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1802.06703
Miguel Sanchis
Miguel-Angel Sanchis-Lozano, Edward K. Sarkisyan-Grinbaum
Searching for new physics with three-particle correlations in $pp$ collisions at the LHC
6 pages, 4 figures
null
10.1016/j.physletb.2018.04.033
CERN-TH-2018-034
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New phenomena involving pseudorapidity and azimuthal correlations among final state particles in $pp$ collisions at the LHC can hint at the existence of hidden sectors beyond the Standard Model. In this paper we rely on a correlated-cluster picture of multiparticle production, which was shown to account for the ridge effect, to assess the effect of a hidden sector on three-particle correlations concluding that there is a potential signature of new physics that can be directly tested by experiments using well-known techniques.
[ { "created": "Mon, 19 Feb 2018 17:02:27 GMT", "version": "v1" }, { "created": "Thu, 19 Apr 2018 09:55:19 GMT", "version": "v2" } ]
2018-04-25
[ [ "Sanchis-Lozano", "Miguel-Angel", "" ], [ "Sarkisyan-Grinbaum", "Edward K.", "" ] ]
New phenomena involving pseudorapidity and azimuthal correlations among final state particles in $pp$ collisions at the LHC can hint at the existence of hidden sectors beyond the Standard Model. In this paper we rely on a correlated-cluster picture of multiparticle production, which was shown to account for the ridge effect, to assess the effect of a hidden sector on three-particle correlations concluding that there is a potential signature of new physics that can be directly tested by experiments using well-known techniques.
1509.08477
James Unwin
Lisa Randall, Jakub Scholtz, and James Unwin
Flooded Dark Matter and S Level Rise
25 pages, 5 figures
null
10.1007/JHEP03(2016)011
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most dark matter (DM) models set the DM relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the DM relic density a later consequence of those interactions. Perhaps a more compelling assumption is that DM is not part of the Standard Model sector and a population of DM too is generated at the end of inflation. This democratic assumption does not necessarily provide a natural value for the DM relic density, and superficially leads to too much entropy in the dark sector. We address the latter issue by the late decay of heavy particles produced at early times, associating the DM relic density with the lifetime of a long-lived state. We ask what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) and discuss several interesting consequences. One is that DM can be very light and furthermore, light DM is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. Moreover, the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as 'Maximum Baroqueness'. We also show that the dark sector should be colder than the ordinary sector, relaxing the free-streaming constraints on light DM. We will discuss the implications for the core-cusp problem in a follow-up paper. FDM also has interesting baryogenesis implications. One possibility is that both DM and baryon asymmetries are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant non-thermal leptogenesis implementation in which decays of a heavy RH neutrino lead to late time reheating of the Standard Model and provide suitable conditions for creation of a lepton asymmetry.
[ { "created": "Mon, 28 Sep 2015 20:13:33 GMT", "version": "v1" }, { "created": "Mon, 7 Mar 2016 02:28:33 GMT", "version": "v2" } ]
2016-03-23
[ [ "Randall", "Lisa", "" ], [ "Scholtz", "Jakub", "" ], [ "Unwin", "James", "" ] ]
Most dark matter (DM) models set the DM relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the DM relic density a later consequence of those interactions. Perhaps a more compelling assumption is that DM is not part of the Standard Model sector and a population of DM too is generated at the end of inflation. This democratic assumption does not necessarily provide a natural value for the DM relic density, and superficially leads to too much entropy in the dark sector. We address the latter issue by the late decay of heavy particles produced at early times, associating the DM relic density with the lifetime of a long-lived state. We ask what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) and discuss several interesting consequences. One is that DM can be very light and furthermore, light DM is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. Moreover, the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as 'Maximum Baroqueness'. We also show that the dark sector should be colder than the ordinary sector, relaxing the free-streaming constraints on light DM. We will discuss the implications for the core-cusp problem in a follow-up paper. FDM also has interesting baryogenesis implications. One possibility is that both DM and baryon asymmetries are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant non-thermal leptogenesis implementation in which decays of a heavy RH neutrino lead to late time reheating of the Standard Model and provide suitable conditions for creation of a lepton asymmetry.
0906.1288
Alexei Nefediev
A.V. Nefediev (ITEP, Moscow), J.E.F.T. Ribeiro (IST, Lisbon)
Real-time approach to quark confined systems at finite temperatures
LaTeX2e, 6 pages, uses jetpl.cls (included), version to appear in JETP Lett
JETP Lett. 90 (2009) 417-422; Pisma Zh.Eksp.Teor.Fiz. 90 (2009) 461-466
10.1134/S0021364009180039
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Generalised Nambu-Jona-Lasinio model for QCD is considered at finite temperatures in the framework of a real-time formalism. The proposed approach allows one to study various properties of the model at T>0, such as chiral symmetry breaking and restoration, properties of the bound-state spectrum, and so on.
[ { "created": "Sat, 6 Jun 2009 15:29:10 GMT", "version": "v1" }, { "created": "Fri, 21 Aug 2009 13:14:46 GMT", "version": "v2" } ]
2015-05-13
[ [ "Nefediev", "A. V.", "", "ITEP, Moscow" ], [ "Ribeiro", "J. E. F. T.", "", "IST, Lisbon" ] ]
Generalised Nambu-Jona-Lasinio model for QCD is considered at finite temperatures in the framework of a real-time formalism. The proposed approach allows one to study various properties of the model at T>0, such as chiral symmetry breaking and restoration, properties of the bound-state spectrum, and so on.
1010.1001
Filipe Joaquim
Andrea Brignole, Filipe R. Joaquim and Anna Rossi
A common source for neutrino and sparticle masses
6 pages, 2 figures. Based on talks presented at "PASCOS 2010, the 16th International Symposium on Particles, Strings and Cosmology" (Valencia, Spain) and "SUSY 2010, the 18th International Conference on Supersymmetry and Unification of Fundamental Interactions" (Bonn, Germany). To appear in the proceedings of PASCOS 2010
J.Phys.Conf.Ser.259:012068,2010
10.1088/1742-6596/259/1/012068
CERN-PH-TH/2010-222
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss supersymmetric scenarios in which neutrino masses arise from effective d=6 operators in the Kahler potential (including SUSY-breaking insertions). Simple explicit realizations of those Kahler operators are presented in the context of the type II seesaw. An appealing scenario emerges upon identifying the seesaw mediators with SUSY-breaking messengers.
[ { "created": "Tue, 5 Oct 2010 20:00:04 GMT", "version": "v1" } ]
2015-03-17
[ [ "Brignole", "Andrea", "" ], [ "Joaquim", "Filipe R.", "" ], [ "Rossi", "Anna", "" ] ]
We discuss supersymmetric scenarios in which neutrino masses arise from effective d=6 operators in the Kahler potential (including SUSY-breaking insertions). Simple explicit realizations of those Kahler operators are presented in the context of the type II seesaw. An appealing scenario emerges upon identifying the seesaw mediators with SUSY-breaking messengers.
hep-ph/0010290
Antal Jakovac
A. Jakovac
Resummation and damping in the O(N) model
Talk given at SEWM2000. 5 pages
null
10.1142/9789812799913_0019
null
hep-ph
null
In this talk I summarize the one loop and higher loop calculations of the effective equations of motion of the O(N) symmetric scalar model in the linear response approximation. At one loop one finds essential difference in long time behavior for the fields below and above a dynamically generated length scale. A partial resummation assuming quasi-particle propagation seems to cancel the relevance of this scale.
[ { "created": "Wed, 25 Oct 2000 13:55:58 GMT", "version": "v1" } ]
2017-08-23
[ [ "Jakovac", "A.", "" ] ]
In this talk I summarize the one loop and higher loop calculations of the effective equations of motion of the O(N) symmetric scalar model in the linear response approximation. At one loop one finds essential difference in long time behavior for the fields below and above a dynamically generated length scale. A partial resummation assuming quasi-particle propagation seems to cancel the relevance of this scale.
1912.03881
Ulf-G. Mei{\ss}ner
Hans-Werner Hammer, Ulf-G. Mei{\ss}ner
The proton radius: From a puzzle to precision
3 pp, solicited article for News&Views, Science Bulletin, accepted for publication, abstract only for the arXiv version
Science Bulletin 65 (2020) pp. 257-258
10.1016/j.scib.2019.12.012
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We comment on the status and history of the proton charge radius determinations.
[ { "created": "Mon, 9 Dec 2019 07:30:22 GMT", "version": "v1" } ]
2020-01-22
[ [ "Hammer", "Hans-Werner", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We comment on the status and history of the proton charge radius determinations.
1606.08348
John R. Hiller
J.R. Hiller
Nonperturbative light-front Hamiltonian methods
67 pages, 14 figures; review to appear in Progress in Particle and Nuclear Physics
null
10.1016/j.ppnp.2016.06.002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the current state-of-the-art in nonperturbative calculations done with Hamiltonians constructed in light-front quantization of various field theories. The language of light-front quantization is introduced, and important (numerical) techniques, such as Pauli--Villars regularization, discrete light-cone quantization, basis light-front quantization, the light-front coupled-cluster method, the renormalization group procedure for effective particles, sector-dependent renormalization, and the Lanczos diagonalization method, are surveyed. Specific applications are discussed for quenched scalar Yukawa theory, $\phi^4$ theory, ordinary Yukawa theory, supersymmetric Yang--Mills theory, quantum electrodynamics, and quantum chromodynamics. The content should serve as an introduction to these methods for anyone interested in doing such calculations and as a rallying point for those who wish to solve quantum chromodynamics in terms of wave functions rather than random samplings of Euclidean field configurations.
[ { "created": "Mon, 27 Jun 2016 16:20:10 GMT", "version": "v1" } ]
2016-06-28
[ [ "Hiller", "J. R.", "" ] ]
We examine the current state-of-the-art in nonperturbative calculations done with Hamiltonians constructed in light-front quantization of various field theories. The language of light-front quantization is introduced, and important (numerical) techniques, such as Pauli--Villars regularization, discrete light-cone quantization, basis light-front quantization, the light-front coupled-cluster method, the renormalization group procedure for effective particles, sector-dependent renormalization, and the Lanczos diagonalization method, are surveyed. Specific applications are discussed for quenched scalar Yukawa theory, $\phi^4$ theory, ordinary Yukawa theory, supersymmetric Yang--Mills theory, quantum electrodynamics, and quantum chromodynamics. The content should serve as an introduction to these methods for anyone interested in doing such calculations and as a rallying point for those who wish to solve quantum chromodynamics in terms of wave functions rather than random samplings of Euclidean field configurations.
hep-ph/9410292
Chyla Jiri
J.Ch\'yla and J. Rame\v{s}
What does the CCFR measurement of the Gross--Llewelyn Smith sum rule tell us?
PRA-HEP/94-09, Latex, 9 pages and 5 uuencoded figures. Raw PS files replaced with uuencoded ones
Phys.Lett. B343 (1995) 351-357
10.1016/0370-2693(94)01469-S
null
hep-ph
null
Recently the CCFR Collaboration reported the measurement of the Gross--Llewellyn Smith sum rule %at $Q^2=3\; \mr{GeV}^2$: $\int^{1}_{0}\mr{d}F_{3}^{\nu p+\bare{\nu}p}(x,Q^2=3\;\mr{GeV}^2)= 2.50\pm 0.018(\mr{stat})$. Subsequently Kataev and Sidorov analyzed the $Q^2$--dependence of this sum rule and pointed out a discrepancy between the results obtained via integration of the NLO fits to $xF_{3}(x,Q^2)$ and the purely perturbative prediction. We suggest an explanation of this disagreement and show that the result of the CCFR measurement of the GLS sum rule integral can be determined from the knowledge of the value of $\Lambda_{\bbare{MS}}$ only.
[ { "created": "Fri, 14 Oct 1994 17:50:22 GMT", "version": "v1" }, { "created": "Tue, 18 Oct 1994 21:32:05 GMT", "version": "v2" } ]
2016-08-14
[ [ "Chýla", "J.", "" ], [ "Rameš", "J.", "" ] ]
Recently the CCFR Collaboration reported the measurement of the Gross--Llewellyn Smith sum rule %at $Q^2=3\; \mr{GeV}^2$: $\int^{1}_{0}\mr{d}F_{3}^{\nu p+\bare{\nu}p}(x,Q^2=3\;\mr{GeV}^2)= 2.50\pm 0.018(\mr{stat})$. Subsequently Kataev and Sidorov analyzed the $Q^2$--dependence of this sum rule and pointed out a discrepancy between the results obtained via integration of the NLO fits to $xF_{3}(x,Q^2)$ and the purely perturbative prediction. We suggest an explanation of this disagreement and show that the result of the CCFR measurement of the GLS sum rule integral can be determined from the knowledge of the value of $\Lambda_{\bbare{MS}}$ only.
hep-ph/9811392
Zhou Bang Rong
Bang-Rong Zhou
Fermion Self-Energy and Chiral Symmetry Breaking from Four-Fermion and Gauge Interactions
9 pages, Latex, 1 figure, the figure put in body of the paper by epsf
Commun.Theor.Phys.30:583-588,1998
10.1088/0253-6102/30/4/583
null
hep-ph
null
The exact analytic solutions of the linearized Schwinger-Dyson equation of fermion self-energy are used to obtain the effective four-fermion and gauge coupling criticality curves for dynamical chiral symmetry breaking. The results show that when the zero-momentum gauge coupling $\alpha(0) < \alpha_0(0)$, the critical gauge coupling in the pure gauge interaction case, the minimal critical four-fermion coupling $\beta_{\rm min}$ is always non-zero and positive and will go up as the $\alpha(0)$ decreases. The use of the exact solutions also allow us to make quite definite estimations of the momentum scales where chiral symmetry breaking would happen if the values of an infrared parameter $\xi$ are given separately.
[ { "created": "Thu, 19 Nov 1998 07:55:10 GMT", "version": "v1" }, { "created": "Mon, 30 Nov 1998 07:46:55 GMT", "version": "v2" } ]
2018-01-17
[ [ "Zhou", "Bang-Rong", "" ] ]
The exact analytic solutions of the linearized Schwinger-Dyson equation of fermion self-energy are used to obtain the effective four-fermion and gauge coupling criticality curves for dynamical chiral symmetry breaking. The results show that when the zero-momentum gauge coupling $\alpha(0) < \alpha_0(0)$, the critical gauge coupling in the pure gauge interaction case, the minimal critical four-fermion coupling $\beta_{\rm min}$ is always non-zero and positive and will go up as the $\alpha(0)$ decreases. The use of the exact solutions also allow us to make quite definite estimations of the momentum scales where chiral symmetry breaking would happen if the values of an infrared parameter $\xi$ are given separately.
hep-ph/9912492
Steve King
S. F. King
Large Mixing Angle MSW and Atmospheric Neutrinos from Single Right-Handed Neutrino Dominance and U(1) Family Symmetry
30 pages, Latex. Unchanged. To appear in Nuclear Physics B
Nucl.Phys. B576 (2000) 85-105
10.1016/S0550-3213(00)00109-7
null
hep-ph
null
Single right-handed neutrino dominance (SRHND) in the 23 sector of the light effective neutrino mass matrix has been proposed as a natural explanation for the concurrent large 23 mixing angle and large 23 mass hierarchy. In this paper we show how large 12 mixing angles, suitable for the large mixing angle (LMA) MSW solution to the solar neutrino problem, may arise from SRHND. In order to understand the conditions for SRHND and LMA MSW we first consider the case of one and two right-handed neutrinos, and obtain simple analytic conditions which are then extended to the case of three right-handed neutrinos. We then introduce a single U(1) family symmetry and show how these analytic conditions may be translated into U(1) charge assignments and perform a systematic search for the simplest examples.
[ { "created": "Thu, 23 Dec 1999 17:21:30 GMT", "version": "v1" }, { "created": "Mon, 27 Mar 2000 10:39:28 GMT", "version": "v2" } ]
2009-10-31
[ [ "King", "S. F.", "" ] ]
Single right-handed neutrino dominance (SRHND) in the 23 sector of the light effective neutrino mass matrix has been proposed as a natural explanation for the concurrent large 23 mixing angle and large 23 mass hierarchy. In this paper we show how large 12 mixing angles, suitable for the large mixing angle (LMA) MSW solution to the solar neutrino problem, may arise from SRHND. In order to understand the conditions for SRHND and LMA MSW we first consider the case of one and two right-handed neutrinos, and obtain simple analytic conditions which are then extended to the case of three right-handed neutrinos. We then introduce a single U(1) family symmetry and show how these analytic conditions may be translated into U(1) charge assignments and perform a systematic search for the simplest examples.
0812.0843
John Terning
Haiying Cai, Hsin-Chia Cheng, and John Terning
A Quirky Little Higgs Model
20 pages, 1 figure
JHEP 0905:045,2009
10.1088/1126-6708/2009/05/045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an extra dimensional model where the quadratically divergent top loop contribution to the Higgs mass is cancelled by an uncolored heavy "top quirk" charged under a different SU(3) gauge group. The cancellation is enforced by bulk gauge symmetries. Thus we have an unusual type of little Higgs model which has some quirky signatures. The top partner in this model could be identified at the Large Hadron Collider due to macroscopic strings that connect quirk and anti-quirks. The model can undergo radiative electroweak symmetry breaking and is consistent with precision electroweak measurements.
[ { "created": "Thu, 4 Dec 2008 01:28:52 GMT", "version": "v1" }, { "created": "Thu, 14 May 2009 22:27:16 GMT", "version": "v2" } ]
2010-01-08
[ [ "Cai", "Haiying", "" ], [ "Cheng", "Hsin-Chia", "" ], [ "Terning", "John", "" ] ]
We consider an extra dimensional model where the quadratically divergent top loop contribution to the Higgs mass is cancelled by an uncolored heavy "top quirk" charged under a different SU(3) gauge group. The cancellation is enforced by bulk gauge symmetries. Thus we have an unusual type of little Higgs model which has some quirky signatures. The top partner in this model could be identified at the Large Hadron Collider due to macroscopic strings that connect quirk and anti-quirks. The model can undergo radiative electroweak symmetry breaking and is consistent with precision electroweak measurements.
1609.07708
Martin Spinrath
Martin Spinrath
Neutrino Mass Sum Rules
3 pages; proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, UK
null
10.1088/1742-6596/888/1/012176
TTP16-039
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino mass sum rules are an important class of predictions in flavour models relating the Majorana phases to the neutrino masses. This leads, for instance, to enormous restrictions on the effective mass as probed in experiments on neutrinoless double beta decay. While up to now these sum rules have in practically all cases been taken to hold exactly, we will go here beyond that. While the effect of the renormalisation group running can be visible, the qualitative features do not change. This changes somewhat for model dependent corrections which might alter even the qualitative predictions but only for large corrections and a high neutrino mass scale close to the edge of the current limits. This finding backs up the solidity of the predictions derived in the literature apart from some exceptions, and it thus marks a very important step in deriving testable and robust predictions from neutrino flavour models.
[ { "created": "Sun, 25 Sep 2016 06:58:58 GMT", "version": "v1" } ]
2017-10-11
[ [ "Spinrath", "Martin", "" ] ]
Neutrino mass sum rules are an important class of predictions in flavour models relating the Majorana phases to the neutrino masses. This leads, for instance, to enormous restrictions on the effective mass as probed in experiments on neutrinoless double beta decay. While up to now these sum rules have in practically all cases been taken to hold exactly, we will go here beyond that. While the effect of the renormalisation group running can be visible, the qualitative features do not change. This changes somewhat for model dependent corrections which might alter even the qualitative predictions but only for large corrections and a high neutrino mass scale close to the edge of the current limits. This finding backs up the solidity of the predictions derived in the literature apart from some exceptions, and it thus marks a very important step in deriving testable and robust predictions from neutrino flavour models.
hep-ph/9804402
Elisabetta Sassaroli
E. Sassaroli
An Explicit Model of Quark Mass Matrix
7 pages
null
null
MIT-CTP-2735
hep-ph
null
A physical model which describes the CKM matrix is analyzed. The elements of such a matrix are field-strength renormalization factors. Each column gives the probability amplitude for the field operators of the coupled Lagrangian to create a one-particle eigenfunction of definite energy. The total conserved charge is the sum of the flavor charges which are not conserved separately.
[ { "created": "Sat, 25 Apr 1998 23:36:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sassaroli", "E.", "" ] ]
A physical model which describes the CKM matrix is analyzed. The elements of such a matrix are field-strength renormalization factors. Each column gives the probability amplitude for the field operators of the coupled Lagrangian to create a one-particle eigenfunction of definite energy. The total conserved charge is the sum of the flavor charges which are not conserved separately.
hep-ph/9710520
null
N.V.Krasnikov
Supersymmetric SU(5) model with large supersymmetry breaking scale
13 pages, latex, no figures
null
null
Preprint INR 869R/97
hep-ph
null
Taking into account uncertainties related with the initial coupling constants and threshold corrections at low and high scales we find that in standard supersymmetric SU(5) model the supersymmetry breaking scale could be up to $10^8$ GeV. In the extensions of the standard supersymmetric SU(5) model the supersymmetry breaking scale could be up to $O(10^{12})$ GeV. In standard SU(5) supersymmetric model it is possible to increase the GUT scale up to $5 \cdot 10^{17}$ GeV provided that the masses of chiral superoctets and supertriplets are $m_{3,8} \sim O(10^{13})$ GeV. For SU(5) supersymmetric model with $10^6$ GeV $\leq M_{SUSY} \leq 10^8$ GeV the Higgs boson mass is predicted to be 120 GeV $\leq m_h \leq $ 150 GeV.
[ { "created": "Wed, 29 Oct 1997 12:47:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Krasnikov", "N. V.", "" ] ]
Taking into account uncertainties related with the initial coupling constants and threshold corrections at low and high scales we find that in standard supersymmetric SU(5) model the supersymmetry breaking scale could be up to $10^8$ GeV. In the extensions of the standard supersymmetric SU(5) model the supersymmetry breaking scale could be up to $O(10^{12})$ GeV. In standard SU(5) supersymmetric model it is possible to increase the GUT scale up to $5 \cdot 10^{17}$ GeV provided that the masses of chiral superoctets and supertriplets are $m_{3,8} \sim O(10^{13})$ GeV. For SU(5) supersymmetric model with $10^6$ GeV $\leq M_{SUSY} \leq 10^8$ GeV the Higgs boson mass is predicted to be 120 GeV $\leq m_h \leq $ 150 GeV.
1611.04441
Lingyun Dai
Ling-Yun Dai and Michael R. Pennington
Pion Polarizabilities from $\gamma\gamma\to\pi\pi$ Analysis
18 pages, 4 figures, a few typos corrected
Phys. Rev. D 94, 116021 (2016)
10.1103/PhysRevD.94.116021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results for pion polarizabilities predicted using dispersion relations from our earlier Amplitude Analysis of world data on two photon production of meson pairs. The helicity-zero polarizabilities are rather stable and insensitive to uncertainties in cross-channel exchanges. The need is first to confirm the recent result on $(\alpha_1-\beta_1)$ for the charged pion by COMPASS at CERN to an accuracy of 10\% by measuring the $\gamma\gamma\to\pi^+\pi^-$ cross-section to an uncertainty of ~1\%. Then the same polarizability, but for the $\pi^0$, is fixed to be $(\alpha_1-\beta_1)_{\pi^0}=(-0.9\pm0.2)\times 10^{-4}$ fm$^{3}$. By analyzing the correlation between uncertainties in the meson polarizability and those in $\gamma\gamma$ cross-sections, we suggest experiments need to measure these cross-sections between $\sqrt{s}\simeq 350$ and 600 MeV. The $\pi^0\pi^0$ cross-section then makes the $(\alpha_2-\beta_2)_{\pi^0}$ the easiest helicity-two polarizability to determine.
