""
]
] | The possibility of a light charged Higgs boson $H^\pm$ that decays predominantly to quarks ($cs$ and/or $cb$) and with a mass in the range 80 GeV $\le m_{H^\pm} \le 90$ GeV is studied in the context of Three-Higgs-Doublet Models (3HDMs). At present the Large Hadron Collider (LHC) has little sensitivity to this scenario, and currently the best constraints are from LEP2 and Tevatron searches. The branching ratio of $H^\pm\to cb$ can be dominant in two of the five types of 3HDM, and we determine the parameter space where this occurs. The decay $H^\pm\to cb$ has recently been searched for at the LHC for the first time, and with increased integrated luminosity one would expect sensitivity to the region 80 GeV $\le m_{H^\pm} \le 90$ GeV due to the smaller backgrounds with respect to $H^\pm\to cs$ decays. |
hep-ph/9411382 | null | Z.K. Silagadze | Pionium in the elementary particle decays | 12 pages, to appear in Pis'ma Zh. Eks. Teor. Fiz. 60(1994),673 | JETP Lett.60:689-693,1994 | null | E2-94-391 (Dubna) | hep-ph | null | Some atomic decays of elementary particles with pionium
($\pi^+\pi^-$-dimesoatom) in the final state are considered. Only for K-meson
atomic decays are the corresponding branching ratios big enough to make their
experimental study realistic. The $O(\alpha)$ order corrections to the lifetime
of pionium are also calculated.
| [
{
"created": "Wed, 23 Nov 1994 18:00:52 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Nov 1994 10:20:12 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Silagadze",
"Z. K.",
""
]
] | Some atomic decays of elementary particles with pionium ($\pi^+\pi^-$-dimesoatom) in the final state are considered. Only for K-meson atomic decays are the corresponding branching ratios big enough to make their experimental study realistic. The $O(\alpha)$ order corrections to the lifetime of pionium are also calculated. |
1011.6403 | Daniel Gomez Dumm | D. Gomez Dumm, S. Noguera, N.N. Scoccola | Pion radiative weak decays in nonlocal chiral quark models | 14 pages, 1 figure, minor changes in text introduced | Phys.Lett.B698:236-242,2011 | 10.1016/j.physletb.2011.03.002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the radiative pion decay pi+ -> e+ nu_e gamma within nonlocal
chiral quark models that include wave function renormalization. In this
framework we calculate the vector and axial-vector form factors FV and FA at
q^2=0 --where q^2 is the (e+ \nu_e) squared invariant mass-- and the slope a of
FV(q^2) at q^2 -> 0. The calculations are carried out considering different
nonlocal form factors, in particular those taken from lattice QCD evaluations,
showing a reasonable agreement with the corresponding experimental data. The
comparison of our results with those obtained in the (local) NJL model and the
relation of FV and a with the form factor in pi^0 -> gamma* gamma decays are
discussed.
| [
{
"created": "Mon, 29 Nov 2010 22:24:49 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Feb 2011 20:53:07 GMT",
"version": "v2"
}
] | 2011-04-28 | [
[
"Dumm",
"D. Gomez",
""
],
[
"Noguera",
"S.",
""
],
[
"Scoccola",
"N. N.",
""
]
] | We analyze the radiative pion decay pi+ -> e+ nu_e gamma within nonlocal chiral quark models that include wave function renormalization. In this framework we calculate the vector and axial-vector form factors FV and FA at q^2=0 --where q^2 is the (e+ \nu_e) squared invariant mass-- and the slope a of FV(q^2) at q^2 -> 0. The calculations are carried out considering different nonlocal form factors, in particular those taken from lattice QCD evaluations, showing a reasonable agreement with the corresponding experimental data. The comparison of our results with those obtained in the (local) NJL model and the relation of FV and a with the form factor in pi^0 -> gamma* gamma decays are discussed. |
hep-ph/0610089 | David A. Kosower | Carola F. Berger, Zvi Bern, Lance J. Dixon, Darren Forde, David A.
Kosower | On-Shell Unitarity Bootstrap for QCD Amplitudes | 10 pages, 9 figures, write-up of talks given by Z. Bern and D. A.
Kosower at Loops & Legs 2006, Eisenach, Germany; v2: added reference | Nucl.Phys.Proc.Suppl.160:261-270,2006 | 10.1016/j.nuclphysbps.2006.09.114 | UCLA/06/TEP/22, SLAC-PUB-12064, Saclay/SPhT-T06/096 | hep-ph | null | We describe the recently developed on-shell bootstrap for computing one-loop
amplitudes in non-supersymmetric theories such as QCD. The method combines the
unitarity method with loop-level on-shell recursion. The unitarity method is
used to compute cut-containing parts of amplitudes, and on-shell recursion is
used for the remaining rational terms.
| [
{
"created": "Sun, 8 Oct 2006 22:35:06 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Oct 2006 16:36:20 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Berger",
"Carola F.",
""
],
[
"Bern",
"Zvi",
""
],
[
"Dixon",
"Lance J.",
""
],
[
"Forde",
"Darren",
""
],
[
"Kosower",
"David A.",
""
]
] | We describe the recently developed on-shell bootstrap for computing one-loop amplitudes in non-supersymmetric theories such as QCD. The method combines the unitarity method with loop-level on-shell recursion. The unitarity method is used to compute cut-containing parts of amplitudes, and on-shell recursion is used for the remaining rational terms. |
1810.12507 | Xian-Qiao Yu | Ze-Rui Liang, Feng-Bo Duan and Xian-Qiao Yu | Study of the quasi-two-body decays B^{0}_{s} \rightarrow
\psi(3770)(\psi(3686))\pi^+\pi^- with perturbative QCD approach | 10 pages, 3 figures | Eur. Phys. J. C (2019) 79:370 | 10.1140/epjc/s10052-019-6877-2 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note, we study the contributions from the S-wave resonances,
f_{0}(980) and f_{0}(1500), to the B^{0}_{s}\rightarrow \psi(3770)\pi^
{+}\pi^{-} decay by introducing the S-wave \pi\pi distribution amplitudes
within the framework of the perturbative QCD approach. Both resonant and
nonresonant contributions are contained in the scalar form factor in the S-wave
distribution amplitude \Phi^S_{\pi\pi}. Since the vector charmonium meson
\psi(3770) is a S-D wave mixed state, we calculated the branching ratios of
S-wave and D-wave respectively, and the results indicate that f_{0}(980) is the
main contribution of the considered decay, and the branching ratio of the
\psi(2S) mode is in good agreement with the experimental data. We also take the
S-D mixed effect into the B^{0}_{s}\rightarrow \psi(3686)\pi^ {+}\pi^{-} decay.
