id
stringlengths
9
14
submitter
stringlengths
1
56
authors
stringlengths
5
7.68k
title
stringlengths
3
299
comments
stringlengths
1
1.15k
journal-ref
stringlengths
9
298
doi
stringlengths
12
97
report-no
stringlengths
3
341
categories
stringclasses
869 values
license
stringclasses
9 values
orig_abstract
stringlengths
16
2.44k
versions
listlengths
1
39
update_date
stringlengths
10
10
authors_parsed
listlengths
1
565
abstract
stringlengths
13
2.44k
0801.0536
Stanislaw Mrowczynski
Stanislaw Mrowczynski
Chromodynamic Fluctuations in Quark-Gluon Plasma
19 pages, numerous but minor corrections, to appear in Phys. Rev. D
Phys.Rev.D77:105022,2008
10.1103/PhysRevD.77.105022
null
hep-ph nucl-th
null
Fluctuations of chromodynamic fields in the collisionless quark-gluon plasma are found as a solution of the initial value linearized problem. The plasma initial state is on average colorless, stationary and homogeneous. When the state is stable, the initial fluctuations decay exponentially and in the long-time limit a stationary spectrum of fluctuations is established. For the equilibrium plasma it reproduces the spectrum which is provided by the fluctuation-dissipation relation. Fluctuations in the unstable plasma, where the memory of initial fluctuations is not lost, are also discussed.
[ { "created": "Thu, 3 Jan 2008 16:56:03 GMT", "version": "v1" }, { "created": "Mon, 21 Jan 2008 16:04:41 GMT", "version": "v2" }, { "created": "Fri, 4 Apr 2008 23:03:11 GMT", "version": "v3" } ]
2008-11-26
[ [ "Mrowczynski", "Stanislaw", "" ] ]
Fluctuations of chromodynamic fields in the collisionless quark-gluon plasma are found as a solution of the initial value linearized problem. The plasma initial state is on average colorless, stationary and homogeneous. When the state is stable, the initial fluctuations decay exponentially and in the long-time limit a stationary spectrum of fluctuations is established. For the equilibrium plasma it reproduces the spectrum which is provided by the fluctuation-dissipation relation. Fluctuations in the unstable plasma, where the memory of initial fluctuations is not lost, are also discussed.
1202.5641
Marcus Pinto B
Sidney S. Avancini, D\'ebora P. Menezes, Marcus B. Pinto and Constan\c{c}a Provid\^encia
The QCD Critical End Point Under Strong Magnetic Fields
5 pages, 2 figures
null
10.1103/PhysRevD.85.091901
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the three-flavor Nambu--Jona-Lasinio model, which includes strangeness and quark physical masses in the mean field approximation, to investigate the influence of strong magnetic fields on the QCD phase diagram covering the whole $T-\mu$ plane. It is found that the size of the first order transition line increases as the field strength increases so that a larger coexistence region for hadronic and quark matter should be expected for strong magnetic fields. The location of the critical end point is also affected by the presence of magnetic fields which invariably increase the temperature value at which the first order line terminates. On the other hand, the critical end point chemical potential value displays a subtle oscillation around the B=0 value for magnetic fields within the $10^{17}-10^{20} \, {\rm G}$ range. These findings may have non trivial consequences for the physics of magnetars and heavy ion collisions.
[ { "created": "Sat, 25 Feb 2012 11:13:14 GMT", "version": "v1" } ]
2015-06-04
[ [ "Avancini", "Sidney S.", "" ], [ "Menezes", "Débora P.", "" ], [ "Pinto", "Marcus B.", "" ], [ "Providência", "Constança", "" ] ]
We use the three-flavor Nambu--Jona-Lasinio model, which includes strangeness and quark physical masses in the mean field approximation, to investigate the influence of strong magnetic fields on the QCD phase diagram covering the whole $T-\mu$ plane. It is found that the size of the first order transition line increases as the field strength increases so that a larger coexistence region for hadronic and quark matter should be expected for strong magnetic fields. The location of the critical end point is also affected by the presence of magnetic fields which invariably increase the temperature value at which the first order line terminates. On the other hand, the critical end point chemical potential value displays a subtle oscillation around the B=0 value for magnetic fields within the $10^{17}-10^{20} \, {\rm G}$ range. These findings may have non trivial consequences for the physics of magnetars and heavy ion collisions.
1610.04410
Tooraj Ghaffary
Tooraj Ghaffary
Comparing Production Cross Sections for QCD Matter, Higgs Boson, Neutrino with Dark Energy in Accelerating Universe
23 pages; 8 figures
null
10.1142/S0219887817501390
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this research, the production cross sections for QCD matter, neutrino and dark energy due to acceleration of Universe is calculated. To obtain these cross sections, the Universe production cross section is multiplied by the particle or dark energy distribution in accelerating Universe. Also missing cross section for each matter and dark energy due to formation of event horizon, is calculated. It is clear that the cross section of particles produced near event horizon of Universe is much larger for higher acceleration of Universe. This is because as the acceleration of Universe becomes larger, the Unruh temperature becomes larger and the thermal radiations of particles are enhanced. There are different channels for producing Higgs boson in accelerating Universe. Universe maybe decay to quark and gluons, and then these particles interact with each other and Higgs boson is produced. Also, some Higgs boson are emitted directly from event horizon of Universe. Comparing Higgs boson cross sections via different channels, it is observed that at lower acceleration, a_Universe<2.5 a_(early Universe), the Universe will not be able to emit Higgs, but is still able to produce a quark and eventually for a_Universe<1.5 a_(early Universe) the Universe can only emit massless gluons. As the acceleration of Universe at the LHC increases, a_Universe>2.5 a_(early Universe), most of Higgs boson production will be due to Unruh effect near event horizon of Universe. Finally comparing the production cross section for dark energy with particle cross sections, it is found that the cross section for dark energy is dominated by QCD matter, Higgs boson and neutrino. This result is consistent with previous predictions for dark energy cross section.
[ { "created": "Fri, 14 Oct 2016 11:18:41 GMT", "version": "v1" }, { "created": "Wed, 19 Oct 2016 00:23:41 GMT", "version": "v2" } ]
2017-10-11
[ [ "Ghaffary", "Tooraj", "" ] ]
In this research, the production cross sections for QCD matter, neutrino and dark energy due to acceleration of Universe is calculated. To obtain these cross sections, the Universe production cross section is multiplied by the particle or dark energy distribution in accelerating Universe. Also missing cross section for each matter and dark energy due to formation of event horizon, is calculated. It is clear that the cross section of particles produced near event horizon of Universe is much larger for higher acceleration of Universe. This is because as the acceleration of Universe becomes larger, the Unruh temperature becomes larger and the thermal radiations of particles are enhanced. There are different channels for producing Higgs boson in accelerating Universe. Universe maybe decay to quark and gluons, and then these particles interact with each other and Higgs boson is produced. Also, some Higgs boson are emitted directly from event horizon of Universe. Comparing Higgs boson cross sections via different channels, it is observed that at lower acceleration, a_Universe<2.5 a_(early Universe), the Universe will not be able to emit Higgs, but is still able to produce a quark and eventually for a_Universe<1.5 a_(early Universe) the Universe can only emit massless gluons. As the acceleration of Universe at the LHC increases, a_Universe>2.5 a_(early Universe), most of Higgs boson production will be due to Unruh effect near event horizon of Universe. Finally comparing the production cross section for dark energy with particle cross sections, it is found that the cross section for dark energy is dominated by QCD matter, Higgs boson and neutrino. This result is consistent with previous predictions for dark energy cross section.
2405.01191
Guotao Xia
Lauri Niemi, Michael J. Ramsey-Musolf, Guotao Xia
Nonperturbative study of the electroweak phase transition in the real scalar singlet extended Standard Model
23 pages, 13 figures
null
null
HIP-2024-7/TH, ACFI T24-03
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a nonperturbative lattice study of the electroweak phase transition in the real singlet scalar extension of the Standard Model.We consider both the heavy and light singlet-like scalar regimes at non-zero singlet-doublet mixing angle. After reviewing features of the lattice method relevant for phase transition studies, we analyze the dependence of phase transition thermodynamics on phenomenologically relevant parameters. In the heavy singlet-like scalar regime, we find that the transition is crossover for small doublet-singlet mixing angles, despite the presence of an energy barrier in the tree-level potential. The transition becomes first order for sufficiently large mixing angles. We find two-loop perturbation theory to agree closely with the lattice results for all thermodynamical quantities considered here (critical temperature, order parameter discontinuity, latent heat) when the transition is strongly first order. For the light singlet-like scalar regime relevant to exotic Higgs decays, we update previous one-loop perturbative results using the two-loop loop dimensionally reduced effective field theory and assess the nature of the transition with lattice simulations at set of benchmark parameter points. For fixed singlet-like scalar mass the transition becomes crossover when the magnitude of the Higgs-singlet portal coupling is small. We perform our simulations in the high-temperature effective theory, which we briefly review, and present analytic expressions for the relevant lattice-continuum relations.
[ { "created": "Thu, 2 May 2024 11:32:02 GMT", "version": "v1" }, { "created": "Sat, 10 Aug 2024 09:29:05 GMT", "version": "v2" } ]
2024-08-13
[ [ "Niemi", "Lauri", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Xia", "Guotao", "" ] ]
We perform a nonperturbative lattice study of the electroweak phase transition in the real singlet scalar extension of the Standard Model.We consider both the heavy and light singlet-like scalar regimes at non-zero singlet-doublet mixing angle. After reviewing features of the lattice method relevant for phase transition studies, we analyze the dependence of phase transition thermodynamics on phenomenologically relevant parameters. In the heavy singlet-like scalar regime, we find that the transition is crossover for small doublet-singlet mixing angles, despite the presence of an energy barrier in the tree-level potential. The transition becomes first order for sufficiently large mixing angles. We find two-loop perturbation theory to agree closely with the lattice results for all thermodynamical quantities considered here (critical temperature, order parameter discontinuity, latent heat) when the transition is strongly first order. For the light singlet-like scalar regime relevant to exotic Higgs decays, we update previous one-loop perturbative results using the two-loop loop dimensionally reduced effective field theory and assess the nature of the transition with lattice simulations at set of benchmark parameter points. For fixed singlet-like scalar mass the transition becomes crossover when the magnitude of the Higgs-singlet portal coupling is small. We perform our simulations in the high-temperature effective theory, which we briefly review, and present analytic expressions for the relevant lattice-continuum relations.
hep-ph/0105261
Steve King
S. F. King (Southampton University)
Neutrino Oscillations: Status, Prospects and Opportunities at a Neutrino Factory
Updated to include the first SNO results and more references. 30 pages, Latex. To appear in J.Phys.G. This is a review article based on invited talks at the IPPP Workshops on Physics at a Future Neutrino Factory, 19 January 2001, RAL and 21-23 March 2001, Durham
J.Phys.G27:2149-2170,2001
10.1088/0954-3899/27/10/313
null
hep-ph hep-ex hep-th
null
We review the current status of neutrino oscillations after 1258 days of Super-Kamiokande, assess their future prospects over the next 10 years as the next generation of experiments come on-line, and discuss the longer-term opportunities presented by a Neutrino Factory. We also give an introduction to the see-saw mechanism and its application to atmospheric and solar neutrinos.
[ { "created": "Fri, 25 May 2001 12:46:49 GMT", "version": "v1" }, { "created": "Wed, 27 Jun 2001 10:03:38 GMT", "version": "v2" } ]
2010-05-28
[ [ "King", "S. F.", "", "Southampton University" ] ]
We review the current status of neutrino oscillations after 1258 days of Super-Kamiokande, assess their future prospects over the next 10 years as the next generation of experiments come on-line, and discuss the longer-term opportunities presented by a Neutrino Factory. We also give an introduction to the see-saw mechanism and its application to atmospheric and solar neutrinos.
hep-ph/9706423
Thomas Meissner
L.S. Kisslinger and T. Meissner
Structure of Vacuum Condensates
8pages (REVTEX), 1 PostScript figure
Phys.Rev.C57:1528-1531,1998
10.1103/PhysRevC.57.1528
null
hep-ph nucl-th
null
It is essential to know the space-time structure of the nonlocal vacuum condensates for application to medium energy processes. Using the Dyson-Schwinger formalism in the rainbow approximation for the quark propagator, we study the nonlocal quark condensate and model forms for the nonperturbative gluon propagator constrained by fits to local condensates and deep inelastic scattering with nucleon targets.
[ { "created": "Thu, 19 Jun 1997 20:40:09 GMT", "version": "v1" }, { "created": "Sat, 7 Mar 1998 21:02:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kisslinger", "L. S.", "" ], [ "Meissner", "T.", "" ] ]
It is essential to know the space-time structure of the nonlocal vacuum condensates for application to medium energy processes. Using the Dyson-Schwinger formalism in the rainbow approximation for the quark propagator, we study the nonlocal quark condensate and model forms for the nonperturbative gluon propagator constrained by fits to local condensates and deep inelastic scattering with nucleon targets.
1211.3026
Ulf-G. Mei{\ss}ner
Ulf-G. Mei{\ss}ner
A walk through the world of chiral dynamics
Plenary talk, The 7th International Workshop on Chiral Dynamics, August 6 -10, 2012, Jefferson Lab, Newport News, Virginia, USA, to appear in the proceedings, references updated
null
null
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hadron-hadron scattering lengths are fine probes of our understanding of nonperturbative QCD. I discuss the status of a variety of scattering processes sensitive to the spontaneous and explicit chiral symmetry breaking of QCD, such as pion-pion, pion-kaon, pion-nucleon, antikaon-nucleon and Goldstone boson scattering off D-mesons. The fruitful interplay of theory, experiment and lattice QCD is emphasized. I point out what has to be done in these fields to gain further insight into these fundamental parameters.
[ { "created": "Mon, 12 Nov 2012 20:07:14 GMT", "version": "v1" }, { "created": "Wed, 3 Jul 2013 10:37:21 GMT", "version": "v2" } ]
2013-07-04
[ [ "Meißner", "Ulf-G.", "" ] ]
Hadron-hadron scattering lengths are fine probes of our understanding of nonperturbative QCD. I discuss the status of a variety of scattering processes sensitive to the spontaneous and explicit chiral symmetry breaking of QCD, such as pion-pion, pion-kaon, pion-nucleon, antikaon-nucleon and Goldstone boson scattering off D-mesons. The fruitful interplay of theory, experiment and lattice QCD is emphasized. I point out what has to be done in these fields to gain further insight into these fundamental parameters.
1909.10836
Shengqin Feng
Bang-Xiang Chen, Sheng-Qin Feng
A systematical study of the chiral magnetic effects at the RHIC and LHC energies
9 pages, 7 figures
Chinese Physics C 44, 024104 (2020)
10.1088/1674-1137/44/2/024104
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
Considering the magnetic field response of the QGP medium, we perform a systematical study of the chiral magnetic effect(CME), and make a comparison it with the experimental results for the background-subtracted correlator $H$ at the energies of the RHIC Beam Energy Scan (BES) and LHC energy. The CME signals from our computations show a centrality trend and beam energy dependence that are qualitatively consistent with the experimental measurements of the charge dependent correlations. The time evolution of the chiral electromagnetic current at the RHIC and LHC energies is systematically studied. The dependence of the time-integrated current signal on the beam energy $\sqrt{s}$ with different centralities is investigated. Our phenomenological analysis shows that the time-integrated electromagnetic current is maximal near the collision energy $\sqrt{s} \approx 39$ GeV. The qualitative trend of the induced electromagnetic current is in agreement with the CME experimental results at the RHIC and LHC energies.
[ { "created": "Tue, 24 Sep 2019 12:22:15 GMT", "version": "v1" }, { "created": "Sun, 22 Dec 2019 09:46:17 GMT", "version": "v2" } ]
2022-01-10
[ [ "Chen", "Bang-Xiang", "" ], [ "Feng", "Sheng-Qin", "" ] ]
Considering the magnetic field response of the QGP medium, we perform a systematical study of the chiral magnetic effect(CME), and make a comparison it with the experimental results for the background-subtracted correlator $H$ at the energies of the RHIC Beam Energy Scan (BES) and LHC energy. The CME signals from our computations show a centrality trend and beam energy dependence that are qualitatively consistent with the experimental measurements of the charge dependent correlations. The time evolution of the chiral electromagnetic current at the RHIC and LHC energies is systematically studied. The dependence of the time-integrated current signal on the beam energy $\sqrt{s}$ with different centralities is investigated. Our phenomenological analysis shows that the time-integrated electromagnetic current is maximal near the collision energy $\sqrt{s} \approx 39$ GeV. The qualitative trend of the induced electromagnetic current is in agreement with the CME experimental results at the RHIC and LHC energies.
1410.0410
Tommy Ohlsson
Sandhya Choubey and Tommy Ohlsson
Bounds on Non-Standard Neutrino Interactions Using PINGU
19 pages, 7 figures. Final version published in Phys. Lett. B
Phys. Lett. B 739 (2014) 357
10.1016/j.physletb.2014.11.010
NSF-KITP-14-173
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the impact of non-standard neutrino interactions (NSIs) on atmospheric neutrinos using the proposed PINGU experiment. In particular, we focus on the matter NSI parameters $\varepsilon_{\mu\tau}$ and $|\varepsilon_{\tau\tau} - \varepsilon_{\mu\mu}|$ that have previously been constrained by the Super-Kamiokande experiment. First, we present approximate analytical formulas for the difference of the muon neutrino survival probability with and without the above-mentioned NSI parameters. Second, we calculate the atmospheric neutrino events at PINGU in the energy range (2-100) GeV, which follow the trend outlined on probability level. Finally, we perform a statistical analysis of PINGU. Using three years of data, we obtain bounds from PINGU given by $-0.0043~(-0.0048) < \varepsilon_{\mu\tau} < 0.0047~(0.0046)$ and $-0.03~(-0.016) < \varepsilon_{\tau\tau} < 0.017~(0.032)$ at 90 % confidence level for normal (inverted) neutrino mass hierarchy, which improve the Super-Kamiokande bounds by one order of magnitude. In addition, we show the expected allowed contour region in the $\varepsilon_{\mu\tau}$-$\varepsilon_{\tau\tau}$ plane if NSIs exist in Nature and the result suggests that there is basically no correlation between $\varepsilon_{\mu\tau}$ and $\varepsilon_{\tau\tau}$.
[ { "created": "Wed, 1 Oct 2014 23:10:12 GMT", "version": "v1" }, { "created": "Tue, 18 Nov 2014 09:57:07 GMT", "version": "v2" } ]
2014-11-19
[ [ "Choubey", "Sandhya", "" ], [ "Ohlsson", "Tommy", "" ] ]
We investigate the impact of non-standard neutrino interactions (NSIs) on atmospheric neutrinos using the proposed PINGU experiment. In particular, we focus on the matter NSI parameters $\varepsilon_{\mu\tau}$ and $|\varepsilon_{\tau\tau} - \varepsilon_{\mu\mu}|$ that have previously been constrained by the Super-Kamiokande experiment. First, we present approximate analytical formulas for the difference of the muon neutrino survival probability with and without the above-mentioned NSI parameters. Second, we calculate the atmospheric neutrino events at PINGU in the energy range (2-100) GeV, which follow the trend outlined on probability level. Finally, we perform a statistical analysis of PINGU. Using three years of data, we obtain bounds from PINGU given by $-0.0043~(-0.0048) < \varepsilon_{\mu\tau} < 0.0047~(0.0046)$ and $-0.03~(-0.016) < \varepsilon_{\tau\tau} < 0.017~(0.032)$ at 90 % confidence level for normal (inverted) neutrino mass hierarchy, which improve the Super-Kamiokande bounds by one order of magnitude. In addition, we show the expected allowed contour region in the $\varepsilon_{\mu\tau}$-$\varepsilon_{\tau\tau}$ plane if NSIs exist in Nature and the result suggests that there is basically no correlation between $\varepsilon_{\mu\tau}$ and $\varepsilon_{\tau\tau}$.
hep-ph/0212210
Hamid Beshtoev
Kh. M. Beshtoev
Some Unsettled Questions in the Problem of Neutrino Oscillations
LATEX, 20 pages, no figures and tables
null
null
null
hep-ph
null
It is noted that the theory of neutrino oscillations can be constructed only in the framework of the particle physics theory, where is a mass shell conception and then transitions (oscillations) between neutrinos with equal masses are real and between neutrinos with different masses are virtual. It is necessary to solve the question: which type of neutrino transitions (oscillations) is realized in nature? There can be three types of neutrino transitions (oscillations). At present it is considered that Dirac and Majorana neutrino oscillations can be realized. It is shown that we cannot put Majorana neutrinos in the standard weak interactions theory without violation of the gauge invariance. Then it is obvious that there can be only realized transitions (oscillations) between Dirac neutrinos with different flowers. Also it is shown that the mechanism of resonance enhancement of neutrino oscillations in matter cannot be realized without violation of the law of energy-momentum conservation. Though it is supposed that we see neutrino oscillations in experiments, indeed there only transitions between neutrinos are registered. In order to register neutrino oscillations it is necessary to see second or even higher neutrino oscillation modes in experiments. For this purpose we can use the elliptic character of the Earth orbit. The analysis shows that the SNO experimental results do not confirm smallest of nu_e to nu_\tau transition angle mixings, which was obtained in CHOOZ experiment. It is also noted that there is contradiction between SNO, Super-Kamiokande, Homestake and the SAGE and GNO (GALLEX) data.
[ { "created": "Sun, 15 Dec 2002 13:38:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Beshtoev", "Kh. M.", "" ] ]
It is noted that the theory of neutrino oscillations can be constructed only in the framework of the particle physics theory, where is a mass shell conception and then transitions (oscillations) between neutrinos with equal masses are real and between neutrinos with different masses are virtual. It is necessary to solve the question: which type of neutrino transitions (oscillations) is realized in nature? There can be three types of neutrino transitions (oscillations). At present it is considered that Dirac and Majorana neutrino oscillations can be realized. It is shown that we cannot put Majorana neutrinos in the standard weak interactions theory without violation of the gauge invariance. Then it is obvious that there can be only realized transitions (oscillations) between Dirac neutrinos with different flowers. Also it is shown that the mechanism of resonance enhancement of neutrino oscillations in matter cannot be realized without violation of the law of energy-momentum conservation. Though it is supposed that we see neutrino oscillations in experiments, indeed there only transitions between neutrinos are registered. In order to register neutrino oscillations it is necessary to see second or even higher neutrino oscillation modes in experiments. For this purpose we can use the elliptic character of the Earth orbit. The analysis shows that the SNO experimental results do not confirm smallest of nu_e to nu_\tau transition angle mixings, which was obtained in CHOOZ experiment. It is also noted that there is contradiction between SNO, Super-Kamiokande, Homestake and the SAGE and GNO (GALLEX) data.
hep-ph/9310380
Matsuda Masahisa
Takemi Hayashi, Masahisa Matsuda and Morimitsu Tanimoto
Penguin Effects on K Pi and PiPi Decays of the $B$ Meson
LATEX-file without figures. Figures will be sent by request to masa@auephyas.aichi-edu.ac.jp
Phys.Lett.B323:78-84,1994
10.1016/0370-2693(94)00045-X
AUE-05-93,EHU-06-93, KGU-03-93
hep-ph
null
We give the detailed analyses for the gluonic-penguin effect on the $\kp$ and $\pp$ decays of the $B$ meson. In the standard model, it is shown that the ratio $BR(B\A\kp)/BR(B\A\pp)$ takes the value $0.5\sim 3.0$ with the strongly depending on the CP violating phase $\phi$ and the KM matrix element $|V_{ub}|$. We obtain the constraint on the form factor by using the experimental branching ratio. It is also found that, in the two-Higgs-doublet model, the charged Higgs contribution which could enhance the $B\A X_s\r$ decay does not a sizable effect on our processes. The effect of the final state interaction on these processes is also discussed.
