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hep-ph/0205311
Piotr Zenczykowski
P. Zenczykowski (Institute of Nuclear Physics, Krakow, Poland)
Connecting nonleptonic and weak radiative hyperon decays
12 LaTeX pages, 1 .ps figure
Acta Phys.Polon. B34 (2003) 2683-2692
null
null
hep-ph
null
Using the recent measurement of the $\Xi ^0 \to \Lambda \gamma $ asymmetry as an input, we reanalyse nonleptonic and weak radiative hyperon decays in a single symmetry-based framework. In this framework the old S:P problem of nonleptonic decays is automatically resolved when the most important features of weak radiative decays are taken into account. Experimental data require that symmetry between the two types of hyperon decays be imposed at the level of currents, not fields. Previously established connections between hyperon decays and nuclear parity violation imply that the conflict, originally suggested by weak radiative decays, has to surface somewhere.
[ { "created": "Tue, 28 May 2002 12:06:45 GMT", "version": "v1" }, { "created": "Wed, 5 Jun 2002 10:15:57 GMT", "version": "v2" }, { "created": "Mon, 8 Jul 2002 09:41:37 GMT", "version": "v3" }, { "created": "Fri, 4 Oct 2002 09:20:03 GMT", "version": "v4" } ]
2007-05-23
[ [ "Zenczykowski", "P.", "", "Institute of Nuclear Physics, Krakow, Poland" ] ]
Using the recent measurement of the $\Xi ^0 \to \Lambda \gamma $ asymmetry as an input, we reanalyse nonleptonic and weak radiative hyperon decays in a single symmetry-based framework. In this framework the old S:P problem of nonleptonic decays is automatically resolved when the most important features of weak radiative decays are taken into account. Experimental data require that symmetry between the two types of hyperon decays be imposed at the level of currents, not fields. Previously established connections between hyperon decays and nuclear parity violation imply that the conflict, originally suggested by weak radiative decays, has to surface somewhere.
2311.13635
Peter Krack
Arman Korajac, Peter Krack, Nudzeim Selimovic
Third-Family Lepton-Quark Fusion
11 pages, 7 figures, Monte Carlo generator can be downloaded from https://github.com/peterkrack/3rd-Lepton-Quark-Fusion v2: version accepted for publication in EPJC
null
10.1140/epjc/s10052-024-12618-8
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We analyze the signatures of new physics scenarios featuring third-family quark-lepton unification at the TeV scale in lepton-quark fusion at hadron colliders. Working with complete UV dynamics based on the $SU(4)$ gauge symmetry in the third-family fermions, we simulate the resonant production of a vector leptoquark at the next-to-leading order, including its decay and matching to the parton showers. The precise theoretical control over this production channel allows us to set robust bounds on the vector leptoquark parameter space which are complementary to the other production channels at colliders. We emphasize the importance of the resonant channel in future searches and discuss the impact of variations in the model space depending on the flavor structure of the vector leptoquark couplings.
[ { "created": "Wed, 22 Nov 2023 19:00:01 GMT", "version": "v1" }, { "created": "Mon, 3 Jun 2024 13:35:32 GMT", "version": "v2" } ]
2024-06-04
[ [ "Korajac", "Arman", "" ], [ "Krack", "Peter", "" ], [ "Selimovic", "Nudzeim", "" ] ]
We analyze the signatures of new physics scenarios featuring third-family quark-lepton unification at the TeV scale in lepton-quark fusion at hadron colliders. Working with complete UV dynamics based on the $SU(4)$ gauge symmetry in the third-family fermions, we simulate the resonant production of a vector leptoquark at the next-to-leading order, including its decay and matching to the parton showers. The precise theoretical control over this production channel allows us to set robust bounds on the vector leptoquark parameter space which are complementary to the other production channels at colliders. We emphasize the importance of the resonant channel in future searches and discuss the impact of variations in the model space depending on the flavor structure of the vector leptoquark couplings.
2202.13063
Shuntaro Aoki
Shuntaro Aoki, Hyun Min Lee, Adriana G. Menkara, and Kimiko Yamashita
Reheating and Dark Matter Freeze-in in the Higgs-$R^2$ Inflation Model
39 pages,7 figures; v2 Published version in JHEP
null
10.1007/JHEP05(2022)121
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We study the post-inflationary dynamics for reheating and freeze-in dark matter in the Higgs-$R^2$ inflation model. Taking the perturbative approach for reheating, we determine the evolution of the temperature for radiation bath produced during reheating and determine the maximum and reheating temperatures of the Universe. Adopting a singlet scalar dark matter with a conformal non-minimal coupling and a vanishing Higgs-portal coupling, we discuss the freeze-in production of dark matter both from the non-thermal scattering during reheating and the thermal scattering after reheating. We find that thermal scattering is dominant for dark matter production in our model due to the high reheating temperature. The reheating temperature in our model is determined dominantly by the Higgs condensate to be up to about $10^{14}\,{\rm GeV}$ and dark matter with masses up to about $10^9\,{\rm GeV}$ can be produced with a correct relic density.
[ { "created": "Sat, 26 Feb 2022 05:17:45 GMT", "version": "v1" }, { "created": "Fri, 29 Apr 2022 13:52:10 GMT", "version": "v2" } ]
2022-06-08
[ [ "Aoki", "Shuntaro", "" ], [ "Lee", "Hyun Min", "" ], [ "Menkara", "Adriana G.", "" ], [ "Yamashita", "Kimiko", "" ] ]
We study the post-inflationary dynamics for reheating and freeze-in dark matter in the Higgs-$R^2$ inflation model. Taking the perturbative approach for reheating, we determine the evolution of the temperature for radiation bath produced during reheating and determine the maximum and reheating temperatures of the Universe. Adopting a singlet scalar dark matter with a conformal non-minimal coupling and a vanishing Higgs-portal coupling, we discuss the freeze-in production of dark matter both from the non-thermal scattering during reheating and the thermal scattering after reheating. We find that thermal scattering is dominant for dark matter production in our model due to the high reheating temperature. The reheating temperature in our model is determined dominantly by the Higgs condensate to be up to about $10^{14}\,{\rm GeV}$ and dark matter with masses up to about $10^9\,{\rm GeV}$ can be produced with a correct relic density.
hep-ph/0109271
Ryutin Roman
A. V. Kisselev, V. A. Petrov, R. A. Ryutin
Do Quark Mass Effects Survive in the High-$Q^2$ Limit of DIS?
11 pages, 3 figures; content is corrected. To be published in Eur. Phys. Journal C
Eur.Phys.J.C26:597-600,2003
10.1140/epjc/s2002-01077-2
null
hep-ph
null
Quark mass effects are analyzed at high $Q^2$ in the current fragmentation region of DIS. It is found that the linear combination $F_2-2.75F^c_2$ scales at large $Q^2$ and small $x$. We obtained a lower bound for the ratio $F^c_2/F_2$ which lies very close to the data from HERA.
[ { "created": "Thu, 27 Sep 2001 16:37:38 GMT", "version": "v1" }, { "created": "Fri, 28 Sep 2001 07:35:17 GMT", "version": "v2" }, { "created": "Mon, 12 Aug 2002 07:32:59 GMT", "version": "v3" } ]
2011-09-13
[ [ "Kisselev", "A. V.", "" ], [ "Petrov", "V. A.", "" ], [ "Ryutin", "R. A.", "" ] ]
Quark mass effects are analyzed at high $Q^2$ in the current fragmentation region of DIS. It is found that the linear combination $F_2-2.75F^c_2$ scales at large $Q^2$ and small $x$. We obtained a lower bound for the ratio $F^c_2/F_2$ which lies very close to the data from HERA.
1905.10918
Dennis E. Krause
D. E. Krause and Q. Le Thien
The 2-Neutrino Exchange Potential with Mixing: A Probe of Neutrino Physics and CP Violation
4 pages; presented at the Eighth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, May 12-16, 2019
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The 2-neutrino exchange potential is a Standard Model weak potential arising from the exchange of virtual neutrino-antineutrino pairs which must include all neutrino properties, including the number of flavors, their masses, fermionic nature (Dirac or Majorana), and CP violation. We describe a new approach for calculating the spin-independent 2-neutrino exchange potential, including the mixing of three neutrino mass states and CP violation.
[ { "created": "Mon, 27 May 2019 01:19:08 GMT", "version": "v1" } ]
2019-05-28
[ [ "Krause", "D. E.", "" ], [ "Thien", "Q. Le", "" ] ]
The 2-neutrino exchange potential is a Standard Model weak potential arising from the exchange of virtual neutrino-antineutrino pairs which must include all neutrino properties, including the number of flavors, their masses, fermionic nature (Dirac or Majorana), and CP violation. We describe a new approach for calculating the spin-independent 2-neutrino exchange potential, including the mixing of three neutrino mass states and CP violation.
1707.08155
Jordi Salvado
Gabriela Barenboim, Jordi Salvado
Cosmology and CPT violating neutrinos
5 pages, 6 figures
null
10.1140/epjc/s10052-017-5347-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The combination Charge Conjugation-Parity-Time Reversal(CPT) is a fundamental symmetry in our current understanding of nature. As such, testing CPT violation is a strongly motivated path to explore new physics. In this paper we study CPT violation in the neutrino sector, giving for the first time a bound, for a fundamental particle, in the CPT violating particle-antiparticle gravitational mass difference. We argue that cosmology is nowadays the only data sensitive to CPT violation for the neutrino-antineutrino mass splitting and we use the latest data release from Planck combined with the current Baryonic-Acoustic-Oscillation measurement to perform a full cosmological analysis. To show the potential of the future experiments we also show the results for Euclid, a next generation large scale structure experiment.
[ { "created": "Tue, 25 Jul 2017 19:04:19 GMT", "version": "v1" } ]
2017-12-06
[ [ "Barenboim", "Gabriela", "" ], [ "Salvado", "Jordi", "" ] ]
The combination Charge Conjugation-Parity-Time Reversal(CPT) is a fundamental symmetry in our current understanding of nature. As such, testing CPT violation is a strongly motivated path to explore new physics. In this paper we study CPT violation in the neutrino sector, giving for the first time a bound, for a fundamental particle, in the CPT violating particle-antiparticle gravitational mass difference. We argue that cosmology is nowadays the only data sensitive to CPT violation for the neutrino-antineutrino mass splitting and we use the latest data release from Planck combined with the current Baryonic-Acoustic-Oscillation measurement to perform a full cosmological analysis. To show the potential of the future experiments we also show the results for Euclid, a next generation large scale structure experiment.
hep-ph/0210161
Bernd Andreas Kniehl
Bernd A. Kniehl, Alexander A. Penin, Vladimir A. Smirnov, Matthias Steinhauser
Heavy-quarkonium creation and annihilation with O(alpha_s^3 ln(alpha_s)) accuracy
10 pages (Latex). Eq. (6) corrected, conclusions unchanged
Phys.Rev.Lett. 90 (2003) 212001
10.1103/PhysRevLett.90.212001
DESY 02-134
hep-ph
null
We calculate the O(alpha_s^3 ln(alpha_s)) contributions to the heavy-quarkonium production and annihilation rates. Our result sheds new light on the structure of the high-order perturbative corrections and opens a new perspective for a high-precision theoretical analysis. We also determine the three-loop anomalous dimensions of the nonrelativistic vector and pseudoscalar currents.
[ { "created": "Thu, 10 Oct 2002 11:44:01 GMT", "version": "v1" }, { "created": "Wed, 30 Apr 2003 15:07:05 GMT", "version": "v2" }, { "created": "Thu, 7 Aug 2003 15:47:25 GMT", "version": "v3" }, { "created": "Fri, 8 Aug 2003 09:44:12 GMT", "version": "v4" } ]
2009-11-07
[ [ "Kniehl", "Bernd A.", "" ], [ "Penin", "Alexander A.", "" ], [ "Smirnov", "Vladimir A.", "" ], [ "Steinhauser", "Matthias", "" ] ]
We calculate the O(alpha_s^3 ln(alpha_s)) contributions to the heavy-quarkonium production and annihilation rates. Our result sheds new light on the structure of the high-order perturbative corrections and opens a new perspective for a high-precision theoretical analysis. We also determine the three-loop anomalous dimensions of the nonrelativistic vector and pseudoscalar currents.
hep-ph/0112057
null
M. Salle, J. Smit and J.C. Vink
Initial conditions for simulated `tachyonic preheating' and the Hartree ensemble approximation
7 pages, talk presented at COSMO-01, Rovaniemi, Finland
null
null
null
hep-ph
null
In numerical simulations studying preheating in the classical approximation there is the problem how to derive the classical initial conditions from the quantum vacuum fluctuations. In past treatments, the initial conditions often put an energy density into the classical field of order of the cutoff, leading to a divergent temperature after thermalization. We suggest a solution to the problem which follows naturally from a Hartree ensemble approximation, introduced recently as an improvement over the standard Hartree approximation. We study the effects on particle numbers of the various treatments, within the context of `tachyonic preheating' in 1+1 dimensional $\phi^4$ theory.
[ { "created": "Tue, 4 Dec 2001 17:40:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Salle", "M.", "" ], [ "Smit", "J.", "" ], [ "Vink", "J. C.", "" ] ]
In numerical simulations studying preheating in the classical approximation there is the problem how to derive the classical initial conditions from the quantum vacuum fluctuations. In past treatments, the initial conditions often put an energy density into the classical field of order of the cutoff, leading to a divergent temperature after thermalization. We suggest a solution to the problem which follows naturally from a Hartree ensemble approximation, introduced recently as an improvement over the standard Hartree approximation. We study the effects on particle numbers of the various treatments, within the context of `tachyonic preheating' in 1+1 dimensional $\phi^4$ theory.
hep-ph/9905452
B. F. L. Ward
S. Jadach (1 and 2), B.F.L. Ward (3 and 4) and Z. Was (1 and 2) ((1) CERN, Theory Division, Geneva, Switzerland, (2) Institute of Nuclear Physics, Krakow, Poland, (3) Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, USA, (4) SLAC, Stanford University, Stanford, CA, USA)
Global Positioning of Spin GPS Scheme for Half-Spin Massive Spinors
13 pages, 1 eps figure
Eur.Phys.J.C22:423-430,2001
10.1007/s100520100818
CERN-TH-98-235, UTHEP-98-0701
hep-ph
null
We present a simple and flexible method of keeping track of the complex phases and spin quantization axes for half-spin initial- and final-state Weyl spinors in scattering amplitudes of Standard Model high energy physics processes. Both cases of massless and massive spinors are discussed. The method is demonstrated and checked numerically for spin correlations in tau tau-bar production and decay. Its main application will be in the forthcoming work of combining effects due to multiple photon emission (exponentiation) and spin, embodied in the Monte Carlo event generators for production and decay of unstable fermions such as the tau lepton, t-quark and hypothetical new heavy particles.
[ { "created": "Sat, 22 May 1999 20:49:48 GMT", "version": "v1" } ]
2011-09-13
[ [ "Jadach", "S.", "", "1 and 2" ], [ "Ward", "B. F. L.", "", "3 and 4" ], [ "Was", "Z.", "", "1 and 2" ] ]
We present a simple and flexible method of keeping track of the complex phases and spin quantization axes for half-spin initial- and final-state Weyl spinors in scattering amplitudes of Standard Model high energy physics processes. Both cases of massless and massive spinors are discussed. The method is demonstrated and checked numerically for spin correlations in tau tau-bar production and decay. Its main application will be in the forthcoming work of combining effects due to multiple photon emission (exponentiation) and spin, embodied in the Monte Carlo event generators for production and decay of unstable fermions such as the tau lepton, t-quark and hypothetical new heavy particles.
hep-ph/0103266
Zuo-tang Liang
Zuo-tang Liang and Chun-xiu Liu
Spin transfer in high energy fragmentation processes
Talk given at the 14th International Spin Symposium, 5 pages
null
null
null
hep-ph
null
We point out that measuring longitudinal polarizations of different hyperons produced in lepton induced reactions are ideal to study the spin transfer of the fragtmenting quark to produced hadron in high energy hadronization processes. We briefly summarize the method used in calculating the hyperon polarizations in these processes, then present some of the results for e+e- and e-p or \nu p reactions obtained using two different pictures for the spin structure of hyperon: that drawn from polarized deep inelastic lepton-nucleon scattering data or that using SU(6) symmetric wave functions. The results show in particular that measurements of such polarizations should provide useful information to the question of which picture is more suitable in describing the spin effects in the fragmentation processes.
[ { "created": "Sun, 25 Mar 2001 03:34:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Liang", "Zuo-tang", "" ], [ "Liu", "Chun-xiu", "" ] ]
We point out that measuring longitudinal polarizations of different hyperons produced in lepton induced reactions are ideal to study the spin transfer of the fragtmenting quark to produced hadron in high energy hadronization processes. We briefly summarize the method used in calculating the hyperon polarizations in these processes, then present some of the results for e+e- and e-p or \nu p reactions obtained using two different pictures for the spin structure of hyperon: that drawn from polarized deep inelastic lepton-nucleon scattering data or that using SU(6) symmetric wave functions. The results show in particular that measurements of such polarizations should provide useful information to the question of which picture is more suitable in describing the spin effects in the fragmentation processes.
hep-ph/0507172
Fei Wang
Fei Wang, Wenyu Wang, Jin Min Yang
Gravitino dark matter from gluino late decay in split supersymmetry
discussions added (version in PRD)
Phys.Rev. D72 (2005) 077701
10.1103/PhysRevD.72.077701
null
hep-ph
null
In split-supersymmetry (split-SUSY), gluino is a metastable particle and thus can freeze out in the early universe. The late decay of such a long-life gluino into the lightest supersymmetric particle (LSP) may provide much of the cosmic dark matter content. In this work, assuming the LSP is gravitino produced from the late decay of the metastable gluino, we examine the WMAP dark matter constraints on the gluino mass. We find that to provide the full abundance of dark matter, the gluino must be heavier than about 14 TeV and thus not accessible at the CERN Large Hadron Collider (LHC).
[ { "created": "Thu, 14 Jul 2005 12:43:40 GMT", "version": "v1" }, { "created": "Sat, 15 Oct 2005 13:20:00 GMT", "version": "v2" } ]
2009-11-11
[ [ "Wang", "Fei", "" ], [ "Wang", "Wenyu", "" ], [ "Yang", "Jin Min", "" ] ]
In split-supersymmetry (split-SUSY), gluino is a metastable particle and thus can freeze out in the early universe. The late decay of such a long-life gluino into the lightest supersymmetric particle (LSP) may provide much of the cosmic dark matter content. In this work, assuming the LSP is gravitino produced from the late decay of the metastable gluino, we examine the WMAP dark matter constraints on the gluino mass. We find that to provide the full abundance of dark matter, the gluino must be heavier than about 14 TeV and thus not accessible at the CERN Large Hadron Collider (LHC).
0712.1453
Julia Garayoa
Julia Garayoa (Valencia U. and Valencia U.-IFIC), Thomas Schwetz (CERN)
Neutrino mass hierarchy and Majorana CP phases within the Higgs triplet model at the LHC
22 pages, 6 figures. Version to be published at JHEP
JHEP 0803:009,2008
10.1088/1126-6708/2008/03/009
CERN-PH-TH/2007-255, IFIC/07-75, FTUV-07-1210
hep-ph
null
Neutrino masses may be generated by the VEV of an $SU(2)_L$ Higgs triplet. We assume that the doubly charged component of such a triplet has a mass in the range of several 100 GeV, such that it is accessible at LHC. Its decay into like-sign leptons provides a clean experimental signature, which allows for a direct test of the neutrino mass matrix. By exploring the branching ratios of this decay into leptons of various flavours, we show that within this model the type of the neutrino mass spectrum (normal, inverted or quasi-degenerate) might actually be resolved at the LHC. Furthermore, we show that within the Higgs triplet model for neutrino mass the decays of the doubly charged scalar into like-sign lepton pairs at the LHC provide a possibility to determine the Majorana CP phases of the lepton mixing matrix.
[ { "created": "Mon, 10 Dec 2007 13:59:54 GMT", "version": "v1" }, { "created": "Fri, 29 Feb 2008 14:04:11 GMT", "version": "v2" } ]
2009-01-06
[ [ "Garayoa", "Julia", "", "Valencia U. and Valencia U.-IFIC" ], [ "Schwetz", "Thomas", "", "CERN" ] ]
Neutrino masses may be generated by the VEV of an $SU(2)_L$ Higgs triplet. We assume that the doubly charged component of such a triplet has a mass in the range of several 100 GeV, such that it is accessible at LHC. Its decay into like-sign leptons provides a clean experimental signature, which allows for a direct test of the neutrino mass matrix. By exploring the branching ratios of this decay into leptons of various flavours, we show that within this model the type of the neutrino mass spectrum (normal, inverted or quasi-degenerate) might actually be resolved at the LHC. Furthermore, we show that within the Higgs triplet model for neutrino mass the decays of the doubly charged scalar into like-sign lepton pairs at the LHC provide a possibility to determine the Majorana CP phases of the lepton mixing matrix.
hep-ph/0612185
Dumitru Ghilencea
D. M. Ghilencea
Threshold effects near the compactification scale for gauge couplings on orbifolds
18 pages, 4 figures; improved presentation
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In 6D orbifold compactifications of N=1 supersymmetric gauge theories, the one-loop behaviour of the 4D {\it effective} gauge coupling and of its beta function are carefully investigated for momentum scales k^2 near the compactification scale(s). It is showed that as k^2 is crossing the compactification scale(s), there exists a smooth transition ("crossover") to a power-like behaviour of the 4D effective coupling, with a continuous one-loop beta function. Contrary to the naive expectation, the power-like behaviour sets in at momentum scales {\it smaller} than the compactification scale, to suggest a {\it global} effect of the Kaluza-Klein modes even below this scale. We argue that the experimental observation of such behaviour is not necessarily a quantum effect of the compactification, as often thought, and is dominated by classical effects. Special attention is paid to convergence issues near compactification scale(s) and to the scheme dependence of the results.
[ { "created": "Fri, 15 Dec 2006 00:02:58 GMT", "version": "v1" }, { "created": "Mon, 2 Feb 2009 22:45:59 GMT", "version": "v2" } ]
2009-02-03
[ [ "Ghilencea", "D. M.", "" ] ]
In 6D orbifold compactifications of N=1 supersymmetric gauge theories, the one-loop behaviour of the 4D {\it effective} gauge coupling and of its beta function are carefully investigated for momentum scales k^2 near the compactification scale(s). It is showed that as k^2 is crossing the compactification scale(s), there exists a smooth transition ("crossover") to a power-like behaviour of the 4D effective coupling, with a continuous one-loop beta function. Contrary to the naive expectation, the power-like behaviour sets in at momentum scales {\it smaller} than the compactification scale, to suggest a {\it global} effect of the Kaluza-Klein modes even below this scale. We argue that the experimental observation of such behaviour is not necessarily a quantum effect of the compactification, as often thought, and is dominated by classical effects. Special attention is paid to convergence issues near compactification scale(s) and to the scheme dependence of the results.
0905.3711
Joern Kersten
Joern Kersten, Oleg Lebedev
Gravitino Dark Matter in Gravity Mediation
10 pages, 3 PDF figures
Phys.Lett.B678:481-484,2009
10.1016/j.physletb.2009.06.062
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study general conditions for the gravitino to be the lightest supersymmetric particle (LSP) in models with gravity mediated supersymmetry breaking. We find that the decisive quantities are the Kaehler potential K and the gauge kinetic function f. In constrained MSSM (CMSSM) type models, the gravitino LSP occurs if the gaugino mass at the GUT scale is greater than approximately 2.5 gravitino masses. This translates into \sqrt{K"}/f' < 0.2, where the derivatives are taken with respect to the dominant SUSY breaking field. This requirement can easily be satisfied in string-motivated setups.
[ { "created": "Fri, 22 May 2009 15:50:05 GMT", "version": "v1" } ]
2010-05-28
[ [ "Kersten", "Joern", "" ], [ "Lebedev", "Oleg", "" ] ]
We study general conditions for the gravitino to be the lightest supersymmetric particle (LSP) in models with gravity mediated supersymmetry breaking. We find that the decisive quantities are the Kaehler potential K and the gauge kinetic function f. In constrained MSSM (CMSSM) type models, the gravitino LSP occurs if the gaugino mass at the GUT scale is greater than approximately 2.5 gravitino masses. This translates into \sqrt{K"}/f' < 0.2, where the derivatives are taken with respect to the dominant SUSY breaking field. This requirement can easily be satisfied in string-motivated setups.
2312.12322
Vicky Singh Thounaojam Mr.
Satyabrata Mahapatra, Sujit Kumar Sahoo, Narendra Sahu, Vicky Singh Thounaojam
Self Interacting Dark Matter and Dirac neutrinos via Lepton Quarticity
13 pages, 13 captioned figures, accepted for publication in Phys. Rev. D
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we put forward a connection between the self-interacting dark matter and the Dirac nature of neutrinos. Our exploration involves a $Z_4 \otimes Z_4'$ discrete symmetry, wherein the Dirac neutrino mass is produced through a type-I seesaw mechanism. This symmetry not only contributes to the generation of the Dirac neutrino mass but also facilitates the realization of self-interacting dark matter with a light mediator that can alleviate small-scale anomalies of the $\Lambda {\rm CDM}$ while being consistent with the latter at large scales, as suggested by astrophysical observations. Thus the stability of the DM and Dirac nature of neutrinos are shown to stem from the same underlying symmetry. The model also features additional relativistic degrees of freedom $\Delta N_{\rm eff}$ of either thermal or non-thermal origin, within the reach of cosmic microwave background (CMB) experiment providing a complementary probe in addition to the detection prospects of DM.
