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2012.00702
Jean-Philippe Lansberg
Jean-Philippe Lansberg, Melih Arslan Ozcelik
Curing the unphysical behaviour of NLO quarkonium production at the LHC and its relevance to constrain the gluon PDF at low scales
LaTeX, 23 pages, 58 figures, 1 table
null
10.1140/epjc/s10052-021-09258-7
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the unphysical energy dependence of quarkonium-hadroproduction cross sections at Next-to-Leading Order (NLO) in alpha_S which we attribute to an over-subtraction in the factorisation of the collinear singularities inside the PDFs in the MSbar scheme. Such over- or under-subtractions have a limited phenomenological relevance in most of the scattering processes in particle physics. On the contrary, it is particularly harmful for P_T-integrated charmonium hadroproduction which renders a wide class of NLO results essentially unusable. Indeed, in such processes, alphaS is not so small, the PDFs are not evolved much and can be rather flat for the corresponding momentum fractions and, finally, some process-dependent NLO pieces are either too small or too large. We propose a scale-fixing criterion which avoids such an over-subtraction. We demonstrate its efficiency for eta(c,b) but also for a fictitious light elementary scalar boson. Having provided stable NLO predictions for eta(c,b) P_T-integrated cross sections, sigma^NLO(eta(Q)), and discussed the options to study eta(b) hadroproduction, we argue that their measurement at the LHC can help better determine the gluon PDF at low scales and tell whether the local minimum in conventional NLO gluon PDFs around x=0.001 at scales below 2 GeV is physical or not.
[ { "created": "Tue, 1 Dec 2020 18:05:27 GMT", "version": "v1" } ]
2021-06-30
[ [ "Lansberg", "Jean-Philippe", "" ], [ "Ozcelik", "Melih Arslan", "" ] ]
We address the unphysical energy dependence of quarkonium-hadroproduction cross sections at Next-to-Leading Order (NLO) in alpha_S which we attribute to an over-subtraction in the factorisation of the collinear singularities inside the PDFs in the MSbar scheme. Such over- or under-subtractions have a limited phenomenological relevance in most of the scattering processes in particle physics. On the contrary, it is particularly harmful for P_T-integrated charmonium hadroproduction which renders a wide class of NLO results essentially unusable. Indeed, in such processes, alphaS is not so small, the PDFs are not evolved much and can be rather flat for the corresponding momentum fractions and, finally, some process-dependent NLO pieces are either too small or too large. We propose a scale-fixing criterion which avoids such an over-subtraction. We demonstrate its efficiency for eta(c,b) but also for a fictitious light elementary scalar boson. Having provided stable NLO predictions for eta(c,b) P_T-integrated cross sections, sigma^NLO(eta(Q)), and discussed the options to study eta(b) hadroproduction, we argue that their measurement at the LHC can help better determine the gluon PDF at low scales and tell whether the local minimum in conventional NLO gluon PDFs around x=0.001 at scales below 2 GeV is physical or not.
2104.03231
Niko Koivunen
Juan C. Criado, Abdelhak Djouadi, Niko Koivunen, Kristjan M\"u\"ursepp, Martti Raidal, Hardi Veerm\"ae
Confronting spin-3/2 and other new fermions with the muon g-2 measurement
References updated, typos fixed and comments added; results unchanged
null
10.1016/j.physletb.2021.136491
null
hep-ph hep-ex hep-th
http://creativecommons.org/licenses/by/4.0/
The new measurement of the muon's anomalous magnetic moment released by the Muon g-2 experiment at Fermilab sets strong constraints on the properties of many new particles. Using an effective field theory approach to the interactions of higher-spin fields, we evaluate the contribution of an electrically neutral and colour singlet spin-3/2 fermion to $(g-2)_\mu$ and derive the corresponding constraints on its mass and couplings. These constraints are then compared with the ones on spin-1/2 fermions, such as the vector-like leptons that are predicted by various extensions of the Standard Model, the excited leptons which appear in composite models, as well as the charginos and neutralinos of supersymmetric theories. Unlike these new spin-1/2 fermions, the spin-3/2 particles generate only small contributions to the muon anomalous magnetic moment.
[ { "created": "Wed, 7 Apr 2021 16:30:16 GMT", "version": "v1" }, { "created": "Thu, 8 Apr 2021 14:22:41 GMT", "version": "v2" } ]
2021-07-07
[ [ "Criado", "Juan C.", "" ], [ "Djouadi", "Abdelhak", "" ], [ "Koivunen", "Niko", "" ], [ "Müürsepp", "Kristjan", "" ], [ "Raidal", "Martti", "" ], [ "Veermäe", "Hardi", "" ] ]
The new measurement of the muon's anomalous magnetic moment released by the Muon g-2 experiment at Fermilab sets strong constraints on the properties of many new particles. Using an effective field theory approach to the interactions of higher-spin fields, we evaluate the contribution of an electrically neutral and colour singlet spin-3/2 fermion to $(g-2)_\mu$ and derive the corresponding constraints on its mass and couplings. These constraints are then compared with the ones on spin-1/2 fermions, such as the vector-like leptons that are predicted by various extensions of the Standard Model, the excited leptons which appear in composite models, as well as the charginos and neutralinos of supersymmetric theories. Unlike these new spin-1/2 fermions, the spin-3/2 particles generate only small contributions to the muon anomalous magnetic moment.
hep-ph/9911254
Nikita Agasyan
N.O. Agasian, I.A. Shushpanov (ITEP, Moscow)
The Quark and Gluon Condensates and Low-Energy QCD Theorems in a Magnetic Field
LaTeX, 9 pages, 2 figures; minor corrections
Phys.Lett. B472 (2000) 143-149
10.1016/S0370-2693(99)01414-8
ITEP-PH-11/99
hep-ph
null
The low-energy QCD theorems are generalized in the presence of a constant magnetic field H. Two-loop approximation for the vacuum energy density in the framework of the chiral perturbation theory was obtained and the quark and gluon condensates were found as the functions of H.
[ { "created": "Fri, 5 Nov 1999 16:01:31 GMT", "version": "v1" }, { "created": "Tue, 16 Nov 1999 15:47:34 GMT", "version": "v2" } ]
2009-10-31
[ [ "Agasian", "N. O.", "", "ITEP, Moscow" ], [ "Shushpanov", "I. A.", "", "ITEP, Moscow" ] ]
The low-energy QCD theorems are generalized in the presence of a constant magnetic field H. Two-loop approximation for the vacuum energy density in the framework of the chiral perturbation theory was obtained and the quark and gluon condensates were found as the functions of H.
hep-ph/0309095
Wolfgang Schweiger
C. F. Berger (INFN, Turin) and W. Schweiger (Graz U.)
Hard exclusive baryon-antibaryon production in 2-$\gamma$ collisions
7 pages, 2 figures; v2: institutions updated, paper unchanged
Fizika B13 (2004) 75-80
null
null
hep-ph
null
We present a perturbative calculation of baryon pair production in two-photon collisions, $\gamma \gamma \to B \bar{B}$, in which baryons are treated as quark-diquark systems. Our approach accounts for constituent mass effects in a systematic way. Taking the diquark-model parameters from foregoing studies of other electron- and photon-induced baryonic reactions, our results agree well with the most recent large momentum-transfer data for the $p\bar{p}$, $\Lambda\bar{\Lambda}$, and $\Sigma^0\bar{\Sigma}^0$ channels.
[ { "created": "Tue, 9 Sep 2003 17:08:42 GMT", "version": "v1" }, { "created": "Wed, 10 Sep 2003 07:52:52 GMT", "version": "v2" } ]
2007-05-23
[ [ "Berger", "C. F.", "", "INFN, Turin" ], [ "Schweiger", "W.", "", "Graz U." ] ]
We present a perturbative calculation of baryon pair production in two-photon collisions, $\gamma \gamma \to B \bar{B}$, in which baryons are treated as quark-diquark systems. Our approach accounts for constituent mass effects in a systematic way. Taking the diquark-model parameters from foregoing studies of other electron- and photon-induced baryonic reactions, our results agree well with the most recent large momentum-transfer data for the $p\bar{p}$, $\Lambda\bar{\Lambda}$, and $\Sigma^0\bar{\Sigma}^0$ channels.
hep-ph/0607035
Thorsten Renk
Thorsten Renk
Signatures of Mach Shocks at RHIC
5 pages, 2 figures, Talk given at the Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions, Hot Quarks 2006, Villasimius, Italy, May 15-20 2006
Eur.Phys.J.C49:13-17,2007
10.1140/epjc/s10052-006-0066-9
null
hep-ph
null
Hard partons propagating through hot and dense matter loose energy, leading to the observed depletion of hard hadron spectra in nucleus nucleus collision as compared to scaled proton proton collisions. This lost energy has to reappear in the medium due to the conservation of energy. Apart from heating the medium, there is the possibility that a propagating collective mode is excited. We outline a formalism that can be used to track the propagation of such a mode through the evolving medium if its dispersion relation is known and to calculate the resulting distortion of hadronic spectra at freeze-out. Using this formalism, we demonstrate within a detailed picture of the evolution of the expanding system and the experimental trigger conditions that the assumption of a sound mode being excited is in line with 2-particle correlation measurements by PHENIX and STAR for a semi-hard trigger. In this case, the measurement is sensitive to the averaged speed of sound in the hot matter. We also make suggestions how this sensitivity can be improved.
[ { "created": "Tue, 4 Jul 2006 10:55:16 GMT", "version": "v1" } ]
2011-09-13
[ [ "Renk", "Thorsten", "" ] ]
Hard partons propagating through hot and dense matter loose energy, leading to the observed depletion of hard hadron spectra in nucleus nucleus collision as compared to scaled proton proton collisions. This lost energy has to reappear in the medium due to the conservation of energy. Apart from heating the medium, there is the possibility that a propagating collective mode is excited. We outline a formalism that can be used to track the propagation of such a mode through the evolving medium if its dispersion relation is known and to calculate the resulting distortion of hadronic spectra at freeze-out. Using this formalism, we demonstrate within a detailed picture of the evolution of the expanding system and the experimental trigger conditions that the assumption of a sound mode being excited is in line with 2-particle correlation measurements by PHENIX and STAR for a semi-hard trigger. In this case, the measurement is sensitive to the averaged speed of sound in the hot matter. We also make suggestions how this sensitivity can be improved.
1011.2447
Jacob Bourjaily
Jacob L. Bourjaily
Efficient Tree-Amplitudes in N=4: Automatic BCFW Recursion in Mathematica
40 pages. Mathematica package "bcfw" and a demonstration notebook is included with this submission
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe an efficient implementation of the BCFW recursion relations for tree-amplitudes in N=4 super Yang-Mills, which can generate analytic formulae for general N^kMHV colour-ordered helicity-amplitudes-which, in particular, includes all those of non-supersymmetric Yang-Mills. This note accompanies the public release of the Mathematica package "bcfw", which can quickly (and automatically) generate these amplitudes in a form that should be easy to export to any computational framework of interest, or which can be evaluated directly within Mathematica given external states specified by four-momenta, spinor-helicity variables or momentum-twistors. Moreover, bcfw is able to solve the BCFW recursion relations using any one of a three-parameter family of recursive `schemes,' leading to an extremely wide variety of distinct analytic representations of any particular amplitude. This flexibility is made possible by bcfw's use of the momentum-twistor Grassmannian integral to describe all tree amplitudes; and this flexibility is accompanied by a remarkable increase in efficiency, leading to formulae that can be evaluated much faster-often by several orders of magnitude-than those previously derived using BCFW.
[ { "created": "Wed, 10 Nov 2010 18:00:11 GMT", "version": "v1" } ]
2010-11-11
[ [ "Bourjaily", "Jacob L.", "" ] ]
We describe an efficient implementation of the BCFW recursion relations for tree-amplitudes in N=4 super Yang-Mills, which can generate analytic formulae for general N^kMHV colour-ordered helicity-amplitudes-which, in particular, includes all those of non-supersymmetric Yang-Mills. This note accompanies the public release of the Mathematica package "bcfw", which can quickly (and automatically) generate these amplitudes in a form that should be easy to export to any computational framework of interest, or which can be evaluated directly within Mathematica given external states specified by four-momenta, spinor-helicity variables or momentum-twistors. Moreover, bcfw is able to solve the BCFW recursion relations using any one of a three-parameter family of recursive `schemes,' leading to an extremely wide variety of distinct analytic representations of any particular amplitude. This flexibility is made possible by bcfw's use of the momentum-twistor Grassmannian integral to describe all tree amplitudes; and this flexibility is accompanied by a remarkable increase in efficiency, leading to formulae that can be evaluated much faster-often by several orders of magnitude-than those previously derived using BCFW.