Our calculations show that the branching ratio of B^{0}_{s}\rightarrow
\psi(3770)(\psi(3686))\pi^ {+}\pi^{-} can be at the order of 10^{-5}, which can
be tested by the running LHC-b experiments.
| [
{
"created": "Tue, 30 Oct 2018 03:08:37 GMT",
"version": "v1"
},
{
"created": "Thu, 9 May 2019 13:38:15 GMT",
"version": "v2"
}
] | 2019-05-10 | [
[
"Liang",
"Ze-Rui",
""
],
[
"Duan",
"Feng-Bo",
""
],
[
"Yu",
"Xian-Qiao",
""
]
] | In this note, we study the contributions from the S-wave resonances, f_{0}(980) and f_{0}(1500), to the B^{0}_{s}\rightarrow \psi(3770)\pi^ {+}\pi^{-} decay by introducing the S-wave \pi\pi distribution amplitudes within the framework of the perturbative QCD approach. Both resonant and nonresonant contributions are contained in the scalar form factor in the S-wave distribution amplitude \Phi^S_{\pi\pi}. Since the vector charmonium meson \psi(3770) is a S-D wave mixed state, we calculated the branching ratios of S-wave and D-wave respectively, and the results indicate that f_{0}(980) is the main contribution of the considered decay, and the branching ratio of the \psi(2S) mode is in good agreement with the experimental data. We also take the S-D mixed effect into the B^{0}_{s}\rightarrow \psi(3686)\pi^ {+}\pi^{-} decay. Our calculations show that the branching ratio of B^{0}_{s}\rightarrow \psi(3770)(\psi(3686))\pi^ {+}\pi^{-} can be at the order of 10^{-5}, which can be tested by the running LHC-b experiments. |
1908.06558 | Qingwu Wang | Qingwu Wang, Chao Shi, Hong-Shi Zong | Non-strange quark stars from NJL model with proper-time regularisation | null | Phys. Rev. D 100, 123003 (2019) | 10.1103/PhysRevD.100.123003 | null | hep-ph astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | The structure of light quark star is studied within a new two-flavor NJL
model. By retaining the contribution from the vector term in the
Fierz-transformed Lagrangian, a two-solar-mass pure quark star is achieved. To
overcome the disadvantage of three-momentum truncation in the regularisation
procedure, we introduce the proper-time regularisation. We also employ the
newly proposed definition of vacuum pressure, in which the quasi-Wigner vacuum
(corresponding to the quasi-Winger solution of the gap equation) is used as the
reference ground state. Free parameter includes only a mixing constant $\alpha$
which weighs contribution from Fierz-transformed Lagrangian. We constrain
$\alpha$ to be around $0.9$ by the observed mass of pulsars $PSR J0348+0432$
and $PSR J1614-2230$. We find the calculated surface energy density meets the
requirement ($> 2.80\times10^{14}$g/cm$^3 $). Besides, for a 1.4 solar mass
star, the tidal Love number $k_2$ and deformability $\Lambda$ are calculated
which satisfies the constrain $200 < \Lambda < 800$.
| [
{
"created": "Mon, 19 Aug 2019 02:09:01 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Dec 2019 00:15:32 GMT",
"version": "v2"
}
] | 2019-12-11 | [
[
"Wang",
"Qingwu",
""
],
[
"Shi",
"Chao",
""
],
[
"Zong",
"Hong-Shi",
""
]
] | The structure of light quark star is studied within a new two-flavor NJL model. By retaining the contribution from the vector term in the Fierz-transformed Lagrangian, a two-solar-mass pure quark star is achieved. To overcome the disadvantage of three-momentum truncation in the regularisation procedure, we introduce the proper-time regularisation. We also employ the newly proposed definition of vacuum pressure, in which the quasi-Wigner vacuum (corresponding to the quasi-Winger solution of the gap equation) is used as the reference ground state. Free parameter includes only a mixing constant $\alpha$ which weighs contribution from Fierz-transformed Lagrangian. We constrain $\alpha$ to be around $0.9$ by the observed mass of pulsars $PSR J0348+0432$ and $PSR J1614-2230$. We find the calculated surface energy density meets the requirement ($> 2.80\times10^{14}$g/cm$^3 $). Besides, for a 1.4 solar mass star, the tidal Love number $k_2$ and deformability $\Lambda$ are calculated which satisfies the constrain $200 < \Lambda < 800$. |
2109.11948 | Adrian Signer | Gilberto Colangelo, Franziska Hagelstein, Adrian Signer, and Peter
Stoffer | A theory vade mecum for PSI experiments | This is Chapter 5 of the Review of Particle Physics at PSI, published
in SciPost Proceedings 5 | SciPost Phys.Proc. 5 (2021) 005 | 10.21468/SciPostPhysProc.5.005 | null | hep-ph hep-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | This article gives a compact introduction and overview of the theory
underlying the experiments described in the rest of this review.
| [
{
"created": "Fri, 24 Sep 2021 13:15:02 GMT",
"version": "v1"
}
] | 2021-09-27 | [
[
"Colangelo",
"Gilberto",
""
],
[
"Hagelstein",
"Franziska",
""
],
[
"Signer",
"Adrian",
""
],
[
"Stoffer",
"Peter",
""
]
] | This article gives a compact introduction and overview of the theory underlying the experiments described in the rest of this review. |
1803.04599 | Yuli Yan | Yu-Li Yan, Tai-Fu Feng, Jin-Lei Yang, Hai-Bin Zhang, Shu-Min Zhao,
Rong-Fei Zhu | Neutrino masses in the minimal gauged $(B-L)$ supersymmetry | 31 pages, 6 figures, accepted by Phys.Rev.D | Phys. Rev. D 97, 055036 (2018) | 10.1103/PhysRevD.97.055036 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the radiative corrections to neutrino masses in a minimal
supersymmetric extension of the standard model with local $U(1)_{B-L}$
symmetry. At tree level, three tiny active neutrinos and two nearly massless
sterile neutrinos can be obtained through the seesaw mechanism. Considering the
one-loop corrections to the neutrino masses, the numerical results indicate
that two sterile neutrinos obtain ${\rm KeV}$ masses and the small
active-sterile neutrino mixing angles. The lighter sterile neutrino is a very
interesting dark matter candidate in cosmology. Meanwhile the active neutrinos
mixing angles and mass squared differences agree with present experimental
data.
| [
{
"created": "Tue, 13 Mar 2018 02:33:54 GMT",
"version": "v1"
}
] | 2018-04-04 | [
[
"Yan",
"Yu-Li",
""
],
[
"Feng",
"Tai-Fu",
""
],
[
"Yang",
"Jin-Lei",
""
],
[
"Zhang",
"Hai-Bin",
""
],
[
"Zhao",
"Shu-Min",
""
],
[
"Zhu",
"Rong-Fei",
""
]
] | We present the radiative corrections to neutrino masses in a minimal supersymmetric extension of the standard model with local $U(1)_{B-L}$ symmetry. At tree level, three tiny active neutrinos and two nearly massless sterile neutrinos can be obtained through the seesaw mechanism. Considering the one-loop corrections to the neutrino masses, the numerical results indicate that two sterile neutrinos obtain ${\rm KeV}$ masses and the small active-sterile neutrino mixing angles. The lighter sterile neutrino is a very interesting dark matter candidate in cosmology. Meanwhile the active neutrinos mixing angles and mass squared differences agree with present experimental data. |
hep-ph/0407280 | Peter Kroll | P. Kroll (Wuppertal University) | Generalized parton distributions and wide-angle exclusive scattering | 5 pages, 4 figures using LATEX with npb.sty | null | 10.1016/j.nuclphysbps.2004.09.045 | W-UB 04-07 | hep-ph | null | The handbag mechanism for wide-angle exlusive scattering reactions is
discussed and compared with other theoretical approaches. Its application to
Compton scattering, meson photoproduction and two-photon annihilations into
pairs of hadrons is reviewed.