[ { "created": "Mon, 1 Nov 1993 02:56:45 GMT", "version": "v1" } ]
2010-11-01
[ [ "Hayashi", "Takemi", "" ], [ "Matsuda", "Masahisa", "" ], [ "Tanimoto", "Morimitsu", "" ] ]
We give the detailed analyses for the gluonic-penguin effect on the $\kp$ and $\pp$ decays of the $B$ meson. In the standard model, it is shown that the ratio $BR(B\A\kp)/BR(B\A\pp)$ takes the value $0.5\sim 3.0$ with the strongly depending on the CP violating phase $\phi$ and the KM matrix element $|V_{ub}|$. We obtain the constraint on the form factor by using the experimental branching ratio. It is also found that, in the two-Higgs-doublet model, the charged Higgs contribution which could enhance the $B\A X_s\r$ decay does not a sizable effect on our processes. The effect of the final state interaction on these processes is also discussed.
1412.3967
Malin Sjodahl
Malin Sjodahl
ColorFull -- a C++ library for calculations in SU(Nc) color space
Version accepted by EPJC, improved description of trace bases in section 3
Eur. Phys. J. C 75 (2015) 5, 236
null
LU TP 14-43, MCNET-14-26
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
ColorFull, a C++ package for treating QCD color structure, is presented. ColorFull, which utilizes the trace basis approach, is intended for interfacing with event generators, but can also be used as a stand-alone package for squaring QCD amplitudes, calculating interferences, and describing the effect of gluon emission and gluon exchange.
[ { "created": "Fri, 12 Dec 2014 12:26:22 GMT", "version": "v1" }, { "created": "Mon, 29 Jun 2015 09:58:21 GMT", "version": "v2" } ]
2015-06-30
[ [ "Sjodahl", "Malin", "" ] ]
ColorFull, a C++ package for treating QCD color structure, is presented. ColorFull, which utilizes the trace basis approach, is intended for interfacing with event generators, but can also be used as a stand-alone package for squaring QCD amplitudes, calculating interferences, and describing the effect of gluon emission and gluon exchange.
1505.06165
Ivo de Medeiros Varzielas
Gustavo C. Branco, Ivo de Medeiros Varzielas, Stephen F. King
Invariant approach to CP in unbroken $\Delta(27)$
24 pages, 1 figure. v2: to be published in NPB
null
10.1016/j.nuclphysb.2015.07.024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The invariant approach is a powerful method for studying CP violation for specific Lagrangians. The method is particularly useful for dealing with discrete family symmetries. We focus on the CP properties of unbroken $\Delta(27)$ invariant Lagrangians with Yukawa-like terms, which proves to be a rich framework, with distinct aspects of CP, making it an ideal group to investigate with the invariant approach. We classify Lagrangians depending on the number of fields transforming as irreducible triplet representations of $\Delta(27)$. For each case, we construct CP-odd weak basis invariants and use them to discuss the respective CP properties. We find that CP violation is sensitive to the number and type of $\Delta(27)$ representations.
[ { "created": "Fri, 22 May 2015 18:00:27 GMT", "version": "v1" }, { "created": "Mon, 3 Aug 2015 14:32:03 GMT", "version": "v2" } ]
2015-12-09
[ [ "Branco", "Gustavo C.", "" ], [ "Varzielas", "Ivo de Medeiros", "" ], [ "King", "Stephen F.", "" ] ]
The invariant approach is a powerful method for studying CP violation for specific Lagrangians. The method is particularly useful for dealing with discrete family symmetries. We focus on the CP properties of unbroken $\Delta(27)$ invariant Lagrangians with Yukawa-like terms, which proves to be a rich framework, with distinct aspects of CP, making it an ideal group to investigate with the invariant approach. We classify Lagrangians depending on the number of fields transforming as irreducible triplet representations of $\Delta(27)$. For each case, we construct CP-odd weak basis invariants and use them to discuss the respective CP properties. We find that CP violation is sensitive to the number and type of $\Delta(27)$ representations.
1807.01125
Ferruccio Feruglio
Juan Carlos Criado and Ferruccio Feruglio
Modular Invariance Faces Precision Neutrino Data
29 pages, 1 figure; further comments, one on the quark sector, added
SciPost Phys. 5, 042 (2018)
10.21468/SciPostPhys.5.5.042
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze a modular invariant model of lepton masses, with neutrino masses originating either from the Weinberg operator or from the seesaw. The constraint provided by modular invariance is so strong that neutrino mass ratios, lepton mixing angles and Dirac/Majorana phases do not depend on any Lagrangian parameter. They only depend on the vacuum of the theory, parametrized in terms of a complex modulus and a real field. Thus eight measurable quantities are described by the three vacuum parameters, whose optimization provides an excellent fit to data for the Weinberg operator and a good fit for the seesaw case. Neutrino masses from the Weinberg operator (seesaw) have inverted (normal) ordering. Several sources of potential corrections, such as higher dimensional operators, renormalization group evolution and supersymmetry breaking effects, are carefully discussed and shown not to affect the predictions under reasonable conditions.
[ { "created": "Tue, 3 Jul 2018 12:44:03 GMT", "version": "v1" }, { "created": "Mon, 16 Jul 2018 17:19:57 GMT", "version": "v2" }, { "created": "Tue, 25 Sep 2018 12:57:47 GMT", "version": "v3" } ]
2018-11-07
[ [ "Criado", "Juan Carlos", "" ], [ "Feruglio", "Ferruccio", "" ] ]
We analyze a modular invariant model of lepton masses, with neutrino masses originating either from the Weinberg operator or from the seesaw. The constraint provided by modular invariance is so strong that neutrino mass ratios, lepton mixing angles and Dirac/Majorana phases do not depend on any Lagrangian parameter. They only depend on the vacuum of the theory, parametrized in terms of a complex modulus and a real field. Thus eight measurable quantities are described by the three vacuum parameters, whose optimization provides an excellent fit to data for the Weinberg operator and a good fit for the seesaw case. Neutrino masses from the Weinberg operator (seesaw) have inverted (normal) ordering. Several sources of potential corrections, such as higher dimensional operators, renormalization group evolution and supersymmetry breaking effects, are carefully discussed and shown not to affect the predictions under reasonable conditions.
1504.02299
Marco Frasca
Marco Frasca
A theorem on the Higgs sector of the Standard Model
15 pages, no figure. Version accepted for publication in European Physical Journal Plus
Eur. Phys. J. Plus (2016) 131: 199
10.1140/epjp/i2016-16199-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide the solution of the classical theory for the Higgs sector of the Standard Model obtaining the exact Green function for the broken phase. Solving the Dyson-Schwinger equations for the Higgs field we show that the propagator coincides with that of the classical theory confirming the spectrum also at the quantum level. In this way we obtain a proof of triviality using the K\"allen-Lehman representation. This has as a consequence that higher excited states must exist for the Higgs particle, representing an internal spectrum for it. Higher excited states have exponentially smaller amplitudes and so, their production rates are significantly depressed.
[ { "created": "Thu, 9 Apr 2015 13:22:28 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 2015 16:29:49 GMT", "version": "v2" }, { "created": "Thu, 19 May 2016 08:04:23 GMT", "version": "v3" } ]
2016-06-16
[ [ "Frasca", "Marco", "" ] ]
We provide the solution of the classical theory for the Higgs sector of the Standard Model obtaining the exact Green function for the broken phase. Solving the Dyson-Schwinger equations for the Higgs field we show that the propagator coincides with that of the classical theory confirming the spectrum also at the quantum level. In this way we obtain a proof of triviality using the K\"allen-Lehman representation. This has as a consequence that higher excited states must exist for the Higgs particle, representing an internal spectrum for it. Higher excited states have exponentially smaller amplitudes and so, their production rates are significantly depressed.
hep-ph/0209243
John Arrington
J. Arrington
How Well Do We Know the Electromagnetic Form Factors of the Proton?
5 pages, 4 figures; Invited talk at Electron-Nucleus Scattering VII, Elba, Italy, June 2002 (to appear in proceedings)
Eur.Phys.J.A17:311-315,2003
10.1140/epja/i2002-10172-y
null
hep-ph nucl-ex
null
Recent measurements of recoil polarization in elastic scattering have been used to extract the ratio of the electric to the magnetic proton form factors. These results disagree with Rosenbluth extractions from cross section measurements, indicating either an inconsistency between the two techniques, or a problem with either the polarization transfer or cross section measurements. To obtain precise knowledge of the proton form factors, we must first understand the source of this discrepancy.
[ { "created": "Fri, 20 Sep 2002 17:38:07 GMT", "version": "v1" } ]
2009-09-24
[ [ "Arrington", "J.", "" ] ]
Recent measurements of recoil polarization in elastic scattering have been used to extract the ratio of the electric to the magnetic proton form factors. These results disagree with Rosenbluth extractions from cross section measurements, indicating either an inconsistency between the two techniques, or a problem with either the polarization transfer or cross section measurements. To obtain precise knowledge of the proton form factors, we must first understand the source of this discrepancy.
1303.2540
Tobias Beranek
T. Beranek, H. Merkel, M. Vanderhaeghen
Theoretical framework to analyze searches for hidden light gauge bosons in electron scattering fixed target experiments
18 pages, 12 figures
null
10.1103/PhysRevD.88.015032
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by anomalies in cosmic ray observations and by attempts to solve questions of the Standad Model of particle physics like the (g-2)_mu discrepancy, U(1) extensions of the Standard Model have been proposed in recent years. Such U(1) extensions allow for the interaction of Dark Matter by exchange of a photon-like massive force carrier \gamma' not included in the Standard Model. In order to search for \gamma' bosons various experimental programs have been started. One approach is the dedicated search at fixed-target experiments at modest energies as performed at MAMI or at the Jefferson Lab. In these experiments the process e(A,Z)->e(A,Z)l^+l^- is investigated and a search for a very narrow resonance in the invariant mass distribution of the l^+l^- pair is performed. In this work we analyze this process in terms of signal and background in order to describe existing data obtained by the A1 experiment at MAMI with the aim to give accurate predictions for exclusion limits in the \gamma' parameter space. We present a detailed theoretical analysis of the cross sections entering in the description of such processes.
[ { "created": "Mon, 11 Mar 2013 14:42:39 GMT", "version": "v1" } ]
2015-06-15
[ [ "Beranek", "T.", "" ], [ "Merkel", "H.", "" ], [ "Vanderhaeghen", "M.", "" ] ]
Motivated by anomalies in cosmic ray observations and by attempts to solve questions of the Standad Model of particle physics like the (g-2)_mu discrepancy, U(1) extensions of the Standard Model have been proposed in recent years. Such U(1) extensions allow for the interaction of Dark Matter by exchange of a photon-like massive force carrier \gamma' not included in the Standard Model. In order to search for \gamma' bosons various experimental programs have been started. One approach is the dedicated search at fixed-target experiments at modest energies as performed at MAMI or at the Jefferson Lab. In these experiments the process e(A,Z)->e(A,Z)l^+l^- is investigated and a search for a very narrow resonance in the invariant mass distribution of the l^+l^- pair is performed. In this work we analyze this process in terms of signal and background in order to describe existing data obtained by the A1 experiment at MAMI with the aim to give accurate predictions for exclusion limits in the \gamma' parameter space. We present a detailed theoretical analysis of the cross sections entering in the description of such processes.
hep-ph/0609290
Stefano Profumo
Stefano Profumo and Alessio Provenza
Increasing the Neutralino Relic Abundance with Slepton Coannihilations: Consequences for Indirect Dark Matter Detection
16 pages, 6 figures, references added, typos corrected, matches with the published version
JCAP0612:019,2006
10.1088/1475-7516/2006/12/019
SISSA-56/2006/EP
hep-ph astro-ph
null
We point out that if the lightest supersymmetric particle (LSP) is a Higgsino- or Wino-like neutralino, the net effect of coannihilations with sleptons is to increase the relic abundance, rather than producing the usual suppression, which takes place if the LSP is Bino-like. The reason for the enhancement lies in the effective thermally averaged cross section at freeze-out: sleptons annihilate (and co-annihilate) less efficiently than the neutralino(s)-chargino system, therefore slepton coannihilations effectively act as parasite degrees of freedom at freeze-out. Henceforth, the thermal relic abundance of LSP's corresponds to the cold Dark Matter abundance for smaller values of the LSP mass, and larger values of the neutralino pair annihilation cross section. In turn, at a given thermal neutralino relic abundance, this implies larger indirect detection rates, as a result of an increase in the fluxes of antimatter, gamma rays and neutrinos from the Sun orginating from neutralino pair annihilations.
[ { "created": "Thu, 28 Sep 2006 00:01:40 GMT", "version": "v1" }, { "created": "Tue, 9 Jan 2007 10:14:07 GMT", "version": "v2" } ]
2008-11-26
[ [ "Profumo", "Stefano", "" ], [ "Provenza", "Alessio", "" ] ]
We point out that if the lightest supersymmetric particle (LSP) is a Higgsino- or Wino-like neutralino, the net effect of coannihilations with sleptons is to increase the relic abundance, rather than producing the usual suppression, which takes place if the LSP is Bino-like. The reason for the enhancement lies in the effective thermally averaged cross section at freeze-out: sleptons annihilate (and co-annihilate) less efficiently than the neutralino(s)-chargino system, therefore slepton coannihilations effectively act as parasite degrees of freedom at freeze-out. Henceforth, the thermal relic abundance of LSP's corresponds to the cold Dark Matter abundance for smaller values of the LSP mass, and larger values of the neutralino pair annihilation cross section. In turn, at a given thermal neutralino relic abundance, this implies larger indirect detection rates, as a result of an increase in the fluxes of antimatter, gamma rays and neutrinos from the Sun orginating from neutralino pair annihilations.
hep-ph/9806451
Manuel Perez-Victoria
F. del Aguila, A. Culatti, R. Munoz-Tapia and M. Perez-Victoria
Techniques for one-loop calculations in constrained differential renormalization
LaTex, 29 pages with 4 Postscript figures
Nucl.Phys. B537 (1999) 561-585
10.1016/S0550-3213(98)00645-2
MIT-CTP-2705, UG-FT-86/98
hep-ph hep-th
null
We describe in detail the constrained procedure of differential renormalization and develop the techniques required for one-loop calculations. As an illustration we renormalize Scalar QED and show that the two-, three- and four-point Ward identities are automatically satisfied.
[ { "created": "Tue, 23 Jun 1998 17:01:46 GMT", "version": "v1" } ]
2015-06-25
[ [ "del Aguila", "F.", "" ], [ "Culatti", "A.", "" ], [ "Munoz-Tapia", "R.", "" ], [ "Perez-Victoria", "M.", "" ] ]
We describe in detail the constrained procedure of differential renormalization and develop the techniques required for one-loop calculations. As an illustration we renormalize Scalar QED and show that the two-, three- and four-point Ward identities are automatically satisfied.
hep-ph/9512352
V. Gribov
V.N. Gribov
Bound states of massless fermions as a source for new physics
9 pages, LaTex, 11 figures (pictex) in separate file. Opening lecture given at the 33rd course of the International School of Subnuclear Physics, Erice, Sicily (1995)
null
null
TK-95-35
hep-ph
null
The contribution of interactions at short and large distances to particle masses is discussed in the framework of the standard model.
[ { "created": "Tue, 19 Dec 1995 14:15:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gribov", "V. N.", "" ] ]
The contribution of interactions at short and large distances to particle masses is discussed in the framework of the standard model.
2108.11605
Wren Yamada
Wren A. Yamada, Osamu Morimatsu, Toru Sato and Koichi Yazaki
Near-threshold Spectrum from Uniformized Mittag-Leffler Expansion -Pole Structure of $Z(3900)$-
13 pages, 7 pdf figures
null
10.1103/PhysRevD.105.014034
KEK-TH-2344, J-PARC-TH-0248, RIKEN-iTHEMS-Report-21
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate how S-matrix poles manifest themselves as the physical spectrum near the upper threshold in the context of the two-channel uniformized Mittag-Leffler expansion, an expression written as a sum of pole terms under an appropriate variable where the S-matrix is made single-valued (uniformization). We show that the transition of the spectrum is continuous as a S-matrix pole moves across the boundaries of the complex energy Riemann sheets and that the physical spectrum peaks at or near the upper threshold when the S-matrix pole is positioned sufficiently close to it on the uniformized plane. There is no essential difference on which sheet the pole is positioned. What is important is the existence of a pole near the upper threshold and the distance between the pole and the physical region, not on which complex energy sheet the pole is positioned. We also point out that when the pole is close to the upper threshold, the complex pole does not have the usual meaning of the resonance. Neither the real part represents the peak energy, nor the imaginary part represents the half width. Subsequently, we try to understand the current status of $Z(3900)$ from the viewpoint of the uniformized Mittag-Leffler expansion reflecting in particular, Phys.Rev.Lett.117, 242001 (2016) in which they concluded that $Z(3900)$ is not a conventional resonance but a threshold cusp. We point out that their results turn out to indicate the existence of S-matrix poles near the $\bar D D^*$ threshold, which is most likely the origin of the peak found in their calculation of the near-threshold spectrum. In order to support our argument, we set up a separable potential model which shares common behavior of poles near the $\bar D D^*$ threshold to the above-mentioned reference and show in our model that the structures near the $\bar D D^*$ threshold are indeed caused by these near-threshold poles.
[ { "created": "Thu, 26 Aug 2021 07:00:28 GMT", "version": "v1" } ]
2022-02-09
[ [ "Yamada", "Wren A.", "" ], [ "Morimatsu", "Osamu", "" ], [ "Sato", "Toru", "" ], [ "Yazaki", "Koichi", "" ] ]
We demonstrate how S-matrix poles manifest themselves as the physical spectrum near the upper threshold in the context of the two-channel uniformized Mittag-Leffler expansion, an expression written as a sum of pole terms under an appropriate variable where the S-matrix is made single-valued (uniformization). We show that the transition of the spectrum is continuous as a S-matrix pole moves across the boundaries of the complex energy Riemann sheets and that the physical spectrum peaks at or near the upper threshold when the S-matrix pole is positioned sufficiently close to it on the uniformized plane. There is no essential difference on which sheet the pole is positioned. What is important is the existence of a pole near the upper threshold and the distance between the pole and the physical region, not on which complex energy sheet the pole is positioned. We also point out that when the pole is close to the upper threshold, the complex pole does not have the usual meaning of the resonance. Neither the real part represents the peak energy, nor the imaginary part represents the half width. Subsequently, we try to understand the current status of $Z(3900)$ from the viewpoint of the uniformized Mittag-Leffler expansion reflecting in particular, Phys.Rev.Lett.117, 242001 (2016) in which they concluded that $Z(3900)$ is not a conventional resonance but a threshold cusp. We point out that their results turn out to indicate the existence of S-matrix poles near the $\bar D D^*$ threshold, which is most likely the origin of the peak found in their calculation of the near-threshold spectrum. In order to support our argument, we set up a separable potential model which shares common behavior of poles near the $\bar D D^*$ threshold to the above-mentioned reference and show in our model that the structures near the $\bar D D^*$ threshold are indeed caused by these near-threshold poles.
hep-ph/0110181
Igor Ivanov
I.P.Ivanov (1 and 2), N.N.Nikolaev (1 and 3), I.F.Ginzburg (2) ((1) IKP, Forschungszentrum Juelich, (2) Sobolev Institute of Mathematics, Novosibirsk, Russia, (3) L. D. Landau Institute for Theoretical Physics, Moscow, Russia)
Possible Odderon discovery at HERA via charge asymmetry in the diffractive pi+pi- production
4 pages, To appear in Proceedings of the 9th International Workshop on Deep Inelastic Scattering (DIS2001), Bologna, Italy, 27 Apr. - 1 May 2001
null
10.1142/9789812778345_0111
null
hep-ph
null
We discuss how the evasive Odderon signal can be enhanced by final state interactions. We suggest the charge asymmetry of pion spectra in diffractive pi+pi- photoproduction as a promising signature of the Odderon exchange.
[ { "created": "Mon, 15 Oct 2001 09:04:23 GMT", "version": "v1" } ]
2015-06-25
[ [ "Ivanov", "I. P.", "", "1 and 2" ], [ "Nikolaev", "N. N.", "", "1 and 3" ], [ "Ginzburg", "I. F.", "" ] ]
We discuss how the evasive Odderon signal can be enhanced by final state interactions. We suggest the charge asymmetry of pion spectra in diffractive pi+pi- photoproduction as a promising signature of the Odderon exchange.
1209.6318
Naoki Yamatsu
Naoki Yamatsu
New Mixing Structures of Chiral Generations in a Model with Noncompact Horizontal Symmetry
22 pages, 7 figures
null
10.1093/ptep/pts079
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New mixing structures between chiral generations of elementary particles at low energy are shown in a vectorlike model with a horizontal symmetry SU(1,1). In this framework the chiral model including odd number chiral generations is realized via the spontaneous symmetry breaking of the horizontal symmetry. It is shown that the Yukawa coupling matrices of chiral generations have naturally hierarchical patterns, and in some cases the overall factors of their Yukawa coupling matrices, e.g. the Yukawa coupling constants of the bottom quark and tau lepton are naturally suppressed.
[ { "created": "Thu, 27 Sep 2012 18:18:23 GMT", "version": "v1" } ]
2016-06-21
[ [ "Yamatsu", "Naoki", "" ] ]
New mixing structures between chiral generations of elementary particles at low energy are shown in a vectorlike model with a horizontal symmetry SU(1,1). In this framework the chiral model including odd number chiral generations is realized via the spontaneous symmetry breaking of the horizontal symmetry. It is shown that the Yukawa coupling matrices of chiral generations have naturally hierarchical patterns, and in some cases the overall factors of their Yukawa coupling matrices, e.g. the Yukawa coupling constants of the bottom quark and tau lepton are naturally suppressed.
1012.4886
Hiroaki Sugiyama
Takeshi Fukuyama (Ritsumeikan U., Kusatsu & Kyoto sangyo U., Kyoto), Hiroaki Sugiyama (Ritsumeikan U., Kusatsu), Koji Tsumura (Natl. Taiwan U., Taipei)
Phenomenology in the Zee Model with the A_4 Symmetry
26 pages, 4 figures, version accepted by PRD
Phys.Rev.D83:056016,2011
10.1103/PhysRevD.83.056016
MISC-2010-21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Zee model generates neutrino masses at the one-loop level by adding charged SU(2)_L-singlet and extra SU(2)_L-doublet scalars to the standard model of particle physics. As the origin of the nontrivial structure of the lepton flavor mixing, we introduce the softly broken A_4 symmetry to the Zee model. This model is compatible with the tribimaximal mixing which agrees well with neutrino oscillation measurements. Then, a sum rule m_1 e^{i alpha_12} + 2 m_2 + 3 m_3 e^{i alpha_32} = 0 is obtained and it results in Delta m^2_31 < 0 and m_3 > 1.8*10^{-2}eV. The effective mass |(M_nu)_{ee}| for the neutrinoless double beta decay is predicted as | (M_\nu)_{ee} | > 1.7*10^{-2}eV. The characteristic particles in this model are SU(2)_L-singlet charged Higgs bosons s^+_alpha (alpha=xi,eta,zeta) which are made from a 3-representation of A_4. Contributions of s^+_alpha to the lepton flavor violating decays of charged leptons are almost forbidden by an approximately remaining Z_3 symmetry; only BR(tau to ebar mu mu) can be sizable by the flavor changing neutral current interaction with SU(2)_L-doublet scalars. Therefore, s^+_alpha can be easily light enough to be discovered at the LHC with satisfying current constraints. The flavor structures of BR(s^-_alpha to ell nu) are also discussed.
