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2310.18109
Mario Pitschmann
Hauke Fischer, Christian K\"ading, Hartmut Lemmel, Stephan Sponar, and Mario Pitschmann
Search for dark energy with neutron interferometry
11 pages, 8 figures
null
10.1093/ptep/ptae014
null
hep-ph astro-ph.CO gr-qc nucl-ex quant-ph
http://creativecommons.org/licenses/by/4.0/
We use previously obtained experimental results by neutron interferometry to effectively constrain the parameter space of several prominent dark energy models. This investigation encompasses the environment-dependent dilaton field, a compelling contender for dark energy that emerges naturally within the strong coupling limit of string theory, alongside symmetron and chameleon fields. Our study presents substantial improvements over previous constraints of the dilaton and symmetron fields, improving parameter constraints by several orders of magnitude. However, the analysis does not yield any new constraints on the chameleon field. Furthermore, we establish constraints for the projected neutron split interferometer, which has recently concluded a decisive proof-of-principle demonstration. Our symmetron simulations reveal that depending on the parameter values there are multiple static solutions with increasing number of nodes and increasing energy inside a cylindrical vacuum chamber. This agrees with results obtained earlier in the literature for infinitely parallel plates. Interestingly, while these multiple solutions can correspond to domain walls forming inside the vacuum chamber, we also find solutions that do not reach their vacuum expectation value inside the vacuum chamber, but display multiple nodes nonetheless.
[ { "created": "Fri, 27 Oct 2023 12:49:01 GMT", "version": "v1" } ]
2024-02-23
[ [ "Fischer", "Hauke", "" ], [ "Käding", "Christian", "" ], [ "Lemmel", "Hartmut", "" ], [ "Sponar", "Stephan", "" ], [ "Pitschmann", "Mario", "" ] ]
We use previously obtained experimental results by neutron interferometry to effectively constrain the parameter space of several prominent dark energy models. This investigation encompasses the environment-dependent dilaton field, a compelling contender for dark energy that emerges naturally within the strong coupling limit of string theory, alongside symmetron and chameleon fields. Our study presents substantial improvements over previous constraints of the dilaton and symmetron fields, improving parameter constraints by several orders of magnitude. However, the analysis does not yield any new constraints on the chameleon field. Furthermore, we establish constraints for the projected neutron split interferometer, which has recently concluded a decisive proof-of-principle demonstration. Our symmetron simulations reveal that depending on the parameter values there are multiple static solutions with increasing number of nodes and increasing energy inside a cylindrical vacuum chamber. This agrees with results obtained earlier in the literature for infinitely parallel plates. Interestingly, while these multiple solutions can correspond to domain walls forming inside the vacuum chamber, we also find solutions that do not reach their vacuum expectation value inside the vacuum chamber, but display multiple nodes nonetheless.
0809.1006
Antonino Flachi
Antonino Flachi, Misao Sasaki, Takahiro Tanaka
Spin Polarization Effects in Micro Black Hole Evaporation
5 pages, 12 figures. Various changes
null
10.1088/1126-6708/2009/05/031
YITP-08-71
hep-ph astro-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the evaporation of rotating micro black holes produced in highly energetic particle collisions, taking into account the polarization due to the coupling between the spin of the emitted particles and the angular momentum of the black hole. The effect of rotation shows up in the helicity dependent angular distribution significantly. By using this effect, there is a possibility to determine the axis of rotation for each black hole formed, suggesting a way to improve the statistics. Deviation from thermal spectrum is also a signature of rotation. This deviation is due to the fact that rapidly rotating holes have an effective temperature $T_{\rm eff}$ significantly higher than the Hawking temperature $T_H$. The deformation of the spectral shape becomes evident only for very rapidly rotating cases. We show that, since the spectrum follows a blackbody profile with an effective temperature, it is difficult to determine both the number of extra-dimensions and the rotation parameter from the energy spectrum alone. We argue that the helicity dependent angular distribution may provide a way to resolve this degeneracy. We illustrate the above results for the case of fermions.
[ { "created": "Fri, 5 Sep 2008 11:14:24 GMT", "version": "v1" }, { "created": "Thu, 2 Apr 2009 09:36:07 GMT", "version": "v2" } ]
2015-05-13
[ [ "Flachi", "Antonino", "" ], [ "Sasaki", "Misao", "" ], [ "Tanaka", "Takahiro", "" ] ]
We consider the evaporation of rotating micro black holes produced in highly energetic particle collisions, taking into account the polarization due to the coupling between the spin of the emitted particles and the angular momentum of the black hole. The effect of rotation shows up in the helicity dependent angular distribution significantly. By using this effect, there is a possibility to determine the axis of rotation for each black hole formed, suggesting a way to improve the statistics. Deviation from thermal spectrum is also a signature of rotation. This deviation is due to the fact that rapidly rotating holes have an effective temperature $T_{\rm eff}$ significantly higher than the Hawking temperature $T_H$. The deformation of the spectral shape becomes evident only for very rapidly rotating cases. We show that, since the spectrum follows a blackbody profile with an effective temperature, it is difficult to determine both the number of extra-dimensions and the rotation parameter from the energy spectrum alone. We argue that the helicity dependent angular distribution may provide a way to resolve this degeneracy. We illustrate the above results for the case of fermions.
hep-ph/9501309
G. T. Gabadadze
G.T. Gabadadze
An Estimate of the Proton Singlet Axial Constant
10 p., LATEX file.
Proceedings, Int. Seminar "Quarks '94", p.581. World Sc. 1995.
null
Preprint JINR E2-94-518 (1994).
hep-ph
null
The value of the proton singlet axial constant is estimated. It has been shown that the axial anomaly plays a crucial role in this calculation. Obtained result is sufficiently suppressed in comparison with the naively expected one. The magnitude of the strange quark contribution for the proton state is also computed approximately.
[ { "created": "Mon, 16 Jan 1995 15:37:26 GMT", "version": "v1" } ]
2016-09-01
[ [ "Gabadadze", "G. T.", "" ] ]
The value of the proton singlet axial constant is estimated. It has been shown that the axial anomaly plays a crucial role in this calculation. Obtained result is sufficiently suppressed in comparison with the naively expected one. The magnitude of the strange quark contribution for the proton state is also computed approximately.
hep-ph/0110110
Eugenio Marco Rubio
E. Marco, R. Hofmann and W. Weise
Note on finite temperature sum rules for vector and axial-vector spectral functions
10 pages, 2 figures
Phys.Lett. B530 (2002) 88-92
10.1016/S0370-2693(02)01343-6
TUM/T39-01-23; MPI-PHT 2001-38
hep-ph
null
An updated analysis of vector and axial-vector spectral functions is presented. The resonant contributions to the spectral integrals are shown to be expressible as multiples of 4 pi^2 f_pi^2, encoding the scale of spontaneous chiral symmetry breaking in QCD. Up to order T^2 this behavior carries over to the case of finite temperature.
[ { "created": "Mon, 8 Oct 2001 15:51:35 GMT", "version": "v1" } ]
2009-11-07
[ [ "Marco", "E.", "" ], [ "Hofmann", "R.", "" ], [ "Weise", "W.", "" ] ]
An updated analysis of vector and axial-vector spectral functions is presented. The resonant contributions to the spectral integrals are shown to be expressible as multiples of 4 pi^2 f_pi^2, encoding the scale of spontaneous chiral symmetry breaking in QCD. Up to order T^2 this behavior carries over to the case of finite temperature.
1812.01568
Jos\'e Francisco Zurita
David Curtin, Kaustubh Deshpande, Oliver Fischer, Jose Zurita
Closing the light gluino gap with electron-proton colliders
7 pages, 5 figures
Phys. Rev. D 99, 055011 (2019)
10.1103/PhysRevD.99.055011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The future electron-proton collider proposals, LHeC and FCC-he, can deliver $\mathcal{O}$(TeV) center-of-mass energy collisions, higher than most of the proposed lepton accelerators, with $\mathcal{O}$(ab$^{-1}$) luminosity, while maintaining a much cleaner experimental environment as compared to the hadron machines. This unique capability of $e^- p$ colliders can be harnessed in probing BSM scenarios giving final states that look like hadronic noise at $pp$ machines. In the present study, we explore the prospects of detecting such a prompt signal having multiple soft jets at the LHeC. Such a signal can come from the decay of gluino in RPV or Stealth SUSY, where there exists a gap in the current experimental search with $m_{\tilde{g}} \approx 50 - 70$ GeV. We perform a simple analysis to demonstrate that, with simple signal selection cuts, we can close this gap at the LHeC at 95 % confidence level, even in the presence of a reasonable systematic error. More sophisticated signal selection strategies and detailed knowledge of the detector can be used to improve the prospects of signal detection.
[ { "created": "Tue, 4 Dec 2018 18:17:25 GMT", "version": "v1" } ]
2019-03-27
[ [ "Curtin", "David", "" ], [ "Deshpande", "Kaustubh", "" ], [ "Fischer", "Oliver", "" ], [ "Zurita", "Jose", "" ] ]
The future electron-proton collider proposals, LHeC and FCC-he, can deliver $\mathcal{O}$(TeV) center-of-mass energy collisions, higher than most of the proposed lepton accelerators, with $\mathcal{O}$(ab$^{-1}$) luminosity, while maintaining a much cleaner experimental environment as compared to the hadron machines. This unique capability of $e^- p$ colliders can be harnessed in probing BSM scenarios giving final states that look like hadronic noise at $pp$ machines. In the present study, we explore the prospects of detecting such a prompt signal having multiple soft jets at the LHeC. Such a signal can come from the decay of gluino in RPV or Stealth SUSY, where there exists a gap in the current experimental search with $m_{\tilde{g}} \approx 50 - 70$ GeV. We perform a simple analysis to demonstrate that, with simple signal selection cuts, we can close this gap at the LHeC at 95 % confidence level, even in the presence of a reasonable systematic error. More sophisticated signal selection strategies and detailed knowledge of the detector can be used to improve the prospects of signal detection.
1211.6230
Leonid Slad
L.M. Slad
Magnetic moment operator of non-Dirac particles and some elements of polarization $ep$-experiments
10 pages; v2 journal version with a modified introduction
Mod. Phys. Lett. A 28 (2013) 1350051
10.1142/S021773231350051X
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An explicit form of the magnetic moment tensor operator for non-Dirac particles with rest spin 1/2 and its essential difference from the spin operator are established. Possible consequences of the last fact for the description of the spin rotation in the magnetic field and for the values of magnetic moments of some nuclei, as well as the impact of this and other facts on the validity of modelling the azimuthal asymmetry of the secondary-scattered protons in $ep$-experiments are noted.
[ { "created": "Tue, 27 Nov 2012 08:24:31 GMT", "version": "v1" }, { "created": "Thu, 11 Apr 2013 09:59:54 GMT", "version": "v2" } ]
2013-04-12
[ [ "Slad", "L. M.", "" ] ]
An explicit form of the magnetic moment tensor operator for non-Dirac particles with rest spin 1/2 and its essential difference from the spin operator are established. Possible consequences of the last fact for the description of the spin rotation in the magnetic field and for the values of magnetic moments of some nuclei, as well as the impact of this and other facts on the validity of modelling the azimuthal asymmetry of the secondary-scattered protons in $ep$-experiments are noted.
1608.06711
Mandip Singh
Mandip Singh
Studying the physics potential of long-baseline experiments in terms of new sensitivity parameters
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate physics opportunities to constraint leptonic CP-violation phase $\delta_{CP}$ through numerical analysis of working neutrino oscillation probability parameters, in the context of long base line experiments. Numerical analysis of two parameters, the " transition probability $\delta_{CP}$ phase sensitivity parameter ($A^M$) " and " CP-violation probability $\delta_{CP}$ phase sensitivity parameter ($A^{CP}$) ", as function of beam energy and/or base line has been preferably carried out. It is an elegant technique to broadly analyze different experiments to constraint $\delta_{CP}$ phase and also to investigate mass hierarchy in the leptonic sector. The positive and negative values of parameter $A^{CP}$ corresponding to either of hierarchy in the specific beam energy ranges, could be a very promising way to explore mass hierarchy and $\delta_{CP}$ phase. The keys to more robust bounds on $\delta_{CP}$ phase are improvements of the involved detection techniques to explore bit low energy and relatively long base line regions with better experimental accuracy.
[ { "created": "Wed, 24 Aug 2016 04:38:55 GMT", "version": "v1" } ]
2016-08-25
[ [ "Singh", "Mandip", "" ] ]
We investigate physics opportunities to constraint leptonic CP-violation phase $\delta_{CP}$ through numerical analysis of working neutrino oscillation probability parameters, in the context of long base line experiments. Numerical analysis of two parameters, the " transition probability $\delta_{CP}$ phase sensitivity parameter ($A^M$) " and " CP-violation probability $\delta_{CP}$ phase sensitivity parameter ($A^{CP}$) ", as function of beam energy and/or base line has been preferably carried out. It is an elegant technique to broadly analyze different experiments to constraint $\delta_{CP}$ phase and also to investigate mass hierarchy in the leptonic sector. The positive and negative values of parameter $A^{CP}$ corresponding to either of hierarchy in the specific beam energy ranges, could be a very promising way to explore mass hierarchy and $\delta_{CP}$ phase. The keys to more robust bounds on $\delta_{CP}$ phase are improvements of the involved detection techniques to explore bit low energy and relatively long base line regions with better experimental accuracy.
hep-ph/0410179
Ngoc-Khanh Tran
P. Q. Hung, A. Soddu and Ngoc-Khanh Tran
Complete CKM quark mixing via dimensional deconstruction
RevTex4, 25 pages, typos in section IIC corrected, published version
Nucl.Phys. B712 (2005) 325-346
10.1016/j.nuclphysb.2005.01.027
null
hep-ph
null
It is shown that the deconstruction of $[SU(2)\times U(1)]^N$ into $[SU(2)\times U(1)]$ is capable of providing all necessary ingredients to completely impliment the complex CKM mixing of quark flavors. The hierarchical structure of quark masses originates from the difference in the deconstructed chiral zero-mode distribution in theory space, while the CP-violating phase comes from the genuinely complex vacuum expectation value of link fields. The mixing is constructed in a specific model to satisfy experimental bounds on quarks' masses and CP violation.
[ { "created": "Tue, 12 Oct 2004 21:20:16 GMT", "version": "v1" }, { "created": "Sun, 30 Jan 2005 22:40:41 GMT", "version": "v2" }, { "created": "Fri, 25 Mar 2005 21:40:47 GMT", "version": "v3" } ]
2009-11-10
[ [ "Hung", "P. Q.", "" ], [ "Soddu", "A.", "" ], [ "Tran", "Ngoc-Khanh", "" ] ]
It is shown that the deconstruction of $[SU(2)\times U(1)]^N$ into $[SU(2)\times U(1)]$ is capable of providing all necessary ingredients to completely impliment the complex CKM mixing of quark flavors. The hierarchical structure of quark masses originates from the difference in the deconstructed chiral zero-mode distribution in theory space, while the CP-violating phase comes from the genuinely complex vacuum expectation value of link fields. The mixing is constructed in a specific model to satisfy experimental bounds on quarks' masses and CP violation.
2106.05904
Jose M. Carmona
Jos\'e Manuel Carmona, Jos\'e Luis Cort\'es and Jos\'e Javier Relancio
Particle-antiparticle asymmetry in a relativistic deformed kinematics
13 pages. Version published in Symmetry (prior to journal proofs); the article belongs to the Special Issue "Symmetry, CPT and Astroparticles"
Symmetry 13(7), 1266 (2021)
10.3390/sym13071266
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Relativistic deformed kinematics are usually considered as a way to capture residual effects of a fundamental quantum gravity theory. These kinematics present a non-commutative addition law for the momenta, so that the total momentum of a multi-particle system depends on the specific ordering in which the momenta are composed. We explore in the present work how this property may be used to generate an asymmetry between particles and antiparticles through a particular ordering prescription, resulting in a violation of CPT symmetry. We study its consequences for muon decay, obtaining a difference in the lifetimes of the particle and the antiparticle as a function the new high-energy scale parameterizing such a relativistic deformed kinematics.
[ { "created": "Thu, 10 Jun 2021 16:45:17 GMT", "version": "v1" }, { "created": "Sat, 17 Jul 2021 08:24:43 GMT", "version": "v2" } ]
2021-07-20
[ [ "Carmona", "José Manuel", "" ], [ "Cortés", "José Luis", "" ], [ "Relancio", "José Javier", "" ] ]
Relativistic deformed kinematics are usually considered as a way to capture residual effects of a fundamental quantum gravity theory. These kinematics present a non-commutative addition law for the momenta, so that the total momentum of a multi-particle system depends on the specific ordering in which the momenta are composed. We explore in the present work how this property may be used to generate an asymmetry between particles and antiparticles through a particular ordering prescription, resulting in a violation of CPT symmetry. We study its consequences for muon decay, obtaining a difference in the lifetimes of the particle and the antiparticle as a function the new high-energy scale parameterizing such a relativistic deformed kinematics.
hep-ph/0611241
Ulrich Baur
U. Baur (Buffalo)
Weak Boson Emission in Hadron Collider Processes
revtex3, 41 pages, 16 figures, 3 tables
Phys.Rev.D75:013005,2007
10.1103/PhysRevD.75.013005
UB-HET-06-02
hep-ph
null
The O(alpha) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(alpha) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(alpha) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, t-bar t, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(alpha) virtual weak radiative corrections partially cancel.
[ { "created": "Fri, 17 Nov 2006 22:34:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Baur", "U.", "", "Buffalo" ] ]
The O(alpha) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(alpha) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(alpha) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, t-bar t, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(alpha) virtual weak radiative corrections partially cancel.
hep-ph/0202056
Martin Beneke
M. Beneke (RWTH Aachen)
Exclusive non-leptonic B meson decays from QCD
7 pages, LaTeX, Talk presented at the 5th KEK Topical Conference -- Frontiers in Flavour Physics, Tsukuba, Japan, November 2001
Nucl.Phys.Proc.Suppl.111:62-68,2002
10.1016/S0920-5632(02)01685-7
PITHA 02/06
hep-ph
null
A brief report on the QCD factorization approach to exclusive B decays and its applications is presented. In an appendix a subtle issue concerning partial integration in the parameterization of infrared-sensitive power corrections is clarified.
[ { "created": "Wed, 6 Feb 2002 19:59:00 GMT", "version": "v1" } ]
2011-01-27
[ [ "Beneke", "M.", "", "RWTH Aachen" ] ]
A brief report on the QCD factorization approach to exclusive B decays and its applications is presented. In an appendix a subtle issue concerning partial integration in the parameterization of infrared-sensitive power corrections is clarified.
1706.02647
Johannes Knaute
J. Knaute, B. K\"ampfer
Holographic Entanglement Entropy in the QCD Phase Diagram with a Critical Point
updated to consistent scaling in arXiv:1702.06731v2; extended discussions and refs added; to appear in PRD
Phys. Rev. D 96, 106003 (2017)
10.1103/PhysRevD.96.106003
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the holographic entanglement entropy for the holographic QCD phase diagram considered in [Knaute, Yaresko, K\"ampfer (2017), arXiv:1702.06731] and explore the resulting qualitative behavior over the temperature-chemical potential plane. In agreement with the thermodynamic result, the phase diagram exhibits the same critical point as the onset of a first-order phase transition curve. We compare the phase diagram of the entanglement entropy to that of the thermodynamic entropy density and find a striking agreement in the vicinity of the critical point. Thus, the holographic entanglement entropy qualifies to characterize different phase structures. The scaling behavior near the critical point is analyzed through the calculation of critical exponents.
[ { "created": "Thu, 8 Jun 2017 15:40:01 GMT", "version": "v1" }, { "created": "Tue, 10 Oct 2017 13:56:05 GMT", "version": "v2" } ]
2017-11-08
[ [ "Knaute", "J.", "" ], [ "Kämpfer", "B.", "" ] ]
We calculate the holographic entanglement entropy for the holographic QCD phase diagram considered in [Knaute, Yaresko, K\"ampfer (2017), arXiv:1702.06731] and explore the resulting qualitative behavior over the temperature-chemical potential plane. In agreement with the thermodynamic result, the phase diagram exhibits the same critical point as the onset of a first-order phase transition curve. We compare the phase diagram of the entanglement entropy to that of the thermodynamic entropy density and find a striking agreement in the vicinity of the critical point. Thus, the holographic entanglement entropy qualifies to characterize different phase structures. The scaling behavior near the critical point is analyzed through the calculation of critical exponents.
hep-ph/0401031
Miguel Sanchis
Miguel-Angel Sanchis-Lozano
Searching for new physics in Upsilon decays
6 pages, 2 eps figures
null
null
IFIC/04-1, FTUV-04-0107
hep-ph
null
We study some possible experimental consequences of new physics on the spectrum and decays of bottomonium states below $B\bar{B}$ threshold. In addition to lepton universality breaking in Upsilon decays, large widths of pseudoscalar $\eta_b$ resonances and mixing with a non-standard CP-odd light Higgs boson might smooth and shift the signal peak from hindered radiative M1 transitions between $\Upsilon$ and $\eta_b$ states in the photon energy spectrum, as searched by CLEO. We also stress the relevance of forthcoming results from CLEO on leptonic branching fractions of $\Upsilon$ resonances to definitely check our hypothesis.
[ { "created": "Wed, 7 Jan 2004 18:27:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sanchis-Lozano", "Miguel-Angel", "" ] ]
We study some possible experimental consequences of new physics on the spectrum and decays of bottomonium states below $B\bar{B}$ threshold. In addition to lepton universality breaking in Upsilon decays, large widths of pseudoscalar $\eta_b$ resonances and mixing with a non-standard CP-odd light Higgs boson might smooth and shift the signal peak from hindered radiative M1 transitions between $\Upsilon$ and $\eta_b$ states in the photon energy spectrum, as searched by CLEO. We also stress the relevance of forthcoming results from CLEO on leptonic branching fractions of $\Upsilon$ resonances to definitely check our hypothesis.
hep-ph/9805397
Marek Olechowski
Y. Kawamura, H.P. Nilles, M. Olechowski and M. Yamaguchi
Relic Abundance of Neutralinos in Heterotic String Theory: Weak Coupling vs. Strong Coupling
24 pages, latex, no figures
JHEP 9806:008,1998
10.1088/1126-6708/1998/06/008
BONN-TH-98-11, SFB-375/297, TUM-TH-314/98, TU-547, RCNS-98-07
hep-ph hep-th
null
The relic abundance of stable neutralinos is investigated in $E_8 \times E_8'$ heterotic string theory when supersymmetry is spontaneously broken by hidden-sector gaugino condensates. In the weak coupling regime, very large scalar masses (compared to gaugino masses) are shown to lead to a too large relic abundance of the neutralinos, incompatible with cosmological observations in most of parameter space. The problem does not arise in the strong coupling regime (heterotic M-theory) because there scalar and gaugino masses are generically of the same order of magnitude.
[ { "created": "Wed, 20 May 1998 14:44:41 GMT", "version": "v1" } ]
2010-02-03
[ [ "Kawamura", "Y.", "" ], [ "Nilles", "H. P.", "" ], [ "Olechowski", "M.", "" ], [ "Yamaguchi", "M.", "" ] ]
The relic abundance of stable neutralinos is investigated in $E_8 \times E_8'$ heterotic string theory when supersymmetry is spontaneously broken by hidden-sector gaugino condensates. In the weak coupling regime, very large scalar masses (compared to gaugino masses) are shown to lead to a too large relic abundance of the neutralinos, incompatible with cosmological observations in most of parameter space. The problem does not arise in the strong coupling regime (heterotic M-theory) because there scalar and gaugino masses are generically of the same order of magnitude.
hep-ph/0205051
Guenter Sigl
Guenter Sigl (GReCO, Institut d'Astrophysique de Paris, CNRS)
Probing Physics at Extreme Energies with Cosmic Ultra-High Energy Radiation
12 latex pages, 2 postscript figures included; based on invited talk at the WHEPP-7 Conference, Allahabad, India (January, 2002)
Annals Phys.301:53-64,2002; Pramana 60:279-290,2003
10.1006/aphy.2002.6295
null
hep-ph astro-ph
null
The highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with gamma-ray and neutrino astrophysics will put strong constraints on these theoretical models. We give an overview over this quickly evolving research field with focus on testing new particle physics.
[ { "created": "Mon, 6 May 2002 16:37:30 GMT", "version": "v1" } ]
2014-11-17
[ [ "Sigl", "Guenter", "", "GReCO, Institut d'Astrophysique de Paris, CNRS" ] ]
The highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a strong increase of statistics at the highest energies and a combination with gamma-ray and neutrino astrophysics will put strong constraints on these theoretical models. We give an overview over this quickly evolving research field with focus on testing new particle physics.