| [
{
"created": "Fri, 23 Jul 2004 11:28:28 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Kroll",
"P.",
"",
"Wuppertal University"
]
] | The handbag mechanism for wide-angle exlusive scattering reactions is discussed and compared with other theoretical approaches. Its application to Compton scattering, meson photoproduction and two-photon annihilations into pairs of hadrons is reviewed. |
1308.1959 | Ulrich Haisch | Rhorry Gauld, Florian Goertz and Ulrich Haisch | On minimal Z' explanations of the B->K*mu+mu- anomaly | 4 pages, 2 figures; v2: minor modifications, typos corrected and
references added | Phys. Rev. D 89, 015005 (2014) | 10.1103/PhysRevD.89.015005 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently LHCb has announced a discrepancy of 3.7 sigma in one of the
theoretically clean observables accessible through studies of angular
correlations in B->K*mu+mu-. We point out that in the most minimal Z' setup
that can address this anomaly there is a model-independent triple-correlation
between new physics (NP) in B->K*mu+mu-, B_s-Bbar_s mixing, and non-unitarity
of the quark-mixing matrix. This triple-correlation can be cast into a simple
analytic formula that relates the NP contribution DeltaC9 to the Wilson
coefficient of the semileptonic vector operator to a shift in the mass
difference DeltaM_{B_s} and a violation of |Vud|^2+ |Vus|^2+ |Vub|^2 = 1. In
contrast to the individual observables the found relation depends only
logarithmically on the Z' mass. We show that that our findings allow for useful
future tests of the pattern of NP suggested by the B->K*mu+mu- anomaly.
| [
{
"created": "Thu, 8 Aug 2013 20:00:08 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Aug 2013 14:09:23 GMT",
"version": "v2"
}
] | 2014-01-15 | [
[
"Gauld",
"Rhorry",
""
],
[
"Goertz",
"Florian",
""
],
[
"Haisch",
"Ulrich",
""
]
] | Recently LHCb has announced a discrepancy of 3.7 sigma in one of the theoretically clean observables accessible through studies of angular correlations in B->K*mu+mu-. We point out that in the most minimal Z' setup that can address this anomaly there is a model-independent triple-correlation between new physics (NP) in B->K*mu+mu-, B_s-Bbar_s mixing, and non-unitarity of the quark-mixing matrix. This triple-correlation can be cast into a simple analytic formula that relates the NP contribution DeltaC9 to the Wilson coefficient of the semileptonic vector operator to a shift in the mass difference DeltaM_{B_s} and a violation of |Vud|^2+ |Vus|^2+ |Vub|^2 = 1. In contrast to the individual observables the found relation depends only logarithmically on the Z' mass. We show that that our findings allow for useful future tests of the pattern of NP suggested by the B->K*mu+mu- anomaly. |
hep-ph/0501042 | Matthias Steinhauser | A.A. Penin, V.A. Smirnov, M. Steinhauser | Heavy Quarkonium Spectrum and Production/Annihilation Rates to order
$\beta_0^3\alpha_s^3$ | 16 pages, 1 figure, references added, version to appear in Nucl.
Phys. B | Nucl.Phys. B716 (2005) 303-318 | 10.1016/j.nuclphysb.2005.03.028 | TTP/05-01, DESY 05-001 | hep-ph | null | We compute the third-order corrections to the heavy quarkonium spectrum and
production/annihilation rates due to the leading renormalization group running
of the static potential. The previously known complete ${\cal
O}(m_q\alpha_s^5)$ result for the heavy quarkonium ground state energy is
extended to the exited states. After including the ${\cal O}(\alpha_s^3)$
corrections the perturbative results are in surprisingly good agreement with
the experimental data on the masses of the excited $\Upsilon$ resonances and
the leptonic width of the $\Upsilon(1S)$ meson. The impact of the corrections
on the $\Upsilon$ sum rules and top quark-antiquark threshold production cross
section is also discussed.
| [
{
"created": "Fri, 7 Jan 2005 08:24:11 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Apr 2005 14:21:08 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Penin",
"A. A.",
""
],
[
"Smirnov",
"V. A.",
""
],
[
"Steinhauser",
"M.",
""
]
] | We compute the third-order corrections to the heavy quarkonium spectrum and production/annihilation rates due to the leading renormalization group running of the static potential. The previously known complete ${\cal O}(m_q\alpha_s^5)$ result for the heavy quarkonium ground state energy is extended to the exited states. After including the ${\cal O}(\alpha_s^3)$ corrections the perturbative results are in surprisingly good agreement with the experimental data on the masses of the excited $\Upsilon$ resonances and the leptonic width of the $\Upsilon(1S)$ meson. The impact of the corrections on the $\Upsilon$ sum rules and top quark-antiquark threshold production cross section is also discussed. |
1501.06658 | Michael Kr\"amer | M. Kr\"amer and M. Muhlleitner | Higgs Physics | 22 pages, Latex, Contribution to the Proceedings of the Final Meeting
of the Collaborative Research Centre / Transregio 9 "Computational Particle
Physics", Durbach, Germany, September 2014, to appear in Nucl. Phys. (Proc.
Suppl.) References and acknowledgments added | null | null | KA-TP-01-2015, SFB/CPP-14-115, SLAC-PUB-16201, TTK-15-05 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the interpretation of the LHC Higgs data and the test of the Higgs
mechanism. This is done in a more model-independent approach relying on an
effective Lagrangian, as well as in specific models like composite Higgs models
and supersymmetric extensions of the Standard Model. The proper interpretation
of the data requires the inclusion of higher-order corrections both for the
relevant Higgs parameters and the production and decay processes. We review
recent results obtained within the Collaborative Research Centre / Transregio 9
"Computational Particle Physics".
| [
{
"created": "Tue, 27 Jan 2015 05:20:35 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Feb 2015 20:59:31 GMT",
"version": "v2"
}
] | 2016-02-22 | [
[
"Krämer",
"M.",
""
],
[
"Muhlleitner",
"M.",
""
]
] | We discuss the interpretation of the LHC Higgs data and the test of the Higgs mechanism. This is done in a more model-independent approach relying on an effective Lagrangian, as well as in specific models like composite Higgs models and supersymmetric extensions of the Standard Model. The proper interpretation of the data requires the inclusion of higher-order corrections both for the relevant Higgs parameters and the production and decay processes. We review recent results obtained within the Collaborative Research Centre / Transregio 9 "Computational Particle Physics". |
2208.14306 | Gergely Mark\'o | Gergely Endr\H{o}di and Gergely Mark\'o | On electric fields in hot QCD: perturbation theory | 16 pages, 4 figures, published version | null | 10.1007/JHEP12(2022)015 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the response of a hot gas of quarks to external electric
fields via leading-order perturbation theory. In particular, we discuss how
equilibrium is maintained in the presence of the electric field and calculate
the electric susceptibility, providing its high-temperature expansion for
arbitrary quark mass. Furthermore, we point out that there is a mismatch
between this, direct determination of the susceptibility at zero field and the
weak-field expansion of the effective action at nonzero electric fields, as
obtained using Schwinger's exact propagator. We discuss the origin of this
mismatch and elaborate on the generalization of our results to full QCD in
electric fields.
| [
{
"created": "Tue, 30 Aug 2022 14:43:59 GMT",
"version": "v1"
},
{
"created": "Wed, 8 Feb 2023 11:10:42 GMT",
"version": "v2"
}
] | 2023-02-09 | [
[
"Endrődi",
"Gergely",
""
],
[
"Markó",
"Gergely",
""
]
] | We investigate the response of a hot gas of quarks to external electric fields via leading-order perturbation theory. In particular, we discuss how equilibrium is maintained in the presence of the electric field and calculate the electric susceptibility, providing its high-temperature expansion for arbitrary quark mass. Furthermore, we point out that there is a mismatch between this, direct determination of the susceptibility at zero field and the weak-field expansion of the effective action at nonzero electric fields, as obtained using Schwinger's exact propagator. We discuss the origin of this mismatch and elaborate on the generalization of our results to full QCD in electric fields. |
1208.1742 | Chunsheng An | S. G. Yuan, C. S. An, K. W. Wei, B. S. Zou and H. S. Xu | Spectrum of low-lying $s^{3}Q\bar{Q}$ configurations with negative
parity | Version published in Phys. Rev. C | null | 10.1103/PhysRevC.87.025205 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Spectrum of low-lying five-quark configurations with strangeness quantum
number $S=-3$ and negative parity is studied in three kinds of constituent
quark models, namely the one gluon exchange, Goldstone Boson exchange, and
instanton-induced hyperfine interaction models, respectively. Our numerical
results show that the lowest energy states in all the three employed models are
lying at $\sim$1800 MeV, about 200 MeV lower than predictions of various
quenched three-quark models. In addition, it is very interesting that the state
with the lowest energy in one gluon exchange model is with spin 3/2, but 1/2 in
the other two models.