[ { "created": "Wed, 22 Dec 2010 06:43:41 GMT", "version": "v1" }, { "created": "Tue, 28 Dec 2010 07:42:55 GMT", "version": "v2" }, { "created": "Wed, 6 Apr 2011 07:57:56 GMT", "version": "v3" } ]
2015-03-17
[ [ "Fukuyama", "Takeshi", "", "Ritsumeikan U., Kusatsu & Kyoto sangyo U., Kyoto" ], [ "Sugiyama", "Hiroaki", "", "Ritsumeikan U., Kusatsu" ], [ "Tsumura", "Koji", "", "Natl. Taiwan U.,\n Taipei" ] ]
The Zee model generates neutrino masses at the one-loop level by adding charged SU(2)_L-singlet and extra SU(2)_L-doublet scalars to the standard model of particle physics. As the origin of the nontrivial structure of the lepton flavor mixing, we introduce the softly broken A_4 symmetry to the Zee model. This model is compatible with the tribimaximal mixing which agrees well with neutrino oscillation measurements. Then, a sum rule m_1 e^{i alpha_12} + 2 m_2 + 3 m_3 e^{i alpha_32} = 0 is obtained and it results in Delta m^2_31 < 0 and m_3 > 1.8*10^{-2}eV. The effective mass |(M_nu)_{ee}| for the neutrinoless double beta decay is predicted as | (M_\nu)_{ee} | > 1.7*10^{-2}eV. The characteristic particles in this model are SU(2)_L-singlet charged Higgs bosons s^+_alpha (alpha=xi,eta,zeta) which are made from a 3-representation of A_4. Contributions of s^+_alpha to the lepton flavor violating decays of charged leptons are almost forbidden by an approximately remaining Z_3 symmetry; only BR(tau to ebar mu mu) can be sizable by the flavor changing neutral current interaction with SU(2)_L-doublet scalars. Therefore, s^+_alpha can be easily light enough to be discovered at the LHC with satisfying current constraints. The flavor structures of BR(s^-_alpha to ell nu) are also discussed.
1006.2132
Zhong-Bo Kang
Zhong-Bo Kang (RIKEN BNL) and Dmitri E. Kharzeev (BNL)
Quark fragmentation in the $\theta$-vacuum
4 pages, 2 figures
Phys.Rev.Lett.106:042001,2011
10.1103/PhysRevLett.106.042001
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The vacuum of Quantum Chromodynamics is a superposition of degenerate states with different topological numbers that are connected by tunneling (the $\theta$-vacuum). The tunneling events are due to topologically non-trivial configurations of gauge fields (e.g. the instantons) that induce local $\p$-odd domains in Minkowski space-time. We study the quark fragmentation in this topologically non-trivial QCD background. We find that even though QCD globally conserves $\p$ and $\cp$ symmetries, two new kinds of $\p$-odd fragmentation functions emerge. They generate interesting dihadron correlations: one is the azimuthal angle correlation $\sim \cos(\phi_1 + \phi_2)$ usually referred to as the Collins effect, and the other is the $\p$-odd correlation $\sim \sin(\phi_1 + \phi_2)$ that vanishes in the cross section summed over many events, but survives on the event-by-event basis. Using the chiral quark model we estimate the magnitude of these new fragmentation functions. We study their experimental manifestations in dihadron production in $e^+e^-$ collisions, and comment on the applicability of our approach in deep-inelastic scattering, proton-proton and heavy ion collisions.
[ { "created": "Thu, 10 Jun 2010 19:55:52 GMT", "version": "v1" } ]
2011-02-01
[ [ "Kang", "Zhong-Bo", "", "RIKEN BNL" ], [ "Kharzeev", "Dmitri E.", "", "BNL" ] ]
The vacuum of Quantum Chromodynamics is a superposition of degenerate states with different topological numbers that are connected by tunneling (the $\theta$-vacuum). The tunneling events are due to topologically non-trivial configurations of gauge fields (e.g. the instantons) that induce local $\p$-odd domains in Minkowski space-time. We study the quark fragmentation in this topologically non-trivial QCD background. We find that even though QCD globally conserves $\p$ and $\cp$ symmetries, two new kinds of $\p$-odd fragmentation functions emerge. They generate interesting dihadron correlations: one is the azimuthal angle correlation $\sim \cos(\phi_1 + \phi_2)$ usually referred to as the Collins effect, and the other is the $\p$-odd correlation $\sim \sin(\phi_1 + \phi_2)$ that vanishes in the cross section summed over many events, but survives on the event-by-event basis. Using the chiral quark model we estimate the magnitude of these new fragmentation functions. We study their experimental manifestations in dihadron production in $e^+e^-$ collisions, and comment on the applicability of our approach in deep-inelastic scattering, proton-proton and heavy ion collisions.
0906.1072
Michael R. Pennington
M.R. Pennington
Hadronic structure from two photon collisions
3 pages, 3 figures Invited talk at the Workshop on Physics with KLOE2, LNF, Frascati, April 9-10, 2009
null
null
IPPP/09/45,DCPT/09/90
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We briefly describe what a two photon capability with KLOE2 can measure and discuss what this will teach us about the world of light hadrons.
[ { "created": "Fri, 5 Jun 2009 09:30:02 GMT", "version": "v1" } ]
2009-06-08
[ [ "Pennington", "M. R.", "" ] ]
We briefly describe what a two photon capability with KLOE2 can measure and discuss what this will teach us about the world of light hadrons.
1512.06819
Nathaniel Craig
Nathaniel Craig
Implications of SUSY Searches for Physics Beyond the Standard Model
8 pages, 3 figures; plenary talk presented at XXVIIth Rencontres de Blois, France, 31 May - 5 June 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss some essential features of the electroweak hierarchy problem and the ensuing motivation for weak-scale supersymmetry. Taking the hierarchy problem seriously, null results in searches for SUSY at the LHC favor specific regions of SUSY parameter space. More broadly, they suggest investigating a variety of alternative approaches to the hierarchy problem with diverse experimental signatures.
[ { "created": "Mon, 21 Dec 2015 20:45:02 GMT", "version": "v1" } ]
2015-12-22
[ [ "Craig", "Nathaniel", "" ] ]
I discuss some essential features of the electroweak hierarchy problem and the ensuing motivation for weak-scale supersymmetry. Taking the hierarchy problem seriously, null results in searches for SUSY at the LHC favor specific regions of SUSY parameter space. More broadly, they suggest investigating a variety of alternative approaches to the hierarchy problem with diverse experimental signatures.
2011.04807
Igor Anikin
I.V. Anikin
On $\xi$-process for DVCS-amplitude
7 pages, 3 figures; a few typos are fixed
Symmetry 2020, 12(12), 1996;
10.3390/sym12121996
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this note, we demonstrate in detail the $\xi$-process implementation applied to the deeply virtual Compton scattering amplitude to ensure both the QCD and QED gauge invariance. The presented details are also important for understanding of the contour gauge used in different processes.
[ { "created": "Mon, 9 Nov 2020 22:15:16 GMT", "version": "v1" }, { "created": "Wed, 2 Dec 2020 21:17:27 GMT", "version": "v2" } ]
2020-12-29
[ [ "Anikin", "I. V.", "" ] ]
In this note, we demonstrate in detail the $\xi$-process implementation applied to the deeply virtual Compton scattering amplitude to ensure both the QCD and QED gauge invariance. The presented details are also important for understanding of the contour gauge used in different processes.
hep-ph/0611102
Alan D. Martin
K. Hagiwara, A.D. Martin, Daisuke Nomura and T. Teubner
Improved predictions for g-2 of the muon and \alpha_{\rm QED}(M_Z^2)
12 pages, 5 figures. Version to be published in Phys. Lett. B
Phys.Lett.B649:173-179,2007
10.1016/j.physletb.2007.04.012
KEK-TH-1112, IPPP/06/72, DCPT/06/144, LTH 729
hep-ph
null
We update the Standard Model predictions of the anomalous magnetic moment of the muon, a_\mu = (g-2)/2, and the value of the QED coupling at the Z-boson mass, incorporating the new e^+e^- \to \pi\pi data obtained by CMD-2 and KLOE, as well as the corrected SND data, and other improvements. The prediction for a_\mu=11659180.4 (5.1) \times 10^{-10} is about 3 \times 10^{-10} lower than before, and has a smaller uncertainty, which corresponds to a 3.4\sigma deviation from the measured value. The prediction for the QED coupling is \alpha(M_Z^2)^{-1}= 128.937 \pm 0.030.
[ { "created": "Wed, 8 Nov 2006 17:35:35 GMT", "version": "v1" }, { "created": "Fri, 6 Apr 2007 14:13:09 GMT", "version": "v2" }, { "created": "Fri, 20 Apr 2007 14:07:31 GMT", "version": "v3" } ]
2008-11-26
[ [ "Hagiwara", "K.", "" ], [ "Martin", "A. D.", "" ], [ "Nomura", "Daisuke", "" ], [ "Teubner", "T.", "" ] ]
We update the Standard Model predictions of the anomalous magnetic moment of the muon, a_\mu = (g-2)/2, and the value of the QED coupling at the Z-boson mass, incorporating the new e^+e^- \to \pi\pi data obtained by CMD-2 and KLOE, as well as the corrected SND data, and other improvements. The prediction for a_\mu=11659180.4 (5.1) \times 10^{-10} is about 3 \times 10^{-10} lower than before, and has a smaller uncertainty, which corresponds to a 3.4\sigma deviation from the measured value. The prediction for the QED coupling is \alpha(M_Z^2)^{-1}= 128.937 \pm 0.030.
1402.5470
Ailin Zhang
Li-Jin Chen, Dan-Dan Ye and Ailin Zhang
Is $Y(4008)$ possibly a $1^{--}$ $\psi(3^3S_1)$ state?
6 pages, 3 figures, 6 tables, RevTex
null
10.1140/epjc/s10052-014-3031-z
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strong decays of the radially excited $\psi(3^3S_1)$ state are studied within the $^3P_0$ model. As a believed $\psi(3^3S_1)$, some strong decay widths and relevant ratios of $\psi(4040)$ are calculated in the model. The theoretical results are consistent with experiments. In a similar way, as a possible $\psi(3^3S_1)$, the same strong decay widths and relevant ratios of $Y(4008)$ are presented. Our study indicates that $Y(4008)$ is hard to be identified with a $\psi(3^3S_1)$ charmonium once it is confirmed under the $D^*\bar{D}^*$ threshold, but it is very possibly a $\psi(3^3S_1)$ charmonium once it is confirmed above the $D^*\bar{D}^*$ threshold by experiment.
[ { "created": "Sat, 22 Feb 2014 03:19:12 GMT", "version": "v1" } ]
2015-06-18
[ [ "Chen", "Li-Jin", "" ], [ "Ye", "Dan-Dan", "" ], [ "Zhang", "Ailin", "" ] ]
The strong decays of the radially excited $\psi(3^3S_1)$ state are studied within the $^3P_0$ model. As a believed $\psi(3^3S_1)$, some strong decay widths and relevant ratios of $\psi(4040)$ are calculated in the model. The theoretical results are consistent with experiments. In a similar way, as a possible $\psi(3^3S_1)$, the same strong decay widths and relevant ratios of $Y(4008)$ are presented. Our study indicates that $Y(4008)$ is hard to be identified with a $\psi(3^3S_1)$ charmonium once it is confirmed under the $D^*\bar{D}^*$ threshold, but it is very possibly a $\psi(3^3S_1)$ charmonium once it is confirmed above the $D^*\bar{D}^*$ threshold by experiment.
2211.13030
Tom Tong
Ashutosh Kotwal, Joaquim Matias, Andrea Mauri, Tom Tong, Lukas Varnhorst
Round table on Standard Model Anomalies
Proceedings of the XVth Quark Confinement and the Hadron Spectrum conference, August 1st - 6th, 2022, University of Stavanger, Norway
null
10.1051/epjconf/202227401006
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This contribution to the XVth Quark Confinement and the Hadron Spectrum conference covers a description, both theoretical and experimental, of the present status of a set of very different anomalies. The discussion ranges from the long standing $b \to sll$ anomalies, $(g-2)$ and the new $M_W$ anomaly.
[ { "created": "Wed, 23 Nov 2022 15:31:58 GMT", "version": "v1" }, { "created": "Sun, 11 Dec 2022 22:02:08 GMT", "version": "v2" } ]
2023-01-11
[ [ "Kotwal", "Ashutosh", "" ], [ "Matias", "Joaquim", "" ], [ "Mauri", "Andrea", "" ], [ "Tong", "Tom", "" ], [ "Varnhorst", "Lukas", "" ] ]
This contribution to the XVth Quark Confinement and the Hadron Spectrum conference covers a description, both theoretical and experimental, of the present status of a set of very different anomalies. The discussion ranges from the long standing $b \to sll$ anomalies, $(g-2)$ and the new $M_W$ anomaly.
1308.4297
Palash Baran Pal
Gautam Bhattacharyya, Dipankar Das, Palash B. Pal, M. N. Rebelo
Scalar sector properties of two-Higgs-doublet models with a global U(1) symmetry
12 pages, 15 eps figure files; minor modifications made and a few references added
JHEP 1310 (2013) 081
10.1007/JHEP10(2013)081
SINP/TNP/2013/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the scalar sector properties of a general class of two-Higgs-doublet models which has a global U(1) symmetry in the quartic terms. We find constraints on the parameters of the potential from the considerations of unitarity of scattering amplitudes, the global stability of the potential and the $\rho$-parameter. We concentrate on the spectrum of the non-standard scalar masses in the decoupling limit which is preferred by the Higgs data at the LHC. We exhibit charged-Higgs induced contributions to the diphoton decay width of the 125\,GeV Higgs boson and its correlation with the corresponding $Z\gamma$ width.
[ { "created": "Tue, 20 Aug 2013 13:14:13 GMT", "version": "v1" }, { "created": "Fri, 20 Sep 2013 06:58:59 GMT", "version": "v2" } ]
2013-10-23
[ [ "Bhattacharyya", "Gautam", "" ], [ "Das", "Dipankar", "" ], [ "Pal", "Palash B.", "" ], [ "Rebelo", "M. N.", "" ] ]
We analyze the scalar sector properties of a general class of two-Higgs-doublet models which has a global U(1) symmetry in the quartic terms. We find constraints on the parameters of the potential from the considerations of unitarity of scattering amplitudes, the global stability of the potential and the $\rho$-parameter. We concentrate on the spectrum of the non-standard scalar masses in the decoupling limit which is preferred by the Higgs data at the LHC. We exhibit charged-Higgs induced contributions to the diphoton decay width of the 125\,GeV Higgs boson and its correlation with the corresponding $Z\gamma$ width.
1701.08019
Yi Liao
Yi Liao, Xiao-Dong Ma
Perturbative Power Counting, Lowest-Index Operators and Their Renormalization in Standard Model Effective Field Theory
7 pages, 2 figures, 2 tables; v2: added a few refs and one sentence, without other changes; v3: minor rewording, published version
Commun. Theor. Phys. 69 (2018) 285
10.1088/0253-6102/69/3/285
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study two aspects of higher dimensional operators in standard model effective field theory. We first introduce a perturbative power counting rule for the entries in the anomalous dimension matrix of operators with equal mass dimension. The power counting is determined by the number of loops and the difference of the indices of the two operators involved, which in turn is defined by assuming that all terms in the standard model Lagrangian have an equal perturbative power. Then we show that the operators with the lowest index are unique at each mass dimension $d$, i.e., $(H^\dagger H)^{d/2}$ for even $d\geq 4$, and $(L^T\epsilon H)C(L^T\epsilon H)^T(H^\dagger H)^{(d-5)/2}$ for odd $d\geq 5$. Here $H,~L$ are the Higgs and lepton doublet, and $\epsilon,~C$ the antisymmetric matrix of rank two and the charge conjugation matrix, respectively. The renormalization group running of these operators can be studied separately from other operators of equal mass dimension at the leading order in power counting. We compute their anomalous dimensions at one loop for general $d$ and find that they are enhanced quadratically in $d$ due to combinatorics. We also make connections with classification of operators in terms of their holomorphic and anti-holomorphic weights.
[ { "created": "Fri, 27 Jan 2017 11:33:53 GMT", "version": "v1" }, { "created": "Fri, 10 Feb 2017 08:58:44 GMT", "version": "v2" }, { "created": "Mon, 5 Mar 2018 14:20:49 GMT", "version": "v3" } ]
2018-04-04
[ [ "Liao", "Yi", "" ], [ "Ma", "Xiao-Dong", "" ] ]
We study two aspects of higher dimensional operators in standard model effective field theory. We first introduce a perturbative power counting rule for the entries in the anomalous dimension matrix of operators with equal mass dimension. The power counting is determined by the number of loops and the difference of the indices of the two operators involved, which in turn is defined by assuming that all terms in the standard model Lagrangian have an equal perturbative power. Then we show that the operators with the lowest index are unique at each mass dimension $d$, i.e., $(H^\dagger H)^{d/2}$ for even $d\geq 4$, and $(L^T\epsilon H)C(L^T\epsilon H)^T(H^\dagger H)^{(d-5)/2}$ for odd $d\geq 5$. Here $H,~L$ are the Higgs and lepton doublet, and $\epsilon,~C$ the antisymmetric matrix of rank two and the charge conjugation matrix, respectively. The renormalization group running of these operators can be studied separately from other operators of equal mass dimension at the leading order in power counting. We compute their anomalous dimensions at one loop for general $d$ and find that they are enhanced quadratically in $d$ due to combinatorics. We also make connections with classification of operators in terms of their holomorphic and anti-holomorphic weights.
1204.3499
Ryosuke Sato
Masahiro Ibe and Ryosuke Sato
A 125 GeV Higgs Boson Mass and Gravitino Dark Matter in R-invariant Direct Gauge Mediation
15 pages, 6 figures; v2: section 5 added (version accepted for the publication of PLB)
null
10.1016/j.physletb.2012.09.018
ICRR-Report-613-2012-2; IPMU-12-0035; UT-12-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the SM-like Higgs boson mass in the MSSM in an R-invariant direct gauge mediation model with the gravitino mass in the O(1) keV range. The gravitino dark matter scenario in this mass range is a good candidate for a slightly warm dark matter. We show that the Higgs boson mass around 125 GeV suggested by the ATLAS and CMS experiments can be easily achieved in the direct gauge mediation model with this gravitino mass range.
[ { "created": "Mon, 16 Apr 2012 14:33:23 GMT", "version": "v1" }, { "created": "Thu, 20 Sep 2012 16:45:35 GMT", "version": "v2" } ]
2015-06-04
[ [ "Ibe", "Masahiro", "" ], [ "Sato", "Ryosuke", "" ] ]
We discuss the SM-like Higgs boson mass in the MSSM in an R-invariant direct gauge mediation model with the gravitino mass in the O(1) keV range. The gravitino dark matter scenario in this mass range is a good candidate for a slightly warm dark matter. We show that the Higgs boson mass around 125 GeV suggested by the ATLAS and CMS experiments can be easily achieved in the direct gauge mediation model with this gravitino mass range.
hep-ph/9403289
Jutta Kunz
Burkhard Kleihaus and Jutta Kunz
Multisphalerons in the Weak Interactions
10 pages, latex, 8 figures in uuencoded postscript files. THU-94/04
Phys.Lett. B329 (1994) 61-67
10.1016/0370-2693(94)90517-7
null
hep-ph
null
We construct multisphaleron solutions in the weak interactions. The multisphaleron solutions carry Chern-Simons charge $n/2$, where $n$ is an integer. The well-known sphaleron has $n=1$ and is spherically symmetric for vanishing mixing angle. In contrast the multisphalerons with $n>1$ are only axially symmetric, even for vanishing mixing angle. The greater $n$, the stronger the energy density deforms. While for small Higgs masses the energy of the multisphalerons is smaller than $n$ times the energy of the sphaleron, the energy of the multisphalerons is larger than $n$ times the energy of the sphaleron for large Higgs masses.
[ { "created": "Tue, 15 Mar 1994 10:30:44 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kleihaus", "Burkhard", "" ], [ "Kunz", "Jutta", "" ] ]
We construct multisphaleron solutions in the weak interactions. The multisphaleron solutions carry Chern-Simons charge $n/2$, where $n$ is an integer. The well-known sphaleron has $n=1$ and is spherically symmetric for vanishing mixing angle. In contrast the multisphalerons with $n>1$ are only axially symmetric, even for vanishing mixing angle. The greater $n$, the stronger the energy density deforms. While for small Higgs masses the energy of the multisphalerons is smaller than $n$ times the energy of the sphaleron, the energy of the multisphalerons is larger than $n$ times the energy of the sphaleron for large Higgs masses.
2011.07799
Xing-Dao Guo
Jian-Wen Zhu, Xing-Dao Guo, Ren-You Zhang, Wen-Gan Ma, and Xue-Qian Li
A possible interpretation for $X(6900)$ observed in four-muon final state by LHCb -- A light Higgs-like boson?
5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A peak structure of $J/\psi$ pair production around $6.9~{\rm GeV}$ was observed and analyzed by the LHCb collaboration using the Run I and II data of LHC. How to understand this peak arouses enthusiastic discussions among both theorists and experimentalists of high energy physics, because this discovery might hint something new. Overwhelming works on this topic tend to attribute the peak as a four-quark state: tetraquark or molecule. Instead, we suggest that this peak is corresponding to a fundamental Higgs-like boson with mass about $6.9~{\rm GeV}$ which is advocated by a BSM effective theory. We present a detailed analysis on both signal and SM background, including integrated cross sections and invariant mass distributions of the final-state $J/\psi$ pair. Our numerical results are well in coincidence with the experimental data, as postulating the resonance observed by LHCb to be a BSM $0^{++}$ scalar. Therefore, the peak at $M_{\text{di-}J/\psi} \sim 6.9~{\rm GeV}$ might be a hint of new physics beyond the SM whose scale is not as large as mostly expected by high energy physicists. More further works are urgently needed in both experimental and theoretical aspects to validate or negate this assumption.
[ { "created": "Mon, 16 Nov 2020 09:00:57 GMT", "version": "v1" } ]
2020-11-17
[ [ "Zhu", "Jian-Wen", "" ], [ "Guo", "Xing-Dao", "" ], [ "Zhang", "Ren-You", "" ], [ "Ma", "Wen-Gan", "" ], [ "Li", "Xue-Qian", "" ] ]
A peak structure of $J/\psi$ pair production around $6.9~{\rm GeV}$ was observed and analyzed by the LHCb collaboration using the Run I and II data of LHC. How to understand this peak arouses enthusiastic discussions among both theorists and experimentalists of high energy physics, because this discovery might hint something new. Overwhelming works on this topic tend to attribute the peak as a four-quark state: tetraquark or molecule. Instead, we suggest that this peak is corresponding to a fundamental Higgs-like boson with mass about $6.9~{\rm GeV}$ which is advocated by a BSM effective theory. We present a detailed analysis on both signal and SM background, including integrated cross sections and invariant mass distributions of the final-state $J/\psi$ pair. Our numerical results are well in coincidence with the experimental data, as postulating the resonance observed by LHCb to be a BSM $0^{++}$ scalar. Therefore, the peak at $M_{\text{di-}J/\psi} \sim 6.9~{\rm GeV}$ might be a hint of new physics beyond the SM whose scale is not as large as mostly expected by high energy physicists. More further works are urgently needed in both experimental and theoretical aspects to validate or negate this assumption.
1604.06800
Tongyan Lin
Yonit Hochberg, Tongyan Lin, Kathryn M. Zurek
Detecting Ultralight Bosonic Dark Matter via Absorption in Superconductors
10 pages, 5 figures
Phys. Rev. D 94, 015019 (2016)
10.1103/PhysRevD.94.015019
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Superconducting targets have recently been proposed for the direct detection of dark matter as light as a keV, via elastic scattering off conduction electrons in Cooper pairs. Detecting such light dark matter requires sensitivity to energies as small as the superconducting gap of O(meV). Here we show that these same superconducting devices can detect much lighter DM, of meV to eV mass, via dark matter absorption on a conduction electron, followed by emission of an athermal phonon. We demonstrate the power of this setup for relic kinetically mixed hidden photons, pseudoscalars, and scalars, showing the reach can exceed current astrophysical and terrestrial constraints with only a moderate exposure.