1508.07930
Julia Gehrlein
Julia Gehrlein, Serguey T. Petcov, Martin Spinrath, Xinyi Zhang
Leptogenesis in an SU(5) x A5 Golden Ratio Flavour Model: Addendum
15 pages, 5 figures; version published in NPB
Nucl. Phys. B899 (2015) 617-630
10.1016/j.nuclphysb.2015.08.019
SISSA 33/2015 FISI, IPMU15-0118, TTP15-024
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive and discuss the solution of the Boltzmann equations for leptogenesis in a phenomenologically viable SU(5) x A5 golden ratio flavour model proposed in arXiv:1410.2057 [hep-ph], arXiv:1502.00110 [hep-ph] . The model employs, in particular, the seesaw mechanism of neutrino mass generation. We find that the results on the baryon asymmetry of the Universe, obtained earlier in arXiv:1502.00110 [hep-ph] using approximate analytic expressions for the relevant CP violating asymmetry and efficiency factors, are correct, as was expected, up to 20-30 %. The phenomenological predictions for the low energy neutrino observables, derived using values of the parameters of the model for which we reproduce the observed value of the baryon asymmetry, change little with respect to those presented in arXiv:1502.00110 [hep-ph]. Among the many predictions of the model we find, for instance, that the neutrinoless double beta decay effective Majorana mass m_ee lies between 3.3 meV and 14.3 meV.
[ { "created": "Mon, 31 Aug 2015 17:40:42 GMT", "version": "v1" } ]
2015-09-01
[ [ "Gehrlein", "Julia", "" ], [ "Petcov", "Serguey T.", "" ], [ "Spinrath", "Martin", "" ], [ "Zhang", "Xinyi", "" ] ]
We derive and discuss the solution of the Boltzmann equations for leptogenesis in a phenomenologically viable SU(5) x A5 golden ratio flavour model proposed in arXiv:1410.2057 [hep-ph], arXiv:1502.00110 [hep-ph] . The model employs, in particular, the seesaw mechanism of neutrino mass generation. We find that the results on the baryon asymmetry of the Universe, obtained earlier in arXiv:1502.00110 [hep-ph] using approximate analytic expressions for the relevant CP violating asymmetry and efficiency factors, are correct, as was expected, up to 20-30 %. The phenomenological predictions for the low energy neutrino observables, derived using values of the parameters of the model for which we reproduce the observed value of the baryon asymmetry, change little with respect to those presented in arXiv:1502.00110 [hep-ph]. Among the many predictions of the model we find, for instance, that the neutrinoless double beta decay effective Majorana mass m_ee lies between 3.3 meV and 14.3 meV.
2401.10125
V\'ictor L\'opez-Pardo
N\'estor Armesto, Miguel \'Angel Escobedo, Elena G. Ferreiro and V\'ictor L\'opez-Pardo
A potential approach to the $X(3872)$ thermal behavior
12 pages, 7 figures
Physics Letters B, 854 (2024) 138760
10.1016/j.physletb.2024.138760
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the potential of $X(3872)$ at finite temperature in the Born-Oppenheimer approximation under the assumption that it is a tetraquark. We argue that, at large number of colors, it is a good approximation to assume that the potential consists in a real part plus a constant imaginary term. The real part is then computed adapting an approach by Rothkopf and Lafferty and using as input lattice QCD determinations of the potential for hybrids. This model allows us to qualitatively estimate at which temperature range the formation of a heavy tetraquark is possible, and to propose a qualitative picture for the dissociation of the state in a medium. Our approach can be applied to other suggested internal structures for the $X(3872)$ and to other exotic states.
[ { "created": "Thu, 18 Jan 2024 16:55:18 GMT", "version": "v1" }, { "created": "Mon, 22 Jan 2024 15:59:49 GMT", "version": "v2" }, { "created": "Fri, 21 Jun 2024 11:27:16 GMT", "version": "v3" } ]
2024-06-24
[ [ "Armesto", "Néstor", "" ], [ "Escobedo", "Miguel Ángel", "" ], [ "Ferreiro", "Elena G.", "" ], [ "López-Pardo", "Víctor", "" ] ]
We study the potential of $X(3872)$ at finite temperature in the Born-Oppenheimer approximation under the assumption that it is a tetraquark. We argue that, at large number of colors, it is a good approximation to assume that the potential consists in a real part plus a constant imaginary term. The real part is then computed adapting an approach by Rothkopf and Lafferty and using as input lattice QCD determinations of the potential for hybrids. This model allows us to qualitatively estimate at which temperature range the formation of a heavy tetraquark is possible, and to propose a qualitative picture for the dissociation of the state in a medium. Our approach can be applied to other suggested internal structures for the $X(3872)$ and to other exotic states.
1405.6836
Sudhanwa Patra Dr.
Sudhanwa Patra and Prativa Pritimita (Siksha 'O' Anusandhan University, Bhubaneswar)
Post-Sphaleron baryogenesis and $n-\bar{n}$ oscillation in non-SUSY SO(10) GUT with gauge coupling unification and proton decay
v2: 28 pages, matches the version to be published in European Physical Journal C
null
10.1140/epjc/s10052-014-3078-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Post-sphaleron baryogenesis, a fresh and profound mechanism of baryogenesis accounts for the matter-antimatter asymmetry of our present universe in a framework of Pati-Salam symmetry. We attempt here to embed this mechanism in a non-SUSY SO(10) grand unified theory by reviving a novel symmetry breaking chain with Pati-Salam symmetry as an intermediate symmetry breaking step and as well to address post-sphaleron baryogenesis and neutron-antineutron oscillation in a rational manner. The Pati-Salam symmetry based on the gauge group $SU(2)_L \times SU(2)_{R} \times SU(4)_C$ is realized in our model at $10^{5}-10^{6}$ GeV and the mixing time for the neutron-antineutron oscillation process having $\Delta B=2$ is found to be $\tau_{n-\bar{n}} \simeq 10^{8}-10^{10}\,\mbox{secs}$ with the model parameters which is within the reach of forthcoming experiments. Other novel features of the model includes low scale right-handed $W^{\pm}_R$, $Z_R$ gauge bosons, explanation for neutrino oscillation data via gauged inverse (or extended) seesaw mechanism and most importantly TeV scale color sextet scalar particles responsible for observable $n-\bar{n}$ oscillation which can be accessible to LHC. We also look after gauge coupling unification and estimation of proton life-time with and without the addition of color sextet scalars.
[ { "created": "Tue, 27 May 2014 08:59:49 GMT", "version": "v1" }, { "created": "Tue, 16 Sep 2014 10:57:27 GMT", "version": "v2" } ]
2015-06-19
[ [ "Patra", "Sudhanwa", "", "Siksha 'O' Anusandhan\n University, Bhubaneswar" ], [ "Pritimita", "Prativa", "", "Siksha 'O' Anusandhan\n University, Bhubaneswar" ] ]
Post-sphaleron baryogenesis, a fresh and profound mechanism of baryogenesis accounts for the matter-antimatter asymmetry of our present universe in a framework of Pati-Salam symmetry. We attempt here to embed this mechanism in a non-SUSY SO(10) grand unified theory by reviving a novel symmetry breaking chain with Pati-Salam symmetry as an intermediate symmetry breaking step and as well to address post-sphaleron baryogenesis and neutron-antineutron oscillation in a rational manner. The Pati-Salam symmetry based on the gauge group $SU(2)_L \times SU(2)_{R} \times SU(4)_C$ is realized in our model at $10^{5}-10^{6}$ GeV and the mixing time for the neutron-antineutron oscillation process having $\Delta B=2$ is found to be $\tau_{n-\bar{n}} \simeq 10^{8}-10^{10}\,\mbox{secs}$ with the model parameters which is within the reach of forthcoming experiments. Other novel features of the model includes low scale right-handed $W^{\pm}_R$, $Z_R$ gauge bosons, explanation for neutrino oscillation data via gauged inverse (or extended) seesaw mechanism and most importantly TeV scale color sextet scalar particles responsible for observable $n-\bar{n}$ oscillation which can be accessible to LHC. We also look after gauge coupling unification and estimation of proton life-time with and without the addition of color sextet scalars.
1602.01110
Dreyer Fr\'ed\'eric
Mrinal Dasgupta, Fr\'ed\'eric A. Dreyer, Gavin P. Salam, Gregory Soyez
Inclusive jet spectrum for small-radius jets
42 pages, 24 figures, additional material at http://microjets.hepforge.org/, updated to match published version
null
10.1007/JHEP06(2016)057
CERN-TH/2016-020
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Following on our earlier work on leading-logarithmic (LLR) resummations for the properties of jets with a small radius, R, we here examine the phenomenological considerations for the inclusive jet spectrum. We discuss how to match the NLO predictions with small-R resummation. As part of the study we propose a new, physically-inspired prescription for fixed-order predictions and their uncertainties. We investigate the R-dependent part of the next-to-next-to-leading order (NNLO) corrections, which is found to be substantial, and comment on the implications for scale choices in inclusive jet calculations. We also examine hadronisation corrections, identifying potential limitations of earlier analytical work with regards to their $p_t$-dependence. Finally we assemble these different elements in order to compare matched (N)NLO+LLR predictions to data from ALICE and ATLAS, finding improved consistency for the R-dependence of the results relative to NLO predictions.
[ { "created": "Tue, 2 Feb 2016 21:03:04 GMT", "version": "v1" }, { "created": "Sat, 23 Jul 2016 11:32:38 GMT", "version": "v2" } ]
2016-07-26
[ [ "Dasgupta", "Mrinal", "" ], [ "Dreyer", "Frédéric A.", "" ], [ "Salam", "Gavin P.", "" ], [ "Soyez", "Gregory", "" ] ]
Following on our earlier work on leading-logarithmic (LLR) resummations for the properties of jets with a small radius, R, we here examine the phenomenological considerations for the inclusive jet spectrum. We discuss how to match the NLO predictions with small-R resummation. As part of the study we propose a new, physically-inspired prescription for fixed-order predictions and their uncertainties. We investigate the R-dependent part of the next-to-next-to-leading order (NNLO) corrections, which is found to be substantial, and comment on the implications for scale choices in inclusive jet calculations. We also examine hadronisation corrections, identifying potential limitations of earlier analytical work with regards to their $p_t$-dependence. Finally we assemble these different elements in order to compare matched (N)NLO+LLR predictions to data from ALICE and ATLAS, finding improved consistency for the R-dependence of the results relative to NLO predictions.
hep-ph/9608491
Patrick Labelle
Patrick Labelle (McGill University)
Effective field theories for QED bound states: extending Nonrelativistic QED to study retardation effects
39 pages, 9 Postscript figures, uses Rev.tex V3.0 and epsf.tex
Phys.Rev.D58:093013,1998
10.1103/PhysRevD.58.093013
McGill/96-33
hep-ph atom-ph
null
Nonrelativistic QED bound states are difficult to study because of the presence of at least three widely different scales: the masses, three-momenta ($p_i$) and kinetic energies ($K_i$) of the constituents. Nonrelativistic QED (NRQED), an effective field theory developed by Caswell and Lepage, simplifies greatly bound state calculations by eliminating the masses as dynamical scales. As we demonstrate, NRQED diagrams involving only photons of energy $E_\gamma \simeq p_i$ contribute, in any calculation, to a unique order in $\alpha$. This is not the case, however, for diagrams involving photons with energies $E_\gamma \simeq K_i$ (``retardation effects"), for which no simple counting counting rules can be given. We present a new effective field theory in which the contribution of those ultra-soft photons can be isolated order by order in $\alpha$. This is effectively accomplished by performing a multipole expansion of the NRQED vertices.
[ { "created": "Thu, 29 Aug 1996 18:27:29 GMT", "version": "v1" } ]
2011-07-19
[ [ "Labelle", "Patrick", "", "McGill University" ] ]
Nonrelativistic QED bound states are difficult to study because of the presence of at least three widely different scales: the masses, three-momenta ($p_i$) and kinetic energies ($K_i$) of the constituents. Nonrelativistic QED (NRQED), an effective field theory developed by Caswell and Lepage, simplifies greatly bound state calculations by eliminating the masses as dynamical scales. As we demonstrate, NRQED diagrams involving only photons of energy $E_\gamma \simeq p_i$ contribute, in any calculation, to a unique order in $\alpha$. This is not the case, however, for diagrams involving photons with energies $E_\gamma \simeq K_i$ (``retardation effects"), for which no simple counting counting rules can be given. We present a new effective field theory in which the contribution of those ultra-soft photons can be isolated order by order in $\alpha$. This is effectively accomplished by performing a multipole expansion of the NRQED vertices.
hep-ph/9307285
null
G. Ecker, H. Neufeld and A. Pich
Non-Leptonic Kaon Decays and the Chiral Anomaly
LaTeX, 31 pages (3 figures, not included), CERN-TH.6920/93
Nucl.Phys. B413 (1994) 321-352
10.1016/0550-3213(94)90623-8
null
hep-ph
null
An investigation is performed of all non-leptonic kaon decays sensitive to the chiral anomaly. Within the framework of chiral perturbation theory, there are two classes of anomalous amplitudes at $O(p^4)$: reducible and direct contributions. Only radiative transitions are affected by the anomaly. The phenomenology of the decays $K_L \to \pi^+ \pi^- \gamma$ and $K^+ \to \pi^+ \pi^0 \gamma$ is studied in detail. Including the dominant contributions of $O(p^6)$, the experimentally observed dependence of the direct emission amplitude for $K_L \to \pi^+ \pi^- \gamma$ on the photon energy can be understood. A survey is made of the rare ``anomalous'' decays $K \to \pi \pi \gamma \gamma$ and $K \to 3 \pi \gamma (\gamma)$, including some numerical estimates.
