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hep-ph/9811300
Bhaskar Dutta
E. Accomando, R. Arnowitt and B. Dutta
Trilepton Signal of Grand Unified Models at the Tevatron
7 pages, latex, 6 figures
Phys.Lett.B475:176-183,2000
10.1016/S0370-2693(00)00071-X
CTP-TAMU-43-98
hep-ph
null
At the Tevatron, the most promising channel to detect supersymmetry is three leptons plus missing energy, where the leptons are $e$'s and/or $\mu$'s. This final state appears from the production of chargino and second lighetst neutralino. However in grand unified models with universal scalar masses at the grand unified scale, this final state mostly consists of $\tau$'s which are hard to detect. We show that for some regions of non universality in the scalar masses at the GUT scale based on unifying groups like SU(5) or SO(10), the final state mostly consists of 3$l$+${\rlap/E}_T$ and $\tau ll$+${\rlap/E}_T$. The first mode has very high detection efficiency and the second one is expected to have high detection efficency as well. We also show that these models can have enough events in these modes to be detected in RUN II.
[ { "created": "Wed, 11 Nov 1998 00:43:08 GMT", "version": "v1" } ]
2008-11-26
[ [ "Accomando", "E.", "" ], [ "Arnowitt", "R.", "" ], [ "Dutta", "B.", "" ] ]
At the Tevatron, the most promising channel to detect supersymmetry is three leptons plus missing energy, where the leptons are $e$'s and/or $\mu$'s. This final state appears from the production of chargino and second lighetst neutralino. However in grand unified models with universal scalar masses at the grand unified scale, this final state mostly consists of $\tau$'s which are hard to detect. We show that for some regions of non universality in the scalar masses at the GUT scale based on unifying groups like SU(5) or SO(10), the final state mostly consists of 3$l$+${\rlap/E}_T$ and $\tau ll$+${\rlap/E}_T$. The first mode has very high detection efficiency and the second one is expected to have high detection efficency as well. We also show that these models can have enough events in these modes to be detected in RUN II.
2307.04710
Michael Dine
Michael Dine
Remarks on the Axion Domain Wall Problem
12 pages
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Theories in which the Peccei-Quinn phase transition occurs after inflation tend to suffer from problematic domain walls. One possible solution involves a small, explicit breaking ot the symmetry. But this raises other potential issues. We review some aspects of axion domain walls, focussing especially on this proposed solution. We argue, in disagreement with some recent literature, that there is little axion radiation from the system until the domains actually collapse. The same applies to gravitational waves and electromagnetic radiation. The final stages of the collapse yields small numbers of extremely energetic axions, which interact only rarely with ordinary matter, and are thus relatively harmless. We then note that, if one accepts a remarkable coincidence, this solution can be acceptable. We consider a possible explanation of the required coincidence
[ { "created": "Mon, 10 Jul 2023 17:19:58 GMT", "version": "v1" } ]
2023-07-13
[ [ "Dine", "Michael", "" ] ]
Theories in which the Peccei-Quinn phase transition occurs after inflation tend to suffer from problematic domain walls. One possible solution involves a small, explicit breaking ot the symmetry. But this raises other potential issues. We review some aspects of axion domain walls, focussing especially on this proposed solution. We argue, in disagreement with some recent literature, that there is little axion radiation from the system until the domains actually collapse. The same applies to gravitational waves and electromagnetic radiation. The final stages of the collapse yields small numbers of extremely energetic axions, which interact only rarely with ordinary matter, and are thus relatively harmless. We then note that, if one accepts a remarkable coincidence, this solution can be acceptable. We consider a possible explanation of the required coincidence
2008.08596
Jasmine Brewer
Jasmine Brewer, Jesse Thaler, and Andrew P. Turner
Data-driven quark and gluon jet modification in heavy-ion collisions
7 pages, 4 figures
Phys. Rev. C 103, 021901 (2021)
10.1103/PhysRevC.103.L021901
MIT-CTP 5219
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Whether quark- and gluon-initiated jets are modified differently by the quark-gluon plasma produced in heavy-ion collisions is a long-standing question that has thus far eluded a definitive experimental answer. A crucial complication for quark-gluon discrimination in both proton-proton and heavy-ion collisions is that all measurements necessarily average over the (unknown) quark-gluon composition of a jet sample. In the heavy-ion context, the simultaneous modification of both the fractions and substructure of quark and gluon jets by the quark-gluon plasma further obscures the interpretation. Here, we demonstrate a fully data-driven method for separating quark and gluon contributions to jet observables using a statistical technique called topic modeling. Assuming that jet distributions are a mixture of underlying "quark-like" and "gluon-like" distributions, we show how to extract quark and gluon jet fractions and constituent multiplicity distributions as a function of the jet transverse momentum. This proof-of-concept study is based on proton-proton and heavy-ion collision events from the Monte Carlo event generator Jewel with statistics accessible in Run 4 of the Large Hadron Collider. These results suggest the potential for an experimental determination of quark and gluon jet modifications.
[ { "created": "Wed, 19 Aug 2020 18:00:03 GMT", "version": "v1" } ]
2021-03-03
[ [ "Brewer", "Jasmine", "" ], [ "Thaler", "Jesse", "" ], [ "Turner", "Andrew P.", "" ] ]
Whether quark- and gluon-initiated jets are modified differently by the quark-gluon plasma produced in heavy-ion collisions is a long-standing question that has thus far eluded a definitive experimental answer. A crucial complication for quark-gluon discrimination in both proton-proton and heavy-ion collisions is that all measurements necessarily average over the (unknown) quark-gluon composition of a jet sample. In the heavy-ion context, the simultaneous modification of both the fractions and substructure of quark and gluon jets by the quark-gluon plasma further obscures the interpretation. Here, we demonstrate a fully data-driven method for separating quark and gluon contributions to jet observables using a statistical technique called topic modeling. Assuming that jet distributions are a mixture of underlying "quark-like" and "gluon-like" distributions, we show how to extract quark and gluon jet fractions and constituent multiplicity distributions as a function of the jet transverse momentum. This proof-of-concept study is based on proton-proton and heavy-ion collision events from the Monte Carlo event generator Jewel with statistics accessible in Run 4 of the Large Hadron Collider. These results suggest the potential for an experimental determination of quark and gluon jet modifications.
1906.08815
Ayres Freitas
Ievgen Dubovyk, Ayres Freitas, Janusz Gluza, Tord Riemann, Johann Usovitsch
Electroweak pseudo-observables and Z-boson form factors at two-loop accuracy
17 pages + references; v2: typos in eqs.(2.9) and (3.1) corrected, non-factorizable corrections consistently included in form factors (Tabs. 5-7)
JHEP 1908 (2019) 113
10.1007/JHEP08(2019)113
DESY 19-103, KW 19-005
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present Standard Model predictions for the complete set of phenomenologically relevant electroweak precision pseudo-observables related to the Z-boson: the leptonic and bottom-quark effective weak mixing angles $\sin^2\theta_{\rm eff}^\ell$, $\sin^2\theta_{\rm eff}^b$, the Z-boson partial decay widths $\Gamma_f$, where $f$ indicates any charged lepton, neutrino and quark flavor (except for the top quark), as well as the total Z decay width $\Gamma_Z$, the branching ratios $R_\ell$, $R_c$, $R_b$, and the hadronic cross section $\sigma_{\rm had}^0$. The input parameters are the masses $M_Z$, $M_H$ and $m_t$, and the couplings $\alpha_s$, $\alpha$. The scheme dependence due to the choice of $M_W$ or its alternative $G_\mu$ as a last input parameter is also discussed. Recent substantial technical progress in the calculation of Minkowskian massive higher-order Feynman integrals allows the calculation of the complete electroweak two-loop radiative corrections to all the observables mentioned. QCD contributions are included appropriately. Results are provided in terms of simple and convenient parameterization formulae whose coefficients have been determined from the full numerical multi-loop calculation. The size of the missing electroweak three-loop or QCD higher-order corrections is estimated. We briefly comment on the prospects for their calculation. Finally, direct predictions for the $Z{\bar f}f$ vector and axial-vector form-factors are given, including a discussion of separate order-by-order contributions.
[ { "created": "Thu, 20 Jun 2019 19:25:55 GMT", "version": "v1" }, { "created": "Thu, 9 Jan 2020 20:42:41 GMT", "version": "v2" } ]
2020-01-13
[ [ "Dubovyk", "Ievgen", "" ], [ "Freitas", "Ayres", "" ], [ "Gluza", "Janusz", "" ], [ "Riemann", "Tord", "" ], [ "Usovitsch", "Johann", "" ] ]
We present Standard Model predictions for the complete set of phenomenologically relevant electroweak precision pseudo-observables related to the Z-boson: the leptonic and bottom-quark effective weak mixing angles $\sin^2\theta_{\rm eff}^\ell$, $\sin^2\theta_{\rm eff}^b$, the Z-boson partial decay widths $\Gamma_f$, where $f$ indicates any charged lepton, neutrino and quark flavor (except for the top quark), as well as the total Z decay width $\Gamma_Z$, the branching ratios $R_\ell$, $R_c$, $R_b$, and the hadronic cross section $\sigma_{\rm had}^0$. The input parameters are the masses $M_Z$, $M_H$ and $m_t$, and the couplings $\alpha_s$, $\alpha$. The scheme dependence due to the choice of $M_W$ or its alternative $G_\mu$ as a last input parameter is also discussed. Recent substantial technical progress in the calculation of Minkowskian massive higher-order Feynman integrals allows the calculation of the complete electroweak two-loop radiative corrections to all the observables mentioned. QCD contributions are included appropriately. Results are provided in terms of simple and convenient parameterization formulae whose coefficients have been determined from the full numerical multi-loop calculation. The size of the missing electroweak three-loop or QCD higher-order corrections is estimated. We briefly comment on the prospects for their calculation. Finally, direct predictions for the $Z{\bar f}f$ vector and axial-vector form-factors are given, including a discussion of separate order-by-order contributions.
1006.0002
Irene Tamborra
Georg G. Raffelt and Irene Tamborra
Synchronization vs. decoherence of neutrino oscillations at intermediate densities
11 pages, including 13 figures. Clarifying paragraphs and 2 figures added; results unchanged. Matches published version in PRD
Phys.Rev.D82:125004,2010
10.1103/PhysRevD.82.125004
MPP-2010-55
hep-ph astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study collective oscillations of a two-flavor neutrino system with arbitrary but fixed density. In the vacuum limit, modes with different energies quickly de-phase (kinematical decoherence), whereas in the limit of infinite density they lock to each other (synchronization). For intermediate densities, we find different classes of solutions. There is always a phase transition in the sense of partial synchronization occurring only above a density threshold. For small mixing angles, partial or complete decoherence can be induced by a parametric resonance, introducing a new time scale to the problem, the final outcome depending on the spectrum and mixing angle. We derive an analytic relation that allows us to calculate the late-time degree of coherence based on the spectrum alone.
[ { "created": "Mon, 31 May 2010 20:00:22 GMT", "version": "v1" }, { "created": "Sun, 12 Dec 2010 16:31:03 GMT", "version": "v2" } ]
2010-12-24
[ [ "Raffelt", "Georg G.", "" ], [ "Tamborra", "Irene", "" ] ]
We study collective oscillations of a two-flavor neutrino system with arbitrary but fixed density. In the vacuum limit, modes with different energies quickly de-phase (kinematical decoherence), whereas in the limit of infinite density they lock to each other (synchronization). For intermediate densities, we find different classes of solutions. There is always a phase transition in the sense of partial synchronization occurring only above a density threshold. For small mixing angles, partial or complete decoherence can be induced by a parametric resonance, introducing a new time scale to the problem, the final outcome depending on the spectrum and mixing angle. We derive an analytic relation that allows us to calculate the late-time degree of coherence based on the spectrum alone.
0911.0972
Xian-Qiao Yu
Xian-Qiao Yu, Xiu-Li Zhou
Study of B_{c}\to J/\psi K decays in the perturbative QCD approach
5 pages,1 figure
Phys.Rev.D81:037501,2010
10.1103/PhysRevD.81.037501
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note, we calculate the branching ratio of B_c\to J/\psi K in the framework of perturbative QCD approach based on k_T factorization. This decay can occur only via tree level diagrams in the Standard Model. We find that the branching ratio of B_c\to J/\psi K is about (1-3)\times10^{-4}. The large branching ratio and the clear signals of the final states make the measurement of B_c\to J/\psi K easily at LHC-b experiments.
[ { "created": "Thu, 5 Nov 2009 04:48:22 GMT", "version": "v1" }, { "created": "Sat, 19 Dec 2009 00:51:29 GMT", "version": "v2" }, { "created": "Mon, 1 Mar 2010 10:21:09 GMT", "version": "v3" } ]
2010-04-06
[ [ "Yu", "Xian-Qiao", "" ], [ "Zhou", "Xiu-Li", "" ] ]
In this note, we calculate the branching ratio of B_c\to J/\psi K in the framework of perturbative QCD approach based on k_T factorization. This decay can occur only via tree level diagrams in the Standard Model. We find that the branching ratio of B_c\to J/\psi K is about (1-3)\times10^{-4}. The large branching ratio and the clear signals of the final states make the measurement of B_c\to J/\psi K easily at LHC-b experiments.
1110.4376
Martin Wolfgang Winkler
Rolf Kappl, Martin Wolfgang Winkler
Dark Matter after BESS-Polar II
15 pages, 4 figures
null
10.1103/PhysRevD.85.123522
null
hep-ph astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The BESS-Polar collaboration has recently performed a precise measurement of the local antiproton flux which is consistent with a pure secondary production of antiprotons. We constrain a possible primary component originating from dark matter pair-annihilations. We derive limits on the annihilation cross section which are stronger than or comparable to those from the PAMELA satellite experiment for dark matter masses up to 200 GeV. Especially, we exclude thermal WIMPs with masses in the range 3-20 GeV if they annihilate dominantly into quark pairs unless their cross section is velocity suppressed.
[ { "created": "Wed, 19 Oct 2011 20:01:49 GMT", "version": "v1" } ]
2013-05-30
[ [ "Kappl", "Rolf", "" ], [ "Winkler", "Martin Wolfgang", "" ] ]
The BESS-Polar collaboration has recently performed a precise measurement of the local antiproton flux which is consistent with a pure secondary production of antiprotons. We constrain a possible primary component originating from dark matter pair-annihilations. We derive limits on the annihilation cross section which are stronger than or comparable to those from the PAMELA satellite experiment for dark matter masses up to 200 GeV. Especially, we exclude thermal WIMPs with masses in the range 3-20 GeV if they annihilate dominantly into quark pairs unless their cross section is velocity suppressed.
1112.4433
Taekoon Lee
Taekoon Lee
Estimation of the large order behavior of the plaquette
7 pages. version published in Phys. Lett. B
Physics Letters B 711 (2012) pp. 360-363
10.1016/j.physletb.2012.04.017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The universality of vacuum condensate can be exploited to relate the infrared renormalon caused large order behaviors of different processes. As an application the normalization constant of the large order behavior of the average plaquette is estimated using the Adler function.
[ { "created": "Mon, 19 Dec 2011 18:54:35 GMT", "version": "v1" }, { "created": "Tue, 10 Jan 2012 16:55:03 GMT", "version": "v2" }, { "created": "Mon, 23 Apr 2012 14:45:34 GMT", "version": "v3" } ]
2012-04-30
[ [ "Lee", "Taekoon", "" ] ]
The universality of vacuum condensate can be exploited to relate the infrared renormalon caused large order behaviors of different processes. As an application the normalization constant of the large order behavior of the average plaquette is estimated using the Adler function.
1712.09695
Sergey Ostapchenko
Sergey Ostapchenko and Marcus Bleicher
Rapidity Gap Survival in Enhanced Pomeron Scheme
null
null
10.1140/epjc/s10052-018-5564-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply the phenomenological Reggeon field theory framework to investigate rapidity gap survival (RGS) probability for diffractive dijet production in proton-proton collisions. In particular, we study in some detail rapidity gap suppression due to elastic rescatterings of intermediate partons in the underlying parton cascades, described by enhanced (Pomeron-Pomeron interaction) diagrams. We demonstrate that such contributions play a subdominant role, compared to the usual, so-called "eikonal", rapidity gap suppression due to elastic rescatterings of constituent partons of the colliding protons. On the other hand, the overall RGS factor proves to be sensitive to color fluctuations in the proton. Hence, experimental data on diffractive dijet production can be used to constrain the respective model approaches.
[ { "created": "Wed, 27 Dec 2017 22:25:27 GMT", "version": "v1" } ]
2018-03-14
[ [ "Ostapchenko", "Sergey", "" ], [ "Bleicher", "Marcus", "" ] ]
We apply the phenomenological Reggeon field theory framework to investigate rapidity gap survival (RGS) probability for diffractive dijet production in proton-proton collisions. In particular, we study in some detail rapidity gap suppression due to elastic rescatterings of intermediate partons in the underlying parton cascades, described by enhanced (Pomeron-Pomeron interaction) diagrams. We demonstrate that such contributions play a subdominant role, compared to the usual, so-called "eikonal", rapidity gap suppression due to elastic rescatterings of constituent partons of the colliding protons. On the other hand, the overall RGS factor proves to be sensitive to color fluctuations in the proton. Hence, experimental data on diffractive dijet production can be used to constrain the respective model approaches.
hep-ph/0307123
Pran Nath
Pran Nath
Twenty Years of SUGRA
Invited talk at the International Conference BEYOND-2003, Schloss Ringberg, Germany, June 10-14, 2003; 21 pages, Latex
null
null
null
hep-ph
null
A brief review is given of the developments of mSUGRA and its extensions since the formulation of these models in 1982. Future directions and prospects are also discussed.
[ { "created": "Wed, 9 Jul 2003 14:16:43 GMT", "version": "v1" }, { "created": "Sun, 20 Jul 2003 14:24:57 GMT", "version": "v2" } ]
2007-05-23
[ [ "Nath", "Pran", "" ] ]
A brief review is given of the developments of mSUGRA and its extensions since the formulation of these models in 1982. Future directions and prospects are also discussed.
hep-ph/9710552
Alexander Ignatiev
A.Yu.Ignatiev and G.C.Joshi
Hybrid $SU(2)\times U(1)$ models, electric charge nonconservation and the photon mass
17 pages, revtex
Chaos Solitons Fractals 10 (1999) 1
null
UM-P-95/99, RCHEP-95/23
hep-ph
null
Hybrid $SU(2) \times U(1)$ models are the models in which $SU(2) \times U(1)$ symmetry is broken down not only spontaneously (as in the Standard Model), but also explicitely by adding a hard mass term for the U(1) field in the lagrangian. We study the issue of electric charge nonconservation and dequantization in these models. For this purpose we construct and analyze a series of hybrid models with different scalar contents. We show that some of these models posess an interesting property: the photon can remain massless (at least, at the tree level) even though the electric charge is not conserved.
[ { "created": "Fri, 31 Oct 1997 02:47:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ignatiev", "A. Yu.", "" ], [ "Joshi", "G. C.", "" ] ]
Hybrid $SU(2) \times U(1)$ models are the models in which $SU(2) \times U(1)$ symmetry is broken down not only spontaneously (as in the Standard Model), but also explicitely by adding a hard mass term for the U(1) field in the lagrangian. We study the issue of electric charge nonconservation and dequantization in these models. For this purpose we construct and analyze a series of hybrid models with different scalar contents. We show that some of these models posess an interesting property: the photon can remain massless (at least, at the tree level) even though the electric charge is not conserved.
hep-ph/0202081
Jonathan Feng
Jaime Alvarez-Muniz, Jonathan L. Feng, Francis Halzen, Tao Han, Dan Hooper
Detecting Microscopic Black Holes with Neutrino Telescopes
20 pages, 9 figures
Phys.Rev.D65:124015,2002
10.1103/PhysRevD.65.124015
MIT-CTP-3221, UCI-TR-2001-43, MADPH-02-1255
hep-ph astro-ph hep-ex
null
If spacetime has more than four dimensions, ultra-high energy cosmic rays may create microscopic black holes. Black holes created by cosmic neutrinos in the Earth will evaporate, and the resulting hadronic showers, muons, and taus may be detected in neutrino telescopes below the Earth's surface. We simulate such events in detail and consider black hole cross sections with and without an exponential suppression factor. We find observable rates in both cases: for conservative cosmogenic neutrino fluxes, several black hole events per year are observable at the IceCube detector; for fluxes at the Waxman-Bahcall bound, tens of events per year are possible. We also present zenith angle and energy distributions for all three channels. The ability of neutrino telescopes to differentiate hadrons, muons, and possibly taus, and to measure these distributions provides a unique opportunity to identify black holes, to experimentally constrain the form of black hole production cross sections, and to study Hawking evaporation.
[ { "created": "Fri, 8 Feb 2002 16:02:57 GMT", "version": "v1" } ]
2011-05-12
[ [ "Alvarez-Muniz", "Jaime", "" ], [ "Feng", "Jonathan L.", "" ], [ "Halzen", "Francis", "" ], [ "Han", "Tao", "" ], [ "Hooper", "Dan", "" ] ]
If spacetime has more than four dimensions, ultra-high energy cosmic rays may create microscopic black holes. Black holes created by cosmic neutrinos in the Earth will evaporate, and the resulting hadronic showers, muons, and taus may be detected in neutrino telescopes below the Earth's surface. We simulate such events in detail and consider black hole cross sections with and without an exponential suppression factor. We find observable rates in both cases: for conservative cosmogenic neutrino fluxes, several black hole events per year are observable at the IceCube detector; for fluxes at the Waxman-Bahcall bound, tens of events per year are possible. We also present zenith angle and energy distributions for all three channels. The ability of neutrino telescopes to differentiate hadrons, muons, and possibly taus, and to measure these distributions provides a unique opportunity to identify black holes, to experimentally constrain the form of black hole production cross sections, and to study Hawking evaporation.
hep-ph/0509309
Jonathan Feng
Jonathan L. Feng
ILC Cosmology
18 pages, Plenary Colloquium presented at the 2005 International Linear Collider Workshop, Stanford, California, USA, 18-22 March 2005
null
null
UCI-TR-2005-34
hep-ph astro-ph hep-ex
null
Recent breakthroughs in cosmology pose questions that require particle physics answers. I review the problems of dark matter, baryogenesis, and dark energy and discuss how particle colliders, particularly the International Linear Collider, may advance our understanding of the contents and evolution of the Universe.
[ { "created": "Tue, 27 Sep 2005 16:41:06 GMT", "version": "v1" } ]
2009-09-29
[ [ "Feng", "Jonathan L.", "" ] ]
Recent breakthroughs in cosmology pose questions that require particle physics answers. I review the problems of dark matter, baryogenesis, and dark energy and discuss how particle colliders, particularly the International Linear Collider, may advance our understanding of the contents and evolution of the Universe.
hep-ph/9908260
Csaba Boros
C. Boros, J.T. Londergan and A.W. Thomas
Structure and Production of Lambda Baryons
24 pages, 9 figures, minor changes
Phys.Rev.D61:014007,2000
10.1103/PhysRevD.61.014007
ADP-99-31/T368, IU/NTC 99-01
hep-ph hep-ex
null
We discuss the quark parton structure of the $\Lambda$ baryon and the fragmentation of quarks into $\Lambda$ baryons. We show that the hyperfine interaction, responsible for the $\Delta$-$N$ and $\Sigma^0$-$\Lambda$ mass splittings, leads not only to sizeable SU(3) and SU(6) symmetry breaking in the quark distributions of the $\Lambda$, but also to significant polarized non-strange quark distributions. The same arguments suggest flavor asymmetric quark fragmentation functions and non-zero polarized non-strange quark fragmentation functions. The calculated fragmentation functions give a good description of all measured observables. We predict significant positive $\Lambda$ polarization in semi-inclusive DIS experiments while models based on SU(3) flavor symmetry predict zero or negative $\Lambda$ polarization. Our approach also provides a natural explanation for the dependence of the maximum of the $\xi=\ln(1/z)$ spectrum on the mass of the particles produced in $e^+e^-$ annihilation.