1512.06877
Jiayin Gu
Nathaniel Craig, Jiayin Gu, Zhen Liu, Kechen Wang
Beyond Higgs Couplings: Probing the Higgs with Angular Observables at Future $e^+ e^-$ Colliders
28 pages, 9 figures. v2: references added, matches published version in JHEP
JHEP 1603 (2016) 050
10.1007/JHEP03(2016)050
FERMILAB-PUB-15-569-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study angular observables in the $e^+e^-\to Z H\to \ell^+ \ell^-\,b\bar{b}$ channel at future circular $e^+ e^-$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $\sqrt{s} =$ 240 GeV and 5 (30) ${\rm ab}^{-1}$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the $H Z \gamma$ coupling and constraining the "blind spot" in indirect limits on supersymmetric scalar top partners.
[ { "created": "Mon, 21 Dec 2015 21:22:28 GMT", "version": "v1" }, { "created": "Wed, 16 Mar 2016 15:30:18 GMT", "version": "v2" } ]
2016-03-17
[ [ "Craig", "Nathaniel", "" ], [ "Gu", "Jiayin", "" ], [ "Liu", "Zhen", "" ], [ "Wang", "Kechen", "" ] ]
We study angular observables in the $e^+e^-\to Z H\to \ell^+ \ell^-\,b\bar{b}$ channel at future circular $e^+ e^-$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $\sqrt{s} =$ 240 GeV and 5 (30) ${\rm ab}^{-1}$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the $H Z \gamma$ coupling and constraining the "blind spot" in indirect limits on supersymmetric scalar top partners.
hep-ph/0207116
Lev Leinson
L.B. Leinson
Direct Urca processes on nucleons in cooling neutron stars
21 pages, 2 figures
Nucl.Phys. A707 (2002) 543-560
10.1016/S0375-9474(02)00991-0
null
hep-ph astro-ph nucl-th
null
We use the field theoretical model to perform relativistic calculations of neutrino energy losses caused by the direct Urca processes on nucleons in the degenerate baryon matter. By our analysis, the direct neutron decay in the superdense nuclear matter under beta equilibrium is open only due to the isovector meson fields, which create a large energy gap between protons and neutrons in the medium. Our expression for the neutrino energy losses, obtained in the mean field approximation, incorporates the effects of nucleon recoil, parity violation, weak magnetism, and pseudoscalar interaction. For numerical testing of our formula, we use a self-consistent relativistic model of the multicomponent baryon matter. The relativistic emissivity of the direct Urca reactions is found substantially larger than predicted in the non-relativistic approach. We found that, due to weak magnetism effects, relativistic emissivities increase by approximately 40-50%, while the pseudoscalar interaction only slightly suppresses the energy losses, approximately by 5%.
[ { "created": "Tue, 9 Jul 2002 10:03:08 GMT", "version": "v1" }, { "created": "Sun, 20 Oct 2002 16:59:55 GMT", "version": "v2" } ]
2009-11-07
[ [ "Leinson", "L. B.", "" ] ]
We use the field theoretical model to perform relativistic calculations of neutrino energy losses caused by the direct Urca processes on nucleons in the degenerate baryon matter. By our analysis, the direct neutron decay in the superdense nuclear matter under beta equilibrium is open only due to the isovector meson fields, which create a large energy gap between protons and neutrons in the medium. Our expression for the neutrino energy losses, obtained in the mean field approximation, incorporates the effects of nucleon recoil, parity violation, weak magnetism, and pseudoscalar interaction. For numerical testing of our formula, we use a self-consistent relativistic model of the multicomponent baryon matter. The relativistic emissivity of the direct Urca reactions is found substantially larger than predicted in the non-relativistic approach. We found that, due to weak magnetism effects, relativistic emissivities increase by approximately 40-50%, while the pseudoscalar interaction only slightly suppresses the energy losses, approximately by 5%.
hep-ph/9309217
Vladimir Braun
I.I. Balitsky, M. Beneke and V.M. Braun
Instanton contributions to the $\tau$ decay widths
LATEX, 13 pages, 3 figures available upon request, MPI-Ph/93-62
Phys.Lett. B318 (1993) 371-381
10.1016/0370-2693(93)90142-5
null
hep-ph
null
Contrary to some previous claims, we find a sizable instanton contribution to the finite energy sum rule used to extract the value of the strong coupling from the measured $\tau$ decay widths. It is of the same order of magnitude as standard nonperturbative corrections induced by vacuum quark and gluon condensates. Our result indicates that there might be no hierarchy of power corrections in finite energy sum rules at the scale of $\tau$ mass. Therefore, the standard nonperturbative corrections do not necessarily improve the accuracy of the theoretical predicition, but can rather be used to estimate an intrinsic accuracy of the pure perturbative calculation, which turns out to be rather high on this evidence, of order one percent.
[ { "created": "Fri, 3 Sep 1993 11:46:18 GMT", "version": "v1" } ]
2009-10-22
[ [ "Balitsky", "I. I.", "" ], [ "Beneke", "M.", "" ], [ "Braun", "V. M.", "" ] ]
Contrary to some previous claims, we find a sizable instanton contribution to the finite energy sum rule used to extract the value of the strong coupling from the measured $\tau$ decay widths. It is of the same order of magnitude as standard nonperturbative corrections induced by vacuum quark and gluon condensates. Our result indicates that there might be no hierarchy of power corrections in finite energy sum rules at the scale of $\tau$ mass. Therefore, the standard nonperturbative corrections do not necessarily improve the accuracy of the theoretical predicition, but can rather be used to estimate an intrinsic accuracy of the pure perturbative calculation, which turns out to be rather high on this evidence, of order one percent.
1312.5664
David Marzocca
David Marzocca, Alberto Parolini, Marco Serone
Supersymmetry with a pNGB Higgs and Partial Compositeness
26 pages, 3 figures. Version to appear in JHEP
JHEP 1403 (2014) 099
10.1007/JHEP03(2014)099
SISSA 58/2013/FISI
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the consequences of combining SUSY with a pseudo Nambu-Goldstone boson Higgs coming from an SO(5)/SO(4) coset and partial compositeness. In particular, we focus on how electroweak symmetry breaking and the Higgs mass are reproduced in models where the symmetry SO(5) is linearly realized. The global symmetry forbids tree-level contributions to the Higgs potential coming from D-terms, differently from what happens in most of the SUSY little-Higgs constructions. While the stops are generally heavy, light fermion top partners below 1 TeV are predicted. In contrast to what happens in non-SUSY composite Higgs models, they are necessary to reproduce the correct top, rather than Higgs, mass. En passant, we point out that, independently of SUSY, models where tR is fully composite and embedded in the 5 of SO(5) generally predict a too light Higgs.
[ { "created": "Thu, 19 Dec 2013 17:48:08 GMT", "version": "v1" }, { "created": "Mon, 10 Mar 2014 09:55:59 GMT", "version": "v2" }, { "created": "Mon, 24 Mar 2014 13:31:46 GMT", "version": "v3" } ]
2014-04-29
[ [ "Marzocca", "David", "" ], [ "Parolini", "Alberto", "" ], [ "Serone", "Marco", "" ] ]
We study the consequences of combining SUSY with a pseudo Nambu-Goldstone boson Higgs coming from an SO(5)/SO(4) coset and partial compositeness. In particular, we focus on how electroweak symmetry breaking and the Higgs mass are reproduced in models where the symmetry SO(5) is linearly realized. The global symmetry forbids tree-level contributions to the Higgs potential coming from D-terms, differently from what happens in most of the SUSY little-Higgs constructions. While the stops are generally heavy, light fermion top partners below 1 TeV are predicted. In contrast to what happens in non-SUSY composite Higgs models, they are necessary to reproduce the correct top, rather than Higgs, mass. En passant, we point out that, independently of SUSY, models where tR is fully composite and embedded in the 5 of SO(5) generally predict a too light Higgs.
0805.0479
Ming-Qiu Huang
Jian-Rong Zhang and Ming-Qiu Huang
Mass spectra of the heavy baryons Lambda_Q and Sigma_Q^(*) from QCD sum rules
RevTeX4, 8 pages with 14 eps figures
Phys.Rev.D77:094002,2008
10.1103/PhysRevD.77.094002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use QCD sum rule approach to calculate the masses of the ground-state Lambda_Q and Sigma_Q^(*) baryons. Contributions of the operators up to dimension six are included in operator product expansion. The resulting heavy baryonic masses from the calculations are m_{Lambda_b}=5.69 +/- 0.13 GeV, and m_{Lambda_c}=2.31 +/- 0.19 GeV for Lambda_Q; m_{Sigma_b}=5.73 +/- 0.21 GeV, m_{Sigma_b^*}=5.81 +/- 0.19 GeV, m_{Sigma_c}=2.40 +/- 0.31 GeV and m_{Sigma_c^*}=2.56 +/- 0.24 GeV for Sigma_Q^(*), respectively, which are in good agreement with the experimental values.
[ { "created": "Mon, 5 May 2008 08:15:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zhang", "Jian-Rong", "" ], [ "Huang", "Ming-Qiu", "" ] ]
We use QCD sum rule approach to calculate the masses of the ground-state Lambda_Q and Sigma_Q^(*) baryons. Contributions of the operators up to dimension six are included in operator product expansion. The resulting heavy baryonic masses from the calculations are m_{Lambda_b}=5.69 +/- 0.13 GeV, and m_{Lambda_c}=2.31 +/- 0.19 GeV for Lambda_Q; m_{Sigma_b}=5.73 +/- 0.21 GeV, m_{Sigma_b^*}=5.81 +/- 0.19 GeV, m_{Sigma_c}=2.40 +/- 0.31 GeV and m_{Sigma_c^*}=2.56 +/- 0.24 GeV for Sigma_Q^(*), respectively, which are in good agreement with the experimental values.
2210.00165
Nicholas J. Benoit
Nicholas J. Benoit, Takuya Morozumi, Yusuke Shimizu, Kenta Takagi, and Akihiro Yuu
Renormalization group effects for a rank degenerate Yukawa matrix and the fate of the massless neutrino
23 pages, 3 figures; updated subsection titles, and added comments end of section 4 per referee comments. Conclusion remains the same
null
null
HUPD-2203
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The Type-I seesaw model is a common extension to the Standard Model that describes neutrino masses. The Type-I seesaw introduces heavy right-handed neutrinos with Majorana mass that transform as Standard Model electroweak gauge singlets. We initially study a case with two right-handed neutrinos called the 3-2 model. At an energy scale above the right-handed neutrinos, the effective neutrino mass matrix is rank degenerate implying the lightest neutrino is massless. After considering renormalization effects below the two right-handed neutrinos, the effective neutrino mass matrix remains rank degenerate. Next, we study a model with three right-handed neutrinos called the 3-3 model. Above the energy scale of the three right-handed neutrinos, we construct the effective neutrino mass matrix to be rank degenerate. After solving for the renormalization effects to energies below the three right-handed neutrinos, we find the rank of the effective neutrino mass matrix depends on the kernel solutions of the renormalization group equations. We prove for the simplest kernel solutions the effective neutrino mass matrix remains rank degenerate.
[ { "created": "Sat, 1 Oct 2022 02:05:07 GMT", "version": "v1" }, { "created": "Mon, 17 Oct 2022 08:54:56 GMT", "version": "v2" } ]
2022-10-18
[ [ "Benoit", "Nicholas J.", "" ], [ "Morozumi", "Takuya", "" ], [ "Shimizu", "Yusuke", "" ], [ "Takagi", "Kenta", "" ], [ "Yuu", "Akihiro", "" ] ]
The Type-I seesaw model is a common extension to the Standard Model that describes neutrino masses. The Type-I seesaw introduces heavy right-handed neutrinos with Majorana mass that transform as Standard Model electroweak gauge singlets. We initially study a case with two right-handed neutrinos called the 3-2 model. At an energy scale above the right-handed neutrinos, the effective neutrino mass matrix is rank degenerate implying the lightest neutrino is massless. After considering renormalization effects below the two right-handed neutrinos, the effective neutrino mass matrix remains rank degenerate. Next, we study a model with three right-handed neutrinos called the 3-3 model. Above the energy scale of the three right-handed neutrinos, we construct the effective neutrino mass matrix to be rank degenerate. After solving for the renormalization effects to energies below the three right-handed neutrinos, we find the rank of the effective neutrino mass matrix depends on the kernel solutions of the renormalization group equations. We prove for the simplest kernel solutions the effective neutrino mass matrix remains rank degenerate.
hep-ph/0010147
George Triantaphyllou
George Triantaphyllou (National Technical University of Athens)
Mass generation and the dynamical role of the Katoptron Group
15 LaTeX pages, some comments added, version published in Modern Physics Letters A
Mod.Phys.Lett. A16 (2001) 53-62
10.1142/S0217732301002274
NTUA-100/00
hep-ph hep-ex
null
Heavy mirror fermions along with a new strong gauge interaction capable of breaking the electroweak gauge symmetry dynamically were recently introduced under the name of katoptrons. Their main function is to provide a viable alternative to the Standard-Model Higgs sector. In such a framework, ordinary fermions acquire masses after the breaking of the strong katoptron group which allows mixing with their katoptron partners. The purpose of this paper is to study the elementary-scalars-free mechanism responsible for this breaking and its implications for the fermion mass hierarchies.
[ { "created": "Sat, 14 Oct 2000 14:44:21 GMT", "version": "v1" }, { "created": "Tue, 17 Apr 2001 06:44:44 GMT", "version": "v2" } ]
2009-10-31
[ [ "Triantaphyllou", "George", "", "National Technical University of Athens" ] ]
Heavy mirror fermions along with a new strong gauge interaction capable of breaking the electroweak gauge symmetry dynamically were recently introduced under the name of katoptrons. Their main function is to provide a viable alternative to the Standard-Model Higgs sector. In such a framework, ordinary fermions acquire masses after the breaking of the strong katoptron group which allows mixing with their katoptron partners. The purpose of this paper is to study the elementary-scalars-free mechanism responsible for this breaking and its implications for the fermion mass hierarchies.
hep-ph/0310247
Tai-Fu Feng
Tai-Fu Feng, Xue-Qian Li, Jukka Maalampi
The anomalous Higgs-top couplings in the MSSM
Latex, 26 pages + 13 ps figures, final version in PRD
Phys.Rev. D69 (2004) 115007
10.1103/PhysRevD.69.115007
null
hep-ph
null
The anomalous couplings of the top quark and the Higgs boson has been studied in an effective theory resulting in the framework of the minimal supersymmetric extension of the standard model (MSSM) when the heavy fields are integrated out. Constraints on the parameters of the model from the experimental data on the ratio $R_b={\Gamma(Z\to b\bar{b})/\Gamma(Z\to hadrons)}$ are derived.
[ { "created": "Tue, 21 Oct 2003 10:29:23 GMT", "version": "v1" }, { "created": "Fri, 19 Mar 2004 07:08:08 GMT", "version": "v2" } ]
2009-11-10
[ [ "Feng", "Tai-Fu", "" ], [ "Li", "Xue-Qian", "" ], [ "Maalampi", "Jukka", "" ] ]
The anomalous couplings of the top quark and the Higgs boson has been studied in an effective theory resulting in the framework of the minimal supersymmetric extension of the standard model (MSSM) when the heavy fields are integrated out. Constraints on the parameters of the model from the experimental data on the ratio $R_b={\Gamma(Z\to b\bar{b})/\Gamma(Z\to hadrons)}$ are derived.
1602.04074
Sebastian Wild
Riccardo Catena, Alejandro Ibarra, Sebastian Wild
DAMA confronts null searches in the effective theory of dark matter-nucleon interactions
19 pages, 3 figures. Matches published version
null
10.1088/1475-7516/2016/05/039
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the dark matter interpretation of the modulation signal reported by the DAMA experiment from the perspective of effective field theories displaying Galilean invariance. We consider the most general effective coupling leading to the elastic scattering of a dark matter particle with spin 0 or 1/2 off a nucleon, and we analyze the compatibility of the DAMA signal with the null results from other direct detection experiments, as well as with the non-observation of a high energy neutrino flux in the direction of the Sun from dark matter annihilation. To this end, we develop a novel semi-analytical approach for comparing experimental results in the high-dimensional parameter space of the non-relativistic effective theory. Assuming the standard halo model, we find a strong tension between the dark matter interpretation of the DAMA modulation signal and the null result experiments. We also list possible ways-out of this conclusion.
[ { "created": "Fri, 12 Feb 2016 15:02:30 GMT", "version": "v1" }, { "created": "Thu, 19 May 2016 11:33:42 GMT", "version": "v2" } ]
2016-05-25
[ [ "Catena", "Riccardo", "" ], [ "Ibarra", "Alejandro", "" ], [ "Wild", "Sebastian", "" ] ]
We examine the dark matter interpretation of the modulation signal reported by the DAMA experiment from the perspective of effective field theories displaying Galilean invariance. We consider the most general effective coupling leading to the elastic scattering of a dark matter particle with spin 0 or 1/2 off a nucleon, and we analyze the compatibility of the DAMA signal with the null results from other direct detection experiments, as well as with the non-observation of a high energy neutrino flux in the direction of the Sun from dark matter annihilation. To this end, we develop a novel semi-analytical approach for comparing experimental results in the high-dimensional parameter space of the non-relativistic effective theory. Assuming the standard halo model, we find a strong tension between the dark matter interpretation of the DAMA modulation signal and the null result experiments. We also list possible ways-out of this conclusion.
2403.11581
Alba Reyes-Torrecilla
A. Reyes-Torrecilla, J. R. Pelaez, P. C. Magalh\~aes
Giant CP violation in charmless three-body $B$ meson decays at LHCb: all order formalism for meson-meson final state interactions
6 pages, 2 figures, presented at ExcitedQCD 2024
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
LHCb has observed giant CP violation in localized regions of the Dalitz plots of B to three charmless light mesons. This has been interpreted as an enhancement due to strong two-body final state interactions. In this talk, we show how such interactions, described with dispersive analyses of data, can be implemented beyond the leading order expansion in the two-body re-scattering amplitude.
[ { "created": "Mon, 18 Mar 2024 08:55:37 GMT", "version": "v1" } ]
2024-03-19
[ [ "Reyes-Torrecilla", "A.", "" ], [ "Pelaez", "J. R.", "" ], [ "Magalhães", "P. C.", "" ] ]
LHCb has observed giant CP violation in localized regions of the Dalitz plots of B to three charmless light mesons. This has been interpreted as an enhancement due to strong two-body final state interactions. In this talk, we show how such interactions, described with dispersive analyses of data, can be implemented beyond the leading order expansion in the two-body re-scattering amplitude.
hep-ph/9403217
null
E. J. Chun, H. B. Kim and A. Lukas
Supersymmetric Singlet Majorons and Cosmology
14 pages, 2 figures, IC/94/40, SNUTP 94-15, TUM - TH - 164/94
Phys.Lett. B328 (1994) 346-353
10.1016/0370-2693(94)91489-3
null
hep-ph
null
We examine cosmological constraints on the lepton number breaking scale in supersymmetric singlet majoron models. Special attention is drawn to the model dependence arising from the particular choice of a certain majoron extension and a cosmological scenario. We find that the bounds on the symmetry breaking scale can vary substantially. Large values of this scale can be allowed if the decoupling temperature of smajoron and majorino exceeds the reheating temperature of inflation. In the opposite case an upper bound depending on the majoron model can be obtained which, however, is unlikely to be much larger than $10^{10}$ GeV.
[ { "created": "Thu, 3 Mar 1994 11:02:14 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chun", "E. J.", "" ], [ "Kim", "H. B.", "" ], [ "Lukas", "A.", "" ] ]
We examine cosmological constraints on the lepton number breaking scale in supersymmetric singlet majoron models. Special attention is drawn to the model dependence arising from the particular choice of a certain majoron extension and a cosmological scenario. We find that the bounds on the symmetry breaking scale can vary substantially. Large values of this scale can be allowed if the decoupling temperature of smajoron and majorino exceeds the reheating temperature of inflation. In the opposite case an upper bound depending on the majoron model can be obtained which, however, is unlikely to be much larger than $10^{10}$ GeV.
2011.10565
Andrea Tesi
Michele Redi, Andrea Tesi, Hannah Tillim
Gravitational Production of a Conformal Dark Sector
24 pages, 2 figures. v2) factor 2 fixed, references and clarifications added, results unchanged
null
10.1007/JHEP05(2021)010
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark sectors with purely gravitational couplings to the Standard Model are unavoidably populated from the SM plasma by graviton exchange, and naturally provide DM candidates. We examine the production in the relativistic regime where the dark sector is approximately scale invariant, providing general analytical formulas that depend solely on the central charge of the dark sector. We then assess the relevance of interactions that can lead to a variety of phenomena including thermalisation, nonperturbative mass gaps, out-of-equilibrium phase transitions and cannibalism in the dark sector. As an illustrative example we consider the dark glueball scenario in this light and show it to be a viable DM candidate due to the suppression of gravitational production. We go on to extend these results to strongly coupled CFTs and their holographic duals at large-N with the dark dilaton as the DM candidate.
[ { "created": "Fri, 20 Nov 2020 18:59:32 GMT", "version": "v1" }, { "created": "Tue, 16 Mar 2021 13:39:24 GMT", "version": "v2" } ]
2021-05-19
[ [ "Redi", "Michele", "" ], [ "Tesi", "Andrea", "" ], [ "Tillim", "Hannah", "" ] ]
Dark sectors with purely gravitational couplings to the Standard Model are unavoidably populated from the SM plasma by graviton exchange, and naturally provide DM candidates. We examine the production in the relativistic regime where the dark sector is approximately scale invariant, providing general analytical formulas that depend solely on the central charge of the dark sector. We then assess the relevance of interactions that can lead to a variety of phenomena including thermalisation, nonperturbative mass gaps, out-of-equilibrium phase transitions and cannibalism in the dark sector. As an illustrative example we consider the dark glueball scenario in this light and show it to be a viable DM candidate due to the suppression of gravitational production. We go on to extend these results to strongly coupled CFTs and their holographic duals at large-N with the dark dilaton as the DM candidate.
hep-ph/0106085
Guido Altarelli
Guido Altarelli
Models of neutrino masses and mixings
22 pages, talk given at the 9th Int. Workshop on Neutrino Telescopes, Venice, March 6-9, 2001
null
null
CERN-TH/2001-144
hep-ph
null
We briefly review models of neutrino masses and mixings. In view of the existing experimental ambiguities many possibilities are still open. After an overview of the main alternative options we focus on the most constrained class of models based on three widely split light neutrinos within SUSY Grand Unification.
[ { "created": "Fri, 8 Jun 2001 09:52:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Altarelli", "Guido", "" ] ]
We briefly review models of neutrino masses and mixings. In view of the existing experimental ambiguities many possibilities are still open. After an overview of the main alternative options we focus on the most constrained class of models based on three widely split light neutrinos within SUSY Grand Unification.
hep-ph/9906203
Brian Cox
B. E. Cox
High-t Diffraction at HERA
3 pages, 2 figures, Talk presented at DIS99, Zeuthen, Germany
Nucl.Phys.Proc.Suppl.79:315-317,1999
10.1016/S0920-5632(99)00709-4
null
hep-ph
null
The double dissociation photoproduction cross section for the process gamma p -> XY, in which the systems X and Y are separated by a large rapidity gap, is measured at large 4-momentum transfer squared |t| > 20 GeV^2 by the H1 Collaboration at HERA. This measurement provides for the first time a direct measurement of the energy dependence of the gap production process at high |t|.
[ { "created": "Tue, 1 Jun 1999 13:16:29 GMT", "version": "v1" } ]
2011-03-23
[ [ "Cox", "B. E.", "" ] ]
The double dissociation photoproduction cross section for the process gamma p -> XY, in which the systems X and Y are separated by a large rapidity gap, is measured at large 4-momentum transfer squared |t| > 20 GeV^2 by the H1 Collaboration at HERA. This measurement provides for the first time a direct measurement of the energy dependence of the gap production process at high |t|.
1405.1434
Florian Staub
Werner Porod, Florian Staub, Avelino Vicente
A Flavor Kit for BSM models
68 pages; PreSARAH and FlavorKit (included in SARAH 4.2.0) can be downloaded at http://sarah.hepforge.org/FlavorKit.html; v2: minor extensions, matches published version; v3: unifying layout in the appendix
Eur. Phys. J. C (2014) 74:2992
10.1140/epjc/s10052-014-2992-2
BONN-TH-2014-07
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new kit for the study of flavor observables in models beyond the standard model. The setup is based on the public codes SARAH and SPheno and allows for an easy implementation of new observables. The Wilson coefficients of the corresponding operators in the effective Lagrangian are computed by SPheno modules written by SARAH. New operators can also be added by the user in a modular way. For this purpose a handy Mathematica package called PreSARAH has been developed. This uses FeynArts and FormCalc to derive the generic form factors at tree- and 1-loop levels and to generate the necessary input files for SARAH. This framework has been used to implement BR($\ell_\alpha\to \ell_\beta \gamma$), BR($\ell_\alpha \to 3\, \ell_\beta$), CR($\mu-e,A$), BR($\tau \to P \, \ell$), BR($h\to \ell_\alpha \ell_\beta$), BR($Z\to \ell_\alpha \ell_\beta$), BR($B_{s,d}^0 \to \ell \bar{\ell}$), BR($\bar B \to X_s\gamma$), BR($\bar B \to X_s \ell \bar{\ell}$), BR($\bar B \to X_{d,s} \nu \bar \nu$), BR($K^+ \to \pi^+ \nu \bar \nu$), BR($K_L \to \pi^0 \nu \bar \nu$), $\Delta M_{B_s,B_d}$, $\Delta M_K$, $\varepsilon_K$, BR($B \to K \mu \bar{\mu}$), BR($B\to \ell \nu$), BR($D_s \to \ell \nu$) and BR($K \to \ell \nu$) in SARAH. Predictions for these observables can now be obtained in a wide range of SUSY and non-SUSY models. Finally, the user can use the same approach to easily compute additional observables.