| [
{
"created": "Wed, 8 Aug 2012 19:21:37 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Mar 2013 10:37:48 GMT",
"version": "v2"
}
] | 2015-06-11 | [
[
"Yuan",
"S. G.",
""
],
[
"An",
"C. S.",
""
],
[
"Wei",
"K. W.",
""
],
[
"Zou",
"B. S.",
""
],
[
"Xu",
"H. S.",
""
]
] | Spectrum of low-lying five-quark configurations with strangeness quantum number $S=-3$ and negative parity is studied in three kinds of constituent quark models, namely the one gluon exchange, Goldstone Boson exchange, and instanton-induced hyperfine interaction models, respectively. Our numerical results show that the lowest energy states in all the three employed models are lying at $\sim$1800 MeV, about 200 MeV lower than predictions of various quenched three-quark models. In addition, it is very interesting that the state with the lowest energy in one gluon exchange model is with spin 3/2, but 1/2 in the other two models. |
1006.2231 | Thomas Hahn | T. Hahn | Feynman Diagram Calculations with FeynArts, FormCalc, and LoopTools | 11 pages, proceedings contribution to ACAT 2010, Jaipur, India, Feb
22-27, 2010 | PoS ACAT2010:078,2010 | null | MPP-2010-65 | hep-ph physics.comp-ph | http://creativecommons.org/licenses/by-nc-sa/3.0/ | This article describes the latest versions of the Mathematica packages
FeynArts, FormCalc, and LoopTools for the generation and evaluation of one-loop
diagrams.
| [
{
"created": "Fri, 11 Jun 2010 08:30:52 GMT",
"version": "v1"
}
] | 2011-04-20 | [
[
"Hahn",
"T.",
""
]
] | This article describes the latest versions of the Mathematica packages FeynArts, FormCalc, and LoopTools for the generation and evaluation of one-loop diagrams. |
1901.10169 | Zheng Li Wang | Zheng-Li Wang and Bing-Song Zou | $\rho\rho$ scattering revisited with coupled-channels of pseudoscalar
mesons | 11 pages with 4 figures | Phys. Rev. D 99, 096014 (2019) | 10.1103/PhysRevD.99.096014 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $\rho\rho$ scattering has been studied by two groups which both claimed a
dynamical generated scalar meson, most likely to be $f_0(1370)$. Here we
investigate the influence of coupled-channels of pseudoscalar mesons, i.e.,
$\pi\pi$ and $\bar KK$, on this dynamical generated scalar state. With the
coupled channel effect included, the pole and partial decay widths are found to
be more close to PDG values for $f_0(1500)$.
| [
{
"created": "Tue, 29 Jan 2019 08:37:57 GMT",
"version": "v1"
},
{
"created": "Fri, 10 May 2019 07:54:20 GMT",
"version": "v2"
}
] | 2019-05-22 | [
[
"Wang",
"Zheng-Li",
""
],
[
"Zou",
"Bing-Song",
""
]
] | The $\rho\rho$ scattering has been studied by two groups which both claimed a dynamical generated scalar meson, most likely to be $f_0(1370)$. Here we investigate the influence of coupled-channels of pseudoscalar mesons, i.e., $\pi\pi$ and $\bar KK$, on this dynamical generated scalar state. With the coupled channel effect included, the pole and partial decay widths are found to be more close to PDG values for $f_0(1500)$. |
2402.10264 | Cara Giovanetti | Cara Giovanetti, Martin Schmaltz, Neal Weiner | Neutrino-Dark Sector Equilibration and Primordial Element Abundances | 6+6 pages | null | null | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | After neutrinos decouple from the photon bath, they can populate a thermal
dark sector. If this occurs at a temperature above ~100 keV, this can have
measurable impacts on light element abundances. We calculate light element
abundances in this scenario, studying the impact from rapid cooling of the
Standard Model neutrinos, and from an increase in the number of relativistic
degrees of freedom $N_{\rm{eff}}$, which can occur in the presence of a mass
threshold. We incorporate these changes in the publicly available BBN code
PRIMAT, using the reaction networks from PRIMAT and from the BBN code
PArthENoPE, to calculate Y$_{\rm{P}}$ and D/H. We provide limits from the two
different reaction networks as well as with expanded errors to include both
results. If electron neutrinos significantly participate in the cooling, we
find limits down to temperatures as low as 100 keV. If electron neutrinos are
weakly participating (for instance if only the mass eigenstate $\nu_3$
equilibrates), cooling places no limits. However, if the dark sector undergoes
a "step" in $N_{\rm{eff}}$, there can be additional, $\omega_b$-dependent
constraints. These limits can vary from strong (for low values of $\omega_b$)
to a mild preference for new physics (for high values of $\omega_b$). Future
analyses including upcoming CMB data should improve these limits.
| [
{
"created": "Thu, 15 Feb 2024 19:00:00 GMT",
"version": "v1"
}
] | 2024-02-27 | [
[
"Giovanetti",
"Cara",
""
],
[
"Schmaltz",
"Martin",
""
],
[
"Weiner",
"Neal",
""
]
] | After neutrinos decouple from the photon bath, they can populate a thermal dark sector. If this occurs at a temperature above ~100 keV, this can have measurable impacts on light element abundances. We calculate light element abundances in this scenario, studying the impact from rapid cooling of the Standard Model neutrinos, and from an increase in the number of relativistic degrees of freedom $N_{\rm{eff}}$, which can occur in the presence of a mass threshold. We incorporate these changes in the publicly available BBN code PRIMAT, using the reaction networks from PRIMAT and from the BBN code PArthENoPE, to calculate Y$_{\rm{P}}$ and D/H. We provide limits from the two different reaction networks as well as with expanded errors to include both results. If electron neutrinos significantly participate in the cooling, we find limits down to temperatures as low as 100 keV. If electron neutrinos are weakly participating (for instance if only the mass eigenstate $\nu_3$ equilibrates), cooling places no limits. However, if the dark sector undergoes a "step" in $N_{\rm{eff}}$, there can be additional, $\omega_b$-dependent constraints. These limits can vary from strong (for low values of $\omega_b$) to a mild preference for new physics (for high values of $\omega_b$). Future analyses including upcoming CMB data should improve these limits. |
1706.07028 | Wen Yin | Wen Yin | Dark Matter, Neutrino mass, Cutoff for Cosmic-Ray Neutrino, and Higgs
Boson Invisible Decay from a Neutrino Portal Interaction | 22 pages, 5 figures, v4: version to appear in Chinese Physics C | null | 10.1088/1674-1137/43/4/045101 | null | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study an effective theory beyond the standard model (SM) where either of
two additional gauge singlets, a Majorana fermion and a real scalar,
constitutes all or some fraction of dark matter. In particular, we focus on the
masses of the two singlets in the range of O(10) MeV-O(10) GeV, with a neutrino
portal interaction which plays important roles not only in particle physics but
also in cosmology and astronomy. We point out that the dark matter abundance
can be thermally explained with (co)annihilation, where the dark matter with a
mass greater than 2 GeV can be tested in future lepton colliders, CEPC, ILC,
FCC-ee and CLIC, in the light of the Higgs boson invisible decay. When the
gauge singlets are lighter than O(100)MeV, the interaction can affect the
neutrino propagation in the universe due to its annihilation with the cosmic
background neutrino into the gauge singlets. Although can not be the dominant
dark matter in this case, the singlets are produced by the invisible decay of
the Higgs boson at a rate fully within the reach of the future lepton
colliders. In particular, a high energy cutoff of cosmic-ray neutrino, which
may account for the non-detection of Greisen-Zatsepin-Kuzmin (GZK) neutrinos or
non-observation of Glashow resonance, can be set. Interestingly, given the
cutoff and the mass (range) of the WIMP, a neutrino mass can be "measured"
kinematically.
