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2008.10027
Xue Jia Cheng
ChongXing Yue and XueJia Cheng
Constraints on the charged-current non-standard neutrino interactions induced by the gauge boson $W'$
22 pages,4 tables, received by Nuclear Physics B
null
10.1016/j.nuclphysb.2020.115280
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many new physics scenarios predict the existence of the extra charged gauge boson $ W'$, which can induce the charged-current (CC) non-standard neutrino interactions (NSI). We investigate the constraints on the CC NSI in model-independent fashion via considering the $ W'$ contributions to the lepton flavor violating (LFV) decays $\ell_{i}\rightarrow \ell_{j}\gamma$, the pure leptonic flavor conservation (FC) decays $\ell_{i}\rightarrow \ell_{j}\nu_{i}\bar{\nu_{j}}$, leptonic decays of charged pion meson, semileptonic $\tau$ decays, and superallowed $\beta$ decays. We find that the constraints on the pure leptonic CC NSI are generally stronger than the ones for the CC NSI with first generation quarks. The most stringent constraints on the CC NSI arise from the LFV decay $\mu \rightarrow e\gamma$.
[ { "created": "Sun, 23 Aug 2020 12:25:06 GMT", "version": "v1" }, { "created": "Mon, 14 Dec 2020 16:45:49 GMT", "version": "v2" } ]
2021-02-03
[ [ "Yue", "ChongXing", "" ], [ "Cheng", "XueJia", "" ] ]
Many new physics scenarios predict the existence of the extra charged gauge boson $ W'$, which can induce the charged-current (CC) non-standard neutrino interactions (NSI). We investigate the constraints on the CC NSI in model-independent fashion via considering the $ W'$ contributions to the lepton flavor violating (LFV) decays $\ell_{i}\rightarrow \ell_{j}\gamma$, the pure leptonic flavor conservation (FC) decays $\ell_{i}\rightarrow \ell_{j}\nu_{i}\bar{\nu_{j}}$, leptonic decays of charged pion meson, semileptonic $\tau$ decays, and superallowed $\beta$ decays. We find that the constraints on the pure leptonic CC NSI are generally stronger than the ones for the CC NSI with first generation quarks. The most stringent constraints on the CC NSI arise from the LFV decay $\mu \rightarrow e\gamma$.
1804.05362
Guo-Yuan Huang
Guo-yuan Huang
Sterile neutrinos as a possible explanation for the upward air shower events at ANITA
12 pages, 3 figures
Phys. Rev. D 98, 043019 (2018)
10.1103/PhysRevD.98.043019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ANITA experiment has observed two unusual upgoing air shower events which are consistent with the $\tau$-lepton decay origin. However, these events are in contradiction with the standard neutrino-matter interaction models as well as the $\rm EeV$ diffuse neutrino flux limits set by the IceCube and the cosmic ray facilities like AUGER. In this paper, we have reinvestigated the possibility of using sterile neutrino hypothesis to explain the ANITA anomalous events. The diffuse flux of the sterile neutrinos is less constrained by the IceCube and AUGER experiments due to the small active-sterile mixing suppression. The quantum decoherence effect should be included for describing the neutrino flux propagating in the Earth matter, because the interactions between neutrinos and the Earth matter are very strong at the EeV scale. After several experimental approximations, we show that the ANITA anomaly itself is able to be explained by the sterile neutrino origin, but we also predict that the IceCube observatory should have more events than ANITA. It makes the sterile neutrino origin very unlikely to account for both of them simultaneously. A more solid conclusion can be drawn by the dedicated ANITA signal simulations.
[ { "created": "Sun, 15 Apr 2018 14:34:04 GMT", "version": "v1" } ]
2018-08-29
[ [ "Huang", "Guo-yuan", "" ] ]
The ANITA experiment has observed two unusual upgoing air shower events which are consistent with the $\tau$-lepton decay origin. However, these events are in contradiction with the standard neutrino-matter interaction models as well as the $\rm EeV$ diffuse neutrino flux limits set by the IceCube and the cosmic ray facilities like AUGER. In this paper, we have reinvestigated the possibility of using sterile neutrino hypothesis to explain the ANITA anomalous events. The diffuse flux of the sterile neutrinos is less constrained by the IceCube and AUGER experiments due to the small active-sterile mixing suppression. The quantum decoherence effect should be included for describing the neutrino flux propagating in the Earth matter, because the interactions between neutrinos and the Earth matter are very strong at the EeV scale. After several experimental approximations, we show that the ANITA anomaly itself is able to be explained by the sterile neutrino origin, but we also predict that the IceCube observatory should have more events than ANITA. It makes the sterile neutrino origin very unlikely to account for both of them simultaneously. A more solid conclusion can be drawn by the dedicated ANITA signal simulations.
1302.1991
Prashant Srivastava Kumar
P. K. Srivastava, and C. P. Singh
QCD Phase Transition in a new Hybrid Model Formulation
5 pages, 4 figures, to be published in proceedings of QGP MEET 2012 held at VECC, Kolkata, INDIA
null
null
Chapter in "Quark Gluon Plasma" Edited by J. Nayak, T. Nayak, S. Sarkar, Narosa Publication, page no. 81
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Search of a proper and realistic equations of state (EOS) for strongly interacting matter used in the study of QCD phase diagram still appears as a challenging task. Recently, we have constructed a hybrid model description for the quark gluon plasma (QGP) as well as hadron gas (HG) phases where we use a new excluded-volume model for HG and a thermodynamically-consistent quasiparticle model for the QGP phase. We attempt to use them to get a QCD phase boundary and a critical point. We test our hybrid model by reproducing the entire lattice QCD data for strongly interacting matter at zero baryon chemical potential ($\mu_{B}$)and predict the results at finite $\mu_{B}$ and $T$.
[ { "created": "Fri, 8 Feb 2013 10:54:20 GMT", "version": "v1" } ]
2018-04-03
[ [ "Srivastava", "P. K.", "" ], [ "Singh", "C. P.", "" ] ]
Search of a proper and realistic equations of state (EOS) for strongly interacting matter used in the study of QCD phase diagram still appears as a challenging task. Recently, we have constructed a hybrid model description for the quark gluon plasma (QGP) as well as hadron gas (HG) phases where we use a new excluded-volume model for HG and a thermodynamically-consistent quasiparticle model for the QGP phase. We attempt to use them to get a QCD phase boundary and a critical point. We test our hybrid model by reproducing the entire lattice QCD data for strongly interacting matter at zero baryon chemical potential ($\mu_{B}$)and predict the results at finite $\mu_{B}$ and $T$.
1106.3440
Philipp Wein
Philipp Wein, Peter C. Bruns, Thomas R. Hemmert and Andreas Sch\"afer
Chiral extrapolation of nucleon wave function normalization constants
null
null
10.1140/epja/i2011-11149-5
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the framework of two-flavor covariant baryon chiral perturbation theory we have expressed the Chernyak-Zhitnitsky, Ioffe and Dosch currents in terms of chiral fields to provide leading one-loop extrapolation formulae for the leading and next-to-leading twist normalization constants $f_N$, $\lambda_1$ and $\lambda_2$. Finite volume effects due to pion loops have been taken into account. The occurring low energy constants are fitted to data obtained from recent lattice QCD simulations in order to extract the values at the physical point.
[ { "created": "Fri, 17 Jun 2011 10:58:10 GMT", "version": "v1" } ]
2015-05-28
[ [ "Wein", "Philipp", "" ], [ "Bruns", "Peter C.", "" ], [ "Hemmert", "Thomas R.", "" ], [ "Schäfer", "Andreas", "" ] ]
Within the framework of two-flavor covariant baryon chiral perturbation theory we have expressed the Chernyak-Zhitnitsky, Ioffe and Dosch currents in terms of chiral fields to provide leading one-loop extrapolation formulae for the leading and next-to-leading twist normalization constants $f_N$, $\lambda_1$ and $\lambda_2$. Finite volume effects due to pion loops have been taken into account. The occurring low energy constants are fitted to data obtained from recent lattice QCD simulations in order to extract the values at the physical point.
1204.2091
Prashant Srivastava Kumar
P. K. Srivastava, C. P. Singh
A Hybrid Model for QCD Deconfining Phase Boundary
22 pages, 10 figures. corrected version published in Physical Review D. arXiv admin note: substantial text overlap with arXiv:1201.0445
Phys. Rev. D 85, 114016 (2012)
10.1103/PhysRevD.85.114016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intensive search for a proper and realistic equations of state (EOS) is still continued for studying the phase diagram existing between quark gluon plasma (QGP) and hadron gas (HG) phases. Lattice calculations provide such EOS for the strongly interacting matter at finite temperature ($T$) and vanishing baryon chemical potential ($\mu_{B}$). These calculations are of limited use at finite $\mu_{B}$ due to the appearance of notorious sign problem. In the recent past, we had constructed a hybrid model description for the QGP as well as HG phases where we make use of a new excluded-volume model for HG and a thermodynamically-consistent quasiparticle model for the QGP phase and used them further to get QCD phase boundary and a critical point. Since then many lattice calculations have appeared showing various thermal and transport properties of QCD matter at finite $T$ and $\mu_{B}=0$. We test our hybrid model by reproducing the entire data for strongly interacting matter and predict our results at finite $\mu_{B}$ so that they can be tested in future. Finally we demonstrate the utility of the model in fixing the precise location, the order of the phase transition and the nature of CP existing on the QCD phase diagram. We thus emphasize the suitability of the hybrid model as formulated here in providing a realistic EOS for the strongly interacting matter.
[ { "created": "Tue, 10 Apr 2012 09:46:28 GMT", "version": "v1" }, { "created": "Sat, 9 Jun 2012 04:48:59 GMT", "version": "v2" } ]
2012-06-12
[ [ "Srivastava", "P. K.", "" ], [ "Singh", "C. P.", "" ] ]
Intensive search for a proper and realistic equations of state (EOS) is still continued for studying the phase diagram existing between quark gluon plasma (QGP) and hadron gas (HG) phases. Lattice calculations provide such EOS for the strongly interacting matter at finite temperature ($T$) and vanishing baryon chemical potential ($\mu_{B}$). These calculations are of limited use at finite $\mu_{B}$ due to the appearance of notorious sign problem. In the recent past, we had constructed a hybrid model description for the QGP as well as HG phases where we make use of a new excluded-volume model for HG and a thermodynamically-consistent quasiparticle model for the QGP phase and used them further to get QCD phase boundary and a critical point. Since then many lattice calculations have appeared showing various thermal and transport properties of QCD matter at finite $T$ and $\mu_{B}=0$. We test our hybrid model by reproducing the entire data for strongly interacting matter and predict our results at finite $\mu_{B}$ so that they can be tested in future. Finally we demonstrate the utility of the model in fixing the precise location, the order of the phase transition and the nature of CP existing on the QCD phase diagram. We thus emphasize the suitability of the hybrid model as formulated here in providing a realistic EOS for the strongly interacting matter.
2309.00358
Dmitri Melikhov
Ilia Belov, Alexander Berezhnoy, and Dmitri Melikhov
Charming-loop contribution to $B_s\to \gamma\gamma$ decay
21 pages, version to be published in Physical Review D
Phys. Rev. D 108, 094022 (2023)
10.1103/PhysRevD.108.094022
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a detailed theoretical study of nonfactorizable contributions of the charm-quark loop to the amplitude of the $B_s\to \gamma\,\gamma$ decay. This contribution involves the $B$-meson three-particle Bethe-Salpeter amplitude, $\langle 0|\bar s(y)G_{\mu\nu}(x)b(0)|\bar B_s(p)\rangle$, for which we take into account constraints from analyticity and continuity. The charming-loop contribution of interest may be described as a correction to the Wilson coefficient $C_{7\gamma}$, $C_{7\gamma}\to C_{7\gamma}(1+\delta C_{7\gamma})$. We calculate an explicit dependence of $\delta C_{7\gamma}$ on the parameter $\lambda_{B_s}$. Taking into account all theoretical uncertainties, $\delta C_{7\gamma}$ may be predicted with better than 10\% accuracy for any given value of $\lambda_{B_s}$. For our benchmark point $\lambda_{B_s}=0.45$ GeV, we obtain $\delta C_{7\gamma}=0.045\pm 0.004$. Presently, $\lambda_{B_s}$ is not known with high accuracy, but its value is expected to lie in the range $0.3\le \lambda_{B_s}({\rm GeV})\le 0.6$. The corresponding range of $\delta C_{7\gamma}$ is found to be $0.02\le \delta C_{7\gamma}\le 0.1$. One therefore expects the correction given by charming loops at the level of at least a few percent.
[ { "created": "Fri, 1 Sep 2023 09:28:25 GMT", "version": "v1" }, { "created": "Mon, 23 Oct 2023 16:41:48 GMT", "version": "v2" } ]
2023-11-17
[ [ "Belov", "Ilia", "" ], [ "Berezhnoy", "Alexander", "" ], [ "Melikhov", "Dmitri", "" ] ]
We present a detailed theoretical study of nonfactorizable contributions of the charm-quark loop to the amplitude of the $B_s\to \gamma\,\gamma$ decay. This contribution involves the $B$-meson three-particle Bethe-Salpeter amplitude, $\langle 0|\bar s(y)G_{\mu\nu}(x)b(0)|\bar B_s(p)\rangle$, for which we take into account constraints from analyticity and continuity. The charming-loop contribution of interest may be described as a correction to the Wilson coefficient $C_{7\gamma}$, $C_{7\gamma}\to C_{7\gamma}(1+\delta C_{7\gamma})$. We calculate an explicit dependence of $\delta C_{7\gamma}$ on the parameter $\lambda_{B_s}$. Taking into account all theoretical uncertainties, $\delta C_{7\gamma}$ may be predicted with better than 10\% accuracy for any given value of $\lambda_{B_s}$. For our benchmark point $\lambda_{B_s}=0.45$ GeV, we obtain $\delta C_{7\gamma}=0.045\pm 0.004$. Presently, $\lambda_{B_s}$ is not known with high accuracy, but its value is expected to lie in the range $0.3\le \lambda_{B_s}({\rm GeV})\le 0.6$. The corresponding range of $\delta C_{7\gamma}$ is found to be $0.02\le \delta C_{7\gamma}\le 0.1$. One therefore expects the correction given by charming loops at the level of at least a few percent.
hep-ph/9912275
Rudolph C. Hwa
Rudolph C. Hwa and Qing-hui Zhang
Erraticity of Rapidity Gaps
10 pages LaTeX + 5 figures ps
Phys.Rev. D62 (2000) 014003
10.1103/PhysRevD.62.014003
OITS-684
hep-ph
null
The use of rapidity gaps is proposed as a measure of the spatial pattern of an event. When the event multiplicity is low, the gaps between neighboring particles carry far more information about an event than multiplicity spikes, which may occur very rarely. Two moments of the gap distrubiton are suggested for characterizing an event. The fluctuations of those moments from event to event are then quantified by an entropy-like measure, which serves to describe erraticity. We use ECOMB to simulate the exclusive rapidity distribution of each event, from which the erraticity measures are calculated. The dependences of those measures on the order of $q$ of the moments provide single-parameter characterizations of erraticity.
[ { "created": "Wed, 8 Dec 1999 21:57:14 GMT", "version": "v1" } ]
2009-10-31
[ [ "Hwa", "Rudolph C.", "" ], [ "Zhang", "Qing-hui", "" ] ]
The use of rapidity gaps is proposed as a measure of the spatial pattern of an event. When the event multiplicity is low, the gaps between neighboring particles carry far more information about an event than multiplicity spikes, which may occur very rarely. Two moments of the gap distrubiton are suggested for characterizing an event. The fluctuations of those moments from event to event are then quantified by an entropy-like measure, which serves to describe erraticity. We use ECOMB to simulate the exclusive rapidity distribution of each event, from which the erraticity measures are calculated. The dependences of those measures on the order of $q$ of the moments provide single-parameter characterizations of erraticity.
1911.10057
Hisakazu Minakata
Hisakazu Minakata, Ivan Martinez-Soler, Kimihiro Okumura
Using low energy atmospheric neutrinos for precision measurement of the mixing parameters
4 pages, 3 figures, Written version of the talk at The 21st international workshop on neutrinos from accelerators (NuFact2019)
null
null
FERMILAB-CONF-19-601-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Use of low energy atmospheric neutrinos is considered for precision measurement of neutrino mixing parameters. At around energy $E \simeq$ a few $\times$100 MeV and baseline $L$ of a few $\times$1000 km, CP phase effect is $\sim$10 times larger than that of the conventional LBL accelerator neutrino experiments. We report here a few progresses: (1) To analyze physics in the region, a new perturbative framework at around the solar-scale enhancement is developed. (2) To know the characteristic features of CP $\delta$ dependence of the atmospheric neutrinos at low energies, we plot the ratio of the $\nu_{e}$ and $\bar{\nu}_{e}$ fluxes $F(\delta)/F(\delta=0)$ for $\delta=\pm \frac{\pi}{2}$ and $\pi$ as a function of $E$ using the Honda {\it et al.} flux. Interestingly, it shows $\delta$ dependence of $\simeq$5-10\% level, with positive (negative) sign for $\nu_{e}$ ($\bar{\nu}_{e}$). (3) To reduce the flux systematic errors, measurement of muon energy distribution around $\sim$1 GeV at high altitude may be useful. Water Cherenkov or muon range detectors may be the options with advantage in the latter if it is magnetized in view of the $\delta$ dependence of the flux.
[ { "created": "Fri, 22 Nov 2019 14:17:44 GMT", "version": "v1" } ]
2019-11-25
[ [ "Minakata", "Hisakazu", "" ], [ "Martinez-Soler", "Ivan", "" ], [ "Okumura", "Kimihiro", "" ] ]
Use of low energy atmospheric neutrinos is considered for precision measurement of neutrino mixing parameters. At around energy $E \simeq$ a few $\times$100 MeV and baseline $L$ of a few $\times$1000 km, CP phase effect is $\sim$10 times larger than that of the conventional LBL accelerator neutrino experiments. We report here a few progresses: (1) To analyze physics in the region, a new perturbative framework at around the solar-scale enhancement is developed. (2) To know the characteristic features of CP $\delta$ dependence of the atmospheric neutrinos at low energies, we plot the ratio of the $\nu_{e}$ and $\bar{\nu}_{e}$ fluxes $F(\delta)/F(\delta=0)$ for $\delta=\pm \frac{\pi}{2}$ and $\pi$ as a function of $E$ using the Honda {\it et al.} flux. Interestingly, it shows $\delta$ dependence of $\simeq$5-10\% level, with positive (negative) sign for $\nu_{e}$ ($\bar{\nu}_{e}$). (3) To reduce the flux systematic errors, measurement of muon energy distribution around $\sim$1 GeV at high altitude may be useful. Water Cherenkov or muon range detectors may be the options with advantage in the latter if it is magnetized in view of the $\delta$ dependence of the flux.
1103.0982
Martin Zdrahal
Karol Kampf, Marc Knecht, Ji\v{r}\'i Novotn\'y and Martin Zdr\'ahal
Analytical dispersive construction of $\eta\to3\pi$ amplitude: First order in isospin breaking
40 pages, 4 figures
Phys. Rev. D 84, 114015 (2011)
10.1103/PhysRevD.84.114015
LU TP 11-11
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Because of their small electromagnetic corrections, the isospin-breaking decays $\eta\to3\pi$ seem to be good candidates for extracting isospin-breaking parameters $ (m_d-m_u)$. This task is unfortunately complicated by large chiral corrections and the discrepancy between the experimentally measured values of the Dalitz parameters describing the energy dependence of the amplitudes of these decays and those predicted from chiral perturbation theory. We present two methods based on an analytic dispersive representation that use the information from the NNLO chiral result and the one from the measurement of the charged $\eta\to3\pi$ decay by KLOE together in a harmonized way in order to determine the value of the quark mass ratio $R$. Our final result is $R=37.7\pm 2.2$. This value supplemented by values of $m_s/\hat{m}$ or even $\hat{m}$ and $m_s$ from other methods (as sum-rules or lattice) enables us to obtain further quark mass characteristics. For instance the recent lattice value for $m_s/\hat{m}~27.5$ leads to $Q= 23.1\pm0.7$. We also quote the corresponding values of the current masses $m_u$ and $m_d$.
[ { "created": "Fri, 4 Mar 2011 20:55:08 GMT", "version": "v1" }, { "created": "Mon, 19 Dec 2011 23:18:39 GMT", "version": "v2" } ]
2011-12-21
[ [ "Kampf", "Karol", "" ], [ "Knecht", "Marc", "" ], [ "Novotný", "Jiří", "" ], [ "Zdráhal", "Martin", "" ] ]
Because of their small electromagnetic corrections, the isospin-breaking decays $\eta\to3\pi$ seem to be good candidates for extracting isospin-breaking parameters $ (m_d-m_u)$. This task is unfortunately complicated by large chiral corrections and the discrepancy between the experimentally measured values of the Dalitz parameters describing the energy dependence of the amplitudes of these decays and those predicted from chiral perturbation theory. We present two methods based on an analytic dispersive representation that use the information from the NNLO chiral result and the one from the measurement of the charged $\eta\to3\pi$ decay by KLOE together in a harmonized way in order to determine the value of the quark mass ratio $R$. Our final result is $R=37.7\pm 2.2$. This value supplemented by values of $m_s/\hat{m}$ or even $\hat{m}$ and $m_s$ from other methods (as sum-rules or lattice) enables us to obtain further quark mass characteristics. For instance the recent lattice value for $m_s/\hat{m}~27.5$ leads to $Q= 23.1\pm0.7$. We also quote the corresponding values of the current masses $m_u$ and $m_d$.
hep-ph/9611371
null
Jogesh C. Pati
Baryon Non-Conservation in Unified Theories, in the Light of Supersymmetry and Superstrings
44 pages, Latex, 4 tables, 8 figures, invited talk presented at the Oak Ridge International Workshop on Baryon Instability, March 1996, to appear in the proceedings
null
null
UMD-PP-97-41
hep-ph
null
The first part of this talk presents the general complexion of baryon and lepton number non-conservation that may arise in the context of quark-lepton unification. The second part presents the status of grand unification with and without supersymmetry and spells out the characteristic proton decay modes, which if seen, will clearly show supersymmetry. The main theme of this talk, that follows next, pertains to two issues: (i) the need to remove the mismatch between MSSM and string-unifications; and especially (ii) the need to resolve naturally the problem of rapid proton decay, that generically arises in SUSY unification. Seeking for a natural solution to this second problem, it is noted that SUSY GUTS, including SUSY SO(10) and E_6, can at best accommodate proton-stability by a suitable choice of the Higgs-multiplets and discrete symmetries, but not really explain it, because they do not possess the desired symmetries to suppress both d=4 and d=5 proton-decay operators. By contrast, following a recent work, I argue that a class of string-solutions, possessing three families, does possess the desired symmetries, which naturally safeguard proton-stability from all potential dangers. They also permit neutrinos to have desired light masses. This shows that, believing in supersymmetry, superstring is needed just to understand why the proton is so stable.
[ { "created": "Tue, 19 Nov 1996 21:27:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pati", "Jogesh C.", "" ] ]
The first part of this talk presents the general complexion of baryon and lepton number non-conservation that may arise in the context of quark-lepton unification. The second part presents the status of grand unification with and without supersymmetry and spells out the characteristic proton decay modes, which if seen, will clearly show supersymmetry. The main theme of this talk, that follows next, pertains to two issues: (i) the need to remove the mismatch between MSSM and string-unifications; and especially (ii) the need to resolve naturally the problem of rapid proton decay, that generically arises in SUSY unification. Seeking for a natural solution to this second problem, it is noted that SUSY GUTS, including SUSY SO(10) and E_6, can at best accommodate proton-stability by a suitable choice of the Higgs-multiplets and discrete symmetries, but not really explain it, because they do not possess the desired symmetries to suppress both d=4 and d=5 proton-decay operators. By contrast, following a recent work, I argue that a class of string-solutions, possessing three families, does possess the desired symmetries, which naturally safeguard proton-stability from all potential dangers. They also permit neutrinos to have desired light masses. This shows that, believing in supersymmetry, superstring is needed just to understand why the proton is so stable.
1612.05609
Matias Leoni
Marco S. Bianchi, Matias Leoni
A $QQ\to QQ$ planar doublebox in canonical form
12 pages, 2 figures
null
10.1016/j.physletb.2017.12.030
QMUL-PH-16-22
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a planar doublebox with four massive external momenta and two massive internal propagators. We derive the system of differential equations for the relevant master integrals, cast it in canonical form, write it as a $d\log$ form and solve it in terms of iterated integrals up to depth four.
[ { "created": "Fri, 16 Dec 2016 19:49:59 GMT", "version": "v1" } ]
2018-02-01
[ [ "Bianchi", "Marco S.", "" ], [ "Leoni", "Matias", "" ] ]
We consider a planar doublebox with four massive external momenta and two massive internal propagators. We derive the system of differential equations for the relevant master integrals, cast it in canonical form, write it as a $d\log$ form and solve it in terms of iterated integrals up to depth four.