[ { "created": "Thu, 5 Aug 1999 03:22:53 GMT", "version": "v1" }, { "created": "Thu, 26 Aug 1999 02:13:37 GMT", "version": "v2" } ]
2010-02-17
[ [ "Boros", "C.", "" ], [ "Londergan", "J. T.", "" ], [ "Thomas", "A. W.", "" ] ]
We discuss the quark parton structure of the $\Lambda$ baryon and the fragmentation of quarks into $\Lambda$ baryons. We show that the hyperfine interaction, responsible for the $\Delta$-$N$ and $\Sigma^0$-$\Lambda$ mass splittings, leads not only to sizeable SU(3) and SU(6) symmetry breaking in the quark distributions of the $\Lambda$, but also to significant polarized non-strange quark distributions. The same arguments suggest flavor asymmetric quark fragmentation functions and non-zero polarized non-strange quark fragmentation functions. The calculated fragmentation functions give a good description of all measured observables. We predict significant positive $\Lambda$ polarization in semi-inclusive DIS experiments while models based on SU(3) flavor symmetry predict zero or negative $\Lambda$ polarization. Our approach also provides a natural explanation for the dependence of the maximum of the $\xi=\ln(1/z)$ spectrum on the mass of the particles produced in $e^+e^-$ annihilation.
1603.06875
Phongpichit Channuie
Phongpichit Channuie (Walailak U.) and Peeravit Koad (Walailak U.)
Preheating after technicolor inflation
v4: 9 pages, 4 figures, minor modification, version accepted for publication in Phys.Rev.D
Phys. Rev. D 94, 043528 (2016)
10.1103/PhysRevD.94.043528
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the particle production due to parametric resonances in model of inflation where the lightest composite state stemming from the minimal walking technicolor theory plays the role of the inflaton. For model of inflation, the effective theory couples non-minimally to gravity. Regarding the preheating, we study in details a model of a composite inflaton field $\phi$ coupled to another scalar field $\chi$ with the interaction term $g^{2}\phi^{2}\chi^{2}$. Particularly, in the Minkowski space, the stage of parametric resonances can be described by the Mathieu equation. Interestingly, we discover that broad resonances can be typically achieved and potentially efficient in our model causing the number of particle density in this process exponentially increases.
[ { "created": "Tue, 22 Mar 2016 17:14:31 GMT", "version": "v1" }, { "created": "Tue, 5 Apr 2016 06:40:51 GMT", "version": "v2" }, { "created": "Mon, 1 Aug 2016 13:09:52 GMT", "version": "v3" }, { "created": "Tue, 9 Aug 2016 04:08:21 GMT", "version": "v4" } ]
2016-08-25
[ [ "Channuie", "Phongpichit", "", "Walailak U." ], [ "Koad", "Peeravit", "", "Walailak U." ] ]
We investigate the particle production due to parametric resonances in model of inflation where the lightest composite state stemming from the minimal walking technicolor theory plays the role of the inflaton. For model of inflation, the effective theory couples non-minimally to gravity. Regarding the preheating, we study in details a model of a composite inflaton field $\phi$ coupled to another scalar field $\chi$ with the interaction term $g^{2}\phi^{2}\chi^{2}$. Particularly, in the Minkowski space, the stage of parametric resonances can be described by the Mathieu equation. Interestingly, we discover that broad resonances can be typically achieved and potentially efficient in our model causing the number of particle density in this process exponentially increases.
hep-ph/0312309
St\'ephane Lavignac
St\'ephane Lavignac
Flavour and CP Violation in the Lepton Sector and New Physics
13 pages, 3 figures, Invited talk at Flavor Physics and CP Violation (FPCP 2003), Paris, France, 3-6 June 2003. Reference added
null
null
null
hep-ph
null
We give a pedagogical review of flavour and CP violation in the lepton sector, with a particular emphasis on new physics - and in particular supersymmetric - contributions to flavour and CP violating observables involving leptons.
[ { "created": "Sun, 21 Dec 2003 20:39:40 GMT", "version": "v1" }, { "created": "Sat, 10 Jan 2004 20:57:08 GMT", "version": "v2" } ]
2007-05-23
[ [ "Lavignac", "Stéphane", "" ] ]
We give a pedagogical review of flavour and CP violation in the lepton sector, with a particular emphasis on new physics - and in particular supersymmetric - contributions to flavour and CP violating observables involving leptons.
2309.15380
Hongxia Huang
Ye Yan, Xiaohuang Hu, Hongxia Huang, and Jialun Ping
Investigating excited $\Omega_c$ states from pentaquark perspective
14 pages, 6 figures. arXiv admin note: text overlap with arXiv:2211.12129
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Inspired by the recent observation of new $\Omega_c^0$ states by the LHCb Collaboration, we explore the excited $\Omega_{c}$ states from the pentaquark perspective in the quark delocalization color screening model. Our results indicate that the $\Omega_c(3185)$ can be well interpreted as a molecular $\Xi D$ predominated resonance state with $J^P=1/2^-$. The $\Omega_c(3120)$ can also be interpreted as a molecular $\Xi_c^* \bar{K}$ state with $J^P=3/2^-$ and a new molecular state $\Xi^*_c \bar{K}^*$ with $J^P=5/2^-$ and a mass of 3527 MeV is predicted, which is worth searching in the future. Other reported $\Omega_c$ states cannot be well described in the framework of pentaquark systems in present work. The three-quark excited state, or the unquenched picture may be a good explanation, which is worth further exploration.
[ { "created": "Wed, 27 Sep 2023 03:17:03 GMT", "version": "v1" } ]
2023-09-28
[ [ "Yan", "Ye", "" ], [ "Hu", "Xiaohuang", "" ], [ "Huang", "Hongxia", "" ], [ "Ping", "Jialun", "" ] ]
Inspired by the recent observation of new $\Omega_c^0$ states by the LHCb Collaboration, we explore the excited $\Omega_{c}$ states from the pentaquark perspective in the quark delocalization color screening model. Our results indicate that the $\Omega_c(3185)$ can be well interpreted as a molecular $\Xi D$ predominated resonance state with $J^P=1/2^-$. The $\Omega_c(3120)$ can also be interpreted as a molecular $\Xi_c^* \bar{K}$ state with $J^P=3/2^-$ and a new molecular state $\Xi^*_c \bar{K}^*$ with $J^P=5/2^-$ and a mass of 3527 MeV is predicted, which is worth searching in the future. Other reported $\Omega_c$ states cannot be well described in the framework of pentaquark systems in present work. The three-quark excited state, or the unquenched picture may be a good explanation, which is worth further exploration.
hep-ph/9712420
Lucas Taylor
John Swain and Lucas Taylor
First determination of the quark mixing matrix element Vtb independent of assumptions of unitarity
4 pages, 2 figures
Phys.Rev. D58 (1998) 093006
10.1103/PhysRevD.58.093006
null
hep-ph
null
We present a new method for the determination of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element $|V_{tb}|$ from electroweak loop corrections, in particular those affecting the process $Z\to b\bar{b}$. From a combined analysis of results from the LEP, SLC, Tevatron, and neutrino scattering experiments we determine $|V_{tb}| = 0.77^{+0.18}_{-0.24}$. This is the first determination of $|V_{tb}|$ which is independent of unitarity assumptions.
[ { "created": "Wed, 17 Dec 1997 16:13:07 GMT", "version": "v1" } ]
2009-10-30
[ [ "Swain", "John", "" ], [ "Taylor", "Lucas", "" ] ]
We present a new method for the determination of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element $|V_{tb}|$ from electroweak loop corrections, in particular those affecting the process $Z\to b\bar{b}$. From a combined analysis of results from the LEP, SLC, Tevatron, and neutrino scattering experiments we determine $|V_{tb}| = 0.77^{+0.18}_{-0.24}$. This is the first determination of $|V_{tb}|$ which is independent of unitarity assumptions.
hep-ph/0110405
Alessandro Papa
R. Fiore, L. Jenkovszky, F. Paccanoni, A. Papa
$J/\psi$ photoproduction at HERA
11 pages, 6 figures, uses axodraw.sty; one figure added, minor changes in the text
Phys.Rev. D65 (2002) 077505
10.1103/PhysRevD.65.077505
DFPD 01/TH/44, DFCAL-TH 01/6, BITP-01-20
hep-ph
null
We revise and update an earlier model for $J/\psi$ photoproduction based on a dipole Pomeron exchange. We show that the H1 and ZEUS experimental data reported recently can be well fitted by a soft Pomeron alone.
[ { "created": "Wed, 31 Oct 2001 13:39:40 GMT", "version": "v1" }, { "created": "Wed, 28 Nov 2001 10:41:31 GMT", "version": "v2" } ]
2009-11-07
[ [ "Fiore", "R.", "" ], [ "Jenkovszky", "L.", "" ], [ "Paccanoni", "F.", "" ], [ "Papa", "A.", "" ] ]
We revise and update an earlier model for $J/\psi$ photoproduction based on a dipole Pomeron exchange. We show that the H1 and ZEUS experimental data reported recently can be well fitted by a soft Pomeron alone.
hep-ph/0612036
Yue Chongxing
Chong-Xing Yue and Li-Na Wang
Non-universal gauge boson $Z'$ and the spin correlation of top quark pair production at $e^{-}e^{+}$ colliders
16 pages, 5 figures
J.Phys.G34:139-150,2007
10.1088/0954-3899/34/1/010
null
hep-ph
null
In the off-diagonal basis, we discuss the contributions of the non-universal gauge boson $Z'$ predicted by the topcolor-assisted technicolor ($TC2$) model to the spin configurations and the spin correlation observable of the top quark pair production via the process $e^{-}e^{+}\to t\bar{t}$. Our numerical results show that the production cross sections for the like-spin states, which vanish in the standard model, can be significantly large as $M_{Z'}\approx \sqrt{S}$. With reasonable values of the $Z'$ mass $M_{Z'}$ and the coupling parameter $k_{1}$, $Z'$ exchange can generate large corrections to the spin correlation observable.
[ { "created": "Tue, 5 Dec 2006 07:57:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Yue", "Chong-Xing", "" ], [ "Wang", "Li-Na", "" ] ]
In the off-diagonal basis, we discuss the contributions of the non-universal gauge boson $Z'$ predicted by the topcolor-assisted technicolor ($TC2$) model to the spin configurations and the spin correlation observable of the top quark pair production via the process $e^{-}e^{+}\to t\bar{t}$. Our numerical results show that the production cross sections for the like-spin states, which vanish in the standard model, can be significantly large as $M_{Z'}\approx \sqrt{S}$. With reasonable values of the $Z'$ mass $M_{Z'}$ and the coupling parameter $k_{1}$, $Z'$ exchange can generate large corrections to the spin correlation observable.
1007.4479
Marco Frasca
Marco Frasca
Glueball spectrum and hadronic processes in low-energy QCD
4 pages. Contribution to proceedings of QCD 10 Conference, (Montpellier, France, 28th June - 3rd July 2010). Added references and improved some contents
Nucl.Phys.Proc.Suppl.207-208:196-199,2010
10.1016/j.nuclphysbps.2010.10.051
null
hep-ph hep-ex hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Low-energy limit of quantum chromodynamics (QCD) is obtained using a mapping theorem recently proved. This theorem states that, classically, solutions of a massless quartic scalar field theory are approximate solutions of Yang-Mills equations in the limit of the gauge coupling going to infinity. Low-energy QCD is described by a Yukawa theory further reducible to a Nambu-Jona-Lasinio model. At the leading order one can compute glue-quark interactions and one is able to calculate the properties of the $\sigma$ and $\eta-\eta'$ mesons. Finally, it is seen that all the physics of strong interactions, both in the infrared and ultraviolet limit, is described by a single constant $\Lambda$ arising in the ultraviolet by dimensional transmutation and in the infrared as an integration constant.
[ { "created": "Mon, 26 Jul 2010 14:56:01 GMT", "version": "v1" }, { "created": "Thu, 29 Jul 2010 08:50:32 GMT", "version": "v2" } ]
2010-12-23
[ [ "Frasca", "Marco", "" ] ]
Low-energy limit of quantum chromodynamics (QCD) is obtained using a mapping theorem recently proved. This theorem states that, classically, solutions of a massless quartic scalar field theory are approximate solutions of Yang-Mills equations in the limit of the gauge coupling going to infinity. Low-energy QCD is described by a Yukawa theory further reducible to a Nambu-Jona-Lasinio model. At the leading order one can compute glue-quark interactions and one is able to calculate the properties of the $\sigma$ and $\eta-\eta'$ mesons. Finally, it is seen that all the physics of strong interactions, both in the infrared and ultraviolet limit, is described by a single constant $\Lambda$ arising in the ultraviolet by dimensional transmutation and in the infrared as an integration constant.
2303.07364
Thorben Finke
Thorben Finke, Michael Kr\"amer, Alexander M\"uck and Jan T\"onshoff
Learning the language of QCD jets with transformers
Few references added; Version accepted for publication by JHEP
null
10.1007/JHEP06(2023)184
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transformers have become the primary architecture for natural language processing. In this study, we explore their use for auto-regressive density estimation in high-energy jet physics, which involves working with a high-dimensional space. We draw an analogy between sentences and words in natural language and jets and their constituents in high-energy physics. Specifically, we investigate density estimation for light QCD jets and hadronically decaying boosted top jets. Since transformers allow easy sampling from learned densities, we exploit their generative capability to assess the quality of the density estimate. Our results indicate that the generated data samples closely resemble the original data, as evidenced by the excellent agreement of distributions such as particle multiplicity or jet mass. Furthermore, the generated samples are difficult to distinguish from the original data, even by a powerful supervised classifier. Given their exceptional data processing capabilities, transformers could potentially be trained directly on the massive LHC data sets to learn the probability densities in high-energy jet physics.
[ { "created": "Mon, 13 Mar 2023 18:00:02 GMT", "version": "v1" }, { "created": "Mon, 20 Mar 2023 15:48:50 GMT", "version": "v2" }, { "created": "Mon, 26 Jun 2023 14:05:35 GMT", "version": "v3" } ]
2023-07-26
[ [ "Finke", "Thorben", "" ], [ "Krämer", "Michael", "" ], [ "Mück", "Alexander", "" ], [ "Tönshoff", "Jan", "" ] ]
Transformers have become the primary architecture for natural language processing. In this study, we explore their use for auto-regressive density estimation in high-energy jet physics, which involves working with a high-dimensional space. We draw an analogy between sentences and words in natural language and jets and their constituents in high-energy physics. Specifically, we investigate density estimation for light QCD jets and hadronically decaying boosted top jets. Since transformers allow easy sampling from learned densities, we exploit their generative capability to assess the quality of the density estimate. Our results indicate that the generated data samples closely resemble the original data, as evidenced by the excellent agreement of distributions such as particle multiplicity or jet mass. Furthermore, the generated samples are difficult to distinguish from the original data, even by a powerful supervised classifier. Given their exceptional data processing capabilities, transformers could potentially be trained directly on the massive LHC data sets to learn the probability densities in high-energy jet physics.
hep-ph/0006298
Jin Changhao
Changhao Jin
Inclusive Heavy Hadron Decays and Light-Cone Dynamics
talk presented at the Workshop on Light-Cone QCD and Nonperturbative Hadron Physics, Adelaide, Australia, December 13-21, 1999. 9 pages
null
null
null
hep-ph
null
The governing role of light-cone dynamics in inclusive heavy hadron decay processes is demonstrated. Nonperturbative QCD effects on the processes can be systematically calculated using light-cone expansion and heavy quark effective theory. The applications of the light-cone approach to studying electroweak and strong interactions and hadron structure with semileptonic and radiative decays of beauty hadrons are briefly reviewed.
[ { "created": "Tue, 27 Jun 2000 06:20:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jin", "Changhao", "" ] ]
The governing role of light-cone dynamics in inclusive heavy hadron decay processes is demonstrated. Nonperturbative QCD effects on the processes can be systematically calculated using light-cone expansion and heavy quark effective theory. The applications of the light-cone approach to studying electroweak and strong interactions and hadron structure with semileptonic and radiative decays of beauty hadrons are briefly reviewed.
2110.14662
Ibrahim Safa
Ibrahim Safa, Jeffrey Lazar, Alex Pizzuto, Oswaldo Vasquez, Carlos A. Arg\"uelles, Justin Vandenbroucke
TauRunner: A Public Python Program to Propagate Neutral and Charged Leptons
15 pages, 7 figures, 1 table. code available at https://github.com/icecube/TauRunner
null
10.1016/j.cpc.2022.108422
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the past decade IceCube's observations have revealed a flux of astrophysical neutrinos extending to $10^{7}~\rm{GeV}$. The forthcoming generation of neutrino observatories promises to grant further insight into the high-energy neutrino sky, with sensitivity reaching energies up to $10^{12}~\rm{GeV}$. At such high energies, a new set of effects becomes relevant, which was not accounted for in the last generation of neutrino propagation software. Thus, it is important to develop new simulations which efficiently and accurately model lepton behavior at this scale. We present TauRunner a PYTHON-based package that propagates neutral and charged leptons. TauRunner supports propagation between $10~\rm{GeV}$ and $10^{12}~\rm{GeV}$. The package accounts for all relevant secondary neutrinos produced in charged-current tau neutrino interactions. Additionally, tau energy losses of taus produced in neutrino interactions is taken into account, and treated stochastically. Finally, TauRunner is broadly adaptable to divers experimental setups, allowing for user-specified trajectories and propagation media, neutrino cross sections, and initial spectra.
[ { "created": "Wed, 27 Oct 2021 18:00:03 GMT", "version": "v1" } ]
2022-06-15
[ [ "Safa", "Ibrahim", "" ], [ "Lazar", "Jeffrey", "" ], [ "Pizzuto", "Alex", "" ], [ "Vasquez", "Oswaldo", "" ], [ "Argüelles", "Carlos A.", "" ], [ "Vandenbroucke", "Justin", "" ] ]
In the past decade IceCube's observations have revealed a flux of astrophysical neutrinos extending to $10^{7}~\rm{GeV}$. The forthcoming generation of neutrino observatories promises to grant further insight into the high-energy neutrino sky, with sensitivity reaching energies up to $10^{12}~\rm{GeV}$. At such high energies, a new set of effects becomes relevant, which was not accounted for in the last generation of neutrino propagation software. Thus, it is important to develop new simulations which efficiently and accurately model lepton behavior at this scale. We present TauRunner a PYTHON-based package that propagates neutral and charged leptons. TauRunner supports propagation between $10~\rm{GeV}$ and $10^{12}~\rm{GeV}$. The package accounts for all relevant secondary neutrinos produced in charged-current tau neutrino interactions. Additionally, tau energy losses of taus produced in neutrino interactions is taken into account, and treated stochastically. Finally, TauRunner is broadly adaptable to divers experimental setups, allowing for user-specified trajectories and propagation media, neutrino cross sections, and initial spectra.
2406.00531
Mohammadmahdi Ettefaghi
M.M. Ettefaghi
Neutrino oscillation with minimal length uncertainty relation via wave packet approach
11 pages, 1 figure, to appear in PLB
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Theories of Quantum Gravity as well as string theory suggest the existence of a minimal measurable length and the related Generalized Uncertainty Principle (GUP). The universality of Quantum Gravity implies that the GUP influences every quantum mechanical process. Neutrino oscillation as a quantum phenomenon exhibits quantumness at macroscopic distances and could provide potentially a suitable room for quantum foundation explorations. In this paper, we perturbatively derive the neutrino oscillation probability based on the GUP and by treating neutrinos as wave packets. We see that the GUP modifications are dependent on the effective position width of the transition amplitude $\sigma_x$ such that with the smaller $\sigma_x$ we can obtain a stronger bound on the minimal length scale in comparison to what is expected from standard model interactions. More explicitly, one can obtain an upper bound about $5\times 10^{25}$ for the deformation parameter, $\beta_0$, with accelerator neutrino experiments such as MINOS, provided that $\sigma_x\sim 10^{-15}\text{m}$ which is reasonable since the energy of these neutrinos is of the order of a few GeV.
[ { "created": "Sat, 1 Jun 2024 18:46:38 GMT", "version": "v1" } ]
2024-06-04
[ [ "Ettefaghi", "M. M.", "" ] ]
Theories of Quantum Gravity as well as string theory suggest the existence of a minimal measurable length and the related Generalized Uncertainty Principle (GUP). The universality of Quantum Gravity implies that the GUP influences every quantum mechanical process. Neutrino oscillation as a quantum phenomenon exhibits quantumness at macroscopic distances and could provide potentially a suitable room for quantum foundation explorations. In this paper, we perturbatively derive the neutrino oscillation probability based on the GUP and by treating neutrinos as wave packets. We see that the GUP modifications are dependent on the effective position width of the transition amplitude $\sigma_x$ such that with the smaller $\sigma_x$ we can obtain a stronger bound on the minimal length scale in comparison to what is expected from standard model interactions. More explicitly, one can obtain an upper bound about $5\times 10^{25}$ for the deformation parameter, $\beta_0$, with accelerator neutrino experiments such as MINOS, provided that $\sigma_x\sim 10^{-15}\text{m}$ which is reasonable since the energy of these neutrinos is of the order of a few GeV.
hep-ph/9908240
Yasunori Nomura
K.-I. Izawa, Yasunori Nomura, and T. Yanagida
Cosmological Constants as Messenger between Branes
7 pages, Latex
Prog.Theor.Phys.102:1181-1185,1999
10.1143/PTP.102.1181
UT-856
hep-ph
null
We present a supersymmetry-breaking scenario in which both the breaking in the hidden sector with no-scale type supergravity and that in the observable sector with gauge mediation are taken into account. The breaking scales in the hidden and observable sectors are related through the vanishing condition of the cosmological constant with a brane-world picture in mind. Suppressing flavor-changing neutral currents, we can naturally obtain the gravitino, Higgs(ino), and soft masses of the electroweak scale.
[ { "created": "Wed, 4 Aug 1999 09:45:55 GMT", "version": "v1" } ]
2009-09-29
[ [ "Izawa", "K. -I.", "" ], [ "Nomura", "Yasunori", "" ], [ "Yanagida", "T.", "" ] ]
We present a supersymmetry-breaking scenario in which both the breaking in the hidden sector with no-scale type supergravity and that in the observable sector with gauge mediation are taken into account. The breaking scales in the hidden and observable sectors are related through the vanishing condition of the cosmological constant with a brane-world picture in mind. Suppressing flavor-changing neutral currents, we can naturally obtain the gravitino, Higgs(ino), and soft masses of the electroweak scale.
hep-ph/0611193
Nils Offen
Alexander Khodjamirian, Thomas Mannel, Nils Offen
Form Factors from Light-Cone Sum Rules with B-Meson Distribution Amplitudes
32 pages, 7 figures, the discussion of numerical results extended, two references added, version to be published in Phys.Rev. D
Phys.Rev.D75:054013,2007
10.1103/PhysRevD.75.054013
SI-HEP-2006-03
hep-ph
null
New sum rules for $B\to \pi,K $ and $B\to \rho,K^*$ form factors are derived from the correlation functions expanded near the light-cone in terms of B-meson distribution amplitudes. The contributions of quark-antiquark and quark-antiquark-gluon components in the B meson are taken into account. Models for the B-meson three-particle distribution amplitudes are suggested, based on QCD sum rules in HQET. Employing the new light-cone sum rules we calculate the form factors at small momentum transfers, including $SU(3)_{fl}$ violation effects. The results agree with the predictions of the conventional light-cone sum rules.
[ { "created": "Tue, 14 Nov 2006 17:07:51 GMT", "version": "v1" }, { "created": "Fri, 2 Feb 2007 18:52:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Khodjamirian", "Alexander", "" ], [ "Mannel", "Thomas", "" ], [ "Offen", "Nils", "" ] ]
New sum rules for $B\to \pi,K $ and $B\to \rho,K^*$ form factors are derived from the correlation functions expanded near the light-cone in terms of B-meson distribution amplitudes. The contributions of quark-antiquark and quark-antiquark-gluon components in the B meson are taken into account. Models for the B-meson three-particle distribution amplitudes are suggested, based on QCD sum rules in HQET. Employing the new light-cone sum rules we calculate the form factors at small momentum transfers, including $SU(3)_{fl}$ violation effects. The results agree with the predictions of the conventional light-cone sum rules.