[ { "created": "Mon, 14 Nov 2016 16:21:22 GMT", "version": "v1" }, { "created": "Wed, 16 Nov 2016 19:01:44 GMT", "version": "v2" }, { "created": "Mon, 10 Sep 2018 03:31:28 GMT", "version": "v3" } ]
2018-09-11
[ [ "Dai", "Ling-Yun", "" ], [ "Pennington", "Michael R.", "" ] ]
We present results for pion polarizabilities predicted using dispersion relations from our earlier Amplitude Analysis of world data on two photon production of meson pairs. The helicity-zero polarizabilities are rather stable and insensitive to uncertainties in cross-channel exchanges. The need is first to confirm the recent result on $(\alpha_1-\beta_1)$ for the charged pion by COMPASS at CERN to an accuracy of 10\% by measuring the $\gamma\gamma\to\pi^+\pi^-$ cross-section to an uncertainty of ~1\%. Then the same polarizability, but for the $\pi^0$, is fixed to be $(\alpha_1-\beta_1)_{\pi^0}=(-0.9\pm0.2)\times 10^{-4}$ fm$^{3}$. By analyzing the correlation between uncertainties in the meson polarizability and those in $\gamma\gamma$ cross-sections, we suggest experiments need to measure these cross-sections between $\sqrt{s}\simeq 350$ and 600 MeV. The $\pi^0\pi^0$ cross-section then makes the $(\alpha_2-\beta_2)_{\pi^0}$ the easiest helicity-two polarizability to determine.
hep-ph/9511439
Elizabeth H. Simmons
E.H. Simmons, R.S. Chivukula, J. Terning
Direct Tests of Dynamical Electroweak Symmetry Breaking
Talk given by E.H.S at the International Symposium on Heavy Flavor and Electroweak Theory in Beijing, 17-19 August, 1995 and the Yukawa International Seminar `95 in Kyoto, 21-26 August, 1995. Latex (uses epsf). 10 pages. 2 figures. Full postscript version available at http://smyrd.bu.edu/htfigs/htfigs.html
null
null
BU-HEP-95-3x
hep-ph
null
We review the connection between $m_t$ and the $Zb\bar b$ vertex in ETC models and discuss the resulting experimental constraint on models with weak-singlet ETC bosons. We mention several recent efforts to bring ETC models into agreement with this constraint, and explore the most promising one (non-commuting ETC) in detail.
[ { "created": "Tue, 28 Nov 1995 17:54:39 GMT", "version": "v1" } ]
2019-08-15
[ [ "Simmons", "E. H.", "" ], [ "Chivukula", "R. S.", "" ], [ "Terning", "J.", "" ] ]
We review the connection between $m_t$ and the $Zb\bar b$ vertex in ETC models and discuss the resulting experimental constraint on models with weak-singlet ETC bosons. We mention several recent efforts to bring ETC models into agreement with this constraint, and explore the most promising one (non-commuting ETC) in detail.
1112.4368
Norma Susana Mankoc Borstnik
A. Hernandez-Galeana, N. S. Mankoc Borstnik
Masses and Mixing Matrices of Families of Quarks and Leptons Within the Spin-Charge-Family theory, predictions beyond the tree level
44 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The {\it theory unifying spin and charges and predicting families}, proposed by N.S.M.B., predicts at the low energy regime two (in the mixing matrix elements decoupled) groups of four families. There are two kinds of contributions to mass matrices in this theory. One kind distinguishes on the tree level only among the members of one family, that is among the $u$-quark, $d$-quark, neutrino and electron, the left and right handed, while the other kind distinguishes only among the families. Mass matrices for $d$-quarks and electrons are on the tree level correspondingly strongly correlated and so are mass matrices for $u$-quarks and neutrinos, up to the term, the Majorana term, which is nonzero only for right handed neutrinos. Beyond the tree level both kinds of contributions start to contribute coherently and it is expected that a detailed study of properties of mass matrices beyond the tree level explains drastic differences in masses and mixing matrices between quarks and leptons. We report in this paper on analysis of one loop corrections to the tree level fermion masses and mixing matrices. Loop diagrams are mediated by the gauge bosons and the two kinds of scalar fields. A detailed numerical analysis of fermion masses and mixing, including neutrinos, within this scenario is in progress and preparation.
[ { "created": "Mon, 19 Dec 2011 15:30:06 GMT", "version": "v1" } ]
2011-12-20
[ [ "Hernandez-Galeana", "A.", "" ], [ "Borstnik", "N. S. Mankoc", "" ] ]
The {\it theory unifying spin and charges and predicting families}, proposed by N.S.M.B., predicts at the low energy regime two (in the mixing matrix elements decoupled) groups of four families. There are two kinds of contributions to mass matrices in this theory. One kind distinguishes on the tree level only among the members of one family, that is among the $u$-quark, $d$-quark, neutrino and electron, the left and right handed, while the other kind distinguishes only among the families. Mass matrices for $d$-quarks and electrons are on the tree level correspondingly strongly correlated and so are mass matrices for $u$-quarks and neutrinos, up to the term, the Majorana term, which is nonzero only for right handed neutrinos. Beyond the tree level both kinds of contributions start to contribute coherently and it is expected that a detailed study of properties of mass matrices beyond the tree level explains drastic differences in masses and mixing matrices between quarks and leptons. We report in this paper on analysis of one loop corrections to the tree level fermion masses and mixing matrices. Loop diagrams are mediated by the gauge bosons and the two kinds of scalar fields. A detailed numerical analysis of fermion masses and mixing, including neutrinos, within this scenario is in progress and preparation.
1503.06283
Kalyan Dey
Kalyan Dey and B. Bhattacharjee
Strange behavior of rapidity dependent strangeness enhancement of particles containing and not containing leading quarks
19 pages and 9 figures
Nucl. Phys. A, 965, 2017
10.1016/j.nuclphysa.2017.05.092
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Rapidity dependent strangeness enhancement factors for the identified particles have been studied with the help of a string based hadronic transport model UrQMD-3.3 (Ultra-relativistic Quantum Molecular Dynamics) at FAIR energies. A strong rapidity dependent strangeness enhancement could be observed with our generated data for $Au + Au$ collisions at the beam energy of 30\textit{A} GeV. The strangeness enhancement is found to be maximum at mid-rapidity for the particles containing leading quarks while for particles consisting of produced quarks only, the situation is seen to be otherwise. Such rapidity dependent strangeness enhancement could be traced back to the dependence of rapidity width on centrality or otherwise on the distribution of net-baryon density.
[ { "created": "Sat, 21 Mar 2015 10:32:03 GMT", "version": "v1" }, { "created": "Mon, 22 May 2017 10:05:09 GMT", "version": "v2" } ]
2017-06-05
[ [ "Dey", "Kalyan", "" ], [ "Bhattacharjee", "B.", "" ] ]
Rapidity dependent strangeness enhancement factors for the identified particles have been studied with the help of a string based hadronic transport model UrQMD-3.3 (Ultra-relativistic Quantum Molecular Dynamics) at FAIR energies. A strong rapidity dependent strangeness enhancement could be observed with our generated data for $Au + Au$ collisions at the beam energy of 30\textit{A} GeV. The strangeness enhancement is found to be maximum at mid-rapidity for the particles containing leading quarks while for particles consisting of produced quarks only, the situation is seen to be otherwise. Such rapidity dependent strangeness enhancement could be traced back to the dependence of rapidity width on centrality or otherwise on the distribution of net-baryon density.
1512.01957
Bo-Qiang Ma
Zhiyuan Wang, Bo-Qiang Ma
A unified approach to hadron phenomenology at zero and finite temperatures in a hard-wall AdS/QCD model
19 latex pages, 5 figures, final version for publication
null
10.1140/epja/i2016-16122-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a unified approach to study meson, nucleon and $\Delta$-baryon properties at zero and finite temperatures in the context of hard-wall AdS/QCD model. We first combine some previous works dealing with mesons and baryons separately, and introduce a new parameter~$\xi$ so that the model could give a universal description of spectrum and couplings of both sectors in a self-consistent way. All observables calculated numerically show reasonable agreement with experimental data. We then study these observables at nonzero temperature by modifying the AdS space-time into AdS-Schwartzchild space-time. Numerically solving the model, we find an interesting temperature dependence of the spectrum and the couplings. We also make a prediction on the finite temperature decay width of some nucleon and $\Delta$ excited states.
[ { "created": "Mon, 7 Dec 2015 09:57:36 GMT", "version": "v1" }, { "created": "Mon, 9 May 2016 16:36:13 GMT", "version": "v2" } ]
2016-05-25
[ [ "Wang", "Zhiyuan", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We propose a unified approach to study meson, nucleon and $\Delta$-baryon properties at zero and finite temperatures in the context of hard-wall AdS/QCD model. We first combine some previous works dealing with mesons and baryons separately, and introduce a new parameter~$\xi$ so that the model could give a universal description of spectrum and couplings of both sectors in a self-consistent way. All observables calculated numerically show reasonable agreement with experimental data. We then study these observables at nonzero temperature by modifying the AdS space-time into AdS-Schwartzchild space-time. Numerically solving the model, we find an interesting temperature dependence of the spectrum and the couplings. We also make a prediction on the finite temperature decay width of some nucleon and $\Delta$ excited states.
2202.08840
Marianne Moore
David McKeen, Marianne Moore, David E. Morrissey, Maxim Pospelov, Harikrishnan Ramani
Accelerating Earth-Bound Dark Matter
20 pages, 12 figures. v2: version accepted for publication
Phys. Rev. D 106, 035011 (2022)
10.1103/PhysRevD.106.035011
MIT-CTP/5405
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/4.0/
A fraction of the dark matter may consist of a particle species that interacts much more strongly with the Standard Model than a typical weakly interacting massive particle (WIMP) of similar mass. Such a strongly interacting dark matter component could have avoided detection in searches for WIMP-like dark matter through its interactions with the material in the atmosphere and the Earth that slow it down significantly before reaching detectors underground. These same interactions can also enhance the density of a strongly interacting dark matter species near the Earth's surface to well above the local galactic dark matter density. In this work we propose two new methods of detecting strongly interacting dark matter based on accelerating the enhanced population expected in the Earth through scattering. The first approach is to use underground nuclear accelerator beams to upscatter the ambient dark matter population into a WIMP-style detector located downstream. In the second technique, dark matter is upscattered with an intense thermal source and detected with a low-threshold dark matter detector. We also discuss potential candidates for strongly interacting dark matter and we show that the scenario can be naturally realized with a hidden fermion coupled to a sub-GeV dark photon.
[ { "created": "Thu, 17 Feb 2022 19:00:00 GMT", "version": "v1" }, { "created": "Thu, 11 Aug 2022 12:09:29 GMT", "version": "v2" } ]
2022-08-12
[ [ "McKeen", "David", "" ], [ "Moore", "Marianne", "" ], [ "Morrissey", "David E.", "" ], [ "Pospelov", "Maxim", "" ], [ "Ramani", "Harikrishnan", "" ] ]
A fraction of the dark matter may consist of a particle species that interacts much more strongly with the Standard Model than a typical weakly interacting massive particle (WIMP) of similar mass. Such a strongly interacting dark matter component could have avoided detection in searches for WIMP-like dark matter through its interactions with the material in the atmosphere and the Earth that slow it down significantly before reaching detectors underground. These same interactions can also enhance the density of a strongly interacting dark matter species near the Earth's surface to well above the local galactic dark matter density. In this work we propose two new methods of detecting strongly interacting dark matter based on accelerating the enhanced population expected in the Earth through scattering. The first approach is to use underground nuclear accelerator beams to upscatter the ambient dark matter population into a WIMP-style detector located downstream. In the second technique, dark matter is upscattered with an intense thermal source and detected with a low-threshold dark matter detector. We also discuss potential candidates for strongly interacting dark matter and we show that the scenario can be naturally realized with a hidden fermion coupled to a sub-GeV dark photon.
2406.00353
Hui-Hui Duan
Hui-Hui Duan, Yong-Lu Liu, Qin Chang and Ming-Qiu Huang
Form factors of $\Lambda_b^0 \to \Lambda_c(2595)^+$ within light-cone QCD sum rules
15 pages, 3 figures and 6 tables
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we calculated the form factors of the weak decay process $\Lambda_b^0 \to \Lambda_c(2595)^+$, where the final charm baryon represents an excited state with spin-parity $\frac{1}{2}^-$. Utilizing the light-cone QCD sum rules approach, we incorporated the contributions of the lowest two charm baryon states: the ground state $\Lambda_c$ with $J^P=\frac{1}{2}^+$ and the excited state $\Lambda_c(2595)^+$ with $J^P=\frac{1}{2}^-$ in the hadronic representation of the $\Lambda_b$ to $\Lambda_c(2595)$ transition correlation function. This approach allowes us to extract the form factors of the $\Lambda_b^0 \to \Lambda_c(2595)^+$ from $\Lambda_b^0 \to \Lambda_c^+$ transition. During the light-cone QCD sum rules procedure, we employed the light-cone distribution amplitudes (LCDAs) of the $\Lambda_b$ baryon. Furthermore, by combining these form factors with the helicity amplitudes of the bottom baryon transition matrix elements, we calculated the differential decay widths for the processes $\Lambda_b^0 \to \Lambda_c(2595)^+\ell^-\bar{\nu}_\ell$. Additionally, within the lifetime of $\Lambda_b^0$, we obtained the absolute branching fractions for the semileptonic decays $\Lambda_b^0 \to \Lambda_c(2595)^+ \ell^- \bar{\nu}_\ell$. With the branching fractions of $\Lambda_b^0 \to \Lambda_c(2595)^+ \ell^- \bar{\nu}_\ell$ calculated in this work, we also determined the parameter $\mathcal{R}(\Lambda_c(2595)^+)$ which tests the lepton flavor universality. This parameter is defined as the ratio of branching fractions $\mathcal{B}r(\Lambda_b^0 \to \Lambda_c(2595)^+\tau^-\bar{\nu}_\tau)$ and $\mathcal{B}r(\Lambda_b^0 \to \Lambda_c(2595)^+\mu^-\bar{\nu}_\mu)$. Our results provide a valuable theoretical test for these decay channels and offer insights into the LCDAs of bottom baryons, paving the way for further in-depth investigations.
[ { "created": "Sat, 1 Jun 2024 08:14:33 GMT", "version": "v1" } ]
2024-06-04
[ [ "Duan", "Hui-Hui", "" ], [ "Liu", "Yong-Lu", "" ], [ "Chang", "Qin", "" ], [ "Huang", "Ming-Qiu", "" ] ]
In this work, we calculated the form factors of the weak decay process $\Lambda_b^0 \to \Lambda_c(2595)^+$, where the final charm baryon represents an excited state with spin-parity $\frac{1}{2}^-$. Utilizing the light-cone QCD sum rules approach, we incorporated the contributions of the lowest two charm baryon states: the ground state $\Lambda_c$ with $J^P=\frac{1}{2}^+$ and the excited state $\Lambda_c(2595)^+$ with $J^P=\frac{1}{2}^-$ in the hadronic representation of the $\Lambda_b$ to $\Lambda_c(2595)$ transition correlation function. This approach allowes us to extract the form factors of the $\Lambda_b^0 \to \Lambda_c(2595)^+$ from $\Lambda_b^0 \to \Lambda_c^+$ transition. During the light-cone QCD sum rules procedure, we employed the light-cone distribution amplitudes (LCDAs) of the $\Lambda_b$ baryon. Furthermore, by combining these form factors with the helicity amplitudes of the bottom baryon transition matrix elements, we calculated the differential decay widths for the processes $\Lambda_b^0 \to \Lambda_c(2595)^+\ell^-\bar{\nu}_\ell$. Additionally, within the lifetime of $\Lambda_b^0$, we obtained the absolute branching fractions for the semileptonic decays $\Lambda_b^0 \to \Lambda_c(2595)^+ \ell^- \bar{\nu}_\ell$. With the branching fractions of $\Lambda_b^0 \to \Lambda_c(2595)^+ \ell^- \bar{\nu}_\ell$ calculated in this work, we also determined the parameter $\mathcal{R}(\Lambda_c(2595)^+)$ which tests the lepton flavor universality. This parameter is defined as the ratio of branching fractions $\mathcal{B}r(\Lambda_b^0 \to \Lambda_c(2595)^+\tau^-\bar{\nu}_\tau)$ and $\mathcal{B}r(\Lambda_b^0 \to \Lambda_c(2595)^+\mu^-\bar{\nu}_\mu)$. Our results provide a valuable theoretical test for these decay channels and offer insights into the LCDAs of bottom baryons, paving the way for further in-depth investigations.
hep-ph/9712359
null
Z. Chacko and R. N. Mohapatra
Supersymmetric Left-Right Model and Light Doubly Charged Higgs Bosons and Higgsinos
9 pages; no figures
Phys.Rev. D58 (1998) 015003
10.1103/PhysRevD.58.015003
null
hep-ph
null
We point out that in a large class of supersymmetric left-right models with automatic R-parity conservation there are a pair of light doubly charged Higgs bosons and Higgsinos. Requiring the mass of these particles to satisfy the LEP Z-width bound implies that $W_R$ mass must be above $10^{9}$ GeV.
[ { "created": "Fri, 12 Dec 1997 20:53:35 GMT", "version": "v1" } ]
2009-10-30
[ [ "Chacko", "Z.", "" ], [ "Mohapatra", "R. N.", "" ] ]
We point out that in a large class of supersymmetric left-right models with automatic R-parity conservation there are a pair of light doubly charged Higgs bosons and Higgsinos. Requiring the mass of these particles to satisfy the LEP Z-width bound implies that $W_R$ mass must be above $10^{9}$ GeV.
2006.11624
Shaikh Saad
Ilja Dor\v{s}ner, Svjetlana Fajfer, Shaikh Saad
$\mu \to e \gamma$ selecting scalar leptoquark solutions for the $(g-2)_{e,\mu}$ puzzles
23 pages, 1 figure, substantial changes implemented, conclusions expanded
Phys. Rev. D 102, 075007 (2020)
10.1103/PhysRevD.102.075007
OSU-HEP-20-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate all potentially viable scenarios that can produce the chiral enhancement required to simultaneously explain the $(g-2)_{e}$ and $(g-2)_{\mu}$ data with either a single scalar leptoquark or a pair of scalar leptoquarks. We provide classification of these scenarios in terms of their ability to satisfy the existing limits on the branching ratio for the $\mu \to e \gamma$ process. The simultaneous explanation of the $(g-2)_{e,\mu}$ discrepancies, coupled with the current experimental data, implies that the $(g-2)_e$ loops are exclusively due to the charm quark propagation whereas the $(g-2)_\mu$ loops are due to the top quark propagation. The scenarios where the $(g-2)_e$ loops are due to the top (bottom) quark propagation are, at best, approximately nine (three) orders of magnitude away from the experimental limit on the $\mu \to e \gamma$ branching ratio. All in all, there are only three particular scenarios that can pass the $\mu \to e \gamma$ test and simultaneously create large enough impact on the $(g-2)_{e,\mu}$ discrepancies when the new physics is based on the Standard Model fermion content. These are the $S_1$, $R_2$, and $S_1 \& S_3$ scenarios, where the first two are already known to be phenomenologically viable candidates with respect to all other flavor and collider data constraints. We show that the third scenario, where the right-chiral couplings to charged leptons are due to $S_1$, the left-chiral couplings to charged leptons are due to $S_3$, and the two leptoquarks mix through the Standard Model Higgs field, cannot address the $(g-2)_{e}$ and $(g-2)_{\mu}$ discrepancies at the $1\sigma$ level due to an interplay between $K_L^0 \to e^\pm \mu^\mp$, $Z \to e^+ e^-$, and $Z \to \mu^+ \mu^-$ data despite the ability of that scenario to avoid the $\mu \to e \gamma$ limit.
[ { "created": "Sat, 20 Jun 2020 17:39:36 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 2020 15:19:37 GMT", "version": "v2" }, { "created": "Fri, 11 Sep 2020 08:28:14 GMT", "version": "v3" } ]
2020-10-14
[ [ "Doršner", "Ilja", "" ], [ "Fajfer", "Svjetlana", "" ], [ "Saad", "Shaikh", "" ] ]
We investigate all potentially viable scenarios that can produce the chiral enhancement required to simultaneously explain the $(g-2)_{e}$ and $(g-2)_{\mu}$ data with either a single scalar leptoquark or a pair of scalar leptoquarks. We provide classification of these scenarios in terms of their ability to satisfy the existing limits on the branching ratio for the $\mu \to e \gamma$ process. The simultaneous explanation of the $(g-2)_{e,\mu}$ discrepancies, coupled with the current experimental data, implies that the $(g-2)_e$ loops are exclusively due to the charm quark propagation whereas the $(g-2)_\mu$ loops are due to the top quark propagation. The scenarios where the $(g-2)_e$ loops are due to the top (bottom) quark propagation are, at best, approximately nine (three) orders of magnitude away from the experimental limit on the $\mu \to e \gamma$ branching ratio. All in all, there are only three particular scenarios that can pass the $\mu \to e \gamma$ test and simultaneously create large enough impact on the $(g-2)_{e,\mu}$ discrepancies when the new physics is based on the Standard Model fermion content. These are the $S_1$, $R_2$, and $S_1 \& S_3$ scenarios, where the first two are already known to be phenomenologically viable candidates with respect to all other flavor and collider data constraints. We show that the third scenario, where the right-chiral couplings to charged leptons are due to $S_1$, the left-chiral couplings to charged leptons are due to $S_3$, and the two leptoquarks mix through the Standard Model Higgs field, cannot address the $(g-2)_{e}$ and $(g-2)_{\mu}$ discrepancies at the $1\sigma$ level due to an interplay between $K_L^0 \to e^\pm \mu^\mp$, $Z \to e^+ e^-$, and $Z \to \mu^+ \mu^-$ data despite the ability of that scenario to avoid the $\mu \to e \gamma$ limit.
1604.02458
Peter Adshead
Peter Adshead, Yanou Cui, and Jessie Shelton
Chilly Dark Sectors and Asymmetric Reheating
22 pages + 3 appendices, 14 figures; v2: references added, version to appear in JHEP
JHEP 1606 (2016) 016
10.1007/JHEP06(2016)016
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, $N_{\mathrm{eff}}$, we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.
[ { "created": "Fri, 8 Apr 2016 20:00:02 GMT", "version": "v1" }, { "created": "Wed, 1 Jun 2016 22:41:18 GMT", "version": "v2" } ]
2016-06-14
[ [ "Adshead", "Peter", "" ], [ "Cui", "Yanou", "" ], [ "Shelton", "Jessie", "" ] ]
In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, $N_{\mathrm{eff}}$, we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.
1608.01325
Jorge Segovia
Pablo G. Ortega, Jorge Segovia, David R. Entem and Francisco Fern\'andez
Canonical description of the new LHCb resonances
7 pages, 8 tables, 2 figures
Phys. Rev. D 94, 114018 (2016)
10.1103/PhysRevD.94.114018
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb Collaboration has recently observed four $J/\psi\phi$ structures called $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$ in the $B^{+}\to J/\psi\phi K^{+}$ decays. We study them herein using a nonrelativistic constituent quark model in which the degrees of freedom are quark-antiquark and meson-meson components. The $X(4140)$ resonance appears as a cusp in the $J/\psi\phi$ channel due to the near coincidence of the $D_{s}^{\pm}D_{s}^{\ast\pm}$ and $J/\psi\phi$ mass thresholds. The remaining three $X(4274)$, $X(4500)$ and $X(4700)$ appear as conventional charmonium states with quantum numbers $3^{3}P_{1}$, $4^{3}P_{0}$ and $5^{3}P_{0}$, respectively; and whose masses and widths are slightly modified due to their coupling with the corresponding closest meson-meson thresholds. A particular feature of our quark model is a lattice-based screened linear confining interaction that has been constrained in the light quark sector and usually produces higher excited heavy-quark states with lower masses than standard quark model predictions.
[ { "created": "Wed, 3 Aug 2016 20:01:07 GMT", "version": "v1" }, { "created": "Tue, 25 Oct 2016 16:43:19 GMT", "version": "v2" } ]
2016-12-28
[ [ "Ortega", "Pablo G.", "" ], [ "Segovia", "Jorge", "" ], [ "Entem", "David R.", "" ], [ "Fernández", "Francisco", "" ] ]
The LHCb Collaboration has recently observed four $J/\psi\phi$ structures called $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$ in the $B^{+}\to J/\psi\phi K^{+}$ decays. We study them herein using a nonrelativistic constituent quark model in which the degrees of freedom are quark-antiquark and meson-meson components. The $X(4140)$ resonance appears as a cusp in the $J/\psi\phi$ channel due to the near coincidence of the $D_{s}^{\pm}D_{s}^{\ast\pm}$ and $J/\psi\phi$ mass thresholds. The remaining three $X(4274)$, $X(4500)$ and $X(4700)$ appear as conventional charmonium states with quantum numbers $3^{3}P_{1}$, $4^{3}P_{0}$ and $5^{3}P_{0}$, respectively; and whose masses and widths are slightly modified due to their coupling with the corresponding closest meson-meson thresholds. A particular feature of our quark model is a lattice-based screened linear confining interaction that has been constrained in the light quark sector and usually produces higher excited heavy-quark states with lower masses than standard quark model predictions.