2211.14331
Moinul Hossain Rahat
Xuce Niu, Moinul Hossain Rahat, Karthik Srinivasan, and Wei Xue
Gravitational Wave Probes of Massive Gauge Bosons at the Cosmological Collider
35 pages, 7 figures, references added, minor modification in gravitational wave sensitivity plots
JCAP02(2023)013
10.1088/1475-7516/2023/02/013
null
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We extend the reach of the ``cosmological collider'' for massive gauge boson production during inflation from the CMB scales to the interferometer scales. Considering a Chern-Simons coupling between the gauge bosons and the pseudoscalar inflaton, one of the transverse gauge modes is efficiently produced and its inverse decay leaves an imprint in the primordial scalar and tensor perturbations. We study the correlation functions of these perturbations and derive the updated constraints on the parameter space from CMB observables. We then extrapolate the tensor power spectrum to smaller scales consistently taking into account the impact of the gauge field on inflationary dynamics. Our results show that the presence of massive gauge fields during inflation can be detected from characteristic gravitational wave signals encompassing the whole range of current and planned interferometers.
[ { "created": "Fri, 25 Nov 2022 19:00:02 GMT", "version": "v1" }, { "created": "Wed, 14 Dec 2022 02:16:18 GMT", "version": "v2" } ]
2023-02-10
[ [ "Niu", "Xuce", "" ], [ "Rahat", "Moinul Hossain", "" ], [ "Srinivasan", "Karthik", "" ], [ "Xue", "Wei", "" ] ]
We extend the reach of the ``cosmological collider'' for massive gauge boson production during inflation from the CMB scales to the interferometer scales. Considering a Chern-Simons coupling between the gauge bosons and the pseudoscalar inflaton, one of the transverse gauge modes is efficiently produced and its inverse decay leaves an imprint in the primordial scalar and tensor perturbations. We study the correlation functions of these perturbations and derive the updated constraints on the parameter space from CMB observables. We then extrapolate the tensor power spectrum to smaller scales consistently taking into account the impact of the gauge field on inflationary dynamics. Our results show that the presence of massive gauge fields during inflation can be detected from characteristic gravitational wave signals encompassing the whole range of current and planned interferometers.
hep-ph/9905554
Hannes Jung
H. Jung (Lund)
CCFM prediction for F_2 and forward jets at HERA
3 pages (Latex), 2 figures (Postscript), to be published in the Proceedings of DIS99 (Zeuthen), fig.1 replaced
Nucl.Phys.Proc.Suppl. 79 (1999) 429-431
10.1016/S0920-5632(99)00743-4
null
hep-ph
null
Predictions of the CCFM evolution equation for F_2 and forward jets at HERA energies are obtained from a modified version of the Monte Carlo program SMALLX. The treatment of the non-Sudakov form factor $\Delta_{ns}$ is discussed as well as the effect of the so called "consistency constraint". For the first time a good description of F_2 and the forward jet data is obtained from the CCFM equation.
[ { "created": "Mon, 31 May 1999 07:52:46 GMT", "version": "v1" }, { "created": "Thu, 3 Jun 1999 16:39:41 GMT", "version": "v2" } ]
2009-10-31
[ [ "Jung", "H.", "", "Lund" ] ]
Predictions of the CCFM evolution equation for F_2 and forward jets at HERA energies are obtained from a modified version of the Monte Carlo program SMALLX. The treatment of the non-Sudakov form factor $\Delta_{ns}$ is discussed as well as the effect of the so called "consistency constraint". For the first time a good description of F_2 and the forward jet data is obtained from the CCFM equation.
2207.08593
Hua-Xing Chen
Hua-Xing Chen, Yi-Xin Yan and Wei Chen
Decay behaviors of the fully-bottom and fully-charm tetraquark states
12 pages, 2 figure, 4 tables, revised version to be published in PRD
Phys. Rev. D 106, 094019 (2022)
10.1103/PhysRevD.106.094019
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study the decay behaviors of the fully-bottom tetraquark states within the diquark-antidiquark picture, and calculate their relative branching ratios through the Fierz rearrangement. Our results suggest that the $C=+$ states can be searched for in the $\mu^+ \mu^- \Upsilon(1S)$ and $\mu^+ \mu^- \Upsilon(2S)$ channels with the relative branching ratio $\mathcal{B}(X \to \mu\mu \Upsilon(2S)) / \mathcal{B}(X \to \mu \mu \Upsilon(1S)) \approx 0.4$. Our results also suggest that the $C=-$ states can be searched for in the $\mu^+ \mu^- \eta_b(1S)$ and $\mu^+ \mu^- \eta_b(2S)$ channels with the similar relative branching ratio $\mathcal{B}(X \to \mu\mu \eta_b(2S)) / \mathcal{B}(X \to \mu \mu \eta_b(1S)) \approx 0.4$. We also reanalysis the fully-charm tetraquark states, and study the $X(6900)$ decay into the $J/\psi \psi(2S)$ channel to obtain the relative branching ratio $\mathcal{B}(X \to J/\psi \psi(2S)) / \mathcal{B}(X \to J/\psi J/\psi) \approx 0.1$.
[ { "created": "Mon, 18 Jul 2022 13:32:50 GMT", "version": "v1" }, { "created": "Mon, 31 Oct 2022 00:41:51 GMT", "version": "v2" } ]
2022-11-17
[ [ "Chen", "Hua-Xing", "" ], [ "Yan", "Yi-Xin", "" ], [ "Chen", "Wei", "" ] ]
We study the decay behaviors of the fully-bottom tetraquark states within the diquark-antidiquark picture, and calculate their relative branching ratios through the Fierz rearrangement. Our results suggest that the $C=+$ states can be searched for in the $\mu^+ \mu^- \Upsilon(1S)$ and $\mu^+ \mu^- \Upsilon(2S)$ channels with the relative branching ratio $\mathcal{B}(X \to \mu\mu \Upsilon(2S)) / \mathcal{B}(X \to \mu \mu \Upsilon(1S)) \approx 0.4$. Our results also suggest that the $C=-$ states can be searched for in the $\mu^+ \mu^- \eta_b(1S)$ and $\mu^+ \mu^- \eta_b(2S)$ channels with the similar relative branching ratio $\mathcal{B}(X \to \mu\mu \eta_b(2S)) / \mathcal{B}(X \to \mu \mu \eta_b(1S)) \approx 0.4$. We also reanalysis the fully-charm tetraquark states, and study the $X(6900)$ decay into the $J/\psi \psi(2S)$ channel to obtain the relative branching ratio $\mathcal{B}(X \to J/\psi \psi(2S)) / \mathcal{B}(X \to J/\psi J/\psi) \approx 0.1$.
hep-ph/9701206
T. S. Kosmas
J.D. Vergados and T.S. Kosmas
LSP-Nucleus Elastic Scattering Cross Sections
6 LATEX pages, 5 Tables, Proc. Dark Matter 96 Conference, Heidelberg, Germany, World Scientific, to appear
null
null
null
hep-ph
null
We calculate LSP-nucleus elastic scattering cross sections using some representative input in the restricted SUSY parameter space. The coherent matrix elements are computed throughout the periodic table while the spin matrix elements for the proposed $^{207}Pb$ target which has a rather simple nuclear structure. The results are compared to those given from other cold dark matter detection targets.
[ { "created": "Thu, 2 Jan 1997 18:17:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vergados", "J. D.", "" ], [ "Kosmas", "T. S.", "" ] ]
We calculate LSP-nucleus elastic scattering cross sections using some representative input in the restricted SUSY parameter space. The coherent matrix elements are computed throughout the periodic table while the spin matrix elements for the proposed $^{207}Pb$ target which has a rather simple nuclear structure. The results are compared to those given from other cold dark matter detection targets.
2205.01425
Mohammad Alhakami
Mohammad H. Alhakami, Numa A. Althubiti and Nwuyer A. Al-shammari
Hadronic loop effects to excited scalar charmed mesons revisited
null
null
10.1088/1361-6471/acb95e
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We re-examine the hadronic loop effects to the masses of $D^*_0$ and $D^*_{s0}$ calculated in quark models in the framework of heavy meson chiral perturbation theory (HMCHPT). The inaccuracy in the choice of the argument of the chiral loop functions in previous works is corrected. Our calculations consider the full one-loop corrections that appear at leading order in the chiral expansion of the effective Lagrangian. Unlike previous approaches, ours leads to satisfactory results in explaining the low mass of the observed scalar charm states reported by the Particle Data Group (PDG). It is found that the mass shift of bare $D^*_{s0}$ ($D^*_{0}$) state is mainly due to the $DK$ ($D\pi$) loop corrections for values of the couplings that are compatible with the measured ones. We show why previous approaches of using HMCHPT in studying mass shift effects due to chiral loops gave unsatisfactory results.
[ { "created": "Tue, 3 May 2022 11:31:15 GMT", "version": "v1" } ]
2023-03-22
[ [ "Alhakami", "Mohammad H.", "" ], [ "Althubiti", "Numa A.", "" ], [ "Al-shammari", "Nwuyer A.", "" ] ]
We re-examine the hadronic loop effects to the masses of $D^*_0$ and $D^*_{s0}$ calculated in quark models in the framework of heavy meson chiral perturbation theory (HMCHPT). The inaccuracy in the choice of the argument of the chiral loop functions in previous works is corrected. Our calculations consider the full one-loop corrections that appear at leading order in the chiral expansion of the effective Lagrangian. Unlike previous approaches, ours leads to satisfactory results in explaining the low mass of the observed scalar charm states reported by the Particle Data Group (PDG). It is found that the mass shift of bare $D^*_{s0}$ ($D^*_{0}$) state is mainly due to the $DK$ ($D\pi$) loop corrections for values of the couplings that are compatible with the measured ones. We show why previous approaches of using HMCHPT in studying mass shift effects due to chiral loops gave unsatisfactory results.
2105.04401
Roberto Bruschini M.S.
R. Bruschini and P. Gonz\'alez
Diabatic description of bottomoniumlike mesons
12 pages, 5 figures, 8 tables; v2: corrected values in Table VII
Phys. Rev. D 103, 114016 (2021)
10.1103/PhysRevD.103.114016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply the diabatic approach, specially suited for a QCD based study of conventional (quark-antiquark) and unconventional (quark-antiquark + meson-meson) meson states, to the description of hidden-bottom mesons. A spectral analysis of the $I=0$, $J^{++}$ and $1^{--}$ resonances with masses up to about $10.8$ GeV is carried out. Masses and widths of all the experimentally known resonances, including conventional and unconventional states, can be well reproduced. In particular, we predict a significant $B\bar{B}^{\ast}$ component in $\Upsilon(10580)$. We also predict the existence of a not yet discovered unconventional $1^{++}$ narrow state, with a significant $B_{s}\bar{B}_{s}^{\ast}$ content making it to decay into $\Upsilon(1S)\phi$, whose experimental discovery would provide definite support to our theoretical analysis.
[ { "created": "Mon, 10 May 2021 14:25:22 GMT", "version": "v1" }, { "created": "Wed, 19 May 2021 10:13:31 GMT", "version": "v2" } ]
2021-06-23
[ [ "Bruschini", "R.", "" ], [ "González", "P.", "" ] ]
We apply the diabatic approach, specially suited for a QCD based study of conventional (quark-antiquark) and unconventional (quark-antiquark + meson-meson) meson states, to the description of hidden-bottom mesons. A spectral analysis of the $I=0$, $J^{++}$ and $1^{--}$ resonances with masses up to about $10.8$ GeV is carried out. Masses and widths of all the experimentally known resonances, including conventional and unconventional states, can be well reproduced. In particular, we predict a significant $B\bar{B}^{\ast}$ component in $\Upsilon(10580)$. We also predict the existence of a not yet discovered unconventional $1^{++}$ narrow state, with a significant $B_{s}\bar{B}_{s}^{\ast}$ content making it to decay into $\Upsilon(1S)\phi$, whose experimental discovery would provide definite support to our theoretical analysis.
1704.05189
Kazunori Kohri
Kazunori Kohri, and Hideo Kodama
Axion-Like Particles and Recent Observations of the Cosmic Infrared Background Radiation
To appear in PRD Rapid Communications, 6 pages, 5 figures
Phys. Rev. D 96, 051701 (2017)
10.1103/PhysRevD.96.051701
KEK-Cosmo-200, KEK-TH-1974
hep-ph astro-ph.CO astro-ph.GA astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CIBER collaboration released their first observational data of the Cosmic IR background (CIB) radiation, which has significant excesses at around the wavelength $\sim$ 1 $\mu$m compared to theoretically-inferred values. The amount of the CIB radiation has a significant influence on the opaqueness of the Universe for TeV gamma-rays emitted from distant sources such as AGNs. With the value of CIB radiation reported by the CIBER experiment, through the reaction of such TeV gamma-rays with the CIB photons, the TeV gamma-rays should be significantly attenuated during propagation, which would lead to energy spectra in disagreement with current observations of TeV gamma ray sources. In this article, we discuss a possible resolution of this tension between the TeV gamma-ray observations and the CIB data in terms of axion [or Axion-Like Particles (ALPs)] that may increase the transparency of the Universe by the anomaly-induced photon-axion mixing. We find a region in the parameter space of the axion mass, $m_a \sim 7 \times 10^{-10} - 5 \times 10^{-8}$eV, and the axion-photon coupling constant, $1.2 \times 10^{-11} {\rm GeV}^{-1} \lesssim g_{a\gamma} \lesssim 8.8 \times 10^{-10} {\rm GeV}^{-1}$ that solves this problem.
[ { "created": "Tue, 18 Apr 2017 03:35:42 GMT", "version": "v1" }, { "created": "Thu, 21 Sep 2017 11:13:29 GMT", "version": "v2" } ]
2017-10-04
[ [ "Kohri", "Kazunori", "" ], [ "Kodama", "Hideo", "" ] ]
The CIBER collaboration released their first observational data of the Cosmic IR background (CIB) radiation, which has significant excesses at around the wavelength $\sim$ 1 $\mu$m compared to theoretically-inferred values. The amount of the CIB radiation has a significant influence on the opaqueness of the Universe for TeV gamma-rays emitted from distant sources such as AGNs. With the value of CIB radiation reported by the CIBER experiment, through the reaction of such TeV gamma-rays with the CIB photons, the TeV gamma-rays should be significantly attenuated during propagation, which would lead to energy spectra in disagreement with current observations of TeV gamma ray sources. In this article, we discuss a possible resolution of this tension between the TeV gamma-ray observations and the CIB data in terms of axion [or Axion-Like Particles (ALPs)] that may increase the transparency of the Universe by the anomaly-induced photon-axion mixing. We find a region in the parameter space of the axion mass, $m_a \sim 7 \times 10^{-10} - 5 \times 10^{-8}$eV, and the axion-photon coupling constant, $1.2 \times 10^{-11} {\rm GeV}^{-1} \lesssim g_{a\gamma} \lesssim 8.8 \times 10^{-10} {\rm GeV}^{-1}$ that solves this problem.
2105.06846
Joachim Kopp
Vedran Brdar, Admir Greljo, Joachim Kopp, Toby Opferkuch
The Neutrino Magnetic Moment Portal
6 pages, 3 figures; contribution to the Proceedings of the 2021 EW session of the 55th Rencontres de Moriond
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss neutrino magnetic moments as a way of constraining physics beyond the Standard Model. In fact, new physics at the TeV scale can easily generate observable neutrino magnetic moments, and there exists a multitude of ways of probing them. We highlight in particular direct dark matter detection experiments (which are sensitive to neutrino magnetic moments because of the predicted modifications to the solar neutrino scattering rate), stellar cooling, and cosmological constraints.
[ { "created": "Fri, 14 May 2021 14:18:09 GMT", "version": "v1" } ]
2021-05-17
[ [ "Brdar", "Vedran", "" ], [ "Greljo", "Admir", "" ], [ "Kopp", "Joachim", "" ], [ "Opferkuch", "Toby", "" ] ]
We discuss neutrino magnetic moments as a way of constraining physics beyond the Standard Model. In fact, new physics at the TeV scale can easily generate observable neutrino magnetic moments, and there exists a multitude of ways of probing them. We highlight in particular direct dark matter detection experiments (which are sensitive to neutrino magnetic moments because of the predicted modifications to the solar neutrino scattering rate), stellar cooling, and cosmological constraints.
hep-ph/0111361
Philip Page
Rui Zhang, Yi-Bing Ding, Xue-Qian Li, Philip R. Page
Molecular States and 1^-+ Exotic Mesons
23 pages, 1 figure, LaTeX
Phys.Rev.D65:096005,2002
10.1103/PhysRevD.65.096005
LA-UR-01-6434
hep-ph
null
This work investigates whether the observed 1^-+ exotic mesons are molecular states. We first use a potential model to calculate the spectra and lifetimes of the f_0(980) and a_0(980), taken to be loosely bound molecular states of K Kbar, then apply the same scenario to the 1^-+ exotic states pi_1(1400) and pi_1(1600), assuming them to be pi eta(1295) and pi eta(1440) molecules respectively. We derive the effective potential in the framework of field theory at the hadronic level. Our results indicate that the present data on pi_1(1400) and pi_1(1600) rule out the specific molecular ansatz. We show that the lifetime of a loosely bound heavy-light molecule with enough angular momentum is fully determined by the lifetimes of its constituent mesons.
[ { "created": "Wed, 28 Nov 2001 00:20:28 GMT", "version": "v1" }, { "created": "Wed, 27 Mar 2002 22:27:32 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zhang", "Rui", "" ], [ "Ding", "Yi-Bing", "" ], [ "Li", "Xue-Qian", "" ], [ "Page", "Philip R.", "" ] ]
This work investigates whether the observed 1^-+ exotic mesons are molecular states. We first use a potential model to calculate the spectra and lifetimes of the f_0(980) and a_0(980), taken to be loosely bound molecular states of K Kbar, then apply the same scenario to the 1^-+ exotic states pi_1(1400) and pi_1(1600), assuming them to be pi eta(1295) and pi eta(1440) molecules respectively. We derive the effective potential in the framework of field theory at the hadronic level. Our results indicate that the present data on pi_1(1400) and pi_1(1600) rule out the specific molecular ansatz. We show that the lifetime of a loosely bound heavy-light molecule with enough angular momentum is fully determined by the lifetimes of its constituent mesons.
1910.06159
R. Sekhar Chivukula
R. Sekhar Chivukula, Dennis Foren, Kirtimaan A Mohan, Dipan Sengupta, and Elizabeth H. Simmons
Sum Rules for Massive Spin-2 Kaluza-Klein Elastic Scattering Amplitudes
Minor revisions added in response to referee
Phys. Rev. D 100, 115033 (2019)
10.1103/PhysRevD.100.115033
MSUHEP-19-023
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has recently been shown explicitly that the high-energy scattering amplitude of the longitudinal modes of massive spin-2 Kaluza Klein states in compactified 5-dimensional gravity, which would naively grow like O(s^5), grow only like O(s). Since the individual contributions to these amplitudes do grow like O(s^5), the required cancellations between these individual contributions result from intricate relationships between the masses of these states and their couplings. Here we report the explicit form of these sum-rule relationships which ensure the necessary cancellations for elastic scattering of spin-2 Kaluza Klein states in a Randall-Sundrum model. We consider an Anti-de-Sitter space of arbitrary curvature, including the special case of a toroidal compactification in which the curvature vanishes. The sum rules demonstrate that the cancellations at O(s^5) and O(s^4) are generic for a compact extra dimension, and arise from the Sturm-Liouville structure of the eigenmode system in the internal space. Separately, the sum rules at O(s^3) and O(s^2) illustrate the essential role of the radion mode of the extra-dimensional metric, which is the dynamical mode related to the size of the internal space.
[ { "created": "Mon, 14 Oct 2019 14:13:42 GMT", "version": "v1" }, { "created": "Wed, 16 Oct 2019 16:11:23 GMT", "version": "v2" }, { "created": "Thu, 5 Dec 2019 05:08:07 GMT", "version": "v3" } ]
2019-12-25
[ [ "Chivukula", "R. Sekhar", "" ], [ "Foren", "Dennis", "" ], [ "Mohan", "Kirtimaan A", "" ], [ "Sengupta", "Dipan", "" ], [ "Simmons", "Elizabeth H.", "" ] ]
It has recently been shown explicitly that the high-energy scattering amplitude of the longitudinal modes of massive spin-2 Kaluza Klein states in compactified 5-dimensional gravity, which would naively grow like O(s^5), grow only like O(s). Since the individual contributions to these amplitudes do grow like O(s^5), the required cancellations between these individual contributions result from intricate relationships between the masses of these states and their couplings. Here we report the explicit form of these sum-rule relationships which ensure the necessary cancellations for elastic scattering of spin-2 Kaluza Klein states in a Randall-Sundrum model. We consider an Anti-de-Sitter space of arbitrary curvature, including the special case of a toroidal compactification in which the curvature vanishes. The sum rules demonstrate that the cancellations at O(s^5) and O(s^4) are generic for a compact extra dimension, and arise from the Sturm-Liouville structure of the eigenmode system in the internal space. Separately, the sum rules at O(s^3) and O(s^2) illustrate the essential role of the radion mode of the extra-dimensional metric, which is the dynamical mode related to the size of the internal space.
2408.06426
Wen Chen
Wen Chen
Semi-automatic Calculations of Multi-loop Feynman Amplitudes with AmpRed
29 pages
null
null
null
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
We present a Mathematica package AmpRed for the semi-automatic calculations of multi-loop Feynman amplitudes with high efficiency and precision. AmpRed implements the methods of integration by parts and differential equations in the Feynman-parameter representation. It allows for the calculations of general parametric integrals (which may not have momentum-space correspondences). Various user-friendly tools for multi-loop calculations, such as those to construct and solve differential equations for Feynman integrals, are provided. It can also deal with tensor algebras in non-relativistic field theories. Interfaces to some packages, like QGRAF and FOMR, are also provided.
[ { "created": "Mon, 12 Aug 2024 18:07:28 GMT", "version": "v1" } ]
2024-08-14
[ [ "Chen", "Wen", "" ] ]
We present a Mathematica package AmpRed for the semi-automatic calculations of multi-loop Feynman amplitudes with high efficiency and precision. AmpRed implements the methods of integration by parts and differential equations in the Feynman-parameter representation. It allows for the calculations of general parametric integrals (which may not have momentum-space correspondences). Various user-friendly tools for multi-loop calculations, such as those to construct and solve differential equations for Feynman integrals, are provided. It can also deal with tensor algebras in non-relativistic field theories. Interfaces to some packages, like QGRAF and FOMR, are also provided.
2404.12182
Jaume Carbonell
Jaume Carbonell1, Vladimir Karmanov, Ekaterina Kupriyanova, Hagop Sazdjian
Abnormal solutions of Bethe--Salpeter equation with massless and massive exchanges
19 pages, 8 figures. Talk given at Workshop Critical Stability, ECT* oct 2023. To appear in Few-Body Systems
Few-Body Syst. 65, 56 (2024)
null
null
hep-ph cond-mat.str-el nucl-th quant-ph
http://creativecommons.org/publicdomain/zero/1.0/
We summarize the main properties of the so called ''abnormal solutions'' of the Wick--Cutkosky model, i.e. two massive scalar particles interacting via massless scalar exchange ("photons"), within the Bethe--Salpeter equation. These solutions do not exist in the non-relativistic limit, in spite of having very small binding energies. They present a genuine many-body character dominated by photons, with a norm of the valence constituent wave function (two-body norm) that vanishes in the limit of zero binding energy. We present new results concerning the massive-exchange case, in particular determine under which conditions is it possible to obtain such peculiar solutions without spoiling the model by tachyonic states ($M^2<0$).
[ { "created": "Thu, 18 Apr 2024 13:41:14 GMT", "version": "v1" } ]
2024-05-17
[ [ "Carbonell1", "Jaume", "" ], [ "Karmanov", "Vladimir", "" ], [ "Kupriyanova", "Ekaterina", "" ], [ "Sazdjian", "Hagop", "" ] ]
We summarize the main properties of the so called ''abnormal solutions'' of the Wick--Cutkosky model, i.e. two massive scalar particles interacting via massless scalar exchange ("photons"), within the Bethe--Salpeter equation. These solutions do not exist in the non-relativistic limit, in spite of having very small binding energies. They present a genuine many-body character dominated by photons, with a norm of the valence constituent wave function (two-body norm) that vanishes in the limit of zero binding energy. We present new results concerning the massive-exchange case, in particular determine under which conditions is it possible to obtain such peculiar solutions without spoiling the model by tachyonic states ($M^2<0$).