[ { "created": "Fri, 16 Jul 1993 15:43:07 GMT", "version": "v1" } ]
2009-10-22
[ [ "Ecker", "G.", "" ], [ "Neufeld", "H.", "" ], [ "Pich", "A.", "" ] ]
An investigation is performed of all non-leptonic kaon decays sensitive to the chiral anomaly. Within the framework of chiral perturbation theory, there are two classes of anomalous amplitudes at $O(p^4)$: reducible and direct contributions. Only radiative transitions are affected by the anomaly. The phenomenology of the decays $K_L \to \pi^+ \pi^- \gamma$ and $K^+ \to \pi^+ \pi^0 \gamma$ is studied in detail. Including the dominant contributions of $O(p^6)$, the experimentally observed dependence of the direct emission amplitude for $K_L \to \pi^+ \pi^- \gamma$ on the photon energy can be understood. A survey is made of the rare ``anomalous'' decays $K \to \pi \pi \gamma \gamma$ and $K \to 3 \pi \gamma (\gamma)$, including some numerical estimates.
hep-ph/0005059
Guetta Dafne
Dafne Guetta and Paul Singer
$\omega-\rho$ Mixing and the $\omega\to\pi\pi\gamma$ Decay
10 pages, LaTeX, 1 ps-figure. Submitted to Phys. Rev. D
Phys.Rev. D63 (2001) 017502
10.1103/PhysRevD.63.017502
null
hep-ph
null
We reexamine the $\omega \to \pi^{0} \pi^{0} \gamma $ decay, adding the effect of $\omega-\rho$ mixing to the amplitude calculated with the aid of chiral perturbation theory and vector meson dominance. We predict the neutral decay to occur with a width of $\Gamma($\omega \to \pi^{0} \pi^{0} \gamma $) =(390\pm96) {\rm eV}$ and also analyze the effect of the $\omega-\rho$ mixing on the $\Gamma($\omega \to \pi^{0} \pi^{0} \gamma $)/ \Gamma($\omega \to \pi^{+} \pi^{-} \gamma $)$ ratio. Several remarks on the effect of $\omega-\rho$ mixing on certain radiative decays of vector mesons are presented.
[ { "created": "Sat, 6 May 2000 17:45:49 GMT", "version": "v1" }, { "created": "Sat, 22 Jul 2000 13:48:07 GMT", "version": "v2" } ]
2009-10-31
[ [ "Guetta", "Dafne", "" ], [ "Singer", "Paul", "" ] ]
We reexamine the $\omega \to \pi^{0} \pi^{0} \gamma $ decay, adding the effect of $\omega-\rho$ mixing to the amplitude calculated with the aid of chiral perturbation theory and vector meson dominance. We predict the neutral decay to occur with a width of $\Gamma($\omega \to \pi^{0} \pi^{0} \gamma $) =(390\pm96) {\rm eV}$ and also analyze the effect of the $\omega-\rho$ mixing on the $\Gamma($\omega \to \pi^{0} \pi^{0} \gamma $)/ \Gamma($\omega \to \pi^{+} \pi^{-} \gamma $)$ ratio. Several remarks on the effect of $\omega-\rho$ mixing on certain radiative decays of vector mesons are presented.
1503.00006
Srimoyee Sen
Thomas D. Cohen and Srimoyee Sen
Deconfinement Transition at High Isospin Chemical Potential and Low Temperature
Added corrections to the speed of Goldstone modes and rephrased abstract
null
10.1016/j.nuclphysa.2015.07.018
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider QCD with two degenerate flavors of light quarks(up and down) at asymptotically high isospin chemical potential with zero baryon chemical potential and calculate for the first time a quantitative expression for the critical temperature of the deconfinement transition in this regime. At high isospin chemical potential and sufficiently low temperatures this theory becomes equivalent to a pure Yang-Mills theory and accordingly has a first order deconfinement phase transition. Although this was conjectured in a seminal paper by Son and Stephanov in the year 2001, the critical temperature of this deconfinement phase transition was not computed. This paper computes the energy scale associated with this transition as a function of the isospin chemical potential by relating the parameters of the equivalent Yang-Mills theory to those of the underlying theory. We also relate the equation of state in one strongly interacting regime of QCD namely at finite isospin density to that in pure Yang-Mills, with the latter being amenable to straightforward numerical calculation. Our results for the critical temperature of deconfinement transition can be compared with future lattice calculations.
[ { "created": "Fri, 27 Feb 2015 21:00:10 GMT", "version": "v1" }, { "created": "Thu, 18 Jun 2015 19:30:50 GMT", "version": "v2" } ]
2015-12-09
[ [ "Cohen", "Thomas D.", "" ], [ "Sen", "Srimoyee", "" ] ]
We consider QCD with two degenerate flavors of light quarks(up and down) at asymptotically high isospin chemical potential with zero baryon chemical potential and calculate for the first time a quantitative expression for the critical temperature of the deconfinement transition in this regime. At high isospin chemical potential and sufficiently low temperatures this theory becomes equivalent to a pure Yang-Mills theory and accordingly has a first order deconfinement phase transition. Although this was conjectured in a seminal paper by Son and Stephanov in the year 2001, the critical temperature of this deconfinement phase transition was not computed. This paper computes the energy scale associated with this transition as a function of the isospin chemical potential by relating the parameters of the equivalent Yang-Mills theory to those of the underlying theory. We also relate the equation of state in one strongly interacting regime of QCD namely at finite isospin density to that in pure Yang-Mills, with the latter being amenable to straightforward numerical calculation. Our results for the critical temperature of deconfinement transition can be compared with future lattice calculations.
0803.0695
Gionata Luisoni
T.Gehrmann, G.Luisoni and H.Stenzel
Matching NLLA+NNLO for event shape distributions
14 pages, 18 figures; typos corrected, published version
Phys.Lett.B664:265-273,2008
10.1016/j.physletb.2008.05.023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the matching of the next-to-leading logarithmic approximation (NLLA) onto the fixed next-to-next-to-leading order (NNLO) calculation for event shape distributions in electron-positron annihilation. The resulting theoretical predictions combine all precision QCD knowledge on the distributions, and are theoretically reliable over an extended kinematical range. Compared to previously available matched NLLA+NLO and fixed order NNLO results, we observe that the effects of the combined NLLA+NNLO are small in the three-jet region, relevant for precision physics.
[ { "created": "Wed, 5 Mar 2008 16:20:31 GMT", "version": "v1" }, { "created": "Thu, 13 Mar 2008 07:45:34 GMT", "version": "v2" }, { "created": "Mon, 5 May 2008 13:59:32 GMT", "version": "v3" }, { "created": "Tue, 15 Jul 2008 14:27:10 GMT", "version": "v4" } ]
2008-11-26
[ [ "Gehrmann", "T.", "" ], [ "Luisoni", "G.", "" ], [ "Stenzel", "H.", "" ] ]
We study the matching of the next-to-leading logarithmic approximation (NLLA) onto the fixed next-to-next-to-leading order (NNLO) calculation for event shape distributions in electron-positron annihilation. The resulting theoretical predictions combine all precision QCD knowledge on the distributions, and are theoretically reliable over an extended kinematical range. Compared to previously available matched NLLA+NLO and fixed order NNLO results, we observe that the effects of the combined NLLA+NNLO are small in the three-jet region, relevant for precision physics.
2406.09237
Andrei Poblaguev
Andrei Poblaguev
Absorptive Corrections to the Electromagnetic Form Factor in High-Energy Elastic Proton-Proton Scattering
6 pages, 4 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recently, it was noted that absorptive corrections to the electromagnetic form factor in high-energy proton-proton scattering are important for the theoretical interpretation of the $p^\uparrow{p}$ and $p^\uparrow{A}$ analyzing power $A_\text{N}(t)$ measurements with the Hydrogen Jet Target polarimeter (HJET) at RHIC. Here, a concise expression for the absorptive correction was derived within the eikonal approach. The resulting analysis reveals a systematic bias, nearly independent of the beam energy, in the experimental determination of the real-to-imaginary ratio $\rho$ when absorption effects are overlooked in the data analysis. Quantification of this bias, as $\rho^\text{meas}=\rho + (0.036\pm0.016)_\text{bias}$, was achieved using a Regge fit applied to available proton-proton measurements of $\rho^\text{meas}(s)$ and $\sigma^\text{meas}_\text{tot}(s)$. Considering the potential impact of such an effect on the experimentally determined $A_\text{N}(t)$, one may enhance consistency between the HJET and STAR measurements of the hadronic spin-flip amplitude. While the sign of the bias in the value of $\rho$ aligns with the anticipated effective increase in the proton charge radius in $pp$ scattering due to absorption, it amplifies the observed discrepancy between $\sigma^\text{meas}_\text{tot}$ and $\rho^\text{meas}$ values at $\sqrt{s}=13\,\text{TeV}$ as measured in the TOTEM experiment. Evaluation (using published TOTEM data) of the measured proton-proton $d\sigma/dt$ dependence on the absorptive corrections indicated that possible soft photon corrections to the hadronic amplitude slope may be essential for such data analysis.
[ { "created": "Thu, 13 Jun 2024 15:39:08 GMT", "version": "v1" } ]
2024-06-14
[ [ "Poblaguev", "Andrei", "" ] ]
Recently, it was noted that absorptive corrections to the electromagnetic form factor in high-energy proton-proton scattering are important for the theoretical interpretation of the $p^\uparrow{p}$ and $p^\uparrow{A}$ analyzing power $A_\text{N}(t)$ measurements with the Hydrogen Jet Target polarimeter (HJET) at RHIC. Here, a concise expression for the absorptive correction was derived within the eikonal approach. The resulting analysis reveals a systematic bias, nearly independent of the beam energy, in the experimental determination of the real-to-imaginary ratio $\rho$ when absorption effects are overlooked in the data analysis. Quantification of this bias, as $\rho^\text{meas}=\rho + (0.036\pm0.016)_\text{bias}$, was achieved using a Regge fit applied to available proton-proton measurements of $\rho^\text{meas}(s)$ and $\sigma^\text{meas}_\text{tot}(s)$. Considering the potential impact of such an effect on the experimentally determined $A_\text{N}(t)$, one may enhance consistency between the HJET and STAR measurements of the hadronic spin-flip amplitude. While the sign of the bias in the value of $\rho$ aligns with the anticipated effective increase in the proton charge radius in $pp$ scattering due to absorption, it amplifies the observed discrepancy between $\sigma^\text{meas}_\text{tot}$ and $\rho^\text{meas}$ values at $\sqrt{s}=13\,\text{TeV}$ as measured in the TOTEM experiment. Evaluation (using published TOTEM data) of the measured proton-proton $d\sigma/dt$ dependence on the absorptive corrections indicated that possible soft photon corrections to the hadronic amplitude slope may be essential for such data analysis.
hep-ph/9809425
H. Sazdjian
H. Sazdjian (U. of Orsay)
Pionium lifetime corrections
9 pages, Latex. Uses Dubna98.sty. Talk given at the Int. Workshop "Hadronic Atoms and Positronium in the Standard Model", Dubna, 26-31 May 1998. To appear in the Proceedings
Proceedings, Dubna (1998) 50-58
null
null
hep-ph
null
Pionium lifetime corrections are evaluated in the frameworks of constrained Bethe-Salpeter equation and chiral perturbation theory. Corrections of order $O(\alpha)$ are calculated with respect to the conventional lowest-order formula, in which the strong interaction amplitude has been calculated to two-loop order with charged pion masses. The total correction is found to be of the order of $(6.1\pm 2.0)%$.
[ { "created": "Thu, 17 Sep 1998 07:42:23 GMT", "version": "v1" } ]
2011-02-09
[ [ "Sazdjian", "H.", "", "U. of Orsay" ] ]
Pionium lifetime corrections are evaluated in the frameworks of constrained Bethe-Salpeter equation and chiral perturbation theory. Corrections of order $O(\alpha)$ are calculated with respect to the conventional lowest-order formula, in which the strong interaction amplitude has been calculated to two-loop order with charged pion masses. The total correction is found to be of the order of $(6.1\pm 2.0)%$.
1010.4525
Fritz W. Bopp
F. W. Bopp
Novel ideas about emergent vacua
8 pages, 4 figures, The interpretation of new experimental results is expanded to include the preliminary CDF boson
Acta Phys.Polon. B42:1917,2011
10.5506/APhysPolB.42.1917
Preprint SI-HEP-2010-17
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Arguments for special emergent vacua which generate fermion and weak boson masses are outlined. Limitations and consequences of the concept are discussed. If confirmed the Australian dipole would give strong support to such a picture. Preliminary support from recent DZero and CDF data is discussed and predictions for LHC are presented.
[ { "created": "Thu, 21 Oct 2010 17:07:15 GMT", "version": "v1" }, { "created": "Fri, 29 Apr 2011 16:53:35 GMT", "version": "v2" } ]
2011-09-16
[ [ "Bopp", "F. W.", "" ] ]
Arguments for special emergent vacua which generate fermion and weak boson masses are outlined. Limitations and consequences of the concept are discussed. If confirmed the Australian dipole would give strong support to such a picture. Preliminary support from recent DZero and CDF data is discussed and predictions for LHC are presented.
