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2202.08392
Shuang-Yong Zhou
Si-Yuan Hou, Paul M. Saffin, Qi-Xin Xie, and Shuang-Yong Zhou
Charge-Swapping Q-balls in a Logarithmic Potential and Affleck-Dine condensate fragmentation
23 pages, 15 figures
null
null
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study charge-swapping Q-balls, a kind of composite Q-ball where positive and negative charges co-exist and swap with time, in models with a logarithmic potential that arises naturally in supersymmetric extensions of the Standard Model. We show that charge-swapping Q-balls can be copiously generated in the Affleck-Dine fragmentation process in the early universe. We find that the charge-swapping Q-balls with the logarithmic potential are extremely stable. By performing long time, parallelized lattice simulations with absorbing boundary conditions, we find that the lifetimes of such objects with low multipoles are at least $4.6 \times 10^5/m$ in 3+1D and $2.5 \times 10^7/m$ in 2+1D, where $m$ is the mass scale of the scalar field. We also chart the attractor basin of the initial conditions to form these charge-swapping Q-balls.
[ { "created": "Thu, 17 Feb 2022 01:12:29 GMT", "version": "v1" } ]
2022-02-21
[ [ "Hou", "Si-Yuan", "" ], [ "Saffin", "Paul M.", "" ], [ "Xie", "Qi-Xin", "" ], [ "Zhou", "Shuang-Yong", "" ] ]
We study charge-swapping Q-balls, a kind of composite Q-ball where positive and negative charges co-exist and swap with time, in models with a logarithmic potential that arises naturally in supersymmetric extensions of the Standard Model. We show that charge-swapping Q-balls can be copiously generated in the Affleck-Dine fragmentation process in the early universe. We find that the charge-swapping Q-balls with the logarithmic potential are extremely stable. By performing long time, parallelized lattice simulations with absorbing boundary conditions, we find that the lifetimes of such objects with low multipoles are at least $4.6 \times 10^5/m$ in 3+1D and $2.5 \times 10^7/m$ in 2+1D, where $m$ is the mass scale of the scalar field. We also chart the attractor basin of the initial conditions to form these charge-swapping Q-balls.
1502.03894
Akira Watanabe
Akira Watanabe and Hsiang-nan Li
Photon structure functions at small $x$ in holographic QCD
6 pages, 5 figures; v2: version accepted for publication in Phys. Lett. B, Fig. 2 and clarifications added to Section 3
null
10.1016/j.physletb.2015.10.069
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the photon structure functions at small Bjorken variable $x$ in the framework of the holographic QCD, assuming dominance of the Pomeron exchange. The quasi-real photon structure functions are expressed as convolution of the Brower-Polchinski-Strassler-Tan (BPST) Pomeron kernel and the known wave functions of the U(1) vector field in the five-dimensional AdS space, in which the involved parameters in the BPST kernel have been fixed in previous studies of the nucleon structure functions. The predicted photon structure functions, as confronted with data, provide a clean test of the BPST kernel. The agreement between theoretical predictions and data is demonstrated, which supports applications of holographic QCD to hadronic processes in the nonperturbative region. Our results are also consistent with those derived from the parton distribution functions of the photon proposed by Gl\"uck, Reya, and Schienbein, implying realization of the vector meson dominance in the present model setup.
[ { "created": "Fri, 13 Feb 2015 06:20:03 GMT", "version": "v1" }, { "created": "Tue, 27 Oct 2015 09:38:53 GMT", "version": "v2" } ]
2015-11-04
[ [ "Watanabe", "Akira", "" ], [ "Li", "Hsiang-nan", "" ] ]
We investigate the photon structure functions at small Bjorken variable $x$ in the framework of the holographic QCD, assuming dominance of the Pomeron exchange. The quasi-real photon structure functions are expressed as convolution of the Brower-Polchinski-Strassler-Tan (BPST) Pomeron kernel and the known wave functions of the U(1) vector field in the five-dimensional AdS space, in which the involved parameters in the BPST kernel have been fixed in previous studies of the nucleon structure functions. The predicted photon structure functions, as confronted with data, provide a clean test of the BPST kernel. The agreement between theoretical predictions and data is demonstrated, which supports applications of holographic QCD to hadronic processes in the nonperturbative region. Our results are also consistent with those derived from the parton distribution functions of the photon proposed by Gl\"uck, Reya, and Schienbein, implying realization of the vector meson dominance in the present model setup.
1811.02567
Masaki Yamada
Ayuki Kamada, Masaki Yamada, Tsutomu T. Yanagida
Self-interacting dark matter with a vector mediator: kinetic mixing with U(1)$_{(B-L)_3}$ gauge boson
27 pages, 2 figures; v2: minor changes, Appendix A added, published version
null
10.1007/JHEP03(2019)021
IPMU18-0179
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A spontaneously broken hidden U(1)$_h$ gauge symmetry can explain both the dark matter stability and the observed relic abundance. In this framework, the light gauge boson can mediate the strong dark matter self-interaction, which addresses astrophysical observations that are hard to explain in collisionless cold dark matter. Motivated by flavoured grand unified theories, we introduce right-handed neutrinos and a flavoured $B - L$ gauge symmetry for the third family U(1)$_{(B-L)_3}$. The unwanted relic of the U(1)$_h$ gauge boson decays into neutrinos via the kinetic mixing with the U(1)$_{(B - L)_3}$ gauge boson. Indirect detection bounds on dark matter are systematically weakened, since dark matter annihilation results in neutrinos. However, the kinetic mixing between U(1)$_{(B - L)_3}$ and U(1)$_Y$ gauge bosons are induced by quantum corrections and leads to an observable signal in direct and indirect detection experiments of dark matter. This model can also explain the baryon asymmetry of the Universe via the thermal leptogenesis. In addition, we discuss the possibility of explaining the lepton flavour universality violation in semi-leptonic $B$ meson decays that is recently found in the LHCb experiment.
[ { "created": "Tue, 6 Nov 2018 19:00:00 GMT", "version": "v1" }, { "created": "Wed, 6 Feb 2019 21:36:30 GMT", "version": "v2" } ]
2019-03-27
[ [ "Kamada", "Ayuki", "" ], [ "Yamada", "Masaki", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
A spontaneously broken hidden U(1)$_h$ gauge symmetry can explain both the dark matter stability and the observed relic abundance. In this framework, the light gauge boson can mediate the strong dark matter self-interaction, which addresses astrophysical observations that are hard to explain in collisionless cold dark matter. Motivated by flavoured grand unified theories, we introduce right-handed neutrinos and a flavoured $B - L$ gauge symmetry for the third family U(1)$_{(B-L)_3}$. The unwanted relic of the U(1)$_h$ gauge boson decays into neutrinos via the kinetic mixing with the U(1)$_{(B - L)_3}$ gauge boson. Indirect detection bounds on dark matter are systematically weakened, since dark matter annihilation results in neutrinos. However, the kinetic mixing between U(1)$_{(B - L)_3}$ and U(1)$_Y$ gauge bosons are induced by quantum corrections and leads to an observable signal in direct and indirect detection experiments of dark matter. This model can also explain the baryon asymmetry of the Universe via the thermal leptogenesis. In addition, we discuss the possibility of explaining the lepton flavour universality violation in semi-leptonic $B$ meson decays that is recently found in the LHCb experiment.
hep-ph/0203137
Edmond Iancu
E. Iancu, K. Itakura, and L. McLerran
Geometric Scaling above the Saturation Scale
24 pages
Nucl.Phys.A708:327-352,2002
10.1016/S0375-9474(02)01010-2
Saclay-T02/027
hep-ph
null
We show that the evolution equations in QCD predict geometric scaling for quark and gluon distribution functions in a large kinematical window, which extends above the saturation scale up to momenta $Q^2$ of order $100 {\rm GeV}^2$. For $Q^2 < Q^2_s$, with $Q_s$ the saturation momentum, this is the scaling predicted by the Colour Glass Condensate and by phenomenological saturation models. For $1 \simle \ln(Q^2/Q_s^2) \ll \ln(Q_s^2/\Lambda^2_{\rm QCD})$, we show that the solution to the BFKL equation shows approximate scaling, with the scale set by $Q_s$. At larger $Q^2$, this solution does not scale any longer. We argue that for the intermediate values of $Q^2$ where we find scaling, the BFKL rather than the double logarithmic approximation to the DGLAP equation properly describes the dynamics. We consider both fixed and running couplings, with the scale for running set by the saturation momentum. The anomalous dimension which characterizes the approach of the gluon distribution function towards saturation is found to be close to, but lower than, one half.
[ { "created": "Thu, 14 Mar 2002 16:48:09 GMT", "version": "v1" } ]
2014-11-17
[ [ "Iancu", "E.", "" ], [ "Itakura", "K.", "" ], [ "McLerran", "L.", "" ] ]
We show that the evolution equations in QCD predict geometric scaling for quark and gluon distribution functions in a large kinematical window, which extends above the saturation scale up to momenta $Q^2$ of order $100 {\rm GeV}^2$. For $Q^2 < Q^2_s$, with $Q_s$ the saturation momentum, this is the scaling predicted by the Colour Glass Condensate and by phenomenological saturation models. For $1 \simle \ln(Q^2/Q_s^2) \ll \ln(Q_s^2/\Lambda^2_{\rm QCD})$, we show that the solution to the BFKL equation shows approximate scaling, with the scale set by $Q_s$. At larger $Q^2$, this solution does not scale any longer. We argue that for the intermediate values of $Q^2$ where we find scaling, the BFKL rather than the double logarithmic approximation to the DGLAP equation properly describes the dynamics. We consider both fixed and running couplings, with the scale for running set by the saturation momentum. The anomalous dimension which characterizes the approach of the gluon distribution function towards saturation is found to be close to, but lower than, one half.
1310.5662
James J. Beatty
J.J. Beatty, A.E. Nelson, A. Olinto, G. Sinnis, A. U. Abeysekara, L.A. Anchordoqui, T. Aramaki, J. Belz, J.H. Buckley, K. Byrum, R. Cameron, M-C. Chen, K. Clark, A. Connolly, D. Cowen, T. DeYoung, P. von Doetinchem J. Dumm, M. Errando, G. Farrar, F. Ferrer, L. Fortson, S. Funk, D. Grant, S. Griffiths, A. Gro\ss, C. Hailey, C. Hogan, J. Holder, B. Humensky, P. Kaaret, S.R. Klein, H. Krawczynski, F. Krennrich, K. Krings, J. Krizmanic, A. Kusenko, J. T. Linnemann, J. H. MacGibbon, J. Matthews, A. McCann, J. Mitchell, R. Mukherjee, D. Nitz, R.A. Ong, M. Orr, N. Otte, T. Paul, E. Resconi, M. A. Sanchez-Conde, P. Sokolsky, F. Stecker, D. Stump, I. Taboada, G.B. Thomson, K. Tollefson, P. von Doetinchem, T. Ukwatta, J. Vandenbroucke, V. Vasileiou, V.V. Vassileiv, T.J. Weiler, D.A. Williams, A. Weinstein, M. Wood, B. Zitzer
Snowmass Cosmic Frontiers 6 (CF6) Working Group Summary --The Bright Side of the Cosmic Frontier: Cosmic Probes of Fundamental Physics
Snowmass 2013 CF6 Working Group Report; author list corrected
null
null
null
hep-ph astro-ph.CO astro-ph.HE astro-ph.IM hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime.
[ { "created": "Mon, 21 Oct 2013 18:14:10 GMT", "version": "v1" }, { "created": "Fri, 25 Oct 2013 15:48:22 GMT", "version": "v2" } ]
2013-10-28
[ [ "Beatty", "J. J.", "" ], [ "Nelson", "A. E.", "" ], [ "Olinto", "A.", "" ], [ "Sinnis", "G.", "" ], [ "Abeysekara", "A. U.", "" ], [ "Anchordoqui", "L. A.", "" ], [ "Aramaki", "T.", "" ], [ "Belz", ...
Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime.
2205.11560
Surabhi Tiwari
V. Ravindran, Aparna Sankar, Surabhi Tiwari
Resummed next-to-soft corrections to rapidity distribution of Higgs Boson to $ \textbf{NNLO} + \overline{\textbf{NNLL} } $
null
null
10.1103/PhysRevD.108.014012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the resumed predictions consisting of both soft-virtual(SV) as well as next-to-SV(NSV) threshold logarithms to all orders in perturbative QCD for the rapidity distribution of Higgs Boson till $\rm NNLO + \overline{NNLL}$ accuracy at LHC. Using our recent formalism\cite{Ajjath:2020lwb}, the resummation is carried out in the double Mellin space by restricting the NSV contributions only from diagonal $gg$ channel. We perform the inverse Mellin ransformation using the minimal prescription procedure and match it with the corresponding fixed order results. We do a detailed analysis of the numerical impact of the resummed result. The K-factor values at different logarithmic accuracy suggest that the prediction for the rapidity distribution converges and becomes more reliable at $\rm NNLO + \overline{NNLL}$ order. We further observed that the inclusion of resumed NSV contribution improves the renormalisation scale uncertainty at every order in perturbation theory. However, the uncertainty due to factorisation scale increases by the addition of resummed SV+NSV predictions to the fixed order rapidity distribution.
[ { "created": "Mon, 23 May 2022 18:20:40 GMT", "version": "v1" } ]
2023-07-26
[ [ "Ravindran", "V.", "" ], [ "Sankar", "Aparna", "" ], [ "Tiwari", "Surabhi", "" ] ]
We present the resumed predictions consisting of both soft-virtual(SV) as well as next-to-SV(NSV) threshold logarithms to all orders in perturbative QCD for the rapidity distribution of Higgs Boson till $\rm NNLO + \overline{NNLL}$ accuracy at LHC. Using our recent formalism\cite{Ajjath:2020lwb}, the resummation is carried out in the double Mellin space by restricting the NSV contributions only from diagonal $gg$ channel. We perform the inverse Mellin ransformation using the minimal prescription procedure and match it with the corresponding fixed order results. We do a detailed analysis of the numerical impact of the resummed result. The K-factor values at different logarithmic accuracy suggest that the prediction for the rapidity distribution converges and becomes more reliable at $\rm NNLO + \overline{NNLL}$ order. We further observed that the inclusion of resumed NSV contribution improves the renormalisation scale uncertainty at every order in perturbation theory. However, the uncertainty due to factorisation scale increases by the addition of resummed SV+NSV predictions to the fixed order rapidity distribution.
hep-ph/9602248
Bob Holdom
B. Holdom
Negative T from a dynamical left-handed neutrino mass
8 pages, postscript, version to be published as Rapid Communications in PRD, PDF file is available at http://miteymac.physics.utoronto.ca/bh/papers/papers.html
Phys.Rev.D54:721-724,1996
10.1103/PhysRevD.54.R721
UTPT-96-01
hep-ph
null
We show how a dynamical Majorana mass for a fourth family left-handed neutrino can make a significant negative contribution to the electroweak correction parameter T without making a large contribution to S or U. We also comment on other possible contributions to T in the context of dynamical symmetry breaking.
[ { "created": "Wed, 7 Feb 1996 18:24:47 GMT", "version": "v1" }, { "created": "Fri, 26 Apr 1996 23:09:08 GMT", "version": "v2" } ]
2009-12-30
[ [ "Holdom", "B.", "" ] ]
We show how a dynamical Majorana mass for a fourth family left-handed neutrino can make a significant negative contribution to the electroweak correction parameter T without making a large contribution to S or U. We also comment on other possible contributions to T in the context of dynamical symmetry breaking.
hep-ph/0002157
Hai-Yang Cheng
Hai-Yang Cheng
The Proton Spin Puzzle: A Status Report
22 pages, 2 figures, invited plenary talk presented at the 2000 Annual Meeting of the Physical Society of ROC, National Cheng-Kung University, Taiwan, ROC, January 31 - February 1, 2000
Chin.J.Phys.38:753,2000
null
null
hep-ph hep-ex
null
The proton spin puzzle inspired by the EMC experiment and its present status are closely examined. Recent experimental progress is reviewed. Various factorization schemes due to the ambiguity arising from the axial anomaly are discussed. Some misconceptions in the literature about the $\MS$ factorization scheme are clarified. It is stressed that the polarized nucleon structure function $g_1(x)$ is independent of the factorization scheme chosen in defining the quark spin density. Consequently, the anomalous gluon and sea-quark interpretations for the deviation of the observed first moment of $g_1^p(x)$ from the Ellis-Jaffe sum rule are equivalent. While it is well known that the total quark spin in the chiral-invariant (CI) factorization scheme (e.g. the improved parton model) can be made to be close to the quark model expectation provided that the gluon spin is positive and large enough, it is much less known that, contrary to the gauge-invariant scheme (e.g. the MSbar scheme), the quark orbital angular momentum in the CI scheme deviates even farther from the relativistic quark model prediction. Recent developments in the NLO analysis of polarized DIS data, orbital angular momentum and lattice calculations of the proton spin content are briefly sketched.
[ { "created": "Tue, 15 Feb 2000 22:38:05 GMT", "version": "v1" }, { "created": "Wed, 8 Mar 2000 03:32:58 GMT", "version": "v2" } ]
2014-11-17
[ [ "Cheng", "Hai-Yang", "" ] ]
The proton spin puzzle inspired by the EMC experiment and its present status are closely examined. Recent experimental progress is reviewed. Various factorization schemes due to the ambiguity arising from the axial anomaly are discussed. Some misconceptions in the literature about the $\MS$ factorization scheme are clarified. It is stressed that the polarized nucleon structure function $g_1(x)$ is independent of the factorization scheme chosen in defining the quark spin density. Consequently, the anomalous gluon and sea-quark interpretations for the deviation of the observed first moment of $g_1^p(x)$ from the Ellis-Jaffe sum rule are equivalent. While it is well known that the total quark spin in the chiral-invariant (CI) factorization scheme (e.g. the improved parton model) can be made to be close to the quark model expectation provided that the gluon spin is positive and large enough, it is much less known that, contrary to the gauge-invariant scheme (e.g. the MSbar scheme), the quark orbital angular momentum in the CI scheme deviates even farther from the relativistic quark model prediction. Recent developments in the NLO analysis of polarized DIS data, orbital angular momentum and lattice calculations of the proton spin content are briefly sketched.
1812.08016
Hiroshi Okada
Takaaki Nomura, Hiroshi Okada
One-loop neutrino mass model with $SU(2)_L$ multiplet fields
18 pages, 1 table, 7 figures, version accepted for publication in Nuclear Physics B
null
10.1016/j.nuclphysb.2019.114621
KIAS-P18115, APCTP Pre2018 - 017
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a one-loop neutrino mass model with several $SU(2)_L$ multiplet fermions and scalar fields in which the inert feature of a scalar to realize the one-loop neutrino mass can be achieved by the cancellation among Higgs couplings thanks to non-trivial terms in the Higgs potential and to present it in a simpler way. Then we discuss our typical cut-off scale by computing renormalization group equation for $SU(2)_L$ gauge coupling, lepton flavor violations, muon anomalous magnetic moment, possibility of dark matter candidate, neutrino mass matrix satisfying the neutrino oscillation data. Finally, we search for our allowed parameter region to satisfy all the constraints, and discuss a possibility of detecting new charged particles at the large hadron collider.
[ { "created": "Tue, 18 Dec 2018 11:47:22 GMT", "version": "v1" }, { "created": "Tue, 16 Apr 2019 02:57:32 GMT", "version": "v2" } ]
2019-06-26
[ [ "Nomura", "Takaaki", "" ], [ "Okada", "Hiroshi", "" ] ]
We propose a one-loop neutrino mass model with several $SU(2)_L$ multiplet fermions and scalar fields in which the inert feature of a scalar to realize the one-loop neutrino mass can be achieved by the cancellation among Higgs couplings thanks to non-trivial terms in the Higgs potential and to present it in a simpler way. Then we discuss our typical cut-off scale by computing renormalization group equation for $SU(2)_L$ gauge coupling, lepton flavor violations, muon anomalous magnetic moment, possibility of dark matter candidate, neutrino mass matrix satisfying the neutrino oscillation data. Finally, we search for our allowed parameter region to satisfy all the constraints, and discuss a possibility of detecting new charged particles at the large hadron collider.
hep-ph/0303074
Domenico Falcone
D. Falcone
Minimal seesaw mechanism
9 pages, RevTex4. Revised
Phys.Lett. B572 (2003) 50-55
10.1016/j.physletb.2003.07.087
DSF-07/2003
hep-ph
null
In the framework of the seesaw mechanism, and adopting a typical form for the Dirac neutrino mass matrix, we discuss the impact of minimal forms of the Majorana neutrino mass matrix. These matrices contain four or three texture zeros and only two parameters, a scale factor and a hierarchy parameter. Some forms are not compatible with large lepton mixing and are ruled out. Moreover, a normal mass hierarchy for neutrinos is predicted.
[ { "created": "Mon, 10 Mar 2003 11:17:12 GMT", "version": "v1" }, { "created": "Tue, 17 Jun 2003 08:13:51 GMT", "version": "v2" }, { "created": "Thu, 19 Jun 2003 10:23:30 GMT", "version": "v3" } ]
2009-11-10
[ [ "Falcone", "D.", "" ] ]
In the framework of the seesaw mechanism, and adopting a typical form for the Dirac neutrino mass matrix, we discuss the impact of minimal forms of the Majorana neutrino mass matrix. These matrices contain four or three texture zeros and only two parameters, a scale factor and a hierarchy parameter. Some forms are not compatible with large lepton mixing and are ruled out. Moreover, a normal mass hierarchy for neutrinos is predicted.
1810.01320
Emanuele Mereghetti
Emanuele Mereghetti
Electric dipole moments: a theory overview
Talk presented at CIPANP2018
null
null
CIPANP2018-Mereghetti, LA-UR-18-29338
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electric dipole moments are extremely sensitive probes of physics beyond the Standard Model. A vibrant experimental program is in place, with the goal of improving existing bounds on the electron and neutron electric dipole moments by one or two orders of magnitude, while testing new ideas for the measurement of electric dipole moments of light ions, such as the proton and the deuteron, at a comparable level. The success of this program, and its implications for physics beyond the Standard Model, relies on the precise calculation of the electric dipole moments in terms of the couplings of CP-violating operators induced by beyond-the-Standard-Model physics. In light of the nonperturbative nature of both QCD at low energy and of the nuclear interactions, these calculations have proven difficult, and are affected by large theoretical uncertainties. In this talk I will review the progress that has been achieved on different aspects of the calculation of hadronic and nuclear EDMs, the challenges that remain to be faced, and the implications for our understanding of physics beyond the Standard Model.
[ { "created": "Tue, 2 Oct 2018 15:17:38 GMT", "version": "v1" } ]
2018-10-03
[ [ "Mereghetti", "Emanuele", "" ] ]
Electric dipole moments are extremely sensitive probes of physics beyond the Standard Model. A vibrant experimental program is in place, with the goal of improving existing bounds on the electron and neutron electric dipole moments by one or two orders of magnitude, while testing new ideas for the measurement of electric dipole moments of light ions, such as the proton and the deuteron, at a comparable level. The success of this program, and its implications for physics beyond the Standard Model, relies on the precise calculation of the electric dipole moments in terms of the couplings of CP-violating operators induced by beyond-the-Standard-Model physics. In light of the nonperturbative nature of both QCD at low energy and of the nuclear interactions, these calculations have proven difficult, and are affected by large theoretical uncertainties. In this talk I will review the progress that has been achieved on different aspects of the calculation of hadronic and nuclear EDMs, the challenges that remain to be faced, and the implications for our understanding of physics beyond the Standard Model.
2202.07373
Jin Hu
Jin Hu
Linear mode analysis from spin transport equation
null
null
10.1103/PhysRevD.106.036004
null
hep-ph nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
We provide a linear analysis on normal modes of the spin Boltzmann equation proposed in \cite{Weickgenannt:2021cuo}, where the non-diagonal or polarized part of the transition rate is neglected to ensure the Hermitian property of linearized collision operator. As an instrumental element of spin kinetic theory, the conservation of total angular momentum is explicitly considered, thus our analysis is relevant to the recent investigation on the issue of local spin polarization. By treating the linearized collision operator as an evolution operator, solving the normal modes turns out a degenerate perturbation problem in quantum mechanics. The dispersion relations of spinless modes are in accordance with well-known calculations, while the frequencies of spin modes are also determined up to second-order in wave vector and the second order expressions are only formal solutions to be further determined. Moreover, the relaxation of spin density is related to our linear mode analysis, which shall play a big role in investigating the issues of the local spin polarization in the relativistic heavy-ion collisions.
[ { "created": "Tue, 15 Feb 2022 12:57:40 GMT", "version": "v1" }, { "created": "Wed, 16 Feb 2022 02:34:32 GMT", "version": "v2" }, { "created": "Mon, 7 Mar 2022 16:09:09 GMT", "version": "v3" }, { "created": "Mon, 20 Jun 2022 14:07:58 GMT", "version": "v4" }, { "cr...