1712.09360
Andreas Trautner
Stuart Raby and Andreas Trautner
A "Vector-like chiral" fourth family to explain muon anomalies
15 pages + Appendix, 4 figures, 4 tables; v2: added references
Phys. Rev. D 97, 095006 (2018)
10.1103/PhysRevD.97.095006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model (SM) is amended by one generation of quarks and leptons which are vector-like (VL) under the SM gauge group but chiral with respect to a new $\mathrm{U}(1)_{3-4}$ gauge symmetry. We show that this model can simultaneously explain the deviation of the muon $g-2$ as well as the observed anomalies in $b\rightarrow s\mu^+\mu^-$ transitions without conflicting with the data on Higgs decays, lepton flavor violation, or $B_s-\bar{B}_s$ mixing. The model is string theory motivated and GUT compatible, i.e. UV complete, and fits the data predicting VL quarks, leptons and a massive $Z'$ at the $\mathrm{TeV}$ scale, as well as $\tau\to3\mu$ and $\tau\to\mu\gamma$ within reach of future experiments. The Higgs couplings to SM generations are automatically aligned in flavor space.
[ { "created": "Tue, 26 Dec 2017 19:00:00 GMT", "version": "v1" }, { "created": "Fri, 5 Jan 2018 12:01:35 GMT", "version": "v2" } ]
2018-05-16
[ [ "Raby", "Stuart", "" ], [ "Trautner", "Andreas", "" ] ]
The Standard Model (SM) is amended by one generation of quarks and leptons which are vector-like (VL) under the SM gauge group but chiral with respect to a new $\mathrm{U}(1)_{3-4}$ gauge symmetry. We show that this model can simultaneously explain the deviation of the muon $g-2$ as well as the observed anomalies in $b\rightarrow s\mu^+\mu^-$ transitions without conflicting with the data on Higgs decays, lepton flavor violation, or $B_s-\bar{B}_s$ mixing. The model is string theory motivated and GUT compatible, i.e. UV complete, and fits the data predicting VL quarks, leptons and a massive $Z'$ at the $\mathrm{TeV}$ scale, as well as $\tau\to3\mu$ and $\tau\to\mu\gamma$ within reach of future experiments. The Higgs couplings to SM generations are automatically aligned in flavor space.
2211.15954
Adam Lackner
Tobias Felkl, Adam Lackner, Michael A. Schmidt
Riding the Seesaw: What Higgsstrahlung May Reveal about Massive Neutrinos
37 pages, 8 figures. v3: Updated to match published version - added references, considered more nuclei for LFV, improved discussion; conclusions unchanged. v2: Added references, corrected error in R(V_us), added Feynman diagrams, improved discussion; conclusions unchanged
Eur.Phys.J.C 83 (2023) 4, 342
10.1140/epjc/s10052-023-11461-7
CPPC-2022-12
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate if the projected high-precision measurements of the cross section of the Higgsstrahlung process $e^+ e^- \to Zh$ at a future electron-positron collider can be utilised to indirectly probe the fermionic Seesaw models. We consider the two centre-of-mass energies $\sqrt{s}=240$ GeV and $365$ GeV, and compare the collider reaches to constraints from electroweak observables, probes of lepton flavour universality and the existing and prospective bounds from searches for lepton flavour violation. For the analysis we assume the limit of an exactly conserved lepton-number symmetry. We find that while any appreciable correction to the Higgsstrahlung cross section is already strictly constrained in the Type-I Seesaw model, effects of up to $\mathcal{O}(10\%)$ are possible within Type-III Seesaw.
[ { "created": "Tue, 29 Nov 2022 06:26:42 GMT", "version": "v1" }, { "created": "Fri, 6 Jan 2023 05:38:05 GMT", "version": "v2" }, { "created": "Wed, 10 May 2023 02:28:09 GMT", "version": "v3" } ]
2023-05-11
[ [ "Felkl", "Tobias", "" ], [ "Lackner", "Adam", "" ], [ "Schmidt", "Michael A.", "" ] ]
We investigate if the projected high-precision measurements of the cross section of the Higgsstrahlung process $e^+ e^- \to Zh$ at a future electron-positron collider can be utilised to indirectly probe the fermionic Seesaw models. We consider the two centre-of-mass energies $\sqrt{s}=240$ GeV and $365$ GeV, and compare the collider reaches to constraints from electroweak observables, probes of lepton flavour universality and the existing and prospective bounds from searches for lepton flavour violation. For the analysis we assume the limit of an exactly conserved lepton-number symmetry. We find that while any appreciable correction to the Higgsstrahlung cross section is already strictly constrained in the Type-I Seesaw model, effects of up to $\mathcal{O}(10\%)$ are possible within Type-III Seesaw.
hep-ph/0508182
Stephen Godfrey
Stephen Godfrey (Carleton University)
New Physics at the TeV Scale and Precision Electroweak Studies
Invited talk at 2005 International Linear Collider Workshop, Stanford Ca (LCWS05) 10 pages, LaTeX, 10 ps figures (PSN 0017). References added and figure corrected
null
null
null
hep-ph
null
In this summary we review some recent developments in New Physics at the TeV scale. We concentrate on measurements at the ILC that can distinguish between some of the models that have recently been discussed, concentrating on results presented at this workshop: The Little Higgs Model, models of Large Extra Dimensions; Randall-Sundrum (RS), Arkani-Hamed Dimopoulos Dvali (ADD), and Universal Extra Dimensions (UED). Some recent results on constraining effective Lagrangian parametrizations of new physics are also presented.
[ { "created": "Wed, 17 Aug 2005 15:47:58 GMT", "version": "v1" }, { "created": "Thu, 25 Aug 2005 20:50:49 GMT", "version": "v2" } ]
2007-05-23
[ [ "Godfrey", "Stephen", "", "Carleton University" ] ]
In this summary we review some recent developments in New Physics at the TeV scale. We concentrate on measurements at the ILC that can distinguish between some of the models that have recently been discussed, concentrating on results presented at this workshop: The Little Higgs Model, models of Large Extra Dimensions; Randall-Sundrum (RS), Arkani-Hamed Dimopoulos Dvali (ADD), and Universal Extra Dimensions (UED). Some recent results on constraining effective Lagrangian parametrizations of new physics are also presented.
hep-ph/0411217
Thomas A. Trainor
Thomas A. Trainor and Duncan J. Prindle
A power-law description of heavy ion collision centrality
21 pages, 18 figures, extensive rewrite, with addition of appendices on numerical integration and systematic errors in participant number calculations
null
null
null
hep-ph
null
The minimum-bias distribution on heavy ion collision multiplicity $n_{ch}$ is well approximated by power-law form $n_{ch}^{-3/4}$, suggesting that a change of variable to $n_{ch}^{1/4}$ may provide more precise access to the structure of the distribution and to A-A collision centrality. We present a detailed centrality study of Hijing-1.37 Monte Carlo data at 200 GeV using the power-law format. We find that the minimum-bias distribution on $n_{participant}^{1/4}$, determined with a Glauber Monte Carlo simulation, is uniform except for a 5% sinusoidal variation. The power-law format reveals precise linear relations between Glauber parameters $n_{part}$ and $n_{bin}$ and the fractional cross section. The power-law format applied to RHIC data facilitates incorporation of extrapolation constraints on data and Glauber distributions to obtain a ten-fold improvement in centrality accuracy for peripheral collisions.
[ { "created": "Wed, 17 Nov 2004 00:45:22 GMT", "version": "v1" }, { "created": "Sat, 8 Oct 2005 23:05:58 GMT", "version": "v2" }, { "created": "Tue, 30 Jan 2007 20:37:36 GMT", "version": "v3" } ]
2007-05-23
[ [ "Trainor", "Thomas A.", "" ], [ "Prindle", "Duncan J.", "" ] ]
The minimum-bias distribution on heavy ion collision multiplicity $n_{ch}$ is well approximated by power-law form $n_{ch}^{-3/4}$, suggesting that a change of variable to $n_{ch}^{1/4}$ may provide more precise access to the structure of the distribution and to A-A collision centrality. We present a detailed centrality study of Hijing-1.37 Monte Carlo data at 200 GeV using the power-law format. We find that the minimum-bias distribution on $n_{participant}^{1/4}$, determined with a Glauber Monte Carlo simulation, is uniform except for a 5% sinusoidal variation. The power-law format reveals precise linear relations between Glauber parameters $n_{part}$ and $n_{bin}$ and the fractional cross section. The power-law format applied to RHIC data facilitates incorporation of extrapolation constraints on data and Glauber distributions to obtain a ten-fold improvement in centrality accuracy for peripheral collisions.
2012.12246
Wolfgang Waltenberger
Wolfgang Waltenberger, Andr\'e Lessa, Sabine Kraml
Artificial Proto-Modelling: Building Precursors of a Next Standard Model from Simplified Model Results
54 pages, 14 figures, two references added in v2. v3 accepted for publication in JHEP. Homepage: https://smodels.github.io/protomodels
Journal of High Energy Physics 2021, 207 (2021)
10.1007/JHEP03(2021)207
null
hep-ph hep-ex stat.AP
http://creativecommons.org/licenses/by/4.0/
We present a novel algorithm to identify potential dispersed signals of new physics in the slew of published LHC results. It employs a random walk algorithm to introduce sets of new particles, dubbed "proto-models", which are tested against simplified-model results from ATLAS and CMS (exploiting the SModelS software framework). A combinatorial algorithm identifies the set of analyses and/or signal regions that maximally violates the SM hypothesis, while remaining compatible with the entirety of LHC constraints in our database. Demonstrating our method by running over the experimental results in the SModelS database, we find as currently best-performing proto-model a top partner, a light-flavor quark partner, and a lightest neutral new particle with masses of the order of 1.2 TeV, 700 GeV and 160 GeV, respectively. The corresponding global p-value for the SM hypothesis is approximately 0.19; by construction no look-elsewhere effect applies.
[ { "created": "Tue, 22 Dec 2020 18:45:22 GMT", "version": "v1" }, { "created": "Tue, 5 Jan 2021 12:05:20 GMT", "version": "v2" }, { "created": "Mon, 15 Mar 2021 11:21:18 GMT", "version": "v3" } ]
2021-03-30
[ [ "Waltenberger", "Wolfgang", "" ], [ "Lessa", "André", "" ], [ "Kraml", "Sabine", "" ] ]
We present a novel algorithm to identify potential dispersed signals of new physics in the slew of published LHC results. It employs a random walk algorithm to introduce sets of new particles, dubbed "proto-models", which are tested against simplified-model results from ATLAS and CMS (exploiting the SModelS software framework). A combinatorial algorithm identifies the set of analyses and/or signal regions that maximally violates the SM hypothesis, while remaining compatible with the entirety of LHC constraints in our database. Demonstrating our method by running over the experimental results in the SModelS database, we find as currently best-performing proto-model a top partner, a light-flavor quark partner, and a lightest neutral new particle with masses of the order of 1.2 TeV, 700 GeV and 160 GeV, respectively. The corresponding global p-value for the SM hypothesis is approximately 0.19; by construction no look-elsewhere effect applies.
hep-ph/9310363
Jim Pantaleone
J. Pantaleone
Constraints on Three-Neutrino Mixing from Atmospheric and Reactor Data
15 pages, preprint IUHET-264
Phys.Rev.D49:2152-2155,1994
10.1103/PhysRevD.49.R2152
null
hep-ph
null
Observations of atmospheric neutrinos are usually analyzed using the simplifying approximation that either \(\nu_\mu \leftrightarrow \nu_\tau\) or \(\nu_e \leftrightarrow \nu_\mu\) two-flavor mixing is relevant. Here we instead consider the data using the simplifying approximation that only one neutrino mass scale is relevant. This approximation is the minimal three-flavor notation that includes the two relevant two-flavor approximations. The constraints in the parameter space orthogonal to the usual, two-flavor analyses are studied.
[ { "created": "Wed, 27 Oct 1993 18:52:38 GMT", "version": "v1" } ]
2009-12-30
[ [ "Pantaleone", "J.", "" ] ]
Observations of atmospheric neutrinos are usually analyzed using the simplifying approximation that either \(\nu_\mu \leftrightarrow \nu_\tau\) or \(\nu_e \leftrightarrow \nu_\mu\) two-flavor mixing is relevant. Here we instead consider the data using the simplifying approximation that only one neutrino mass scale is relevant. This approximation is the minimal three-flavor notation that includes the two relevant two-flavor approximations. The constraints in the parameter space orthogonal to the usual, two-flavor analyses are studied.
0708.3759
Bojan Golli
Bojan Golli, Simon Sirca
Roper resonances in chiral quark models
17 pages, 7 figures
Eur.Phys.J.A38:271-286,2008
10.1140/epja/i2008-10677-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a method to calculate the multi-channel K matrix applicable to a broad class of models in which mesons linearly couple to the quark core. The method is used to calculate pion scattering amplitudes in the energy region of low-lying P11 and P33 resonances. A good agreement with experimental data is achieved if in addition to the elastic channel we include the $\pi\Delta$ and $\sigma N$ ($\sigma\Delta$) channels where the $\sigma$-meson models the correlated two-pion decay. We solve the integral equation for the K matrix in the approximation of separable kernels; it yields a sizable increase of the widths of the $\Delta(1232)$ and the N(1440) resonances compared to the bare quark values.
[ { "created": "Tue, 28 Aug 2007 11:28:45 GMT", "version": "v1" }, { "created": "Thu, 30 Oct 2008 10:22:27 GMT", "version": "v2" } ]
2008-12-18
[ [ "Golli", "Bojan", "" ], [ "Sirca", "Simon", "" ] ]
We derive a method to calculate the multi-channel K matrix applicable to a broad class of models in which mesons linearly couple to the quark core. The method is used to calculate pion scattering amplitudes in the energy region of low-lying P11 and P33 resonances. A good agreement with experimental data is achieved if in addition to the elastic channel we include the $\pi\Delta$ and $\sigma N$ ($\sigma\Delta$) channels where the $\sigma$-meson models the correlated two-pion decay. We solve the integral equation for the K matrix in the approximation of separable kernels; it yields a sizable increase of the widths of the $\Delta(1232)$ and the N(1440) resonances compared to the bare quark values.
hep-ph/0608207
Martin Hirsch
M. Hirsch, S. Kovalenko, I. Schmidt
Extended Black Box Theorem for Lepton Number and Flavor Violating processes
11 pages, 1 fig
Phys.Lett.B642:106-110,2006
10.1016/j.physletb.2006.09.012
USM-TH-193
hep-ph
null
We revisit the well known "Black Box" theorem establishing a fundamental relation between the amplitude of neutrinoless double beta decay and the effective Majorana neutrino mass. We extend this theorem to the general case of arbitrary lepton number and lepton flavor violating (LFNV) processes and to the three generation Majorana neutrino mass matrix. We demonstrate the existence of a general set of one-to-one correspondence relations between the effective operators generating these processes, and elements of the neutrino mass matrix, such that if one of these two quantities vanishes the other is guaranteed to vanish as well, and moreover, if one of these quantities is non-zero the other is guaranteed to be non-zero. We stress that this statement remains valid even in the presence of arbitrary new physics contributions. As a particularly important example, we then show that neutrino oscillation data imply that neutrinoless double beta decay must occur at a certain non-zero rate.
[ { "created": "Fri, 18 Aug 2006 09:34:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hirsch", "M.", "" ], [ "Kovalenko", "S.", "" ], [ "Schmidt", "I.", "" ] ]
We revisit the well known "Black Box" theorem establishing a fundamental relation between the amplitude of neutrinoless double beta decay and the effective Majorana neutrino mass. We extend this theorem to the general case of arbitrary lepton number and lepton flavor violating (LFNV) processes and to the three generation Majorana neutrino mass matrix. We demonstrate the existence of a general set of one-to-one correspondence relations between the effective operators generating these processes, and elements of the neutrino mass matrix, such that if one of these two quantities vanishes the other is guaranteed to vanish as well, and moreover, if one of these quantities is non-zero the other is guaranteed to be non-zero. We stress that this statement remains valid even in the presence of arbitrary new physics contributions. As a particularly important example, we then show that neutrino oscillation data imply that neutrinoless double beta decay must occur at a certain non-zero rate.
2210.01148
Aleksandr Chatrchyan Dr.
Aleksandr Chatrchyan and G\'eraldine Servant
The Stochastic Relaxion
35 pages and 16 figures in main text, and 15 pages and 2 figures in appendices
null
10.1007/JHEP06(2023)107
DESY-22-149
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We revisit the original proposal of cosmological relaxation of the electroweak scale by Graham, Kaplan and Rajendran in which the Higgs mass is scanned during inflation by an axion field, the relaxion. We investigate the regime where the relaxion is subject to large fluctuations during inflation. The stochastic dynamics of the relaxion is described by means of the Fokker-Planck formalism. We derive a new stopping condition for the relaxion taking into account transitions between the neighboring local minima of its potential. Relaxion fluctuations have important consequences even in the "classical-beats-quantum" regime. We determine that for a large Hubble parameter during inflation, the random walk prevents the relaxion from getting trapped at the first minimum. The relaxion stops much further away, where the potential is less shallow. Interestingly, this essentially jeopardises the "runaway relaxion" threat from finite-density effects, restoring most of the relaxion parameter space. We also explore the "quantum-beats-classical" regime, opening large new regions of parameter space. We investigate the consequences for both the QCD and the non-QCD relaxion. The misalignment of the relaxion due to fluctuations around its local minimum opens new phenomenological opportunities.
[ { "created": "Mon, 3 Oct 2022 18:00:51 GMT", "version": "v1" } ]
2023-07-05
[ [ "Chatrchyan", "Aleksandr", "" ], [ "Servant", "Géraldine", "" ] ]
We revisit the original proposal of cosmological relaxation of the electroweak scale by Graham, Kaplan and Rajendran in which the Higgs mass is scanned during inflation by an axion field, the relaxion. We investigate the regime where the relaxion is subject to large fluctuations during inflation. The stochastic dynamics of the relaxion is described by means of the Fokker-Planck formalism. We derive a new stopping condition for the relaxion taking into account transitions between the neighboring local minima of its potential. Relaxion fluctuations have important consequences even in the "classical-beats-quantum" regime. We determine that for a large Hubble parameter during inflation, the random walk prevents the relaxion from getting trapped at the first minimum. The relaxion stops much further away, where the potential is less shallow. Interestingly, this essentially jeopardises the "runaway relaxion" threat from finite-density effects, restoring most of the relaxion parameter space. We also explore the "quantum-beats-classical" regime, opening large new regions of parameter space. We investigate the consequences for both the QCD and the non-QCD relaxion. The misalignment of the relaxion due to fluctuations around its local minimum opens new phenomenological opportunities.
1410.6288
Roman Nevzorov
P. Athron, M. Muhlleitner, R. Nevzorov, A.G. Williams
Non-Standard Higgs Decays in U(1) Extensions of the MSSM
38 pages, 1 figure, some minor changes to the text, references added
null
10.1007/JHEP01(2015)153
ADP-14-29-T887, KA-TP-29-2014, SFB/CPP-14-79
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In U(1) extensions of the Minimal Supersymmetric extension of the Standard Model there is a simple mechanism that leads to a heavy Z' boson with a mass which is substantially larger than the supersymmetry breaking scale. This mechanism may also result in a pseudoscalar state that is light enough for decays of the 125 GeV Standard Model-like Higgs boson into a pair of such pseudoscalars to be kinematically allowed. We study these decays within E6 inspired supersymmetric models with an exact custodial symmetry that forbids tree-level flavor-changing transitions and the most dangerous baryon and lepton number violating operators. We argue that the branching ratio of the lightest Higgs boson decays into a pair of the light pseudoscalar states may not be negligibly small.
[ { "created": "Thu, 23 Oct 2014 08:34:38 GMT", "version": "v1" }, { "created": "Wed, 5 Nov 2014 10:40:54 GMT", "version": "v2" } ]
2015-06-23
[ [ "Athron", "P.", "" ], [ "Muhlleitner", "M.", "" ], [ "Nevzorov", "R.", "" ], [ "Williams", "A. G.", "" ] ]
In U(1) extensions of the Minimal Supersymmetric extension of the Standard Model there is a simple mechanism that leads to a heavy Z' boson with a mass which is substantially larger than the supersymmetry breaking scale. This mechanism may also result in a pseudoscalar state that is light enough for decays of the 125 GeV Standard Model-like Higgs boson into a pair of such pseudoscalars to be kinematically allowed. We study these decays within E6 inspired supersymmetric models with an exact custodial symmetry that forbids tree-level flavor-changing transitions and the most dangerous baryon and lepton number violating operators. We argue that the branching ratio of the lightest Higgs boson decays into a pair of the light pseudoscalar states may not be negligibly small.
hep-ph/0009290
Zurab Berezhiani
Zurab Berezhiani, Leonida Gianfagna, Maurizio Giannotti
Strong CP problem and mirror world: the Weinberg Wilczek axion revisited
13 LaTex pages, 3 Postscript figures
Phys.Lett. B500 (2001) 286-296
10.1016/S0370-2693(00)01392-7
null
hep-ph
null
A new possibility for solving the strong CP-problem is suggested,which assumes that apart of the ordinary world of observable particles described by standard model, there exits a mirror sector of particles and two sectors share the same Peccei-Quinn symmetry realized {\it a l\`a} Weinberg-Wilczek model. The mirror gauge group is completely analogous to that of the standard model for ordinary particles but having somewhat larger electroweak scale,which in turn implies the infrared scale $\Lambda'$ of the mirror strong interactions has to be larger than the ordinary QCD scale $\Lambda$. In this way, the axion mass and interaction constants are actually determined by mirror sector scales $v'$ and $\Lambda'$, while the $\theta$ terms are simultaneously cancelled in both sectors due to mirror symmetry. The experimental and astrophysical limits on such an axion is discussed. An interesting parameter window is found where $f_a \sim {\rm few}\times 10^4$ GeV whereas the axion mass is $\sim 1$ MeV.
[ { "created": "Mon, 25 Sep 2000 21:28:40 GMT", "version": "v1" }, { "created": "Mon, 29 Jan 2001 17:33:18 GMT", "version": "v2" } ]
2009-10-31
[ [ "Berezhiani", "Zurab", "" ], [ "Gianfagna", "Leonida", "" ], [ "Giannotti", "Maurizio", "" ] ]
A new possibility for solving the strong CP-problem is suggested,which assumes that apart of the ordinary world of observable particles described by standard model, there exits a mirror sector of particles and two sectors share the same Peccei-Quinn symmetry realized {\it a l\`a} Weinberg-Wilczek model. The mirror gauge group is completely analogous to that of the standard model for ordinary particles but having somewhat larger electroweak scale,which in turn implies the infrared scale $\Lambda'$ of the mirror strong interactions has to be larger than the ordinary QCD scale $\Lambda$. In this way, the axion mass and interaction constants are actually determined by mirror sector scales $v'$ and $\Lambda'$, while the $\theta$ terms are simultaneously cancelled in both sectors due to mirror symmetry. The experimental and astrophysical limits on such an axion is discussed. An interesting parameter window is found where $f_a \sim {\rm few}\times 10^4$ GeV whereas the axion mass is $\sim 1$ MeV.
hep-ph/0509337
Kwei-Chou Yang
Kwei-Chou Yang (CYCU)
Light-Cone Distribution Amplitudes for the Light $1^1P_1$ Mesons
18 pages, 9 figures, v3: a sentence revised in the introduction, to appear in JHEP
JHEP0510:108,2005
10.1088/1126-6708/2005/10/108
null
hep-ph
null
We present a study of light-cone distribution amplitudes of the light $1^1P_1$ mesons. The first few Gegenbauer moments of leading twist light-cone distribution amplitudes are calculated by using the QCD sum rule technique.
[ { "created": "Wed, 28 Sep 2005 23:35:54 GMT", "version": "v1" }, { "created": "Thu, 13 Oct 2005 18:24:42 GMT", "version": "v2" }, { "created": "Thu, 27 Oct 2005 14:19:09 GMT", "version": "v3" } ]
2009-11-11
[ [ "Yang", "Kwei-Chou", "", "CYCU" ] ]
We present a study of light-cone distribution amplitudes of the light $1^1P_1$ mesons. The first few Gegenbauer moments of leading twist light-cone distribution amplitudes are calculated by using the QCD sum rule technique.