0906.0167
Peter Orland
Jing Xiao
Renormalization of QCD under longitudinal rescaling
Ph.D. dissertation, CUNY graduate program, Latex, 60 pages
null
null
BCCUNY-HEP/09-05
hep-ph cond-mat.stat-mech hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The form of the quantum Yang-Mills action, under a longitudinal rescaling is determined using a Wilsonian renormalization group. The high-energy limit, is the extreme limit of such a rescaling. We compute the anomalous dimensions and discuss the validity of the high-energy limit. This thesis is an expanded version of joint work with P. Orland, which appeared in arXiv:0901.2955.
[ { "created": "Sun, 31 May 2009 16:40:55 GMT", "version": "v1" } ]
2009-06-02
[ [ "Xiao", "Jing", "" ] ]
The form of the quantum Yang-Mills action, under a longitudinal rescaling is determined using a Wilsonian renormalization group. The high-energy limit, is the extreme limit of such a rescaling. We compute the anomalous dimensions and discuss the validity of the high-energy limit. This thesis is an expanded version of joint work with P. Orland, which appeared in arXiv:0901.2955.
2111.03400
Daniel Schuh
Andreas Ipp, David I. M\"uller, Daniel Schuh
Transverse momentum broadening in real-time lattice simulations of the glasma
11 pages, 4 figures, submitted to LATTICE21 conference proceedings
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of jets in heavy-ion collisions provides important information about the interaction of partons with the medium that they traverse. The seeds of jets are highly energetic partons, which are produced from hard scatterings during the collision event. As such, they are affected by all different stages of the medium's time evolution, including the glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma. Here we report on our numerical lattice simulations of partons traversing the boost-invariant, non-perturbative glasma as created at the early stages of collisions at RHIC and LHC. We find that partons quickly accumulate transverse momentum up to the saturation momentum during the glasma stage. Furthermore, we observe an interesting anisotropy in transverse momentum broadening of partons with larger broadening in the rapidity than in the azimuthal direction. Its origin can be related to correlations among the longitudinal color-electric and color-magnetic flux tubes in the initial state of the glasma. We compare these observations to the semi-analytic results obtained by a weak-field approximation, where we also find such an anisotropy in a parton's transverse momentum broadening.
[ { "created": "Fri, 5 Nov 2021 11:21:59 GMT", "version": "v1" } ]
2021-11-08
[ [ "Ipp", "Andreas", "" ], [ "Müller", "David I.", "" ], [ "Schuh", "Daniel", "" ] ]
The study of jets in heavy-ion collisions provides important information about the interaction of partons with the medium that they traverse. The seeds of jets are highly energetic partons, which are produced from hard scatterings during the collision event. As such, they are affected by all different stages of the medium's time evolution, including the glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma. Here we report on our numerical lattice simulations of partons traversing the boost-invariant, non-perturbative glasma as created at the early stages of collisions at RHIC and LHC. We find that partons quickly accumulate transverse momentum up to the saturation momentum during the glasma stage. Furthermore, we observe an interesting anisotropy in transverse momentum broadening of partons with larger broadening in the rapidity than in the azimuthal direction. Its origin can be related to correlations among the longitudinal color-electric and color-magnetic flux tubes in the initial state of the glasma. We compare these observations to the semi-analytic results obtained by a weak-field approximation, where we also find such an anisotropy in a parton's transverse momentum broadening.
hep-ph/9504272
Sean Fleming Northwestern University
Sean Fleming and Ivan Maksymyk
Can light Goldstone boson loops counter the `S-argument' against Technicolor?
We have considerably shortened this paper. The bulk of the derivation of the $STUVWX$ formalism has been removed and will be presented elsewhere. More emphasis has been placed on the calculation of $STUVWX$ in a one-family Technicolor model with light psuedo-goldstone bosons. Though the result remains the same, the `S-argument' can not be countered, we have elucidated some interesting points in the calculation. In particular we emphasize the fact that it is not possible to tell from the outset what the calculated value of $S$ at the $Z$-pole will be
Phys.Rev. D53 (1996) 2781-2788
10.1103/PhysRevD.53.2781
null
hep-ph
null
We examine the oblique correction phenomenology of one-family Technicolor with light pseudo-Goldstone bosons. From loop calculations based on a gauged chiral lagrangian for Technicolor, we are lead to conclude that even though loops with light Goldstone bosons give a negative contribution to $S$ measured at the $Z$-pole, this effect is not sufficiently large to unambiguously counter the `S-argument' against one-family Technicolor. This result cannot be guessed \apriori, but must be explicitly calculated. Our analysis entails an extended version of the $STU$ oblique parametrization of Peskin and Takeuchi. In principle, this extended formalism ($STUVWX$) must be used when there are light new particles in loops.
[ { "created": "Mon, 10 Apr 1995 19:31:42 GMT", "version": "v1" }, { "created": "Mon, 5 Jun 1995 20:16:00 GMT", "version": "v2" } ]
2009-10-28
[ [ "Fleming", "Sean", "" ], [ "Maksymyk", "Ivan", "" ] ]
We examine the oblique correction phenomenology of one-family Technicolor with light pseudo-Goldstone bosons. From loop calculations based on a gauged chiral lagrangian for Technicolor, we are lead to conclude that even though loops with light Goldstone bosons give a negative contribution to $S$ measured at the $Z$-pole, this effect is not sufficiently large to unambiguously counter the `S-argument' against one-family Technicolor. This result cannot be guessed \apriori, but must be explicitly calculated. Our analysis entails an extended version of the $STU$ oblique parametrization of Peskin and Takeuchi. In principle, this extended formalism ($STUVWX$) must be used when there are light new particles in loops.
hep-ph/9305262
Jan Louis
R. Barbieri, J. Louis, M. Moretti
Phenomenological Implications of Supersymmetry Breaking by the Dilaton
14 pages, (4 figures not included, available upon request), CERN-TH.6856/93 (In the previous version of this article the gaugino masses were given incorrectly. As a consequences the quantitative analysis of the low energy spectrum changes.)
Phys.Lett.B312:451-460,1993; ERRATUM-ibid.B316:632,1993
10.1016/0370-2693(93)90981-M
null
hep-ph hep-th
null
We investigate the low energy properties of string vacua with spontaneously broken $N=1$ supersymmetry by a dilaton $F$-term. As a consequence of the universal couplings of the dilaton, the supersymmetric mass spectrum is determined in terms of only three independent parameters and more constrained than in the minimal supersymmetric Standard Model. For a $\mu$-term induced by the \K\ potential the parameter space becomes two-dimensional; in the allowed regions of this parameter space we find that most supersymmetric particles are determined solely by the gluino mass. The Higgs is rather light and the top-quark mass always lower than 180 GeV.
[ { "created": "Thu, 13 May 1993 20:49:56 GMT", "version": "v1" }, { "created": "Tue, 6 Jul 1993 17:46:43 GMT", "version": "v2" } ]
2011-07-19
[ [ "Barbieri", "R.", "" ], [ "Louis", "J.", "" ], [ "Moretti", "M.", "" ] ]
We investigate the low energy properties of string vacua with spontaneously broken $N=1$ supersymmetry by a dilaton $F$-term. As a consequence of the universal couplings of the dilaton, the supersymmetric mass spectrum is determined in terms of only three independent parameters and more constrained than in the minimal supersymmetric Standard Model. For a $\mu$-term induced by the \K\ potential the parameter space becomes two-dimensional; in the allowed regions of this parameter space we find that most supersymmetric particles are determined solely by the gluino mass. The Higgs is rather light and the top-quark mass always lower than 180 GeV.
0710.1632
Itay Yavin
Paul Langacker, Gil Paz, Lian-Tao Wang, Itay Yavin
Z'-mediated Supersymmetry Breaking
Minor modifications to text to comply by PRL standards
Phys.Rev.Lett.100:041802,2008
10.1103/PhysRevLett.100.041802
null
hep-ph hep-ex hep-th
null
We consider a class of models in which supersymmetry breaking is communicated dominantly via a U'(1) gauge interaction, which also helps solve the \mu problem. Such models can emerge naturally in top-down constructions and are a version of split supersymmetry. The spectrum contains heavy sfermions, Higgsinos, exotics, and Z' ~ 10-100 TeV; light gauginos ~ 100-1000 GeV; a light Higgs ~ 140 GeV; and a light singlino. A specific set of U'(1) charges and exotics is analyzed, and we present five benchmark models. Implications for the gluino lifetime, cold dark matter, and the gravitino and neutrino masses are discussed.
[ { "created": "Mon, 8 Oct 2007 20:02:48 GMT", "version": "v1" }, { "created": "Tue, 5 Feb 2008 19:27:56 GMT", "version": "v2" } ]
2008-11-26
[ [ "Langacker", "Paul", "" ], [ "Paz", "Gil", "" ], [ "Wang", "Lian-Tao", "" ], [ "Yavin", "Itay", "" ] ]
We consider a class of models in which supersymmetry breaking is communicated dominantly via a U'(1) gauge interaction, which also helps solve the \mu problem. Such models can emerge naturally in top-down constructions and are a version of split supersymmetry. The spectrum contains heavy sfermions, Higgsinos, exotics, and Z' ~ 10-100 TeV; light gauginos ~ 100-1000 GeV; a light Higgs ~ 140 GeV; and a light singlino. A specific set of U'(1) charges and exotics is analyzed, and we present five benchmark models. Implications for the gluino lifetime, cold dark matter, and the gravitino and neutrino masses are discussed.
hep-ph/9403250
null
G. Degrassi, S. Fanchiotti and P. Gambino
Two-loop next-to-leading $\mt$ corrections to the $\rho$ parameter
CERN-TH.7180/94, DFPD 94/TH/12 and NYU-Th-94/02/01, 26 pages (LaTeX + PS figures, needs psfig (optional to include figures), doublespace, equations, and cite styles)
Int.J.Mod.Phys. A10 (1995) 1377-1392
10.1142/S0217751X95000668
null
hep-ph
null
The $O(G^2_\mu m_t^4)$ correction to the $\rho$ parameter is computed within the Standard Model using the current algebra formulation of radiative corrections. This approach is proved to be equivalent to the effective Lagrangian method proposed by Barbieri {\em et al.} Using the same framework, the $O(G^2_\mu m_t^2 m_z^2)$ correction to the ratio of neutral-to-charged current amplitudes is analysed in an $SU(2)$ model. The $O(G^2_\mu m_t^2 m_z^2)$ contribution is shown to be numerically comparable to the leading $O(G^2_\mu m_t^4)$ term for realistic values of the top mass. The resummation of higher-order effects is discussed.
[ { "created": "Wed, 9 Mar 1994 12:00:04 GMT", "version": "v1" } ]
2015-06-25
[ [ "Degrassi", "G.", "" ], [ "Fanchiotti", "S.", "" ], [ "Gambino", "P.", "" ] ]
The $O(G^2_\mu m_t^4)$ correction to the $\rho$ parameter is computed within the Standard Model using the current algebra formulation of radiative corrections. This approach is proved to be equivalent to the effective Lagrangian method proposed by Barbieri {\em et al.} Using the same framework, the $O(G^2_\mu m_t^2 m_z^2)$ correction to the ratio of neutral-to-charged current amplitudes is analysed in an $SU(2)$ model. The $O(G^2_\mu m_t^2 m_z^2)$ contribution is shown to be numerically comparable to the leading $O(G^2_\mu m_t^4)$ term for realistic values of the top mass. The resummation of higher-order effects is discussed.
1401.6458
Christopher McCabe
Celine Boehm, Matthew J. Dolan, Christopher McCabe, Michael Spannowsky, Chris J. Wallace
Extended gamma-ray emission from Coy Dark Matter
8 pages, 3 figures. v2: Minor changes to match published (JCAP) version
null
10.1088/1475-7516/2014/05/009
IPPP/13/31, DCPT/13/62, SLAC-PUB-15893
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that it is possible for WIMP dark matter to produce a large signal in indirect dark matter searches without producing signals elsewhere. We illustrate our point by fitting the Fermi-LAT extended galactic gamma-ray excess with a simple model of Dirac dark matter that annihilates primarily into b quarks via a pseudoscalar. Current collider constraints are weak while the 14 TeV LHC run will constrain a limited portion of the parameter space. No signal is expected in additional indirect searches or at future direct detection experiments. Our results emphasise the importance of fully understanding potential indirect signals of dark matter as they may provide the only information about the dark matter particle.
[ { "created": "Fri, 24 Jan 2014 21:00:19 GMT", "version": "v1" }, { "created": "Thu, 8 May 2014 12:17:32 GMT", "version": "v2" } ]
2014-05-09
[ [ "Boehm", "Celine", "" ], [ "Dolan", "Matthew J.", "" ], [ "McCabe", "Christopher", "" ], [ "Spannowsky", "Michael", "" ], [ "Wallace", "Chris J.", "" ] ]
We show that it is possible for WIMP dark matter to produce a large signal in indirect dark matter searches without producing signals elsewhere. We illustrate our point by fitting the Fermi-LAT extended galactic gamma-ray excess with a simple model of Dirac dark matter that annihilates primarily into b quarks via a pseudoscalar. Current collider constraints are weak while the 14 TeV LHC run will constrain a limited portion of the parameter space. No signal is expected in additional indirect searches or at future direct detection experiments. Our results emphasise the importance of fully understanding potential indirect signals of dark matter as they may provide the only information about the dark matter particle.
1410.1873
Mathieu Cliche
Kfir Blum, Mathieu Cliche, Csaba Csaki and Seung J. Lee
WIMP Dark Matter through the Dilaton Portal
28 pages, LaTeX; v2: section 4 corrected
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a model in which dark matter couples to the Standard Model through a dilaton of a sector with spontaneously broken approximate scale invariance. Scale invariance fixes the dilaton couplings to the Standard Model and dark matter fields, leaving three main free parameters: the symmetry breaking scale $f$, the dilaton mass $m_{\sigma}$, and the dark matter mass $m_{\chi}$. We analyze the experimental constraints on the parameter space from collider, direct and indirect detection experiments including the effect of Sommerfeld enhancement, and show that dilaton exchange provides a consistent, calculable framework for cold dark matter with $f,\,m_\sigma,\,m_\chi$ of roughly similar magnitude and in the range $\sim 1-10$ TeV. Direct and indirect detection experiments, notably future ground-based gamma ray and space-based cosmic ray measurements, can probe the model all the way to dark matter mass in the multi-TeV regime.
[ { "created": "Tue, 7 Oct 2014 20:00:01 GMT", "version": "v1" }, { "created": "Thu, 30 Oct 2014 14:32:37 GMT", "version": "v2" } ]
2014-10-31
[ [ "Blum", "Kfir", "" ], [ "Cliche", "Mathieu", "" ], [ "Csaki", "Csaba", "" ], [ "Lee", "Seung J.", "" ] ]
We study a model in which dark matter couples to the Standard Model through a dilaton of a sector with spontaneously broken approximate scale invariance. Scale invariance fixes the dilaton couplings to the Standard Model and dark matter fields, leaving three main free parameters: the symmetry breaking scale $f$, the dilaton mass $m_{\sigma}$, and the dark matter mass $m_{\chi}$. We analyze the experimental constraints on the parameter space from collider, direct and indirect detection experiments including the effect of Sommerfeld enhancement, and show that dilaton exchange provides a consistent, calculable framework for cold dark matter with $f,\,m_\sigma,\,m_\chi$ of roughly similar magnitude and in the range $\sim 1-10$ TeV. Direct and indirect detection experiments, notably future ground-based gamma ray and space-based cosmic ray measurements, can probe the model all the way to dark matter mass in the multi-TeV regime.
1801.10528
Qing-Feng Sun
Qing-Feng Sun and An-Min Wang
Next-to-leading order QCD corrections to the decay of Higgs to vector meson and Z boson
10 pages, 3 figures, 3 tables
Chinese Physics C, Vol. 42, No. 3 (2018) 033105
10.1088/1674-1137/42/3/033105
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The exclusive decay of the Higgs boson to a vector meson ($ J/\psi $ or $ \Upsilon(1S) $) and $ Z $ boson is studied in this work. The decay amplitudes are separated into two parts in a gauge invariant manner. The first part comes from the direct coupling of the Higgs boson to the charm (bottom) quark and the other from the $ HZZ^{*} $ or the loop-induced $ HZ\gamma^{*} $ vertexes in the standard model. While the branching ratios from the direct channel are much smaller than those of the indirect channel, their interference terms give nontrivial contributions. We further calculate the QCD radiative corrections to both channels, which reduce the total branching ratios by around 20% for both $ J/\psi $ and $ \Upsilon(1S) $ production. These results may help to check the SM predictions of the $ H c\bar{c}(H b\bar{b}) $ coupling and to seek for hints of new physics at the High Luminosity LHC or future hadron colliders.
[ { "created": "Wed, 31 Jan 2018 16:27:38 GMT", "version": "v1" } ]
2018-02-01
[ [ "Sun", "Qing-Feng", "" ], [ "Wang", "An-Min", "" ] ]
The exclusive decay of the Higgs boson to a vector meson ($ J/\psi $ or $ \Upsilon(1S) $) and $ Z $ boson is studied in this work. The decay amplitudes are separated into two parts in a gauge invariant manner. The first part comes from the direct coupling of the Higgs boson to the charm (bottom) quark and the other from the $ HZZ^{*} $ or the loop-induced $ HZ\gamma^{*} $ vertexes in the standard model. While the branching ratios from the direct channel are much smaller than those of the indirect channel, their interference terms give nontrivial contributions. We further calculate the QCD radiative corrections to both channels, which reduce the total branching ratios by around 20% for both $ J/\psi $ and $ \Upsilon(1S) $ production. These results may help to check the SM predictions of the $ H c\bar{c}(H b\bar{b}) $ coupling and to seek for hints of new physics at the High Luminosity LHC or future hadron colliders.
hep-ph/0202038
Koshiro Suzuki
Masaaki Fujii and Koshiro Suzuki
Investigation of noscale supersymmetry breaking models with a gauged U(1)_{B-L} symmetry
23 pages, 5 eps figures
Phys.Rev. D66 (2002) 035002
10.1103/PhysRevD.66.035002
UT-02-06
hep-ph
null
Noscale supersymmetry (SUSY) breaking model is investigated in the minimal extension of the minimal supersymmetric standard model (MSSM) with a gauged U(1)_{B-L} symmetry. We specifically consider a unification-inspired model with the gauge groups SU(3)_{C} \times SU(2)_{L} \times U(1)_Y \times U(1)_{B-L} \subset SU(5) \times U(1)_{5} for illustration. While the noscale boundary condition at the grand unification scale (M_{G}\simeq 2\times 10^{16} GeV) in the MSSM is not consistent with phenomenological constraints, we show that it is if the gaugino of the U(1)_{5} multiplet is several times heavier than the gauginos of the MSSM. However, if SU(5) \times U(1)_{5} is further embedded in a larger simple group, e.g. SO(10), the noscale boundary condition at M_{G} is inconsistent with phenomenological constraints. If we relax the noscale boundary condition and allow non-zero soft scalar masses for the Higgs fields which spontaneously break the U(1)_{5} symmetry, the resultant spectrum of SUSY particles becomes consistent with all the phenomenological constraints, even if we impose the GUT relation on the gauge coupling and the gaugino mass of the U(1)_{5}. In this case, the SUSY CP problem is also solved, since the condition B\mu =0 at the boundary can be imposed consistently with the electroweak symmetry breaking.
[ { "created": "Tue, 5 Feb 2002 14:08:59 GMT", "version": "v1" } ]
2009-11-07
[ [ "Fujii", "Masaaki", "" ], [ "Suzuki", "Koshiro", "" ] ]
Noscale supersymmetry (SUSY) breaking model is investigated in the minimal extension of the minimal supersymmetric standard model (MSSM) with a gauged U(1)_{B-L} symmetry. We specifically consider a unification-inspired model with the gauge groups SU(3)_{C} \times SU(2)_{L} \times U(1)_Y \times U(1)_{B-L} \subset SU(5) \times U(1)_{5} for illustration. While the noscale boundary condition at the grand unification scale (M_{G}\simeq 2\times 10^{16} GeV) in the MSSM is not consistent with phenomenological constraints, we show that it is if the gaugino of the U(1)_{5} multiplet is several times heavier than the gauginos of the MSSM. However, if SU(5) \times U(1)_{5} is further embedded in a larger simple group, e.g. SO(10), the noscale boundary condition at M_{G} is inconsistent with phenomenological constraints. If we relax the noscale boundary condition and allow non-zero soft scalar masses for the Higgs fields which spontaneously break the U(1)_{5} symmetry, the resultant spectrum of SUSY particles becomes consistent with all the phenomenological constraints, even if we impose the GUT relation on the gauge coupling and the gaugino mass of the U(1)_{5}. In this case, the SUSY CP problem is also solved, since the condition B\mu =0 at the boundary can be imposed consistently with the electroweak symmetry breaking.
hep-ph/0503096
Kamal Benslama
G. Azuelos, K. Benslama and J. Ferland
Prospects for the Search for a Doubly-Charged Higgs in the Left-Right Symmetric Model with ATLAS
null
J.Phys.G32:73-92,2006
10.1088/0954-3899/32/2/002
null
hep-ph
null
We estimate the potential for observation at the LHC of a doubly charged Higgs boson, as predicted in Left-Right symmetric models. Single production by vector boson fusion, $W^+W^+ \to \Delta_{L,R}^{++}$ and pair production by the Drell-Yan process $q \bar q \to \Delta_{L,R}^{++}\Delta_{L,R}^{--}$ are considered. Various decay channels are investigated: dileptons, including pairs of $\tau$'s, as well as $WW$
[ { "created": "Thu, 10 Mar 2005 18:09:34 GMT", "version": "v1" } ]
2009-11-11
[ [ "Azuelos", "G.", "" ], [ "Benslama", "K.", "" ], [ "Ferland", "J.", "" ] ]
We estimate the potential for observation at the LHC of a doubly charged Higgs boson, as predicted in Left-Right symmetric models. Single production by vector boson fusion, $W^+W^+ \to \Delta_{L,R}^{++}$ and pair production by the Drell-Yan process $q \bar q \to \Delta_{L,R}^{++}\Delta_{L,R}^{--}$ are considered. Various decay channels are investigated: dileptons, including pairs of $\tau$'s, as well as $WW$
1606.05270
Adil Jueid
Abdesslam Arhrib and Adil Jueid
$tbW$ Anomalous Couplings in the Two Higgs Doublet Model
30 pages, 7 figures and 6 tables. Matches published version
JHEP 1608 (2016) 082
10.1007/JHEP08(2016)082
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We make a complete one loop calculation of the $tbW$ couplings in the Two Higgs Doublet Model. We evaluate both the anomalous couplings $g_L$ and $g_R$ as well as left handed and right handed component of $tbW$. The computation is done in the Feynman gauge using the on-shell scheme renormalization for the Standard Model wave functions and parameters. We first show that the relative corrections to these anomalous couplings are rather small in most regions of the parameter space. We then analyze the effects of these anomalous couplings on certain observables such as top quark polarization in single top production through $t-$channel as well as $W^\pm$ boson helicity fractions in top decay.
[ { "created": "Thu, 16 Jun 2016 17:06:30 GMT", "version": "v1" }, { "created": "Thu, 23 Jun 2016 22:53:40 GMT", "version": "v2" }, { "created": "Sun, 27 Oct 2019 16:59:20 GMT", "version": "v3" } ]
2019-10-29
[ [ "Arhrib", "Abdesslam", "" ], [ "Jueid", "Adil", "" ] ]
We make a complete one loop calculation of the $tbW$ couplings in the Two Higgs Doublet Model. We evaluate both the anomalous couplings $g_L$ and $g_R$ as well as left handed and right handed component of $tbW$. The computation is done in the Feynman gauge using the on-shell scheme renormalization for the Standard Model wave functions and parameters. We first show that the relative corrections to these anomalous couplings are rather small in most regions of the parameter space. We then analyze the effects of these anomalous couplings on certain observables such as top quark polarization in single top production through $t-$channel as well as $W^\pm$ boson helicity fractions in top decay.