[ { "created": "Tue, 6 May 2014 20:01:10 GMT", "version": "v1" }, { "created": "Wed, 3 Sep 2014 16:13:15 GMT", "version": "v2" }, { "created": "Mon, 9 May 2016 19:48:50 GMT", "version": "v3" } ]
2016-05-11
[ [ "Porod", "Werner", "" ], [ "Staub", "Florian", "" ], [ "Vicente", "Avelino", "" ] ]
We present a new kit for the study of flavor observables in models beyond the standard model. The setup is based on the public codes SARAH and SPheno and allows for an easy implementation of new observables. The Wilson coefficients of the corresponding operators in the effective Lagrangian are computed by SPheno modules written by SARAH. New operators can also be added by the user in a modular way. For this purpose a handy Mathematica package called PreSARAH has been developed. This uses FeynArts and FormCalc to derive the generic form factors at tree- and 1-loop levels and to generate the necessary input files for SARAH. This framework has been used to implement BR($\ell_\alpha\to \ell_\beta \gamma$), BR($\ell_\alpha \to 3\, \ell_\beta$), CR($\mu-e,A$), BR($\tau \to P \, \ell$), BR($h\to \ell_\alpha \ell_\beta$), BR($Z\to \ell_\alpha \ell_\beta$), BR($B_{s,d}^0 \to \ell \bar{\ell}$), BR($\bar B \to X_s\gamma$), BR($\bar B \to X_s \ell \bar{\ell}$), BR($\bar B \to X_{d,s} \nu \bar \nu$), BR($K^+ \to \pi^+ \nu \bar \nu$), BR($K_L \to \pi^0 \nu \bar \nu$), $\Delta M_{B_s,B_d}$, $\Delta M_K$, $\varepsilon_K$, BR($B \to K \mu \bar{\mu}$), BR($B\to \ell \nu$), BR($D_s \to \ell \nu$) and BR($K \to \ell \nu$) in SARAH. Predictions for these observables can now be obtained in a wide range of SUSY and non-SUSY models. Finally, the user can use the same approach to easily compute additional observables.
hep-ph/0410090
Bilenky Samoil
S. M. Bilenky
The History of Neutrino Oscillations
A report at the ``Nobel Symposium on Neutrino physics'', Haga Slott, Enkoping, Sweden, August 19-24, 2004
Phys.Scripta T121 (2005) 17-22
10.1088/0031-8949/2005/T121/001
null
hep-ph
null
The early history of neutrino masses, mixing and oscillations is briefly reviewed.
[ { "created": "Wed, 6 Oct 2004 14:48:46 GMT", "version": "v1" } ]
2009-11-10
[ [ "Bilenky", "S. M.", "" ] ]
The early history of neutrino masses, mixing and oscillations is briefly reviewed.
hep-ph/0604053
Andreas Vogt
A. Mitov, S. Moch (DESY, Zeuthen), A. Vogt (Durham Univ., IPPP)
Next-to-Next-to-Leading Order Evolution of Non-Singlet Fragmentation Functions
10 pages, LaTeX, 2 eps-figures
Phys.Lett.B638:61-67,2006
10.1016/j.physletb.2006.05.005
DESY 06-036, DCPT/06/40, IPPP/06/20
hep-ph
null
We have investigated the next-to-next-to-leading order (NNLO) corrections to inclusive hadron production in e^+e^- annihilation and the related parton fragmentation distributions, the `time-like' counterparts of the `space-like' deep-inelastic structure functions and parton densities. We have re-derived the corresponding second-order coefficient functions in massless perturbative QCD, which so far had been calculated only by one group. Moreover we present, for the first time, the third-order splitting functions governing the NNLO evolution of flavour non-singlet fragmentation distributions. These results have been obtained by two independent methods relating time-like quantities to calculations performed in deep-inelastic scattering. We briefly illustrate the numerical size of the NNLO corrections, and make a prediction for the difference of the yet unknown time-like and space-like splitting functions at the fourth order in the strong coupling constant.
[ { "created": "Thu, 6 Apr 2006 09:57:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mitov", "A.", "", "DESY, Zeuthen" ], [ "Moch", "S.", "", "DESY, Zeuthen" ], [ "Vogt", "A.", "", "Durham Univ., IPPP" ] ]
We have investigated the next-to-next-to-leading order (NNLO) corrections to inclusive hadron production in e^+e^- annihilation and the related parton fragmentation distributions, the `time-like' counterparts of the `space-like' deep-inelastic structure functions and parton densities. We have re-derived the corresponding second-order coefficient functions in massless perturbative QCD, which so far had been calculated only by one group. Moreover we present, for the first time, the third-order splitting functions governing the NNLO evolution of flavour non-singlet fragmentation distributions. These results have been obtained by two independent methods relating time-like quantities to calculations performed in deep-inelastic scattering. We briefly illustrate the numerical size of the NNLO corrections, and make a prediction for the difference of the yet unknown time-like and space-like splitting functions at the fourth order in the strong coupling constant.
0808.2305
D. Delepine
D. Delepine, J. L. Lucio M. (Universidad de Guanajuato, Mexico), J. A. Mendoza S.(Universidad de Pamplona, Colombia), Carlos A. Ramirez (Universidad Industrial de Santander, Colombia)
A Consistent Scenario for B to PS Decays
10 pages, no figures
Phys.Rev.D78:114016,2008
10.1103/PhysRevD.78.114016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider B to PS decays where P stands for pseudoscalar and S for a heavy (~1500 MeV) scalar meson. We achieve agreement with available experimental data -- which includes a two orders of magnitude hierarchy -- assuming the scalars mesons are two quark states. The contribution of the dipolar penguin operator O_{11} is quantified.
[ { "created": "Sun, 17 Aug 2008 18:24:47 GMT", "version": "v1" } ]
2008-12-30
[ [ "Delepine", "D.", "", "Universidad de Guanajuato, Mexico" ], [ "M.", "J. L. Lucio", "", "Universidad de Guanajuato, Mexico" ], [ "S.", "J. A. Mendoza", "", "Universidad de Pamplona, Colombia" ], [ "Ramirez", "Carlos A.", "", "Universidad\n Industrial de Santander, Colombia" ] ]
We consider B to PS decays where P stands for pseudoscalar and S for a heavy (~1500 MeV) scalar meson. We achieve agreement with available experimental data -- which includes a two orders of magnitude hierarchy -- assuming the scalars mesons are two quark states. The contribution of the dipolar penguin operator O_{11} is quantified.
1905.00184
Sunil Bansal
R. Kumar, M. Bansal, S. Bansal
Jet fragmentation as a tool to explore double parton scattering using Z-boson + jets processes at the LHC
14 pages, 4 figures
Phys. Rev. D 99, 094025 (2019)
10.1103/PhysRevD.99.094025
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Large Hadron Collider witnesses the highest ever production cross-section of double parton scattering processes. The production of a Z-boson along with two jets from double parton scattering provides a unique opportunity to explore the kinematics of double parton scattering processes and their dependence on the scale of the second interaction. The experimental measurement of this process is largely contaminated by Z + jets production from single parton scattering. In this paper, fragmentation properties of a jet are explored to check their sensitivity towards double parton scattering. The present study is performed using simulated Z + jets events, produced with \textsc{madgraph} and \textsc{powheg} Monte-Carlo event generators, hadronized and parton showered using \textsc{pythia}8. The effect of different hadronization model on the discrimination based on the fragmentation properties of a jet is also investigated by using events simulated with \textsc{herwig}++. It is observed that discrimination based on the fragmentation properties of a jet can significantly suppress the background from single parton scattering, which results into 40--50\% gain in the contribution of double parton scattering.
[ { "created": "Wed, 1 May 2019 04:47:44 GMT", "version": "v1" } ]
2019-05-22
[ [ "Kumar", "R.", "" ], [ "Bansal", "M.", "" ], [ "Bansal", "S.", "" ] ]
The Large Hadron Collider witnesses the highest ever production cross-section of double parton scattering processes. The production of a Z-boson along with two jets from double parton scattering provides a unique opportunity to explore the kinematics of double parton scattering processes and their dependence on the scale of the second interaction. The experimental measurement of this process is largely contaminated by Z + jets production from single parton scattering. In this paper, fragmentation properties of a jet are explored to check their sensitivity towards double parton scattering. The present study is performed using simulated Z + jets events, produced with \textsc{madgraph} and \textsc{powheg} Monte-Carlo event generators, hadronized and parton showered using \textsc{pythia}8. The effect of different hadronization model on the discrimination based on the fragmentation properties of a jet is also investigated by using events simulated with \textsc{herwig}++. It is observed that discrimination based on the fragmentation properties of a jet can significantly suppress the background from single parton scattering, which results into 40--50\% gain in the contribution of double parton scattering.
hep-ph/0502060
Joaquim Matias
Frank Kr\"uger and Joaquim Matias
Probing New Physics Via the Transverse Amplitudes of B0-> K*0(-> K- pi+) l+l- at Large Recoil
21 pages, 16 figures. Minor typo in Eq. (4.8) corrected; version to appear in Phys. Rev. D
Phys.Rev.D71:094009,2005
10.1103/PhysRevD.71.094009
UAB-FT 560
hep-ph
null
We perform an analysis of the K* polarization states in the exclusive B meson decay B0->K*0(-> K- pi+)l+ l- (l=e, mu, tau) in the low dilepton mass region, where the final vector meson has a large energy. Working in the transversity basis, we study various observables that involve the K* spin amplitudes Aperp, Apar, A0 by exploiting the heavy-to-light form factor relations in the heavy quark and large-E_K* limit. We find that at leading order in 1/m_b and alpha_s the form-factor dependence of the asymmetries that involve transversely polarized K* completely drops out. At next-to-leading logarithmic order, including factorizable and non-factorizable corrections, the theoretical errors for the transverse asymmetries turn out to be small in the standard model (SM). Integrating over the lower part of the dimuon mass region, and varying the theoretical input parameters, the SM predicts A_T^(1)=0.9986+/- 0.0002 and A_T^(2)=-0.043+/- 0.003. In addition, the longitudinal and transverse polarization fractions are found to be (69+/-3)% and (31+/-3)% respectively, so that Gamma_L/Gamma_T = 2.23+/-0.31. Beyond the SM, we focus on new physics that mainly gives sizable contributions to the coefficients C_7^eff' of the electromagnetic dipole operators. Taking into account experimental data on rare B decays, we find large effects of new physics in the transverse asymmetries. Furthermore, we show that a measurement of longitudinal and transverse polarization fractions will provide complementary information on physics beyond the SM.
[ { "created": "Mon, 7 Feb 2005 10:28:17 GMT", "version": "v1" }, { "created": "Tue, 19 Apr 2005 14:42:31 GMT", "version": "v2" } ]
2011-07-19
[ [ "Krüger", "Frank", "" ], [ "Matias", "Joaquim", "" ] ]
We perform an analysis of the K* polarization states in the exclusive B meson decay B0->K*0(-> K- pi+)l+ l- (l=e, mu, tau) in the low dilepton mass region, where the final vector meson has a large energy. Working in the transversity basis, we study various observables that involve the K* spin amplitudes Aperp, Apar, A0 by exploiting the heavy-to-light form factor relations in the heavy quark and large-E_K* limit. We find that at leading order in 1/m_b and alpha_s the form-factor dependence of the asymmetries that involve transversely polarized K* completely drops out. At next-to-leading logarithmic order, including factorizable and non-factorizable corrections, the theoretical errors for the transverse asymmetries turn out to be small in the standard model (SM). Integrating over the lower part of the dimuon mass region, and varying the theoretical input parameters, the SM predicts A_T^(1)=0.9986+/- 0.0002 and A_T^(2)=-0.043+/- 0.003. In addition, the longitudinal and transverse polarization fractions are found to be (69+/-3)% and (31+/-3)% respectively, so that Gamma_L/Gamma_T = 2.23+/-0.31. Beyond the SM, we focus on new physics that mainly gives sizable contributions to the coefficients C_7^eff' of the electromagnetic dipole operators. Taking into account experimental data on rare B decays, we find large effects of new physics in the transverse asymmetries. Furthermore, we show that a measurement of longitudinal and transverse polarization fractions will provide complementary information on physics beyond the SM.
1810.00574
Kohei Fujikura
Kohei Fujikura, Kohei Kamada, Yuichiro Nakai, Masahide Yamaguchi
Phase Transitions in Twin Higgs Models
33 pages, 5 figures; v2: journal version
JHEP 1812 (2018) 018
10.1007/JHEP12(2018)018
CTPU-PTC-18-27, RESCEU-12/18
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study twin Higgs models at non-zero temperature and discuss cosmological phase transitions as well as their implications on electroweak baryogenesis and gravitational waves. It is shown that the expectation value of the Higgs field at the critical temperature of the electroweak phase transition is much smaller than the critical temperature, which indicates two important facts: (i) the electroweak phase transition cannot be analyzed perturbatively (ii) the electroweak baryogenesis is hardly realized in the typical realizations of twin Higgs models. We also analyze the phase transition associated with the global symmetry breaking, through which the Standard Model Higgs is identified with one of the pseudo-Nambu-Goldstone bosons in terms of its linear realization, with and without supersymmetry. For this phase transition, we show that, only in the supersymmetric case, there are still some parameter spaces, in which the perturbative approach is validated and the phase transition is the first order. We find that the stochastic gravitational wave background is generated through this first order phase transition, but it is impossible to be detected by DECIGO or BBO in the linear realization and the decoupling limit. The detection of stochastic gravitational wave background with the feature of first order phase transition, therefore, will give strong constraints on twin Higgs models.
[ { "created": "Mon, 1 Oct 2018 08:27:14 GMT", "version": "v1" }, { "created": "Tue, 25 Dec 2018 04:59:19 GMT", "version": "v2" } ]
2018-12-27
[ [ "Fujikura", "Kohei", "" ], [ "Kamada", "Kohei", "" ], [ "Nakai", "Yuichiro", "" ], [ "Yamaguchi", "Masahide", "" ] ]
We study twin Higgs models at non-zero temperature and discuss cosmological phase transitions as well as their implications on electroweak baryogenesis and gravitational waves. It is shown that the expectation value of the Higgs field at the critical temperature of the electroweak phase transition is much smaller than the critical temperature, which indicates two important facts: (i) the electroweak phase transition cannot be analyzed perturbatively (ii) the electroweak baryogenesis is hardly realized in the typical realizations of twin Higgs models. We also analyze the phase transition associated with the global symmetry breaking, through which the Standard Model Higgs is identified with one of the pseudo-Nambu-Goldstone bosons in terms of its linear realization, with and without supersymmetry. For this phase transition, we show that, only in the supersymmetric case, there are still some parameter spaces, in which the perturbative approach is validated and the phase transition is the first order. We find that the stochastic gravitational wave background is generated through this first order phase transition, but it is impossible to be detected by DECIGO or BBO in the linear realization and the decoupling limit. The detection of stochastic gravitational wave background with the feature of first order phase transition, therefore, will give strong constraints on twin Higgs models.
1407.8321
Karim Benakli
Karim Benakli, Luc Darm\'e and Yaron Oz
The Slow Gravitino
24 pages
null
10.1007/JHEP10(2014)121
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When the supersymmetry breaking sector is a fluid background, Lorentz invariance is broken spontaneously. The super-Higgs mechanism leads to a gravitino Lagrangian with Lorentz symmetry violating terms. We analyse the resulting field equations and constraints. We identify the physical spin 3/2 and spin 1/2 helicity states, derive their equations of motion and construct the propagator. The violation of Lorentz symmetry implies that the longitudinal mode has a non-relativistic dispersion relation, whose speed is lower than the speed of light. We briefly comment on possible implications to gravitino cosmology and phenomenology.
[ { "created": "Thu, 31 Jul 2014 09:01:37 GMT", "version": "v1" } ]
2015-06-22
[ [ "Benakli", "Karim", "" ], [ "Darmé", "Luc", "" ], [ "Oz", "Yaron", "" ] ]
When the supersymmetry breaking sector is a fluid background, Lorentz invariance is broken spontaneously. The super-Higgs mechanism leads to a gravitino Lagrangian with Lorentz symmetry violating terms. We analyse the resulting field equations and constraints. We identify the physical spin 3/2 and spin 1/2 helicity states, derive their equations of motion and construct the propagator. The violation of Lorentz symmetry implies that the longitudinal mode has a non-relativistic dispersion relation, whose speed is lower than the speed of light. We briefly comment on possible implications to gravitino cosmology and phenomenology.
1311.4697
Kanchan Khemchandani
K. P. Khemchandani, A. Martinez Torres, M. Nielsen, F. S. Navarra, D. Jido, A. Hosaka, E. Oset
Interpreting the peak structures around 1800 MeV in the BES data on $J/\Psi \to \phi \pi^+ \pi^-$, $J/\Psi\to \gamma \omega \phi$
Proceedings for the nuclear physics meeting ("XXXVI Reuni\~ao de trabalho sobre f\'isica nuclear no Brasil") held in Maresias during Sept. 1-5. To be published as AIP proceedings
null
10.1063/1.4901801
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we present an interpretation for the experimental data available on two different processes, namely, $J/\Psi \to \phi \pi^+ \pi^-$, $J/\Psi\to \gamma \omega \phi$, which seem to indicate existence of two new resonances with the same quantum numbers ($J^{\pi c}=0^{++}, I = 0$) and very similar mass (~1800 MeV) but with very different decay properties. However, our studies show that the peak structure found in the $\omega \phi$ invariant mass, in $J/\Psi \to \gamma \omega \phi$, is a manifestation of the well known $f_0(1710)$ while the cross section enhancement found in $J/\Psi \to \phi \pi^+ \pi^-$ is indeed a new $f_0$ resonance with mass near 1800 MeV. We present an explanation for the different decay properties of these two scalar resonances.
[ { "created": "Tue, 19 Nov 2013 11:18:09 GMT", "version": "v1" } ]
2015-06-17
[ [ "Khemchandani", "K. P.", "" ], [ "Torres", "A. Martinez", "" ], [ "Nielsen", "M.", "" ], [ "Navarra", "F. S.", "" ], [ "Jido", "D.", "" ], [ "Hosaka", "A.", "" ], [ "Oset", "E.", "" ] ]
In this talk we present an interpretation for the experimental data available on two different processes, namely, $J/\Psi \to \phi \pi^+ \pi^-$, $J/\Psi\to \gamma \omega \phi$, which seem to indicate existence of two new resonances with the same quantum numbers ($J^{\pi c}=0^{++}, I = 0$) and very similar mass (~1800 MeV) but with very different decay properties. However, our studies show that the peak structure found in the $\omega \phi$ invariant mass, in $J/\Psi \to \gamma \omega \phi$, is a manifestation of the well known $f_0(1710)$ while the cross section enhancement found in $J/\Psi \to \phi \pi^+ \pi^-$ is indeed a new $f_0$ resonance with mass near 1800 MeV. We present an explanation for the different decay properties of these two scalar resonances.
hep-ph/9509317
Christoph Best
A. Schafer
Interplay between polarized DIS and RHIC spin physics
Talk given at the Workshop on Deep Inelastic scattering and QCD, Paris, April 1995, LaTeX, 4 pp, 5 eps figures and style file included as compressed tar file. Available at ftp://ftp.th.physik.uni-frankfurt.de/pub/schaefer/dis.ps.Z [added figures - we had an email delay; corrected URL]
null
null
null
hep-ph
null
The complementarity of polarized DIS experiments and polarized Proton-Proton experiments is illustrated for two examples. It is shown how the twist-3 part of the second moment of $g_2(x,Q^2)$ and the single-spin photon asymmetry are connected and it is discussed how the polarized gluon distribution can be obtained from the measurement of direct gamma asymmetries.
[ { "created": "Mon, 18 Sep 1995 11:18:27 GMT", "version": "v1" }, { "created": "Tue, 19 Sep 1995 10:40:31 GMT", "version": "v2" } ]
2008-02-03
[ [ "Schafer", "A.", "" ] ]
The complementarity of polarized DIS experiments and polarized Proton-Proton experiments is illustrated for two examples. It is shown how the twist-3 part of the second moment of $g_2(x,Q^2)$ and the single-spin photon asymmetry are connected and it is discussed how the polarized gluon distribution can be obtained from the measurement of direct gamma asymmetries.
2011.11105
Ilkay Turk Cakir
I. Turk Cakir (Giresun University), O. Cakir (Ankara University), H. Denizli (Bolu Abant Izzet Baysal University), A. Senol (Bolu Abant Izzet Baysal University), A. Yilmaz (Giresun University)
Investigation of Charged Higgs Boson in the Bottom and Top Quark Decay Channel at the FCC-hh
5 pages, 8 figures
null
10.1016/j.physletb.2021.136375
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
After the recent discovery of a neutral Higgs boson with a mass about 125 GeV, we assess the extend of discovery potential of future circular hadron collider (FCC-hh) for a charged Higgs boson in the bottom and top quark decay channel. The charged Higgs boson can be produced through the pp->h^{-}t+X process with a subsequent decay h^{-}->b bar{t} channel. This decay channel is particularly important for studying the charged Higgs boson heavier than the top quark. We consider an extension of the standard model Higgs sector, namely two Higgs doublet model (2HDM), and perform a dedicated signal significance analysis to test this channel for the FCC-hh running at the center of mass energy of 100 TeV and the integrated luminosity of 1 ab^{-1} (initial) and 30 ab^{-1} (ultimate). We find that an important part of the parameter spaces of two Higgs doublet model are examinable at the FCC-hh.
[ { "created": "Sun, 22 Nov 2020 21:01:26 GMT", "version": "v1" }, { "created": "Wed, 9 Dec 2020 09:27:49 GMT", "version": "v2" } ]
2021-05-26
[ [ "Cakir", "I. Turk", "", "Giresun University" ], [ "Cakir", "O.", "", "Ankara University" ], [ "Denizli", "H.", "", "Bolu Abant Izzet Baysal University" ], [ "Senol", "A.", "", "Bolu Abant Izzet\n Baysal University" ], [ "Yilmaz", "A.", "", "Giresun University" ] ]
After the recent discovery of a neutral Higgs boson with a mass about 125 GeV, we assess the extend of discovery potential of future circular hadron collider (FCC-hh) for a charged Higgs boson in the bottom and top quark decay channel. The charged Higgs boson can be produced through the pp->h^{-}t+X process with a subsequent decay h^{-}->b bar{t} channel. This decay channel is particularly important for studying the charged Higgs boson heavier than the top quark. We consider an extension of the standard model Higgs sector, namely two Higgs doublet model (2HDM), and perform a dedicated signal significance analysis to test this channel for the FCC-hh running at the center of mass energy of 100 TeV and the integrated luminosity of 1 ab^{-1} (initial) and 30 ab^{-1} (ultimate). We find that an important part of the parameter spaces of two Higgs doublet model are examinable at the FCC-hh.
1601.07288
Haijing Zhou
Haijing Zhou, Zhaoxia Heng, Dongwei Li
The properties of the Higgs bosons and Pair Production of the SM-like Higgs Boson in \lambda-SUSY at the LHC
16 pages,8 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
Compared with the MSSM or the NMSSM with a low \lambda, \lambda-SUSY theory with a large \lambda around one has been deemed as a most natural realization of NMSSM. In this work, we treat the next-to-lightest CP-even Higgs boson as the SM-like Higgs boson in \lambda-SUSY and study the properties of the Higgs bosons and the pair production of the SM-like Higgs boson by considering various experiment constraints. We find that naturalness plays an important role in selecting the parameter space of \lambda-SUSY. In the most natural region of parameter space, the triple self coupling of the SM-like Higgs boson compared with its SM prediction may get enhanced by a factor about 7, and the most dominant contribution to the Higgs pair production comes from the triple self coupling of the SM-like Higgs boson and the production rate can be greatly enhanced, maximally 10 times larger than the SM prediction.