1705.03466
Torsten Bringmann
Torsten Bringmann, Francesca Calore, Ahmad Galea and Mathias Garny
Electroweak and Higgs Boson Internal Bremsstrahlung: General considerations for Majorana dark matter annihilation and application to MSSM neutralinos
64 pages with jheppub.sty, 15 figures and 12 tables. Slightly extended discussion + minor updates to match published version
JHEP 1709 (2017) 041
10.1007/JHEP09(2017)041
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that the annihilation of Majorana dark matter into fermions is helicity suppressed. Here, we point out that the underlying mechanism is a subtle combination of two distinct effects, and we present a comprehensive analysis of how the suppression can be partially or fully lifted by the internal bremsstrahlung of an additional boson in the final state. As a concrete illustration, we compute analytically the full amplitudes and annihilation rates of supersymmetric neutralinos to final states that contain any combination of two standard model fermions, plus one electroweak gauge boson or one of the five physical Higgs bosons that appear in the minimal supersymmetric standard model. We classify the various ways in which these three-body rates can be large compared to the two-body rates, identifying cases that have not been pointed out before. In our analysis, we put special emphasis on how to avoid the double counting of identical kinematic situations that appear for two-body and three-body final states, in particular on how to correctly treat differential rates and the spectrum of the resulting stable particles that is relevant for indirect dark matter searches. We find that both the total annihilation rates and the yields can be significantly enhanced when taking into account the corrections computed here, in particular for models with somewhat small annihilation rates at tree-level which otherwise would not be testable with indirect dark matter searches. Even more importantly, however, we find that the resulting annihilation spectra of positrons, neutrinos, gamma-rays and antiprotons differ in general substantially from the model-independent spectra that are commonly adopted, for these final states, when constraining particle dark matter with indirect detection experiments.
[ { "created": "Tue, 9 May 2017 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 19 Sep 2017 17:48:47 GMT", "version": "v2" } ]
2017-09-20
[ [ "Bringmann", "Torsten", "" ], [ "Calore", "Francesca", "" ], [ "Galea", "Ahmad", "" ], [ "Garny", "Mathias", "" ] ]
It is well known that the annihilation of Majorana dark matter into fermions is helicity suppressed. Here, we point out that the underlying mechanism is a subtle combination of two distinct effects, and we present a comprehensive analysis of how the suppression can be partially or fully lifted by the internal bremsstrahlung of an additional boson in the final state. As a concrete illustration, we compute analytically the full amplitudes and annihilation rates of supersymmetric neutralinos to final states that contain any combination of two standard model fermions, plus one electroweak gauge boson or one of the five physical Higgs bosons that appear in the minimal supersymmetric standard model. We classify the various ways in which these three-body rates can be large compared to the two-body rates, identifying cases that have not been pointed out before. In our analysis, we put special emphasis on how to avoid the double counting of identical kinematic situations that appear for two-body and three-body final states, in particular on how to correctly treat differential rates and the spectrum of the resulting stable particles that is relevant for indirect dark matter searches. We find that both the total annihilation rates and the yields can be significantly enhanced when taking into account the corrections computed here, in particular for models with somewhat small annihilation rates at tree-level which otherwise would not be testable with indirect dark matter searches. Even more importantly, however, we find that the resulting annihilation spectra of positrons, neutrinos, gamma-rays and antiprotons differ in general substantially from the model-independent spectra that are commonly adopted, for these final states, when constraining particle dark matter with indirect detection experiments.
1611.09145
Takaaki Nomura
Seungwon Baek, Takaaki Nomura
Dark matter physics in neutrino specific two Higgs doublet model
18 pages, 5 figures, Version accepted by JHEP
null
10.1007/JHEP03(2017)059
KIAS-P16086
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although the seesaw mechanism is a natural explanation for the small neutrino masses, there are cases when the Majorana mass terms for the right-handed neutrinos are not allowed due to symmetry. In that case, if neutrino-specific Higgs doublet is introduced, neutrinos become Dirac particles and their small masses can be explained by its small VEV. We show that the same symmetry, which we assume a global $U(1)_X$, can also be used to explain the stability of dark matter. In our model, a new singlet scalar breaks the global symmetry spontaneously down to a discrete $Z_2$ symmetry. The dark matter particle, lightest $Z_2$-odd fermion, is stabilized. We discuss the phenomenology of dark matter: relic density, direct detection, and indirect detection. We find that the relic density can be explained by a novel Goldstone boson channel or by resonance channel. In the most region of parameter space considered, the direct detections is suppressed well below the current experimental bound. Our model can be further tested in indirect detection experiments such as FermiLAT gamma ray searches or neutrinoless double beta decay experiments.
[ { "created": "Mon, 28 Nov 2016 14:44:06 GMT", "version": "v1" }, { "created": "Mon, 13 Mar 2017 13:23:00 GMT", "version": "v2" } ]
2017-04-05
[ [ "Baek", "Seungwon", "" ], [ "Nomura", "Takaaki", "" ] ]
Although the seesaw mechanism is a natural explanation for the small neutrino masses, there are cases when the Majorana mass terms for the right-handed neutrinos are not allowed due to symmetry. In that case, if neutrino-specific Higgs doublet is introduced, neutrinos become Dirac particles and their small masses can be explained by its small VEV. We show that the same symmetry, which we assume a global $U(1)_X$, can also be used to explain the stability of dark matter. In our model, a new singlet scalar breaks the global symmetry spontaneously down to a discrete $Z_2$ symmetry. The dark matter particle, lightest $Z_2$-odd fermion, is stabilized. We discuss the phenomenology of dark matter: relic density, direct detection, and indirect detection. We find that the relic density can be explained by a novel Goldstone boson channel or by resonance channel. In the most region of parameter space considered, the direct detections is suppressed well below the current experimental bound. Our model can be further tested in indirect detection experiments such as FermiLAT gamma ray searches or neutrinoless double beta decay experiments.
hep-ph/0702220
Shin Muroya
Shin Muroya
Transport coefficients of Relativistic Causal Hydrodynamics for Hadrons
To appear in the proceedings of "International Workshop On Hadron Physics and Property of High Baryon Density Matter" held at Xian on Nov.22-25, 2006
null
null
null
hep-ph nucl-th
null
We investigate coefficients in the Israel-Stewart's causal hydrodynamics and discuss the way to calculate them with a microscopic theory. Based on the hadro-molecular simulation based on an event generator URASiMA, we evaluate the coefficients for a hot and dense hadronic fluid.
[ { "created": "Wed, 21 Feb 2007 16:05:37 GMT", "version": "v1" }, { "created": "Thu, 22 Feb 2007 14:49:08 GMT", "version": "v2" } ]
2007-05-23
[ [ "Muroya", "Shin", "" ] ]
We investigate coefficients in the Israel-Stewart's causal hydrodynamics and discuss the way to calculate them with a microscopic theory. Based on the hadro-molecular simulation based on an event generator URASiMA, we evaluate the coefficients for a hot and dense hadronic fluid.
2310.16890
Christian Weiss
June-Young Kim, Christian Weiss
Instanton effects in twist-3 generalized parton distributions
6 pages, 1 figure
null
null
JLAB-THY-23-3946
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The instanton vacuum picture is used to study hadronic matrix elements of the twist-3 (dimension-4, spin-1) QCD operators measuring the quark spin density and spin-orbit correlations. The QCD operators are converted to effective operators in the low-energy effective theory emerging after chiral symmetry breaking, in a systematic approach based on the diluteness of the instanton medium and the $1/N_c$ expansion. The instanton fields induce spin-flavor-dependent "potential" terms in the effective operators, complementing the "kinetic" terms from the quark field momenta. As a result, the effective operators obey the same equation-of-motion relations as the original QCD operators. The spin-orbit correlations are qualitatively different from naive quark model expectations.
[ { "created": "Wed, 25 Oct 2023 18:00:04 GMT", "version": "v1" } ]
2023-10-27
[ [ "Kim", "June-Young", "" ], [ "Weiss", "Christian", "" ] ]
The instanton vacuum picture is used to study hadronic matrix elements of the twist-3 (dimension-4, spin-1) QCD operators measuring the quark spin density and spin-orbit correlations. The QCD operators are converted to effective operators in the low-energy effective theory emerging after chiral symmetry breaking, in a systematic approach based on the diluteness of the instanton medium and the $1/N_c$ expansion. The instanton fields induce spin-flavor-dependent "potential" terms in the effective operators, complementing the "kinetic" terms from the quark field momenta. As a result, the effective operators obey the same equation-of-motion relations as the original QCD operators. The spin-orbit correlations are qualitatively different from naive quark model expectations.
1309.7154
Ailin Zhang
Xue-Feng Li and Ailin Zhang
Scalar glueball in a soft-wall model of AdS/QCD
4 page, 1 table, 1 figure, RevTex
null
10.1088/1674-1137/38/1/013102
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scalar glueball is investigated in a soft-wall model of AdS/QCD. Constraints of the mass of the scalar glueball are given through an analysis of a relation between the bulk mass and the anomalous dimension. The mass of the ground scalar glueball is located at $0.96^{+0.04}_{-0.07} \rm{GeV}<m_G<1.36^{+0.05}_{-0.10}\rm{GeV}$. In terms of a background dilaton field $\Phi(z)=cz^2$, the two-point correlation function for the scalar gluon operator is obtained. The two-point correlation function at $\Delta=4$ gives a different behavior compared with the one in QCD.
[ { "created": "Fri, 27 Sep 2013 08:43:45 GMT", "version": "v1" } ]
2015-06-17
[ [ "Li", "Xue-Feng", "" ], [ "Zhang", "Ailin", "" ] ]
The scalar glueball is investigated in a soft-wall model of AdS/QCD. Constraints of the mass of the scalar glueball are given through an analysis of a relation between the bulk mass and the anomalous dimension. The mass of the ground scalar glueball is located at $0.96^{+0.04}_{-0.07} \rm{GeV}<m_G<1.36^{+0.05}_{-0.10}\rm{GeV}$. In terms of a background dilaton field $\Phi(z)=cz^2$, the two-point correlation function for the scalar gluon operator is obtained. The two-point correlation function at $\Delta=4$ gives a different behavior compared with the one in QCD.
2404.15136
Zhen-Yan Lu
Hong-Fang Gong, Qi Lu, Zhen-Yan Lu, Lu-Meng Liu, Xun Chen, Shu-Peng Wang
QCD topology and axion properties in an isotropic hot and dense medium
10 pages, 10 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the QCD topology and axion properties at finite temperature and chemical potential in the framework of the two-flavor Nambu$-$Jona-Lasinio model. We find that the behaviors of the two lowest cumulants of the QCD topological charge distribution and axion properties are highly sensitive to the critical behavior of the chiral phase transition. In particular, the topological susceptibility and the axion mass follow the response of the chiral condensate to temperature and chemical potential, showing that both quantities decrease monotonically with the increment of temperature and/or chemical potential. However, it is important to note that the normalized fourth cumulant behaves differently depending on the temperature. At low temperatures, it is a non-monotonic function of the chemical potential, while at high temperatures, it monotonically decreases. Additionally, its value invariably approaches the asymptotic value of $b_2^{\text {inst }}=-1/12$, predicted by the dilute instanton gas model. We also observe that with the increase in chemical potential at relatively low temperatures, the axion self-coupling constant exhibits a sharp peak around the critical point, which can even be more than twice its vacuum value. After that, the self-coupling drops sharply to a much lower value than its vacuum value, eventually approaching zero in the high chemical potential limit. The finding that the axion self-coupling constant is significantly enhanced in high-density environments near the chiral phase transition could lead to the creation or enhancement of an axion Bose-Einstein condensate in compact astrophysical objects.
[ { "created": "Tue, 23 Apr 2024 15:40:04 GMT", "version": "v1" } ]
2024-04-24
[ [ "Gong", "Hong-Fang", "" ], [ "Lu", "Qi", "" ], [ "Lu", "Zhen-Yan", "" ], [ "Liu", "Lu-Meng", "" ], [ "Chen", "Xun", "" ], [ "Wang", "Shu-Peng", "" ] ]
We study the QCD topology and axion properties at finite temperature and chemical potential in the framework of the two-flavor Nambu$-$Jona-Lasinio model. We find that the behaviors of the two lowest cumulants of the QCD topological charge distribution and axion properties are highly sensitive to the critical behavior of the chiral phase transition. In particular, the topological susceptibility and the axion mass follow the response of the chiral condensate to temperature and chemical potential, showing that both quantities decrease monotonically with the increment of temperature and/or chemical potential. However, it is important to note that the normalized fourth cumulant behaves differently depending on the temperature. At low temperatures, it is a non-monotonic function of the chemical potential, while at high temperatures, it monotonically decreases. Additionally, its value invariably approaches the asymptotic value of $b_2^{\text {inst }}=-1/12$, predicted by the dilute instanton gas model. We also observe that with the increase in chemical potential at relatively low temperatures, the axion self-coupling constant exhibits a sharp peak around the critical point, which can even be more than twice its vacuum value. After that, the self-coupling drops sharply to a much lower value than its vacuum value, eventually approaching zero in the high chemical potential limit. The finding that the axion self-coupling constant is significantly enhanced in high-density environments near the chiral phase transition could lead to the creation or enhancement of an axion Bose-Einstein condensate in compact astrophysical objects.
1909.09473
Vincent Mathieu
V. Mathieu
Moments of Angular Distribution in Two Mesons Photoproduction
9 pages, 1 figures, MENU 2019 conference proceedings
null
10.1063/5.0008590
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The formalism devoted to the production of two pseudoscalar mesons with a linearly polarized photon beam has been detailed and illustrated in Phys. Rev. D100 (2019) 054017. This document reports the necessary formulas, without proof, to perform an analysis of the angular distribution of two mesons photoproduction. The relations to extract moments of the angular distribution are provided, as well as the relations between moments and partial waves for a system involving $S$, $P$ and $D$ waves. The expressions of the integrated beam asymmetry and the beam asymmetry along the $y$ axis in term of moments are mentioned.
[ { "created": "Fri, 20 Sep 2019 12:49:20 GMT", "version": "v1" } ]
2020-08-26
[ [ "Mathieu", "V.", "" ] ]
The formalism devoted to the production of two pseudoscalar mesons with a linearly polarized photon beam has been detailed and illustrated in Phys. Rev. D100 (2019) 054017. This document reports the necessary formulas, without proof, to perform an analysis of the angular distribution of two mesons photoproduction. The relations to extract moments of the angular distribution are provided, as well as the relations between moments and partial waves for a system involving $S$, $P$ and $D$ waves. The expressions of the integrated beam asymmetry and the beam asymmetry along the $y$ axis in term of moments are mentioned.
2406.19083
Qiuyue Liang
Qiuyue Liang, Xavier Ponce D\'iaz, Tsutomu T. Yanagida
Axion Detection Experiments Meet the Majoron
null
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The majoron is a well-motivated light (pseudo-Nambu-Goldstone) boson associated with the spontaneous breaking of a global lepton-number symmetry. In this {\it letter}, we relate the spontaneous breaking scale and its soft-breaking mass by requiring that the majoron is the main component of the dark matter. An electromagnetic-anomalous coupling can be induced by minimally modifying the original majoron model, surprisingly, predicting a parameter region that largely overlaps with the QCD-axion dark matter band. Thus, we expect that axion search experiments meet the majoron.
[ { "created": "Thu, 27 Jun 2024 11:10:18 GMT", "version": "v1" } ]
2024-06-28
[ [ "Liang", "Qiuyue", "" ], [ "Díaz", "Xavier Ponce", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
The majoron is a well-motivated light (pseudo-Nambu-Goldstone) boson associated with the spontaneous breaking of a global lepton-number symmetry. In this {\it letter}, we relate the spontaneous breaking scale and its soft-breaking mass by requiring that the majoron is the main component of the dark matter. An electromagnetic-anomalous coupling can be induced by minimally modifying the original majoron model, surprisingly, predicting a parameter region that largely overlaps with the QCD-axion dark matter band. Thus, we expect that axion search experiments meet the majoron.
hep-ph/0606318
Thomas Binoth Dr.
T. Binoth, A. Guffanti, J.-Ph. Guillet, S. Karg, N. Kauer, T. Reiter
New one-loop techniques and first applications to LHC phenomenology
5 pages, to appear in the proceedings of the conference "Loops and Legs", Eisenach, 2006
null
10.1016/j.nuclphysbps.2006.09.102
Edinburgh 2006/13, LAPTH-1154/06
hep-ph
null
In this talk we describe our approach for the computation of multi-leg one-loop amplitudes and present some first results relevant for LHC phenomenology.
[ { "created": "Fri, 30 Jun 2006 09:08:22 GMT", "version": "v1" } ]
2009-11-11
[ [ "Binoth", "T.", "" ], [ "Guffanti", "A.", "" ], [ "Guillet", "J. -Ph.", "" ], [ "Karg", "S.", "" ], [ "Kauer", "N.", "" ], [ "Reiter", "T.", "" ] ]
In this talk we describe our approach for the computation of multi-leg one-loop amplitudes and present some first results relevant for LHC phenomenology.
1511.09313
Isobel Kolb\'e
Isobel Kolb\'e and W. A. Horowitz
Short path length corrections to Djordjevic-Gyulassy-Levai-Vitev energy loss
28 pages, 10 figures, submitted to Phys. Rev. C
Phys. Rev. C 100, 024913 (2019)
10.1103/PhysRevC.100.024913
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the correction to the energy loss of a hard parton due to short separation distances between the creation of the particle and the in-medium scattering center that stimulates bremsstrahlung radiation, to first order in opacity. In deriving the result we make full use of the large formation time assumption, which results in a significant reduction of the number of diagrams contributing to the small separation distance correction. An asymptotic analysis of our small separation distance correction term finds that the correction dominates at large $\sim 100$ GeV parent parton energies; scales like $L$ with the size of the system for small $L$, but like $L^0$ at larger $L$; and breaks color triviality. An extensive numerical investigation of the correction term confirms the aforementioned analytic findings, reveals that the correction term does not go to zero for large $L$, finds that the correction is sensitive to the mass of the parent parton, and shows a crucial dependence of the energy loss on a proper treatment of the physics of separation distances on the order of the Debye screening length. However, an examination of the large formation time approximation shows that it is violated for much of the phase space of the emitted radiation, implying a need to investigate the sensitivity of jet quenching results from relaxing this approximation. Our result constitutes an important step toward understanding partonic energy loss in small colliding systems.
[ { "created": "Mon, 30 Nov 2015 14:08:35 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2018 16:47:42 GMT", "version": "v2" }, { "created": "Mon, 26 Aug 2019 18:53:27 GMT", "version": "v3" } ]
2019-08-28
[ [ "Kolbé", "Isobel", "" ], [ "Horowitz", "W. A.", "" ] ]
We compute the correction to the energy loss of a hard parton due to short separation distances between the creation of the particle and the in-medium scattering center that stimulates bremsstrahlung radiation, to first order in opacity. In deriving the result we make full use of the large formation time assumption, which results in a significant reduction of the number of diagrams contributing to the small separation distance correction. An asymptotic analysis of our small separation distance correction term finds that the correction dominates at large $\sim 100$ GeV parent parton energies; scales like $L$ with the size of the system for small $L$, but like $L^0$ at larger $L$; and breaks color triviality. An extensive numerical investigation of the correction term confirms the aforementioned analytic findings, reveals that the correction term does not go to zero for large $L$, finds that the correction is sensitive to the mass of the parent parton, and shows a crucial dependence of the energy loss on a proper treatment of the physics of separation distances on the order of the Debye screening length. However, an examination of the large formation time approximation shows that it is violated for much of the phase space of the emitted radiation, implying a need to investigate the sensitivity of jet quenching results from relaxing this approximation. Our result constitutes an important step toward understanding partonic energy loss in small colliding systems.
hep-ph/9506301
Papageorgiu
Elena Papageorgiu
Fermion masses and mixing from an extra gauge symmetry
7 pages of LATEX
null
10.1007/3-540-59163-X_297
LPTHE-ORSAY Preprint 94-84, in proceedings of the G\"ursey Memorial Conference I on Strings and Symmetries, held at Istanbul, 6-10 June 1994, eds. Aktas et al., Springer-Verlag 1995
hep-ph
null
Assuming that a horizontal abelian (gauge) symmetry is at the origin of texture zeros in the fermion mass matrices we show how realistic mass patterns can be generated in the presence of scalar fields whose vacuum expectation value breaks the extra $U(1)$ symmetry. In the simplest scenario with just one pair of singlet fields and under the assumption of L-R symmetry one obtains quark mass matrices {\it \`a la Fritzsch}. The $U(1)$ symmetry can be made anomaly free by the Green-Schwarz mechanism in which case the canonical unification of the gauge couplings emerges as its byproduct. The generation of neutrino masses requires either two extra heavy scalar (Higgs) fields to determine the texture structure of the righthanded neutrino mass matrix or the latter will contain a hierarchy of scales.
[ { "created": "Mon, 12 Jun 1995 20:26:49 GMT", "version": "v1" } ]
2015-06-25
[ [ "Papageorgiu", "Elena", "" ] ]
Assuming that a horizontal abelian (gauge) symmetry is at the origin of texture zeros in the fermion mass matrices we show how realistic mass patterns can be generated in the presence of scalar fields whose vacuum expectation value breaks the extra $U(1)$ symmetry. In the simplest scenario with just one pair of singlet fields and under the assumption of L-R symmetry one obtains quark mass matrices {\it \`a la Fritzsch}. The $U(1)$ symmetry can be made anomaly free by the Green-Schwarz mechanism in which case the canonical unification of the gauge couplings emerges as its byproduct. The generation of neutrino masses requires either two extra heavy scalar (Higgs) fields to determine the texture structure of the righthanded neutrino mass matrix or the latter will contain a hierarchy of scales.
2311.14991
Giovanni Stagnitto
A. Gehrmann-De Ridder, T. Gehrmann, E. W. N. Glover, A. Huss, A. Rodriguez Garcia, G. Stagnitto
Precise QCD predictions for W-boson production in association with a charm jet
26 pages, 15 figures, 5 tables
null
null
ZU-TH 76/23, IPPP/23/69, CERN-TH-2023-217
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The production of a $W$-boson with a charm quark jet provides a highly sensitive probe of the strange quark distribution in the proton. Employing a novel flavour dressing procedure to define charm quark jets, we compute $W$+charm-jet production up to next-to-next-to-leading order (NNLO) in QCD. We study the perturbative stability of production cross sections with same-sign and opposite-sign charge combinations for the $W$ boson and the charm jet. A detailed breakdown according to different partonic initial states allows us to identify particularly suitable observables for the study of the quark parton distributions of different flavours.
[ { "created": "Sat, 25 Nov 2023 10:34:41 GMT", "version": "v1" } ]
2023-11-28
[ [ "Ridder", "A. Gehrmann-De", "" ], [ "Gehrmann", "T.", "" ], [ "Glover", "E. W. N.", "" ], [ "Huss", "A.", "" ], [ "Garcia", "A. Rodriguez", "" ], [ "Stagnitto", "G.", "" ] ]
The production of a $W$-boson with a charm quark jet provides a highly sensitive probe of the strange quark distribution in the proton. Employing a novel flavour dressing procedure to define charm quark jets, we compute $W$+charm-jet production up to next-to-next-to-leading order (NNLO) in QCD. We study the perturbative stability of production cross sections with same-sign and opposite-sign charge combinations for the $W$ boson and the charm jet. A detailed breakdown according to different partonic initial states allows us to identify particularly suitable observables for the study of the quark parton distributions of different flavours.
1409.0990
Pedro Fernando Simoes Costa
Alexandre Biguet, Hubert Hansen, Pedro Costa, Pierre Borgnat, Timoth\'ee Brugi\`ere
Sensitivity of predictions in an effective model -- application to the chiral critical end point position in the Nambu--Jona-Lasinio model
Improved version: slightly modified title, the introduction of the sensitivity was improved; reformulation of the sections; v2 with 20 pages and only 9 figures. Version accepted for publication in EPJA
Eur.Phys.J. A51 (2015) 9, 121
10.1140/epja/i2015-15121-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The measurement of the position of the chiral critical end point (CEP) in the QCD phase diagram is under debate. While it is possible to predict its position by using effective models specifically built to reproduce some of the features of the underlying theory (QCD), the quality of the predictions (\textit{e.g.}, the CEP position) obtained by such effective models, depends on whether solving the model equations constitute a well- or ill-posed inverse problem. Considering these predictions as being inverse problems provides tools to evaluate if the problem is ill-conditioned, meaning that infinitesimal variations of the inputs of the model can cause comparatively large variations of the predictions. If it is ill-conditioned, it has major consequences because of finite variations that could come from experimental and/or theoretical errors. In the following, we shall apply such a reasoning on the predictions of a particular Nambu--Jona-Lasinio model within the mean field + ring approximations, with special attention to the prediction of the chiral CEP position in the $(T-\mu)$ plane. We find that the problem is ill-conditioned (\idest very sensitive to input variations) for the $T$-coordinate of the CEP, whereas, it is well-posed for the $\mu$-coordinate of the CEP. As a consequence, when the chiral condensate varies in a $10$ MeV range, $\mu_{CEP}$ varies far less. As an illustration to understand how problematic this could be, we show that the main consequence when taking into account finite variation of the inputs, is that the existence of the CEP itself cannot be predicted anymore: for a deviation as low as 0.6 \% with respect to vacuum phenomenology (well within the estimation of the first correction to the ring approximation) the CEP may or may not exist.