[ { "created": "Tue, 19 Dec 2023 16:51:32 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2024 05:55:21 GMT", "version": "v2" } ]
2024-03-05
[ [ "Mahapatra", "Satyabrata", "" ], [ "Sahoo", "Sujit Kumar", "" ], [ "Sahu", "Narendra", "" ], [ "Thounaojam", "Vicky Singh", "" ] ]
In this paper, we put forward a connection between the self-interacting dark matter and the Dirac nature of neutrinos. Our exploration involves a $Z_4 \otimes Z_4'$ discrete symmetry, wherein the Dirac neutrino mass is produced through a type-I seesaw mechanism. This symmetry not only contributes to the generation of the Dirac neutrino mass but also facilitates the realization of self-interacting dark matter with a light mediator that can alleviate small-scale anomalies of the $\Lambda {\rm CDM}$ while being consistent with the latter at large scales, as suggested by astrophysical observations. Thus the stability of the DM and Dirac nature of neutrinos are shown to stem from the same underlying symmetry. The model also features additional relativistic degrees of freedom $\Delta N_{\rm eff}$ of either thermal or non-thermal origin, within the reach of cosmic microwave background (CMB) experiment providing a complementary probe in addition to the detection prospects of DM.
hep-ph/0510001
Tetsuya Shinozaki
Tetsuya Shinozaki, Makoto Oka, Sachiko Takeuchi
P-wave Pentaquark and its Decay in the Quark Model with Instanton Induced Interaction
9 pages, 5 figures
Phys.Rev.D74:054029,2006
10.1103/PhysRevD.74.054029
null
hep-ph
null
P-wave pentaquarks with strangeness +1, I=0 and J^P=1/2^+ are studied in the non-relativistic quark model with instanton induced interaction (III). We present their mass splittings and orbital-spin-isospin-color structures. It is found that decompositions of the wave functions are sensitive to III, while the mass splittings are insensitive. The decay of the lowest energy pentaquark, \Theta^+, is found to be suppressed when the contribution of III is increased. Its wave function is dominated by Jaffe-Wilczek-type configuration at large III.
[ { "created": "Fri, 30 Sep 2005 18:39:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Shinozaki", "Tetsuya", "" ], [ "Oka", "Makoto", "" ], [ "Takeuchi", "Sachiko", "" ] ]
P-wave pentaquarks with strangeness +1, I=0 and J^P=1/2^+ are studied in the non-relativistic quark model with instanton induced interaction (III). We present their mass splittings and orbital-spin-isospin-color structures. It is found that decompositions of the wave functions are sensitive to III, while the mass splittings are insensitive. The decay of the lowest energy pentaquark, \Theta^+, is found to be suppressed when the contribution of III is increased. Its wave function is dominated by Jaffe-Wilczek-type configuration at large III.
hep-ph/0107051
Kazuo Koike
K. Koike
Generation Structure and Proton Decay Problem
9 pages
Prog.Theor.Phys. 106 (2001) 963-970
10.1143/PTP.106.963
Kagawa-17
hep-ph
null
Possible generation structure is investigated. We considere alternative possibility of combination of leptons and quarks to compose each generation, where the combination of $(\nu_{\tau},{\tau})$ and $(u,d)$ compose a generation. Our model exhibits the hierarcy structure after sea-saw mechanism provived that possible existence of realistic right-handed neutrinos are taken into account. Then, in the GUTs model based on our scheme, possible inter-generation properties are examined together with the classification of gauge bosons. It is shown that if our scheme is realized, the proton decay exhibits different mode from ordinary one.
[ { "created": "Thu, 5 Jul 2001 15:46:09 GMT", "version": "v1" } ]
2009-11-07
[ [ "Koike", "K.", "" ] ]
Possible generation structure is investigated. We considere alternative possibility of combination of leptons and quarks to compose each generation, where the combination of $(\nu_{\tau},{\tau})$ and $(u,d)$ compose a generation. Our model exhibits the hierarcy structure after sea-saw mechanism provived that possible existence of realistic right-handed neutrinos are taken into account. Then, in the GUTs model based on our scheme, possible inter-generation properties are examined together with the classification of gauge bosons. It is shown that if our scheme is realized, the proton decay exhibits different mode from ordinary one.
1610.00447
Nejc Ko\v{s}nik
Nejc Kosnik
New physics facing LFU and LFV tests in B physics
9 pages, 2 figures, Proceedings for the LHCP Conference, Lund, June 2016
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton flavor universality in the Standard Model and hints of its violation in neutral ($R_K$) and charged currents $(R_{D^{(*)}})$ in $B$ decays are presented. We discuss model independent features as well as several leptoquark scenarios which are well suited to fit current values of $R_K$ and/or $R_{D^{(*)}}$.
[ { "created": "Mon, 3 Oct 2016 08:57:00 GMT", "version": "v1" } ]
2016-10-04
[ [ "Kosnik", "Nejc", "" ] ]
Lepton flavor universality in the Standard Model and hints of its violation in neutral ($R_K$) and charged currents $(R_{D^{(*)}})$ in $B$ decays are presented. We discuss model independent features as well as several leptoquark scenarios which are well suited to fit current values of $R_K$ and/or $R_{D^{(*)}}$.
1205.2372
David Sanford
Jonathan L. Feng, David Sanford
A Natural 125 GeV Higgs Boson in the MSSM from Focus Point Supersymmetry with A-Terms
18 pages, 8 figures
null
10.1103/PhysRevD.86.055015
UCI-TR-2012-12
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that a 125 GeV Higgs boson and percent-level fine-tuning are simultaneously attainable in the MSSM, with no additional fields and supersymmetry breaking generated at the GUT scale. The Higgs mass is raised by large radiative contributions from top squarks with significant left-right mixing, and naturalness is preserved by the focus point mechanism with large $A$-terms, which suppresses large log-enhanced sensitivities to variations in the fundamental parameters. The focus point mechanism is independent of almost all supersymmetry-breaking parameters, but is predictive in the top sector, requiring the GUT-scale relation $m_{H_u}^2 : m_{\bar{U}_3}^2 : m_{Q_3}^2 : A_t^2 = 1 : 1+x - 3y : 1-x : 9y$, where $x$ and $y$ are constants. We derive this condition analytically and then investigate three representative models through detailed numerical analysis. The models generically predict heavy superpartners, but dark matter searches in the case of non-unified gaugino masses are promising, as are searches for top squarks and gluinos with top and bottom-rich cascade decays at the LHC. This framework may be viewed as a simple update to mSUGRA/CMSSM to accommodate both naturalness and current Higgs boson constraints, and provides an ideal framework for presenting new results from LHC searches.
[ { "created": "Thu, 10 May 2012 20:00:04 GMT", "version": "v1" } ]
2013-05-30
[ [ "Feng", "Jonathan L.", "" ], [ "Sanford", "David", "" ] ]
We show that a 125 GeV Higgs boson and percent-level fine-tuning are simultaneously attainable in the MSSM, with no additional fields and supersymmetry breaking generated at the GUT scale. The Higgs mass is raised by large radiative contributions from top squarks with significant left-right mixing, and naturalness is preserved by the focus point mechanism with large $A$-terms, which suppresses large log-enhanced sensitivities to variations in the fundamental parameters. The focus point mechanism is independent of almost all supersymmetry-breaking parameters, but is predictive in the top sector, requiring the GUT-scale relation $m_{H_u}^2 : m_{\bar{U}_3}^2 : m_{Q_3}^2 : A_t^2 = 1 : 1+x - 3y : 1-x : 9y$, where $x$ and $y$ are constants. We derive this condition analytically and then investigate three representative models through detailed numerical analysis. The models generically predict heavy superpartners, but dark matter searches in the case of non-unified gaugino masses are promising, as are searches for top squarks and gluinos with top and bottom-rich cascade decays at the LHC. This framework may be viewed as a simple update to mSUGRA/CMSSM to accommodate both naturalness and current Higgs boson constraints, and provides an ideal framework for presenting new results from LHC searches.
hep-ph/9906425
Dario Sassi Thober
Dario Sassi Thober
The definition of a magnetic monopole in Electrodynamics combined with Gravitation
11 pages
null
null
CPTUS-06/1999
hep-ph
null
It is discussed the singular string associated to the gauge field of monopoles must be a physical observable if the monopole charge is different from zero. It is naturally found that if the gauge is to be an observable, it is possibly connected to gravity.
[ { "created": "Thu, 17 Jun 1999 23:35:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Thober", "Dario Sassi", "" ] ]
It is discussed the singular string associated to the gauge field of monopoles must be a physical observable if the monopole charge is different from zero. It is naturally found that if the gauge is to be an observable, it is possibly connected to gravity.
hep-ph/0411064
Dmitri Kazakov
D.I.Kazakov
Beyond The Standard Model
52 pages, 51 eps figures, Lectures given at the European School on High Energy Physics, May-June 2004, Sant Feliu de Guixols, Spain
null
null
null
hep-ph
null
The present lectures contain an introduction to possible new physics beyond the Standard Model. Having in mind first of all accelerator experiments of the nearest future we concentrate on supersymmetry, a new symmetry that relates bosons and fermions, as the first target of experimental search. Since supersymmetry is widely covered in the literature, we mostly consider novel developments and applications to hadron colliders. We describe then the so-called extra dimensional models in less detail and discuss their possible manifestations.
[ { "created": "Thu, 4 Nov 2004 14:41:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kazakov", "D. I.", "" ] ]
The present lectures contain an introduction to possible new physics beyond the Standard Model. Having in mind first of all accelerator experiments of the nearest future we concentrate on supersymmetry, a new symmetry that relates bosons and fermions, as the first target of experimental search. Since supersymmetry is widely covered in the literature, we mostly consider novel developments and applications to hadron colliders. We describe then the so-called extra dimensional models in less detail and discuss their possible manifestations.
hep-ph/0503149
Seung-Il Nam
Seung-Il Nam (RCNP, Osaka University, Japan and Department of Physics & NuRI, Pusan National University, Republic of Korea), Atsushi Hosaka (RCNP, Osaka University, Japan) and Hyun-Chul Kim (Department of Physics & NuRI, Pusan National University, Republic of Korea)
Lambda(1520,3/2^-) photoproduction reaction via gamma N -> K Lambda(1520)
16 pages, 31 figures
Phys.Rev.D71:114012,2005
10.1103/PhysRevD.71.114012
PNU-NTG-6/2005
hep-ph
null
We investigate Lambda(1520,3/2^-,D_03) photoproduction via the gamma N -> K Lambda^* reaction process. Using effective Lagrangians, we compute the total and differential cross sections as well as the dependence on the momentum transfer for the photoproduction at the tree-level. We employ two different form factors: The four-dimensional gauge-invariant type and the three dimensional one depending on the external momenta. We find that the total cross sections for the proton target are well reproduced as compared with the experimental data. It turns out that the total cross sections for the neutron target are significantly smaller than those for the proton target. We also compare the present results with the gamma N -> bar{K} Theta^+ reaction in order to extract information of Theta^+. Finally the role of K^*--exchange in the production reaction is discussed.
[ { "created": "Wed, 16 Mar 2005 02:12:54 GMT", "version": "v1" }, { "created": "Thu, 7 Jul 2005 07:34:29 GMT", "version": "v2" } ]
2009-12-17
[ [ "Nam", "Seung-Il", "", "RCNP, Osaka University, Japan and Department of Physics\n & NuRI, Pusan National University, Republic of Korea" ], [ "Hosaka", "Atsushi", "", "RCNP,\n Osaka University, Japan" ], [ "Kim", "Hyun-Chul", "", "Department of Physics & Nu...
We investigate Lambda(1520,3/2^-,D_03) photoproduction via the gamma N -> K Lambda^* reaction process. Using effective Lagrangians, we compute the total and differential cross sections as well as the dependence on the momentum transfer for the photoproduction at the tree-level. We employ two different form factors: The four-dimensional gauge-invariant type and the three dimensional one depending on the external momenta. We find that the total cross sections for the proton target are well reproduced as compared with the experimental data. It turns out that the total cross sections for the neutron target are significantly smaller than those for the proton target. We also compare the present results with the gamma N -> bar{K} Theta^+ reaction in order to extract information of Theta^+. Finally the role of K^*--exchange in the production reaction is discussed.
2012.06566
Fabrizio Rompineve
Ricardo Z. Ferreira, Alessio Notari, Fabrizio Rompineve
The DFSZ axion in the CMB
14 pages, 10 figures
Phys. Rev. D 103, 063524 (2021)
10.1103/PhysRevD.103.063524
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform for the first time a dedicated analysis of cosmological constraints on DFSZ QCD axion models. Such constructions are especially interesting in light of the recent Xenon-1T excess and of hints from stellar cooling. In DFSZ models, for $m_a\gtrsim 0.1$ eV, scatterings of pions and muons can produce a sizable cosmic background of thermal axions, that behave similarly to massive neutrinos. However, the pion coupling depends on the alignment between the vevs of two Higgs doublets, and can be significantly suppressed or enhanced with respect to the KSVZ scenario. Using the latest Planck and BAO data, we find $m_a\leq 0.2~\text{eV}$ at $95\%$ C.L., when the axion coupling to pions $c_{a\pi}$ is maximal. Constraints on $m_a$, instead, can be significantly relaxed when $c_{a\pi}$ is small. In particular, we point out that in the so-called DFSZ-II model, where the axion coupling to leptons does not vanish simultaneously with $c_{a\pi}$, production via muons gives $m_a\leq 0.6~\text{eV}$ at $95\%$ C.L., whereas in the DFSZ-I model bounds on $m_a$ can be fully lifted. We then combine cosmological data with recent hints of a DFSZ axion coupled to electrons from the Xenon-1T experiment, finding in this case that the axion mass is constrained to be in the window $0.07 ~\text{eV} \lesssim m_a \lesssim 1.8\, (0.3)~\text{eV}$ for the DFSZ-I (DFSZ-II) model. A similar analysis with stellar cooling hints gives $3 ~\text{meV} \lesssim m_a \lesssim 0.2 ~\text{eV}$ for DFSZ-II, while no constraint arises in the DFSZ-I case. Forthcoming CMB Stage 4 experiments will be able to further test such scenarios; for instance the Xenon-1T window should be fully probed at $2\sigma$ for a DFSZ-I axion.
[ { "created": "Fri, 11 Dec 2020 18:53:55 GMT", "version": "v1" } ]
2021-03-31
[ [ "Ferreira", "Ricardo Z.", "" ], [ "Notari", "Alessio", "" ], [ "Rompineve", "Fabrizio", "" ] ]
We perform for the first time a dedicated analysis of cosmological constraints on DFSZ QCD axion models. Such constructions are especially interesting in light of the recent Xenon-1T excess and of hints from stellar cooling. In DFSZ models, for $m_a\gtrsim 0.1$ eV, scatterings of pions and muons can produce a sizable cosmic background of thermal axions, that behave similarly to massive neutrinos. However, the pion coupling depends on the alignment between the vevs of two Higgs doublets, and can be significantly suppressed or enhanced with respect to the KSVZ scenario. Using the latest Planck and BAO data, we find $m_a\leq 0.2~\text{eV}$ at $95\%$ C.L., when the axion coupling to pions $c_{a\pi}$ is maximal. Constraints on $m_a$, instead, can be significantly relaxed when $c_{a\pi}$ is small. In particular, we point out that in the so-called DFSZ-II model, where the axion coupling to leptons does not vanish simultaneously with $c_{a\pi}$, production via muons gives $m_a\leq 0.6~\text{eV}$ at $95\%$ C.L., whereas in the DFSZ-I model bounds on $m_a$ can be fully lifted. We then combine cosmological data with recent hints of a DFSZ axion coupled to electrons from the Xenon-1T experiment, finding in this case that the axion mass is constrained to be in the window $0.07 ~\text{eV} \lesssim m_a \lesssim 1.8\, (0.3)~\text{eV}$ for the DFSZ-I (DFSZ-II) model. A similar analysis with stellar cooling hints gives $3 ~\text{meV} \lesssim m_a \lesssim 0.2 ~\text{eV}$ for DFSZ-II, while no constraint arises in the DFSZ-I case. Forthcoming CMB Stage 4 experiments will be able to further test such scenarios; for instance the Xenon-1T window should be fully probed at $2\sigma$ for a DFSZ-I axion.
0707.4511
Stephan Narison
G. Mennessier, P. Minkowski, S. Narison and W. Ochs
Can the gamma-gamma processes reveal the nature of the sigma ?
null
null
null
null
hep-ph
null
We reanalyse the gamma-gamma scattering data and conclude that in the mass region below 1 GeV the cross section for gamma-gamma to pi^0-pi^0 can be largely explained by the one pion exchange process with pi-pi rescattering. The radiative width of the sigma is estimated and a model dependent separation into contributions from direct gamma-gamma decay and decay through rescattering is obtained. We confront these findings with QCD spectral sum rule (QSSR) predictions and conclude that the sigma can have a large gluonium component in its wave function.
[ { "created": "Tue, 31 Jul 2007 19:59:40 GMT", "version": "v1" }, { "created": "Wed, 1 Aug 2007 09:08:33 GMT", "version": "v2" } ]
2007-08-01
[ [ "Mennessier", "G.", "" ], [ "Minkowski", "P.", "" ], [ "Narison", "S.", "" ], [ "Ochs", "W.", "" ] ]
We reanalyse the gamma-gamma scattering data and conclude that in the mass region below 1 GeV the cross section for gamma-gamma to pi^0-pi^0 can be largely explained by the one pion exchange process with pi-pi rescattering. The radiative width of the sigma is estimated and a model dependent separation into contributions from direct gamma-gamma decay and decay through rescattering is obtained. We confront these findings with QCD spectral sum rule (QSSR) predictions and conclude that the sigma can have a large gluonium component in its wave function.
1403.1229
Tiziano Peraro
Tiziano Peraro
Ninja: Automated Integrand Reduction via Laurent Expansion for One-Loop Amplitudes
Published version
Computer Physics Communications 185 (2014), pp. 2771-2797
10.1016/j.cpc.2014.06.017
MPP-2014-50
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the public C++ library Ninja, which implements the Integrand Reduction via Laurent Expansion method for the computation of one-loop integrals. The algorithm is suited for applications to complex one-loop processes.
[ { "created": "Wed, 5 Mar 2014 19:10:00 GMT", "version": "v1" }, { "created": "Mon, 21 Jul 2014 07:39:59 GMT", "version": "v2" } ]
2014-07-22
[ [ "Peraro", "Tiziano", "" ] ]
We present the public C++ library Ninja, which implements the Integrand Reduction via Laurent Expansion method for the computation of one-loop integrals. The algorithm is suited for applications to complex one-loop processes.
1911.08423
Igor Ivanov
Igor P. Ivanov, Nikolai Korchagin, Alexandr Pimikov, Pengming Zhang
Doing spin physics with unpolarized particles
5+2 pages, 2 figures
Phys. Rev. Lett. 124, 192001 (2020)
10.1103/PhysRevLett.124.192001
CFTP/19-030
hep-ph hep-ex quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Twisted, or vortex, particles refer to freely propagating non-plane-wave states with helicoidal wave fronts. In this state, the particle possesses a non-zero orbital angular momentum with respect to its average propagation direction. Twisted photons and electrons have been experimentally demonstrated, and creation of other particles in twisted states can be anticipated. If brought in collisions, twisted states offer a new degree of freedom to particle physics, and it is timely to analyze what new insights may follow. Here, we theoretically investigate resonance production in twisted photon collisions and twisted $e^+e^-$ annihilation and show that these processes emerge as a completely novel probe of spin and parity-sensitive observables in fully inclusive cross sections with unpolarized initial particles. This is possible because the initial state with a non-zero angular momentum explicitly breaks the left-right symmetry even when averaging over helicities. In particular, we show how one can produce almost $100\%$ polarized vector mesons in unpolarized twisted $e^+e^-$ annihilation and how to control its polarization state.
[ { "created": "Tue, 19 Nov 2019 17:39:51 GMT", "version": "v1" } ]
2020-05-20
[ [ "Ivanov", "Igor P.", "" ], [ "Korchagin", "Nikolai", "" ], [ "Pimikov", "Alexandr", "" ], [ "Zhang", "Pengming", "" ] ]
Twisted, or vortex, particles refer to freely propagating non-plane-wave states with helicoidal wave fronts. In this state, the particle possesses a non-zero orbital angular momentum with respect to its average propagation direction. Twisted photons and electrons have been experimentally demonstrated, and creation of other particles in twisted states can be anticipated. If brought in collisions, twisted states offer a new degree of freedom to particle physics, and it is timely to analyze what new insights may follow. Here, we theoretically investigate resonance production in twisted photon collisions and twisted $e^+e^-$ annihilation and show that these processes emerge as a completely novel probe of spin and parity-sensitive observables in fully inclusive cross sections with unpolarized initial particles. This is possible because the initial state with a non-zero angular momentum explicitly breaks the left-right symmetry even when averaging over helicities. In particular, we show how one can produce almost $100\%$ polarized vector mesons in unpolarized twisted $e^+e^-$ annihilation and how to control its polarization state.
1304.2223
Vladyslav Pauk
V. Pauk, V. Pascalutsa, M. Vanderhaeghen
Analytic structure of $\phi^4$ theory using light-by-light sum rules
12 pages, 7 figures
null
10.1016/j.physletb.2013.07.058
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply a sum rule for the forward light-by-light scattering process within the context of the $\phi^4$ quantum field theory. As a consequence of the sum rule a stringent causality criterion is presented and the resulting constraints are studied within a particular resummation of graphs. Such resummation is demonstrated to be consistent with the sum rule to all orders of perturbation theory. We furthermore show the appearance of particular non-perturbative solutions within such approximation to be a necessary requirement of the sum rule. For a range of values of the coupling constant, these solutions manifest themselves as a physical bound state and a $K$-matrix pole. For another domain however, they appear as tachyon solutions, showing the inconsistency of the approximation in this region.
[ { "created": "Mon, 8 Apr 2013 14:42:45 GMT", "version": "v1" } ]
2015-06-15
[ [ "Pauk", "V.", "" ], [ "Pascalutsa", "V.", "" ], [ "Vanderhaeghen", "M.", "" ] ]
We apply a sum rule for the forward light-by-light scattering process within the context of the $\phi^4$ quantum field theory. As a consequence of the sum rule a stringent causality criterion is presented and the resulting constraints are studied within a particular resummation of graphs. Such resummation is demonstrated to be consistent with the sum rule to all orders of perturbation theory. We furthermore show the appearance of particular non-perturbative solutions within such approximation to be a necessary requirement of the sum rule. For a range of values of the coupling constant, these solutions manifest themselves as a physical bound state and a $K$-matrix pole. For another domain however, they appear as tachyon solutions, showing the inconsistency of the approximation in this region.
1801.09703
Gregory Soyez
P. Caucal, E. Iancu, A.H. Mueller and G. Soyez
Vacuum-like jet fragmentation in a dense QCD medium
5 pages, 3 figures
Phys. Rev. Lett. 120, 232001 (2018)
10.1103/PhysRevLett.120.232001
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fragmentation of a jet propagating in a dense quark-gluon plasma. Using a leading, double-logarithmic approximation in perturbative QCD, we compute for the first time the effects of the medium on the vacuum-like emissions. We show that, due to the scatterings off the plasma, the in-medium parton showers differ from the vacuum ones in two crucial aspects: their phase-space is reduced and the first emission outside the medium can violate angular ordering. We compute the jet fragmentation function and find results in qualitative agreement with measurements at the LHC.
[ { "created": "Mon, 29 Jan 2018 19:01:15 GMT", "version": "v1" } ]
2018-06-13
[ [ "Caucal", "P.", "" ], [ "Iancu", "E.", "" ], [ "Mueller", "A. H.", "" ], [ "Soyez", "G.", "" ] ]
We study the fragmentation of a jet propagating in a dense quark-gluon plasma. Using a leading, double-logarithmic approximation in perturbative QCD, we compute for the first time the effects of the medium on the vacuum-like emissions. We show that, due to the scatterings off the plasma, the in-medium parton showers differ from the vacuum ones in two crucial aspects: their phase-space is reduced and the first emission outside the medium can violate angular ordering. We compute the jet fragmentation function and find results in qualitative agreement with measurements at the LHC.
hep-ph/0008051
Matthias Burkardt
M. Burkardt (New Mexico State University)
Off-forward parton distributions and impact parameter dependent parton structure
10 pages, sprocl.sty, talk given at workshop on Continuous Advances in QCD, Minneapolis, May 12-14, 2000
null
null
null
hep-ph
null
The connection between parton distributions as a function of the impact parameter and off-forward parton distributions is discussed in the limit of vanishing skewedness parameter $\xi$, i.e. when the off-forwardness is purely transverse. It is also illustrated how to relate $\xi\neq 0$ data to $\xi=0$ data, which is important for experimental measurements of these observables.