[ { "created": "Wed, 27 Jan 2016 08:41:46 GMT", "version": "v1" }, { "created": "Fri, 29 Jan 2016 08:35:12 GMT", "version": "v2" } ]
2016-02-01
[ [ "Zhou", "Haijing", "" ], [ "Heng", "Zhaoxia", "" ], [ "Li", "Dongwei", "" ] ]
Compared with the MSSM or the NMSSM with a low \lambda, \lambda-SUSY theory with a large \lambda around one has been deemed as a most natural realization of NMSSM. In this work, we treat the next-to-lightest CP-even Higgs boson as the SM-like Higgs boson in \lambda-SUSY and study the properties of the Higgs bosons and the pair production of the SM-like Higgs boson by considering various experiment constraints. We find that naturalness plays an important role in selecting the parameter space of \lambda-SUSY. In the most natural region of parameter space, the triple self coupling of the SM-like Higgs boson compared with its SM prediction may get enhanced by a factor about 7, and the most dominant contribution to the Higgs pair production comes from the triple self coupling of the SM-like Higgs boson and the production rate can be greatly enhanced, maximally 10 times larger than the SM prediction.
hep-ph/0411007
Yogendra Srivastava
G. Pancheri, Y. Srivastava, N. Staffolani
A sum rule for elastic scattering
Presented by Y. Srivastava at ISMD04, Sonoma State University. Under publication in Acta Physica Polonica. Latex format, 1 *.eps file, 7 pages
Acta Phys.Polon. B36 (2005) 749-754
null
null
hep-ph
null
A sum rule is derived for elastic scattering of hadrons at high energies which is in good agreement with experimental data on $p\bar{p}$ available upto the maximum energy $\sqrt{s} = 2 TeV$. Physically, our sum rule reflects the way unitarity correlates and limits how large the elastic amplitude can be as a function of energy to how fast it decreases as a function of the momentum transfer. The universality of our result is justified through our earlier result on equipartition of quark and glue momenta obtained from the virial theorem for massless quarks and the Wilson conjecture
[ { "created": "Sat, 30 Oct 2004 20:21:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pancheri", "G.", "" ], [ "Srivastava", "Y.", "" ], [ "Staffolani", "N.", "" ] ]
A sum rule is derived for elastic scattering of hadrons at high energies which is in good agreement with experimental data on $p\bar{p}$ available upto the maximum energy $\sqrt{s} = 2 TeV$. Physically, our sum rule reflects the way unitarity correlates and limits how large the elastic amplitude can be as a function of energy to how fast it decreases as a function of the momentum transfer. The universality of our result is justified through our earlier result on equipartition of quark and glue momenta obtained from the virial theorem for massless quarks and the Wilson conjecture
1808.07224
Helen Brooks
Helen Brooks, Peter Skands
Average Event Properties from LHC to FCC-hh
25 pages, 10 figures, 9 tables; updated to version accepted for publication
P. Eur. Phys. J. C (2018) 78: 963
10.1140/epjc/s10052-018-6460-2
CoEPP-MN-18-4, MCNET-18-23
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of design studies for future $pp$ colliders, we present a set of predictions for average soft-QCD event properties for $pp$ collisions at $E_\mathrm{CM} = 14$, $27$, and $100$ TeV. The current default Monash 2013 tune of the PYTHIA 8.2 event generator is used as the baseline for the extrapolations, with uncertainties evaluated via variations of cross-section parametrisations, PDFs, MPI energy-scaling parameters, and colour-reconnection modelling, subject to current LHC constraints. The observables included in the study are total and inelastic cross sections, inelastic average energy and track densities per unit pseudorapidity (inside $|\eta|\le 6$), average track $p_\perp$, and jet cross sections for 50- and 100-GeV anti-$k_T$ jets with $\Delta R=0.4$, using aMC@NLO in conjunction with PYTHIA 8 for the latter.
[ { "created": "Wed, 22 Aug 2018 05:22:29 GMT", "version": "v1" }, { "created": "Tue, 27 Nov 2018 02:17:40 GMT", "version": "v2" } ]
2018-11-28
[ [ "Brooks", "Helen", "" ], [ "Skands", "Peter", "" ] ]
In the context of design studies for future $pp$ colliders, we present a set of predictions for average soft-QCD event properties for $pp$ collisions at $E_\mathrm{CM} = 14$, $27$, and $100$ TeV. The current default Monash 2013 tune of the PYTHIA 8.2 event generator is used as the baseline for the extrapolations, with uncertainties evaluated via variations of cross-section parametrisations, PDFs, MPI energy-scaling parameters, and colour-reconnection modelling, subject to current LHC constraints. The observables included in the study are total and inelastic cross sections, inelastic average energy and track densities per unit pseudorapidity (inside $|\eta|\le 6$), average track $p_\perp$, and jet cross sections for 50- and 100-GeV anti-$k_T$ jets with $\Delta R=0.4$, using aMC@NLO in conjunction with PYTHIA 8 for the latter.
hep-ph/0505044
Joan Rojo
Joan Rojo and Andrea Piccione (for the NNPDF Collaboration)
The neural network approach to parton fitting
To appear in the proceedings of "DIS 2005: XIII International Workshop on Deep Inelatic Scattering" (Madison, Wisconsin, April 2005). 5 pages, 4 figures
null
null
null
hep-ph
null
We introduce the neural network approach to global fits of parton distribution functions. First we review previous work on unbiased parametrizations of deep-inelastic structure functions with faithful estimation of their uncertainties, and then we summarize the current status of neural network parton distribution fits.
[ { "created": "Fri, 6 May 2005 09:40:08 GMT", "version": "v1" }, { "created": "Thu, 12 May 2005 07:37:34 GMT", "version": "v2" } ]
2019-08-14
[ [ "Rojo", "Joan", "", "for the NNPDF Collaboration" ], [ "Piccione", "Andrea", "", "for the NNPDF Collaboration" ] ]
We introduce the neural network approach to global fits of parton distribution functions. First we review previous work on unbiased parametrizations of deep-inelastic structure functions with faithful estimation of their uncertainties, and then we summarize the current status of neural network parton distribution fits.
hep-ph/0202180
R. A. Schneider
R. A. Schneider, T. Renk, W. Weise
Quasiparticles in QCD thermodynamics and applications
6 pages, 4 figures, Talk given at the International Workshop XXX on Gross Properties of Nuclei and Nuclear Excitations, Hirschegg, Austria
null
null
null
hep-ph
null
We propose a novel quasiparticle interpretation of the equation of state of deconfined QCD at finite temperature. Using appropriate thermal masses, we introduce a phenomenological parametrization of the onset of confinement in the vicinity of the phase transition. Lattice results of the energy density, the pressure and the interaction measure of pure SU(3) gauge theory are well reproduced. A relation between the thermal energy density of the Yang-Mills vacuum and the chromomagnetic condensate <B^2>_T is found. We also present the two flavour QCD equation of state for realistic quark masses and apply the model to dilepton production in ultrarelativistic heavy-ion collisions.
[ { "created": "Tue, 19 Feb 2002 10:21:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schneider", "R. A.", "" ], [ "Renk", "T.", "" ], [ "Weise", "W.", "" ] ]
We propose a novel quasiparticle interpretation of the equation of state of deconfined QCD at finite temperature. Using appropriate thermal masses, we introduce a phenomenological parametrization of the onset of confinement in the vicinity of the phase transition. Lattice results of the energy density, the pressure and the interaction measure of pure SU(3) gauge theory are well reproduced. A relation between the thermal energy density of the Yang-Mills vacuum and the chromomagnetic condensate <B^2>_T is found. We also present the two flavour QCD equation of state for realistic quark masses and apply the model to dilepton production in ultrarelativistic heavy-ion collisions.
hep-ph/0405086
Pedro Bicudo
P. Bicudo
Prediction of the masses and decay processes of strange, charmed and bottomed pentaquarks from the linear molecular crypto-heptaquark model
8 pages, 1 figure, 5 tables. Submitted to Journal of Physics G
J.Phys.G32:787-798,2006
10.1088/0954-3899/32/6/004
null
hep-ph
null
In this paper the masses and decay processes of several new strange, charmed and bottomed exotic pentaquarks are predicted. Multiquarks are studied microscopically in a standard quark model. In pure ground-state pentaquarks the short-range interaction is computed and it is shown to be repulsive. The long-range and medium-range interactions are not expected to provide sufficient attraction. An additional quark-antiquark pair is then considered, and this is suggested to produce a narrow linear molecular system. The quarks assemble in three hadronic clusters, and the central hadron provides stability. The possible crypto-heptaquark hadrons with exotic pentaquark flavours, with any number of strange, charmed and bottomed quarks, are listed. Several new exotics may still be observed.
[ { "created": "Mon, 10 May 2004 22:52:52 GMT", "version": "v1" }, { "created": "Tue, 18 May 2004 12:47:46 GMT", "version": "v2" }, { "created": "Mon, 19 Dec 2005 19:40:32 GMT", "version": "v3" } ]
2011-01-27
[ [ "Bicudo", "P.", "" ] ]
In this paper the masses and decay processes of several new strange, charmed and bottomed exotic pentaquarks are predicted. Multiquarks are studied microscopically in a standard quark model. In pure ground-state pentaquarks the short-range interaction is computed and it is shown to be repulsive. The long-range and medium-range interactions are not expected to provide sufficient attraction. An additional quark-antiquark pair is then considered, and this is suggested to produce a narrow linear molecular system. The quarks assemble in three hadronic clusters, and the central hadron provides stability. The possible crypto-heptaquark hadrons with exotic pentaquark flavours, with any number of strange, charmed and bottomed quarks, are listed. Several new exotics may still be observed.
1707.04138
Alexei P. Martynenko
A.E. Dorokhov, N.I. Kochelev, A.P. Martynenko, F.A. Martynenko, A.E. Radzhabov
The contribution of axial-vector mesons to hyperfine structure of muonic hydrogen
14 pages, 2 figures
Phys.Lett. B776 (2018) 105-110
10.1016/j.physletb.2017.11.027
null
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The contribution from the axial-vector meson exchange to the potential of the muon-proton interaction in muonic hydrogen induced by anomalous axial-vector meson coupling to two photon state is calculated. It is shown that such contribution to the hyperfine splitting in muonic hydrogen is large and important for a comparison with precise experimental data. In the light of our result, the proton radius "puzzle" is discussed.
[ { "created": "Thu, 13 Jul 2017 14:15:48 GMT", "version": "v1" }, { "created": "Wed, 19 Jul 2017 18:23:14 GMT", "version": "v2" }, { "created": "Tue, 7 Nov 2017 19:58:43 GMT", "version": "v3" } ]
2017-11-28
[ [ "Dorokhov", "A. E.", "" ], [ "Kochelev", "N. I.", "" ], [ "Martynenko", "A. P.", "" ], [ "Martynenko", "F. A.", "" ], [ "Radzhabov", "A. E.", "" ] ]
The contribution from the axial-vector meson exchange to the potential of the muon-proton interaction in muonic hydrogen induced by anomalous axial-vector meson coupling to two photon state is calculated. It is shown that such contribution to the hyperfine splitting in muonic hydrogen is large and important for a comparison with precise experimental data. In the light of our result, the proton radius "puzzle" is discussed.
1603.02184
Dr. Rukmani Mohanta
C Soumya, R. Mohanta
Implications of lepton flavour violation on long baseline neutrino oscillation experiments
21 pages, 10 figures, version to appear in Phys. Rev. D
Phys. Rev. D 94, 053008 (2016)
10.1103/PhysRevD.94.053008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-standard neutrino interactions (NSIs), the sub-leading effects in the flavour transitions of neutrinos, play a crucial role in the determination of the various unknowns in neutrino oscillations, such as neutrino mass hierarchy, Dirac CP violating phase and the octant of atmospheric mixing angle. In this work, we focus on the possible implications of lepton flavour violating (LFV) NSIs, which generally affect the neutrino propagation, on the determination of the these unknown oscillation parameters. We study the effect of these NSIs on the physics potential of the currently running and upcoming long-baseline experiments, i.e., T2K, NO$\nu$A and DUNE. We also check the allowed oscillation parameter space in presence of LFV NSIs.
[ { "created": "Mon, 7 Mar 2016 18:08:48 GMT", "version": "v1" }, { "created": "Sat, 17 Sep 2016 15:25:30 GMT", "version": "v2" } ]
2016-09-28
[ [ "Soumya", "C", "" ], [ "Mohanta", "R.", "" ] ]
Non-standard neutrino interactions (NSIs), the sub-leading effects in the flavour transitions of neutrinos, play a crucial role in the determination of the various unknowns in neutrino oscillations, such as neutrino mass hierarchy, Dirac CP violating phase and the octant of atmospheric mixing angle. In this work, we focus on the possible implications of lepton flavour violating (LFV) NSIs, which generally affect the neutrino propagation, on the determination of the these unknown oscillation parameters. We study the effect of these NSIs on the physics potential of the currently running and upcoming long-baseline experiments, i.e., T2K, NO$\nu$A and DUNE. We also check the allowed oscillation parameter space in presence of LFV NSIs.
hep-ph/0205263
Sechul Oh
C. S. Kim, Jong-Phil Lee, and Sechul Oh
Nonleptonic two-body charmless B decays involving a tensor meson in ISGW2 model
23 pages, REVTEX; minor clarifications included; to appear in Phys. Rev. D
Phys.Rev. D67 (2003) 014002
10.1103/PhysRevD.67.014002
null
hep-ph
null
Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic uncertainties and ambiguities of the form factors which appear in the literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to evaluate the relevant hadronic matrix elements. We calculate the branching ratios and CP asymmetries for various $B\to P(V)T$ decay processes. With the ISGW2 model, the branching ratios are enhanced by about an order of magnitude compared to the previous estimates. We show that the ratios $\calB(B\to VT)/\calB(B\to PT)$ for some strangeness-changing processes are very sensitive to the CKM angle $\gamma$ ($\phi_3$).
[ { "created": "Thu, 23 May 2002 11:19:09 GMT", "version": "v1" }, { "created": "Tue, 19 Nov 2002 14:20:30 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kim", "C. S.", "" ], [ "Lee", "Jong-Phil", "" ], [ "Oh", "Sechul", "" ] ]
Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic uncertainties and ambiguities of the form factors which appear in the literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to evaluate the relevant hadronic matrix elements. We calculate the branching ratios and CP asymmetries for various $B\to P(V)T$ decay processes. With the ISGW2 model, the branching ratios are enhanced by about an order of magnitude compared to the previous estimates. We show that the ratios $\calB(B\to VT)/\calB(B\to PT)$ for some strangeness-changing processes are very sensitive to the CKM angle $\gamma$ ($\phi_3$).
1806.06036
Luc Darm\'e
Luc Darm\'e, Kamila Kowalska, Leszek Roszkowski, Enrico Maria Sessolo
Flavor anomalies and dark matter in SUSY with an extra U(1)
38 pages, 8 figures, 4 tables. References added, matches published version
JHEP 1810 (2018) 052
10.1007/JHEP10(2018)052
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the recent anomalies in $b\rightarrow s$ transitions that emerged at LHCb, we consider a model with an $L_\mu - L_\tau$ gauge symmetry and additional vector-like fermions. We find that by introducing supersymmetry the model can be made consistent with the long-standing deviation in the measured value of the anomalous magnetic moment of the muon, $g-2$, and neutralino dark matter of broad mass ranges and properties. In particular, dark matter candidates include the well-known 1 TeV higgsino, which in the MSSM is typically not compatible with solutions to the $g-2$ puzzle. Moreover, its spin-independent cross section could be at the origin of the recent small excess in XENON-1T data. We apply to the model constraints arising from flavor precision measurements and direct searches at the Large Hadron Collider and show that they do not currently exclude the relevant parameter space regions.
[ { "created": "Fri, 15 Jun 2018 16:23:29 GMT", "version": "v1" }, { "created": "Mon, 15 Oct 2018 09:58:58 GMT", "version": "v2" } ]
2018-10-16
[ [ "Darmé", "Luc", "" ], [ "Kowalska", "Kamila", "" ], [ "Roszkowski", "Leszek", "" ], [ "Sessolo", "Enrico Maria", "" ] ]
Motivated by the recent anomalies in $b\rightarrow s$ transitions that emerged at LHCb, we consider a model with an $L_\mu - L_\tau$ gauge symmetry and additional vector-like fermions. We find that by introducing supersymmetry the model can be made consistent with the long-standing deviation in the measured value of the anomalous magnetic moment of the muon, $g-2$, and neutralino dark matter of broad mass ranges and properties. In particular, dark matter candidates include the well-known 1 TeV higgsino, which in the MSSM is typically not compatible with solutions to the $g-2$ puzzle. Moreover, its spin-independent cross section could be at the origin of the recent small excess in XENON-1T data. We apply to the model constraints arising from flavor precision measurements and direct searches at the Large Hadron Collider and show that they do not currently exclude the relevant parameter space regions.
hep-ph/0402205
Vladimir Dzhunushaliev
V. Dzhunushaliev, D. Singleton and T. Nikulicheva
Nonperturbative calculational method in quantum field theory
one typo in eq. (5.51) is corrected
null
null
null
hep-ph hep-th
null
An approximate procedure for performing nonperturbative calculations in quantum field theories is presented. The focus will be quantum non-Abelian gauge theories with the goal of understanding some of the open questions of these theories such as the confinement phenomenon and glueballs. One aspect of this nonperturbative method is the breaking down of the non-Abelian gauge group into smaller pieces. For example $SU(2) \to U(1) + coset$ or $SU(3) \to SU(2) + coset$. The procedure also uses some aspects of an old method by Heisenberg to calculate the n-point Green's function of a strongly interacting, non-linear theory. Using these ideas we will give approximate calculations of the 2 and 4-points Green's function of the theories considered.
[ { "created": "Thu, 19 Feb 2004 03:02:41 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 2004 07:20:39 GMT", "version": "v2" }, { "created": "Sun, 6 Feb 2005 06:30:10 GMT", "version": "v3" } ]
2007-05-23
[ [ "Dzhunushaliev", "V.", "" ], [ "Singleton", "D.", "" ], [ "Nikulicheva", "T.", "" ] ]
An approximate procedure for performing nonperturbative calculations in quantum field theories is presented. The focus will be quantum non-Abelian gauge theories with the goal of understanding some of the open questions of these theories such as the confinement phenomenon and glueballs. One aspect of this nonperturbative method is the breaking down of the non-Abelian gauge group into smaller pieces. For example $SU(2) \to U(1) + coset$ or $SU(3) \to SU(2) + coset$. The procedure also uses some aspects of an old method by Heisenberg to calculate the n-point Green's function of a strongly interacting, non-linear theory. Using these ideas we will give approximate calculations of the 2 and 4-points Green's function of the theories considered.
1312.0304
Farinaldo Queiroz
D. Cogollo, Farinaldo S. Queiroz, P. Vasconcelos
Flavor Changing Neutral Current Processes in a Reduced Minimal Scalar Sector
21 pages, 2 figures, 2 tables. Matches version accepted for publication
null
10.1142/S0217732314501739
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we overhaul previous studies of Flavor Changing Neutral Current processes in the context of the Reduced Minimal 3-3-1 model(RM331). We sift the individual contributions from the CP even scalars and the $Z^{\prime}$ gauge boson using two different parametrizations schemes and compare our results with current measurements. In particular, studying the $B^{0}-\bar{B^{0}}$ meson system we find the most stringent bounds in the literature on this model, namely $M_{Z^{\prime}} \gtrsim 3326$~GeV, $M_{V^{\pm}} \gtrsim 910$~GeV, $M_{U^{++}} \gtrsim 914$~GeV and $m_{h_2^0} \gtrsim 889$~GeV.
[ { "created": "Mon, 2 Dec 2013 02:06:51 GMT", "version": "v1" }, { "created": "Thu, 20 Feb 2014 22:21:42 GMT", "version": "v2" }, { "created": "Mon, 26 May 2014 02:46:02 GMT", "version": "v3" }, { "created": "Tue, 26 Aug 2014 18:16:59 GMT", "version": "v4" } ]
2015-06-18
[ [ "Cogollo", "D.", "" ], [ "Queiroz", "Farinaldo S.", "" ], [ "Vasconcelos", "P.", "" ] ]
In this work we overhaul previous studies of Flavor Changing Neutral Current processes in the context of the Reduced Minimal 3-3-1 model(RM331). We sift the individual contributions from the CP even scalars and the $Z^{\prime}$ gauge boson using two different parametrizations schemes and compare our results with current measurements. In particular, studying the $B^{0}-\bar{B^{0}}$ meson system we find the most stringent bounds in the literature on this model, namely $M_{Z^{\prime}} \gtrsim 3326$~GeV, $M_{V^{\pm}} \gtrsim 910$~GeV, $M_{U^{++}} \gtrsim 914$~GeV and $m_{h_2^0} \gtrsim 889$~GeV.
1709.01647
Yufei Wang
Yu-Fei Wang
Unitarity Analyses of $\pi N$ Elastic Scattering Amplitudes
4 pages, 2 figures (the first figure contains 6 sub-figures), from proceedings of the 11th APCTP - BLTP JINR - PNPI NRC KI - SPbU Joint Workshop (held in Saint-Petersburg in July 23-28th)
null
10.1134/S1547477118040234
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The pion - nucleon scattering phase shifts in $s$ and $p$ waves are analyzed using PKU unitarization approach that can separate the phase shifts into different contributions from poles and branch cuts. It is found that in $S_{11}$ and $P_{11}$ channels, there exist large and positive missing contributions when one compares the phase shift from known resonances plus branch cuts with the experimental data, which indicates that those two channels may contain sizable effects from $N^*(1535)$ and $N^*(1440)$ shadow poles. Those results are obtained using tree level results of the $\pi N$ amplitude.
[ { "created": "Wed, 6 Sep 2017 01:34:47 GMT", "version": "v1" }, { "created": "Thu, 7 Sep 2017 01:48:55 GMT", "version": "v2" } ]
2018-08-01
[ [ "Wang", "Yu-Fei", "" ] ]
The pion - nucleon scattering phase shifts in $s$ and $p$ waves are analyzed using PKU unitarization approach that can separate the phase shifts into different contributions from poles and branch cuts. It is found that in $S_{11}$ and $P_{11}$ channels, there exist large and positive missing contributions when one compares the phase shift from known resonances plus branch cuts with the experimental data, which indicates that those two channels may contain sizable effects from $N^*(1535)$ and $N^*(1440)$ shadow poles. Those results are obtained using tree level results of the $\pi N$ amplitude.
1601.07339
Takaaki Nomura
Takaaki Nomura, Hiroshi Okada
Generalized Zee-Babu model with 750 GeV Diphoton Resonance
21 pages, 3 figures, 1 table. published version
null
10.1016/j.physletb.2016.03.034
KIAS-P16011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a generalized Zee-Babu model with a global $U(1)$ B-L symmetry, in which we classify the model in terms of the number of the hypercharge $N/2$ of the isospin doublet exotic charged fermions. Corresponding to each of the number of $N$, we need to introduce some multiply charged bosons in order to make the exotic fields decay into the standard model fields. We also discuss the muon anomalous magnetic moment and the diphoton excess depending on $N$, and we show what kind of models are in favor of these phenomenologies.
[ { "created": "Wed, 27 Jan 2016 12:14:25 GMT", "version": "v1" }, { "created": "Thu, 19 May 2016 14:36:19 GMT", "version": "v2" } ]
2016-05-20
[ [ "Nomura", "Takaaki", "" ], [ "Okada", "Hiroshi", "" ] ]
We propose a generalized Zee-Babu model with a global $U(1)$ B-L symmetry, in which we classify the model in terms of the number of the hypercharge $N/2$ of the isospin doublet exotic charged fermions. Corresponding to each of the number of $N$, we need to introduce some multiply charged bosons in order to make the exotic fields decay into the standard model fields. We also discuss the muon anomalous magnetic moment and the diphoton excess depending on $N$, and we show what kind of models are in favor of these phenomenologies.
hep-ph/0206036
Andrej Arbuzov
Andrej Arbuzov
Higher order QED corrections to muon decay spectrum
version submitted to JHEP
JHEP 0303 (2003) 063
10.1088/1126-6708/2003/03/063
Alberta-Thy-10-02
hep-ph
null
QED radiative corrections to polarized muon decay spectrum are considered. Leading and next--to--leading logarithmic approximations are used. Exponentiation of soft radiation is discussed. The present theoretical uncertainty of the spectrum description is estimated.
[ { "created": "Tue, 4 Jun 2002 17:38:07 GMT", "version": "v1" }, { "created": "Thu, 3 Apr 2003 05:34:12 GMT", "version": "v2" } ]
2009-11-07
[ [ "Arbuzov", "Andrej", "" ] ]
QED radiative corrections to polarized muon decay spectrum are considered. Leading and next--to--leading logarithmic approximations are used. Exponentiation of soft radiation is discussed. The present theoretical uncertainty of the spectrum description is estimated.