[ { "created": "Wed, 3 Sep 2014 08:32:37 GMT", "version": "v1" }, { "created": "Mon, 14 Sep 2015 09:59:16 GMT", "version": "v2" } ]
2015-10-06
[ [ "Biguet", "Alexandre", "" ], [ "Hansen", "Hubert", "" ], [ "Costa", "Pedro", "" ], [ "Borgnat", "Pierre", "" ], [ "Brugière", "Timothée", "" ] ]
The measurement of the position of the chiral critical end point (CEP) in the QCD phase diagram is under debate. While it is possible to predict its position by using effective models specifically built to reproduce some of the features of the underlying theory (QCD), the quality of the predictions (\textit{e.g.}, the CEP position) obtained by such effective models, depends on whether solving the model equations constitute a well- or ill-posed inverse problem. Considering these predictions as being inverse problems provides tools to evaluate if the problem is ill-conditioned, meaning that infinitesimal variations of the inputs of the model can cause comparatively large variations of the predictions. If it is ill-conditioned, it has major consequences because of finite variations that could come from experimental and/or theoretical errors. In the following, we shall apply such a reasoning on the predictions of a particular Nambu--Jona-Lasinio model within the mean field + ring approximations, with special attention to the prediction of the chiral CEP position in the $(T-\mu)$ plane. We find that the problem is ill-conditioned (\idest very sensitive to input variations) for the $T$-coordinate of the CEP, whereas, it is well-posed for the $\mu$-coordinate of the CEP. As a consequence, when the chiral condensate varies in a $10$ MeV range, $\mu_{CEP}$ varies far less. As an illustration to understand how problematic this could be, we show that the main consequence when taking into account finite variation of the inputs, is that the existence of the CEP itself cannot be predicted anymore: for a deviation as low as 0.6 \% with respect to vacuum phenomenology (well within the estimation of the first correction to the ring approximation) the CEP may or may not exist.
1401.2145
Farvah Mahmoudi
F. Mahmoudi, S. Neshatpour and J. Virto
B -> K* mu+ mu- optimised observables in the MSSM
20 pages, 6 figures
Eur. Phys. J. C74 (2014) 2927
null
CERN-PH-TH/2014-004, QFET-2014-01, SI-HEP-2014-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a detailed analysis of the impact of the newly measured optimised observables in the B -> K* mu+ mu- decay by the LHCb experiment. The analysis is performed in the MSSM, both in the context of the usual constrained scenarios, and in the context of a more general set-up where the SUSY partner masses are independent. We show that the global agreement of the MSSM solutions with the data is still very good. Nevertheless, especially in the constrained scenarios, the limits from B -> K* mu+ mu- are now very strong, and are at the same level as the well-known b -> s gamma constraints. We describe the implications of the B -> K* mu+ mu- measurements both on the Wilson coefficients and on the SUSY parameters.
[ { "created": "Thu, 9 Jan 2014 20:34:58 GMT", "version": "v1" } ]
2014-06-20
[ [ "Mahmoudi", "F.", "" ], [ "Neshatpour", "S.", "" ], [ "Virto", "J.", "" ] ]
We provide a detailed analysis of the impact of the newly measured optimised observables in the B -> K* mu+ mu- decay by the LHCb experiment. The analysis is performed in the MSSM, both in the context of the usual constrained scenarios, and in the context of a more general set-up where the SUSY partner masses are independent. We show that the global agreement of the MSSM solutions with the data is still very good. Nevertheless, especially in the constrained scenarios, the limits from B -> K* mu+ mu- are now very strong, and are at the same level as the well-known b -> s gamma constraints. We describe the implications of the B -> K* mu+ mu- measurements both on the Wilson coefficients and on the SUSY parameters.
hep-ph/0008004
Joao Silva
Joao P. Silva (SLAC) and Lincoln Wolfenstein (CMU)
Implications of the possibility that sin(2 beta) is small
3 pages, revtex and psfig, 2 eps figures included
Phys.Rev.D63:056001,2001
10.1103/PhysRevD.63.056001
SLAC-PUB-8548
hep-ph
null
Recently, the Babar and Belle collaborations have reported their first measurements of the CP-violating asymmetry in Bd --> psi KS, and more precise results will follow soon. We discuss what a future evidence for small sin(2 beta) could mean, contrasting the usual possibility of new physics in the Bd system, with the interesting alternative that the new physics effects are confined to the kaon system.
[ { "created": "Tue, 1 Aug 2000 08:21:36 GMT", "version": "v1" } ]
2014-11-17
[ [ "Silva", "Joao P.", "", "SLAC" ], [ "Wolfenstein", "Lincoln", "", "CMU" ] ]
Recently, the Babar and Belle collaborations have reported their first measurements of the CP-violating asymmetry in Bd --> psi KS, and more precise results will follow soon. We discuss what a future evidence for small sin(2 beta) could mean, contrasting the usual possibility of new physics in the Bd system, with the interesting alternative that the new physics effects are confined to the kaon system.
1711.09742
Johannes Bl\"umlein
J. Ablinger, A. Behring, J. Bl\"umlein, A. De Freitas, E. Imamoglu, M. van Hoeij A. von Manteuffel, C.G. Raab, C.-S. Radu, and C. Schneider
Iterative and Iterative-Noniterative Integral Solutions in 3-Loop Massive QCD Calculations
13 pages LATEX, 2 Figures
null
null
DESY 17-110, DO-TH 17/35, TTK-17-41, MSUHEP-17-022
hep-ph hep-th math-ph math.AG math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the anomalous dimensions to 3-loop order, the massless Wilson coefficients and also different massive operator matrix elements. Starting at 3-loop order, however, also other letters appear in the case of massive operator matrix elements, the so called iterative non-iterative integrals, which are related to solutions based on complete elliptic integrals or any other special function with an integral representation that is definite but not a Volterra-type integral. After outlining the formalism leading to iterative non-iterative integrals,we present examples for both of these cases with the 3-loop anomalous dimension $\gamma_{qg}^{(2)}$ and the structure of the principle solution in the iterative non-interative case of the 3-loop QCD corrections to the $\rho$-parameter.
[ { "created": "Mon, 27 Nov 2017 15:10:56 GMT", "version": "v1" } ]
2017-11-28
[ [ "Ablinger", "J.", "" ], [ "Behring", "A.", "" ], [ "Blümlein", "J.", "" ], [ "De Freitas", "A.", "" ], [ "Imamoglu", "E.", "" ], [ "von Manteuffel", "M. van Hoeij A.", "" ], [ "Raab", "C. G.", "" ], [ "Radu", "C. -S.", "" ], [ "Schneider", "C.", "" ] ]
Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the anomalous dimensions to 3-loop order, the massless Wilson coefficients and also different massive operator matrix elements. Starting at 3-loop order, however, also other letters appear in the case of massive operator matrix elements, the so called iterative non-iterative integrals, which are related to solutions based on complete elliptic integrals or any other special function with an integral representation that is definite but not a Volterra-type integral. After outlining the formalism leading to iterative non-iterative integrals,we present examples for both of these cases with the 3-loop anomalous dimension $\gamma_{qg}^{(2)}$ and the structure of the principle solution in the iterative non-interative case of the 3-loop QCD corrections to the $\rho$-parameter.
1410.6427
Tomas Gonzalo
Frank F. Deppisch, Tomas E. Gonzalo, Sudhanwa Patra, Narendra Sahu, Utpal Sarkar
Double Beta Decay, Lepton Flavour Violation and Collider Signatures of Left-Right Symmetric Models with Spontaneous D Parity Breaking
20 pages, 11 figures
null
10.1103/PhysRevD.91.015018
LCTS/2014-42
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a class of left-right symmetric models (LRSMs) with spontaneous D parity breaking, where SU(2)_R breaks at the TeV scale while discrete left-right symmetry breaks around 10^9 GeV. By embedding this framework in a non-supersymmetric SO(10) Grand Unified Theory (GUT) with Pati-Salam symmetry as the highest intermediate breaking step, we obtain g_R / g_L ~ 0.6 between the right- and left-handed gauge couplings at the TeV scale. This leads to a suppression of beyond the Standard Model phenomena induced by the right-handed gauge coupling. Here we focus specifically on the consequences for neutrinoless double beta decay, low energy lepton flavour violation and LHC signatures due to the suppressed right handed currents. Interestingly, the reduced g_R allows us to interpret an excess of events observed recently in the range of 1.9 TeV to 2.4 TeV by the CMS group at the LHC as the signature of a right handed gauge boson in LRSMs with spontaneous D parity breaking. Moreover, the reduced right-handed gauge coupling also strongly suppresses the non-standard contribution of heavy states to the neutrinoless double beta decay rate as well as the amplitude of low energy lepton flavour violating processes. In a dominant type-II Seesaw mechanism of neutrino mass generation, we find that both sets of observables provide stringent and complimentary bounds which make it challenging to observe the scenario at the LHC.
[ { "created": "Thu, 23 Oct 2014 17:38:45 GMT", "version": "v1" } ]
2015-06-23
[ [ "Deppisch", "Frank F.", "" ], [ "Gonzalo", "Tomas E.", "" ], [ "Patra", "Sudhanwa", "" ], [ "Sahu", "Narendra", "" ], [ "Sarkar", "Utpal", "" ] ]
We propose a class of left-right symmetric models (LRSMs) with spontaneous D parity breaking, where SU(2)_R breaks at the TeV scale while discrete left-right symmetry breaks around 10^9 GeV. By embedding this framework in a non-supersymmetric SO(10) Grand Unified Theory (GUT) with Pati-Salam symmetry as the highest intermediate breaking step, we obtain g_R / g_L ~ 0.6 between the right- and left-handed gauge couplings at the TeV scale. This leads to a suppression of beyond the Standard Model phenomena induced by the right-handed gauge coupling. Here we focus specifically on the consequences for neutrinoless double beta decay, low energy lepton flavour violation and LHC signatures due to the suppressed right handed currents. Interestingly, the reduced g_R allows us to interpret an excess of events observed recently in the range of 1.9 TeV to 2.4 TeV by the CMS group at the LHC as the signature of a right handed gauge boson in LRSMs with spontaneous D parity breaking. Moreover, the reduced right-handed gauge coupling also strongly suppresses the non-standard contribution of heavy states to the neutrinoless double beta decay rate as well as the amplitude of low energy lepton flavour violating processes. In a dominant type-II Seesaw mechanism of neutrino mass generation, we find that both sets of observables provide stringent and complimentary bounds which make it challenging to observe the scenario at the LHC.
hep-ph/9807557
Michael Pluemacher
M. Plumacher
Baryon Asymmetry, Neutrino Mixing and Supersymmetric SO(10) Unification
Ph.D. thesis, latex2e, 109 pages, 26 figures
null
null
DESY-THESIS 1998-009
hep-ph
null
The baryon asymmetry of the universe can be explained by the out-of-equilibrium decays of heavy right-handed neutrinos. We analyse this mechanism in the framework of a supersymmetric extension of the Standard Model and show that lepton number violating scatterings are indispensable for baryogenesis, even though they may wash-out a generated asymmetry. By assuming a similar pattern of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10) unification, we can generate the observed baryon asymmetry without any fine tuning, if (B-L) is broken at the unification scale \Lambda_{GUT}\sim 10^{16} GeV and, if m_{\nu_\mu} \sim 3\cdot 10^{-3} eV as preferred by the MSW solution to the solar neutrino deficit.
[ { "created": "Thu, 30 Jul 1998 15:21:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Plumacher", "M.", "" ] ]
The baryon asymmetry of the universe can be explained by the out-of-equilibrium decays of heavy right-handed neutrinos. We analyse this mechanism in the framework of a supersymmetric extension of the Standard Model and show that lepton number violating scatterings are indispensable for baryogenesis, even though they may wash-out a generated asymmetry. By assuming a similar pattern of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10) unification, we can generate the observed baryon asymmetry without any fine tuning, if (B-L) is broken at the unification scale \Lambda_{GUT}\sim 10^{16} GeV and, if m_{\nu_\mu} \sim 3\cdot 10^{-3} eV as preferred by the MSW solution to the solar neutrino deficit.
hep-ph/9606438
Jose Ramon Espinosa
D. Comelli (Valencia) and J.R. Espinosa (DESY)
Bosonic Thermal Masses in Supersymmetry
20 pages, LaTeX, plus one postscript figure
Phys.Rev.D55:6253-6263,1997
10.1103/PhysRevD.55.6253
DESY 96-114,FTUV/96-37,IFIC/96-45,IEM-FT-134/96
hep-ph
null
Effective thermal masses of bosonic particles in a plasma play an important role in many different phenomena. We compute them in general supersymmetric models at leading order. The origin of different corrections is explicitly shown for the formulas to be applicable when some particles decouple. The correct treatment of Boltzmann decoupling in the presence of trilinear couplings and mass mixing is also discussed. As a relevant example, we present results for the Minimal Supersymmetric Standard Model.
[ { "created": "Wed, 26 Jun 1996 10:36:36 GMT", "version": "v1" } ]
2014-11-17
[ [ "Comelli", "D.", "", "Valencia" ], [ "Espinosa", "J. R.", "", "DESY" ] ]
Effective thermal masses of bosonic particles in a plasma play an important role in many different phenomena. We compute them in general supersymmetric models at leading order. The origin of different corrections is explicitly shown for the formulas to be applicable when some particles decouple. The correct treatment of Boltzmann decoupling in the presence of trilinear couplings and mass mixing is also discussed. As a relevant example, we present results for the Minimal Supersymmetric Standard Model.
0803.4270
Xiang Liu
Xiang Liu, Bo Zhang, Shi-Lin Zhu
The two-body open charm decays of $Z^+(4430)$
6 pages, 3 figures, 1 table
Phys.Rev.D77:114021,2008
10.1103/PhysRevD.77.114021
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The two-body open charm decays $Z^+(4430)\to D^{+}\bar{D}^{*0}, D^{*+}\bar{D}^{0}, D^{*+}\bar{D}^{*0}$ occur through the re-scattering mechanism and their branching ratios are strongly suppressed if $Z^+(4430)$ is a $D_1\bar D^*$ molecular state. In contrast, $Z^+(4430)$ falls apart into these modes easily with large phase space and they become the main decay modes if $Z^+(4430)$ is a tetraquark state. Experimental search of these two-body open charm modes and the hidden charm mode $\chi_{cJ}\rho$ will help distinguish different theoretical schemes.
[ { "created": "Mon, 31 Mar 2008 15:17:41 GMT", "version": "v1" }, { "created": "Tue, 1 Apr 2008 08:27:47 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liu", "Xiang", "" ], [ "Zhang", "Bo", "" ], [ "Zhu", "Shi-Lin", "" ] ]
The two-body open charm decays $Z^+(4430)\to D^{+}\bar{D}^{*0}, D^{*+}\bar{D}^{0}, D^{*+}\bar{D}^{*0}$ occur through the re-scattering mechanism and their branching ratios are strongly suppressed if $Z^+(4430)$ is a $D_1\bar D^*$ molecular state. In contrast, $Z^+(4430)$ falls apart into these modes easily with large phase space and they become the main decay modes if $Z^+(4430)$ is a tetraquark state. Experimental search of these two-body open charm modes and the hidden charm mode $\chi_{cJ}\rho$ will help distinguish different theoretical schemes.
hep-ph/9611248
Passarino Giampiero
Giampiero Passarino (Torino University and INFN Torino)
Standard Higgs Boson Searches at LEP 2
47 pages, 21 Postscript figures
Nucl.Phys. B488 (1997) 3-38
10.1016/S0550-3213(97)00031-X
null
hep-ph
null
For the first time at LEP most of the events will have four fermions in the finals state and we have the unique opportunity of testing a complete calculation with the experimental data, well beyond the usual approximation of computing production cross section times branching ratios of Higgs into decay products. Calculation of the total cross sections and of different kinds of differential distributions at the partonic level are made available to access the widest information for choosing cuts, for discussing the physics of a standard Higgs boson with a mass around 90 GeV where the Higgs and the Z signal become degenerate and for a comprehensive analysis of the various background components.
[ { "created": "Wed, 6 Nov 1996 07:04:10 GMT", "version": "v1" } ]
2009-10-30
[ [ "Passarino", "Giampiero", "", "Torino University and INFN Torino" ] ]
For the first time at LEP most of the events will have four fermions in the finals state and we have the unique opportunity of testing a complete calculation with the experimental data, well beyond the usual approximation of computing production cross section times branching ratios of Higgs into decay products. Calculation of the total cross sections and of different kinds of differential distributions at the partonic level are made available to access the widest information for choosing cuts, for discussing the physics of a standard Higgs boson with a mass around 90 GeV where the Higgs and the Z signal become degenerate and for a comprehensive analysis of the various background components.
hep-ph/0004048
Sven Bergmann
Sven Bergmann, H.V. Klapdor-Kleingrothaus and Heinrich P\"as
Lepton number violating interactions and their effects on neutrino oscillation experiments
28 pages, 2 figures, Latex
Phys.Rev. D62 (2000) 113002
10.1103/PhysRevD.62.113002
WIS-4/00/Apr-DPP
hep-ph
null
Mixing between bosons that transform differently under the standard model gauge group, but identically under its unbroken subgroup, can induce interactions that violate the total lepton number. We discuss four-fermion operators that mediate lepton number violating neutrino interactions both in a model-independent framework and within supersymmetry (SUSY) without R-parity. The effective couplings of such operators are constrained by: i) the upper bounds on the relevant elementary couplings between the bosons and the fermions, ii) by the limit on universality violation in pion decays, iii) by the data on neutrinoless double beta decay and, iv) by loop-induced neutrino masses. We find that the present bounds imply that lepton number violating neutrino interactions are not relevant for the solar and atmospheric neutrino problems. Within SUSY without R-parity also the LSND anomaly cannot be explained by such interactions, but one cannot rule out an effect model-independently. Possible consequences for future terrestrial neutrino oscillation experiments and for neutrinos from a supernova are discussed.
[ { "created": "Thu, 6 Apr 2000 09:56:09 GMT", "version": "v1" }, { "created": "Thu, 18 May 2000 11:46:40 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bergmann", "Sven", "" ], [ "Klapdor-Kleingrothaus", "H. V.", "" ], [ "Päs", "Heinrich", "" ] ]
Mixing between bosons that transform differently under the standard model gauge group, but identically under its unbroken subgroup, can induce interactions that violate the total lepton number. We discuss four-fermion operators that mediate lepton number violating neutrino interactions both in a model-independent framework and within supersymmetry (SUSY) without R-parity. The effective couplings of such operators are constrained by: i) the upper bounds on the relevant elementary couplings between the bosons and the fermions, ii) by the limit on universality violation in pion decays, iii) by the data on neutrinoless double beta decay and, iv) by loop-induced neutrino masses. We find that the present bounds imply that lepton number violating neutrino interactions are not relevant for the solar and atmospheric neutrino problems. Within SUSY without R-parity also the LSND anomaly cannot be explained by such interactions, but one cannot rule out an effect model-independently. Possible consequences for future terrestrial neutrino oscillation experiments and for neutrinos from a supernova are discussed.
1204.2111
Karsten Schnitter
Karsten Schnitter
Higgs Mass Spectrum in non-SUSY SU(5)
12 pages, 3 tables
null
null
SI-HEP-2012-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-supersymmetric grand unified theories based on SU(5) have had a revival during the past years. This is mainly due to their ability to connect neutrino masses with unification and proton decay. In that way they provide a framework for testable models at coming experiments. We study the mass spectrum of such models and determine naturally light multiplets within the LHC reach.
[ { "created": "Tue, 10 Apr 2012 11:37:33 GMT", "version": "v1" } ]
2012-04-11
[ [ "Schnitter", "Karsten", "" ] ]
Non-supersymmetric grand unified theories based on SU(5) have had a revival during the past years. This is mainly due to their ability to connect neutrino masses with unification and proton decay. In that way they provide a framework for testable models at coming experiments. We study the mass spectrum of such models and determine naturally light multiplets within the LHC reach.
1010.1094
Kanchan Khemchandani
K. P. Khemchandani, Eef van Beveren, George Rupp
Drawbacks of applying perturbative schemes to meson spectroscopy
null
Prog.Theor.Phys.125:581-602,2011
10.1143/PTP.125.581
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study meson-meson scattering in a soluble model which describes asymptotically free mesons and confined quark-antiquark pairs via coupled channels. Concretely, the two scattered mesons are assumed to interact through s-channel meson-exchange diagrams. Furthermore, we develop a perturbative expansion of the model, and show that the thus found resonance pole positions, including contributions up to fourth order in perturbation theory, completely fail to reproduce the exact results. This shows that the resonance predictions based on perturbative approximations in quark models may be highly unreliable.
[ { "created": "Wed, 6 Oct 2010 09:07:23 GMT", "version": "v1" } ]
2011-06-07
[ [ "Khemchandani", "K. P.", "" ], [ "van Beveren", "Eef", "" ], [ "Rupp", "George", "" ] ]
We study meson-meson scattering in a soluble model which describes asymptotically free mesons and confined quark-antiquark pairs via coupled channels. Concretely, the two scattered mesons are assumed to interact through s-channel meson-exchange diagrams. Furthermore, we develop a perturbative expansion of the model, and show that the thus found resonance pole positions, including contributions up to fourth order in perturbation theory, completely fail to reproduce the exact results. This shows that the resonance predictions based on perturbative approximations in quark models may be highly unreliable.
1805.04426
Nick Houston
Nick Houston, Chuang Li, Tianjun Li, Qiaoli Yang, Xin Zhang
Natural explanation for 21cm absorption signals via axion-induced cooling
5 pages, 2 figures. v3: updated to match version appearing in Phys. Rev. Lett
Phys. Rev. Lett. 121, 111301 (2018)
10.1103/PhysRevLett.121.111301
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The EDGES Collaboration has reported an anomalously strong 21cm absorption feature corresponding to the era of first star formation, which may indirectly betray the influence of dark matter during this epoch. We demonstrate that, by virtue of the ability to mediate cooling processes whilst in the condensed phase, a small amount of axion dark matter can explain these observations within the context of standard models of axions and axion-like-particles. The EDGES best-fit result favours an axion-like-particles mass in the (10, 450) meV range, which can be compressed for the QCD axion to (100, 450) meV in the absence of fine tuning. Future experiments and large scale surveys, particularly the International Axion Observatory (IAXO) and EUCLID, should have the capability to directly test this scenario.
[ { "created": "Fri, 11 May 2018 14:37:35 GMT", "version": "v1" }, { "created": "Wed, 23 May 2018 12:09:16 GMT", "version": "v2" }, { "created": "Thu, 23 Aug 2018 10:28:50 GMT", "version": "v3" } ]
2018-09-19
[ [ "Houston", "Nick", "" ], [ "Li", "Chuang", "" ], [ "Li", "Tianjun", "" ], [ "Yang", "Qiaoli", "" ], [ "Zhang", "Xin", "" ] ]
The EDGES Collaboration has reported an anomalously strong 21cm absorption feature corresponding to the era of first star formation, which may indirectly betray the influence of dark matter during this epoch. We demonstrate that, by virtue of the ability to mediate cooling processes whilst in the condensed phase, a small amount of axion dark matter can explain these observations within the context of standard models of axions and axion-like-particles. The EDGES best-fit result favours an axion-like-particles mass in the (10, 450) meV range, which can be compressed for the QCD axion to (100, 450) meV in the absence of fine tuning. Future experiments and large scale surveys, particularly the International Axion Observatory (IAXO) and EUCLID, should have the capability to directly test this scenario.
2306.16966
Mengchao Zhang
Chengcheng Han, Ke-Pan Xie, Jin Min Yang, Mengchao Zhang
Self-interacting dark matter implied by nano-Hertz gravitational waves
5 pages, 2 figures, more references added
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The self-interacting dark matter (SIDM) paradigm offers a potential solution to small-scale structure problems faced by the collision-less cold dark matter. This framework incorporates self-interactions among dark matter particles, typically mediated by a particle with a MeV-scale mass. Recent evidences of nano-Hertz gravitational waves from pulsar timing arrays (PTAs) such as NANOGrav, CPTA, EPTA, and PPTA suggest the occurrence of a first-order phase transition (FOPT) at a MeV-scale temperature. Considering the close proximity between these two scales, we propose that the mediator mass in the SIDM model originates from the spontaneous breaking of a $U(1)'$ symmetry, which is driven by the FOPT indicated by PTA data. Consequently, the alignment of these two scales is believed to be deeply connected by the same underlying physics. By extensively exploring the parameter space, remarkably, we find that the parameter space favored by SIDM just provides an explanation for the PTA data.