1401.3631
Daniele Binosi
A. C. Aguilar, D. Binosi, J. Papavassiliou
Renormalization group analysis of the gluon mass equation
33 pages, 11 figures
Phys. Rev. D 89, 085032 (2014)
10.1103/PhysRevD.89.085032
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work we carry out a systematic study of the renormalization properties of the integral equation that determines the momentum evolution of the effective gluon mass. A detailed, all-order analysis of the complete kernel appearing in this particular equation reveals that the renormalization procedure may be accomplished through the sole use of ingredients known from the standard perturbative treatment of the theory, with no additional assumptions. However, the subtle interplay of terms operating at the level of the exact equation gets distorted by the approximations usually employed when evaluating the aforementioned kernel. This fact is reflected in the form of the obtained solutions, whose deviations from the correct behavior are best quantified by resorting to appropriately defined renormalization-group invariant quantities. This analysis, in turn, provides a solid guiding principle for improving the form of the kernel, and furnishes a well-defined criterion for discriminating between various possibilities. Certain renormalization-group inspired Ans\"atze for the kernel are then proposed, and their numerical implications are explored in detail. One of the solutions obtained fulfills the theoretical expectations to a high degree of accuracy, yielding a gluon mass that is positive-definite throughout the entire range of physical momenta, and displays in the ultraviolet the so-called "power-law" running, in agreement with standard arguments based on the operator product expansion. Some of the technical difficulties thwarting a more rigorous determination of the kernel are discussed, and possible future directions are briefly mentioned.
[ { "created": "Wed, 15 Jan 2014 15:36:32 GMT", "version": "v1" } ]
2014-04-23
[ [ "Aguilar", "A. C.", "" ], [ "Binosi", "D.", "" ], [ "Papavassiliou", "J.", "" ] ]
In the present work we carry out a systematic study of the renormalization properties of the integral equation that determines the momentum evolution of the effective gluon mass. A detailed, all-order analysis of the complete kernel appearing in this particular equation reveals that the renormalization procedure may be accomplished through the sole use of ingredients known from the standard perturbative treatment of the theory, with no additional assumptions. However, the subtle interplay of terms operating at the level of the exact equation gets distorted by the approximations usually employed when evaluating the aforementioned kernel. This fact is reflected in the form of the obtained solutions, whose deviations from the correct behavior are best quantified by resorting to appropriately defined renormalization-group invariant quantities. This analysis, in turn, provides a solid guiding principle for improving the form of the kernel, and furnishes a well-defined criterion for discriminating between various possibilities. Certain renormalization-group inspired Ans\"atze for the kernel are then proposed, and their numerical implications are explored in detail. One of the solutions obtained fulfills the theoretical expectations to a high degree of accuracy, yielding a gluon mass that is positive-definite throughout the entire range of physical momenta, and displays in the ultraviolet the so-called "power-law" running, in agreement with standard arguments based on the operator product expansion. Some of the technical difficulties thwarting a more rigorous determination of the kernel are discussed, and possible future directions are briefly mentioned.
1207.2626
Giulia Zanderighi
Barbara Jager, Steven Schneider and Giulia Zanderighi
Next-to-leading order QCD corrections to electroweak Zjj production in the POWHEGBOX
12 pages, 5 figures
null
10.1007/JHEP09(2012)083
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an implementation of electroweak Z-boson production in association with two jets at hadron colliders in the POWHEG framework, a method that allows the interfacing of NLO-QCD calculations with parton-shower Monte Carlo programs. We focus on the leptonic decays of the weak gauge boson, and take photonic and non-resonant contributions to the matrix elements fully into account. We provide results for observables of particular importance for the suppression of QCD backgrounds to vector-boson fusion processes by means of central-jet-veto techniques. While parton-shower effects are small for most observables associated with the two hardest jets, they can be more pronounced for distributions that are employed in central-jet-veto studies.
[ { "created": "Wed, 11 Jul 2012 13:04:24 GMT", "version": "v1" } ]
2015-06-05
[ [ "Jager", "Barbara", "" ], [ "Schneider", "Steven", "" ], [ "Zanderighi", "Giulia", "" ] ]
We present an implementation of electroweak Z-boson production in association with two jets at hadron colliders in the POWHEG framework, a method that allows the interfacing of NLO-QCD calculations with parton-shower Monte Carlo programs. We focus on the leptonic decays of the weak gauge boson, and take photonic and non-resonant contributions to the matrix elements fully into account. We provide results for observables of particular importance for the suppression of QCD backgrounds to vector-boson fusion processes by means of central-jet-veto techniques. While parton-shower effects are small for most observables associated with the two hardest jets, they can be more pronounced for distributions that are employed in central-jet-veto studies.
1108.6009
N\'estor Quintero
D. Delepine, G. Lopez Castro and N. Quintero
Lepton number violation in top quark and neutral B meson decays
15 pages, 6 figures, "Added comments on sensitivities. Version accepted for publication"
Phys. Rev. D 84, 096011 (2011)
10.1103/PhysRevD.84.096011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton number violation (LNV) can be induced by Majorana neutrinos in four-body decays of the neutral B meson and the top quark. We study the effects of Majorana neutrinos in these |\Delta L|=2 decays in an scenario where a single heavy neutrino can enhance the amplitude via the resonant mechanism. Using current bounds on heavy neutrino mixings, the most optimistic branching ratios turn out to be at the level of 10^{-6} for \bar{B} -> D^+e^-e^-\pi^+ and t -> bl^+l^+W^- decays. Searches for these LNV decays at future facilities can provide complementary constraints on masses and mixings of Majorana neutrinos.
[ { "created": "Tue, 30 Aug 2011 16:49:36 GMT", "version": "v1" }, { "created": "Mon, 31 Oct 2011 22:29:17 GMT", "version": "v2" } ]
2011-12-05
[ [ "Delepine", "D.", "" ], [ "Castro", "G. Lopez", "" ], [ "Quintero", "N.", "" ] ]
Lepton number violation (LNV) can be induced by Majorana neutrinos in four-body decays of the neutral B meson and the top quark. We study the effects of Majorana neutrinos in these |\Delta L|=2 decays in an scenario where a single heavy neutrino can enhance the amplitude via the resonant mechanism. Using current bounds on heavy neutrino mixings, the most optimistic branching ratios turn out to be at the level of 10^{-6} for \bar{B} -> D^+e^-e^-\pi^+ and t -> bl^+l^+W^- decays. Searches for these LNV decays at future facilities can provide complementary constraints on masses and mixings of Majorana neutrinos.
hep-ph/0601075
Francois Arleo
Francois Arleo
Hard pion and prompt photon at RHIC, from single to double inclusive production
31 pages, 11 figures
JHEP 0609 (2006) 015
10.1088/1126-6708/2006/09/015
CERN-PH-TH/2005-222
hep-ph nucl-th
null
Single pion and prompt photon large transverse momentum spectra in p-p and Au-Au collisions are computed in perturbative QCD at RHIC energy, s^1/2 = 200 GeV. Next-to-leading order calculations are discussed and compared with p-p scattering data. Subsequently, quenching factors are computed to leading order for both pions and photons within the same energy loss model. The good agreement with PHENIX preliminary data allows for a lower estimate of the energy density reached in central Au-Au collisions, epsilon > 10 GeV/fm^3. Double inclusive photon-pion production in p-p and Au-Au collisions is then addressed. Next-to-leading order corrections prove rather small in p-p scattering. In Au-Au collisions, the quenching of momentum-correlation spectra is seen to be sensitive to parton energy loss processes, which would help to understand how the fragmentation dynamics is modified in nuclear collisions at RHIC.
[ { "created": "Tue, 10 Jan 2006 13:06:27 GMT", "version": "v1" } ]
2009-11-11
[ [ "Arleo", "Francois", "" ] ]
Single pion and prompt photon large transverse momentum spectra in p-p and Au-Au collisions are computed in perturbative QCD at RHIC energy, s^1/2 = 200 GeV. Next-to-leading order calculations are discussed and compared with p-p scattering data. Subsequently, quenching factors are computed to leading order for both pions and photons within the same energy loss model. The good agreement with PHENIX preliminary data allows for a lower estimate of the energy density reached in central Au-Au collisions, epsilon > 10 GeV/fm^3. Double inclusive photon-pion production in p-p and Au-Au collisions is then addressed. Next-to-leading order corrections prove rather small in p-p scattering. In Au-Au collisions, the quenching of momentum-correlation spectra is seen to be sensitive to parton energy loss processes, which would help to understand how the fragmentation dynamics is modified in nuclear collisions at RHIC.
hep-ph/0409334
Junjie Cao
Junjie Cao, Guoli Liu, Jin Min Yang
Probing Topcolor-Assisted Technicolor from Like-sign Top Pair Production at LHC
10 pages, 6 figs
Phys.Rev.D70:114035,2004
10.1103/PhysRevD.70.114035
null
hep-ph hep-ex
null
The topcolor-assisted technicolor (TC2) theory predicts tree-level flavor-changing neutral-current (FCNC) top quark Yukawa couplings with top-pions. Such FCNC interactions will induce like-sign top quark pair productions at CERN Large Hadron Collider (LHC). While these rare productions are far below the observable level in the Standard Model and other popular new physics models such as the Minimal Supersymmetric Model, we find that in a sound part of parameter space the TC2 model can enhance the production cross sections to several tens of fb and thus may be observable at the LHC due to rather low backgrounds. Searching for these productions at the LHC will serve as an excellent probe for the TC2 model.
[ { "created": "Wed, 29 Sep 2004 11:11:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cao", "Junjie", "" ], [ "Liu", "Guoli", "" ], [ "Yang", "Jin Min", "" ] ]
The topcolor-assisted technicolor (TC2) theory predicts tree-level flavor-changing neutral-current (FCNC) top quark Yukawa couplings with top-pions. Such FCNC interactions will induce like-sign top quark pair productions at CERN Large Hadron Collider (LHC). While these rare productions are far below the observable level in the Standard Model and other popular new physics models such as the Minimal Supersymmetric Model, we find that in a sound part of parameter space the TC2 model can enhance the production cross sections to several tens of fb and thus may be observable at the LHC due to rather low backgrounds. Searching for these productions at the LHC will serve as an excellent probe for the TC2 model.
1705.07446
Gennady Lykasov I
A.P.Ierusalimov, G.I.Lykasov
Dielectron production in pion-nucleon reactions at intermediate energies
12 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dielectron production in the $\pi N$ interaction at not large energies is studied. The dominant contribution of the $\Delta$-isobar creation in the intermediate state at incident pion momenta of about 0.3-0.4 GeV$/$c is shown. The experimental distributions over the angle and effective mass $M_{e^+e_-}$ of the $e^+e^-$ pair are described satisfactorily. This stimulated us to present theoretical predictions for the $M_{e^+e_-}$ distribution in the process $\pi^- p\rightarrow ne^+e^-$ at different incident momenta, which could be verified, for example, by the HADES experiments.
[ { "created": "Sun, 21 May 2017 13:31:10 GMT", "version": "v1" } ]
2017-05-23
[ [ "Ierusalimov", "A. P.", "" ], [ "Lykasov", "G. I.", "" ] ]
Dielectron production in the $\pi N$ interaction at not large energies is studied. The dominant contribution of the $\Delta$-isobar creation in the intermediate state at incident pion momenta of about 0.3-0.4 GeV$/$c is shown. The experimental distributions over the angle and effective mass $M_{e^+e_-}$ of the $e^+e^-$ pair are described satisfactorily. This stimulated us to present theoretical predictions for the $M_{e^+e_-}$ distribution in the process $\pi^- p\rightarrow ne^+e^-$ at different incident momenta, which could be verified, for example, by the HADES experiments.
1812.04067
Julian Heeck
Julian Heeck, Manfred Lindner, Werner Rodejohann, Stefan Vogl
Non-Standard Neutrino Interactions and Neutral Gauge Bosons
25 pages; improved discussion of mass-mixing case; to appear in SciPost
SciPost Phys. 6, 038 (2019)
10.21468/SciPostPhys.6.3.038
ULB-TH/18-15, UCI-TR-2018-20
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate Non-Standard Neutrino Interactions (NSI) arising from a flavor-sensitive $Z'$ boson of a new $U(1)'$ symmetry. We compare the limits from neutrino oscillations, coherent elastic neutrino-nucleus scattering, and $Z'$ searches at different beam and collider experiments for a variety of straightforward anomaly-free $U(1)'$ models generated by linear combinations of $B-L$ and lepton-family-number differences $L_\alpha-L_\beta$. Depending on the flavor structure of those models it is easily possible to avoid NSI signals in long-baseline neutrino oscillation experiments or change the relative importance of the various experimental searches. We also point out that kinetic $Z$-$Z'$ mixing gives vanishing NSI in long-baseline experiments if a direct coupling between the $U(1)'$ gauge boson and matter is absent. In contrast, $Z$-$Z'$ mass mixing generates such NSI, which in turn means that there is a Higgs multiplet charged under both the Standard Model and the new $U(1)'$ symmetry.
[ { "created": "Mon, 10 Dec 2018 20:22:50 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2019 12:28:21 GMT", "version": "v2" } ]
2019-03-28
[ [ "Heeck", "Julian", "" ], [ "Lindner", "Manfred", "" ], [ "Rodejohann", "Werner", "" ], [ "Vogl", "Stefan", "" ] ]
We investigate Non-Standard Neutrino Interactions (NSI) arising from a flavor-sensitive $Z'$ boson of a new $U(1)'$ symmetry. We compare the limits from neutrino oscillations, coherent elastic neutrino-nucleus scattering, and $Z'$ searches at different beam and collider experiments for a variety of straightforward anomaly-free $U(1)'$ models generated by linear combinations of $B-L$ and lepton-family-number differences $L_\alpha-L_\beta$. Depending on the flavor structure of those models it is easily possible to avoid NSI signals in long-baseline neutrino oscillation experiments or change the relative importance of the various experimental searches. We also point out that kinetic $Z$-$Z'$ mixing gives vanishing NSI in long-baseline experiments if a direct coupling between the $U(1)'$ gauge boson and matter is absent. In contrast, $Z$-$Z'$ mass mixing generates such NSI, which in turn means that there is a Higgs multiplet charged under both the Standard Model and the new $U(1)'$ symmetry.
hep-ph/9401306
Steve Godfrey
G. Couture and S. Godfrey
A Phenomenological Study of the Process $e^+e^-\to\mu^+\mu^-\nu_l\bar\nu_l$ at High Energy $e^+e^-$ Colliders and Measurement of the $ZWW$ and $\gamma WW$ Couplings
33 pages, OCIP/C 93-18, UQAM-PHE-9306
Phys.Rev. D49 (1994) 5709-5719
10.1103/PhysRevD.49.5709
null
hep-ph
null
We perform a detailed study of the process $e^+e^-\to \mu^+\mu^-\nu_l\bar\nu_l$ including all contributions. The contributions other than from real gauge boson production leads to a rich phenomenology. We explore the use of the process as a means of precision measurement of the $ZWW$ and $\gamma WW$ vertices. We concentrate on LEP II energies, $\sqrt{s}=200$ GeV, and energies appropriate to the proposed Next Linear Collider (NLC) high energy $e^+e^-$ collider with center of mass energies $\sqrt{s}=500$ and 1~TeV. At 200 GeV, the process offers, at best, a consistency check of other processes being considered at LEP200. At 500~GeV, the parameters $\kappa_\gamma$, $\lambda_\gamma$, $\kappa_Z$, and $\lambda_Z$ can be measured to about $\pm 0.1$ or better at 95\% C.L. while at 1 TeV, they can be measured to about $\pm 0.01$. At the high luminosities anticipated at high energy linear colliders precision measurements are likely to be limited by systematic rather than statistical errors.
[ { "created": "Fri, 21 Jan 1994 18:51:53 GMT", "version": "v1" } ]
2009-10-28
[ [ "Couture", "G.", "" ], [ "Godfrey", "S.", "" ] ]
We perform a detailed study of the process $e^+e^-\to \mu^+\mu^-\nu_l\bar\nu_l$ including all contributions. The contributions other than from real gauge boson production leads to a rich phenomenology. We explore the use of the process as a means of precision measurement of the $ZWW$ and $\gamma WW$ vertices. We concentrate on LEP II energies, $\sqrt{s}=200$ GeV, and energies appropriate to the proposed Next Linear Collider (NLC) high energy $e^+e^-$ collider with center of mass energies $\sqrt{s}=500$ and 1~TeV. At 200 GeV, the process offers, at best, a consistency check of other processes being considered at LEP200. At 500~GeV, the parameters $\kappa_\gamma$, $\lambda_\gamma$, $\kappa_Z$, and $\lambda_Z$ can be measured to about $\pm 0.1$ or better at 95\% C.L. while at 1 TeV, they can be measured to about $\pm 0.01$. At the high luminosities anticipated at high energy linear colliders precision measurements are likely to be limited by systematic rather than statistical errors.
hep-ph/0511155
Marco Ruggieri
V. Laporta and M. Ruggieri
Effect of neutrino trapping on the three flavor FFLO phase of QCD
12 pages, 2 figures, RevTeX4 class. Changed Fig. 2 (see text) and some reference added
Phys.Lett.B633:734-738,2006; Erratum-ibid.B673:383,2006
10.1016/j.physletb.2006.03.066
null
hep-ph
null
We compute the effect of a non-zero lepton chemical potential on the structure of the three flavor Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase of QCD at finite temperature. We show that, as in the BCS case, the lepton chemical potential favors two-species color superconductivity and disfavors the three species pairing. We stress that this study could be relevant for the cooling of a proto-neutron star with a FFLO core, if the temperatures are higher than the un-trapping temperature.
[ { "created": "Sat, 12 Nov 2005 19:12:56 GMT", "version": "v1" }, { "created": "Thu, 23 Mar 2006 14:04:57 GMT", "version": "v2" } ]
2010-11-11
[ [ "Laporta", "V.", "" ], [ "Ruggieri", "M.", "" ] ]
We compute the effect of a non-zero lepton chemical potential on the structure of the three flavor Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase of QCD at finite temperature. We show that, as in the BCS case, the lepton chemical potential favors two-species color superconductivity and disfavors the three species pairing. We stress that this study could be relevant for the cooling of a proto-neutron star with a FFLO core, if the temperatures are higher than the un-trapping temperature.
hep-ph/0005140
Piet Mulders
A. Bacchetta, M. Boglione, A. Henneman and P.J. Mulders
The full spin structure of quarks in the nucleon
10 pages with figures, LaTex, uses epsfig.sty. Invited talk by P.J. Mulders at the workshop on Nucleon Structure in the High x-Bjorken Region (HiX2000), Temple University, Philadelphia, PA, USA; March 30 - April 1, 2000
null
null
null
hep-ph
null
We discuss bounds on the distribution and fragmentation functions that appear at leading order in deep inelastic 1-particle inclusive leptoproduction or in Drell-Yan processes. These bounds simply follow from positivity of the quark-hadron scattering matrix elements and are an important guide in estimating the magnitude of the azimuthal and spin asymmetries in these processes. We focus on an example relevant for deep inelastic scattering at relatively low energies.
[ { "created": "Mon, 15 May 2000 15:05:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bacchetta", "A.", "" ], [ "Boglione", "M.", "" ], [ "Henneman", "A.", "" ], [ "Mulders", "P. J.", "" ] ]
We discuss bounds on the distribution and fragmentation functions that appear at leading order in deep inelastic 1-particle inclusive leptoproduction or in Drell-Yan processes. These bounds simply follow from positivity of the quark-hadron scattering matrix elements and are an important guide in estimating the magnitude of the azimuthal and spin asymmetries in these processes. We focus on an example relevant for deep inelastic scattering at relatively low energies.
hep-ph/9301277
null
X. Zhang
Operator Analysis for the Higgs Potential and Cosmological Bound on the Higgs-Boson Mass
10 Pages, Tex, UMDHEP 93-074
Phys.Rev. D47 (1993) 3065-3067
10.1103/PhysRevD.47.3065
null
hep-ph
null
Using effective lagrangian, we examine the impacts of new physics on the electroweak baryogenesis. By analysing the high dimensional operators relevent to the Higgs potential we point out that the Higgs mass bound required by electroweak baryogenesis can be relaxed to the region allowed by experiments, provided that new physics appears at the TeV scale.
[ { "created": "Tue, 26 Jan 1993 18:24:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Zhang", "X.", "" ] ]
Using effective lagrangian, we examine the impacts of new physics on the electroweak baryogenesis. By analysing the high dimensional operators relevent to the Higgs potential we point out that the Higgs mass bound required by electroweak baryogenesis can be relaxed to the region allowed by experiments, provided that new physics appears at the TeV scale.
hep-ph/0509359
Walter Winter
Andre de Gouvea and Walter Winter
What would it take to determine the neutrino mass hierarchy if $\theta_{13}$ were too small?
22 pages, 10 color figures
Phys.Rev. D73 (2006) 033003
10.1103/PhysRevD.73.033003
NUHEP-TH/05-09
hep-ph hep-ex
null
We discuss the experimental requirements for a mass hierarchy measurement for $\theta_{13}=0$ using muon neutrino disappearance. We find that a specially optimized neutrino factory at $L \simeq 6 \,000 \, \mathrm{km}$ could do this measurement using extreme luminosities. In particular, we do not require charge identification for this purpose. In order to measure the mass hierarchy for more adequate luminosities, we explore the capabilities of low energy narrow band off-axis beams, which have relatively more events at low energies. We find that, in this case, the energy resolution of the detector quickly becomes the limiting factor of the measurement, and significantly affects the baseline optimization for determining the mass hierarchy.
[ { "created": "Thu, 29 Sep 2005 21:22:02 GMT", "version": "v1" } ]
2013-05-29
[ [ "de Gouvea", "Andre", "" ], [ "Winter", "Walter", "" ] ]
We discuss the experimental requirements for a mass hierarchy measurement for $\theta_{13}=0$ using muon neutrino disappearance. We find that a specially optimized neutrino factory at $L \simeq 6 \,000 \, \mathrm{km}$ could do this measurement using extreme luminosities. In particular, we do not require charge identification for this purpose. In order to measure the mass hierarchy for more adequate luminosities, we explore the capabilities of low energy narrow band off-axis beams, which have relatively more events at low energies. We find that, in this case, the energy resolution of the detector quickly becomes the limiting factor of the measurement, and significantly affects the baseline optimization for determining the mass hierarchy.
1710.07352
Aurore Courtoy
A. Courtoy
The Tensor and the Scalar Charges of the Nucleon from Hadron Phenomenology
To appear in the proceedings of the ISMD 2017, held in Tlaxcala, Mexico, September 11-15, 2017. Includes .cls and .bst files for EPJ Web of Conferences. arXiv admin note: substantial text overlap with arXiv:1608.04429
null
10.1051/epjconf/201817203007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the impact of the determination of the nucleon tensor charge on searches for physics Beyond the Standard Model. We also comment on the future extraction of the subleading-twist PDF $e(x)$ from Jefferson Lab soon-to-be-released Beam Spin Asymmetry data as well as from the expected data of CLAS12, as the latter is related to the scalar charge. These analyses are possible through the phenomenology of Dihadron Fragmentation Functions related processes, which we report on here as well.