1812.05617
Martin Hoferichter
Martin Hoferichter, Philipp Klos, Javier Men\'endez, Achim Schwenk
Nuclear structure factors for general spin-independent WIMP-nucleus scattering
24 pages, 19 figures, Python notebook available at https://theorie.ikp.physik.tu-darmstadt.de/strongint/ChiralEFT4DM.html; further details on nuclear structure added, journal version
Phys. Rev. D 99, 055031 (2019)
10.1103/PhysRevD.99.055031
INT-PUB-18-059
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present nuclear structure factors that describe the generalized spin-independent coupling of weakly interacting massive particles (WIMPs) to nuclei. Our results are based on state-of-the-art nuclear structure calculations using the large-scale nuclear shell model. Starting from quark- and gluon-level operators, we consider all possible coherently enhanced couplings of spin-1/2 and spin-0 WIMPs to one and two nucleons up to third order in chiral effective field theory. This includes a comprehensive discussion of the structure factors corresponding to the leading two-nucleon currents covering, for the first time, the contribution of spin-2 operators. We provide results for the most relevant nuclear targets considered in present and planned dark matter direct detection experiments: fluorine, silicon, argon, and germanium, complementing our previous work on xenon. All results are also publicly available in a Python notebook.
[ { "created": "Thu, 13 Dec 2018 19:00:01 GMT", "version": "v1" }, { "created": "Fri, 29 Mar 2019 15:19:39 GMT", "version": "v2" } ]
2019-04-01
[ [ "Hoferichter", "Martin", "" ], [ "Klos", "Philipp", "" ], [ "Menéndez", "Javier", "" ], [ "Schwenk", "Achim", "" ] ]
We present nuclear structure factors that describe the generalized spin-independent coupling of weakly interacting massive particles (WIMPs) to nuclei. Our results are based on state-of-the-art nuclear structure calculations using the large-scale nuclear shell model. Starting from quark- and gluon-level operators, we consider all possible coherently enhanced couplings of spin-1/2 and spin-0 WIMPs to one and two nucleons up to third order in chiral effective field theory. This includes a comprehensive discussion of the structure factors corresponding to the leading two-nucleon currents covering, for the first time, the contribution of spin-2 operators. We provide results for the most relevant nuclear targets considered in present and planned dark matter direct detection experiments: fluorine, silicon, argon, and germanium, complementing our previous work on xenon. All results are also publicly available in a Python notebook.
hep-ph/9812278
Kaustubh Agashe
K. Agashe and N.G. Deshpande (ITS, University of Oregon)
Determining the Weak Phase $\gamma$ in the Presence of Rescattering
LaTeX file, 15 pages including 2 figures. Replacing an earlier version. In version 4, we have corrected some typographic errors. We have also clarified which decay modes require external tagging and have changed/added some comments
Phys.Lett. B451 (1999) 215-223
10.1016/S0370-2693(99)00159-8
OITS-667
hep-ph
null
We suggest a new technique to determine the CKM phase $\gamma$ {\em without} neglecting the (soft) final state rescattering effects. We use (time integrated) $B$ meson decay rates to $\pi$'s and $K$'s. A set of 5 $\Delta S = 0$ (or 1 $\Delta S =0$ and 4 $\Delta S= 1$) decay rates is used to compute the strong phases and magnitudes of the tree level and penguin contributions as functions of $\gamma$. These are used to {\em predict} a $\Delta S = 1$ $(\Delta S = 0) B_{d/s}$ decay rate as a function of $\gamma$ (using SU(3) symmetry). The measurement of this decay rate then gives $\gamma$. We illustrate this technique using different cases. Most of the decay modes we use are expected to be accessible at the B-factories (e^+ e^- or hadron machines).
[ { "created": "Tue, 8 Dec 1998 00:24:04 GMT", "version": "v1" }, { "created": "Thu, 17 Dec 1998 00:38:03 GMT", "version": "v2" }, { "created": "Sat, 19 Dec 1998 01:34:22 GMT", "version": "v3" }, { "created": "Wed, 20 Jan 1999 23:34:50 GMT", "version": "v4" } ]
2009-10-31
[ [ "Agashe", "K.", "", "ITS, University of Oregon" ], [ "Deshpande", "N. G.", "", "ITS, University of Oregon" ] ]
We suggest a new technique to determine the CKM phase $\gamma$ {\em without} neglecting the (soft) final state rescattering effects. We use (time integrated) $B$ meson decay rates to $\pi$'s and $K$'s. A set of 5 $\Delta S = 0$ (or 1 $\Delta S =0$ and 4 $\Delta S= 1$) decay rates is used to compute the strong phases and magnitudes of the tree level and penguin contributions as functions of $\gamma$. These are used to {\em predict} a $\Delta S = 1$ $(\Delta S = 0) B_{d/s}$ decay rate as a function of $\gamma$ (using SU(3) symmetry). The measurement of this decay rate then gives $\gamma$. We illustrate this technique using different cases. Most of the decay modes we use are expected to be accessible at the B-factories (e^+ e^- or hadron machines).
1508.07161
Kari Rummukainen
Michela D'Onofrio (1 and 2), Kari Rummukainen (2) ((1) University of Bern, (2) University of Helsinki)
The Standard Model cross-over on the lattice
10 pages
Phys. Rev. D 93, 025003 (2016)
10.1103/PhysRevD.93.025003
HIP-2015-30/TH
hep-ph astro-ph.CO hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the physical Higgs mass the Standard Model symmetry restoration phase transition is a smooth cross-over. We study the thermodynamics of the cross-over using numerical lattice Monte Carlo simulations of an effective SU(2) X U(1) gauge + Higgs theory, significantly improving on previously published results. We measure the Higgs field expectation value, thermodynamic quantities like pressure, energy density, speed of sound and heat capacity, and screening masses associated with the Higgs and Z fields. While the cross-over is smooth, it is very well defined with a width of only approximately 5 GeV. We measure the cross-over temperature from the maximum of the susceptibility of the Higgs condensate, with the result $T_c = 159.5 \pm 1.5$ GeV. Outside of the narrow cross-over region the perturbative results agree well with non-perturbative ones.
[ { "created": "Fri, 28 Aug 2015 10:42:18 GMT", "version": "v1" } ]
2016-01-13
[ [ "D'Onofrio", "Michela", "", "1 and 2" ], [ "Rummukainen", "Kari", "" ] ]
With the physical Higgs mass the Standard Model symmetry restoration phase transition is a smooth cross-over. We study the thermodynamics of the cross-over using numerical lattice Monte Carlo simulations of an effective SU(2) X U(1) gauge + Higgs theory, significantly improving on previously published results. We measure the Higgs field expectation value, thermodynamic quantities like pressure, energy density, speed of sound and heat capacity, and screening masses associated with the Higgs and Z fields. While the cross-over is smooth, it is very well defined with a width of only approximately 5 GeV. We measure the cross-over temperature from the maximum of the susceptibility of the Higgs condensate, with the result $T_c = 159.5 \pm 1.5$ GeV. Outside of the narrow cross-over region the perturbative results agree well with non-perturbative ones.
2303.10562
Jing-Yu Zhu
Federica Pompa, Thomas Schwetz and Jing-Yu Zhu
Impact of nuclear matrix element calculations for current and future neutrinoless double beta decay searches
29 pages, 14 figures, the version to be published in JHEP
null
10.1007/JHEP06(2023)104
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
Nuclear matrix elements (NME) are a crucial input for the interpretation of neutrinoless double beta decay data. We consider a representative set of recent NME calculations from different methods and investigate the impact on the present bound on the effective Majorana mass $m_{\beta\beta}$ by performing a combined analysis of the available data as well as on the sensitivity reach of future projects. A crucial role is played by the recently discovered short-range contribution to the NME, induced by light Majorana neutrino masses. Depending on the NME model and the relative sign of the long- and short-range contributions, the current $3\sigma$ bound can change between $m_{\beta\beta} < 40$ meV and 600 meV. The sign-uncertainty may either boost the sensitivity of next-generation experiments beyond the region for $m_{\beta\beta}$ predicted for inverted mass ordering or prevent even advanced setups to reach this region. Furthermore, we study the possibility to distinguish between different NME calculations by assuming a positive signal and by combining measurements from different isotopes. Such a discrimination will be impossible if the relative sign of the long- and short-range contribution remains unknown, but can become feasible if $m_{\beta\beta} \gtrsim 40$ meV and if the relative sign is known to be positive. Sensitivities will be dominated by the advanced $^{76}$Ge and $^{136}$Xe setups assumed here, but NME model-discrimination improves if data from a third isotope is added, e.g., from $^{130}$Te or $^{100}$Mo.
[ { "created": "Sun, 19 Mar 2023 04:38:47 GMT", "version": "v1" }, { "created": "Mon, 5 Jun 2023 07:11:34 GMT", "version": "v2" } ]
2023-07-05
[ [ "Pompa", "Federica", "" ], [ "Schwetz", "Thomas", "" ], [ "Zhu", "Jing-Yu", "" ] ]
Nuclear matrix elements (NME) are a crucial input for the interpretation of neutrinoless double beta decay data. We consider a representative set of recent NME calculations from different methods and investigate the impact on the present bound on the effective Majorana mass $m_{\beta\beta}$ by performing a combined analysis of the available data as well as on the sensitivity reach of future projects. A crucial role is played by the recently discovered short-range contribution to the NME, induced by light Majorana neutrino masses. Depending on the NME model and the relative sign of the long- and short-range contributions, the current $3\sigma$ bound can change between $m_{\beta\beta} < 40$ meV and 600 meV. The sign-uncertainty may either boost the sensitivity of next-generation experiments beyond the region for $m_{\beta\beta}$ predicted for inverted mass ordering or prevent even advanced setups to reach this region. Furthermore, we study the possibility to distinguish between different NME calculations by assuming a positive signal and by combining measurements from different isotopes. Such a discrimination will be impossible if the relative sign of the long- and short-range contribution remains unknown, but can become feasible if $m_{\beta\beta} \gtrsim 40$ meV and if the relative sign is known to be positive. Sensitivities will be dominated by the advanced $^{76}$Ge and $^{136}$Xe setups assumed here, but NME model-discrimination improves if data from a third isotope is added, e.g., from $^{130}$Te or $^{100}$Mo.
1112.5115
Daniel Almeida Fagundes
D. A. Fagundes, M. J. Menon
Total Hadronic Cross Section and the Elastic Slope: An Almost Model-Independent Connection
15 pages, 4 figures, v4: few typos corrected, final version to be published in Nucl. Phys. A
null
10.1016/j.nuclphysa.2012.01.017
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An almost model-independent parametrization for the ratio of the total cross section to the elastic slope, as function of the center of mass energy, is introduced. The analytical result is based on the approximate relation of this quantity with the ratio $R$ of the elastic to total cross section and empirical fits to the $R$ data from proton-proton scattering above 10 GeV, under the conditions of asymptotic unitarity and the black-disk limit. This parametrization may be useful in studies of extensive air showers and the determination of the proton-proton total cross section from proton-air production cross section in cosmic-ray experiments.
[ { "created": "Wed, 21 Dec 2011 18:08:31 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2012 13:13:50 GMT", "version": "v2" }, { "created": "Wed, 1 Feb 2012 13:15:39 GMT", "version": "v3" } ]
2012-02-02
[ [ "Fagundes", "D. A.", "" ], [ "Menon", "M. J.", "" ] ]
An almost model-independent parametrization for the ratio of the total cross section to the elastic slope, as function of the center of mass energy, is introduced. The analytical result is based on the approximate relation of this quantity with the ratio $R$ of the elastic to total cross section and empirical fits to the $R$ data from proton-proton scattering above 10 GeV, under the conditions of asymptotic unitarity and the black-disk limit. This parametrization may be useful in studies of extensive air showers and the determination of the proton-proton total cross section from proton-air production cross section in cosmic-ray experiments.
hep-ph/9406362
Dam Thanh Son
V. A. Rubakov and D. T. Son
Renormalization Group for Multiparticle Production in (2+1) Dimensions Around the Threshold
based on talk at International Seminar Quarks-94, 11-18 May 1994, Vladimir, Russia, REVTEX 3.0, 13pp, 3 figures included (use bezier.sty)
null
null
null
hep-ph
null
Multiparticle production in (2+1) dimensions is investigated. We show that in a small region around the threshold the perturbation theory becomes unapplicable due to infrared divergencies in a class of Feynman graphs with rescattering in final state. We develop a technique based on renormalization group for summing up leading logarithms and apply it to the $\phi^4$ models with and without symmetry breaking and to the $O(N)$ $\phi^4$ theory.
[ { "created": "Wed, 22 Jun 1994 13:02:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rubakov", "V. A.", "" ], [ "Son", "D. T.", "" ] ]
Multiparticle production in (2+1) dimensions is investigated. We show that in a small region around the threshold the perturbation theory becomes unapplicable due to infrared divergencies in a class of Feynman graphs with rescattering in final state. We develop a technique based on renormalization group for summing up leading logarithms and apply it to the $\phi^4$ models with and without symmetry breaking and to the $O(N)$ $\phi^4$ theory.
2012.10727
Daniel Boyanovsky
Mudit Rai, Daniel Boyanovsky
Interaction rates in cosmology: heavy particle production and scattering
more discussions
Class. Quantum Grav. 38 195014 (2021)
10.1088/1361-6382/ac1b47
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study transition rates and cross sections from first principles in a spatially flat radiation dominated cosmology. We consider a model of scalar particles to study scattering and heavy particle production from pair annihilation, drawing more general conclusions. The S-matrix formulation is ill suited to study these ubiquitous processes in a rapidly expanding cosmology. We introduce a physically motivated adiabatic expansion that relies on wavelengths much smaller than the particle horizon at a given time. The leading order in this expansion dominates the transition rates and cross sections. Several important and general results are direct consequences of the cosmological redshift and a finite particle horizon: i) a violation of local Lorentz invariance, ii) freeze-out of the production cross section at a finite time, iii) sub-threshold production of heavier particles as a consequence of the uncertainty in the local energy from a finite particle horizon, a manifestation of the \emph{antizeno} effect. If heavy dark matter is produced via annihilation of a lighter species, sub-threshold production yields an enhanced abundance. We discuss several possible consequences of these effects.
[ { "created": "Sat, 19 Dec 2020 16:11:17 GMT", "version": "v1" }, { "created": "Wed, 21 Apr 2021 22:43:13 GMT", "version": "v2" }, { "created": "Thu, 2 Sep 2021 11:19:59 GMT", "version": "v3" } ]
2021-09-03
[ [ "Rai", "Mudit", "" ], [ "Boyanovsky", "Daniel", "" ] ]
We study transition rates and cross sections from first principles in a spatially flat radiation dominated cosmology. We consider a model of scalar particles to study scattering and heavy particle production from pair annihilation, drawing more general conclusions. The S-matrix formulation is ill suited to study these ubiquitous processes in a rapidly expanding cosmology. We introduce a physically motivated adiabatic expansion that relies on wavelengths much smaller than the particle horizon at a given time. The leading order in this expansion dominates the transition rates and cross sections. Several important and general results are direct consequences of the cosmological redshift and a finite particle horizon: i) a violation of local Lorentz invariance, ii) freeze-out of the production cross section at a finite time, iii) sub-threshold production of heavier particles as a consequence of the uncertainty in the local energy from a finite particle horizon, a manifestation of the \emph{antizeno} effect. If heavy dark matter is produced via annihilation of a lighter species, sub-threshold production yields an enhanced abundance. We discuss several possible consequences of these effects.
2312.04953
Xuan Luo
Xuan Luo, Ruitian Li, Hao Sun
Theoretical study of the $B^+\to D^-D_s^{+}\pi^+$ reaction
8 pages, 7 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Prompted by the recent discoveries of $T_{c\bar{s}0}(2900)^{++}$ in the $D_s^+\pi^+$ invariant mass distribution of $B^+\to D^-D_s^+\pi^+$ process, we present a model that hopes to help us investigate the nature of $T_{c\bar{s}0}(2900)^{++}$ by reproducing the mass distribution of $D^-\pi^+, D_s^+\pi^+$ and $D^-D_s^+$ in $B^+ \to D^-D_s^+\pi^+$ decays. The structure of the triangular singularity peak generated from the $\chi_{c1}D^{*+}K^{*+}$ loop near the $D^{*+}K^{*+}$ threshold is considered in our model may be the experimentally discovered resonance-like state structure $T_{c\bar{s}0}(2900)^{++}$. In addition, we employ a coupled-channel approach to describe the dominant contribution of the $D\pi$ $S\text{-wave}$ amplitude, and also consider other excitations. Our model provides a well fit to the invariant mass distributions of $D^-\pi^+, D_s^+\pi^+$ and $D^-D_s^+$ simultaneously.
[ { "created": "Fri, 8 Dec 2023 10:32:08 GMT", "version": "v1" }, { "created": "Mon, 8 Jan 2024 12:30:31 GMT", "version": "v2" } ]
2024-01-09
[ [ "Luo", "Xuan", "" ], [ "Li", "Ruitian", "" ], [ "Sun", "Hao", "" ] ]
Prompted by the recent discoveries of $T_{c\bar{s}0}(2900)^{++}$ in the $D_s^+\pi^+$ invariant mass distribution of $B^+\to D^-D_s^+\pi^+$ process, we present a model that hopes to help us investigate the nature of $T_{c\bar{s}0}(2900)^{++}$ by reproducing the mass distribution of $D^-\pi^+, D_s^+\pi^+$ and $D^-D_s^+$ in $B^+ \to D^-D_s^+\pi^+$ decays. The structure of the triangular singularity peak generated from the $\chi_{c1}D^{*+}K^{*+}$ loop near the $D^{*+}K^{*+}$ threshold is considered in our model may be the experimentally discovered resonance-like state structure $T_{c\bar{s}0}(2900)^{++}$. In addition, we employ a coupled-channel approach to describe the dominant contribution of the $D\pi$ $S\text{-wave}$ amplitude, and also consider other excitations. Our model provides a well fit to the invariant mass distributions of $D^-\pi^+, D_s^+\pi^+$ and $D^-D_s^+$ simultaneously.
1511.00865
Toshifumi Yamada
Cheng-Wei Chiang, An-Li Kuo, Toshifumi Yamada
Searches of exotic Higgs bosons in general mass spectra of the Georgi-Machacek model at the LHC
Version accepted for publication in JHEP
null
10.1007/JHEP01(2016)120
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the most general sets of viable mass spectra of the exotic Higgs bosons in the Georgi-Machacek model that are consistent with the theoretical constraints of vacuum stability and perturbative unitarity and the experimental constraints of electroweak precision observables, $Zb \bar b$ coupling and Higgs boson signal strengths. Branching ratios of various cascade decay channels of the doubly-charged Higgs boson in the ${\bf 5}$ representation, the singly-charged Higgs boson in ${\bf 3}$, and the singlet Higgs boson are further computed. As one of the most promising channels for discovering the model, we study the prospects for detecting the doubly-charged Higgs boson that is produced via the vector boson fusion process and decays into final states containing a pair of same-sign leptons at the 14-TeV LHC and a 100-TeV future $pp$ collider. For this purpose, we evaluate acceptance times efficiency for signals of the doubly-charged Higgs boson with general viable mass spectra and compare it with the standard model background estimates.
[ { "created": "Tue, 3 Nov 2015 11:49:03 GMT", "version": "v1" }, { "created": "Wed, 4 Nov 2015 16:44:45 GMT", "version": "v2" }, { "created": "Wed, 13 Jan 2016 16:34:09 GMT", "version": "v3" } ]
2016-02-17
[ [ "Chiang", "Cheng-Wei", "" ], [ "Kuo", "An-Li", "" ], [ "Yamada", "Toshifumi", "" ] ]
We derive the most general sets of viable mass spectra of the exotic Higgs bosons in the Georgi-Machacek model that are consistent with the theoretical constraints of vacuum stability and perturbative unitarity and the experimental constraints of electroweak precision observables, $Zb \bar b$ coupling and Higgs boson signal strengths. Branching ratios of various cascade decay channels of the doubly-charged Higgs boson in the ${\bf 5}$ representation, the singly-charged Higgs boson in ${\bf 3}$, and the singlet Higgs boson are further computed. As one of the most promising channels for discovering the model, we study the prospects for detecting the doubly-charged Higgs boson that is produced via the vector boson fusion process and decays into final states containing a pair of same-sign leptons at the 14-TeV LHC and a 100-TeV future $pp$ collider. For this purpose, we evaluate acceptance times efficiency for signals of the doubly-charged Higgs boson with general viable mass spectra and compare it with the standard model background estimates.
1112.6304
Pedro Fernando Simoes Costa
M. C. Ruivo, M. Santos, Pedro Costa, C. A. de Sousa
Interplay between chiral and axial symmetries in a SU(2) Nambu--Jona-Lasinio Model with the Polyakov loop
21 pages, 5 figures; PRD version
Phys.Rev. D85 (2012) 036001
10.1103/PhysRevD.85.036001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a two flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model where the Lagrangian includes an interaction term that explicitly breaks the U$_A(1)$ anomaly. At finite temperature, the restoration of chiral and axial symmetries, signaled by the behavior of several observables, is investigated. We compare the effects of two regularizations at finite temperature, one of them, that allows high momentum quarks states, leading to the full recovery of chiral symmetry. From the analysis of the behavior of the topological susceptibility and of the mesonic masses of the axial partners, it is found in the SU(2) model that, unlike the SU(3) results, the recovery of the axial symmetry is not a consequence of the full recovery of the chiral symmetry. Thus, one needs to use an additional idea, by means of a temperature dependence of the anomaly coefficient, that simulates instanton suppression effects.
[ { "created": "Thu, 29 Dec 2011 13:26:34 GMT", "version": "v1" } ]
2012-02-21
[ [ "Ruivo", "M. C.", "" ], [ "Santos", "M.", "" ], [ "Costa", "Pedro", "" ], [ "de Sousa", "C. A.", "" ] ]
We consider a two flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model where the Lagrangian includes an interaction term that explicitly breaks the U$_A(1)$ anomaly. At finite temperature, the restoration of chiral and axial symmetries, signaled by the behavior of several observables, is investigated. We compare the effects of two regularizations at finite temperature, one of them, that allows high momentum quarks states, leading to the full recovery of chiral symmetry. From the analysis of the behavior of the topological susceptibility and of the mesonic masses of the axial partners, it is found in the SU(2) model that, unlike the SU(3) results, the recovery of the axial symmetry is not a consequence of the full recovery of the chiral symmetry. Thus, one needs to use an additional idea, by means of a temperature dependence of the anomaly coefficient, that simulates instanton suppression effects.
0710.1869
Gilad Perez
A. Liam Fitzpatrick, Gilad Perez and Lisa Randall
Flavor from Minimal Flavor Violation & a Viable Randall-Sundrum Model
5 pages
Phys.Rev.Lett.100:171604,2008
10.1103/PhysRevLett.100.171604
null
hep-ph
null
We present a variant of the warped extra dimension, Randall-Sundrum (RS), framework which is based on five dimensional (5D) minimal flavor violation (MFV), in which the only sources of flavor breaking are two 5D anarchic Yukawa matrices. The Yukawa matrices also control the bulk masses, which are responsible for the resulting flavor structure and mass hierarchy in the low energy theory. An interesting result of this set-up is that at low energies the theory flows to next to MFV model where flavor violation is dominantly coming from the third generation. Low energy flavor violation is further suppressed by a single parameter that dials the amount of violation in the up or down sector. There is therefore a sharp limit in which there is no flavor violation in the down type quark sector which, remarkably, is favored when we fit for the flavor parameters. This mechanism is used to eliminate the current RS flavor and CP problem even with a Kaluza-Klein scale as low as 2 TeV! Our construction also suggests that economic supersymmetric and non-supersymmetric, strong dynamic-based, flavor models may be built based on the same concepts.
[ { "created": "Wed, 10 Oct 2007 14:22:25 GMT", "version": "v1" } ]
2009-08-12
[ [ "Fitzpatrick", "A. Liam", "" ], [ "Perez", "Gilad", "" ], [ "Randall", "Lisa", "" ] ]
We present a variant of the warped extra dimension, Randall-Sundrum (RS), framework which is based on five dimensional (5D) minimal flavor violation (MFV), in which the only sources of flavor breaking are two 5D anarchic Yukawa matrices. The Yukawa matrices also control the bulk masses, which are responsible for the resulting flavor structure and mass hierarchy in the low energy theory. An interesting result of this set-up is that at low energies the theory flows to next to MFV model where flavor violation is dominantly coming from the third generation. Low energy flavor violation is further suppressed by a single parameter that dials the amount of violation in the up or down sector. There is therefore a sharp limit in which there is no flavor violation in the down type quark sector which, remarkably, is favored when we fit for the flavor parameters. This mechanism is used to eliminate the current RS flavor and CP problem even with a Kaluza-Klein scale as low as 2 TeV! Our construction also suggests that economic supersymmetric and non-supersymmetric, strong dynamic-based, flavor models may be built based on the same concepts.
1710.09231
Christoph Gnendiger
C. Gnendiger, A. Signer
$\gamma_{5}$ in FDH
28 pages, 7 figures
Phys. Rev. D 97, 096006 (2018)
10.1103/PhysRevD.97.096006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the regularization-scheme dependent treatment of $\gamma_{5}$ in the framework of dimensional regularization, mainly focusing on the four-dimensional helicity scheme (FDH). Evaluating distinctive examples, we find that for one-loop calculations, the recently proposed four-dimensional formulation (FDF) of the FDH scheme constitutes a viable and efficient alternative compared to more traditional approaches. In addition, we extend the considerations to the two-loop level and compute the pseudo-scalar form factors of quarks and gluons in FDH. We provide the necessary operator renormalization and discuss at a practical level how the complexity of intermediate calculational steps can be reduced in an efficient way.