[ { "created": "Thu, 29 Jun 2023 14:15:27 GMT", "version": "v1" }, { "created": "Sun, 2 Jul 2023 12:42:23 GMT", "version": "v2" } ]
2023-07-04
[ [ "Han", "Chengcheng", "" ], [ "Xie", "Ke-Pan", "" ], [ "Yang", "Jin Min", "" ], [ "Zhang", "Mengchao", "" ] ]
The self-interacting dark matter (SIDM) paradigm offers a potential solution to small-scale structure problems faced by the collision-less cold dark matter. This framework incorporates self-interactions among dark matter particles, typically mediated by a particle with a MeV-scale mass. Recent evidences of nano-Hertz gravitational waves from pulsar timing arrays (PTAs) such as NANOGrav, CPTA, EPTA, and PPTA suggest the occurrence of a first-order phase transition (FOPT) at a MeV-scale temperature. Considering the close proximity between these two scales, we propose that the mediator mass in the SIDM model originates from the spontaneous breaking of a $U(1)'$ symmetry, which is driven by the FOPT indicated by PTA data. Consequently, the alignment of these two scales is believed to be deeply connected by the same underlying physics. By extensively exploring the parameter space, remarkably, we find that the parameter space favored by SIDM just provides an explanation for the PTA data.
hep-ph/9711282
Paul Frampton
Paul H. Frampton and Masayasu Harada
S and T for Leptoquarks and Bileptons
4 pages RevTex. 2 figures (gz.tar) included at end. In replacement, only report no. changed
null
null
IFP-746-UNC
hep-ph
null
We calculate contributions to the oblique parameters $S$ and $T$ for leptoquarks and bileptons, and find phenomenological constraints on their allowed masses. Leptoquarks suggested by the neutral and charged current anomalies at HERA can give improved agreement with both $S$ and $T$. If bileptons are the only new states, the singly-charged one must be heavier than the directly-established lower limit. We also consider SU(15) grand unification to find when it can be consistent with precision electroweak measurements.
[ { "created": "Tue, 11 Nov 1997 02:43:12 GMT", "version": "v1" }, { "created": "Wed, 12 Nov 1997 19:40:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Frampton", "Paul H.", "" ], [ "Harada", "Masayasu", "" ] ]
We calculate contributions to the oblique parameters $S$ and $T$ for leptoquarks and bileptons, and find phenomenological constraints on their allowed masses. Leptoquarks suggested by the neutral and charged current anomalies at HERA can give improved agreement with both $S$ and $T$. If bileptons are the only new states, the singly-charged one must be heavier than the directly-established lower limit. We also consider SU(15) grand unification to find when it can be consistent with precision electroweak measurements.
2205.02530
Xiuwu Wang
Xiu-Wu Wang and Zhi-Gang Wang
Study of isospin eigenstates of the pentaquark molecular states with strangeness
null
Int. J. Mod. Phys. A, 37 (2022) 2250189
10.1142/S0217751X22501895
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the paper, we construct eight color singlet-singlet type five-quark currents with distinguished isospins to study the $\bar{D}\Xi^{\prime}$, $\bar{D}\Xi_c^{*}$, $\bar{D}^{*}\Xi_c^{\prime}$ and $\bar{D}^{*}\Xi_c^{*}$ molecular states with strangeness via the QCD sum rules. Numerical results show that the central values of the pentaquark masses with higher (lower) isospin are slightly above (below) the thresholds of the corresponding meson-baryon pairs, and support assigning the $P_{cs}(4459)$ as the $\bar{D}\Xi_c^{*}$ molecular state with the quantum numbers $IJ^P=0{\frac{3}{2}}^-$. The other predictions can be confronted to the experimental data in the future.
[ { "created": "Thu, 5 May 2022 09:32:48 GMT", "version": "v1" }, { "created": "Sat, 15 Oct 2022 13:29:30 GMT", "version": "v2" } ]
2023-01-18
[ [ "Wang", "Xiu-Wu", "" ], [ "Wang", "Zhi-Gang", "" ] ]
In the paper, we construct eight color singlet-singlet type five-quark currents with distinguished isospins to study the $\bar{D}\Xi^{\prime}$, $\bar{D}\Xi_c^{*}$, $\bar{D}^{*}\Xi_c^{\prime}$ and $\bar{D}^{*}\Xi_c^{*}$ molecular states with strangeness via the QCD sum rules. Numerical results show that the central values of the pentaquark masses with higher (lower) isospin are slightly above (below) the thresholds of the corresponding meson-baryon pairs, and support assigning the $P_{cs}(4459)$ as the $\bar{D}\Xi_c^{*}$ molecular state with the quantum numbers $IJ^P=0{\frac{3}{2}}^-$. The other predictions can be confronted to the experimental data in the future.
hep-ph/0202121
Goran Duplancic
W. Behr, N.G. Deshpande, G. Duplancic, P. Schupp, J. Trampetic and J. Wess
The Z -> gamma gamma, gg Decays in the Noncommutative Standard Model
6 pages, 4 figures; v2: more detailed discussion and 3 new figures; v3: final version to appear in EPJC
Eur.Phys.J.C29:441-446,2003
10.1140/epjc/s2003-01207-4
null
hep-ph hep-th
null
On noncommutative spacetime, the Standard Model allows new, usually Standard Model forbidden, triple gauge boson interactions. In this letter we propose the Standard Model strictly forbidden Z -> gamma gamma and Z -> gg decay modes coming from the gauge sector of the Noncommutative Standard Model as a place where noncommutativity could be experimentally discovered.
[ { "created": "Wed, 13 Feb 2002 13:48:03 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2002 19:55:04 GMT", "version": "v2" }, { "created": "Tue, 13 May 2003 16:16:29 GMT", "version": "v3" } ]
2011-09-13
[ [ "Behr", "W.", "" ], [ "Deshpande", "N. G.", "" ], [ "Duplancic", "G.", "" ], [ "Schupp", "P.", "" ], [ "Trampetic", "J.", "" ], [ "Wess", "J.", "" ] ]
On noncommutative spacetime, the Standard Model allows new, usually Standard Model forbidden, triple gauge boson interactions. In this letter we propose the Standard Model strictly forbidden Z -> gamma gamma and Z -> gg decay modes coming from the gauge sector of the Noncommutative Standard Model as a place where noncommutativity could be experimentally discovered.
hep-ph/0311291
Yann Mambrini
Y. Mambrini
Phenomenological Aspects of Heterotic Effective Models At One Loop
5 pages, 2 figures, To appear in the proceedings of 2nd International Conference on String Phenomenology 2003, Durham, England, 29 Jul - 4 Aug 2003
null
10.1142/9789812702463_0036
null
hep-ph
null
We provide a study of the phenomenology of orbifold compactifications of the heterotic string within the context of supergravity effective theories. Our investigation focuses on those models where the soft Lagrangian is dominated by loop contributions to the various soft supersymmetry breaking parameters. We consider the pattern of masses that are governed by these soft terms and investigate the implications of certain indirect constraints on supersymmetric models, such as flavor-changing neutral currents, the anomalous magnetic moment of the muon and the density of thermal relic neutralinos.
[ { "created": "Sat, 22 Nov 2003 17:29:55 GMT", "version": "v1" }, { "created": "Sun, 21 Dec 2003 15:58:16 GMT", "version": "v2" } ]
2017-08-23
[ [ "Mambrini", "Y.", "" ] ]
We provide a study of the phenomenology of orbifold compactifications of the heterotic string within the context of supergravity effective theories. Our investigation focuses on those models where the soft Lagrangian is dominated by loop contributions to the various soft supersymmetry breaking parameters. We consider the pattern of masses that are governed by these soft terms and investigate the implications of certain indirect constraints on supersymmetric models, such as flavor-changing neutral currents, the anomalous magnetic moment of the muon and the density of thermal relic neutralinos.
2407.00969
Basabendu Barman
Basabendu Barman, Arindam Das, Sanjoy Mandal
Dark matter-electron scattering and freeze-in scenarios in the light of $Z^\prime$ mediation
22 pages, 6 figures
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We investigate dark matter (DM)-electron scattering in a minimal $U(1)_X$ extension of the Standard Model (SM), where the DM can appear as a Majorana fermion, a complex singlet scalar or a Dirac fermion. To study bounds on the $U(1)_X$ gauge coupling $(g_X)$ and new gauge boson mass $(M_{Z^\prime})$, from DM-electron scattering, we consider several direct search experiments like CDMS, DAMIC, SENSEI, PandaX-II, DarkSide-50 and XENON1T-S2 for different $U(1)_X$ charges. In this set-up we consider DM production via freeze-in both in radiation dominated and modified cosmological background to project sensitivities on $g_X-M_{Z^\prime}$ plane satisfying observed relic abundance. DM-electron scattering could provide comparable, or even stronger bounds than those obtained from the electron/ muon $(g-2)$, low energy scattering and intensity frontier experiments within 0.01 GeV $\lesssim M_{Z^\prime} \lesssim$ 0.1 GeV. Constrains from freeze-in could provide stronger sensitivities for $M_{Z^\prime}\gtrsim \mathcal{O}(1)$ GeV, however, these limits are comparable to those obtained from LHCb, LEP experiments for $\mathcal{O}(10)$ GeV $\lesssim M_{Z^\prime} \lesssim 150$ GeV. In future, electron-muon scattering (MUonE), proton (FASER, DUNE) and electron/positron (ILC) beam dump experiments could probe these parameters.
[ { "created": "Mon, 1 Jul 2024 05:06:14 GMT", "version": "v1" } ]
2024-07-02
[ [ "Barman", "Basabendu", "" ], [ "Das", "Arindam", "" ], [ "Mandal", "Sanjoy", "" ] ]
We investigate dark matter (DM)-electron scattering in a minimal $U(1)_X$ extension of the Standard Model (SM), where the DM can appear as a Majorana fermion, a complex singlet scalar or a Dirac fermion. To study bounds on the $U(1)_X$ gauge coupling $(g_X)$ and new gauge boson mass $(M_{Z^\prime})$, from DM-electron scattering, we consider several direct search experiments like CDMS, DAMIC, SENSEI, PandaX-II, DarkSide-50 and XENON1T-S2 for different $U(1)_X$ charges. In this set-up we consider DM production via freeze-in both in radiation dominated and modified cosmological background to project sensitivities on $g_X-M_{Z^\prime}$ plane satisfying observed relic abundance. DM-electron scattering could provide comparable, or even stronger bounds than those obtained from the electron/ muon $(g-2)$, low energy scattering and intensity frontier experiments within 0.01 GeV $\lesssim M_{Z^\prime} \lesssim$ 0.1 GeV. Constrains from freeze-in could provide stronger sensitivities for $M_{Z^\prime}\gtrsim \mathcal{O}(1)$ GeV, however, these limits are comparable to those obtained from LHCb, LEP experiments for $\mathcal{O}(10)$ GeV $\lesssim M_{Z^\prime} \lesssim 150$ GeV. In future, electron-muon scattering (MUonE), proton (FASER, DUNE) and electron/positron (ILC) beam dump experiments could probe these parameters.
hep-ph/9311365
Stefano Forte
Mauro Anselmino and Stefano Forte
An Instanton-Induced Contribution to the Decay of the Eta_c into P-Pbar
plain TeX with harvmac (b mode); 15 pages, 1 figure (included as a plain uncompressed postscript file); DFTT 73/93
Phys.Lett. B323 (1994) 71-77
10.1016/0370-2693(94)90458-8
null
hep-ph
null
We compute the decay rate for the process $\eta_c\to p\bar p$ using an effective helicity-flipping proton-antiproton-gluon vertex which incorporates nonperturbative chiral symmetry breaking effects induced by instantons. We fix the strength of the vertex by requiring it to account for the screening of the proton's axial charge observed in deep-inelastic scattering, and we estimate the size of the instanton effects by assuming them to depend linearly on the instanton density. We find that, despite a large suppression, the instanton-induced process occurs with a sizable rate comparable to the observed one, whereas the process is forbidden in perturbative QCD and not understood using standard methods.
[ { "created": "Thu, 25 Nov 1993 20:13:02 GMT", "version": "v1" } ]
2009-10-22
[ [ "Anselmino", "Mauro", "" ], [ "Forte", "Stefano", "" ] ]
We compute the decay rate for the process $\eta_c\to p\bar p$ using an effective helicity-flipping proton-antiproton-gluon vertex which incorporates nonperturbative chiral symmetry breaking effects induced by instantons. We fix the strength of the vertex by requiring it to account for the screening of the proton's axial charge observed in deep-inelastic scattering, and we estimate the size of the instanton effects by assuming them to depend linearly on the instanton density. We find that, despite a large suppression, the instanton-induced process occurs with a sizable rate comparable to the observed one, whereas the process is forbidden in perturbative QCD and not understood using standard methods.
2306.16468
Jason Arakawa
Jason Arakawa, Joshua Eby, Marianna S. Safronova, Volodymyr Takhistov, and Muhammad H. Zaheer
Detection of Bosenovae with Quantum Sensors on Earth and in Space
16 pages, 9 figures
null
null
IPMU23-0024, KEK-QUP-2023-0014, KEK-TH-2534, KEK-Cosmo-0316
hep-ph astro-ph.CO astro-ph.HE physics.atom-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
In a broad class of theories, the accumulation of ultralight dark matter (ULDM) with particles of mass $10^{-22}~\textrm{eV} < m_{\phi} < 1~\textrm{eV}$ leads the to formation of long-lived bound states known as boson stars. When the ULDM exhibits self-interactions, prodigious bursts of energy carried by relativistic bosons are released from collapsing boson stars in bosenova explosions. We extensively explore the potential reach of terrestrial and space-based experiments for detecting transient signatures of emitted relativistic bursts of scalar particles, including ULDM coupled to photons, electrons, and gluons, capturing a wide range of motivated theories. For the scenario of relaxion ULDM, we demonstrate that upcoming experiments and technology such as nuclear clocks as well as space-based interferometers will be able to sensitively probe orders of magnitude in the ULDM coupling-mass parameter space, challenging to study otherwise, by detecting signatures of transient bosenova events. Our analysis can be readily extended to different scenarios of relativistic scalar particle emission.
[ { "created": "Wed, 28 Jun 2023 18:00:29 GMT", "version": "v1" } ]
2023-06-30
[ [ "Arakawa", "Jason", "" ], [ "Eby", "Joshua", "" ], [ "Safronova", "Marianna S.", "" ], [ "Takhistov", "Volodymyr", "" ], [ "Zaheer", "Muhammad H.", "" ] ]
In a broad class of theories, the accumulation of ultralight dark matter (ULDM) with particles of mass $10^{-22}~\textrm{eV} < m_{\phi} < 1~\textrm{eV}$ leads the to formation of long-lived bound states known as boson stars. When the ULDM exhibits self-interactions, prodigious bursts of energy carried by relativistic bosons are released from collapsing boson stars in bosenova explosions. We extensively explore the potential reach of terrestrial and space-based experiments for detecting transient signatures of emitted relativistic bursts of scalar particles, including ULDM coupled to photons, electrons, and gluons, capturing a wide range of motivated theories. For the scenario of relaxion ULDM, we demonstrate that upcoming experiments and technology such as nuclear clocks as well as space-based interferometers will be able to sensitively probe orders of magnitude in the ULDM coupling-mass parameter space, challenging to study otherwise, by detecting signatures of transient bosenova events. Our analysis can be readily extended to different scenarios of relativistic scalar particle emission.
2408.01783
Muhammad Goharipour
The MMGPDs Collaboration, Muhammad Goharipour, Fatemeh Irani, Hadi Hashamipour, K. Azizi
The charge and magnetic radii of the nucleons from the generalized parton distributions
8 Pages, 4 Figures and 2 Tables
null
null
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
The proton-radius puzzle refers to the discrepancy observed in measurements of the proton's charge radius when using different methods. This inconsistency has prompted extensive research and debate within the physics community, as it challenges the understanding of quantum electrodynamics and the fundamental properties of protons. In the present study, we determine the charge and magnetic radii of the proton and neutron through a global analysis of the generalized parton distributions (GPDs) at zero skewness for the first time. Our results challenge the measurements or analyses in which the nucleon's radii are extracted considering just a particular experiment or observable, or using only data points covering particular kinematic regions. We emphasize that simultaneous analysis of all available experimental data related to the radii of the nucleons would be preferable to determine their exact values. The final results obtained from our analysis by this way are: $ r_{pE} = 0.8558 \pm 0.0135~\textrm{fm} $, $ r_{pM} = 0.8268 \pm 0.0533~\textrm{fm} $, $ \left<r_{nE}^2\right> = -0.1181 \pm 0.0270~\textrm{fm}^2 $, and $ r_{nM} = 0.8367 \pm 0.0845~\textrm{fm} $.
[ { "created": "Sat, 3 Aug 2024 13:35:05 GMT", "version": "v1" } ]
2024-08-06
[ [ "The MMGPDs Collaboration", "", "" ], [ "Goharipour", "Muhammad", "" ], [ "Irani", "Fatemeh", "" ], [ "Hashamipour", "Hadi", "" ], [ "Azizi", "K.", "" ] ]
The proton-radius puzzle refers to the discrepancy observed in measurements of the proton's charge radius when using different methods. This inconsistency has prompted extensive research and debate within the physics community, as it challenges the understanding of quantum electrodynamics and the fundamental properties of protons. In the present study, we determine the charge and magnetic radii of the proton and neutron through a global analysis of the generalized parton distributions (GPDs) at zero skewness for the first time. Our results challenge the measurements or analyses in which the nucleon's radii are extracted considering just a particular experiment or observable, or using only data points covering particular kinematic regions. We emphasize that simultaneous analysis of all available experimental data related to the radii of the nucleons would be preferable to determine their exact values. The final results obtained from our analysis by this way are: $ r_{pE} = 0.8558 \pm 0.0135~\textrm{fm} $, $ r_{pM} = 0.8268 \pm 0.0533~\textrm{fm} $, $ \left<r_{nE}^2\right> = -0.1181 \pm 0.0270~\textrm{fm}^2 $, and $ r_{nM} = 0.8367 \pm 0.0845~\textrm{fm} $.
1809.04991
Pierre Fayet
Pierre Fayet
MICROSCOPE limits on the strength of a new force, with comparisons to gravity and electromagnetism
13 pages, matches published version
Phys. Rev. D 99, 055043 (2019)
10.1103/PhysRevD.99.055043
LPTENS/18/12
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extremely weak new forces could lead to apparent violations of the Equivalence Principle. The MICROSCOPE experiment implies that the relative strength of a new long-range force, compared with gravity, is constrained to $|\bar\alpha_g|<3.2\ 10^{-11},2.3\ 10^{-13},2.2\ 10^{-13},6.7\ 10^{-13}$ and $1.5\ 10^{-12}$ at $2\sigma$, for a coupling to $B,\ L,\ B-L,\ B+L$ or $3B+L$; or, for a coupling to isospin, $|\alpha_g|<8.4\ 10^{-12}$. This is a gain in sensitivity $\simeq 3$ for a coupling to $B$, to $\approx$ 15 in the other cases, including $B-L$ as suggested by grand unification. This requires paying attention to the definition of $\bar\alpha_g$. A force coupled to $L$ (or $B-L$) would act effectively on protons (or neutrons) only, its relative intensity being reduced from $\alpha_g$ to about $\bar\alpha_g=\alpha_g/4$ for an average nucleon. It is thus convenient to view such forces as acting on $\bar Q =B,\ 2L,\ 2(B-L),2(B+L)/3$ or $2(3B+L)/7$, leading to $\bar\alpha_g=\alpha_g\times(1,1/4,1/4,9/4$ or $49/4$). The sensitivity for a coupling to $L$ or $B-L$ is better than for $B$ by two orders of magnitude (as $\Delta (2L/A_r)\simeq 144\ \Delta (B/A_r)$ for Ti-Pt); and about 3 or 7 times better than for $B+L$ or $3B+L$. A coupling to $(\epsilon_BB+\epsilon_{Q_{el}}Q_{el})e$ should verify $|\epsilon_B|<5\ 10^{-24}$; similarly $|\epsilon_L|$ or $|\epsilon_{B-L}|<.9\ 10^{-24}$, $|\epsilon_{B+L}|<.5\ 10^{-24},|\epsilon_{3B+L}|<.32\ 10^{-24}$ and $|\epsilon_{B-2L}|<2.6\ 10^{-24}$, implying a new interaction weaker than electromagnetism by more than $10^{46}$ to $10^{48}$. The resulting hierarchy between couplings, typically by $>10^{24}$, may be related within supersymmetry with a large hierarchy in energy scales by $>10^{12}$. This points to a $\sqrt\xi\approx 10^{16}$ GeV scale, associated with a huge vacuum energy density that may be responsible for the inflation of the early Universe.
[ { "created": "Thu, 13 Sep 2018 14:40:54 GMT", "version": "v1" }, { "created": "Thu, 4 Apr 2019 12:43:56 GMT", "version": "v2" } ]
2019-04-05
[ [ "Fayet", "Pierre", "" ] ]
Extremely weak new forces could lead to apparent violations of the Equivalence Principle. The MICROSCOPE experiment implies that the relative strength of a new long-range force, compared with gravity, is constrained to $|\bar\alpha_g|<3.2\ 10^{-11},2.3\ 10^{-13},2.2\ 10^{-13},6.7\ 10^{-13}$ and $1.5\ 10^{-12}$ at $2\sigma$, for a coupling to $B,\ L,\ B-L,\ B+L$ or $3B+L$; or, for a coupling to isospin, $|\alpha_g|<8.4\ 10^{-12}$. This is a gain in sensitivity $\simeq 3$ for a coupling to $B$, to $\approx$ 15 in the other cases, including $B-L$ as suggested by grand unification. This requires paying attention to the definition of $\bar\alpha_g$. A force coupled to $L$ (or $B-L$) would act effectively on protons (or neutrons) only, its relative intensity being reduced from $\alpha_g$ to about $\bar\alpha_g=\alpha_g/4$ for an average nucleon. It is thus convenient to view such forces as acting on $\bar Q =B,\ 2L,\ 2(B-L),2(B+L)/3$ or $2(3B+L)/7$, leading to $\bar\alpha_g=\alpha_g\times(1,1/4,1/4,9/4$ or $49/4$). The sensitivity for a coupling to $L$ or $B-L$ is better than for $B$ by two orders of magnitude (as $\Delta (2L/A_r)\simeq 144\ \Delta (B/A_r)$ for Ti-Pt); and about 3 or 7 times better than for $B+L$ or $3B+L$. A coupling to $(\epsilon_BB+\epsilon_{Q_{el}}Q_{el})e$ should verify $|\epsilon_B|<5\ 10^{-24}$; similarly $|\epsilon_L|$ or $|\epsilon_{B-L}|<.9\ 10^{-24}$, $|\epsilon_{B+L}|<.5\ 10^{-24},|\epsilon_{3B+L}|<.32\ 10^{-24}$ and $|\epsilon_{B-2L}|<2.6\ 10^{-24}$, implying a new interaction weaker than electromagnetism by more than $10^{46}$ to $10^{48}$. The resulting hierarchy between couplings, typically by $>10^{24}$, may be related within supersymmetry with a large hierarchy in energy scales by $>10^{12}$. This points to a $\sqrt\xi\approx 10^{16}$ GeV scale, associated with a huge vacuum energy density that may be responsible for the inflation of the early Universe.
1307.2395
Kazem Azizi
E. Yazici, E. Veli Veliev, K. Azizi, H. Sundu
Investigation of the $D^{\ast}_{s}D_{s} \eta^{(\prime)}$ and $B^{\ast}_{s}B_{s} \eta^{(\prime)}$ vertices via QCD sum rules
11 Pages, 4 Figures and 3 Tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strong coupling constants among mesons are very important quantities as they can provide useful information on the nature of strong interaction among hadrons as well as the QCD vacuum. In this article, we investigate the strong vertices of the $D^{\ast}_{s}D_{s} \eta^{(\prime)}$ and $B^{\ast}_{s}B_{s} \eta^{(\prime)}$ in the framework of the QCD sum rule approach choosing the $\eta$ or $D_{s} (B_{s})$ meson as an off-shell state. We obtain the results $g_{D_s^*D_s\eta}=(1.46\pm 0.30)GeV^{-1}$, $g_{D_s^*D_s\eta^{\prime}}=(0.74\pm 0.16)GeV^{-1}$, $g_{B_s^*B_s\eta}=(5.29\pm 1.06)GeV^{-1}$ and $g_{B_s^*B_s\eta^{\prime}}=(2.29\pm 0.48)GeV^{-1}$ for the strong coupling constants under consideration, which can be checked in future experiments.