[ { "created": "Fri, 22 Apr 2016 20:00:01 GMT", "version": "v1" } ]
2016-07-27
[ [ "Hochberg", "Yonit", "" ], [ "Lin", "Tongyan", "" ], [ "Zurek", "Kathryn M.", "" ] ]
Superconducting targets have recently been proposed for the direct detection of dark matter as light as a keV, via elastic scattering off conduction electrons in Cooper pairs. Detecting such light dark matter requires sensitivity to energies as small as the superconducting gap of O(meV). Here we show that these same superconducting devices can detect much lighter DM, of meV to eV mass, via dark matter absorption on a conduction electron, followed by emission of an athermal phonon. We demonstrate the power of this setup for relic kinetically mixed hidden photons, pseudoscalars, and scalars, showing the reach can exceed current astrophysical and terrestrial constraints with only a moderate exposure.
hep-ph/9809413
Avtandil Tkabladze
Wolf-Dieter Nowak and Avto Tkabladze (DESY, Zeuthen)
Double Spin Asymmetries in P-wave Charmonium Hadroproduction
10 pages, LaTeX, with 5 eps figs included with epsfig.sty
Phys.Lett. B443 (1998) 379-386
10.1016/S0370-2693(98)01289-1
DESY 98-139
hep-ph
null
We discuss the double spin asymmetries in P-wave charmonium hadroproduction with non-zero transverse momenta at fixed target energies, $\sqrt{s}\simeq40$ GeV, within the framework of the NRQCD factorization approach. The size of the asymmetries and the projected statistical errors in a future option of HERA with longitudinally polarized protons scattering off a polarized target (HERA-$\vec N$) are calculated. Measurements of the $\chi_{c1}$ and $\chi_{c2}$ decays into dilepton plus photon should allow to distinguish between different parametrizations for the polarized gluon distribution in the proton. At higher energies ($\sqrt{s}=200$ GeV) the situation appears less favourable with the presently envisaged integrated luminosities of the polarized RHIC collider.
[ { "created": "Wed, 16 Sep 1998 14:37:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Nowak", "Wolf-Dieter", "", "DESY, Zeuthen" ], [ "Tkabladze", "Avto", "", "DESY, Zeuthen" ] ]
We discuss the double spin asymmetries in P-wave charmonium hadroproduction with non-zero transverse momenta at fixed target energies, $\sqrt{s}\simeq40$ GeV, within the framework of the NRQCD factorization approach. The size of the asymmetries and the projected statistical errors in a future option of HERA with longitudinally polarized protons scattering off a polarized target (HERA-$\vec N$) are calculated. Measurements of the $\chi_{c1}$ and $\chi_{c2}$ decays into dilepton plus photon should allow to distinguish between different parametrizations for the polarized gluon distribution in the proton. At higher energies ($\sqrt{s}=200$ GeV) the situation appears less favourable with the presently envisaged integrated luminosities of the polarized RHIC collider.
2112.09111
Alessandro Strumia
Alessandro Strumia
Dark Matter interpretation of the neutron decay anomaly
15 pages, 3 figures. Published version. Associated webinar: https://youtu.be/Q1bUrpQqTQs
null
10.1007/JHEP02(2022)067
null
hep-ph astro-ph.HE hep-ex
http://creativecommons.org/licenses/by/4.0/
We add to the Standard Model a new fermion $\chi$ with minimal baryon number 1/3. Neutron decay $n \to \chi\chi\chi$ into non-relativistic $\chi$ can account for the neutron decay anomaly, compatibly with bounds from neutron stars. $\chi$ can be Dark Matter, and its cosmological abundance can be generated by freeze-in dominated at $T \sim m_n$. The associated processes $n \to \chi\chi\chi \gamma$, hydrogen decay ${\rm H}\to \chi\chi \chi\nu(\gamma)$ and DM-induced neutron disappearance $\bar\chi n \to \chi \chi (\gamma)$ have rates below experimental bounds and can be of interest for future experiments.
[ { "created": "Thu, 16 Dec 2021 18:51:01 GMT", "version": "v1" }, { "created": "Fri, 18 Mar 2022 16:07:01 GMT", "version": "v2" } ]
2022-03-21
[ [ "Strumia", "Alessandro", "" ] ]
We add to the Standard Model a new fermion $\chi$ with minimal baryon number 1/3. Neutron decay $n \to \chi\chi\chi$ into non-relativistic $\chi$ can account for the neutron decay anomaly, compatibly with bounds from neutron stars. $\chi$ can be Dark Matter, and its cosmological abundance can be generated by freeze-in dominated at $T \sim m_n$. The associated processes $n \to \chi\chi\chi \gamma$, hydrogen decay ${\rm H}\to \chi\chi \chi\nu(\gamma)$ and DM-induced neutron disappearance $\bar\chi n \to \chi \chi (\gamma)$ have rates below experimental bounds and can be of interest for future experiments.
hep-ph/9510306
Daniel Ng
Daniel Ng and John N. Ng
A note on Majorana neutrinos, leptonic CKM and electron electric dipole moment
7 pages and 1 figure
Mod.Phys.Lett.A11:211-216,1996
10.1142/S0217732396000254
TRI-PP-95-69
hep-ph
null
The electric dipole moment of the electron, $d_e$, is known to vanish up to thre e-loops in the standard model with massless neutrinos. However, if neutrinos are massive Majorana particles, we obtain the result that $d_e$ induced by leptonic CKM mechanism is non-vanishing at two-loop order, and it applies to all massive Majorana neutrino models.
[ { "created": "Mon, 16 Oct 1995 19:07:14 GMT", "version": "v1" } ]
2014-11-17
[ [ "Ng", "Daniel", "" ], [ "Ng", "John N.", "" ] ]
The electric dipole moment of the electron, $d_e$, is known to vanish up to thre e-loops in the standard model with massless neutrinos. However, if neutrinos are massive Majorana particles, we obtain the result that $d_e$ induced by leptonic CKM mechanism is non-vanishing at two-loop order, and it applies to all massive Majorana neutrino models.
1910.09431
Zhao-Huan Yu
Yu-Pan Zeng, Chengfeng Cai, Dan-Yang Liu, Zhao-Huan Yu, Hong-Hao Zhang
Probing quadruplet scalar dark matter at current and future $pp$ colliders
29 pages, 9 figures; revisions to match the published version
Phys. Rev. D 101, 115033 (2020)
10.1103/PhysRevD.101.115033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a dark matter model involving an inert $\mathrm{SU}(2)_\mathrm{L}$ quadruplet scalar with hypercharge 1/2. After the electroweak symmetry breaking, the dark sector contains one doubly charged, two singly charged, and two neutral scalars. The lighter neutral scalar can be a viable dark matter candidate. Electroweak production of these scalars at the Large Hadron Collider leads to potential signals in the $\text{monojet} + /\!\!\!\!E_\mathrm{T}$ and $\text{soft-leptons} + \text{jets} + /\!\!\!\!E_\mathrm{T}$ channels. We thus derive constraints on the model by reinterpreting recent experimental searches. Based on simulation, we further evaluate the sensitivity at a future 100 TeV $pp$ collider.
[ { "created": "Mon, 21 Oct 2019 15:07:03 GMT", "version": "v1" }, { "created": "Fri, 25 Oct 2019 09:56:40 GMT", "version": "v2" }, { "created": "Thu, 25 Jun 2020 03:41:08 GMT", "version": "v3" } ]
2020-06-26
[ [ "Zeng", "Yu-Pan", "" ], [ "Cai", "Chengfeng", "" ], [ "Liu", "Dan-Yang", "" ], [ "Yu", "Zhao-Huan", "" ], [ "Zhang", "Hong-Hao", "" ] ]
We investigate a dark matter model involving an inert $\mathrm{SU}(2)_\mathrm{L}$ quadruplet scalar with hypercharge 1/2. After the electroweak symmetry breaking, the dark sector contains one doubly charged, two singly charged, and two neutral scalars. The lighter neutral scalar can be a viable dark matter candidate. Electroweak production of these scalars at the Large Hadron Collider leads to potential signals in the $\text{monojet} + /\!\!\!\!E_\mathrm{T}$ and $\text{soft-leptons} + \text{jets} + /\!\!\!\!E_\mathrm{T}$ channels. We thus derive constraints on the model by reinterpreting recent experimental searches. Based on simulation, we further evaluate the sensitivity at a future 100 TeV $pp$ collider.
hep-ph/0209003
Keith OIive
D. A. Demir, Tony Gherghetta, and Keith A. Olive
Preserving the Lepton Asymmetry in the Brane World
13 pages, latex, 2 eps figure clarifications and reference added
Phys.Lett.B549:194-203,2002
10.1016/S0370-2693(02)02902-7
UMN-TH-2110/02, TPI-MINN-02/39
hep-ph
null
In models where the Standard Model spectrum is localized on a brane embedded in a higher dimensional spacetime, we discuss the lepton number violation induced by the emission of right-handed neutrinos from the brane. We show that quite generically the presence of the right-handed neutrinos in the bulk leads to rapid lepton number violating processes which above the electroweak scale would wash away any prior lepton or baryon asymmetry. In order to preserve the lepton asymmetry, the brane-bulk couplings for at least one lepton flavor must be extremely suppressed. We show that this has a natural interpretation in the brane world.
[ { "created": "Fri, 30 Aug 2002 23:30:01 GMT", "version": "v1" }, { "created": "Mon, 9 Sep 2002 20:14:26 GMT", "version": "v2" } ]
2009-09-15
[ [ "Demir", "D. A.", "" ], [ "Gherghetta", "Tony", "" ], [ "Olive", "Keith A.", "" ] ]
In models where the Standard Model spectrum is localized on a brane embedded in a higher dimensional spacetime, we discuss the lepton number violation induced by the emission of right-handed neutrinos from the brane. We show that quite generically the presence of the right-handed neutrinos in the bulk leads to rapid lepton number violating processes which above the electroweak scale would wash away any prior lepton or baryon asymmetry. In order to preserve the lepton asymmetry, the brane-bulk couplings for at least one lepton flavor must be extremely suppressed. We show that this has a natural interpretation in the brane world.
hep-ph/0308103
Mayda M. Velasco
David Asner, Stephen Asztalos, Albert De Roeck, Sven Heinemeyer, Jeff Gronberg, John F. Gunion, Heather E. Logan, Victoria Martin, Michal Szleper, Mayda M. Velasco
Complementarity of a Low Energy Photon Collider and LHC Physics
29 pages, 37 figure, LP-2003
null
null
nuhep-exp/03-003, uCD-03-08
hep-ph
null
We discuss the complementarity between the LHC and a low energy photon collider. We mostly consider the scenario, where the first linear collider is a photon collider based on dual beam technology like CLIC.
[ { "created": "Sat, 9 Aug 2003 01:57:35 GMT", "version": "v1" } ]
2009-09-29
[ [ "Asner", "David", "" ], [ "Asztalos", "Stephen", "" ], [ "De Roeck", "Albert", "" ], [ "Heinemeyer", "Sven", "" ], [ "Gronberg", "Jeff", "" ], [ "Gunion", "John F.", "" ], [ "Logan", "Heather E.", "" ], [ "Martin", "Victoria", "" ], [ "Szleper", "Michal", "" ], [ "Velasco", "Mayda M.", "" ] ]
We discuss the complementarity between the LHC and a low energy photon collider. We mostly consider the scenario, where the first linear collider is a photon collider based on dual beam technology like CLIC.
1207.4609
Samuel Wallon
T. Altinoluk, B. Pire, L. Szymanowski, S. Wallon
Resumming soft and collinear contributions in deeply virtual Compton scattering
14 figures
null
10.1007/JHEP10(2012)049
CPHT-RR066.0712; LPT-ORSAY-12-82
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the quark coefficient function Tq(x,xi) that enters the factorized amplitude for deeply virtual Compton scattering (DVCS) at all order in a soft and collinear gluon approximation, focusing on the leading double logarithmic behavior in x +/- xi, where x +/- xi is the light cone momentum fraction of the incoming/outgoing quarks. We show that the dominant part of the known one loop result can be understood in an axial gauge as the result of a semi-eikonal approximation to the box diagram. We then derive an all order result for the leading contribution of the ladder diagrams and deduce a resummation formula valid in the vicinity of the boundaries of the regions defining the energy flows of the incoming/outcoming quarks, i.e. x = +/- xi. The resummed series results in a simple closed expression.
[ { "created": "Thu, 19 Jul 2012 10:41:10 GMT", "version": "v1" } ]
2015-06-05
[ [ "Altinoluk", "T.", "" ], [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ], [ "Wallon", "S.", "" ] ]
We calculate the quark coefficient function Tq(x,xi) that enters the factorized amplitude for deeply virtual Compton scattering (DVCS) at all order in a soft and collinear gluon approximation, focusing on the leading double logarithmic behavior in x +/- xi, where x +/- xi is the light cone momentum fraction of the incoming/outgoing quarks. We show that the dominant part of the known one loop result can be understood in an axial gauge as the result of a semi-eikonal approximation to the box diagram. We then derive an all order result for the leading contribution of the ladder diagrams and deduce a resummation formula valid in the vicinity of the boundaries of the regions defining the energy flows of the incoming/outcoming quarks, i.e. x = +/- xi. The resummed series results in a simple closed expression.
hep-ph/9803429
Gabriel Sanchez-Colon
V. Gupta (1), P. Ritto (1), and G. Sanchez-Colon (1,2) ((1) CINVESTAV-Merida, (2) UC-Riverside)
Masses, Magnetic Moments, and Semileptonic Decays of Spin 1/2 Baryons with Sea Contribution
Submitted to Int. J. of Mod. Phys. A (1998)
Mod.Phys.Lett. A13 (1998) 2887-2902
10.1142/S0217732398003065
IJMPA_0398
hep-ph
null
The spin 1/2 baryons are pictured as a composite system made out of a "core" of three valence quarks (as in the simple quark model) surrounded by a "sea" (of gluon and $q\bar{q}$ pairs) which is specified by its total quantum numbers. We assume the sea is a SU(3) flavor octet with spin 0 or 1 but no color. This model, considered earlier, is used to obtain simultaneous fits for masses, magnetic moments and $G_A/G_V$ for semileptonic decays. These fits give predictions for nucleon spin distributions in reasonable agreement with experiment.
[ { "created": "Mon, 23 Mar 1998 20:03:02 GMT", "version": "v1" } ]
2009-10-31
[ [ "Gupta", "V.", "" ], [ "Ritto", "P.", "" ], [ "Sanchez-Colon", "G.", "" ] ]
The spin 1/2 baryons are pictured as a composite system made out of a "core" of three valence quarks (as in the simple quark model) surrounded by a "sea" (of gluon and $q\bar{q}$ pairs) which is specified by its total quantum numbers. We assume the sea is a SU(3) flavor octet with spin 0 or 1 but no color. This model, considered earlier, is used to obtain simultaneous fits for masses, magnetic moments and $G_A/G_V$ for semileptonic decays. These fits give predictions for nucleon spin distributions in reasonable agreement with experiment.
hep-ph/9409378
Alexander Khodjamirian
A. Khodjamirian, R. R\"uckl
Heavy Meson Form Factors, Couplings and Exclusive Decays in QCD
5 pages +1 figure added as uuencoded .ps file, LaTeX ( presented by R. R\"uckl at the QCD-94 Workshop " Montpellier, July 7-13 1994), MPI-PhT/94-63, LMU-16/94
Nucl.Phys.Proc.Suppl. 39BC (1995) 396-398
10.1016/0920-5632(95)00108-L
null
hep-ph
null
We discuss the form factors of the heavy-to-light transitions $B \ra \pi$ and $D\ra \pi$, the $B^*B \pi$ and $D^*D \pi$ coupling constants, and the nonfactorizable amplitude of the decay $ B \ra J/\psi K$ in the framework of QCD sum rules.
[ { "created": "Wed, 21 Sep 1994 19:02:28 GMT", "version": "v1" } ]
2009-10-28
[ [ "Khodjamirian", "A.", "" ], [ "Rückl", "R.", "" ] ]
We discuss the form factors of the heavy-to-light transitions $B \ra \pi$ and $D\ra \pi$, the $B^*B \pi$ and $D^*D \pi$ coupling constants, and the nonfactorizable amplitude of the decay $ B \ra J/\psi K$ in the framework of QCD sum rules.
1902.04110
Fabio Siringo
Fabio Siringo
Calculation of the non-perturbative strong coupling from first principles
In the last versions a typo has been corrected in Table I and a figure has been added (fig1b), illustrating the optimization of the ghost function
Phys. Rev. D 100, 074014 (2019)
10.1103/PhysRevD.100.074014
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The success of the screened massive expansion is investigated in the framework of a screened momentum-subtraction scheme for the running of the strong coupling in pure Yang-Mills theory. By the exact Slavnov-Taylor and Nielsen identities, a very predictive and self-contained set of stationary conditions are derived for the optimization of the fixed-coupling expansion, yielding explicit analytical one-loop expressions for the propagators, the coupling and the beta function, from first principles. An excellent agreement is found with the lattice data. In the proposed screened renormalization scheme, a monotonic running coupling emerges which saturates in the IR at the finite IR stable fixed point $g=9.40$ where the beta function crosses the zero. A simple analytical expression is derived for the leading behavior of the beta in the IR.
[ { "created": "Mon, 11 Feb 2019 19:39:39 GMT", "version": "v1" }, { "created": "Sat, 28 Sep 2019 08:59:27 GMT", "version": "v2" }, { "created": "Sun, 6 Oct 2019 19:53:00 GMT", "version": "v3" } ]
2019-10-16
[ [ "Siringo", "Fabio", "" ] ]
The success of the screened massive expansion is investigated in the framework of a screened momentum-subtraction scheme for the running of the strong coupling in pure Yang-Mills theory. By the exact Slavnov-Taylor and Nielsen identities, a very predictive and self-contained set of stationary conditions are derived for the optimization of the fixed-coupling expansion, yielding explicit analytical one-loop expressions for the propagators, the coupling and the beta function, from first principles. An excellent agreement is found with the lattice data. In the proposed screened renormalization scheme, a monotonic running coupling emerges which saturates in the IR at the finite IR stable fixed point $g=9.40$ where the beta function crosses the zero. A simple analytical expression is derived for the leading behavior of the beta in the IR.
hep-ph/0611131
Jinfeng Liao
Jinfeng Liao and Edward Shuryak
Strongly coupled plasma with electric and magnetic charges
2nd version, 22 pages, 32 figures: two important new figures have been included to compare our results with RHIC experiments and AdS/CFT results; a few new references and comments are added as well
Phys.Rev.C75:054907,2007
10.1103/PhysRevC.75.054907
null
hep-ph
null
A number of theoretical and lattice results lead us to believe that Quark-Gluon Plasma not too far from $T_c$ contains not only electrically charged quasiparticles -- quarks and gluons -- but magnetically charged ones -- monopoles and dyons -- as well. Although binary systems like charge-monopole and charge-dyon were considered in details before in both classical and quantum settings, it is the first study of coexisting electric and magnetic particles in many-body context. We perform Molecular Dynamics study of strongly coupled plasmas with $\sim 1000$ particles and different fraction of magnetic charges. Correlation functions and Kubo formulae lead to such transport properties as diffusion constant, shear viscosity and electric conductivity: we compare the first two with empirical data from RHIC experiments as well as results from AdS/CFT correspondence. We also study a number of collective excitations in these systems.
[ { "created": "Thu, 9 Nov 2006 20:48:13 GMT", "version": "v1" }, { "created": "Tue, 12 Dec 2006 02:20:09 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liao", "Jinfeng", "" ], [ "Shuryak", "Edward", "" ] ]
A number of theoretical and lattice results lead us to believe that Quark-Gluon Plasma not too far from $T_c$ contains not only electrically charged quasiparticles -- quarks and gluons -- but magnetically charged ones -- monopoles and dyons -- as well. Although binary systems like charge-monopole and charge-dyon were considered in details before in both classical and quantum settings, it is the first study of coexisting electric and magnetic particles in many-body context. We perform Molecular Dynamics study of strongly coupled plasmas with $\sim 1000$ particles and different fraction of magnetic charges. Correlation functions and Kubo formulae lead to such transport properties as diffusion constant, shear viscosity and electric conductivity: we compare the first two with empirical data from RHIC experiments as well as results from AdS/CFT correspondence. We also study a number of collective excitations in these systems.
hep-ph/9712445
Bhaskar Dutta
N.G. Deshpande, B. Dutta, and Sechul Oh
Branching Ratios and CP Asymmetries of B Decays to a Vector and a Pseudoscalar Meson
15 pages(Latex), 3 Figures
Phys.Lett. B473 (2000) 141-147
10.1016/S0370-2693(99)01460-4
OITS-644, COLO-HEP-394
hep-ph
null
We consider two body decays of B meson into a light vector (V) and a pseudoscalar (P) meson. The constraint obtained from the $B\to P P$ modes on the parameter space of the input parameters is imposed also on $B\to V P$ modes. In particular we constrain $\xi\equiv (1/N_c)$ for those modes from recently measured $B\to \omega K, \phi K$ and are able to get a satisfactory pictures for all modes where data exists. Modes that should be seen shortly and those with possibly large CP asymmetries are identified.
[ { "created": "Thu, 18 Dec 1997 22:17:49 GMT", "version": "v1" } ]
2009-10-30
[ [ "Deshpande", "N. G.", "" ], [ "Dutta", "B.", "" ], [ "Oh", "Sechul", "" ] ]
We consider two body decays of B meson into a light vector (V) and a pseudoscalar (P) meson. The constraint obtained from the $B\to P P$ modes on the parameter space of the input parameters is imposed also on $B\to V P$ modes. In particular we constrain $\xi\equiv (1/N_c)$ for those modes from recently measured $B\to \omega K, \phi K$ and are able to get a satisfactory pictures for all modes where data exists. Modes that should be seen shortly and those with possibly large CP asymmetries are identified.
hep-ph/9207250
null
A. Zhitnitsky
Once more on $\theta$-vacua in $2+1$ dimensional QED and 3+1 dimensional gluodynamics
15 pages
Phys.Lett.B291:465-472,1992
10.1016/0370-2693(92)91405-X
IASSNS 91-76
hep-ph
null
Two different but tightly connected problems, $U(1)$ and strong CP violation problems, are discussed in two different models which exhibit both asymptotic freedom and confinement. One of them is the 3d Polyakov's model of compact QED and the other is 4d gluodynamics. It is shown that although both these models possess the long range interactions of the topological charges, only in the former case physics does not depend on $\theta$; while the latter exhibits an explicit $\theta$- dependence. The crucial difference is due to the observation, that the pseudoparticles of 4d gluodynamics possess an aditional quantum number, apart of the topological charge $Q$ .
[ { "created": "Tue, 21 Jul 1992 08:39:46 GMT", "version": "v1" } ]
2010-11-01
[ [ "Zhitnitsky", "A.", "" ] ]
Two different but tightly connected problems, $U(1)$ and strong CP violation problems, are discussed in two different models which exhibit both asymptotic freedom and confinement. One of them is the 3d Polyakov's model of compact QED and the other is 4d gluodynamics. It is shown that although both these models possess the long range interactions of the topological charges, only in the former case physics does not depend on $\theta$; while the latter exhibits an explicit $\theta$- dependence. The crucial difference is due to the observation, that the pseudoparticles of 4d gluodynamics possess an aditional quantum number, apart of the topological charge $Q$ .
1612.01795
Reza Goldouzian
Reza Goldouzian and Barbara Clerbaux
Search for anomalous tq$\gamma$ FCNC Couplings in direct single top quark production at the LHC
Presented at '9th International Workshop on Top Quark Physics', Olomouc, Czech Republic, September 19-23 (2016). Complete paper can be found in arXiv:1609.04838
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we propose and study direct single top quark production channel for probing the tq$\gamma$ flavor-changing neutral current (FCNC) interactions at the LHC. We reinterpret the experimental results of a search for direct single top quark production performed by ATLAS collaboration at 8 TeV to set upper bounds on the FCNC top quark decay branching fractions through the proposed channel, resulting in ${\cal B}$(t$\rightarrow$ u$\gamma$) $<$ 0.05\% and ${\cal B}$(t$\rightarrow$ c$\gamma$) $<$ 0.14\%. Finally, the expected sensitivity at 13 TeV for various integrated luminosity scenarios is estimated.