[ { "created": "Sat, 5 Aug 2000 23:18:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Burkardt", "M.", "", "New Mexico State University" ] ]
The connection between parton distributions as a function of the impact parameter and off-forward parton distributions is discussed in the limit of vanishing skewedness parameter $\xi$, i.e. when the off-forwardness is purely transverse. It is also illustrated how to relate $\xi\neq 0$ data to $\xi=0$ data, which is important for experimental measurements of these observables.
2405.10303
Wen Yin
Wen Yin, Shota Nakagawa, Tamaki Murokoshi, and Makoto Hattori
Asymmetric Warm Dark Matter: from Cosmological Asymmetry to Chirality of Life
22pages, 3figures, comments are welcome
null
null
null
hep-ph astro-ph.CO astro-ph.GA astro-ph.IM physics.bio-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a novel scenario involving asymmetric keV-range dark matter (DM) in the form of right-handed (sterile) neutrinos. Based on the Fermi-Dirac distribution, we demonstrate that asymmetric fermionic DM forms a Fermi degenerate gas, making it potentially colder than symmetric fermionic DM. This setup simultaneously accounts for the Universe's baryon asymmetry through tiny Yukawa interactions with Standard Model leptons and the Higgs field, and the homochirality of amino acids via decay into circularly polarized photons. This scenario can be investigated through soft X-ray searches conducted by current and upcoming space missions. The helical X-rays is a smoking-gun signal of our scenario. Additionally, we propose a new mechanism to suppress DM thermal production by introducing a light modulus, which may also benefit cosmology involving generic right-handed neutrinos with large mixing.
[ { "created": "Thu, 16 May 2024 17:56:16 GMT", "version": "v1" } ]
2024-05-17
[ [ "Yin", "Wen", "" ], [ "Nakagawa", "Shota", "" ], [ "Murokoshi", "Tamaki", "" ], [ "Hattori", "Makoto", "" ] ]
We investigate a novel scenario involving asymmetric keV-range dark matter (DM) in the form of right-handed (sterile) neutrinos. Based on the Fermi-Dirac distribution, we demonstrate that asymmetric fermionic DM forms a Fermi degenerate gas, making it potentially colder than symmetric fermionic DM. This setup simultaneously accounts for the Universe's baryon asymmetry through tiny Yukawa interactions with Standard Model leptons and the Higgs field, and the homochirality of amino acids via decay into circularly polarized photons. This scenario can be investigated through soft X-ray searches conducted by current and upcoming space missions. The helical X-rays is a smoking-gun signal of our scenario. Additionally, we propose a new mechanism to suppress DM thermal production by introducing a light modulus, which may also benefit cosmology involving generic right-handed neutrinos with large mixing.
1310.3620
Soumya Rao
Joydeep Chakrabortty, Subhendra Mohanty and Soumya Rao
Non-universal gaugino mass GUT models in the light of dark matter and LHC constraints
22 pages, 6 tables, 7 figures; new results added along with discussion; matches version to be published in JHEP
JHEP02(2014)074
10.1007/JHEP02(2014)074
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a comprehensive study of $SU(5)$, $SO(10)$ and $E(6)$ supersymmetric GUT models where the gaugino masses are generated through the F-term breaking vacuum expectation values of the non-singlet scalar fields. In these models the gauginos are non-universal at the GUT scale unlike in the mSUGRA scenario. We discuss the properties of the LSP which is stable and a viable candidate for cold dark matter. We look for the GUT scale parameter space that leads to the the lightest SM like Higgs mass in the range of 122-127 GeV compatible with the observations at ATLAS and CMS, the relic density in the allowed range of WMAP-PLANCK and compatible with other constraints from colliders and direct detection experiments. We scan universal scalar ($m_0^G$), trilinear coupling $A_0$ and $SU(3)_C$ gaugino mass ($M_3^G$) as the independent free parameters for these models. Based on the gaugino mass ratios at the GUT scale, we classify 25 SUSY GUT models and find that of these only 13 models satisfy the dark matter and collider constraints. Out of these 13 models there is only one model where there is a sizeable SUSY contribution to muon $(g-2)$.
[ { "created": "Mon, 14 Oct 2013 10:30:50 GMT", "version": "v1" }, { "created": "Mon, 3 Feb 2014 07:58:31 GMT", "version": "v2" } ]
2014-03-03
[ [ "Chakrabortty", "Joydeep", "" ], [ "Mohanty", "Subhendra", "" ], [ "Rao", "Soumya", "" ] ]
We perform a comprehensive study of $SU(5)$, $SO(10)$ and $E(6)$ supersymmetric GUT models where the gaugino masses are generated through the F-term breaking vacuum expectation values of the non-singlet scalar fields. In these models the gauginos are non-universal at the GUT scale unlike in the mSUGRA scenario. We discuss the properties of the LSP which is stable and a viable candidate for cold dark matter. We look for the GUT scale parameter space that leads to the the lightest SM like Higgs mass in the range of 122-127 GeV compatible with the observations at ATLAS and CMS, the relic density in the allowed range of WMAP-PLANCK and compatible with other constraints from colliders and direct detection experiments. We scan universal scalar ($m_0^G$), trilinear coupling $A_0$ and $SU(3)_C$ gaugino mass ($M_3^G$) as the independent free parameters for these models. Based on the gaugino mass ratios at the GUT scale, we classify 25 SUSY GUT models and find that of these only 13 models satisfy the dark matter and collider constraints. Out of these 13 models there is only one model where there is a sizeable SUSY contribution to muon $(g-2)$.
0907.0296
Matthias Burkardt
Matthias Burkardt (New Mexico State University)
Generalized Parton Distributions, Deeply Virtual Compton Scattering and TMDs
4 pages, invited talk at CIPANP09
AIP Conf.Proc.1182:859-863,2009
10.1063/1.3293944
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when target and/or quark are transversely polarized. In combination with the final state interactions, this transverse deformation provides a natural mechanism for naive-T odd transverse single-spin asymmetries in semi-inclusive DIS. The deformation of PDFs in impact parameter space can also be related to the transverse force acting on the active quark in polarized DIS at higher twist.
[ { "created": "Thu, 2 Jul 2009 07:02:04 GMT", "version": "v1" }, { "created": "Tue, 4 Aug 2009 20:45:44 GMT", "version": "v2" } ]
2010-01-15
[ [ "Burkardt", "Matthias", "", "New Mexico State University" ] ]
Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when target and/or quark are transversely polarized. In combination with the final state interactions, this transverse deformation provides a natural mechanism for naive-T odd transverse single-spin asymmetries in semi-inclusive DIS. The deformation of PDFs in impact parameter space can also be related to the transverse force acting on the active quark in polarized DIS at higher twist.
2102.04617
Kiyoharu Kawana
Yuta Hamada, Hikaru Kawai, Kiyoharu Kawana, Kin-ya Oda, and Kei Yagyu
Minimal scenario of Criticality for Electroweak scale, Neutrino Masses, Dark Matter, and Inflation
30 pages, 7 figures; Version accepted in EPJC (v2)
null
10.1140/epjc/s10052-021-09735-z
OU-HET-1087
hep-ph gr-qc
http://creativecommons.org/licenses/by/4.0/
We propose a minimal model that can explain the electroweak scale, neutrino masses, Dark Matter (DM), and successful inflation all at once based on the multicritical-point principle (MPP). The model has two singlet scalar fields that realize an analogue of the Coleman-Weinberg mechanism, in addition to the Standard Model with heavy Majorana right-handed neutrinos. By assuming a $Z_2 $ symmetry, one of the scalars becomes a DM candidate whose property is almost the same as the minimal Higgs-portal scalar DM. In this model, the MPP can naturally realize a saddle point in the Higgs potential at high energy scales. By the renormalization-group analysis, we study the critical Higgs inflation with non-minimal coupling $\xi |H|^2 R$ that utilizes the saddle point of the Higgs potential. We find that it is possible to realize successful inflation even for $\xi=25$ and that the heaviest right-handed neutrino is predicted to have a mass around $10^{14}$ GeV to meet the current cosmological observations. Such a small value of $\xi$ can be realized by the Higgs-portal coupling $\lambda_{SH}\simeq 0.32$ and the vacuum expectation value of the additional neutral scalar $\langle\phi\rangle\simeq 2.7$ TeV, which correspond to the dark matter mass 2.0 TeV, its spin-independent cross section $1.8\times10^{-9}$ pb, and the mass of additional neutral scalar 190 GeV.
[ { "created": "Tue, 9 Feb 2021 02:55:54 GMT", "version": "v1" }, { "created": "Wed, 5 Jan 2022 06:08:00 GMT", "version": "v2" } ]
2022-01-06
[ [ "Hamada", "Yuta", "" ], [ "Kawai", "Hikaru", "" ], [ "Kawana", "Kiyoharu", "" ], [ "Oda", "Kin-ya", "" ], [ "Yagyu", "Kei", "" ] ]
We propose a minimal model that can explain the electroweak scale, neutrino masses, Dark Matter (DM), and successful inflation all at once based on the multicritical-point principle (MPP). The model has two singlet scalar fields that realize an analogue of the Coleman-Weinberg mechanism, in addition to the Standard Model with heavy Majorana right-handed neutrinos. By assuming a $Z_2 $ symmetry, one of the scalars becomes a DM candidate whose property is almost the same as the minimal Higgs-portal scalar DM. In this model, the MPP can naturally realize a saddle point in the Higgs potential at high energy scales. By the renormalization-group analysis, we study the critical Higgs inflation with non-minimal coupling $\xi |H|^2 R$ that utilizes the saddle point of the Higgs potential. We find that it is possible to realize successful inflation even for $\xi=25$ and that the heaviest right-handed neutrino is predicted to have a mass around $10^{14}$ GeV to meet the current cosmological observations. Such a small value of $\xi$ can be realized by the Higgs-portal coupling $\lambda_{SH}\simeq 0.32$ and the vacuum expectation value of the additional neutral scalar $\langle\phi\rangle\simeq 2.7$ TeV, which correspond to the dark matter mass 2.0 TeV, its spin-independent cross section $1.8\times10^{-9}$ pb, and the mass of additional neutral scalar 190 GeV.
1801.04203
Marco Zaro
C.F. Anders (1), A. Ballestrero (2), J. Balz (3), R. Bellan (4), B. Biedermann (5), C. Bittrich (6), S. Bra{\ss} (7), I. Brivio (8), L.S. Bruni (9), J. Butterworth (10), M. Cacciari (11), A. Cardini (12), C. Charlot (13), V. Ciulli (12), R. Covarelli (4), J. Cuevas (14), A. Denner (5), L. Di Ciaccio (15), S. Dittmaier (16), S. Duric (17,18), S. Farrington (19), P. Ferrari (9), P. Ferreira Silva (20), L. Finco (4), D. Giljanovi\'c (21), N. Glover (22), R. Gomez-Ambrosio (4,22), G. Gomez-Ceballos (23), G. Gonella (16), P. Govoni (24), C. Goy (15), P. Gras (25), C. Grojean (26), E. Gross (27), M. Grossi (28), M. Grunewald (29), L. Helary (20), M. Herndon (17), T. Herrmann (6), A. Hinzmann (30), F. Iltzsche (6), B. J\"ager (31), X. Janssen (32), H. Jung (26), A. Karlberg (33), O. Kepka (34), B. Kersevan (35), M. Klute (23), M. Kobel (6), I. Koletsou (15), K. Kordas (36), T. Lampen (37), J.G.E. Lauwers (32), D. Lelas (21), P. Lenzi (12), Q. Li (38), K. Lipka (26), K. Lohwasser (39), K. Long (17), N. Lorenzo Martinez (15), E. Maina (4), F. Maltoni (40), J. Manjarres (6), C. Mariotti (2), O. Mattelaer (22), M.U. Mozer (41), M. Mulders (20), J. Novak (35), C. Oleari (24), A. Paganoni (42), M. Pellen (5), G. Pelliccioli (4), C. Petridou (36), P. Pigard (13), M. Pleier (43), G. Polesello (44), K. Potamianos (26), D. Price (45), I. Puljak (21), M. Rauch (41), D. Rebuzzi (46), J. Reuter (26), F. Riva (20), V. Rothe (26), L. Russo (47), R. Salerno (13), D. Sampsonidou (36), L. Sangalli (42), E. Sauvan (15), M. Schumacher (16), C. Schwan (16), M. Sekulla (41), M. Selvaggi (20), F. Siegert (6), M. Slawinska (48), H. Snoek (9), P. Sommer (39), F. Span\`o (49), M. Spannowsky (22), P. Stienemeier (26), J. Strandberg (50), M. Szleper (51), A. Sznajder (52), S. Tkaczyk (53), S. Todt (6), M. Trott (8), S. Tzamarias (36), B. Van Eijk (9), A. Vicini (54), M. Voutilainen (37), E. Vryonidou (20), G. Zanderighi (20), M. Zaro (11,9), D. Zeppenfeld (41) ((1) Ruprecht-Karls-Universit\"at Heidelberg (DE), (2) INFN Torino (IT), (3) Johannes-Gutenberg-Universit\"at Mainz (DE), (4) University and INFN Torino (IT), (5) University of W\"urzburg (DE), (6) Technische Universitaet Dresden (DE), (7) University of Siegen (DE), (8) Niels Bohr International Academy and Discovery Center, Niels Bohr Institute, Copenhagen University (DK), (9) Nikhef National institute for subatomic physics (NL), (10) Department of Physics and Astronomy, University College London (UK), (11) Sorbonne Universit\'es and CNRS, LPTHE, Paris (FR), (12) University and INFN, Firenze (IT), (13) LLR, \'Ecole polytechnique, CNRS/IN2P3, Universit\'e Paris-Saclay (FR), (14) University of Oviedo (SP), (15) LAPP, Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS/IN2P3, Annecy (FR), (16) Albert-Ludwigs-Universit\"at Freiburg (DE), (17) University of Wisconsin-Madison (US), (18) Kansas State University (US), (19) Department of Physics, University of Warwick, Coventry (UK), (20) CERN (CH), (21) University of Split, FESB (HR), (22) Institute for Particle Physics Phenomenology, Department of Physics, University of Durham (UK), (23) Massachusetts Institute of Technology, Cambridge (US), (24) University and INFN, Milano-Bicocca (IT), (25) CEA/Saclay - IRFU (FR), (26) Deutsches Elektronen-Synchrotron, Hamburg (DE), (27) Weizmann Institute of Science (IL), (28) University of Pavia and IBM Italia (IT), (29) University College Dublin (IE), (30) University of Hamburg (DE), (31) University of T\"ubingen (DE), (32) University of Antwerp (BE), (33) Universit\"at Z\"urich (CH), (34) Institute of Physics, Academy of Sciences of the Czech Republic, Praha (CZ), (35) Department of Experimental Particle Physics, Jo\v{z}ef Stefan Institute and Department of Physics, University of Ljubljana (SI), (36) Aristotle University of Thessalon\'iki (GR), (37) University of Helsinki and HIP (FI), (38) School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing (CN), (39) University of Sheffield (GB), (40) Centre for Cosmology, Particle Physics and Phenomenology Universit\'e catholique de Louvain (BE), (41) KIT - Karlsruhe Institute of Technology (DE), (42) MOX - Department of Mathematics, Politecnico di Milano (IT), (43) Physics Department, Brookhaven National Laboratory, Upton NY (US), (44) INFN Pavia (IT), (45) University of Manchester (GB), (46) University and INFN, Pavia (IT), (47) University of Siena and INFN Firenze (IT), (48) Polish Academy of Sciences (PL), (49) Royal Holloway University of London (UK), (50) KTH Royal Institute of Technology (SE), (51) National Center for Nuclear Research, Warsaw (PL), (52) University of the State of Rio de Janeiro (BR), (53) Fermi National Accelerator Laboratory, Batavia (US), (54) Universit\`a degli Studi di Milano (IT))
Vector boson scattering: Recent experimental and theory developments
41 pages including references, 11 figures, summary of the talks and discussions happened during the first VBSCan workshop: https://indico.cern.ch/event/629638/. Note that in v2 the original title "VBSCan Split 2017 Workshop Summary" has been modified according to the published version
Rev.Phys. 3 (2018) 44-63
10.1016/j.revip.2018.11.001
VBSCan-PUB-01-17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This document summarises the talks and discussions happened during the VBSCan Split17 workshop, the first general meeting of the VBSCan COST Action network. This collaboration is aiming at a consistent and coordinated study of vector-boson scattering from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
[ { "created": "Fri, 12 Jan 2018 15:35:49 GMT", "version": "v1" }, { "created": "Thu, 13 Dec 2018 17:00:47 GMT", "version": "v2" } ]
2018-12-14
[ [ "Anders", "C. F.", "" ], [ "Ballestrero", "A.", "" ], [ "Balz", "J.", "" ], [ "Bellan", "R.", "" ], [ "Biedermann", "B.", "" ], [ "Bittrich", "C.", "" ], [ "Braß", "S.", "" ], [ "Brivio", "I.", ...
This document summarises the talks and discussions happened during the VBSCan Split17 workshop, the first general meeting of the VBSCan COST Action network. This collaboration is aiming at a consistent and coordinated study of vector-boson scattering from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
1601.04990
Alvaro de Rujula
A. De R\'ujula and M. Lusignoli
The calorimetric spectrum of the electron-capture decay of $^{163}$Ho. The spectral endpoint region
Clarifying changes suggested by a referee. Results unchanged. 14 pages, 15 figures
null
10.1007/JHEP05(2016)015
null
hep-ph nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electron-neutrino mass (or masses and mixing angles) may be directly measurable in weak electron-capture decays. The favoured experimental technique is "calorimetric". The optimal nuclide is $^{163}$Ho, and several experiments (ECHo, HOLMES and NuMECS) are currently studying its decay. The most relevant range of the calorimetric-energy spectrum extends for the last few hundred eV below its endpoint. It has not yet been well measured. We explore the theory, mainly in the cited range, of electron capture in $^{163}$Ho decay. A so far neglected process turns out to be most relevant: electron-capture accompanied by the shake-off of a second electron. Our two main conclusions are very encouraging: the counting rate close to the endpoint may be more than an order of magnitude larger than previously expected; the "pile-up" problem may be significantly reduced.
[ { "created": "Tue, 19 Jan 2016 16:54:20 GMT", "version": "v1" }, { "created": "Sun, 20 Mar 2016 18:21:34 GMT", "version": "v2" } ]
2016-05-25
[ [ "De Rújula", "A.", "" ], [ "Lusignoli", "M.", "" ] ]
The electron-neutrino mass (or masses and mixing angles) may be directly measurable in weak electron-capture decays. The favoured experimental technique is "calorimetric". The optimal nuclide is $^{163}$Ho, and several experiments (ECHo, HOLMES and NuMECS) are currently studying its decay. The most relevant range of the calorimetric-energy spectrum extends for the last few hundred eV below its endpoint. It has not yet been well measured. We explore the theory, mainly in the cited range, of electron capture in $^{163}$Ho decay. A so far neglected process turns out to be most relevant: electron-capture accompanied by the shake-off of a second electron. Our two main conclusions are very encouraging: the counting rate close to the endpoint may be more than an order of magnitude larger than previously expected; the "pile-up" problem may be significantly reduced.
2407.18196
Andrew Long
Andrew J. Long and Jessica Turner
Thermal pressure on ultrarelativistic bubbles from a semiclassical formalism
29 pages plus appendices, 4 figures, 1 table
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a planar bubble wall that is traveling at an ultrarelativistic speed through a thermal plasma. This situation may arise during a first order electroweak phase transition in the early universe. As particles cross the wall, it is assumed that their mass grows from $m_a$ to $m_b$, and they are decelerated causing them to emit massless radiation. We are interested in the momentum transfer to the wall, the thermal pressure felt by the wall, and the resultant terminal velocity of the wall. We employ the semiclassical current radiation (SCR) formalism to perform these calculations. An incident charged particle is treated as a point-like classical electromagnetic current, and the spectrum of quantum electromagnetic radiation (photons) is derived by calculating appropriate matrix elements. To understand how the spectrum depends on the thickness of the wall, we explore simplified models for the current corresponding to an abrupt and a gradual deceleration. For the model of abrupt deceleration, we find that the SCR formalism can reproduce the $P_\mathrm{therm} \propto \gamma_w^0$ scaling found in earlier work by assuming that the emission is soft, but if the emission is not soft the SCR formalism can be used to obtain $P_\mathrm{therm} \propto \gamma_w^2$ instead. For the model of gradual deceleration, we find that the wall thickness $L_w$ enters to cutoff the otherwise log-flat radiation spectrum above a momentum of $\sim \gamma_w^2 / L_w$, and we discuss the connections with classical electromagnetic bremsstrahlung.
[ { "created": "Thu, 25 Jul 2024 16:59:38 GMT", "version": "v1" } ]
2024-07-26
[ [ "Long", "Andrew J.", "" ], [ "Turner", "Jessica", "" ] ]
We study a planar bubble wall that is traveling at an ultrarelativistic speed through a thermal plasma. This situation may arise during a first order electroweak phase transition in the early universe. As particles cross the wall, it is assumed that their mass grows from $m_a$ to $m_b$, and they are decelerated causing them to emit massless radiation. We are interested in the momentum transfer to the wall, the thermal pressure felt by the wall, and the resultant terminal velocity of the wall. We employ the semiclassical current radiation (SCR) formalism to perform these calculations. An incident charged particle is treated as a point-like classical electromagnetic current, and the spectrum of quantum electromagnetic radiation (photons) is derived by calculating appropriate matrix elements. To understand how the spectrum depends on the thickness of the wall, we explore simplified models for the current corresponding to an abrupt and a gradual deceleration. For the model of abrupt deceleration, we find that the SCR formalism can reproduce the $P_\mathrm{therm} \propto \gamma_w^0$ scaling found in earlier work by assuming that the emission is soft, but if the emission is not soft the SCR formalism can be used to obtain $P_\mathrm{therm} \propto \gamma_w^2$ instead. For the model of gradual deceleration, we find that the wall thickness $L_w$ enters to cutoff the otherwise log-flat radiation spectrum above a momentum of $\sim \gamma_w^2 / L_w$, and we discuss the connections with classical electromagnetic bremsstrahlung.
1602.07697
Howard Baer
Howard Baer, Vernon Barger, Michael Savoy and Hasan Serce
The Higgs mass and natural supersymmetric spectrum from the landscape
5 pages plus 3 figures; version 2 coincides with published version, some references added
null
10.1016/j.physletb.2016.05.010
OU-HEP-160225
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In supersymmetric models where the superpotential mu term is generated with mu<< m_{soft} (e.g. from radiative Peccei-Quinn symmetry breaking or compactified string models with sequestration and stabilized moduli), and where the string landscape 1. favors soft supersymmetry (SUSY) breaking terms as large as possible and 2. where the anthropic condition that electroweak symmetry is properly broken with a weak scale m_{W,Z,h}~100 GeV ({\it i.e.} not too weak of weak interactions), then these combined landscape/anthropic requirements act as an attractor pulling the soft SUSY breaking terms towards values required by models with radiatively-driven naturalness: near the line of criticality where electroweak symmetry is barely broken and the Higgs mass is ~125 GeV. The pull on the soft terms serves to ameliorate the SUSY flavor and CP problems. The resulting sparticle mass spectrum may barely be accessible at high-luminosity LHC while the required light higgsinos should be visible at a linear e^+e^- collider with \sqrt{s}>2m(higgsino).
[ { "created": "Wed, 24 Feb 2016 21:00:06 GMT", "version": "v1" }, { "created": "Tue, 10 May 2016 16:55:19 GMT", "version": "v2" } ]
2016-06-22
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Savoy", "Michael", "" ], [ "Serce", "Hasan", "" ] ]
In supersymmetric models where the superpotential mu term is generated with mu<< m_{soft} (e.g. from radiative Peccei-Quinn symmetry breaking or compactified string models with sequestration and stabilized moduli), and where the string landscape 1. favors soft supersymmetry (SUSY) breaking terms as large as possible and 2. where the anthropic condition that electroweak symmetry is properly broken with a weak scale m_{W,Z,h}~100 GeV ({\it i.e.} not too weak of weak interactions), then these combined landscape/anthropic requirements act as an attractor pulling the soft SUSY breaking terms towards values required by models with radiatively-driven naturalness: near the line of criticality where electroweak symmetry is barely broken and the Higgs mass is ~125 GeV. The pull on the soft terms serves to ameliorate the SUSY flavor and CP problems. The resulting sparticle mass spectrum may barely be accessible at high-luminosity LHC while the required light higgsinos should be visible at a linear e^+e^- collider with \sqrt{s}>2m(higgsino).
hep-ph/0101034
Abhijit Samanta
Amitava Datta, Anirban Kundu and Abhijit Samanta
New Bounds on Slepton and Wino Masses in Anomaly Mediated Supersymmetry Breaking Models
4 pages, 1 postscript figure, uses revtex.sty (included). Some points clarified in v2, conclusion unchanged, to be published in Phys. Rev. D
Phys.Rev. D64 (2001) 095016
10.1103/PhysRevD.64.095016
null
hep-ph
null
We show how the spectrum of the minimal anomaly-mediated supersymmetry breaking model can be constrained from the condition that the electroweak symmetry breaking minimum of the scalar potential is the deepest point in the field space. Applying the current experimental bounds and scanning over the whole parameter space, we rule out selectrons below 378 GeV and staus below 269 GeV, the numbers having a modest uncertainty. We also find a new upper bound on the wino-like chargino mass for a given slepton mass. This rules out the possibility of slepton pair production at ongoing or upcoming colliders like the Tevatron or the Next Linear Collider at $\sqrt{s}=500$ GeV, where pair production of charginos may be the only available signal.