| [
{
"created": "Wed, 21 Jun 2017 17:42:07 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Jul 2017 17:57:29 GMT",
"version": "v2"
},
{
"created": "Fri, 17 Nov 2017 18:58:31 GMT",
"version": "v3"
},
{
"created": "Tue, 5 Mar 2019 12:52:47 GMT",
"version": "v4"
}
] | 2019-05-22 | [
[
"Yin",
"Wen",
""
]
] | We study an effective theory beyond the standard model (SM) where either of two additional gauge singlets, a Majorana fermion and a real scalar, constitutes all or some fraction of dark matter. In particular, we focus on the masses of the two singlets in the range of O(10) MeV-O(10) GeV, with a neutrino portal interaction which plays important roles not only in particle physics but also in cosmology and astronomy. We point out that the dark matter abundance can be thermally explained with (co)annihilation, where the dark matter with a mass greater than 2 GeV can be tested in future lepton colliders, CEPC, ILC, FCC-ee and CLIC, in the light of the Higgs boson invisible decay. When the gauge singlets are lighter than O(100)MeV, the interaction can affect the neutrino propagation in the universe due to its annihilation with the cosmic background neutrino into the gauge singlets. Although can not be the dominant dark matter in this case, the singlets are produced by the invisible decay of the Higgs boson at a rate fully within the reach of the future lepton colliders. In particular, a high energy cutoff of cosmic-ray neutrino, which may account for the non-detection of Greisen-Zatsepin-Kuzmin (GZK) neutrinos or non-observation of Glashow resonance, can be set. Interestingly, given the cutoff and the mass (range) of the WIMP, a neutrino mass can be "measured" kinematically. |
1009.3803 | Leonard Gamberg | H. Gao, L. Gamberg, J.-P. Chen, X. Qian, Y. Qiang, M. Huang, A.
Afanasev, M. Anselmino, H. Avakian, G. Cates, E. Chudakov, E. Cisbani, C. de
Jager, F. Garibaldi, B.T. Hu, X. Jiang, K.S. Kumar, X.M. Li, H.J. Lu, Z.-E.
Meziani, B.-Q. Ma, Y.J. Mao, J.-C. Peng, A. Prokudin, M. Schlegel, P. Souder,
Z.G. Xiao, Y. Ye, L. Zhu | Transverse Spin Structure of the Nucleon through Target Single Spin
Asymmetry in Semi-Inclusive Deep-Inelastic $(e,e^\prime \pi^\pm)$ Reaction at
Jefferson Lab | 23 pages, 13 figures, minor corrections, matches published version | Eur.Phys.J.Plus 126:2,2011 | 10.1140/epjp/i2011-11002-4 | null | hep-ph nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Jefferson Lab (JLab) 12 GeV energy upgrade provides a golden opportunity to
perform precision studies of the transverse spin and
transverse-momentum-dependent structure in the valence quark region for both
the proton and the neutron. In this paper, we focus our discussion on a
recently approved experiment on the neutron as an example of the precision
studies planned at JLab. The new experiment will perform precision measurements
of target Single Spin Asymmetries (SSA) from semi-inclusive electro-production
of charged pions from a 40-cm long transversely polarized $^3$He target in
Deep-Inelastic-Scattering kinematics using 11 and 8.8 GeV electron beams. This
new coincidence experiment in Hall A will employ a newly proposed solenoid
spectrometer (SoLID). The large acceptance spectrometer and the high polarized
luminosity will provide precise 4-D ($x$, $z$, $P_T$ and $Q^2$) data on the
Collins, Sivers, and pretzelocity asymmetries for the neutron through the
azimuthal angular dependence. The full 2$\pi$ azimuthal angular coverage in the
lab is essential in controlling the systematic uncertainties. The results from
this experiment, when combined with the proton Collins asymmetry measurement
and the Collins fragmentation function determined from the e$^+$e$^-$ collision
data, will allow for a quark flavor separation in order to achieve a
determination of the tensor charge of the d quark to a 10% accuracy. The
extracted Sivers and pretzelocity asymmetries will provide important
information to understand the correlations between the quark orbital angular
momentum and the nucleon spin and between the quark spin and nucleon spin.
| [
{
"created": "Mon, 20 Sep 2010 12:56:44 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Oct 2010 04:40:26 GMT",
"version": "v2"
},
{
"created": "Thu, 13 Jan 2011 06:08:07 GMT",
"version": "v3"
}
] | 2011-04-14 | [
[
"Gao",
"H.",
""
],
[
"Gamberg",
"L.",
""
],
[
"Chen",
"J. -P.",
""
],
[
"Qian",
"X.",
""
],
[
"Qiang",
"Y.",
""
],
[
"Huang",
"M.",
""
],
[
"Afanasev",
"A.",
""
],
[
"Anselmino",
"M.",
""
],
[
"Avakian",
"H.",
""
],
[
"Cates",
"G.",
""
],
[
"Chudakov",
"E.",
""
],
[
"Cisbani",
"E.",
""
],
[
"de Jager",
"C.",
""
],
[
"Garibaldi",
"F.",
""
],
[
"Hu",
"B. T.",
""
],
[
"Jiang",
"X.",
""
],
[
"Kumar",
"K. S.",
""
],
[
"Li",
"X. M.",
""
],
[
"Lu",
"H. J.",
""
],
[
"Meziani",
"Z. -E.",
""
],
[
"Ma",
"B. -Q.",
""
],
[
"Mao",
"Y. J.",
""
],
[
"Peng",
"J. -C.",
""
],
[
"Prokudin",
"A.",
""
],
[
"Schlegel",
"M.",
""
],
[
"Souder",
"P.",
""
],
[
"Xiao",
"Z. G.",
""
],
[
"Ye",
"Y.",
""
],
[
"Zhu",
"L.",
""
]
] | Jefferson Lab (JLab) 12 GeV energy upgrade provides a golden opportunity to perform precision studies of the transverse spin and transverse-momentum-dependent structure in the valence quark region for both the proton and the neutron. In this paper, we focus our discussion on a recently approved experiment on the neutron as an example of the precision studies planned at JLab. The new experiment will perform precision measurements of target Single Spin Asymmetries (SSA) from semi-inclusive electro-production of charged pions from a 40-cm long transversely polarized $^3$He target in Deep-Inelastic-Scattering kinematics using 11 and 8.8 GeV electron beams. This new coincidence experiment in Hall A will employ a newly proposed solenoid spectrometer (SoLID). The large acceptance spectrometer and the high polarized luminosity will provide precise 4-D ($x$, $z$, $P_T$ and $Q^2$) data on the Collins, Sivers, and pretzelocity asymmetries for the neutron through the azimuthal angular dependence. The full 2$\pi$ azimuthal angular coverage in the lab is essential in controlling the systematic uncertainties. The results from this experiment, when combined with the proton Collins asymmetry measurement and the Collins fragmentation function determined from the e$^+$e$^-$ collision data, will allow for a quark flavor separation in order to achieve a determination of the tensor charge of the d quark to a 10% accuracy. The extracted Sivers and pretzelocity asymmetries will provide important information to understand the correlations between the quark orbital angular momentum and the nucleon spin and between the quark spin and nucleon spin. |
hep-ph/0007291 | Ian Jack | I. Jack, D.R.T. Jones and S. Parsons | The Fayet-Iliopoulos D-term and its renormalisation in softly-broken
supersymmetric theories | 30 pages, Revtex, 15 Figures. Minor changes, and inadvertent omission
of author from this abstract corrected | Phys.Rev. D62 (2000) 125022 | 10.1103/PhysRevD.62.125022 | LTH 480 | hep-ph | null | We consider the renormalisation of the Fayet-Iliopoulos D-term in a
softly-broken abelian supersymmetric theory, and calculate the associated
beta-function through three loops. We show that there exists (at least through
three loops) a renormalisation group invariant trajectory for the coefficient
of the D-term, corresponding to the conformal anomaly solution for the soft
masses and couplings.