[ { "created": "Wed, 25 Oct 2017 13:43:00 GMT", "version": "v1" } ]
2018-05-16
[ [ "Gnendiger", "C.", "" ], [ "Signer", "A.", "" ] ]
We investigate the regularization-scheme dependent treatment of $\gamma_{5}$ in the framework of dimensional regularization, mainly focusing on the four-dimensional helicity scheme (FDH). Evaluating distinctive examples, we find that for one-loop calculations, the recently proposed four-dimensional formulation (FDF) of the FDH scheme constitutes a viable and efficient alternative compared to more traditional approaches. In addition, we extend the considerations to the two-loop level and compute the pseudo-scalar form factors of quarks and gluons in FDH. We provide the necessary operator renormalization and discuss at a practical level how the complexity of intermediate calculational steps can be reduced in an efficient way.
0809.3064
Yuji Omura
Tatsuo Kobayashi, Yuji Omura, Koichi Yoshioka
Flavor Symmetry Breaking and Vacuum Alignment on Orbifolds
21 pages
Phys.Rev.D78:115006,2008
10.1103/PhysRevD.78.115006
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor symmetry has been widely studied for figuring out the masses and mixing angles of standard-model fermions. In this paper we present a framework for handling flavor symmetry breaking where the symmetry breaking is triggered by boundary conditions of scalar fields in extra-dimensional space. The alignment of scalar expectation values is achieved without referring to any details of scalar potential and its minimization procedure. As applications to non-abelian discrete flavor symmetries, illustrative lepton mass models are constructed where the S3 and A4 flavor symmetries are broken down to the directions leading to the tri-bimaximal form of lepton mixing and realistic mass patterns.
[ { "created": "Thu, 18 Sep 2008 05:11:01 GMT", "version": "v1" } ]
2008-12-30
[ [ "Kobayashi", "Tatsuo", "" ], [ "Omura", "Yuji", "" ], [ "Yoshioka", "Koichi", "" ] ]
Flavor symmetry has been widely studied for figuring out the masses and mixing angles of standard-model fermions. In this paper we present a framework for handling flavor symmetry breaking where the symmetry breaking is triggered by boundary conditions of scalar fields in extra-dimensional space. The alignment of scalar expectation values is achieved without referring to any details of scalar potential and its minimization procedure. As applications to non-abelian discrete flavor symmetries, illustrative lepton mass models are constructed where the S3 and A4 flavor symmetries are broken down to the directions leading to the tri-bimaximal form of lepton mixing and realistic mass patterns.
2207.10788
Adam Freese
Adam Freese and Wim Cosyn
Spatial densities of the photon on the light front
20 pages, 5 figures
null
10.1103/PhysRevD.106.114014
NT@UW-2207
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The light front densities of momentum, angular momentum, and intrinsic pressure are calculated for the photon, both in the free case and at leading order in quantum electrodynamics. In the latter case, we moreover decompose the form factors into photon and electron contributions. Circularly and linearly polarized photons are both considered, with the latter containing significant azimuthal modulations in both the momentum density and in intrinsic stresses. We find that the D-term of the photon is positive instead of negative, and accordingly the intrinsic radial pressure of the photon is negative. Despite this, the radiation pressure exerted by the photon is positive. We illustrate through explicit calculation how the intrinsic pressure associated with the D-term and the radiation pressure exerted by the photon are different quantities.
[ { "created": "Thu, 21 Jul 2022 23:40:01 GMT", "version": "v1" }, { "created": "Tue, 13 Dec 2022 05:18:59 GMT", "version": "v2" } ]
2022-12-28
[ [ "Freese", "Adam", "" ], [ "Cosyn", "Wim", "" ] ]
The light front densities of momentum, angular momentum, and intrinsic pressure are calculated for the photon, both in the free case and at leading order in quantum electrodynamics. In the latter case, we moreover decompose the form factors into photon and electron contributions. Circularly and linearly polarized photons are both considered, with the latter containing significant azimuthal modulations in both the momentum density and in intrinsic stresses. We find that the D-term of the photon is positive instead of negative, and accordingly the intrinsic radial pressure of the photon is negative. Despite this, the radiation pressure exerted by the photon is positive. We illustrate through explicit calculation how the intrinsic pressure associated with the D-term and the radiation pressure exerted by the photon are different quantities.
2012.13499
Jun Jiang
Eric Braaten, Li-Ping He, Kevin Ingles, and Jun Jiang
Production of $X(3872)$ at High Multiplicity
6 pages, 3 figures
Phys. Rev. D 103, 071901 (2021)
10.1103/PhysRevD.103.L071901
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The dependence of the production of the $X(3872)$ meson on the hadron multiplicity in $pp$ collisions has been used as evidence against $X$ being a charm-meson molecule. The argument is based in part on the incorrect assumption that the cross section for the breakup of $X$ by scattering with comovers can be approximated by a geometric cross section inversely proportional to the binding energy of $X$. The breakup cross section should instead be approximated by the probability-weighted sum of the cross sections for the scattering of comoving pions from the charm-meson constituents of $X$, which is insensitive to the binding energy. A simple modification of the comover interaction model gives excellent fits to the data from the LHCb collaboration on the multiplicity dependence of the production of $X$ and $\psi(2S)$ using parameters compatible with $X$ being a loosely bound charm-meson molecule.
[ { "created": "Fri, 25 Dec 2020 03:12:18 GMT", "version": "v1" } ]
2021-04-21
[ [ "Braaten", "Eric", "" ], [ "He", "Li-Ping", "" ], [ "Ingles", "Kevin", "" ], [ "Jiang", "Jun", "" ] ]
The dependence of the production of the $X(3872)$ meson on the hadron multiplicity in $pp$ collisions has been used as evidence against $X$ being a charm-meson molecule. The argument is based in part on the incorrect assumption that the cross section for the breakup of $X$ by scattering with comovers can be approximated by a geometric cross section inversely proportional to the binding energy of $X$. The breakup cross section should instead be approximated by the probability-weighted sum of the cross sections for the scattering of comoving pions from the charm-meson constituents of $X$, which is insensitive to the binding energy. A simple modification of the comover interaction model gives excellent fits to the data from the LHCb collaboration on the multiplicity dependence of the production of $X$ and $\psi(2S)$ using parameters compatible with $X$ being a loosely bound charm-meson molecule.
1505.05553
Amir Fariborz
Amir H. Fariborz, A.Pokraka, T.G. Steele
Connections between chiral Lagrangians and QCD sum-rules
5 pages, 1 figure
Mod. Phys. Lett. A, Vol. 31, No. 3 (2016) 1650023
10.1142/S0217732316500231
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown how a chiral Lagrangian framework can be used to derive relationships connecting quark-level QCD correlation functions to mesonic-level two-point functions. Crucial ingredients of this connection are scale factor matrices relating each distinct quark-level substructure (e.g., quark-antiquark, four-quark) to its mesonic counterpart. The scale factors and mixing angles are combined into a projection matrix to obtain the physical (hadronic) projection of the QCD correlation function matrix. Such relationships provide a powerful bridge between chiral Lagrangians and QCD sum-rules that are particularly effective in studies of the substructure of light scalar mesons with multiple complicated resonance shapes and substantial underlying mixings. The validity of these connections is demonstrated for the example of the isotriplet $a_0(980)$-$a_0(1450)$ system, resulting in an unambiguous determination of the scale factors from the combined inputs of QCD sum-rules and chiral Lagrangians. These scale factors lead to a remarkable agreement between the quark condensates in QCD and the mesonic vacuum expectation values that induce spontaneous chiral symmetry breaking in chiral Lagrangians. This concrete example shows a clear sensitivity to the underlying $a_0$-system mixing angle, illustrating the value of this methodology in extensions to more complicated mesonic systems.
[ { "created": "Wed, 20 May 2015 23:21:29 GMT", "version": "v1" } ]
2016-01-12
[ [ "Fariborz", "Amir H.", "" ], [ "Pokraka", "A.", "" ], [ "Steele", "T. G.", "" ] ]
It is shown how a chiral Lagrangian framework can be used to derive relationships connecting quark-level QCD correlation functions to mesonic-level two-point functions. Crucial ingredients of this connection are scale factor matrices relating each distinct quark-level substructure (e.g., quark-antiquark, four-quark) to its mesonic counterpart. The scale factors and mixing angles are combined into a projection matrix to obtain the physical (hadronic) projection of the QCD correlation function matrix. Such relationships provide a powerful bridge between chiral Lagrangians and QCD sum-rules that are particularly effective in studies of the substructure of light scalar mesons with multiple complicated resonance shapes and substantial underlying mixings. The validity of these connections is demonstrated for the example of the isotriplet $a_0(980)$-$a_0(1450)$ system, resulting in an unambiguous determination of the scale factors from the combined inputs of QCD sum-rules and chiral Lagrangians. These scale factors lead to a remarkable agreement between the quark condensates in QCD and the mesonic vacuum expectation values that induce spontaneous chiral symmetry breaking in chiral Lagrangians. This concrete example shows a clear sensitivity to the underlying $a_0$-system mixing angle, illustrating the value of this methodology in extensions to more complicated mesonic systems.
1206.5404
C. Boehm
Genevieve Belanger, Sanjoy Biswas, Celine Boehm, Biswarup Mukhopadhyaya
Light neutralino dark matter in the MSSM and its implication for LHC searches for staus
19p, 4 Figs
null
10.1007/JHEP12(2012)076
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was shown in a previous study that a lightest neutralino with mass below 30 GeV was severely constrained in the minimal supersymmetric standard model (MSSM), unless it annihilates via a light stau and thus yields the observed dark matter abundance. In such a scenario, while the stau is the next-to-lightest supersymmetric particle (NLSP), the charginos and the other neutralinos as well as sleptons of the first two families are also likely to be not too far above the mass bounds laid down by the Large Electron Positron (LEP) collider. As the branching ratios of decays of the charginos and the next-to-lightest neutralino into staus are rather large, one expects significant rates of tau-rich final states in such a case. With this in view, we investigate the same-sign ditau and tri-tau signals of this scenario at the Large Hadron Collider (LHC) for two MSSM benchmark points corresponding to light neutralino dark matter. The associated signal rates for these channels are computed, for the centre-of-mass energy of 14 TeV. We find that both channels lead to appreciable rates if the squarks and the gluino are not too far above a TeV, thus allowing to probe scenarios with light neutralinos in the 14 TeV LHC run with 10-100 fb^{-1}.
[ { "created": "Sat, 23 Jun 2012 15:52:05 GMT", "version": "v1" }, { "created": "Tue, 17 Jul 2012 14:26:56 GMT", "version": "v2" }, { "created": "Fri, 19 Oct 2012 10:45:25 GMT", "version": "v3" } ]
2015-06-05
[ [ "Belanger", "Genevieve", "" ], [ "Biswas", "Sanjoy", "" ], [ "Boehm", "Celine", "" ], [ "Mukhopadhyaya", "Biswarup", "" ] ]
It was shown in a previous study that a lightest neutralino with mass below 30 GeV was severely constrained in the minimal supersymmetric standard model (MSSM), unless it annihilates via a light stau and thus yields the observed dark matter abundance. In such a scenario, while the stau is the next-to-lightest supersymmetric particle (NLSP), the charginos and the other neutralinos as well as sleptons of the first two families are also likely to be not too far above the mass bounds laid down by the Large Electron Positron (LEP) collider. As the branching ratios of decays of the charginos and the next-to-lightest neutralino into staus are rather large, one expects significant rates of tau-rich final states in such a case. With this in view, we investigate the same-sign ditau and tri-tau signals of this scenario at the Large Hadron Collider (LHC) for two MSSM benchmark points corresponding to light neutralino dark matter. The associated signal rates for these channels are computed, for the centre-of-mass energy of 14 TeV. We find that both channels lead to appreciable rates if the squarks and the gluino are not too far above a TeV, thus allowing to probe scenarios with light neutralinos in the 14 TeV LHC run with 10-100 fb^{-1}.
1708.02076
Moritz Greif
Moritz Greif, Carsten Greiner, Bj\"orn Schenke, S\"oren Schlichting, Zhe Xu
Importance of initial and final state effects for azimuthal correlations in p+Pb collisions
6 pages, 4 figures
Phys. Rev. D 96, 091504 (2017)
10.1103/PhysRevD.96.091504
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the relative importance of initial and final state effects on azimuthal correlations of gluons in low and high multiplicity p+Pb collisions. To achieve this, we couple Yang-Mills dynamics of pre-equilibrium gluon fields (IP-GLASMA) to a perturbative QCD based parton cascade for the final state evolution (BAMPS) on an event-by-event basis. We find that signatures of both the initial state correlations and final state interactions are seen in azimuthal correlation observables, such as $v_2\left\lbrace2PC\right\rbrace(p_T)$, their strength depending on the event multiplicity and transverse momentum. Initial state correlations dominate $v_2\left\lbrace2PC\right\rbrace(p_T)$ in low multiplicity events for transverse momenta $p_T>2~{\rm GeV}$. While final state interactions are dominant in high multiplicity events, initial state correlations affect $v_2\left\lbrace2PC\right\rbrace(p_T)$ for $p_T>2~{\rm GeV}$ as well as the pT integrated $v_2\left\lbrace2PC\right\rbrace$.
[ { "created": "Mon, 7 Aug 2017 11:33:24 GMT", "version": "v1" } ]
2017-12-06
[ [ "Greif", "Moritz", "" ], [ "Greiner", "Carsten", "" ], [ "Schenke", "Björn", "" ], [ "Schlichting", "Sören", "" ], [ "Xu", "Zhe", "" ] ]
We investigate the relative importance of initial and final state effects on azimuthal correlations of gluons in low and high multiplicity p+Pb collisions. To achieve this, we couple Yang-Mills dynamics of pre-equilibrium gluon fields (IP-GLASMA) to a perturbative QCD based parton cascade for the final state evolution (BAMPS) on an event-by-event basis. We find that signatures of both the initial state correlations and final state interactions are seen in azimuthal correlation observables, such as $v_2\left\lbrace2PC\right\rbrace(p_T)$, their strength depending on the event multiplicity and transverse momentum. Initial state correlations dominate $v_2\left\lbrace2PC\right\rbrace(p_T)$ in low multiplicity events for transverse momenta $p_T>2~{\rm GeV}$. While final state interactions are dominant in high multiplicity events, initial state correlations affect $v_2\left\lbrace2PC\right\rbrace(p_T)$ for $p_T>2~{\rm GeV}$ as well as the pT integrated $v_2\left\lbrace2PC\right\rbrace$.
hep-ph/9412253
null
C.W. Kim, A. Sinibaldi and J. Song
A New Scale-Dependent Cosmology with the Generalized Robertson--Walker Metric and Einstein Equation
Revtex file, 9 pages + 1 figure (included)
null
null
JHU-TIPAC 940023; DFF-215/12/94
hep-ph astro-ph gr-qc
null
Based on the observed increase of $\Omega _0$ as a function of cosmic scale, the Robertson--Walker metric and the Einstein equation are generalized so that $ \Omega_0$, $H_0$, and the age of the Universe, $t_0$, all become functions of cosmic scales at which we observe them. The calculated local (within our galaxy) age of the Universe is about 18 Gyr, consistent with the ages of the oldest stars and globular clusters in our galaxy, while the ages at distant scales are shorter than the local age, solving the age puzzle. It is also shown that $H_0$ increases as scale increases, qualitatively consistent with the recent observations.
[ { "created": "Wed, 7 Dec 1994 12:45:11 GMT", "version": "v1" }, { "created": "Wed, 25 Jan 1995 15:32:57 GMT", "version": "v2" } ]
2009-09-25
[ [ "Kim", "C. W.", "" ], [ "Sinibaldi", "A.", "" ], [ "Song", "J.", "" ] ]
Based on the observed increase of $\Omega _0$ as a function of cosmic scale, the Robertson--Walker metric and the Einstein equation are generalized so that $ \Omega_0$, $H_0$, and the age of the Universe, $t_0$, all become functions of cosmic scales at which we observe them. The calculated local (within our galaxy) age of the Universe is about 18 Gyr, consistent with the ages of the oldest stars and globular clusters in our galaxy, while the ages at distant scales are shorter than the local age, solving the age puzzle. It is also shown that $H_0$ increases as scale increases, qualitatively consistent with the recent observations.
1503.02669
Jia Liu
Joachim Kopp, Jia Liu, Xiao-Ping Wang (MITP, Johannes Gutenberg University Mainz)
Boosted Dark Matter in IceCube and at the Galactic Center
26 pages, 9 figures, 2 tables. v2: References added, matches version to be published in JHEP. v3: Acknowledgement added
JHEP 04 (2015) 105
10.1007/JHEP04(2015)105
MITP/15-014
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the event excess observed by the IceCube collaboration at TeV--PeV energies, usually interpreted as evidence for astrophysical neutrinos, can be explained alternatively by the scattering of highly boosted dark matter particles. Specifically, we consider a scenario where a $\sim 4$ PeV scalar dark matter particle $\phi$ can decay to a much lighter dark fermion $\chi$, which in turn scatters off nuclei in the IceCube detector. Besides these events, which are exclusively shower-like, the model also predicts a secondary population of events at $\mathcal{O}(100 \text{TeV})$ originating from the 3-body decay $\phi \to \chi \bar\chi a$, where $a$ is a pseudoscalar which mediates dark matter--Standard Model interactions and whose decay products include neutrinos. This secondary population also includes track-like events, and both populations together provide an excellent fit to the IceCube data. We then argue that a relic abundance of light Dark Matter particles $\chi$, which may constitute a subdominant component of the Dark Matter in the Universe, can have exactly the right properties to explain the observed excess in GeV gamma rays from the galactic center region. Our boosted Dark Matter scenario also predicts fluxes of $\mathcal{O}(10)$ TeV positrons and $\mathcal{O}(100 \text{TeV})$ photons from 3-body cascade decays of the heavy Dark Matter particle $\phi$, and we show how these can be used to constrain parts of the viable parameter space of the model. Direct detection limits are weak due to the pseudoscalar couplings of $\chi$. Accelerator constraints on the pseudoscalar mediator $a$ lead to the conclusion that the preferred mass of $a$ is $\gtrsim 10$ GeV and that large coupling to $b$ quarks but suppressed or vanishing coupling to leptons are preferred.
[ { "created": "Mon, 9 Mar 2015 20:00:36 GMT", "version": "v1" }, { "created": "Fri, 17 Apr 2015 10:23:33 GMT", "version": "v2" }, { "created": "Thu, 21 May 2015 12:58:00 GMT", "version": "v3" } ]
2015-05-22
[ [ "Kopp", "Joachim", "", "MITP, Johannes Gutenberg\n University Mainz" ], [ "Liu", "Jia", "", "MITP, Johannes Gutenberg\n University Mainz" ], [ "Wang", "Xiao-Ping", "", "MITP, Johannes Gutenberg\n University Mainz" ] ]
We show that the event excess observed by the IceCube collaboration at TeV--PeV energies, usually interpreted as evidence for astrophysical neutrinos, can be explained alternatively by the scattering of highly boosted dark matter particles. Specifically, we consider a scenario where a $\sim 4$ PeV scalar dark matter particle $\phi$ can decay to a much lighter dark fermion $\chi$, which in turn scatters off nuclei in the IceCube detector. Besides these events, which are exclusively shower-like, the model also predicts a secondary population of events at $\mathcal{O}(100 \text{TeV})$ originating from the 3-body decay $\phi \to \chi \bar\chi a$, where $a$ is a pseudoscalar which mediates dark matter--Standard Model interactions and whose decay products include neutrinos. This secondary population also includes track-like events, and both populations together provide an excellent fit to the IceCube data. We then argue that a relic abundance of light Dark Matter particles $\chi$, which may constitute a subdominant component of the Dark Matter in the Universe, can have exactly the right properties to explain the observed excess in GeV gamma rays from the galactic center region. Our boosted Dark Matter scenario also predicts fluxes of $\mathcal{O}(10)$ TeV positrons and $\mathcal{O}(100 \text{TeV})$ photons from 3-body cascade decays of the heavy Dark Matter particle $\phi$, and we show how these can be used to constrain parts of the viable parameter space of the model. Direct detection limits are weak due to the pseudoscalar couplings of $\chi$. Accelerator constraints on the pseudoscalar mediator $a$ lead to the conclusion that the preferred mass of $a$ is $\gtrsim 10$ GeV and that large coupling to $b$ quarks but suppressed or vanishing coupling to leptons are preferred.
1802.10313
Fernand Renard M
Fernand M Renard
Polarization effects due to dark matter interaction between massive standard particles
19 pages, 12 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose deeper tests of the existence of DM interactions between heavy particles in $e^+e^-\to t\bar t, ZZ, W^+W^-$ by looking at the effects on final state polarization. We show that indeed $t$, $W$ and $Z$ polarization are particularly sensitive to the structure of these interactions, to their relation with the origin of the masses and to the quantum numbers of the possibly exchanged dark particles.
[ { "created": "Wed, 28 Feb 2018 09:03:56 GMT", "version": "v1" } ]
2018-03-01
[ [ "Renard", "Fernand M", "" ] ]
We propose deeper tests of the existence of DM interactions between heavy particles in $e^+e^-\to t\bar t, ZZ, W^+W^-$ by looking at the effects on final state polarization. We show that indeed $t$, $W$ and $Z$ polarization are particularly sensitive to the structure of these interactions, to their relation with the origin of the masses and to the quantum numbers of the possibly exchanged dark particles.
1911.04137
Egle Tomasi-Gustafsson
Yu.M. Bystritskiy and V.A. Zykunov and A. Dbeyssi and M. Zambrana and F. Maas and E. Tomasi-Gustafsson
Radiative corrections in proton--antiproton annihilation to electron-positron and their application to the PANDA experiment
16 pages 12 figures
null
10.1140/epja/s10050-020-00063-6
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Radiative corrections to the annihilation of proton--antiproton into electron--positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.
[ { "created": "Mon, 11 Nov 2019 08:36:44 GMT", "version": "v1" } ]
2020-03-18
[ [ "Bystritskiy", "Yu. M.", "" ], [ "Zykunov", "V. A.", "" ], [ "Dbeyssi", "A.", "" ], [ "Zambrana", "M.", "" ], [ "Maas", "F.", "" ], [ "Tomasi-Gustafsson", "E.", "" ] ]
Radiative corrections to the annihilation of proton--antiproton into electron--positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.
1204.2474
Keun-young Kim
Raul Alvares, Nick Evans, and Keun-Young Kim
Holography of the Conformal Window
10 pages, 2 figures, v2: minor corrections, improved Figure 2
Phys.Rev. D86 (2012) 026008
10.1103/PhysRevD.86.026008
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the model of Jarvinen and Kiritsis, we present a simple holographic model for the on set of chiral symmetry breaking at the edge of the conformal window in QCD in the Veneziano limit. Our most naive model enforces the QCD two loop running coupling on a D3/D7 holographic brane system. The mass of the holographic field, describing the chiral condensate in the model, is driven below the BF bound when the running is sufficiently strong, triggering chiral symmetry breaking for N_f/N_c<2.9. This model though contains too great a remnant of supersymmetry and does not correctly encode the perturbative anomalous dimensions of QCD. In a second model we impose the QCD anomalous dimension result and find chiral symmetry breaking sets in for N_f/N_c=4 at a BKT-type phase transition. In this case the transition is triggered when the anomalous dimension of the mass operator \gamma_m=1.
[ { "created": "Wed, 11 Apr 2012 15:29:01 GMT", "version": "v1" }, { "created": "Thu, 6 Sep 2012 02:55:10 GMT", "version": "v2" } ]
2015-06-04
[ [ "Alvares", "Raul", "" ], [ "Evans", "Nick", "" ], [ "Kim", "Keun-Young", "" ] ]
Inspired by the model of Jarvinen and Kiritsis, we present a simple holographic model for the on set of chiral symmetry breaking at the edge of the conformal window in QCD in the Veneziano limit. Our most naive model enforces the QCD two loop running coupling on a D3/D7 holographic brane system. The mass of the holographic field, describing the chiral condensate in the model, is driven below the BF bound when the running is sufficiently strong, triggering chiral symmetry breaking for N_f/N_c<2.9. This model though contains too great a remnant of supersymmetry and does not correctly encode the perturbative anomalous dimensions of QCD. In a second model we impose the QCD anomalous dimension result and find chiral symmetry breaking sets in for N_f/N_c=4 at a BKT-type phase transition. In this case the transition is triggered when the anomalous dimension of the mass operator \gamma_m=1.