1403.4736
Rui Santos
P.M. Ferreira, John F. Gunion, Howard E. Haber and Rui Santos
Probing wrong-sign Yukawa couplings at the LHC and a future linear collider
28 pages, 21 figures
Phys. Rev. D 89, 115003 (2014)
10.1103/PhysRevD.89.115003
SCIPP 14/02; UCD-2014-2
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the two-Higgs-doublet model as a framework in which to evaluate the viability of scenarios in which the sign of the coupling of the observed Higgs boson to down-type fermions (in particular, $b$-quark pairs) is opposite to that of the Standard Model (SM), while at the same time all other tree-level couplings are close to the SM values. We show that, whereas such a scenario is consistent with current LHC observations, both future running at the LHC and a future $e^+ e^-$ linear collider could determine the sign of the Higgs coupling to $b$-quark pairs. Discrimination is possible for two reasons. First, the interference between the $b$-quark and the $t$-quark loop contributions to the $ggh$ coupling changes sign. Second, the charged-Higgs loop contribution to the $\gamma \gamma h$ coupling is large and fairly constant up to the largest charged-Higgs mass allowed by tree-level unitarity bounds when the $b$-quark Yukawa coupling has the opposite sign from that of the SM (the change in sign of the interference terms between the $b$-quark loop and the $W$ and $t$ loops having negligible impact).
[ { "created": "Wed, 19 Mar 2014 08:51:51 GMT", "version": "v1" }, { "created": "Wed, 26 Mar 2014 22:05:37 GMT", "version": "v2" }, { "created": "Sat, 7 Jun 2014 14:00:13 GMT", "version": "v3" }, { "created": "Tue, 10 Jun 2014 10:12:54 GMT", "version": "v4" } ]
2014-06-11
[ [ "Ferreira", "P. M.", "" ], [ "Gunion", "John F.", "" ], [ "Haber", "Howard E.", "" ], [ "Santos", "Rui", "" ] ]
We consider the two-Higgs-doublet model as a framework in which to evaluate the viability of scenarios in which the sign of the coupling of the observed Higgs boson to down-type fermions (in particular, $b$-quark pairs) is opposite to that of the Standard Model (SM), while at the same time all other tree-level couplings are close to the SM values. We show that, whereas such a scenario is consistent with current LHC observations, both future running at the LHC and a future $e^+ e^-$ linear collider could determine the sign of the Higgs coupling to $b$-quark pairs. Discrimination is possible for two reasons. First, the interference between the $b$-quark and the $t$-quark loop contributions to the $ggh$ coupling changes sign. Second, the charged-Higgs loop contribution to the $\gamma \gamma h$ coupling is large and fairly constant up to the largest charged-Higgs mass allowed by tree-level unitarity bounds when the $b$-quark Yukawa coupling has the opposite sign from that of the SM (the change in sign of the interference terms between the $b$-quark loop and the $W$ and $t$ loops having negligible impact).
hep-ph/9305267
null
Patricia Ball
The Semileptonic Decays $D\to \pi(\rho) e \nu$ and $B\to \pi (\rho) e \nu$ from QCD Sum Rules
23 pages, 12 figures included as uu-encoded file, needs REVTEX, TUM--T31--39/93
Phys.Rev.D48:3190-3203,1993
10.1103/PhysRevD.48.3190
null
hep-ph
null
We investigate the semileptonic decays of B and D mesons into $\pi$ and $\rho$ mesons, respectively, by means of QCD sum rules. We find that for the vector formfactors involved the pole dominance hypothesis is valid to good accuracy with pole masses in the expected range. Pole dominance, however, does not apply to the axial formfactors which results in specific predictions for the predominant polarization of the $\rho$ meson and the shape of the lepton spectrum. For the total decay rates we find $\Gamma (\bar B^0 \to \pi^+ e^- \bar\nu) = (5.1\pm 1.1)\,|V_{ub}|^2\, 10^{12}\,{\rm s^{-1}}$, $\Gamma ( D^0 \to \pi^- e^+ \nu) = (8.0\pm 1.7)\,|V_{cd}|^2\, 10^{10}\,{\rm s^{-1}}$, $\Gamma (\bar B^0 \to \rho^+ e^- \bar\nu) = (1.2\pm 0.4\,)\,|V_{ub}|^2\, 10^{13}\,{\rm s^{-1}}$ and $\Gamma (D^0 \to \rho^- e^+\nu) = (2.4\pm 0.7)\,|V_{cd}|^2\, 10^{9}\,{\rm s^{-1}}$.
[ { "created": "Fri, 14 May 1993 07:28:19 GMT", "version": "v1" } ]
2010-11-01
[ [ "Ball", "Patricia", "" ] ]
We investigate the semileptonic decays of B and D mesons into $\pi$ and $\rho$ mesons, respectively, by means of QCD sum rules. We find that for the vector formfactors involved the pole dominance hypothesis is valid to good accuracy with pole masses in the expected range. Pole dominance, however, does not apply to the axial formfactors which results in specific predictions for the predominant polarization of the $\rho$ meson and the shape of the lepton spectrum. For the total decay rates we find $\Gamma (\bar B^0 \to \pi^+ e^- \bar\nu) = (5.1\pm 1.1)\,|V_{ub}|^2\, 10^{12}\,{\rm s^{-1}}$, $\Gamma ( D^0 \to \pi^- e^+ \nu) = (8.0\pm 1.7)\,|V_{cd}|^2\, 10^{10}\,{\rm s^{-1}}$, $\Gamma (\bar B^0 \to \rho^+ e^- \bar\nu) = (1.2\pm 0.4\,)\,|V_{ub}|^2\, 10^{13}\,{\rm s^{-1}}$ and $\Gamma (D^0 \to \rho^- e^+\nu) = (2.4\pm 0.7)\,|V_{cd}|^2\, 10^{9}\,{\rm s^{-1}}$.
hep-ph/0501189
Marek Karliner
Marek Karliner and Harry J. Lipkin
New tests for experiments producing pentaquarks
Following readers' comments, stressing applicability to both fixed target and collider exps, in both Theta^+ and Theta_c searches, especially with low stats; reflected also in title change
Phys.Lett. B616 (2005) 191-195
10.1016/j.physletb.2005.04.048
Cavendish-HEP-05/04, TAUP 2794-05, WIS/1/05-JAN-DPP, ANL-HEP-PR-05-5
hep-ph hep-ex nucl-ex
null
The distribution of the squared momentum difference |P_A|^2 - |P_B|^2 between the momenta in the laboratory system of two experimentally observed particles A and B provides a test for whether an observed mass peak indicates a real resonance rather than nonresonant background or kinematic reflection. The angular distribution of the relative momenta in the center-of-mass system exhibits a forward-backward symmetry in the production and decay of any resonance with a definite parity. This symmetry is not expected in other nonresonant processes and can be expressed without needing angular distributions in terms of the easily measured momenta in the laboratory frame that are already measured and used to calculate the invariant mass of the system. Our test is especially useful for low statistics experiments where the full angular distribution cannot be determined. It can be applied to both fixed-target and collider searches for the Theta^+ and Theta_c pentaquarks.
[ { "created": "Thu, 20 Jan 2005 13:36:41 GMT", "version": "v1" }, { "created": "Mon, 24 Jan 2005 19:58:56 GMT", "version": "v2" } ]
2010-04-05
[ [ "Karliner", "Marek", "" ], [ "Lipkin", "Harry J.", "" ] ]
The distribution of the squared momentum difference |P_A|^2 - |P_B|^2 between the momenta in the laboratory system of two experimentally observed particles A and B provides a test for whether an observed mass peak indicates a real resonance rather than nonresonant background or kinematic reflection. The angular distribution of the relative momenta in the center-of-mass system exhibits a forward-backward symmetry in the production and decay of any resonance with a definite parity. This symmetry is not expected in other nonresonant processes and can be expressed without needing angular distributions in terms of the easily measured momenta in the laboratory frame that are already measured and used to calculate the invariant mass of the system. Our test is especially useful for low statistics experiments where the full angular distribution cannot be determined. It can be applied to both fixed-target and collider searches for the Theta^+ and Theta_c pentaquarks.
1703.02964
Georgios K. Karananas Dr.
Georgios K. Karananas, Mikhail Shaposhnikov
Gauge coupling unification without leptoquarks
Journal version---discussion extended, typos corrected, references added
Phys. Lett. B 771 (2017) 332-338
10.1016/j.physletb.2017.05.065
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an interpretation of the gauge coupling unification scale which is not related to any new particle threshold. We revisit Grand Unified Theories and show that it is possible to completely eliminate the scalar as well as vector leptoquarks from the particle physics spectrum. As a consequence, in our approach the gauge hierarchy problem is put on different grounds, and the proton may be absolutely stable. In order to achieve that, we employ a number of nonlinear gauge-invariant constraints which only affect the superheavy degrees of freedom. We illustrate our considerations in a model based on the SU(5) group, with the generalization to other groups being straightforward. We discuss how scale or conformal invariance may be added to our proposal.
[ { "created": "Wed, 8 Mar 2017 18:44:13 GMT", "version": "v1" }, { "created": "Fri, 2 Jun 2017 09:09:21 GMT", "version": "v2" } ]
2017-06-05
[ [ "Karananas", "Georgios K.", "" ], [ "Shaposhnikov", "Mikhail", "" ] ]
We propose an interpretation of the gauge coupling unification scale which is not related to any new particle threshold. We revisit Grand Unified Theories and show that it is possible to completely eliminate the scalar as well as vector leptoquarks from the particle physics spectrum. As a consequence, in our approach the gauge hierarchy problem is put on different grounds, and the proton may be absolutely stable. In order to achieve that, we employ a number of nonlinear gauge-invariant constraints which only affect the superheavy degrees of freedom. We illustrate our considerations in a model based on the SU(5) group, with the generalization to other groups being straightforward. We discuss how scale or conformal invariance may be added to our proposal.
0907.4319
Ralf Rapp
R. Rapp, F. Riek, H. van Hees, V. Greco, M. Mannarelli
Nonperturbative Heavy-Quark Interactions in the QGP
4 pages + 6 eps figures, proceedings contribution to Quark Matter 2009, Knoxville (TN), Mar 30 - Apr 04; v2: 3 figs. updated for b/w viewing
Nucl.Phys.A830:861c-864c,2009
10.1016/j.nuclphysa.2009.10.078
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We adopt a $T$-matrix approach to study quarkonium properties and heavy-quark transport in a Quark-Gluon Plasma. The $T$-matrix approach is well suited to implement potential scattering and thus provides a common framework for low-momentum transfer interactions in heavy-heavy and heavy-light quark systems. We assume that the underlying potentials can be estimated from the heavy-quark free energy computed in lattice QCD. We discuss constraints from vacuum spectroscopy, uncertainties arising from different choices of the potential, and the role of elastic and inelastic widths which are naturally accounted for in the $T$-matrix formalism.
[ { "created": "Fri, 24 Jul 2009 15:21:14 GMT", "version": "v1" }, { "created": "Thu, 24 Sep 2009 16:19:12 GMT", "version": "v2" } ]
2009-11-18
[ [ "Rapp", "R.", "" ], [ "Riek", "F.", "" ], [ "van Hees", "H.", "" ], [ "Greco", "V.", "" ], [ "Mannarelli", "M.", "" ] ]
We adopt a $T$-matrix approach to study quarkonium properties and heavy-quark transport in a Quark-Gluon Plasma. The $T$-matrix approach is well suited to implement potential scattering and thus provides a common framework for low-momentum transfer interactions in heavy-heavy and heavy-light quark systems. We assume that the underlying potentials can be estimated from the heavy-quark free energy computed in lattice QCD. We discuss constraints from vacuum spectroscopy, uncertainties arising from different choices of the potential, and the role of elastic and inelastic widths which are naturally accounted for in the $T$-matrix formalism.
hep-ph/9712473
Hai-Yang Cheng
Hai-Yang Cheng
Remarks on Next-to-Leading Order Analysis of Polarized Deep Inelastic Scattering Data
10 pages, 1 figure. A new reference is added and a new paragraph after Eq.(10) is presented. To be published in Phys. Lett. B
Phys.Lett. B427 (1998) 371-376
10.1016/S0370-2693(98)00366-9
null
hep-ph hep-ex
null
Since the x dependence of the axial-anomaly effect in inclusive polarized deep inelastic scattering is fixed, the transformation from the $\bar{MS}$ scheme to different factorization schemes are not arbitrary. If the quark spin distribution is demanded to be anomaly-free so that it does not evolve with $Q^2$ and hard gluons contribute to the first moment of $g_1(x)$, then all the moments of coefficient and splitting functions are fixed by perturbative QCD for a given $\gamma_5$ prescription, contrary to the commonly used Adler-Bardeen (AB) or AB-like scheme. It is urged that, in order to correctly demonstrate the effect of factorization scheme dependence, the QCD analysis of polarized structure functions in next-to-leading order should be performed, besides the $\bar{MS}$ scheme, in the chiral-invariant factorization scheme in which the axial anomaly resides in the gluon coefficient function, instead of the less consistent and ambiguous AB scheme.
[ { "created": "Sun, 21 Dec 1997 23:24:32 GMT", "version": "v1" }, { "created": "Thu, 25 Dec 1997 23:23:14 GMT", "version": "v2" }, { "created": "Fri, 27 Mar 1998 23:25:21 GMT", "version": "v3" } ]
2009-10-30
[ [ "Cheng", "Hai-Yang", "" ] ]
Since the x dependence of the axial-anomaly effect in inclusive polarized deep inelastic scattering is fixed, the transformation from the $\bar{MS}$ scheme to different factorization schemes are not arbitrary. If the quark spin distribution is demanded to be anomaly-free so that it does not evolve with $Q^2$ and hard gluons contribute to the first moment of $g_1(x)$, then all the moments of coefficient and splitting functions are fixed by perturbative QCD for a given $\gamma_5$ prescription, contrary to the commonly used Adler-Bardeen (AB) or AB-like scheme. It is urged that, in order to correctly demonstrate the effect of factorization scheme dependence, the QCD analysis of polarized structure functions in next-to-leading order should be performed, besides the $\bar{MS}$ scheme, in the chiral-invariant factorization scheme in which the axial anomaly resides in the gluon coefficient function, instead of the less consistent and ambiguous AB scheme.