[ { "created": "Thu, 4 Jan 2001 08:28:53 GMT", "version": "v1" }, { "created": "Fri, 27 Jul 2001 13:16:51 GMT", "version": "v2" } ]
2009-11-07
[ [ "Datta", "Amitava", "" ], [ "Kundu", "Anirban", "" ], [ "Samanta", "Abhijit", "" ] ]
We show how the spectrum of the minimal anomaly-mediated supersymmetry breaking model can be constrained from the condition that the electroweak symmetry breaking minimum of the scalar potential is the deepest point in the field space. Applying the current experimental bounds and scanning over the whole parameter space, we rule out selectrons below 378 GeV and staus below 269 GeV, the numbers having a modest uncertainty. We also find a new upper bound on the wino-like chargino mass for a given slepton mass. This rules out the possibility of slepton pair production at ongoing or upcoming colliders like the Tevatron or the Next Linear Collider at $\sqrt{s}=500$ GeV, where pair production of charginos may be the only available signal.
1408.2297
Tao Zhong
Tao Zhong, Xing-Gang Wu and Tao Huang
Heavy Pseudoscalar Leading-Twist Distribution Amplitudes within QCD Theory in Background Fields
14 pages, 14 figures
Eur.Phys.J. C75 (2015) 2, 45
10.1140/epjc/s10052-015-3271-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the leading-twist distribution amplitude (DA) of the heavy pseudoscalars (HPs), such as $\eta_c$, $\eta_b$ and $B_c$, within the QCD theory in the background fields. New sum rules up to dimension-six condensates for both the HP decay constants and their leading-twist DA moments are presented. From the sum rules for the HP decay constants, we obtain $f_{\eta_c} = 453 \pm 4 \textrm{MeV}$, $f_{B_c} = 498 \pm 14 \textrm{MeV}$, and $f_{\eta_b} = 811 \pm 34 \textrm{MeV}$. Basing on the sum rules for the HPs' leading-twist DA moments, we construct a new model for the $\eta_c$, $\eta_b$ and $B_c$ leading-twist DAs. Our present HP DA model can also be adaptable for the light pseudo-scalar DAs, such as the pion and kaon DAs. Thus, it shall be applicable for a wide range of QCD exclusive processes. As an application, we apply the $\eta_c$ leading-twist DA to calculate the $B_c \to \eta_c$ transition form factor $f_+^{B_c \to \eta_c}(q^2)$. At the maximum recoil region, we obtain $f_+^{B_c \to \eta_c}(0) = 0.612^{+0.053}_{-0.052}$. After further extrapolating the TFF $f_+^{B_c \to \eta_c}(q^2)$ to its allowable $q^2$ region, we predict the branching ratio for the semi-leptonic decay $B_c \to \eta_c l \nu$. We obtain ${\cal B}(B_c \to \eta_c l \nu)=\left(7.70^{+1.65}_{-1.48}\right) \times 10^{-3}$ for massless leptons, which is consistent with the LCSRs estimation obtained in the literature.
[ { "created": "Mon, 11 Aug 2014 02:50:20 GMT", "version": "v1" } ]
2015-09-21
[ [ "Zhong", "Tao", "" ], [ "Wu", "Xing-Gang", "" ], [ "Huang", "Tao", "" ] ]
In this paper, we study the leading-twist distribution amplitude (DA) of the heavy pseudoscalars (HPs), such as $\eta_c$, $\eta_b$ and $B_c$, within the QCD theory in the background fields. New sum rules up to dimension-six condensates for both the HP decay constants and their leading-twist DA moments are presented. From the sum rules for the HP decay constants, we obtain $f_{\eta_c} = 453 \pm 4 \textrm{MeV}$, $f_{B_c} = 498 \pm 14 \textrm{MeV}$, and $f_{\eta_b} = 811 \pm 34 \textrm{MeV}$. Basing on the sum rules for the HPs' leading-twist DA moments, we construct a new model for the $\eta_c$, $\eta_b$ and $B_c$ leading-twist DAs. Our present HP DA model can also be adaptable for the light pseudo-scalar DAs, such as the pion and kaon DAs. Thus, it shall be applicable for a wide range of QCD exclusive processes. As an application, we apply the $\eta_c$ leading-twist DA to calculate the $B_c \to \eta_c$ transition form factor $f_+^{B_c \to \eta_c}(q^2)$. At the maximum recoil region, we obtain $f_+^{B_c \to \eta_c}(0) = 0.612^{+0.053}_{-0.052}$. After further extrapolating the TFF $f_+^{B_c \to \eta_c}(q^2)$ to its allowable $q^2$ region, we predict the branching ratio for the semi-leptonic decay $B_c \to \eta_c l \nu$. We obtain ${\cal B}(B_c \to \eta_c l \nu)=\left(7.70^{+1.65}_{-1.48}\right) \times 10^{-3}$ for massless leptons, which is consistent with the LCSRs estimation obtained in the literature.
hep-ph/9909421
Hubert Spiesberger
H. Spiesberger
Beyond the Standard Model at HERA
13 pages, 7 eps-figures included. Lecture notes to appear in the proceedings of the Ringberg Workshop 'New Trends in HERA Physics 1999'
null
null
MZ-TH/99-39
hep-ph
null
The prospects of physics beyond the standard model in deep inelastic scattering are reviewed, emphasizing the search for contact interactions, for leptoquarks and for supersymmetry with R-parity violation. R-parity violating supersymmetry is explored as a speculative source of events with high energy muons and missing transverse momentum, but no convincing explanation for events of this type observed at H1 is found.
[ { "created": "Fri, 17 Sep 1999 14:53:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Spiesberger", "H.", "" ] ]
The prospects of physics beyond the standard model in deep inelastic scattering are reviewed, emphasizing the search for contact interactions, for leptoquarks and for supersymmetry with R-parity violation. R-parity violating supersymmetry is explored as a speculative source of events with high energy muons and missing transverse momentum, but no convincing explanation for events of this type observed at H1 is found.
2011.13397
Yizhuang Liu
Xiangdong Ji, Yizhuang Liu, Andreas Sch\"afer, Feng Yuan
Single Transverse-Spin Asymmetry and Sivers Function in Large Momentum Effective Theory
12 pages, 6 figures
Phys. Rev. D 103, 074005 (2021)
10.1103/PhysRevD.103.074005
null
hep-ph hep-ex hep-lat nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
We apply recent developments in large momentum effective theory (LaMET) to formulate a non-perturbative calculation of the single-transverse spin asymmetry in terms of the quasi transverse-momentum-dependent quark distribution functions from the so-called Sivers mechanism. When the spin asymmetry is defined as the ratio of the quark Sivers function over the spin averaged distribution, it can be directly calculated in terms of the relevant quasi distributions with the soft functions and perturbative matching kernels cancelling out. Apart from the general formula presented, we have verified the result in the small transverse distance limit at one-loop order, which reduces to a collinear expansion at twist-three level.
[ { "created": "Thu, 26 Nov 2020 17:24:28 GMT", "version": "v1" } ]
2021-04-14
[ [ "Ji", "Xiangdong", "" ], [ "Liu", "Yizhuang", "" ], [ "Schäfer", "Andreas", "" ], [ "Yuan", "Feng", "" ] ]
We apply recent developments in large momentum effective theory (LaMET) to formulate a non-perturbative calculation of the single-transverse spin asymmetry in terms of the quasi transverse-momentum-dependent quark distribution functions from the so-called Sivers mechanism. When the spin asymmetry is defined as the ratio of the quark Sivers function over the spin averaged distribution, it can be directly calculated in terms of the relevant quasi distributions with the soft functions and perturbative matching kernels cancelling out. Apart from the general formula presented, we have verified the result in the small transverse distance limit at one-loop order, which reduces to a collinear expansion at twist-three level.
2306.17830
Simone Blasi
Simone Blasi, Alberto Mariotti, A\"aron Rase, Alexander Sevrin
Axionic domain walls at Pulsar Timing Arrays: QCD bias and particle friction
15 pages, 4 figures
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent results from the Pulsar Timing Array (PTA) collaborations show the first evidence for the detection of a stochastic background of gravitational waves at the nHz frequencies. This discovery has profound implications for the physics of both the late and the early Universe. In fact, together with the possible interpretation in terms of super massive black hole binaries, many sources in the early Universe can provide viable explanations as well. In this paper, we study the gravitational wave background sourced by a network of axion-like-particle (ALP) domain walls at temperatures around the QCD crossover, where the QCD-induced potential provides the necessary bias to annihilate the network. Remarkably, this implies a peak amplitude at frequencies around the sensitivity range of PTAs. We extend previous analysis by taking into account the unavoidable friction on the network stemming from the topological coupling of the ALP to QCD in terms of gluon and pion reflection off the domain walls at high and low temperatures, respectively. We identify the regions of parameter space where the network annihilates in the scaling regime ensuring compatibility with the PTA results, as well as those where friction can be important and a more detailed study around the QCD crossover is required.
[ { "created": "Fri, 30 Jun 2023 17:50:20 GMT", "version": "v1" } ]
2023-07-03
[ [ "Blasi", "Simone", "" ], [ "Mariotti", "Alberto", "" ], [ "Rase", "Aäron", "" ], [ "Sevrin", "Alexander", "" ] ]
The recent results from the Pulsar Timing Array (PTA) collaborations show the first evidence for the detection of a stochastic background of gravitational waves at the nHz frequencies. This discovery has profound implications for the physics of both the late and the early Universe. In fact, together with the possible interpretation in terms of super massive black hole binaries, many sources in the early Universe can provide viable explanations as well. In this paper, we study the gravitational wave background sourced by a network of axion-like-particle (ALP) domain walls at temperatures around the QCD crossover, where the QCD-induced potential provides the necessary bias to annihilate the network. Remarkably, this implies a peak amplitude at frequencies around the sensitivity range of PTAs. We extend previous analysis by taking into account the unavoidable friction on the network stemming from the topological coupling of the ALP to QCD in terms of gluon and pion reflection off the domain walls at high and low temperatures, respectively. We identify the regions of parameter space where the network annihilates in the scaling regime ensuring compatibility with the PTA results, as well as those where friction can be important and a more detailed study around the QCD crossover is required.
hep-ph/9903349
Jie Jie Zhu
Jie-Jie Zhu, Mu-Lin Yan (USTC)
Covariant amplitudes for mesons
30 pages, RevTeX, 3 eps figures
null
null
null
hep-ph hep-ex
null
We show how to construct covariant amplitudes for processes involving higher spins in this paper. First we give the explicit expressions of Rarita-Schwinger wave functions and propagators for bosons with spins, then kinematic singularity free 3-leg effective vertexes are derived and given in a list. Equivalence relations are worked out to get these independent vertexes. Constraints of space reflection symmetry and boson symmetry are considered and shown in a explicit way. Some helicity amplitudes for two-body decays in center of frame are calculated. Finally the covariant helicity amplitudes for the process $a_1\to \pi^+\pi^+\pi^-$ are constructed to illustrate how to include background (1PI) amplitudes. Both background amplitudes and resonance amplitudes are needed to give reliable descriptions to high energy reactions.
[ { "created": "Mon, 15 Mar 1999 02:12:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zhu", "Jie-Jie", "", "USTC" ], [ "Yan", "Mu-Lin", "", "USTC" ] ]
We show how to construct covariant amplitudes for processes involving higher spins in this paper. First we give the explicit expressions of Rarita-Schwinger wave functions and propagators for bosons with spins, then kinematic singularity free 3-leg effective vertexes are derived and given in a list. Equivalence relations are worked out to get these independent vertexes. Constraints of space reflection symmetry and boson symmetry are considered and shown in a explicit way. Some helicity amplitudes for two-body decays in center of frame are calculated. Finally the covariant helicity amplitudes for the process $a_1\to \pi^+\pi^+\pi^-$ are constructed to illustrate how to include background (1PI) amplitudes. Both background amplitudes and resonance amplitudes are needed to give reliable descriptions to high energy reactions.
1106.1734
Brian Feldstein
Jason Evans, Brian Feldstein, William Klemm, Hitoshi Murayama and Tsutomu T. Yanagida
Hermitian Flavor Violation
18 pages, 3 figures
Phys.Lett.B703:599-605,2011
10.1016/j.physletb.2011.08.059
IPMU11-0067
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The fundamental constraint on two Higgs doublet models comes from the requirement of sufficiently suppressing flavor-changing neutral currents. There are various standard approaches for dealing with this problem, but they all tend to share a common feature; all of the Higgs doublets couple very weakly to the first generation quarks. Here we consider a simple two Higgs doublet model which is able to have large couplings to the first generation, while also being safe from flavor constraints. We assume only that there is an SU(3)_f flavor symmetry which is respected by the couplings of one of the Higgs doublets, and which is broken by Hermitian Yukawa couplings of the second doublet. As a result of the large permitted couplings to the first generation quarks, this scenario may be used to address the excess in W+dijet events recently observed by CDF at the Tevatron. Moreover, Hermitian Yukawa coupling matrices arise naturally in a broad class of solutions to the strong CP problem, providing a compelling context for the model.
[ { "created": "Thu, 9 Jun 2011 08:12:42 GMT", "version": "v1" } ]
2011-09-13
[ [ "Evans", "Jason", "" ], [ "Feldstein", "Brian", "" ], [ "Klemm", "William", "" ], [ "Murayama", "Hitoshi", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
The fundamental constraint on two Higgs doublet models comes from the requirement of sufficiently suppressing flavor-changing neutral currents. There are various standard approaches for dealing with this problem, but they all tend to share a common feature; all of the Higgs doublets couple very weakly to the first generation quarks. Here we consider a simple two Higgs doublet model which is able to have large couplings to the first generation, while also being safe from flavor constraints. We assume only that there is an SU(3)_f flavor symmetry which is respected by the couplings of one of the Higgs doublets, and which is broken by Hermitian Yukawa couplings of the second doublet. As a result of the large permitted couplings to the first generation quarks, this scenario may be used to address the excess in W+dijet events recently observed by CDF at the Tevatron. Moreover, Hermitian Yukawa coupling matrices arise naturally in a broad class of solutions to the strong CP problem, providing a compelling context for the model.
hep-ph/9712517
Evgeny Levin
E.Gotsman, E. levin and U.Maor (Tel Aviv Univ.)
The $F_2$ slope and shadowing corrections in DIS
Latex file 10 pp, figs in eps files
Phys.Lett.B425:369-374,1998
10.1016/S0370-2693(98)00230-5
TAUP 2471/97
hep-ph
null
Recent HERA low $Q^2$ data show that the logarithmic slope of the protonstructure function ($\frac{\partial F_2}{\partial \ln Q^2}$) is significantly different from perturbative QCD expectations for smallvalues of $Q^2$ at exeedingly small values of $x$. We show that shadowing (screening) corrections provide a natural explanation for this experimental observation.
[ { "created": "Wed, 24 Dec 1997 08:21:02 GMT", "version": "v1" } ]
2019-08-17
[ [ "Gotsman", "E.", "", "Tel Aviv Univ." ], [ "levin", "E.", "", "Tel Aviv Univ." ], [ "Maor", "U.", "", "Tel Aviv Univ." ] ]
Recent HERA low $Q^2$ data show that the logarithmic slope of the protonstructure function ($\frac{\partial F_2}{\partial \ln Q^2}$) is significantly different from perturbative QCD expectations for smallvalues of $Q^2$ at exeedingly small values of $x$. We show that shadowing (screening) corrections provide a natural explanation for this experimental observation.
1107.0649
Dilip Kumar Ghosh
Dilip Kumar Ghosh, Manas Maity, Sourov Roy
R parity violating supersymmetric explanation for the CDF Wjj excess
4 pages, 2 ps figures, revtex4, typos corrected, one new reference added, version to appear in PRD
Phys.Rev.D84:035022,2011
10.1103/PhysRevD.84.035022
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently CDF has reported a 4.1 sigma excess in the distribution of the dijet invariant mass between 120-160 GeV in Wjj event sample in 7.3 fb^{-1} of data, which has generated considerable interest. We offer a possible explanation of this observation in the general framework of MSSM with R-parity violation through resonance production of tau sneutrino decaying into the LSP stau_1 and W boson. We also give the predictions of this scenario for the LHC operating at 7 TeV center of mass energy.
[ { "created": "Mon, 4 Jul 2011 15:06:59 GMT", "version": "v1" }, { "created": "Fri, 19 Aug 2011 08:07:38 GMT", "version": "v2" } ]
2011-09-14
[ [ "Ghosh", "Dilip Kumar", "" ], [ "Maity", "Manas", "" ], [ "Roy", "Sourov", "" ] ]
Recently CDF has reported a 4.1 sigma excess in the distribution of the dijet invariant mass between 120-160 GeV in Wjj event sample in 7.3 fb^{-1} of data, which has generated considerable interest. We offer a possible explanation of this observation in the general framework of MSSM with R-parity violation through resonance production of tau sneutrino decaying into the LSP stau_1 and W boson. We also give the predictions of this scenario for the LHC operating at 7 TeV center of mass energy.
2104.10709
Jia Zhou
Michael J. Ramsey-Musolf and Jiang-Hao Yu and Jia Zhou
Probing Extended Scalar Sectors with Precision $e^+e^-\to Zh$ and Higgs Diphoton Studies
43 pages, 11 figures; v3: major revision requested by editor
null
10.1007/JHEP10(2021)155
ACFI-T21-01
hep-ph
http://creativecommons.org/licenses/by/4.0/
We compute the one-loop corrections to $\sigma(e^+ e^- \to Z h)$ arising from representative extended Standard Model scalar sector scenarios. According to the new scalar $\mathrm{SU(2)_L}$ representations, we consider the inert doublet, real and complex triplet, quintuplet, and septuplet models. With the sub-percent level precision expected for prospective future $e+e-$ collider measurements of $\sigma(e^+ e^- \to Z h)$, studies of the Higgsstrahlung process will probe extended scalar sector particle spectrum and interactions in a manner complementary to direct searches at the Large Hadron Collider and possible future $pp$ colliders. We also compare with the sensitivity of future Higgs diphoton decay rate measurements. We find that the $\sigma(e^+ e^- \to Z h)$ and $\Gamma(h\to\gamma\gamma)$ complementarity is particularly pronounced for the complex triplet model.
[ { "created": "Wed, 21 Apr 2021 18:16:53 GMT", "version": "v1" }, { "created": "Mon, 7 Jun 2021 16:27:47 GMT", "version": "v2" }, { "created": "Tue, 7 Sep 2021 18:34:44 GMT", "version": "v3" } ]
2021-11-03
[ [ "Ramsey-Musolf", "Michael J.", "" ], [ "Yu", "Jiang-Hao", "" ], [ "Zhou", "Jia", "" ] ]
We compute the one-loop corrections to $\sigma(e^+ e^- \to Z h)$ arising from representative extended Standard Model scalar sector scenarios. According to the new scalar $\mathrm{SU(2)_L}$ representations, we consider the inert doublet, real and complex triplet, quintuplet, and septuplet models. With the sub-percent level precision expected for prospective future $e+e-$ collider measurements of $\sigma(e^+ e^- \to Z h)$, studies of the Higgsstrahlung process will probe extended scalar sector particle spectrum and interactions in a manner complementary to direct searches at the Large Hadron Collider and possible future $pp$ colliders. We also compare with the sensitivity of future Higgs diphoton decay rate measurements. We find that the $\sigma(e^+ e^- \to Z h)$ and $\Gamma(h\to\gamma\gamma)$ complementarity is particularly pronounced for the complex triplet model.
1205.5555
Jessica Goodman
Linda M. Carpenter and Jessica Goodman
Pseudo-Higgs Signals a the LHC
6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider general fermi-phobic scenarios in which excess events in diphoton or WW/ZZ resonances may be seen at LHC. These Higgs like signals do not necessarily suggest that the new resonance is a particle with Yukawa couplings nor do we know that it is responsible for electroweak symmetry breaking. We can, however, extract two facts from it, this particle couples to pairs of SU(2) and U(1) gauge bosons and it must be a scalar, pseudoscalar, or tensor. We consider the signals of general operators up to effective dimension 5 in which a new scalar, psuedo-scalar, or tensor particle may couple to pairs of standard model gauge bosons. This particle may or may not be charged under the standard model gauge groups, and may be produced via gluon fusion or EW vector boson fusion.
[ { "created": "Thu, 24 May 2012 20:00:03 GMT", "version": "v1" } ]
2015-03-20
[ [ "Carpenter", "Linda M.", "" ], [ "Goodman", "Jessica", "" ] ]
We consider general fermi-phobic scenarios in which excess events in diphoton or WW/ZZ resonances may be seen at LHC. These Higgs like signals do not necessarily suggest that the new resonance is a particle with Yukawa couplings nor do we know that it is responsible for electroweak symmetry breaking. We can, however, extract two facts from it, this particle couples to pairs of SU(2) and U(1) gauge bosons and it must be a scalar, pseudoscalar, or tensor. We consider the signals of general operators up to effective dimension 5 in which a new scalar, psuedo-scalar, or tensor particle may couple to pairs of standard model gauge bosons. This particle may or may not be charged under the standard model gauge groups, and may be produced via gluon fusion or EW vector boson fusion.
hep-ph/0509021
Gouranga Nayak
Gouranga C. Nayak (SUNY, Stony Brook), Jian-Wei Qiu (Iowa State U.), George Sterman (SUNY, Stony Brook)
Fragmentation, NRQCD and NNLO Factorization Analysis in Heavy Quarkonium Production
53 pages latex, 37 eps files, version to appear in Phys. Rev. D
Phys.Rev.D72:114012,2005
10.1103/PhysRevD.72.114012
YITP-SB-05-26
hep-ph nucl-th
null
We discuss heavy quarkonium production through parton fragmentation, including a review of arguments for the factorization of high-p_T particles into fragmentation functions for hadronic initial states. We investigate the further factorization of fragmentation functions in the NRQCD formalism, and argue that this requires a modification of NRQCD octet production matrix elements to include nonabelian phases, which makes them gauge invariant. We describe the calculation of uncanceled infrared divergences in fragmentation functions that must be factorized at NNLO, and verify that they are absorbed into the new, gauge invariant matrix elements.
[ { "created": "Fri, 2 Sep 2005 20:28:55 GMT", "version": "v1" }, { "created": "Wed, 30 Nov 2005 22:02:38 GMT", "version": "v2" } ]
2012-07-30
[ [ "Nayak", "Gouranga C.", "", "SUNY, Stony Brook" ], [ "Qiu", "Jian-Wei", "", "Iowa State U." ], [ "Sterman", "George", "", "SUNY, Stony Brook" ] ]
We discuss heavy quarkonium production through parton fragmentation, including a review of arguments for the factorization of high-p_T particles into fragmentation functions for hadronic initial states. We investigate the further factorization of fragmentation functions in the NRQCD formalism, and argue that this requires a modification of NRQCD octet production matrix elements to include nonabelian phases, which makes them gauge invariant. We describe the calculation of uncanceled infrared divergences in fragmentation functions that must be factorized at NNLO, and verify that they are absorbed into the new, gauge invariant matrix elements.
hep-ph/9408251
null
F. Hautmann
Next-to-Leading Corrections at Small X from Quark Evolution
8 pages (+ 3 figures not included, available from the author), Latex, Cavendish-HEP-94/08
null
null
null
hep-ph
null
Deep inelastic processes at small x are discussed in the framework of perturbative QCD at high energy. New results are presented on the quark anomalous dimensions beyond the leading logarithmic approximation, and their relevance to the structure functions being measured at HERA is pointed out. *Talk given at the XXIX Rencontres de Moriond, 19-26 March 1994, Meribel, France, to appear in the Proceedings.
[ { "created": "Mon, 8 Aug 1994 13:39:25 GMT", "version": "v1" } ]
2009-09-25
[ [ "Hautmann", "F.", "" ] ]
Deep inelastic processes at small x are discussed in the framework of perturbative QCD at high energy. New results are presented on the quark anomalous dimensions beyond the leading logarithmic approximation, and their relevance to the structure functions being measured at HERA is pointed out. *Talk given at the XXIX Rencontres de Moriond, 19-26 March 1994, Meribel, France, to appear in the Proceedings.
hep-ph/9612272
Steven Abel
S.A.Abel
CP in R-parity Violating Models
11 pages requires axodraw.sty (included). Error corrected and comments added. Final version - to appear in Phys.Lett.B
Phys.Lett. B410 (1997) 173-180
10.1016/S0370-2693(97)01034-4
ULB-TH-96/21
hep-ph
null
It is shown that in R-parity violating models of supersymmetry, the CP violation observed in the kaon system could arise purely from the R-parity violating scalar interactions (A-terms), with no CP violation in the CKM matrix. The direct CP violating parameter, epsilon', could be as large or larger than that expected in the Standard Model. CP violation in the B system however is expected to be negligible.