[ { "created": "Tue, 6 Dec 2016 13:16:01 GMT", "version": "v1" } ]
2016-12-07
[ [ "Goldouzian", "Reza", "" ], [ "Clerbaux", "Barbara", "" ] ]
In this paper we propose and study direct single top quark production channel for probing the tq$\gamma$ flavor-changing neutral current (FCNC) interactions at the LHC. We reinterpret the experimental results of a search for direct single top quark production performed by ATLAS collaboration at 8 TeV to set upper bounds on the FCNC top quark decay branching fractions through the proposed channel, resulting in ${\cal B}$(t$\rightarrow$ u$\gamma$) $<$ 0.05\% and ${\cal B}$(t$\rightarrow$ c$\gamma$) $<$ 0.14\%. Finally, the expected sensitivity at 13 TeV for various integrated luminosity scenarios is estimated.
2106.15053
Zhan-Wei Liu
Ming-Wei Li, Zhan-Wei Liu, Zhi-Feng Sun, Rui Chen
Magnetic moments and transition magnetic moments of $P_c$ and $P_{cs}$ states
8 pages, 5 tables; version appeared in Phys. Rev. D
Phys. Rev. D 104, 054016 (2021)
10.1103/PhysRevD.104.054016
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the magnetic moments and transition magnetic moments of $P_c$ and $P_{cs}$ states in the molecular picture. We first revisit the magnetic moments of $P_c$ states as the $S$ wave molecular states without coupled channel effects. The coupled channel effects and the $D$ wave contributions are then investigated carefully. The coupled channel effects contribute to the change of $0.1\sim 0.4$ nuclear magneton $\mu_N$ for most cases while the $D$ wave only induces the variation of less than $0.03 ~\mu_N$. In addition, we obtain the transition magnetic moments between different $P_c$ states and the related electromagnetic decay widths of $P_c'\to P_c\gamma$. The magnetic moments of $P_{cs}$ are much different for the assumption of spin being 1/2 and 3/2. The study of electromagnetic properties will help us disclose further the structure of these unconventional states.
[ { "created": "Tue, 29 Jun 2021 01:47:35 GMT", "version": "v1" }, { "created": "Thu, 16 Sep 2021 15:54:59 GMT", "version": "v2" } ]
2021-09-22
[ [ "Li", "Ming-Wei", "" ], [ "Liu", "Zhan-Wei", "" ], [ "Sun", "Zhi-Feng", "" ], [ "Chen", "Rui", "" ] ]
We study the magnetic moments and transition magnetic moments of $P_c$ and $P_{cs}$ states in the molecular picture. We first revisit the magnetic moments of $P_c$ states as the $S$ wave molecular states without coupled channel effects. The coupled channel effects and the $D$ wave contributions are then investigated carefully. The coupled channel effects contribute to the change of $0.1\sim 0.4$ nuclear magneton $\mu_N$ for most cases while the $D$ wave only induces the variation of less than $0.03 ~\mu_N$. In addition, we obtain the transition magnetic moments between different $P_c$ states and the related electromagnetic decay widths of $P_c'\to P_c\gamma$. The magnetic moments of $P_{cs}$ are much different for the assumption of spin being 1/2 and 3/2. The study of electromagnetic properties will help us disclose further the structure of these unconventional states.
1303.1603
Paul Hoyer
Paul Hoyer
Are hadrons simpler than they seem?
4 pages. Talk presented at the 3rd Workshop on the QCD Structure of the Nucleon (QCD-N'12), 22-26 October 2012 in Bilbao, Spain
null
10.1393/ncc/i2013-11573-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I briefly review a systematic approximation scheme of QCD in which the quark model picture of hadrons emerges at lowest order. A linear A^0 potential arises if Gauss' law is solved with a non-vanishing boundary condition at spatial infinity. Similarly to the Dirac case one can describe relativistic states including any number of particle pairs (sea quarks) using valence wave functions, whose norms give {\em inclusive} probability densities. Provided \alpha_s(Q^2) freezes in the infrared, perturbative corrections to the S-matrix can be calculated in the usual way, but with states bound by the linear \order{\alpha_s^0} potential instead of plane waves in the in and out states.
[ { "created": "Thu, 7 Mar 2013 04:52:43 GMT", "version": "v1" } ]
2022-03-02
[ [ "Hoyer", "Paul", "" ] ]
I briefly review a systematic approximation scheme of QCD in which the quark model picture of hadrons emerges at lowest order. A linear A^0 potential arises if Gauss' law is solved with a non-vanishing boundary condition at spatial infinity. Similarly to the Dirac case one can describe relativistic states including any number of particle pairs (sea quarks) using valence wave functions, whose norms give {\em inclusive} probability densities. Provided \alpha_s(Q^2) freezes in the infrared, perturbative corrections to the S-matrix can be calculated in the usual way, but with states bound by the linear \order{\alpha_s^0} potential instead of plane waves in the in and out states.
hep-ph/9502364
G. B. Pivovarov
Grigorii B. Pivovarov
Gauge Dependence of Four-Fermion QED Green Function and Atom-Like Bound State Calculations
10 pages, latex, no figures, lines longer than 80 char corrected
null
null
INR-0881/95
hep-ph
null
We derive a relation between four-fermion QED Green functions of different covariant gauges which defines the gauge dependence completely. We use the derived gauge dependence to check the gauge invariance of atom-like bound state calculations. We find that the existing QED procedure does not provide gauge invariant binding energies. A way to a corrected gauge invariant procedure is pointed out.
[ { "created": "Wed, 22 Feb 1995 09:18:26 GMT", "version": "v1" }, { "created": "Thu, 23 Feb 1995 12:54:46 GMT", "version": "v2" } ]
2016-09-01
[ [ "Pivovarov", "Grigorii B.", "" ] ]
We derive a relation between four-fermion QED Green functions of different covariant gauges which defines the gauge dependence completely. We use the derived gauge dependence to check the gauge invariance of atom-like bound state calculations. We find that the existing QED procedure does not provide gauge invariant binding energies. A way to a corrected gauge invariant procedure is pointed out.
1912.13129
Yevgeny Stadnik
V. V. Flambaum, M. Pospelov, A. Ritz, Y. V. Stadnik
Sensitivity of EDM experiments in paramagnetic atoms and molecules to hadronic CP violation
7 pages, 3 figures, version accepted for publication in Physical Review D
Phys. Rev. D 102, 035001 (2020)
10.1103/PhysRevD.102.035001
null
hep-ph nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experiments searching for the electric dipole moment (EDM) of the electron $d_e$ utilise atomic/molecular states with one or more uncompensated electron spins, and these paramagnetic systems have recently achieved remarkable sensitivity to $d_e$. If the source of $CP$ violation resides entirely in the hadronic sector, the two-photon exchange processes between electrons and the nucleus induce $CP$-odd semileptonic interactions, parametrised by the Wilson coefficient $C_{SP}$, and provide the dominant source of EDMs in paramagnetic systems instead of $d_e$. We evaluate the $C_{SP}$ coefficients induced by the leading hadronic sources of $CP$ violation, namely nucleon EDMs and $CP$-odd pion-nucleon couplings, by calculating the nucleon-number-enhanced $CP$-odd nuclear scalar polarisability, employing chiral perturbation theory at the nucleon level and the Fermi-gas model for the nucleus. This allows us to translate the ACME EDM limits from paramagnetic ThO into novel independent constraints on the QCD theta term $|\bar \theta| < 3 \times 10^{-8}$, proton EDM $|d_p| < 2 \times 10^{-23}\,e\,{\rm cm}$, isoscalar $CP$-odd pion-nucleon coupling $|\bar g^{(1)}_{\pi NN}| < 4 \times 10^{-10}$, and colour EDMs of quarks $|\tilde d_u - \tilde d_d| < 2 \times 10^{-24}\,{\rm cm}$. We note that further experimental progress with EDM experiments in paramagnetic systems may allow them to rival the sensitivity of EDM experiments with neutrons and diamagnetic atoms to these quantities.
[ { "created": "Tue, 31 Dec 2019 00:52:10 GMT", "version": "v1" }, { "created": "Wed, 22 Apr 2020 09:30:39 GMT", "version": "v2" }, { "created": "Tue, 28 Jul 2020 03:45:37 GMT", "version": "v3" } ]
2020-08-12
[ [ "Flambaum", "V. V.", "" ], [ "Pospelov", "M.", "" ], [ "Ritz", "A.", "" ], [ "Stadnik", "Y. V.", "" ] ]
Experiments searching for the electric dipole moment (EDM) of the electron $d_e$ utilise atomic/molecular states with one or more uncompensated electron spins, and these paramagnetic systems have recently achieved remarkable sensitivity to $d_e$. If the source of $CP$ violation resides entirely in the hadronic sector, the two-photon exchange processes between electrons and the nucleus induce $CP$-odd semileptonic interactions, parametrised by the Wilson coefficient $C_{SP}$, and provide the dominant source of EDMs in paramagnetic systems instead of $d_e$. We evaluate the $C_{SP}$ coefficients induced by the leading hadronic sources of $CP$ violation, namely nucleon EDMs and $CP$-odd pion-nucleon couplings, by calculating the nucleon-number-enhanced $CP$-odd nuclear scalar polarisability, employing chiral perturbation theory at the nucleon level and the Fermi-gas model for the nucleus. This allows us to translate the ACME EDM limits from paramagnetic ThO into novel independent constraints on the QCD theta term $|\bar \theta| < 3 \times 10^{-8}$, proton EDM $|d_p| < 2 \times 10^{-23}\,e\,{\rm cm}$, isoscalar $CP$-odd pion-nucleon coupling $|\bar g^{(1)}_{\pi NN}| < 4 \times 10^{-10}$, and colour EDMs of quarks $|\tilde d_u - \tilde d_d| < 2 \times 10^{-24}\,{\rm cm}$. We note that further experimental progress with EDM experiments in paramagnetic systems may allow them to rival the sensitivity of EDM experiments with neutrons and diamagnetic atoms to these quantities.
2101.11200
Xiang Liu
Fu-Lai Wang, Xin-Dian Yang, Rui Chen and Xiang Liu
Hidden-charm pentaquarks with triple strangeness due to the $\Omega_{c}^{(*)}\bar{D}_s^{(*)}$ interactions
11 pages, 3 figures and 7 tables. More discussions added. Accepted by Phys. Rev. D
Phys. Rev. D 103, 054025 (2021)
10.1103/PhysRevD.103.054025
null
hep-ph hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
Motivated by the successful interpretation of these observed $P_c$ and $P_{cs}$ states under the meson-baryon molecular picture, we systematically investigate the possible hidden-charm molecular pentaquark states with triple strangeness which is due to the $\Omega_{c}^{(*)}\bar{D}_s^{(*)}$ interactions. We perform a dynamical calculation of the possible hidden-charm molecular pentaquarks with triple strangeness by the one-boson-exchange model, where the $S$-$D$ wave mixing effect and the coupled channel effect are taken into account in our calculation. Our results suggest that the $\Omega_{c}\bar D_s^*$ state with $J^P={3}/{2}^{-}$ and the $\Omega_{c}^{*}\bar D_s^*$ state with $J^P={5}/{2}^{-}$ can be recommended as the candidates of the hidden-charm molecular pentaquark with triple strangeness. Furthermore, we discuss the two-body hidden-charm strong decay behaviors of these possible hidden-charm molecular pentaquarks with triple strangeness by adopting the quark-interchange model. These predictions are expected to be tested at the LHCb, which can be as a potential research issue with more accumulated experimental data in near future.
[ { "created": "Wed, 27 Jan 2021 04:37:22 GMT", "version": "v1" }, { "created": "Wed, 24 Feb 2021 08:23:38 GMT", "version": "v2" }, { "created": "Mon, 22 Mar 2021 16:07:07 GMT", "version": "v3" } ]
2021-03-31
[ [ "Wang", "Fu-Lai", "" ], [ "Yang", "Xin-Dian", "" ], [ "Chen", "Rui", "" ], [ "Liu", "Xiang", "" ] ]
Motivated by the successful interpretation of these observed $P_c$ and $P_{cs}$ states under the meson-baryon molecular picture, we systematically investigate the possible hidden-charm molecular pentaquark states with triple strangeness which is due to the $\Omega_{c}^{(*)}\bar{D}_s^{(*)}$ interactions. We perform a dynamical calculation of the possible hidden-charm molecular pentaquarks with triple strangeness by the one-boson-exchange model, where the $S$-$D$ wave mixing effect and the coupled channel effect are taken into account in our calculation. Our results suggest that the $\Omega_{c}\bar D_s^*$ state with $J^P={3}/{2}^{-}$ and the $\Omega_{c}^{*}\bar D_s^*$ state with $J^P={5}/{2}^{-}$ can be recommended as the candidates of the hidden-charm molecular pentaquark with triple strangeness. Furthermore, we discuss the two-body hidden-charm strong decay behaviors of these possible hidden-charm molecular pentaquarks with triple strangeness by adopting the quark-interchange model. These predictions are expected to be tested at the LHCb, which can be as a potential research issue with more accumulated experimental data in near future.
0907.5387
Guido Mueller
Guido Mueller, Pierre Sikivie, D.B. Tanner, Karl van Bibber
Detailed design of a resonantly-enhanced axion-photon regeneration experiment
10 pages, 5 figures
Phys.Rev.D80:072004,2009
10.1103/PhysRevD.80.072004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A resonantly-enhanced photon-regeneration experiment to search for the axion or axion-like particles is described. This experiment is a shining light through walls study, where photons travelling through a strong magnetic field are (in part) converted to axions; the axions can pass through an opaque wall and convert (in part) back to photons in a second region of strong magnetic field. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon regeneration magnet. Compared to simple single-pass photon regeneration, this technique would result in a gain of (F/pi)^2, where F is the finesse of each cavity. This gain could feasibly be as high as 10^(10), corresponding to an improvement in the sensitivity to the axion-photon coupling, g_(agg), of order (F/pi)^(1/2) ~ 300. This improvement would enable, for the first time, a purely laboratory experiment to probe axion-photon couplings at a level competitive with, or superior to, limits from stellar evolution or solar axion searches. This report gives a detailed discussion of the scheme for actively controlling the two Fabry-Perot cavities and the laser frequencies, and describes the heterodyne signal detection system, with limits ultimately imposed by shot noise.
[ { "created": "Thu, 30 Jul 2009 18:20:51 GMT", "version": "v1" }, { "created": "Wed, 16 Sep 2009 22:03:27 GMT", "version": "v2" } ]
2009-10-29
[ [ "Mueller", "Guido", "" ], [ "Sikivie", "Pierre", "" ], [ "Tanner", "D. B.", "" ], [ "van Bibber", "Karl", "" ] ]
A resonantly-enhanced photon-regeneration experiment to search for the axion or axion-like particles is described. This experiment is a shining light through walls study, where photons travelling through a strong magnetic field are (in part) converted to axions; the axions can pass through an opaque wall and convert (in part) back to photons in a second region of strong magnetic field. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon regeneration magnet. Compared to simple single-pass photon regeneration, this technique would result in a gain of (F/pi)^2, where F is the finesse of each cavity. This gain could feasibly be as high as 10^(10), corresponding to an improvement in the sensitivity to the axion-photon coupling, g_(agg), of order (F/pi)^(1/2) ~ 300. This improvement would enable, for the first time, a purely laboratory experiment to probe axion-photon couplings at a level competitive with, or superior to, limits from stellar evolution or solar axion searches. This report gives a detailed discussion of the scheme for actively controlling the two Fabry-Perot cavities and the laser frequencies, and describes the heterodyne signal detection system, with limits ultimately imposed by shot noise.
2209.10816
Cong Zhang
Jinmian Li, Junle Pei, Cong Zhang
Investigating the collinear splitting effects of boosted dark matter at neutrino detectors
27 pages, 7 figures, version to appear in JHEP
null
10.1007/JHEP02(2023)068
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the probing prospects of cosmic ray boosted dark matter (DM) in the framework of simplified electron-philic dark photon model. Focusing on the dark matter and dark photon masses around keV $\sim $ MeV scale, we consider the bounds obtained from the XENON1T and Super-K experiments. The electron bound state effects are treated carefully in calculating the XENON1T constraint. As for the detection at neutrino detector where the energy threshold is relatively higher, the large logarithmic effects induced by the scale hierarchy between the masses and momentum transfer are considered by introducing the DM parton distribution function (PDF). The logarithmic effects will reduce the electron recoil rate for DM scattering in neutrino detectors. Moreover, we find the DUNE and JUNO experiments provide high sensitivities for probing the dark photon component in the DM PDF through the dark Compton process. We also check the Bullet Cluster constraint on the DM self-scattering cross section.
[ { "created": "Thu, 22 Sep 2022 06:49:01 GMT", "version": "v1" }, { "created": "Tue, 7 Feb 2023 07:04:12 GMT", "version": "v2" } ]
2023-02-13
[ [ "Li", "Jinmian", "" ], [ "Pei", "Junle", "" ], [ "Zhang", "Cong", "" ] ]
We study the probing prospects of cosmic ray boosted dark matter (DM) in the framework of simplified electron-philic dark photon model. Focusing on the dark matter and dark photon masses around keV $\sim $ MeV scale, we consider the bounds obtained from the XENON1T and Super-K experiments. The electron bound state effects are treated carefully in calculating the XENON1T constraint. As for the detection at neutrino detector where the energy threshold is relatively higher, the large logarithmic effects induced by the scale hierarchy between the masses and momentum transfer are considered by introducing the DM parton distribution function (PDF). The logarithmic effects will reduce the electron recoil rate for DM scattering in neutrino detectors. Moreover, we find the DUNE and JUNO experiments provide high sensitivities for probing the dark photon component in the DM PDF through the dark Compton process. We also check the Bullet Cluster constraint on the DM self-scattering cross section.
hep-ph/9901207
Robert Brandenberger
V. Zanchin, A. Maia Jr., W. Craig and R. Brandenberger
Reheating in the Presence of Inhomogeneous Noise
21 pages, 4 figures
Phys.Rev. D60 (1999) 023505
10.1103/PhysRevD.60.023505
BROWN-HET-1085
hep-ph astro-ph gr-qc
null
Explosive particle production due to parametric resonance is a crucial feature of reheating in an inflationary cosmology. Coherent oscillations of the inflaton field lead to a periodically varying mass in the evolution equation of matter and gravitational fluctuations and often induce a parametric resonance instability. In a previous paper (hep-ph/9709273) it was shown that homogeneous (i.e. space independent) noise leads to an increase of the generalized Floquet exponent for all modes, at least if the noise is temporally uncorrelated. Here we extend the results to the physically more realistic case of spatially inhomogeneous noise. We demonstrate - modulo some mathematical fine points which are addressed in a companion paper - that the Floquet exponent is a non- decreasing function of the amplitude of the noise. We provide numerical evidence for an even stronger statement, namely that in the presence of inhomogeneous noise, the Floquet exponent of each mode is larger than the maximal Floquet exponent of the system in the absence of noise.
[ { "created": "Sat, 2 Jan 1999 22:33:43 GMT", "version": "v1" } ]
2009-10-31
[ [ "Zanchin", "V.", "" ], [ "Maia", "A.", "Jr." ], [ "Craig", "W.", "" ], [ "Brandenberger", "R.", "" ] ]
Explosive particle production due to parametric resonance is a crucial feature of reheating in an inflationary cosmology. Coherent oscillations of the inflaton field lead to a periodically varying mass in the evolution equation of matter and gravitational fluctuations and often induce a parametric resonance instability. In a previous paper (hep-ph/9709273) it was shown that homogeneous (i.e. space independent) noise leads to an increase of the generalized Floquet exponent for all modes, at least if the noise is temporally uncorrelated. Here we extend the results to the physically more realistic case of spatially inhomogeneous noise. We demonstrate - modulo some mathematical fine points which are addressed in a companion paper - that the Floquet exponent is a non- decreasing function of the amplitude of the noise. We provide numerical evidence for an even stronger statement, namely that in the presence of inhomogeneous noise, the Floquet exponent of each mode is larger than the maximal Floquet exponent of the system in the absence of noise.
hep-ph/0606165
Erhan Iltan
Erhan O. Iltan
Charged Lepton Flavor Physics and Extra Dimensions
23 pages, 13 pages
Mod.Phys.Lett.A22:1513-1531,2007
10.1142/S0217732307021731
null
hep-ph
null
We estimate the charged lepton electric dipole moments and the branching ratios of radiative lepton flavor violating decays in the framework of the two Higgs doublet model with the inclusion two extra dimensions. Here, we consider that the new Higgs doublet is accessible to one of the extra dimensions with a Gaussian profile and the fermions are accessible to the other extra dimension with uniform zero mode profile. We observe that the numerical values of the physical quantities studied enhance with the additional effects due to the extra dimensions and they are sensitive to the new Higgs localization.
[ { "created": "Wed, 14 Jun 2006 20:05:41 GMT", "version": "v1" }, { "created": "Sat, 19 May 2007 13:56:26 GMT", "version": "v2" } ]
2008-11-26
[ [ "Iltan", "Erhan O.", "" ] ]
We estimate the charged lepton electric dipole moments and the branching ratios of radiative lepton flavor violating decays in the framework of the two Higgs doublet model with the inclusion two extra dimensions. Here, we consider that the new Higgs doublet is accessible to one of the extra dimensions with a Gaussian profile and the fermions are accessible to the other extra dimension with uniform zero mode profile. We observe that the numerical values of the physical quantities studied enhance with the additional effects due to the extra dimensions and they are sensitive to the new Higgs localization.
hep-ph/0201210
Yu-Ping Kuang
Yu-Ping Kuang
S-D Mixing and Searching for the psi(1P1) State at the Beijing Electron-Positron Coolider
9-page RevTex file. Version for publication in Phys. Rev. D
Phys.Rev. D65 (2002) 094024
10.1103/PhysRevD.65.094024
TUHEP-TH-01129
hep-ph
null
The psi(1P1) state can be produced at the Beijing Electron-Positron Collider (BEPC) in the process psi'-->psi(1P1)+pi(0). We calculate the rate of this process taking account of the S-D mixing effect in psi'. It is shown that the rate is about a factor of 3 smaller than the simple result without considering the S-D mixing effect. Possible detecting channels are suggested and it is shown that psi(1P1) is able to be found with the accumulation of 30 million events of psi' at BEPC.
[ { "created": "Tue, 22 Jan 2002 22:49:36 GMT", "version": "v1" }, { "created": "Thu, 24 Jan 2002 10:02:27 GMT", "version": "v2" }, { "created": "Sun, 10 Feb 2002 11:00:48 GMT", "version": "v3" }, { "created": "Fri, 12 Apr 2002 13:21:26 GMT", "version": "v4" } ]
2009-11-07
[ [ "Kuang", "Yu-Ping", "" ] ]
The psi(1P1) state can be produced at the Beijing Electron-Positron Collider (BEPC) in the process psi'-->psi(1P1)+pi(0). We calculate the rate of this process taking account of the S-D mixing effect in psi'. It is shown that the rate is about a factor of 3 smaller than the simple result without considering the S-D mixing effect. Possible detecting channels are suggested and it is shown that psi(1P1) is able to be found with the accumulation of 30 million events of psi' at BEPC.