0904.2005
Sally Dawson
Sally Dawson and Wenbin Yan
Hiding the Higgs Boson with Multiple Scalars
13 pages
Phys.Rev.D79:095002,2009
10.1103/PhysRevD.79.095002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider models with multiple Higgs scalar gauge singlets and the resulting restrictions on the parameters from precision electroweak measurements. In these models, the scalar singlets mix with the SU(2) Higgs doublet, potentially leading to reduced couplings of the scalars to fermions and gauge bosons relative to the Standard Model Higgs boson couplings. Such models can make the Higgs sector difficult to explore at the LHC. We emphasize the new physics resulting from the addition of at least two scalar Higgs singlets.
[ { "created": "Mon, 13 Apr 2009 20:07:08 GMT", "version": "v1" } ]
2009-10-29
[ [ "Dawson", "Sally", "" ], [ "Yan", "Wenbin", "" ] ]
We consider models with multiple Higgs scalar gauge singlets and the resulting restrictions on the parameters from precision electroweak measurements. In these models, the scalar singlets mix with the SU(2) Higgs doublet, potentially leading to reduced couplings of the scalars to fermions and gauge bosons relative to the Standard Model Higgs boson couplings. Such models can make the Higgs sector difficult to explore at the LHC. We emphasize the new physics resulting from the addition of at least two scalar Higgs singlets.
1608.00087
Yuya Yamaguchi
Naoyuki Haba, Hiroyuki Ishida, Nobuchika Okada and Yuya Yamaguchi
Multiple-point principle with a scalar singlet extension of the Standard Model
17 pages, 6 figures, version accepted for publication in PTEP
Prog. Theor. Exp. Phys. (2017) 013B03
10.1093/ptep/ptw186
SU-HET-04-2016
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a scalar singlet extension of the standard model, in which the multiple-point principle (MPP) condition of a vanishing Higgs potential at the Planck scale is realized. Although there have been lots of attempts to realize the MPP at the Planck scale, the realization with keeping naturalness is quite difficult. Our model can easily achieve the MPP at the Planck scale without large Higgs mass corrections. It is worth noting that the electroweak symmetry can be radiatively broken in our model. In the naturalness point of view, the singlet scalar mass should be of ${\cal O}(1)\,{\rm TeV}$ or less. We also consider right-handed neutrino extension of the model for neutrino mass generation. The model does not affect the MPP scenario, and might keep the naturalness with the new particle mass scale beyond TeV, thanks to accidental cancellation of Higgs mass corrections.
[ { "created": "Sat, 30 Jul 2016 07:59:50 GMT", "version": "v1" }, { "created": "Mon, 23 Jan 2017 06:57:46 GMT", "version": "v2" } ]
2017-01-24
[ [ "Haba", "Naoyuki", "" ], [ "Ishida", "Hiroyuki", "" ], [ "Okada", "Nobuchika", "" ], [ "Yamaguchi", "Yuya", "" ] ]
We suggest a scalar singlet extension of the standard model, in which the multiple-point principle (MPP) condition of a vanishing Higgs potential at the Planck scale is realized. Although there have been lots of attempts to realize the MPP at the Planck scale, the realization with keeping naturalness is quite difficult. Our model can easily achieve the MPP at the Planck scale without large Higgs mass corrections. It is worth noting that the electroweak symmetry can be radiatively broken in our model. In the naturalness point of view, the singlet scalar mass should be of ${\cal O}(1)\,{\rm TeV}$ or less. We also consider right-handed neutrino extension of the model for neutrino mass generation. The model does not affect the MPP scenario, and might keep the naturalness with the new particle mass scale beyond TeV, thanks to accidental cancellation of Higgs mass corrections.
hep-ph/0504176
Sameer Ikhdair
Sameer M. Ikhdair
Theoretical Status of the $B_{c}$ Meson in the Shifted l-Expansion Technique
33 pages, 1 figure
null
null
null
hep-ph
null
In the framework of phenomenological static and QCD-motivated model potentials for heavy quarkonium, we compute the $\bar{b}c$ mass spectrum as well as its $\QTR{rm}{1S}$ hyperfine splitting using the recently introduced shifted $l$- expansion technique. We also predict the leptonic constant \ $f_{B_{c}}$ of the lightest pseudoscalar $B_{c}$ and $f_{B_{c}^{\ast}}$ of the vector $B_{c}^{\ast}$ states taking into account the one-loop and two-loop QCD corrections. Further, we use the scaling relation to predict the leptonic constant of the R{rm}{nS}$-states of the $\bar{b}c$ system. For the sake of comparison, we use the same fitting parameters of our previous model potentials. From our results we conclude that shifted $l$-expansion method has the same accuracy, convergence and status as our previous work.
[ { "created": "Wed, 20 Apr 2005 14:10:47 GMT", "version": "v1" }, { "created": "Thu, 21 Apr 2005 11:49:20 GMT", "version": "v2" } ]
2007-05-23
[ [ "Ikhdair", "Sameer M.", "" ] ]
In the framework of phenomenological static and QCD-motivated model potentials for heavy quarkonium, we compute the $\bar{b}c$ mass spectrum as well as its $\QTR{rm}{1S}$ hyperfine splitting using the recently introduced shifted $l$- expansion technique. We also predict the leptonic constant \ $f_{B_{c}}$ of the lightest pseudoscalar $B_{c}$ and $f_{B_{c}^{\ast}}$ of the vector $B_{c}^{\ast}$ states taking into account the one-loop and two-loop QCD corrections. Further, we use the scaling relation to predict the leptonic constant of the R{rm}{nS}$-states of the $\bar{b}c$ system. For the sake of comparison, we use the same fitting parameters of our previous model potentials. From our results we conclude that shifted $l$-expansion method has the same accuracy, convergence and status as our previous work.
1012.4922
Romuald Wit
K. Fialkowski and R. Wit
On the multiplicity distributions at LHC energies
12 pages, 6 figures
Acta Physica Polonica B42 (2011) 293
10.5506/APhysPolB.42.293
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ALICE and CMS data on the multiplicity distributions are compared with the lower energy data and with the results from the 8.142 version of the PYTHIA MC event generator with two tunings. The ALICE data for moments are used to calculate the factorial cumulants. It is suggested that the data on moments or cumulants are well suited to specify the optimal tuning of the model parameters.
[ { "created": "Wed, 22 Dec 2010 10:06:17 GMT", "version": "v1" } ]
2011-02-22
[ [ "Fialkowski", "K.", "" ], [ "Wit", "R.", "" ] ]
The ALICE and CMS data on the multiplicity distributions are compared with the lower energy data and with the results from the 8.142 version of the PYTHIA MC event generator with two tunings. The ALICE data for moments are used to calculate the factorial cumulants. It is suggested that the data on moments or cumulants are well suited to specify the optimal tuning of the model parameters.
hep-ph/9908457
Asakawa Eri
Eri Asakawa
Heavy Higgs Productions at $\gamma \gamma$ Colliders
5 pages, LaTeX file with 2 PS figures. Figures and tables changed. Talk given at World-Wide Study of Physics and Detectors for Future Linear Colliders (LCWS 99), Sitges, Barcelona, Spain, 28 Apr - 5 May 1999
null
null
OCHA-PP-140
hep-ph
null
Multi-Higgs doublet models include more than one neutral Higgs bosons, some of which have different properties under a CP transformation. We examine their productions at $\gamma \gamma$ colliders. It is found that helicity observations of final top-pairs can be powerful tools to distinguish their CP properties, especially when masses of the Higgs bosons are almost degenerate.
[ { "created": "Wed, 25 Aug 1999 03:02:01 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 1999 14:12:18 GMT", "version": "v2" } ]
2007-05-23
[ [ "Asakawa", "Eri", "" ] ]
Multi-Higgs doublet models include more than one neutral Higgs bosons, some of which have different properties under a CP transformation. We examine their productions at $\gamma \gamma$ colliders. It is found that helicity observations of final top-pairs can be powerful tools to distinguish their CP properties, especially when masses of the Higgs bosons are almost degenerate.
hep-ph/9302270
Evan Reidell
E. P. Gilson and R. L. Jaffe
Very Small Strangelets
13 pages, MIT CTP#2173
Phys.Rev.Lett. 71 (1993) 332-335
10.1103/PhysRevLett.71.332
null
hep-ph
null
We study the stability of small strangelets by employing a simple model of strange matter as a gas of non-interacting fermions confined in a bag. We solve the Dirac equation and populate the energy levels of the bag one quark at a time. Our results show that for system parameters such that strange matter is unbound in bulk, there may still exist strangelets with $A<100$ that are stable and/or metastable. The lifetime of these strangelets may be too small to detect in current accelerator experiments, however.
[ { "created": "Wed, 17 Feb 1993 20:53:05 GMT", "version": "v1" } ]
2009-10-22
[ [ "Gilson", "E. P.", "" ], [ "Jaffe", "R. L.", "" ] ]
We study the stability of small strangelets by employing a simple model of strange matter as a gas of non-interacting fermions confined in a bag. We solve the Dirac equation and populate the energy levels of the bag one quark at a time. Our results show that for system parameters such that strange matter is unbound in bulk, there may still exist strangelets with $A<100$ that are stable and/or metastable. The lifetime of these strangelets may be too small to detect in current accelerator experiments, however.
1202.2019
Simon Badger
Simon Badger, Hjalte Frellesvig, Yang Zhang
Hepta-Cuts of Two-Loop Scattering Amplitudes
37 pages, 6 figures. version 2 : minor updates, published version
null
10.1007/JHEP04(2012)055
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values. Using Gram matrix constraints we derive a general parameterisation of the integrand which can be computed using polynomial fitting techniques. The resulting expression is further reduced to master integrals using conventional integration by parts methods. We consider both planar and non-planar topologies for 2 to 2 scattering processes and apply the method to compute hepta-cut contributions to gluon-gluon scattering in Yang-Mills theory with adjoint fermions and scalars.
[ { "created": "Thu, 9 Feb 2012 15:33:46 GMT", "version": "v1" }, { "created": "Tue, 17 Apr 2012 15:24:14 GMT", "version": "v2" } ]
2012-04-18
[ [ "Badger", "Simon", "" ], [ "Frellesvig", "Hjalte", "" ], [ "Zhang", "Yang", "" ] ]
We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values. Using Gram matrix constraints we derive a general parameterisation of the integrand which can be computed using polynomial fitting techniques. The resulting expression is further reduced to master integrals using conventional integration by parts methods. We consider both planar and non-planar topologies for 2 to 2 scattering processes and apply the method to compute hepta-cut contributions to gluon-gluon scattering in Yang-Mills theory with adjoint fermions and scalars.
hep-ph/0504255
Szymanowski Lech dr
B. Pire and L. Szymanowski
QCD analysis of bar p N -> gamma* pi in the scaling limit
15 pages, 1 .eps figure, to be published in Phys. Lett. B. Equation 23 corrected in version 3
Phys.Lett.B622:83-92,2005
10.1016/j.physletb.2005.06.080
null
hep-ph
null
We study the scaling regime of nucleon - anti-nucleon annihilation into a deeply virtual photon and a meson, bar p N -> gamma* pi. We obtain the leading twist amplitude in the kinematical region where it factorizes into an antiproton distribution amplitude, a short-distance matrix element related to nucleon form factor and the long-distance dominated transition distribution amplitudes which describe the nucleon to meson transition. We give the Q^2 evolution equation for these transition distribution amplitudes. The scaling of the cross section of this process may be tested at the proposed GSI intense anti-proton beam facility FAIR with the PANDA or PAX detectors. We comment on related processes such as pi N -> N' gamma* and gamma* N -> N' pi which may be experimentally studied at intense meson beams facilities and at JLab or Hermes, respectively.
[ { "created": "Wed, 27 Apr 2005 09:54:37 GMT", "version": "v1" }, { "created": "Tue, 28 Jun 2005 16:50:11 GMT", "version": "v2" }, { "created": "Thu, 8 Feb 2007 17:56:15 GMT", "version": "v3" } ]
2014-11-18
[ [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ] ]
We study the scaling regime of nucleon - anti-nucleon annihilation into a deeply virtual photon and a meson, bar p N -> gamma* pi. We obtain the leading twist amplitude in the kinematical region where it factorizes into an antiproton distribution amplitude, a short-distance matrix element related to nucleon form factor and the long-distance dominated transition distribution amplitudes which describe the nucleon to meson transition. We give the Q^2 evolution equation for these transition distribution amplitudes. The scaling of the cross section of this process may be tested at the proposed GSI intense anti-proton beam facility FAIR with the PANDA or PAX detectors. We comment on related processes such as pi N -> N' gamma* and gamma* N -> N' pi which may be experimentally studied at intense meson beams facilities and at JLab or Hermes, respectively.
hep-ph/0306138
Mirco Cannoni
D. A. Anipko, M. Cannoni, I. F. Ginzburg, O. Panella, A. V. Pak
Charge asymmetries in $\gamma\gamma \to \mu^+\mu^- + \nu_{\mu} \bar{\nu}_\mu$ / $\gamma \gamma \to W^\pm\mu^\mp +\nu_\mu$ with polarized photons
Talk presented by I. F. Ginzburg at Photon 2003: International Conference on the Structure and Interactions of the Photon and 15th International Workshop on Photon-Photon Collisions, Frascati, Italy, 7-11 Apr 2003
null
10.1016/S0920-5632(03)02357-0
null
hep-ph
null
It is shown that the difference in the distributions of positive ($\mu^+$) and negative charged leptons ($\mu^-$) in reactions $\gamma \gamma \to \mu^+\mu^-+\nu\bar\nu$ and $\gamma \gamma \to W^\pm\mu^\mp +\nu(\bar\nu)$ at $\sqrt{s}>200$ GeV leads to observable {\em charge asymmetry} of muons which is sensitive to New Physics effects.