[ { "created": "Wed, 18 Oct 2017 16:46:12 GMT", "version": "v1" } ]
2018-03-14
[ [ "Courtoy", "A.", "" ] ]
We discuss the impact of the determination of the nucleon tensor charge on searches for physics Beyond the Standard Model. We also comment on the future extraction of the subleading-twist PDF $e(x)$ from Jefferson Lab soon-to-be-released Beam Spin Asymmetry data as well as from the expected data of CLAS12, as the latter is related to the scalar charge. These analyses are possible through the phenomenology of Dihadron Fragmentation Functions related processes, which we report on here as well.
hep-ph/9704314
Yuri Golubkov
Yu.A.Golubkov (Moscow State University) and R.V.Konoplich (Moscow Engineering Physics Institute)
Cosmic Ray Constraints On the Annihilation of Heavy Stable Neutrinos in the Galactic Halo
19 pages, 4 Postscript figures, Latex
Yad.Fiz. 61 (1998) 675; Phys.Atom.Nucl. 61 (1998) 602
null
DESY 97-057
hep-ph astro-ph
null
We carry out a detailed analysis of fluxes of cosmic ray antiprotons, positrons, electrons and photons to be expected from the annihilation of relic heavy neutrinos in the galactic halo. The spectra of particles are evaluated by Monte Carlo simulation. The results of calculations show that the investigation of cosmic ray positron spectra at high energies could provide a distinctive signal for annihilation of very heavy neutrinos in the Galaxy and give an important information on parameters of dark matter particles.
[ { "created": "Mon, 14 Apr 1997 07:42:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Golubkov", "Yu. A.", "", "Moscow State University" ], [ "Konoplich", "R. V.", "", "Moscow\n Engineering Physics Institute" ] ]
We carry out a detailed analysis of fluxes of cosmic ray antiprotons, positrons, electrons and photons to be expected from the annihilation of relic heavy neutrinos in the galactic halo. The spectra of particles are evaluated by Monte Carlo simulation. The results of calculations show that the investigation of cosmic ray positron spectra at high energies could provide a distinctive signal for annihilation of very heavy neutrinos in the Galaxy and give an important information on parameters of dark matter particles.
hep-ph/0502151
Ben Allanach
B.C. Allanach, A. Brignole and L.E. Ibanez
Phenomenology of a Fluxed MSSM
18 pages, minor revisions
JHEP0505:030,2005
10.1088/1126-6708/2005/05/030
null
hep-ph hep-th
null
We analyze the phenomenology of a set of minimal supersymmetric standard model (MSSM) soft terms inspired by flux-induced supersymmetry (SUSY)-breaking in Type IIB string orientifolds. The scheme is extremely constrained with essentially only two free mass parameters: a parameter M, which sets the scale of soft terms, and the mu parameter. After imposing consistent radiative electro-weak symmetry breaking (EWSB) the model depends upon one mass parameter (say, M). In spite of being so constrained one finds consistency with EWSB conditions. We demonstrate that those conditions have two solutions for mu<0, and none for mu>0. The parameter tan beta results as a prediction and is approximately 3-5 for one solution, and 25-40 for the other, depending upon M and the top mass. We examine further constraints on the model coming from b->s gamma, the muon g-2, Higgs mass limits and WMAP constraints on dark matter. The MSSM spectrum is predicted in terms of the single free parameter M. The low tan beta branch is consistent with a relatively light spectrum although it is compatible with standard cosmology only if the lightest neutralino is unstable. The high tan beta branch is compatible with all phenomenological constraints, but has quite a heavy spectrum. We argue that the fine-tuning associated to this heavy spectrum would be substantially ameliorated if an additional relationship mu=-2M were present in the underlying theory.
[ { "created": "Wed, 16 Feb 2005 18:24:52 GMT", "version": "v1" }, { "created": "Thu, 7 Apr 2005 10:19:10 GMT", "version": "v2" } ]
2009-11-11
[ [ "Allanach", "B. C.", "" ], [ "Brignole", "A.", "" ], [ "Ibanez", "L. E.", "" ] ]
We analyze the phenomenology of a set of minimal supersymmetric standard model (MSSM) soft terms inspired by flux-induced supersymmetry (SUSY)-breaking in Type IIB string orientifolds. The scheme is extremely constrained with essentially only two free mass parameters: a parameter M, which sets the scale of soft terms, and the mu parameter. After imposing consistent radiative electro-weak symmetry breaking (EWSB) the model depends upon one mass parameter (say, M). In spite of being so constrained one finds consistency with EWSB conditions. We demonstrate that those conditions have two solutions for mu<0, and none for mu>0. The parameter tan beta results as a prediction and is approximately 3-5 for one solution, and 25-40 for the other, depending upon M and the top mass. We examine further constraints on the model coming from b->s gamma, the muon g-2, Higgs mass limits and WMAP constraints on dark matter. The MSSM spectrum is predicted in terms of the single free parameter M. The low tan beta branch is consistent with a relatively light spectrum although it is compatible with standard cosmology only if the lightest neutralino is unstable. The high tan beta branch is compatible with all phenomenological constraints, but has quite a heavy spectrum. We argue that the fine-tuning associated to this heavy spectrum would be substantially ameliorated if an additional relationship mu=-2M were present in the underlying theory.
1812.01151
Thomas A. Trainor
Thomas A. Trainor
A two-component model for identified-hadron $\bf p_t$ spectra from 5 TeV p-Pb collisions
20 pages, 10 figures, updated to published version
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In preparation for the heavy ion program at the relativistic heavy ion collider (RHIC) $d$-Au collisions were designated as a control experiment for possible discovery of a quark-gluon plasma (QGP) in more-central Au-Au collisions, and contrasting results from the two systems seemed to support such a discovery. In contrast, recent results ($p_t$-spectrum and angular-correlation features) from $p$-Pb collisions at the large hadron collider (LHC) have been interpreted to support claims of hydrodynamic flows and QGP formation even in small collision systems. The present study addresses such claims via a two-component (soft + hard) model (TCM) of identified-hadron (PID) $p_t$ spectra from 5 TeV $p$-Pb collisions. $p$-Pb centrality is adopted from a previous study of ensemble-mean $\bar p_t$ data from the same system. $p$-Pb $p_t$ spectra for pions, kaons, protons and Lambdas are described by the TCM within their point-to-point uncertainties. Invariance of the TCM hard component vs $p$-Pb centrality indicates that jet formation remains unchanged in $p$-Pb collisions relative to $p$-$p$ collisions, and radial-flow contributions to spectra are negligible. These $p$-Pb TCM results have implications for interpretation of similar data features from A-A collisions in terms of QGP formation.
[ { "created": "Tue, 4 Dec 2018 00:57:58 GMT", "version": "v1" }, { "created": "Fri, 10 Jan 2020 23:19:08 GMT", "version": "v2" } ]
2020-01-14
[ [ "Trainor", "Thomas A.", "" ] ]
In preparation for the heavy ion program at the relativistic heavy ion collider (RHIC) $d$-Au collisions were designated as a control experiment for possible discovery of a quark-gluon plasma (QGP) in more-central Au-Au collisions, and contrasting results from the two systems seemed to support such a discovery. In contrast, recent results ($p_t$-spectrum and angular-correlation features) from $p$-Pb collisions at the large hadron collider (LHC) have been interpreted to support claims of hydrodynamic flows and QGP formation even in small collision systems. The present study addresses such claims via a two-component (soft + hard) model (TCM) of identified-hadron (PID) $p_t$ spectra from 5 TeV $p$-Pb collisions. $p$-Pb centrality is adopted from a previous study of ensemble-mean $\bar p_t$ data from the same system. $p$-Pb $p_t$ spectra for pions, kaons, protons and Lambdas are described by the TCM within their point-to-point uncertainties. Invariance of the TCM hard component vs $p$-Pb centrality indicates that jet formation remains unchanged in $p$-Pb collisions relative to $p$-$p$ collisions, and radial-flow contributions to spectra are negligible. These $p$-Pb TCM results have implications for interpretation of similar data features from A-A collisions in terms of QGP formation.
hep-ph/9910541
Masayuki Matsuzaki
Masayuki Matsuzaki (Fukuoka University of Education)
Spatial structure of quark Cooper pairs in a color superconductor
10 pages, 3 figures. The frequency dependence of the gap and the limitation on the type I/type II discussion are mentioned briefly. To appear in Phys. Rev. D
Phys.Rev. D62 (2000) 017501
10.1103/PhysRevD.62.017501
null
hep-ph astro-ph nucl-th
null
Spatial structure of Cooper pairs with quantum numbers color 3^*, I=J=L=S=0 in ud 2 flavor quark matter is studied by solving the gap equation and calculating the coherence length in full momentum range without the weak coupling approximation. Although the gap at the Fermi surface and the coherence length depend on density weakly, the shape of the r-space pair wave function varies strongly with density. This result indicates that quark Cooper pairs become more bosonic at higher densities.
[ { "created": "Fri, 29 Oct 1999 08:43:48 GMT", "version": "v1" }, { "created": "Thu, 9 Mar 2000 09:01:19 GMT", "version": "v2" } ]
2009-10-31
[ [ "Matsuzaki", "Masayuki", "", "Fukuoka University of Education" ] ]
Spatial structure of Cooper pairs with quantum numbers color 3^*, I=J=L=S=0 in ud 2 flavor quark matter is studied by solving the gap equation and calculating the coherence length in full momentum range without the weak coupling approximation. Although the gap at the Fermi surface and the coherence length depend on density weakly, the shape of the r-space pair wave function varies strongly with density. This result indicates that quark Cooper pairs become more bosonic at higher densities.
2006.04640
Alessandra Filippi
Alessandra Filippi and Marzio De Napoli
Searching in the dark: the hunt for the dark photon
36 pages, 12 figures ~ Changes in new submission: Fig.12 caption, line 8: ref. [52] replaces [71] ~ Additional references suggested after proofs submission: about dark photon "thermal targets" and the definition of y: Izaguirre E. et al., Phys. Rev. Lett. 115 (2015), 251301 - about inelastic dark matter models: R. Foot and S. Vagnozzi, Phys. Rev. D 91 (2015) 023512; JCAP 1607 (2016) 013
Rev.Phys. 5 (2020) 100042
10.1016/j.revip.2020.100042
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence of Dark Matter (DM) is a well established fact since many decades, thanks to the observation of the effects of its gravitational interaction with the ordinary matter in the Universe. However, our knowledge of the Dark Matter features is still rather scarce. Indeed, one of the biggest quests in fundamental science today is the investigation of Dark Matter nature, from its origin to its composition, and the way its constituents interact with the ordinary matter, apart from gravity. Huge and ambitious efforts have been spent in the last years into its identification, concentrating especially on the search of viable Weakly Interacting Massive Particle candidates. However, no positive results have been achieved so far along this direction. On the other hand, many fascinating new ideas and models for its interpretation have been blooming: among them, an intriguing hypothesis is that the Dark Matter constituents could be neutral under Standard Model interactions, but they could interact through a new, still unknown, force under a "hidden" charge. This new hidden symmetry would be mediated by a massive gauge boson, the dark photon, which is expected to couple to the Standard Model via a kinetic mixing. The search for such a massive mediator has been pursued with large enthusiasm and dedication in the latest years, as its observation could be within the reach of many already existing experimental facilities, both based on accelerators
[ { "created": "Mon, 8 Jun 2020 14:41:09 GMT", "version": "v1" }, { "created": "Mon, 7 Sep 2020 10:55:22 GMT", "version": "v2" } ]
2020-09-08
[ [ "Filippi", "Alessandra", "" ], [ "De Napoli", "Marzio", "" ] ]
The existence of Dark Matter (DM) is a well established fact since many decades, thanks to the observation of the effects of its gravitational interaction with the ordinary matter in the Universe. However, our knowledge of the Dark Matter features is still rather scarce. Indeed, one of the biggest quests in fundamental science today is the investigation of Dark Matter nature, from its origin to its composition, and the way its constituents interact with the ordinary matter, apart from gravity. Huge and ambitious efforts have been spent in the last years into its identification, concentrating especially on the search of viable Weakly Interacting Massive Particle candidates. However, no positive results have been achieved so far along this direction. On the other hand, many fascinating new ideas and models for its interpretation have been blooming: among them, an intriguing hypothesis is that the Dark Matter constituents could be neutral under Standard Model interactions, but they could interact through a new, still unknown, force under a "hidden" charge. This new hidden symmetry would be mediated by a massive gauge boson, the dark photon, which is expected to couple to the Standard Model via a kinetic mixing. The search for such a massive mediator has been pursued with large enthusiasm and dedication in the latest years, as its observation could be within the reach of many already existing experimental facilities, both based on accelerators
1007.1913
Boris Kopeliovich
B. Z. Kopeliovich, H. J. Pirner, I. K. Potashnikova, and Ivan Schmidt
Mutual boosting of the saturation scales in colliding nuclei
12 pages, 4 figures. Extended version to be published in Phys. Lett. B
Phys.Lett.B697:333-338,2011
10.1016/j.physletb.2011.02.018
USM-TH-269
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Saturation of small-x gluons in a nucleus, which has the form of transverse momentum broadening of projectile gluons in pA collisions in the nuclear rest frame, leads to a modification of the parton distribution functions in the beam compared with pp collisions. The DGLAP driven gluon distribution turns out to be suppressed at large x, but significantly enhanced at x<<1. This is a high twist effect. In the case of nucleus-nucleus collisions all participating nucleons on both sides get enriched in gluon density at small x, which leads to a further boosting of the saturation scale. We derive reciprocity equations for the saturation scales corresponding to a collision of two nuclei. The solution of these equations for central collisions of two heavy nuclei demonstrate a significant, up to several times, enhancement of Q_{sA}^2, in AA compared with pA collisions.
[ { "created": "Mon, 12 Jul 2010 14:36:42 GMT", "version": "v1" }, { "created": "Fri, 4 Feb 2011 20:20:03 GMT", "version": "v2" } ]
2011-03-03
[ [ "Kopeliovich", "B. Z.", "" ], [ "Pirner", "H. J.", "" ], [ "Potashnikova", "I. K.", "" ], [ "Schmidt", "Ivan", "" ] ]
Saturation of small-x gluons in a nucleus, which has the form of transverse momentum broadening of projectile gluons in pA collisions in the nuclear rest frame, leads to a modification of the parton distribution functions in the beam compared with pp collisions. The DGLAP driven gluon distribution turns out to be suppressed at large x, but significantly enhanced at x<<1. This is a high twist effect. In the case of nucleus-nucleus collisions all participating nucleons on both sides get enriched in gluon density at small x, which leads to a further boosting of the saturation scale. We derive reciprocity equations for the saturation scales corresponding to a collision of two nuclei. The solution of these equations for central collisions of two heavy nuclei demonstrate a significant, up to several times, enhancement of Q_{sA}^2, in AA compared with pA collisions.
1511.04283
Rob Knoops
Ignatios Antoniadis, Rob Knoops
Gauging MSSM global symmetries and SUSY breaking in de Sitter vacuum
23 pages, 5 figures
null
10.1016/j.nuclphysb.2015.12.016
CERN-PH-TH-2015-268
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We elaborate on a recent study of a model of supersymmetry breaking we proposed recently, in the presence of a tunable positive cosmological constant, based on a gauged shift symmetry of a string modulus, external to the Standard Model (SM) sector. Here, we identify this symmetry with a global symmetry of the SM and work out the corresponding phenomenology. A particularly attracting possibility is to use a combination of Baryon and Lepton number that contains the known matter parity and guarantees absence of dimension-four and five operators that violate B and L.
[ { "created": "Fri, 13 Nov 2015 14:11:25 GMT", "version": "v1" } ]
2016-02-17
[ [ "Antoniadis", "Ignatios", "" ], [ "Knoops", "Rob", "" ] ]
We elaborate on a recent study of a model of supersymmetry breaking we proposed recently, in the presence of a tunable positive cosmological constant, based on a gauged shift symmetry of a string modulus, external to the Standard Model (SM) sector. Here, we identify this symmetry with a global symmetry of the SM and work out the corresponding phenomenology. A particularly attracting possibility is to use a combination of Baryon and Lepton number that contains the known matter parity and guarantees absence of dimension-four and five operators that violate B and L.
2111.15310
Christian Fischer
Nico Santowsky and Christian S. Fischer
Four-quark states with charm quarks in a two-body Bethe-Salpeter approach
9 pages, 4 figures; v2: minor changes, version accepted for EPJC
null
10.1140/epjc/s10052-022-10272-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the internal structure of a range of four-quark states with charm quark contributions using a two-body Bethe-Salpeter equation. Thereby, we examine charmonium-like states with hidden charm and quark content $c\bar{c}q\bar{q}$, open-charm states with quark content $cc\bar{q}\bar{q}$ and all-charm states with $cc\bar{c}\bar{c}$. In particular we study the internal competition between meson-meson components and diquark-antidiquark components in the wave functions of these states. Our results indicate that the $\chi_{c1}(3872)$ and the $Z_c(3900)$ are predominantly $D\bar D^*$ states and that the recently discovered open-charm state $T_{cc}^+$ is dominated by an internal $DD^*$ component. In both cases the diquark components are negligible. For the all-charm state $X(6900)$ with as yet unknown quantum numbers we identify candidates in the excitation spectra of $0^+$ and $1^+$ states. Furthermore, our framework serves to provide predictions for further, yet undiscovered open and hidden charm four-quark states.
[ { "created": "Tue, 30 Nov 2021 11:46:27 GMT", "version": "v1" }, { "created": "Thu, 7 Apr 2022 07:18:53 GMT", "version": "v2" } ]
2022-04-27
[ [ "Santowsky", "Nico", "" ], [ "Fischer", "Christian S.", "" ] ]
We study the internal structure of a range of four-quark states with charm quark contributions using a two-body Bethe-Salpeter equation. Thereby, we examine charmonium-like states with hidden charm and quark content $c\bar{c}q\bar{q}$, open-charm states with quark content $cc\bar{q}\bar{q}$ and all-charm states with $cc\bar{c}\bar{c}$. In particular we study the internal competition between meson-meson components and diquark-antidiquark components in the wave functions of these states. Our results indicate that the $\chi_{c1}(3872)$ and the $Z_c(3900)$ are predominantly $D\bar D^*$ states and that the recently discovered open-charm state $T_{cc}^+$ is dominated by an internal $DD^*$ component. In both cases the diquark components are negligible. For the all-charm state $X(6900)$ with as yet unknown quantum numbers we identify candidates in the excitation spectra of $0^+$ and $1^+$ states. Furthermore, our framework serves to provide predictions for further, yet undiscovered open and hidden charm four-quark states.
0709.1371
Emil Avsar
Emil Avsar
On the Dipole Swing and the Search for Frame Independence in the Dipole Model
null
JHEP0711:027,2007
10.1088/1126-6708/2007/11/027
null
hep-ph
null
Small-x evolution in QCD is conveniently described by Mueller's dipole model which, however, does not include saturation effects in a way consistent with boost invariance. In this paper we first show that the recently studied zero and one dimensional toy models exhibiting saturation and explicit boost invariance can be interpreted in terms positive definite k-> k+1 dipole vertices. Such k-> k+1 vertices can in the full model be generated by combining the usual dipole splitting with k-1 simultaneous dipole swings. We show that, for a system consisting of N dipoles, one needs to combine the dipole splitting with at most N-1 simultaneous swings in order to generate all colour correlations induced by the multiple dipole interactions.
[ { "created": "Mon, 10 Sep 2007 14:45:50 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2007 12:32:08 GMT", "version": "v2" } ]
2008-11-26
[ [ "Avsar", "Emil", "" ] ]
Small-x evolution in QCD is conveniently described by Mueller's dipole model which, however, does not include saturation effects in a way consistent with boost invariance. In this paper we first show that the recently studied zero and one dimensional toy models exhibiting saturation and explicit boost invariance can be interpreted in terms positive definite k-> k+1 dipole vertices. Such k-> k+1 vertices can in the full model be generated by combining the usual dipole splitting with k-1 simultaneous dipole swings. We show that, for a system consisting of N dipoles, one needs to combine the dipole splitting with at most N-1 simultaneous swings in order to generate all colour correlations induced by the multiple dipole interactions.
hep-ph/0410127
Yuri B. Ivanov
Yu.B. Ivanov, V.V. Skokov, V.D. Toneev
Equation of state of deconfined matter within dynamical quasiparticle description
18 pages, 11 figures, version accepted to Phys. Rev. D
Phys.Rev. D71 (2005) 014005
10.1103/PhysRevD.71.014005
null
hep-ph hep-lat nucl-th
null
A simple quasiparticle model, motivated by lowest-order perturbative QCD, is proposed. It is applied to interpret the lattice QCD equation of state. A reasonable reproduction of the lattice data is obtained. In contrast to existing quasiparticle models, the present model is formulated in dynamical rather than thermodynamical terms, and is easily applicable to a system with finite baryon density. In particular, the model simulates the confinement property.
[ { "created": "Fri, 8 Oct 2004 10:19:23 GMT", "version": "v1" }, { "created": "Mon, 13 Dec 2004 09:28:02 GMT", "version": "v2" } ]
2009-11-10
[ [ "Ivanov", "Yu. B.", "" ], [ "Skokov", "V. V.", "" ], [ "Toneev", "V. D.", "" ] ]
A simple quasiparticle model, motivated by lowest-order perturbative QCD, is proposed. It is applied to interpret the lattice QCD equation of state. A reasonable reproduction of the lattice data is obtained. In contrast to existing quasiparticle models, the present model is formulated in dynamical rather than thermodynamical terms, and is easily applicable to a system with finite baryon density. In particular, the model simulates the confinement property.
hep-ph/9905372
Marc Vanderhaeghen
M. Vanderhaeghen, P.A.M. Guichon and M. Guidal
Deeply virtual electroproduction of photons and mesons on the nucleon : leading order amplitudes and power corrections
59 pages, 21 figures
Phys.Rev. D60 (1999) 094017
10.1103/PhysRevD.60.094017
null
hep-ph
null
We estimate the leading order amplitudes for exclusive photon and meson electroproduction reactions at large Q^2 in the valence region in terms of skewed quark distributions. As experimental investigations can currently only be envisaged at moderate values of Q^2, we estimate power corrections due to the intrinsic transverse momentum of the partons in the meson wavefunction and in the nucleon. To this aim the skewed parton distribution formalism is generalized so as to include the parton intrinsic transverse momentum dependence. Furthermore, for the meson electroproduction reactions, we calculate the soft overlap type contributions and compare with the leading order amplitudes. We give first estimates for these different power corrections in kinematics which are relevant for experiments in the near future.
[ { "created": "Mon, 17 May 1999 18:28:57 GMT", "version": "v1" } ]
2016-09-06
[ [ "Vanderhaeghen", "M.", "" ], [ "Guichon", "P. A. M.", "" ], [ "Guidal", "M.", "" ] ]
We estimate the leading order amplitudes for exclusive photon and meson electroproduction reactions at large Q^2 in the valence region in terms of skewed quark distributions. As experimental investigations can currently only be envisaged at moderate values of Q^2, we estimate power corrections due to the intrinsic transverse momentum of the partons in the meson wavefunction and in the nucleon. To this aim the skewed parton distribution formalism is generalized so as to include the parton intrinsic transverse momentum dependence. Furthermore, for the meson electroproduction reactions, we calculate the soft overlap type contributions and compare with the leading order amplitudes. We give first estimates for these different power corrections in kinematics which are relevant for experiments in the near future.
0704.1103
Dr A. N. Mitra
A.N. Mitra
Spin Dynamics Of $qqq$ Wave Function On Light Front In High Momentum Limit Of QCD : Role Of $qqq$ Force
28 pages dvi with 1 figure
Annals Phys.323:845-865,2008
10.1016/j.aop.2007.05.008
null
hep-ph
null
The contribution of a spin-rich $qqq$ force (in conjunction with pairwise $qq$ forces) to the analytical structure of the $qqq$ wave function is worked out in the high momentum regime of QCD where the confining interaction may be ignored, so that the dominant effect is $Coulombic$. A distinctive feature of this study is that the spin-rich $qqq$ force is generated by a $ggg$ vertex (a genuine part of the QCD Lagrangian) wherein the 3 radiating gluon lines end on as many quark lines, giving rise to a (Mercedes-Benz type) $Y$-shaped diagram. The dynamics is that of a Salpeter-like equation (3D support for the kernel) formulated covariantly on the light front, a la Markov-Yukawa Transversality Principle (MYTP) which warrants a 2-way interconnection between the 3D and 4D Bethe-Salpeter (BSE) forms for 2 as well as 3 fermion quarks. With these ingredients, the differential equation for the 3D wave function $\phi$ receives well-defined contributions from the $qq$ and $qqq$ forces. In particular a $negative$ eigenvalue of the spin operator $i \sigma_1.\sigma_2\times \sigma_3$ which is an integral part of the $qqq$ force, causes a characteristic singularity in the differential equation, signalling the dynamical effect of a spin-rich $qqq$ force not yet considered in the literature. The potentially crucial role of this interesting effect vis-a-vis the so-called `spin anomaly' of the proton, is a subject of considerable physical interest.