[ { "created": "Tue, 9 Jul 2013 10:44:02 GMT", "version": "v1" }, { "created": "Tue, 8 Oct 2013 12:52:08 GMT", "version": "v2" } ]
2013-10-09
[ [ "Yazici", "E.", "" ], [ "Veliev", "E. Veli", "" ], [ "Azizi", "K.", "" ], [ "Sundu", "H.", "" ] ]
The strong coupling constants among mesons are very important quantities as they can provide useful information on the nature of strong interaction among hadrons as well as the QCD vacuum. In this article, we investigate the strong vertices of the $D^{\ast}_{s}D_{s} \eta^{(\prime)}$ and $B^{\ast}_{s}B_{s} \eta^{(\prime)}$ in the framework of the QCD sum rule approach choosing the $\eta$ or $D_{s} (B_{s})$ meson as an off-shell state. We obtain the results $g_{D_s^*D_s\eta}=(1.46\pm 0.30)GeV^{-1}$, $g_{D_s^*D_s\eta^{\prime}}=(0.74\pm 0.16)GeV^{-1}$, $g_{B_s^*B_s\eta}=(5.29\pm 1.06)GeV^{-1}$ and $g_{B_s^*B_s\eta^{\prime}}=(2.29\pm 0.48)GeV^{-1}$ for the strong coupling constants under consideration, which can be checked in future experiments.
hep-ph/9506218
Davison Soper
Davison E. Soper (Oregon)
Summary of the XXX Rencontre de Moriond QCD Session
12 pages, Latex, no figures
null
null
null
hep-ph
null
The main topics covered in this summary talk are the Large Hadron Collider, heavy ion collisions, renormalons, parton distribution functions, measurements of the strong coupling and the top quark. Of special interest this year was the discovery of the top quark by the CDF and D0 groups at Fermilab. I conclude that the evidence is compelling and that the best fit of the Standard Model top hypothesis to the data gives a top mass of $170 +/- 9 GeV with a good chisquared.
[ { "created": "Thu, 1 Jun 1995 23:36:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Soper", "Davison E.", "", "Oregon" ] ]
The main topics covered in this summary talk are the Large Hadron Collider, heavy ion collisions, renormalons, parton distribution functions, measurements of the strong coupling and the top quark. Of special interest this year was the discovery of the top quark by the CDF and D0 groups at Fermilab. I conclude that the evidence is compelling and that the best fit of the Standard Model top hypothesis to the data gives a top mass of $170 +/- 9 GeV with a good chisquared.
hep-ph/0312334
Thomas Binoth Dr.
T. Binoth, J. Ph. Guillet, F. Mahmoudi
A compact representation of the 2 photon 3 gluon amplitude
15 pages Latex, 6 eps files included, revised version
JHEP 0402 (2004) 057
10.1088/1126-6708/2004/02/057
WUE-ITP-2003-038, LAPTH-1021/03
hep-ph
null
A compact representation of the loop amplitude gamma gamma ggg -> 0 is presented. The result has been obtained by using helicity methods and sorting with respect to an irreducible function basis. We show how to convert spinor representations into a field strength representation of the amplitude. The amplitude defines a background contribution for Higgs boson searches at the LHC in the channel H -> gamma gamma + jet which was earlier extracted indirectly from the one-loop representation of the 5-gluon amplitude.
[ { "created": "Tue, 23 Dec 2003 17:17:34 GMT", "version": "v1" }, { "created": "Fri, 30 Jan 2004 14:26:49 GMT", "version": "v2" } ]
2009-11-10
[ [ "Binoth", "T.", "" ], [ "Guillet", "J. Ph.", "" ], [ "Mahmoudi", "F.", "" ] ]
A compact representation of the loop amplitude gamma gamma ggg -> 0 is presented. The result has been obtained by using helicity methods and sorting with respect to an irreducible function basis. We show how to convert spinor representations into a field strength representation of the amplitude. The amplitude defines a background contribution for Higgs boson searches at the LHC in the channel H -> gamma gamma + jet which was earlier extracted indirectly from the one-loop representation of the 5-gluon amplitude.
2406.16298
Chen Qian
Sihao Wu, Chen Qian, Qun Wang and Xiao-Rong Zhou
Bell nonlocality and entanglement in $e^{+}e^{-} \rightarrow Y\bar{Y}$ at BESIII
9 pages, 4 figures, 4 tables. We corrected a few errors in plotting figures from analytical formula. Some results in tables read from figures have also been corrected. A new table (Table III) was added for the maximum concurrence and their corresponding angles. A few references were added
null
null
null
hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
The Bell nonlocality and entanglement are two kinds of quantum correlations in quantum systems. Due to the recent upgrade in Beijing Spectrometer III (BESIII) experiment, it is possible to explore the nonlocality and entanglement in hyperon-antihyperon systems produced in electron-positron annihilation with high precision data. We provide a systematic method for studying quantum correlations in spin-1/2 hyperon-antihyperon systems through the measures for the nonlocality and entanglement. We find that with nonvanishing polarizations of the hyperon and its antihyperon, the kinematic region of nonlocality in the hyperon-antihyperon system is more restricted than the $\tau^{+}\tau^{-}$ system in which polarizations of $\tau$ leptons are vanishing. We also present an experimental proposal to probe the nonlocality and entanglement in hyperon-antihyperon systems at BSEIII.
[ { "created": "Mon, 24 Jun 2024 03:51:52 GMT", "version": "v1" }, { "created": "Fri, 28 Jun 2024 07:55:15 GMT", "version": "v2" } ]
2024-07-01
[ [ "Wu", "Sihao", "" ], [ "Qian", "Chen", "" ], [ "Wang", "Qun", "" ], [ "Zhou", "Xiao-Rong", "" ] ]
The Bell nonlocality and entanglement are two kinds of quantum correlations in quantum systems. Due to the recent upgrade in Beijing Spectrometer III (BESIII) experiment, it is possible to explore the nonlocality and entanglement in hyperon-antihyperon systems produced in electron-positron annihilation with high precision data. We provide a systematic method for studying quantum correlations in spin-1/2 hyperon-antihyperon systems through the measures for the nonlocality and entanglement. We find that with nonvanishing polarizations of the hyperon and its antihyperon, the kinematic region of nonlocality in the hyperon-antihyperon system is more restricted than the $\tau^{+}\tau^{-}$ system in which polarizations of $\tau$ leptons are vanishing. We also present an experimental proposal to probe the nonlocality and entanglement in hyperon-antihyperon systems at BSEIII.
1407.4111
Thomas Becher
Thomas Becher, Guido Bell, Christian Lorentzen and Stefanie Marti
The transverse-momentum spectrum of Higgs bosons near threshold at NNLO
17 pages, 9 Figures; v2: journal version, correction in the qg channel
null
10.1007/JHEP11(2014)026
OUTP-14-13P
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give next-to-next-to-leading order (NNLO) predictions for the Higgs production cross section at large transverse momentum in the threshold limit. Near the partonic threshold, all radiation is either soft or collinear to the final state jet which recoils against the Higgs boson. We find that the real emission corrections are of moderate size, but that the virtual corrections are large. We discuss the origin of these corrections and give numerical predictions for the transverse-momentum spectrum. The threshold result is matched to the known NLO result and implemented in the public code PeTeR.
[ { "created": "Tue, 15 Jul 2014 19:50:27 GMT", "version": "v1" }, { "created": "Fri, 28 Nov 2014 16:08:11 GMT", "version": "v2" } ]
2015-06-22
[ [ "Becher", "Thomas", "" ], [ "Bell", "Guido", "" ], [ "Lorentzen", "Christian", "" ], [ "Marti", "Stefanie", "" ] ]
We give next-to-next-to-leading order (NNLO) predictions for the Higgs production cross section at large transverse momentum in the threshold limit. Near the partonic threshold, all radiation is either soft or collinear to the final state jet which recoils against the Higgs boson. We find that the real emission corrections are of moderate size, but that the virtual corrections are large. We discuss the origin of these corrections and give numerical predictions for the transverse-momentum spectrum. The threshold result is matched to the known NLO result and implemented in the public code PeTeR.
1308.0332
Christoph Luhn
Herbi K. Dreiner, Christoph Luhn, Toby Opferkuch
Froggatt-Nielsen models with a residual Z_4^R symmetry
19 pages
Phys. Rev. D 88, 115005 (2013)
10.1103/PhysRevD.88.115005
IPPP/13/57, DCPT/13/114
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Froggatt-Nielsen mechanism provides an elegant explanation for the hierarchies of fermion masses and mixings in terms of a U(1) symmetry. Promoting such a family symmetry to an R-symmetry, we explicitly construct supersymmetric Froggatt-Nielsen models which are gauged, family dependent U(1)_R completions of the Z_4^R symmetry proposed by Lee, Raby, Ratz, Ross, Schieren, Schmidt-Hoberg and Vaudrevange in 2010. Forbidden by Z_4^R, the mu-term is generated around the supersymmetry breaking scale m_3/2 from either the Kahler potential or the superpotential. Neutrinos acquire their mass via the type I seesaw mechanism with three right-handed neutrino superfields. Taking into account the Green-Schwarz anomaly cancellation conditions, we arrive at a total of 3 x 34 distinct phenomenologically viable charge assignments for the standard model fields, most of which feature highly fractional charges.
[ { "created": "Thu, 1 Aug 2013 20:00:01 GMT", "version": "v1" } ]
2013-12-16
[ [ "Dreiner", "Herbi K.", "" ], [ "Luhn", "Christoph", "" ], [ "Opferkuch", "Toby", "" ] ]
The Froggatt-Nielsen mechanism provides an elegant explanation for the hierarchies of fermion masses and mixings in terms of a U(1) symmetry. Promoting such a family symmetry to an R-symmetry, we explicitly construct supersymmetric Froggatt-Nielsen models which are gauged, family dependent U(1)_R completions of the Z_4^R symmetry proposed by Lee, Raby, Ratz, Ross, Schieren, Schmidt-Hoberg and Vaudrevange in 2010. Forbidden by Z_4^R, the mu-term is generated around the supersymmetry breaking scale m_3/2 from either the Kahler potential or the superpotential. Neutrinos acquire their mass via the type I seesaw mechanism with three right-handed neutrino superfields. Taking into account the Green-Schwarz anomaly cancellation conditions, we arrive at a total of 3 x 34 distinct phenomenologically viable charge assignments for the standard model fields, most of which feature highly fractional charges.
hep-ph/0412004
Guidal
M. Guidal
Deep Virtual Compton Scattering and the Nucleon Generalized Parton Distributions
12 pages, 5 figures
Nucl.Phys.A751:180-191,2005
10.1016/j.nuclphysa.2005.02.011
null
hep-ph
null
In the following, the subject of Deep Virtual Compton Scattering on the nucleon and its relation to the recently introduced concept of Generalized Parton Distributions are briefly reviewed. The general theoretical framework and the links between theory and experiment will be outlined and the recently published data which look promising for the development of this field will be discussed. Finally, the experimental prospectives of the domain will be presented.
[ { "created": "Wed, 1 Dec 2004 10:58:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Guidal", "M.", "" ] ]
In the following, the subject of Deep Virtual Compton Scattering on the nucleon and its relation to the recently introduced concept of Generalized Parton Distributions are briefly reviewed. The general theoretical framework and the links between theory and experiment will be outlined and the recently published data which look promising for the development of this field will be discussed. Finally, the experimental prospectives of the domain will be presented.
2205.08380
BoQiang Lu
Bo-Qiang Lu, Cheng-Wei Chiang, and Da Huang
Probing WIMPs in space-based gravitational wave experiments
11 pages, 2 figures, 2 tables
Physics Letters B 833 (2022) 137308
10.1016/j.physletb.2022.137308
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
Although searches for dark matter have lasted for decades, no convincing signal has been found without ambiguity in underground detections, cosmic ray observations, and collider experiments. We show by example that gravitational wave (GW) observations can be a supplement to dark matter detections if the production of dark matter follows a strong first-order cosmological phase transition. We explore this possibility in a complex singlet extension of the standard model with CP symmetry. We demonstrate three benchmarks in which the GW signals from the first-order phase transition are loud enough for future space-based GW observations, for example, BBO, U-DECIGO, LISA, Taiji, and TianQin. While satisfying the constraints from the XENON1T experiment and the Fermi-LAT gamma-ray observations, the dark matter candidate with its mass around $\sim 1$~TeV in these scenarios has a correct relic abundance obtained by the Planck observations of the cosmic microwave background radiation.
[ { "created": "Tue, 17 May 2022 14:02:58 GMT", "version": "v1" }, { "created": "Sun, 24 Jul 2022 15:15:56 GMT", "version": "v2" } ]
2022-07-26
[ [ "Lu", "Bo-Qiang", "" ], [ "Chiang", "Cheng-Wei", "" ], [ "Huang", "Da", "" ] ]
Although searches for dark matter have lasted for decades, no convincing signal has been found without ambiguity in underground detections, cosmic ray observations, and collider experiments. We show by example that gravitational wave (GW) observations can be a supplement to dark matter detections if the production of dark matter follows a strong first-order cosmological phase transition. We explore this possibility in a complex singlet extension of the standard model with CP symmetry. We demonstrate three benchmarks in which the GW signals from the first-order phase transition are loud enough for future space-based GW observations, for example, BBO, U-DECIGO, LISA, Taiji, and TianQin. While satisfying the constraints from the XENON1T experiment and the Fermi-LAT gamma-ray observations, the dark matter candidate with its mass around $\sim 1$~TeV in these scenarios has a correct relic abundance obtained by the Planck observations of the cosmic microwave background radiation.
hep-ph/0601091
Kopylov
A.Kopylov, I.Orekhov, V.Petukhov, A.Solomatin
A Lithium Experiment in the Program of Solar Neutrino Research
6 pages, 2 figures, 1 table, A report made by A.Kopylov at International Conference NANP-2005, June 2005, Dubna, Russia
Phys.Atom.Nucl.69:1829-1832,2006
10.1134/S1063778806110044
null
hep-ph
null
The experiments sensitive to pp-neutrinos from the Sun are very perspective for the precise measurement of a mixing angle $\theta_{12}$. A $\nu $e$^{-}$ scattering experiment (Xmass) and/or a charged-current experiment (the indium detector) can measure the flux of electron pp-neutrinos. One can find the total flux of pp-neutrinos from a luminosity constraint after the contribution of $^7$Be and CNO neutrinos to the total luminosity of the Sun are measured. The radiochemical experiment utilizing a lithium target has the high sensitivity to the CNO neutrinos, thus, it has a good promise for the precise measurement of a mixing angle and for the test of a current theory of the evolution of the stars.
[ { "created": "Thu, 12 Jan 2006 07:24:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kopylov", "A.", "" ], [ "Orekhov", "I.", "" ], [ "Petukhov", "V.", "" ], [ "Solomatin", "A.", "" ] ]
The experiments sensitive to pp-neutrinos from the Sun are very perspective for the precise measurement of a mixing angle $\theta_{12}$. A $\nu $e$^{-}$ scattering experiment (Xmass) and/or a charged-current experiment (the indium detector) can measure the flux of electron pp-neutrinos. One can find the total flux of pp-neutrinos from a luminosity constraint after the contribution of $^7$Be and CNO neutrinos to the total luminosity of the Sun are measured. The radiochemical experiment utilizing a lithium target has the high sensitivity to the CNO neutrinos, thus, it has a good promise for the precise measurement of a mixing angle and for the test of a current theory of the evolution of the stars.
1201.1413
Salah Nasri
Abdessamad Abada and Salah Nasri
Phenomenology of a Light Cold Dark Matter Two-Singlet Model
16 pages, 8 figures
null
10.1103/PhysRevD.85.075009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the implications of phenomenological processes on a two-singlet extension of the Standard Model we introduced in a previous work to describe light cold dark matter. We look into the rare decays of $\Upsilon $ and $B$ mesons, most particularly the invisible channels, and study the decay channels of the Higgs particle. Preferred regions of the parameter space are indicated, together with others that are excluded. Comments in relation to recent Higgs searches and finds at the LHC are made.
[ { "created": "Fri, 6 Jan 2012 13:43:37 GMT", "version": "v1" } ]
2013-05-30
[ [ "Abada", "Abdessamad", "" ], [ "Nasri", "Salah", "" ] ]
We study the implications of phenomenological processes on a two-singlet extension of the Standard Model we introduced in a previous work to describe light cold dark matter. We look into the rare decays of $\Upsilon $ and $B$ mesons, most particularly the invisible channels, and study the decay channels of the Higgs particle. Preferred regions of the parameter space are indicated, together with others that are excluded. Comments in relation to recent Higgs searches and finds at the LHC are made.
1111.1719
Christoph Englert
Christoph Englert, Joerg Jaeckel, Emanuele Re, Michael Spannowsky
Evasive Higgs Maneuvers at the LHC
10 pages, 6 figures, references added, final version accepted for publication in PRD
null
10.1103/PhysRevD.85.035008
IPPP/11/73; DCPT/11/146; LPN11-61
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-standard decays of the Higgs boson produced at the Large Hadron Collider can lead to signatures which can easily be missed due to non-adapted trigger or search strategies. Keeping electroweak symmetry breaking Standard Model-like we classify the phenomenology of an evasive Higgs boson into three categories and discuss how they can be described in an effective field theory. We comment on how one can improve the search strategies to also detect such an evasive Higgs.
[ { "created": "Mon, 7 Nov 2011 21:00:01 GMT", "version": "v1" }, { "created": "Wed, 18 Jan 2012 16:10:05 GMT", "version": "v2" } ]
2015-06-03
[ [ "Englert", "Christoph", "" ], [ "Jaeckel", "Joerg", "" ], [ "Re", "Emanuele", "" ], [ "Spannowsky", "Michael", "" ] ]
Non-standard decays of the Higgs boson produced at the Large Hadron Collider can lead to signatures which can easily be missed due to non-adapted trigger or search strategies. Keeping electroweak symmetry breaking Standard Model-like we classify the phenomenology of an evasive Higgs boson into three categories and discuss how they can be described in an effective field theory. We comment on how one can improve the search strategies to also detect such an evasive Higgs.
hep-ph/9603243
Frank Cuypers
Frank Cuypers (PSI)
Selectron Searches in $e^-e^-$, $e^-\gamma$ and $\gamma\gamma$ Scattering
8 pages, talk presented at the LCWS95 Workshop on Physics and Experiments with Linear Colliders held at Morioka, Sep 8-13, 1995
null
null
MPI-PhT/95-128
hep-ph
null
We review the selectron production mechanisms in the linear collider modes which do not require positrons. The standard model backgrounds can be rendered harmless or even be nearly eliminated with polarized beams. We insist on the complementarity of these different experiments.
[ { "created": "Thu, 7 Mar 1996 07:35:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cuypers", "Frank", "", "PSI" ] ]
We review the selectron production mechanisms in the linear collider modes which do not require positrons. The standard model backgrounds can be rendered harmless or even be nearly eliminated with polarized beams. We insist on the complementarity of these different experiments.
0708.4091
Muneto Nitta
Muneto Nitta and Noriko Shiiki
Non-Abelian Global Strings at Chiral Phase Transition
10 pages, 2 figures
Phys.Lett.B658:143-147,2008
10.1016/j.physletb.2007.10.055
null
hep-ph astro-ph hep-th nucl-th
null
We construct non-Abelian global string solutions in the U(N)_L x U(N)_R linear sigma model. These strings are the most fundamental objects which are expected to form during the chiral phase transitions, because the Abelian eta' string is marginally decomposed into N of them. We point out Nambu-Goldstone modes of CP^{N-1} for breaking of U(N)_V arise around a non-Abelian vortex.
[ { "created": "Thu, 30 Aug 2007 08:18:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nitta", "Muneto", "" ], [ "Shiiki", "Noriko", "" ] ]
We construct non-Abelian global string solutions in the U(N)_L x U(N)_R linear sigma model. These strings are the most fundamental objects which are expected to form during the chiral phase transitions, because the Abelian eta' string is marginally decomposed into N of them. We point out Nambu-Goldstone modes of CP^{N-1} for breaking of U(N)_V arise around a non-Abelian vortex.
hep-ph/9608354
Hannes Uibo
Kari Enqvist, Petteri Ker\"anen, Jukka Maalampi and Hannes Uibo (Department of Physics, University of Helsinki, Finland)
Cosmological abundances of right-handed neutrinos
LaTeX, 18 pages, 5 PostScript figures
Nucl.Phys.B484:403-418,1997
10.1016/S0550-3213(96)00604-9
HU-TFT-96-34
hep-ph astro-ph
null
We study the equilibration of the right-helicity states of light Dirac neutrinos in the early universe by solving the momentum dependent Boltzmann equations numerically. We show that the main effect is due to electroweak gauge boson poles, which enhance thermalization rates by some three orders of magnitude. The right-helicity states of tau neutrinos will be brought in equilibrium independently of their initial distribution at a temperature above the poles if the tau neutrino mass is larger than about 10 keV.
[ { "created": "Sat, 17 Aug 1996 12:18:45 GMT", "version": "v1" } ]
2011-02-01
[ [ "Enqvist", "Kari", "", "Department of Physics, University of Helsinki, Finland" ], [ "Keränen", "Petteri", "", "Department of Physics, University of Helsinki, Finland" ], [ "Maalampi", "Jukka", "", "Department of Physics, University of Helsinki, Finland" ], [ "Uibo", "Hannes", "", "Department of Physics, University of Helsinki, Finland" ] ]
We study the equilibration of the right-helicity states of light Dirac neutrinos in the early universe by solving the momentum dependent Boltzmann equations numerically. We show that the main effect is due to electroweak gauge boson poles, which enhance thermalization rates by some three orders of magnitude. The right-helicity states of tau neutrinos will be brought in equilibrium independently of their initial distribution at a temperature above the poles if the tau neutrino mass is larger than about 10 keV.
hep-ph/9912427
Carlo Giunti
Carlo Giunti
Neutrino oscillations and neutrinoless double-beta decay
7 pages. Presented at TAUP'99, 6-10 September 1999, College de France, Paris, France
Nucl.Phys.Proc.Suppl. 87 (2000) 324-326
10.1016/S0920-5632(00)00693-9
DFTT 71/99
hep-ph
null
We consider the scheme with mixing of three neutrinos and a mass hierarchy. We shown that, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses, the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay. We also discuss briefly neutrinoless double-beta decay in schemes with mixing of four neutrinos. We show that one of them is favored by the data.
[ { "created": "Mon, 20 Dec 1999 16:05:33 GMT", "version": "v1" } ]
2009-10-31
[ [ "Giunti", "Carlo", "" ] ]
We consider the scheme with mixing of three neutrinos and a mass hierarchy. We shown that, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses, the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay. We also discuss briefly neutrinoless double-beta decay in schemes with mixing of four neutrinos. We show that one of them is favored by the data.
hep-ph/9906212
Jin Changhao
Changhao Jin
Some theoretical results on V_ub and V_cb
9 pages, a footnote added, references updated
null
null
null
hep-ph
null
Some theoretical results on V_ub and V_cb determinations from inclusive decays of b hadrons are highlighted.
[ { "created": "Wed, 2 Jun 1999 07:57:47 GMT", "version": "v1" }, { "created": "Mon, 12 Jul 1999 06:46:59 GMT", "version": "v2" } ]
2007-05-23
[ [ "Jin", "Changhao", "" ] ]
Some theoretical results on V_ub and V_cb determinations from inclusive decays of b hadrons are highlighted.
hep-ph/0302048
Tania Robens
Tania Robens
Odderon induced Pion-Photoproduction at e+e- Colliders
Diploma Thesis; 147 pages, 80 figures
null
null
null
hep-ph
null
In diffractive hadronic scattering processes, the Pomeron trajectory, originating from Regge theory, significantly contributes to the behavior of the total and differential cross sections; the same holds for the description of the proton structure function in deep inelastic scattering. So far, the Odderon as the odd-parity partner of the Pomeron has only been observed in differences between differential cross sections for p p and p pbar scattering at low t. We investigate exclusive photoproduction of two neutral pion final states at e+e- colliders; in this reaction, Pomeron exchange is forbidden by C-parity conservation. The Odderon is described by an effective propagator. The Odderon contribution produces significant modifications of the differential cross sections. We investigate the effects of variation of trajectory and coupling parameters. We provide numerical results for total and differential cross sections for OPAL, BaBar, TESLA and the TESLA photon collider including detector cuts.
[ { "created": "Thu, 6 Feb 2003 20:33:19 GMT", "version": "v1" }, { "created": "Thu, 6 Feb 2003 23:15:25 GMT", "version": "v2" } ]
2007-05-23
[ [ "Robens", "Tania", "" ] ]
In diffractive hadronic scattering processes, the Pomeron trajectory, originating from Regge theory, significantly contributes to the behavior of the total and differential cross sections; the same holds for the description of the proton structure function in deep inelastic scattering. So far, the Odderon as the odd-parity partner of the Pomeron has only been observed in differences between differential cross sections for p p and p pbar scattering at low t. We investigate exclusive photoproduction of two neutral pion final states at e+e- colliders; in this reaction, Pomeron exchange is forbidden by C-parity conservation. The Odderon is described by an effective propagator. The Odderon contribution produces significant modifications of the differential cross sections. We investigate the effects of variation of trajectory and coupling parameters. We provide numerical results for total and differential cross sections for OPAL, BaBar, TESLA and the TESLA photon collider including detector cuts.
hep-ph/0104043
Haijun Pan
G. Cheng
Decoupled oscillations and resonances of three neutrinos in matter
14 pages
null
null
null
hep-ph
null
In a previous paper, we gave a new theoretical framework in which three neutrino mixing in matter are discussed. Rigorous analytical solutions are obtained. In present paper an approximate method is developed for studying three flavor neutrino oscillations in matter in the new framework. Using condition of $\Delta m_{1}^{2}\ll \Delta m_{2}^{2}$, decoupled resonances, which is discovered by Kuo {\it et al.} previously, are obtained without small angle approximation. Calculation and approximation is consistent and rigorous. All the formulae appear in simple symmetric form and some physical characteristic are more explicit. Around the two resonant points, the mass eigenvalue whose eigenfunction does not take part in the oscillation process, can be easily calculated to higher precision. We find, the oscillation amplitude is dominated by vacuum mixing and is smaller than 1 for smaller A resonance, but it is not in the larger A. This is characteristic for the three flavor oscillations, but do not exist in two flavor.