1609.06104
Edmond Iancu
Miguel A. Escobedo and Edmond Iancu
Multi-particle correlations and KNO scaling in the medium-induced jet evolution
31 pages, 7 figures
null
10.1007/JHEP12(2016)104
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations the evolution of the jet can be described as a classical stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions (the n-body densities in the space of energy). The corresponding results for the one-point and the two-point functions were already known, but those for the higher-point functions are new. These results demonstrate strong correlations associated with the existence of common ancestors in the branching process. By integrating these n-point functions over the gluon energies, we deduce the mean gluon multiplicity $\langle N\rangle$ as well as the higher moments $\langle N^p\rangle$ with $p\ge 2$. We find that the multiplicities of the soft gluons are parametrically large and show a remarkable regularity, known as Koba-Nielsen-Olesen (KNO) scaling: the reduced moments $\langle N^p\rangle/\langle N\rangle^p$ are pure numbers, independent of any of the physical parameters of the problem. We recognize a special negative binomial distribution which is characterized by large statistical fluctuations. These predictions can be tested in Pb+Pb collisions at the LHC, via event-by-event measurements of the di-jet asymmetry.
[ { "created": "Tue, 20 Sep 2016 11:21:57 GMT", "version": "v1" } ]
2017-02-01
[ [ "Escobedo", "Miguel A.", "" ], [ "Iancu", "Edmond", "" ] ]
We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations the evolution of the jet can be described as a classical stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions (the n-body densities in the space of energy). The corresponding results for the one-point and the two-point functions were already known, but those for the higher-point functions are new. These results demonstrate strong correlations associated with the existence of common ancestors in the branching process. By integrating these n-point functions over the gluon energies, we deduce the mean gluon multiplicity $\langle N\rangle$ as well as the higher moments $\langle N^p\rangle$ with $p\ge 2$. We find that the multiplicities of the soft gluons are parametrically large and show a remarkable regularity, known as Koba-Nielsen-Olesen (KNO) scaling: the reduced moments $\langle N^p\rangle/\langle N\rangle^p$ are pure numbers, independent of any of the physical parameters of the problem. We recognize a special negative binomial distribution which is characterized by large statistical fluctuations. These predictions can be tested in Pb+Pb collisions at the LHC, via event-by-event measurements of the di-jet asymmetry.
1907.06927
Franziska Hagelstein
Franziska Hagelstein (AEC Bern) and Vladimir Pascalutsa (JGU Mainz)
Pseudoscalar-Meson Contributions to g-2 via Schwinger's Sum Rule
Contribution to the proceedings of the 9th International Workshop on Chiral Dynamics, 17-21 September 2018 (Durham, NC, USA). 7 pages, 7 figures, 2 tables
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Schwinger sum rule is presented as a new promising tool to study the hadronic contributions to the muon anomalous magnetic moment. In particular, we show preliminary results for the light-by-light scattering contribution of pseudoscalar mesons.
[ { "created": "Tue, 16 Jul 2019 10:18:03 GMT", "version": "v1" } ]
2019-07-17
[ [ "Hagelstein", "Franziska", "", "AEC Bern" ], [ "Pascalutsa", "Vladimir", "", "JGU Mainz" ] ]
The Schwinger sum rule is presented as a new promising tool to study the hadronic contributions to the muon anomalous magnetic moment. In particular, we show preliminary results for the light-by-light scattering contribution of pseudoscalar mesons.
0803.4161
Tania Robens
J. Kalinowski, W. Kilian, J. Reuter, T. Robens, K. Rolbiecki
(N)LO Simulation of Chargino Production and Decay
10 pages, 6 figures; Talk presented at the Cracow Epiphany Conference on LHC Physics 2008; Submitted to Acta Physica Polonica B
Acta Phys.Polon.B39:1705-1714,2008
null
PITHA 08/08, SFB-CPP-08-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider NLO chargino production and decays at the ILC. For this, we present an NLO extension of the Monte Carlo Event Generator Whizard including the NLO production. For photonic corrections, we use both a fixed order and a resummation approach. The latter method evades the problem of negative event weights and automatically includes leading higher order corrections. We present results for cross sections and event generation for both methods. As a first step towards a full NLO Monte Carlo, we consider a LO implementation of the chargino production and subsequent leptonic decay and investigate the precision of the sneutrino mass determination by means of lepton energy distributions in chargino decays. The SM and SUSY backgrounds are included in our study using full matrix elements as well as smearing effects from ISR and beamstrahlung. Without using energy distribution fits, the sneutrino mass can be determined with an error in the percent regime.
[ { "created": "Fri, 28 Mar 2008 16:45:27 GMT", "version": "v1" } ]
2008-12-19
[ [ "Kalinowski", "J.", "" ], [ "Kilian", "W.", "" ], [ "Reuter", "J.", "" ], [ "Robens", "T.", "" ], [ "Rolbiecki", "K.", "" ] ]
We consider NLO chargino production and decays at the ILC. For this, we present an NLO extension of the Monte Carlo Event Generator Whizard including the NLO production. For photonic corrections, we use both a fixed order and a resummation approach. The latter method evades the problem of negative event weights and automatically includes leading higher order corrections. We present results for cross sections and event generation for both methods. As a first step towards a full NLO Monte Carlo, we consider a LO implementation of the chargino production and subsequent leptonic decay and investigate the precision of the sneutrino mass determination by means of lepton energy distributions in chargino decays. The SM and SUSY backgrounds are included in our study using full matrix elements as well as smearing effects from ISR and beamstrahlung. Without using energy distribution fits, the sneutrino mass can be determined with an error in the percent regime.
1003.5360
LiPing Sun
Peng Sun, Li-Ping Sun, Cong-Feng Qiao
The Next-to-Leading Order Corrections to Top Quark Decays to Heavy Quarkonia
14 pages, 7 figures. Typos and misspellings are corrected, numerical results and conclusions remain
Phys.Rev.D81:114035,2010
10.1103/PhysRevD.81.114035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay widths of top quark to S-wave $b\bar{c}$ and $b\bar{b}$ bound states are evaluated at the next-to-leading(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO corrections to these processes are remarkable. The quantum chromodynamics(QCD) renormalization scale dependence of the results are obviously depressed, and hence the uncertainties lying in the leading order calculation are reduced.
[ { "created": "Sun, 28 Mar 2010 11:22:21 GMT", "version": "v1" }, { "created": "Mon, 24 May 2010 02:58:21 GMT", "version": "v2" } ]
2014-11-20
[ [ "Sun", "Peng", "" ], [ "Sun", "Li-Ping", "" ], [ "Qiao", "Cong-Feng", "" ] ]
The decay widths of top quark to S-wave $b\bar{c}$ and $b\bar{b}$ bound states are evaluated at the next-to-leading(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO corrections to these processes are remarkable. The quantum chromodynamics(QCD) renormalization scale dependence of the results are obviously depressed, and hence the uncertainties lying in the leading order calculation are reduced.
hep-ph/0502255
Marco Serone
Giuliano Panico and Marco Serone
The Electroweak Phase Transition on Orbifolds with Gauge-Higgs Unification
35 pages, 34 figures; v2: discussion on higher loop contributions improved, two figures added, minor corrections
JHEP 0505:024,2005
10.1088/1126-6708/2005/05/024
SISSA-15/2005/EP
hep-ph hep-th
null
The dynamics of five dimensional Wilson line phases at finite temperature is studied in the one-loop approximation. We show that at temperatures of order T \sim 1/L, where L is the length of the compact space, the gauge symmetry is always restored and the electroweak phase transition appears to be of first order. Particular attention is devoted to the study of a recently proposed five dimensional orbifold model (on S1/Z2) where the Wilson line phase is identified with the Higgs field (gauge-Higgs unification). Interestingly enough, an estimate of the leading higher-loop ``daisy'' (or ``ring'') diagram contributions to the effective potential in a simple five dimensional model, seems to suggest that the electroweak phase transition can be studied in perturbation theory even for Higgs masses above the current experimental limit of 114 GeV. The transition is still of first order for such values of the Higgs mass. If large localized gauge kinetic terms are present, the transition might be strong enough to give baryogenesis at the electroweak transition.
[ { "created": "Mon, 28 Feb 2005 19:17:10 GMT", "version": "v1" }, { "created": "Fri, 11 Mar 2005 09:46:23 GMT", "version": "v2" } ]
2010-02-03
[ [ "Panico", "Giuliano", "" ], [ "Serone", "Marco", "" ] ]
The dynamics of five dimensional Wilson line phases at finite temperature is studied in the one-loop approximation. We show that at temperatures of order T \sim 1/L, where L is the length of the compact space, the gauge symmetry is always restored and the electroweak phase transition appears to be of first order. Particular attention is devoted to the study of a recently proposed five dimensional orbifold model (on S1/Z2) where the Wilson line phase is identified with the Higgs field (gauge-Higgs unification). Interestingly enough, an estimate of the leading higher-loop ``daisy'' (or ``ring'') diagram contributions to the effective potential in a simple five dimensional model, seems to suggest that the electroweak phase transition can be studied in perturbation theory even for Higgs masses above the current experimental limit of 114 GeV. The transition is still of first order for such values of the Higgs mass. If large localized gauge kinetic terms are present, the transition might be strong enough to give baryogenesis at the electroweak transition.
0707.1275
Agnieszka Grzeli\'nska
Henryk Czyz and Agnieszka Grzelinska
Radiative return physics program within EURIDICE network
Presented by H. Czyz at The Final EURIDICE Meeting "Effective theories of colours and flavours: from EURODAPHNE to EURIDICE", Kazimierz, Poland, 24-27 August, 2006, minor linquistic changes
ActaPhys.Polon.B38:2989-2998,2007
null
TTP07-15
hep-ph hep-ex
null
A short review of both theoretical and experimental aspects of the radiative return method is presented with the emphasize on the results obtained within the EURIDICE network. It is shown that the method gives not only possibility of an independent from the scan method measurement of the hadronic cross section, but also can provide information concerning details of the hadronic interactions.
[ { "created": "Mon, 9 Jul 2007 15:07:23 GMT", "version": "v1" }, { "created": "Wed, 8 Aug 2007 07:22:49 GMT", "version": "v2" } ]
2008-11-26
[ [ "Czyz", "Henryk", "" ], [ "Grzelinska", "Agnieszka", "" ] ]
A short review of both theoretical and experimental aspects of the radiative return method is presented with the emphasize on the results obtained within the EURIDICE network. It is shown that the method gives not only possibility of an independent from the scan method measurement of the hadronic cross section, but also can provide information concerning details of the hadronic interactions.
hep-ph/9308277
null
Ann E. Nelson and Lisa Randall
Naturally Large Tan $\beta$
8 pages (uses harvmac), UCSD/PTH 93-24, MIT-CTP-2230
Phys.Lett.B316:516-520,1993
10.1016/0370-2693(93)91037-N
null
hep-ph
null
We show that if there are only two Higgs doublets in the supersymmetric standard model, large $\tan\beta$ requires a fine tuning in the parameters of the Lagrangian of order ($1/\tan\beta$), which cannot be explained by any approximate symmetry. With an extended Higgs sector, large $\tan\beta$ can be natural. We give an explicit example with four doublets in which it is possible to achieve large $\tan\beta$ as a result of an approximate symmetry, without any light superpartners. The approximate symmetry can be extended to explain all the hierarchies in the quark mass matrix.
[ { "created": "Sun, 15 Aug 1993 22:56:28 GMT", "version": "v1" } ]
2009-09-15
[ [ "Nelson", "Ann E.", "" ], [ "Randall", "Lisa", "" ] ]
We show that if there are only two Higgs doublets in the supersymmetric standard model, large $\tan\beta$ requires a fine tuning in the parameters of the Lagrangian of order ($1/\tan\beta$), which cannot be explained by any approximate symmetry. With an extended Higgs sector, large $\tan\beta$ can be natural. We give an explicit example with four doublets in which it is possible to achieve large $\tan\beta$ as a result of an approximate symmetry, without any light superpartners. The approximate symmetry can be extended to explain all the hierarchies in the quark mass matrix.
1307.0574
Jiajun Wu
Jia-Jun Wu and Bing-Song Zou
Hyperon production from neutrino-nucleon reaction
19 pages, 10 figures
null
10.1007/s00601-015-0973-0
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutrino induced hyperon production processes $\bar{\nu}_{e/\mu} + p \to e^+/\mu^+ + \pi + \Lambda/\Sigma$ may provide a unique clean place for studying low energy $\pi\Lambda/\Sigma$ interaction and hyperon resonances below $KN$ threshold. The production rates for some neutrino induced hyperon production processes are estimated with theoretical models. Suggestions are made for the study of hyperon production from neutrino-nucleon reaction at present and future neutrino facilities.
[ { "created": "Tue, 2 Jul 2013 02:20:54 GMT", "version": "v1" }, { "created": "Mon, 13 Apr 2015 06:19:02 GMT", "version": "v2" } ]
2015-04-14
[ [ "Wu", "Jia-Jun", "" ], [ "Zou", "Bing-Song", "" ] ]
The neutrino induced hyperon production processes $\bar{\nu}_{e/\mu} + p \to e^+/\mu^+ + \pi + \Lambda/\Sigma$ may provide a unique clean place for studying low energy $\pi\Lambda/\Sigma$ interaction and hyperon resonances below $KN$ threshold. The production rates for some neutrino induced hyperon production processes are estimated with theoretical models. Suggestions are made for the study of hyperon production from neutrino-nucleon reaction at present and future neutrino facilities.
2007.05345
Rayan Haindl
Vittorio Del Duca, Claude Duhr, Rayan Haindl, Achilleas Lazopoulos and Martin Michel
Tree-level splitting amplitudes for a gluon into four collinear partons
31 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1912.06425
null
10.1007/JHEP10(2020)093
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute in conventional dimensional regularisation the tree-level splitting amplitudes for a gluon parent which splits into four collinear partons. This is part of the universal infrared behaviour of the QCD scattering amplitudes at next- to-next-to-next-to-leading order (N$^3$LO) in the strong coupling constant. Combined with our earlier results for a quark parent, this completes the set of tree-level splitting amplitudes required at this order. We also study iterated collinear limits where a subset of the four collinear partons become themselves collinear.
[ { "created": "Wed, 8 Jul 2020 20:18:48 GMT", "version": "v1" } ]
2020-10-28
[ [ "Del Duca", "Vittorio", "" ], [ "Duhr", "Claude", "" ], [ "Haindl", "Rayan", "" ], [ "Lazopoulos", "Achilleas", "" ], [ "Michel", "Martin", "" ] ]
We compute in conventional dimensional regularisation the tree-level splitting amplitudes for a gluon parent which splits into four collinear partons. This is part of the universal infrared behaviour of the QCD scattering amplitudes at next- to-next-to-next-to-leading order (N$^3$LO) in the strong coupling constant. Combined with our earlier results for a quark parent, this completes the set of tree-level splitting amplitudes required at this order. We also study iterated collinear limits where a subset of the four collinear partons become themselves collinear.
1512.03001
Mikl\'os Horv\'ath
M. Horv\'ath, A. Jakov\'ac
Shear viscosity over entropy density ratio with extended quasi-particles
13 pages, 7 figures, uses revtex4-1; published version
Phys. Rev. D 93, 056010 (2016)
10.1103/PhysRevD.93.056010
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an effective field theory description of beyond-quasi-particle excitations aiming to associate the transport properties of the system with the spectral density of states. Tuning various properties of the many-particle correlations, we investigate how the robust microscopic features are translated into the macroscopic observables like shear viscosity and entropy density. The liquid-gas crossover is analysed using several examples. A thermal constraint on the fluidity measure, the ratio of shear viscosity to entropy density, is discussed.
[ { "created": "Wed, 9 Dec 2015 19:26:29 GMT", "version": "v1" }, { "created": "Mon, 25 Jan 2016 16:24:27 GMT", "version": "v2" }, { "created": "Tue, 29 Mar 2016 16:31:21 GMT", "version": "v3" } ]
2016-03-30
[ [ "Horváth", "M.", "" ], [ "Jakovác", "A.", "" ] ]
We consider an effective field theory description of beyond-quasi-particle excitations aiming to associate the transport properties of the system with the spectral density of states. Tuning various properties of the many-particle correlations, we investigate how the robust microscopic features are translated into the macroscopic observables like shear viscosity and entropy density. The liquid-gas crossover is analysed using several examples. A thermal constraint on the fluidity measure, the ratio of shear viscosity to entropy density, is discussed.
2302.05383
Roy Forestano
Roy T. Forestano, Konstantin T. Matchev, Katia Matcheva, Alexander Roman, Eyup B. Unlu, Sarunas Verner
Discovering Sparse Representations of Lie Groups with Machine Learning
14 pages, 6 figures
null
10.1016/j.physletb.2023.138086
null
hep-ph cs.LG math-ph math.GR math.MP
http://creativecommons.org/licenses/by/4.0/
Recent work has used deep learning to derive symmetry transformations, which preserve conserved quantities, and to obtain the corresponding algebras of generators. In this letter, we extend this technique to derive sparse representations of arbitrary Lie algebras. We show that our method reproduces the canonical (sparse) representations of the generators of the Lorentz group, as well as the $U(n)$ and $SU(n)$ families of Lie groups. This approach is completely general and can be used to find the infinitesimal generators for any Lie group.
[ { "created": "Fri, 10 Feb 2023 17:12:05 GMT", "version": "v1" } ]
2023-08-09
[ [ "Forestano", "Roy T.", "" ], [ "Matchev", "Konstantin T.", "" ], [ "Matcheva", "Katia", "" ], [ "Roman", "Alexander", "" ], [ "Unlu", "Eyup B.", "" ], [ "Verner", "Sarunas", "" ] ]
Recent work has used deep learning to derive symmetry transformations, which preserve conserved quantities, and to obtain the corresponding algebras of generators. In this letter, we extend this technique to derive sparse representations of arbitrary Lie algebras. We show that our method reproduces the canonical (sparse) representations of the generators of the Lorentz group, as well as the $U(n)$ and $SU(n)$ families of Lie groups. This approach is completely general and can be used to find the infinitesimal generators for any Lie group.
0803.0960
Andrzej Czarnecki
Alexey Pak and Andrzej Czarnecki
Mass effects in muon and semileptonic b -> c decays
5 pages, 2 figures
Phys.Rev.Lett.100:241807,2008
10.1103/PhysRevLett.100.241807
Alberta Thy 12-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum chromodynamics (QCD) effects in the semileptonic decay b -> c l nu are evaluated to the second order in the coupling constant, O(alpha_s^2), and to several orders in the expansion in quark masses, m_c/m_b. Corrections are calculated for the total decay rate as well as for the first two moments of the lepton energy and the hadron system energy distributions. Applied to the muon decay, they decrease its predicted rate by -0.43 ppm.
[ { "created": "Thu, 6 Mar 2008 20:25:48 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pak", "Alexey", "" ], [ "Czarnecki", "Andrzej", "" ] ]
Quantum chromodynamics (QCD) effects in the semileptonic decay b -> c l nu are evaluated to the second order in the coupling constant, O(alpha_s^2), and to several orders in the expansion in quark masses, m_c/m_b. Corrections are calculated for the total decay rate as well as for the first two moments of the lepton energy and the hadron system energy distributions. Applied to the muon decay, they decrease its predicted rate by -0.43 ppm.
1312.0770
Magno Machado
G. Sampaio dos Santos, M.V.T. Machado
Exclusive photoproduction of quarkonium in proton-nucleus collisions at energies available at the CERN Large Hadron Collider
05 pages, 5 figures. Version to be published in Phys. Rev. C
Phys. Rev. C 89, 025201 (2014)
10.1103/PhysRevC.89.025201
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we investigate the coherent photoproduction of psi(1S), psi(2S) and Upsilon (1S) states in the proton-nucleus collisions in the LHC energies. Predictions for the rapidity distributions are presented using the color dipole formalism and including saturation effects that are expected to be relevant at high energies. Calculations are done at the energy 5.02 TeV and also for the next LHC run at 8.8 TeV in proton-lead mode. Discussion is performed on the main theoretical uncertainties associated to the calculations.
[ { "created": "Tue, 3 Dec 2013 11:19:31 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2014 19:04:31 GMT", "version": "v2" }, { "created": "Wed, 18 Jun 2014 16:46:31 GMT", "version": "v3" } ]
2014-06-19
[ [ "Santos", "G. Sampaio dos", "" ], [ "Machado", "M. V. T.", "" ] ]
In this work we investigate the coherent photoproduction of psi(1S), psi(2S) and Upsilon (1S) states in the proton-nucleus collisions in the LHC energies. Predictions for the rapidity distributions are presented using the color dipole formalism and including saturation effects that are expected to be relevant at high energies. Calculations are done at the energy 5.02 TeV and also for the next LHC run at 8.8 TeV in proton-lead mode. Discussion is performed on the main theoretical uncertainties associated to the calculations.
1406.3439
Tom\'a\v{s} Brauner
Jens O. Andersen, Tomas Brauner, Christoph P. Hofmann, Aleksi Vuorinen
Effective Lagrangians for quantum many-body systems
45 pages
JHEP08(2014)088
10.1007/JHEP08(2014)088
HIP-2014-17/TH
hep-ph cond-mat.str-el hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The low-energy and low-momentum dynamics of systems with a spontaneously broken continuous symmetry is dominated by the ensuing Nambu-Goldstone bosons. It can be conveniently encoded in a model-independent effective field theory whose structure is fixed by symmetry up to a set of effective coupling constants. We construct the most general effective Lagrangian for the Nambu-Goldstone bosons of spontaneously broken global internal symmetry up to the fourth order in derivatives. Rotational invariance and spatial dimensionality of one, two or three are assumed in order to obtain compact explicit expressions, but our method is completely general and can be applied without modifications to condensed matter systems with a discrete space group as well as to higher-dimensional theories. The general low-energy effective Lagrangian for relativistic systems follows as a special case. We also discuss the effects of explicit symmetry breaking and classify the corresponding terms in the Lagrangian. Diverse examples are worked out in order to make the results accessible to a wide theoretical physics community.
[ { "created": "Fri, 13 Jun 2014 07:13:45 GMT", "version": "v1" } ]
2014-08-19
[ [ "Andersen", "Jens O.", "" ], [ "Brauner", "Tomas", "" ], [ "Hofmann", "Christoph P.", "" ], [ "Vuorinen", "Aleksi", "" ] ]
The low-energy and low-momentum dynamics of systems with a spontaneously broken continuous symmetry is dominated by the ensuing Nambu-Goldstone bosons. It can be conveniently encoded in a model-independent effective field theory whose structure is fixed by symmetry up to a set of effective coupling constants. We construct the most general effective Lagrangian for the Nambu-Goldstone bosons of spontaneously broken global internal symmetry up to the fourth order in derivatives. Rotational invariance and spatial dimensionality of one, two or three are assumed in order to obtain compact explicit expressions, but our method is completely general and can be applied without modifications to condensed matter systems with a discrete space group as well as to higher-dimensional theories. The general low-energy effective Lagrangian for relativistic systems follows as a special case. We also discuss the effects of explicit symmetry breaking and classify the corresponding terms in the Lagrangian. Diverse examples are worked out in order to make the results accessible to a wide theoretical physics community.
1811.07923
Jose Alonso Carpio Dumler
Jose Carpio, Eduardo Massoni and Alberto Gago
Testing quantum decoherence at DUNE
null
Phys. Rev. D 100, 015035 (2019)
10.1103/PhysRevD.100.015035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address some theoretical issues of the quantum decoherence phenomenon within the neutrino oscillation framework and carry out various tests under DUNE simulated experimental environment. On the theoretical side, we provide a general expression for an invariant decoherence matrix under a quantum basis rotation. On the simulated experimental side, considering a rotation invariant and a non-invariant decoherence matrix, we study the impact on the fitting of the standard oscillation parameters, the sensitivity in the mass hierarchy and CP violation, combining the neutrino and antineutrino mode and all available neutrino oscillation probabilities channels. Furthermore, a sensitivity for the decoherence parameter of order $10^{-24}\text{GeV}$ at 3$\sigma$, is obtained for our best case.