[ { "created": "Mon, 9 Apr 2007 13:08:21 GMT", "version": "v1" } ]
2009-04-21
[ [ "Mitra", "A. N.", "" ] ]
The contribution of a spin-rich $qqq$ force (in conjunction with pairwise $qq$ forces) to the analytical structure of the $qqq$ wave function is worked out in the high momentum regime of QCD where the confining interaction may be ignored, so that the dominant effect is $Coulombic$. A distinctive feature of this study is that the spin-rich $qqq$ force is generated by a $ggg$ vertex (a genuine part of the QCD Lagrangian) wherein the 3 radiating gluon lines end on as many quark lines, giving rise to a (Mercedes-Benz type) $Y$-shaped diagram. The dynamics is that of a Salpeter-like equation (3D support for the kernel) formulated covariantly on the light front, a la Markov-Yukawa Transversality Principle (MYTP) which warrants a 2-way interconnection between the 3D and 4D Bethe-Salpeter (BSE) forms for 2 as well as 3 fermion quarks. With these ingredients, the differential equation for the 3D wave function $\phi$ receives well-defined contributions from the $qq$ and $qqq$ forces. In particular a $negative$ eigenvalue of the spin operator $i \sigma_1.\sigma_2\times \sigma_3$ which is an integral part of the $qqq$ force, causes a characteristic singularity in the differential equation, signalling the dynamical effect of a spin-rich $qqq$ force not yet considered in the literature. The potentially crucial role of this interesting effect vis-a-vis the so-called `spin anomaly' of the proton, is a subject of considerable physical interest.
2406.03931
C. J. A. P. Martins
J. R. C. C. C. Correia, C. J. A. P. Martins, F. C. N. Q. Pimenta
Evolution of current-carrying string networks
11 pages, 2 figures, 3 tables; to appear in Phys. Lett. B
null
null
null
hep-ph astro-ph.CO physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmic string networks are expected to form in early Universe phase transitions via the Kibble mechanism and are unavoidable in several Beyond the Standard Model theories. While most predictions of observational signals of string networks assume featureless Abelian-Higgs or Nambu-Goto string networks, in many such extensions the networks can carry additional degrees of freedom, including charges and currents; these are often generically known as superconducting strings. All such degrees of freedom can impact the evolution of the networks and therefore their observational signatures. We report on the results of $2048^3$ field theory simulations of the evolution of a current-carrying network of strings, highlighting the different scaling behaviours of the network in the radiation and matter eras. We also report the first numerical measurements of the coherence length scales for the charge and current and of the condensate equation of state, and show that the latter mainly depends on the expansion rate, with chirality occurring for the matter era. Qualitatively, the fact that the matter era is the optimal expansion rate for these networks to reach scaling is in agreement with recent analytic modeling.
[ { "created": "Thu, 6 Jun 2024 10:17:35 GMT", "version": "v1" } ]
2024-06-07
[ [ "Correia", "J. R. C. C. C.", "" ], [ "Martins", "C. J. A. P.", "" ], [ "Pimenta", "F. C. N. Q.", "" ] ]
Cosmic string networks are expected to form in early Universe phase transitions via the Kibble mechanism and are unavoidable in several Beyond the Standard Model theories. While most predictions of observational signals of string networks assume featureless Abelian-Higgs or Nambu-Goto string networks, in many such extensions the networks can carry additional degrees of freedom, including charges and currents; these are often generically known as superconducting strings. All such degrees of freedom can impact the evolution of the networks and therefore their observational signatures. We report on the results of $2048^3$ field theory simulations of the evolution of a current-carrying network of strings, highlighting the different scaling behaviours of the network in the radiation and matter eras. We also report the first numerical measurements of the coherence length scales for the charge and current and of the condensate equation of state, and show that the latter mainly depends on the expansion rate, with chirality occurring for the matter era. Qualitatively, the fact that the matter era is the optimal expansion rate for these networks to reach scaling is in agreement with recent analytic modeling.
hep-ph/0101084
Nick van Eijndhoven
Nick van Eijndhoven and Wouter Wetzels
In-event background and signal reconstruction for two-photon invariant-mass analyses
null
Nucl.Instrum.Meth. A482 (2002) 513-519
10.1016/S0168-9002(01)01558-3
null
hep-ph
null
A method is presented for the reconstruction of both the background and signal in invariant-mass analyses for two-photon decays. The procedure does not make use of event mixing techniques and as such is based exclusively on an event-by-event analysis. Consequently, topological correlations of the event (e.g. jet structures) are automatically taken into account. By means of the decay process $\pi^{0} \to \gamma \gamma$ it will be demonstrated how the procedure allows for determination of the $\pi^{0}$ yield from the observed decay photons.
[ { "created": "Tue, 9 Jan 2001 17:55:01 GMT", "version": "v1" } ]
2009-11-07
[ [ "van Eijndhoven", "Nick", "" ], [ "Wetzels", "Wouter", "" ] ]
A method is presented for the reconstruction of both the background and signal in invariant-mass analyses for two-photon decays. The procedure does not make use of event mixing techniques and as such is based exclusively on an event-by-event analysis. Consequently, topological correlations of the event (e.g. jet structures) are automatically taken into account. By means of the decay process $\pi^{0} \to \gamma \gamma$ it will be demonstrated how the procedure allows for determination of the $\pi^{0}$ yield from the observed decay photons.
2101.01958
Bing-Dong Wan
Rui Ding, Bing-Dong Wan, Zi-Qiang Chen, Guo-Li Wang, and Cong-Feng Qiao
Finding $B_c(3S)$ States via Their Strong Decays
10 pages, 1 figure, to appear in PLB
null
10.1016/j.physletb.2021.136277
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The experimentally known $B_c$ states are all below open bottom-charm threshold, which experience three main decay modes, and all induced by weak interaction. In this work, we investigate the mass spectrum and strong decays of the $B_c(3S)$ states, which just above the threshold, in the Bethe-Salpeter formalism and $^3P_0$ model. The numerical estimation gives $M(B_c(3^1S_0))=7273\ {\rm MeV}$, $M(B_c^*(3^3S_1))=7304\ {\rm MeV}$, $\Gamma\left(B_c(3^1S_0)\to B^*D\right)=26.02^{+2.33}_{-2.21}\ {\rm MeV}$, $\Gamma\left(B_c^*(3^3S_1)\to BD\right)=3.39^{+0.27}_{-0.26}\ {\rm MeV}$, $\Gamma\left(B_c^*(3^3S_1)\to B^*D\right)=14.77^{+1.40}_{-1.33}\ {\rm MeV}$ and $\Gamma\left(B_c^*(3^3S_1)\to BD^*\right)=6.14^{+0.58}_{-0.54}\ {\rm MeV}$. Compared with previous studies in non-relativistic approximation, our results indicate that the relativistic effects are notable in $B_c(3S)$ exclusive strong decays. According to the results, we suggest to find the $B_c(3S)$ states in their hadronic decays to $B$ and $D$ mesons in experiment, like the LHCb.
[ { "created": "Wed, 6 Jan 2021 10:32:37 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2021 12:17:07 GMT", "version": "v2" } ]
2021-04-14
[ [ "Ding", "Rui", "" ], [ "Wan", "Bing-Dong", "" ], [ "Chen", "Zi-Qiang", "" ], [ "Wang", "Guo-Li", "" ], [ "Qiao", "Cong-Feng", "" ] ]
The experimentally known $B_c$ states are all below open bottom-charm threshold, which experience three main decay modes, and all induced by weak interaction. In this work, we investigate the mass spectrum and strong decays of the $B_c(3S)$ states, which just above the threshold, in the Bethe-Salpeter formalism and $^3P_0$ model. The numerical estimation gives $M(B_c(3^1S_0))=7273\ {\rm MeV}$, $M(B_c^*(3^3S_1))=7304\ {\rm MeV}$, $\Gamma\left(B_c(3^1S_0)\to B^*D\right)=26.02^{+2.33}_{-2.21}\ {\rm MeV}$, $\Gamma\left(B_c^*(3^3S_1)\to BD\right)=3.39^{+0.27}_{-0.26}\ {\rm MeV}$, $\Gamma\left(B_c^*(3^3S_1)\to B^*D\right)=14.77^{+1.40}_{-1.33}\ {\rm MeV}$ and $\Gamma\left(B_c^*(3^3S_1)\to BD^*\right)=6.14^{+0.58}_{-0.54}\ {\rm MeV}$. Compared with previous studies in non-relativistic approximation, our results indicate that the relativistic effects are notable in $B_c(3S)$ exclusive strong decays. According to the results, we suggest to find the $B_c(3S)$ states in their hadronic decays to $B$ and $D$ mesons in experiment, like the LHCb.
hep-ph/9604278
Ralf Hempfling
Ralf Hempfling
The Next-to-Minimal Coleman-Weinberg Model
LaTeX typo corrected. 9 pages, 3 figs
Phys.Lett. B379 (1996) 153-158
10.1016/0370-2693(96)00446-7
MPI-PhT/96-03
hep-ph
null
In the standard model (SM) the condition that the Higgs mass parameter vanishes is stable under radiative corrections and yields a theory that can be renormalized using dimensional regularization. Thus, this model allows to predict the Higgs boson mass. However, it is phenomenologically ruled out in its minimal version. Here, we present a phenomenologically viable, minimal extension which only includes an additional SM singlet and a U(1)$_X$ gauge symmetry.
[ { "created": "Wed, 10 Apr 1996 07:33:44 GMT", "version": "v1" }, { "created": "Thu, 11 Apr 1996 15:14:52 GMT", "version": "v2" } ]
2009-10-28
[ [ "Hempfling", "Ralf", "" ] ]
In the standard model (SM) the condition that the Higgs mass parameter vanishes is stable under radiative corrections and yields a theory that can be renormalized using dimensional regularization. Thus, this model allows to predict the Higgs boson mass. However, it is phenomenologically ruled out in its minimal version. Here, we present a phenomenologically viable, minimal extension which only includes an additional SM singlet and a U(1)$_X$ gauge symmetry.
1402.0777
Jialun Ping
Chengrong Deng, Jialun Ping, Fan Wang
Interpreting $Z_c(3900)$ and $Z_c(4025)/Z_c(4020)$ as charged tetraquark states
8 pages, no figure
Phys. Rev. D 90, 054009 (2014)
10.1103/PhysRevD.90.054009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of color flux-tube model with a four-body confinement potential, the lowest charged tetraquark states $[Qq][\bar{Q}'\bar{q}']~(Q=c,b,q=u,d,s)$ are studied by using the variational method, Gaussian expansion method. The results indicate that some compact resonance states can be formed, the states can not decay into two color singlet mesons $Q\bar{q}'$ and $\bar{Q}'q$ through the breakdown and recombination of color flux tubes but into $Q\bar{Q}'$ and $q\bar{q}'$. The four-body confinement potential is an crucial dynamical mechanism for the formation of states, The decay mechanism is similar to that of compound nucleus and therefore the states should be called "color confined, multi-quark resonance" states. The newly observed charged states $Z_c(3900)$ and $Z_c(4025)/Z_c(4020)$ can be accommodated in the color flux-tube model and can be interpreted as the $S$-wave tetraquark states $[cu][{\bar{c}\bar{d}}]$ with quantum numbers $I=1$ and $J=1$ and 2, respectively.
[ { "created": "Tue, 4 Feb 2014 15:52:26 GMT", "version": "v1" } ]
2014-09-17
[ [ "Deng", "Chengrong", "" ], [ "Ping", "Jialun", "" ], [ "Wang", "Fan", "" ] ]
In the framework of color flux-tube model with a four-body confinement potential, the lowest charged tetraquark states $[Qq][\bar{Q}'\bar{q}']~(Q=c,b,q=u,d,s)$ are studied by using the variational method, Gaussian expansion method. The results indicate that some compact resonance states can be formed, the states can not decay into two color singlet mesons $Q\bar{q}'$ and $\bar{Q}'q$ through the breakdown and recombination of color flux tubes but into $Q\bar{Q}'$ and $q\bar{q}'$. The four-body confinement potential is an crucial dynamical mechanism for the formation of states, The decay mechanism is similar to that of compound nucleus and therefore the states should be called "color confined, multi-quark resonance" states. The newly observed charged states $Z_c(3900)$ and $Z_c(4025)/Z_c(4020)$ can be accommodated in the color flux-tube model and can be interpreted as the $S$-wave tetraquark states $[cu][{\bar{c}\bar{d}}]$ with quantum numbers $I=1$ and $J=1$ and 2, respectively.
1604.07975
Matthew McCullough
Christoph Englert, Matthew McCullough, and Michael Spannowsky
S-Channel Dark Matter Simplified Models and Unitarity
15 pages
null
null
DCPT/16/52, IPPP/16/26, CERN-TH-2016-094
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ultraviolet structure of $s$-channel mediator dark matter simplified models at hadron colliders is considered. In terms of commonly studied $s$-channel mediator simplified models it is argued that at arbitrarily high energies the perturbative description of dark matter production in high energy scattering at hadron colliders will break down in a number of cases. This is analogous to the well documented breakdown of an EFT description of dark matter collider production. With this in mind, to diagnose whether or not the use of simplified models at the LHC is valid, perturbative unitarity of the scattering amplitude in the processes relevant to LHC dark matter searches is studied. The results are as one would expect: at the LHC and future proton colliders the simplified model descriptions of dark matter production are in general valid. As a result of the general discussion, a simple new class of previously unconsidered `Fermiophobic Scalar' simplified models is proposed, in which a scalar mediator couples to electroweak vector bosons. The Fermiophobic simplified model is well motivated and exhibits interesting collider and direct detection phenomenology.
[ { "created": "Wed, 27 Apr 2016 08:41:18 GMT", "version": "v1" } ]
2016-04-28
[ [ "Englert", "Christoph", "" ], [ "McCullough", "Matthew", "" ], [ "Spannowsky", "Michael", "" ] ]
The ultraviolet structure of $s$-channel mediator dark matter simplified models at hadron colliders is considered. In terms of commonly studied $s$-channel mediator simplified models it is argued that at arbitrarily high energies the perturbative description of dark matter production in high energy scattering at hadron colliders will break down in a number of cases. This is analogous to the well documented breakdown of an EFT description of dark matter collider production. With this in mind, to diagnose whether or not the use of simplified models at the LHC is valid, perturbative unitarity of the scattering amplitude in the processes relevant to LHC dark matter searches is studied. The results are as one would expect: at the LHC and future proton colliders the simplified model descriptions of dark matter production are in general valid. As a result of the general discussion, a simple new class of previously unconsidered `Fermiophobic Scalar' simplified models is proposed, in which a scalar mediator couples to electroweak vector bosons. The Fermiophobic simplified model is well motivated and exhibits interesting collider and direct detection phenomenology.
hep-ph/9805495
Matthias Burkardt
M. Burkardt and H.El-Khozondar (New Mexico State University)
Wilson Fermions on a Transverse Lattice
14 pages, RevTeX
Phys.Rev. D60 (1999) 054504
10.1103/PhysRevD.60.054504
null
hep-ph
null
In the light-front formulation of field theory, it is possible to write down a chirally invariant mass term. It thus appears as if one could solve the species doubling problem on a light-front quantized transverse lattice in a chirally invariant way. However, upon introducing link fields and after renormalizing, one finds exactly the same LF Hamiltonian as if one had started from the standard Wilson action in the first place. The (light-front) chirally invariant transverse lattice regularization is thus not chirally invariant in the conventional sense. As an application of the Wilson formulation for fermions on a $\perp$ lattice, we calculate spectrum, distribution functions and distribution amplitudes for mesons below $2 GeV$ in a truncated Fock space.
[ { "created": "Thu, 28 May 1998 19:08:59 GMT", "version": "v1" } ]
2009-10-31
[ [ "Burkardt", "M.", "", "New Mexico State University" ], [ "El-Khozondar", "H.", "", "New Mexico State University" ] ]
In the light-front formulation of field theory, it is possible to write down a chirally invariant mass term. It thus appears as if one could solve the species doubling problem on a light-front quantized transverse lattice in a chirally invariant way. However, upon introducing link fields and after renormalizing, one finds exactly the same LF Hamiltonian as if one had started from the standard Wilson action in the first place. The (light-front) chirally invariant transverse lattice regularization is thus not chirally invariant in the conventional sense. As an application of the Wilson formulation for fermions on a $\perp$ lattice, we calculate spectrum, distribution functions and distribution amplitudes for mesons below $2 GeV$ in a truncated Fock space.
1004.0087
A. V. Luchinsky
A.K. Likhoded, A.V. Luchinsky
Light hadron production in $B_{c}\to B_{s}^{(*)}+X$ decays
minor changes, some references added
Phys.Rev.D82:014012,2010
10.1103/PhysRevD.82.014012
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The article is devoted to Bc->Bs+n pi, Bc->Bs*+n pi decays with n=1, 2, 3, 4. In the framework of factorization theorem the branching fractions of these processes can be written as convolution of hard part, describing Bc->Bs W, Bc->Bs* W vertices, and spectral functions, that correspond to transition of virtual $W$-boson into a final pi-meson system. These functions were obtained from the fit of experimental data on $\tau$-lepton decay and electron-positron annihilation. Using different sets of Bc->Bs decay form-factors we present branching fractions and distributions over the invariant mass of the final pi-meson system.
[ { "created": "Thu, 1 Apr 2010 09:13:39 GMT", "version": "v1" }, { "created": "Fri, 7 May 2010 09:07:04 GMT", "version": "v2" } ]
2015-03-13
[ [ "Likhoded", "A. K.", "" ], [ "Luchinsky", "A. V.", "" ] ]
The article is devoted to Bc->Bs+n pi, Bc->Bs*+n pi decays with n=1, 2, 3, 4. In the framework of factorization theorem the branching fractions of these processes can be written as convolution of hard part, describing Bc->Bs W, Bc->Bs* W vertices, and spectral functions, that correspond to transition of virtual $W$-boson into a final pi-meson system. These functions were obtained from the fit of experimental data on $\tau$-lepton decay and electron-positron annihilation. Using different sets of Bc->Bs decay form-factors we present branching fractions and distributions over the invariant mass of the final pi-meson system.
hep-ph/9403255
null
Hitoshi Yamamoto
Isospin Analysis of Two-body B Decays and Test of Factorization
8 pages, HUTP94/A006
null
null
null
hep-ph
null
It is shown that the existing data on two-body B decays, some of them only upper limits, are precise enough to perform an isospin analysis to extract the phase shifts due to final state interaction. Unlike charm decays, no significant final state interaction is observed in decays $B\to D\pi, D\rho$, and $D^*\pi$ supporting the factorization hypothesis in these decays. By fitting directly the isospin amplitudes obtained, we extract the ratio $a_2/a_1$, where $a_1$ and $a_2$ are the coefficients in the factorized effective Hamiltonian.
[ { "created": "Wed, 9 Mar 1994 19:26:19 GMT", "version": "v1" } ]
2009-09-25
[ [ "Yamamoto", "Hitoshi", "" ] ]
It is shown that the existing data on two-body B decays, some of them only upper limits, are precise enough to perform an isospin analysis to extract the phase shifts due to final state interaction. Unlike charm decays, no significant final state interaction is observed in decays $B\to D\pi, D\rho$, and $D^*\pi$ supporting the factorization hypothesis in these decays. By fitting directly the isospin amplitudes obtained, we extract the ratio $a_2/a_1$, where $a_1$ and $a_2$ are the coefficients in the factorized effective Hamiltonian.
0705.2510
Daniele Dominici
R. Casalbuoni, S. De Curtis, D. Dominici and D. Dolce
Holographic approach to a minimal Higgsless model
Latex file, 23 pages
JHEP 0708:053,2007
10.1088/1126-6708/2007/08/053
null
hep-ph hep-th
null
In this work, following an holographic approach, we carry out a low energy effective study of a minimal Higgsless model based on SU(2) bulk symmetry broken by boundary conditions, both in flat and warped metric. The holographic procedure turns out to be an useful computation technique to achieve an effective four dimensional formulation of the model taking into account the corrections coming from the extra dimensional sector. This technique is used to compute both oblique and direct contributions to the electroweak parameters in presence of fermions delocalized along the fifth dimension.
[ { "created": "Thu, 17 May 2007 11:06:24 GMT", "version": "v1" } ]
2009-04-21
[ [ "Casalbuoni", "R.", "" ], [ "De Curtis", "S.", "" ], [ "Dominici", "D.", "" ], [ "Dolce", "D.", "" ] ]
In this work, following an holographic approach, we carry out a low energy effective study of a minimal Higgsless model based on SU(2) bulk symmetry broken by boundary conditions, both in flat and warped metric. The holographic procedure turns out to be an useful computation technique to achieve an effective four dimensional formulation of the model taking into account the corrections coming from the extra dimensional sector. This technique is used to compute both oblique and direct contributions to the electroweak parameters in presence of fermions delocalized along the fifth dimension.
hep-ph/0001219
Mary K. Gaillard
Mary K. Gaillard and Joel Giedt
A D-moduli problem?
11 pages, full postscript also available from http://phyweb.lbl.gov/theorygroup/papers/44856.ps
Phys.Lett.B479:308-314,2000
10.1016/S0370-2693(00)00336-1
LBNL-44856, UCB-PTH-00/02
hep-ph hep-th
null
We point out a generic problem in string-inspired supergravity models with an anomalous $U(1)_X$. A large number of matter multiplets charged under $U(1)_X$ remain massless above the supersymmetry-breaking scale because of degeneracy of vacua solving the D-flatness conditions. A toy model is analyzed as an illustration of the mechanism; we find the surprising result that many scalars remain massless after supersymmetry-breaking in a hidden sector.
[ { "created": "Thu, 20 Jan 2000 23:14:35 GMT", "version": "v1" } ]
2014-11-17
[ [ "Gaillard", "Mary K.", "" ], [ "Giedt", "Joel", "" ] ]
We point out a generic problem in string-inspired supergravity models with an anomalous $U(1)_X$. A large number of matter multiplets charged under $U(1)_X$ remain massless above the supersymmetry-breaking scale because of degeneracy of vacua solving the D-flatness conditions. A toy model is analyzed as an illustration of the mechanism; we find the surprising result that many scalars remain massless after supersymmetry-breaking in a hidden sector.
1407.7374
Michael Gronau
Mchael Gronau
New physics in singly Cabibbo-suppressed D decays
References added, to be published in Physics Letters B
null
10.1016/j.physletb.2014.09.034
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A U-spin relation among four ratios of amplitudes for $D^0 \to \pi^+K^-$, $K^+\pi^-$, $K^+K^-, \pi^+\pi^-$, including first, second and third order U-spin breaking, has been derived recently with a precision of $10^{-3}$. We study effects of new $|\Delta C|=1$ operators on this relation. We find that it is not affected by U-spin scalar operators, including QCD penguin and chromomagnetic dipole operators occurring in supersymmetric and extra-dimensional models. The relation is modified by new $U=1$ operators with a sensitivity of a few percent characteristic of second order U-spin breaking. Combining this relation with CP asymmetries in $D^0\to K^+K^-, \pi^+\pi^-$ leads to a more solid constraint on $U=1$ operators than from asymmetries alone.
[ { "created": "Mon, 28 Jul 2014 10:23:55 GMT", "version": "v1" }, { "created": "Tue, 2 Sep 2014 14:46:23 GMT", "version": "v2" } ]
2014-09-24
[ [ "Gronau", "Mchael", "" ] ]
A U-spin relation among four ratios of amplitudes for $D^0 \to \pi^+K^-$, $K^+\pi^-$, $K^+K^-, \pi^+\pi^-$, including first, second and third order U-spin breaking, has been derived recently with a precision of $10^{-3}$. We study effects of new $|\Delta C|=1$ operators on this relation. We find that it is not affected by U-spin scalar operators, including QCD penguin and chromomagnetic dipole operators occurring in supersymmetric and extra-dimensional models. The relation is modified by new $U=1$ operators with a sensitivity of a few percent characteristic of second order U-spin breaking. Combining this relation with CP asymmetries in $D^0\to K^+K^-, \pi^+\pi^-$ leads to a more solid constraint on $U=1$ operators than from asymmetries alone.