[ { "created": "Wed, 4 Apr 2001 02:32:21 GMT", "version": "v1" }, { "created": "Fri, 6 Apr 2001 01:36:09 GMT", "version": "v2" }, { "created": "Thu, 12 Apr 2001 23:43:50 GMT", "version": "v3" } ]
2007-05-23
[ [ "Cheng", "G.", "" ] ]
In a previous paper, we gave a new theoretical framework in which three neutrino mixing in matter are discussed. Rigorous analytical solutions are obtained. In present paper an approximate method is developed for studying three flavor neutrino oscillations in matter in the new framework. Using condition of $\Delta m_{1}^{2}\ll \Delta m_{2}^{2}$, decoupled resonances, which is discovered by Kuo {\it et al.} previously, are obtained without small angle approximation. Calculation and approximation is consistent and rigorous. All the formulae appear in simple symmetric form and some physical characteristic are more explicit. Around the two resonant points, the mass eigenvalue whose eigenfunction does not take part in the oscillation process, can be easily calculated to higher precision. We find, the oscillation amplitude is dominated by vacuum mixing and is smaller than 1 for smaller A resonance, but it is not in the larger A. This is characteristic for the three flavor oscillations, but do not exist in two flavor.
hep-ph/0109258
Park Seong Chan
Seong Chan Park and Hee Sung Song
Implication of Brane fluctuations to indirect collider signals
JHEP accepted version with some corrections
JHEP 0304:033,2003
10.1088/1126-6708/2003/04/033
SNUTP 01-033, KIAS P-03025
hep-ph hep-ex hep-th
null
We study the effect of brane fluctuation on the indirect signals of high energy colliders. Brane fluctuation could act as a regulator of divergent expression of infinite tower of Kaluza-Klein graviton effects. The phenomenological parameter $\lambda$, introduced by Hewett, is shown to be determined in our setting, and its dramatic behaviors depending on the $D=4+\delta$ dimensional gravitation scale $M_D$, `softening parameter' $\Delta$, and $\sqrt{s}$ of collider are presented. The present exclusion bounds from the processes $e^+e^-\to \gamma\gamma$ and $p\bar{p}\to e^+ e^-, \gamma\gamma(\gamma)$ are considered within the parameter space $(M_D, \Delta)$ with respect to the number of extra dimensions.
[ { "created": "Thu, 27 Sep 2001 10:26:33 GMT", "version": "v1" }, { "created": "Tue, 9 Oct 2001 07:03:46 GMT", "version": "v2" }, { "created": "Wed, 23 Apr 2003 11:21:26 GMT", "version": "v3" }, { "created": "Thu, 24 Apr 2003 03:52:30 GMT", "version": "v4" } ]
2010-02-03
[ [ "Park", "Seong Chan", "" ], [ "Song", "Hee Sung", "" ] ]
We study the effect of brane fluctuation on the indirect signals of high energy colliders. Brane fluctuation could act as a regulator of divergent expression of infinite tower of Kaluza-Klein graviton effects. The phenomenological parameter $\lambda$, introduced by Hewett, is shown to be determined in our setting, and its dramatic behaviors depending on the $D=4+\delta$ dimensional gravitation scale $M_D$, `softening parameter' $\Delta$, and $\sqrt{s}$ of collider are presented. The present exclusion bounds from the processes $e^+e^-\to \gamma\gamma$ and $p\bar{p}\to e^+ e^-, \gamma\gamma(\gamma)$ are considered within the parameter space $(M_D, \Delta)$ with respect to the number of extra dimensions.
2203.11204
Rinku Maji
George Lazarides, Rinku Maji, Qaisar Shafi
Gravitational Waves from Quasi-stable Strings
18 pages, 7 figures, published version
JCAP 08 (2022) 042
10.1088/1475-7516/2022/08/042
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We estimate the stochastic gravitational wave spectrum emitted from a network of cosmic strings in which the latter are effectively stable against breaking by monopole pair creation. The monopoles are produced at a higher scale from an earlier symmetry breaking and experience significant inflation before reentering the horizon. This gives rise to monopole-antimonopole pairs connected by string segments and the string loop formation essentially ceases. As a consequence, the lower frequency portion of the gravitational wave spectrum is suppressed relative to the no-inflation case with stable strings, which evades the stringent PPTA bound on the dimensionless string tension $G\mu$. We display the modified spectrum, accessible in the ongoing and future experiments, for $G\mu$ values in the range $10^{-10} - 10^{-15}$. We show how this `quasi-stable' string network is realized in realistic grand unified theories.
[ { "created": "Sun, 20 Mar 2022 18:13:27 GMT", "version": "v1" }, { "created": "Tue, 23 Aug 2022 12:57:26 GMT", "version": "v2" } ]
2022-08-24
[ [ "Lazarides", "George", "" ], [ "Maji", "Rinku", "" ], [ "Shafi", "Qaisar", "" ] ]
We estimate the stochastic gravitational wave spectrum emitted from a network of cosmic strings in which the latter are effectively stable against breaking by monopole pair creation. The monopoles are produced at a higher scale from an earlier symmetry breaking and experience significant inflation before reentering the horizon. This gives rise to monopole-antimonopole pairs connected by string segments and the string loop formation essentially ceases. As a consequence, the lower frequency portion of the gravitational wave spectrum is suppressed relative to the no-inflation case with stable strings, which evades the stringent PPTA bound on the dimensionless string tension $G\mu$. We display the modified spectrum, accessible in the ongoing and future experiments, for $G\mu$ values in the range $10^{-10} - 10^{-15}$. We show how this `quasi-stable' string network is realized in realistic grand unified theories.
0904.1733
Thomas A. Trainor
Thomas A. Trainor
ZYAM and $\bf v_2$: Underestimating jet yields from dihadron azimuth correlations
14 pages, 11 figures
Phys.Rev.C81:014905,2010
10.1103/PhysRevC.81.014905
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dihadron azimuth correlations can provide combinatoric access to jet structure in nuclear collisions. To isolate true jet yields a background must be subtracted, including a constant offset and a contribution from "elliptic flow" (azimuth quadrupole measured by $v^2_2$). The principle of "zero yield at minimum" (ZYAM) has been introduced to determine the constant offset. Independent measurements determine $v_2^2$. This analysis demonstrates that the ZYAM concept is invalid (offset typically overestimated) and $v_2^2$ is also overestimated by conventional measurements. Jet yields are thus substantially underestimated in more-central A-A collisions, and the "away-side" azimuth peak (back-to-back jet correlations) is strongly distorted, leading to incorrect inference of "Mach shocks."
[ { "created": "Fri, 10 Apr 2009 19:20:43 GMT", "version": "v1" }, { "created": "Sun, 12 Apr 2009 20:12:14 GMT", "version": "v2" } ]
2010-04-06
[ [ "Trainor", "Thomas A.", "" ] ]
Dihadron azimuth correlations can provide combinatoric access to jet structure in nuclear collisions. To isolate true jet yields a background must be subtracted, including a constant offset and a contribution from "elliptic flow" (azimuth quadrupole measured by $v^2_2$). The principle of "zero yield at minimum" (ZYAM) has been introduced to determine the constant offset. Independent measurements determine $v_2^2$. This analysis demonstrates that the ZYAM concept is invalid (offset typically overestimated) and $v_2^2$ is also overestimated by conventional measurements. Jet yields are thus substantially underestimated in more-central A-A collisions, and the "away-side" azimuth peak (back-to-back jet correlations) is strongly distorted, leading to incorrect inference of "Mach shocks."
2407.09869
Hyun-Chul Kim
Nam-Yong Ghim, Hyun-Chul Kim, Ulugbek Yakhshiev, and Ghil-Seok Yang
Properties of neutron stars and strangeness-mixed stars from a pion mean-field approach
15 pages, 8 figures
null
null
INHA-NTG-02/2024
hep-ph astro-ph.HE astro-ph.SR nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the properties of the static neutron stars and strangeness-mixed stars, based on the equations of state derived from a pion mean-field approach. Using the empirical data on the pion-nucleus scattering and bulk properties of nuclear matter, we have already fixed all the parameters in a previous work, where the nucleons and hyperons were shown to be modified in various nuclear medium. In the current work, we first examine the energy and pressure inside a neutron star. We show that the central densities in various neutron stars vary within the range of $(3-6)\rho_0$, where $\rho_0$ is the normal nuclear matter density. The mass-radius relations are obtained and discussed. As the slope parameter for neutron matter increases, the radii of the neutron stars increase with their masses fixed. We also study the strangeness-mixed stars or the hyperon stars using the same sets of the parameters. As the strangeness content of strange matter increases, the binding energy per nucleon is saturated and the corresponding equation of state becomes softened. Consequently, the central densities of the strangeness-mixed stars increase. Assuming that recently observed neutron stars are the strangeness-mixed ones, we find that the central densities increase. In the case of the pure strange stars, the central densities reach almost $(5-6)\rho_0$.
[ { "created": "Sat, 13 Jul 2024 12:40:14 GMT", "version": "v1" } ]
2024-07-16
[ [ "Ghim", "Nam-Yong", "" ], [ "Kim", "Hyun-Chul", "" ], [ "Yakhshiev", "Ulugbek", "" ], [ "Yang", "Ghil-Seok", "" ] ]
We investigate the properties of the static neutron stars and strangeness-mixed stars, based on the equations of state derived from a pion mean-field approach. Using the empirical data on the pion-nucleus scattering and bulk properties of nuclear matter, we have already fixed all the parameters in a previous work, where the nucleons and hyperons were shown to be modified in various nuclear medium. In the current work, we first examine the energy and pressure inside a neutron star. We show that the central densities in various neutron stars vary within the range of $(3-6)\rho_0$, where $\rho_0$ is the normal nuclear matter density. The mass-radius relations are obtained and discussed. As the slope parameter for neutron matter increases, the radii of the neutron stars increase with their masses fixed. We also study the strangeness-mixed stars or the hyperon stars using the same sets of the parameters. As the strangeness content of strange matter increases, the binding energy per nucleon is saturated and the corresponding equation of state becomes softened. Consequently, the central densities of the strangeness-mixed stars increase. Assuming that recently observed neutron stars are the strangeness-mixed ones, we find that the central densities increase. In the case of the pure strange stars, the central densities reach almost $(5-6)\rho_0$.
hep-ph/9507231
Albrecht Buck
A. Buck, H. Reinhardt
Octet and Decuplet Baryons in the Hadronized Nambu--Jona-Lasinio Model with Proper Spin Projection
9 pages, LaTeX, revised version accepted by Phys. Lett. B
Phys.Lett. B356 (1995) 168-174
10.1016/0370-2693(95)00847-E
UNITUE-THEP-10/1995
hep-ph
null
Octet and Decuplet baryons are described within the hadronized NJL model as diquark--quark states, which are bound by quark exchange. Including scalar and axial--vector diquark correlations, we project the previously obtained relativistic Faddeev equation in a Poincar\'e invariant fashion onto good spin, using a static approximation to the exchanged quark. The resulting equations for the spin 1/2 octet and the spin 3/2 decuplet are solved numerically.
[ { "created": "Wed, 5 Jul 1995 15:15:29 GMT", "version": "v1" } ]
2009-10-28
[ [ "Buck", "A.", "" ], [ "Reinhardt", "H.", "" ] ]
Octet and Decuplet baryons are described within the hadronized NJL model as diquark--quark states, which are bound by quark exchange. Including scalar and axial--vector diquark correlations, we project the previously obtained relativistic Faddeev equation in a Poincar\'e invariant fashion onto good spin, using a static approximation to the exchanged quark. The resulting equations for the spin 1/2 octet and the spin 3/2 decuplet are solved numerically.
hep-ph/0301149
V. M. Strakhovenko
V. M. Strakhovenko
Emission of polarized photons from unpolarized electrons moving in crystals
16 pages, 7 PostScript figures
Phys.Rev.A68:042901,2003
10.1103/PhysRevA.68.042901
Budker INP 2002-54
hep-ph
null
Radiation emitted by unpolarized high-energy electrons penetrating crystals may be linearly polarized. This occurs when the particle velocity makes an angle, with respect to some major crystal axis, being sufficiently larger than the axial-channelling angle. For such orientation, a complete description of spectral and polarization characteristics of the radiation is derived. At planar channelling, a non-perturbative contribution to the probability of the process appears caused by the plane field, and we must solve exactly a one~-~dimensional mechanical problem. For that, the approximate form of the actual plane potential is suggested which provides a precise fit for any crystal plane and an analytical solution to the motion problem. In a practical case, we must consider electron-photon showers developing in sufficiently thick crystals. For the first time, this development is described taking into account the polarization of photons. We discuss qualitative features of the phenomenon, present results of numerical calculations for thin and thick crystals, and evaluate the possibility of the use of differently oriented crystals in a polarized hard photon source.
[ { "created": "Sun, 19 Jan 2003 09:45:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Strakhovenko", "V. M.", "" ] ]
Radiation emitted by unpolarized high-energy electrons penetrating crystals may be linearly polarized. This occurs when the particle velocity makes an angle, with respect to some major crystal axis, being sufficiently larger than the axial-channelling angle. For such orientation, a complete description of spectral and polarization characteristics of the radiation is derived. At planar channelling, a non-perturbative contribution to the probability of the process appears caused by the plane field, and we must solve exactly a one~-~dimensional mechanical problem. For that, the approximate form of the actual plane potential is suggested which provides a precise fit for any crystal plane and an analytical solution to the motion problem. In a practical case, we must consider electron-photon showers developing in sufficiently thick crystals. For the first time, this development is described taking into account the polarization of photons. We discuss qualitative features of the phenomenon, present results of numerical calculations for thin and thick crystals, and evaluate the possibility of the use of differently oriented crystals in a polarized hard photon source.
hep-ph/9611230
null
I.I. Balitsky (MIT), V.M. Braun (NORDITA), Y. Koike (Niigata Univ.) and K. Tanaka (Juntendo Univ.)
Q^2-evolution of chiral-odd twist-3 distributions h_L(x,Q^2) and e(x, Q^2) in the large N_c limit
3 pages, LaTeX. To appear in the proceedings of the XII International Symposium on High Energy Spin Physics (SPIN96), 10-14 Sept 1996, Amsterdam, The Netherlands
null
null
null
hep-ph
null
We prove that the twist-3 chiral-odd parton distributions obey simple GLAP evolution equations in the limit $N_c\to\infty$ and give analytic formulae for the corresponding anomalous dimensions. The results are valid to O(1/N_{c}^2) accuracy and will be useful in confronting with future experiments.
[ { "created": "Tue, 5 Nov 1996 08:05:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Balitsky", "I. I.", "", "MIT" ], [ "Braun", "V. M.", "", "NORDITA" ], [ "Koike", "Y.", "", "Niigata Univ." ], [ "Tanaka", "K.", "", "Juntendo Univ." ] ]
We prove that the twist-3 chiral-odd parton distributions obey simple GLAP evolution equations in the limit $N_c\to\infty$ and give analytic formulae for the corresponding anomalous dimensions. The results are valid to O(1/N_{c}^2) accuracy and will be useful in confronting with future experiments.
1103.1748
Kensuke Homma
Kensuke Homma, Dieter Habs, and Toshiki Tajima
Probing the semi-macroscopic vacuum by higher-harmonic generation under focused intense laser fields
13 pages, 5 figures. Accepted by Applied Physics B: Lasers and Optics
null
10.1007/s00340-011-4567-3
null
hep-ph gr-qc physics.optics
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The invention of the laser immediately enabled the detection of nonlinear photon-matter interactions, as manifested for example by Franken et al.'s detection of second-harmonic generation. With the recent advancement in high-power, high-energy lasers and the examples of nonlinearity studies of the laser-matter interaction by virtue of properly arranging lasers and detectors, we envision the possibility of probing nonlinearities of the photon interaction in vacuum over substantial space-time scales, compared to the microscopic scale provided by high-energy accelerators. Specifically, we introduce the photon-photon interaction in a quasi-parallel colliding system and the detection of higher harmonics in that system. The method proposed should realize a far greater sensitivity of probing possible low-mass and weakly coupling fields that have been postulated. With the availability of a large number of coherent photons, we suggest a scheme for the detection of higher harmonics via the averaged resonant production and decay of these postulated fields within the uncertainty of the center-of-mass energy between incoming laser photons. The method carves out a substantial swath of new experimental parameter regimes on the coupling of these fields to photons, under appropriate laser technologies, even weaker than that of gravity in the mass range well below 1 eV.
[ { "created": "Wed, 9 Mar 2011 10:03:49 GMT", "version": "v1" }, { "created": "Wed, 16 Mar 2011 15:43:02 GMT", "version": "v2" }, { "created": "Sat, 21 May 2011 10:49:09 GMT", "version": "v3" } ]
2011-05-24
[ [ "Homma", "Kensuke", "" ], [ "Habs", "Dieter", "" ], [ "Tajima", "Toshiki", "" ] ]
The invention of the laser immediately enabled the detection of nonlinear photon-matter interactions, as manifested for example by Franken et al.'s detection of second-harmonic generation. With the recent advancement in high-power, high-energy lasers and the examples of nonlinearity studies of the laser-matter interaction by virtue of properly arranging lasers and detectors, we envision the possibility of probing nonlinearities of the photon interaction in vacuum over substantial space-time scales, compared to the microscopic scale provided by high-energy accelerators. Specifically, we introduce the photon-photon interaction in a quasi-parallel colliding system and the detection of higher harmonics in that system. The method proposed should realize a far greater sensitivity of probing possible low-mass and weakly coupling fields that have been postulated. With the availability of a large number of coherent photons, we suggest a scheme for the detection of higher harmonics via the averaged resonant production and decay of these postulated fields within the uncertainty of the center-of-mass energy between incoming laser photons. The method carves out a substantial swath of new experimental parameter regimes on the coupling of these fields to photons, under appropriate laser technologies, even weaker than that of gravity in the mass range well below 1 eV.
1712.06614
Matthias Steinhauser
Florian Herren, Luminita Mihaila, Matthias Steinhauser
Gauge and Yukawa coupling beta functions of two-Higgs-doublet models to three-loop order
29 pages, 2 figures; v2: typos in eqs. (44) and (45) fixed
Phys. Rev. D 97, 015016 (2018); (E) Phys. Rev. D 101 (2020)
10.1103/PhysRevD.97.015016
TTP17-046
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the beta functions for the three gauge couplings and the Yukawa matrices of a general two-Higgs-doublet model in the modified minimal subtraction scheme to three loops. The calculations are performed using Lorenz gauge in the unbroken phase. We discuss in detail the occurence of poles in anomalous dimensions and propose practical prescriptions to avoid them. We provide explicit results for the often used $\mathbb{Z}_2$-symmetric versions of the two-Higgs-doublet model of type I, II, X and Y. Furthermore, we provide the first independent cross-check of the three-loop Yukawa coupling beta functions of the Standard Model.
[ { "created": "Mon, 18 Dec 2017 19:01:03 GMT", "version": "v1" }, { "created": "Wed, 22 Apr 2020 09:11:36 GMT", "version": "v2" } ]
2020-04-23
[ [ "Herren", "Florian", "" ], [ "Mihaila", "Luminita", "" ], [ "Steinhauser", "Matthias", "" ] ]
We compute the beta functions for the three gauge couplings and the Yukawa matrices of a general two-Higgs-doublet model in the modified minimal subtraction scheme to three loops. The calculations are performed using Lorenz gauge in the unbroken phase. We discuss in detail the occurence of poles in anomalous dimensions and propose practical prescriptions to avoid them. We provide explicit results for the often used $\mathbb{Z}_2$-symmetric versions of the two-Higgs-doublet model of type I, II, X and Y. Furthermore, we provide the first independent cross-check of the three-loop Yukawa coupling beta functions of the Standard Model.
0711.0364
Matthew Buckley
Matthew R. Buckley, Hitoshi Murayama, William Klemm, Vikram Rentala
Discriminating spin through quantum interference
11 pages, 11 figures
Phys.Rev.D78:014028,2008
10.1103/PhysRevD.78.014028
null
hep-ph
null
Many of the proposed solutions to the hierarchy and naturalness problems postulate new `partner' fields to the standard model particles. Determining the spins of these new particles will be critical in distinguishing among the various possible SM extensions, yet proposed methods rely on the underlying models. We propose a new model-independent method for spin measurements which takes advantage of quantum interference among helicity states. We demonstrate that this method will be able to discriminate scalar particles from higher spin states at the ILC, and discuss application to higher spins and possible uses at the LHC.
[ { "created": "Fri, 2 Nov 2007 17:49:53 GMT", "version": "v1" }, { "created": "Fri, 25 Jan 2008 08:11:47 GMT", "version": "v2" } ]
2008-11-26
[ [ "Buckley", "Matthew R.", "" ], [ "Murayama", "Hitoshi", "" ], [ "Klemm", "William", "" ], [ "Rentala", "Vikram", "" ] ]
Many of the proposed solutions to the hierarchy and naturalness problems postulate new `partner' fields to the standard model particles. Determining the spins of these new particles will be critical in distinguishing among the various possible SM extensions, yet proposed methods rely on the underlying models. We propose a new model-independent method for spin measurements which takes advantage of quantum interference among helicity states. We demonstrate that this method will be able to discriminate scalar particles from higher spin states at the ILC, and discuss application to higher spins and possible uses at the LHC.
hep-ph/9512406
W. James Stirling
T.Gehrmann, W.J.Stirling
Polarized Parton Distributions in the Nucleon
18 pages, LATEX, 6 figures available as .uu file
Phys.Rev.D53:6100-6109,1996
10.1103/PhysRevD.53.6100
DTP/95/82
hep-ph
null
The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$, we determine these distributions both at leading and next-to-leading order in perturbation theory. We suggest three different, equally possible scenarios for the polarized gluon distribution, which is found to be only loosely constrained by current experimental data. We examine various possibilities of measuring polarized parton distributions at future experiments.
[ { "created": "Fri, 22 Dec 1995 16:14:42 GMT", "version": "v1" } ]
2014-11-17
[ [ "Gehrmann", "T.", "" ], [ "Stirling", "W. J.", "" ] ]
The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$, we determine these distributions both at leading and next-to-leading order in perturbation theory. We suggest three different, equally possible scenarios for the polarized gluon distribution, which is found to be only loosely constrained by current experimental data. We examine various possibilities of measuring polarized parton distributions at future experiments.
hep-ph/0409128
Pedro Jimenez Delgado
P. Jimenez-Delgado
Pentaquark Masses and Magnetic Moments in a Quark Cluster Approach
8 pages with 1 figure
Few Body Syst. 37 (2005) 215-229
null
null
hep-ph
null
We study the stability of the different quark substructures in a quark cluster approach to pentaquark states considering the color-magnetic spin-spin interactions between quarks. The most likely configuration is found to be a triquark-diquark one where the two quarks of the diquark are coupled to spin zero and anti-triplet representations of flavor and color, and the triquark has spin one-half and belongs to the triplet representation of color and to anti-sextet of flavor. To ensure total antisymmetry under the interchange of identical particles, triquark and diquark are in relative p-wave. Using this configuration we estimate the masses and magnetic moments of pentaquarks. Finally the calculation of the masses has been extended to some charmed pentaquarks.
[ { "created": "Mon, 13 Sep 2004 14:49:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jimenez-Delgado", "P.", "" ] ]
We study the stability of the different quark substructures in a quark cluster approach to pentaquark states considering the color-magnetic spin-spin interactions between quarks. The most likely configuration is found to be a triquark-diquark one where the two quarks of the diquark are coupled to spin zero and anti-triplet representations of flavor and color, and the triquark has spin one-half and belongs to the triplet representation of color and to anti-sextet of flavor. To ensure total antisymmetry under the interchange of identical particles, triquark and diquark are in relative p-wave. Using this configuration we estimate the masses and magnetic moments of pentaquarks. Finally the calculation of the masses has been extended to some charmed pentaquarks.