[ { "created": "Fri, 6 Dec 1996 10:59:35 GMT", "version": "v1" }, { "created": "Mon, 13 Jan 1997 17:32:59 GMT", "version": "v2" }, { "created": "Tue, 14 Jan 1997 09:33:49 GMT", "version": "v3" }, { "created": "Tue, 19 Aug 1997 10:38:50 GMT", "version": "v4" } ]
2009-10-30
[ [ "Abel", "S. A.", "" ] ]
It is shown that in R-parity violating models of supersymmetry, the CP violation observed in the kaon system could arise purely from the R-parity violating scalar interactions (A-terms), with no CP violation in the CKM matrix. The direct CP violating parameter, epsilon', could be as large or larger than that expected in the Standard Model. CP violation in the B system however is expected to be negligible.
2207.10021
Malcolm Fairbairn
Ahmad Alachkar, John Ellis and Malcolm Fairbairn
Dark Matter Constraints from the Eccentric Supermassive Black Hole Binary OJ 287
Matches version accepted for publication
null
10.1103/PhysRevD.107.103033
KCL-PH-TH/2022-40, CERN-TH-2022-115
hep-ph astro-ph.HE gr-qc
http://creativecommons.org/licenses/by/4.0/
OJ 287 is a blazar thought to be a binary system containing a ~ 18 billion solar mass primary black hole accompanied by a ~ 150 million solar mass secondary black hole in an eccentric orbit, which triggers electromagnetic flares twice in every ~ 12 year orbital period when it traverses the accretion disk of the primary. The times of these emissions are consistent with the predictions of general relativity calculated to the 4.5th post-Newtonian order. The orbit of the secondary black hole samples the gravitational field at distances between O(10) and O(50) Schwarzschild radii around the primary, and hence is sensitive to the possible presence of a dark matter spike around it. We find that the agreement of general-relativistic calculations with the measured timings of flares from OJ 287 constrains the mass of such a spike to < 3% of the primary mass.
[ { "created": "Tue, 12 Jul 2022 16:44:56 GMT", "version": "v1" }, { "created": "Mon, 17 Apr 2023 15:38:16 GMT", "version": "v2" } ]
2023-05-31
[ [ "Alachkar", "Ahmad", "" ], [ "Ellis", "John", "" ], [ "Fairbairn", "Malcolm", "" ] ]
OJ 287 is a blazar thought to be a binary system containing a ~ 18 billion solar mass primary black hole accompanied by a ~ 150 million solar mass secondary black hole in an eccentric orbit, which triggers electromagnetic flares twice in every ~ 12 year orbital period when it traverses the accretion disk of the primary. The times of these emissions are consistent with the predictions of general relativity calculated to the 4.5th post-Newtonian order. The orbit of the secondary black hole samples the gravitational field at distances between O(10) and O(50) Schwarzschild radii around the primary, and hence is sensitive to the possible presence of a dark matter spike around it. We find that the agreement of general-relativistic calculations with the measured timings of flares from OJ 287 constrains the mass of such a spike to < 3% of the primary mass.
hep-ph/0010188
Blazenka Melic
J.G. Koerner and B. Melic
Exclusive and Inclusive Semileptonic Lambda_b-Decays
Talk given by J.G. Koerner at 4th International Conference on Hyperons, Charm and Beauty Hadrons, Valencia, Spain, 27-30 Jun 2000; 7 pages
Nucl.Phys.Proc.Suppl. 93 (2000) 13-17
10.1016/S0920-5632(00)01049-5
MZ-TH/00-43, IRB-TH-11/00
hep-ph
null
In this talk we present theoretical evidence that the exclusive/inclusive ratio of semileptonic Lambda_b-decays exceeds that of semileptonic B-decays, where the experimental exclusive/inclusive ratio amounts to about 66%. We start from the observation that the spectator quark model provides a lower bound on the leading order Isgur-Wise function of the Lambda_b -> Lambda_c transition in terms of the corresponding B -> D,D^* mesonic Isgur-Wise function. Using experimental data for the B -> D,D^* mesonic Isgur-Wise functions this bound is established. Applying a QCD sum rule estimate of the Lambda_b -> Lambda_c transition form factor which satisfy the spectator quark model bound we predict the exclusive/inclusive ratio of semileptonic Lambda_b decay rates to lie in a range between 0.81 and 0.89. We also provide an upper bound on the baryonic Isgur-Wise function which is determined from the requirement that the exclusive rate should not exceed the inclusive rate. Our pre-Osaka results are discussed in the light of new recent preliminary experimental results on the pertinent mesonic and baryonic form factors presented at the Osaka ICHEP 2000 Conference.
[ { "created": "Tue, 17 Oct 2000 15:03:01 GMT", "version": "v1" } ]
2009-10-31
[ [ "Koerner", "J. G.", "" ], [ "Melic", "B.", "" ] ]
In this talk we present theoretical evidence that the exclusive/inclusive ratio of semileptonic Lambda_b-decays exceeds that of semileptonic B-decays, where the experimental exclusive/inclusive ratio amounts to about 66%. We start from the observation that the spectator quark model provides a lower bound on the leading order Isgur-Wise function of the Lambda_b -> Lambda_c transition in terms of the corresponding B -> D,D^* mesonic Isgur-Wise function. Using experimental data for the B -> D,D^* mesonic Isgur-Wise functions this bound is established. Applying a QCD sum rule estimate of the Lambda_b -> Lambda_c transition form factor which satisfy the spectator quark model bound we predict the exclusive/inclusive ratio of semileptonic Lambda_b decay rates to lie in a range between 0.81 and 0.89. We also provide an upper bound on the baryonic Isgur-Wise function which is determined from the requirement that the exclusive rate should not exceed the inclusive rate. Our pre-Osaka results are discussed in the light of new recent preliminary experimental results on the pertinent mesonic and baryonic form factors presented at the Osaka ICHEP 2000 Conference.
2306.02540
Jaseer Ahmed
Jaseer Ahmed, P. G. Blunden, W. Melnitchouk
Normal single-spin asymmetries in electron-proton scattering: two-photon exchange with intermediate state resonances
31 pages, 7 figures, 3 tables
null
null
JLAB-THY-23-3835, ADP-23-15/T1224
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the beam ($B_n$) and target ($A_n$) normal single-spin asymmetries in electron-proton elastic scattering from two-photon exchange amplitudes with resonance intermediate states of spin-parity $1/2^\pm$ and $3/2^\pm$ and mass $W \lesssim 1.8$ GeV. The latest CLAS exclusive meson electroproduction data are used as input for the transition amplitudes from the proton to the excited resonance states. For $B_n$, the spin 3/2 resonances dominate by an order of magnitude over the spin 1/2 states. In general we observe cancellations between the negative contributions of the $\Delta(1232)$ and $N(1520)$ across both beam energy and scattering angle, and the positive contributions of the $\Delta(1700)$ and $N(1720)$, leading to a rather large overall uncertainty band in the total $B_n$. At forward angles and beam energies $E_\textrm{lab}<1$ GeV, where the $\Delta(1232)$ dominates, the calculated $B_n$ tend to overshoot the A4 and SAMPLE data. The calculated $B_n$ compare well with the measured values from the A4 and $Q_{\textrm{weak}}$ experiments with $E_\textrm{lab}>1$ GeV.
[ { "created": "Mon, 5 Jun 2023 02:20:56 GMT", "version": "v1" } ]
2023-06-06
[ [ "Ahmed", "Jaseer", "" ], [ "Blunden", "P. G.", "" ], [ "Melnitchouk", "W.", "" ] ]
We calculate the beam ($B_n$) and target ($A_n$) normal single-spin asymmetries in electron-proton elastic scattering from two-photon exchange amplitudes with resonance intermediate states of spin-parity $1/2^\pm$ and $3/2^\pm$ and mass $W \lesssim 1.8$ GeV. The latest CLAS exclusive meson electroproduction data are used as input for the transition amplitudes from the proton to the excited resonance states. For $B_n$, the spin 3/2 resonances dominate by an order of magnitude over the spin 1/2 states. In general we observe cancellations between the negative contributions of the $\Delta(1232)$ and $N(1520)$ across both beam energy and scattering angle, and the positive contributions of the $\Delta(1700)$ and $N(1720)$, leading to a rather large overall uncertainty band in the total $B_n$. At forward angles and beam energies $E_\textrm{lab}<1$ GeV, where the $\Delta(1232)$ dominates, the calculated $B_n$ tend to overshoot the A4 and SAMPLE data. The calculated $B_n$ compare well with the measured values from the A4 and $Q_{\textrm{weak}}$ experiments with $E_\textrm{lab}>1$ GeV.
hep-ph/9710470
Sunil Mukhi
Sunil Mukhi (Tata Institute of Fundamental Research, Mumbai)
Recent Developments in String Theory: A Brief Review for Particle Physicists
harvmac, 15 pages (b), two eps figures, Based on a talk delivered at the XII DAE Symposium on High-Energy Physics, Guwahati, December 1996
null
null
TIFR/TH/97-55
hep-ph
null
At the present time, string theory (and its generalizations) remain relatively abstruse subjects to the particle phenomenologist and experimentalist. Yet, striking developments of the last two years offer hope that a fundamental non-perturbative formulation of this theory will be found, and that this formulation will permit us to make contact with supersymmetric standard-model physics. This article is based on a talk which attempted to convey the essence of these recent developments in string theory, in a non-technical manner, to an audience of particle theorists, phenomenologists and experimentalists.
[ { "created": "Mon, 27 Oct 1997 06:02:34 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mukhi", "Sunil", "", "Tata Institute of Fundamental Research, Mumbai" ] ]
At the present time, string theory (and its generalizations) remain relatively abstruse subjects to the particle phenomenologist and experimentalist. Yet, striking developments of the last two years offer hope that a fundamental non-perturbative formulation of this theory will be found, and that this formulation will permit us to make contact with supersymmetric standard-model physics. This article is based on a talk which attempted to convey the essence of these recent developments in string theory, in a non-technical manner, to an audience of particle theorists, phenomenologists and experimentalists.
1205.3683
Alexander Korchin
Alexander Yu. Korchin, Vladimir A. Kovalchuk
Contribution of vector resonances to the {\bar B}_d^0 -> {\bar K}^{*0} mu^+ mu^- decay
12 pages, 4 figures, SVJour3 style; introduction and discussion sections extended, references added; version accepted for publication in Eur. Phys. J. C. arXiv admin note: substantial text overlap with arXiv:1111.4093
Eur. Phys. J. C 72 (2012) 2155
10.1140/epjc/s10052-012-2155-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The fully differential angular distribution for the rare flavor-changing neutral current decay \bar{B}_d^0 -> \bar{K}^{*0} (-> K- pi+) mu+ mu- is studied. The emphasis is placed on accurate treatment of the contribution from the processes \bar{B}_d^0 -> \bar{K}^{*0} (-> K- pi+) V with intermediate vector resonances V = rho(770), omega(782), phi(1020), J/psi, psi(2S), ... decaying into the mu+ mu- pair. The dilepton invariant-mass dependence of the branching ratio, longitudinal polarization fraction f_L of the \bar{K}^{*0} meson, and forward-backward asymmetry A_{FB} is calculated and compared with data from Belle, CDF and LHCb. It is shown that inclusion of the resonance contribution may considerably modify the branching ratio, calculated in the SM without resonances, even in the invariant-mass region far from the so-called charmonia cuts applied in the experimental analyses. This conclusion crucially depends on values of the unknown phases of the B^0 -> K^{*0} J/psi and B^0 -> K^{*0} psi(2S) decay amplitudes with zero helicity.
[ { "created": "Wed, 16 May 2012 14:08:31 GMT", "version": "v1" }, { "created": "Thu, 6 Sep 2012 05:42:25 GMT", "version": "v2" } ]
2012-10-03
[ [ "Korchin", "Alexander Yu.", "" ], [ "Kovalchuk", "Vladimir A.", "" ] ]
The fully differential angular distribution for the rare flavor-changing neutral current decay \bar{B}_d^0 -> \bar{K}^{*0} (-> K- pi+) mu+ mu- is studied. The emphasis is placed on accurate treatment of the contribution from the processes \bar{B}_d^0 -> \bar{K}^{*0} (-> K- pi+) V with intermediate vector resonances V = rho(770), omega(782), phi(1020), J/psi, psi(2S), ... decaying into the mu+ mu- pair. The dilepton invariant-mass dependence of the branching ratio, longitudinal polarization fraction f_L of the \bar{K}^{*0} meson, and forward-backward asymmetry A_{FB} is calculated and compared with data from Belle, CDF and LHCb. It is shown that inclusion of the resonance contribution may considerably modify the branching ratio, calculated in the SM without resonances, even in the invariant-mass region far from the so-called charmonia cuts applied in the experimental analyses. This conclusion crucially depends on values of the unknown phases of the B^0 -> K^{*0} J/psi and B^0 -> K^{*0} psi(2S) decay amplitudes with zero helicity.
2112.08912
Philipp Schicho
Joonas Hirvonen, Johan L\"ofgren, Michael J. Ramsey-Musolf, Philipp Schicho and Tuomas V. I. Tenkanen
Computing the gauge-invariant bubble nucleation rate in finite temperature effective field theory
64 pages, 3 figures, 2 tables; v2: Journal version, added figures 1 and 2, extended sections 1 and 3.4
null
10.1007/JHEP07(2022)135
ACFI-T21-16, HIP-2021-45/TH, NORDITA 2021-111
hep-ph
http://creativecommons.org/licenses/by/4.0/
A gauge-invariant framework for computing bubble nucleation rates at finite temperature in the presence of radiative barriers was presented and advocated for model-building and phenomenological studies in an accompanying article arXiv:2112.05472. Here, we detail this computation using the Abelian Higgs Model as an illustrative example. Subsequently, we recast this approach in the dimensionally-reduced high-temperature effective field theory for nucleation. This allows for including several higher order thermal resummations and furthermore delineate clearly the approach's limits of validity. This approach provides for robust perturbative treatments of bubble nucleation during possible first-order cosmic phase transitions, with implications for electroweak baryogenesis and production of a stochastic gravitational wave background. Furthermore, it yields a sound comparison between results of perturbative and non-perturbative computations.
[ { "created": "Thu, 16 Dec 2021 14:27:38 GMT", "version": "v1" }, { "created": "Thu, 28 Jul 2022 14:16:22 GMT", "version": "v2" } ]
2022-08-10
[ [ "Hirvonen", "Joonas", "" ], [ "Löfgren", "Johan", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Schicho", "Philipp", "" ], [ "Tenkanen", "Tuomas V. I.", "" ] ]
A gauge-invariant framework for computing bubble nucleation rates at finite temperature in the presence of radiative barriers was presented and advocated for model-building and phenomenological studies in an accompanying article arXiv:2112.05472. Here, we detail this computation using the Abelian Higgs Model as an illustrative example. Subsequently, we recast this approach in the dimensionally-reduced high-temperature effective field theory for nucleation. This allows for including several higher order thermal resummations and furthermore delineate clearly the approach's limits of validity. This approach provides for robust perturbative treatments of bubble nucleation during possible first-order cosmic phase transitions, with implications for electroweak baryogenesis and production of a stochastic gravitational wave background. Furthermore, it yields a sound comparison between results of perturbative and non-perturbative computations.
hep-ph/9310374
null
D. Comelli, A. Masiero, M. Pietroni and A. Riotto
Spontaneous Breaking of R parity in the Minimal Supersymmetric Standard Model Revisited
10 pages, DFPD 93/TH/68, UTS-DFT-93-27, SISSA 93/168/A preprints, 2 figures available upon e-mail request
Phys.Lett. B324 (1994) 397-402
10.1016/0370-2693(94)90212-7
null
hep-ph
null
We reconsider the possibility of spontaneous breaking of $R$ parity in the Minimal Supersymmetric Standard Model. By a renormalization group analysis we find the parameter space in which a sneutrino gets a vacuum expectation value, leading to the spontaneous breaking of the lepton number and to the appearance of a phenomenologically unacceptable massless Goldstone boson. We then analyze the effect of operators giving rise to a tiny amount of explicit violation of lepton number, which could emerge as remnants of physics at some superheavy (Planck or GUT) scale in the low energy effective theory. We show that the conspiracy between the spontaneous and the explicit breaking scales can provide a mass to the Goldstone boson larger than the ${\rm Z}^0$ boson mass, hence allowing for a non vanishing sneutrino vacuum expectation value without increasing the invisible width of the ${\rm Z}^0$.
[ { "created": "Fri, 29 Oct 1993 15:36:16 GMT", "version": "v1" } ]
2009-10-22
[ [ "Comelli", "D.", "" ], [ "Masiero", "A.", "" ], [ "Pietroni", "M.", "" ], [ "Riotto", "A.", "" ] ]
We reconsider the possibility of spontaneous breaking of $R$ parity in the Minimal Supersymmetric Standard Model. By a renormalization group analysis we find the parameter space in which a sneutrino gets a vacuum expectation value, leading to the spontaneous breaking of the lepton number and to the appearance of a phenomenologically unacceptable massless Goldstone boson. We then analyze the effect of operators giving rise to a tiny amount of explicit violation of lepton number, which could emerge as remnants of physics at some superheavy (Planck or GUT) scale in the low energy effective theory. We show that the conspiracy between the spontaneous and the explicit breaking scales can provide a mass to the Goldstone boson larger than the ${\rm Z}^0$ boson mass, hence allowing for a non vanishing sneutrino vacuum expectation value without increasing the invisible width of the ${\rm Z}^0$.
hep-ph/9704389
Mihir P. Worah
Mihir P. Worah
Supersymmetric Baryogenesis and Flavor Physics
PRL version. Suppression factor explicitly identified below Eq. 5. More references added. Minor cosmetic changes in discussions. All results unchanged
Phys.Rev.Lett. 79 (1997) 3810-3813
10.1103/PhysRevLett.79.3810
SLAC-PUB-7476
hep-ph
null
We study the flavor physics implications of baryogenesis in the Minimal Supersymmetric Standard Model. Enhanced $B-\bar B$ mixing and $b \to s \gamma$ rates are generic to all scenarios. Depending on the origin of the CP violating phase responsible for baryogenesis there could be a large neutron electric dipole moment, large CP violating $D-\bar D$ mixing or CP violation in top quark production. We discuss how the combination of these measurements with the requirement of baryogenesis shed light on the MSSM parameter space and the source of CP violation.
[ { "created": "Wed, 23 Apr 1997 22:27:51 GMT", "version": "v1" }, { "created": "Fri, 19 Sep 1997 18:57:27 GMT", "version": "v2" } ]
2009-10-30
[ [ "Worah", "Mihir P.", "" ] ]
We study the flavor physics implications of baryogenesis in the Minimal Supersymmetric Standard Model. Enhanced $B-\bar B$ mixing and $b \to s \gamma$ rates are generic to all scenarios. Depending on the origin of the CP violating phase responsible for baryogenesis there could be a large neutron electric dipole moment, large CP violating $D-\bar D$ mixing or CP violation in top quark production. We discuss how the combination of these measurements with the requirement of baryogenesis shed light on the MSSM parameter space and the source of CP violation.
hep-ph/9611202
ChangMoh kim
Seung Woo Ham, Sun Kun Oh, and Bjong Ro Kim
The gauge boson contributions to the radiatively corrected mass of the scalar Higgs boson in the minimal supersymmetric standard model
10 pages (2 figures are included)
null
null
KKUCC-96
hep-ph
null
We derive analytic formulas for the radiatively corrected mass of the scalar Higgs boson in the framework of the minimal supersymmetric standard model (MSSM). Since the scalar-top-quark mass in our analysis include terms proportional to the gauge couplings in the 1-loop effective potential, the radiatively corrected mass of the scalar Higgs boson partially contains the gauge boson contributions. At the 1-loop level, the upper bound on the lighter scalar Higgs boson mass can be increased about 20 GeV in favor of the partial contributions of the gauge bosons. Thus the improved absolute upper bound on the lighter scalar Higgs boson mass is about 150 GeV.
[ { "created": "Fri, 1 Nov 1996 08:01:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ham", "Seung Woo", "" ], [ "Oh", "Sun Kun", "" ], [ "Kim", "Bjong Ro", "" ] ]
We derive analytic formulas for the radiatively corrected mass of the scalar Higgs boson in the framework of the minimal supersymmetric standard model (MSSM). Since the scalar-top-quark mass in our analysis include terms proportional to the gauge couplings in the 1-loop effective potential, the radiatively corrected mass of the scalar Higgs boson partially contains the gauge boson contributions. At the 1-loop level, the upper bound on the lighter scalar Higgs boson mass can be increased about 20 GeV in favor of the partial contributions of the gauge bosons. Thus the improved absolute upper bound on the lighter scalar Higgs boson mass is about 150 GeV.
1601.03386
Yu-Jie Zhang Dr.
Guang-Zhi Xu, Yue Qiu, Cheng-Ping Shen, and Yu-Jie Zhang
$B^*_{s,d} \to \mu^+ \mu^-$ and its impact on $B_{s,d} \to \mu^+ \mu^-$
Comments and suggestions are welcome
null
10.1140/epjc/s10052-016-4423-z
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
The decay of $B^*_{s,d} \to \mu^+ \mu^-$~ and its impact on $B_{s,d} \to \mu^+ \mu^-$ is studied here. The $ \mu^+ \mu^-$ decay widths of vector mesons $B^*_{s,d}$ are about a factor of 700 larger than the corresponding scalar mesons $B_{s,d}$. The obtained ratio of the branching fractions $Br({B_{s,d}^*\to \mu^+\mu^-})/{Br({B_{s,d}\to\mu^+\mu^-})}$ is about $\frac{0.3 \times {\rm eV}}{{\Gamma(B^*_{s,d} \to B_{s,d} \gamma)}}$. At the same time, the hadronic contribution $B_{s,d} \to B^*_{s,d} \gamma \to \mu^+ \mu^-$ is estimated too. The relative increase of the amplitude of $B_{s,d}\to \mu^+\mu^-$ is about $(0.01\pm 0.006) \sqrt{\frac{{\Gamma(B^*_{s,d} \to B_{s,d} \gamma)}}{{100~ {\rm eV}}}}$. If we choose $\Gamma(B^*_{s,d} \to B_{s,d} \gamma)=2~$eV, the branching fractions of the vector mesons to lepton pair are $(6.2 \pm 0.6) \times 10^{-10}$ and $(1.7 \pm 0.2) \times 10^{-11}$ for $B^*_{s}$ and $B^*_{d}$ respectively. If we choose $\Gamma(B^*_{s,d} \to B_{s,d} \gamma)=200~$eV, the updated branching fractions of the scalar mesons to muon pair are $(3.78 \pm 0.25)\times 10^{-9}$ and $(1.09 \pm 0.09)\times 10^{-10}$ for $B_{s}$ and $B_{d}$ respectively. Further studies on $B^*_{s,d}$ are usefully here, including dielectron decay, two-body decay with $J/\psi$, and so on.
[ { "created": "Mon, 21 Dec 2015 23:08:42 GMT", "version": "v1" }, { "created": "Tue, 23 Feb 2016 20:56:28 GMT", "version": "v2" } ]
2016-11-23
[ [ "Xu", "Guang-Zhi", "" ], [ "Qiu", "Yue", "" ], [ "Shen", "Cheng-Ping", "" ], [ "Zhang", "Yu-Jie", "" ] ]
The decay of $B^*_{s,d} \to \mu^+ \mu^-$~ and its impact on $B_{s,d} \to \mu^+ \mu^-$ is studied here. The $ \mu^+ \mu^-$ decay widths of vector mesons $B^*_{s,d}$ are about a factor of 700 larger than the corresponding scalar mesons $B_{s,d}$. The obtained ratio of the branching fractions $Br({B_{s,d}^*\to \mu^+\mu^-})/{Br({B_{s,d}\to\mu^+\mu^-})}$ is about $\frac{0.3 \times {\rm eV}}{{\Gamma(B^*_{s,d} \to B_{s,d} \gamma)}}$. At the same time, the hadronic contribution $B_{s,d} \to B^*_{s,d} \gamma \to \mu^+ \mu^-$ is estimated too. The relative increase of the amplitude of $B_{s,d}\to \mu^+\mu^-$ is about $(0.01\pm 0.006) \sqrt{\frac{{\Gamma(B^*_{s,d} \to B_{s,d} \gamma)}}{{100~ {\rm eV}}}}$. If we choose $\Gamma(B^*_{s,d} \to B_{s,d} \gamma)=2~$eV, the branching fractions of the vector mesons to lepton pair are $(6.2 \pm 0.6) \times 10^{-10}$ and $(1.7 \pm 0.2) \times 10^{-11}$ for $B^*_{s}$ and $B^*_{d}$ respectively. If we choose $\Gamma(B^*_{s,d} \to B_{s,d} \gamma)=200~$eV, the updated branching fractions of the scalar mesons to muon pair are $(3.78 \pm 0.25)\times 10^{-9}$ and $(1.09 \pm 0.09)\times 10^{-10}$ for $B_{s}$ and $B_{d}$ respectively. Further studies on $B^*_{s,d}$ are usefully here, including dielectron decay, two-body decay with $J/\psi$, and so on.
hep-ph/9505232
Chi-Yee Cheung
Chi-Yee Cheung, Wei-Min Zhang, and Guey-lin Lin
Light-Front Heavy Quark Effective Theory and Heavy Meson Bound States
23 pages, Revtex, no figures
Phys.Rev. D52 (1995) 2915-2925
10.1103/PhysRevD.52.2915
IP-ASTP-05-95
hep-ph
null
The heavy quark effective theory is developed on the light-front. Based on this effective theory, a light-front heavy meson bound state with definite spin and parity is constructed. Within the effective theory, the Isgur-Wise function is derived in terms of the asymptotic light-front bound state amplitudes in the limit $m_Q\rightarrow\infty$; the result is a general expression for arbitrary recoil velocities. With the asymptotic form of the BSW amplitudes, the Isgur-Wise function is given by $\xi(v\cdot v')=1/v\cdot v'$. The slope at the zero-recoil point is $\rho^2=-\xi'(1)=1$, in excellent agreement with the recent CLEO result of $\rho^2=1.01\pm0.15\pm0.09$.