1607.01504
Vladimir Braun M
I.V. Anikin, V.M. Braun, N. Offen
Axial form factor of the nucleon at large momentum transfers
A comparison to the new neutrino data analysis and several references added. Final version to appear in Phys.Rev.D
Phys. Rev. D 94, 034011 (2016)
10.1103/PhysRevD.94.034011
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the emerging possibilities to study threshold pion electroproduction at large momentum transfers at Jefferson Laboratory following the 12 GeV upgrade, we provide a short theory summary and an estimate of the nucleon axial form factor for large virtualities in the $Q^2 = 1-10~\text{GeV}^2$ range using next-to-leading order light-cone sum rules.
[ { "created": "Wed, 6 Jul 2016 08:11:16 GMT", "version": "v1" }, { "created": "Wed, 27 Jul 2016 09:48:53 GMT", "version": "v2" } ]
2016-08-10
[ [ "Anikin", "I. V.", "" ], [ "Braun", "V. M.", "" ], [ "Offen", "N.", "" ] ]
Motivated by the emerging possibilities to study threshold pion electroproduction at large momentum transfers at Jefferson Laboratory following the 12 GeV upgrade, we provide a short theory summary and an estimate of the nucleon axial form factor for large virtualities in the $Q^2 = 1-10~\text{GeV}^2$ range using next-to-leading order light-cone sum rules.
hep-ph/0301259
Scott Chapman
Dr. Scott Chapman
New Exact Solutions for QCD
19 pages, no figures, clarified Lorentz invariance, extremum conditions
null
null
null
hep-ph
null
A new class of exact quantum solutions of QCD is presented. These solutions have negative energy and are stable to all fluctuations. The lowest-energy solution state is explicitly constructed and proposed as a candidate for the QCD vacuum. This vacuum exhibits confinement in the sense that any colored quark configurations require infinite energy to create. In addition to the vacuum, other solutions include hadrons whose mass and radius are self-consistently determined as local minima of the energy.
[ { "created": "Thu, 30 Jan 2003 04:49:44 GMT", "version": "v1" }, { "created": "Thu, 6 Feb 2003 02:44:15 GMT", "version": "v2" } ]
2007-05-23
[ [ "Chapman", "Dr. Scott", "" ] ]
A new class of exact quantum solutions of QCD is presented. These solutions have negative energy and are stable to all fluctuations. The lowest-energy solution state is explicitly constructed and proposed as a candidate for the QCD vacuum. This vacuum exhibits confinement in the sense that any colored quark configurations require infinite energy to create. In addition to the vacuum, other solutions include hadrons whose mass and radius are self-consistently determined as local minima of the energy.
1607.07106
Artru
X. Artru, Z. Belghobsi, and E. Redouane-Salah
Transverse momentum correlations of quarks in recursive jet models
7 pages, 3 figures, 1 table
Phys. Rev. D 94, 034034 (2016)
10.1103/PhysRevD.94.034034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the symmetric string fragmentation recipe adopted by PYTHIA for jet simulations, the transverse momenta of successive quarks are uncorrelated. This is a simplification but has no theoretical reason. Transverse momentum correlations are naturally expected, for instance, in a covariant multiperipheral model of quark hadronization. We propose a simple recipe of string fragmentation which lead to such correlations. The definition of the jet axis and its relation with the primordial transverse momentum of the quark is also discussed.
[ { "created": "Sun, 24 Jul 2016 22:34:15 GMT", "version": "v1" }, { "created": "Thu, 11 Aug 2016 07:26:11 GMT", "version": "v2" } ]
2016-08-31
[ [ "Artru", "X.", "" ], [ "Belghobsi", "Z.", "" ], [ "Redouane-Salah", "E.", "" ] ]
In the symmetric string fragmentation recipe adopted by PYTHIA for jet simulations, the transverse momenta of successive quarks are uncorrelated. This is a simplification but has no theoretical reason. Transverse momentum correlations are naturally expected, for instance, in a covariant multiperipheral model of quark hadronization. We propose a simple recipe of string fragmentation which lead to such correlations. The definition of the jet axis and its relation with the primordial transverse momentum of the quark is also discussed.
2110.10177
Henning Bahl
Henning Bahl, Simon Brass
Constraining CP-violation in the Higgs-top-quark interaction using machine-learning-based inference
23 pages, 4 figures; v2: matches JHEP version
null
10.1007/JHEP03(2022)017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While CP violation in the Higgs interactions with massive vector boson is already tightly constrained, the CP nature of the Higgs interactions with fermions is far less constrained. In this work, we assess the potential of machine-learning-based inference methods to constrain CP violation in the Higgs top-Yukawa coupling. This approach enables the use of the full available kinematic information. Concentrating on top-associated Higgs production with the Higgs decaying to two photons, we derive expected exclusion bounds for the LHC and the high-luminosity phase of the LHC. We also study the dependence of these bounds on the Higgs interaction with massive vector bosons and their robustness against theoretical uncertainties. In addition to deriving expected exclusion bounds, we discuss at which level a non-zero CP-violating top-Yukawa coupling can be distinguished from the SM. Moreover, we analyze which kinematic distributions are most sensitive to a CP-violating top-Yukawa coupling.
[ { "created": "Tue, 19 Oct 2021 18:00:04 GMT", "version": "v1" }, { "created": "Tue, 1 Mar 2022 03:33:54 GMT", "version": "v2" } ]
2022-03-23
[ [ "Bahl", "Henning", "" ], [ "Brass", "Simon", "" ] ]
While CP violation in the Higgs interactions with massive vector boson is already tightly constrained, the CP nature of the Higgs interactions with fermions is far less constrained. In this work, we assess the potential of machine-learning-based inference methods to constrain CP violation in the Higgs top-Yukawa coupling. This approach enables the use of the full available kinematic information. Concentrating on top-associated Higgs production with the Higgs decaying to two photons, we derive expected exclusion bounds for the LHC and the high-luminosity phase of the LHC. We also study the dependence of these bounds on the Higgs interaction with massive vector bosons and their robustness against theoretical uncertainties. In addition to deriving expected exclusion bounds, we discuss at which level a non-zero CP-violating top-Yukawa coupling can be distinguished from the SM. Moreover, we analyze which kinematic distributions are most sensitive to a CP-violating top-Yukawa coupling.
1309.1955
Wei-Min Yang
Wei-Min Yang
The Matter-Antimatter Asymmetry and Cold Dark Matter from The Left-Right Mirror Symmetric Model with The Global $U(1)_{B-L}\otimes U(1)_{D}$
23 pages, 5 figures, the paper is revised and added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper suggests a left-right mirror symmetric model with the global $U(1)_{B-L}\otimes U(1)_{D}$ symmetries. The model can simultaneously accommodate the standard model, neutrino physics, matter-antimatter asymmetry and cold dark matter. The model naturally and elegantly accounts for the origin of the tiny neutrino mass, matter-antimatter asymmetry and cold dark matter. In particular, it predicts a number of interesting results, e.g. a right-handed neutrino asymmetry and a dark Goldstone boson. It is also feasible and promising to test the model in future experiments.
[ { "created": "Sun, 8 Sep 2013 13:15:43 GMT", "version": "v1" }, { "created": "Wed, 9 Oct 2013 02:45:35 GMT", "version": "v2" }, { "created": "Mon, 9 Dec 2013 14:06:55 GMT", "version": "v3" }, { "created": "Wed, 15 Jan 2014 01:27:49 GMT", "version": "v4" }, { "crea...
2014-03-05
[ [ "Yang", "Wei-Min", "" ] ]
The paper suggests a left-right mirror symmetric model with the global $U(1)_{B-L}\otimes U(1)_{D}$ symmetries. The model can simultaneously accommodate the standard model, neutrino physics, matter-antimatter asymmetry and cold dark matter. The model naturally and elegantly accounts for the origin of the tiny neutrino mass, matter-antimatter asymmetry and cold dark matter. In particular, it predicts a number of interesting results, e.g. a right-handed neutrino asymmetry and a dark Goldstone boson. It is also feasible and promising to test the model in future experiments.
2302.05566
Parada Hutauruk T. P.
Parada T. P. Hutauruk, Seung-il Nam
Updated analyses of gluon distribution functions for the pion and kaon from the gauge-invariant nonlocal chiral quark model
9 pages, 2 tables, 6 figures, REVTeX
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
In this work, we investigate the gluon distribution functions for the pion and kaon, in addition to the improved result of the valence-quark ones, in the gauge-invariant nonlocal chiral-quark model (NL$\chi$QM), in which the momentum dependence of the quark interactions is properly taken into account. We then analyze the gluon distribution functions, generated dynamically through the splitting functions in the DGLAP QCD evolution. By comparing with the recent lattice QCD results and JAM global analyses, it is found that the present numerical results for the gluon parton distribution functions for the pion exhibit a remarkable agreement, followed by the valence up-quark distribution results for the pion by reproducing the reanalyzed experimental data. Our prediction on the gluon distribution functions for the kaon is also consistent with the recent lattice data for the kaon within the errors.
[ { "created": "Sat, 11 Feb 2023 02:01:46 GMT", "version": "v1" } ]
2023-02-14
[ [ "Hutauruk", "Parada T. P.", "" ], [ "Nam", "Seung-il", "" ] ]
In this work, we investigate the gluon distribution functions for the pion and kaon, in addition to the improved result of the valence-quark ones, in the gauge-invariant nonlocal chiral-quark model (NL$\chi$QM), in which the momentum dependence of the quark interactions is properly taken into account. We then analyze the gluon distribution functions, generated dynamically through the splitting functions in the DGLAP QCD evolution. By comparing with the recent lattice QCD results and JAM global analyses, it is found that the present numerical results for the gluon parton distribution functions for the pion exhibit a remarkable agreement, followed by the valence up-quark distribution results for the pion by reproducing the reanalyzed experimental data. Our prediction on the gluon distribution functions for the kaon is also consistent with the recent lattice data for the kaon within the errors.
hep-ph/9711364
Erwin Mirkes
J.H. Kuehn and E. Mirkes
CP Violation from Charged Higgs Exchange in Hadronic Tau Decays with Unpolarized Beams
Talk given by E. Mirkes at the International Europhysics Conference on High-Energy Physics (HEP 97), Jerusalem, Israel, 19-26 Aug 1997. Latex, 4 pages. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
null
null
TTP97-48
hep-ph
null
CP violating signals in semileptonic $\tau$ decays induced by an exotic scalar exchange are studied in a completely model-independent way. These can be observed in decays of unpolarized single $\tau$'s even if their rest frame cannot be reconstructed. No beam polarization is required. The importance of the two-meson channel, in particular the $K\pi$ final state is emphasized.
[ { "created": "Tue, 18 Nov 1997 09:59:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kuehn", "J. H.", "" ], [ "Mirkes", "E.", "" ] ]
CP violating signals in semileptonic $\tau$ decays induced by an exotic scalar exchange are studied in a completely model-independent way. These can be observed in decays of unpolarized single $\tau$'s even if their rest frame cannot be reconstructed. No beam polarization is required. The importance of the two-meson channel, in particular the $K\pi$ final state is emphasized.
2405.03749
Pavel Fileviez Perez
Jon Butterworth, Hridoy Debnath, Pavel Fileviez Perez, Yoran Yeh
Dark Matter from Anomaly Cancellation at the LHC
null
null
null
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a class of theories that predict a fermionic dark matter candidate from gauge anomaly cancellation. As an explicit example, we study the predictions in theories where the global symmetry associated with baryon number is promoted to a local gauge symmetry. In this context the symmetry-breaking scale has to be below the multi-TeV scale in order to be in agreement with the cosmological constraints on the dark matter relic density. The new physical "Cucuyo" Higgs boson in the theory has very interesting properties, decaying mainly into two photons in the low mass region, and mainly into dark matter in the intermediate mass region. We study the most important signatures at the Large Hadron Collider, evaluating the experimental bounds. We discuss the correlation between the dark matter relic density, direct detection and collider constraints. We find that these theories are still viable, and are susceptible to being probed in current, and future high-luminosity, running.
[ { "created": "Mon, 6 May 2024 18:00:01 GMT", "version": "v1" } ]
2024-05-13
[ [ "Butterworth", "Jon", "" ], [ "Debnath", "Hridoy", "" ], [ "Perez", "Pavel Fileviez", "" ], [ "Yeh", "Yoran", "" ] ]
We discuss a class of theories that predict a fermionic dark matter candidate from gauge anomaly cancellation. As an explicit example, we study the predictions in theories where the global symmetry associated with baryon number is promoted to a local gauge symmetry. In this context the symmetry-breaking scale has to be below the multi-TeV scale in order to be in agreement with the cosmological constraints on the dark matter relic density. The new physical "Cucuyo" Higgs boson in the theory has very interesting properties, decaying mainly into two photons in the low mass region, and mainly into dark matter in the intermediate mass region. We study the most important signatures at the Large Hadron Collider, evaluating the experimental bounds. We discuss the correlation between the dark matter relic density, direct detection and collider constraints. We find that these theories are still viable, and are susceptible to being probed in current, and future high-luminosity, running.
0706.1457
Robi Peschanski
Guillaume Beuf, Robi Peschanski and Sebastian Sapeta
Universality of traveling waves with QCD running coupling
4 pages, 3 figures,, Invited talk given at the DIS 2007 Conference, Munich, Germany, April 2007; Change of title
null
10.1103/PhysRevD.75.114001
spht-07
hep-ph
null
``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio Q/Q_S, where Q_S(Y) is the rapidity-dependent \saturation scale, can be theoretically obtained from universal ``traveling wave'' solutions of the nonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We examine the similar mean-field predictions beyond leading-logarithmic order, including running QCD coupling.
[ { "created": "Mon, 11 Jun 2007 12:24:11 GMT", "version": "v1" }, { "created": "Wed, 20 Jun 2007 12:15:20 GMT", "version": "v2" } ]
2015-05-13
[ [ "Beuf", "Guillaume", "" ], [ "Peschanski", "Robi", "" ], [ "Sapeta", "Sebastian", "" ] ]
``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio Q/Q_S, where Q_S(Y) is the rapidity-dependent \saturation scale, can be theoretically obtained from universal ``traveling wave'' solutions of the nonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We examine the similar mean-field predictions beyond leading-logarithmic order, including running QCD coupling.
1505.00134
Po-Yan Tseng
Yu-Heng Chen, Kingman Cheung, and Po-Yan Tseng
Dark Matter with multi-annihilation channels and AMS-02 positron excess and antiproton
25 pages, 11 figures
null
10.1103/PhysRevD.93.015015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels, if DM is the source of this positron excess. Therefore, we consider the scenario that the DM can annihilate into leptonic, quark, and massive gauge boson channels simultaneously with floating branching ratios to test this hypothesis. We also study the impacts from MAX, MED, MIN, and DC diffusion models as well as from isothermal, NFW, and Einasto DM density profiles on our results. We found two parameter regions that can satisfy both AMS-02 $\frac{e^+}{e^++e^-}$ and $\bar{p}/p$ datasets at 95\% CL. i) Under the NFW-MIN combination with $M_{\chi}\subset[10,30]$ TeV. ii) Under the Einasto-DC combination with $M_{\chi}\subset[500,1500]$ GeV.
[ { "created": "Fri, 1 May 2015 09:46:49 GMT", "version": "v1" }, { "created": "Wed, 13 Jan 2016 08:24:01 GMT", "version": "v2" } ]
2016-02-17
[ [ "Chen", "Yu-Heng", "" ], [ "Cheung", "Kingman", "" ], [ "Tseng", "Po-Yan", "" ] ]
AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels, if DM is the source of this positron excess. Therefore, we consider the scenario that the DM can annihilate into leptonic, quark, and massive gauge boson channels simultaneously with floating branching ratios to test this hypothesis. We also study the impacts from MAX, MED, MIN, and DC diffusion models as well as from isothermal, NFW, and Einasto DM density profiles on our results. We found two parameter regions that can satisfy both AMS-02 $\frac{e^+}{e^++e^-}$ and $\bar{p}/p$ datasets at 95\% CL. i) Under the NFW-MIN combination with $M_{\chi}\subset[10,30]$ TeV. ii) Under the Einasto-DC combination with $M_{\chi}\subset[500,1500]$ GeV.
1309.5015
Chong Sheng Li
Ding Yu Shao, Chong Sheng Li and Hai Tao Li
Resummation Prediction on Higgs and Vector Boson Associated Production with a Jet Veto at the LHC
22 pages, 10 figures and 2 tables; final version in JHEP
JHEP02(2014)117
10.1007/JHEP02(2014)117
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the resummation effects for the SM Higgs and vector boson associated production at the LHC with a jet veto in soft-collinear effective theory using "collinear anomalous" formalism. We calculate the jet vetoed invariant mass distribution and the cross section for this process at Next-to-Next-to-Leading-Logarithmic level, which are matched to the QCD Next-to-Leading Order results, and compare the differences of the resummation effects with different jet veto $p_{T}^{\rm veto}$ and jet radius $R$. Our results show that both resummation enhancement effects and the scale uncertainties decrease with the increasing of jet veto $p_{T}^{\rm veto}$ and jet radius $R$, respectively. When $p_{T}^{\rm veto}=25$ GeV and $R=0.4~(0.5)$, the resummation effects reduce the scale uncertainties of the Next-to-Leading Order jet vetoed cross sections to about $7\%~(6\%)$, which lead to increased confidence on the theoretical predictions. Besides, after including resummation effects, the PDF uncertainties of jet vetoed cross section are about $7\%$.
[ { "created": "Thu, 19 Sep 2013 15:19:40 GMT", "version": "v1" }, { "created": "Sun, 2 Mar 2014 06:00:57 GMT", "version": "v2" } ]
2014-03-04
[ [ "Shao", "Ding Yu", "" ], [ "Li", "Chong Sheng", "" ], [ "Li", "Hai Tao", "" ] ]
We investigate the resummation effects for the SM Higgs and vector boson associated production at the LHC with a jet veto in soft-collinear effective theory using "collinear anomalous" formalism. We calculate the jet vetoed invariant mass distribution and the cross section for this process at Next-to-Next-to-Leading-Logarithmic level, which are matched to the QCD Next-to-Leading Order results, and compare the differences of the resummation effects with different jet veto $p_{T}^{\rm veto}$ and jet radius $R$. Our results show that both resummation enhancement effects and the scale uncertainties decrease with the increasing of jet veto $p_{T}^{\rm veto}$ and jet radius $R$, respectively. When $p_{T}^{\rm veto}=25$ GeV and $R=0.4~(0.5)$, the resummation effects reduce the scale uncertainties of the Next-to-Leading Order jet vetoed cross sections to about $7\%~(6\%)$, which lead to increased confidence on the theoretical predictions. Besides, after including resummation effects, the PDF uncertainties of jet vetoed cross section are about $7\%$.
1002.1134
Sunando Patra
Anirban Kundu, Soumitra Nandi, Sunando Kumar Patra
Probing CPT Violation in B Systems
14 pages, 5 encapsulated postscript figures. Some typographical errors corrected
Phys.Rev.D81:076010,2010
10.1103/PhysRevD.81.076010
CU-PHYSICS/1-2010
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss how a possible violation of the combined symmetry CPT in the B meson system can be investigated at the LHC. We show how a tagged and an untagged analysis of the decay modes of both B(d) and B(s) mesons can lead not only to a possible detection of a CPT-violating new physics but also to an understanding of its precise nature. The implication of CPT violation to a large mixing phase in the B(s) system is also discussed.
[ { "created": "Fri, 5 Feb 2010 06:19:51 GMT", "version": "v1" }, { "created": "Sun, 7 Feb 2010 07:29:44 GMT", "version": "v2" }, { "created": "Tue, 6 Apr 2010 17:28:26 GMT", "version": "v3" }, { "created": "Mon, 6 May 2013 09:02:08 GMT", "version": "v4" } ]
2013-05-07
[ [ "Kundu", "Anirban", "" ], [ "Nandi", "Soumitra", "" ], [ "Patra", "Sunando Kumar", "" ] ]
We discuss how a possible violation of the combined symmetry CPT in the B meson system can be investigated at the LHC. We show how a tagged and an untagged analysis of the decay modes of both B(d) and B(s) mesons can lead not only to a possible detection of a CPT-violating new physics but also to an understanding of its precise nature. The implication of CPT violation to a large mixing phase in the B(s) system is also discussed.
0707.2320
Francois Arleo
Francois Arleo
Prompt photons in heavy ion collisions at the LHC: A ''multi-purpose'' observable
2 pages, 2 figures. Presented at the Workshop on Heavy Ion Collisions at the LHC: Last Call for Predictions, CERN, 14 May-8 Jun 2007
null
null
CERN-PH-TH/2007-11, LAPTH-1197/07
hep-ph nucl-ex nucl-th
null
I emphasize in this contribution how prompt photons can be used to probe nuclear parton densities as well as medium-modified fragmentation functions in heavy ion collisions. Various predictions in p-A and A-A collisions at LHC energies are given.
[ { "created": "Mon, 16 Jul 2007 13:41:00 GMT", "version": "v1" } ]
2007-07-18
[ [ "Arleo", "Francois", "" ] ]
I emphasize in this contribution how prompt photons can be used to probe nuclear parton densities as well as medium-modified fragmentation functions in heavy ion collisions. Various predictions in p-A and A-A collisions at LHC energies are given.
1410.4782
Jie Lu
Johan Bijnens, Jie Lu
Effective Theories for QCD-like at TeV Scale
7 pages, 2 figures, Contribution to the proceedings of the ICHEP 2014 conference, Valencia, Spain
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Effective Field Theory of three QCD-like theories, which can be classified by having quarks in a complex, real or pseudo-real representations of the gauge group. The Lagrangians are written in a very similar way so that the calculations can be done using techniques from Chiral Perturbation Theory (ChPT). We calculated the vacuum-expectation-value, the mass and the decay constant of pseudo-Goldstone Bosons up to next-to-next-to leading order (NNLO) \cite{Bijnens:2009qm}. The various channels of general $n$ flavour meson-meson scattering of the three theories are systematically studied and calculated up to NNLO \cite{Bijnens:2011fm}. We also calculated the vector, axial-vector, scalar, pseudo-scalar two-point functions and pseudo-scalar decay constant up NNLO order \cite{Bijnens:2011xt}. The analytic expressions of the S parameter for the three different QCD-like theories are obtained at TeV scale. Our results are useful for chiral extrapolation in lattice calculation on theory of strong dynamical and finite baryon density.
[ { "created": "Fri, 17 Oct 2014 16:08:47 GMT", "version": "v1" } ]
2014-10-20
[ [ "Bijnens", "Johan", "" ], [ "Lu", "Jie", "" ] ]
We study the Effective Field Theory of three QCD-like theories, which can be classified by having quarks in a complex, real or pseudo-real representations of the gauge group. The Lagrangians are written in a very similar way so that the calculations can be done using techniques from Chiral Perturbation Theory (ChPT). We calculated the vacuum-expectation-value, the mass and the decay constant of pseudo-Goldstone Bosons up to next-to-next-to leading order (NNLO) \cite{Bijnens:2009qm}. The various channels of general $n$ flavour meson-meson scattering of the three theories are systematically studied and calculated up to NNLO \cite{Bijnens:2011fm}. We also calculated the vector, axial-vector, scalar, pseudo-scalar two-point functions and pseudo-scalar decay constant up NNLO order \cite{Bijnens:2011xt}. The analytic expressions of the S parameter for the three different QCD-like theories are obtained at TeV scale. Our results are useful for chiral extrapolation in lattice calculation on theory of strong dynamical and finite baryon density.