2022-08-17
[ [ "Hu", "Jin", "" ] ]
We provide a linear analysis on normal modes of the spin Boltzmann equation proposed in \cite{Weickgenannt:2021cuo}, where the non-diagonal or polarized part of the transition rate is neglected to ensure the Hermitian property of linearized collision operator. As an instrumental element of spin kinetic theory, the conservation of total angular momentum is explicitly considered, thus our analysis is relevant to the recent investigation on the issue of local spin polarization. By treating the linearized collision operator as an evolution operator, solving the normal modes turns out a degenerate perturbation problem in quantum mechanics. The dispersion relations of spinless modes are in accordance with well-known calculations, while the frequencies of spin modes are also determined up to second-order in wave vector and the second order expressions are only formal solutions to be further determined. Moreover, the relaxation of spin density is related to our linear mode analysis, which shall play a big role in investigating the issues of the local spin polarization in the relativistic heavy-ion collisions.
1008.0569
Jo\~ao Moreira
J. Moreira, B. Hiller, A. A. Osipov, A. H. Blin
Thermodynamic potential with correct asymptotics for PNJL model
16 pages, 5 figures, extended version, title changed
International Journal of Modern Physics A; Vol. 27, No. 00 (2012) 1250060
10.1142/S0217751X12500601
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An attempt is made to resolve certain incongruities within the Nambu - Jona-Lasinio (NJL) and Polyakov loop extended NJL models (PNJL) which currently are used to extract the thermodynamic characteristics of the quark-gluon system. It is argued that the most attractive resolution of these incongruities is the possibility to obtain the thermodynamic potential directly from the corresponding extremum conditions (gap equations) by integrating them, an integration constant being fixed in accordance with the Stefan-Boltzmann law. The advantage of the approach is that the regulator is kept finite both in divergent and finite valued integrals at finite temperature and chemical potential. The Pauli-Villars regularization is used, although a standard 3D sharp cutoff can be applied as well.
[ { "created": "Tue, 3 Aug 2010 15:18:37 GMT", "version": "v1" }, { "created": "Wed, 24 Nov 2010 21:07:31 GMT", "version": "v2" }, { "created": "Wed, 14 Sep 2011 11:29:22 GMT", "version": "v3" }, { "created": "Thu, 15 Sep 2011 08:26:55 GMT", "version": "v4" } ]
2012-04-18
[ [ "Moreira", "J.", "" ], [ "Hiller", "B.", "" ], [ "Osipov", "A. A.", "" ], [ "Blin", "A. H.", "" ] ]
An attempt is made to resolve certain incongruities within the Nambu - Jona-Lasinio (NJL) and Polyakov loop extended NJL models (PNJL) which currently are used to extract the thermodynamic characteristics of the quark-gluon system. It is argued that the most attractive resolution of these incongruities is the possibility to obtain the thermodynamic potential directly from the corresponding extremum conditions (gap equations) by integrating them, an integration constant being fixed in accordance with the Stefan-Boltzmann law. The advantage of the approach is that the regulator is kept finite both in divergent and finite valued integrals at finite temperature and chemical potential. The Pauli-Villars regularization is used, although a standard 3D sharp cutoff can be applied as well.
hep-ph/9906371
Valeri Yudichev
M. K. Volkov, V. L. Yudichev (JINR, Dubna, Russia)
Radially excited scalar, pseudoscalar, and vector meson nonets in a chiral quark model
LaTeX, 56 pages, 6 figures, psfig; Submitted to Phys. Part. Nuclei
Phys.Part.Nucl. 31 (2000) 282-311; Fiz.Elem.Chast.Atom.Yadra 31 (2000) 576-633
null
null
hep-ph
null
A chiral Lagrangian containing, besides the usual meson fields, their first radial excitations is constructed. The Lagrangian is derived by bosonization of a Nambu--Jona-Lasinio (NJL) type quark model with separable nonlocal interactions. The nonlocality is described by form factors corresponding to 3-dimensional excited state wave functions. The spontaneous breaking of chiral symmetry is governed by the standard NJL gap equations. A simple SU(2)xSU(2) version of the model is used to demonstrate all low-energy theorems to hold valid in the chiral limit. A more realistic U(3)xU(3) model with 't Hooft interaction is constructed to describe the mass spectrum of excited scalar, pseudoscalar, and vector mesons. On the basis of global chiral symmetry, we use the same form factors for the scalar and pseudoscalar mesons. Having fixed the form factor parameters by masses of pseudoscalar mesons, we predict the mass spectrum of scalar mesons. This allows us to interpret experimentally observed scalar, pseudoscalar, and vector meson states as members of quark-antiquark nonets. It is shown that the a_0(1450), K^*_0(1430), f_0(1370), f_J(1710) scalar meson states are the first radial excitations of the ground states: a_0(980), K^*_0(960), f_0(400-1200), f_0(980). The weak decay constants F_\pi, F_{\pi'}, F_K, F_{K'} and the main strong decay widths of the scalar, pseudoscalar, and vector meson nonets are calculated.
[ { "created": "Tue, 15 Jun 1999 17:10:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Volkov", "M. K.", "", "JINR, Dubna, Russia" ], [ "Yudichev", "V. L.", "", "JINR, Dubna, Russia" ] ]
A chiral Lagrangian containing, besides the usual meson fields, their first radial excitations is constructed. The Lagrangian is derived by bosonization of a Nambu--Jona-Lasinio (NJL) type quark model with separable nonlocal interactions. The nonlocality is described by form factors corresponding to 3-dimensional excited state wave functions. The spontaneous breaking of chiral symmetry is governed by the standard NJL gap equations. A simple SU(2)xSU(2) version of the model is used to demonstrate all low-energy theorems to hold valid in the chiral limit. A more realistic U(3)xU(3) model with 't Hooft interaction is constructed to describe the mass spectrum of excited scalar, pseudoscalar, and vector mesons. On the basis of global chiral symmetry, we use the same form factors for the scalar and pseudoscalar mesons. Having fixed the form factor parameters by masses of pseudoscalar mesons, we predict the mass spectrum of scalar mesons. This allows us to interpret experimentally observed scalar, pseudoscalar, and vector meson states as members of quark-antiquark nonets. It is shown that the a_0(1450), K^*_0(1430), f_0(1370), f_J(1710) scalar meson states are the first radial excitations of the ground states: a_0(980), K^*_0(960), f_0(400-1200), f_0(980). The weak decay constants F_\pi, F_{\pi'}, F_K, F_{K'} and the main strong decay widths of the scalar, pseudoscalar, and vector meson nonets are calculated.
hep-ph/9601351
Torbjorn Sjostrand
T. Sjostrand, J.K. Storrow and A. Vogt
Parton distributions of real and virtual photons
10 pages, LaTeX, 4 eps figures included in file using filecontents environments
J.Phys.G22:893-902,1996
10.1088/0954-3899/22/6/022
LU TP 96-5 and MC-TH-96/04
hep-ph
null
Recent progress on the parton distribution functions of the photon, both real and virtual, is briefly reviewed and experimental possibilities at HERA are discussed.
[ { "created": "Mon, 29 Jan 1996 10:15:13 GMT", "version": "v1" } ]
2008-11-26
[ [ "Sjostrand", "T.", "" ], [ "Storrow", "J. K.", "" ], [ "Vogt", "A.", "" ] ]
Recent progress on the parton distribution functions of the photon, both real and virtual, is briefly reviewed and experimental possibilities at HERA are discussed.
1710.00418
Walter Wilcox
Suman Baral and Walter Wilcox
The Thomas-Fermi quark model and mesonic matter
8 pages, 9 figures, Talk presented at the APS Division of Particles and Fields Meeting (DPF 2017), July 31-August 4, 2017, Fermilab. C170731
null
null
BU-HEPP-17-02
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first results of a new application of the Thomas-Fermi statistical quark model to mesonic matter is presented. Interesting aspects of the theory are discussed, distinguishing such states from baryonic matter. A major motivation of this study is the tetraquark states discovered by the Belle and other collaborations and the possibility that stable multi-quark families of such states exist. Similar to our previous baryonic study, we use a two-inequivalent wave function approach to investigate aspects of multi-quark matter. We think of our model as a tool for quickly assessing the characteristics of new, possibly bound, particle states of higher quark number content, which can not yet be examined by lattice methods.
[ { "created": "Sun, 1 Oct 2017 21:45:52 GMT", "version": "v1" } ]
2017-10-03
[ [ "Baral", "Suman", "" ], [ "Wilcox", "Walter", "" ] ]
The first results of a new application of the Thomas-Fermi statistical quark model to mesonic matter is presented. Interesting aspects of the theory are discussed, distinguishing such states from baryonic matter. A major motivation of this study is the tetraquark states discovered by the Belle and other collaborations and the possibility that stable multi-quark families of such states exist. Similar to our previous baryonic study, we use a two-inequivalent wave function approach to investigate aspects of multi-quark matter. We think of our model as a tool for quickly assessing the characteristics of new, possibly bound, particle states of higher quark number content, which can not yet be examined by lattice methods.
1705.09214
Matheus Hostert
Peter Ballett, Matheus Hostert and Silvia Pascoli
Light Sterile Neutrinos at $\nu$STORM: Decoherence and CP violation
Poster presented at NuPhys2016 (London, 12-14 December 2016). 4 pages, LaTeX, 7 figures
null
null
NuPhys2016-Hostert
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light sterile neutrino oscillations can be partially or completely washed out at short-baseline experiments due to the breaking of neutrino production coherence. In this work we address this issue in sterile searches at $\nu$STORM, an experimental proposal for a beam of neutrinos from the decay of stored muons. We work with 3+1 and 3+2 models, the latter introducing CP violation at short-baselines. We find that decoherence effects are only relevant for sterile masses above $\Delta m^2 \gtrsim 10$ eV$^2$, and that, even in that regime, we are able to place strong appearance bounds in such clean environments. In addition, the novel signatures of CP violation in the parameter space of interest can be identified with a significance of up to $\gtrsim 3 \sigma$.
[ { "created": "Thu, 25 May 2017 15:09:23 GMT", "version": "v1" } ]
2017-05-26
[ [ "Ballett", "Peter", "" ], [ "Hostert", "Matheus", "" ], [ "Pascoli", "Silvia", "" ] ]
Light sterile neutrino oscillations can be partially or completely washed out at short-baseline experiments due to the breaking of neutrino production coherence. In this work we address this issue in sterile searches at $\nu$STORM, an experimental proposal for a beam of neutrinos from the decay of stored muons. We work with 3+1 and 3+2 models, the latter introducing CP violation at short-baselines. We find that decoherence effects are only relevant for sterile masses above $\Delta m^2 \gtrsim 10$ eV$^2$, and that, even in that regime, we are able to place strong appearance bounds in such clean environments. In addition, the novel signatures of CP violation in the parameter space of interest can be identified with a significance of up to $\gtrsim 3 \sigma$.
1307.6824
Arman Esmaili
Arman Esmaili and Alexei Yu. Smirnov
Restricting the LSND and MiniBooNE sterile neutrinos with the IceCube atmospheric neutrino data
30 pages, 10 figures; v3: several clarifications added, figures added, references added, matches the version published in JHEP
JHEP12(2013)014
10.1007/JHEP12(2013)014
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study oscillations of the high energy atmospheric neutrinos in the Earth into sterile neutrinos with the eV-scale mass. The MSW resonance and parametric enhancement of the $\bar{\nu}_\mu\to\bar{\nu}_s$ oscillations lead to distortion of the zenith angle distribution of the muon-track events which can be observed by IceCube. Due to matter effect, the IceCube signal depends not only on the mixing element $U_{\mu 4}$ relevant for LSND and MiniBooNE but also on $U_{\tau 4}$ and the CP-violating phase $\delta_{24}$. We show that the case with $U_{\tau 4} = \delta_{24} = 0$ leads to the weakest IceCube signal and therefore should be used to bound $U_{\mu 4}$. We compute the zenith angle distributions of the $\nu_\mu-$events for different energy intervals in the range (0.1 - 10) TeV and find that inclusion of the energy information (binning in energy) improves the sensitivity to $\nu_s$ drastically. We estimate that with already collected (during 3 - 4 years) IceCube statistics the bound $|U_{\mu 4}|^2 < 0.01$ ($99\%$ C.L.) can be established and the mixing required by LSND and MiniBooNE can be excluded at $(4 - 6) \sigma$ confidence level.
[ { "created": "Thu, 25 Jul 2013 17:50:17 GMT", "version": "v1" }, { "created": "Fri, 26 Jul 2013 20:00:40 GMT", "version": "v2" }, { "created": "Thu, 5 Dec 2013 16:13:21 GMT", "version": "v3" } ]
2015-06-16
[ [ "Esmaili", "Arman", "" ], [ "Smirnov", "Alexei Yu.", "" ] ]
We study oscillations of the high energy atmospheric neutrinos in the Earth into sterile neutrinos with the eV-scale mass. The MSW resonance and parametric enhancement of the $\bar{\nu}_\mu\to\bar{\nu}_s$ oscillations lead to distortion of the zenith angle distribution of the muon-track events which can be observed by IceCube. Due to matter effect, the IceCube signal depends not only on the mixing element $U_{\mu 4}$ relevant for LSND and MiniBooNE but also on $U_{\tau 4}$ and the CP-violating phase $\delta_{24}$. We show that the case with $U_{\tau 4} = \delta_{24} = 0$ leads to the weakest IceCube signal and therefore should be used to bound $U_{\mu 4}$. We compute the zenith angle distributions of the $\nu_\mu-$events for different energy intervals in the range (0.1 - 10) TeV and find that inclusion of the energy information (binning in energy) improves the sensitivity to $\nu_s$ drastically. We estimate that with already collected (during 3 - 4 years) IceCube statistics the bound $|U_{\mu 4}|^2 < 0.01$ ($99\%$ C.L.) can be established and the mixing required by LSND and MiniBooNE can be excluded at $(4 - 6) \sigma$ confidence level.
2302.12906
Armand Rousselot
Armand Rousselot and Michael Spannowsky
Generative Invertible Quantum Neural Networks
18 pages, 7 figures Changes in v2: Add references 49-51, provided gitlab link to code repository Changes in v3: Incorporate rebuttal from https://scipost.org/submissions/2302.12906v2/
SciPost Phys. 16, 146 (2024)
10.21468/SciPostPhys.16.6.146
IPPP/23/10
hep-ph cs.AI cs.LG quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Invertible Neural Networks (INN) have become established tools for the simulation and generation of highly complex data. We propose a quantum-gate algorithm for a Quantum Invertible Neural Network (QINN) and apply it to the LHC data of jet-associated production of a Z-boson that decays into leptons, a standard candle process for particle collider precision measurements. We compare the QINN's performance for different loss functions and training scenarios. For this task, we find that a hybrid QINN matches the performance of a significantly larger purely classical INN in learning and generating complex data.
[ { "created": "Fri, 24 Feb 2023 21:25:07 GMT", "version": "v1" }, { "created": "Tue, 28 Mar 2023 11:17:58 GMT", "version": "v2" }, { "created": "Thu, 22 Feb 2024 15:55:13 GMT", "version": "v3" } ]
2024-06-05
[ [ "Rousselot", "Armand", "" ], [ "Spannowsky", "Michael", "" ] ]
Invertible Neural Networks (INN) have become established tools for the simulation and generation of highly complex data. We propose a quantum-gate algorithm for a Quantum Invertible Neural Network (QINN) and apply it to the LHC data of jet-associated production of a Z-boson that decays into leptons, a standard candle process for particle collider precision measurements. We compare the QINN's performance for different loss functions and training scenarios. For this task, we find that a hybrid QINN matches the performance of a significantly larger purely classical INN in learning and generating complex data.
1811.08876
Li-Ping He
Eric Braaten, Li-Ping He, Kevin Ingles
Estimates of the $X(3872)$ Cross Section at a Hadron Collider
14 pages, 1 figure. Extensively revised to focus mainly on the production of $X(3872)$ at hadron colliders. Material on production of $X(3872)$ plus a pion was removed. Text overlap with arXiv:1903:04355
Phys. Rev. D 100, 094024 (2019)
10.1103/PhysRevD.100.094024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The claim that the $X(3872)$ meson cannot be a charm-meson molecule because its prompt production cross section at hadron colliders is too large is based on an upper bound in terms of a cross section for producing charm-meson pairs. Assuming $X$ is sufficiently weakly bound, we derive an equality between the $X$ cross section and a charm-meson pair cross section that takes into account the threshold enhancement from the $X$ resonance. The cross section for producing $X$ is equal to that for producing $D^{*0} \bar{D}^0$ integrated up to a relative momentum $k_\mathrm{max} = 7.7\,\gamma_X$, where $\gamma_X$ is the binding momentum of $X$. We also derive an order-of-magnitude estimate of the $X$ cross section in terms of a naive charm-meson pair cross section that does not take into account the threshold enhancement, such as that produced by a Monte Carlo event generator. The cross section for producing $X$ can be approximated by the naive cross section for producing $D^{*0} \bar{D}^0$ integrated up to a relative momentum $k_\mathrm{max}$ of order $(m_\pi^2 \gamma_X)^{1/3}$. The estimates of the prompt $X$ cross section at hadron colliders are consistent with the cross sections observed at the Tevatron and the LHC.
[ { "created": "Wed, 21 Nov 2018 18:46:39 GMT", "version": "v1" }, { "created": "Fri, 11 Oct 2019 15:03:27 GMT", "version": "v2" } ]
2019-11-28
[ [ "Braaten", "Eric", "" ], [ "He", "Li-Ping", "" ], [ "Ingles", "Kevin", "" ] ]
The claim that the $X(3872)$ meson cannot be a charm-meson molecule because its prompt production cross section at hadron colliders is too large is based on an upper bound in terms of a cross section for producing charm-meson pairs. Assuming $X$ is sufficiently weakly bound, we derive an equality between the $X$ cross section and a charm-meson pair cross section that takes into account the threshold enhancement from the $X$ resonance. The cross section for producing $X$ is equal to that for producing $D^{*0} \bar{D}^0$ integrated up to a relative momentum $k_\mathrm{max} = 7.7\,\gamma_X$, where $\gamma_X$ is the binding momentum of $X$. We also derive an order-of-magnitude estimate of the $X$ cross section in terms of a naive charm-meson pair cross section that does not take into account the threshold enhancement, such as that produced by a Monte Carlo event generator. The cross section for producing $X$ can be approximated by the naive cross section for producing $D^{*0} \bar{D}^0$ integrated up to a relative momentum $k_\mathrm{max}$ of order $(m_\pi^2 \gamma_X)^{1/3}$. The estimates of the prompt $X$ cross section at hadron colliders are consistent with the cross sections observed at the Tevatron and the LHC.
2103.08680
Xiaohui Liu
Hao-yu Liu, Xiaohui Liu and Sven-Olaf Moch
Anti-$k_T$ jet function at next-to-next-to-leading order
12 pages, update the references, add a plot to demonstrate the fully differential nature of the calculated jet function, match the punished version, corrected an unnecessary approximation, numbers updated
Phys. Rev. D 104, 014016 (2021)
10.1103/PhysRevD.104.014016
DESY 21-032
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Jets constructed via clustering algorithms (e.g., anti-$k_T$, soft-drop) have been proposed for many precision measurements, such as the strong coupling $\alpha_s$ and the nucleon intrinsic dynamics. However, the theoretical accuracy is affected by missing QCD corrections at higher orders for the jet functions in the associated factorization theorems. Their calculation is complicated by the jet clustering procedure. In this work, we propose a method to evaluate jet functions at higher orders in QCD. The calculation involves the phase space sector decomposition with suitable soft subtractions. As a concrete example, we present the quark-jet function using the anti-$k_T$ algorithm with E-scheme recombination at next-to-next-to-leading order.
[ { "created": "Mon, 15 Mar 2021 19:50:57 GMT", "version": "v1" }, { "created": "Tue, 27 Jul 2021 12:21:28 GMT", "version": "v2" }, { "created": "Sun, 13 Nov 2022 16:23:30 GMT", "version": "v3" } ]
2022-11-15
[ [ "Liu", "Hao-yu", "" ], [ "Liu", "Xiaohui", "" ], [ "Moch", "Sven-Olaf", "" ] ]
Jets constructed via clustering algorithms (e.g., anti-$k_T$, soft-drop) have been proposed for many precision measurements, such as the strong coupling $\alpha_s$ and the nucleon intrinsic dynamics. However, the theoretical accuracy is affected by missing QCD corrections at higher orders for the jet functions in the associated factorization theorems. Their calculation is complicated by the jet clustering procedure. In this work, we propose a method to evaluate jet functions at higher orders in QCD. The calculation involves the phase space sector decomposition with suitable soft subtractions. As a concrete example, we present the quark-jet function using the anti-$k_T$ algorithm with E-scheme recombination at next-to-next-to-leading order.
hep-ph/0207065
Namit Mahajan
Namit Mahajan (Univ. of Delhi)
$\tau$ polarization and Randall-Sundrum scenario at $e^+e^-$ colliders
7 page Latex including 3 postscript figures. Needs axodraw
J.Phys.G29:2677-2684,2003
10.1088/0954-3899/29/12/001
null
hep-ph
null
We study polarized cross-sections and forward-backward asymmetry for the process $e^+e-\to \tau^+\tau^-$ in the stabilized Randall-Sundrum scenario. It is shown that there is substantial deviation from the Standard Model predictions, both in terms of the actual numerical values and angular distributions.
[ { "created": "Thu, 4 Jul 2002 09:22:08 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mahajan", "Namit", "", "Univ. of Delhi" ] ]
We study polarized cross-sections and forward-backward asymmetry for the process $e^+e-\to \tau^+\tau^-$ in the stabilized Randall-Sundrum scenario. It is shown that there is substantial deviation from the Standard Model predictions, both in terms of the actual numerical values and angular distributions.
1605.08183
Yuchen Guo
Yu-Chen Guo, Chong-Xing Yue and Zhen-hua Zhao
750 GeV diphoton excess confronted with a top-pion in the TTM model
12 pages, 3 figures, Int. J. Mod. Phys. A (2016)
Int. J. Mod. Phys. A 31, 1650086 (2016)
10.1142/S0217751X1650086X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The latest LHC data suggest an intriguing excess at $m_{\gamma\gamma} = 750$ GeV which apparently requires an explanation from the beyond standard model physics. In this note we explore the possibility for this signal to arise from a top-pion in the Top Triangle Moose model which can be viewed as a dimensional-deconstruction version of the top-color assisted technicolor model. We demonstrate that the observed excess can be accommodated by and has important implications for this interesting model.
[ { "created": "Thu, 26 May 2016 07:56:29 GMT", "version": "v1" }, { "created": "Sat, 28 May 2016 01:47:24 GMT", "version": "v2" }, { "created": "Mon, 6 Jun 2016 13:38:28 GMT", "version": "v3" } ]
2016-06-14
[ [ "Guo", "Yu-Chen", "" ], [ "Yue", "Chong-Xing", "" ], [ "Zhao", "Zhen-hua", "" ] ]
The latest LHC data suggest an intriguing excess at $m_{\gamma\gamma} = 750$ GeV which apparently requires an explanation from the beyond standard model physics. In this note we explore the possibility for this signal to arise from a top-pion in the Top Triangle Moose model which can be viewed as a dimensional-deconstruction version of the top-color assisted technicolor model. We demonstrate that the observed excess can be accommodated by and has important implications for this interesting model.
hep-ph/9801242
null
Amitava Datta, Aseshkrishna Datta and M.K. Parida
Signatures of Non-Universal Soft Breaking Sfermion Masses at Hadron Colliders
17 pages, two ps figures, LaTeX format
Phys.Lett. B431 (1998) 347-353
10.1016/S0370-2693(98)00507-3
null
hep-ph
null
We identify several mass patterns, within the framework of N=1 SUGRA with nonuniversal soft breaking masses for the sfermions, which may significantly alter SUSY signals and the current squark-gluino mass limits from the Tevatron. These effects are illustrated in a SO(10) SUSY GUT with an intermediate mass scale, but the conclusions are also valid in SUSY SO(10) models with grand deserts.
[ { "created": "Thu, 8 Jan 1998 09:44:33 GMT", "version": "v1" } ]
2009-10-31
[ [ "Datta", "Amitava", "" ], [ "Datta", "Aseshkrishna", "" ], [ "Parida", "M. K.", "" ] ]
We identify several mass patterns, within the framework of N=1 SUGRA with nonuniversal soft breaking masses for the sfermions, which may significantly alter SUSY signals and the current squark-gluino mass limits from the Tevatron. These effects are illustrated in a SO(10) SUSY GUT with an intermediate mass scale, but the conclusions are also valid in SUSY SO(10) models with grand deserts.
2010.08451
Tyler Corbett
Tyler Corbett, Michael Trott
One loop verification of SMEFT Ward Identities
40 pages, 1 Figure
SciPost Phys. 10, 144 (2021)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We verify Standard Model Effective Field Theory Ward identities to one loop order when background field gauge is used to quantize the theory. The results we present lay the foundation of next to leading order automatic generation of results in the SMEFT, in both the perturbative and non-perturbative expansion using the geoSMEFT formalism, and background field gauge.