1205.4896
Sergey Gevorkyan
S. R. Gevorkyan, E. A. Kuraev, M. K. Volkov
Vector exchanges in production of light meson pairs and elementary atoms
12 pages, 2 figures
J. Phys. G. Nucl. Part. Phys. 40: 015001,2013
10.1088/0954-3899/40/1/015001
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The production of pseudoscalar and scalar mesons pairs and bound states (positronium or pionium atoms) in high energy $\gamma\gamma$ collisions at high energies provided by photon or vector meson exchanges are considered. The vector exchanges lead to nondecreasing with energy cross section of binary process $\gamma+\gamma\to h_a+h_b$ with $h_a, h_b$ states in the fragmentation regions of initial particles. The production of light mesons pairs $\pi\pi, \eta\eta, \eta'\eta', \sigma\sigma $ as well as a pairs of positronium $Ps$ and pionium $A_\pi$ atoms in peripheral kinematics are discussed. Unlike the photon exchange the vector meson exchange needs a reggeization, leading to fall with energy. Nevertheless due to peripheral kinematics out of very forward production angles the vector meson exchanges dominated. The proposed approach allows to express the matrix elements of the considered processes through impact factors, which can be calculated in perturbation models like Chiral Perturbation Theory (ChPT) or Nambu-Jona-Lasinio (NJL) model or determined from $\gamma\gamma$ sub-processes or vector mesons radiative decay widths. We obtain the cross sections for pionium atom production in collisions of high energy pions and electrons with protons. The possibility to measure these processes in experiment are discussed.
[ { "created": "Tue, 22 May 2012 12:38:18 GMT", "version": "v1" } ]
2015-06-05
[ [ "Gevorkyan", "S. R.", "" ], [ "Kuraev", "E. A.", "" ], [ "Volkov", "M. K.", "" ] ]
The production of pseudoscalar and scalar mesons pairs and bound states (positronium or pionium atoms) in high energy $\gamma\gamma$ collisions at high energies provided by photon or vector meson exchanges are considered. The vector exchanges lead to nondecreasing with energy cross section of binary process $\gamma+\gamma\to h_a+h_b$ with $h_a, h_b$ states in the fragmentation regions of initial particles. The production of light mesons pairs $\pi\pi, \eta\eta, \eta'\eta', \sigma\sigma $ as well as a pairs of positronium $Ps$ and pionium $A_\pi$ atoms in peripheral kinematics are discussed. Unlike the photon exchange the vector meson exchange needs a reggeization, leading to fall with energy. Nevertheless due to peripheral kinematics out of very forward production angles the vector meson exchanges dominated. The proposed approach allows to express the matrix elements of the considered processes through impact factors, which can be calculated in perturbation models like Chiral Perturbation Theory (ChPT) or Nambu-Jona-Lasinio (NJL) model or determined from $\gamma\gamma$ sub-processes or vector mesons radiative decay widths. We obtain the cross sections for pionium atom production in collisions of high energy pions and electrons with protons. The possibility to measure these processes in experiment are discussed.
1009.5413
Konstantin Goulianos
Konstantin Goulianos
Diffractive cross sections and event final states at the LHC
5 pages, 3 figures; to appear in Proceedings of Forward Physics at LHC Workshop (May 27-29, 2010), Elba Island, Italy
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a phenomenological model that describes results on diffractive pp and pbar-p cross sections and event final states up to the Fermilab Tevatron collider energy of 1.96 TeV and use it to make predictions for Large Hadron Collider (LHC) collision energies up to 14 TeV and asymptotically as the pp collision energy goes to infinity. The model is anchored in a saturation effect observed in single diffraction dissociation that explains quantitatively the factorization breaking observed in soft and hard pp and pbar-p diffractive processes and in diffractive photoproduction and low Q-square deep inelastic scattering.
[ { "created": "Mon, 27 Sep 2010 23:52:19 GMT", "version": "v1" }, { "created": "Thu, 30 Dec 2010 01:30:08 GMT", "version": "v2" } ]
2011-01-04
[ [ "Goulianos", "Konstantin", "" ] ]
We discuss a phenomenological model that describes results on diffractive pp and pbar-p cross sections and event final states up to the Fermilab Tevatron collider energy of 1.96 TeV and use it to make predictions for Large Hadron Collider (LHC) collision energies up to 14 TeV and asymptotically as the pp collision energy goes to infinity. The model is anchored in a saturation effect observed in single diffraction dissociation that explains quantitatively the factorization breaking observed in soft and hard pp and pbar-p diffractive processes and in diffractive photoproduction and low Q-square deep inelastic scattering.
1504.07673
Jo\~ao Moreira
J. Moreira, B. Hiller, A. A. Osipov and A. H. Blin
Nonuniform phases in the 't Hooft extended Nambu--Jona-Lasinio Model
5 pages, 4 figures. To appear in the Conference Proceedings for XI Quark Confinement and the Hadron Spectrum, St. Petersburg, Russia, September 8-12 2014
null
10.1063/1.4938697
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The phase diagram of cold dense quark matter is studied using the 't Hooft extended Nambu--Jona-Lasinio Model applied to the light quark sector with a finite current mass for the strange quark (up and down are considered in the chiral limit). By relaxing the traditional uniformity assumptions and considering a modulated light quark condensate background we investigate the possible existence of non-uniform phases in this region of the phase diagram. The effects of changes in the coupling strengths of the model are studied and it is shown that the inclusion of flavour mixing combined with the finite current mass of the strange quark catalyses the appearance of the non-uniform phases, extending the domain for their existence.
[ { "created": "Tue, 28 Apr 2015 22:13:14 GMT", "version": "v1" } ]
2016-02-17
[ [ "Moreira", "J.", "" ], [ "Hiller", "B.", "" ], [ "Osipov", "A. A.", "" ], [ "Blin", "A. H.", "" ] ]
The phase diagram of cold dense quark matter is studied using the 't Hooft extended Nambu--Jona-Lasinio Model applied to the light quark sector with a finite current mass for the strange quark (up and down are considered in the chiral limit). By relaxing the traditional uniformity assumptions and considering a modulated light quark condensate background we investigate the possible existence of non-uniform phases in this region of the phase diagram. The effects of changes in the coupling strengths of the model are studied and it is shown that the inclusion of flavour mixing combined with the finite current mass of the strange quark catalyses the appearance of the non-uniform phases, extending the domain for their existence.
0802.2025
Kacper Zalewski
K. Zalewski
Use of cumulants to quantify uncertainties in the HBT measurements of the homogeneity regions
LateX, 10 pages, no figures
Phys.Rev.D77:074006,2008
10.1103/PhysRevD.77.074006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Let us denote p(x|K) the space density of the points where identical particles of some kind, e.g. pi+ mesons, with momentum K are produced. When using the HBT method to determine p(x|K) one encounters ambiguities. We show that these ambiguities do not affect the even cumulants of the distribution p(x|K). In particular, the HBT radii of the homogeneity regions, which are given by the second order cumulants, and the distribution of distances between the pairs of production points for particles with momentum K can be reliably measured. The odd cumulants are ambiguous. The are, however, correlated. In particular, when the average position <x>(K) is known as a function of K there is no further ambiguity.
[ { "created": "Thu, 14 Feb 2008 14:34:24 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zalewski", "K.", "" ] ]
Let us denote p(x|K) the space density of the points where identical particles of some kind, e.g. pi+ mesons, with momentum K are produced. When using the HBT method to determine p(x|K) one encounters ambiguities. We show that these ambiguities do not affect the even cumulants of the distribution p(x|K). In particular, the HBT radii of the homogeneity regions, which are given by the second order cumulants, and the distribution of distances between the pairs of production points for particles with momentum K can be reliably measured. The odd cumulants are ambiguous. The are, however, correlated. In particular, when the average position <x>(K) is known as a function of K there is no further ambiguity.
hep-ph/0105240
Yukinari Sumino
Y. Sumino
Quarkonium Spectroscopy and Perturbative QCD: A New Perspective
20 pages, 10 figures, Talk given at ``Accelerator and Particle Physics Institute (APPI 2001)'', Morioka, Japan, Feb. 20--22, 2001
null
null
TU-623
hep-ph hep-lat
null
We report new aspects of the recent theoretical progress in heavy quarkonium physics. (1) Contrary to wide beliefs, the gross structure of the bottomonium spectrum is described well by the non-relativistic boundstate theory based on perturbative QCD. (2) This leads to a new physical picture of the bottomonium states: the boundstate mass is composed mainly of the self-energies of b and bbar accumulated inside the boundstate. (3) A connection to the conventional phenomenological potential-model approaches is provided.
[ { "created": "Wed, 23 May 2001 07:05:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sumino", "Y.", "" ] ]
We report new aspects of the recent theoretical progress in heavy quarkonium physics. (1) Contrary to wide beliefs, the gross structure of the bottomonium spectrum is described well by the non-relativistic boundstate theory based on perturbative QCD. (2) This leads to a new physical picture of the bottomonium states: the boundstate mass is composed mainly of the self-energies of b and bbar accumulated inside the boundstate. (3) A connection to the conventional phenomenological potential-model approaches is provided.
0705.2621
Guo-Li Wang
Guo-Li Wang
Decay constants of $P$-wave mesons
11 pages,5 tables,version to be published in Phys. Lett. B
Phys.Lett.B650:15-21,2007
10.1016/j.physletb.2007.05.001
null
hep-ph
null
Decay constants of $P$-wave mesons are computed in the framework of instantaneous Bethe-Salpeter method (Salpeter method). By analyzing the parity and possible charge conjugation parity, we give the relativistic configurations of wave functions with definite parity and possible charge conjugation parity. With these wave functions as input, the full Salpeter equations for different $P$-wave states are solved, and the mass spectra as well as the numerical values of wave functions are obtained. Finally we compute the leptonic decay constants of heavy-heavy and heavy-light $^3P_0$, $^3P_1$ and $^1P_1$ states.
[ { "created": "Fri, 18 May 2007 01:13:39 GMT", "version": "v1" } ]
2008-11-26
[ [ "Wang", "Guo-Li", "" ] ]
Decay constants of $P$-wave mesons are computed in the framework of instantaneous Bethe-Salpeter method (Salpeter method). By analyzing the parity and possible charge conjugation parity, we give the relativistic configurations of wave functions with definite parity and possible charge conjugation parity. With these wave functions as input, the full Salpeter equations for different $P$-wave states are solved, and the mass spectra as well as the numerical values of wave functions are obtained. Finally we compute the leptonic decay constants of heavy-heavy and heavy-light $^3P_0$, $^3P_1$ and $^1P_1$ states.
1605.07188
Nicol\'as Bernal Dr.
Nicol\'as Bernal, Chee Sheng Fong, Nayara Fonseca
Sharing but not Caring: Dark Matter and the Baryon Asymmetry of the Universe
26 pages, 4 figures. v2: version published in JCAP
null
10.1088/1475-7516/2016/09/005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly $share$ the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do $not$ $care$ about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.
[ { "created": "Mon, 23 May 2016 20:00:10 GMT", "version": "v1" }, { "created": "Fri, 2 Sep 2016 14:34:54 GMT", "version": "v2" } ]
2016-09-21
[ [ "Bernal", "Nicolás", "" ], [ "Fong", "Chee Sheng", "" ], [ "Fonseca", "Nayara", "" ] ]
We consider scenarios where Dark Matter (DM) particles carry baryon and/or lepton numbers, which can be defined if there exist operators connecting the dark to the visible sector. As a result, the DM fields become intimately linked to the Standard Model (SM) ones and can be maximally asymmetric just like the ordinary matter. In particular, we discuss minimal scenarios where the DM is a complex scalar or a Dirac fermion coupled to operators with nonzero baryon and/or lepton numbers, and that consist of only SM fields. We consider an initial asymmetry stored in either the SM or the DM sector; the main role of these operators is to properly $share$ the asymmetry between the two sectors, in accordance with observations. After the chemical decoupling, the DM and SM sectors do $not$ $care$ about each other as there is only an ineffective communication between them. Once the DM mass is specified, the Wilson coefficients of these operators are fixed by the requirement of the correct transfer of the asymmetry. We study the phenomenology of this framework at colliders, direct detection and indirect detection experiments. In particular, the LHC phenomenology is very rich and can be tested in different channels such as the two same-sign leptons with two jets, monojet and monojet with a monolepton.
1802.03244
Marta Luszczak Mrs
Marta Luszczak, Wolfgang Sch\"afer and Antoni Szczurek
Production of $W^+ W^-$ pairs via $\gamma^*\gamma^* \to W^+ W^-$ subprocess with photon transverse momenta
20 pages, 17 figures, 2 tables
null
10.1007/JHEP05(2018)064
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss production of $W^+ W^-$ pairs in proton-proton collisions induced by two-photon fusion including, for a first time, transverse momenta of incoming photons. The unintegrated inelastic fluxes (related to proton dissociation) of photons are calculated based on modern parametrizations of deep inelastic structure functions in a broad range of their arguments ($x$ and $Q^2$). In our approach we can get separate contributions of different $W$ helicities states. Several one- and two-dimensional differential distributions are shown and discussed. The present results are compared to the results of previous calculations within collinear factorization approach. Similar results are found except of some observables such as e.g. transverse momentum of the pair of $W^+$ and $W^-$. We find large contributions to the cross section from the region of large photon virtualities. We show decomposition of the total cross section as well as invariant mass distribution into polarisation states of both W bosons. The role of the longitudinal $F_L$ structure function is quantified. Its inclusion leads to a 4-5 % decrease of the cross section, almost independent of $M_{WW}$.
[ { "created": "Fri, 9 Feb 2018 13:11:01 GMT", "version": "v1" }, { "created": "Mon, 19 Feb 2018 09:10:41 GMT", "version": "v2" }, { "created": "Fri, 23 Mar 2018 14:09:36 GMT", "version": "v3" }, { "created": "Tue, 24 Apr 2018 21:50:24 GMT", "version": "v4" } ]
2018-06-13
[ [ "Luszczak", "Marta", "" ], [ "Schäfer", "Wolfgang", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss production of $W^+ W^-$ pairs in proton-proton collisions induced by two-photon fusion including, for a first time, transverse momenta of incoming photons. The unintegrated inelastic fluxes (related to proton dissociation) of photons are calculated based on modern parametrizations of deep inelastic structure functions in a broad range of their arguments ($x$ and $Q^2$). In our approach we can get separate contributions of different $W$ helicities states. Several one- and two-dimensional differential distributions are shown and discussed. The present results are compared to the results of previous calculations within collinear factorization approach. Similar results are found except of some observables such as e.g. transverse momentum of the pair of $W^+$ and $W^-$. We find large contributions to the cross section from the region of large photon virtualities. We show decomposition of the total cross section as well as invariant mass distribution into polarisation states of both W bosons. The role of the longitudinal $F_L$ structure function is quantified. Its inclusion leads to a 4-5 % decrease of the cross section, almost independent of $M_{WW}$.
2112.13218
Qin-Tao Song
S. Kumano, Qin-Tao Song
Equation-of-motion and Lorentz-invariance relations for tensor-polarized parton distribution functions of spin-1 hadrons
5 pages
Physics Letters B 826(2022)136908
10.1016/j.physletb.2022.136908
KEK-TH-2335, J-PARC-TH-0245
hep-ph hep-ex hep-lat nucl-th
http://creativecommons.org/licenses/by/4.0/
Structure functions of polarized spin-1 hadrons will be measured at various accelerator facilities in the near future. Recently, transverse-momentum-dependent and collinear parton distribution functions were theoretically proposed at twist 3 and twist 4 in addition to the twist-2 ones, so that full investigations became possible for structure functions of spin-1 hadrons in the same level with those of the spin-1/2 nucleons. Furthermore, twist-3 tensor-polarized multiparton distribution functions were also recently found for spin-1 hadrons. In this work, we show relations among the collinear parton- and multiparton-distribution functions for spin-1 hadrons by using equation of motion for quarks. These relations are valuable in constraining the distribution functions and learning about multiparton correlations in spin-1 hadrons.
[ { "created": "Sat, 25 Dec 2021 09:39:26 GMT", "version": "v1" }, { "created": "Wed, 26 Jan 2022 18:13:12 GMT", "version": "v2" } ]
2022-01-27
[ [ "Kumano", "S.", "" ], [ "Song", "Qin-Tao", "" ] ]
Structure functions of polarized spin-1 hadrons will be measured at various accelerator facilities in the near future. Recently, transverse-momentum-dependent and collinear parton distribution functions were theoretically proposed at twist 3 and twist 4 in addition to the twist-2 ones, so that full investigations became possible for structure functions of spin-1 hadrons in the same level with those of the spin-1/2 nucleons. Furthermore, twist-3 tensor-polarized multiparton distribution functions were also recently found for spin-1 hadrons. In this work, we show relations among the collinear parton- and multiparton-distribution functions for spin-1 hadrons by using equation of motion for quarks. These relations are valuable in constraining the distribution functions and learning about multiparton correlations in spin-1 hadrons.
hep-ph/0608270
Berndt Muller
Masayuki Asakawa, Steffen A. Bass, and Berndt M\"uller
Anomalous Transport Processes in Anisotropically Expanding Quark-Gluon Plasmas
31 pages, 1 figure, some typos in published version are corrected
Prog.Theor.Phys.116:725-755,2007
10.1143/PTP.116.725
null
hep-ph nucl-th
null
We derive an expression for the anomalous viscosity in an anisotropically expanding quark-gluon-plasma, which arises from interactions of thermal partons with dynamically generated color fields. The anomalous viscosity dominates over the collisional viscosity for large velocity gradients or weak coupling. This effect may provide an explanation for the apparent ``nearly perfect'' liquidity of the matter produced in nuclear collisions at RHIC without the assumption that it is a strongly coupled state.
[ { "created": "Thu, 24 Aug 2006 02:18:51 GMT", "version": "v1" }, { "created": "Thu, 23 Nov 2006 09:06:02 GMT", "version": "v2" } ]
2008-11-26
[ [ "Asakawa", "Masayuki", "" ], [ "Bass", "Steffen A.", "" ], [ "Müller", "Berndt", "" ] ]
We derive an expression for the anomalous viscosity in an anisotropically expanding quark-gluon-plasma, which arises from interactions of thermal partons with dynamically generated color fields. The anomalous viscosity dominates over the collisional viscosity for large velocity gradients or weak coupling. This effect may provide an explanation for the apparent ``nearly perfect'' liquidity of the matter produced in nuclear collisions at RHIC without the assumption that it is a strongly coupled state.
0709.4427
Shang-Yung Wang
S.-Y. Wang
Dynamical Electron Mass in a Strong Magnetic Field
5 pages, 1 figure, published version
Phys.Rev.D77:025031,2008
10.1103/PhysRevD.77.025031
null
hep-ph astro-ph
null
Motivated by recent interest in understanding properties of strongly magnetized matter, we study the dynamical electron mass generated through approximate chiral symmetry breaking in QED in a strong magnetic field. We reliably calculate the dynamical electron mass by numerically solving the nonperturbative Schwinger-Dyson equations in a consistent truncation within the lowest Landau level approximation. It is shown that the generation of dynamical electron mass in a strong magnetic field is significantly enhanced by the perturbative electron mass that explicitly breaks chiral symmetry in the absence of a magnetic field.
[ { "created": "Thu, 27 Sep 2007 15:23:19 GMT", "version": "v1" }, { "created": "Thu, 20 Dec 2007 05:41:11 GMT", "version": "v2" }, { "created": "Mon, 28 Jan 2008 15:09:27 GMT", "version": "v3" } ]
2008-11-26
[ [ "Wang", "S. -Y.", "" ] ]
Motivated by recent interest in understanding properties of strongly magnetized matter, we study the dynamical electron mass generated through approximate chiral symmetry breaking in QED in a strong magnetic field. We reliably calculate the dynamical electron mass by numerically solving the nonperturbative Schwinger-Dyson equations in a consistent truncation within the lowest Landau level approximation. It is shown that the generation of dynamical electron mass in a strong magnetic field is significantly enhanced by the perturbative electron mass that explicitly breaks chiral symmetry in the absence of a magnetic field.
1010.5392
Hannu Paukkunen
Hannu Paukkunen and Carlos A. Salgado
Constraints for the nuclear parton distributions from Z and W production at the LHC
The version accepted for publication in JHEP. New figures has been added, and we also discuss the single charged lepton production
JHEP 1103:071,2011
10.1007/JHEP03(2011)071
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHC is foreseen to finally bring also the nuclear collisions to the TeV scale thereby providing new possibilities for physics studies, in particular related to the electro-weak sector of the Standard Model. We study here the Z and W production in proton-lead and lead-lead collisions at the LHC, concentrating on the prospects of testing the factorization and constraining the nuclear modifications of the parton distribution functions (PDFs). Especially, we find that the rapidity asymmetries in proton-nucleus collisions, arising from the differences in the PDFs between the colliding objects, provide a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus case. We comment on how such studies will help to improve our knowledge of the nuclear PDFs.
[ { "created": "Tue, 26 Oct 2010 13:34:57 GMT", "version": "v1" }, { "created": "Fri, 11 Mar 2011 10:47:19 GMT", "version": "v2" } ]
2015-03-17
[ [ "Paukkunen", "Hannu", "" ], [ "Salgado", "Carlos A.", "" ] ]
The LHC is foreseen to finally bring also the nuclear collisions to the TeV scale thereby providing new possibilities for physics studies, in particular related to the electro-weak sector of the Standard Model. We study here the Z and W production in proton-lead and lead-lead collisions at the LHC, concentrating on the prospects of testing the factorization and constraining the nuclear modifications of the parton distribution functions (PDFs). Especially, we find that the rapidity asymmetries in proton-nucleus collisions, arising from the differences in the PDFs between the colliding objects, provide a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus case. We comment on how such studies will help to improve our knowledge of the nuclear PDFs.
hep-ph/0001012
Mohamed Tarek Hussein
M. T. Hussein, R. Elmualed and N. M. Hassan
Electron - Proton Scattering as a Probe of Nucleon Structure
6 pages (revtex), 8 figures/gif
26th ICRC(1999) Utah Univ. USA, HE.1.3.29
null
null
hep-ph
null
The problem of electron-proton scattering is handed over both the elastic and inelastic scattering. Two models are presented in this sense. The first, depends on the multi photon exchange ladder diagram, where the transition matrix is expanded in multi steps form. The second model uses the multi peripheral mechanism developed for the electromagnetic field. It allows the particle production in the inelastic scattering processes. An iterative procedure is found and inserted in a Monte Carlo program to reproduce the differential cross section of the reaction. The comparison with the experimental data shows bid fair in most cases.
[ { "created": "Mon, 3 Jan 2000 11:20:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hussein", "M. T.", "" ], [ "Elmualed", "R.", "" ], [ "Hassan", "N. M.", "" ] ]
The problem of electron-proton scattering is handed over both the elastic and inelastic scattering. Two models are presented in this sense. The first, depends on the multi photon exchange ladder diagram, where the transition matrix is expanded in multi steps form. The second model uses the multi peripheral mechanism developed for the electromagnetic field. It allows the particle production in the inelastic scattering processes. An iterative procedure is found and inserted in a Monte Carlo program to reproduce the differential cross section of the reaction. The comparison with the experimental data shows bid fair in most cases.
2110.14015
Ignacio Borsa Sanjuan
Ignacio Borsa, Daniel de Florian, Rodolfo Sassot, Marco Stratmann
Pion Fragmentation Functions at High Energy Colliders
5 pages, 6 figures
null
10.1103/PhysRevD.105.L031502
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We revisit the description of pion production in proton-proton collisions in the light of the very precise data taken at the Large Hadron Collider (LHC) over the past decade. First attempts to include LHC results in next-to-leading order global QCD analyses of parton-to-pion fragmentation functions insinuated some conflict between data sets at different center-of-mass system energies. We show that the data can be well described within their uncertainties by a consistent set of pion fragmentation functions once the theoretical scale dependence is taken into account in the global QCD analysis.