| [
{
"created": "Wed, 26 Jul 2000 15:55:16 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Aug 2000 14:06:20 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Jack",
"I.",
""
],
[
"Jones",
"D. R. T.",
""
],
[
"Parsons",
"S.",
""
]
] | We consider the renormalisation of the Fayet-Iliopoulos D-term in a softly-broken abelian supersymmetric theory, and calculate the associated beta-function through three loops. We show that there exists (at least through three loops) a renormalisation group invariant trajectory for the coefficient of the D-term, corresponding to the conformal anomaly solution for the soft masses and couplings. |
1710.01991 | Sanjin Beni\'c | Sanjin Beni\'c, Adrian Dumitru | Prompt photon - jet angular correlations at central rapidities in p+A
collisions | v3: more elaborated discussions on photon isolation cut, a few new
references, results unchanged, accepted for publication in PRD | Phys. Rev. D 97, 014012 (2018) | 10.1103/PhysRevD.97.014012 | ZTF-EP-12-17 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Photon-jet azimuthal correlations in proton-nucleus collisions are a
promising tool for gaining information on the gluon distribution of the nucleus
in the regime of non-linear color fields. We compute such correlations from the
process $g+A\to q \bar{q} \gamma$ in the rapidity regime where both the
projectile and target light-cone momentum fractions are small. By integrating
over the phase space of the quark which emits the photon, subject to the
restriction that the photon picks up most of the transverse momentum (to pass
an isolation cut), we effectively obtain a $g+A\to q \gamma$ process. For
nearly back-to-back photon-jet configurations we find that it dominates over
the leading order process $q+A\to q \gamma$ by two less powers of $Q_\perp /
Q_S$, where $\boldsymbol{Q}_\perp$ and $Q_S$ denote the net photon-jet pair
momentum and the saturation scale of the nucleus, respectively. We determine
the transverse momentum dependent gluon distributions involved in $g+A\to q
\gamma$ and the scale where they are evaluated. Finally, we provide analytic
expressions for $\langle\cos n\phi\rangle$ moments, where $\phi$ is the angle
between $\boldsymbol{Q}_\perp$ and the average photon-jet transverse momentum
$\tilde{\boldsymbol{P}}_\perp$, and first qualitative estimates of their
transverse momentum dependence.
| [
{
"created": "Thu, 5 Oct 2017 12:53:32 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Oct 2017 10:27:32 GMT",
"version": "v2"
},
{
"created": "Wed, 20 Dec 2017 16:11:03 GMT",
"version": "v3"
}
] | 2018-01-31 | [
[
"Benić",
"Sanjin",
""
],
[
"Dumitru",
"Adrian",
""
]
] | Photon-jet azimuthal correlations in proton-nucleus collisions are a promising tool for gaining information on the gluon distribution of the nucleus in the regime of non-linear color fields. We compute such correlations from the process $g+A\to q \bar{q} \gamma$ in the rapidity regime where both the projectile and target light-cone momentum fractions are small. By integrating over the phase space of the quark which emits the photon, subject to the restriction that the photon picks up most of the transverse momentum (to pass an isolation cut), we effectively obtain a $g+A\to q \gamma$ process. For nearly back-to-back photon-jet configurations we find that it dominates over the leading order process $q+A\to q \gamma$ by two less powers of $Q_\perp / Q_S$, where $\boldsymbol{Q}_\perp$ and $Q_S$ denote the net photon-jet pair momentum and the saturation scale of the nucleus, respectively. We determine the transverse momentum dependent gluon distributions involved in $g+A\to q \gamma$ and the scale where they are evaluated. Finally, we provide analytic expressions for $\langle\cos n\phi\rangle$ moments, where $\phi$ is the angle between $\boldsymbol{Q}_\perp$ and the average photon-jet transverse momentum $\tilde{\boldsymbol{P}}_\perp$, and first qualitative estimates of their transverse momentum dependence. |
hep-ph/0512224 | Charanjit S. Aulakh | Charanjit Singh Aulakh and Sumit Kumar Garg | MSGUT : From Bloom to Doom | 34 pages, Graphical presentation of results compressed and improved
with 15 eps figures included in the body of paper. Additional references,
discussion and a Note added on confirmatory work | Nucl.Phys.B757:47-78,2006 | 10.1016/j.nuclphysb.2006.07.030 | null | hep-ph | null | By a systematic survey of the parameter space we confirm our
surmise\cite{gmblm} that the Minimal Supersymmetric GUT(MSGUT) based on the
${\bf{210\oplus 126\oplus {\bar {126}}\oplus 10}}$ Higgs system is incompatible
with the generic Type I and Type II seesaw mechanisms. The incompatibility of
the Type II seesaw mechanism with this MSGUT is due to its generic extreme
sub-dominance with respect to the Type I contribution. The Type I mechanism
although dominant over Type II is itself unable to provide Neutrino masses
larger than $ \sim 10^{-3}$ eV anywhere in the parameter space. Our
Renormalization Group based analysis shows the origin of these difficulties to
lie in a conflict between baryon stability and neutrino oscillation. The MSGUT
completed with a {\bf{120}}-plet Higgs is the natural next to minimal
candidate. We propose a scenario where the {\bf{120}}-plet collaborates with
the {\bf{10}}-plet to fit the charged fermion masses. The freed
{{\bf{126}}}-plet couplings can then give sub-dominant contributions to charged
fermion masses {\textit{and}} enhance the Type I seesaw masses sufficiently to
provide a viable seesaw mechanism. We give formulae required to verify this
scenario.