[ { "created": "Fri, 16 Oct 2020 15:28:58 GMT", "version": "v1" }, { "created": "Wed, 16 Jun 2021 10:35:45 GMT", "version": "v2" } ]
2021-06-23
[ [ "Corbett", "Tyler", "" ], [ "Trott", "Michael", "" ] ]
We verify Standard Model Effective Field Theory Ward identities to one loop order when background field gauge is used to quantize the theory. The results we present lay the foundation of next to leading order automatic generation of results in the SMEFT, in both the perturbative and non-perturbative expansion using the geoSMEFT formalism, and background field gauge.
1603.01256
Chien-Yi Chen
Chien-Yi Chen, Michel Lefebvre, Maxim Pospelov, Yi-Ming Zhong
Diphoton Excess through Dark Mediators
38 pages, 7 figures, 2 tables, references added
null
10.1007/JHEP07(2016)063
YITP-SB-16-05
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Preliminary ATLAS and CMS results from the first 13 TeV LHC run have encountered an intriguing excess of events in the diphoton channel around the invariant mass of 750 GeV. We investigate a possibility that the current excess is due to a heavy resonance decaying to light metastable states, which in turn give displaced decays to very highly collimated $e^+e^-$ pairs. Such decays may pass the photon selection criteria, and successfully mimic the diphoton events, especially at low counts. We investigate two classes of such models, characterized by the following underlying production and decay chains: $gg \to S\to A'A'\to (e^+e^-)(e^+e^-)$ and $q\bar q \to Z' \to sa\to (e^+e^-)(e^+e^-)$, where at the first step a heavy scalar, $S$, or vector, $Z'$, resonances are produced that decay to light metastable vectors, $A'$, or (pseudo-)scalars, $s$ and $a$. Setting the parameters of the models to explain the existing excess, and taking the ATLAS detector geometry into account, we marginalize over the properties of heavy resonances in order to derive the expected lifetimes and couplings of metastable light resonances. We observe that in the case of $A'$, the suggested range of masses and mixing angles $\epsilon$ is within reach of several new-generation intensity frontier experiments.
[ { "created": "Thu, 3 Mar 2016 20:56:19 GMT", "version": "v1" }, { "created": "Mon, 4 Apr 2016 19:55:40 GMT", "version": "v2" } ]
2016-08-24
[ [ "Chen", "Chien-Yi", "" ], [ "Lefebvre", "Michel", "" ], [ "Pospelov", "Maxim", "" ], [ "Zhong", "Yi-Ming", "" ] ]
Preliminary ATLAS and CMS results from the first 13 TeV LHC run have encountered an intriguing excess of events in the diphoton channel around the invariant mass of 750 GeV. We investigate a possibility that the current excess is due to a heavy resonance decaying to light metastable states, which in turn give displaced decays to very highly collimated $e^+e^-$ pairs. Such decays may pass the photon selection criteria, and successfully mimic the diphoton events, especially at low counts. We investigate two classes of such models, characterized by the following underlying production and decay chains: $gg \to S\to A'A'\to (e^+e^-)(e^+e^-)$ and $q\bar q \to Z' \to sa\to (e^+e^-)(e^+e^-)$, where at the first step a heavy scalar, $S$, or vector, $Z'$, resonances are produced that decay to light metastable vectors, $A'$, or (pseudo-)scalars, $s$ and $a$. Setting the parameters of the models to explain the existing excess, and taking the ATLAS detector geometry into account, we marginalize over the properties of heavy resonances in order to derive the expected lifetimes and couplings of metastable light resonances. We observe that in the case of $A'$, the suggested range of masses and mixing angles $\epsilon$ is within reach of several new-generation intensity frontier experiments.
1709.08175
Byung-Geel Yu
Byung-Geel Yu and Kook-Jin Kong
Regge phenomenology of photoproduction of $\pi^-\Delta^{++}$ and scaling with saturation of trajectory
5 pages 6 figures
null
10.1134/S1547477118040076
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we investigate the reaction $\gamma p\to\pi^-\Delta^{++}$ in the Reggeized model for $\pi(138)+\rho(775)+a_2(1320)$ exchanges in the $t$-channel. For a convergence of the reaction cross section at high energies the minimal forms of proton and $\Delta^{++}$ exchanges are introduced in the direct and crossed channels for gauge invariance of $\pi$ Regge-pole exchange. The role of spin-2 tensor meson $a_2$ is found to be crucial to agree with existing data at high energies. Electromagnetic multipoles of $\Delta^{++}$ baryon are analyzed in the $\Delta$ resonance region. Based on the constituents counting rule the scaled differential cross section at $E_\gamma=4$ GeV is reproduced with the Regge trajectory saturated at large momentum transfer $-t$.
[ { "created": "Sun, 24 Sep 2017 10:13:58 GMT", "version": "v1" }, { "created": "Wed, 11 Oct 2017 21:10:30 GMT", "version": "v2" } ]
2018-08-01
[ [ "Yu", "Byung-Geel", "" ], [ "Kong", "Kook-Jin", "" ] ]
In this work we investigate the reaction $\gamma p\to\pi^-\Delta^{++}$ in the Reggeized model for $\pi(138)+\rho(775)+a_2(1320)$ exchanges in the $t$-channel. For a convergence of the reaction cross section at high energies the minimal forms of proton and $\Delta^{++}$ exchanges are introduced in the direct and crossed channels for gauge invariance of $\pi$ Regge-pole exchange. The role of spin-2 tensor meson $a_2$ is found to be crucial to agree with existing data at high energies. Electromagnetic multipoles of $\Delta^{++}$ baryon are analyzed in the $\Delta$ resonance region. Based on the constituents counting rule the scaled differential cross section at $E_\gamma=4$ GeV is reproduced with the Regge trajectory saturated at large momentum transfer $-t$.
0810.4449
Bruno Machet
Quentin Duret (LPTHE), Bruno Machet (LPTHE), M. I. Vysotsky (ITEP)
Quark Lagrangian diagonalization versus non-diagonal kinetic terms
2 pages, 1 figure
Modern Physics Letters A 24, 4 (2009) 273-275
10.1142/S0217732309030084
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Loop corrections induce a dependence on the momentum squared of the coefficients of the Standard Model Lagrangian, making highly non-trivial (or even impossible) the diagonalization of its quadratic part. Fortunately, the introduction of appropriate counterterms solves this puzzle.
[ { "created": "Fri, 24 Oct 2008 13:10:13 GMT", "version": "v1" } ]
2009-07-06
[ [ "Duret", "Quentin", "", "LPTHE" ], [ "Machet", "Bruno", "", "LPTHE" ], [ "Vysotsky", "M. I.", "", "ITEP" ] ]
Loop corrections induce a dependence on the momentum squared of the coefficients of the Standard Model Lagrangian, making highly non-trivial (or even impossible) the diagonalization of its quadratic part. Fortunately, the introduction of appropriate counterterms solves this puzzle.
1105.0376
Danny van Dyk
Christoph Bobeth, Gudrun Hiller and Danny van Dyk
More Benefits of Semileptonic Rare B Decays at Low Recoil: CP Violation
18 pages, 3 fig.; 1 reference and comment on higher order effects added; EOS link fixed. Minor adjustments to Eqs 4.1-4.3 to match the (lower) q^2-cut as given in paper. Main results and conclusions unchanged; v3+v4: treatment of exp. uncert. in likelihood-function in EOS fixed and constraints from scan on C9,C10 updated (Fig 2,3 and Eqs 3.2,3.3). Main results and conclusions absolutely unchanged
JHEP 1107:067,2011
10.1007/JHEP07(2011)067
DO-TH 10/16
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a systematic analysis of the angular distribution of Bbar -> Kbar^\ast (-> Kbar pi) l^+ l^- decays with l = e, mu in the low recoil region (i.e. at high dilepton invariant masses of the order of the mass of the b-quark) to account model-independently for CP violation beyond the Standard Model, working to next-to-leading order QCD. From the employed heavy quark effective theory framework we identify the key CP observables with reduced hadronic uncertainties. Since some of the CP asymmetries are CP-odd they can be measured without B-flavour tagging. This is particularly beneficial for Bbar_s,B_s -> phi(-> K^+ K^-) l^+ l^- decays, which are not self-tagging, and we work out the corresponding time-integrated CP asymmetries. Presently available experimental constraints allow the proposed CP asymmetries to be sizeable, up to values of the order ~ 0.2, while the corresponding Standard Model values receive a strong parametric suppression at the level of O(10^-4). Furthermore, we work out the allowed ranges of the short-distance (Wilson) coefficients C_9,C_10 in the presence of CP violation beyond the Standard Model but no further Dirac structures. We find the Bbar_s -> mu^+ mu^- branching ratio to be below 9*10^-9 (at 95% CL). Possibilities to check the performance of the theoretical low recoil framework are pointed out.
[ { "created": "Mon, 2 May 2011 16:36:30 GMT", "version": "v1" }, { "created": "Tue, 12 Jul 2011 13:10:56 GMT", "version": "v2" }, { "created": "Wed, 5 Oct 2011 13:40:33 GMT", "version": "v3" }, { "created": "Thu, 8 Dec 2011 14:40:02 GMT", "version": "v4" } ]
2011-12-09
[ [ "Bobeth", "Christoph", "" ], [ "Hiller", "Gudrun", "" ], [ "van Dyk", "Danny", "" ] ]
We present a systematic analysis of the angular distribution of Bbar -> Kbar^\ast (-> Kbar pi) l^+ l^- decays with l = e, mu in the low recoil region (i.e. at high dilepton invariant masses of the order of the mass of the b-quark) to account model-independently for CP violation beyond the Standard Model, working to next-to-leading order QCD. From the employed heavy quark effective theory framework we identify the key CP observables with reduced hadronic uncertainties. Since some of the CP asymmetries are CP-odd they can be measured without B-flavour tagging. This is particularly beneficial for Bbar_s,B_s -> phi(-> K^+ K^-) l^+ l^- decays, which are not self-tagging, and we work out the corresponding time-integrated CP asymmetries. Presently available experimental constraints allow the proposed CP asymmetries to be sizeable, up to values of the order ~ 0.2, while the corresponding Standard Model values receive a strong parametric suppression at the level of O(10^-4). Furthermore, we work out the allowed ranges of the short-distance (Wilson) coefficients C_9,C_10 in the presence of CP violation beyond the Standard Model but no further Dirac structures. We find the Bbar_s -> mu^+ mu^- branching ratio to be below 9*10^-9 (at 95% CL). Possibilities to check the performance of the theoretical low recoil framework are pointed out.
1809.05424
Rafal Maciula
Victor P. Goncalves, Rafal Maciula, and Antoni Szczurek
From $D_{s}^{\pm}$ production asymmetry at the LHC to prompt $\nu_{\tau}$ at IceCube
6 pages, 3 figures
null
10.1016/j.physletb.2019.05.026
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The description of the heavy meson production at large energies and forward rapidities at the LHC is fundamental to derive realistic predictions of the prompt atmospheric neutrino flux at the IceCube Observatory. In particular, the prompt tau neutrino flux is determined by the decay of $D_s$ mesons produced in cosmic ray - air interactions at high energies and large values of the Feynman - $x_F$ variable. Recent data from the LHCb Collaboration indicate a production asymmetry for $D_s^+$ and $D_s^-$ mesons, which cannot be explained in terms of the standard modelling of the hadronization process. In this paper we demonstrate that this asymmetry can be described assuming an asymmetric strange sea ($s(x) \ne \bar s(x)$) in the proton wave function and taking into account of the charm and strange fragmentation into $D_s$ mesons. Moreover, we show that the strange quark fragmentation contribution is dominant at large - $x_F$ ($\ge 0.3$). The prompt $\nu_{\tau}$ flux is calculated and the enhancement associated to the strange quark fragmentation contribution, disregarded in previous calculations, is estimated.
[ { "created": "Fri, 14 Sep 2018 13:52:27 GMT", "version": "v1" }, { "created": "Wed, 26 Sep 2018 10:39:39 GMT", "version": "v2" } ]
2019-06-26
[ [ "Goncalves", "Victor P.", "" ], [ "Maciula", "Rafal", "" ], [ "Szczurek", "Antoni", "" ] ]
The description of the heavy meson production at large energies and forward rapidities at the LHC is fundamental to derive realistic predictions of the prompt atmospheric neutrino flux at the IceCube Observatory. In particular, the prompt tau neutrino flux is determined by the decay of $D_s$ mesons produced in cosmic ray - air interactions at high energies and large values of the Feynman - $x_F$ variable. Recent data from the LHCb Collaboration indicate a production asymmetry for $D_s^+$ and $D_s^-$ mesons, which cannot be explained in terms of the standard modelling of the hadronization process. In this paper we demonstrate that this asymmetry can be described assuming an asymmetric strange sea ($s(x) \ne \bar s(x)$) in the proton wave function and taking into account of the charm and strange fragmentation into $D_s$ mesons. Moreover, we show that the strange quark fragmentation contribution is dominant at large - $x_F$ ($\ge 0.3$). The prompt $\nu_{\tau}$ flux is calculated and the enhancement associated to the strange quark fragmentation contribution, disregarded in previous calculations, is estimated.
1912.03142
Tiziano Peraro
Tiziano Peraro
Analytic multi-loop results using finite fields and dataflow graphs with FiniteFlow
10 pages, 3 figures, Contribution to the proceedings of the RADCOR2019 conference, 9-13 September 2019, Avignon, France
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
FiniteFlow is a public framework for defining and executing numerical algorithms over finite fields and reconstructing multivariate rational functions. The framework allows to build complex algorithms by combining basic building blocks into graphical representations of the calculation, known as dataflow graphs. It offers an easy-to-use Mathematica interface for implementing efficient custom algorithms without any low-level coding. We report on some new features of FiniteFlow which have been published after its initial release, give some simple example of usage for common tasks and review recent cutting-edge applications to two-loop five-point scattering and the four-loop cusp anomalous dimension.
[ { "created": "Fri, 6 Dec 2019 14:21:19 GMT", "version": "v1" } ]
2019-12-09
[ [ "Peraro", "Tiziano", "" ] ]
FiniteFlow is a public framework for defining and executing numerical algorithms over finite fields and reconstructing multivariate rational functions. The framework allows to build complex algorithms by combining basic building blocks into graphical representations of the calculation, known as dataflow graphs. It offers an easy-to-use Mathematica interface for implementing efficient custom algorithms without any low-level coding. We report on some new features of FiniteFlow which have been published after its initial release, give some simple example of usage for common tasks and review recent cutting-edge applications to two-loop five-point scattering and the four-loop cusp anomalous dimension.
2407.21120
Wen Chen
Long-Bin Chen, Wen Chen, Feng Feng, Yu Jia
Confronting perturbative QCD with the hardest exclusive reactions: kaon electromagnetic form factors
10 pages, 2 tables, 4 figures. Ancillary file containing hard-scattering kernels through NNLO
null
null
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
Among countless channels of hard exclusive reactions, the kaon electromagnetic form factors (EMFFs) are of special interest, which have been measured up to $Q^2 \sim 50\;{\rm GeV}^2$ in the timelike domain. The kaon EMFFs thereby serve an ideal platform to critically examine the validity and effectiveness of perturbative QCD (pQCD) in accounting for hard exclusive processes. In this work we confront the pQCD predictions that incorporate the next-to-next-to-leading-order (NNLO) perturbative corrections, with the available kaon EMFFs data set from experimental measurements and from lattice predictions. The inclusion of the NNLO corrections turns out to have a substantial and positive impact. If the profiles of the kaon light-cone distribution amplitudes (LCDAs) are taken from the recent lattice QCD prediction by {\tt LPC} Collaboration, the satisfactory agreement between theory and data can be reached for both charged and neutral kaons, in both spacelike and timelike large-$Q^2$ domains.
[ { "created": "Tue, 30 Jul 2024 18:23:17 GMT", "version": "v1" } ]
2024-08-01
[ [ "Chen", "Long-Bin", "" ], [ "Chen", "Wen", "" ], [ "Feng", "Feng", "" ], [ "Jia", "Yu", "" ] ]
Among countless channels of hard exclusive reactions, the kaon electromagnetic form factors (EMFFs) are of special interest, which have been measured up to $Q^2 \sim 50\;{\rm GeV}^2$ in the timelike domain. The kaon EMFFs thereby serve an ideal platform to critically examine the validity and effectiveness of perturbative QCD (pQCD) in accounting for hard exclusive processes. In this work we confront the pQCD predictions that incorporate the next-to-next-to-leading-order (NNLO) perturbative corrections, with the available kaon EMFFs data set from experimental measurements and from lattice predictions. The inclusion of the NNLO corrections turns out to have a substantial and positive impact. If the profiles of the kaon light-cone distribution amplitudes (LCDAs) are taken from the recent lattice QCD prediction by {\tt LPC} Collaboration, the satisfactory agreement between theory and data can be reached for both charged and neutral kaons, in both spacelike and timelike large-$Q^2$ domains.
hep-ph/9801417
J. Gunion
John F. Gunion (U.C. Davis)
Searching for Low-Energy Supersymmetry
60 pages, to appear in Quantum Effects in the MSSM, the Proceedings of the ``International Workshop on Quantum Effects in the MSSM'', UAB, Barcelona, September 9--13, 1997; full postscript file, including embedded figures, is available via anonymous ftp at ftp://ucdhep.ucdavis.edu/gunion/barcelona_hepph.ps
null
null
UCD-98-2
hep-ph hep-ex
null
A review of supersymmetry theory and phenomenology is presented. Topics discussed include: gravity-mediated (SUGRA) and gauge-mediated (GMSB) supersymmetry breaking models; an overview of non-universal soft-supersymmetry-breaking masses and the resulting experimental implications; the phenomenology of and constraints on the possibility that a massive gluino is the lightest supersymmetric particle; current status of the phenomenology of the Higgs bosons of the minimal and next-to-minimal supersymmetric models; and, the signals for GMSB and/or R-parity-violating models coming from delayed decays of the lightest supersymmetric partner of the Standard Model particles.
[ { "created": "Tue, 27 Jan 1998 17:29:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gunion", "John F.", "", "U.C. Davis" ] ]
A review of supersymmetry theory and phenomenology is presented. Topics discussed include: gravity-mediated (SUGRA) and gauge-mediated (GMSB) supersymmetry breaking models; an overview of non-universal soft-supersymmetry-breaking masses and the resulting experimental implications; the phenomenology of and constraints on the possibility that a massive gluino is the lightest supersymmetric particle; current status of the phenomenology of the Higgs bosons of the minimal and next-to-minimal supersymmetric models; and, the signals for GMSB and/or R-parity-violating models coming from delayed decays of the lightest supersymmetric partner of the Standard Model particles.
2109.12385
Anatoly Serebrov
A. Serebrov, R. Samoilov, M. Chaikovskii
Experimental indications of the 3+1 neutrino model with one sterile neutrino
7 pages, 5 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The possibility of the validation of the 3+1 neutrino model is considered in the context of the new result of the Neutrino-4 experiment, the direct observation of the oscillation effect at parameter region $\Delta m_{14}^2=(7.3 \pm 0.13_{stat} \pm 1.16_{syst})\text{eV}^2$ and $\sin^2(2\theta_{14}) = 0.36 \pm 0.12_{stat} (2.9\sigma)$, also using LSND anomaly, MiniBooNE anomaly, reactor antineutrino anomaly, and gallium anomaly observed in experiments with radioactive sources GALLEX/GNO and SAGE. We analyze agreement of the neutrino parameter values obtained in the Neutrino-4 experiment with the results of other reactor type experiments NEOS, DANSS, STEREO, PROSPECT, the experiments at accelerators MiniBooNE, LSND, and the IceCube experiment. We present the analysis of the 3+1 neutrino model which demonstrates the agreement among the experiments within current experimental accuracy. Also, current accuracy allows us to make estimations of the effective masses of the neutrinos. The mass of the sterile neutrino obtained in the Neutrino-4 experiment (in assumption $m_2^2 \approx \Delta m_{14}^2$) is $m_4 = (2.70\pm0.22)\text{eV}$. Using the estimations of the mixing angles we calculated the values of the electron, muon and tau neutrinos: $m_{4\nu_e}^{\text{eff}}=(0.82\pm0.18)\text{eV}, m_{4\nu_{\mu}}^{\text{eff}}=(0.41\pm0.26)\text{eV}, m_{4\nu_{\tau}}^{\text{eff}}\leq 0.60\text{eV}$. These results are compared with the values obtained in the experiments in the direct measurement of the neutrino mass KATRIN and GERDA. The Pontecorvo-Maki-Nakagawa-Sakata matrix with four states and the mixing scheme of the flavor neutrinos with the sterile state are presented.
[ { "created": "Sat, 25 Sep 2021 15:24:55 GMT", "version": "v1" }, { "created": "Fri, 1 Oct 2021 12:13:23 GMT", "version": "v2" }, { "created": "Thu, 21 Oct 2021 11:38:32 GMT", "version": "v3" } ]
2021-10-22
[ [ "Serebrov", "A.", "" ], [ "Samoilov", "R.", "" ], [ "Chaikovskii", "M.", "" ] ]
The possibility of the validation of the 3+1 neutrino model is considered in the context of the new result of the Neutrino-4 experiment, the direct observation of the oscillation effect at parameter region $\Delta m_{14}^2=(7.3 \pm 0.13_{stat} \pm 1.16_{syst})\text{eV}^2$ and $\sin^2(2\theta_{14}) = 0.36 \pm 0.12_{stat} (2.9\sigma)$, also using LSND anomaly, MiniBooNE anomaly, reactor antineutrino anomaly, and gallium anomaly observed in experiments with radioactive sources GALLEX/GNO and SAGE. We analyze agreement of the neutrino parameter values obtained in the Neutrino-4 experiment with the results of other reactor type experiments NEOS, DANSS, STEREO, PROSPECT, the experiments at accelerators MiniBooNE, LSND, and the IceCube experiment. We present the analysis of the 3+1 neutrino model which demonstrates the agreement among the experiments within current experimental accuracy. Also, current accuracy allows us to make estimations of the effective masses of the neutrinos. The mass of the sterile neutrino obtained in the Neutrino-4 experiment (in assumption $m_2^2 \approx \Delta m_{14}^2$) is $m_4 = (2.70\pm0.22)\text{eV}$. Using the estimations of the mixing angles we calculated the values of the electron, muon and tau neutrinos: $m_{4\nu_e}^{\text{eff}}=(0.82\pm0.18)\text{eV}, m_{4\nu_{\mu}}^{\text{eff}}=(0.41\pm0.26)\text{eV}, m_{4\nu_{\tau}}^{\text{eff}}\leq 0.60\text{eV}$. These results are compared with the values obtained in the experiments in the direct measurement of the neutrino mass KATRIN and GERDA. The Pontecorvo-Maki-Nakagawa-Sakata matrix with four states and the mixing scheme of the flavor neutrinos with the sterile state are presented.
2007.04990
Marco Gorghetto
Marco Gorghetto, Edward Hardy, Giovanni Villadoro
More Axions from Strings
19 pages + appendices
SciPost Phys. 10, 050 (2021)
10.21468/SciPostPhys.10.2.050
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the contribution to the QCD axion dark matter abundance that is produced by string defects during the so-called scaling regime. Clear evidence of scaling violations is found, the most conservative extrapolation of which strongly suggests a large number of axions from strings. In this regime, nonlinearities at around the QCD scale are shown to play an important role in determining the final abundance. The overall result is a lower bound on the QCD axion mass in the post-inflationary scenario that is substantially stronger than the naive one from misalignment.
[ { "created": "Thu, 9 Jul 2020 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 22 Mar 2021 14:29:48 GMT", "version": "v2" } ]
2021-03-23
[ [ "Gorghetto", "Marco", "" ], [ "Hardy", "Edward", "" ], [ "Villadoro", "Giovanni", "" ] ]
We study the contribution to the QCD axion dark matter abundance that is produced by string defects during the so-called scaling regime. Clear evidence of scaling violations is found, the most conservative extrapolation of which strongly suggests a large number of axions from strings. In this regime, nonlinearities at around the QCD scale are shown to play an important role in determining the final abundance. The overall result is a lower bound on the QCD axion mass in the post-inflationary scenario that is substantially stronger than the naive one from misalignment.
hep-ph/0610428
Shinta Kasuya
Shinta Kasuya
Towards the robustness of Affleck-Dine mechanism
6 pages, to appear in the proceedings of IRGAC 2006, 2nd International Conference on Quantum Theories and Renormalization Group in Gravity and Cosmology, Barcelona, July 11-15 2006
J.Phys.A40:6999-7004,2007
10.1088/1751-8113/40/25/S52
null
hep-ph
null
In this talk we considered the Affleck-Dine mechanism with various types of the Kahler potential, and investigate whether or not the Affleck-Dine field could acquire a large VEV as an initial condition for successful baryogenesis. In addition to a negative Hubble-induced mass term, we found examples that large enough Hubble-induced A-terms could also develop the minima at large amplitude of the field. It is concluded, therefore, that the Affleck-Dine mechanism works for broader classes of the theories. This talk is based on Ref.[1]. Here I extend the discussion from more generic standpoint, and find that essentially there are three cases that large enough A terms develop minima at large field values.