[ { "created": "Tue, 26 Oct 2021 20:43:47 GMT", "version": "v1" } ]
2022-02-23
[ [ "Borsa", "Ignacio", "" ], [ "de Florian", "Daniel", "" ], [ "Sassot", "Rodolfo", "" ], [ "Stratmann", "Marco", "" ] ]
We revisit the description of pion production in proton-proton collisions in the light of the very precise data taken at the Large Hadron Collider (LHC) over the past decade. First attempts to include LHC results in next-to-leading order global QCD analyses of parton-to-pion fragmentation functions insinuated some conflict between data sets at different center-of-mass system energies. We show that the data can be well described within their uncertainties by a consistent set of pion fragmentation functions once the theoretical scale dependence is taken into account in the global QCD analysis.
hep-ph/0110261
Harold W. Fearing
T. Ebertsh\"auser, H. W. Fearing, S. Scherer
The anomalous chiral perturbation theory meson Lagrangian to order $p^6$ revisited
21 pages, Latex, using RevTeX
Phys.Rev. D65 (2002) 054033
10.1103/PhysRevD.65.054033
MKPH-T-01-22, TRI-PP-01-34
hep-ph
null
We present a revised and extended construction of the mesonic Lagrangian density in chiral perturbation theory (ChPT) at order $p^6$ in the anomalous (or epsilon) sector, ${\cal{L}}_{6,\epsilon}$. After improving several aspects of the strategy we used originally, i.e., a more efficient application of partial integration, the implementation of so-called Bianchi identities, and additional trace relations, we find the new monomial sets to include 24 $SU(N_f)$, 23 SU(3), and 5 SU(2) elements. Furthermore, we introduce 8 supplementary terms due to the extension of the chiral group to $SU(N_f)_L \times SU(N_f)_R \times U(1)_V$.
[ { "created": "Thu, 18 Oct 2001 18:47:12 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ebertshäuser", "T.", "" ], [ "Fearing", "H. W.", "" ], [ "Scherer", "S.", "" ] ]
We present a revised and extended construction of the mesonic Lagrangian density in chiral perturbation theory (ChPT) at order $p^6$ in the anomalous (or epsilon) sector, ${\cal{L}}_{6,\epsilon}$. After improving several aspects of the strategy we used originally, i.e., a more efficient application of partial integration, the implementation of so-called Bianchi identities, and additional trace relations, we find the new monomial sets to include 24 $SU(N_f)$, 23 SU(3), and 5 SU(2) elements. Furthermore, we introduce 8 supplementary terms due to the extension of the chiral group to $SU(N_f)_L \times SU(N_f)_R \times U(1)_V$.
2201.02576
Johann Usovitsch
Ievgen Dubovyk, Ayres Freitas, Janusz Gluza, Krzysztof Grzanka, Martijn Hidding, Johann Usovitsch
Evaluation of multi-loop multi-scale Feynman integrals for precision physics
null
null
10.1103/PhysRevD.106.L111301
CERN-TH-2021-230, UUITP-66/21
hep-ph
http://creativecommons.org/licenses/by/4.0/
Modern particle physics is increasingly becoming a precision science that relies on advanced theoretical predictions for the analysis and interpretation of experimental results. The planned physics program at the LHC and future colliders will require three-loop electroweak and mixed electroweak-QCD corrections to single-particle production and decay processes and two-loop electroweak corrections to pair production processes, all of which are beyond the reach of existing analytical and numerical techniques in their current form. This article presents a new semi-numerical approach based on differential equations with boundary terms specified at Euclidean kinematic points. These Euclidean boundary terms can be computed numerically with high accuracy using sector decomposition or other numerical methods. They are then mapped to the physical kinematic configuration with a series solution of the differential equation system. The method is able to deliver 8 or more digits precision, and it has a built-in mechanism for checking the accuracy of the obtained results. Its efficacy is illustrated with examples for three-loop self-energy and vertex integrals and two-loop box integrals.
[ { "created": "Fri, 7 Jan 2022 18:16:22 GMT", "version": "v1" }, { "created": "Wed, 26 Jan 2022 18:30:59 GMT", "version": "v2" } ]
2023-01-04
[ [ "Dubovyk", "Ievgen", "" ], [ "Freitas", "Ayres", "" ], [ "Gluza", "Janusz", "" ], [ "Grzanka", "Krzysztof", "" ], [ "Hidding", "Martijn", "" ], [ "Usovitsch", "Johann", "" ] ]
Modern particle physics is increasingly becoming a precision science that relies on advanced theoretical predictions for the analysis and interpretation of experimental results. The planned physics program at the LHC and future colliders will require three-loop electroweak and mixed electroweak-QCD corrections to single-particle production and decay processes and two-loop electroweak corrections to pair production processes, all of which are beyond the reach of existing analytical and numerical techniques in their current form. This article presents a new semi-numerical approach based on differential equations with boundary terms specified at Euclidean kinematic points. These Euclidean boundary terms can be computed numerically with high accuracy using sector decomposition or other numerical methods. They are then mapped to the physical kinematic configuration with a series solution of the differential equation system. The method is able to deliver 8 or more digits precision, and it has a built-in mechanism for checking the accuracy of the obtained results. Its efficacy is illustrated with examples for three-loop self-energy and vertex integrals and two-loop box integrals.
hep-ph/9806506
Georg Raffelt
G.Raffelt (MPP, Munich)
Axion Hunting at the Turn of the Millenium
6 pages, 4 eps figs, to be published in Proc. Neutrino 98, 4-9 June 1998, Takayama, Japan, ed. by Y.Suzuki and Y.Totsuka
Nucl.Phys.Proc.Suppl. 77 (1999) 456-461
10.1016/S0920-5632(99)00467-3
null
hep-ph
null
The status of several current and proposed experiments to search for galactic dark-matter and solar axions is reviewed in the light of astrophysical and cosmological limits on the Peccei-Quinn scale.
[ { "created": "Sat, 27 Jun 1998 12:12:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Raffelt", "G.", "", "MPP, Munich" ] ]
The status of several current and proposed experiments to search for galactic dark-matter and solar axions is reviewed in the light of astrophysical and cosmological limits on the Peccei-Quinn scale.
0906.0368
Alexandre Arbey
A. Arbey and F. Mahmoudi
SUSY Constraints, Relic Density, and Very Early Universe
11 pages, 5 figures. v2: new figures added
JHEP 1005:051,2010
10.1007/JHEP05(2010)051
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The sensitivity of the lightest supersymmetric particle relic density calculation to different cosmological scenarios is discussed. In particular, we investigate the effects of modifications of the expansion rate and of the entropy content in the Early Universe. These effects, even with no observational consequences, can still drastically modify the relic density constraints on the SUSY parameter space. We suggest general parametrizations to evaluate such effects, and derive also constraints from Big-Bang nucleosynthesis. We show that using the relic density in the context of supersymmetric constraints requires a clear statement of the underlying cosmological model assumptions to avoid misinterpretations. On the other hand, we note that combining the relic density calculation with the eventual future discoveries at the LHC will hopefully shed light on the Very Early Universe properties.
[ { "created": "Tue, 2 Jun 2009 15:15:27 GMT", "version": "v1" }, { "created": "Tue, 6 Jul 2010 13:46:14 GMT", "version": "v2" } ]
2010-07-07
[ [ "Arbey", "A.", "" ], [ "Mahmoudi", "F.", "" ] ]
The sensitivity of the lightest supersymmetric particle relic density calculation to different cosmological scenarios is discussed. In particular, we investigate the effects of modifications of the expansion rate and of the entropy content in the Early Universe. These effects, even with no observational consequences, can still drastically modify the relic density constraints on the SUSY parameter space. We suggest general parametrizations to evaluate such effects, and derive also constraints from Big-Bang nucleosynthesis. We show that using the relic density in the context of supersymmetric constraints requires a clear statement of the underlying cosmological model assumptions to avoid misinterpretations. On the other hand, we note that combining the relic density calculation with the eventual future discoveries at the LHC will hopefully shed light on the Very Early Universe properties.
1404.5195
Oscar Castillo Felisola Dr.
Oscar Castillo-Felisola and Cristobal Corral and Ivan Schmidt and Alfonso R. Zerwekh
Updated limits on extra dimensions through torsion and LHC data
10 pages. Accepted for publication on Mod. Phys. Lett. A. arXiv admin note: substantial text overlap with arXiv:1211.4359
Mod. Phys. Lett. A 29, 1450081 (2014)
10.1142/S0217732314500813
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that inclusion of torsion in the gravitational formalism, leads to four-fermion interactions. Although the coupling constant of this interaction is strongly suppressed in four dimensions, its value is enhanced in models with $n$ extra dimensions. In this context, we reinterpret the recent limits established by LHC experiments to four-fermion contact interactions, to set bounds on the size of the extra dimensions. For $n=2$, the limits are comparable to those in the literature, while for $n\ge 3$ the volume of the extra dimensions is strongly constrained.
[ { "created": "Mon, 21 Apr 2014 13:51:21 GMT", "version": "v1" } ]
2014-05-27
[ [ "Castillo-Felisola", "Oscar", "" ], [ "Corral", "Cristobal", "" ], [ "Schmidt", "Ivan", "" ], [ "Zerwekh", "Alfonso R.", "" ] ]
It is well known that inclusion of torsion in the gravitational formalism, leads to four-fermion interactions. Although the coupling constant of this interaction is strongly suppressed in four dimensions, its value is enhanced in models with $n$ extra dimensions. In this context, we reinterpret the recent limits established by LHC experiments to four-fermion contact interactions, to set bounds on the size of the extra dimensions. For $n=2$, the limits are comparable to those in the literature, while for $n\ge 3$ the volume of the extra dimensions is strongly constrained.
2302.01372
Eric S. Swanson
E.S. Swanson
Light Hybrid Meson Mixing and Phenomenology
16 pages, 7 figures
null
10.1103/PhysRevD.107.074028
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
A simple constituent model of gluodynamics that is motivated by lattice field theory and the QCD Hamiltonian in Coulomb gauge is applied to descriptions of hybrid meson flavor mixing and vector hybrid configuration mixing. Good agreement with lattice gauge computations is obtained for flavor multiplet masses, while mixing angles are in approximate agreement, given large errors. The configuration mixing results are also in rough agreement with lattice NRQCD calculations. Thus the viability of constituent gluon models of hybrid hadrons and glueballs is supported. The results suggest that a flavor multiplet of vector hybrids should appear with masses of approximately 2100, 2200, and 2300 MeV and that the isovector vector hybrid decay constant is about 20 MeV. Similarly, the $\pi_1$ exotic hybrid should have isospin partner states near 1760 and 1900 MeV, and it is suggested that the recently seen $\eta_1$ hybrid signal is the latter state.
[ { "created": "Thu, 2 Feb 2023 19:16:25 GMT", "version": "v1" } ]
2023-05-03
[ [ "Swanson", "E. S.", "" ] ]
A simple constituent model of gluodynamics that is motivated by lattice field theory and the QCD Hamiltonian in Coulomb gauge is applied to descriptions of hybrid meson flavor mixing and vector hybrid configuration mixing. Good agreement with lattice gauge computations is obtained for flavor multiplet masses, while mixing angles are in approximate agreement, given large errors. The configuration mixing results are also in rough agreement with lattice NRQCD calculations. Thus the viability of constituent gluon models of hybrid hadrons and glueballs is supported. The results suggest that a flavor multiplet of vector hybrids should appear with masses of approximately 2100, 2200, and 2300 MeV and that the isovector vector hybrid decay constant is about 20 MeV. Similarly, the $\pi_1$ exotic hybrid should have isospin partner states near 1760 and 1900 MeV, and it is suggested that the recently seen $\eta_1$ hybrid signal is the latter state.
2308.08612
Felix Yu
Felix Yu
Primer on Axion Physics
15 pages, 1 figure; invited contribution to Annalen der Physik
Ann. Phys.(Berlin) 2023, 2300106
10.1002/andp.202300106
MITP-23-038
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review the canonical axion potential, with an emphasis on the field theory underlying radial and angular modes of complex scalar fields. I present the explicit calculation of the instanton-induced breaking of the Goldstone field direction necessary to derive the canonical axion mass and decay constant relation. The primer is intended to serve an audience with elementary quantum field theory expertise.
[ { "created": "Wed, 16 Aug 2023 18:06:50 GMT", "version": "v1" } ]
2023-10-10
[ [ "Yu", "Felix", "" ] ]
I review the canonical axion potential, with an emphasis on the field theory underlying radial and angular modes of complex scalar fields. I present the explicit calculation of the instanton-induced breaking of the Goldstone field direction necessary to derive the canonical axion mass and decay constant relation. The primer is intended to serve an audience with elementary quantum field theory expertise.
hep-ph/0510297
Alexander E. Dorokhov
A.E. Dorokhov
Hadronic corrections to muon anomalous magnetic moment within the instanton liquid model
32 pages, 17 figures. Presented at The Cracow School of Theoretical Physics, XLV Course,Zakopane june 2005. To appear in Acta Physica Polonica
Acta Phys.Polon. B36 (2005) 3751-3782
null
null
hep-ph
null
The current status of the muon anomalous magnetic moment problem is briefly presented. The corrections to muon anomaly coming from the effects of hadronic vacuum polarization, Z*\gamma\gamma* effective vertex and light-by-light scattering are estimated within the instanton model of QCD vacuum.
[ { "created": "Sat, 22 Oct 2005 09:40:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dorokhov", "A. E.", "" ] ]
The current status of the muon anomalous magnetic moment problem is briefly presented. The corrections to muon anomaly coming from the effects of hadronic vacuum polarization, Z*\gamma\gamma* effective vertex and light-by-light scattering are estimated within the instanton model of QCD vacuum.
1505.00513
Natsumi Nagata
Jason L. Evans and Natsumi Nagata
Signatures of Leptoquarks at the LHC and Right-handed Neutrinos
25 pages, 2 figures
Phys. Rev. D 92, 015022 (2015)
10.1103/PhysRevD.92.015022
FTPI-MINN-15/20, UMN-TH-3433/15, IPMU15-0063
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we argue that an extension of the Standard Model with a single leptoquark and three right-handed neutrinos can explain the excess in the first-generation leptoquark search at the LHC. We also find that when the leptoquark has similarly sized couplings to all three generations, it produces additional signals which will soon be tested in the second- and third-generation leptoquark searches, as well as in decay channels consisting of two mixed flavor leptons and two jets. If the leptoquark only couples to the first generation, on the other hand, two of the right-handed neutrinos need to be fairly degenerate in mass with the leptoquark while the other right-handed neutrinos mass should be much lighter. This hierarchical structure could explain dark matter and the baryon asymmetry of the Universe. These simple models may be regarded as benchmark models for explaining the excess, which can be tested in the next stage of the LHC running.
[ { "created": "Mon, 4 May 2015 02:24:27 GMT", "version": "v1" }, { "created": "Wed, 22 Jul 2015 19:18:01 GMT", "version": "v2" } ]
2015-07-23
[ [ "Evans", "Jason L.", "" ], [ "Nagata", "Natsumi", "" ] ]
In this paper, we argue that an extension of the Standard Model with a single leptoquark and three right-handed neutrinos can explain the excess in the first-generation leptoquark search at the LHC. We also find that when the leptoquark has similarly sized couplings to all three generations, it produces additional signals which will soon be tested in the second- and third-generation leptoquark searches, as well as in decay channels consisting of two mixed flavor leptons and two jets. If the leptoquark only couples to the first generation, on the other hand, two of the right-handed neutrinos need to be fairly degenerate in mass with the leptoquark while the other right-handed neutrinos mass should be much lighter. This hierarchical structure could explain dark matter and the baryon asymmetry of the Universe. These simple models may be regarded as benchmark models for explaining the excess, which can be tested in the next stage of the LHC running.
1402.4817
Andrew Spray
David E. Morrissey and Andrew Paul Spray
New Limits on Light Hidden Sectors from Fixed-Target Experiments
44 pages + appendices/references, 28 figures. Figures in secs 5 and 7 updated to correct error in hadronic exclusions; limits slightly weaker, but qualitative conclusions unchanged
JHEP 1406 (2014) 083
10.1007/JHEP06(2014)083
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New physics can be light if it is hidden, coupling very weakly to the Standard Model. In this work we investigate the discovery prospects of Abelian hidden sectors in lower-energy fixed-target and high-precision experiments. We focus on a minimal supersymmetric realization consisting of an Abelian vector multiplet, coupled to hypercharge by kinetic mixing, and a pair of chiral Higgs multiplets. This simple theory can give rise to a broad range of experimental signals, including both commonly-studied patterns of hidden vector decay as well as new and distinctive hidden sector cascades. We find limits from the production of hidden states other than the vector itself. In particular, we show that if the hidden Abelian symmetry is higgsed, and the corresponding hidden Higgs boson has visible decays, it severely restricts the ability of the hidden sector to explain the anomalous muon magnetic moment.
[ { "created": "Wed, 19 Feb 2014 21:00:24 GMT", "version": "v1" }, { "created": "Thu, 27 Feb 2014 09:13:08 GMT", "version": "v2" }, { "created": "Thu, 26 Mar 2015 00:44:25 GMT", "version": "v3" }, { "created": "Sun, 29 Mar 2015 01:27:33 GMT", "version": "v4" } ]
2015-03-31
[ [ "Morrissey", "David E.", "" ], [ "Spray", "Andrew Paul", "" ] ]
New physics can be light if it is hidden, coupling very weakly to the Standard Model. In this work we investigate the discovery prospects of Abelian hidden sectors in lower-energy fixed-target and high-precision experiments. We focus on a minimal supersymmetric realization consisting of an Abelian vector multiplet, coupled to hypercharge by kinetic mixing, and a pair of chiral Higgs multiplets. This simple theory can give rise to a broad range of experimental signals, including both commonly-studied patterns of hidden vector decay as well as new and distinctive hidden sector cascades. We find limits from the production of hidden states other than the vector itself. In particular, we show that if the hidden Abelian symmetry is higgsed, and the corresponding hidden Higgs boson has visible decays, it severely restricts the ability of the hidden sector to explain the anomalous muon magnetic moment.
hep-ph/0206027
Volodymyr Magas
R. Fiore, A. Flachi, L.L. Jenkovszky, A.I. Lengyel, V.K. Magas
Explicit model realizing parton-hadron duality
29 pages, 7 figures
Eur.Phys.J. A15 (2002) 505-515
null
null
hep-ph
null
An explicit model realizing parton-hadron duality and fitting the data is suggested. Complex nonlinear Regge trajectories are important ingredients of the model. The inclusion of $\Delta$ and $N^*$ trajectories should account for all resonances in the direct channel. The exotic trajectory is responsible for the smooth background.
[ { "created": "Tue, 4 Jun 2002 12:24:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fiore", "R.", "" ], [ "Flachi", "A.", "" ], [ "Jenkovszky", "L. L.", "" ], [ "Lengyel", "A. I.", "" ], [ "Magas", "V. K.", "" ] ]
An explicit model realizing parton-hadron duality and fitting the data is suggested. Complex nonlinear Regge trajectories are important ingredients of the model. The inclusion of $\Delta$ and $N^*$ trajectories should account for all resonances in the direct channel. The exotic trajectory is responsible for the smooth background.
0910.2852
Dario Schalla
E. A. Paschos, Dario Schalla
Coherent Pion Production by Neutrinos
5 pages, 7 figures, Proceedings of the Sixth International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt09), May 18-22, Sitges, Barcelona, Spain
null
10.1063/1.3274158
DO-TH-09/16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk I review the main features of the coherent/diffractive pion production by neutrinos on nuclei. The method is based on PCAC and relates the reaction $\textbf{boson} + \textbf{nucleus} \to \textbf{pion} + \textbf{nucleus}$ to elastic pion-nucleus scattering. Estimates for the expected rates and distributions in neutrino reactions are presented with the help of hadronic data. The absolute rates are significantly smaller than the older estimates which brings theory in agreement with the neutral current measurements and the bounds in charged current reactions.
[ { "created": "Thu, 15 Oct 2009 12:31:43 GMT", "version": "v1" } ]
2015-05-14
[ [ "Paschos", "E. A.", "" ], [ "Schalla", "Dario", "" ] ]
In this talk I review the main features of the coherent/diffractive pion production by neutrinos on nuclei. The method is based on PCAC and relates the reaction $\textbf{boson} + \textbf{nucleus} \to \textbf{pion} + \textbf{nucleus}$ to elastic pion-nucleus scattering. Estimates for the expected rates and distributions in neutrino reactions are presented with the help of hadronic data. The absolute rates are significantly smaller than the older estimates which brings theory in agreement with the neutral current measurements and the bounds in charged current reactions.
1402.3991
Tim Ledwig
L. Alvarez-Ruso, T. Ledwig, J. Martin-Camalich, M.J. Vicente Vacas
The nucleon mass and pion-nucleon sigma term from a chiral analysis of Nf = 2+1 lattice QCD world data
Contribution to the NSTAR 2013 conference, 4 pages, 4 figures
null
10.1051/epjconf/20146606001
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fits of the p^4 covariant SU(2) baryon chiral perturbation theory to lattice QCD nucleon mass data from several collaborations for 2 and 2+1 flavors are presented. We consider contributions from explicit Delta(1232) degrees of freedom, finite volume and finite spacing corrections. We emphasize here our Nf=2+1 study. We obtain low-energy constants of natural size that are compatible with the rather linear pion-mass dependence of the nucleon mass observed in lattice QCD. We report a value for the pion-nucleon sigma term of 41(5)(4) MeV for the 2 flavor case and 52(3)(8) MeV for 2+1 flavors.
[ { "created": "Mon, 17 Feb 2014 13:14:18 GMT", "version": "v1" } ]
2015-06-18
[ [ "Alvarez-Ruso", "L.", "" ], [ "Ledwig", "T.", "" ], [ "Martin-Camalich", "J.", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
Fits of the p^4 covariant SU(2) baryon chiral perturbation theory to lattice QCD nucleon mass data from several collaborations for 2 and 2+1 flavors are presented. We consider contributions from explicit Delta(1232) degrees of freedom, finite volume and finite spacing corrections. We emphasize here our Nf=2+1 study. We obtain low-energy constants of natural size that are compatible with the rather linear pion-mass dependence of the nucleon mass observed in lattice QCD. We report a value for the pion-nucleon sigma term of 41(5)(4) MeV for the 2 flavor case and 52(3)(8) MeV for 2+1 flavors.
0903.3358
Andrey Lobanov
E. V. Arbuzova, A. E. Lobanov, E. M. Murchikova
Pure quantum states of a neutrino with rotating spin in dense magnetized matter
21 pages, Latex. Final version
Phys.Rev.D81:045001,2010
10.1103/PhysRevD.81.045001
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of neutrino spin rotation in dense matter and in strong electromagnetic fields is solved in accordance with the basic principles of quantum mechanics. We obtain a complete system of wave functions for a massive Dirac neutrino with an anomalous magnetic moment which are the eigenfunctions of the kinetic momentum operator and have the form of nonspreading wave packets. These wave functions enable one to consider the states of neutrino with rotating spin as pure quantum states and can be used for calculating probabilities of various processes with the neutrino in the framework of the Furry picture.
[ { "created": "Thu, 19 Mar 2009 16:26:23 GMT", "version": "v1" }, { "created": "Mon, 20 Apr 2009 21:14:22 GMT", "version": "v2" }, { "created": "Mon, 1 Feb 2010 23:37:18 GMT", "version": "v3" } ]
2010-04-06
[ [ "Arbuzova", "E. V.", "" ], [ "Lobanov", "A. E.", "" ], [ "Murchikova", "E. M.", "" ] ]
The problem of neutrino spin rotation in dense matter and in strong electromagnetic fields is solved in accordance with the basic principles of quantum mechanics. We obtain a complete system of wave functions for a massive Dirac neutrino with an anomalous magnetic moment which are the eigenfunctions of the kinetic momentum operator and have the form of nonspreading wave packets. These wave functions enable one to consider the states of neutrino with rotating spin as pure quantum states and can be used for calculating probabilities of various processes with the neutrino in the framework of the Furry picture.
2105.00217
Jens Erler
Jens Erler
Global Vision of Precision Measurements
6 pages, 10 figures, contributions to Les Rencontres de Physique de la Vall\'ee d'Aoste (La Thuile 2021), March 9--11, 2021; and to the 2021 EW session of the 55th Rencontres de Moriond, March 21--27, 2021
null
null
MITP/21-022
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I summarize recent developments in electroweak precision physics and global fits. Expectations for future measurements, both at lower energies and the energy frontier, are also discussed.