1904.09921
Hannu Paukkunen
Ilkka Helenius, John Lajoie, Joseph D. Osborn, Petja Paakkinen, Hannu Paukkunen
Nuclear gluons at RHIC in a multi-observable approach
10 pages, the version to appear in PRD
Phys. Rev. D 100, 014004 (2019)
10.1103/PhysRevD.100.014004
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility of measuring nuclear gluon distributions at the Relativistic Heavy-Ion Collider (RHIC) with $\sqrt{s}=200 \, {\rm GeV}$ proton-nucleus collisions. In addition to measurements at central rapidity, we consider also observables at forward rapidity, consistent with proposed upgrades to the experimental capabilities of STAR and sPHENIX. The processes we consider consist of Drell-Yan dilepton, dijet, and direct photon-jet production. The Drell-Yan process is found to be an efficient probe of gluons at small momentum fractions. In order to fully utilize the potential of Drell-Yan measurements we demonstrate how the overall normalization uncertainty present in the experimental data can be fixed using other experimental observables. An asset of the RHIC collider is its flexibility to run with different ion beams, and we outline how this ability could be taken advantage of to measure the $A$ dependence of gluon distributions for which the current constraints are scarce.
[ { "created": "Mon, 22 Apr 2019 15:23:41 GMT", "version": "v1" }, { "created": "Mon, 10 Jun 2019 07:02:43 GMT", "version": "v2" } ]
2019-07-17
[ [ "Helenius", "Ilkka", "" ], [ "Lajoie", "John", "" ], [ "Osborn", "Joseph D.", "" ], [ "Paakkinen", "Petja", "" ], [ "Paukkunen", "Hannu", "" ] ]
We explore the possibility of measuring nuclear gluon distributions at the Relativistic Heavy-Ion Collider (RHIC) with $\sqrt{s}=200 \, {\rm GeV}$ proton-nucleus collisions. In addition to measurements at central rapidity, we consider also observables at forward rapidity, consistent with proposed upgrades to the experimental capabilities of STAR and sPHENIX. The processes we consider consist of Drell-Yan dilepton, dijet, and direct photon-jet production. The Drell-Yan process is found to be an efficient probe of gluons at small momentum fractions. In order to fully utilize the potential of Drell-Yan measurements we demonstrate how the overall normalization uncertainty present in the experimental data can be fixed using other experimental observables. An asset of the RHIC collider is its flexibility to run with different ion beams, and we outline how this ability could be taken advantage of to measure the $A$ dependence of gluon distributions for which the current constraints are scarce.
1303.5284
Michele Frigerio
Michele Frigerio (L2C, Montpellier) and Albert Villanova del Moral (LUPM, Montpellier)
Minimal lepton flavour structures lead to non-maximal 2-3 mixing
24 pages, 10 figures
JHEP 1307 (2013) 146
10.1007/JHEP07(2013)146
L2C:13-045, LUPM:13-004
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Present data prefer a large but non-maximal 2-3 mixing in the lepton sector. We argue that this value, in connection with $\sin\theta_{13}\simeq 0.15$, is the generic outcome of minimal flavour structures. We present a few different incarnations of this statement, in terms of lepton mass matrices depending on a small number of parameters, that can be justified by discrete flavour symmetries. We also propose a general procedure to study the correlation between $\theta_{23}$, the absolute scale and ordering of the neutrino masses, and the leptonic CP-violating phases.
[ { "created": "Thu, 21 Mar 2013 15:06:09 GMT", "version": "v1" } ]
2017-08-15
[ [ "Frigerio", "Michele", "", "L2C, Montpellier" ], [ "del Moral", "Albert Villanova", "", "LUPM, Montpellier" ] ]
Present data prefer a large but non-maximal 2-3 mixing in the lepton sector. We argue that this value, in connection with $\sin\theta_{13}\simeq 0.15$, is the generic outcome of minimal flavour structures. We present a few different incarnations of this statement, in terms of lepton mass matrices depending on a small number of parameters, that can be justified by discrete flavour symmetries. We also propose a general procedure to study the correlation between $\theta_{23}$, the absolute scale and ordering of the neutrino masses, and the leptonic CP-violating phases.
2306.17591
Marcos Vinicius dos Santos
Marcos V. dos Santos, Pedro C. de Holanda, Pedro Dedin Neto, Ernesto Kemp
On the Effects of Quantum Decoherence in a Future Supernova Neutrino Detection
null
null
null
null
hep-ph astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
Quantum decoherence effects in neutrinos, described by the open quantum systems formalism, serve as a gateway to explore potential new physics, including quantum gravity. Previous research extensively investigated these effects across various neutrino sources, imposing stringent constraints on the spontaneous loss of coherence. In this study, we demonstrate that even within the Supernovae environment, where neutrinos are released as incoherent states, quantum decoherence could influence the flavor equipartition of $3\nu$ mixing. Additionally, we examine the potential energy dependence of quantum decoherence parameters ($\Gamma = \Gamma_0 (E/E_0)^n$) with different power laws ($n = 0, 2, 5/2$). Our findings indicate that future-generation detectors (DUNE, Hyper-K, and JUNO) can significantly constrain quantum decoherence effects under different scenarios. For a Supernova located 10 kpc away from Earth, DUNE could potentially establish $3\sigma$ bounds of $\Gamma \leq 6.2 \times 10^{-14}$ eV in the normal mass hierarchy (NH) scenario, while Hyper-K could impose a $2\sigma$ limit of $\Gamma \leq 3.6 \times 10^{-14}$ eV for the inverted mass hierarchy (IH) scenario with $n=0$ - assuming no energy exchange between the neutrino subsystem and non-standard environment ($[H,V_p] = 0$). These limits become even more restrictive for a closer Supernova. When we relax the assumption of energy exchange ($[H,V_p] \neq 0$), for a 10 kpc SN, DUNE can establish a $3\sigma$ limit of $\Gamma_8 \leq 4.2 \times 10^{-28}$ eV for NH, while Hyper-K could constrain $\Gamma_8 \leq 1.3 \times 10^{-27}$ eV for IH ($n=0$) with $2\sigma$, representing the most stringent bounds reported to date. Furthermore, we examine the impact of neutrino loss during propagation for future Supernova detection.
[ { "created": "Fri, 30 Jun 2023 12:12:24 GMT", "version": "v1" }, { "created": "Tue, 11 Jul 2023 13:34:21 GMT", "version": "v2" } ]
2023-07-12
[ [ "Santos", "Marcos V. dos", "" ], [ "de Holanda", "Pedro C.", "" ], [ "Neto", "Pedro Dedin", "" ], [ "Kemp", "Ernesto", "" ] ]
Quantum decoherence effects in neutrinos, described by the open quantum systems formalism, serve as a gateway to explore potential new physics, including quantum gravity. Previous research extensively investigated these effects across various neutrino sources, imposing stringent constraints on the spontaneous loss of coherence. In this study, we demonstrate that even within the Supernovae environment, where neutrinos are released as incoherent states, quantum decoherence could influence the flavor equipartition of $3\nu$ mixing. Additionally, we examine the potential energy dependence of quantum decoherence parameters ($\Gamma = \Gamma_0 (E/E_0)^n$) with different power laws ($n = 0, 2, 5/2$). Our findings indicate that future-generation detectors (DUNE, Hyper-K, and JUNO) can significantly constrain quantum decoherence effects under different scenarios. For a Supernova located 10 kpc away from Earth, DUNE could potentially establish $3\sigma$ bounds of $\Gamma \leq 6.2 \times 10^{-14}$ eV in the normal mass hierarchy (NH) scenario, while Hyper-K could impose a $2\sigma$ limit of $\Gamma \leq 3.6 \times 10^{-14}$ eV for the inverted mass hierarchy (IH) scenario with $n=0$ - assuming no energy exchange between the neutrino subsystem and non-standard environment ($[H,V_p] = 0$). These limits become even more restrictive for a closer Supernova. When we relax the assumption of energy exchange ($[H,V_p] \neq 0$), for a 10 kpc SN, DUNE can establish a $3\sigma$ limit of $\Gamma_8 \leq 4.2 \times 10^{-28}$ eV for NH, while Hyper-K could constrain $\Gamma_8 \leq 1.3 \times 10^{-27}$ eV for IH ($n=0$) with $2\sigma$, representing the most stringent bounds reported to date. Furthermore, we examine the impact of neutrino loss during propagation for future Supernova detection.
1605.05900
Jose Miguel No
Jose Miguel No
Is it $SU(2)_{\mathrm{L}}$ or just $U(1)_{\mathrm{Y}}$? $750$ GeV di-photon probes of the electroweak nature of new states
6 Pages, 5 Figures
Phys. Rev. D 94, 035020 (2016)
10.1103/PhysRevD.94.035020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence of a 750 GeV di-photon spin-0 resonance $S$ would imply the additional presence of new particles beyond the Standard Model, coupling directly to $S$ and electromagnetically charged. For an $SU(2)_{\mathrm{L}}$ singlet $S$, we explore the possibility of probing the $SU(2)_{\mathrm{L}}$ and $U(1)_{\mathrm{Y}}$ quantum numbers of the new states at the LHC by measuring/constraining the $WW$, $Z\gamma$ and $ZZ$ decays of $S$. We obtain robust prospects on the required LHC integrated luminosity to discover the new decay modes of $S$, and discuss the implications of these measurements for probing the electroweak nature of the new states. We also discuss the impact of $S$ mixing with the SM Higgs in such probes.
[ { "created": "Thu, 19 May 2016 11:48:45 GMT", "version": "v1" } ]
2016-08-31
[ [ "No", "Jose Miguel", "" ] ]
The existence of a 750 GeV di-photon spin-0 resonance $S$ would imply the additional presence of new particles beyond the Standard Model, coupling directly to $S$ and electromagnetically charged. For an $SU(2)_{\mathrm{L}}$ singlet $S$, we explore the possibility of probing the $SU(2)_{\mathrm{L}}$ and $U(1)_{\mathrm{Y}}$ quantum numbers of the new states at the LHC by measuring/constraining the $WW$, $Z\gamma$ and $ZZ$ decays of $S$. We obtain robust prospects on the required LHC integrated luminosity to discover the new decay modes of $S$, and discuss the implications of these measurements for probing the electroweak nature of the new states. We also discuss the impact of $S$ mixing with the SM Higgs in such probes.
0911.0687
John Kehayias
John Kehayias and Stefano Profumo
Semi-Analytic Calculation of the Gravitational Wave Signal From the Electroweak Phase Transition for General Quartic Scalar Effective Potentials
accepted by JCAP, revisions: removed turbulence contribution, minor changes to experimental sensitivity, fixed various minor typos and text revisions, added references, made it clear we consider only detonations; 17 pages, 4 figures, revtex4
JCAP 1003:003,2010
10.1088/1475-7516/2010/03/003
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Upcoming gravitational wave (GW) detectors might detect a stochastic background of GWs potentially arising from many possible sources, including bubble collisions from a strongly first-order electroweak phase transition. We investigate whether it is possible to connect, via a semi-analytical approximation to the tunneling rate of scalar fields with quartic potentials, the GW signal through detonations with the parameters entering the potential that drives the electroweak phase transition. To this end, we consider a finite temperature effective potential similar in form to the Higgs potential in the Standard Model (SM). In the context of a semi-analytic approximation to the three dimensional Euclidean action, we derive a general approximate form for the tunneling temperature and the relevant GW parameters. We explore the GW signal across the parameter space describing the potential which drives the phase transition. We comment on the potential detectability of a GW signal with future experiments, and physical relevance of the associated potential parameters in the context of theories which have effective potentials similar in form to that of the SM. In particular we consider singlet, triplet, higher dimensional operators, and top-flavor extensions to the Higgs sector of the SM. We find that the addition of a temperature independent cubic term in the potential, arising from a gauge singlet for instance, can greatly enhance the GW power. The other parameters have milder, but potentially noticeable, effects.
[ { "created": "Tue, 3 Nov 2009 21:03:14 GMT", "version": "v1" }, { "created": "Sat, 20 Feb 2010 00:41:45 GMT", "version": "v2" }, { "created": "Wed, 24 Feb 2010 19:55:49 GMT", "version": "v3" } ]
2014-11-20
[ [ "Kehayias", "John", "" ], [ "Profumo", "Stefano", "" ] ]
Upcoming gravitational wave (GW) detectors might detect a stochastic background of GWs potentially arising from many possible sources, including bubble collisions from a strongly first-order electroweak phase transition. We investigate whether it is possible to connect, via a semi-analytical approximation to the tunneling rate of scalar fields with quartic potentials, the GW signal through detonations with the parameters entering the potential that drives the electroweak phase transition. To this end, we consider a finite temperature effective potential similar in form to the Higgs potential in the Standard Model (SM). In the context of a semi-analytic approximation to the three dimensional Euclidean action, we derive a general approximate form for the tunneling temperature and the relevant GW parameters. We explore the GW signal across the parameter space describing the potential which drives the phase transition. We comment on the potential detectability of a GW signal with future experiments, and physical relevance of the associated potential parameters in the context of theories which have effective potentials similar in form to that of the SM. In particular we consider singlet, triplet, higher dimensional operators, and top-flavor extensions to the Higgs sector of the SM. We find that the addition of a temperature independent cubic term in the potential, arising from a gauge singlet for instance, can greatly enhance the GW power. The other parameters have milder, but potentially noticeable, effects.
2204.05945
Luca Di Luzio
Luca Di Luzio, Marco Nardecchia, Claudio Toni
Light vectors coupled to anomalous currents with harmless Wess-Zumino terms
23 pages, 1 figure. Minor corrections and references added. Matches published version
Phys. Rev. D 105, 115042 (2022)
10.1103/PhysRevD.105.115042
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We reconsider the case of light vectors coupled to anomalous fermionic currents, focussing on the interplay between UV and IR dynamics. Taking as a general framework the gauging of the Standard Model accidental symmetries, we show that it is possible to devise an anomaly-free UV completion with mostly-chiral heavy fermions such that anomalous Wess-Zumino terms are suppressed in the IR, thus relaxing would-be strong bounds from the longitudinal emission of light vectors coupled to non-conserved currents. We classify such scenarios and show that they will be extensively probed at the high-luminosity phase of the LHC via the measurement of the $h \to Z \gamma$ rate and the direct search for non-decoupling charged leptons.
[ { "created": "Tue, 12 Apr 2022 16:52:44 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2022 15:27:02 GMT", "version": "v2" } ]
2022-06-30
[ [ "Di Luzio", "Luca", "" ], [ "Nardecchia", "Marco", "" ], [ "Toni", "Claudio", "" ] ]
We reconsider the case of light vectors coupled to anomalous fermionic currents, focussing on the interplay between UV and IR dynamics. Taking as a general framework the gauging of the Standard Model accidental symmetries, we show that it is possible to devise an anomaly-free UV completion with mostly-chiral heavy fermions such that anomalous Wess-Zumino terms are suppressed in the IR, thus relaxing would-be strong bounds from the longitudinal emission of light vectors coupled to non-conserved currents. We classify such scenarios and show that they will be extensively probed at the high-luminosity phase of the LHC via the measurement of the $h \to Z \gamma$ rate and the direct search for non-decoupling charged leptons.
hep-ph/0005232
Thomas Gehrmann
T.Gehrmann, E. Remiddi
Using differential equations to compute two-loop box integrals
5 pages, LaTeX, uses espcrc2.sty; presented at Loops and Legs in Quantum Field Theory, April 2000, Bastei, Germany
Nucl.Phys.Proc.Suppl.89:251-255,2000
10.1016/S0920-5632(00)00851-3
Karlsruhe TTP00-10
hep-ph
null
The calculation of exclusive observables beyond the one-loop level requires elaborate techniques for the computation of multi-leg two-loop integrals. We discuss how the large number of different integrals appearing in actual two-loop calculations can be reduced to a small number of master integrals. An efficient method to compute these master integrals is to derive and solve differential equations in the external invariants for them. As an application of the differential equation method, we compute the ${\cal O}(\epsilon)$-term of a particular combination of on-shell massless planar double box integrals, which appears in the tensor reduction of $2 \to 2$ scattering amplitudes at two loops.
[ { "created": "Tue, 23 May 2000 15:28:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gehrmann", "T.", "" ], [ "Remiddi", "E.", "" ] ]
The calculation of exclusive observables beyond the one-loop level requires elaborate techniques for the computation of multi-leg two-loop integrals. We discuss how the large number of different integrals appearing in actual two-loop calculations can be reduced to a small number of master integrals. An efficient method to compute these master integrals is to derive and solve differential equations in the external invariants for them. As an application of the differential equation method, we compute the ${\cal O}(\epsilon)$-term of a particular combination of on-shell massless planar double box integrals, which appears in the tensor reduction of $2 \to 2$ scattering amplitudes at two loops.
1912.10225
Pengxuan Zhu
Junjie Cao, Jingwei Lian, Lei Meng, Yuanfang Yue and Pengxuan Zhu
Anomalous Muon Magnetic Moment in the Inverse Seesaw Extended Next-to-Minimal Supersymmetric Standard Model
18 pages, 4 figures
Phys. Rev. D 101, 095009 (2020)
10.1103/PhysRevD.101.095009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present work investigates the possibility that both dark matter and the anomalous magnetic moment of the muon may be explained within the context of the inverse seesaw extended Next-to-Minimal Supersymmetric Standard Model (ISS-NMSSM). In ISS-NMSSM, the newly introduced Higgs-neutrino Yukawa coupling $Y_\nu$ provides additional Higgsino-sneutrino loop contribution to $(g-2)_{\mu}$. If the deviation between the experimental observations and the Standard Model predictions of the anomalous muon magnetic moment is confirmed by the further experimental and theoretical studies, it can be explained naturally within the ISS-NMSSM framework without conflicting with the current stringent limits on the direct detection of dark matter and Large Hadron Collider searches.
[ { "created": "Sat, 21 Dec 2019 08:55:15 GMT", "version": "v1" }, { "created": "Sun, 19 Jan 2020 10:09:17 GMT", "version": "v2" }, { "created": "Fri, 24 Apr 2020 08:59:25 GMT", "version": "v3" } ]
2020-05-12
[ [ "Cao", "Junjie", "" ], [ "Lian", "Jingwei", "" ], [ "Meng", "Lei", "" ], [ "Yue", "Yuanfang", "" ], [ "Zhu", "Pengxuan", "" ] ]
The present work investigates the possibility that both dark matter and the anomalous magnetic moment of the muon may be explained within the context of the inverse seesaw extended Next-to-Minimal Supersymmetric Standard Model (ISS-NMSSM). In ISS-NMSSM, the newly introduced Higgs-neutrino Yukawa coupling $Y_\nu$ provides additional Higgsino-sneutrino loop contribution to $(g-2)_{\mu}$. If the deviation between the experimental observations and the Standard Model predictions of the anomalous muon magnetic moment is confirmed by the further experimental and theoretical studies, it can be explained naturally within the ISS-NMSSM framework without conflicting with the current stringent limits on the direct detection of dark matter and Large Hadron Collider searches.
1610.05123
Wolfgang Sch\"afer
Wolfgang Sch\"afer, Antoni Szczurek
Drell-Yan production at forward rapidities: a hybrid factorization approach
talk given by WS at the 24th Low-x Meeting, Gy\"ongy\"os, Hungary, June 6-11 2016
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the Drell-Yan production of dileptons at high energies in the forward rapidity region of proton-proton collisions in a hybrid high-energy approach. This approach uses unintegrated gluon distributions in one proton and collinear quark/antiquark distributions in the second proton. We compute various distributions for the case of low-mass dilepton production and compare to the LHCb and ATLAS experimental data on dilepton mass distributions. In distinction to dipole approaches, we include four Drell-Yan structure functions as well as cuts at the level of lepton kinematics. The impact of the interference structure functions is rather small for typical experimental cuts. We find that both side contributions ($g q/\bar q$ and $q/\bar q g$) have to be included even for the LHCb rapidity coverage which is in contradiction with what is usually done in the dipole approach. We present results for different unintegrated gluon distributions from the literature. Some of them include saturation effects, but we see no clear hints of saturation even at small $M_{ll}$.
[ { "created": "Mon, 17 Oct 2016 14:04:34 GMT", "version": "v1" } ]
2016-10-18
[ [ "Schäfer", "Wolfgang", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss the Drell-Yan production of dileptons at high energies in the forward rapidity region of proton-proton collisions in a hybrid high-energy approach. This approach uses unintegrated gluon distributions in one proton and collinear quark/antiquark distributions in the second proton. We compute various distributions for the case of low-mass dilepton production and compare to the LHCb and ATLAS experimental data on dilepton mass distributions. In distinction to dipole approaches, we include four Drell-Yan structure functions as well as cuts at the level of lepton kinematics. The impact of the interference structure functions is rather small for typical experimental cuts. We find that both side contributions ($g q/\bar q$ and $q/\bar q g$) have to be included even for the LHCb rapidity coverage which is in contradiction with what is usually done in the dipole approach. We present results for different unintegrated gluon distributions from the literature. Some of them include saturation effects, but we see no clear hints of saturation even at small $M_{ll}$.
1103.0908
Wilco J. den Dunnen
Daniel Boer, Wilco J. den Dunnen, Aram Kotzinian
Double Sivers effect asymmetries and their impact on transversity measurements at RHIC
12 pages, 11 eps figures, minor changes, matches the published version
Phys.Rev.D83:114032,2011
10.1103/PhysRevD.83.114032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study double transverse spin asymmetries in the Drell-Yan process at measured transverse momentum of the lepton pair. Contrary to what a collinear factorization approach would suggest, a nonzero double transverse spin asymmetry in the laboratory frame a priori does not imply nonzero transversity. TMD effects, such as the double Sivers effect, in principle form a background. Using the current knowledge of the relevant TMDs we estimate their contribution in the laboratory frame for Drell-Yan and W production at RHIC and point out a cross check asymmetry measurement to bound the TMD contributions. We also comment on the transverse momentum integrated asymmetries that only receive power suppressed background contributions.
[ { "created": "Fri, 4 Mar 2011 14:30:46 GMT", "version": "v1" }, { "created": "Thu, 30 Jun 2011 10:15:54 GMT", "version": "v2" } ]
2011-07-04
[ [ "Boer", "Daniel", "" ], [ "Dunnen", "Wilco J. den", "" ], [ "Kotzinian", "Aram", "" ] ]
We study double transverse spin asymmetries in the Drell-Yan process at measured transverse momentum of the lepton pair. Contrary to what a collinear factorization approach would suggest, a nonzero double transverse spin asymmetry in the laboratory frame a priori does not imply nonzero transversity. TMD effects, such as the double Sivers effect, in principle form a background. Using the current knowledge of the relevant TMDs we estimate their contribution in the laboratory frame for Drell-Yan and W production at RHIC and point out a cross check asymmetry measurement to bound the TMD contributions. We also comment on the transverse momentum integrated asymmetries that only receive power suppressed background contributions.
hep-ph/9907229
Fred Jegerlehner
F. Jegerlehner, K. Kolodziej
The hard bremsstrahlung correction to e^+ e^- -> 4f with finite fermion masses: results for e^+ e^- -> u d-bar mu^- nu
18 pages, 6 figures
Eur.Phys.J.C12:77-86,2000
10.1007/s100529900202
Univ. of Silesia Katowice TP-USl/99/01, DESY 99-052
hep-ph
null
An improved efficient method of calculating the hard bremsstrahlung correction to e^+ e^- -> 4f for non-zero fermion masses is presented. The non-vanishing fermion masses allow us to perform the phase space integrations to the very collinear limit. We therefore can calculate cross sections independent of angular cuts. Such calculations are important for background studies. Results are presented for the total and some differential cross sections for e^+ e^- -> u d-bar mu^- nu and the corresponding hard bremsstrahlung process. The latter is of particular interest for a detailed investigation of the effects of final state radiation. In principle, the process e^+ e^- -> u d-bar mu^- nu gamma is also interesting since it helps to set bounds on possible anomalous triple and quartic gauge boson couplings involving photons. The size of mass effects is illustrated by comparing the final states u d-bar mu^- nu (gamma), c s-bar mu^- nu (gamma) and u d-bar tau^- nu(gamma).
[ { "created": "Mon, 5 Jul 1999 11:48:37 GMT", "version": "v1" } ]
2009-01-07
[ [ "Jegerlehner", "F.", "" ], [ "Kolodziej", "K.", "" ] ]
An improved efficient method of calculating the hard bremsstrahlung correction to e^+ e^- -> 4f for non-zero fermion masses is presented. The non-vanishing fermion masses allow us to perform the phase space integrations to the very collinear limit. We therefore can calculate cross sections independent of angular cuts. Such calculations are important for background studies. Results are presented for the total and some differential cross sections for e^+ e^- -> u d-bar mu^- nu and the corresponding hard bremsstrahlung process. The latter is of particular interest for a detailed investigation of the effects of final state radiation. In principle, the process e^+ e^- -> u d-bar mu^- nu gamma is also interesting since it helps to set bounds on possible anomalous triple and quartic gauge boson couplings involving photons. The size of mass effects is illustrated by comparing the final states u d-bar mu^- nu (gamma), c s-bar mu^- nu (gamma) and u d-bar tau^- nu(gamma).
hep-ph/0504127
Bertram Klein
J. Braun (1), B. Klein (2), H.J. Pirner (1 and 3) ((1) Institute for Theoretical Physics, University of Heidelberg, (2) GSI Darmstadt, (3) Max-Planck-Institut fuer Kernphysik, Heidelberg)
Influence of quark boundary conditions on the pion mass in finite volume
24 pages, 5 figures, RevTex4, published version, discussion of lattice results extended
Phys.Rev. D72 (2005) 034017
10.1103/PhysRevD.72.034017
null
hep-ph
null
We calculate the mass shift for the pion in a finite volume with renormalization group (RG) methods in the framework of the quark-mesons model. In particular, we investigate the importance of the quark effects on the pion mass. As in lattice gauge theory, the choice of quark boundary conditions has a noticeable effect on the pion mass shift in small volumes, in addition to the shift due to pion interactions. We compare our results to chiral perturbation theory calculations and find differences due to the fact that chiral perturbation theory only considers pion effects in the finite volume.