[ { "created": "Thu, 4 May 1995 14:41:07 GMT", "version": "v1" } ]
2009-10-28
[ [ "Cheung", "Chi-Yee", "" ], [ "Zhang", "Wei-Min", "" ], [ "Lin", "Guey-lin", "" ] ]
The heavy quark effective theory is developed on the light-front. Based on this effective theory, a light-front heavy meson bound state with definite spin and parity is constructed. Within the effective theory, the Isgur-Wise function is derived in terms of the asymptotic light-front bound state amplitudes in the limit $m_Q\rightarrow\infty$; the result is a general expression for arbitrary recoil velocities. With the asymptotic form of the BSW amplitudes, the Isgur-Wise function is given by $\xi(v\cdot v')=1/v\cdot v'$. The slope at the zero-recoil point is $\rho^2=-\xi'(1)=1$, in excellent agreement with the recent CLEO result of $\rho^2=1.01\pm0.15\pm0.09$.
2110.08017
Emmet Byrne
Emmet P. Byrne
Logarithmic corrections for jet production at the LHC
Proceedings of 50th International Symposium on Multiparticle Dynamics (ISMD2021)
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Several important processes and analyses at the LHC are sensitive to higher-order perturbative corrections beyond what can currently be calculated at fixed order. One important class of logarithmic corrections are those which appear when the centre-of-mass energy of a QCD collision is much larger than the transverse momenta of the observed jets. We describe the High Energy Jets (HEJ) framework, which includes the dominant high-energy logarithms to provide all-order predictions for several LHC processes including Higgs, $W$, or $Z$ boson production in association with jets. We will summarise some recent developments, in particular the first matching of HEJ to a NLO calculation.
[ { "created": "Fri, 15 Oct 2021 11:27:33 GMT", "version": "v1" }, { "created": "Thu, 3 Feb 2022 11:03:19 GMT", "version": "v2" } ]
2022-02-04
[ [ "Byrne", "Emmet P.", "" ] ]
Several important processes and analyses at the LHC are sensitive to higher-order perturbative corrections beyond what can currently be calculated at fixed order. One important class of logarithmic corrections are those which appear when the centre-of-mass energy of a QCD collision is much larger than the transverse momenta of the observed jets. We describe the High Energy Jets (HEJ) framework, which includes the dominant high-energy logarithms to provide all-order predictions for several LHC processes including Higgs, $W$, or $Z$ boson production in association with jets. We will summarise some recent developments, in particular the first matching of HEJ to a NLO calculation.
2306.16449
Zachary Polonsky
Jason Aebischer, Marko Pesut, Zachary Polonsky
Renormalization scheme factorization of one-loop Fierz identities
28 pages, 2 figures Updated to match published version
null
10.1007/JHEP01(2024)060
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a proof of the factorization of renormalization scheme in one-loop-corrected Fierz identities. This scheme factorization facilitates the simultaneous transformation of operator basis and renormalization scheme using only relations between physical operators; the evanescent operators in the respective bases may be chosen entirely independently of each other. The relations between evanescent operators in the two bases is automatically accounted for by the corrected Fierz identities. We illustrate the utility of this result with a two-loop anomalous dimension matrix computation using the Naive-Dimensional Regularization scheme, which is then transformed via one-loop Fierz identities to the known result in the literature given in a different basis and calculated in the Larin scheme. Additionally, we reproduce results from the literature of basis transformations involving the rotation of evanescent operators into the physical basis using our method, without the need to explicitly compute one-loop matrix elements of evanescent operators.
[ { "created": "Wed, 28 Jun 2023 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 11 Jun 2024 11:48:19 GMT", "version": "v2" } ]
2024-06-12
[ [ "Aebischer", "Jason", "" ], [ "Pesut", "Marko", "" ], [ "Polonsky", "Zachary", "" ] ]
We present a proof of the factorization of renormalization scheme in one-loop-corrected Fierz identities. This scheme factorization facilitates the simultaneous transformation of operator basis and renormalization scheme using only relations between physical operators; the evanescent operators in the respective bases may be chosen entirely independently of each other. The relations between evanescent operators in the two bases is automatically accounted for by the corrected Fierz identities. We illustrate the utility of this result with a two-loop anomalous dimension matrix computation using the Naive-Dimensional Regularization scheme, which is then transformed via one-loop Fierz identities to the known result in the literature given in a different basis and calculated in the Larin scheme. Additionally, we reproduce results from the literature of basis transformations involving the rotation of evanescent operators into the physical basis using our method, without the need to explicitly compute one-loop matrix elements of evanescent operators.
1706.01071
Sibo Zheng
Sibo Zheng
Effective Higgs Theories in Supersymmetric Grand Unification
9 pages, references added
Eur. Phys. J. C77 (2017) 588
10.1140/epjc/s10052-017-5174-1
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The effective Higgs theories at the TeV scale in supersymmetric $SU(5)$ grand unification models are systematically derived. Restricted to extensions on $\mathbf{5}_{H}$ containing the Higgs sector we show that only two types of real (vector-like) models and one type of chiral model are found to be consistent with perturbative grand unification. While the chiral model has been excluded by the LHC data, the fate of perturbative unification will be uniquely determined by the two classes of vector-like models.
[ { "created": "Sun, 4 Jun 2017 13:24:53 GMT", "version": "v1" }, { "created": "Fri, 25 Aug 2017 11:38:13 GMT", "version": "v2" } ]
2017-09-08
[ [ "Zheng", "Sibo", "" ] ]
The effective Higgs theories at the TeV scale in supersymmetric $SU(5)$ grand unification models are systematically derived. Restricted to extensions on $\mathbf{5}_{H}$ containing the Higgs sector we show that only two types of real (vector-like) models and one type of chiral model are found to be consistent with perturbative grand unification. While the chiral model has been excluded by the LHC data, the fate of perturbative unification will be uniquely determined by the two classes of vector-like models.
2105.13869
Felix Karbstein
Felix Karbstein, Chantal Sundqvist, Kai S. Schulze, Ingo Uschmann, Holger Gies, Gerhard G. Paulus
Vacuum birefringence at x-ray free-electron lasers
26 pages, 2 figures; matches journal version
New J. Phys. 23 095001(2021)
10.1088/1367-2630/ac1df4
null
hep-ph physics.optics quant-ph
http://creativecommons.org/licenses/by/4.0/
We study the perspectives of measuring the phenomenon of vacuum birefringence predicted by quantum electrodynamics using an x-ray free-electron laser (XFEL) alone. We devise an experimental scheme allowing the XFEL beam to collide with itself under a finite angle, and thus act as both pump and probe field for the effect. The signature of vacuum birefringence is encoded in polarization-flipped signal photons to be detected with high-purity x-ray polarimetry. Our findings for idealized scenarios underline that the discovery potential of solely XFEL-based setups can be comparable to those involving optical high-intensity lasers. For currently achievable scenarios, we identify several key details of the x-ray optical ingredients that exert a strong influence on the magnitude of the desired signatures.
[ { "created": "Fri, 28 May 2021 14:25:50 GMT", "version": "v1" }, { "created": "Sat, 21 Aug 2021 12:16:32 GMT", "version": "v2" } ]
2021-09-02
[ [ "Karbstein", "Felix", "" ], [ "Sundqvist", "Chantal", "" ], [ "Schulze", "Kai S.", "" ], [ "Uschmann", "Ingo", "" ], [ "Gies", "Holger", "" ], [ "Paulus", "Gerhard G.", "" ] ]
We study the perspectives of measuring the phenomenon of vacuum birefringence predicted by quantum electrodynamics using an x-ray free-electron laser (XFEL) alone. We devise an experimental scheme allowing the XFEL beam to collide with itself under a finite angle, and thus act as both pump and probe field for the effect. The signature of vacuum birefringence is encoded in polarization-flipped signal photons to be detected with high-purity x-ray polarimetry. Our findings for idealized scenarios underline that the discovery potential of solely XFEL-based setups can be comparable to those involving optical high-intensity lasers. For currently achievable scenarios, we identify several key details of the x-ray optical ingredients that exert a strong influence on the magnitude of the desired signatures.
1708.08503
Jared Evans
Jared A. Evans
Detecting Hidden Particles with MATHUSLA
5 pages, 4 figures; References added, minor changes
Phys. Rev. D 97, 055046 (2018)
10.1103/PhysRevD.97.055046
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A hidden sector containing light long-lived particles provides a well-motivated place to find new physics. The recently proposed MATHUSLA experiment has the potential to be extremely sensitive to light particles originating from rare meson decays in the very long lifetime region. In this work, we illustrate this strength with the specific example of a light scalar mixed with the standard model-like Higgs boson, a model where MATHUSLA can further probe unexplored parameter space from exotic Higgs decays. Design augmentations should be considered in order to maximize the ability of MATHUSLA to discover very light hidden sector particles.
[ { "created": "Mon, 28 Aug 2017 19:49:11 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2017 20:23:06 GMT", "version": "v2" } ]
2018-04-04
[ [ "Evans", "Jared A.", "" ] ]
A hidden sector containing light long-lived particles provides a well-motivated place to find new physics. The recently proposed MATHUSLA experiment has the potential to be extremely sensitive to light particles originating from rare meson decays in the very long lifetime region. In this work, we illustrate this strength with the specific example of a light scalar mixed with the standard model-like Higgs boson, a model where MATHUSLA can further probe unexplored parameter space from exotic Higgs decays. Design augmentations should be considered in order to maximize the ability of MATHUSLA to discover very light hidden sector particles.
hep-ph/9703215
Janusz Gluza
J. Gluza (Un. of Silesia), J. Maalampi (Un. of Helsinki), M. Raidal (Un. of Valencia and IFIC) and M. Zralek (Un. of Silesia)
Heavy neutrino mixing and single production at Linear Collider
latex, 14 pages, 4 ps files
Phys.Lett. B407 (1997) 45-52
10.1016/S0370-2693(97)00713-2
TP-USL/97/15, FTUV/96-24
hep-ph
null
We study the single production of heavy neutrinos via the processes $e^-e^+ \to \nu N$ and $e^-\gamma \to W^- N$ at future linear colliders. As a base of our considerations we take a wide class of models, both with vanishing and non-vanishing left-handed Majorana neutrino mass matrix $m_L$. We perform a model independent analyses of the existing experimental data and find connections between the characteristic of heavy neutrinos (masses, mixings, CP eigenvalues) and the $m_L$ parameters. We show that with the present experimental constraints heavy neutrino masses almost up to the collision energy can be tested in the future experiments.
[ { "created": "Mon, 3 Mar 1997 09:48:44 GMT", "version": "v1" } ]
2016-09-06
[ [ "Gluza", "J.", "", "Un. of Silesia" ], [ "Maalampi", "J.", "", "Un. of Helsinki" ], [ "Raidal", "M.", "", "Un. of Valencia and IFIC" ], [ "Zralek", "M.", "", "Un. of Silesia" ] ]
We study the single production of heavy neutrinos via the processes $e^-e^+ \to \nu N$ and $e^-\gamma \to W^- N$ at future linear colliders. As a base of our considerations we take a wide class of models, both with vanishing and non-vanishing left-handed Majorana neutrino mass matrix $m_L$. We perform a model independent analyses of the existing experimental data and find connections between the characteristic of heavy neutrinos (masses, mixings, CP eigenvalues) and the $m_L$ parameters. We show that with the present experimental constraints heavy neutrino masses almost up to the collision energy can be tested in the future experiments.
1708.00912
Valerio Bertone Dr
Valerio Bertone
The photon PDF from high-mass Drell-Yan data at the LHC
8 pages, 6 figures, Proceedings of the PHOTON'17 workshop
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present a determination of the photon PDF from a fit to the recent ATLAS measurements of high-mass Drell-Yan lepton-pair production at $\sqrt{s} = 8$ TeV. This analysis is based on the {\tt xFitter} framework interfaced to the {\tt APFEL} program, that accounts for NLO QED effects, and to the {\tt aMCfast} code to account for the photon-initiated contributions within {\tt MadGraph5\_aMC@NLO}. The result is compared with other recent determinations of the photon PDF finding a general good agreement.
[ { "created": "Wed, 2 Aug 2017 20:00:18 GMT", "version": "v1" } ]
2017-08-04
[ [ "Bertone", "Valerio", "" ] ]
I present a determination of the photon PDF from a fit to the recent ATLAS measurements of high-mass Drell-Yan lepton-pair production at $\sqrt{s} = 8$ TeV. This analysis is based on the {\tt xFitter} framework interfaced to the {\tt APFEL} program, that accounts for NLO QED effects, and to the {\tt aMCfast} code to account for the photon-initiated contributions within {\tt MadGraph5\_aMC@NLO}. The result is compared with other recent determinations of the photon PDF finding a general good agreement.
1605.07192
Simone Alioli
Simone Alioli, Christian W. Bauer, Sam Guns and Frank J. Tackmann
Underlying event sensitive observables in Drell-Yan production using GENEVA
23 pages, 11 figures. v3: version accepted by EPJC
Eur.Phys.J. C76 (2016) no.11, 614
10.1140/epjc/s10052-016-4458-1
null
hep-ph hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
We present an extension of the GENEVA Monte Carlo framework to include multiple parton interactions (MPI) provided by PYTHIA8. This allows us to obtain predictions for underlying-event sensitive measurements in Drell-Yan production, in conjunction with GENEVA's fully-differential NNLO calculation, NNLL' resummation for the 0-jet resolution variable (beam thrust), and NLL resummation for the 1-jet resolution variable. We describe the interface with the parton shower algorithm and MPI model of PYTHIA8, which preserves both the precision of partonic N-jet cross sections in GENEVA as well as the shower accuracy and good description of soft hadronic physics of PYTHIA8. We present results for several underlying-event sensitive observables and compare to data from ATLAS and CMS as well as to standalone PYTHIA8 predictions. This includes a comparison with the recent ATLAS measurement of the beam thrust spectrum, which provides a potential avenue to fully disentangle the physical effects from the primary hard interaction, primary soft radiation, multiple parton interactions, and nonperturbative hadronization.
[ { "created": "Mon, 23 May 2016 20:00:17 GMT", "version": "v1" }, { "created": "Tue, 13 Sep 2016 16:47:37 GMT", "version": "v2" }, { "created": "Tue, 14 Mar 2017 17:12:21 GMT", "version": "v3" } ]
2017-03-16
[ [ "Alioli", "Simone", "" ], [ "Bauer", "Christian W.", "" ], [ "Guns", "Sam", "" ], [ "Tackmann", "Frank J.", "" ] ]
We present an extension of the GENEVA Monte Carlo framework to include multiple parton interactions (MPI) provided by PYTHIA8. This allows us to obtain predictions for underlying-event sensitive measurements in Drell-Yan production, in conjunction with GENEVA's fully-differential NNLO calculation, NNLL' resummation for the 0-jet resolution variable (beam thrust), and NLL resummation for the 1-jet resolution variable. We describe the interface with the parton shower algorithm and MPI model of PYTHIA8, which preserves both the precision of partonic N-jet cross sections in GENEVA as well as the shower accuracy and good description of soft hadronic physics of PYTHIA8. We present results for several underlying-event sensitive observables and compare to data from ATLAS and CMS as well as to standalone PYTHIA8 predictions. This includes a comparison with the recent ATLAS measurement of the beam thrust spectrum, which provides a potential avenue to fully disentangle the physical effects from the primary hard interaction, primary soft radiation, multiple parton interactions, and nonperturbative hadronization.
hep-ph/9502245
Joerg Schaldach
D.Diakonov, M.Polyakov, P.Sieber, J.Schaldach, K.Goeke
Sphaleron transitions in the Minimal Standard Model and the upper bound for the Higgs Mass
49 pages, 5 figures (uuencoded PostScript); fixing of the renormalization scale has been improved, numerics has been extended
Phys.Rev. D53 (1996) 3366-3391
10.1103/PhysRevD.53.3366
RUB-TPII-25/95
hep-ph
null
We calculate the dissipation of the baryon number after the electroweak phase transition due to thermal fluctuations above the sphaleron barrier. We consider not only the classical Boltzmann factor but also fermionic and bosonic one-loop contributions. We find that both bosonic and especially fermionic fluctuations can considerably suppress the transition rate. Assuming the Langer--Affleck formalism for this rate, the condition that an initial baryon asymmetry must not be washed out by sphaleron transitions leads, in the Minimal Standard Model ($\sin\theta_W=0$), to an upper bound for the Higgs mass in the range 60 to 75 GeV.
[ { "created": "Tue, 7 Feb 1995 15:33:01 GMT", "version": "v1" }, { "created": "Tue, 18 Jul 1995 12:42:27 GMT", "version": "v2" } ]
2009-10-28
[ [ "Diakonov", "D.", "" ], [ "Polyakov", "M.", "" ], [ "Sieber", "P.", "" ], [ "Schaldach", "J.", "" ], [ "Goeke", "K.", "" ] ]
We calculate the dissipation of the baryon number after the electroweak phase transition due to thermal fluctuations above the sphaleron barrier. We consider not only the classical Boltzmann factor but also fermionic and bosonic one-loop contributions. We find that both bosonic and especially fermionic fluctuations can considerably suppress the transition rate. Assuming the Langer--Affleck formalism for this rate, the condition that an initial baryon asymmetry must not be washed out by sphaleron transitions leads, in the Minimal Standard Model ($\sin\theta_W=0$), to an upper bound for the Higgs mass in the range 60 to 75 GeV.
2312.13952
Tulio Eduardo Restrepo Medina
Eduardo S. Fraga and Let\'icia F. Palhares and Tulio E. Restrepo
Cold and dense perturbative QCD in a very strong magnetic background
14 pages, 8 figures
Eduardo S. Fraga, Let\'icia F. Palhares, and Tulio E. Restrepo, Phys.Rev.D 109 (2024) 5, 054033
10.1103/PhysRevD.109.054033
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We compute the pressure from first principles within perturbative QCD at finite baryon density and very high magnetic fields up to two-loops and with physical quark masses. The region of validity for our framework is given by $m_s \ll \mu_q \ll \sqrt{eB}$, where $m_s$ is the strange quark mass, $\mu_q$ is the quark chemical potential, $e$ is the fundamental electric charge, and $B$ is the magnetic field strength. We include the effects of the renormalization scale in the running coupling, $\alpha_s (\mu_q,\sqrt{eB})$, and running strange quark mass. We also discuss the simplifications that come about in the chiral limit. The effectively negligible contribution of the exchange diagram allows for building a simple analytic model for the equation of state for pure quark magnetars and computing their mass and radius at very large values of $B$. These results provide constraints on the behavior of the maximum mass and associated radius from perturbative QCD. We also discuss the magnetic bag model for extreme magnetic fields.
[ { "created": "Thu, 21 Dec 2023 15:40:04 GMT", "version": "v1" }, { "created": "Thu, 28 Mar 2024 15:44:08 GMT", "version": "v2" } ]
2024-03-29
[ [ "Fraga", "Eduardo S.", "" ], [ "Palhares", "Letícia F.", "" ], [ "Restrepo", "Tulio E.", "" ] ]
We compute the pressure from first principles within perturbative QCD at finite baryon density and very high magnetic fields up to two-loops and with physical quark masses. The region of validity for our framework is given by $m_s \ll \mu_q \ll \sqrt{eB}$, where $m_s$ is the strange quark mass, $\mu_q$ is the quark chemical potential, $e$ is the fundamental electric charge, and $B$ is the magnetic field strength. We include the effects of the renormalization scale in the running coupling, $\alpha_s (\mu_q,\sqrt{eB})$, and running strange quark mass. We also discuss the simplifications that come about in the chiral limit. The effectively negligible contribution of the exchange diagram allows for building a simple analytic model for the equation of state for pure quark magnetars and computing their mass and radius at very large values of $B$. These results provide constraints on the behavior of the maximum mass and associated radius from perturbative QCD. We also discuss the magnetic bag model for extreme magnetic fields.
2205.12234
Paolo Cea
Paolo Cea
The Higgs condensate as a quantum liquid: Comparison with the full Run 2 CMS data
10 pages, 2 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare our proposal for an additional heavy Standard Model Higgs boson to the available full data set collected by the CMS detector during Run 2 at the Large Hadron Collider (LHC) corresponding to an integrated luminosity of 138 fb$^{-1}$. The CMS Collaboration performed a search for a high mass Higgs boson decaying into a pair of W bosons in the dileptonic channel. Our analysis of the CMS data indicated the presence of a broad excess in the mass range 600 GeV - 800 GeV with respect to the expected Standard Model background with a rather significative statistical significance. We found that our theoretical proposal is in reasonable agreement with the experimental observations.
[ { "created": "Tue, 24 May 2022 17:42:05 GMT", "version": "v1" } ]
2022-05-26
[ [ "Cea", "Paolo", "" ] ]
We compare our proposal for an additional heavy Standard Model Higgs boson to the available full data set collected by the CMS detector during Run 2 at the Large Hadron Collider (LHC) corresponding to an integrated luminosity of 138 fb$^{-1}$. The CMS Collaboration performed a search for a high mass Higgs boson decaying into a pair of W bosons in the dileptonic channel. Our analysis of the CMS data indicated the presence of a broad excess in the mass range 600 GeV - 800 GeV with respect to the expected Standard Model background with a rather significative statistical significance. We found that our theoretical proposal is in reasonable agreement with the experimental observations.
1503.05483
Steven D. Bass
Steven D. Bass
Vacuum energy and the cosmological constant
15 pages, Contributed paper to the Special Issue "Fundamental Constants in Physics and Their Time Variation" (Modern Physics Letters A, Guest Editor Joan Sol\`a)
Mod.Phys.Lett. A30 (2015) 1540033
10.1142/S0217732315400337
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The accelerating expansion of the Universe points to a small positive value for the cosmological constant or vacuum energy density. We discuss recent ideas that the cosmological constant plus LHC results might hint at critical phenomena near the Planck scale.
[ { "created": "Wed, 18 Mar 2015 16:47:03 GMT", "version": "v1" } ]
2015-07-09
[ [ "Bass", "Steven D.", "" ] ]
The accelerating expansion of the Universe points to a small positive value for the cosmological constant or vacuum energy density. We discuss recent ideas that the cosmological constant plus LHC results might hint at critical phenomena near the Planck scale.
1907.01416
Akira Watanabe
Akira Watanabe
Differential and total cross sections of high energy proton-proton scattering in holographic QCD
6 pages, 2 figures, prepared for the proceedings of the XXVII International Workshop on Deep Inelastic Scattering and Related Subjects (DIS2019), 8 - 12 April 2019, Torino, Italy
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The analysis on the high energy proton-proton scattering is presented, focusing on the Regge regime and considering the Pomeron exchange to describe the involved nonperturbative dynamics in the framework of holographic QCD. We combine the Reggeized spin-2 particle propagator and the proton gravitational form factor, which is obtained from the bottom-up AdS/QCD model, and calculate the differential and total cross sections. We explicitly demonstrate the comparison between our calculations and the currently available experimental data including the recent ones measured at $\sqrt{s} = 13$ TeV by the TOTEM collaboration at the LHC. It is shown that our results are consistent with the data, which implies that the present framework works in the considered TeV scale.
[ { "created": "Tue, 2 Jul 2019 14:52:20 GMT", "version": "v1" } ]
2019-07-03
[ [ "Watanabe", "Akira", "" ] ]
The analysis on the high energy proton-proton scattering is presented, focusing on the Regge regime and considering the Pomeron exchange to describe the involved nonperturbative dynamics in the framework of holographic QCD. We combine the Reggeized spin-2 particle propagator and the proton gravitational form factor, which is obtained from the bottom-up AdS/QCD model, and calculate the differential and total cross sections. We explicitly demonstrate the comparison between our calculations and the currently available experimental data including the recent ones measured at $\sqrt{s} = 13$ TeV by the TOTEM collaboration at the LHC. It is shown that our results are consistent with the data, which implies that the present framework works in the considered TeV scale.