[ { "created": "Mon, 19 Nov 2018 19:02:06 GMT", "version": "v1" }, { "created": "Tue, 19 May 2020 04:06:59 GMT", "version": "v2" } ]
2020-05-20
[ [ "Carpio", "Jose", "" ], [ "Massoni", "Eduardo", "" ], [ "Gago", "Alberto", "" ] ]
We address some theoretical issues of the quantum decoherence phenomenon within the neutrino oscillation framework and carry out various tests under DUNE simulated experimental environment. On the theoretical side, we provide a general expression for an invariant decoherence matrix under a quantum basis rotation. On the simulated experimental side, considering a rotation invariant and a non-invariant decoherence matrix, we study the impact on the fitting of the standard oscillation parameters, the sensitivity in the mass hierarchy and CP violation, combining the neutrino and antineutrino mode and all available neutrino oscillation probabilities channels. Furthermore, a sensitivity for the decoherence parameter of order $10^{-24}\text{GeV}$ at 3$\sigma$, is obtained for our best case.
hep-ph/0311104
Abdelkader-Salim Safir
A. Salim Safir (Munich U.)
CP Violation in B Decays within QCD Factorization
3 pages; 2 figures; To appear in the proceedings of International Europhysics Conference on High-Energy Physics (HEP 2003), Aachen, Germany, 17-23 Jul 2003
Eur.Phys.J.C33:s373-s375,2004
10.1140/epjcd/s2004-03-1831-x
LMU 26/03
hep-ph
null
We analyze the extraction of weak phases from CP violation in $B\to\pi^+\pi^-$ decays. By combining the information on mixing induced CP violation in $B\to\pi^+\pi^-$, namely $S_{\pi\pi}$, with the precision observable $\sin 2\beta$ obtained from the ``gold-plated''mode $B\to\psi K_S$, we propose the determination of the unitarity triangle. We also discuss alternative ways to analyze $S_{\pi\pi}$ which can be useful if new physics affects $B_d$--$\bar B_d$ mixing. Predictions and uncertainties for $r$ and $\phi$ in QCD factorization are examined in detail. It is pointed out that a simultaneous expansion in $1/m_b$ and $1/N_C$ leads to interesting simplifications. At first order infrared divergences are absent, while the most important effects are retained. Independent experimental tests of the factorization framework are briefly discussed.
[ { "created": "Sat, 8 Nov 2003 14:58:06 GMT", "version": "v1" } ]
2010-11-23
[ [ "Safir", "A. Salim", "", "Munich U." ] ]
We analyze the extraction of weak phases from CP violation in $B\to\pi^+\pi^-$ decays. By combining the information on mixing induced CP violation in $B\to\pi^+\pi^-$, namely $S_{\pi\pi}$, with the precision observable $\sin 2\beta$ obtained from the ``gold-plated''mode $B\to\psi K_S$, we propose the determination of the unitarity triangle. We also discuss alternative ways to analyze $S_{\pi\pi}$ which can be useful if new physics affects $B_d$--$\bar B_d$ mixing. Predictions and uncertainties for $r$ and $\phi$ in QCD factorization are examined in detail. It is pointed out that a simultaneous expansion in $1/m_b$ and $1/N_C$ leads to interesting simplifications. At first order infrared divergences are absent, while the most important effects are retained. Independent experimental tests of the factorization framework are briefly discussed.
2406.07447
En-Hung Chao
En-Hung Chao and Norman Christ
Calculating the two-photon exchange contribution to $K_L\rightarrow\mu^+\mu^-$ decay
31 pages, 10 figures
null
null
null
hep-ph hep-lat
http://creativecommons.org/licenses/by-nc-nd/4.0/
We present a theoretical framework within which both the real and imaginary parts of the complex, two-photon exchange amplitude contributing to $K_L\rightarrow\mu^+\mu^-$ decay can be calculated using lattice QCD. The real part of this two-photon amplitude is of approximately the same size as that coming from a second-order weak strangeness-changing neutral-current process. Thus a test of the standard model prediction for this second-order weak process depends on an accurate result of this two-photon amplitude. A limiting factor of our proposed method comes from low-energy three-particle $\pi\pi\gamma$ states. The contribution from these states will be significantly distorted by the finite volume of our calculation -- a distortion for which there is no available correction. However, a simple estimate of the contribution of these three-particle states suggests their contribution to be at most a few percent allowing their neglect in a lattice calculation with a 10% target accuracy.
[ { "created": "Tue, 11 Jun 2024 16:53:33 GMT", "version": "v1" } ]
2024-06-12
[ [ "Chao", "En-Hung", "" ], [ "Christ", "Norman", "" ] ]
We present a theoretical framework within which both the real and imaginary parts of the complex, two-photon exchange amplitude contributing to $K_L\rightarrow\mu^+\mu^-$ decay can be calculated using lattice QCD. The real part of this two-photon amplitude is of approximately the same size as that coming from a second-order weak strangeness-changing neutral-current process. Thus a test of the standard model prediction for this second-order weak process depends on an accurate result of this two-photon amplitude. A limiting factor of our proposed method comes from low-energy three-particle $\pi\pi\gamma$ states. The contribution from these states will be significantly distorted by the finite volume of our calculation -- a distortion for which there is no available correction. However, a simple estimate of the contribution of these three-particle states suggests their contribution to be at most a few percent allowing their neglect in a lattice calculation with a 10% target accuracy.
0804.1099
T. Goldman
H. Burkhardt (1), J. Lowe (1), G.J. Stephenson Jr. (1), T. Goldman (2)and Bruce H.J. McKellar (3) ((1) U. of New Mexico, (2) LANL, (3) U. of Melbourne)
Oscillations in the GSI electron capture experiment
3pp., no figs
null
null
LA-UR-2070
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent paper, oscillations observed in the electron capture probability were attributed to the mixing of neutrino mass eigenstates. This paper is shown to be in error in two respects.
[ { "created": "Mon, 7 Apr 2008 18:04:58 GMT", "version": "v1" } ]
2008-04-08
[ [ "Burkhardt", "H.", "" ], [ "Lowe", "J.", "" ], [ "Stephenson", "G. J.", "Jr." ], [ "Goldman", "T.", "" ], [ "McKellar", "and Bruce H. J.", "" ] ]
In a recent paper, oscillations observed in the electron capture probability were attributed to the mixing of neutrino mass eigenstates. This paper is shown to be in error in two respects.
1310.8042
Jackson Clarke
Jackson D. Clarke, Robert Foot, Raymond R. Volkas
Phenomenology of a very light scalar (100 MeV $<m_h<$ 10 GeV) mixing with the SM Higgs
13 pages, 9 figures
JHEP 1402 (2014) 123
10.1007/JHEP02(2014)123
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate the phenomenology of a very light scalar, $h$, with mass 100 MeV $<m_h<$ 10 GeV, mixing with the SM Higgs. As a benchmark model we take the real singlet scalar extension of the SM. We point out apparently unresolved uncertainties in the branching ratios and lifetime of $h$ in a crucial region of parameter space for LHC phenomenology. Bounds from LEP, meson decays and fixed target experiments are reviewed. We also examine prospects at the LHC. For $m_h \lesssim m_B$ the dominant production mechanism is via meson decay; our main result is the calculation of the differential $p_T$ spectrum of $h$ scalars originating from B mesons and the subsequent prediction of up to thousands of moderate (triggerable) $p_T$ displaced dimuons possibly hiding in the existing dataset at ATLAS/CMS or at LHCb. We also demonstrate that the subdominant $Vh$ production channel has the best sensitivity for $m_h \gtrsim m_B$ and that future bounds in this region could conceivably compete with those of LEP.
[ { "created": "Wed, 30 Oct 2013 06:50:29 GMT", "version": "v1" }, { "created": "Sun, 2 Mar 2014 23:13:26 GMT", "version": "v2" } ]
2014-03-04
[ [ "Clarke", "Jackson D.", "" ], [ "Foot", "Robert", "" ], [ "Volkas", "Raymond R.", "" ] ]
In this paper we investigate the phenomenology of a very light scalar, $h$, with mass 100 MeV $<m_h<$ 10 GeV, mixing with the SM Higgs. As a benchmark model we take the real singlet scalar extension of the SM. We point out apparently unresolved uncertainties in the branching ratios and lifetime of $h$ in a crucial region of parameter space for LHC phenomenology. Bounds from LEP, meson decays and fixed target experiments are reviewed. We also examine prospects at the LHC. For $m_h \lesssim m_B$ the dominant production mechanism is via meson decay; our main result is the calculation of the differential $p_T$ spectrum of $h$ scalars originating from B mesons and the subsequent prediction of up to thousands of moderate (triggerable) $p_T$ displaced dimuons possibly hiding in the existing dataset at ATLAS/CMS or at LHCb. We also demonstrate that the subdominant $Vh$ production channel has the best sensitivity for $m_h \gtrsim m_B$ and that future bounds in this region could conceivably compete with those of LEP.
1504.06421
Marco Sampaio
Raul Costa, Ant\'onio P. Morais, Marco O. P. Sampaio, Rui Santos
Two-loop stability of singlet extensions of the SM with dark matter
Proceeding of the 2nd Toyama Workshop "Higgs as a Probe of New Physics 2015", 11-15 February 2015. 5 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a study of the high energy stability of a minimal complex singlet extension of the Standard Model with or without dark matter (CxSM). We start by obtaining the beta functions of the couplings of the theory from the effective potential and then perform the RGE evolution for the allowed parameter space of the model at the electroweak scale. We obtain the scale up to which the model survives and combine this information with all the LHC measurements as well as bounds from dark matter detection experiments as well as the relic density best measurement from Planck. We conclude that scenarios which solve both the dark matter and stability problems must contain a dark particle heavier than 50 GeV and a new visible state (mixing with the SM-like Higgs) heavier than 170 GeV.
[ { "created": "Fri, 24 Apr 2015 08:31:58 GMT", "version": "v1" } ]
2015-04-27
[ [ "Costa", "Raul", "" ], [ "Morais", "António P.", "" ], [ "Sampaio", "Marco O. P.", "" ], [ "Santos", "Rui", "" ] ]
We present a study of the high energy stability of a minimal complex singlet extension of the Standard Model with or without dark matter (CxSM). We start by obtaining the beta functions of the couplings of the theory from the effective potential and then perform the RGE evolution for the allowed parameter space of the model at the electroweak scale. We obtain the scale up to which the model survives and combine this information with all the LHC measurements as well as bounds from dark matter detection experiments as well as the relic density best measurement from Planck. We conclude that scenarios which solve both the dark matter and stability problems must contain a dark particle heavier than 50 GeV and a new visible state (mixing with the SM-like Higgs) heavier than 170 GeV.
1704.01364
Aritra Bandyopadhyay
Aritra Bandyopadhyay and S. Mallik
Effect of magnetic field on dilepton production in a hot plasma
14 pages, 5 figures; Accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.95.074019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Noncentral collision of heavy ions can generate large magnetic field in its neighbourhood. We describe a method to calculate the effect of this field on the dilepton emission rate from the colliding region, when it reaches thermal equilibrium. It is calculated in the real time method of thermal field theory. We find that the rate is affected significantly only for lower momenta of dileptons.
[ { "created": "Wed, 5 Apr 2017 11:02:45 GMT", "version": "v1" } ]
2017-04-26
[ [ "Bandyopadhyay", "Aritra", "" ], [ "Mallik", "S.", "" ] ]
Noncentral collision of heavy ions can generate large magnetic field in its neighbourhood. We describe a method to calculate the effect of this field on the dilepton emission rate from the colliding region, when it reaches thermal equilibrium. It is calculated in the real time method of thermal field theory. We find that the rate is affected significantly only for lower momenta of dileptons.
hep-ph/0403151
Valery Yudichev
D. Blaschke, D. Ebert, K. G. Klimenko, M. K. Volkov and V. L. Yudichev
Abnormal number of Nambu-Goldstone bosons in the color-asymmetric 2SC phase of an NJL-type model
13 pages, 4 figures, revtex4
Phys.Rev. D70 (2004) 014006
10.1103/PhysRevD.70.014006
null
hep-ph
null
We consider an extended Nambu--Jona-Lasinio model including both (q \bar q)- and (qq)-interactions with two light-quark flavors in the presence of a single (quark density) chemical potential. In the color superconducting phase of the quark matter the color SU(3) symmetry is spontaneously broken down to SU(2). If the usual counting of Goldstone bosons would apply, five Nambu-Goldstone (NG) bosons corresponding to the five broken color generators should appear in the mass spectrum. Unlike that expectation, we find only three gapless diquark excitations of quark matter. One of them is an SU(2)-singlet, the remaining two form an SU(2)-(anti)doublet and have a quadratic dispersion law in the small momentum limit. These results are in agreement with the Nielsen-Chadha theorem, according to which NG-bosons in Lorentz-noninvariant systems, having a quadratic dispersion law, must be counted differently. The origin of the abnormal number of NG-bosons is shown to be related to a nonvanishing expectation value of the color charge operator Q_8 reflecting the lack of color neutrality of the ground state. Finally, by requiring color neutrality, two massive diquarks are argued to become massless, resulting in a normal number of five NG-bosons with usual linear dispersion laws.
[ { "created": "Sun, 14 Mar 2004 11:51:08 GMT", "version": "v1" } ]
2009-11-10
[ [ "Blaschke", "D.", "" ], [ "Ebert", "D.", "" ], [ "Klimenko", "K. G.", "" ], [ "Volkov", "M. K.", "" ], [ "Yudichev", "V. L.", "" ] ]
We consider an extended Nambu--Jona-Lasinio model including both (q \bar q)- and (qq)-interactions with two light-quark flavors in the presence of a single (quark density) chemical potential. In the color superconducting phase of the quark matter the color SU(3) symmetry is spontaneously broken down to SU(2). If the usual counting of Goldstone bosons would apply, five Nambu-Goldstone (NG) bosons corresponding to the five broken color generators should appear in the mass spectrum. Unlike that expectation, we find only three gapless diquark excitations of quark matter. One of them is an SU(2)-singlet, the remaining two form an SU(2)-(anti)doublet and have a quadratic dispersion law in the small momentum limit. These results are in agreement with the Nielsen-Chadha theorem, according to which NG-bosons in Lorentz-noninvariant systems, having a quadratic dispersion law, must be counted differently. The origin of the abnormal number of NG-bosons is shown to be related to a nonvanishing expectation value of the color charge operator Q_8 reflecting the lack of color neutrality of the ground state. Finally, by requiring color neutrality, two massive diquarks are argued to become massless, resulting in a normal number of five NG-bosons with usual linear dispersion laws.
1509.08735
Fabio Dahia
F. Dahia and A. S. Lemos
Is the proton radius puzzle evidence of extra dimensions?
Updated with new data
null
10.1140/epjc/s10052-016-4266-7
null
hep-ph gr-qc hep-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.
[ { "created": "Tue, 29 Sep 2015 13:11:52 GMT", "version": "v1" }, { "created": "Thu, 11 Aug 2016 18:41:01 GMT", "version": "v2" } ]
2016-08-24
[ [ "Dahia", "F.", "" ], [ "Lemos", "A. S.", "" ] ]
The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.
2004.11450
Antonio Enrique C\'arcamo Hern\'andez
A. E. C\'arcamo Hern\'andez, D. T. Huong, Sergey Kovalenko, Antonio P. Morais, Roman Pasechnik, Ivan Schmidt
How low-scale Trinification sheds light in the flavour hierarchies, neutrino puzzle, dark matter and leptogenesis
Version published in PRD
Phys. Rev. D 102, 095003 (2020)
10.1103/PhysRevD.102.095003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a low-scale renormalizable trinification theory that successfully explains the flavor hierarchies and neutrino puzzle in the Standard Model (SM), as well as provides a dark matter candidate and also contains the necessary means for efficient leptogenesis. The proposed theory is based on the trinification $\SU{3}{C}\times \SU{3}{L}\times \SU{3}{R}$ gauge symmetry, which is supplemented with an additional flavor symmetry $\U{X}\times Z_{2}^{(1)} \times Z_{2}^{(2)}$. In the proposed model the top quark and the exotic fermions acquire tree-level masses, whereas the lighter SM charged fermions gain masses radiatively at one-loop level. In addition, the light active neutrino masses arise from a combination of radiative and type-I seesaw mechanisms, with the Dirac neutrino mass matrix generated at one-loop level.
[ { "created": "Thu, 23 Apr 2020 20:43:29 GMT", "version": "v1" }, { "created": "Tue, 19 May 2020 14:02:26 GMT", "version": "v2" }, { "created": "Thu, 31 Dec 2020 13:51:24 GMT", "version": "v3" } ]
2021-01-01
[ [ "Hernández", "A. E. Cárcamo", "" ], [ "Huong", "D. T.", "" ], [ "Kovalenko", "Sergey", "" ], [ "Morais", "Antonio P.", "" ], [ "Pasechnik", "Roman", "" ], [ "Schmidt", "Ivan", "" ] ]
We propose a low-scale renormalizable trinification theory that successfully explains the flavor hierarchies and neutrino puzzle in the Standard Model (SM), as well as provides a dark matter candidate and also contains the necessary means for efficient leptogenesis. The proposed theory is based on the trinification $\SU{3}{C}\times \SU{3}{L}\times \SU{3}{R}$ gauge symmetry, which is supplemented with an additional flavor symmetry $\U{X}\times Z_{2}^{(1)} \times Z_{2}^{(2)}$. In the proposed model the top quark and the exotic fermions acquire tree-level masses, whereas the lighter SM charged fermions gain masses radiatively at one-loop level. In addition, the light active neutrino masses arise from a combination of radiative and type-I seesaw mechanisms, with the Dirac neutrino mass matrix generated at one-loop level.
1910.07522
Vitaly Magerya
Vitaly Magerya, Andrey Pikelner
Cutting massless four-loop propagators
57 pages, 15 tables, 1 figure, auxiliary files
null
10.1007/JHEP12(2019)026
DESY 19-133
hep-ph
http://creativecommons.org/licenses/by/4.0/
Among the unitarity cuts of 4-loop massless propagators two kinds are currently fully known: the 2-particle cuts with 3 loops corresponding to form-factors, and the 5-particle phase-space integrals. In this paper we calculate master integrals for the remaining ones: 3-particle cuts with 2 loops, and 4-particle cuts with 1 loop. The 4-particle cuts are calculated by solving dimensional recurrence relations. The 3-particle cuts are integrated directly using 1->3 amplitudes with 2 loops, which we also re-derive here up to transcendentality weight 7. The results are verified both numerically, and by showing consistency with previously known integrals using Cutkosky rules. We provide the analytic results in the space-time dimension 4-2{\epsilon} as series in {\epsilon} with coefficients being multiple zeta values up to weight 12. In the ancillary files we also provide dimensional recurrence matrices and SummerTime files suitable for numerical evaluation of the series in arbitrary dimensions with any precision.
[ { "created": "Wed, 16 Oct 2019 13:31:40 GMT", "version": "v1" } ]
2020-01-29
[ [ "Magerya", "Vitaly", "" ], [ "Pikelner", "Andrey", "" ] ]
Among the unitarity cuts of 4-loop massless propagators two kinds are currently fully known: the 2-particle cuts with 3 loops corresponding to form-factors, and the 5-particle phase-space integrals. In this paper we calculate master integrals for the remaining ones: 3-particle cuts with 2 loops, and 4-particle cuts with 1 loop. The 4-particle cuts are calculated by solving dimensional recurrence relations. The 3-particle cuts are integrated directly using 1->3 amplitudes with 2 loops, which we also re-derive here up to transcendentality weight 7. The results are verified both numerically, and by showing consistency with previously known integrals using Cutkosky rules. We provide the analytic results in the space-time dimension 4-2{\epsilon} as series in {\epsilon} with coefficients being multiple zeta values up to weight 12. In the ancillary files we also provide dimensional recurrence matrices and SummerTime files suitable for numerical evaluation of the series in arbitrary dimensions with any precision.
1808.02188
Qin Chang
Qin Chang, Jie Zhu, Na Wang and Ru-Min Wang
Probing the effects of new physics in $\bar{B}^* \to P \ell \bar{\nu}_\ell$ decays
24 pages, 4 figures
Advances in High Energy Physics 2018 (2018) 7231354
10.1155/2018/7231354/
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The significant divergence between the SM predictions and experimental measurements for the ratios, $R_{D^{(*)}}\equiv \mathcal{B}(\bar{B}\to D^{(*)}\tau^- \bar{\nu}_\tau)/ \mathcal{B}(\bar{B}\to D^{(*)} \ell^{\prime-} \bar{\nu}_{\ell^{\prime}})$ with $(\ell^{\prime}=e\,,\mu)$, implies possible hint of new physics in the flavour sector. In this paper, motivated by the "$R_{D^{(*)}}$ puzzle" and abundant $B^*$ data samples at high-luminosity heavy-flavor experiments in the future, we try to probe possible effects of new physics in the semileptonic $\bar{B}^*_{u,d,s} \to P \ell^- \bar{\nu}_\ell$ $(P=D\,,D_s\,,\pi\,,K)$ decays induced by $b \to (u,\,c)\ell^- \bar{\nu}_{\ell}$ transitions in the model-independent vector and scalar scenarios. Using the spaces of NP parameters obtained by fitting to the data of $R_{D}$ and $R_{D^{*}}$, the NP effects on the observables including branching fraction, ratio $R_P^{\ast}$, lepton spin asymmetry and lepton forward-backward asymmetry are studied in detail. We find that the vector type couplings have large effects on the branching fraction and ratio $R_P^{\ast}$. Meanwhile, the scalar type couplings provide significant contributions to all of the observables. The future measurements of these observables in the $\bar{B}^* \to P \ell^- \bar{\nu}_\ell$ decays at the LHCb and Belle-II could provide a way to crosscheck the various NP solutions to the "$R_{D^{(*)}}$ puzzle".
[ { "created": "Tue, 7 Aug 2018 03:00:13 GMT", "version": "v1" } ]
2018-10-02
[ [ "Chang", "Qin", "" ], [ "Zhu", "Jie", "" ], [ "Wang", "Na", "" ], [ "Wang", "Ru-Min", "" ] ]
The significant divergence between the SM predictions and experimental measurements for the ratios, $R_{D^{(*)}}\equiv \mathcal{B}(\bar{B}\to D^{(*)}\tau^- \bar{\nu}_\tau)/ \mathcal{B}(\bar{B}\to D^{(*)} \ell^{\prime-} \bar{\nu}_{\ell^{\prime}})$ with $(\ell^{\prime}=e\,,\mu)$, implies possible hint of new physics in the flavour sector. In this paper, motivated by the "$R_{D^{(*)}}$ puzzle" and abundant $B^*$ data samples at high-luminosity heavy-flavor experiments in the future, we try to probe possible effects of new physics in the semileptonic $\bar{B}^*_{u,d,s} \to P \ell^- \bar{\nu}_\ell$ $(P=D\,,D_s\,,\pi\,,K)$ decays induced by $b \to (u,\,c)\ell^- \bar{\nu}_{\ell}$ transitions in the model-independent vector and scalar scenarios. Using the spaces of NP parameters obtained by fitting to the data of $R_{D}$ and $R_{D^{*}}$, the NP effects on the observables including branching fraction, ratio $R_P^{\ast}$, lepton spin asymmetry and lepton forward-backward asymmetry are studied in detail. We find that the vector type couplings have large effects on the branching fraction and ratio $R_P^{\ast}$. Meanwhile, the scalar type couplings provide significant contributions to all of the observables. The future measurements of these observables in the $\bar{B}^* \to P \ell^- \bar{\nu}_\ell$ decays at the LHCb and Belle-II could provide a way to crosscheck the various NP solutions to the "$R_{D^{(*)}}$ puzzle".
hep-ph/0611274
Jeff Forshaw
Jeffrey R. Forshaw
Diffractive Higgs production
8 pages. Talk presented at "Diffraction 2006"
PoSDIFF2006:055,2006
null
MAN/HEP/2006/33
hep-ph
null
Instrumenting the LHC to measure the outgoing protons in the process pp -> p+X+p opens up new possibilities for physics studies in the Standard Model and beyond. In this talk I first present an overview of the underlying QCD calculation and its uncertainties. I then move on to present a variety of new physics scenarios which one would want to explore via this unique channel. There is a short discussion of the recent CDF data which may provide evidence for the existence of central exclusive jet production at the Tevatron.