[ { "created": "Tue, 31 Oct 2006 13:55:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kasuya", "Shinta", "" ] ]
In this talk we considered the Affleck-Dine mechanism with various types of the Kahler potential, and investigate whether or not the Affleck-Dine field could acquire a large VEV as an initial condition for successful baryogenesis. In addition to a negative Hubble-induced mass term, we found examples that large enough Hubble-induced A-terms could also develop the minima at large amplitude of the field. It is concluded, therefore, that the Affleck-Dine mechanism works for broader classes of the theories. This talk is based on Ref.[1]. Here I extend the discussion from more generic standpoint, and find that essentially there are three cases that large enough A terms develop minima at large field values.
0902.3764
Gouranga Nayak
Gouranga C Nayak (U. Arizona)
String Theory at LHC Using Top Quarks From String Balls
20 pages latex, 6 figures, final version
JHEP 0906:071,2009
10.1088/1126-6708/2009/06/071
null
hep-ph gr-qc hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
According to string theory, string ball is a highly excited long string which decays to standard model particles at the Hagedorn temperature with thermal spectrum. If there are extra dimensions, the string scale can be $\sim$ TeV, and we should produce string balls at CERN LHC. In this paper we study top quark production from string balls at LHC and compare with the parton fusion results at NNLO using pQCD. We find significant top quark production from string balls at LHC which is comparable to standard model pQCD results. We also find that $\frac{d\sigma}{dp_T}$ of top quarks from string balls does not decrease significantly with increase in $p_T$, whereas it deceases sharply in case of standard model pQCD scenario. Hence, in the absence of black hole production at LHC, an enhancement in top quark cross section and its abnormal $p_T$ distribution can be a signature of TeV scale string physics at LHC. String theory is also studied at LHC via string Regge excitations in the weak coupling limit in model independent framework. Since massive quark production amplitude is not available in string Regge excitations scenario, we compute massless quark production in string Regge excitations scenario and make a clear comparison with that produced from string balls at LHC for a given luminosity.
[ { "created": "Mon, 23 Feb 2009 19:04:39 GMT", "version": "v1" }, { "created": "Tue, 23 Jun 2009 14:15:44 GMT", "version": "v2" } ]
2009-07-22
[ [ "Nayak", "Gouranga C", "", "U. Arizona" ] ]
According to string theory, string ball is a highly excited long string which decays to standard model particles at the Hagedorn temperature with thermal spectrum. If there are extra dimensions, the string scale can be $\sim$ TeV, and we should produce string balls at CERN LHC. In this paper we study top quark production from string balls at LHC and compare with the parton fusion results at NNLO using pQCD. We find significant top quark production from string balls at LHC which is comparable to standard model pQCD results. We also find that $\frac{d\sigma}{dp_T}$ of top quarks from string balls does not decrease significantly with increase in $p_T$, whereas it deceases sharply in case of standard model pQCD scenario. Hence, in the absence of black hole production at LHC, an enhancement in top quark cross section and its abnormal $p_T$ distribution can be a signature of TeV scale string physics at LHC. String theory is also studied at LHC via string Regge excitations in the weak coupling limit in model independent framework. Since massive quark production amplitude is not available in string Regge excitations scenario, we compute massless quark production in string Regge excitations scenario and make a clear comparison with that produced from string balls at LHC for a given luminosity.
1403.4634
Mathias Garny
Mathias Garny, Alejandro Ibarra, Sara Rydbeck, Stefan Vogl
Majorana Dark Matter with a Coloured Mediator: Collider vs Direct and Indirect Searches
32 pages, 9 figures
null
10.1007/JHEP06(2014)169
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the signatures at the Large Hadron Collider of a minimal model where the dark matter particle is a Majorana fermion that couples to the Standard Model via one or several coloured mediators. We emphasize the importance of the production channel of coloured scalars through the exchange of a dark matter particle in the t-channel, and perform a dedicated analysis of searches for jets and missing energy for this model. We find that the collider constraints are highly competitive compared to direct detection, and can even be considerably stronger over a wide range of parameters. We also discuss the complementarity with searches for spectral features at gamma-ray telescopes and comment on the possibility of several coloured mediators, which is further constrained by flavour observables.
[ { "created": "Tue, 18 Mar 2014 22:24:23 GMT", "version": "v1" } ]
2015-06-19
[ [ "Garny", "Mathias", "" ], [ "Ibarra", "Alejandro", "" ], [ "Rydbeck", "Sara", "" ], [ "Vogl", "Stefan", "" ] ]
We investigate the signatures at the Large Hadron Collider of a minimal model where the dark matter particle is a Majorana fermion that couples to the Standard Model via one or several coloured mediators. We emphasize the importance of the production channel of coloured scalars through the exchange of a dark matter particle in the t-channel, and perform a dedicated analysis of searches for jets and missing energy for this model. We find that the collider constraints are highly competitive compared to direct detection, and can even be considerably stronger over a wide range of parameters. We also discuss the complementarity with searches for spectral features at gamma-ray telescopes and comment on the possibility of several coloured mediators, which is further constrained by flavour observables.
1611.07755
Zhun Lu
Yongliang Yang and Zhun Lu
Polarized Lambda hyperon production in Semi-inclusive deep inelastic scattering off an unpolarized nulceon target
11 pages, 2 figures, match the version published in PRD
Phys. Rev. D 95, 074026 (2017)
10.1103/PhysRevD.95.074026
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production of polarized $\Lambda$ hyperon in semi-inclusive deep inelastic scattering off an unpolarized target. We include the cases in which the $\Lambda$ hyperon is longitudinally polarized or transversely polarized, and in which the lepton beam is unpolarized or longitudinally polarized. Within the framework of the transverse momentum dependent factorization, we take into account the complete decomposition of the parton correlator for fragmentation up to twist-3. We present the cross section of the process to order $1/Q$. The expressions of the polarized structure functions, which may give rise to various spin asymmetries, are also given.
[ { "created": "Wed, 23 Nov 2016 12:02:46 GMT", "version": "v1" }, { "created": "Tue, 25 Apr 2017 00:06:05 GMT", "version": "v2" } ]
2017-04-26
[ [ "Yang", "Yongliang", "" ], [ "Lu", "Zhun", "" ] ]
We study the production of polarized $\Lambda$ hyperon in semi-inclusive deep inelastic scattering off an unpolarized target. We include the cases in which the $\Lambda$ hyperon is longitudinally polarized or transversely polarized, and in which the lepton beam is unpolarized or longitudinally polarized. Within the framework of the transverse momentum dependent factorization, we take into account the complete decomposition of the parton correlator for fragmentation up to twist-3. We present the cross section of the process to order $1/Q$. The expressions of the polarized structure functions, which may give rise to various spin asymmetries, are also given.
1606.05552
Naoya Kitajima
Tetsutaro Higaki, Kwang Sik Jeong, Naoya Kitajima, Toyokazu Sekiguchi, Fuminobu Takahashi
Topological Defects and nano-Hz Gravitational Waves in Aligned Axion Models
23 pages, 7 figures
null
10.1007/JHEP08(2016)044
PNUTP-16/A12, TU-1025, IPMU16-0083, APCTP Pre2016-015, CTPU-16-16
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.
[ { "created": "Fri, 17 Jun 2016 15:10:10 GMT", "version": "v1" } ]
2016-08-24
[ [ "Higaki", "Tetsutaro", "" ], [ "Jeong", "Kwang Sik", "" ], [ "Kitajima", "Naoya", "" ], [ "Sekiguchi", "Toyokazu", "" ], [ "Takahashi", "Fuminobu", "" ] ]
We study the formation and evolution of topological defects in an aligned axion model with multiple Peccei-Quinn scalars, where the QCD axion is realized by a certain combination of the axions with decay constants much smaller than the conventional Peccei-Quinn breaking scale. When the underlying U(1) symmetries are spontaneously broken, the aligned structure in the axion field space exhibits itself as a complicated string-wall network in the real space. We find that the string-wall network likely survives until the QCD phase transition if the number of the Peccei-Quinn scalars is greater than two. The string-wall system collapses during the QCD phase transition, producing a significant amount of gravitational waves in the nano-Hz range at present. The typical decay constant is constrained to be below O(100) TeV by the pulsar timing observations, and the constraint will be improved by a factor of 2 in the future SKA observations.
1308.5802
Ivan Girardi
Ivan Girardi, Aurora Meroni and S. T. Petcov
Neutrinoless Double Beta Decay in the Presence of Light Sterile Neutrinos
36 pages, 22 figures, 5 tables, results unchanged, discussion of cosmological constraints on sterile neutrinos added, the presentation of figures 7, 13, 17 and 21 changed; version to be published in JHEP
JHEP 1311 (2013) 146
10.1007/JHEP11(2013)146
SISSA 37/2013/FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the predictions for neutrinoless double beta ($(\beta \beta)_{0 \nu}$-) decay effective Majorana mass $\left| \langle \, m \, \rangle \right|$ in the 3+1 and 3+2 schemes with one and two additional sterile neutrinos with masses at the eV scale. The two schemes are suggested by the neutrino oscillation interpretation of the reactor neutrino and Gallium "anomalies" and of the data of the LSND and MiniBooNE experiments. We analyse in detail the possibility of a complete or partial cancellation between the different terms in $\left| \langle \, m \, \rangle \right|$, leading to a strong suppression of $\left| \langle \, m \, \rangle \right|$. We determine the regions of the relevant parameter spaces where such a suppression can occure. This allows us to derive the conditions under which the effective Majorana mass satisfies $\left| \langle \, m \, \rangle \right| > 0.01$ eV, which is the range planned to be exploited by the next generation of $(\beta \beta)_{0 \nu}$-experiments.
[ { "created": "Tue, 27 Aug 2013 09:12:54 GMT", "version": "v1" }, { "created": "Tue, 29 Oct 2013 20:44:13 GMT", "version": "v2" } ]
2014-06-10
[ [ "Girardi", "Ivan", "" ], [ "Meroni", "Aurora", "" ], [ "Petcov", "S. T.", "" ] ]
We investigate the predictions for neutrinoless double beta ($(\beta \beta)_{0 \nu}$-) decay effective Majorana mass $\left| \langle \, m \, \rangle \right|$ in the 3+1 and 3+2 schemes with one and two additional sterile neutrinos with masses at the eV scale. The two schemes are suggested by the neutrino oscillation interpretation of the reactor neutrino and Gallium "anomalies" and of the data of the LSND and MiniBooNE experiments. We analyse in detail the possibility of a complete or partial cancellation between the different terms in $\left| \langle \, m \, \rangle \right|$, leading to a strong suppression of $\left| \langle \, m \, \rangle \right|$. We determine the regions of the relevant parameter spaces where such a suppression can occure. This allows us to derive the conditions under which the effective Majorana mass satisfies $\left| \langle \, m \, \rangle \right| > 0.01$ eV, which is the range planned to be exploited by the next generation of $(\beta \beta)_{0 \nu}$-experiments.
1301.4455
Zhi-Guo He
Zhi-Guo He, and Jian-Xiong Wang
The QED contribution to $J/\psi$ plus light hadrons production at B-factories
19 pages, 6 figures
Phys. Rev. D 100, 114025 (2019)
10.1103/PhysRevD.100.114025
DESY 13-009
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To understand the direct $J/\psi+X_{\mathrm{non-c\bar{c}}}$ production mechanism in $e^{+}e^{-}$ annihilation, in this work, we propose to measure the inclusive $J/\psi$ plus light hadrons (LH) production at B-factories and present a detailed study on its QED production due to $\psi(2S)$ feed-down, where the $\psi(2S)$ are produced in $e^{+}e^{-}\to \psi(2S)+\gamma$ and $e^{+}e^{-}\to \psi(2S)+f\bar{f}, f=lepton,light quark$, and QED contribution to direct $J/\psi+q\bar{q}$ production with $q=u,d,s$ quark. We find that the QED contribution is huge in the whole phase space region, but can be reduced largely and is in the same order as the QCD contribution when a suitable cut on the angel $\theta_{J/\psi}$ between $J/\psi$ and the $e^{+}e^{-}$ beam is made. In this way, the cross section of $J/\psi+LH$ QCD production %which was predicted theoretical at next-to-leading order QCD together with relativistic correction, can be obtained by subtracting the QED contribution from the experimental measurement on inclusive $J/\psi$ plus light hadrons. To help to remove the QED background, we also calculate the angular and momentum distribution of $J/\psi$ in the QED contribution.
[ { "created": "Fri, 18 Jan 2013 18:33:37 GMT", "version": "v1" } ]
2019-12-25
[ [ "He", "Zhi-Guo", "" ], [ "Wang", "Jian-Xiong", "" ] ]
To understand the direct $J/\psi+X_{\mathrm{non-c\bar{c}}}$ production mechanism in $e^{+}e^{-}$ annihilation, in this work, we propose to measure the inclusive $J/\psi$ plus light hadrons (LH) production at B-factories and present a detailed study on its QED production due to $\psi(2S)$ feed-down, where the $\psi(2S)$ are produced in $e^{+}e^{-}\to \psi(2S)+\gamma$ and $e^{+}e^{-}\to \psi(2S)+f\bar{f}, f=lepton,light quark$, and QED contribution to direct $J/\psi+q\bar{q}$ production with $q=u,d,s$ quark. We find that the QED contribution is huge in the whole phase space region, but can be reduced largely and is in the same order as the QCD contribution when a suitable cut on the angel $\theta_{J/\psi}$ between $J/\psi$ and the $e^{+}e^{-}$ beam is made. In this way, the cross section of $J/\psi+LH$ QCD production %which was predicted theoretical at next-to-leading order QCD together with relativistic correction, can be obtained by subtracting the QED contribution from the experimental measurement on inclusive $J/\psi$ plus light hadrons. To help to remove the QED background, we also calculate the angular and momentum distribution of $J/\psi$ in the QED contribution.
0710.2891
Stuart Raby
Stuart Raby
SUSY Model Building
Submitted for the SUSY07 proceedings, some references added
null
null
OHSTPY-HEP-T-07-004
hep-ph
null
I review some of the latest directions in supersymmetric model building, focusing on SUSY breaking mechanisms in the minimal supersymmetric standard model [MSSM], the "little" hierarchy and $\mu$ problems, etc. I then discuss SUSY GUTs and UV completions in string theory.
[ { "created": "Mon, 15 Oct 2007 18:38:44 GMT", "version": "v1" }, { "created": "Tue, 16 Oct 2007 14:06:38 GMT", "version": "v2" }, { "created": "Fri, 19 Oct 2007 18:27:32 GMT", "version": "v3" } ]
2011-11-10
[ [ "Raby", "Stuart", "" ] ]
I review some of the latest directions in supersymmetric model building, focusing on SUSY breaking mechanisms in the minimal supersymmetric standard model [MSSM], the "little" hierarchy and $\mu$ problems, etc. I then discuss SUSY GUTs and UV completions in string theory.
hep-ph/9708226
Masahiro Kawasaki
J. Hashiba, M. Kawasaki and T. Yanagida
Cosmological Constraint on the String Dilaton in Gauge-mediated Supersymmetry Breaking Theories
13 pages (RevTex file including one figure, use psfig), revised version to be published in Physical Review Letters
Phys.Rev.Lett. 79 (1997) 4525-4528
10.1103/PhysRevLett.79.4525
null
hep-ph astro-ph
null
The dilaton field in string theories (if exists) is expected to have a mass of the order of the gravitino mass $m_{3/2}$ which is in a range of $10^{-2}$keV--1GeV in gauge-mediated supersymmetry breaking models. If it is the case, the cosmic energy density of coherent dilaton oscillation easily exceeds the critical density of the present universe. We show that even if this problem is solved by a late-time entropy production (thermal inflation) a stringent constraint on the energy density of the dilaton oscillation is derived from experimental upperbounds on the cosmic X($\gamma$)-ray backgrounds. This excludes an interesting mass region, $500keV \lesssim m_{3/2} \lesssim 1GeV$, in gauge-mediated supersymmetry breaking models.
[ { "created": "Mon, 4 Aug 1997 04:58:39 GMT", "version": "v1" }, { "created": "Fri, 3 Oct 1997 10:44:02 GMT", "version": "v2" } ]
2009-10-30
[ [ "Hashiba", "J.", "" ], [ "Kawasaki", "M.", "" ], [ "Yanagida", "T.", "" ] ]
The dilaton field in string theories (if exists) is expected to have a mass of the order of the gravitino mass $m_{3/2}$ which is in a range of $10^{-2}$keV--1GeV in gauge-mediated supersymmetry breaking models. If it is the case, the cosmic energy density of coherent dilaton oscillation easily exceeds the critical density of the present universe. We show that even if this problem is solved by a late-time entropy production (thermal inflation) a stringent constraint on the energy density of the dilaton oscillation is derived from experimental upperbounds on the cosmic X($\gamma$)-ray backgrounds. This excludes an interesting mass region, $500keV \lesssim m_{3/2} \lesssim 1GeV$, in gauge-mediated supersymmetry breaking models.
1612.04249
Chun-Khiang Chua
Chun-Khiang Chua
Rates and $CP$ asymmetries of Charmless Two-body Baryonic $B_{u,d,s}$ Decays
To appear in Phys. Rev. D, 58 pages, 3 figures, 17 tables, some useful formulas from arXiv:1312.2335 are collected (with minor correction) in appendices
Phys. Rev. D 95, 096004 (2017)
10.1103/PhysRevD.95.096004
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the experimental evidences of $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\overline p$ decays, it is now possible to extract both tree and penguin amplitudes of the charmless two-body baryonic $B$ decays for the first time. The extracted penguin-tree ratio agrees with the expectation. Using the topological amplitude approach with the experimental results on $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\bar p$ decay rates as input, predictions on all other $\overline B_q\to {\cal B} \overline {\cal B}$, ${\cal B} \overline {\cal D}$, ${\cal D} \overline {\cal B}$ and ${\cal D} \overline {\cal D}$ decay rates, where ${\mathcal B}$ and ${\cal D}$ are the low lying octet and decuplet baryons, respectively, are given. It is non-trivial that the results do not violate any existing experimental upper limit. From the analysis it is understandable that why $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\bar p$ modes are the first two modes with experimental evidences. Relations on rates are verified using the numerical results. We note that the predicted $B^-\to p\overline{\Delta^{++}}$ rate is close to the experimental bound, which has not been updated in the last ten years. Direct $CP$ asymmetries of all $\overline B_q\to {\cal B} \overline {\cal B}$, ${\cal B} \overline {\cal D}$, ${\cal D} \overline {\cal B}$ and ${\cal D} \overline {\cal D}$ modes are explored. Relations on $CP$ asymmetries are examined using the numerical results. The direct $CP$ asymmetry of $\overline B {}^0\to p \overline{p}$ decay can be as large as $\pm 50\%$. The $CP$ asymmetries of $\Delta S=-1$ pure penguin modes are constrained to be of few $\%$. These modes are expected to be sensitive to New Physics contributions and are good candidates to be added to the list of the tests of the Standard Model.
[ { "created": "Tue, 13 Dec 2016 16:00:07 GMT", "version": "v1" }, { "created": "Wed, 14 Dec 2016 15:47:05 GMT", "version": "v2" }, { "created": "Mon, 6 Mar 2017 16:11:44 GMT", "version": "v3" }, { "created": "Wed, 19 Apr 2017 07:15:05 GMT", "version": "v4" } ]
2017-05-17
[ [ "Chua", "Chun-Khiang", "" ] ]
With the experimental evidences of $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\overline p$ decays, it is now possible to extract both tree and penguin amplitudes of the charmless two-body baryonic $B$ decays for the first time. The extracted penguin-tree ratio agrees with the expectation. Using the topological amplitude approach with the experimental results on $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\bar p$ decay rates as input, predictions on all other $\overline B_q\to {\cal B} \overline {\cal B}$, ${\cal B} \overline {\cal D}$, ${\cal D} \overline {\cal B}$ and ${\cal D} \overline {\cal D}$ decay rates, where ${\mathcal B}$ and ${\cal D}$ are the low lying octet and decuplet baryons, respectively, are given. It is non-trivial that the results do not violate any existing experimental upper limit. From the analysis it is understandable that why $\overline B {}^0\to p \overline{p}$ and $B^-\to\Lambda\bar p$ modes are the first two modes with experimental evidences. Relations on rates are verified using the numerical results. We note that the predicted $B^-\to p\overline{\Delta^{++}}$ rate is close to the experimental bound, which has not been updated in the last ten years. Direct $CP$ asymmetries of all $\overline B_q\to {\cal B} \overline {\cal B}$, ${\cal B} \overline {\cal D}$, ${\cal D} \overline {\cal B}$ and ${\cal D} \overline {\cal D}$ modes are explored. Relations on $CP$ asymmetries are examined using the numerical results. The direct $CP$ asymmetry of $\overline B {}^0\to p \overline{p}$ decay can be as large as $\pm 50\%$. The $CP$ asymmetries of $\Delta S=-1$ pure penguin modes are constrained to be of few $\%$. These modes are expected to be sensitive to New Physics contributions and are good candidates to be added to the list of the tests of the Standard Model.
hep-ph/0109118
Steve King
G. L. Kane and S. F. King
Intermediate Scale Supersymmetric Inflation, Matter and Dark Energy
Version to appear in New Journal of Physics. 19 pages, Latex
NewJ.Phys.3:21,2001
10.1088/1367-2630/3/1/321
MCTP-01-42, SHEP 01-25
hep-ph
null
We consider supersymmetric inflation models in which inflation occurs at an intermediate scale and which provide a solution to the $\mu$ problem and the strong CP problem. Such models are particularly attractive since inflation, baryogenesis and the relic abundance of cold dark matter are all related by a set of parameters which also affect particle physics collider phenomena, neutrino masses and the strong CP problem. For such models the natural situation is a universe containing matter composed of baryons, massive neutrinos, lightest superpartner cold dark matter, and axions. The present day relic abundances of these different forms of matter are (in principle) calculable from the supersymmetric inflation model together with a measurement of the CMB temperature and the Hubble constant. From these relic abundances one can deduce the amount of the present day dark energy density.
[ { "created": "Thu, 13 Sep 2001 17:51:50 GMT", "version": "v1" }, { "created": "Tue, 25 Sep 2001 08:31:00 GMT", "version": "v2" }, { "created": "Tue, 30 Oct 2001 13:57:48 GMT", "version": "v3" } ]
2008-11-26
[ [ "Kane", "G. L.", "" ], [ "King", "S. F.", "" ] ]
We consider supersymmetric inflation models in which inflation occurs at an intermediate scale and which provide a solution to the $\mu$ problem and the strong CP problem. Such models are particularly attractive since inflation, baryogenesis and the relic abundance of cold dark matter are all related by a set of parameters which also affect particle physics collider phenomena, neutrino masses and the strong CP problem. For such models the natural situation is a universe containing matter composed of baryons, massive neutrinos, lightest superpartner cold dark matter, and axions. The present day relic abundances of these different forms of matter are (in principle) calculable from the supersymmetric inflation model together with a measurement of the CMB temperature and the Hubble constant. From these relic abundances one can deduce the amount of the present day dark energy density.
2109.09058
A. Bashir
L.X. Guti\'errez-Guerrero, G. Paredes-Torres, A. Bashir
Mesons and Baryons: Parity Partners
10 pages, 4 figures
null
10.1103/PhysRevD.104.094013
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We calculate masses of light and heavy mesons as well as baryons of negative parity containing $u,d,s,c$ and $b$ quarks. It is an extension of our previous work where we had studied the positive parity baryons. We adopt a quark-diquark picture of baryons where the diquarks are non-pointlike with a finite spatial extension. The mathematical foundation for this analysis is implemented through a symmetry-preserving Schwinger-Dyson equations treatment of a vector-vector contact interaction, which preserves key features of quantum chromodynamics, such as confinement, chiral symmetry breaking, axial vector Ward-Takahashi identity and low-energy Goldberger-Treiman relations. This treatment simultaneously describes mesons and provides attractive correlations for diquarks in the $\overline{3}$ representation. Employing this model, we compute the spectrum and masses of all spin-1/2 and spin-3/2 baryons of negative parity, supplementing our earlier evaluation of positive parity baryons, containing 1, 2 or 3 heavy quarks. In the process, we calculate masses of a multitude of mesons and corresponding diquarks. Wherever possible, we make comparisons of our results with known experimental observations as well as theoretical predictions of several models and approaches including lattice quantum chromodynamics, finding satisfactory agreement. We also make predictions for heavier states not yet observed in the experiment.