[ { "created": "Sat, 1 May 2021 11:21:29 GMT", "version": "v1" } ]
2021-05-05
[ [ "Erler", "Jens", "" ] ]
I summarize recent developments in electroweak precision physics and global fits. Expectations for future measurements, both at lower energies and the energy frontier, are also discussed.
1311.6726
Yuri Goncharov
Yu. P. Goncharov and F. F. Pavlov
Estimates for Parameters and Characteristics of the Confining SU(3)-gluonic Field in $\phi$-meson from Leptonic Widths
11 pages in LaTeX. arXiv admin note: substantial text overlap with arXiv:1010.1562, arXiv:1201.4327, arXiv:hep-ph/0609135
Few-Body Syst. (2014), Vol. 55, No. 1, pp. 35-45
10.1007/s00601-013-0730-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper is devoted to applying the confinement mechanism proposed earlier by one of the authors to estimate the possible parameters of the confining SU(3)-gluonic field in vector $\phi$-meson. The estimates obtained are consistent with the leptonic widths of the given meson. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the meson under consideration.
[ { "created": "Tue, 26 Nov 2013 16:24:23 GMT", "version": "v1" } ]
2014-01-09
[ [ "Goncharov", "Yu. P.", "" ], [ "Pavlov", "F. F.", "" ] ]
The paper is devoted to applying the confinement mechanism proposed earlier by one of the authors to estimate the possible parameters of the confining SU(3)-gluonic field in vector $\phi$-meson. The estimates obtained are consistent with the leptonic widths of the given meson. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the meson under consideration.
1401.3099
Shotaro Imai
Shotaro Imai and Hideo Suganuma
A non-perturbative effect of gluons for scalar diquark in the Schwinger-Dyson formalism
5 pages, 5 figures, Contribution of proceedings of XV International Conference on Hadron Spectroscopy-Hadron 2013 (Hadron 2013)
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The diquark has been considered to be important effective degrees of freedom in hadron physics, especially for multi-quark physics and the structure of heavy hadronic states. Using the Schwinger-Dyson formalism, we investigate the non-perturbative effect of gluons for scalar diquarks with renormalization-group improved coupling in the Landau gauge. Here, we treat the scalar diquark as an effective degree of freedom with a peculiar size, while the diquark is originally a bound-state-like object of two quarks. Since the diquark has a non-zero color charge, it strongly interacts with gluons. We evaluate the gluonic non-perturbative effect to the diquark, considering the size effect of the diquark. We investigate the mass function of the diquark in both cases with a constant bare diquark mass and twice of the running quark self-energy. It is found that the diquark, especially the small diquark, obtains a large effective mass by the gluonic dressing effect. The scalar diquark mass seems to be dynamically generated by the non-perturbative effect, although it does not have the chiral symmetry.
[ { "created": "Tue, 14 Jan 2014 08:27:22 GMT", "version": "v1" }, { "created": "Thu, 6 Feb 2014 01:16:34 GMT", "version": "v2" } ]
2014-02-07
[ [ "Imai", "Shotaro", "" ], [ "Suganuma", "Hideo", "" ] ]
The diquark has been considered to be important effective degrees of freedom in hadron physics, especially for multi-quark physics and the structure of heavy hadronic states. Using the Schwinger-Dyson formalism, we investigate the non-perturbative effect of gluons for scalar diquarks with renormalization-group improved coupling in the Landau gauge. Here, we treat the scalar diquark as an effective degree of freedom with a peculiar size, while the diquark is originally a bound-state-like object of two quarks. Since the diquark has a non-zero color charge, it strongly interacts with gluons. We evaluate the gluonic non-perturbative effect to the diquark, considering the size effect of the diquark. We investigate the mass function of the diquark in both cases with a constant bare diquark mass and twice of the running quark self-energy. It is found that the diquark, especially the small diquark, obtains a large effective mass by the gluonic dressing effect. The scalar diquark mass seems to be dynamically generated by the non-perturbative effect, although it does not have the chiral symmetry.
1910.12691
Alejandro Segarra
Jose Bernabeu, Alejandro Segarra
Genuine and Matter-induced Components of the CPV Asymmetry for Neutrino Oscillations
7 pages, 5 figures, 1 table. Proceedings of EPS-HEP 2019
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These results represent the solution for the historical problem of the contamination by matter effects on the CPV Asymmetry for neutrino oscillations. Vacuum is CPT-symmetric and matter is T-symmetric, the goal is accomplished by using this guiding principle. Independent of the theoretical framework for the dynamics of the active neutrino flavors, we prove the Disentanglement Theorem A(CP)=A(CP, T)+A(CP, CPT) for the experimental CPV Asymmetry, with A(CP, T) genuine T-odd and A(CP, CPT) fake CPT-odd. For the effective Hamiltonian written as the sum of free mass propagation plus the matter potential for electron-neutrinos, the two components have definite parities under the baseline L, the matter potential "a", the imaginary part $\sin\delta$ of the PMNS mixing matrix and the hierarchy "h"=$\pm 1$ in the neutrino mass ordering: A(CP, T) is odd in L and $\sin\delta$ plus even in a and h; A(CP, CPT) is even in L and $\sin\delta$ plus odd in a and almost odd in h. For present terrestrial accelerator sources of muon-neutrinos and antineutrinos, the two components of the appearance CPV asymmetry A(CP) can be disentangled by either baseline dependence (HKK) or energy dependence (DUNE). At the DUNE baseline, the higher energy region above the first oscillation node provides a dominant matter-induced A(CP, CPT) component and the sign of the experimental asymmetry A(CP) gives the hierarchy in the neutrino mass ordering. On the contrary, there is a "magic energy" E around the second oscillation maximum in which the fake A(CP, CPT) component has a first-rank zero whereas the genuine A(CP, T) component has a maximum proportional to sin{\delta}. With a modest energy resolution $\Delta E \sim 200$ MeV an effective zero remains in the matter-induced A(CP, CPT).
[ { "created": "Mon, 28 Oct 2019 14:07:05 GMT", "version": "v1" } ]
2019-10-29
[ [ "Bernabeu", "Jose", "" ], [ "Segarra", "Alejandro", "" ] ]
These results represent the solution for the historical problem of the contamination by matter effects on the CPV Asymmetry for neutrino oscillations. Vacuum is CPT-symmetric and matter is T-symmetric, the goal is accomplished by using this guiding principle. Independent of the theoretical framework for the dynamics of the active neutrino flavors, we prove the Disentanglement Theorem A(CP)=A(CP, T)+A(CP, CPT) for the experimental CPV Asymmetry, with A(CP, T) genuine T-odd and A(CP, CPT) fake CPT-odd. For the effective Hamiltonian written as the sum of free mass propagation plus the matter potential for electron-neutrinos, the two components have definite parities under the baseline L, the matter potential "a", the imaginary part $\sin\delta$ of the PMNS mixing matrix and the hierarchy "h"=$\pm 1$ in the neutrino mass ordering: A(CP, T) is odd in L and $\sin\delta$ plus even in a and h; A(CP, CPT) is even in L and $\sin\delta$ plus odd in a and almost odd in h. For present terrestrial accelerator sources of muon-neutrinos and antineutrinos, the two components of the appearance CPV asymmetry A(CP) can be disentangled by either baseline dependence (HKK) or energy dependence (DUNE). At the DUNE baseline, the higher energy region above the first oscillation node provides a dominant matter-induced A(CP, CPT) component and the sign of the experimental asymmetry A(CP) gives the hierarchy in the neutrino mass ordering. On the contrary, there is a "magic energy" E around the second oscillation maximum in which the fake A(CP, CPT) component has a first-rank zero whereas the genuine A(CP, T) component has a maximum proportional to sin{\delta}. With a modest energy resolution $\Delta E \sim 200$ MeV an effective zero remains in the matter-induced A(CP, CPT).
hep-ph/0504027
Simonetta Liuti
S. Liuti and S.K. Taneja
Nuclear Medium Modifications of Hadrons from Generalized Parton Distributions
29 pages, 10 figures
Phys.Rev. C72 (2005) 034902
10.1103/PhysRevC.72.034902
null
hep-ph
null
We study the structure of generalized parton distributions in spin 0 nuclei within a microscopic approach for nuclear dynamics. GPDs can be used on one side as tools to unravel the deep inelastic transverse structure of nuclei in terms of both transverse spatial and transverse momentum degrees of freedom. On the other, one can obtain information on GPDs themselves by observing how they become modified in the nuclear environment. We derive the structure of the nuclear deeply virtual Compton scattering tensor and generalized parton distributions at leading order in $Q$ in a field-theoretical framework. The nuclear generalized parton distributions are calculated using a two step process -- the convolution approach -- where the scattering process happens from a quark inside a nucleon, itself inside a nucleus, disregarding final state interactions with both the nuclear and nucleon debris. We point out that details of the nuclear long range interactions such as two-body currents, can be disregarded compared to the deep inelastic induced modifications of the bound GPDs. We show how the pattern of nuclear modifications predicted, and in particular the deviations of off-shell effects from the longitudinal convolution provide clear signals to be sought in experimental measurements. Finally, we find interesting relationships by studying Mellin moments in nuclei: in particular we predict the $A$-dependence for the $D$-term of GPDs within a microscopic approach, and the behavior with $t$ of the total momentum carried by quarks in a nucleus. The latter provides an important element for the evaluation of nuclear hadronization phenomena which are vital for interpreting current and future data at RHIC, HERMES and Jefferson Lab.
[ { "created": "Mon, 4 Apr 2005 22:32:54 GMT", "version": "v1" }, { "created": "Fri, 6 May 2005 21:51:03 GMT", "version": "v2" } ]
2009-11-11
[ [ "Liuti", "S.", "" ], [ "Taneja", "S. K.", "" ] ]
We study the structure of generalized parton distributions in spin 0 nuclei within a microscopic approach for nuclear dynamics. GPDs can be used on one side as tools to unravel the deep inelastic transverse structure of nuclei in terms of both transverse spatial and transverse momentum degrees of freedom. On the other, one can obtain information on GPDs themselves by observing how they become modified in the nuclear environment. We derive the structure of the nuclear deeply virtual Compton scattering tensor and generalized parton distributions at leading order in $Q$ in a field-theoretical framework. The nuclear generalized parton distributions are calculated using a two step process -- the convolution approach -- where the scattering process happens from a quark inside a nucleon, itself inside a nucleus, disregarding final state interactions with both the nuclear and nucleon debris. We point out that details of the nuclear long range interactions such as two-body currents, can be disregarded compared to the deep inelastic induced modifications of the bound GPDs. We show how the pattern of nuclear modifications predicted, and in particular the deviations of off-shell effects from the longitudinal convolution provide clear signals to be sought in experimental measurements. Finally, we find interesting relationships by studying Mellin moments in nuclei: in particular we predict the $A$-dependence for the $D$-term of GPDs within a microscopic approach, and the behavior with $t$ of the total momentum carried by quarks in a nucleus. The latter provides an important element for the evaluation of nuclear hadronization phenomena which are vital for interpreting current and future data at RHIC, HERMES and Jefferson Lab.
1706.01190
Nakul Soni Mr.
N. R. Soni and J. N. Pandya
Decay ${\mathit{D} \to} {{\mathit K}^{(*)}}{{\mathit \ell}^{+}}{{\mathit \nu}_{{{{\mathit \ell}}}}}$ in covariant quark model
20 pages, 6 tables, 7 figures
Phys. Rev. D 96, 016017 (2017)
10.1103/PhysRevD.96.016017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the leptonic and semileptonic $D$-meson decays (${{\mathit D} \to} {{\mathit \ell}^{+}}{{\mathit \nu}_{{{{\mathit \ell}}}}}$ and ${\mathit{D} \to} {{\mathit K}^{(*)}}{{\mathit \ell}^{+}}{{\mathit \nu}_{{{{\mathit \ell}}}}}$) in the framework of covariant quark model with built-in infrared confinement. We compute the required form factors in the entire kinematical momentum transfer region. The calculated form factors are used to evaluate the branching fractions of these transitions. We determine the following ratios of the partial widths: $\Gamma ({{\mathit D}^{0}} \rightarrow {{\mathit K}^{-}}{{\mathit e}^{+}}{{\mathit \nu}_{{e}}})/\Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit e}^{+}}{{\mathit \nu}_{{e}}}) = 1.02$, $\Gamma({{\mathit D}^{0}} \rightarrow {{\mathit K}^{-}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}})/\Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}) = 0.99$ and $\Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}) / \Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit e}^{+}}{{\mathit \nu}_{{e}}}) = 0.97$ which are in close resemblance with the iso-spin invariance and experimental results.
[ { "created": "Mon, 5 Jun 2017 04:51:40 GMT", "version": "v1" }, { "created": "Sat, 8 Jul 2017 11:40:45 GMT", "version": "v2" } ]
2017-08-02
[ [ "Soni", "N. R.", "" ], [ "Pandya", "J. N.", "" ] ]
We study the leptonic and semileptonic $D$-meson decays (${{\mathit D} \to} {{\mathit \ell}^{+}}{{\mathit \nu}_{{{{\mathit \ell}}}}}$ and ${\mathit{D} \to} {{\mathit K}^{(*)}}{{\mathit \ell}^{+}}{{\mathit \nu}_{{{{\mathit \ell}}}}}$) in the framework of covariant quark model with built-in infrared confinement. We compute the required form factors in the entire kinematical momentum transfer region. The calculated form factors are used to evaluate the branching fractions of these transitions. We determine the following ratios of the partial widths: $\Gamma ({{\mathit D}^{0}} \rightarrow {{\mathit K}^{-}}{{\mathit e}^{+}}{{\mathit \nu}_{{e}}})/\Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit e}^{+}}{{\mathit \nu}_{{e}}}) = 1.02$, $\Gamma({{\mathit D}^{0}} \rightarrow {{\mathit K}^{-}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}})/\Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}) = 0.99$ and $\Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}) / \Gamma({{\mathit D}^{+}} \rightarrow {{\overline{\mathit K}}^{0}}{{\mathit e}^{+}}{{\mathit \nu}_{{e}}}) = 0.97$ which are in close resemblance with the iso-spin invariance and experimental results.
hep-ph/0701001
Shouhua Zhu
Shou-hua Zhu (Peking University)
U-boson at BESIII
3 refs added, minor text modification, PRD version
Phys.Rev.D75:115004,2007
10.1103/PhysRevD.75.115004
null
hep-ph hep-ex
null
The $O$(MeV) spin-1 U-boson has been proposed to mediate the interaction among electron-positron and $O$(MeV) dark matter, in order to account for the 511 keV $\gamma$-ray observation by SPI/INTEGRAL. In this paper the observability of such kind of U-boson at BESIII is investigated through the processes $e^+e^- \to U \gamma$ and $e^+e^- \to J/\Psi \to e^+e^- U$. We find that BESIII and high luminosity B-factories have the comparable capacity to detect such U-boson. If U-boson decays mainly into dark matter, i.e. invisibly, BESIII can measure the coupling among U-boson and electron-positron $g_{eR}$ (see text) down to $O(10^{-5})$, and cover large parameter space which can account for 511 keV $\gamma$-ray observation. On the other hand, provided that U decays mainly into electron-positron, BESIII can detect $g_{eR}$ down to $O(10^{-3})$, and it is hard to explore 511 keV $\gamma$-ray measurement allowed parameter space due to the irreducible QED backgrounds.
[ { "created": "Fri, 29 Dec 2006 21:11:01 GMT", "version": "v1" }, { "created": "Fri, 11 May 2007 01:39:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zhu", "Shou-hua", "", "Peking University" ] ]
The $O$(MeV) spin-1 U-boson has been proposed to mediate the interaction among electron-positron and $O$(MeV) dark matter, in order to account for the 511 keV $\gamma$-ray observation by SPI/INTEGRAL. In this paper the observability of such kind of U-boson at BESIII is investigated through the processes $e^+e^- \to U \gamma$ and $e^+e^- \to J/\Psi \to e^+e^- U$. We find that BESIII and high luminosity B-factories have the comparable capacity to detect such U-boson. If U-boson decays mainly into dark matter, i.e. invisibly, BESIII can measure the coupling among U-boson and electron-positron $g_{eR}$ (see text) down to $O(10^{-5})$, and cover large parameter space which can account for 511 keV $\gamma$-ray observation. On the other hand, provided that U decays mainly into electron-positron, BESIII can detect $g_{eR}$ down to $O(10^{-3})$, and it is hard to explore 511 keV $\gamma$-ray measurement allowed parameter space due to the irreducible QED backgrounds.
2103.11412
Xing-Hua Yang
Xing-Hua Yang and Zhong-Juan Yang
Doubly Charged Higgs Production at Future $ep$ Colliders
21 pages, 9 figures
null
10.1088/1674-1137/ac581b
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Higgs sector of the standard model can be extended by introducing an $SU(2)_L$ Higgs triplet $\Delta$ to generate the tiny neutrino masses in the framework of type-II seesaw mechanism. In this paper, we study the pair production of the introduced Higgs triplet at future $e^{-}p$ colliders. The corresponding production cross sections via vector boson fusion process at FCC-ep and ILC$\otimes$FCC are predicted, where the production of a pair of doubly charged Higgs is found to be dominant and then used to investigate the collider phenomenology of the Higgs triplet. Depending on the size of the Higgs triplet vacuum expectation value, the doubly charged Higgs may decay into a pair of same-sign charged leptons or a pair of same-sign $W$ bosons. In order to explore the discovery potential of the doubly charged Higgs at future $e^{-}p$ colliders, we discuss these two decay scenarios in detail and show respectively the detection sensitivity on the mass of the doubly charged Higgs.
[ { "created": "Sun, 21 Mar 2021 14:39:25 GMT", "version": "v1" } ]
2022-06-08
[ [ "Yang", "Xing-Hua", "" ], [ "Yang", "Zhong-Juan", "" ] ]
The Higgs sector of the standard model can be extended by introducing an $SU(2)_L$ Higgs triplet $\Delta$ to generate the tiny neutrino masses in the framework of type-II seesaw mechanism. In this paper, we study the pair production of the introduced Higgs triplet at future $e^{-}p$ colliders. The corresponding production cross sections via vector boson fusion process at FCC-ep and ILC$\otimes$FCC are predicted, where the production of a pair of doubly charged Higgs is found to be dominant and then used to investigate the collider phenomenology of the Higgs triplet. Depending on the size of the Higgs triplet vacuum expectation value, the doubly charged Higgs may decay into a pair of same-sign charged leptons or a pair of same-sign $W$ bosons. In order to explore the discovery potential of the doubly charged Higgs at future $e^{-}p$ colliders, we discuss these two decay scenarios in detail and show respectively the detection sensitivity on the mass of the doubly charged Higgs.
1807.11300
Mikhail Ivanov
Thomas Gutsche, Mikhail A. Ivanov, J\"urgen G. K\"orner, Valery E. Lyubovitskij, Pietro Santorelli, Chien-Thang Tran
Analyzing lepton flavor universality in the decays $\Lambda_b\to\Lambda_c^{(\ast)}(\frac12^\pm,\frac32^-) + \ell\,\bar\nu_\ell$
some references added
Phys. Rev. D 98, 053003 (2018)
10.1103/PhysRevD.98.053003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton flavor universality can be tested in the semileptonic decays $\Lambda_b\to \Lambda_c^{(\ast)}$ where $\Lambda_c^{(\ast)}$ denotes either the ground state $\Lambda_c(2286)$ (with $J^P=1/2^+$) or its orbital excitations $\Lambda_c(2595)$ (with $J^P=1/2^-$) and $\Lambda_c(2625)$ (with $J^P=3/2^-$). We calculate the differential decay rates as well as the branching fractions of these decays for both tauonic and muonic modes with form factors obtained from a covariant confined quark model previously developed by us. We present results for the rate ratios of the tauonic and muonic modes which provide important tests of lepton flavor universality in forthcoming experiments.
[ { "created": "Mon, 30 Jul 2018 11:53:35 GMT", "version": "v1" }, { "created": "Wed, 12 Sep 2018 14:07:16 GMT", "version": "v2" } ]
2018-09-19
[ [ "Gutsche", "Thomas", "" ], [ "Ivanov", "Mikhail A.", "" ], [ "Körner", "Jürgen G.", "" ], [ "Lyubovitskij", "Valery E.", "" ], [ "Santorelli", "Pietro", "" ], [ "Tran", "Chien-Thang", "" ] ]
Lepton flavor universality can be tested in the semileptonic decays $\Lambda_b\to \Lambda_c^{(\ast)}$ where $\Lambda_c^{(\ast)}$ denotes either the ground state $\Lambda_c(2286)$ (with $J^P=1/2^+$) or its orbital excitations $\Lambda_c(2595)$ (with $J^P=1/2^-$) and $\Lambda_c(2625)$ (with $J^P=3/2^-$). We calculate the differential decay rates as well as the branching fractions of these decays for both tauonic and muonic modes with form factors obtained from a covariant confined quark model previously developed by us. We present results for the rate ratios of the tauonic and muonic modes which provide important tests of lepton flavor universality in forthcoming experiments.
hep-ph/0005066
Dolors Eiras
Dolors Eiras and Joan Soto
Light Fermion Finite Mass Effects in Non-relativistic Bound States
12 pages, 3 figures
Phys.Lett. B491 (2000) 101-110
10.1016/S0370-2693(00)01004-2
null
hep-ph nucl-th physics.atom-ph
null
We present analytic expressions for the vacuum polarization effects due to a light fermion with finite mass in the binding energy and in the wave function at the origin of QED and (weak coupling) QCD non-relativistic bound states. Applications to exotic atoms, \Upsilon (1s) and t\bar{t} production near threshold are briefly discussed.
[ { "created": "Mon, 8 May 2000 09:53:08 GMT", "version": "v1" }, { "created": "Thu, 7 Sep 2000 10:40:18 GMT", "version": "v2" } ]
2009-10-31
[ [ "Eiras", "Dolors", "" ], [ "Soto", "Joan", "" ] ]
We present analytic expressions for the vacuum polarization effects due to a light fermion with finite mass in the binding energy and in the wave function at the origin of QED and (weak coupling) QCD non-relativistic bound states. Applications to exotic atoms, \Upsilon (1s) and t\bar{t} production near threshold are briefly discussed.
2010.02943
Pierluca Carenza
Pierluca Carenza, Bryce Fore, Maurizio Giannotti, Alessandro Mirizzi, Sanjay Reddy
Enhanced Supernova Axion Emission and its Implications
6 pages, 1 figure. v2: minor corrections to match the published version. Added a discussion on the trapping regime
Phys. Rev. Lett. 126, 071102 (2021)
10.1103/PhysRevLett.126.071102
null
hep-ph astro-ph.HE astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the axion emission rate from reactions involving thermal pions in matter encountered in supernovae and neutron star mergers, identify unique spectral features, and explore their implications for astrophysics and particle physics. We find that it is about 2-5 times larger than nucleon-nucleon bremsstrahlung, which in past studies was considered to be the dominant process. The axion spectrum is also found be much harder. Together, the larger rates and higher axion energies imply a stronger bound on the mass of the QCD axion, and better prospects for direct detection in a large underground neutrino detector from a nearby galactic supernova.
[ { "created": "Tue, 6 Oct 2020 18:00:13 GMT", "version": "v1" }, { "created": "Sat, 20 Feb 2021 06:56:51 GMT", "version": "v2" } ]
2021-02-23
[ [ "Carenza", "Pierluca", "" ], [ "Fore", "Bryce", "" ], [ "Giannotti", "Maurizio", "" ], [ "Mirizzi", "Alessandro", "" ], [ "Reddy", "Sanjay", "" ] ]
We calculate the axion emission rate from reactions involving thermal pions in matter encountered in supernovae and neutron star mergers, identify unique spectral features, and explore their implications for astrophysics and particle physics. We find that it is about 2-5 times larger than nucleon-nucleon bremsstrahlung, which in past studies was considered to be the dominant process. The axion spectrum is also found be much harder. Together, the larger rates and higher axion energies imply a stronger bound on the mass of the QCD axion, and better prospects for direct detection in a large underground neutrino detector from a nearby galactic supernova.