[ { "created": "Mon, 16 Jun 2003 17:19:11 GMT", "version": "v1" } ]
2009-11-10
[ [ "Anipko", "D. A.", "" ], [ "Cannoni", "M.", "" ], [ "Ginzburg", "I. F.", "" ], [ "Panella", "O.", "" ], [ "Pak", "A. V.", "" ] ]
It is shown that the difference in the distributions of positive ($\mu^+$) and negative charged leptons ($\mu^-$) in reactions $\gamma \gamma \to \mu^+\mu^-+\nu\bar\nu$ and $\gamma \gamma \to W^\pm\mu^\mp +\nu(\bar\nu)$ at $\sqrt{s}>200$ GeV leads to observable {\em charge asymmetry} of muons which is sensitive to New Physics effects.
hep-ph/0009204
Adrian Kent
Adrian Kent (DAMTP, University of Cambridge)
A critical look at risk assessments for global catastrophes
Minor corrections and note added July 2015. Previous arxiv version corresponds to 2004 journal published version
Risk Anal. 24 (2004) 157-168
null
DAMTP-2000-105
hep-ph hep-th physics.soc-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent papers by Busza et al. (BJSW) and Dar et al. (DDH) argue that astrophysical data can be used to establish small bounds on the risk of a "killer strangelet" catastrophe scenario in the RHIC and ALICE collider experiments. DDH and other commentators (initially including BJSW) suggested that these empirical bounds alone do give sufficient reassurance. This seems unsupportable when the bounds are expressed in terms of expected cost -- a good measure, according to standard risk analysis arguments. For example, DDH's main bound, $p_{\rm catastrophe} < 2 \times 10^{-8}$, implies only that the expectation value of the number of deaths is bounded by 120. This paper reappraises the DDH and BJSW risk bounds by comparing risk policy in other areas. For example, it is noted that, even if highly risk tolerant assumptions are made and no value is placed on the lives of future generations, a catastrophe risk no higher than $\approx 10^{-15}$ per year would be required for consistency with established policy for radiation hazard risk minimization. It is concluded that the costs of small risks of catastrophe have been significantly underestimated by BJSW (initially), by DDH and by other commentators. Lessons for future policy are proposed.
[ { "created": "Mon, 18 Sep 2000 16:07:30 GMT", "version": "v1" }, { "created": "Thu, 21 Sep 2000 11:05:26 GMT", "version": "v2" }, { "created": "Thu, 30 Aug 2001 14:07:58 GMT", "version": "v3" }, { "created": "Mon, 21 Oct 2002 05:41:19 GMT", "version": "v4" }, { "created": "Wed, 13 Nov 2002 03:04:42 GMT", "version": "v5" }, { "created": "Wed, 10 Dec 2003 15:20:49 GMT", "version": "v6" }, { "created": "Fri, 24 Jul 2015 11:50:09 GMT", "version": "v7" } ]
2015-07-27
[ [ "Kent", "Adrian", "", "DAMTP, University of Cambridge" ] ]
Recent papers by Busza et al. (BJSW) and Dar et al. (DDH) argue that astrophysical data can be used to establish small bounds on the risk of a "killer strangelet" catastrophe scenario in the RHIC and ALICE collider experiments. DDH and other commentators (initially including BJSW) suggested that these empirical bounds alone do give sufficient reassurance. This seems unsupportable when the bounds are expressed in terms of expected cost -- a good measure, according to standard risk analysis arguments. For example, DDH's main bound, $p_{\rm catastrophe} < 2 \times 10^{-8}$, implies only that the expectation value of the number of deaths is bounded by 120. This paper reappraises the DDH and BJSW risk bounds by comparing risk policy in other areas. For example, it is noted that, even if highly risk tolerant assumptions are made and no value is placed on the lives of future generations, a catastrophe risk no higher than $\approx 10^{-15}$ per year would be required for consistency with established policy for radiation hazard risk minimization. It is concluded that the costs of small risks of catastrophe have been significantly underestimated by BJSW (initially), by DDH and by other commentators. Lessons for future policy are proposed.
hep-ph/9905558
Jan Kalinowski
Jan Kalinowski
Determining SUSY Parameters from Chargino Pair Production
9 pages, 5 figures, uses JHEP.cls (included), talk given at the Corfu Summer Institute on Elementary Particle Physics, 1998
null
null
IFT/99-10
hep-ph
null
A procedure to determine the chargino mixing angles and, subsequently, the fundamental SUSY parameters M2, mu and tan(beta) by measurements of the total cross section and the spin correlations in e+e- annihilation to chi1^+ chi1^- chargino pairs is discussed.
[ { "created": "Mon, 31 May 1999 09:27:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kalinowski", "Jan", "" ] ]
A procedure to determine the chargino mixing angles and, subsequently, the fundamental SUSY parameters M2, mu and tan(beta) by measurements of the total cross section and the spin correlations in e+e- annihilation to chi1^+ chi1^- chargino pairs is discussed.
0909.4444
Christopher Smith
Christopher Smith
Minimal flavor violation in supersymmetric theories
10 pages. Talk given at the Flavianet Topical Workshop "Low energy constraints on extensions of the Standard Model", July 23-27, Kazimierz, Poland
Acta Phys.Polon.Supp.3:53-64,2010
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The minimal flavor violation hypothesis is presented in the context of the MSSM. Its fundamental principles are introduced and motivated, and its phenomenological consequences for FCNC and CP-violating observables as well as for R-parity violating processes are briefly described.
[ { "created": "Thu, 24 Sep 2009 13:50:06 GMT", "version": "v1" } ]
2010-11-02
[ [ "Smith", "Christopher", "" ] ]
The minimal flavor violation hypothesis is presented in the context of the MSSM. Its fundamental principles are introduced and motivated, and its phenomenological consequences for FCNC and CP-violating observables as well as for R-parity violating processes are briefly described.
hep-ph/9812255
J. G. Contreras
J. G. Contreras (CINVESTAV-Merida)
The intercept of the BFKL pomeron from Forward Jets at HERA
10 pages, one figure, accepted for publication in PLB
Phys.Lett. B446 (1999) 158-162
10.1016/S0370-2693(98)01519-6
null
hep-ph
null
Recently the H1 and ZEUS collaborations have presented cross sections for DIS events with a forward jet. The BFKL formalism is able to produce an excellent fit to these data. The extracted intercept of the hard pomeron suggests that when all higher order corrections are taken into account the cross section will still rise very rapidly as expected for low $x$ dynamics.
[ { "created": "Fri, 4 Dec 1998 16:16:04 GMT", "version": "v1" } ]
2009-10-31
[ [ "Contreras", "J. G.", "", "CINVESTAV-Merida" ] ]
Recently the H1 and ZEUS collaborations have presented cross sections for DIS events with a forward jet. The BFKL formalism is able to produce an excellent fit to these data. The extracted intercept of the hard pomeron suggests that when all higher order corrections are taken into account the cross section will still rise very rapidly as expected for low $x$ dynamics.
hep-ph/0310106
Mauro Napsuciale
M. Napsuciale and C. A. Vaquera-Araujo
Equations of motion as projectors and the gyromagnetic factor g_{s}=1/s} from first principles
14 pages, new material included, title changed accordingly
null
null
null
hep-ph
null
In this work we adopt the point of view that the equations of motion satisfied by a field are just a consequence of the representation space which the field belongs to, and the discrete symmetries we impose on it. We illustrate this view point by rederiving Dirac and Proca equations as projectors over the subspaces with well defined parity of (1/2,0)+(0,1/2) and (1/2,0)X(0,1/2) representations respectively. We formulate the equation of motion corresponding to the identification of elementary systems with states in the invariant subspaces of the squared Pauli-Lubanski operator and couple minimally to electromagnetism the corresponding equation for the (s,0)+(0,s) representation space using the gauge principle. We obtain g=1/s for particles with arbitrary spin s as conjectured by Belinfante long ago.
[ { "created": "Thu, 9 Oct 2003 01:19:42 GMT", "version": "v1" }, { "created": "Thu, 15 Jul 2004 23:26:45 GMT", "version": "v2" } ]
2007-05-23
[ [ "Napsuciale", "M.", "" ], [ "Vaquera-Araujo", "C. A.", "" ] ]
In this work we adopt the point of view that the equations of motion satisfied by a field are just a consequence of the representation space which the field belongs to, and the discrete symmetries we impose on it. We illustrate this view point by rederiving Dirac and Proca equations as projectors over the subspaces with well defined parity of (1/2,0)+(0,1/2) and (1/2,0)X(0,1/2) representations respectively. We formulate the equation of motion corresponding to the identification of elementary systems with states in the invariant subspaces of the squared Pauli-Lubanski operator and couple minimally to electromagnetism the corresponding equation for the (s,0)+(0,s) representation space using the gauge principle. We obtain g=1/s for particles with arbitrary spin s as conjectured by Belinfante long ago.
2210.10819
Ting Cheng
Ting Cheng, Manfred Lindner, Manibrata Sen
Implications of a matter-antimatter mass asymmetry in Penning-trap experiments
6 pages, 2 figures, Matches with published version
Phys.Lett.B 844 (2023) 138068
10.1016/j.physletb.2023.138068
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The Standard Model (SM) of particle physics, being a local, unitary and Lorentz-invariant quantum field theory, remains symmetric under the combined action of Charge, Parity, and Time Reversal (CPT) symmetry. This automatically implies that fundamental properties of particles and antiparticles should be equal in magnitude. These fundamental tenets of the CPT principle have been put to stringent tests in recent Penning-trap experiments, where the matter-antimatter mass asymmetry has been measured. In light of these recent advances, we compare the bounds arising on CPT invariance from kaon systems with those from Penning-trap experiments. Using a simple yet powerful argument of mass decomposition of hadrons, we show that bounds on quark-antiquark mass differences from kaon oscillations are way beyond the reach of Penning-trap experiments. We lay out a roadmap to discuss possible reformulations of our understanding of the SM in the case of a discovery of CPT violation by these precision experiments.
[ { "created": "Wed, 19 Oct 2022 18:11:03 GMT", "version": "v1" }, { "created": "Mon, 17 Jul 2023 19:45:16 GMT", "version": "v2" } ]
2023-07-19
[ [ "Cheng", "Ting", "" ], [ "Lindner", "Manfred", "" ], [ "Sen", "Manibrata", "" ] ]
The Standard Model (SM) of particle physics, being a local, unitary and Lorentz-invariant quantum field theory, remains symmetric under the combined action of Charge, Parity, and Time Reversal (CPT) symmetry. This automatically implies that fundamental properties of particles and antiparticles should be equal in magnitude. These fundamental tenets of the CPT principle have been put to stringent tests in recent Penning-trap experiments, where the matter-antimatter mass asymmetry has been measured. In light of these recent advances, we compare the bounds arising on CPT invariance from kaon systems with those from Penning-trap experiments. Using a simple yet powerful argument of mass decomposition of hadrons, we show that bounds on quark-antiquark mass differences from kaon oscillations are way beyond the reach of Penning-trap experiments. We lay out a roadmap to discuss possible reformulations of our understanding of the SM in the case of a discovery of CPT violation by these precision experiments.
hep-ph/0111139
Tamas Csorgo
T. Csorgo
Simple solutions of fireball hydrodynamics for self-similar, ellipsoidal flows
4 pages, revtex4, 3 eps figures, discussion on other exact solutions added (final version)
ActaPhys.Polon.B37:483-494,2006
null
null
hep-ph astro-ph nucl-th physics.flu-dyn
null
A new family of simple, analytic solutions of self-similarly expanding fireballs is found for systems with ellipsoidal symmetry and a direction dependent, generalized Hubble flow. Gaussian, shell like or oscillating density profiles emerge for simple choices of an arbitrary scaling function. New, cylindrically or spherically symmetric as well as approximately one dimensional hydrodynamical solutions are obtained for various special choices of the initial conditions.