[ { "created": "Tue, 21 Nov 2006 10:55:09 GMT", "version": "v1" } ]
2008-11-26
[ [ "Forshaw", "Jeffrey R.", "" ] ]
Instrumenting the LHC to measure the outgoing protons in the process pp -> p+X+p opens up new possibilities for physics studies in the Standard Model and beyond. In this talk I first present an overview of the underlying QCD calculation and its uncertainties. I then move on to present a variety of new physics scenarios which one would want to explore via this unique channel. There is a short discussion of the recent CDF data which may provide evidence for the existence of central exclusive jet production at the Tevatron.
1301.0197
Zhenjun Xiao
Wen-Fei Wang, Ying-Ying Fan, Min Liu, and Zhen-Jun Xiao
Semileptonic decays $B/B_s \to (\eta,\etar, G)(l^+l^-,l\bar{\nu},\nu\bar{\nu})$ in the perturbative QCD approach beyond the leading order
8 pages, 1 figure. Published in Phys.Rev. D87, 097501 (2013)
null
10.1103/PhysRevD.87.097501
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we make a systematic study of the semileptonic decays $B/B_s \to (\eta,\etar, G)(l^+l^-,l\bar{\nu},\nu\bar{\nu})$ by employing the perturbative QCD (pQCD) factorization approach. The next-to-leading-order (NLO) contributions to the relevant form factors are included, and the ordinary $\eta$-$\etar$ mixing scheme and the $\eta$-$\etar$-$G$ mixing scheme are considered separately, where $G$ denotes a pseudoscalar glueball. The numerical results and the phenomenological analysis indicate that (a) the NLO contributions to the relevant form factors provide 25% enhancement to the leading-order pQCD predictions for the branching ratios $Br(B^-\to \eta^{(')} l^-\bar{\nu}_l)$, leading to a good agreement between the predictions and the data; (b) for all considered decays, the pQCD results are basically consistent with those from other different theoretical models; (c) the pQCD predictions in the two considered mixing schemes agree well with each other within theoretical errors. The outcomes presented here can be tested by LHCb and forthcoming Super-$B$ experiments.
[ { "created": "Wed, 2 Jan 2013 10:00:10 GMT", "version": "v1" }, { "created": "Sat, 11 May 2013 12:21:34 GMT", "version": "v2" } ]
2013-05-14
[ [ "Wang", "Wen-Fei", "" ], [ "Fan", "Ying-Ying", "" ], [ "Liu", "Min", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper we make a systematic study of the semileptonic decays $B/B_s \to (\eta,\etar, G)(l^+l^-,l\bar{\nu},\nu\bar{\nu})$ by employing the perturbative QCD (pQCD) factorization approach. The next-to-leading-order (NLO) contributions to the relevant form factors are included, and the ordinary $\eta$-$\etar$ mixing scheme and the $\eta$-$\etar$-$G$ mixing scheme are considered separately, where $G$ denotes a pseudoscalar glueball. The numerical results and the phenomenological analysis indicate that (a) the NLO contributions to the relevant form factors provide 25% enhancement to the leading-order pQCD predictions for the branching ratios $Br(B^-\to \eta^{(')} l^-\bar{\nu}_l)$, leading to a good agreement between the predictions and the data; (b) for all considered decays, the pQCD results are basically consistent with those from other different theoretical models; (c) the pQCD predictions in the two considered mixing schemes agree well with each other within theoretical errors. The outcomes presented here can be tested by LHCb and forthcoming Super-$B$ experiments.
hep-ph/0101221
Graham Shaw
A Donnachie, J Gravelis and G Shaw (University of Manchester)
A Unified Model of Exclusive $\rho^0$, $\phi$ and $\jpsi$ Electroproduction
30 pages, 35 figures
Phys.Rev. D63 (2001) 114013
10.1103/PhysRevD.63.114013
M/C-TH-01/01
hep-ph
null
A two-component model is developed for diffractive electroproduction of $\rho^0$, $\phi$ and $\jpsi$, based on non-perturbative and perturbative two-gluon exchange. This provides a common kinematical structure for non-perturbative and perturbative effects, and allows the role of the vector-meson vertex functions to be explored independently of the production dynamics. A good global description of the vector-meson data is obtained.
[ { "created": "Fri, 19 Jan 2001 16:26:14 GMT", "version": "v1" } ]
2009-11-07
[ [ "Donnachie", "A", "", "University of Manchester" ], [ "Gravelis", "J", "", "University of Manchester" ], [ "Shaw", "G", "", "University of Manchester" ] ]
A two-component model is developed for diffractive electroproduction of $\rho^0$, $\phi$ and $\jpsi$, based on non-perturbative and perturbative two-gluon exchange. This provides a common kinematical structure for non-perturbative and perturbative effects, and allows the role of the vector-meson vertex functions to be explored independently of the production dynamics. A good global description of the vector-meson data is obtained.
hep-ph/0309009
Hannes Jung
M. Hansson, H. Jung (Lund University, Sweden)
Status of CCFM - unintegrated gluon densities
to be published in DIS03 proceedings
null
null
null
hep-ph
null
New fits of the unintegrated gluon density obtained from CCFM evolution to HERA $F_2(x,Q^2)$ data are presented. Also predictions of the unintegrated gluon density of the real photon are presented.
[ { "created": "Mon, 1 Sep 2003 11:28:53 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2003 15:00:37 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hansson", "M.", "", "Lund University, Sweden" ], [ "Jung", "H.", "", "Lund University, Sweden" ] ]
New fits of the unintegrated gluon density obtained from CCFM evolution to HERA $F_2(x,Q^2)$ data are presented. Also predictions of the unintegrated gluon density of the real photon are presented.
1902.05556
Spencer Chang
Spencer Chang, Markus A. Luty
The Higgs Trilinear Coupling and the Scale of New Physics
28 pages, 3 figures, added discussion. Final published version in JHEP
J. High Energ. Phys. 2020, 140 (2020)
10.1007/JHEP03(2020)140
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider modifications of the Higgs potential due to new physics at high energy scales. These upset delicate cancellations predicted by the Standard Model for processes involving Higgs bosons and longitudinal gauge bosons, and lead to a breakdown of the theory at high energies. We focus on modifications of the Higgs trilinear coupling and use the violation of tree-level unitarity as an estimate of the scale where the theory breaks down. We obtain a completely model-independent bound of ~ 13 TeV for an order-1 modification of the trilinear. We argue that this bound can be saturated only in fine-tuned models, and the scale of new physics is likely to be much lower. The most stringent bounds are obtained from amplitudes involving multiparticle states that are not conventional scattering states. Our results show that a future determination of the Higgs cubic coupling can point to a well-defined scale of new physics that can be targeted and explored at future colliders.
[ { "created": "Thu, 14 Feb 2019 19:00:02 GMT", "version": "v1" }, { "created": "Tue, 31 Mar 2020 07:00:40 GMT", "version": "v2" } ]
2020-04-01
[ [ "Chang", "Spencer", "" ], [ "Luty", "Markus A.", "" ] ]
We consider modifications of the Higgs potential due to new physics at high energy scales. These upset delicate cancellations predicted by the Standard Model for processes involving Higgs bosons and longitudinal gauge bosons, and lead to a breakdown of the theory at high energies. We focus on modifications of the Higgs trilinear coupling and use the violation of tree-level unitarity as an estimate of the scale where the theory breaks down. We obtain a completely model-independent bound of ~ 13 TeV for an order-1 modification of the trilinear. We argue that this bound can be saturated only in fine-tuned models, and the scale of new physics is likely to be much lower. The most stringent bounds are obtained from amplitudes involving multiparticle states that are not conventional scattering states. Our results show that a future determination of the Higgs cubic coupling can point to a well-defined scale of new physics that can be targeted and explored at future colliders.
2303.12781
Giancarlo Ferrera
Stefano Camarda, Leandro Cieri and Giancarlo Ferrera
Drell-Yan lepton-pair production: $q_T$ resummation at approximate N$^4$LL+N$^4$LO accuracy
20 pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider Drell-Yan lepton pairs produced in hadronic collisions. We present high-accuracy QCD predictions for the transverse-momentum ($q_T$) distribution and fiducial cross sections in the small $q_T$ region. We resum to all perturbative orders the logarithmically enhanced contributions up to the next-to-next-to-next-to-next-to-leading logarithmic (N$^4$LL) accuracy and we include the hard-virtual coefficient at the next-to-next-to-next-to-leading order (N$^3$LO) (i.e. $\mathcal{O}(\alpha_S^3)$) with an approximation of the N$^4$LO coefficients. The massive axial-vector and vector contributions up to three loops have also been consistently included. The resummed partonic cross section is convoluted with approximate N$^3$LO parton distribution functions. We show numerical results at LHC energies of resummed $q_T$ distributions for $Z/\gamma^*, W^\pm$ production and decay, including the $W^\pm$ and $Z/\gamma^*$ ratio, estimating the corresponding uncertainties from missing higher orders corrections and from incomplete or missing perturbative information coefficients at N$^4$LL and N$^4$LO. Our resummed calculation has been encoded in the public numerical program DYTurbo.
[ { "created": "Wed, 22 Mar 2023 17:51:32 GMT", "version": "v1" } ]
2023-03-23
[ [ "Camarda", "Stefano", "" ], [ "Cieri", "Leandro", "" ], [ "Ferrera", "Giancarlo", "" ] ]
We consider Drell-Yan lepton pairs produced in hadronic collisions. We present high-accuracy QCD predictions for the transverse-momentum ($q_T$) distribution and fiducial cross sections in the small $q_T$ region. We resum to all perturbative orders the logarithmically enhanced contributions up to the next-to-next-to-next-to-next-to-leading logarithmic (N$^4$LL) accuracy and we include the hard-virtual coefficient at the next-to-next-to-next-to-leading order (N$^3$LO) (i.e. $\mathcal{O}(\alpha_S^3)$) with an approximation of the N$^4$LO coefficients. The massive axial-vector and vector contributions up to three loops have also been consistently included. The resummed partonic cross section is convoluted with approximate N$^3$LO parton distribution functions. We show numerical results at LHC energies of resummed $q_T$ distributions for $Z/\gamma^*, W^\pm$ production and decay, including the $W^\pm$ and $Z/\gamma^*$ ratio, estimating the corresponding uncertainties from missing higher orders corrections and from incomplete or missing perturbative information coefficients at N$^4$LL and N$^4$LO. Our resummed calculation has been encoded in the public numerical program DYTurbo.
1305.7340
Matthias Steinhauser
Jonathan Grigo, Jens Hoff, Kirill Melnikov, Matthias Steinhauser
On the Higgs boson pair production at the LHC
19 pages, 10 figures
null
10.1016/j.nuclphysb.2013.06.024
SFB/CPP-13-29, TTP13-13, LPN13-030
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the production cross section of a pair of Standard Model Higgs bosons at the LHC at next-to-leading order in QCD, including corrections in inverse powers of the top quark mass. We calculate these power corrections through ${\cal O}(1/M_t^8)$ and study their relevance for phenomenology of the double Higgs production. We find that power corrections are significant, even for moderate values of partonic center-of-mass energies, and that convergence of the $1/M_t$ expansion can be dramatically improved by factorizing the leading order cross section with full $M_t$-dependence.
[ { "created": "Fri, 31 May 2013 09:38:11 GMT", "version": "v1" } ]
2015-06-16
[ [ "Grigo", "Jonathan", "" ], [ "Hoff", "Jens", "" ], [ "Melnikov", "Kirill", "" ], [ "Steinhauser", "Matthias", "" ] ]
We compute the production cross section of a pair of Standard Model Higgs bosons at the LHC at next-to-leading order in QCD, including corrections in inverse powers of the top quark mass. We calculate these power corrections through ${\cal O}(1/M_t^8)$ and study their relevance for phenomenology of the double Higgs production. We find that power corrections are significant, even for moderate values of partonic center-of-mass energies, and that convergence of the $1/M_t$ expansion can be dramatically improved by factorizing the leading order cross section with full $M_t$-dependence.
hep-ph/0212030
Volodymyr Magas
R. Fiore, A. Flachi, L.L. Jenkovszky, A. Lengyel, V.K. Magas
Generalized distribution amplitudes: new tools to study hadrons' structure and interactions
12 pages, 2 figures, style file included
Proceedings of the NATO Advanced Research Workshop "Diffraction 2002", Alushta, Crimea, Ukraine, August 31 - September 6, 2002, edited by R. Fiore, A. Papa, L.L. Jenkovszky, M.I. Kotsky, V.K. Magas (Kluwer Academic 2003) NATO ASI series II: Mathematics, physics and chemistry. 101 pp. 123-134
null
null
hep-ph
null
A non-perturbative approach to Generalized Parton Distributions, and to Deeply Virtual Compton Scattering in particular, based on off mass shell extension of dual amplitudes with Mandelstam analyticity (DAMA) is developed with the spin and helicity structure as well as the threshold behavior accounted for. The model is tested against the data on deep inelastic electron-proton scattering from JLab.
[ { "created": "Mon, 2 Dec 2002 21:21:11 GMT", "version": "v1" }, { "created": "Fri, 3 Oct 2003 14:50:19 GMT", "version": "v2" } ]
2007-05-23
[ [ "Fiore", "R.", "" ], [ "Flachi", "A.", "" ], [ "Jenkovszky", "L. L.", "" ], [ "Lengyel", "A.", "" ], [ "Magas", "V. K.", "" ] ]
A non-perturbative approach to Generalized Parton Distributions, and to Deeply Virtual Compton Scattering in particular, based on off mass shell extension of dual amplitudes with Mandelstam analyticity (DAMA) is developed with the spin and helicity structure as well as the threshold behavior accounted for. The model is tested against the data on deep inelastic electron-proton scattering from JLab.
1601.03736
David Vanegas Forero
David V. Forero, Patrick Huber
Hints for leptonic CP violation or New Physics?
4 pages, 2 figures
Phys. Rev. Lett. 117, 031801 (2016)
10.1103/PhysRevLett.117.031801
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the major open questions in the neutrino sector is the issue of leptonic CP violation. Current global oscillation data shows a mild preference for a large, potentially maximal value for the Dirac CP phase in the neutrino mixing matrix. In this letter, we point out that New Physics in the form of neutral-current like non-standard interactions with real couplings would likely yield a similar conclusion even if CP in the neutrino sector were conserved. Therefore, the claim for a discovery of leptonic CP violation will require a robust ability to test New Physics scenarios.
[ { "created": "Thu, 14 Jan 2016 21:00:01 GMT", "version": "v1" } ]
2016-07-20
[ [ "Forero", "David V.", "" ], [ "Huber", "Patrick", "" ] ]
One of the major open questions in the neutrino sector is the issue of leptonic CP violation. Current global oscillation data shows a mild preference for a large, potentially maximal value for the Dirac CP phase in the neutrino mixing matrix. In this letter, we point out that New Physics in the form of neutral-current like non-standard interactions with real couplings would likely yield a similar conclusion even if CP in the neutrino sector were conserved. Therefore, the claim for a discovery of leptonic CP violation will require a robust ability to test New Physics scenarios.
1501.03088
Bruno Os\'orio Rodrigues
B. Os\'orio Rodrigues, M. E. Bracco, M. Chiapparini, A. Cerqueira Jr
A QCD sum rules calculation of the $J/\psi D_s^* D_s$ strong coupling constant
17 pages, 4 figures
null
10.1140/epja/i2015-15028-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we calculate the form factors and the coupling constant of the strange-charmed vertex $J/\psi D_s^* D_s$ in the framework of the QCD sum rules by studying their three-point correlation functions. All the possible off-shell cases are considered, $D_s$, $D_s^*$ and $J/\psi$, resulting in three different form factors. These form factors are extrapolated to the pole of their respective off-shell mesons, giving the same coupling constant for the process. Our final result for the $J/\psi D_s^* D_s$ coupling constant is $g_{J/\psi D^*_s D_s} = 4.30^{+0.42}_{-0.37}\text{GeV}^{-1}$.
[ { "created": "Tue, 13 Jan 2015 17:54:15 GMT", "version": "v1" } ]
2015-06-23
[ [ "Rodrigues", "B. Osório", "" ], [ "Bracco", "M. E.", "" ], [ "Chiapparini", "M.", "" ], [ "Cerqueira", "A.", "Jr" ] ]
In this work, we calculate the form factors and the coupling constant of the strange-charmed vertex $J/\psi D_s^* D_s$ in the framework of the QCD sum rules by studying their three-point correlation functions. All the possible off-shell cases are considered, $D_s$, $D_s^*$ and $J/\psi$, resulting in three different form factors. These form factors are extrapolated to the pole of their respective off-shell mesons, giving the same coupling constant for the process. Our final result for the $J/\psi D_s^* D_s$ coupling constant is $g_{J/\psi D^*_s D_s} = 4.30^{+0.42}_{-0.37}\text{GeV}^{-1}$.
hep-ph/0604238
Chao-Hsi Chang
Chao-Hsi Chang, Jian-Xiong Wang and Xing-Gang Wu
An Upgraded Version of the Generator BCVEGPY2.0 for Hadronic Production of $B_c$ Meson and Its Excited States
9 pages, 1 figure. Add explanation and correct the typos etc
Comput.Phys.Commun.175:624-627,2006
10.1016/j.cpc.2006.07.014
null
hep-ph hep-ex
null
An upgraded version of the package [BCVEGPY2.0: Chao-Hsi Chang, Jian-Xiong Wang and Xing-Gang Wu, Comput. Phys. Commun. {\bf 174} (2006) 241-251] is presented, which works under LINUX system and is named as BCVEGPY2.1. Using this version with a GNU C compiler, users may simulate the $B_c$-events in various experimental environments very conveniently. It has been rearranged for better modularity and code reusability (less dependency among various modules) than BCVEGPY2.0 has. Furthermore, in the upgraded version a special and convenient executable-file {\bf run} as default is available according to one's wish, i.e., the file is obtained in the way that the GNU command {\bf make} compiles the codes requested by precise purpose with the help of a master {\bf makefile} in the main code directory. Finally, this paper may also be considered as an erratum of the original BCVEGPY2.0, i.e., here the errors (typo mainly) in BCVEGPY2.0 have been corrected.
[ { "created": "Thu, 27 Apr 2006 09:57:10 GMT", "version": "v1" }, { "created": "Tue, 4 Jul 2006 11:18:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chang", "Chao-Hsi", "" ], [ "Wang", "Jian-Xiong", "" ], [ "Wu", "Xing-Gang", "" ] ]
An upgraded version of the package [BCVEGPY2.0: Chao-Hsi Chang, Jian-Xiong Wang and Xing-Gang Wu, Comput. Phys. Commun. {\bf 174} (2006) 241-251] is presented, which works under LINUX system and is named as BCVEGPY2.1. Using this version with a GNU C compiler, users may simulate the $B_c$-events in various experimental environments very conveniently. It has been rearranged for better modularity and code reusability (less dependency among various modules) than BCVEGPY2.0 has. Furthermore, in the upgraded version a special and convenient executable-file {\bf run} as default is available according to one's wish, i.e., the file is obtained in the way that the GNU command {\bf make} compiles the codes requested by precise purpose with the help of a master {\bf makefile} in the main code directory. Finally, this paper may also be considered as an erratum of the original BCVEGPY2.0, i.e., here the errors (typo mainly) in BCVEGPY2.0 have been corrected.
1903.05664
Khushboo Dixit
Khushboo Dixit, Javid Naikoo, Banibrata Mukhopadhyay, Subhashish Banerjee
Quantum correlations in neutrino oscillations in curved spacetime
7 pages, 5 figures, Matches the published version
Phys. Rev. D 100, 055021 (2019)
10.1103/PhysRevD.100.055021
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravity induced neutrino-antineutrino oscillations are studied in the context of one and two flavor scenarios. This allows one to investigate the particle-antiparticle correlations in two and four level systems, respectively. Flavor entropy is used to probe the entanglement in the system. The well known witnesses of non-classicality such as Mermin and Svetlichly inequalities are investigated. Since the extent of neutrino-antineutrino oscillation is governed by the strength of the gravitational field, the behavior of non-classicality shows interesting features as one varies the strength of the gravitational field. Specifically, the suppression of the entanglement with the increase of the gravitational field is observed which is witnessed in the form of decrease in the flavor entropy of the system. The features of the Mermin and the Svetlichny inequalities allow one to make statements about the degeneracy of neutrino mass eigenstates.
[ { "created": "Wed, 13 Mar 2019 18:27:46 GMT", "version": "v1" }, { "created": "Thu, 19 Sep 2019 10:32:39 GMT", "version": "v2" } ]
2019-09-20
[ [ "Dixit", "Khushboo", "" ], [ "Naikoo", "Javid", "" ], [ "Mukhopadhyay", "Banibrata", "" ], [ "Banerjee", "Subhashish", "" ] ]
Gravity induced neutrino-antineutrino oscillations are studied in the context of one and two flavor scenarios. This allows one to investigate the particle-antiparticle correlations in two and four level systems, respectively. Flavor entropy is used to probe the entanglement in the system. The well known witnesses of non-classicality such as Mermin and Svetlichly inequalities are investigated. Since the extent of neutrino-antineutrino oscillation is governed by the strength of the gravitational field, the behavior of non-classicality shows interesting features as one varies the strength of the gravitational field. Specifically, the suppression of the entanglement with the increase of the gravitational field is observed which is witnessed in the form of decrease in the flavor entropy of the system. The features of the Mermin and the Svetlichny inequalities allow one to make statements about the degeneracy of neutrino mass eigenstates.
hep-ph/9511244
null
A. Dobado and J. Morales
A note on the GG-->PI 0 PI 0 reaction in the 1/N expansion of ChPT
16 pages, LaTeX
Phys.Lett. B365 (1996) 264-274
10.1016/0370-2693(95)01240-0
null
hep-ph
null
In this work we present the results of a complete calculation of the $\gamma \gamma\rightarrow \pi^0\pi^0$ amplitude to leading order in the large $N$ approximation ($N$ being the number of Goldstone bosons) up to order $m^2_{\pi}/F^2$. The amplitude turns to be proportional to that of $\pi^+\pi^-\rightarrow \pi^0\pi^0$. In spite of the fact that this factorization property cannot hold in general (as it was recently pointed out by Morgan and Penington), it appears here since in the large $N$ limit only the $I=J=0$ channel contributes to the $\gamma \gamma\rightarrow \pi^0\pi^0$ reaction. Moreover it seems to be a reasonable approximation in this case since it is possible to reproduce, as a prediction, the experimental data starting from a one-parameter fit of the $\pi\pi$ scattering data.
[ { "created": "Mon, 6 Nov 1995 08:17:14 GMT", "version": "v1" } ]
2016-09-01
[ [ "Dobado", "A.", "" ], [ "Morales", "J.", "" ] ]
In this work we present the results of a complete calculation of the $\gamma \gamma\rightarrow \pi^0\pi^0$ amplitude to leading order in the large $N$ approximation ($N$ being the number of Goldstone bosons) up to order $m^2_{\pi}/F^2$. The amplitude turns to be proportional to that of $\pi^+\pi^-\rightarrow \pi^0\pi^0$. In spite of the fact that this factorization property cannot hold in general (as it was recently pointed out by Morgan and Penington), it appears here since in the large $N$ limit only the $I=J=0$ channel contributes to the $\gamma \gamma\rightarrow \pi^0\pi^0$ reaction. Moreover it seems to be a reasonable approximation in this case since it is possible to reproduce, as a prediction, the experimental data starting from a one-parameter fit of the $\pi\pi$ scattering data.
0806.0418
Ina Sarcevic
Rikard Enberg (Arizona), Mary Hall Reno (Iowa) and Ina Sarcevic (Arizona)
Prompt neutrino fluxes from atmospheric charm
13 pages with 11 figures; expanded discussion, added references, version to be published in Phys. Rev. D
Phys.Rev.D78:043005,2008
10.1103/PhysRevD.78.043005
null
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the prompt neutrino flux from atmospheric charm production by cosmic rays, using the dipole picture in a perturbative QCD framework, which incorporates the parton saturation effects present at high energies. We compare our results with the next-to-leading order perturbative QCD result and find that saturation effects are large for neutrino energies above 10^6 GeV, leading to a substantial suppression of the prompt neutrino flux. We comment on the range of prompt neutrino fluxes due to theoretical uncertainties.