| [
{
"created": "Mon, 19 Dec 2005 10:22:00 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Jul 2006 19:11:08 GMT",
"version": "v2"
}
] | 2011-02-09 | [
[
"Aulakh",
"Charanjit Singh",
""
],
[
"Garg",
"Sumit Kumar",
""
]
] | By a systematic survey of the parameter space we confirm our surmise\cite{gmblm} that the Minimal Supersymmetric GUT(MSGUT) based on the ${\bf{210\oplus 126\oplus {\bar {126}}\oplus 10}}$ Higgs system is incompatible with the generic Type I and Type II seesaw mechanisms. The incompatibility of the Type II seesaw mechanism with this MSGUT is due to its generic extreme sub-dominance with respect to the Type I contribution. The Type I mechanism although dominant over Type II is itself unable to provide Neutrino masses larger than $ \sim 10^{-3}$ eV anywhere in the parameter space. Our Renormalization Group based analysis shows the origin of these difficulties to lie in a conflict between baryon stability and neutrino oscillation. The MSGUT completed with a {\bf{120}}-plet Higgs is the natural next to minimal candidate. We propose a scenario where the {\bf{120}}-plet collaborates with the {\bf{10}}-plet to fit the charged fermion masses. The freed {{\bf{126}}}-plet couplings can then give sub-dominant contributions to charged fermion masses {\textit{and}} enhance the Type I seesaw masses sufficiently to provide a viable seesaw mechanism. We give formulae required to verify this scenario. |
1205.0752 | Andreas Windisch | Andreas Windisch, Reinhard Alkofer, Gundolf Haase and Manfred Liebmann | Examining the Analytic Structure of Green's Functions: Massive Parallel
Complex Integration using GPUs | 16 pages, 8 figures, 1 table | Computer Physics Communications 184 (2013), 109-116 | 10.1016/j.cpc.2012.09.003 | null | hep-ph hep-th physics.comp-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Graphics Processing Units (GPUs) are employed for a numerical determination
of the analytic structure of two-point correlation functions of Quantum Field
Theories. These functions are represented through integrals in d-dimensional
Euclidean momentum space. Such integrals can in general not be solved
analytically, and therefore one has to rely on numerical procedures to extract
their analytic structures if needed. After describing the general outline of
the corresponding algorithm we demonstrate the procedure by providing a
completely worked-out example in four dimensions for which an exact solution
exists. We resolve the analytic structure by highly parallel evaluation of the
correlation functions momentum space integral in the complex plane. The
(logarithmically) divergent integral is regularized by applying a BPHZ-like
Taylor subtraction to the integrand. We find perfect agreement with the exact
solution. The fact that each point in the complex plane does not need any
information from other points makes this a perfect candidate for GPU treatment.
A significant gain in speed as compared to sequential execution is obtained. We
also provide typical running times on several GPUs.
| [
{
"created": "Thu, 3 May 2012 16:14:10 GMT",
"version": "v1"
}
] | 2013-01-16 | [
[
"Windisch",
"Andreas",
""
],
[
"Alkofer",
"Reinhard",
""
],
[
"Haase",
"Gundolf",
""
],
[
"Liebmann",
"Manfred",
""
]
] | Graphics Processing Units (GPUs) are employed for a numerical determination of the analytic structure of two-point correlation functions of Quantum Field Theories. These functions are represented through integrals in d-dimensional Euclidean momentum space. Such integrals can in general not be solved analytically, and therefore one has to rely on numerical procedures to extract their analytic structures if needed. After describing the general outline of the corresponding algorithm we demonstrate the procedure by providing a completely worked-out example in four dimensions for which an exact solution exists. We resolve the analytic structure by highly parallel evaluation of the correlation functions momentum space integral in the complex plane. The (logarithmically) divergent integral is regularized by applying a BPHZ-like Taylor subtraction to the integrand. We find perfect agreement with the exact solution. The fact that each point in the complex plane does not need any information from other points makes this a perfect candidate for GPU treatment. A significant gain in speed as compared to sequential execution is obtained. We also provide typical running times on several GPUs. |
0911.1951 | Jan Kalinowski | S.Y. Choi, J. Kalinowski, J.M. Kim and E. Popenda | Scalar gluons and Dirac gluinos at the LHC | 10 pages, 4 figures, presented at the XXXIII International Conference
on Theoretical Physics "Matter to the Deepest", Ustron, Poland, September
11-16, 2009. To appear in Acta Physica Polonica B | Acta Phys.Polon.B40:2913-2922,2009 | null | CERN-PH-TH/2009-214 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hybrid N=1/N=2 supersymmetric model predicts scalar gluons (sgluons) as
SUSY partners of the Dirac gluino. Their strikingly distinct phenomenology at
the CERN Large Hadron Collider is discussed.
| [
{
"created": "Tue, 10 Nov 2009 17:37:47 GMT",
"version": "v1"
}
] | 2010-02-09 | [
[
"Choi",
"S. Y.",
""
],
[
"Kalinowski",
"J.",
""
],
[
"Kim",
"J. M.",
""
],
[
"Popenda",
"E.",
""
]
] | The hybrid N=1/N=2 supersymmetric model predicts scalar gluons (sgluons) as SUSY partners of the Dirac gluino. Their strikingly distinct phenomenology at the CERN Large Hadron Collider is discussed. |
1503.05896 | Richard Williams | Helios Sanchis-Alepuz, Richard Williams | Hadronic Observables from Dyson-Schwinger and Bethe-Salpeter equations | 15 pages. Talk given at Discrete 2014 - Fourth Symposium on Prospects
in the Physics of Discrete Symmetries. 2-6 December, 2014 - King's College,
London, England. Version with corrected typos and additional/updated
references | null | 10.1088/1742-6596/631/1/012064 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these proceedings we present a mini-review on the topic of the
Dyson-Schwinger/Bethe-Salpeter approach to the study of relativistic
bound-states in physics. In particular, we present a self-contained discussion
of their derivation, as well as their truncation such that important symmetries
are maintained.
| [
{
"created": "Thu, 19 Mar 2015 19:18:57 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Apr 2015 09:55:44 GMT",
"version": "v2"
},
{
"created": "Thu, 30 Apr 2015 09:16:52 GMT",
"version": "v3"
}
] | 2015-09-02 | [
[
"Sanchis-Alepuz",
"Helios",
""
],
[
"Williams",
"Richard",
""
]
] | In these proceedings we present a mini-review on the topic of the Dyson-Schwinger/Bethe-Salpeter approach to the study of relativistic bound-states in physics. In particular, we present a self-contained discussion of their derivation, as well as their truncation such that important symmetries are maintained. |
hep-ph/0201034 | Dario Zappala | M. Consoli | Spontaneous symmetry breaking and the $p \to 0$ limit | 17 pages, LaTex, small changes and some comments added | Phys.Rev. D65 (2002) 105017 | 10.1103/PhysRevD.65.105017 | null | hep-ph | null | We point out a basic ambiguity in the $p \to 0$ limit of the connected
propagator in a spontaneously broken phase. This may represent an indication
that the conventional singlet Higgs boson, rather than being a purely massive
field, might have a gap-less branch. This would dominate the energy spectrum
for ${\bf{p}} \to 0$ and give rise to a very weak, long-range force. The
natural interpretation is in terms of density fluctuations of the `Higgs
condensate': in the region of very long wavelengths, infinitely larger than the
Fermi scale, it cannot be treated as a purely classical c-number field.
| [
{
"created": "Mon, 7 Jan 2002 15:19:35 GMT",
"version": "v1"
},
{
"created": "Mon, 25 Mar 2002 11:21:56 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Consoli",
"M.",
""
]
] | We point out a basic ambiguity in the $p \to 0$ limit of the connected propagator in a spontaneously broken phase. This may represent an indication that the conventional singlet Higgs boson, rather than being a purely massive field, might have a gap-less branch. This would dominate the energy spectrum for ${\bf{p}} \to 0$ and give rise to a very weak, long-range force. The natural interpretation is in terms of density fluctuations of the `Higgs condensate': in the region of very long wavelengths, infinitely larger than the Fermi scale, it cannot be treated as a purely classical c-number field. |
hep-ph/9411347 | null | Rathin ADhikari and Biswarup Mukhopadhyaya | Light Neutralinos in B-Decays | 9 pages, LaTex, 2 figures (hard copies of the figures available from
the Authors on request) | Phys.Rev. D52 (1995) 3125-3127 | 10.1103/PhysRevD.52.3125 | MRI-PHY/21/94 (November, 1994) | hep-ph | null | We consider the decays of a $B_s$-meson into a pair of lightest
supersymmetric particles (LSP) in the minimal supersymmetric standard model. It
is found that the parameter space for light LSP's in the range of 1 GeV can be
appreciably constrained by looking for such decays.