[ { "created": "Sun, 19 Sep 2021 04:47:20 GMT", "version": "v1" } ]
2021-11-24
[ [ "Gutiérrez-Guerrero", "L. X.", "" ], [ "Paredes-Torres", "G.", "" ], [ "Bashir", "A.", "" ] ]
We calculate masses of light and heavy mesons as well as baryons of negative parity containing $u,d,s,c$ and $b$ quarks. It is an extension of our previous work where we had studied the positive parity baryons. We adopt a quark-diquark picture of baryons where the diquarks are non-pointlike with a finite spatial extension. The mathematical foundation for this analysis is implemented through a symmetry-preserving Schwinger-Dyson equations treatment of a vector-vector contact interaction, which preserves key features of quantum chromodynamics, such as confinement, chiral symmetry breaking, axial vector Ward-Takahashi identity and low-energy Goldberger-Treiman relations. This treatment simultaneously describes mesons and provides attractive correlations for diquarks in the $\overline{3}$ representation. Employing this model, we compute the spectrum and masses of all spin-1/2 and spin-3/2 baryons of negative parity, supplementing our earlier evaluation of positive parity baryons, containing 1, 2 or 3 heavy quarks. In the process, we calculate masses of a multitude of mesons and corresponding diquarks. Wherever possible, we make comparisons of our results with known experimental observations as well as theoretical predictions of several models and approaches including lattice quantum chromodynamics, finding satisfactory agreement. We also make predictions for heavier states not yet observed in the experiment.
hep-ph/9410317
null
N.N.Nikolaev, B.G.Zakharov and V.R.Zoller
The direct calculation of the slope of the QCD pomeron's trajectory
null
JETP Lett. 60 (1994) 694-698
null
ITEP-74-94, October 1994
hep-ph
null
We demonstrate that the diffraction slope of the generalized BFKL pomeron amplitude has the conventional Regge growth $B(s) = B(0) + 2\alpha_{\Pom}'\log(s)$. This proves that the generalized BFKL pomeron is described by the moving $j$-plane singularity. We give an estimate for the slope $\alpha_{\Pom}'$ in terms of the correlation radius for the perturbative gluons.
[ { "created": "Wed, 19 Oct 1994 13:50:35 GMT", "version": "v1" }, { "created": "Fri, 21 Oct 1994 10:02:36 GMT", "version": "v2" }, { "created": "Tue, 25 Oct 1994 08:49:13 GMT", "version": "v3" } ]
2009-09-25
[ [ "Nikolaev", "N. N.", "" ], [ "Zakharov", "B. G.", "" ], [ "Zoller", "V. R.", "" ] ]
We demonstrate that the diffraction slope of the generalized BFKL pomeron amplitude has the conventional Regge growth $B(s) = B(0) + 2\alpha_{\Pom}'\log(s)$. This proves that the generalized BFKL pomeron is described by the moving $j$-plane singularity. We give an estimate for the slope $\alpha_{\Pom}'$ in terms of the correlation radius for the perturbative gluons.
hep-ph/0001035
Stefan Soldner-Rembold
A Donnachie, S Soldner-Rembold
Gamma(*)Gamma(*) reaction at high energies
6 pages, 6 figures, submitted to proceedings of the Durham Collider Workshop, 22-26 September 1999
J.Phys.G26:689-695,2000
10.1088/0954-3899/26/5/328
FREIBURG EHEP-2000-01
hep-ph hep-ex
null
The energy available for gamma(*)gamma(*) physics at LEP2 is opening a new window on the study of diffractive phenomena, both non-perturbative and perturbative. We discuss some of the uncertainties and problems connected with the experimental measurements and their interpretation.
[ { "created": "Wed, 5 Jan 2000 13:34:05 GMT", "version": "v1" }, { "created": "Tue, 11 Jan 2000 08:52:47 GMT", "version": "v2" } ]
2008-11-26
[ [ "Donnachie", "A", "" ], [ "Soldner-Rembold", "S", "" ] ]
The energy available for gamma(*)gamma(*) physics at LEP2 is opening a new window on the study of diffractive phenomena, both non-perturbative and perturbative. We discuss some of the uncertainties and problems connected with the experimental measurements and their interpretation.
1704.05478
Daniele Barducci
D. Barducci, M. Fabbrichesi and A. Tonero
Constraints on top quark non-standard interactions from Higgs and $t \bar t$ production cross sections
12 pages, 9 figures, 3 tables. Discussion with the relation of the considered operators with the ones of the Warsaw basis extended. Missing contribution to the gluon fusion amplitude added. Main results unchanged
Phys. Rev. D 96, 075022 (2017)
10.1103/PhysRevD.96.075022
SISSA-21-2017-FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We identify the differential cross sections for $t\bar t$ production and the total cross section for Higgs production through gluon fusion as the processes in which the two effective operators describing the leading non-standard interactions of the top quark with the gluon can be disentangled and studied in an independent fashion. Current data on the Higgs production and the $ {\rm d}\sigma/{\rm d} {p^t_T}$ differential cross section provide limits comparable, but not more stringent, than those from the total $t\bar t$ cross sections measurements at the LHC and Tevatron, where however the two operators enter on the same footing and can only be constrained together. Given the present uncertainties, we find that the most stringent bounds are provided by a combination of data on the $t \bar t$ total cross sections together with those from the Higgs production. We conclude by stating the (modest) reduction in the uncertainties necessary to provide more stringent limits by means of the Higgs production and $t\bar t$ differential cross section observables at the LHC with the future luminosity of 300 and 3000 fb$^{-1}$.
[ { "created": "Tue, 18 Apr 2017 18:04:42 GMT", "version": "v1" }, { "created": "Wed, 11 Oct 2017 17:01:39 GMT", "version": "v2" } ]
2017-10-25
[ [ "Barducci", "D.", "" ], [ "Fabbrichesi", "M.", "" ], [ "Tonero", "A.", "" ] ]
We identify the differential cross sections for $t\bar t$ production and the total cross section for Higgs production through gluon fusion as the processes in which the two effective operators describing the leading non-standard interactions of the top quark with the gluon can be disentangled and studied in an independent fashion. Current data on the Higgs production and the $ {\rm d}\sigma/{\rm d} {p^t_T}$ differential cross section provide limits comparable, but not more stringent, than those from the total $t\bar t$ cross sections measurements at the LHC and Tevatron, where however the two operators enter on the same footing and can only be constrained together. Given the present uncertainties, we find that the most stringent bounds are provided by a combination of data on the $t \bar t$ total cross sections together with those from the Higgs production. We conclude by stating the (modest) reduction in the uncertainties necessary to provide more stringent limits by means of the Higgs production and $t\bar t$ differential cross section observables at the LHC with the future luminosity of 300 and 3000 fb$^{-1}$.
1907.01726
Brian Maddock
Wolfgang Altmannshofer, Brian Maddock, Stefano Profumo
Doubly Blind Spots in Scalar Dark Matter Models
21 pages, 8 figures
Phys. Rev. D 100, 055033 (2019)
10.1103/PhysRevD.100.055033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a framework where the Standard Model is augmented by a second SU(2) scalar doublet and by a real scalar singlet that, protected by a Z2 symmetry, provides a particle Dark Matter candidate. We show that this setup allows for doubly blind spots at both collider searches for anomalies in the Higgs invisible decay width, and at direct Dark Matter detection. The blind spots originate from cancellations between interfering diagrams featuring different neutral scalar exchanges, and from cancellations driven by the two-Higgs doublet structure in the vertex coupling the singlet state with the Standard-Model-like Higgs. We demonstrate that the blind spots arise in a wide and generic array of realizations for the two-Higgs doublet model, including scenarios with a non-trivial flavor structure. We provide analytical formul{\ae} that describe the location of the blind spots in the theory parameter space, and we discuss the resulting phenomenology.
[ { "created": "Wed, 3 Jul 2019 03:59:16 GMT", "version": "v1" }, { "created": "Mon, 30 Sep 2019 16:57:45 GMT", "version": "v2" } ]
2019-10-02
[ [ "Altmannshofer", "Wolfgang", "" ], [ "Maddock", "Brian", "" ], [ "Profumo", "Stefano", "" ] ]
We consider a framework where the Standard Model is augmented by a second SU(2) scalar doublet and by a real scalar singlet that, protected by a Z2 symmetry, provides a particle Dark Matter candidate. We show that this setup allows for doubly blind spots at both collider searches for anomalies in the Higgs invisible decay width, and at direct Dark Matter detection. The blind spots originate from cancellations between interfering diagrams featuring different neutral scalar exchanges, and from cancellations driven by the two-Higgs doublet structure in the vertex coupling the singlet state with the Standard-Model-like Higgs. We demonstrate that the blind spots arise in a wide and generic array of realizations for the two-Higgs doublet model, including scenarios with a non-trivial flavor structure. We provide analytical formul{\ae} that describe the location of the blind spots in the theory parameter space, and we discuss the resulting phenomenology.
1507.00352
Hye-Sung Lee
Hooman Davoudiasl, Hye-Sung Lee, William J. Marciano
Low Q^2 Weak Mixing Angle Measurements and Rare Higgs Decays
Version to appear in PRD
Phys. Rev. D 92, 055005 (2015)
10.1103/PhysRevD.92.055005
CERN-PH-TH-2015-151
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A weighted average weak mixing angle theta_W derived from relatively low Q^2 experiments is compared with the Standard Model prediction obtained from precision measurements. The approximate 1.8 sigma discrepancy is fit with an intermediate mass (~ 10-35 GeV) "dark" Z boson Z_d, corresponding to a U(1)_d gauge symmetry of hidden dark matter, which couples to our world via kinetic and Z-Z_d mass mixing. Constraints on such a scenario are obtained from precision electroweak bounds and searches for the rare Higgs decays H -> Z Z_d -> 4 charged leptons at the LHC. The sensitivity of future anticipated low Q^2 measurements of sin^2 theta_W(Q^2) to intermediate mass Z_d is also illustrated. This dark Z scenario can provide interesting concomitant signals in low energy parity violating measurements and rare Higgs decays at the LHC, over the next few years.
[ { "created": "Wed, 1 Jul 2015 20:02:24 GMT", "version": "v1" }, { "created": "Thu, 27 Aug 2015 16:13:24 GMT", "version": "v2" } ]
2015-09-09
[ [ "Davoudiasl", "Hooman", "" ], [ "Lee", "Hye-Sung", "" ], [ "Marciano", "William J.", "" ] ]
A weighted average weak mixing angle theta_W derived from relatively low Q^2 experiments is compared with the Standard Model prediction obtained from precision measurements. The approximate 1.8 sigma discrepancy is fit with an intermediate mass (~ 10-35 GeV) "dark" Z boson Z_d, corresponding to a U(1)_d gauge symmetry of hidden dark matter, which couples to our world via kinetic and Z-Z_d mass mixing. Constraints on such a scenario are obtained from precision electroweak bounds and searches for the rare Higgs decays H -> Z Z_d -> 4 charged leptons at the LHC. The sensitivity of future anticipated low Q^2 measurements of sin^2 theta_W(Q^2) to intermediate mass Z_d is also illustrated. This dark Z scenario can provide interesting concomitant signals in low energy parity violating measurements and rare Higgs decays at the LHC, over the next few years.
hep-ph/9205213
Lowell Brown
Lowell S. Brown, Laurence G. Yaffe, and Chengxing Zhai
Large-order perturbation theory for the electromagnetic current-current correlation function
62 pages
Phys.Rev. D46 (1992) 4712-4735
10.1103/PhysRevD.46.4712
null
hep-ph
null
The constraints imposed by asymptotic freedom and analyticity on the large-order behavior of perturbation theory for the electromagnetic current-current correlation function are examined. By suitably applying the renormalization group, the coefficients of the asymptotic expansion in the deep Euclidean region may be expressed explicitly in terms of the perturbative coefficients of the Minkowski space discontinuity (the $R$-ratio in $e^+ e^-$ scattering). This relation yields a ``generic'' prediction for the large-order behavior of the Euclidean perturbation series and suggests the presence of non-perturbative $1/q^2$ correction in the Euclidian correlation function. No such ``generic'' prediction can be made for the physically measurable $R$-ratio. A novel functional method is developed to obtain these results.
[ { "created": "Sat, 9 May 1992 02:26:30 GMT", "version": "v1" } ]
2009-10-22
[ [ "Brown", "Lowell S.", "" ], [ "Yaffe", "Laurence G.", "" ], [ "Zhai", "Chengxing", "" ] ]
The constraints imposed by asymptotic freedom and analyticity on the large-order behavior of perturbation theory for the electromagnetic current-current correlation function are examined. By suitably applying the renormalization group, the coefficients of the asymptotic expansion in the deep Euclidean region may be expressed explicitly in terms of the perturbative coefficients of the Minkowski space discontinuity (the $R$-ratio in $e^+ e^-$ scattering). This relation yields a ``generic'' prediction for the large-order behavior of the Euclidean perturbation series and suggests the presence of non-perturbative $1/q^2$ correction in the Euclidian correlation function. No such ``generic'' prediction can be made for the physically measurable $R$-ratio. A novel functional method is developed to obtain these results.
2011.02529
Nodoka Yamanaka
Nanako Shitara, Nodoka Yamanaka, Bijaya Kumar Sahoo, Toshio Watanabe, Bhanu Pratap Das
CP violating effects in $^{210}$Fr and prospects for new physics beyond the Standard Model
17 pages, 6 figures, published version
JHEP02(2021)124
10.1007/JHEP02(2021)124
null
hep-ph nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report theoretical results of the electric dipole moment (EDM) of $^{210}$Fr which arises from the interaction of the EDM of an electron with the internal electric field in an atom and the scalar-pseudoscalar electron-nucleus interaction; the two dominant sources of CP violation in this atom. Employing the relativistic coupled-cluster theory, we evaluate the enhancement factors for these two CP violating interactions to an accuracy of about 3% and analyze the contributions of the many-body effects. These two quantities in combination with the projected sensitivity of the $^{210}$Fr EDM experiment provide constraints on new physics beyond the Standard Model. Particularly, we demonstrate that their precise values are necessary to account for the effect of the bottom quark in models in which the Higgs sector is augmented by nonstandard Yukawa interactions such as the two-Higgs doublet model.
[ { "created": "Wed, 4 Nov 2020 20:51:20 GMT", "version": "v1" }, { "created": "Sun, 21 Feb 2021 07:45:31 GMT", "version": "v2" } ]
2021-02-23
[ [ "Shitara", "Nanako", "" ], [ "Yamanaka", "Nodoka", "" ], [ "Sahoo", "Bijaya Kumar", "" ], [ "Watanabe", "Toshio", "" ], [ "Das", "Bhanu Pratap", "" ] ]
We report theoretical results of the electric dipole moment (EDM) of $^{210}$Fr which arises from the interaction of the EDM of an electron with the internal electric field in an atom and the scalar-pseudoscalar electron-nucleus interaction; the two dominant sources of CP violation in this atom. Employing the relativistic coupled-cluster theory, we evaluate the enhancement factors for these two CP violating interactions to an accuracy of about 3% and analyze the contributions of the many-body effects. These two quantities in combination with the projected sensitivity of the $^{210}$Fr EDM experiment provide constraints on new physics beyond the Standard Model. Particularly, we demonstrate that their precise values are necessary to account for the effect of the bottom quark in models in which the Higgs sector is augmented by nonstandard Yukawa interactions such as the two-Higgs doublet model.
2205.01021
Zhen-hua Zhao
Zhen-hua Zhao
A split seesaw model with hidden neutrinoless double beta decay but successful leptogenesis
20 pages, 9 figures, version accepted for publication in EPJC
Eur. Phys. J. C (2022) 82:1020
10.1140/epjc/s10052-022-10989-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a paper by Asaka, Ishida and Tanaka \cite{hiding}, they proposed a novel possibility (which will be referred to as the AIT ansatz) that, in spite of the Majorana nature of neutrinos, the neutrinoless double beta ($0\nu \beta\beta$) decay can be hidden. In the original AIT model, the AIT ansatz is realized in the minimal seesaw model with two right-handed neutrinos which have a hierarchical mass structure: the lighter and heavier right-handed neutrinos are respectively much lighter and heavier than the typical Fermi-momentum scale of nuclei. However, the original AIT model does not accommodate a successful leptogenesis. For this problem, in this paper we study a split seesaw model with one lighter right-handed neutrino but two heavier right-handed neutrinos which can realize the AIT ansatz and accommodate a successful leptogenesis simultaneously. We first give the condition on the neutrino Yukawa couplings for realizing the AIT ansatz, discuss its realization by employing an Abelian flavor symmetry, and study its implications for the mixing of the lighter right-handed neutrino with three left-handed neutrinos. We then successively study the implications for leptogenesis of the interesting scenarios where $M^{}_{\rm D}$ is a triangular matrix (which has maximally-restricted texture zeros, in line with the simplicity principle) or respects the $\mu$-$\tau$ reflection symmetry (which is well motivated by the experimental results), on top of the AIT ansatz.
[ { "created": "Mon, 2 May 2022 16:48:51 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2022 08:33:13 GMT", "version": "v2" } ]
2022-11-15
[ [ "Zhao", "Zhen-hua", "" ] ]
In a paper by Asaka, Ishida and Tanaka \cite{hiding}, they proposed a novel possibility (which will be referred to as the AIT ansatz) that, in spite of the Majorana nature of neutrinos, the neutrinoless double beta ($0\nu \beta\beta$) decay can be hidden. In the original AIT model, the AIT ansatz is realized in the minimal seesaw model with two right-handed neutrinos which have a hierarchical mass structure: the lighter and heavier right-handed neutrinos are respectively much lighter and heavier than the typical Fermi-momentum scale of nuclei. However, the original AIT model does not accommodate a successful leptogenesis. For this problem, in this paper we study a split seesaw model with one lighter right-handed neutrino but two heavier right-handed neutrinos which can realize the AIT ansatz and accommodate a successful leptogenesis simultaneously. We first give the condition on the neutrino Yukawa couplings for realizing the AIT ansatz, discuss its realization by employing an Abelian flavor symmetry, and study its implications for the mixing of the lighter right-handed neutrino with three left-handed neutrinos. We then successively study the implications for leptogenesis of the interesting scenarios where $M^{}_{\rm D}$ is a triangular matrix (which has maximally-restricted texture zeros, in line with the simplicity principle) or respects the $\mu$-$\tau$ reflection symmetry (which is well motivated by the experimental results), on top of the AIT ansatz.
hep-ph/0602164
Richard Thomson
Richard Thomson, Alex Pang, Chueng-Ryong Ji
Real and Virtual Nucleon Compton Scattering in the Perturbative Limit
36 pages, 11 figures
Phys.Rev.D73:054023,2006
10.1103/PhysRevD.73.054023
null
hep-ph
null
We present the results of calculations analyzing nucleon Compton scattering to lowest order using perturbative QCD (pQCD) methods. Two scenarios are considered: (1) the incoming photon is real; and (2) the incoming photon is virtual. The case of a real photon has been previously analyzed at least 5 times using pQCD, but no two results are in agreement. Here it is shown that our result agrees with that of Brooks and Dixon published in 2000. The case of a virtual photon has been previously analyzed only once using pQCD. However, doubt has been cast on the validity of that result. The results presented here for virtual photon are believed to be more reliable. Some consideration is given of how to compare these results with experiment. Following the lead of Brooks and Dixon, for the proton, this involves normalizing the cross section using the Dirac proton form factor, which we also calculate. Finally, there is a comparison of our results with recent experiments.
[ { "created": "Fri, 17 Feb 2006 15:42:55 GMT", "version": "v1" }, { "created": "Mon, 20 Feb 2006 21:02:43 GMT", "version": "v2" } ]
2008-11-26
[ [ "Thomson", "Richard", "" ], [ "Pang", "Alex", "" ], [ "Ji", "Chueng-Ryong", "" ] ]
We present the results of calculations analyzing nucleon Compton scattering to lowest order using perturbative QCD (pQCD) methods. Two scenarios are considered: (1) the incoming photon is real; and (2) the incoming photon is virtual. The case of a real photon has been previously analyzed at least 5 times using pQCD, but no two results are in agreement. Here it is shown that our result agrees with that of Brooks and Dixon published in 2000. The case of a virtual photon has been previously analyzed only once using pQCD. However, doubt has been cast on the validity of that result. The results presented here for virtual photon are believed to be more reliable. Some consideration is given of how to compare these results with experiment. Following the lead of Brooks and Dixon, for the proton, this involves normalizing the cross section using the Dirac proton form factor, which we also calculate. Finally, there is a comparison of our results with recent experiments.
1909.10691
Henry Lamm
Thomas D. Cohen, Henry Lamm, Richard F. Lebed
Precision Model-Independent Bounds from Global Analysis of $b \to c \ell \nu$ Form Factors
13 pages, 8 figures
Phys. Rev. D 100, 094503 (2019)
10.1103/PhysRevD.100.094503
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model-independent global analysis of hadronic form factors for the semileptonic decays $b\rightarrow c\ell\nu$ that exploits lattice-QCD data, dispersion relations, and heavy-quark symmetries. The analysis yields predictions for the relevant form factors, within quantifiable bounds. These form factors are used to compute the semileptonic ratios $R(H_c)$ and various decay-product polarizations. In particular, we find $R(D_s^*)=0.20(3)$ and $R(J/\psi)=0.25(3)$, predictions that can be compared to results of upcoming LHCb measurements. In developing this treatment, we obtain leading-order NRQCD results for the nonzero-recoil relations between the $B_c^+ \rightarrow \{J/\psi , \eta_c \}$ form factors.
[ { "created": "Tue, 24 Sep 2019 03:17:11 GMT", "version": "v1" } ]
2019-11-20
[ [ "Cohen", "Thomas D.", "" ], [ "Lamm", "Henry", "" ], [ "Lebed", "Richard F.", "" ] ]
We present a model-independent global analysis of hadronic form factors for the semileptonic decays $b\rightarrow c\ell\nu$ that exploits lattice-QCD data, dispersion relations, and heavy-quark symmetries. The analysis yields predictions for the relevant form factors, within quantifiable bounds. These form factors are used to compute the semileptonic ratios $R(H_c)$ and various decay-product polarizations. In particular, we find $R(D_s^*)=0.20(3)$ and $R(J/\psi)=0.25(3)$, predictions that can be compared to results of upcoming LHCb measurements. In developing this treatment, we obtain leading-order NRQCD results for the nonzero-recoil relations between the $B_c^+ \rightarrow \{J/\psi , \eta_c \}$ form factors.
1710.02695
Anton Rebhan
Frederic Br\"unner and Anton Rebhan
Predictions for production and decay of the pseudoscalar glueball from the Witten-Sakai-Sugimoto model
1+4 pages, PoS contribution to EPS-HEP conference 5-12 July 2017, Venice
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Witten-Sakai-Sugimoto model, a top-down gauge/gravity model of large-$N_c$ low-energy QCD based on type-IIA string theory and $N_c$ D4 branes with chiral quarks added by probe D8 branes, involves only one dimensionless parameter, the 't Hooft coupling at its cutoff (Kaluza-Klein) scale. Although this cutoff scale is around 1 GeV, the model has turned out to be surprisingly predictive also quantitatively, reproducing masses of vector and axial vector mesons, their decay rates, as well as the anomalous mass of the \eta' meson, all within 10-30% errors. Using it as a guide for glueball signatures, we have argued that it indicates that the meson $f_0(1710)$ may be a nearly pure glueball, with rather specific predictions for the still-to-be-measured 4\pi and \eta\eta' decays. Here we present our new predictions for the decay pattern of the (very narrow) pseudoscalar glueball, which is closely related to the U(1)$_A$ problem that the model is in fact handling correctly.
[ { "created": "Sat, 7 Oct 2017 14:52:33 GMT", "version": "v1" } ]
2017-10-10
[ [ "Brünner", "Frederic", "" ], [ "Rebhan", "Anton", "" ] ]
The Witten-Sakai-Sugimoto model, a top-down gauge/gravity model of large-$N_c$ low-energy QCD based on type-IIA string theory and $N_c$ D4 branes with chiral quarks added by probe D8 branes, involves only one dimensionless parameter, the 't Hooft coupling at its cutoff (Kaluza-Klein) scale. Although this cutoff scale is around 1 GeV, the model has turned out to be surprisingly predictive also quantitatively, reproducing masses of vector and axial vector mesons, their decay rates, as well as the anomalous mass of the \eta' meson, all within 10-30% errors. Using it as a guide for glueball signatures, we have argued that it indicates that the meson $f_0(1710)$ may be a nearly pure glueball, with rather specific predictions for the still-to-be-measured 4\pi and \eta\eta' decays. Here we present our new predictions for the decay pattern of the (very narrow) pseudoscalar glueball, which is closely related to the U(1)$_A$ problem that the model is in fact handling correctly.
2208.14219
Wei Zhu
Wei Zhu, Qihui Chen, Zhiyi Cui and Jianhong Ruan
The gluon condensation in hadron collisions
30 pages, 11 figures, 2 tables, Accepted for publication in NPB. arXiv admin note: text overlap with arXiv:2109.09826
Nuclear Physics B984 (2022) 115961
10.1016/j.nuclphysb.2022.115961
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Gluons may converge to a stable state at a critical momentum in hadrons. This gluon condensation is predicted by a nonlinear QCD evolution equation. We review the understanding of the gluon condensation and present a clear physical picture that produces the gluon condensation from the colour glass condensate. We summarize the applications of the GC effect in the $p-p(A)$ collisions and predict that the $p-Pb$ and $Pb-Pb$ collisions at the LHC are close to the energy region of the gluon condensation. We warn that for the next generation of hadron colliders with the increasing of the collision energy, the extremely strong gamma-rays will be emitted in a narrow space of the accelerator due to the gluon condensation effect. Such artificial mini gamma-ray bursts in the laboratory may damage the detectors.