[ { "created": "Tue, 3 Jun 2008 01:06:57 GMT", "version": "v1" }, { "created": "Wed, 16 Jul 2008 14:16:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Enberg", "Rikard", "", "Arizona" ], [ "Reno", "Mary Hall", "", "Iowa" ], [ "Sarcevic", "Ina", "", "Arizona" ] ]
We calculate the prompt neutrino flux from atmospheric charm production by cosmic rays, using the dipole picture in a perturbative QCD framework, which incorporates the parton saturation effects present at high energies. We compare our results with the next-to-leading order perturbative QCD result and find that saturation effects are large for neutrino energies above 10^6 GeV, leading to a substantial suppression of the prompt neutrino flux. We comment on the range of prompt neutrino fluxes due to theoretical uncertainties.
0803.4110
Rahul Basu
Rahul Basu, Debajyoti Choudhury and H. S. Mani
Fermionic un-particles, gauge interactions and the $\beta$ function
15 pages, LateX, uses axocolor.sty, included
Eur.Phys.J.C61:461-470,2009
10.1140/epjc/s10052-009-1022-2
IMSc/2008/03/03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dynamics of fermionic unparticles is developed from first principles. It is shown that any unparticle, whether fermionic or bosonic, can be recast in terms of a canonically quantized field, but with non-local interaction terms. We further develop a possible gauge theory for fermionic unparticles. Computing the consequent contribution of un-fermions to the $\beta$ function of the theory, it is shown that this can be viewed as the sum of two contributions, one fermion-like and the other scalar-like. However, if full conformal invariance is imposed, the latter vanishes identically. We discuss the consequences thereof as well as some general phenomenological issues.
[ { "created": "Fri, 28 Mar 2008 13:17:57 GMT", "version": "v1" } ]
2009-07-22
[ [ "Basu", "Rahul", "" ], [ "Choudhury", "Debajyoti", "" ], [ "Mani", "H. S.", "" ] ]
The dynamics of fermionic unparticles is developed from first principles. It is shown that any unparticle, whether fermionic or bosonic, can be recast in terms of a canonically quantized field, but with non-local interaction terms. We further develop a possible gauge theory for fermionic unparticles. Computing the consequent contribution of un-fermions to the $\beta$ function of the theory, it is shown that this can be viewed as the sum of two contributions, one fermion-like and the other scalar-like. However, if full conformal invariance is imposed, the latter vanishes identically. We discuss the consequences thereof as well as some general phenomenological issues.
hep-ph/0206113
Silas R. Beane
Silas R. Beane and Martin J. Savage
Variation of Fundamental Couplings and Nuclear Forces
16 pages LaTeX, 4 eps figs, 12 ps figs
Nucl.Phys.A713:148-164,2003
10.1016/S0375-9474(02)01268-X
NT@UW-02-015
hep-ph astro-ph hep-lat hep-th nucl-th
null
The dependence of the nuclear force on standard model parameters plays an important role in bounding time and space variations of fundamental couplings over cosmological time scales. We discuss the quark-mass dependence of deuteron and di-neutron binding in a systematic chiral expansion. The leading quark-mass dependence of the nuclear force arises from one-pion exchange and from local quark-mass dependent four-nucleon operators with coefficients that are presently unknown. By varying these coefficients while leaving nuclear observables at the physical values of the quark masses invariant, we find scenarios where two-nucleon physics depends both weakly and strongly on the quark masses. While the determination of these coefficients is an exciting future opportunity for lattice QCD, we conclude that, at present, bounds on time and space variations of fundamental parameters from the two-nucleon sector are much weaker than previously claimed. This brings into question the reliability of coupling-constant bounds derived from more complex nuclei and nuclear processes.
[ { "created": "Wed, 12 Jun 2002 20:26:55 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2002 16:23:06 GMT", "version": "v2" } ]
2014-11-17
[ [ "Beane", "Silas R.", "" ], [ "Savage", "Martin J.", "" ] ]
The dependence of the nuclear force on standard model parameters plays an important role in bounding time and space variations of fundamental couplings over cosmological time scales. We discuss the quark-mass dependence of deuteron and di-neutron binding in a systematic chiral expansion. The leading quark-mass dependence of the nuclear force arises from one-pion exchange and from local quark-mass dependent four-nucleon operators with coefficients that are presently unknown. By varying these coefficients while leaving nuclear observables at the physical values of the quark masses invariant, we find scenarios where two-nucleon physics depends both weakly and strongly on the quark masses. While the determination of these coefficients is an exciting future opportunity for lattice QCD, we conclude that, at present, bounds on time and space variations of fundamental parameters from the two-nucleon sector are much weaker than previously claimed. This brings into question the reliability of coupling-constant bounds derived from more complex nuclei and nuclear processes.
1302.0672
Sudhanwa Patra Dr.
Ram Lal Awasthi (HRI, Allhabad), M. K. Parida (CETMS, SOA Univ., Bhubaneswar) and Sudhanwa Patra (CETMS, SOA Univ., Bhubaneswar)
Neutrino masses, dominant neutrinoless double beta decay, and observable lepton flavor violation in left-right models and SO(10) grand unification with low mass $\bf W_R, Z_R$ bosons
46 pages latex, 13 figures, 11 Tables, JHEP version accepted for publication
JHEP 08 (2013) 122
10.1007/JHEP08(2013)122
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While the detection of $W_R$-boson at the Large Hadron Collider is likely to resolve the mystery of parity violation in weak interaction, observation of neutrinoless double beta decay ($0\nu\beta\beta$) is expected to determine whether neutrinos are Majorana fermions. In this work we consider a class of LR models with TeV scale $W_R, Z_R$ bosons but having parity restoration at high scales where they originate from well known Pati-Salam symmetry or $SO(10)$ grand unified theory minimally extended to accommodate inverse seesaw frame work for neutrino masses. Most dominant new contribution to neutrinoless double beta decay is noted to occur via $W_L^{-}W_L^{-}$ mediation involving lighter sterile neutrino exchanges. The next dominant contribution is found to be through $W_L^{-}W_R^{-}$ mediation involving both light and heavy right-handed neutrino or sterile neutrino exchanges. The quark-lepton symmetric origin of the computed value of the Dirac neutrino mass matrix is also found to play a crucial role in determining these and other results on lepton flavor violating branching ratios for $\tau \rightarrow e + \gamma$, $\tau \rightarrow \mu + \gamma$, and $\mu \rightarrow e + \gamma$ accessible to ongoing search experiments. The underlying non-unitarity matrix is found to manifest in substantial CP-violating effects even when the leptonic Dirac phase $\delta_{\rm CP} \simeq 0, \pi, 2 \pi$. Finally we explore a possible origin of the model in non-supersymmetric SO(10) grand unified theory where, in addition to low mass $W_R^\pm$ and $Z_R$ bosons accessible to Large Hadron Collider, the model is found to predict observable neutron-antineutron oscillation and lepto-quark gauge boson mediated rare kaon decay with $\mbox{Br} \left(K_{\rm L} \rightarrow \mu\, \bar{e}\right) \simeq \left(10^{-9}- 10^{-11} \right)$.
[ { "created": "Mon, 4 Feb 2013 12:47:41 GMT", "version": "v1" }, { "created": "Wed, 7 Aug 2013 13:50:32 GMT", "version": "v2" } ]
2013-09-03
[ [ "Awasthi", "Ram Lal", "", "HRI, Allhabad" ], [ "Parida", "M. K.", "", "CETMS, SOA Univ.,\n Bhubaneswar" ], [ "Patra", "Sudhanwa", "", "CETMS, SOA Univ., Bhubaneswar" ] ]
While the detection of $W_R$-boson at the Large Hadron Collider is likely to resolve the mystery of parity violation in weak interaction, observation of neutrinoless double beta decay ($0\nu\beta\beta$) is expected to determine whether neutrinos are Majorana fermions. In this work we consider a class of LR models with TeV scale $W_R, Z_R$ bosons but having parity restoration at high scales where they originate from well known Pati-Salam symmetry or $SO(10)$ grand unified theory minimally extended to accommodate inverse seesaw frame work for neutrino masses. Most dominant new contribution to neutrinoless double beta decay is noted to occur via $W_L^{-}W_L^{-}$ mediation involving lighter sterile neutrino exchanges. The next dominant contribution is found to be through $W_L^{-}W_R^{-}$ mediation involving both light and heavy right-handed neutrino or sterile neutrino exchanges. The quark-lepton symmetric origin of the computed value of the Dirac neutrino mass matrix is also found to play a crucial role in determining these and other results on lepton flavor violating branching ratios for $\tau \rightarrow e + \gamma$, $\tau \rightarrow \mu + \gamma$, and $\mu \rightarrow e + \gamma$ accessible to ongoing search experiments. The underlying non-unitarity matrix is found to manifest in substantial CP-violating effects even when the leptonic Dirac phase $\delta_{\rm CP} \simeq 0, \pi, 2 \pi$. Finally we explore a possible origin of the model in non-supersymmetric SO(10) grand unified theory where, in addition to low mass $W_R^\pm$ and $Z_R$ bosons accessible to Large Hadron Collider, the model is found to predict observable neutron-antineutron oscillation and lepto-quark gauge boson mediated rare kaon decay with $\mbox{Br} \left(K_{\rm L} \rightarrow \mu\, \bar{e}\right) \simeq \left(10^{-9}- 10^{-11} \right)$.
hep-ph/9408237
Ernest Ma
Ernest Ma
Unifiable Supersymmetric Left-Right Model with E_6 Particle Content
12 pages (1 figure not included), UCRHEP-T129 (July 1994)
Phys.Lett. B344 (1995) 164-168
10.1016/0370-2693(94)01496-Y
null
hep-ph
null
A new supersymmetric gauge model is proposed with particle content chosen only from the 27 and 27* representations of E_6. The gauge symmetry SU(3) X SU(2)_L X SU(2)_R X U(1) is realized at the TeV energy scale and the gauge couplings converge to a single value at around 10^{16} GeV. A discrete Z_4 X Z_2 symmetry leads to a generalized definition of lepton number and ensures the absence of tree-level flavor-changing neutral-current interactions at the electroweak energy scale.
[ { "created": "Thu, 4 Aug 1994 22:43:22 GMT", "version": "v1" } ]
2009-10-28
[ [ "Ma", "Ernest", "" ] ]
A new supersymmetric gauge model is proposed with particle content chosen only from the 27 and 27* representations of E_6. The gauge symmetry SU(3) X SU(2)_L X SU(2)_R X U(1) is realized at the TeV energy scale and the gauge couplings converge to a single value at around 10^{16} GeV. A discrete Z_4 X Z_2 symmetry leads to a generalized definition of lepton number and ensures the absence of tree-level flavor-changing neutral-current interactions at the electroweak energy scale.
hep-ph/0311136
Aiichi Iwazaki
A. Iwazaki
Color Ferromagnetism and Quantum Hall states in Quark Matter
Talk at (or Contribution to) the International Workshop on QCD: QCD@Work 2003 - Conversano (Italy) 14-18 June 2003 (eConf C030614)
null
null
NISHO-2003-3
hep-ph
null
We discuss a possibility of the presence of a stable color ferromagnetic state in SU(2) gauge theory of quark matter; a color magnetic field is spontaneously generated due tothe gluon's dynamics. The state arises between the hadronic state and the color superconducting state when the density of quarks is varied. Although the state has been known to have unstable modes, we show that unstable modes form quantum Hall states, in which the instability disappears. Namely, the quark matter possesses a stable phase with the ferromagnetic state and the quantum Hall state of gluons.
[ { "created": "Tue, 11 Nov 2003 08:35:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Iwazaki", "A.", "" ] ]
We discuss a possibility of the presence of a stable color ferromagnetic state in SU(2) gauge theory of quark matter; a color magnetic field is spontaneously generated due tothe gluon's dynamics. The state arises between the hadronic state and the color superconducting state when the density of quarks is varied. Although the state has been known to have unstable modes, we show that unstable modes form quantum Hall states, in which the instability disappears. Namely, the quark matter possesses a stable phase with the ferromagnetic state and the quantum Hall state of gluons.
hep-ph/0211250
Matthew J. Lewis
Katherine Freese, Matthew Lewis, and Jan Pieter van der Schaar
Observational Tests of Open Strings in Braneworld Scenarios
Minor grammatical corrections and two reference added. 27 pages, 1 eps figure. Submitted to JHEP
JHEP 0307 (2003) 026
10.1088/1126-6708/2003/07/026
CERN-TH/2002-332; MCTP-02-60
hep-ph astro-ph hep-th
null
We consider some consequences of describing the gauge and matter degrees of freedom in our universe by open strings, as suggested by the braneworld scenario. We focus on the geometric effects described by the open string metric and investigate their observational implications. The causal structure of spacetime on the brane is altered; it is described not by the usual metric $g_{\mu\nu}$, but instead by the open string metric, that incorporates the electromagnetic background, $G_{\mu\nu} = g_{\mu\nu} - (2\pi \alpha^\prime)^2 (F^2)_{\mu\nu}$. The speed of light is now slower when propagating along directions transverse to electromagnetic fields or an NS-NS two form, so that Lorentz invariance is explicitly broken. A generalized equivalence principle guarantees that the propagation of {\it all} particles, not just photons, (with the exception of gravitons) is slower in these transverse directions. We describe a variety of astrophysical and laboratory-based experiments designed to detect the predicted variations in the causal structure. We show that current technology cannot probe beyond open string lengths of $10^{-13}$ cm, corresponding to MeV string scales. We also point out that in a braneworld scenario, constraints on large scale electromagnetic fields together with a modest phenomenological bound on the NS-NS two-form naturally lead to a bound on the scale of canonical noncommutativity that is two orders of magnitude below the string length. By invoking theoretical constraints on the NS-NS two-form this bound can be improved to give an extremely strong bound on the noncommutative scale well below the Planck length, $\sqrt{|\theta|_{max}} < 10^{-35} {\rm cm} \times ({{\rm TeV} \over {\rm string} {\rm scale}}
[ { "created": "Fri, 15 Nov 2002 20:44:06 GMT", "version": "v1" }, { "created": "Tue, 19 Nov 2002 23:17:25 GMT", "version": "v2" } ]
2009-11-07
[ [ "Freese", "Katherine", "" ], [ "Lewis", "Matthew", "" ], [ "van der Schaar", "Jan Pieter", "" ] ]
We consider some consequences of describing the gauge and matter degrees of freedom in our universe by open strings, as suggested by the braneworld scenario. We focus on the geometric effects described by the open string metric and investigate their observational implications. The causal structure of spacetime on the brane is altered; it is described not by the usual metric $g_{\mu\nu}$, but instead by the open string metric, that incorporates the electromagnetic background, $G_{\mu\nu} = g_{\mu\nu} - (2\pi \alpha^\prime)^2 (F^2)_{\mu\nu}$. The speed of light is now slower when propagating along directions transverse to electromagnetic fields or an NS-NS two form, so that Lorentz invariance is explicitly broken. A generalized equivalence principle guarantees that the propagation of {\it all} particles, not just photons, (with the exception of gravitons) is slower in these transverse directions. We describe a variety of astrophysical and laboratory-based experiments designed to detect the predicted variations in the causal structure. We show that current technology cannot probe beyond open string lengths of $10^{-13}$ cm, corresponding to MeV string scales. We also point out that in a braneworld scenario, constraints on large scale electromagnetic fields together with a modest phenomenological bound on the NS-NS two-form naturally lead to a bound on the scale of canonical noncommutativity that is two orders of magnitude below the string length. By invoking theoretical constraints on the NS-NS two-form this bound can be improved to give an extremely strong bound on the noncommutative scale well below the Planck length, $\sqrt{|\theta|_{max}} < 10^{-35} {\rm cm} \times ({{\rm TeV} \over {\rm string} {\rm scale}}
1408.3211
Kim Siyeon
Sin Kyu Kang, Yeong-Duk Kim, Young-Ju Ko, Kim Siyeon
Four-neutrino analysis of 1.5km-baseline reactor antineutrino oscillations
14 pages, 7 figures. arXiv admin note: text overlap with arXiv:1303.6173
Adv.High Energy Phys. 2013 (2013) 138109
10.1155/2013/138109
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The masses of sterile neutrinos are not yet known, and depending on the orders of magnitudes, their existence may explain reactor anomalies or the spectral shape of reactor neutrino events at 1.5km-baseline detector. Here, we present four-neutrino analysis of the results announced by RENO and Daya Bay, which performed the definitive measurements of $\theta_{13}$ based on the disappearance of reactor antineutrinos at km-order baselines. Our results using 3+1 scheme include the exclusion curve of $\Delta m^2_{41}$ vs. $\theta_{14}$ and the adjustment of $\theta_{13}$ due to correlation with $\theta_{14}$. The value of $\theta_{13}$ obtained by RENO and Daya Bay with a three-neutrino oscillation analysis is included in the $1\sigma$ interval of $\theta_{13}$ allowed by our four-neutrino analysis.
[ { "created": "Thu, 14 Aug 2014 08:02:35 GMT", "version": "v1" }, { "created": "Tue, 19 Aug 2014 18:11:28 GMT", "version": "v2" } ]
2014-08-20
[ [ "Kang", "Sin Kyu", "" ], [ "Kim", "Yeong-Duk", "" ], [ "Ko", "Young-Ju", "" ], [ "Siyeon", "Kim", "" ] ]
The masses of sterile neutrinos are not yet known, and depending on the orders of magnitudes, their existence may explain reactor anomalies or the spectral shape of reactor neutrino events at 1.5km-baseline detector. Here, we present four-neutrino analysis of the results announced by RENO and Daya Bay, which performed the definitive measurements of $\theta_{13}$ based on the disappearance of reactor antineutrinos at km-order baselines. Our results using 3+1 scheme include the exclusion curve of $\Delta m^2_{41}$ vs. $\theta_{14}$ and the adjustment of $\theta_{13}$ due to correlation with $\theta_{14}$. The value of $\theta_{13}$ obtained by RENO and Daya Bay with a three-neutrino oscillation analysis is included in the $1\sigma$ interval of $\theta_{13}$ allowed by our four-neutrino analysis.
hep-ph/9805480
Elisabetta Sassaroli
E. Sassaroli
Neutrino Flavor Mixing and Oscillations in Field Theory
4 pages, LaTex file, no figures. Contribution to the proceedings of PASCOS 1998, Northeastern University, March 1998
null
null
null
hep-ph
null
The Lagrangian that is normally associated with Dirac neutrinos is analyzed in a complete and simple way through field theory. It is found that the elements of the neutrino mass matrix are field strength renormalization constants and that the flavor fields can be directly applied to the one-particle energy states through these rescaling factors. Moreover this Lagrangian describes neutrinos which are in a state of mixed flavor at any space-time point and therefore does not describe the phenomenology of neutrino oscillations properly, except in the ultra-relativistic limit where such a description is possible.
[ { "created": "Wed, 27 May 1998 15:17:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sassaroli", "E.", "" ] ]
The Lagrangian that is normally associated with Dirac neutrinos is analyzed in a complete and simple way through field theory. It is found that the elements of the neutrino mass matrix are field strength renormalization constants and that the flavor fields can be directly applied to the one-particle energy states through these rescaling factors. Moreover this Lagrangian describes neutrinos which are in a state of mixed flavor at any space-time point and therefore does not describe the phenomenology of neutrino oscillations properly, except in the ultra-relativistic limit where such a description is possible.
1911.08873
Michael Andreas Schmidt
Shyam Balaji and Michael A. Schmidt
Unified SU(4) theory for the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ anomalies
21 pages, 4 figures; v2: minor changes, matches published version
Phys. Rev. D 101, 015026 (2020)
10.1103/PhysRevD.101.015026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a chiral Pati-Salam theory based on the gauge group $SU(4)_C\times SU(2)_L\times SU(2)_R$. The left-handed quarks and leptons are unified into a fundamental representation of $SU(4)_C$, while right-handed quarks and leptons have a separate treatment. The deviations measured in the rare semi-leptonic decays $B\to D^{(*)} \tau\bar\nu$ are explained by a scalar leptoquark which couples to right-handed fields and is contained in the $SU(4)_C\times SU(2)_R$ breaking scalar multiplet. The measured deviation of lepton flavor universality in the rare decays $\bar B\to \bar K^{(*)}\ell^+\ell^-$, $\ell=\mu,e$ is explained via the $SU(4)_C$ leptoquark gauge boson. The model predicts a new sub-GeV scale sterile neutrino which participates in the anomaly and can be searched for in upcoming neutrino experiments. The theory satisfies the current most sensitive experimental constraints and its allowable parameter regions will be probed as more precise measurements from the LHCb and Belle II experiments become available.
[ { "created": "Wed, 20 Nov 2019 13:04:31 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2020 00:43:36 GMT", "version": "v2" } ]
2020-02-05
[ [ "Balaji", "Shyam", "" ], [ "Schmidt", "Michael A.", "" ] ]
We propose a chiral Pati-Salam theory based on the gauge group $SU(4)_C\times SU(2)_L\times SU(2)_R$. The left-handed quarks and leptons are unified into a fundamental representation of $SU(4)_C$, while right-handed quarks and leptons have a separate treatment. The deviations measured in the rare semi-leptonic decays $B\to D^{(*)} \tau\bar\nu$ are explained by a scalar leptoquark which couples to right-handed fields and is contained in the $SU(4)_C\times SU(2)_R$ breaking scalar multiplet. The measured deviation of lepton flavor universality in the rare decays $\bar B\to \bar K^{(*)}\ell^+\ell^-$, $\ell=\mu,e$ is explained via the $SU(4)_C$ leptoquark gauge boson. The model predicts a new sub-GeV scale sterile neutrino which participates in the anomaly and can be searched for in upcoming neutrino experiments. The theory satisfies the current most sensitive experimental constraints and its allowable parameter regions will be probed as more precise measurements from the LHCb and Belle II experiments become available.
1506.06755
Rui Santos
Duarte Fontes, Jorge C. Rom\~ao, Rui Santos, Jo\~ao P. Silva
Undoubtable signs of CP-violation in Higgs decays at the LHC run 2
16 pages
Phys. Rev. D 92, 055014 (2015)
10.1103/PhysRevD.92.055014
CFTP/15-006
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the discovery of the Higgs boson at the Large Hadron Collider the high energy physics community's attention has now turned to understanding the properties of the Higgs boson, together with the hope of finding more scalars during run 2. In this work we discuss scenarios where using a combination of three decays, involving the 125 GeV Higgs boson, the Z boson and at least one more scalar, an indisputable signal of CP-violation arises. We use a complex two-Higgs doublet model as a reference model and present some benchmark points that have passed all current experimental and theoretical constraints, and that have cross sections large enough to be probed during run 2.
[ { "created": "Mon, 22 Jun 2015 20:00:42 GMT", "version": "v1" }, { "created": "Tue, 14 Jul 2015 13:35:14 GMT", "version": "v2" }, { "created": "Fri, 28 Aug 2015 10:25:48 GMT", "version": "v3" } ]
2015-09-16
[ [ "Fontes", "Duarte", "" ], [ "Romão", "Jorge C.", "" ], [ "Santos", "Rui", "" ], [ "Silva", "João P.", "" ] ]
With the discovery of the Higgs boson at the Large Hadron Collider the high energy physics community's attention has now turned to understanding the properties of the Higgs boson, together with the hope of finding more scalars during run 2. In this work we discuss scenarios where using a combination of three decays, involving the 125 GeV Higgs boson, the Z boson and at least one more scalar, an indisputable signal of CP-violation arises. We use a complex two-Higgs doublet model as a reference model and present some benchmark points that have passed all current experimental and theoretical constraints, and that have cross sections large enough to be probed during run 2.