1207.6642
Alexander Friedland
Alexander Friedland and Ian M. Shoemaker
Searching for Novel Neutrino Interactions at NOvA and Beyond in Light of Large theta_13
10 pages, 8 figures
null
null
LA-UR-12-22243
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the prospects of probing nonstandard interactions (NSI) of neutrinos in the e-tau sector with upcoming long-baseline nu_mu -> nu_e oscillation experiments. First conjectured decades ago, neutrino NSI remain of great interest, especially in light of the recent 8B solar neutrino measurements by SNO, Super-Kamiokande, and Borexino. We observe that the recent discovery of large theta_13 implies that long-baseline experiments have considerable NSI sensitivity, thanks to the interference of the standard and new physics conversion amplitudes. In particular, in some parts of NSI parameter space, the upcoming NOvA experiment will be sensitive enough to see ~ 3sigma deviations from the SM-only hypothesis. On the flip side, NSI introduce important ambiguities in interpreting NOvA results as measurements of CP-violation, the mass hierarchy and the octant of theta_23. In particular, observed CP violation could be due to a phase coming from NSI, rather than the vacuum Hamiltonian. The proposed LBNE experiment, with its longer ~ 1300 km baseline, may break many of these interpretative degeneracies.
[ { "created": "Fri, 27 Jul 2012 20:05:21 GMT", "version": "v1" } ]
2012-07-31
[ [ "Friedland", "Alexander", "" ], [ "Shoemaker", "Ian M.", "" ] ]
We examine the prospects of probing nonstandard interactions (NSI) of neutrinos in the e-tau sector with upcoming long-baseline nu_mu -> nu_e oscillation experiments. First conjectured decades ago, neutrino NSI remain of great interest, especially in light of the recent 8B solar neutrino measurements by SNO, Super-Kamiokande, and Borexino. We observe that the recent discovery of large theta_13 implies that long-baseline experiments have considerable NSI sensitivity, thanks to the interference of the standard and new physics conversion amplitudes. In particular, in some parts of NSI parameter space, the upcoming NOvA experiment will be sensitive enough to see ~ 3sigma deviations from the SM-only hypothesis. On the flip side, NSI introduce important ambiguities in interpreting NOvA results as measurements of CP-violation, the mass hierarchy and the octant of theta_23. In particular, observed CP violation could be due to a phase coming from NSI, rather than the vacuum Hamiltonian. The proposed LBNE experiment, with its longer ~ 1300 km baseline, may break many of these interpretative degeneracies.
hep-ph/0108103
Matthias Neubert
Matthias Neubert, Alexey A. Petrov (Cornell University)
Comments on Color-Suppressed Hadronic B Decays
9 pages, 2 figures
Phys.Lett. B519 (2001) 50-56
10.1016/S0370-2693(01)01093-0
CLNS 01/1753
hep-ph
null
Recent experimental results on the color-suppressed nonleptonic decays B^0 -> D^{(*)0} pi^0 provide evidence for a failure of the naive factorization model and for sizeable relative strong-interaction phases between class-1 and class-2 B -> D^(*) pi decay amplitudes. The allowed regions for the corresponding ratios of (complex) isospin amplitudes and a_2/a_1 parameters are determined. The results are interpreted in the context of QCD factorization for the related class-1 amplitudes in the heavy-quark limit.
[ { "created": "Fri, 10 Aug 2001 20:15:23 GMT", "version": "v1" } ]
2009-11-07
[ [ "Neubert", "Matthias", "", "Cornell University" ], [ "Petrov", "Alexey A.", "", "Cornell University" ] ]
Recent experimental results on the color-suppressed nonleptonic decays B^0 -> D^{(*)0} pi^0 provide evidence for a failure of the naive factorization model and for sizeable relative strong-interaction phases between class-1 and class-2 B -> D^(*) pi decay amplitudes. The allowed regions for the corresponding ratios of (complex) isospin amplitudes and a_2/a_1 parameters are determined. The results are interpreted in the context of QCD factorization for the related class-1 amplitudes in the heavy-quark limit.
0905.3056
Stefano Morisi
M.Hirsch, S.Morisi, J.W.F.Valle
A4-based tri-bimaximal mixing within inverse and linear seesaw schemes
8 pages, 3 figures. Experimental references added and figure 1 updated
Phys.Lett.B679:454-459,2009
10.1016/j.physletb.2009.08.003
IFIC/09-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider tri-bimaximal lepton mixing within low-scale seesaw schemes where light neutrino masses arise from TeV scale physics, potentially accessible at the Large Hadron Collider (LHC). Two examples are considered, based on the A4 flavor symmetry realized within the inverse or the linear seesaw mechanisms. Both are highly predictive so that in both the light neutrino sector effectively depends only on three mass parameters and one Majorana phase, with no CP violation in neutrino oscillations. We find that the linear seesaw leads to a lower bound for neutrinoless double beta decay while the inverse seesaw does not. The models also lead to potentially sizeable decay rates for lepton flavor violating processes, tightly related by the assumed flavor symmetry.
[ { "created": "Tue, 19 May 2009 12:32:35 GMT", "version": "v1" }, { "created": "Wed, 20 May 2009 13:11:24 GMT", "version": "v2" } ]
2010-05-28
[ [ "Hirsch", "M.", "" ], [ "Morisi", "S.", "" ], [ "Valle", "J. W. F.", "" ] ]
We consider tri-bimaximal lepton mixing within low-scale seesaw schemes where light neutrino masses arise from TeV scale physics, potentially accessible at the Large Hadron Collider (LHC). Two examples are considered, based on the A4 flavor symmetry realized within the inverse or the linear seesaw mechanisms. Both are highly predictive so that in both the light neutrino sector effectively depends only on three mass parameters and one Majorana phase, with no CP violation in neutrino oscillations. We find that the linear seesaw leads to a lower bound for neutrinoless double beta decay while the inverse seesaw does not. The models also lead to potentially sizeable decay rates for lepton flavor violating processes, tightly related by the assumed flavor symmetry.
1305.5739
Stefano Bertolini
Stefano Bertolini, Alessio Maiezza, Fabrizio Nesti
K to \pi\pi\ hadronic matrix elements of left-right current-current operators
Minor text changes. To appear on Phys. Rev. D
null
10.1103/PhysRevD.88.034014
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective \Delta S=1 four fermion operators involving left- and right-handed currents are relevant in left-right gauge extensions of the standard model and scalar extension of the Yukawa sector. They induce K to \pi\pi\ decays which are strictly constrained by experimental data, typically resulting in strong bounds on the new physics scales or parameters. We evaluate the K to \pi\pi\ hadronic matrix elements of such operators within the phenomenological framework of the Chiral Quark Model. The results are consistent with the estimates used in a previous work on TeV scale left-right symmetry, thus confirming the conclusions obtained there.
[ { "created": "Fri, 24 May 2013 14:02:41 GMT", "version": "v1" }, { "created": "Mon, 5 Aug 2013 12:12:25 GMT", "version": "v2" } ]
2015-06-16
[ [ "Bertolini", "Stefano", "" ], [ "Maiezza", "Alessio", "" ], [ "Nesti", "Fabrizio", "" ] ]
Effective \Delta S=1 four fermion operators involving left- and right-handed currents are relevant in left-right gauge extensions of the standard model and scalar extension of the Yukawa sector. They induce K to \pi\pi\ decays which are strictly constrained by experimental data, typically resulting in strong bounds on the new physics scales or parameters. We evaluate the K to \pi\pi\ hadronic matrix elements of such operators within the phenomenological framework of the Chiral Quark Model. The results are consistent with the estimates used in a previous work on TeV scale left-right symmetry, thus confirming the conclusions obtained there.
1908.00376
Dibyakrupa Sahoo
C. S. Kim, Youngjoon Kwon, Donghun Lee, Sechul Oh and Dibyakrupa Sahoo
Probing sterile neutrino in $B$ ($D$) meson decays at Belle II (BESIII)
9 pages, 6 figures. This is a pre-print of an article published in European Physical Journal C. The final authenticated version is available online at https://doi.org/10.1140/epjc/s10052-020-8310-2
Eur. Phys. J. C 80, no.8, 730 (2020)
10.1140/epjc/s10052-020-8310-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present, how a systematic study of $B \to D\ell N$ ($D \to K \ell N$) decays with $\ell=\mu,\tau$, at Belle II (BESIII) can provide unambiguous signature of a heavy neutrino $N$ and/or constrain its mixing with active neutrinos $\nu_\ell$, which is parameterized by $|U_{\ell N}|^2$. Our constraint on $|U_{\mu N}|^2$ that can be achieved from the full Belle II data is comparable with what can be obtained from the much larger data set of the upgraded LHCb. Additionally, our method offers better constraint on $|U_{\mu N}|^2$ for mass of sterile neutrino $m_N < 2$ GeV. We can also probe the Dirac and Majorana nature of $N$ by observing the sequential decay of $N$, including suppression from observation of a displaced vertex as well as helicity flip, for Majorana $N$.
[ { "created": "Thu, 1 Aug 2019 13:11:34 GMT", "version": "v1" }, { "created": "Tue, 18 Aug 2020 14:26:15 GMT", "version": "v2" } ]
2020-08-19
[ [ "Kim", "C. S.", "" ], [ "Kwon", "Youngjoon", "" ], [ "Lee", "Donghun", "" ], [ "Oh", "Sechul", "" ], [ "Sahoo", "Dibyakrupa", "" ] ]
We present, how a systematic study of $B \to D\ell N$ ($D \to K \ell N$) decays with $\ell=\mu,\tau$, at Belle II (BESIII) can provide unambiguous signature of a heavy neutrino $N$ and/or constrain its mixing with active neutrinos $\nu_\ell$, which is parameterized by $|U_{\ell N}|^2$. Our constraint on $|U_{\mu N}|^2$ that can be achieved from the full Belle II data is comparable with what can be obtained from the much larger data set of the upgraded LHCb. Additionally, our method offers better constraint on $|U_{\mu N}|^2$ for mass of sterile neutrino $m_N < 2$ GeV. We can also probe the Dirac and Majorana nature of $N$ by observing the sequential decay of $N$, including suppression from observation of a displaced vertex as well as helicity flip, for Majorana $N$.
1512.01766
Ren-You Zhang
Zhang Wen-Juan, Ma Wen-Gan, Zhang Ren-You, Li Xiao-Zhou, Guo Lei, and Chen Chong
Double Higgs boson production and decay in Randall-Sundrum model at hadron colliders
26 pages, 11 figures
Phys. Rev. D 92 (2015) 116005
10.1103/PhysRevD.92.116005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the double Higgs production and decay at the $14~ {\rm TeV}$ LHC and $33~ {\rm TeV}$ HE-LHC in both the standard model and Randall-Sundrum (RS) model. In our calculation we consider reasonably only the contribution of the lightest two Kaluza-Klein (KK) gravitons. We present the integrated cross sections and some kinematic distributions in both models. Our results show that the RS effect in the vicinities of $M_{HH} \sim M_{1}$, $M_{2}$ (the masses of the lightest two KK gravitons) or in the central Higgs rapidity region is quite significant, and can be extracted from the heavy SM background by imposing proper kinematic cuts on final particles. We also study the dependence of the cross section on the RS model parameters, the first KK graviton mass $M_1$ and the effective coupling $c_0$, and find that the RS effect is reduced obviously with the increment of $M_1$ or decrement of $c_0$.
[ { "created": "Sun, 6 Dec 2015 10:02:05 GMT", "version": "v1" }, { "created": "Mon, 7 Mar 2016 02:49:00 GMT", "version": "v2" } ]
2016-03-08
[ [ "Wen-Juan", "Zhang", "" ], [ "Wen-Gan", "Ma", "" ], [ "Ren-You", "Zhang", "" ], [ "Xiao-Zhou", "Li", "" ], [ "Lei", "Guo", "" ], [ "Chong", "Chen", "" ] ]
We investigate the double Higgs production and decay at the $14~ {\rm TeV}$ LHC and $33~ {\rm TeV}$ HE-LHC in both the standard model and Randall-Sundrum (RS) model. In our calculation we consider reasonably only the contribution of the lightest two Kaluza-Klein (KK) gravitons. We present the integrated cross sections and some kinematic distributions in both models. Our results show that the RS effect in the vicinities of $M_{HH} \sim M_{1}$, $M_{2}$ (the masses of the lightest two KK gravitons) or in the central Higgs rapidity region is quite significant, and can be extracted from the heavy SM background by imposing proper kinematic cuts on final particles. We also study the dependence of the cross section on the RS model parameters, the first KK graviton mass $M_1$ and the effective coupling $c_0$, and find that the RS effect is reduced obviously with the increment of $M_1$ or decrement of $c_0$.
1502.00034
Natsumi Nagata
Jason L. Evans, Natsumi Nagata, and Keith A. Olive
SU(5) Grand Unification in Pure Gravity Mediation
23 pages, 7 figures. Version accepted for publication in Physical Review D
Phys. Rev. D 91, 055027 (2015)
10.1103/PhysRevD.91.055027
FTPI-MINN-15/02, UMN-TH-3417/15, IPMU15-0011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the proton lifetime in pure gravity mediation models with non-universal Higgs soft masses. Pure gravity mediation offers a simple framework for studying SU(5) grand unified theories with a split supersymmetry like spectra. We find that for much of the parameter space gauge coupling unification is quite good leading to rather long lifetimes for the proton. However, for $m_{3/2}\sim 60$ TeV and $\tan\beta\sim 4$, for which gauge coupling unification is also good, the proton lifetime is short enough that it could be in reach of future experiments.
[ { "created": "Fri, 30 Jan 2015 22:19:10 GMT", "version": "v1" }, { "created": "Sat, 28 Mar 2015 01:11:26 GMT", "version": "v2" } ]
2015-04-01
[ [ "Evans", "Jason L.", "" ], [ "Nagata", "Natsumi", "" ], [ "Olive", "Keith A.", "" ] ]
We discuss the proton lifetime in pure gravity mediation models with non-universal Higgs soft masses. Pure gravity mediation offers a simple framework for studying SU(5) grand unified theories with a split supersymmetry like spectra. We find that for much of the parameter space gauge coupling unification is quite good leading to rather long lifetimes for the proton. However, for $m_{3/2}\sim 60$ TeV and $\tan\beta\sim 4$, for which gauge coupling unification is also good, the proton lifetime is short enough that it could be in reach of future experiments.
1808.01841
Raghunath Sahoo
Suman Deb, Dhananjaya Thakur, Sudipan De, and Raghunath Sahoo
Multiplicity Dependence of J/$\psi$ Production and QCD Dynamics in $p+p$ Collisions at $\sqrt{s}$ = 13 TeV
Same as published version
Eur. Phys. J. A (2020) 56:134
10.1140/epja/s10050-020-00138-4
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In inelastic $p+p$ collisions, the interacting objects are quarks and gluons (partons). It is believed that there are multiple interactions between the partons in a single $p+p$ event. Recent studies of multiplicity dependence of particle production in $p+p$ collisions have gathered considerable interest in the scientific community. According to several theoretical calculations, multiple gluon participation in hadronic collisions is the cause of high-multiplicity events. If the interaction is hard enough (large $p_{\rm T}$ transfer), the semi-hard processes of multiple interactions of partons might also lead to production of heavy particles like J/$\psi$. At the LHC, an approximately linear increase of the relative J/$\psi$ yield with charged particle multiplicity is observed in $p+p$ collisions. In the present work, we have studied the contribution of quarks and gluons to the multiplicity dependence of J/$\psi$ production using pQCD inspired event generator, PYTHIA8 tune 4C, in $p+p$ collisions at $\sqrt{s} =$13 TeV by investigating relative J/$\psi$ yield and relative $\langle p_{\rm T} \rangle$ of J/$\psi$ as a function of charged particle multiplicity for different hard-QCD processes. We have estimated a newly defined ratio, $r_{pp} = {\langle p_{\rm T}^{2} \rangle}_{i}/{\langle p_{\rm T}^{2} \rangle}_{\rm MB}$, to understand J/$\psi$ production in high-multiplicity $p+p$ collisions. For the first time we attempt to study the nuclear modification factor like observables ($R_{\rm pp}$ and $R_{\rm cp}$) to understand the QCD medium formed in high-multiplicity $p+p$ collisions.
[ { "created": "Mon, 6 Aug 2018 12:22:51 GMT", "version": "v1" }, { "created": "Wed, 20 May 2020 16:20:45 GMT", "version": "v2" } ]
2020-05-21
[ [ "Deb", "Suman", "" ], [ "Thakur", "Dhananjaya", "" ], [ "De", "Sudipan", "" ], [ "Sahoo", "Raghunath", "" ] ]
In inelastic $p+p$ collisions, the interacting objects are quarks and gluons (partons). It is believed that there are multiple interactions between the partons in a single $p+p$ event. Recent studies of multiplicity dependence of particle production in $p+p$ collisions have gathered considerable interest in the scientific community. According to several theoretical calculations, multiple gluon participation in hadronic collisions is the cause of high-multiplicity events. If the interaction is hard enough (large $p_{\rm T}$ transfer), the semi-hard processes of multiple interactions of partons might also lead to production of heavy particles like J/$\psi$. At the LHC, an approximately linear increase of the relative J/$\psi$ yield with charged particle multiplicity is observed in $p+p$ collisions. In the present work, we have studied the contribution of quarks and gluons to the multiplicity dependence of J/$\psi$ production using pQCD inspired event generator, PYTHIA8 tune 4C, in $p+p$ collisions at $\sqrt{s} =$13 TeV by investigating relative J/$\psi$ yield and relative $\langle p_{\rm T} \rangle$ of J/$\psi$ as a function of charged particle multiplicity for different hard-QCD processes. We have estimated a newly defined ratio, $r_{pp} = {\langle p_{\rm T}^{2} \rangle}_{i}/{\langle p_{\rm T}^{2} \rangle}_{\rm MB}$, to understand J/$\psi$ production in high-multiplicity $p+p$ collisions. For the first time we attempt to study the nuclear modification factor like observables ($R_{\rm pp}$ and $R_{\rm cp}$) to understand the QCD medium formed in high-multiplicity $p+p$ collisions.
hep-ph/0503111
Cristian Valenzuela
Cristian Valenzuela
Spontaneous CP Symmetry Breaking at the Electroweak Scale
25 pages, LaTeX. References and comment added
Phys.Rev. D71 (2005) 095014
10.1103/PhysRevD.71.095014
null
hep-ph
null
We present a top-condensation model in which the CP symmetry is spontaneously broken at the electroweak scale due to the condensation of two composite Higgs doublets. In particular the CP-violating phase of the CKM matrix is generated. A simpler model where only one quark family is included is also discussed. In this case, for a general four-fermion interaction ($G_{tb}\neq 0$), the particle spectrum is the one of the one Higgs doublet model.
[ { "created": "Fri, 11 Mar 2005 20:51:28 GMT", "version": "v1" }, { "created": "Tue, 7 Jun 2005 23:33:47 GMT", "version": "v2" }, { "created": "Tue, 14 Jun 2005 15:28:32 GMT", "version": "v3" } ]
2009-11-11
[ [ "Valenzuela", "Cristian", "" ] ]
We present a top-condensation model in which the CP symmetry is spontaneously broken at the electroweak scale due to the condensation of two composite Higgs doublets. In particular the CP-violating phase of the CKM matrix is generated. A simpler model where only one quark family is included is also discussed. In this case, for a general four-fermion interaction ($G_{tb}\neq 0$), the particle spectrum is the one of the one Higgs doublet model.
2005.14536
Henning Bahl
H. Bahl, P. Bechtle, S. Heinemeyer, S. Liebler, T. Stefaniak, G. Weiglein
HL-LHC and ILC sensitivities in the hunt for heavy Higgs bosons
42 pages, 15 figures (incl. 10 W\"ascheleinen-lots); matches version to be published in EPJC
null
10.1140/epjc/s10052-020-08472-z
BONN-TH 2019-04, DESY 19-093, KA-TP-09-2019, IFT-UAM/CSIC-19-075
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The prediction of additional Higgs bosons is one of the key features of physics beyond the Standard Model (SM) that gives rise to an extended Higgs sector. We assess the sensitivity of the Large Hadron Collider (LHC) in the high luminosity (HL) run alone and in combination with a possible future International Linear Collider (ILC) to probe heavy neutral Higgs bosons. We employ the Minimal Supersymmetric Standard Model (MSSM) as a framework and assume the light CP-even MSSM Higgs boson to be the Higgs boson observed at 125 GeV. We discuss the constraints on the MSSM parameter space arising from the precision measurements of the rates of the detected signal at 125 GeV and from direct searches for new heavy Higgs bosons in the $\tau^+\tau^-$, $b\bar{b}$ and di-Higgs ($hh$) final states. A new benchmark scenario for heavy Higgs searches in the $b\bar{b}$ channel is proposed in this context. For the future Higgs rate measurements at the HL-LHC and ILC two different scenarios are investigated, namely the case where the future rate measurements agree with the SM prediction and the case where the rates agree with the predictions of possible realizations of the MSSM Higgs sector in nature.
[ { "created": "Fri, 29 May 2020 12:40:58 GMT", "version": "v1" }, { "created": "Thu, 17 Sep 2020 12:16:14 GMT", "version": "v2" } ]
2020-10-28
[ [ "Bahl", "H.", "" ], [ "Bechtle", "P.", "" ], [ "Heinemeyer", "S.", "" ], [ "Liebler", "S.", "" ], [ "Stefaniak", "T.", "" ], [ "Weiglein", "G.", "" ] ]
The prediction of additional Higgs bosons is one of the key features of physics beyond the Standard Model (SM) that gives rise to an extended Higgs sector. We assess the sensitivity of the Large Hadron Collider (LHC) in the high luminosity (HL) run alone and in combination with a possible future International Linear Collider (ILC) to probe heavy neutral Higgs bosons. We employ the Minimal Supersymmetric Standard Model (MSSM) as a framework and assume the light CP-even MSSM Higgs boson to be the Higgs boson observed at 125 GeV. We discuss the constraints on the MSSM parameter space arising from the precision measurements of the rates of the detected signal at 125 GeV and from direct searches for new heavy Higgs bosons in the $\tau^+\tau^-$, $b\bar{b}$ and di-Higgs ($hh$) final states. A new benchmark scenario for heavy Higgs searches in the $b\bar{b}$ channel is proposed in this context. For the future Higgs rate measurements at the HL-LHC and ILC two different scenarios are investigated, namely the case where the future rate measurements agree with the SM prediction and the case where the rates agree with the predictions of possible realizations of the MSSM Higgs sector in nature.
hep-ph/9403381
null
E.Shuryak and M.Velkovsky (Physics Department, State University of New York, Stony Brook, NY)
The Instanton Density at Finite Temperatures
null
Phys.Rev. D50 (1994) 3323-3327
10.1103/PhysRevD.50.3323
null
hep-ph
null
For {\it low} T new strict results for the instanton density n(T) are reported. Using the PCAC methods, we express n(T) in terms of {\it vacuum} average values of certain operators, times their {\it calculated} T-dependence. At high T, we discuss the {\it applicability} limits of the perturbative results. We further speculate about possible behaviour of n(T) at $T\sim T_c$.
[ { "created": "Mon, 28 Mar 1994 23:18:47 GMT", "version": "v1" } ]
2009-10-28
[ [ "Shuryak", "E.", "", "Physics Department, State University of New\n York, Stony Brook, NY" ], [ "Velkovsky", "M.", "", "Physics Department, State University of New\n York, Stony Brook, NY" ] ]
For {\it low} T new strict results for the instanton density n(T) are reported. Using the PCAC methods, we express n(T) in terms of {\it vacuum} average values of certain operators, times their {\it calculated} T-dependence. At high T, we discuss the {\it applicability} limits of the perturbative results. We further speculate about possible behaviour of n(T) at $T\sim T_c$.
hep-ph/9706301
null
She-Sheng Xue
Neutrino masses and mixings
LaTex 11 pages
Mod.Phys.Lett.A14:2701-2708,1999
10.1142/S0217732399002844
null
hep-ph
null
We propose a novel theoretical understanding of neutrino masses and mixings, which is attributed to the intrinsic vector-like feature of the regularized Standard Model at short distances. We try to explain the smallness of Dirac neutrino masses and the decoupling of the right-handed neutrino as a free particle. Neutrino masses and mixing angles are completely related to each other in the Schwinger-Dyson equations for their self-energy functions. The solutions to these equations and a possible pattern of masses and mixings are discussed.