[ { "created": "Mon, 12 Nov 2001 15:24:11 GMT", "version": "v1" }, { "created": "Mon, 13 Feb 2006 01:14:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Csorgo", "T.", "" ] ]
A new family of simple, analytic solutions of self-similarly expanding fireballs is found for systems with ellipsoidal symmetry and a direction dependent, generalized Hubble flow. Gaussian, shell like or oscillating density profiles emerge for simple choices of an arbitrary scaling function. New, cylindrically or spherically symmetric as well as approximately one dimensional hydrodynamical solutions are obtained for various special choices of the initial conditions.
hep-ph/0510058
Mikhail Tokarev V
M.Tokarev (1), I.Zborovsky (2) ((1) Joint Institute for Nuclear Research, Dubna, Moscow region, Russia (2) Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Czech Republic)
Verification of Z-scaling in pp Collisions at RHIC
6 pages, LaTeX, 12 figures, Presented at the XXXV International Symposium on Multiparticle Dynamics, Kromeriz, Czech Republic, August 9-15, 2005
AIP Conf.Proc.828:205-210,2006
10.1063/1.2197418
null
hep-ph
null
New experimental data on inclusive spectra of identified particles produced in pp collisions at the RHIC are used to test z-scaling. Energy and multiplicity independence of the scaling function is established. The RHIC data confirm z-scaling observed at U70, ISR, SpS and Tevatron energies. The obtained results are of interest to search for new physics phenomena of particle production in high transverse momentum and high multiplicity region at RHIC, Tevatron and LHC.
[ { "created": "Wed, 5 Oct 2005 13:46:49 GMT", "version": "v1" } ]
2011-03-23
[ [ "Tokarev", "M.", "" ], [ "Zborovsky", "I.", "" ] ]
New experimental data on inclusive spectra of identified particles produced in pp collisions at the RHIC are used to test z-scaling. Energy and multiplicity independence of the scaling function is established. The RHIC data confirm z-scaling observed at U70, ISR, SpS and Tevatron energies. The obtained results are of interest to search for new physics phenomena of particle production in high transverse momentum and high multiplicity region at RHIC, Tevatron and LHC.
1802.07507
Ben King
B. King
Electron-seeded ALP production and ALP decay in an oscillating electromagnetic field
7 pages, 4 figures
null
10.1016/j.physletb.2018.06.016
null
hep-ph physics.optics physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Certain models involving ALPs (axion-like-particles) allow for the coupling of scalars and pseudoscalars to fermions. A derivation of the total rate for production of massive scalars and pseudoscalars by an electron in a monochromatic, circularly-polarised electromagnetic background is presented. In addition, a derivation and the total rate for the decay of massive scalars and pseudoscalars into electron-positron pairs in the same electromagnetic background is given. We conclude by approximating the total yield of ALP production for a typical laser-particle experimental scenario.
[ { "created": "Wed, 21 Feb 2018 10:51:14 GMT", "version": "v1" } ]
2018-06-21
[ [ "King", "B.", "" ] ]
Certain models involving ALPs (axion-like-particles) allow for the coupling of scalars and pseudoscalars to fermions. A derivation of the total rate for production of massive scalars and pseudoscalars by an electron in a monochromatic, circularly-polarised electromagnetic background is presented. In addition, a derivation and the total rate for the decay of massive scalars and pseudoscalars into electron-positron pairs in the same electromagnetic background is given. We conclude by approximating the total yield of ALP production for a typical laser-particle experimental scenario.
1810.04939
Xin-Qiang Li
Quan-Yi Hu, Xin-Qiang Li and Ya-Dong Yang
$b\to c\tau\nu$ Transitions in the Standard Model Effective Field Theory
43 pages, 3 figures and 5 tables; references updated and more discussions added, final version to be published in the journal
null
10.1140/epjc/s10052-019-6766-8
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $R(D^{(\ast)})$ anomalies observed in $B\to D^{(\ast)}\tau\nu$ decays have attracted much attention in recent years. In this paper, we study the $B\to D^{(\ast)}\tau\nu$, $\Lambda_b\to\Lambda_c\tau\nu$, $B_c\to (J/\psi,\,\eta_c)\tau\nu$, $B\to X_c\tau\nu$, and $B_c\to\tau\nu$ decays, all being mediated by the same quark-level $b\to c\tau\nu$ transition, in the Standard Model Effective Field Theory. The most relevant dimension-six operators for these processes are $Q_{lq}^{(3)}$, $Q_{ledq}$, $Q^{(1)}_{lequ}$, and $Q^{(3)}_{lequ}$ in the Warsaw basis. Evolution of the corresponding Wilson coefficients from the new physics scale $\Lambda=1$~TeV down to the characteristic scale $\mu_b\simeq m_b$ is performed at three-loop in QCD and one-loop in EW/QED. It is found that, after taking into account the constraint ${\cal B}(B_c\to\tau\nu)\lesssim 10\%$, a single $\left[C_{lq}^{(3)}\right]_{3323}(\Lambda)$ or $\left[C^{(3)}_{lequ}\right]_{3332}(\Lambda)$ can still be used to resolve the $R(D^{(\ast)})$ anomalies at $1\sigma$, while a single $\left[C^{(1)}_{lequ}\right]_{3332}(\Lambda)$ is already ruled out by the measured $R(D^{(\ast)})$ at more than $3\sigma$. By minimizing the $\chi^2(C_i)$ function constructed based on the current data on $R(D)$, $R(D^\ast)$, $P_\tau(D^\ast)$, $R(J/\psi)$, and $R(X_c)$, we obtain eleven most trustworthy scenarios, each of which can provide a good explanation of the $R(D^{(\ast)})$ anomalies at $1\sigma$. To further discriminate these different scenarios, we predict thirty-one observables associated with the processes considered under each NP scenario. It is found that most of the scenarios can be differentiated from each other by using these observables and their correlations.
[ { "created": "Thu, 11 Oct 2018 10:14:11 GMT", "version": "v1" }, { "created": "Tue, 19 Mar 2019 09:55:05 GMT", "version": "v2" } ]
2019-05-01
[ [ "Hu", "Quan-Yi", "" ], [ "Li", "Xin-Qiang", "" ], [ "Yang", "Ya-Dong", "" ] ]
The $R(D^{(\ast)})$ anomalies observed in $B\to D^{(\ast)}\tau\nu$ decays have attracted much attention in recent years. In this paper, we study the $B\to D^{(\ast)}\tau\nu$, $\Lambda_b\to\Lambda_c\tau\nu$, $B_c\to (J/\psi,\,\eta_c)\tau\nu$, $B\to X_c\tau\nu$, and $B_c\to\tau\nu$ decays, all being mediated by the same quark-level $b\to c\tau\nu$ transition, in the Standard Model Effective Field Theory. The most relevant dimension-six operators for these processes are $Q_{lq}^{(3)}$, $Q_{ledq}$, $Q^{(1)}_{lequ}$, and $Q^{(3)}_{lequ}$ in the Warsaw basis. Evolution of the corresponding Wilson coefficients from the new physics scale $\Lambda=1$~TeV down to the characteristic scale $\mu_b\simeq m_b$ is performed at three-loop in QCD and one-loop in EW/QED. It is found that, after taking into account the constraint ${\cal B}(B_c\to\tau\nu)\lesssim 10\%$, a single $\left[C_{lq}^{(3)}\right]_{3323}(\Lambda)$ or $\left[C^{(3)}_{lequ}\right]_{3332}(\Lambda)$ can still be used to resolve the $R(D^{(\ast)})$ anomalies at $1\sigma$, while a single $\left[C^{(1)}_{lequ}\right]_{3332}(\Lambda)$ is already ruled out by the measured $R(D^{(\ast)})$ at more than $3\sigma$. By minimizing the $\chi^2(C_i)$ function constructed based on the current data on $R(D)$, $R(D^\ast)$, $P_\tau(D^\ast)$, $R(J/\psi)$, and $R(X_c)$, we obtain eleven most trustworthy scenarios, each of which can provide a good explanation of the $R(D^{(\ast)})$ anomalies at $1\sigma$. To further discriminate these different scenarios, we predict thirty-one observables associated with the processes considered under each NP scenario. It is found that most of the scenarios can be differentiated from each other by using these observables and their correlations.
hep-ph/0305311
Gerhard Ecker
V. Cirigliano, G. Ecker, H. Neufeld and A. Pich
Meson resonances, large N_c and chiral symmetry
14 pages
JHEP 0306 (2003) 012
10.1088/1126-6708/2003/06/012
IFIC/03-23, UWThPh-2003-8
hep-ph
null
We investigate the implications of large N_c and chiral symmetry for the mass spectra of meson resonances. Unlike for most other mesons, the mass matrix of the light scalars deviates strongly from its large-N_c limit. We discuss the possible assignments for the lightest scalar nonet that survives in the large-N_c limit.
[ { "created": "Wed, 28 May 2003 15:36:23 GMT", "version": "v1" } ]
2009-11-10
[ [ "Cirigliano", "V.", "" ], [ "Ecker", "G.", "" ], [ "Neufeld", "H.", "" ], [ "Pich", "A.", "" ] ]
We investigate the implications of large N_c and chiral symmetry for the mass spectra of meson resonances. Unlike for most other mesons, the mass matrix of the light scalars deviates strongly from its large-N_c limit. We discuss the possible assignments for the lightest scalar nonet that survives in the large-N_c limit.
hep-ph/0403043
Kazunori Kohri
Kazunori Kohri, Masahiro Yamaguchi and Jun'ichi Yokoyama
Production and dilution of gravitinos by modulus decay
18 pages, 4 figures, to appear in Phys. Rev. D
Phys.Rev. D70 (2004) 043522
10.1103/PhysRevD.70.043522
OU-TAP-227, TU-711
hep-ph astro-ph
null
We study the cosmological consequences of generic scalar fields like moduli which decay only through gravitationally suppressed interactions. We consider a new production mechanism of gravitinos from moduli decay, which might be more effective than previously known mechanisms, and calculate the final gravitino-to-entropy ratio to compare with the constraints imposed by successful big bang nucleosynthesis (BBN) etc., taking possible hadronic decays of gravitinos into account. We find the modulus mass smaller than $\sim 10^4$ TeV is excluded. On the other hand, inflation models with high reheating temperatures $T_{R,\rm inf} \sim 10^{16}$ GeV can be compatible with BBN thanks to the late-time entropy production from the moduli decay if model parameters are appropriately chosen.
[ { "created": "Thu, 4 Mar 2004 08:09:09 GMT", "version": "v1" }, { "created": "Thu, 22 Apr 2004 12:02:32 GMT", "version": "v2" } ]
2009-11-10
[ [ "Kohri", "Kazunori", "" ], [ "Yamaguchi", "Masahiro", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
We study the cosmological consequences of generic scalar fields like moduli which decay only through gravitationally suppressed interactions. We consider a new production mechanism of gravitinos from moduli decay, which might be more effective than previously known mechanisms, and calculate the final gravitino-to-entropy ratio to compare with the constraints imposed by successful big bang nucleosynthesis (BBN) etc., taking possible hadronic decays of gravitinos into account. We find the modulus mass smaller than $\sim 10^4$ TeV is excluded. On the other hand, inflation models with high reheating temperatures $T_{R,\rm inf} \sim 10^{16}$ GeV can be compatible with BBN thanks to the late-time entropy production from the moduli decay if model parameters are appropriately chosen.
1705.09787
Cai-Dian Lu
Cai-Dian Lu and Si-Hong Zhou
Charmless Two-Body B Meson Decays In Factorization Assisted Topological Amplitude Approach
4 pages, no figures. talk given at 52nd Rencontres de Moriond QCD and High Energy Interactions, La Thuile, March 25 - April 1, 2017
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze charmless two-body non-leptonic $B$ decays under the framework of factorization assisted topological amplitude approach. Unlike the conventional flavor diagram approach, we consider flavor $SU(3)$ breaking effect assisted by factorization hypothesis for topological diagram amplitudes of different decay modes, by factorizing out the corresponding decay constants and form factors. The non-perturbative parameters of topology diagram magnitudes $\chi$ and strong phase $\phi$ are universal that can be extracted by $\chi^2$ fit from current abundant experimental data of charmless $B$ decays. The number of free parameters and the $\chi^2$ per degree of freedom are both reduced comparing with previous analysis. With these best fitted parameters, we predict branching fractions and $CP$ asymmetry parameters of nearly 100 $B_{u,d}$ and $B_s$ decay modes. The long-standing $\pi \pi$ and $\pi K$-$CP$ puzzles are solved simultaneously.
[ { "created": "Sat, 27 May 2017 08:53:21 GMT", "version": "v1" } ]
2017-05-30
[ [ "Lu", "Cai-Dian", "" ], [ "Zhou", "Si-Hong", "" ] ]
We analyze charmless two-body non-leptonic $B$ decays under the framework of factorization assisted topological amplitude approach. Unlike the conventional flavor diagram approach, we consider flavor $SU(3)$ breaking effect assisted by factorization hypothesis for topological diagram amplitudes of different decay modes, by factorizing out the corresponding decay constants and form factors. The non-perturbative parameters of topology diagram magnitudes $\chi$ and strong phase $\phi$ are universal that can be extracted by $\chi^2$ fit from current abundant experimental data of charmless $B$ decays. The number of free parameters and the $\chi^2$ per degree of freedom are both reduced comparing with previous analysis. With these best fitted parameters, we predict branching fractions and $CP$ asymmetry parameters of nearly 100 $B_{u,d}$ and $B_s$ decay modes. The long-standing $\pi \pi$ and $\pi K$-$CP$ puzzles are solved simultaneously.