[ { "created": "Fri, 15 Apr 2005 14:55:07 GMT", "version": "v1" }, { "created": "Fri, 23 Jun 2006 15:51:15 GMT", "version": "v2" } ]
2009-11-11
[ [ "Braun", "J.", "", "1 and 3" ], [ "Klein", "B.", "", "1 and 3" ], [ "Pirner", "H. J.", "", "1 and 3" ] ]
We calculate the mass shift for the pion in a finite volume with renormalization group (RG) methods in the framework of the quark-mesons model. In particular, we investigate the importance of the quark effects on the pion mass. As in lattice gauge theory, the choice of quark boundary conditions has a noticeable effect on the pion mass shift in small volumes, in addition to the shift due to pion interactions. We compare our results to chiral perturbation theory calculations and find differences due to the fact that chiral perturbation theory only considers pion effects in the finite volume.
hep-ph/0401210
Chris Quigg
Estia J. Eichten, Kenneth Lane, and Chris Quigg
Charmonium levels near threshold and the narrow state $X(3872) \to \pi^{+}\pi^{-}\jpsi$
8 pages, 6 figures, uses RevTeX and boxedeps; few transcription errors corrected in Tables IV and VI, three entries added in Table V, updated references. Version to appear in Phys. Rev. D
Phys.Rev.D69:094019,2004
10.1103/PhysRevD.69.094019
FERMILAB-Pub-04/001-T, BUHEP-04-01
hep-ph
null
We explore the influence of open-charm channels on charmonium properties, and profile the 1:3D2, 1:3D3 and 2:1P1 charmonium candidates for X(3872). The favored candidates, the 1:3D2 and 1:3D3 levels, both have prominent radiative decays. The 1:3D2 might be visible in the $D^{0}\bar{D}^{*0}$ channel, while the dominant decay of the 1:3D3 state should be into $D\bar{D}$. We propose that additional discrete charmonium levels can be discovered as narrow resonances of charmed and anticharmed mesons.
[ { "created": "Mon, 26 Jan 2004 19:39:06 GMT", "version": "v1" }, { "created": "Fri, 23 Apr 2004 19:29:15 GMT", "version": "v2" } ]
2008-11-26
[ [ "Eichten", "Estia J.", "" ], [ "Lane", "Kenneth", "" ], [ "Quigg", "Chris", "" ] ]
We explore the influence of open-charm channels on charmonium properties, and profile the 1:3D2, 1:3D3 and 2:1P1 charmonium candidates for X(3872). The favored candidates, the 1:3D2 and 1:3D3 levels, both have prominent radiative decays. The 1:3D2 might be visible in the $D^{0}\bar{D}^{*0}$ channel, while the dominant decay of the 1:3D3 state should be into $D\bar{D}$. We propose that additional discrete charmonium levels can be discovered as narrow resonances of charmed and anticharmed mesons.
hep-ph/9911494
Hou Defu
Hou Defu, M.E. Carrington, R. Kobes and U. Heinz
Four-Point Spectral Functions and Ward Identities in Hot QED
16 pages in Revtex with 3 figures, dense version, a typo corrected
Phys.Rev.D61:085013,2000; Erratum-ibid.D67:049902,2003
10.1103/PhysRevD.61.085013 10.1103/PhysRevD.67.049902
CERN-TH/99-351
hep-ph hep-th
null
We derive spectral representations for the different components of the 4-point function at finite temperature in the real time formalism in terms of five real spectral densities. We explicitly calculate all these functions in QED in the hard thermal loop approximation. The Ward identities obeyed by the 1-loop 3- and 4-point functions in real time and their spectral functions are derived. We compare our results with those derived previously in the imaginary-time formalism for retarded functions in hot QCD, and we discuss the generalization of our results to non-equilibrium situations.
[ { "created": "Thu, 25 Nov 1999 18:49:57 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 1999 16:56:36 GMT", "version": "v2" } ]
2014-11-17
[ [ "Defu", "Hou", "" ], [ "Carrington", "M. E.", "" ], [ "Kobes", "R.", "" ], [ "Heinz", "U.", "" ] ]
We derive spectral representations for the different components of the 4-point function at finite temperature in the real time formalism in terms of five real spectral densities. We explicitly calculate all these functions in QED in the hard thermal loop approximation. The Ward identities obeyed by the 1-loop 3- and 4-point functions in real time and their spectral functions are derived. We compare our results with those derived previously in the imaginary-time formalism for retarded functions in hot QCD, and we discuss the generalization of our results to non-equilibrium situations.
1704.07627
Sven Heinemeyer
S. Heinemeyer, C. Schappacher
Chargino and Neutralino Production at e+e- Colliders in the Complex MSSM: A Full One-Loop Analysis
45 pages, 26 figures. arXiv admin note: substantial text overlap with arXiv:1606.06981, arXiv:1511.06002
null
10.1140/epjc/s10052-017-5195-9
IFT-UAM/CSIC-17-013
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For the search for charginos and neutralinos in the Minimal Supersymmetric Standard Model (MSSM) as well as for future precision analyses of these particles an accurate knowledge of their production and decay properties is mandatory. We evaluate the cross sections for the chargino and neutralino production at e+e- colliders in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of the production mechanisms e+e- -> cha_c cha_c' and e+e- -> neu_n neu_n', including soft and hard photon radiation. We mostly restricted ourselves to a version of our renormalization scheme which is valid for |M_1| < |M_2|, |mu| and M_2 != mu to simplify the analysis, even though we are able to switch to other parameter regions and correspondingly different renormalization schemes. The dependence of the chargino/neutralino cross sections on the relevant cMSSM parameters is analyzed numerically. We find sizable contributions to many production cross sections. They amount roughly 10-20% of the tree-level results, but can go up to 40% or higher in extreme cases. Also the complex phase dependence of the one-loop corrections was found non-negligible. The full one-loop contributions are thus crucial for physics analyses at a future linear e+e- collider such as the ILC or CLIC.
[ { "created": "Tue, 25 Apr 2017 10:54:45 GMT", "version": "v1" } ]
2017-10-25
[ [ "Heinemeyer", "S.", "" ], [ "Schappacher", "C.", "" ] ]
For the search for charginos and neutralinos in the Minimal Supersymmetric Standard Model (MSSM) as well as for future precision analyses of these particles an accurate knowledge of their production and decay properties is mandatory. We evaluate the cross sections for the chargino and neutralino production at e+e- colliders in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of the production mechanisms e+e- -> cha_c cha_c' and e+e- -> neu_n neu_n', including soft and hard photon radiation. We mostly restricted ourselves to a version of our renormalization scheme which is valid for |M_1| < |M_2|, |mu| and M_2 != mu to simplify the analysis, even though we are able to switch to other parameter regions and correspondingly different renormalization schemes. The dependence of the chargino/neutralino cross sections on the relevant cMSSM parameters is analyzed numerically. We find sizable contributions to many production cross sections. They amount roughly 10-20% of the tree-level results, but can go up to 40% or higher in extreme cases. Also the complex phase dependence of the one-loop corrections was found non-negligible. The full one-loop contributions are thus crucial for physics analyses at a future linear e+e- collider such as the ILC or CLIC.
0909.3977
Andrea Wulzer Dr
Jan Mrazek, Andrea Wulzer
A Strong Sector at the LHC: Top Partners in Same-Sign Dileptons
Corrected some typos, added a reference, 23 pages
Phys.Rev.D81:075006,2010
10.1103/PhysRevD.81.075006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy partners of the top quark are a common prediction of many models in which a new strongly-coupled sector is responsible for the breaking of the EW symmetry. In this paper we investigate their experimental signature at the LHC, focusing on the particularly clean channel of same-sign dileptons. We show that, thank to a strong interaction with the top quark which allows them to be singly produced at a sizable rate, the top partners will be discovered at the LHC if their mass is below 1.5 TeV, higher masses being possible in particularly favorable (but plausible) situations. Being the partners expected to be lighter in both the Higgsless and Composite-Higgs scenarios, the one of same-sign dileptons is found to be a very promising channel in which these models could be tested. We also discuss several experimental signatures which would allow, after the discovery of the excess, to uniquely attribute it to the top partners production and to measure the relevant physical parameters, i.e. the top partners masses and couplings. We believe that our results constitute a valid starting point for a more detailed experimental study.
[ { "created": "Tue, 22 Sep 2009 12:43:27 GMT", "version": "v1" }, { "created": "Tue, 15 Dec 2009 15:33:08 GMT", "version": "v2" } ]
2010-04-14
[ [ "Mrazek", "Jan", "" ], [ "Wulzer", "Andrea", "" ] ]
Heavy partners of the top quark are a common prediction of many models in which a new strongly-coupled sector is responsible for the breaking of the EW symmetry. In this paper we investigate their experimental signature at the LHC, focusing on the particularly clean channel of same-sign dileptons. We show that, thank to a strong interaction with the top quark which allows them to be singly produced at a sizable rate, the top partners will be discovered at the LHC if their mass is below 1.5 TeV, higher masses being possible in particularly favorable (but plausible) situations. Being the partners expected to be lighter in both the Higgsless and Composite-Higgs scenarios, the one of same-sign dileptons is found to be a very promising channel in which these models could be tested. We also discuss several experimental signatures which would allow, after the discovery of the excess, to uniquely attribute it to the top partners production and to measure the relevant physical parameters, i.e. the top partners masses and couplings. We believe that our results constitute a valid starting point for a more detailed experimental study.
hep-ph/0105282
Roberto Pittau
R. Pittau (Turin U. & INFN, Turin)
Theoretical issues at LEP2 and LC
3 pages. Talk given at 13th Convegno sulla Fisica al LEP (LEPTRE 2001), Rome, Italy, 18-20 Apr 2001
null
null
null
hep-ph
null
After 12 years of glorious data taking LEP has been shut down. During the past two years an incredible effort has been devoted to get more accurate predictions and estimates of the related theoretical uncertainties. Many of the theoretical questions driven by LEP are also relevant at the LC, where predictions will be needed with even higher accuracy. This is particularly true for 4-fermion Physics. In this contribution, I review some of the most important theoretical achievements at LEP in understanding W and Z pair production, 4-fermion + 1 visible photon signatures and in solving problems related with gauge invariance. Issues on single W Physics are covered elsewhere. Part of the presented work is in progress, the final LEP2 analysis still being under way.
[ { "created": "Sun, 27 May 2001 16:43:09 GMT", "version": "v1" } ]
2016-09-06
[ [ "Pittau", "R.", "", "Turin U. & INFN, Turin" ] ]
After 12 years of glorious data taking LEP has been shut down. During the past two years an incredible effort has been devoted to get more accurate predictions and estimates of the related theoretical uncertainties. Many of the theoretical questions driven by LEP are also relevant at the LC, where predictions will be needed with even higher accuracy. This is particularly true for 4-fermion Physics. In this contribution, I review some of the most important theoretical achievements at LEP in understanding W and Z pair production, 4-fermion + 1 visible photon signatures and in solving problems related with gauge invariance. Issues on single W Physics are covered elsewhere. Part of the presented work is in progress, the final LEP2 analysis still being under way.
hep-ph/0211231
Luis Anchordoqui
Luis A. Anchordoqui, Diego F. Torres, Thomas P. McCauley, Gustavo E. Romero, and Felix A. Aharonian
Neutrinos from Accreting Neutron Stars
7 pages, 5 figures. Updates to match accepted version in Astrophys. J
Astrophys.J. 589 (2003) 481-486
10.1086/374551
NUB-3235-TH-02
hep-ph astro-ph hep-ex
null
The magnetospheres of accreting neutron stars develop electrostatic gaps with huge potential drops. Protons and ions, accelerated in these gaps along the dipolar magnetic field lines to energies greater than 100 TeV, can impact onto a surrounding accretion disc. A proton-induced cascade so develops, and $\nu$-emission is produced from charged pion decays. Using GEANT4, a computer code that tracks particles produced in high energy collisions, we have calculated the resulting $\nu$-spectrum with extensive disc shower simulations. We show that the $\nu$-spectrum produced out of the proton beam is a power law. We use this result to propose accretion-powered X-ray binaries (with highly magnetized neutron stars) as a new population of point-like $\nu$-sources for km-scale detectors, such as ICECUBE. As a particular example we discuss the case of A0535+26. We show that ICECUBE should find A0535+26 to be a periodic $\nu$-source: one for which the formation and loss of its accretion disc can be fully detected. Finally, we briefly comment on the possibility that smaller telescopes, like AMANDA, could also detect A0535+26 by folding observations with the orbital period.
[ { "created": "Thu, 14 Nov 2002 21:02:12 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2003 17:11:03 GMT", "version": "v2" } ]
2009-11-07
[ [ "Anchordoqui", "Luis A.", "" ], [ "Torres", "Diego F.", "" ], [ "McCauley", "Thomas P.", "" ], [ "Romero", "Gustavo E.", "" ], [ "Aharonian", "Felix A.", "" ] ]
The magnetospheres of accreting neutron stars develop electrostatic gaps with huge potential drops. Protons and ions, accelerated in these gaps along the dipolar magnetic field lines to energies greater than 100 TeV, can impact onto a surrounding accretion disc. A proton-induced cascade so develops, and $\nu$-emission is produced from charged pion decays. Using GEANT4, a computer code that tracks particles produced in high energy collisions, we have calculated the resulting $\nu$-spectrum with extensive disc shower simulations. We show that the $\nu$-spectrum produced out of the proton beam is a power law. We use this result to propose accretion-powered X-ray binaries (with highly magnetized neutron stars) as a new population of point-like $\nu$-sources for km-scale detectors, such as ICECUBE. As a particular example we discuss the case of A0535+26. We show that ICECUBE should find A0535+26 to be a periodic $\nu$-source: one for which the formation and loss of its accretion disc can be fully detected. Finally, we briefly comment on the possibility that smaller telescopes, like AMANDA, could also detect A0535+26 by folding observations with the orbital period.
1008.0308
Basudeb Dasgupta
Sandhya Choubey, Basudeb Dasgupta, Amol Dighe and Alessandro Mirizzi
Signatures of collective and matter effects on supernova neutrinos at large detectors
18 Pages, 5 figures and 4 tables
null
null
TIFR/TH/10-20
hep-ph astro-ph.SR hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the expected galactic supernova neutrino signal at large next-generation underground detectors. At different epochs after the explosion, the primary fluxes can be quite different. For these primary neutrino fluxes, spectral splits induced by collective neutrino flavor transformations can arise for either mass hierarchy in both neutrino and antineutrino channels. We classify flux models according to the nature and number of these splits, and calculate the observable electron-neutrino and electron-antineutrino spectra at Earth, taking into account subsequent matter effects. We find that some of the spectral splits could occur sufficiently close to the peak energies to produce significant distortions in the observable SN neutrino signal. The most striking signature of this effect would be presence of peculiar energy dependent modulations associated with Earth matter crossing, present only in portions of the SN neutrino energy spectra demarcated by spectral splits. These signatures at proposed large water Cherenkov, scintillation, and liquid Argon detectors could give hints about the primary SN neutrino fluxes, as well as on the neutrino mass hierarchy and the mixing angle theta_{13}.
[ { "created": "Mon, 2 Aug 2010 14:04:33 GMT", "version": "v1" } ]
2010-08-03
[ [ "Choubey", "Sandhya", "" ], [ "Dasgupta", "Basudeb", "" ], [ "Dighe", "Amol", "" ], [ "Mirizzi", "Alessandro", "" ] ]
We calculate the expected galactic supernova neutrino signal at large next-generation underground detectors. At different epochs after the explosion, the primary fluxes can be quite different. For these primary neutrino fluxes, spectral splits induced by collective neutrino flavor transformations can arise for either mass hierarchy in both neutrino and antineutrino channels. We classify flux models according to the nature and number of these splits, and calculate the observable electron-neutrino and electron-antineutrino spectra at Earth, taking into account subsequent matter effects. We find that some of the spectral splits could occur sufficiently close to the peak energies to produce significant distortions in the observable SN neutrino signal. The most striking signature of this effect would be presence of peculiar energy dependent modulations associated with Earth matter crossing, present only in portions of the SN neutrino energy spectra demarcated by spectral splits. These signatures at proposed large water Cherenkov, scintillation, and liquid Argon detectors could give hints about the primary SN neutrino fluxes, as well as on the neutrino mass hierarchy and the mixing angle theta_{13}.
2104.11369
Lucas Johns
Lucas Johns
Collisional flavor instabilities of supernova neutrinos
6 pages, 3 figures
Phys. Rev. Lett. 130, 191001 (2023)
10.1103/PhysRevLett.130.191001
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A lingering mystery in core-collapse supernova theory is how collective neutrino oscillations affect the dynamics. All previously identified flavor instabilities, some of which might make the effects considerable, are essentially collisionless phenomena. Here it is shown that collisional instabilities exist as well. They are associated with asymmetries between the neutrino and antineutrino interaction rates, are possibly prevalent deep inside supernovae, and pose an unusual instance of decoherent interactions with a thermal environment causing the sustained growth of quantum coherence.
[ { "created": "Fri, 23 Apr 2021 01:32:00 GMT", "version": "v1" }, { "created": "Mon, 8 May 2023 16:23:36 GMT", "version": "v2" } ]
2023-05-09
[ [ "Johns", "Lucas", "" ] ]
A lingering mystery in core-collapse supernova theory is how collective neutrino oscillations affect the dynamics. All previously identified flavor instabilities, some of which might make the effects considerable, are essentially collisionless phenomena. Here it is shown that collisional instabilities exist as well. They are associated with asymmetries between the neutrino and antineutrino interaction rates, are possibly prevalent deep inside supernovae, and pose an unusual instance of decoherent interactions with a thermal environment causing the sustained growth of quantum coherence.
2408.07496
Natasha Sharma
Peter Braun-Munzinger, Krzysztof Redlich, Natasha Sharma and Johanna Stachel
Emergence of New Systematics for Open Charm Production in High Energy Collisions
10 pages, 7 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
We present the production systematics of open charm hadron yields in high-energy collisions and their description based on the Statistical Hadronization Model. The rapidity density of $D^0, D^+, D^{*+}, D_s^+$ mesons and $\Lambda_c^+$ baryons in heavy ion and proton-proton collisions is analyzed for different collision energies and centralities. The Statistical Hadronization Model is extended to open charm production in minimum-bias and high-multiplicity pp collisions. In this context, we use the link established in [1], see also the further development in [2], between the rapidity density of open charm hadron yields, $dN_i/dy$, and the rapidity density of charm-anticharm quark pairs, $dN_{c\bar c}/d\eta$ to demonstrate that, in pp, pA and AA collisions, $dN_i/dy$ scales in leading order with $dN_{c\bar c}/d\eta$ and the slope coefficient is quantified by the appropriate thermal density ratio calculated at the chiral crossover temperature, $T_c=156.5$ MeV. It is also shown that, in high energy collisions and within uncertainties, $dN_i/dy$ exhibits the power-law scaling with the charged-particle pseudo-rapidity density. Furthermore, presently available data on different ratios of open charm rapidity densities in high-energy collisions are independent of collision energy and system size, as expected in the Statistical Hadronization Model.
[ { "created": "Wed, 14 Aug 2024 12:21:21 GMT", "version": "v1" } ]
2024-08-15
[ [ "Braun-Munzinger", "Peter", "" ], [ "Redlich", "Krzysztof", "" ], [ "Sharma", "Natasha", "" ], [ "Stachel", "Johanna", "" ] ]
We present the production systematics of open charm hadron yields in high-energy collisions and their description based on the Statistical Hadronization Model. The rapidity density of $D^0, D^+, D^{*+}, D_s^+$ mesons and $\Lambda_c^+$ baryons in heavy ion and proton-proton collisions is analyzed for different collision energies and centralities. The Statistical Hadronization Model is extended to open charm production in minimum-bias and high-multiplicity pp collisions. In this context, we use the link established in [1], see also the further development in [2], between the rapidity density of open charm hadron yields, $dN_i/dy$, and the rapidity density of charm-anticharm quark pairs, $dN_{c\bar c}/d\eta$ to demonstrate that, in pp, pA and AA collisions, $dN_i/dy$ scales in leading order with $dN_{c\bar c}/d\eta$ and the slope coefficient is quantified by the appropriate thermal density ratio calculated at the chiral crossover temperature, $T_c=156.5$ MeV. It is also shown that, in high energy collisions and within uncertainties, $dN_i/dy$ exhibits the power-law scaling with the charged-particle pseudo-rapidity density. Furthermore, presently available data on different ratios of open charm rapidity densities in high-energy collisions are independent of collision energy and system size, as expected in the Statistical Hadronization Model.
1703.07136
Sushant Raut
Sushant K. Raut
Matter effects at the T2HK and T2HKK experiments
Version accepted for publication in Phys. Rev. D (Originally titled "T2HK and T2HKK: Does more matter matter?", changed at insistence of the editorial team.)
Phys. Rev. D 96, 075029 (2017)
10.1103/PhysRevD.96.075029
CTPU-17-10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Determining the neutrino mass hierarchy and measuring the CP-violating phase $\delta_{CP}$ are two of the main aims in neutrino physics today. The upcoming T2HK (with small matter effects and high statistics) and DUNE (with large matter effects) experiments have been shown to have excellent sensitivity to $\delta_{CP}$ and the neutrino mass hierarchy, respectively. The recent T2HKK proposal aims to improve the hierarchy sensitivity of T2HK by placing one of the two tanks of the HK detector at a site in Korea, to collect data at $\sim 1100$ km baseline. In light of the fact that DUNE will anyway collect data at $\sim 1300$ km, we explore whether it is advantageous to collect additional long-baseline data as proposed with T2HKK, or to enhance the $\delta_{CP}$-precision with the `conventional' T2HK by keeping both detector tanks in Japan. We do this by comparing the physics reach of these two options in conjunction with DUNE. We find that DUNE+T2HKK is better at excluding the wrong hierarchy, reaching $\Delta\chi^2 > 175$ irrespective of the true parameters. While DUNE+T2HK can measure $\delta_{CP}$ with more precision in some parts of the parameter space, both DUNE+T2HK and DUNE+T2HKK perform equally well near the current best-fit point, giving a $\delta_{CP}$ width of around $15^\circ$. The T2HKK setup allows us to correlate and constrain the systematic errors between the two detectors collecting data from the same source, which can increase the sensitivity of the experiment by up to 25\%. Such a reduction of the systematic errors is crucial for determining the oscillation parameters with greater significance.
[ { "created": "Tue, 21 Mar 2017 10:44:07 GMT", "version": "v1" }, { "created": "Wed, 18 Oct 2017 08:55:59 GMT", "version": "v2" } ]
2017-10-25
[ [ "Raut", "Sushant K.", "" ] ]
Determining the neutrino mass hierarchy and measuring the CP-violating phase $\delta_{CP}$ are two of the main aims in neutrino physics today. The upcoming T2HK (with small matter effects and high statistics) and DUNE (with large matter effects) experiments have been shown to have excellent sensitivity to $\delta_{CP}$ and the neutrino mass hierarchy, respectively. The recent T2HKK proposal aims to improve the hierarchy sensitivity of T2HK by placing one of the two tanks of the HK detector at a site in Korea, to collect data at $\sim 1100$ km baseline. In light of the fact that DUNE will anyway collect data at $\sim 1300$ km, we explore whether it is advantageous to collect additional long-baseline data as proposed with T2HKK, or to enhance the $\delta_{CP}$-precision with the `conventional' T2HK by keeping both detector tanks in Japan. We do this by comparing the physics reach of these two options in conjunction with DUNE. We find that DUNE+T2HKK is better at excluding the wrong hierarchy, reaching $\Delta\chi^2 > 175$ irrespective of the true parameters. While DUNE+T2HK can measure $\delta_{CP}$ with more precision in some parts of the parameter space, both DUNE+T2HK and DUNE+T2HKK perform equally well near the current best-fit point, giving a $\delta_{CP}$ width of around $15^\circ$. The T2HKK setup allows us to correlate and constrain the systematic errors between the two detectors collecting data from the same source, which can increase the sensitivity of the experiment by up to 25\%. Such a reduction of the systematic errors is crucial for determining the oscillation parameters with greater significance.