[ { "created": "Mon, 9 Jun 1997 17:18:58 GMT", "version": "v1" } ]
2014-11-17
[ [ "Xue", "She-Sheng", "" ] ]
We propose a novel theoretical understanding of neutrino masses and mixings, which is attributed to the intrinsic vector-like feature of the regularized Standard Model at short distances. We try to explain the smallness of Dirac neutrino masses and the decoupling of the right-handed neutrino as a free particle. Neutrino masses and mixing angles are completely related to each other in the Schwinger-Dyson equations for their self-energy functions. The solutions to these equations and a possible pattern of masses and mixings are discussed.
hep-ph/9709307
Manuel Malheiro
M. Malheiro and W. Melnitchouk
Nucleon Strange Magnetic Moment and Relativistic Covariance
8 pages revtex, 2 postscript figures, to appear in Phys. Rev. C, Rapid Communications
Phys.Rev.C56:2373-2377,1997
10.1103/PhysRevC.56.R2373
UMD PP 97-109
hep-ph nucl-th
null
We calculate the corrections to the strange matrix elements of the nucleon resulting from the breaking of rotational invariance on the light-cone. In the meson cloud model, the strange magnetic moment mu_S is seen to change sign once the spurious form factors arising from this violation are subtracted. The resulting mu_S is small and slightly positive, in agreement with the trend of the recent data from the SAMPLE experiment. The value of the strange magnetic form factor is predicted to be largely Q^2 independent over the range accessible in upcoming experiments.
[ { "created": "Wed, 10 Sep 1997 21:52:39 GMT", "version": "v1" } ]
2008-11-26
[ [ "Malheiro", "M.", "" ], [ "Melnitchouk", "W.", "" ] ]
We calculate the corrections to the strange matrix elements of the nucleon resulting from the breaking of rotational invariance on the light-cone. In the meson cloud model, the strange magnetic moment mu_S is seen to change sign once the spurious form factors arising from this violation are subtracted. The resulting mu_S is small and slightly positive, in agreement with the trend of the recent data from the SAMPLE experiment. The value of the strange magnetic form factor is predicted to be largely Q^2 independent over the range accessible in upcoming experiments.
hep-ph/0412082
Igor O. Cherednikov
A.E. Dorokhov, I.O Cherednikov
QCD instantons in high energy diffractive scattering: Instanton model of Pomeron
Important references added, minor correction in the text
null
10.1016/j.nuclphysbps.2005.02.080
null
hep-ph
null
The role of the QCD vacuum effects in high energy diffractive quark-quark and quark-antiquark scattering is studied with the Instanton Liquid Model. The special attention is given to the problem of formation of the soft Pomeron. We show that in the leading approximation in instanton density the $C-$odd instanton contribution to the diffractive amplitude is suppressed as $1/s$ compared to the $C-$even one.
[ { "created": "Mon, 6 Dec 2004 13:59:38 GMT", "version": "v1" }, { "created": "Tue, 7 Dec 2004 20:06:00 GMT", "version": "v2" } ]
2009-11-10
[ [ "Dorokhov", "A. E.", "" ], [ "Cherednikov", "I. O", "" ] ]
The role of the QCD vacuum effects in high energy diffractive quark-quark and quark-antiquark scattering is studied with the Instanton Liquid Model. The special attention is given to the problem of formation of the soft Pomeron. We show that in the leading approximation in instanton density the $C-$odd instanton contribution to the diffractive amplitude is suppressed as $1/s$ compared to the $C-$even one.
hep-ph/0208193
Kerry Whisnant
K. Whisnant, Jin Min Yang, Bing-Lin Young
Measuring CP violation and mass ordering in joint long baseline experiments with superbeams
25 RevTEX pages, 16 PS figures, revised figure captions and references added
Phys.Rev. D67 (2003) 013004
10.1103/PhysRevD.67.013004
AMES-HET-02-05
hep-ph
null
We propose to measure the CP phase $\delta_{\rm CP}$, the magnitude of the neutrino mixing matrix element $|U_{e3}|$ and the sign of the atmopheric scale mass--squared difference $\Delta{\rm m}^2_{31}$ with a superbeam by the joint analysis of two different long baseline neutrino oscillation experiments. One is a long baseline experiment (LBL) at 300 km and the other is a very long baseline (VLBL) experiment at 2100 km. We take the neutrino source to be the approved high intensity proton synchrotron, HIPA. The neutrino beam for the LBL is the 2-degree off-axis superbeam and for the VLBL, a narrow band superbeam. Taking into account all possible errors, we evaluate the event rates required and the sensitivities that can be attained for the determination of $\delta_{\rm CP}$ and the sign of $\Delta m^2_{31}$. We arrive at a representative scenario for a reasonably precise probe of this part of the neutrino physics.
[ { "created": "Wed, 21 Aug 2002 16:24:23 GMT", "version": "v1" }, { "created": "Fri, 15 Nov 2002 21:40:33 GMT", "version": "v2" } ]
2009-11-07
[ [ "Whisnant", "K.", "" ], [ "Yang", "Jin Min", "" ], [ "Young", "Bing-Lin", "" ] ]
We propose to measure the CP phase $\delta_{\rm CP}$, the magnitude of the neutrino mixing matrix element $|U_{e3}|$ and the sign of the atmopheric scale mass--squared difference $\Delta{\rm m}^2_{31}$ with a superbeam by the joint analysis of two different long baseline neutrino oscillation experiments. One is a long baseline experiment (LBL) at 300 km and the other is a very long baseline (VLBL) experiment at 2100 km. We take the neutrino source to be the approved high intensity proton synchrotron, HIPA. The neutrino beam for the LBL is the 2-degree off-axis superbeam and for the VLBL, a narrow band superbeam. Taking into account all possible errors, we evaluate the event rates required and the sensitivities that can be attained for the determination of $\delta_{\rm CP}$ and the sign of $\Delta m^2_{31}$. We arrive at a representative scenario for a reasonably precise probe of this part of the neutrino physics.
0907.4901
Alexei Nefediev
Yu.S.Kalashnikova, A.V.Nefediev (ITEP, Moscow)
Nature of X(3872) from data
RevTeX4, 25 pages
Phys.Rev.D80:074004,2009
10.1103/PhysRevD.80.074004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Properties of the charmonium-like state X(3872) are investigated and its nature is discussed as based on the existing experimental data. In particular, we analyse the new data from Belle and BaBar Collaborations and argue that, while the BaBar data prefer the dynamically generated virtual state in the D\bar{D}* system, the new Belle data clearly indicate a sizable c\bar{c} 2^3P_1 component in the X wave function.
[ { "created": "Tue, 28 Jul 2009 12:37:17 GMT", "version": "v1" } ]
2009-11-06
[ [ "Kalashnikova", "Yu. S.", "", "ITEP, Moscow" ], [ "Nefediev", "A. V.", "", "ITEP, Moscow" ] ]
Properties of the charmonium-like state X(3872) are investigated and its nature is discussed as based on the existing experimental data. In particular, we analyse the new data from Belle and BaBar Collaborations and argue that, while the BaBar data prefer the dynamically generated virtual state in the D\bar{D}* system, the new Belle data clearly indicate a sizable c\bar{c} 2^3P_1 component in the X wave function.
1011.2274
Wen-long Sang
Jungil Lee, WenLong Sang (Korea U.), Seyong Kim (Sejong U.)
Relativistic corrections to the axial vector and vector currents in the bar{b}c meson system at order alpha_s
34 pages, no figure
JHEP 1101:113,2011
10.1007/JHEP01(2011)113
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
We compute the short distance coefficients for the NRQCD factorization formulas of the meson-to-vacuum matrix elements for the axial vector and vector parts of the charged weak current in the $S$-wave spin-singlet and -triplet bar{b}c mesons, respectively. The computation is carried out to order alpha_s including relativistic corrections of all orders in vec{q}^{2n}, where vec{q} is the relative momentum of the bar{b} and c in the meson rest frame. The relativistic corrections at order alpha_s are new. The results reveal that the relativistic corrections to the leptonic decay rate of the B_c meson at order alpha_s or less converge rapidly, which shows a strong contrast to the uncomfortably large corrections of order alpha_s^2|vec{q}|^0. The short distance coefficients listed in this paper can be employed to compute the resummation of relativistic corrections to the phenomenological measurables that involve B_c and B_c^* production and decay.
[ { "created": "Wed, 10 Nov 2010 05:09:47 GMT", "version": "v1" } ]
2011-05-13
[ [ "Lee", "Jungil", "", "Korea U." ], [ "Sang", "WenLong", "", "Korea U." ], [ "Kim", "Seyong", "", "Sejong U." ] ]
We compute the short distance coefficients for the NRQCD factorization formulas of the meson-to-vacuum matrix elements for the axial vector and vector parts of the charged weak current in the $S$-wave spin-singlet and -triplet bar{b}c mesons, respectively. The computation is carried out to order alpha_s including relativistic corrections of all orders in vec{q}^{2n}, where vec{q} is the relative momentum of the bar{b} and c in the meson rest frame. The relativistic corrections at order alpha_s are new. The results reveal that the relativistic corrections to the leptonic decay rate of the B_c meson at order alpha_s or less converge rapidly, which shows a strong contrast to the uncomfortably large corrections of order alpha_s^2|vec{q}|^0. The short distance coefficients listed in this paper can be employed to compute the resummation of relativistic corrections to the phenomenological measurables that involve B_c and B_c^* production and decay.
1406.3684
Hideko Nagahiro
Hideko Nagahiro and Atsushi Hosaka
Elementarity of composite systems
13 pages, 8 figures, title changed, published
Phys. Rev. C 90, 065201 (2014)
10.1103/PhysRevC.90.065201
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The "compositeness" or "elementarity" is investigated for s-wave composite states dynamically generated by energy-dependent and independent interactions. The bare mass of the corresponding fictitious elementary particle in an equivalent Yukawa model is shown to be infinite, indicating that the wave function renormalization constant Z is equal to zero. The idea can be equally applied to both resonant and bound states. In a special case of zero-energy bound states, the condition Z = 0 does not necessarily mean that the elementary particle has the infinite bare mass. We also emphasize arbitrariness in the "elementarity" leading to multiple interpretations of a physical state, which can be either a pure composite state with Z = 0 or an elementary particle with Z \ne 0. The arbitrariness is unavoidable because the renormalization constant Z is not a physical observable.
[ { "created": "Sat, 14 Jun 2014 05:16:16 GMT", "version": "v1" }, { "created": "Tue, 2 Dec 2014 02:30:40 GMT", "version": "v2" } ]
2014-12-10
[ [ "Nagahiro", "Hideko", "" ], [ "Hosaka", "Atsushi", "" ] ]
The "compositeness" or "elementarity" is investigated for s-wave composite states dynamically generated by energy-dependent and independent interactions. The bare mass of the corresponding fictitious elementary particle in an equivalent Yukawa model is shown to be infinite, indicating that the wave function renormalization constant Z is equal to zero. The idea can be equally applied to both resonant and bound states. In a special case of zero-energy bound states, the condition Z = 0 does not necessarily mean that the elementary particle has the infinite bare mass. We also emphasize arbitrariness in the "elementarity" leading to multiple interpretations of a physical state, which can be either a pure composite state with Z = 0 or an elementary particle with Z \ne 0. The arbitrariness is unavoidable because the renormalization constant Z is not a physical observable.
2005.07003
Mamiya Kawaguchi
Mamiya Kawaguchi, Shinya Matsuzaki, Akio Tomiya
Analysis on nonperturbative flavor violation at chiral crossover criticality in QCD
25 pages, 13 figures, minor corrections made, some revision made
Phys. Rev. D 103, 054034 (2021)
10.1103/PhysRevD.103.054034
null
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the violation of quark-flavor symmetry at high temperatures, induced from nonperturbative thermal loop corrections and axial anomaly, based on a three-flavor linear-sigma model including an axial-anomaly induced-flavor breaking term. We employ a nonperturbative analysis following the Cornwall-Jackiw-Tomboulis formalism, and show that the model undergoes a chiral crossover with a pseudo-critical temperature, consistently with lattice observations. We find following features regarding the flavor breaking eminent around and above the pseudo-critical temperature: i) up-and down-quark condensates drop faster than the strange quark's toward the criticality, but still keep nonzero value even going far above the critical temperature; ii) the introduced anomaly-related flavor-breaking effect acts as a catalyzer toward the chiral restoration, and reduces the amount of flavor breaking in the up, down and strange quark condensates; iii) a dramatic deformation for the meson flavor mixing structure is observed, in which the anomaly-induced favor breaking is found to be almost irrelevant; iv) the meson spectroscopy gets corrected by the net nonperturbative flavor breaking effects, where the scalar meson mass hierarchy (inverse mass hierarchy) is significantly altered by the presence of the anomaly-related flavor breaking; v) the topological susceptibility significantly gets the contribution from the surviving strange quark condensate, which cannot be dictated by the chiral perturbation theory, and deviates from the dilute instanton gas prediction. There the anomaly-induced flavor breaking plays a role of the destructive interference for the net flavor violation; vi) the U(1)_A breaking is enhanced by the strange quark condensate, which may account for the tension in the effective U(1)_A restoration observed on lattices with two flavors and 2+1 flavors near the chiral limit.
[ { "created": "Thu, 14 May 2020 14:23:42 GMT", "version": "v1" }, { "created": "Tue, 5 Jan 2021 03:32:17 GMT", "version": "v2" } ]
2021-03-31
[ [ "Kawaguchi", "Mamiya", "" ], [ "Matsuzaki", "Shinya", "" ], [ "Tomiya", "Akio", "" ] ]
We discuss the violation of quark-flavor symmetry at high temperatures, induced from nonperturbative thermal loop corrections and axial anomaly, based on a three-flavor linear-sigma model including an axial-anomaly induced-flavor breaking term. We employ a nonperturbative analysis following the Cornwall-Jackiw-Tomboulis formalism, and show that the model undergoes a chiral crossover with a pseudo-critical temperature, consistently with lattice observations. We find following features regarding the flavor breaking eminent around and above the pseudo-critical temperature: i) up-and down-quark condensates drop faster than the strange quark's toward the criticality, but still keep nonzero value even going far above the critical temperature; ii) the introduced anomaly-related flavor-breaking effect acts as a catalyzer toward the chiral restoration, and reduces the amount of flavor breaking in the up, down and strange quark condensates; iii) a dramatic deformation for the meson flavor mixing structure is observed, in which the anomaly-induced favor breaking is found to be almost irrelevant; iv) the meson spectroscopy gets corrected by the net nonperturbative flavor breaking effects, where the scalar meson mass hierarchy (inverse mass hierarchy) is significantly altered by the presence of the anomaly-related flavor breaking; v) the topological susceptibility significantly gets the contribution from the surviving strange quark condensate, which cannot be dictated by the chiral perturbation theory, and deviates from the dilute instanton gas prediction. There the anomaly-induced flavor breaking plays a role of the destructive interference for the net flavor violation; vi) the U(1)_A breaking is enhanced by the strange quark condensate, which may account for the tension in the effective U(1)_A restoration observed on lattices with two flavors and 2+1 flavors near the chiral limit.
1801.07726
Hyun Min Lee
Soo-Min Choi, Hyun Min Lee, Pyungwon Ko, Alexander Natale
Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances
9 pages, 4 figures, Title changed, Accepted to Physical Review D
Phys. Rev. D 98, 015034 (2018)
10.1103/PhysRevD.98.015034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a light dark matter candidate which is produced by the freeze-out mechanism with $3\rightarrow2$ annihilations, the so called Strongly Interacting Massive Particles (SIMPs). SIMPs are identified as dark pions in dark chiral perturbation theory (ChPT) where both light mass and strong coupling needed for SIMPs can be realized by strong dynamics. In QCD-like theories with $SU(3)_L \times SU(3)_R /SU(3)_V$ flavor symmetry, including dark vector mesons in the hidden local symmetry scheme, we illustrate that dark vector mesons unitarize the dark ChPT efficiently, thus determine the correct relic density condition within the validity of the dark ChPT.
[ { "created": "Tue, 23 Jan 2018 19:00:16 GMT", "version": "v1" }, { "created": "Tue, 17 Jul 2018 14:09:47 GMT", "version": "v2" } ]
2018-08-01
[ [ "Choi", "Soo-Min", "" ], [ "Lee", "Hyun Min", "" ], [ "Ko", "Pyungwon", "" ], [ "Natale", "Alexander", "" ] ]
We consider a light dark matter candidate which is produced by the freeze-out mechanism with $3\rightarrow2$ annihilations, the so called Strongly Interacting Massive Particles (SIMPs). SIMPs are identified as dark pions in dark chiral perturbation theory (ChPT) where both light mass and strong coupling needed for SIMPs can be realized by strong dynamics. In QCD-like theories with $SU(3)_L \times SU(3)_R /SU(3)_V$ flavor symmetry, including dark vector mesons in the hidden local symmetry scheme, we illustrate that dark vector mesons unitarize the dark ChPT efficiently, thus determine the correct relic density condition within the validity of the dark ChPT.
1707.00657
C.-P. Yuan
Tie-Jiun Hou, Sayipjamal Dulat, Jun Gao, Marco Guzzi, Joey Huston, Pavel Nadolsky, Carl Schmidt, Jan Winter, Keping Xie, and C.-P. Yuan
CT14 Intrinsic Charm Parton Distribution Functions from CTEQ-TEA Global Analysis
57 pages, 19 figures, and 3 tables
null
10.1007/JHEP02(2018)059
MSUHEP-17-012
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes. The "fitted charm" PDF obtained in various QCD analyses contains a process-dependent component that is partly traced to power-suppressed radiative contributions in DIS and is generally different at the LHC. We discuss separation of the universal component of the nonperturbative charm from the rest of the radiative contributions and estimate its magnitude in the CT14 global QCD analysis at the next-to-next-to leading order in the QCD coupling strength, including the latest experimental data from HERA and the Large Hadron Collider. Models for the nonperturbative charm PDF are examined as a function of the charm quark mass and other parameters. The prospects for testing these models in the associated production of a Z boson and a charm jet at the LHC are studied under realistic assumptions, including effects of the final-state parton showering.
[ { "created": "Mon, 3 Jul 2017 17:14:51 GMT", "version": "v1" }, { "created": "Thu, 20 Jul 2017 06:30:16 GMT", "version": "v2" }, { "created": "Thu, 25 Jan 2018 17:32:17 GMT", "version": "v3" } ]
2018-04-04
[ [ "Hou", "Tie-Jiun", "" ], [ "Dulat", "Sayipjamal", "" ], [ "Gao", "Jun", "" ], [ "Guzzi", "Marco", "" ], [ "Huston", "Joey", "" ], [ "Nadolsky", "Pavel", "" ], [ "Schmidt", "Carl", "" ], [ "Winter", ...
We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes. The "fitted charm" PDF obtained in various QCD analyses contains a process-dependent component that is partly traced to power-suppressed radiative contributions in DIS and is generally different at the LHC. We discuss separation of the universal component of the nonperturbative charm from the rest of the radiative contributions and estimate its magnitude in the CT14 global QCD analysis at the next-to-next-to leading order in the QCD coupling strength, including the latest experimental data from HERA and the Large Hadron Collider. Models for the nonperturbative charm PDF are examined as a function of the charm quark mass and other parameters. The prospects for testing these models in the associated production of a Z boson and a charm jet at the LHC are studied under realistic assumptions, including effects of the final-state parton showering.
1207.6542
P. S. Bhupal Dev
P. S. Bhupal Dev, Subhadeep Mondal, Biswarup Mukhopadhyaya, Sourov Roy
Phenomenology of Light Sneutrino Dark Matter in cMSSM/mSUGRA with Inverse Seesaw
24 pages, 4 figures, 7 tables; matches published version
JHEP 09, 110 (2012)
10.1007/JHEP09(2012)110
RECAPP-HRI-2012-009
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility of a light Dark Matter (DM) within a constrained Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM singlet-pair sector to account for the non-zero neutrino masses by inverse seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed at high scale and the singlet neutrino sector at low scale, we find that, contrary to the case of the usual cMSSM where the neutralino DM cannot be very light, we can have a light sneutrino DM with mass below 100 GeV satisfying all the current experimental constraints from cosmology, collider as well as low-energy experiments. We also note that the supersymmetric inverse seesaw mechanism with sneutrino as the lightest supersymmetric partner can have enhanced same-sign dilepton final states with large missing transverse energy (mET) coming from the gluino- and squark-pair as well as the squark-gluino associated productions and their cascade decay through charginos. We present a collider study for the same-sign dilepton+jets+mET signal in this scenario and propose some distinctions with the usual cMSSM. We also comment on the implications of such a light DM scenario on the invisible decay width of an 125 GeV Higgs boson.
[ { "created": "Fri, 27 Jul 2012 13:43:40 GMT", "version": "v1" }, { "created": "Mon, 3 Sep 2012 08:56:33 GMT", "version": "v2" }, { "created": "Sun, 25 Nov 2012 12:20:14 GMT", "version": "v3" } ]
2014-10-13
[ [ "Dev", "P. S. Bhupal", "" ], [ "Mondal", "Subhadeep", "" ], [ "Mukhopadhyaya", "Biswarup", "" ], [ "Roy", "Sourov", "" ] ]
We study the possibility of a light Dark Matter (DM) within a constrained Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM singlet-pair sector to account for the non-zero neutrino masses by inverse seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed at high scale and the singlet neutrino sector at low scale, we find that, contrary to the case of the usual cMSSM where the neutralino DM cannot be very light, we can have a light sneutrino DM with mass below 100 GeV satisfying all the current experimental constraints from cosmology, collider as well as low-energy experiments. We also note that the supersymmetric inverse seesaw mechanism with sneutrino as the lightest supersymmetric partner can have enhanced same-sign dilepton final states with large missing transverse energy (mET) coming from the gluino- and squark-pair as well as the squark-gluino associated productions and their cascade decay through charginos. We present a collider study for the same-sign dilepton+jets+mET signal in this scenario and propose some distinctions with the usual cMSSM. We also comment on the implications of such a light DM scenario on the invisible decay width of an 125 GeV Higgs boson.
hep-ph/0002028
Lars Brucher
Lars Brucher
Automatic Feynman diagram calculation with xloops--a short overview
Contribution to Proceedings of 6th Rhine Workshop on Computer Algebra (Sankt Augustin, Germany, March-April 1998), ed. J. Calmet
null
null
null
hep-ph
null
xloops is a program package that calculates Feynman diagrams by using computer algebra systems. In this paper it is shown which problems to be solved by computer algebra arise during such calculations, and how this problems are handled in the framework of xloops.
[ { "created": "Wed, 2 Feb 2000 17:19:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Brucher", "Lars", "" ] ]
xloops is a program package that calculates Feynman diagrams by using computer algebra systems. In this paper it is shown which problems to be solved by computer algebra arise during such calculations, and how this problems are handled in the framework of xloops.
0903.2631
Melahat Bayar
V. Bashiry, M. Bayar
Analysis of Various Polarization Asymmetries In The Inclusive $b\to s \ell^+ \ell^-$ Decay In The Fourth-Generation Standard Model
19 Pages, 10 Figures, 3 Tables
Eur.Phys.J.C61:451-459,2009
10.1140/epjc/s10052-009-1004-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study a systematical analysis of various polarization asymmetries in inclusive $b \rar s \ell^+ \ell^-$ decay in the standard model (SM) with four generation of quarks is carried out. We found that the various asymmetries are sensitive to the new mixing and quark masses for both of the $\mu$ and $\tau$ channels. Sizeable deviations from the SM values are obtained. Hence, $b \rar s \ell^+ \ell^-$ decay is a valuable tool for searching physics beyond the SM, especially in the indirect searches for the fourth-generation of quarks ($t', b')$.
[ { "created": "Sun, 15 Mar 2009 13:23:52 GMT", "version": "v1" } ]
2009-07-22
[ [ "Bashiry", "V.", "" ], [ "Bayar", "M.", "" ] ]
In this study a systematical analysis of various polarization asymmetries in inclusive $b \rar s \ell^+ \ell^-$ decay in the standard model (SM) with four generation of quarks is carried out. We found that the various asymmetries are sensitive to the new mixing and quark masses for both of the $\mu$ and $\tau$ channels. Sizeable deviations from the SM values are obtained. Hence, $b \rar s \ell^+ \ell^-$ decay is a valuable tool for searching physics beyond the SM, especially in the indirect searches for the fourth-generation of quarks ($t', b')$.
hep-ph/9806267
Vadim Guzey
Andreas Freund, Vadim Guzey (The Pennsylvania State University)
Study of Nondiagonal Parton Distribution Models
17 pages, 6 figures, RevTex. Some figures have been corrected due to a recently discovered small error in the evolution code
Phys.Lett.B462:178-188,1999
10.1016/S0370-2693(99)00881-3
null
hep-ph
null
In this paper we examine predictions from different models of nondiagonal parton distributions. This will be achieved by examining whether certain predictions of relationships between diagonal and nondiagonal parton distributions also hold after having evolved the different distributions.
[ { "created": "Fri, 5 Jun 1998 15:39:25 GMT", "version": "v1" }, { "created": "Wed, 23 Sep 1998 15:56:52 GMT", "version": "v2" }, { "created": "Fri, 11 Dec 1998 02:08:23 GMT", "version": "v3" }, { "created": "Thu, 11 Feb 1999 18:59:43 GMT", "version": "v4" } ]
2014-11-17
[ [ "Freund", "Andreas", "", "The Pennsylvania State University" ], [ "Guzey", "Vadim", "", "The Pennsylvania State University" ] ]
In this paper we examine predictions from different models of nondiagonal parton distributions. This will be achieved by examining whether certain predictions of relationships between diagonal and nondiagonal parton distributions also hold after having evolved the different distributions.