1103.5757
Nuno Barros
N. F. de Barros, K. Zuber
Solar neutrino-electron scattering as background limitation for double beta decay
null
J.Phys.G38:105201,2011
10.1088/0954-3899/38/10/105201
null
hep-ph nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The background on double beta decay searches due to elastic electron scattering of solar neutrinos of all double beta emitters with Q-value larger than 2 MeV is calculated, taking into account survival probability and flux uncertainties of solar neutrinos. This work determines the background level to be [1-2]E-7 counts /keV/kg/yr, depending on the precise Q-value of the double beta emitter. It is also shown that the background level increases dramatically if going to lower Q-values. Furthermore, studies are done for various detector systems under consideration for next generation experiments. It was found that experiments based on loaded liquid scintillator have to expect a higher background. Within the given nuclear matrix element uncertainties any approach exploring the normal hierarchy has to face this irreducible background, which is a limitation on the minimal achievable background for purely calorimetric approaches. Large scale liquid scintillator experiments might encounter this problem already while exploring the inverted hierarchy. Potential caveats by using more sophisticated experimental setups are also discussed.
[ { "created": "Tue, 29 Mar 2011 20:04:36 GMT", "version": "v1" }, { "created": "Fri, 16 Sep 2011 15:55:03 GMT", "version": "v2" } ]
2015-03-19
[ [ "de Barros", "N. F.", "" ], [ "Zuber", "K.", "" ] ]
The background on double beta decay searches due to elastic electron scattering of solar neutrinos of all double beta emitters with Q-value larger than 2 MeV is calculated, taking into account survival probability and flux uncertainties of solar neutrinos. This work determines the background level to be [1-2]E-7 counts /keV/kg/yr, depending on the precise Q-value of the double beta emitter. It is also shown that the background level increases dramatically if going to lower Q-values. Furthermore, studies are done for various detector systems under consideration for next generation experiments. It was found that experiments based on loaded liquid scintillator have to expect a higher background. Within the given nuclear matrix element uncertainties any approach exploring the normal hierarchy has to face this irreducible background, which is a limitation on the minimal achievable background for purely calorimetric approaches. Large scale liquid scintillator experiments might encounter this problem already while exploring the inverted hierarchy. Potential caveats by using more sophisticated experimental setups are also discussed.
hep-ph/9906349
David John Summers
C.G.Lester and D.J.Summers (Cavendish, Cambridge)
Measuring masses of semi-invisibly decaying particles pair produced at hadron colliders
8 pages, 3 figures, LaTeX
Phys.Lett.B463:99-103,1999
10.1016/S0370-2693(99)00945-4
Cavendish-HEP-99/07
hep-ph hep-ex
null
We introduce a variable useful for measuring masses of particles pair produced at hadron colliders, where each particle decays to one particle that is directly observable and another particle whose existence can only be inferred from missing transverse momenta. This variable is closely related to the transverse mass variable commonly used for measuring the $W$ mass at hadron colliders, and like the transverse mass our variable extracts masses in a reasonably model independent way. Without considering either backgrounds or measurement errors we consider how our variable would perform measuring the mass of selectrons in a mSUGRA SUSY model at the LHC.
[ { "created": "Sat, 12 Jun 1999 18:23:58 GMT", "version": "v1" } ]
2010-04-06
[ [ "Lester", "C. G.", "", "Cavendish, Cambridge" ], [ "Summers", "D. J.", "", "Cavendish, Cambridge" ] ]
We introduce a variable useful for measuring masses of particles pair produced at hadron colliders, where each particle decays to one particle that is directly observable and another particle whose existence can only be inferred from missing transverse momenta. This variable is closely related to the transverse mass variable commonly used for measuring the $W$ mass at hadron colliders, and like the transverse mass our variable extracts masses in a reasonably model independent way. Without considering either backgrounds or measurement errors we consider how our variable would perform measuring the mass of selectrons in a mSUGRA SUSY model at the LHC.
hep-ph/9504282
Bernard Pire
Bernard PIRE
Exclusive Scattering at ELFE
18 pages , LATEX , figures available upon request
null
null
null
hep-ph
null
The theoretical framework of hard exclusive reactions is reviewed with special emphasis on the Elfe project program. Perturbative QCD studies have shown that factorization properties allow to separate well-defined non perturbative objects which are crucial in the understanding of confinement dynamics from perturbatively calculable hard processes. The applicability of this factorization in a definite energy domain is controlled by some definite statements, as the dimensional counting rules, the helicity conservation law and the appearance of color transparency. The few data available indicate that the Elfe parameters indeed correspond to this well defined physics.
[ { "created": "Tue, 11 Apr 1995 14:10:38 GMT", "version": "v1" } ]
2009-09-25
[ [ "PIRE", "Bernard", "" ] ]
The theoretical framework of hard exclusive reactions is reviewed with special emphasis on the Elfe project program. Perturbative QCD studies have shown that factorization properties allow to separate well-defined non perturbative objects which are crucial in the understanding of confinement dynamics from perturbatively calculable hard processes. The applicability of this factorization in a definite energy domain is controlled by some definite statements, as the dimensional counting rules, the helicity conservation law and the appearance of color transparency. The few data available indicate that the Elfe parameters indeed correspond to this well defined physics.
hep-ph/9402311
Naoya Hata
Naoya Hata
Vacuum Oscillations and Future Solar Neutrino Experiments
(Revtex 3.0, 19 pages + 8 figures (uuencoded ps files attached), Easy way: ps file of entire text with embedded figures available by anonymous ftp at upenn5.hep.upenn.edu, get vacuum.uu in pub/hata/papers/, UPR-0605T)
null
null
null
hep-ph astro-ph
null
Vacuum oscillations are considered for the combined solar neutrino observations, including the Kamiokande II spectrum data and incorporating theoretical uncertainties and their correlations. Despite the conceptual difficulty of the fine tuning between the neutrino parameters and the Sun-Earth distance, 2-flavor vacuum oscillations provide phenomenologically acceptable solutions. There are allowed regions at 99\% C.L. for $\Delta m^2 = (0.45 - 1.2) \times 10^{-10} \; \mbox{eV}\,^2$ and $\sin^22\theta = 0.6 - 1$; the best fit solution is $\chi^2 / \mbox{d.f.} = 19.2 / 16$, which is acceptable at 16\% C.L. Oscillations for sterile neutrinos are, however, excluded by the averaged data at 99.4\% C.L. The vacuum oscillation solutions predict characteristic energy spectrum distortions and seasonal variations in Sudbury Neutrino Observatory, Super-Kamiokande, and BOREXINO. Those predictions are given in detail, emphasizing that the vacuum solutions are distinguishable from the MSW solutions.
[ { "created": "Thu, 17 Feb 1994 22:05:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hata", "Naoya", "" ] ]
Vacuum oscillations are considered for the combined solar neutrino observations, including the Kamiokande II spectrum data and incorporating theoretical uncertainties and their correlations. Despite the conceptual difficulty of the fine tuning between the neutrino parameters and the Sun-Earth distance, 2-flavor vacuum oscillations provide phenomenologically acceptable solutions. There are allowed regions at 99\% C.L. for $\Delta m^2 = (0.45 - 1.2) \times 10^{-10} \; \mbox{eV}\,^2$ and $\sin^22\theta = 0.6 - 1$; the best fit solution is $\chi^2 / \mbox{d.f.} = 19.2 / 16$, which is acceptable at 16\% C.L. Oscillations for sterile neutrinos are, however, excluded by the averaged data at 99.4\% C.L. The vacuum oscillation solutions predict characteristic energy spectrum distortions and seasonal variations in Sudbury Neutrino Observatory, Super-Kamiokande, and BOREXINO. Those predictions are given in detail, emphasizing that the vacuum solutions are distinguishable from the MSW solutions.
hep-ph/0103160
Alfonso R. Zerwekh
Alfonso R. Zerwekh
New Limits on the Color-Octet Technirho Mass from its Decay to Dijets
8 pages. Submitted to Physics Letters B
null
null
USM-TH-103
hep-ph
null
Recently has been shown that the physical (mass eigenstate) color-octet technirho does not couple to two gluons. In this letter we study how this result affects the presently accepted limits for the color-octet technirho mass obtained from the study of dijets production at the Tevatron. First we show that data from Tevatron Run 1b can not exclude any mass range. Finally, we obtain limits for the Tevatron Run II.
[ { "created": "Wed, 14 Mar 2001 15:01:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zerwekh", "Alfonso R.", "" ] ]
Recently has been shown that the physical (mass eigenstate) color-octet technirho does not couple to two gluons. In this letter we study how this result affects the presently accepted limits for the color-octet technirho mass obtained from the study of dijets production at the Tevatron. First we show that data from Tevatron Run 1b can not exclude any mass range. Finally, we obtain limits for the Tevatron Run II.
1705.03229
Guo-Liang Yu
Guo Liang Yu, Zhi Gang Wang, Zhen Yu Li
Analysis of the strong vertexes of $\Sigma_c^{*} ND$ and $\Sigma_b^{*}NB$ in QCD sum rules
null
Int. J. Mod. Phys. A 32, 1750203 (2017)
10.1142/S0217751X17502037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we analyze the strong vertexes $\Sigma_{c}^{*}ND$ and $\Sigma_{b}^{*}NB$ using the three-point QCD sum rules under the Dirac structure of $q\!\!\!/p\!\!\!/\gamma_{\mu}$. We perform our analysis by considering the contributions of the perturbative part and the condensate terms of $<\overline{q}q>$ and $<\frac{\alpha_{s}}{\pi}GG>$. After the form factors are calculated, they are then fitted into analytical functions which are used to get the strong coupling constants for these two vertexes. The final results are $g_{\Sigma_{c}^{*}ND}=7.19^{+8.49}_{-3.11}\pm1.76$ and $g_{\Sigma_{b}^{*}NB}=10.54^{+15.59}_{-5.23}\pm1.82$.
[ { "created": "Tue, 9 May 2017 08:41:37 GMT", "version": "v1" } ]
2017-12-25
[ [ "Yu", "Guo Liang", "" ], [ "Wang", "Zhi Gang", "" ], [ "Li", "Zhen Yu", "" ] ]
In this article, we analyze the strong vertexes $\Sigma_{c}^{*}ND$ and $\Sigma_{b}^{*}NB$ using the three-point QCD sum rules under the Dirac structure of $q\!\!\!/p\!\!\!/\gamma_{\mu}$. We perform our analysis by considering the contributions of the perturbative part and the condensate terms of $<\overline{q}q>$ and $<\frac{\alpha_{s}}{\pi}GG>$. After the form factors are calculated, they are then fitted into analytical functions which are used to get the strong coupling constants for these two vertexes. The final results are $g_{\Sigma_{c}^{*}ND}=7.19^{+8.49}_{-3.11}\pm1.76$ and $g_{\Sigma_{b}^{*}NB}=10.54^{+15.59}_{-5.23}\pm1.82$.
hep-ph/9806403
Per Elmfors
Per Elmfors, Kari Enqvist, Kimmo Kainulainen
Strongly first order electroweak phase transition induced by primordial hypermagnetic fields
11 pages, 1 ps figure. Minor corrections in the published version
Phys.Lett.B440:269-274,1998
10.1016/S0370-2693(98)01117-4
HIP-1998-31/TH, NORDITA-98/45 HE, SUITP-98-10
hep-ph astro-ph hep-th
null
We consider the effect of the presence of a hypermagnetic field at the electroweak phase transition. Screening of the Z-component inside a bubble of the broken phase delays the phase transition and makes it stronger first order. We show that the sphaleron constraint can be evaded for m_H up to 100 GeV if a B_Y\gsim 0.3 T^2 exists at the time of the EW phase transition, thus resurrecting the possibility for baryogenesis within the minimal standard model (provided enough CP violation can be obtained). We estimate that for m_H\gsim 100 GeV the Higgs condendsate behaves like a type II superconductor with Z-vortices penetrating the bubble. Also, for such high Higgs masses the minimum B_Y field required for a strong first order phase transition is large enough to render the W-field unstable towards forming a condensate which changes the simple picture of the symmetry breaking.
[ { "created": "Thu, 18 Jun 1998 11:44:45 GMT", "version": "v1" }, { "created": "Fri, 28 Aug 1998 09:39:45 GMT", "version": "v2" } ]
2011-07-19
[ [ "Elmfors", "Per", "" ], [ "Enqvist", "Kari", "" ], [ "Kainulainen", "Kimmo", "" ] ]
We consider the effect of the presence of a hypermagnetic field at the electroweak phase transition. Screening of the Z-component inside a bubble of the broken phase delays the phase transition and makes it stronger first order. We show that the sphaleron constraint can be evaded for m_H up to 100 GeV if a B_Y\gsim 0.3 T^2 exists at the time of the EW phase transition, thus resurrecting the possibility for baryogenesis within the minimal standard model (provided enough CP violation can be obtained). We estimate that for m_H\gsim 100 GeV the Higgs condendsate behaves like a type II superconductor with Z-vortices penetrating the bubble. Also, for such high Higgs masses the minimum B_Y field required for a strong first order phase transition is large enough to render the W-field unstable towards forming a condensate which changes the simple picture of the symmetry breaking.
1111.4176
Kiel Howe
Peter W. Graham, Kiel Howe, Surjeet Rajendran, Daniel Stolarski
New Measurements with Stopped Particles at the LHC
31 pages, 6 figures. References added, updated to reflect recent experimental results, version accepted for publication in Physical Review D
null
10.1103/PhysRevD.86.034020
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Metastable particles are common in many models of new physics at the TeV scale. If charged or colored, a reasonable fraction of all such particles produced at the LHC will stop in the detectors and give observable out of time decays. We demonstrate that significant information may be learned from such decays about the properties (e.g. charge or spin) of this particle and of any other particles to which it decays, for example a dark matter candidate. We discuss strategies for measuring the type of decay (two- vs three-body), the types of particles produced, and the angular distribution of the produced particles using the LHC detectors. We demonstrate that with O(10-100) observed decay events, not only can the properties of the new particles be measured but indeed even the Lorentz structure of the decay operator can be distinguished in the case of three-body decays. These measurements can not only reveal the correct model of new physics at the TeV scale, but also give information on physics giving rise to the decay at energy scales far above those the LHC can probe directly.
[ { "created": "Thu, 17 Nov 2011 18:55:12 GMT", "version": "v1" }, { "created": "Wed, 25 Jul 2012 19:40:05 GMT", "version": "v2" } ]
2015-03-19
[ [ "Graham", "Peter W.", "" ], [ "Howe", "Kiel", "" ], [ "Rajendran", "Surjeet", "" ], [ "Stolarski", "Daniel", "" ] ]
Metastable particles are common in many models of new physics at the TeV scale. If charged or colored, a reasonable fraction of all such particles produced at the LHC will stop in the detectors and give observable out of time decays. We demonstrate that significant information may be learned from such decays about the properties (e.g. charge or spin) of this particle and of any other particles to which it decays, for example a dark matter candidate. We discuss strategies for measuring the type of decay (two- vs three-body), the types of particles produced, and the angular distribution of the produced particles using the LHC detectors. We demonstrate that with O(10-100) observed decay events, not only can the properties of the new particles be measured but indeed even the Lorentz structure of the decay operator can be distinguished in the case of three-body decays. These measurements can not only reveal the correct model of new physics at the TeV scale, but also give information on physics giving rise to the decay at energy scales far above those the LHC can probe directly.
2306.09508
Michael Andreas Schmidt
Maksym Ovchynnikov, Michael A. Schmidt, Thomas Schwetz
Complementarity of $B\to K^{(*)} \mu \bar \mu$ and $B\to K^{(*)} + \mathrm{inv}$ for searches of GeV-scale Higgs-like scalars
18 pages, 6 figures, corrected factor 2 in Eq (28) and Figs 3-5, main conclusions unchanged, matches version accepted by EPJC
null
null
CPPC-2023-02
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The rare decays $B^+\to K^+ \mu\bar \mu$ and $B^0\to K^{*0} \mu\bar\mu$ provide the strongest constraints on the mixing of a light scalar with the Higgs boson for GeV-scale masses. The constraints sensitively depend on the branching ratio to muons. Additional decay channels like an invisible partial width may substantially weaken the constraints. This scenario will be probed at Belle II in $B\to K^{(*)} + \mathrm{inv}$. We illustrate the complementarity of scalar decays to muons and invisible decays using the currently available results of LHCb and BaBar. We provide two simple model realisations providing a sizeable invisible scalar width, one based on a real scalar and one based on a $U(1)_{B-L}$ gauge symmetry. In both examples the scalar decays into heavy neutral leptons which can be motivated by the seesaw mechanism for neutrino masses.
[ { "created": "Thu, 15 Jun 2023 21:04:55 GMT", "version": "v1" }, { "created": "Wed, 6 Sep 2023 07:59:01 GMT", "version": "v2" } ]
2023-09-07
[ [ "Ovchynnikov", "Maksym", "" ], [ "Schmidt", "Michael A.", "" ], [ "Schwetz", "Thomas", "" ] ]
The rare decays $B^+\to K^+ \mu\bar \mu$ and $B^0\to K^{*0} \mu\bar\mu$ provide the strongest constraints on the mixing of a light scalar with the Higgs boson for GeV-scale masses. The constraints sensitively depend on the branching ratio to muons. Additional decay channels like an invisible partial width may substantially weaken the constraints. This scenario will be probed at Belle II in $B\to K^{(*)} + \mathrm{inv}$. We illustrate the complementarity of scalar decays to muons and invisible decays using the currently available results of LHCb and BaBar. We provide two simple model realisations providing a sizeable invisible scalar width, one based on a real scalar and one based on a $U(1)_{B-L}$ gauge symmetry. In both examples the scalar decays into heavy neutral leptons which can be motivated by the seesaw mechanism for neutrino masses.
1312.6419
Anton Ilderton
Victor Dinu, Tom Heinzl, Anton Ilderton, Mattias Marklund and Greger Torgrimsson
Vacuum refractive indices and helicity flip in strong-field QED
Version 2: additional results added, including discussion of vacuum refractive indices, analysis of flip and non-flip ampltidues at high-energy, additional plots, new title. Now 17 pages, 10 figures
Phys. Rev. D 89, 125003 (2014)
10.1103/PhysRevD.89.125003
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Vacuum birefringence is governed by the amplitude for a photon to flip helicity or polarisation state in an external field. Here we calculate the flip and non-flip amplitudes in arbitrary plane wave backgrounds, along with the induced spacetime-dependent refractive indices of the vacuum. We compare the behaviour of the amplitudes in the low energy and high energy regimes, and analyse the impact of pulse shape and energy. We also provide the first lightfront-QED derivation of the coefficients in the Heisenberg-Euler effective action.
[ { "created": "Sun, 22 Dec 2013 20:21:35 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2014 13:04:31 GMT", "version": "v2" } ]
2014-06-11
[ [ "Dinu", "Victor", "" ], [ "Heinzl", "Tom", "" ], [ "Ilderton", "Anton", "" ], [ "Marklund", "Mattias", "" ], [ "Torgrimsson", "Greger", "" ] ]
Vacuum birefringence is governed by the amplitude for a photon to flip helicity or polarisation state in an external field. Here we calculate the flip and non-flip amplitudes in arbitrary plane wave backgrounds, along with the induced spacetime-dependent refractive indices of the vacuum. We compare the behaviour of the amplitudes in the low energy and high energy regimes, and analyse the impact of pulse shape and energy. We also provide the first lightfront-QED derivation of the coefficients in the Heisenberg-Euler effective action.
1407.6695
Hee Sok Chung
Geoffrey T. Bodwin, Hee Sok Chung (Argonne), June-Haak Ee, Jungil Lee (Korea U.), Frank Petriello (Argonne and Northwestern U.)
Relativistic corrections to Higgs boson decays to quarkonia
24 pages, 2 figures, minor revisions, version published in PRD
Phys. Rev. D 90, 113010 (2014)
10.1103/PhysRevD.90.113010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We improve the theoretical predictions for the decays of the Higgs boson to an $S$-wave vector quarkonium plus a photon by calculating the relativistic correction of order $v^2$, where $v$ is the heavy-quark velocity in the quarkonium rest frame. Our numerical results are given for the $J/\psi$ and $\Upsilon(nS)$ channels, with $n=1,2,3$. The numerical results include a previously calculated correction of order $\alpha_s$ and summations, to all orders in $\alpha_s$, of leading logarithms of $m_H^2/m_Q^2$, where $m_H$ is the Higgs-boson mass and $m_Q$ is the heavy-quark mass. These QCD corrections apply to the contribution of leading order in $v$ and to part of the order-$v^2$ correction. For the remainder of the order-$v^2$ correction, we sum leading logarithms of $m_H/m_Q$ through order $\alpha_s^2$. These refinements reduce the theoretical uncertainties in the direct-production amplitudes for $H \to J/\psi+\gamma$ and $H \to \Upsilon(1S)+\gamma$ by approximately a factor of 3 and open the door to improved determinations at the LHC of the Higgs-boson Yukawa couplings to the charm and bottom quarks.
[ { "created": "Thu, 24 Jul 2014 19:12:04 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2014 23:32:13 GMT", "version": "v2" }, { "created": "Fri, 19 Dec 2014 22:38:04 GMT", "version": "v3" } ]
2014-12-23
[ [ "Bodwin", "Geoffrey T.", "", "Argonne" ], [ "Chung", "Hee Sok", "", "Argonne" ], [ "Ee", "June-Haak", "", "Korea U." ], [ "Lee", "Jungil", "", "Korea U." ], [ "Petriello", "Frank", "", "Argonne and Northwestern U." ]...
We improve the theoretical predictions for the decays of the Higgs boson to an $S$-wave vector quarkonium plus a photon by calculating the relativistic correction of order $v^2$, where $v$ is the heavy-quark velocity in the quarkonium rest frame. Our numerical results are given for the $J/\psi$ and $\Upsilon(nS)$ channels, with $n=1,2,3$. The numerical results include a previously calculated correction of order $\alpha_s$ and summations, to all orders in $\alpha_s$, of leading logarithms of $m_H^2/m_Q^2$, where $m_H$ is the Higgs-boson mass and $m_Q$ is the heavy-quark mass. These QCD corrections apply to the contribution of leading order in $v$ and to part of the order-$v^2$ correction. For the remainder of the order-$v^2$ correction, we sum leading logarithms of $m_H/m_Q$ through order $\alpha_s^2$. These refinements reduce the theoretical uncertainties in the direct-production amplitudes for $H \to J/\psi+\gamma$ and $H \to \Upsilon(1S)+\gamma$ by approximately a factor of 3 and open the door to improved determinations at the LHC of the Higgs-boson Yukawa couplings to the charm and bottom quarks.
hep-ph/9803443
Petr Zavada
P.Zavada
Nucleon spin structure and mass of quarks
27 pages, Tex, 7 PostSript figures. Revised version contains more detailed explanation of some steps. The Fig.6 is replaced by corrected version. Minor modifications in the text and the reference list
null
null
null
hep-ph
null
The alternative to the standard formulation of the quark-parton model is proposed. Our relativistically covariant approach is based on the solution of the master equations relating the structure and distribution functions, which consistently takes into account the intrinsic quark motion - in contradistinction to the standard infinite momentum approach, in which this motion is latently suppressed. The model well reproduces the experimental data on the both polarized and unpolarized structure functions, assuming that only the valence quarks term contributes to the nucleon spin. It is shown, the combined analysis of the polarized and unpolarized data can give an information about the effective masses and intrinsic motion of the quarks inside the nucleon. Simultaneously, it is shown that the rate of the nucleon energy carried by the quarks can be less, than estimated from the standard approach. As an addition, a prediction for the proton spin function $g_2$ is given.
[ { "created": "Wed, 25 Mar 1998 12:35:29 GMT", "version": "v1" }, { "created": "Wed, 29 Jul 1998 08:45:43 GMT", "version": "v2" }, { "created": "Wed, 2 Jun 1999 09:43:48 GMT", "version": "v3" } ]
2007-05-23
[ [ "Zavada", "P.", "" ] ]
The alternative to the standard formulation of the quark-parton model is proposed. Our relativistically covariant approach is based on the solution of the master equations relating the structure and distribution functions, which consistently takes into account the intrinsic quark motion - in contradistinction to the standard infinite momentum approach, in which this motion is latently suppressed. The model well reproduces the experimental data on the both polarized and unpolarized structure functions, assuming that only the valence quarks term contributes to the nucleon spin. It is shown, the combined analysis of the polarized and unpolarized data can give an information about the effective masses and intrinsic motion of the quarks inside the nucleon. Simultaneously, it is shown that the rate of the nucleon energy carried by the quarks can be less, than estimated from the standard approach. As an addition, a prediction for the proton spin function $g_2$ is given.