1010.5815
Arlene Cristina Aguilar
A. C. Aguilar and J. Papavassiliou
Chiral symmetry breaking with lattice propagators
32 pages, 13 figures
Phys.Rev.D83:014013,2011
10.1103/PhysRevD.83.014013
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study chiral symmetry breaking using the standard gap equation, supplemented with the infrared-finite gluon propagator and ghost dressing function obtained from large-volume lattice simulations. One of the most important ingredients of this analysis is the non-abelian quark-gluon vertex, which controls the way the ghost sector enters into the gap equation. Specifically, this vertex introduces a numerically crucial dependence on the ghost dressing function and the quark-ghost scattering amplitude. This latter quantity satisfies its own, previously unexplored, dynamical equation, which may be decomposed into individual integral equations for its various form factors. In particular, the scalar form factor is obtained from an approximate version of the "one-loop dressed" integral equation, and its numerical impact turns out to be rather considerable. The detailed numerical analysis of the resulting gap equation reveals that the constituent quark mass obtained is about 300 MeV, while fermions in the adjoint representation acquire a mass in the range of (750-962) MeV.
[ { "created": "Wed, 27 Oct 2010 21:47:06 GMT", "version": "v1" } ]
2011-02-01
[ [ "Aguilar", "A. C.", "" ], [ "Papavassiliou", "J.", "" ] ]
We study chiral symmetry breaking using the standard gap equation, supplemented with the infrared-finite gluon propagator and ghost dressing function obtained from large-volume lattice simulations. One of the most important ingredients of this analysis is the non-abelian quark-gluon vertex, which controls the way the ghost sector enters into the gap equation. Specifically, this vertex introduces a numerically crucial dependence on the ghost dressing function and the quark-ghost scattering amplitude. This latter quantity satisfies its own, previously unexplored, dynamical equation, which may be decomposed into individual integral equations for its various form factors. In particular, the scalar form factor is obtained from an approximate version of the "one-loop dressed" integral equation, and its numerical impact turns out to be rather considerable. The detailed numerical analysis of the resulting gap equation reveals that the constituent quark mass obtained is about 300 MeV, while fermions in the adjoint representation acquire a mass in the range of (750-962) MeV.
1511.03632
Nosheen Akbar
Nosheen Akbar, M. Atif Sultan, Bilal Masud, Faisal Akram
Higher Hybrid Bottomonia in an Extended Potential Model
20 pages,1 figures
Phys. Rev. D 95, 074018 (2017)
10.1103/PhysRevD.95.074018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using our extension of the quark potential model to hybrid mesons that fits well to the available lattice results, we now calculate the masses, radii, wave functions at origin, leptonic and two photon decay widths, E1 and M1 radiative transitions for a significant number of bottomonium mesons. These mesons include both conventional and hybrid ones with radial and angular excitations. Our numerical solutions of the Schrodinger equation are related to QCD through the Born-Oppenheimer approach. Relativistic corrections in masses and decay widths are also calculated by applying the leading order perturbation theory. The calculated results are compared with available experimental data and the theoretical results by other groups. We also identify the states of $\Upsilon(10860)$, $\Upsilon(11020)$, and $Y_b(10890)$ mesons by comparing their experimental masses and decay widths with our results.
[ { "created": "Wed, 11 Nov 2015 19:59:22 GMT", "version": "v1" }, { "created": "Sat, 19 Dec 2015 16:41:16 GMT", "version": "v2" }, { "created": "Thu, 20 Apr 2017 07:36:44 GMT", "version": "v3" } ]
2017-04-21
[ [ "Akbar", "Nosheen", "" ], [ "Sultan", "M. Atif", "" ], [ "Masud", "Bilal", "" ], [ "Akram", "Faisal", "" ] ]
Using our extension of the quark potential model to hybrid mesons that fits well to the available lattice results, we now calculate the masses, radii, wave functions at origin, leptonic and two photon decay widths, E1 and M1 radiative transitions for a significant number of bottomonium mesons. These mesons include both conventional and hybrid ones with radial and angular excitations. Our numerical solutions of the Schrodinger equation are related to QCD through the Born-Oppenheimer approach. Relativistic corrections in masses and decay widths are also calculated by applying the leading order perturbation theory. The calculated results are compared with available experimental data and the theoretical results by other groups. We also identify the states of $\Upsilon(10860)$, $\Upsilon(11020)$, and $Y_b(10890)$ mesons by comparing their experimental masses and decay widths with our results.
1309.0313
Wei Wang
Xin Liu, Wei Wang, Yuehong Xie
Penguin Pollution in $B\to J/\psi V$ Decays and Impact on the Extraction of the $B_s-\bar B_s$ mixing phase
19 pages, 3 figures; v2: ratios of branching fractions updated
Phys. Rev. D 89, 094010 (2014)
10.1103/PhysRevD.89.094010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We formulate the most-general time-dependent decay distributions of $B_s\to J/\psi (\to l^+l^-) \phi(\to K^+K^-)$ in which the direct CP violation is explicitly incorporated. We then investigate the $B \to J/\psi V$ decays in the perturbative QCD approach where $V$ is a light vector meson. Apart from the leading-order factorizable contributions, we also take into account various QCD corrections and the hard-spectator diagrams. With the inclusion of these sizable corrections, our theoretical results for CP-averaged branching ratios, polarization fractions, CP-violating asymmetries, and relative phases are in good consistency with the available data. Based on the global agreement, we further explore the penguin contributions and point out that the $\phi_s$ extracted from $B_s\to J/\psi \phi$ can be shifted away by ${\cal O}(10^{-3})$.
[ { "created": "Mon, 2 Sep 2013 07:48:35 GMT", "version": "v1" }, { "created": "Fri, 10 Jul 2015 09:22:18 GMT", "version": "v2" } ]
2015-07-13
[ [ "Liu", "Xin", "" ], [ "Wang", "Wei", "" ], [ "Xie", "Yuehong", "" ] ]
We formulate the most-general time-dependent decay distributions of $B_s\to J/\psi (\to l^+l^-) \phi(\to K^+K^-)$ in which the direct CP violation is explicitly incorporated. We then investigate the $B \to J/\psi V$ decays in the perturbative QCD approach where $V$ is a light vector meson. Apart from the leading-order factorizable contributions, we also take into account various QCD corrections and the hard-spectator diagrams. With the inclusion of these sizable corrections, our theoretical results for CP-averaged branching ratios, polarization fractions, CP-violating asymmetries, and relative phases are in good consistency with the available data. Based on the global agreement, we further explore the penguin contributions and point out that the $\phi_s$ extracted from $B_s\to J/\psi \phi$ can be shifted away by ${\cal O}(10^{-3})$.
hep-ph/9810308
Wilfried Buchmuller
W. Buchm\"uller, T. Yanagida
Quark Lepton Mass Hierarchies and the Baryon Asymmetry
7 pages
Phys.Lett. B445 (1999) 399-402
10.1016/S0370-2693(98)01480-4
DESY-98-155
hep-ph
null
The mass hierarchies of quarks and charged leptons as well as a large $\n_\m$-$\n_\t$ mixing angle are naturally explained by the Frogatt-Nielsen mechanism with a nonparallel family structure of chiral charges. We extend this mechanism to right-handed neutrinos. Their out-of-equilibrium decay generates a cosmological baryon asymmetry whose size is quantized in powers of the hierarchy parameter $\e^2$. For the simplest hierarchy pattern the neutrino mass $\bar{m}_\n= (m_{\n_\m}m_{\n_\t})^{1/2} \sim 10^{-2}$ eV, which is inferred from present indications for neutrino oscillations, implies a baryon asymmetry $n_B/s \sim 10^{-10}$. The corresponding baryogenesis temperature is $T_B \sim 10^{10}$ GeV.
[ { "created": "Fri, 9 Oct 1998 12:56:09 GMT", "version": "v1" } ]
2009-10-31
[ [ "Buchmüller", "W.", "" ], [ "Yanagida", "T.", "" ] ]
The mass hierarchies of quarks and charged leptons as well as a large $\n_\m$-$\n_\t$ mixing angle are naturally explained by the Frogatt-Nielsen mechanism with a nonparallel family structure of chiral charges. We extend this mechanism to right-handed neutrinos. Their out-of-equilibrium decay generates a cosmological baryon asymmetry whose size is quantized in powers of the hierarchy parameter $\e^2$. For the simplest hierarchy pattern the neutrino mass $\bar{m}_\n= (m_{\n_\m}m_{\n_\t})^{1/2} \sim 10^{-2}$ eV, which is inferred from present indications for neutrino oscillations, implies a baryon asymmetry $n_B/s \sim 10^{-10}$. The corresponding baryogenesis temperature is $T_B \sim 10^{10}$ GeV.
hep-ph/9807447
Gronau
Michael Gronau and Jonathan L. Rosner Comments 8 pages, 1 figure, Latex
Final State Interaction Effects on $\gamma$ from $B \to D K$
null
Phys.Lett. B439 (1998) 171-175
10.1016/S0370-2693(98)00988-5
null
hep-ph
null
The implications of a negligible annihilation contribution in $B \to D K$ decays are reanalyzed and are shown to lead to no new constraints on the weak phase $\gamma$ from color-allowed $B^{\pm} \to D K^{\pm}$ decays. A test of negligible annihilation is proposed in $B^+ \to D^+ K^0$ (or $B^+ \to D^+ K^{*0}$), and an application is presented in which $\gamma$ can be determined from these processes (or corresponding $B \to D K^*$ decays) supplemented with isospin-related neutral $B$ decays.
[ { "created": "Tue, 21 Jul 1998 15:11:08 GMT", "version": "v1" } ]
2016-09-06
[ [ "Gronau", "Michael", "" ], [ "pages", "Jonathan L. Rosner Comments 8", "" ], [ "figure", "1", "" ], [ "Latex", "", "" ] ]
The implications of a negligible annihilation contribution in $B \to D K$ decays are reanalyzed and are shown to lead to no new constraints on the weak phase $\gamma$ from color-allowed $B^{\pm} \to D K^{\pm}$ decays. A test of negligible annihilation is proposed in $B^+ \to D^+ K^0$ (or $B^+ \to D^+ K^{*0}$), and an application is presented in which $\gamma$ can be determined from these processes (or corresponding $B \to D K^*$ decays) supplemented with isospin-related neutral $B$ decays.
2205.11919
Tomohiro Abe
Tomohiro Abe, Yu Hamada
A model of pseudo-Nambu-Goldstone dark matter from a softly broken $SU(2)$ global symmetry with a $U(1)$ gauge symmetry
30 pages, 10 figures. v3: Published version in PTEP
null
10.1093/ptep/ptad021
KEK-TH-2428
hep-ph
http://creativecommons.org/licenses/by/4.0/
A model of the pseudo-Nambu-Goldstone (pNG) dark matter (DM) is proposed. We assume that there is an $SU(2)_g$ global symmetry and a $U(1)_X$ gauge symmetry in the dark sector, and they are spontaneously broken into a $U(1)_D$ global symmetry after a scalar field develops a vacuum expectation value. We add a soft symmetry breaking term that breaks the $SU(2)_g$ global symmetry into the $U(1)_g$ global symmetry explicitly. Our model predicts a stable complex pNG particle under the $U(1)_D$ global symmetry. One of the virtues of the pNG DM models is that the models can explain the current null results in the direct detection experiments. The small momentum transfer suppresses the scattering amplitudes thanks to the low energy behavior of the Nambu-Goldstone boson. In our model, the soft symmetry breaking term is uniquely determined. This is the advantage of our model to some earlier works in which some soft symmetry breaking terms cannot be forbidden but are simply assumed to be absent to avoid the constraints from the direct detection experiments. We calculate the thermal relic abundance of the pNG DM and find that model can explain the measured value of the DM energy density under some constraints from the perturbative unitarity.
[ { "created": "Tue, 24 May 2022 09:25:54 GMT", "version": "v1" }, { "created": "Thu, 2 Jun 2022 06:41:39 GMT", "version": "v2" }, { "created": "Thu, 16 Feb 2023 12:02:06 GMT", "version": "v3" } ]
2023-02-17
[ [ "Abe", "Tomohiro", "" ], [ "Hamada", "Yu", "" ] ]
A model of the pseudo-Nambu-Goldstone (pNG) dark matter (DM) is proposed. We assume that there is an $SU(2)_g$ global symmetry and a $U(1)_X$ gauge symmetry in the dark sector, and they are spontaneously broken into a $U(1)_D$ global symmetry after a scalar field develops a vacuum expectation value. We add a soft symmetry breaking term that breaks the $SU(2)_g$ global symmetry into the $U(1)_g$ global symmetry explicitly. Our model predicts a stable complex pNG particle under the $U(1)_D$ global symmetry. One of the virtues of the pNG DM models is that the models can explain the current null results in the direct detection experiments. The small momentum transfer suppresses the scattering amplitudes thanks to the low energy behavior of the Nambu-Goldstone boson. In our model, the soft symmetry breaking term is uniquely determined. This is the advantage of our model to some earlier works in which some soft symmetry breaking terms cannot be forbidden but are simply assumed to be absent to avoid the constraints from the direct detection experiments. We calculate the thermal relic abundance of the pNG DM and find that model can explain the measured value of the DM energy density under some constraints from the perturbative unitarity.
1701.05514
Oleksandr Tomalak
Oleksandr Tomalak
Forward two-photon exchange in elastic lepton-proton scattering and hyperfine-splitting correction
27 pages, 7 figures, correct description of corrections
Eur. Phys. J. C 77, no. 8, 517 (2017)
10.1140/epjc/s10052-017-5087-z
null
hep-ph nucl-ex nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We relate the forward two-photon exchange (TPE) amplitudes to integrals of the inclusive lepton-proton scattering cross sections. These relations yield an alternative way for the evaluation of the TPE correction to hyperfine-splitting (HFS) in the hydrogen-like atoms with an equivalent to the standard approach (Iddings, Drell and Sullivan) result implying the Burkhardt-Cottingham sum rule. For evaluation of the individual effects (e.g., elastic contribution) our approach yields a distinct result. We compare both methods numerically on examples of the elastic contribution and the full TPE correction to HFS in electronic and muonic hydrogen.
[ { "created": "Thu, 19 Jan 2017 17:13:41 GMT", "version": "v1" }, { "created": "Thu, 23 Feb 2017 12:59:02 GMT", "version": "v2" }, { "created": "Fri, 24 Feb 2017 02:26:56 GMT", "version": "v3" }, { "created": "Mon, 7 Aug 2017 17:08:43 GMT", "version": "v4" }, { "created": "Thu, 21 Sep 2017 14:51:52 GMT", "version": "v5" } ]
2017-09-22
[ [ "Tomalak", "Oleksandr", "" ] ]
We relate the forward two-photon exchange (TPE) amplitudes to integrals of the inclusive lepton-proton scattering cross sections. These relations yield an alternative way for the evaluation of the TPE correction to hyperfine-splitting (HFS) in the hydrogen-like atoms with an equivalent to the standard approach (Iddings, Drell and Sullivan) result implying the Burkhardt-Cottingham sum rule. For evaluation of the individual effects (e.g., elastic contribution) our approach yields a distinct result. We compare both methods numerically on examples of the elastic contribution and the full TPE correction to HFS in electronic and muonic hydrogen.
0805.2090
Vladimir Zoller
R. Fiore and V.R. Zoller
Full of charm neutrino DIS
4 pages, 1 figure To appear in the Proceedings of the 43rd Rencontres de Moriond "QCD and High Energy Interactions" La Thuile, Aosta Valley, Italy, 08-15 March 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The color dipole analysis of small-$(x, Q^2)$ neutrino DIS induced by the charmed-strange ($cs$) current reveals ordering of dipole sizes $m_c^{-2}<r^2<m_s^{-2}$ typical of the Double Leading Log Approximation (DLLA). The DLLA resummation leads to the $cs$ component of the longitudinal structure function $F_L$ rising to small $x$ much faster than its light quark component. Based on the color dipole BFKL approach we report quantitative predictions for this effect in the kinematical range of the CCFR/NuTeV experiment.
[ { "created": "Wed, 14 May 2008 15:26:58 GMT", "version": "v1" } ]
2008-05-15
[ [ "Fiore", "R.", "" ], [ "Zoller", "V. R.", "" ] ]
The color dipole analysis of small-$(x, Q^2)$ neutrino DIS induced by the charmed-strange ($cs$) current reveals ordering of dipole sizes $m_c^{-2}<r^2<m_s^{-2}$ typical of the Double Leading Log Approximation (DLLA). The DLLA resummation leads to the $cs$ component of the longitudinal structure function $F_L$ rising to small $x$ much faster than its light quark component. Based on the color dipole BFKL approach we report quantitative predictions for this effect in the kinematical range of the CCFR/NuTeV experiment.
2211.02610
John Hardin
J.M. Hardin, I. Martinez-Soler, A. Diaz, M. Jin, N.W. Kamp, C.A. Arg\"uelles, J.M. Conrad, M.H. Shaevitz
New Clues About Light Sterile Neutrinos: Preference for Models with Damping Effects in Global Fits
Minor updates addressing referee comments
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article reports global fits of short-baseline neutrino data to oscillation models involving light sterile neutrinos. In the commonly-used 3+1 plane wave model, there is a well-known 4.9$\sigma$ tension between data sets sensitive to appearance versus disappearance of neutrinos. We find that models that damp the oscillation prediction for the reactor data sets, especially at low energy, substantially improve the fits and reduce the tension. We consider two such scenarios. The first scenario introduces the quantum mechanical wavepacket effect that accounts for the source size in reactor experiments into the 3+1 model. We find that inclusion of the wavepacket effect greatly improves the overall fit compared to a 3$\nu$ model by $\Delta \chi^2/$DOF$=61.1/4$ ($7.1\sigma$ improvement) with best-fit $\Delta m^2=1.4$ eV$^2$ and wavepacket length of 67fm. The internal tension is reduced to 3.4$\sigma$. If reactor-data only is fit, then the wavepacket preferred length is 91 fm ($>20$ fm at 99\% CL). The second model introduces oscillations involving sterile flavor and allows the decay of the heaviest, mostly sterile mass state, $\nu_4$. This model introduces a damping term similar to the wavepacket effect, but across all experiments. Compared to a three-neutrino fit, this has a $\Delta \chi^2/$DOF$=60.6/4$ ($7\sigma$ improvement) with preferred $\Delta m^2=1.4$ eV$^2$ and decay $\Gamma = 0.35$ eV$^2$. The internal tension is reduced to 3.7$\sigma$. For many years, the reactor event rates have been observed to have structure that deviates from prediction. Community discussion has focused on an excess compared to prediction observed at 5 MeV; however, other deviations are apparent. This structure has $L$ dependence that is well-fit by the damped models. Before assuming this points to new physics, we urge closer examination of systematic effects that could lead to this $L$ dependence.
[ { "created": "Fri, 4 Nov 2022 17:29:35 GMT", "version": "v1" }, { "created": "Fri, 11 Nov 2022 18:39:09 GMT", "version": "v2" }, { "created": "Fri, 7 Apr 2023 20:52:21 GMT", "version": "v3" }, { "created": "Mon, 24 Apr 2023 21:06:04 GMT", "version": "v4" }, { "created": "Fri, 11 Aug 2023 19:43:44 GMT", "version": "v5" } ]
2023-08-15
[ [ "Hardin", "J. M.", "" ], [ "Martinez-Soler", "I.", "" ], [ "Diaz", "A.", "" ], [ "Jin", "M.", "" ], [ "Kamp", "N. W.", "" ], [ "Argüelles", "C. A.", "" ], [ "Conrad", "J. M.", "" ], [ "Shaevitz", "M. H.", "" ] ]
This article reports global fits of short-baseline neutrino data to oscillation models involving light sterile neutrinos. In the commonly-used 3+1 plane wave model, there is a well-known 4.9$\sigma$ tension between data sets sensitive to appearance versus disappearance of neutrinos. We find that models that damp the oscillation prediction for the reactor data sets, especially at low energy, substantially improve the fits and reduce the tension. We consider two such scenarios. The first scenario introduces the quantum mechanical wavepacket effect that accounts for the source size in reactor experiments into the 3+1 model. We find that inclusion of the wavepacket effect greatly improves the overall fit compared to a 3$\nu$ model by $\Delta \chi^2/$DOF$=61.1/4$ ($7.1\sigma$ improvement) with best-fit $\Delta m^2=1.4$ eV$^2$ and wavepacket length of 67fm. The internal tension is reduced to 3.4$\sigma$. If reactor-data only is fit, then the wavepacket preferred length is 91 fm ($>20$ fm at 99\% CL). The second model introduces oscillations involving sterile flavor and allows the decay of the heaviest, mostly sterile mass state, $\nu_4$. This model introduces a damping term similar to the wavepacket effect, but across all experiments. Compared to a three-neutrino fit, this has a $\Delta \chi^2/$DOF$=60.6/4$ ($7\sigma$ improvement) with preferred $\Delta m^2=1.4$ eV$^2$ and decay $\Gamma = 0.35$ eV$^2$. The internal tension is reduced to 3.7$\sigma$. For many years, the reactor event rates have been observed to have structure that deviates from prediction. Community discussion has focused on an excess compared to prediction observed at 5 MeV; however, other deviations are apparent. This structure has $L$ dependence that is well-fit by the damped models. Before assuming this points to new physics, we urge closer examination of systematic effects that could lead to this $L$ dependence.
2207.13213
Pierre Ramond
Pierre Ramond
Tri-Bi-Maximal Mixing in Asymmetric Textures
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
At the occasion of his eighty fifth birthday, I wish to to recognize the crucial role that my advisor, Professor Ayalam Balachandran, played in enabling me to evolve from engineering to physics. So many years later, this student presents his latest efforts: the importance of asymmetry in the Yukawa matrices. We start with a purely phenomenological approach with Tri-Bi-Maximal mixing as input: it predicts the value of the CP-violating angle with the three mixing angles within one sigma of their pdf values. To ensure as much naturalness as possible, a model which starts from $SU_5$ and extends to $E_6$ is discussed, in the context of finite family groups which are subgroups $G_2$.
[ { "created": "Tue, 26 Jul 2022 23:32:26 GMT", "version": "v1" } ]
2022-07-28
[ [ "Ramond", "Pierre", "" ] ]
At the occasion of his eighty fifth birthday, I wish to to recognize the crucial role that my advisor, Professor Ayalam Balachandran, played in enabling me to evolve from engineering to physics. So many years later, this student presents his latest efforts: the importance of asymmetry in the Yukawa matrices. We start with a purely phenomenological approach with Tri-Bi-Maximal mixing as input: it predicts the value of the CP-violating angle with the three mixing angles within one sigma of their pdf values. To ensure as much naturalness as possible, a model which starts from $SU_5$ and extends to $E_6$ is discussed, in the context of finite family groups which are subgroups $G_2$.
1304.7476
Chris Kouvaris
Chris Kouvaris
Composite Millicharged Dark Matter
10 pages, published version
Phys.Rev. D88 (2013) 015001
10.1103/PhysRevD.88.015001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a composite millicharged dark matter model. The dark matter is in the form of pion-like objects emerging from a higher scale QCD-like theory. We present two distinct possibilities with interesting phenomenological consequences based on the choice of the parameters. In the first one, the dark matter is produced non-thermally and it could potentially account for the 130 GeV Fermi photon line via decays of the "dark pions". We estimate the self-interaction cross section which might play an important role both in changing the dark matter halo profile at the center of the galaxy and in making the dark matter warmer. In the second version the dark matter is produced via the freeze-in mechanism. Finally we impose all possible astrophysical, cosmological and experimental constraints. We study in detail generic constraints on millicharged dark matter that can arise from anomalous isotope searches of different elements and we show why constraints based on direct searches from underground detectors are not generally valid.