[ { "created": "Tue, 30 Aug 2022 12:51:35 GMT", "version": "v1" } ]
2022-09-28
[ [ "Zhu", "Wei", "" ], [ "Chen", "Qihui", "" ], [ "Cui", "Zhiyi", "" ], [ "Ruan", "Jianhong", "" ] ]
Gluons may converge to a stable state at a critical momentum in hadrons. This gluon condensation is predicted by a nonlinear QCD evolution equation. We review the understanding of the gluon condensation and present a clear physical picture that produces the gluon condensation from the colour glass condensate. We summarize the applications of the GC effect in the $p-p(A)$ collisions and predict that the $p-Pb$ and $Pb-Pb$ collisions at the LHC are close to the energy region of the gluon condensation. We warn that for the next generation of hadron colliders with the increasing of the collision energy, the extremely strong gamma-rays will be emitted in a narrow space of the accelerator due to the gluon condensation effect. Such artificial mini gamma-ray bursts in the laboratory may damage the detectors.
1012.4587
Thomas Hambye
Thomas Hambye
On the stability of particle dark matter
Talk presented at the "Identification of Dark Matter 2010" conference, July 26-30, Montpellier, France
null
null
ULB-TH/10-40
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
From the particle physics point of view, the most peculiar property of the dark matter particle is its stability on cosmological time scales. We briefly review the possible origins of this characteristic feature for candidates whose relic density results from the thermal freeze-out of their annihilation. We emphasize that each stabilization mechanism implies an all specific phenomenology. The models reviewed include supersymmetric and non-supersymmetric models where the stability is a consequence of grand-unification, models where stability is due to an unbroken gauge group and models where the DM stability is accidental. The latter possibility includes minimal dark matter, hidden vector dark matter and composite DM models.
[ { "created": "Tue, 21 Dec 2010 10:10:12 GMT", "version": "v1" } ]
2010-12-22
[ [ "Hambye", "Thomas", "" ] ]
From the particle physics point of view, the most peculiar property of the dark matter particle is its stability on cosmological time scales. We briefly review the possible origins of this characteristic feature for candidates whose relic density results from the thermal freeze-out of their annihilation. We emphasize that each stabilization mechanism implies an all specific phenomenology. The models reviewed include supersymmetric and non-supersymmetric models where the stability is a consequence of grand-unification, models where stability is due to an unbroken gauge group and models where the DM stability is accidental. The latter possibility includes minimal dark matter, hidden vector dark matter and composite DM models.
2312.10566
Igor Samsonov
V.A. Dzuba, V.V. Flambaum, I.B. Samsonov
Migdal-type effect in the dark matter absorption process
7 pages + appendices; journal version
null
null
null
hep-ph hep-ex physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new mechanism of absorption of dark matter particles in atoms which resembles the Migdal effect of inelastic dark matter scattering. In this process, atom may be ionized upon absorption of a scalar particle through the scalar-nucleon Yukawa-type interaction. The crucial difference from the inelastic dark matter scattering on atoms is that the total energy of the particle, including its rest mass $mc^2$-term, is transferred to the electron. As a result, the emitted electron kinetic energy is about six orders in magnitude bigger than that in the dark matter scattering process. This absorption process allows one to probe dark matter particles with a relatively small mass, in the range from 1 to 100 keV, that cannot be detected in the scattering process. It is also possible to detect hypothetical scalar particles emitted from the Sun. We calculate absorption cross sections of this process in Na, Si, Ar, Ge, I, Xe, and Tl target atoms and extract limits on the scalar-nucleon interaction constant from null results of XENONnT experiment.
[ { "created": "Sun, 17 Dec 2023 00:15:10 GMT", "version": "v1" }, { "created": "Sun, 9 Jun 2024 08:51:38 GMT", "version": "v2" } ]
2024-06-11
[ [ "Dzuba", "V. A.", "" ], [ "Flambaum", "V. V.", "" ], [ "Samsonov", "I. B.", "" ] ]
We propose a new mechanism of absorption of dark matter particles in atoms which resembles the Migdal effect of inelastic dark matter scattering. In this process, atom may be ionized upon absorption of a scalar particle through the scalar-nucleon Yukawa-type interaction. The crucial difference from the inelastic dark matter scattering on atoms is that the total energy of the particle, including its rest mass $mc^2$-term, is transferred to the electron. As a result, the emitted electron kinetic energy is about six orders in magnitude bigger than that in the dark matter scattering process. This absorption process allows one to probe dark matter particles with a relatively small mass, in the range from 1 to 100 keV, that cannot be detected in the scattering process. It is also possible to detect hypothetical scalar particles emitted from the Sun. We calculate absorption cross sections of this process in Na, Si, Ar, Ge, I, Xe, and Tl target atoms and extract limits on the scalar-nucleon interaction constant from null results of XENONnT experiment.
2112.00975
Muhammad Ajaz
Muhammad Waqas, Guang-Xiong Peng, Muhammad Ajaz, Abd Al Karim Haj Ismail, Pei-Pin Yang, Zafar Wazir
Extraction of freezeout parameters and their dependence on collision energy and collision cross-section
8 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We used the Blast wave model with Boltzmann Gibbs statistics and analyzed the experimental data of transverse momentum spectra ($p_T$) measured by NA61/SHINE and NA 49 Collaborations in inelastic (INEL) proton-proton, and the most central Beryllium-Beryllium (Be-Be), Argon-Scandium (Ar-Sc) and Lead-Lead (Pb-Pb) collisions. The model results fit the experimental data of NA61/SHINE and NA 49 Collaborations very well. We extracted kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume directly from the spectra. We also calculated mean transverse momentum and initial temperature from the fit function. It is observed that the kinetic freezeout temperature increases with increasing the collision energy as well as collision cross-section (size of the colliding system). Furthermore, the transverse flow remains unchanged with increasing the collision energy, while it changes randomly with the collision cross-section. Similarly, with the increase in collision energy or the collision cross-section, the freeze-out volume and the average $p_T$ increase. The initial temperature is also observed to be an increasing function of the collision cross-section.
[ { "created": "Thu, 2 Dec 2021 04:17:27 GMT", "version": "v1" } ]
2021-12-03
[ [ "Waqas", "Muhammad", "" ], [ "Peng", "Guang-Xiong", "" ], [ "Ajaz", "Muhammad", "" ], [ "Ismail", "Abd Al Karim Haj", "" ], [ "Yang", "Pei-Pin", "" ], [ "Wazir", "Zafar", "" ] ]
We used the Blast wave model with Boltzmann Gibbs statistics and analyzed the experimental data of transverse momentum spectra ($p_T$) measured by NA61/SHINE and NA 49 Collaborations in inelastic (INEL) proton-proton, and the most central Beryllium-Beryllium (Be-Be), Argon-Scandium (Ar-Sc) and Lead-Lead (Pb-Pb) collisions. The model results fit the experimental data of NA61/SHINE and NA 49 Collaborations very well. We extracted kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume directly from the spectra. We also calculated mean transverse momentum and initial temperature from the fit function. It is observed that the kinetic freezeout temperature increases with increasing the collision energy as well as collision cross-section (size of the colliding system). Furthermore, the transverse flow remains unchanged with increasing the collision energy, while it changes randomly with the collision cross-section. Similarly, with the increase in collision energy or the collision cross-section, the freeze-out volume and the average $p_T$ increase. The initial temperature is also observed to be an increasing function of the collision cross-section.
hep-ph/9701243
Markus Finkemeier
Markus Finkemeier, Howard Georgi, Matt McIrvin (Harvard University)
Reparameterization Invariance Revisited
20 pages, no figures, Latex. Revised version: Discussion of reparameterization invariance constraints on class-II operators added
Phys.Rev.D55:6933-6943,1997
10.1103/PhysRevD.55.6933
HUTP-96/A053
hep-ph
null
Reparameterization invariance, a symmetry of heavy quark effective theory, appears in different forms in the literature. The most commonly cited forms of the reparameterization transformation are shown to induce the same constraints on operators that do not vanish under the equation of motion to order $1/m^2$, and to be related by a redefinition of the heavy quark field. We give a new, very straightforward proof that that the reparameterization invariance constraints apply to all orders in $\alpha_s$ under matching to full QCD and renormalization-group running, at least up to and including $O(1/m^2)$.
[ { "created": "Tue, 7 Jan 1997 22:35:47 GMT", "version": "v1" }, { "created": "Sat, 25 Jan 1997 01:17:24 GMT", "version": "v2" } ]
2009-09-11
[ [ "Finkemeier", "Markus", "", "Harvard University" ], [ "Georgi", "Howard", "", "Harvard University" ], [ "McIrvin", "Matt", "", "Harvard University" ] ]
Reparameterization invariance, a symmetry of heavy quark effective theory, appears in different forms in the literature. The most commonly cited forms of the reparameterization transformation are shown to induce the same constraints on operators that do not vanish under the equation of motion to order $1/m^2$, and to be related by a redefinition of the heavy quark field. We give a new, very straightforward proof that that the reparameterization invariance constraints apply to all orders in $\alpha_s$ under matching to full QCD and renormalization-group running, at least up to and including $O(1/m^2)$.
2006.07717
Christoph Peter Hofmann
Christoph P. Hofmann
Chiral Perturbation Theory Analysis of the Quark Condensate in a Magnetic Field
27 pages, 4 figures
Phys. Rev. D 102, 094010 (2020)
10.1103/PhysRevD.102.094010
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present two-loop results for the quark condensate in an external magnetic field within chiral perturbation theory using coordinate space techniques. At finite temperature, we explore the impact of the magnetic field on the pion-pion interaction in the quark condensate for arbitrary pion masses and derive the correct weak magnetic field expansion in the chiral limit. At zero temperature, we provide the complete two-loop representation for the vacuum energy density and the quark condensate.
[ { "created": "Sat, 13 Jun 2020 20:46:02 GMT", "version": "v1" } ]
2020-11-18
[ [ "Hofmann", "Christoph P.", "" ] ]
We present two-loop results for the quark condensate in an external magnetic field within chiral perturbation theory using coordinate space techniques. At finite temperature, we explore the impact of the magnetic field on the pion-pion interaction in the quark condensate for arbitrary pion masses and derive the correct weak magnetic field expansion in the chiral limit. At zero temperature, we provide the complete two-loop representation for the vacuum energy density and the quark condensate.
1111.3158
Marc Wagner
Falk Bruckmann, Simon Dinter, Ernst-Michael Ilgenfritz, Benjamin Maier, Michael Muller-Preussker, Marc Wagner
Confining dyon gas with finite-volume effects under control
23 pages, 4 figures; minor modifications
Phys.Rev.D85:034502,2012
10.1103/PhysRevD.85.034502
HU-EP-11/50; SFB/CPP-11-59; DESY 11-211
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As an approach to describe the long-range properties of non-Abelian gauge theories at non-zero temperature T < T_c, we consider a non-interacting ensemble of dyons (magnetic monopoles) with non-trivial holonomy. We show analytically, that the quark-antiquark free energy from the Polyakov loop correlator grows linearly with the distance, and how the string tension scales with the dyon density. In numerical treatments, the long-range tails of the dyon fields cause severe finite-volume effects. Therefore, we demonstrate the application of Ewald's summation method to this system. Finite-volume effects are shown to be under control, which is a crucial requirement for numerical studies of interacting dyon ensembles.
[ { "created": "Mon, 14 Nov 2011 09:53:00 GMT", "version": "v1" }, { "created": "Tue, 10 Jan 2012 15:56:23 GMT", "version": "v2" } ]
2012-02-16
[ [ "Bruckmann", "Falk", "" ], [ "Dinter", "Simon", "" ], [ "Ilgenfritz", "Ernst-Michael", "" ], [ "Maier", "Benjamin", "" ], [ "Muller-Preussker", "Michael", "" ], [ "Wagner", "Marc", "" ] ]
As an approach to describe the long-range properties of non-Abelian gauge theories at non-zero temperature T < T_c, we consider a non-interacting ensemble of dyons (magnetic monopoles) with non-trivial holonomy. We show analytically, that the quark-antiquark free energy from the Polyakov loop correlator grows linearly with the distance, and how the string tension scales with the dyon density. In numerical treatments, the long-range tails of the dyon fields cause severe finite-volume effects. Therefore, we demonstrate the application of Ewald's summation method to this system. Finite-volume effects are shown to be under control, which is a crucial requirement for numerical studies of interacting dyon ensembles.
hep-ph/0606199
Alvaro de Rujula
Arnon Dar and Alvaro De Rujula
A theory of Cosmic Rays
Updated to discuss recent data, mainly from Auger
Phys.Rept.466:179-241,2008
10.1016/j.physrep.2008.05.004
null
hep-ph astro-ph
null
We present a theory of non-solar cosmic rays (CRs) in which the bulk of their observed flux is due to a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the `knee(s)' and `ankle', and the CR composition and its variation with energy are all predicted in terms of very simple and completely `standard' physics. The source of CRs is extremely `economical': it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are `priors', that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a `unified view of high-energy astrophysics' --based on the `Cannonball' model of the relativistic ejecta of accreting black holes and neutron stars. The model has been extremely successful in predicting all the novel properties of Gamma Ray Bursts recently observed with help of the Swift satellite. If correct, this model is only lacking a satisfactory theoretical understanding of the `cannon' that emits the cannonballs in catastrophic processes of accretion.
[ { "created": "Mon, 19 Jun 2006 15:11:54 GMT", "version": "v1" }, { "created": "Wed, 7 May 2008 13:39:29 GMT", "version": "v2" } ]
2009-09-29
[ [ "Dar", "Arnon", "" ], [ "De Rujula", "Alvaro", "" ] ]
We present a theory of non-solar cosmic rays (CRs) in which the bulk of their observed flux is due to a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the `knee(s)' and `ankle', and the CR composition and its variation with energy are all predicted in terms of very simple and completely `standard' physics. The source of CRs is extremely `economical': it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are `priors', that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a `unified view of high-energy astrophysics' --based on the `Cannonball' model of the relativistic ejecta of accreting black holes and neutron stars. The model has been extremely successful in predicting all the novel properties of Gamma Ray Bursts recently observed with help of the Swift satellite. If correct, this model is only lacking a satisfactory theoretical understanding of the `cannon' that emits the cannonballs in catastrophic processes of accretion.
hep-ph/9403231
Randall J. Scalise
John C. Collins and Randall J. Scalise
The Renormalization of Composite Operators in Yang-Mills Theories Using General Covariant Gauge
52 pages, uuencoded compressed PostScript, PSU/TH/141. [Minor typo- graphical errors in the references and in Eqs. (A.5) and (A.7) corrected.]
Phys.Rev. D50 (1994) 4117-4136
10.1103/PhysRevD.50.4117
null
hep-ph hep-th
null
Essential to QCD applications of the operator product expansion, etc., is a knowledge of those operators that mix with gauge-invariant operators. A standard theorem asserts that the renormalization matrix is triangular: Gauge-invariant operators have `alien' gauge-variant operators among their counterterms, but, with a suitably chosen basis, the necessary alien operators have only themselves as counterterms. Moreover, the alien operators are supposed to vanish in physical matrix elements. A recent calculation by Hamberg and van Neerven apparently contradicts these results. By explicit calculations with the energy-momentum tensor, we show that the problems arise because of subtle infra-red singularities that appear when gluonic matrix elements are taken on-shell at zero momentum transfer. Keywords: twist-two covariant gluon operator, finite part, mixing, non-abelian, anomalous dimension, Ward identity, BRST, modified LSZ reduction, Dixon, Taylor, Joglekar, Lee.
[ { "created": "Fri, 4 Mar 1994 16:37:33 GMT", "version": "v1" }, { "created": "Mon, 21 Mar 1994 21:08:16 GMT", "version": "v2" } ]
2009-10-28
[ [ "Collins", "John C.", "" ], [ "Scalise", "Randall J.", "" ] ]
Essential to QCD applications of the operator product expansion, etc., is a knowledge of those operators that mix with gauge-invariant operators. A standard theorem asserts that the renormalization matrix is triangular: Gauge-invariant operators have `alien' gauge-variant operators among their counterterms, but, with a suitably chosen basis, the necessary alien operators have only themselves as counterterms. Moreover, the alien operators are supposed to vanish in physical matrix elements. A recent calculation by Hamberg and van Neerven apparently contradicts these results. By explicit calculations with the energy-momentum tensor, we show that the problems arise because of subtle infra-red singularities that appear when gluonic matrix elements are taken on-shell at zero momentum transfer. Keywords: twist-two covariant gluon operator, finite part, mixing, non-abelian, anomalous dimension, Ward identity, BRST, modified LSZ reduction, Dixon, Taylor, Joglekar, Lee.
1702.02924
Jusak Tandean
Chia-Feng Chang, Xiao-Gang He, Jusak Tandean
Two-Higgs-Doublet-Portal Dark-Matter Models in Light of Direct Search and LHC Data
26 pages, 10 figures, somewhat expanded, references added, main conclusions unchanged, matches publication
JHEP 04 (2017) 107
10.1007/JHEP04(2017)107
NCTS-PH/1707
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore simple Higgs-portal models of dark matter (DM) with spin 1/2, 3/2, and 1, respectively, applying to them constraints from the LUX and PandaX-II direct detection experiments and from LHC measurements on the 125-GeV Higgs boson. With only one Higgs doublet, we find that the spin-1/2 DM having a purely scalar effective coupling to the doublet is viable only in a narrow range of mass near the Higgs pole, whereas the vector DM is still allowed if its mass is also close to the Higgs pole or exceeds 1.4 TeV, both in line with earlier analyses. Moreover, the spin-3/2 DM is in a roughly similar situation to the spin-1/2 DM, but has surviving parameter space which is even more restricted. We also consider the two-Higgs-doublet extension of each of the preceding models, assuming that the expanded Yukawa sector is that of the two-Higgs-doublet model of type II. We show that in these two-Higgs-doublet-portal models significant portions of the DM mass regions excluded in the simplest scenarios by direct search bounds can be reclaimed due to suppression of the effective DM interactions with nucleons at some ratios of the $CP$-even Higgs bosons' couplings to the up and down quarks. The regained parameter space contains areas which can yield a DM-nucleon scattering cross-section that is far less than its current experimental limit or even goes below the neutrino-background floor.
[ { "created": "Thu, 9 Feb 2017 18:15:28 GMT", "version": "v1" }, { "created": "Thu, 20 Apr 2017 13:32:18 GMT", "version": "v2" } ]
2017-04-21
[ [ "Chang", "Chia-Feng", "" ], [ "He", "Xiao-Gang", "" ], [ "Tandean", "Jusak", "" ] ]
We explore simple Higgs-portal models of dark matter (DM) with spin 1/2, 3/2, and 1, respectively, applying to them constraints from the LUX and PandaX-II direct detection experiments and from LHC measurements on the 125-GeV Higgs boson. With only one Higgs doublet, we find that the spin-1/2 DM having a purely scalar effective coupling to the doublet is viable only in a narrow range of mass near the Higgs pole, whereas the vector DM is still allowed if its mass is also close to the Higgs pole or exceeds 1.4 TeV, both in line with earlier analyses. Moreover, the spin-3/2 DM is in a roughly similar situation to the spin-1/2 DM, but has surviving parameter space which is even more restricted. We also consider the two-Higgs-doublet extension of each of the preceding models, assuming that the expanded Yukawa sector is that of the two-Higgs-doublet model of type II. We show that in these two-Higgs-doublet-portal models significant portions of the DM mass regions excluded in the simplest scenarios by direct search bounds can be reclaimed due to suppression of the effective DM interactions with nucleons at some ratios of the $CP$-even Higgs bosons' couplings to the up and down quarks. The regained parameter space contains areas which can yield a DM-nucleon scattering cross-section that is far less than its current experimental limit or even goes below the neutrino-background floor.
1305.3493
Pere Masjuan
Pere Masjuan, Enrique Ruiz Arriola, and Wojciech Broniowski
Reply to "Comment on 'Systematics of radial and angular-momentum Regge trajectories of light non-strange qqbar-states' "
3 pages, 2 figures. Version to appear in Phys.Rev. D
null
10.1103/PhysRevD.87.118502
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In his Comment, D. Bugg argues against our usage of the PDG collection of light non-strange states together with the half-width rule to analyze the linearity of radial and angular-moment Regge trajectories in the large-N_c limit. After taking into account his observations on our choice of data, the radial Regge trajectories are again analyzed. We still find that our conclusion on the lack of universality between radial- and angular-momentum Regge trajectories is valid.
[ { "created": "Wed, 15 May 2013 14:28:43 GMT", "version": "v1" } ]
2015-06-15
[ [ "Masjuan", "Pere", "" ], [ "Arriola", "Enrique Ruiz", "" ], [ "Broniowski", "Wojciech", "" ] ]
In his Comment, D. Bugg argues against our usage of the PDG collection of light non-strange states together with the half-width rule to analyze the linearity of radial and angular-moment Regge trajectories in the large-N_c limit. After taking into account his observations on our choice of data, the radial Regge trajectories are again analyzed. We still find that our conclusion on the lack of universality between radial- and angular-momentum Regge trajectories is valid.
2308.06389
Stephen Mrenna
Stefano Frixione, Simone Amoroso, Stephen Mrenna
Matrix element corrections in the Pythia8 parton shower in the context of matched simulations at next-to-leading order
16 pages, 9 figures
null
null
FERMILAB-PUB-23-413-CSAID
hep-ph
http://creativecommons.org/licenses/by/4.0/
We discuss the role of matrix element corrections (MEC) to parton showers in the context of MC@NLO-type matchings for processes that feature unstable resonances, where MEC are liable to result in double-counting issues, and are thus generally not employed. By working with Pythia8, we show that disabling all MEC is actually unnecessary in computations based on the narrow-width approximation, and we propose alternative MEC settings which, while still avoiding double counting, allow one to include hard-recoil effects in the simulations of resonance decays. We illustrate our findings by considering top-antitop production at the LHC, and by comparing MadGraph_aMC@NLO predictions with those of POWHEG-BOX and standalone Pythia8.
[ { "created": "Fri, 11 Aug 2023 21:11:13 GMT", "version": "v1" } ]
2023-08-15
[ [ "Frixione", "Stefano", "" ], [ "Amoroso", "Simone", "" ], [ "Mrenna", "Stephen", "" ] ]
We discuss the role of matrix element corrections (MEC) to parton showers in the context of MC@NLO-type matchings for processes that feature unstable resonances, where MEC are liable to result in double-counting issues, and are thus generally not employed. By working with Pythia8, we show that disabling all MEC is actually unnecessary in computations based on the narrow-width approximation, and we propose alternative MEC settings which, while still avoiding double counting, allow one to include hard-recoil effects in the simulations of resonance decays. We illustrate our findings by considering top-antitop production at the LHC, and by comparing MadGraph_aMC@NLO predictions with those of POWHEG-BOX and standalone Pythia8.
hep-ph/9706413
null
Sergio Scopetta and Vicente Vento (Valencia)
A quark model analysis of the transversity distribution
10 pages, Latex; 4 postscript figures generated by epsf.sty included in submission
Phys.Lett. B424 (1998) 25-32
10.1016/S0370-2693(98)00212-3
FTUV 97-29; IFIC 97-29
hep-ph
null
The feasibility of measuring chiral-odd parton distribution functions in polarized Drell-Yan and semi-inclusive experiments has renewed theoretical interest in their study. Models of hadron structure have proven succesful in describing the gross features of the chiral-even structure functions. Similar expectations support our study of the transversity parton distributions in the Isgur-Karl and MIT bag models. We confirm the diverse low x behavior of the transversity and spin structure functions at the experimental scale and show that it is fundamentally a consequence of the different behavior under evolution of these functions. The inequalities of Soffer establish constraints between data and model calculations of the chiral-odd transversity function. The approximate compatibility of our model calculations with these constraints conferes credibility to our estimates.
[ { "created": "Thu, 19 Jun 1997 09:27:38 GMT", "version": "v1" } ]
2009-10-30
[ [ "Scopetta", "Sergio", "", "Valencia" ], [ "Vento", "Vicente", "", "Valencia" ] ]
The feasibility of measuring chiral-odd parton distribution functions in polarized Drell-Yan and semi-inclusive experiments has renewed theoretical interest in their study. Models of hadron structure have proven succesful in describing the gross features of the chiral-even structure functions. Similar expectations support our study of the transversity parton distributions in the Isgur-Karl and MIT bag models. We confirm the diverse low x behavior of the transversity and spin structure functions at the experimental scale and show that it is fundamentally a consequence of the different behavior under evolution of these functions. The inequalities of Soffer establish constraints between data and model calculations of the chiral-odd transversity function. The approximate compatibility of our model calculations with these constraints conferes credibility to our estimates.
hep-ph/0209033
Gubankova
E. Gubankova
Diquark interaction and gaps for color superconductivity
3 pages, Lattice2002(nonzerot), talk presented at 20th International Symposium on Lattice Field Theory (LATTICE2002), Boston, Massachusetts, 24-29 June 2002
null
10.1016/S0920-5632(03)01621-9
null
hep-ph
null
Using flow equations, we derive an effective quark-quark interaction and obtain the coupled set of gap equations for the condensates of the CFL phase of massless $N_f=3$ dense QCD. The formalism developed here enables one to consider more general case of nonzero $s$-quark mass.