| [
{
"created": "Mon, 21 Nov 1994 14:54:29 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"ADhikari",
"Rathin",
""
],
[
"Mukhopadhyaya",
"Biswarup",
""
]
] | We consider the decays of a $B_s$-meson into a pair of lightest supersymmetric particles (LSP) in the minimal supersymmetric standard model. It is found that the parameter space for light LSP's in the range of 1 GeV can be appreciably constrained by looking for such decays. |
hep-ph/0611269 | Kristian McDonald | A. Coulthurst, A. Demaria, K. L. McDonald and B. H. J. McKellar | Developments In 5D Quark-Lepton Symmetric Models | 4 pages,Talk given by K.L.McDonald at the Joint Meeting of Pacific
Region Particle Physics Communities, Honolulu, Hawaii, October 29th -
November 3rd 2006 | null | null | null | hep-ph | null | We outline some recent developments in higher dimensional Quark-Lepton (QL)
symmetric models. The QL symmetric model in five dimensions is discussed, with
particular emphasis on the use of split fermions. An interesting fermionic
geography which utilises the QL symmetry to suppress the proton decay rate and
to motivate the flavor differences in the quark and leptonic sectors is
considered. The 5D quartification model is outlined and contrasted with 4D
constructs.
| [
{
"created": "Tue, 21 Nov 2006 04:55:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Coulthurst",
"A.",
""
],
[
"Demaria",
"A.",
""
],
[
"McDonald",
"K. L.",
""
],
[
"McKellar",
"B. H. J.",
""
]
] | We outline some recent developments in higher dimensional Quark-Lepton (QL) symmetric models. The QL symmetric model in five dimensions is discussed, with particular emphasis on the use of split fermions. An interesting fermionic geography which utilises the QL symmetry to suppress the proton decay rate and to motivate the flavor differences in the quark and leptonic sectors is considered. The 5D quartification model is outlined and contrasted with 4D constructs. |
1805.04523 | Sonia El Hedri | Sonia El Hedri, Ann E. Nelson, Devin G.E. Walker | Reducing the Quadratic Divergence in the Higgs Mass Squared Without Top
Partners | 15 pages, 7 figures Modified figure 1, added references | Phys. Rev. D 98, 035029 (2018) | 10.1103/PhysRevD.98.035029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine a model with multiple scalar fields to see whether it is possible
to reduce the fine- tuning of the SM Higgs mass without introducing low scale
top partners. Our approach may be regarded as a generalization of the condition
proposed by Veltman, who attempted to predict the Higgs mass using the
criterion that the various low energy contributions to the quadratic divergence
of the Higgs mass cancel. Although the Veltman condition predicts the wrong
Higgs mass in the Standard Model, it can still be adapted to extended Higgs
sectors. Furthermore, theories with additional Higgs bosons can lead to
suppressed Yukawa couplings of the top quark to the 125 GeV Higgs, making the
associated one-loop divergence smaller. Here, we review possible extensions of
the Standard Model where the Veltman condition could be realized, and study in
detail one minimal model with two extra scalar fields. For this model and for a
cutoff of 5 TeV, we show that the overall fine-tuning can be considerably
lowered without introducing low-scale Landau poles, albeit the Higgs sector
will be strongly coupled at the cutoff. Models where the top Yukawa coupling is
reduced, in particular, will be within the reach of the upcoming LHC searches.
| [
{
"created": "Fri, 11 May 2018 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 23 May 2018 13:04:24 GMT",
"version": "v2"
}
] | 2018-08-29 | [
[
"Hedri",
"Sonia El",
""
],
[
"Nelson",
"Ann E.",
""
],
[
"Walker",
"Devin G. E.",
""
]
] | We examine a model with multiple scalar fields to see whether it is possible to reduce the fine- tuning of the SM Higgs mass without introducing low scale top partners. Our approach may be regarded as a generalization of the condition proposed by Veltman, who attempted to predict the Higgs mass using the criterion that the various low energy contributions to the quadratic divergence of the Higgs mass cancel. Although the Veltman condition predicts the wrong Higgs mass in the Standard Model, it can still be adapted to extended Higgs sectors. Furthermore, theories with additional Higgs bosons can lead to suppressed Yukawa couplings of the top quark to the 125 GeV Higgs, making the associated one-loop divergence smaller. Here, we review possible extensions of the Standard Model where the Veltman condition could be realized, and study in detail one minimal model with two extra scalar fields. For this model and for a cutoff of 5 TeV, we show that the overall fine-tuning can be considerably lowered without introducing low-scale Landau poles, albeit the Higgs sector will be strongly coupled at the cutoff. Models where the top Yukawa coupling is reduced, in particular, will be within the reach of the upcoming LHC searches. |
2310.12564 | Shiryo Owa | Shiryo Owa, Derek B. Leinweber, Anthony W. Thomas, and Xuan-Gong Wang | Chiral Analysis of the Nucleon Mass and Sigma Commutator | 23 pages, 6 figures | null | 10.1103/PhysRevD.109.116022 | ADP-23-24/T1233 | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Schemes for describing the light quark mass dependence of the nucleon mass
calculated in lattice QCD are compared. The three schemes in consideration
include a fully relativistic and Lorentz covariant scheme, one that is fully
relativistic but not Lorentz covariant, and a semirelativistic scheme utilizing
the heavy baryon approximation. Calculations of observables involving
pseudoscalar meson loop diagrams generate nonanalytic terms proportional to
square roots and logarithms of the quark mass. The three schemes all yield the
correct model independent leading and next-to-leading nonanalytic terms of the
chiral expansion of the baryon mass. Results for the masses of the other
members of the octet are also presented. Here, low-energy coefficients of the
analytic terms of the expansion for the nucleon and hyperons are constrained by
lattice QCD results and are demonstrated to be independent of the
renormalization scheme used. The differences in the leading coefficient of the
chiral expansions are found to be consistent with strange quark counting. Using
the schemes examined herein, we report results for the pion-nucleon sigma
commutator based upon recent lattice results from the CLS Collaboration. We
find $\sigma_{\pi N}=51.7 \pm 3.2 \pm 1.4$ MeV where the uncertainties are
statistical and systematic respectively.
| [
{
"created": "Thu, 19 Oct 2023 08:17:35 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Jun 2024 01:20:54 GMT",
"version": "v2"
}
] | 2024-06-28 | [
[
"Owa",
"Shiryo",
""
],
[
"Leinweber",
"Derek B.",
""
],
[
"Thomas",
"Anthony W.",
""
],
[
"Wang",
"Xuan-Gong",
""
]
] | Schemes for describing the light quark mass dependence of the nucleon mass calculated in lattice QCD are compared. The three schemes in consideration include a fully relativistic and Lorentz covariant scheme, one that is fully relativistic but not Lorentz covariant, and a semirelativistic scheme utilizing the heavy baryon approximation. Calculations of observables involving pseudoscalar meson loop diagrams generate nonanalytic terms proportional to square roots and logarithms of the quark mass. The three schemes all yield the correct model independent leading and next-to-leading nonanalytic terms of the chiral expansion of the baryon mass. Results for the masses of the other members of the octet are also presented. Here, low-energy coefficients of the analytic terms of the expansion for the nucleon and hyperons are constrained by lattice QCD results and are demonstrated to be independent of the renormalization scheme used. The differences in the leading coefficient of the chiral expansions are found to be consistent with strange quark counting. Using the schemes examined herein, we report results for the pion-nucleon sigma commutator based upon recent lattice results from the CLS Collaboration. We find $\sigma_{\pi N}=51.7 \pm 3.2 \pm 1.4$ MeV where the uncertainties are statistical and systematic respectively. |
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