[ { "created": "Sun, 28 Apr 2013 15:10:40 GMT", "version": "v1" }, { "created": "Thu, 29 Aug 2013 20:38:53 GMT", "version": "v2" } ]
2015-06-15
[ [ "Kouvaris", "Chris", "" ] ]
We study a composite millicharged dark matter model. The dark matter is in the form of pion-like objects emerging from a higher scale QCD-like theory. We present two distinct possibilities with interesting phenomenological consequences based on the choice of the parameters. In the first one, the dark matter is produced non-thermally and it could potentially account for the 130 GeV Fermi photon line via decays of the "dark pions". We estimate the self-interaction cross section which might play an important role both in changing the dark matter halo profile at the center of the galaxy and in making the dark matter warmer. In the second version the dark matter is produced via the freeze-in mechanism. Finally we impose all possible astrophysical, cosmological and experimental constraints. We study in detail generic constraints on millicharged dark matter that can arise from anomalous isotope searches of different elements and we show why constraints based on direct searches from underground detectors are not generally valid.
hep-ph/9504428
Alakabha Datta
Alakabha Datta
Non-Leptonic two body decays of Charmed and \Lambda_b Baryons
15 pages, Latex, no figures, minor typing errors corrected
null
null
UH-511-824-95
hep-ph
null
We calculate the two body Cabibbo allowed non-leptonic decays of charmed baryons $\Lambda_c$ and $\Xi_c$ which involve transitions of a heavy quark to a light quark. We use data on the Cabbibo favoured non-leptonic decays $\Lambda_c \rightarrow \Lambda \pi^{+}$ and $\Lambda_c \rightarrow \Sigma^{+} \pi^{0 }$ to obtain information on the form factors in the $c \rightarrow s $ transition. We also calculate the decay $\Lambda_c \rightarrow p \phi$. Using HQET the information on form factors from the $c \rightarrow s $ transition is used to model the form factors in $b \rightarrow s $ transition which are then used in the study of $\Lambda_b \rightarrow J/ \psi \Lambda $ decay.
[ { "created": "Sat, 29 Apr 1995 00:24:01 GMT", "version": "v1" }, { "created": "Mon, 1 May 1995 01:06:48 GMT", "version": "v2" } ]
2008-02-03
[ [ "Datta", "Alakabha", "" ] ]
We calculate the two body Cabibbo allowed non-leptonic decays of charmed baryons $\Lambda_c$ and $\Xi_c$ which involve transitions of a heavy quark to a light quark. We use data on the Cabbibo favoured non-leptonic decays $\Lambda_c \rightarrow \Lambda \pi^{+}$ and $\Lambda_c \rightarrow \Sigma^{+} \pi^{0 }$ to obtain information on the form factors in the $c \rightarrow s $ transition. We also calculate the decay $\Lambda_c \rightarrow p \phi$. Using HQET the information on form factors from the $c \rightarrow s $ transition is used to model the form factors in $b \rightarrow s $ transition which are then used in the study of $\Lambda_b \rightarrow J/ \psi \Lambda $ decay.
1008.4197
Simonetta Liuti
K. Holcomb, S. Liuti and D.Z. Perry
Self-Organizing Maps and Parton Distributions Functions
8 pages, 4 figures, to appear in the proceedings of "Workshop on Exclusive Reactions at High Momentum Transfer (IV)", Jefferson Lab, May 18th -21st, 2010
null
10.1142/9789814329569_0008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new method to extract parton distribution functions from high energy experimental data based on a specific type of neural networks, the Self-Organizing Maps. We illustrate the features of our new procedure that are particularly useful for an anaysis directed at extracting generalized parton distributions from data. We show quantitative results of our initial analysis of the parton distribution functions from inclusive deep inelastic scattering.
[ { "created": "Wed, 25 Aug 2010 03:43:04 GMT", "version": "v1" } ]
2017-08-23
[ [ "Holcomb", "K.", "" ], [ "Liuti", "S.", "" ], [ "Perry", "D. Z.", "" ] ]
We present a new method to extract parton distribution functions from high energy experimental data based on a specific type of neural networks, the Self-Organizing Maps. We illustrate the features of our new procedure that are particularly useful for an anaysis directed at extracting generalized parton distributions from data. We show quantitative results of our initial analysis of the parton distribution functions from inclusive deep inelastic scattering.
0805.0784
Alexei Bazavov
Alexei Bazavov, Bernd A. Berg, Adrian Dumitru
Thermalization in SU(3) gauge theory after a deconfining quench
7 pages, 7 figures
Phys.Rev.D78:034024,2008
10.1103/PhysRevD.78.034024
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the time evolution of fluctuations of the Polyakov loop after a quench into the deconfined phase of SU(3) gauge theory from a simple classical relativistic Lagrangian. We compare the structure factors, which indicate spinodal decomposition followed by relaxation, to those obtained via Markov Chain Monte Carlo techniques in SU(3) lattice gauge theory. We find that the time when the structure factor peaks diverges like $\sim 1/k^2$ in the long-wavelength limit. This is due to formation of competing Z(3) domains for configurations where the Polyakov loop exhibits non-perturbatively large variations in space, which delay thermalization of long wavelength modes. For realistic temperatures, and away from the extreme weak-coupling limit, we find that even modes with $k$ on the order of $T$ experience delayed thermalization. Relaxation times of very long wavelength modes are found to be on the order of the size of the system; thus, the dynamics of competing domains should accompany the hydrodynamic description of the deconfined vacuum.
[ { "created": "Tue, 6 May 2008 19:36:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bazavov", "Alexei", "" ], [ "Berg", "Bernd A.", "" ], [ "Dumitru", "Adrian", "" ] ]
We determine the time evolution of fluctuations of the Polyakov loop after a quench into the deconfined phase of SU(3) gauge theory from a simple classical relativistic Lagrangian. We compare the structure factors, which indicate spinodal decomposition followed by relaxation, to those obtained via Markov Chain Monte Carlo techniques in SU(3) lattice gauge theory. We find that the time when the structure factor peaks diverges like $\sim 1/k^2$ in the long-wavelength limit. This is due to formation of competing Z(3) domains for configurations where the Polyakov loop exhibits non-perturbatively large variations in space, which delay thermalization of long wavelength modes. For realistic temperatures, and away from the extreme weak-coupling limit, we find that even modes with $k$ on the order of $T$ experience delayed thermalization. Relaxation times of very long wavelength modes are found to be on the order of the size of the system; thus, the dynamics of competing domains should accompany the hydrodynamic description of the deconfined vacuum.
1306.2658
Xiao-Gang He
Xiao-Gang He, Siao-Fong Li, Hsiu-Hsien Lin
CP Violation in $B^0_s \to K^-\pi^+$, $B^0 \to K^+\pi^-$ Decays and Tests for SU(3) Flavor Symmetry Predictions
RevTex, 16 pages with no figures. A new reference added and some minor modifications
null
10.1007/JHEP08(2013)065
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb collaboration has recently measured the first direct CP violation in $B^0_s$ decays with a rate asymmetry $A_{CP}(B^0_s\to K^- \pi^+)$ given by $0.27 \pm 0.04(stat)\pm 0.01(syst)$. At the same time they also made the most precise measurement for $A_{CP}(B^0 \to K^+ \pi^-) = -0.080\pm 0.007(stat)\pm 0.003(syst)$. These data confirm the predicted relation, $A_{CP}(B^0 \to K^+ \pi^-)/A_{CP}(B^0_s \to K^- \pi^+) = - Br(B^0_s\to K^- \pi^+)\tau_{B^0}/Br(B^0 \to K^+ \pi^-)\tau_{B^0_s}$, in the standard model with SU(3) flavor symmetry. We discuss possible modifications due to SU(3) breaking effects to this relation. There are several other similar relations in B decays. Using current available data we study whether relevant relations hold in $B^0$ and $B^0_s$ to $PP$ and $PV$ decays. Here $P$ and $V$ indicate pesudoscalar and vector mesons in the flavor octet representations.
[ { "created": "Tue, 11 Jun 2013 20:49:48 GMT", "version": "v1" }, { "created": "Mon, 22 Jul 2013 01:27:16 GMT", "version": "v2" } ]
2015-06-16
[ [ "He", "Xiao-Gang", "" ], [ "Li", "Siao-Fong", "" ], [ "Lin", "Hsiu-Hsien", "" ] ]
The LHCb collaboration has recently measured the first direct CP violation in $B^0_s$ decays with a rate asymmetry $A_{CP}(B^0_s\to K^- \pi^+)$ given by $0.27 \pm 0.04(stat)\pm 0.01(syst)$. At the same time they also made the most precise measurement for $A_{CP}(B^0 \to K^+ \pi^-) = -0.080\pm 0.007(stat)\pm 0.003(syst)$. These data confirm the predicted relation, $A_{CP}(B^0 \to K^+ \pi^-)/A_{CP}(B^0_s \to K^- \pi^+) = - Br(B^0_s\to K^- \pi^+)\tau_{B^0}/Br(B^0 \to K^+ \pi^-)\tau_{B^0_s}$, in the standard model with SU(3) flavor symmetry. We discuss possible modifications due to SU(3) breaking effects to this relation. There are several other similar relations in B decays. Using current available data we study whether relevant relations hold in $B^0$ and $B^0_s$ to $PP$ and $PV$ decays. Here $P$ and $V$ indicate pesudoscalar and vector mesons in the flavor octet representations.
hep-ph/9609395
Naoyuki Haba
Naoyuki Haba (Nagoya University, Nagoya, Japan)
Can the Higgs Sector Trigger CP Violation in the MSSM?
13 pages, LaTex
Phys.Lett.B398:305-310,1997
10.1016/S0370-2693(97)00247-5
DPNU-96-49
hep-ph
null
We reanalyze the possibility of CP violation in the Higgs sector of the minimal supersymmetric standard model (MSSM). Contrary to the result of previous analysis, spontaneous CP violation can not occur by only chargino and neutralino radiative corrections since the vacuum does not stable. Top and stop radiative corrections are crucially needed. However even with this correction there is no experimentally allowed region in \tan \beta \geq 1. This situation is not remedied even if the stop left-right mixing is included. We also analyze explicit CP violation in the Higgs sector of the MSSM and show that the effect is too small to influence the phenomenology. We thus show that the Higgs sector can not, by itself, trigger CP violation in the MSSM.
[ { "created": "Wed, 18 Sep 1996 09:16:05 GMT", "version": "v1" } ]
2011-01-13
[ [ "Haba", "Naoyuki", "", "Nagoya University, Nagoya, Japan" ] ]
We reanalyze the possibility of CP violation in the Higgs sector of the minimal supersymmetric standard model (MSSM). Contrary to the result of previous analysis, spontaneous CP violation can not occur by only chargino and neutralino radiative corrections since the vacuum does not stable. Top and stop radiative corrections are crucially needed. However even with this correction there is no experimentally allowed region in \tan \beta \geq 1. This situation is not remedied even if the stop left-right mixing is included. We also analyze explicit CP violation in the Higgs sector of the MSSM and show that the effect is too small to influence the phenomenology. We thus show that the Higgs sector can not, by itself, trigger CP violation in the MSSM.
hep-ph/9505234
null
Zheng Huang and Mahiko Suzuki (LBL)
Isospin Coherence and Final-State Scattering of Disoriented Chiral Condensate
12 pages, one uuencoded postscript figure
Phys.Rev.D52:2610-2613,1995
10.1103/PhysRevD.52.R2610
LBL-37189, UCB-PTH-95/12
hep-ph nucl-th
null
We examine the validity of the notion of the coherent state for pions and the quantum scattering effect in the final state of pion emission. When the number of particles is large, the effect caused by the small but finite mass difference between the neutral and charged pions can add up substantially in the quantum evolution of an initially coherent state. As a result, the states with quite different numbers of neutral or charged pions are essentially incoherent. The importance of the quantum scattering in the final-state isospin charge distribution of a disoriented chiral condensate (DCC) is investigated. We find that the scattering effect significantly reduces the spectacular Centauro and anti-Centauro events. The deformation of a charge distribution $dP/df$ predicted by the classical field theory is significant only for a DCC with the size of 10 fm or more.
[ { "created": "Fri, 5 May 1995 01:01:08 GMT", "version": "v1" } ]
2010-01-08
[ [ "Huang", "Zheng", "", "LBL" ], [ "Suzuki", "Mahiko", "", "LBL" ] ]
We examine the validity of the notion of the coherent state for pions and the quantum scattering effect in the final state of pion emission. When the number of particles is large, the effect caused by the small but finite mass difference between the neutral and charged pions can add up substantially in the quantum evolution of an initially coherent state. As a result, the states with quite different numbers of neutral or charged pions are essentially incoherent. The importance of the quantum scattering in the final-state isospin charge distribution of a disoriented chiral condensate (DCC) is investigated. We find that the scattering effect significantly reduces the spectacular Centauro and anti-Centauro events. The deformation of a charge distribution $dP/df$ predicted by the classical field theory is significant only for a DCC with the size of 10 fm or more.
hep-ph/9502260
null
J.L. Feng, H. Murayama, M.E. Peskin, and X. Tata
TESTING SUPERSYMMETRY AT THE NEXT LINEAR COLLIDER
26pp, Revtex, 7 figures available upon request (text and figures available as ps at ftp://preprint.slac.stanford.edu/preprints/hep-ph/9502/ )
Phys.Rev.D52:1418-1432,1995
10.1103/PhysRevD.52.1418
SLAC-PUB-6654, LBL-36101, UH-511-804-94
hep-ph
null
Up to now, almost all discussion of supersymmetry at future colliders has been concerned with particle searches. However, if candidates for supersymmetric particles are found, there is much more that we will want to know about them. Supersymmetry predicts quantitative relations among the couplings and masses of supersymmetric particles. We discuss the prospects for testing such relations at a future $e^+e^-$ linear collider, using measurements that exploit the availability of polarized beams. Precision tests from chargino production are investigated in two representative cases, and sfermion and neutralino processes are also discussed.
[ { "created": "Thu, 9 Feb 1995 07:17:00 GMT", "version": "v1" }, { "created": "Thu, 9 Feb 1995 07:55:00 GMT", "version": "v2" } ]
2016-09-01
[ [ "Feng", "J. L.", "" ], [ "Murayama", "H.", "" ], [ "Peskin", "M. E.", "" ], [ "Tata", "X.", "" ] ]
Up to now, almost all discussion of supersymmetry at future colliders has been concerned with particle searches. However, if candidates for supersymmetric particles are found, there is much more that we will want to know about them. Supersymmetry predicts quantitative relations among the couplings and masses of supersymmetric particles. We discuss the prospects for testing such relations at a future $e^+e^-$ linear collider, using measurements that exploit the availability of polarized beams. Precision tests from chargino production are investigated in two representative cases, and sfermion and neutralino processes are also discussed.
1802.03174
Andrew Cheek
D.G. Cerdeno, A. Cheek, E. Reid, and H. Schulz
Surrogate Models for Direct Dark Matter Detection
35 pages, 19 figures
null
10.1088/1475-7516/2018/08/011
IPPP/18/12; DCTP/18/24
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we introduce RAPIDD, a surrogate model that speeds up the computation of the expected spectrum of dark matter particles in direct detection experiments. RAPIDD replaces the exact calculation of the dark matter differential rate (which in general involves up to three nested integrals) with a much faster parametrization in terms of ordinary polynomials of the dark matter mass and couplings, obtained in an initial training phase. In this article, we validate our surrogate model on the multi-dimensional parameter space resulting from the effective field theory description of dark matter interactions with nuclei, including also astrophysical uncertainties in the description of the dark matter halo. As a concrete example, we use this tool to study the complementarity of different targets to discriminate simplified dark matter models. We demonstrate that RAPIDD is fast and accurate, and particularly well-suited to explore a multi-dimensional parameter space, such as the one in effective field theory approach, and scans with a large number of evaluations.
[ { "created": "Fri, 9 Feb 2018 09:04:12 GMT", "version": "v1" }, { "created": "Fri, 14 Sep 2018 16:42:45 GMT", "version": "v2" } ]
2018-09-17
[ [ "Cerdeno", "D. G.", "" ], [ "Cheek", "A.", "" ], [ "Reid", "E.", "" ], [ "Schulz", "H.", "" ] ]
In this work we introduce RAPIDD, a surrogate model that speeds up the computation of the expected spectrum of dark matter particles in direct detection experiments. RAPIDD replaces the exact calculation of the dark matter differential rate (which in general involves up to three nested integrals) with a much faster parametrization in terms of ordinary polynomials of the dark matter mass and couplings, obtained in an initial training phase. In this article, we validate our surrogate model on the multi-dimensional parameter space resulting from the effective field theory description of dark matter interactions with nuclei, including also astrophysical uncertainties in the description of the dark matter halo. As a concrete example, we use this tool to study the complementarity of different targets to discriminate simplified dark matter models. We demonstrate that RAPIDD is fast and accurate, and particularly well-suited to explore a multi-dimensional parameter space, such as the one in effective field theory approach, and scans with a large number of evaluations.
hep-ph/9711447
Morris L. Swartz
M. L. Swartz (SLAC)
A Complete Order-alpha**3 Calculation of the Cross Section for Polarized Compton Scattering
37 pages, RevTeX document, 7 figures. The FORTRAN code comrad.f is available in gzip-compressed form at ftp://ftp.slac.stanford.edu/users/morris/comrad.f.gz and /afs/slac.stanford.edu/public/users/morris/comrad.f.gz. Cosmetically updated draft (moves some detail into an appendix)
Phys. Rev. D 58, 014010 (1998)
10.1103/PhysRevD.58.014010
SLAC-PUB-7701
hep-ph hep-ex
null
The construction of a computer code to calculate the cross sections for the spin-polarized processes e-gamma=>e-gamma,e-gamma-gamma,e-e+e- to order-alpha**3 is described. The code calculates cross sections for circularly-polarized initial-state photons and arbitrarily polarized initial-state electrons. The application of the code to the SLD Compton polarimeter indicates that the order-alpha**3 corrections produce a fractional shift in the SLC polarization scale of -0.1% which is too small and of the wrong sign to account for the discrepancy in the Z-pole asymmetries measured by the SLD Collaboration and the LEP Collaborations.
[ { "created": "Mon, 24 Nov 1997 20:30:50 GMT", "version": "v1" }, { "created": "Fri, 20 Mar 1998 20:09:25 GMT", "version": "v2" } ]
2016-08-25
[ [ "Swartz", "M. L.", "", "SLAC" ] ]
The construction of a computer code to calculate the cross sections for the spin-polarized processes e-gamma=>e-gamma,e-gamma-gamma,e-e+e- to order-alpha**3 is described. The code calculates cross sections for circularly-polarized initial-state photons and arbitrarily polarized initial-state electrons. The application of the code to the SLD Compton polarimeter indicates that the order-alpha**3 corrections produce a fractional shift in the SLC polarization scale of -0.1% which is too small and of the wrong sign to account for the discrepancy in the Z-pole asymmetries measured by the SLD Collaboration and the LEP Collaborations.
hep-ph/9807548
Elisabeth Kraus
Elisabeth Kraus (1), Georg Weiglein (2) ((1) Univ. Bonn, (2) Univ. Karlsruhe)
The Callan-Symanzik equation of the electroweak Standard Model and its 1-loop functions
39 pages, LaTeX
Nucl.Phys. B551 (1999) 117-154
10.1016/S0550-3213(99)00202-3
Bonn-TH-98-16, KA-TP-12-1998
hep-ph hep-th
null
We derive the Callan-Symanzik equation of the electroweak Standard Model in the QED-like on-shell parameterization. The various coefficient functions, the $\beta$-functions and anomalous dimensions, are determined in one-loop order in the most general linear gauge compatible with rigid symmetry. In this way the basic elements for a systematic investigation of higher-order leading logarithmic contributions in the Standard Model are provided. The one-loop $\beta$-function of the electromagnetic coupling turns out to be independent of mass ratios and it is QED-like in this sense. Besides the QED-contributions of fermions it contains non-abelian contributions from vectors and ghosts with negative sign, which overcompensate the contributions of the fermions if one restricts the latter to one fermion generation. We also compare our results with the symmetric theory and give relations between the $\beta$-functions of the spontaneously broken and the symmetric theory valid in one-loop order.
[ { "created": "Thu, 30 Jul 1998 10:21:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kraus", "Elisabeth", "" ], [ "Weiglein", "Georg", "" ] ]
We derive the Callan-Symanzik equation of the electroweak Standard Model in the QED-like on-shell parameterization. The various coefficient functions, the $\beta$-functions and anomalous dimensions, are determined in one-loop order in the most general linear gauge compatible with rigid symmetry. In this way the basic elements for a systematic investigation of higher-order leading logarithmic contributions in the Standard Model are provided. The one-loop $\beta$-function of the electromagnetic coupling turns out to be independent of mass ratios and it is QED-like in this sense. Besides the QED-contributions of fermions it contains non-abelian contributions from vectors and ghosts with negative sign, which overcompensate the contributions of the fermions if one restricts the latter to one fermion generation. We also compare our results with the symmetric theory and give relations between the $\beta$-functions of the spontaneously broken and the symmetric theory valid in one-loop order.
1408.5694
Shengqin Feng
Yang Zhong, Chunbin Yang, Xu Cai and Shengqin Feng
A systematic study of magnetic field in Relativistic Heavy-ion Collisions in the RHIC and LHC energy regions
8 pages, 7 figures
Advance In High Energy Physics, 2014 (2014), 193039
10.1155/2014/193039
null
hep-ph nucl-th
http://creativecommons.org/licenses/by-nc-sa/3.0/
The features of magnetic field in relativistic heavy-ion collisions are systematically studied by using a modified magnetic field model in this paper. The features of magnetic field distributions in the central point are studied in the RHIC and LHC energy regions. We also predict the feature of magnetic fields at LHC $\sqrt{s_{NN}}$= 900, 2760 and 7000 GeV based on the detailed study at RHIC $\sqrt{s_{NN}}$ = 62.4, 130 and 200 GeV. The dependencies of the features of magnetic fields on the collision energies, centralities and collision time are systematically investigated, respectively.
[ { "created": "Mon, 25 Aug 2014 09:27:50 GMT", "version": "v1" } ]
2014-08-28
[ [ "Zhong", "Yang", "" ], [ "Yang", "Chunbin", "" ], [ "Cai", "Xu", "" ], [ "Feng", "Shengqin", "" ] ]
The features of magnetic field in relativistic heavy-ion collisions are systematically studied by using a modified magnetic field model in this paper. The features of magnetic field distributions in the central point are studied in the RHIC and LHC energy regions. We also predict the feature of magnetic fields at LHC $\sqrt{s_{NN}}$= 900, 2760 and 7000 GeV based on the detailed study at RHIC $\sqrt{s_{NN}}$ = 62.4, 130 and 200 GeV. The dependencies of the features of magnetic fields on the collision energies, centralities and collision time are systematically investigated, respectively.
1712.05401
Thomas Edwards
Thomas D. P. Edwards and Christoph Weniger
swordfish: Efficient Forecasting of New Physics Searches without Monte Carlo
17 pages including appendix, 13 figures
null
null
null
hep-ph physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce swordfish, a Monte-Carlo-free Python package to predict expected exclusion limits, the discovery reach and expected confidence contours for a large class of experiments relevant for particle- and astrophysics. The tool is applicable to any counting experiment, supports general correlated background uncertainties, and gives exact results in both the signal- and systematics-limited regimes. Instead of time-intensive Monte Carlo simulations and likelihood maximization, it internally utilizes new approximation methods that are built on information geometry. Out of the box, swordfish provides straightforward methods for accurately deriving many of the common sensitivity measures. In addition, it allows one to examine experimental abilities in great detail by employing the notion of information flux. This new concept generalizes signal-to-noise ratios to situations where background uncertainties and component mixing cannot be neglected. The user interface of swordfish is designed with ease-of-use in mind, which we demonstrate by providing typical examples from indirect and direct dark matter searches as jupyter notebooks.
[ { "created": "Thu, 14 Dec 2017 18:59:54 GMT", "version": "v1" } ]
2017-12-15
[ [ "Edwards", "Thomas D. P.", "" ], [ "Weniger", "Christoph", "" ] ]
We introduce swordfish, a Monte-Carlo-free Python package to predict expected exclusion limits, the discovery reach and expected confidence contours for a large class of experiments relevant for particle- and astrophysics. The tool is applicable to any counting experiment, supports general correlated background uncertainties, and gives exact results in both the signal- and systematics-limited regimes. Instead of time-intensive Monte Carlo simulations and likelihood maximization, it internally utilizes new approximation methods that are built on information geometry. Out of the box, swordfish provides straightforward methods for accurately deriving many of the common sensitivity measures. In addition, it allows one to examine experimental abilities in great detail by employing the notion of information flux. This new concept generalizes signal-to-noise ratios to situations where background uncertainties and component mixing cannot be neglected. The user interface of swordfish is designed with ease-of-use in mind, which we demonstrate by providing typical examples from indirect and direct dark matter searches as jupyter notebooks.