[ { "created": "Tue, 3 Sep 2002 21:56:56 GMT", "version": "v1" } ]
2009-11-07
[ [ "Gubankova", "E.", "" ] ]
Using flow equations, we derive an effective quark-quark interaction and obtain the coupled set of gap equations for the condensates of the CFL phase of massless $N_f=3$ dense QCD. The formalism developed here enables one to consider more general case of nonzero $s$-quark mass.
1507.06522
R. Sekhar Chivukula
R. Sekhar Chivukula, Elizabeth H. Simmons, and Natascia Vignaroli
The Jet Energy Profile: A BSM Analysis Tool
15 pages, contribution to Sakata Memorial KMI Workshop on "Origin of Mass and Strong Coupling Gauge Theories (SCGT15)", 3-6 March 2015, Nagoya University
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new heavy di-jet resonance could be discovered at the 14 TeV LHC. In this talk we present a strategy to reveal the nature of such a particle; in particular to discern whether it is a quark-antiquark (q qbar), quark-gluon (qg), or gluon-gluon (gg) resonance. The strategy is based on the study of the energy profiles of the two leading jets in the di-jet channel. Including statistical uncertainties in the signal and the QCD backgrounds, we show that one can distinguish between gg, qg, and q bar resonances; an evaluation of systematic uncertainties in the measurement of the jet energy profile will require a detailed detector study once sufficient 14 TeV di-jet data is in hand.
[ { "created": "Thu, 23 Jul 2015 15:04:42 GMT", "version": "v1" } ]
2015-07-24
[ [ "Chivukula", "R. Sekhar", "" ], [ "Simmons", "Elizabeth H.", "" ], [ "Vignaroli", "Natascia", "" ] ]
A new heavy di-jet resonance could be discovered at the 14 TeV LHC. In this talk we present a strategy to reveal the nature of such a particle; in particular to discern whether it is a quark-antiquark (q qbar), quark-gluon (qg), or gluon-gluon (gg) resonance. The strategy is based on the study of the energy profiles of the two leading jets in the di-jet channel. Including statistical uncertainties in the signal and the QCD backgrounds, we show that one can distinguish between gg, qg, and q bar resonances; an evaluation of systematic uncertainties in the measurement of the jet energy profile will require a detailed detector study once sufficient 14 TeV di-jet data is in hand.
hep-ph/0411353
Eiji Nakano
E. Nakano, T. Suzuki and H. Yabu
Colour-SU(3)-Ginzburg-Landau Effective Potential for Order Parameter with $3 \times 3$ Symmetry II : A Complete Classification of Phase Diagrams
14 pages, 11 figures
null
null
null
hep-ph
null
Phase structure is studied for a system which has symmetry group SU(3) and is described by SU(3)-${\bf 3 \times 3}$ order parameter. The study is rested on SU(3)-Ginzburg-Landau effective potential constructed as a preliminary.
[ { "created": "Sat, 27 Nov 2004 07:19:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nakano", "E.", "" ], [ "Suzuki", "T.", "" ], [ "Yabu", "H.", "" ] ]
Phase structure is studied for a system which has symmetry group SU(3) and is described by SU(3)-${\bf 3 \times 3}$ order parameter. The study is rested on SU(3)-Ginzburg-Landau effective potential constructed as a preliminary.
1901.07399
Kazem Azizi
N. Er, K. Azizi
Fate of the doubly heavy spin$-3/2$ baryons in a dense medium
24 Pages, 5 Figures and 3 Tables
Phys. Rev. D 99, 074012 (2019)
10.1103/PhysRevD.99.074012
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the behavior of the doubly heavy spin$-3/2$ baryons in cold nuclear matter. In particular, we study the variations of the spectroscopic parameters of the ground state $\Xi^*_{QQ'}$ and $\Omega^*_{QQ'}$ particles, with $ Q $ and $ Q' $ being $b $ or $ c $ quark, with respect to the changes in the density of the nuclear medium. We find the shifts on the parameters under question at saturation medium density compared to their vacuum values. It is observed that the parameters of the $\Xi^*_{QQ'}$ states containing two heavy quarks and one up or down quark are affected by the medium, considerably. The parameters of the $\Omega^*_{QQ'}$ states containing two heavy quarks and one strange quark, however, do not show any sensitivity to the density of the cold nuclear medium. We also discuss the variations of the vector self-energy at each channel with respect to the changes in the density. The negative shifts in the mass of $\Xi^*_{QQ'}$ states due to nucleons in the medium can be used to study the doubly heavy baryons' interactions with the nucleons. The results obtained can also be used in analyses of the results of the future in-medium experiments.
[ { "created": "Tue, 22 Jan 2019 15:12:23 GMT", "version": "v1" }, { "created": "Fri, 1 Feb 2019 12:58:25 GMT", "version": "v2" }, { "created": "Wed, 27 Mar 2019 07:29:03 GMT", "version": "v3" }, { "created": "Thu, 4 Apr 2019 11:18:08 GMT", "version": "v4" } ]
2019-04-17
[ [ "Er", "N.", "" ], [ "Azizi", "K.", "" ] ]
We investigate the behavior of the doubly heavy spin$-3/2$ baryons in cold nuclear matter. In particular, we study the variations of the spectroscopic parameters of the ground state $\Xi^*_{QQ'}$ and $\Omega^*_{QQ'}$ particles, with $ Q $ and $ Q' $ being $b $ or $ c $ quark, with respect to the changes in the density of the nuclear medium. We find the shifts on the parameters under question at saturation medium density compared to their vacuum values. It is observed that the parameters of the $\Xi^*_{QQ'}$ states containing two heavy quarks and one up or down quark are affected by the medium, considerably. The parameters of the $\Omega^*_{QQ'}$ states containing two heavy quarks and one strange quark, however, do not show any sensitivity to the density of the cold nuclear medium. We also discuss the variations of the vector self-energy at each channel with respect to the changes in the density. The negative shifts in the mass of $\Xi^*_{QQ'}$ states due to nucleons in the medium can be used to study the doubly heavy baryons' interactions with the nucleons. The results obtained can also be used in analyses of the results of the future in-medium experiments.
hep-ph/9602314
null
M. Kacir, M. Prakash and I. Zahed
Hadrons and QCD Instantons: a Bosonized View
59 pages LaTex, 42 postscript file figures
Acta Phys.Polon. B30 (1999) 287-348
null
SUNY-NTG-95-05
hep-ph
null
In a dilute system of instantons and antiinstantons, the U$_{\rm A}$(1) and scale anomalies are shown to be directly related to the bulk susceptibility and compressibility of the system. Using $1/N_c$ (where $N_c$ is the number of colors) as a book-keeping argument, mesonic, baryonic and gluonic correlators are worked out in p-space and Fourier transformed to x-space for a comparison with recently simulated correlators. The results are in overall agreement with simulations and lattice calculations, for distances up to 1.5 fm, despite the fact that some channels lack the necessary physical singularities. We analyze various space-like form factors of the nucleon and show that they are amenable to constituent quark form factors to leading order in $1/N_c$. Issues related to the lack of confinement in the model and its consequence on the various correlation functions and form factors are also discussed.
[ { "created": "Wed, 14 Feb 1996 20:34:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kacir", "M.", "" ], [ "Prakash", "M.", "" ], [ "Zahed", "I.", "" ] ]
In a dilute system of instantons and antiinstantons, the U$_{\rm A}$(1) and scale anomalies are shown to be directly related to the bulk susceptibility and compressibility of the system. Using $1/N_c$ (where $N_c$ is the number of colors) as a book-keeping argument, mesonic, baryonic and gluonic correlators are worked out in p-space and Fourier transformed to x-space for a comparison with recently simulated correlators. The results are in overall agreement with simulations and lattice calculations, for distances up to 1.5 fm, despite the fact that some channels lack the necessary physical singularities. We analyze various space-like form factors of the nucleon and show that they are amenable to constituent quark form factors to leading order in $1/N_c$. Issues related to the lack of confinement in the model and its consequence on the various correlation functions and form factors are also discussed.
1509.06436
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the ${\frac{1}{2}}^{\pm}$ pentaquark states in the diquark-diquark-antiquark model with QCD sum rules
34 pages, 16 figures. arXiv admin note: substantial text overlap with arXiv:1508.04189
Eur.Phys.J.C76 (2016) 142
10.1140/epjc/s10052-016-3983-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we construct both the axialvector-diquark-axialvector-diquark-antiquark type and axialvector-diquark-scalar-diquark-antiquark type interpolating currents, then calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the masses and pole residues of the $J^P={\frac{1}{2}}^\pm$ hidden-charm pentaquark states with the QCD sum rules in a systematic way. In calculations, we use the formula $\mu=\sqrt{M^2_{P}-(2{\mathbb{M}}_c)^2}$ to determine the energy scales of the QCD spectral densities. We take into account the $SU(3)$ breaking effects of the light quarks, and obtain the masses of the hidden charm pentaquark states with the strangeness $S=0,\,-1,\,-2,\,-3$, which can be confronted with the experimental data in the future.
[ { "created": "Tue, 22 Sep 2015 00:55:07 GMT", "version": "v1" }, { "created": "Tue, 22 Dec 2015 02:16:19 GMT", "version": "v2" }, { "created": "Tue, 16 Feb 2016 03:30:25 GMT", "version": "v3" } ]
2016-03-16
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we construct both the axialvector-diquark-axialvector-diquark-antiquark type and axialvector-diquark-scalar-diquark-antiquark type interpolating currents, then calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the masses and pole residues of the $J^P={\frac{1}{2}}^\pm$ hidden-charm pentaquark states with the QCD sum rules in a systematic way. In calculations, we use the formula $\mu=\sqrt{M^2_{P}-(2{\mathbb{M}}_c)^2}$ to determine the energy scales of the QCD spectral densities. We take into account the $SU(3)$ breaking effects of the light quarks, and obtain the masses of the hidden charm pentaquark states with the strangeness $S=0,\,-1,\,-2,\,-3$, which can be confronted with the experimental data in the future.
2308.03849
Shakeel Ur Rahaman
Joydeep Chakrabortty, Shakeel Ur Rahaman, and Kaanapuli Ramkumar
One-loop Effective Action up to Dimension Eight: Integrating out Heavy Fermion(s)
1 Table, 42 pages
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We present the universal one-loop effective action up to dimension eight after integrating out heavy fermion(s) using the Heat-Kernel method. We have discussed how the Dirac operator being a weak elliptic operator, the fermionic operator still can be written in the form of a strong elliptic one such that the Heat-Kernel coefficients can be used to compute the fermionic effective action. This action captures the footprint of both the CP conserving as well as violating UV interactions. As it does not rely on the specific forms of either UV or low energy theories, can be applicable for a very generic action. Our result encapsulates the effects of heavy fermion loops only.
[ { "created": "Mon, 7 Aug 2023 18:01:21 GMT", "version": "v1" } ]
2023-08-09
[ [ "Chakrabortty", "Joydeep", "" ], [ "Rahaman", "Shakeel Ur", "" ], [ "Ramkumar", "Kaanapuli", "" ] ]
We present the universal one-loop effective action up to dimension eight after integrating out heavy fermion(s) using the Heat-Kernel method. We have discussed how the Dirac operator being a weak elliptic operator, the fermionic operator still can be written in the form of a strong elliptic one such that the Heat-Kernel coefficients can be used to compute the fermionic effective action. This action captures the footprint of both the CP conserving as well as violating UV interactions. As it does not rely on the specific forms of either UV or low energy theories, can be applicable for a very generic action. Our result encapsulates the effects of heavy fermion loops only.
1710.09376
Claudio Muselli
Claudio Muselli
Double Differential High Energy Resummation
25 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study a general framework to perform leading log high energy resummation with complete dependence from the rapidity and the transverse momentum of the studied system. As an application, high energy resummed expression for the Higgs boson production in the effective field theory framework will be derived. Explicit result for this process will be cross-checked against fixed order evaluations up to NNLO. Consistency with known high energy resummation for single differential rapidity or transverse momentum distribution, as well as for inclusive cross section, will also be shown.
[ { "created": "Wed, 25 Oct 2017 18:00:00 GMT", "version": "v1" } ]
2017-10-27
[ [ "Muselli", "Claudio", "" ] ]
In this paper we study a general framework to perform leading log high energy resummation with complete dependence from the rapidity and the transverse momentum of the studied system. As an application, high energy resummed expression for the Higgs boson production in the effective field theory framework will be derived. Explicit result for this process will be cross-checked against fixed order evaluations up to NNLO. Consistency with known high energy resummation for single differential rapidity or transverse momentum distribution, as well as for inclusive cross section, will also be shown.
hep-ph/9505230
Eric Laenen
E. Laenen and S. Riemersma
Charm Production in Deep-Inelastic $e\gamma$ Scattering To Next-To-Leading Order in QCD
7 pages Latex, with 2 eps figs., uuencoded
Z.Phys. C75 (1997) 539-554
null
CERN-TH/95-103, SMU HEP 95 02
hep-ph
null
We discuss the calculation of $F_2^{\gamma}({\rm charm})$ to next-to-leading order (NLO) in QCD, including contributions from both hadronlike and pointlike photons. We show that the former dominates strongly below $x\simeq 0.01$, and the latter above this value. This fact makes $F_2^{\gamma}({\rm charm})$ for $x \geq 0.01$ calculable, whereas for $x \leq 0.01$ it serves to constrain the small-$x$ gluon density in the photon. Both ranges in $x$ are accessible at LEP2. Theoretical uncertainties are well under control. We present rates for single-tag events for the process for $e^+e^- \rightarrow e^+e^- c X$ for LEP2. Although these event rates are small, we believe a measurement of $F_2^{\gamma}({\rm charm})$ is feasible.
[ { "created": "Thu, 4 May 1995 11:59:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Laenen", "E.", "" ], [ "Riemersma", "S.", "" ] ]
We discuss the calculation of $F_2^{\gamma}({\rm charm})$ to next-to-leading order (NLO) in QCD, including contributions from both hadronlike and pointlike photons. We show that the former dominates strongly below $x\simeq 0.01$, and the latter above this value. This fact makes $F_2^{\gamma}({\rm charm})$ for $x \geq 0.01$ calculable, whereas for $x \leq 0.01$ it serves to constrain the small-$x$ gluon density in the photon. Both ranges in $x$ are accessible at LEP2. Theoretical uncertainties are well under control. We present rates for single-tag events for the process for $e^+e^- \rightarrow e^+e^- c X$ for LEP2. Although these event rates are small, we believe a measurement of $F_2^{\gamma}({\rm charm})$ is feasible.
hep-ph/0311260
Comelli Denis
P. Ciafaloni, D. Comelli, A. Vergine
Sudakov Electroweak effects in transversely polarized beams
5 pages,4 figures
JHEP 0407 (2004) 039
10.1088/1126-6708/2004/07/039
null
hep-ph
null
We study Standard Model electroweak radiative corrections for fully inclusive observables with polarized fermionic beams. Our calculations are relevant in view of the possibility for Next Generation Linear colliders of having transversely and/or longitudinally polarized beams. The case of initial transverse polarization is particularly interesting because of the interplay of infrared/collinear logarithms of different origins, related both to the nonabelian SU(2) and abelian U(1) sectors. The Standard model effects turn out to be in the 10% range at the TeV scale, therefore particularly relevant in order to disentangle possible New Physics effects.
[ { "created": "Thu, 20 Nov 2003 15:45:45 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ciafaloni", "P.", "" ], [ "Comelli", "D.", "" ], [ "Vergine", "A.", "" ] ]
We study Standard Model electroweak radiative corrections for fully inclusive observables with polarized fermionic beams. Our calculations are relevant in view of the possibility for Next Generation Linear colliders of having transversely and/or longitudinally polarized beams. The case of initial transverse polarization is particularly interesting because of the interplay of infrared/collinear logarithms of different origins, related both to the nonabelian SU(2) and abelian U(1) sectors. The Standard model effects turn out to be in the 10% range at the TeV scale, therefore particularly relevant in order to disentangle possible New Physics effects.
0902.3756
Adrian Palcu
Adrian Palcu
Electro-weak $SU(4)_L\otimes U(1)_Y$ models without exotic electric charges
14 pages, 2 Tables, no figures
Int.J.Mod.Phys.A24:4923-4938,2009
10.1142/S0217751X09046011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For the particular class of \textbf{$SU(4)_{L}\otimes U(1)_{Y}$} electro-weak models without exotic electric charges, some plausible phenomenological predictions - such as the boson mass spectrum and charges of all the fermions involved therein - are made by using the algebraical approach of the exactly solving method for gauge models with high symmetries. Along with the one-parameter resulting mass scale (to be confirmed at TeV scale in LHC, LEP, CDF and other high energy experiments) our approach predicts the exact expressions of the charges (both electric and neutral) in the fermion sector, while all the Standard Model phenomenology is naturally recovered.
[ { "created": "Sat, 21 Feb 2009 20:54:13 GMT", "version": "v1" } ]
2014-11-18
[ [ "Palcu", "Adrian", "" ] ]
For the particular class of \textbf{$SU(4)_{L}\otimes U(1)_{Y}$} electro-weak models without exotic electric charges, some plausible phenomenological predictions - such as the boson mass spectrum and charges of all the fermions involved therein - are made by using the algebraical approach of the exactly solving method for gauge models with high symmetries. Along with the one-parameter resulting mass scale (to be confirmed at TeV scale in LHC, LEP, CDF and other high energy experiments) our approach predicts the exact expressions of the charges (both electric and neutral) in the fermion sector, while all the Standard Model phenomenology is naturally recovered.
hep-ph/0106230
Bachir Moussallam
B. Ananthanarayan (IIs, Bangalore), P. B\"uttiker (J\"ulich), B. Moussallam (IPN, Orsay)
$\pi K$ sum rules and the SU(3) chiral expansion
28 pages, 7 figures [v1: small corrections and improvements]
Eur.Phys.J.C22:133-148,2001
10.1007/s100520100766
IISc-CTS-12/01, FZJ-IKP(Th)-2001-10, IPNO-DR 01-014
hep-ph
null
A recently proposed set of sum rules, based on the pion-Kaon scattering amplitudes and their crossing-symmetric conjugates are analysed in detail. A key role is played by the $l=0$ $\pi\pi\to K\overline K$ amplitude which requires an extrapolation to be performed. It is shown how this is tightly constrained from analyticity, chiral counting and the available experimental data, and its stability is tested. A re-evaluation of the $O(p^4)$ chiral couplings $L_1$, $L_2$, $L_3$ is obtained, as well as a new evaluation of the large $N_c$ suppressed coupling $L_4$.
[ { "created": "Thu, 21 Jun 2001 09:54:16 GMT", "version": "v1" }, { "created": "Tue, 31 Jul 2001 09:58:11 GMT", "version": "v2" } ]
2009-01-07
[ [ "Ananthanarayan", "B.", "", "IIs, Bangalore" ], [ "Büttiker", "P.", "", "Jülich" ], [ "Moussallam", "B.", "", "IPN, Orsay" ] ]
A recently proposed set of sum rules, based on the pion-Kaon scattering amplitudes and their crossing-symmetric conjugates are analysed in detail. A key role is played by the $l=0$ $\pi\pi\to K\overline K$ amplitude which requires an extrapolation to be performed. It is shown how this is tightly constrained from analyticity, chiral counting and the available experimental data, and its stability is tested. A re-evaluation of the $O(p^4)$ chiral couplings $L_1$, $L_2$, $L_3$ is obtained, as well as a new evaluation of the large $N_c$ suppressed coupling $L_4$.
1711.08469
Mikko Laine
J. Ghiglieri, M. Laine
GeV-scale hot sterile neutrino oscillations: a numerical solution
26 pages. v2: clarifications and references added
JHEP 1802 (2018) 078
10.1007/JHEP02(2018)078
CERN-TH-2018-022
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scenario of baryogenesis through GeV-scale sterile neutrino oscillations is governed by non-linear differential equations for the time evolution of a sterile neutrino density matrix and Standard Model lepton and baryon asymmetries. By employing up-to-date rate coefficients and a non-perturbatively estimated Chern-Simons diffusion rate, we present a numerical solution of this system, incorporating the full momentum and helicity dependences of the density matrix. The density matrix deviates significantly from kinetic equilibrium, with the IR modes equilibrating much faster than the UV modes. For equivalent input parameters, our final results differ moderately (~50%) from recent benchmarks in the literature. The possibility of producing an observable baryon asymmetry is nevertheless confirmed. We illustrate the dependence of the baryon asymmetry on the sterile neutrino mass splitting and on the CP-violating phase measurable in active neutrino oscillation experiments.
[ { "created": "Wed, 22 Nov 2017 19:00:09 GMT", "version": "v1" }, { "created": "Fri, 16 Feb 2018 08:31:10 GMT", "version": "v2" } ]
2018-02-19
[ [ "Ghiglieri", "J.", "" ], [ "Laine", "M.", "" ] ]
The scenario of baryogenesis through GeV-scale sterile neutrino oscillations is governed by non-linear differential equations for the time evolution of a sterile neutrino density matrix and Standard Model lepton and baryon asymmetries. By employing up-to-date rate coefficients and a non-perturbatively estimated Chern-Simons diffusion rate, we present a numerical solution of this system, incorporating the full momentum and helicity dependences of the density matrix. The density matrix deviates significantly from kinetic equilibrium, with the IR modes equilibrating much faster than the UV modes. For equivalent input parameters, our final results differ moderately (~50%) from recent benchmarks in the literature. The possibility of producing an observable baryon asymmetry is nevertheless confirmed. We illustrate the dependence of the baryon asymmetry on the sterile neutrino mass splitting and on the CP-violating phase measurable in active neutrino oscillation experiments.
1812.11533
Soeren Schlichting
Y. Mehtar-Tani, S. Schlichting
Jet fragmentation in a QCD medium: Universal quark/gluon ration and Wave turbulence
Proceedings of the Hard Probes 2018 conference, 30 Sept. - 5 Oct. 2018, Aix-les-Bains, France; 4 pages, 2 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the evolution of a jet shower due to medium induced splittings in the deep LPM regime. Due to the characteristic energy dependence of the formation time $t_{\rm form}(\omega)= \sqrt{\omega /\hat{\bar{q}}}$, the radiative break-up process exhibits turbulent characteristics, allowing for analytic predictions of various inclusive properties of the medium induced cascade in an inertial range of energies $T \ll \omega \ll E$, where $E$ is the energy of the jet and $T$ is the temperature of the medium.
[ { "created": "Sun, 30 Dec 2018 13:44:55 GMT", "version": "v1" } ]
2019-01-01
[ [ "Mehtar-Tani", "Y.", "" ], [ "Schlichting", "S.", "" ] ]
We calculate the evolution of a jet shower due to medium induced splittings in the deep LPM regime. Due to the characteristic energy dependence of the formation time $t_{\rm form}(\omega)= \sqrt{\omega /\hat{\bar{q}}}$, the radiative break-up process exhibits turbulent characteristics, allowing for analytic predictions of various inclusive properties of the medium induced cascade in an inertial range of energies $T \ll \omega \ll E$, where $E$ is the energy of the jet and $T$ is the temperature of the medium.
hep-ph/0006003
Chi-Tau Yan
Chao-Shang Huang, Chun Liu, Chi-Tau Yan (ITP, Beijing)
1/m_Q Corrections to the Heavy-to-Light-Vector Transitions in the HQET
RevTeX, 9 pages, no figures
Phys.Rev. D62 (2000) 054019
10.1103/PhysRevD.62.054019
null
hep-ph
null
Within the HQET, the heavy to light vector meson transitions are systematically analyzed to the order of 1/m_Q. Besides the four universal functions at the leading order, there are twenty-two independent universal form factors at the order of 1/m_Q. Both the semileptonic decay B->\rho which is relevant to the |V_{ub}| extraction, and the penguin induced decay B -> K^* which is important to new physics discovering, depend on these form factors. Phenomenological implications are discussed.
[ { "created": "Thu, 1 Jun 2000 07:55:16 GMT", "version": "v1" } ]
2009-10-31
[ [ "Huang", "Chao-Shang", "", "ITP, Beijing" ], [ "Liu", "Chun", "", "ITP, Beijing" ], [ "Yan", "Chi-Tau", "", "ITP, Beijing" ] ]
Within the HQET, the heavy to light vector meson transitions are systematically analyzed to the order of 1/m_Q. Besides the four universal functions at the leading order, there are twenty-two independent universal form factors at the order of 1/m_Q. Both the semileptonic decay B->\rho which is relevant to the |V_{ub}| extraction, and the penguin induced decay B -> K^* which is important to new physics discovering, depend on these form factors. Phenomenological implications are discussed.
0901.2941
Wim de Boer
W. de Boer (Univ. of Karlsruhe, Germany)
Indirect Dark Matter Signals from EGRET and PAMELA compared
10 pages, 4 figures, Contributed paper to the Eighth UCLA Symposium: Sources and Detection of Dark Matter and Dark Energy in the Universe
null
10.1063/1.3232175
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the features expected from DMA. The new precise measurements of the antiproton and positron fractions from PAMELA are compared with the EGRET excess. It is shown that the charged particles are strongly dependent on the propagation model used. The usual propagation models with isotropic propagation models are incompatible with the recently observed convection in our Galaxy. Convection leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in the halo to outer space. It is shown that such anisotropic propagation models including convection prefer a contribution from DMA for the antiprotons, but the rise in the positron fraction, as observed by PAMELA, is incompatible with DMA, if compared with the EGRET excess. A rise in the positron/electron ratio is expected, if the observed rise in the proton/electron ratio is carefully fitted in a propagation model, although the rise is slightly larger than expected, so additional local sources may contribute as well within the limited accuracy of the data.
[ { "created": "Mon, 19 Jan 2009 21:47:38 GMT", "version": "v1" } ]
2015-05-13
[ [ "de Boer", "W.", "", "Univ. of Karlsruhe, Germany" ] ]
Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the features expected from DMA. The new precise measurements of the antiproton and positron fractions from PAMELA are compared with the EGRET excess. It is shown that the charged particles are strongly dependent on the propagation model used. The usual propagation models with isotropic propagation models are incompatible with the recently observed convection in our Galaxy. Convection leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in the halo to outer space. It is shown that such anisotropic propagation models including convection prefer a contribution from DMA for the antiprotons, but the rise in the positron fraction, as observed by PAMELA, is incompatible with DMA, if compared with the EGRET excess. A rise in the positron/electron ratio is expected, if the observed rise in the proton/electron ratio is carefully fitted in a propagation model, although the rise is slightly larger than expected, so additional local sources may contribute as well within the limited accuracy of the data.
hep-ph/0307154
David Atwood
David Atwood, Amarjit Soni
Measurement of gamma at B Factories Using Inclusive D Decays
Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 (eConf C0304052). 4 pages LaTeX, 4 eps figures
ECONF C0304052:WG402,2003
null
null
hep-ph
null
We discuss the determination of the CKM phase gamma through the decay B- -> K- D0 and related processes. In particular, we consider the use of this methods when the D0 subsequently decays to an inclusive state. We emphasize that strong phase information obtained at a psi(3770) charm factory can provide additional information which will be helpful in determining gamma.
[ { "created": "Thu, 10 Jul 2003 20:26:14 GMT", "version": "v1" } ]
2010-11-23
[ [ "Atwood", "David", "" ], [ "Soni", "Amarjit", "" ] ]
We discuss the determination of the CKM phase gamma through the decay B- -> K- D0 and related processes. In particular, we consider the use of this methods when the D0 subsequently decays to an inclusive state. We emphasize that strong phase information obtained at a psi(3770) charm factory can provide additional information which will be helpful in determining gamma.
hep-ph/0110278
Robert Fleischer
Robert Fleischer (DESY Hamburg)
Extraction of gamma
12 pages, LaTeX, 1 figure. Invited talk given at the 9th International Symposium on Heavy Flavor Physics, Caltech, Pasadena, 10-13 September 2001. To appear in the Proceedings
AIP Conf.Proc.618:266-275,2002
10.1063/1.1478845
DESY 01-162
hep-ph
null
After a brief look at the well-known standard approaches to determine the angle gamma of the unitarity triangle, we focus on two kinds of strategies, employing $B\to\pi K$ modes, and U-spin-related B decays. Interesting "puzzles", which may already be indicated by the present B-factory data, are pointed out, and the importance of the extraction of hadronic parameters, which are provided by these strategies as by-products, is emphasized.
[ { "created": "Mon, 22 Oct 2001 09:36:39 GMT", "version": "v1" } ]
2010-11-23
[ [ "Fleischer", "Robert", "", "DESY Hamburg" ] ]
After a brief look at the well-known standard approaches to determine the angle gamma of the unitarity triangle, we focus on two kinds of strategies, employing $B\to\pi K$ modes, and U-spin-related B decays. Interesting "puzzles", which may already be indicated by the present B-factory data, are pointed out, and the importance of the extraction of hadronic parameters, which are provided by these strategies as by-products, is emphasized.
1505.05872
Jussi Virkaj\"arvi
Francesco Sannino, Jussi Virkaj\"arvi
First Order Electroweak Phase Transition from (Non)Conformal Extensions of the Standard Model
v3: Typos corrected from Eq. 70, results unchanged. v2: Few typos corrected and few comments added, match with the published version. 44 pages, 11 figures
Phys. Rev. D 92, 045015 (2015)
10.1103/PhysRevD.92.045015
CP3-Origins-2015-016 DNRF90
hep-ph astro-ph.CO hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse and compare the finite-temperature electroweak phase transition properties of classically (non)conformal extensions of the Standard Model. In the classically conformal scenarios the breaking of the electroweak symmetry is generated radiatively. The models feature new scalars coupled conformally to the Higgs sector as well as new fermions. We uncover the parameter space leading to a first order phase transition with(out) the Veltman conditions. We also discuss dark (matter) aspects of some of the models and compare with existing literature when appropriate. We observe that to accommodate both, a first order electroweak phase transition, and a phenomenologically viable dark matter candidate requires to go beyond the simplest extensions of the Standard Model. Furthermore these extensions must all feature new degrees of freedom that are naturally lighter than a TeV and therefore the associated models are testable at the upcoming Large Hadron Collider run two experiments.
[ { "created": "Thu, 21 May 2015 11:25:54 GMT", "version": "v1" }, { "created": "Thu, 27 Aug 2015 08:09:26 GMT", "version": "v2" }, { "created": "Tue, 10 Mar 2020 13:37:23 GMT", "version": "v3" } ]
2020-03-11
[ [ "Sannino", "Francesco", "" ], [ "Virkajärvi", "Jussi", "" ] ]
We analyse and compare the finite-temperature electroweak phase transition properties of classically (non)conformal extensions of the Standard Model. In the classically conformal scenarios the breaking of the electroweak symmetry is generated radiatively. The models feature new scalars coupled conformally to the Higgs sector as well as new fermions. We uncover the parameter space leading to a first order phase transition with(out) the Veltman conditions. We also discuss dark (matter) aspects of some of the models and compare with existing literature when appropriate. We observe that to accommodate both, a first order electroweak phase transition, and a phenomenologically viable dark matter candidate requires to go beyond the simplest extensions of the Standard Model. Furthermore these extensions must all feature new degrees of freedom that are naturally lighter than a TeV and therefore the associated models are testable at the upcoming Large Hadron Collider run two experiments.
0910.5428
Kresimir Kumericki
Jan O. Eeg, Kresimir Kumericki
The Isgur-Wise Function within a Modified Heavy-Light Chiral Quark Model
20 pages, 7 PS figure, LaTeX
Phys.Rev.D81:074015,2010
10.1103/PhysRevD.81.074015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the Isgur-Wise function xi(omega) within a new modified version of a heavy-light chiral quark model. While early versions of such models gave too small absolute value of the slope, namely xi'(1) of about -0.4 to -0.3, we show how extended version(s) may lead to values around -1, in better agreement with recent measurements. This is obtained by introducing a new mass parameter in the heavy quark propagator. We also shortly comment on the consequences for the decay modes B --> D D-bar.
[ { "created": "Wed, 28 Oct 2009 16:48:15 GMT", "version": "v1" } ]
2010-05-12
[ [ "Eeg", "Jan O.", "" ], [ "Kumericki", "Kresimir", "" ] ]
We consider the Isgur-Wise function xi(omega) within a new modified version of a heavy-light chiral quark model. While early versions of such models gave too small absolute value of the slope, namely xi'(1) of about -0.4 to -0.3, we show how extended version(s) may lead to values around -1, in better agreement with recent measurements. This is obtained by introducing a new mass parameter in the heavy quark propagator. We also shortly comment on the consequences for the decay modes B --> D D-bar.
hep-ph/0506122
Kristjan Kannike
John Ellis, Andi Hektor, Mario Kadastik, Kristjan Kannike, Martti Raidal
Running of Low-Energy Neutrino Masses, Mixing Angles and CP Violation
14 pages, 7 figures
Phys.Lett.B631:32-41,2005
10.1016/j.physletb.2005.09.056
CERN-PH-TH-2005/089
hep-ph
null
We calculate the running of low-energy neutrino parameters from the bottom up, parameterizing the unknown seesaw parameters in terms of the dominance matrix $R$. We find significant running only if the $R$ matrix is non-trivial and the light-neutrino masses are moderately degenerate. If the light-neutrino masses are very hierarchical, the quark-lepton complementarity relation $\theta_c + \theta_{12} = \pi/4$ is quite stable, but $\theta_{13,23}$ may run beyond their likely future experimental errors. The running of the oscillation phase $\delta$ is enhanced by the smallness of $\theta_{13}$, and jumps in the mixing angles occur in cases where the light-neutrino mass eigenstates cross.
[ { "created": "Mon, 13 Jun 2005 15:27:06 GMT", "version": "v1" } ]
2009-09-11
[ [ "Ellis", "John", "" ], [ "Hektor", "Andi", "" ], [ "Kadastik", "Mario", "" ], [ "Kannike", "Kristjan", "" ], [ "Raidal", "Martti", "" ] ]
We calculate the running of low-energy neutrino parameters from the bottom up, parameterizing the unknown seesaw parameters in terms of the dominance matrix $R$. We find significant running only if the $R$ matrix is non-trivial and the light-neutrino masses are moderately degenerate. If the light-neutrino masses are very hierarchical, the quark-lepton complementarity relation $\theta_c + \theta_{12} = \pi/4$ is quite stable, but $\theta_{13,23}$ may run beyond their likely future experimental errors. The running of the oscillation phase $\delta$ is enhanced by the smallness of $\theta_{13}$, and jumps in the mixing angles occur in cases where the light-neutrino mass eigenstates cross.
hep-ph/0606155
Michel Davier
M. Davier, M. Peskin, A. Snyder
Two-photon exchange model for production of neutral meson pairs in e+e- annihilation
7 pages, 2 figures, 1 table
null
null
null
hep-ph
null
A vector-dominance two-photon exchange model is proposed to explain the recently observed production of $\rho^0\rho^0$ and $\rho^0\phi$ pairs in $e^+e^-$ annihilation at 10.58 GeV with the BaBar detector. All the observed features of the data --angular and decay distributions, rates-- are in agreement with the model. Predictions are made for yet-unobserved final states.
[ { "created": "Tue, 13 Jun 2006 20:36:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Davier", "M.", "" ], [ "Peskin", "M.", "" ], [ "Snyder", "A.", "" ] ]
A vector-dominance two-photon exchange model is proposed to explain the recently observed production of $\rho^0\rho^0$ and $\rho^0\phi$ pairs in $e^+e^-$ annihilation at 10.58 GeV with the BaBar detector. All the observed features of the data --angular and decay distributions, rates-- are in agreement with the model. Predictions are made for yet-unobserved final states.
hep-ph/9809511
Gerhard Buchalla
Gerhard Buchalla (CERN)
Non-perturbative Effects in $B\to X_sl^+l^-$
Invited Talk presented at the QCD Euroconference 98, Montpellier, 2-8 July 1998, 7 pages, 1 figure
Nucl.Phys.Proc.Suppl.74:255-259,1999
10.1016/S0920-5632(99)00174-7
CERN-TH/98-314
hep-ph
null
The rare decay $B\to X_sl^+l^-$ provides excellent prospects for precision tests of Standard Model flavour dynamics. The process can be computed in perturbation theory with small uncertainty. However, in order to ensure a reliable theoretical prediction, also potentially important effects from non-perturbative QCD have to be controlled with sufficient accuracy. The present article summarizes recent developments related to this topic.
[ { "created": "Wed, 23 Sep 1998 20:32:33 GMT", "version": "v1" } ]
2009-10-09
[ [ "Buchalla", "Gerhard", "", "CERN" ] ]
The rare decay $B\to X_sl^+l^-$ provides excellent prospects for precision tests of Standard Model flavour dynamics. The process can be computed in perturbation theory with small uncertainty. However, in order to ensure a reliable theoretical prediction, also potentially important effects from non-perturbative QCD have to be controlled with sufficient accuracy. The present article summarizes recent developments related to this topic.
hep-ph/0507052
Enrico Cattaruzza
E. Cattaruzza, A. Del Fabbro and D. Treleani
Fractional momentum correlations in multiple production of W bosons and of b-anti_b pairs in high energy pp collisions
Submitted to Phys. Rev. D
Phys.Rev.D72:034022,2005
10.1103/PhysRevD.72.034022
null
hep-ph
null
Multiple parton collisions will represent a rather common feature in pp collisions at the LHC, where regimes with very large momentum transfer may be studied and events rare in lower energy accelerators might occur with a significant rate. A reason of interest in large p_t regimes is that, differently from low p_t, evolution will induce correlations in x in the multiparton structure functions. We have estimated the cross section of multiple production of W bosons with equal sign, where the correlations in x induced by evolution are particularly relevant, and the cross section of b-bar_b b-bar_b production, where the effects of evolution are much smaller. Our result is that, in the case of multiple production of W bosons, the terms with correlations may represent a correction of the order of 40% of the cross sections, for pp collisions at 1 TeV c.m. energy, and a correction of the order of 20% at 14 TeV. In the case of b-bar_b pairs the correction terms are of the order of 10-15% at 1 TeV and of the order of 5% at 14 TeV.
[ { "created": "Tue, 5 Jul 2005 09:03:00 GMT", "version": "v1" } ]
2011-03-23
[ [ "Cattaruzza", "E.", "" ], [ "Del Fabbro", "A.", "" ], [ "Treleani", "D.", "" ] ]
Multiple parton collisions will represent a rather common feature in pp collisions at the LHC, where regimes with very large momentum transfer may be studied and events rare in lower energy accelerators might occur with a significant rate. A reason of interest in large p_t regimes is that, differently from low p_t, evolution will induce correlations in x in the multiparton structure functions. We have estimated the cross section of multiple production of W bosons with equal sign, where the correlations in x induced by evolution are particularly relevant, and the cross section of b-bar_b b-bar_b production, where the effects of evolution are much smaller. Our result is that, in the case of multiple production of W bosons, the terms with correlations may represent a correction of the order of 40% of the cross sections, for pp collisions at 1 TeV c.m. energy, and a correction of the order of 20% at 14 TeV. In the case of b-bar_b pairs the correction terms are of the order of 10-15% at 1 TeV and of the order of 5% at 14 TeV.
1402.2287
Grant Remmen
Clifford Cheung and Grant N. Remmen
Naturalness and the Weak Gravity Conjecture
5 pages, 1 figure. Discussion of EFT cutoffs added. Text rearranged/shortened for publication in PRL
Phys. Rev. Lett. 113, 051601 (2014)
10.1103/PhysRevLett.113.051601
CALT-68-2879
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weak gravity conjecture (WGC) is an ultraviolet consistency condition asserting that an Abelian force requires a state of charge $q$ and mass $m$ with $q>m/m_{\rm Pl}$. We generalize the WGC to product gauge groups and study its tension with the naturalness principle for a charged scalar coupled to gravity. Reconciling naturalness with the WGC either requires a Higgs phase or a low cutoff at $\Lambda \sim q m_{\rm Pl}$. If neither applies, one can construct simple models that forbid a natural electroweak scale and whose observation would rule out the naturalness principle.
[ { "created": "Mon, 10 Feb 2014 21:00:21 GMT", "version": "v1" }, { "created": "Wed, 30 Jul 2014 02:06:24 GMT", "version": "v2" } ]
2014-07-31
[ [ "Cheung", "Clifford", "" ], [ "Remmen", "Grant N.", "" ] ]
The weak gravity conjecture (WGC) is an ultraviolet consistency condition asserting that an Abelian force requires a state of charge $q$ and mass $m$ with $q>m/m_{\rm Pl}$. We generalize the WGC to product gauge groups and study its tension with the naturalness principle for a charged scalar coupled to gravity. Reconciling naturalness with the WGC either requires a Higgs phase or a low cutoff at $\Lambda \sim q m_{\rm Pl}$. If neither applies, one can construct simple models that forbid a natural electroweak scale and whose observation would rule out the naturalness principle.
2405.08046
Luiz Vale Silva
Luiz Vale Silva
2023 update of the extraction of the CKM matrix elements
Presented at the 12th Workshop on the CKM Unitarity Triangle, 18-22 September 2023, Santiago de Compostela. arXiv admin note: text overlap with arXiv:1812.04396
null
null
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements under the Standard Model (SM) framework from a global fit combining observables that satisfy the double requirement of being precisely known both experimentally and theoretically. The analysis shown here relies on the CKMfitter package, consisting of a frequentist approach that employs the Range fit (Rfit) scheme to handle theoretical uncertainties.
[ { "created": "Mon, 13 May 2024 15:13:32 GMT", "version": "v1" } ]
2024-05-15
[ [ "Silva", "Luiz Vale", "" ] ]
I discuss the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements under the Standard Model (SM) framework from a global fit combining observables that satisfy the double requirement of being precisely known both experimentally and theoretically. The analysis shown here relies on the CKMfitter package, consisting of a frequentist approach that employs the Range fit (Rfit) scheme to handle theoretical uncertainties.
hep-ph/9602260
Subir Sarkar
Subir Sarkar (Oxford)
Big Bang nucleosynthesis and physics beyond the Standard Model
156 pages LaTeX, including 18 PostScript figures; uses ioplppt.sty, epsf, and personal style file (incl.); Revised and updated to include, e.g. implications of new deuterium observations in primordial clouds; 2-up PostScript version (78 pages) available at ftp://ftp.physics.ox.ac.uk/pub/local/users/sarkar/BBNreview.ps.gz ; to appear in Reports on Progress in Physics
Rept.Prog.Phys.59:1493-1610,1996
10.1088/0034-4885/59/12/001
OUTP-95-16P
hep-ph astro-ph nucl-th
null
The Hubble expansion of galaxies, the $2.73\dK$ blackbody radiation background and the cosmic abundances of the light elements argue for a hot, dense origin of the universe --- the standard Big Bang cosmology --- and enable its evolution to be traced back fairly reliably to the nucleosynthesis era when the temperature was of $\Or(1)$ MeV corresponding to an expansion age of $\Or(1)$ sec. All particles, known and hypothetical, would have been created at higher temperatures in the early universe and analyses of their possible effects on the abundances of the synthesized elements enable many interesting constraints to be obtained on particle properties. These arguments have usefully complemented laboratory experiments in guiding attempts to extend physics beyond the Standard $SU(3)_{\c}{\otimes}SU(2)_{\L}{\otimes}U(1)_{Y}$ Model, incorporating ideas such as supersymmetry, compositeness and unification. We first present a pedagogical account of relativistic cosmology and primordial nucleosynthesis, discussing both theoretical and observational aspects, and then proceed to examine such constraints in detail, in particular those pertaining to new massless particles and massive unstable particles. Finally, in a section aimed at particle physicists, we illustrate applications of such constraints to models of new physics.
[ { "created": "Thu, 8 Feb 1996 20:51:34 GMT", "version": "v1" }, { "created": "Sun, 15 Sep 1996 11:34:11 GMT", "version": "v2" } ]
2011-02-16
[ [ "Sarkar", "Subir", "", "Oxford" ] ]
The Hubble expansion of galaxies, the $2.73\dK$ blackbody radiation background and the cosmic abundances of the light elements argue for a hot, dense origin of the universe --- the standard Big Bang cosmology --- and enable its evolution to be traced back fairly reliably to the nucleosynthesis era when the temperature was of $\Or(1)$ MeV corresponding to an expansion age of $\Or(1)$ sec. All particles, known and hypothetical, would have been created at higher temperatures in the early universe and analyses of their possible effects on the abundances of the synthesized elements enable many interesting constraints to be obtained on particle properties. These arguments have usefully complemented laboratory experiments in guiding attempts to extend physics beyond the Standard $SU(3)_{\c}{\otimes}SU(2)_{\L}{\otimes}U(1)_{Y}$ Model, incorporating ideas such as supersymmetry, compositeness and unification. We first present a pedagogical account of relativistic cosmology and primordial nucleosynthesis, discussing both theoretical and observational aspects, and then proceed to examine such constraints in detail, in particular those pertaining to new massless particles and massive unstable particles. Finally, in a section aimed at particle physicists, we illustrate applications of such constraints to models of new physics.
0704.0328
Seung Woo Ham
S.W. Ham, E.J. Yoo, S.K. OH
Electroweak phase transitions in the MSSM with an extra $U(1)'$
17 pages, 2 tables, 3 figures
Phys.Rev.D76:075011,2007
10.1103/PhysRevD.76.075011
null
hep-ph
null
We investigate the possibility of electroweak phase transition in the minimal supersymmetric standard model (MSSM) with an extra $U(1)'$. This model has two Higgs doublets and a singlet, in addition to a singlet exotic quark superfield. We find that at the one-loop level this model may accommodate the electroweak phase transitions that are strongly first-order in a reasonably large region of the parameter space. In the parameter region where the phase transitions take place, we observe that the lightest scalar Higgs boson has a smaller mass when the strength of the phase transition becomes weaker. Also, the other three heavier neutral Higgs bosons get more large masses when the strength of the phase transition becomes weaker.
[ { "created": "Tue, 3 Apr 2007 07:10:04 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ham", "S. W.", "" ], [ "Yoo", "E. J.", "" ], [ "OH", "S. K.", "" ] ]
We investigate the possibility of electroweak phase transition in the minimal supersymmetric standard model (MSSM) with an extra $U(1)'$. This model has two Higgs doublets and a singlet, in addition to a singlet exotic quark superfield. We find that at the one-loop level this model may accommodate the electroweak phase transitions that are strongly first-order in a reasonably large region of the parameter space. In the parameter region where the phase transitions take place, we observe that the lightest scalar Higgs boson has a smaller mass when the strength of the phase transition becomes weaker. Also, the other three heavier neutral Higgs bosons get more large masses when the strength of the phase transition becomes weaker.
hep-ph/0210193
Tatsu Takeuchi
Will Loinaz, Naotoshi Okamura, Tatsu Takeuchi, and L. C. R. Wijewardhana
The NuTeV Anomaly, Neutrino Mixing, and a Heavy Higgs Boson
19 pages, REVTeX4, 8 postscript figures. Updated references. Typos corrected
Phys.Rev. D67 (2003) 073012
10.1103/PhysRevD.67.073012
VPI-IPPAP-02-11
hep-ph
null
Recent results from the NuTeV experiment at Fermilab and the deviation of the Z invisible width, measured at LEP/SLC, from its Standard Model (SM) prediction suggest the suppression of neutrino-Z couplings. Such suppressions occur naturally in models which mix the neutrinos with heavy gauge singlet states. We postulate a universal suppression of the Z-nu-nu couplings by a factor of (1-epsilon) and perform a fit to the Z-pole and NuTeV observables with epsilon and the oblique correction parameters S and T. Compared to a fit with S and T only, inclusion of epsilon leads to a dramatic improvement in the quality of the fit. The values of S and T preferred by the fit can be obtained within the SM by a simple increase in the Higgs boson mass. However, if the W mass is also included in the fit, a non-zero U parameter becomes necessary which cannot be supplied within the SM. The preferred value of epsilon suggests that the seesaw mechanism may not be the reason why neutrinos are so light.
[ { "created": "Mon, 14 Oct 2002 01:48:16 GMT", "version": "v1" }, { "created": "Mon, 27 Jan 2003 20:00:13 GMT", "version": "v2" }, { "created": "Thu, 20 Mar 2003 23:51:30 GMT", "version": "v3" } ]
2007-05-23
[ [ "Loinaz", "Will", "" ], [ "Okamura", "Naotoshi", "" ], [ "Takeuchi", "Tatsu", "" ], [ "Wijewardhana", "L. C. R.", "" ] ]
Recent results from the NuTeV experiment at Fermilab and the deviation of the Z invisible width, measured at LEP/SLC, from its Standard Model (SM) prediction suggest the suppression of neutrino-Z couplings. Such suppressions occur naturally in models which mix the neutrinos with heavy gauge singlet states. We postulate a universal suppression of the Z-nu-nu couplings by a factor of (1-epsilon) and perform a fit to the Z-pole and NuTeV observables with epsilon and the oblique correction parameters S and T. Compared to a fit with S and T only, inclusion of epsilon leads to a dramatic improvement in the quality of the fit. The values of S and T preferred by the fit can be obtained within the SM by a simple increase in the Higgs boson mass. However, if the W mass is also included in the fit, a non-zero U parameter becomes necessary which cannot be supplied within the SM. The preferred value of epsilon suggests that the seesaw mechanism may not be the reason why neutrinos are so light.