1110.0302
Shi-Yuan Li
Shi-Yuan Li
OPERA Collaboration have observed phase speed of neutrino wave function, while advanced time displacement is mainly due to finite life time of pion
12 pages for 12pt
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First we call the attention that velocity defined by ratio between some intervals of space and time respectively is sometimes ambiguous, in the framework of quantum theory. Velocity in general is not possible to be well defined as some generator of certain space-time symmetry operation. Then in section 3 by analyzing the OPERA experiment we show that the OPERA Collaboration may have measured the phase speed of the neutrino wave function. Employing a very (maybe too) simple model which is just a reproduction from Brillouin's classical book, we demonstrate the phase velocity and group velocity. These are just a qualitative illustration rather than aiming to quantitively explain the OPERA data. However, how to rigorously define the phase containing the particle production ordering information as a space-time distribution observable in QFT needs more investigations. Due to the finite life time of the pions (w.r.t. its flying time in the 1 km long tunnel) which decay to the muon neutrinos, the wave form for neutrinos recorded by OPERA is deformed from that of the proton. Such an effect is estimated to lead to an advanced time displacement of the order of 100ns, which coincides with the measured. Such an effect can only be significant when measuring phase speed and the recorded neutrino events per extraction of proton smaller than one, as the OPERA case.
[ { "created": "Mon, 3 Oct 2011 08:54:51 GMT", "version": "v1" }, { "created": "Tue, 25 Oct 2011 08:45:04 GMT", "version": "v2" }, { "created": "Sun, 4 Dec 2011 06:24:08 GMT", "version": "v3" } ]
2011-12-06
[ [ "Li", "Shi-Yuan", "" ] ]
First we call the attention that velocity defined by ratio between some intervals of space and time respectively is sometimes ambiguous, in the framework of quantum theory. Velocity in general is not possible to be well defined as some generator of certain space-time symmetry operation. Then in section 3 by analyzing the OPERA experiment we show that the OPERA Collaboration may have measured the phase speed of the neutrino wave function. Employing a very (maybe too) simple model which is just a reproduction from Brillouin's classical book, we demonstrate the phase velocity and group velocity. These are just a qualitative illustration rather than aiming to quantitively explain the OPERA data. However, how to rigorously define the phase containing the particle production ordering information as a space-time distribution observable in QFT needs more investigations. Due to the finite life time of the pions (w.r.t. its flying time in the 1 km long tunnel) which decay to the muon neutrinos, the wave form for neutrinos recorded by OPERA is deformed from that of the proton. Such an effect is estimated to lead to an advanced time displacement of the order of 100ns, which coincides with the measured. Such an effect can only be significant when measuring phase speed and the recorded neutrino events per extraction of proton smaller than one, as the OPERA case.
1009.2680
Sven Heinemeyer
S. Heinemeyer, V.A. Khoze, M.G. Ryskin, M. Tasevsky, G. Weiglein
BSM Higgs Physics at the LHC in the Forward Proton Mode
4 pages, 1 figure, talk given by S.H. at the "Physics at the LHC 2010", May 2010, DESY Hamburg, Germany
null
null
DCPT/10/152, DESY 10-152, IPPP/10/76
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the prospects for Central Exclusive Diffractive (CED) production of Higgs bosons in the SM with a fourth generation of fermions at the LHC using forward proton detectors installed at 220m and 420m distance around ATLAS and / or CMS. We discuss the determination of Higgs spin-parity and coupling structures at the LHC and show that the forward proton mode would provide a critical information on the CP properties of the Higgs bosons.
[ { "created": "Tue, 14 Sep 2010 14:27:43 GMT", "version": "v1" } ]
2010-09-15
[ [ "Heinemeyer", "S.", "" ], [ "Khoze", "V. A.", "" ], [ "Ryskin", "M. G.", "" ], [ "Tasevsky", "M.", "" ], [ "Weiglein", "G.", "" ] ]
We review the prospects for Central Exclusive Diffractive (CED) production of Higgs bosons in the SM with a fourth generation of fermions at the LHC using forward proton detectors installed at 220m and 420m distance around ATLAS and / or CMS. We discuss the determination of Higgs spin-parity and coupling structures at the LHC and show that the forward proton mode would provide a critical information on the CP properties of the Higgs bosons.
2208.12254
Andreas Crivellin
Andreas Crivellin, Claudio Andrea Manzari, Bruce Mellado, Salah-Eddine Dahbi
Consistency and Interpretation of the LHC (Di-)Di-Jet Excesses
9 pages, 4 figures, version accepted for publication in PRD
null
10.1103/PhysRevD.107.054045
PSI-PR-22-27, ZU-TH 42/22
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
ATLAS observed a limit for {the cross section of di-jets resonances, which is weaker than expected for a} mass slightly below $\approx$1\TeV. In addition, CMS reported hints for the (non-resonant) pair production of di-jet resonances $X$ via a particle $Y$ at a very similar mass range with a local (global) significance of 3.6\,$\sigma$ (2.5\,$\sigma$) at $m_X\approx950\,$GeV. In this article we show that using the preferred range for $m_X$ from the ATLAS analysis, one can reinterpret the CMS analysis of di-di-jets in terms of a resonant search with $Y\to XX$, with a significantly reduced look-elsewhere effect, finding an excess for $m_Y\!\approx\!3.6$\TeV with a significance of $4.0\,\sigma$ ($3.2\,\sigma$) locally (globally). We present two possible UV completions capable of explaining the (di-)di-jet excesses, one containing two scalar di-quarks, the other one involving heavy gluons based on an $SU(3)_1\!\times\! SU(3)_2\!\times\! SU(3)_3$ gauge symmetry, spontaneously broken to $SU(3)$ color. In the latter case, non-perturbative couplings are required, pointing towards a composite or extra-dimensional framework. In fact, using 5D-AdS space-time, one obtains the correct mass ratio for $m_X/m_Y$, assuming the $X$ is the lowest lying resonance, and predicts a third (di-)di-jet resonance with a mass around $\approx2.2$\TeV.
[ { "created": "Thu, 25 Aug 2022 17:57:36 GMT", "version": "v1" }, { "created": "Mon, 29 Aug 2022 21:59:47 GMT", "version": "v2" }, { "created": "Fri, 24 Mar 2023 15:30:49 GMT", "version": "v3" } ]
2023-04-12
[ [ "Crivellin", "Andreas", "" ], [ "Manzari", "Claudio Andrea", "" ], [ "Mellado", "Bruce", "" ], [ "Dahbi", "Salah-Eddine", "" ] ]
ATLAS observed a limit for {the cross section of di-jets resonances, which is weaker than expected for a} mass slightly below $\approx$1\TeV. In addition, CMS reported hints for the (non-resonant) pair production of di-jet resonances $X$ via a particle $Y$ at a very similar mass range with a local (global) significance of 3.6\,$\sigma$ (2.5\,$\sigma$) at $m_X\approx950\,$GeV. In this article we show that using the preferred range for $m_X$ from the ATLAS analysis, one can reinterpret the CMS analysis of di-di-jets in terms of a resonant search with $Y\to XX$, with a significantly reduced look-elsewhere effect, finding an excess for $m_Y\!\approx\!3.6$\TeV with a significance of $4.0\,\sigma$ ($3.2\,\sigma$) locally (globally). We present two possible UV completions capable of explaining the (di-)di-jet excesses, one containing two scalar di-quarks, the other one involving heavy gluons based on an $SU(3)_1\!\times\! SU(3)_2\!\times\! SU(3)_3$ gauge symmetry, spontaneously broken to $SU(3)$ color. In the latter case, non-perturbative couplings are required, pointing towards a composite or extra-dimensional framework. In fact, using 5D-AdS space-time, one obtains the correct mass ratio for $m_X/m_Y$, assuming the $X$ is the lowest lying resonance, and predicts a third (di-)di-jet resonance with a mass around $\approx2.2$\TeV.
hep-ph/0202238
Yuri V. Kovchegov
Yuri V. Kovchegov (University of Washington)
High Energy QCD and the Large Nc Limit
20 pages, 8 figures, to be published in the proceedings of "The Phenomenology of Large Nc QCD" workshop, 9-11 January 2002, Arizona State University, Tempe, AZ
null
10.1142/9789812776914_0007
NT@UW-02-003
hep-ph
null
We review recent progress in understanding QCD at high energies and the role played in it by the large Nc limit. We discuss unitarization of total hadronic cross sections and saturation of structure functions at high energies.
[ { "created": "Mon, 25 Feb 2002 21:52:44 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kovchegov", "Yuri V.", "", "University of Washington" ] ]
We review recent progress in understanding QCD at high energies and the role played in it by the large Nc limit. We discuss unitarization of total hadronic cross sections and saturation of structure functions at high energies.
hep-ph/0412405
Osamu Yasuda
Osamu Yasuda
Degeneracy and strategies of long baseline and reactor experiments
3 pages, 3 sets of figures, uses espcrc2.sty. Talk given at 6th International Workshop on Neutrino Factories and Superbeams (NuFact 04), Osaka, Japan, 26 Jul - 1 Aug 2004
null
10.1016/j.nuclphysbps.2005.05.049
null
hep-ph
null
Assuming that the JPARC experiment measures the oscillation probabilities $P(\nu_\mu\to\nu_e)$ and $P(\bar{\nu}_\mu\to\bar{\nu}_e)$ at $|\Delta m^2_{31}|L/4E=\pi/2$, I discuss what kind of extra experiment (long baseline or reactor) can contribute to determination of $\theta_{13}$ and the CP phase $\delta$.
[ { "created": "Wed, 29 Dec 2004 09:35:16 GMT", "version": "v1" } ]
2009-11-10
[ [ "Yasuda", "Osamu", "" ] ]
Assuming that the JPARC experiment measures the oscillation probabilities $P(\nu_\mu\to\nu_e)$ and $P(\bar{\nu}_\mu\to\bar{\nu}_e)$ at $|\Delta m^2_{31}|L/4E=\pi/2$, I discuss what kind of extra experiment (long baseline or reactor) can contribute to determination of $\theta_{13}$ and the CP phase $\delta$.
hep-ph/0404222
Stephen Wong
S.M.H. Wong
Out-of-Equilibrium Collinear Enhanced Equilibration in the Bottom-Up Thermalization Scenario in Heavy Ion Collisions
7 embedded EPS figures
null
null
null
hep-ph
null
Experimental measurement of the elliptic flow parameter $v_2$ and hydrodynamic model together showed that thermalization in the central region at the Relativistic Heavy Ion Collider to be perplexingly fast. This is a mystery in itself since none of the numerical perturbative QCD models are able to achieve such a feat. By exploiting a theoretical oversight on collinear processes in an out-of-equilibrium system it is argued that, in the bottom-up thermalization scenario, equilibration can proceed at a higher rate than what is expected in the conventional perturbative QCD picture.
[ { "created": "Sun, 25 Apr 2004 18:54:24 GMT", "version": "v1" }, { "created": "Wed, 28 Apr 2004 07:41:25 GMT", "version": "v2" } ]
2007-05-23
[ [ "Wong", "S. M. H.", "" ] ]
Experimental measurement of the elliptic flow parameter $v_2$ and hydrodynamic model together showed that thermalization in the central region at the Relativistic Heavy Ion Collider to be perplexingly fast. This is a mystery in itself since none of the numerical perturbative QCD models are able to achieve such a feat. By exploiting a theoretical oversight on collinear processes in an out-of-equilibrium system it is argued that, in the bottom-up thermalization scenario, equilibration can proceed at a higher rate than what is expected in the conventional perturbative QCD picture.
1006.0387
Ioannis Bouras
I. Bouras, E. Molnar, H. Niemi, Z. Xu, A. El, O. Fochler, C. Greiner, D.H. Rischke
Investigation of shock waves in the relativistic Riemann problem: A comparison of viscous fluid dynamics to kinetic theory
Version as published in PRC 82, 024910 (2010); 16 pages, 16 figures, typos corrected
Phys.Rev.C82:024910,2010
10.1103/PhysRevC.82.024910
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We solve the relativistic Riemann problem in viscous matter using the relativistic Boltzmann equation and the relativistic causal dissipative fluid-dynamical approach of Israel and Stewart. Comparisons between these two approaches clarify and point out the regime of validity of second-order fluid dynamics in relativistic shock phenomena. The transition from ideal to viscous shocks is demonstrated by varying the shear viscosity to entropy density ratio $\eta/s$. We also find that a good agreement between these two approaches requires a Knudsen number $Kn < 1/2$.
[ { "created": "Wed, 2 Jun 2010 14:18:59 GMT", "version": "v1" }, { "created": "Mon, 7 Jun 2010 17:04:34 GMT", "version": "v2" }, { "created": "Tue, 31 Aug 2010 22:17:51 GMT", "version": "v3" } ]
2014-11-21
[ [ "Bouras", "I.", "" ], [ "Molnar", "E.", "" ], [ "Niemi", "H.", "" ], [ "Xu", "Z.", "" ], [ "El", "A.", "" ], [ "Fochler", "O.", "" ], [ "Greiner", "C.", "" ], [ "Rischke", "D. H.", "" ] ]
We solve the relativistic Riemann problem in viscous matter using the relativistic Boltzmann equation and the relativistic causal dissipative fluid-dynamical approach of Israel and Stewart. Comparisons between these two approaches clarify and point out the regime of validity of second-order fluid dynamics in relativistic shock phenomena. The transition from ideal to viscous shocks is demonstrated by varying the shear viscosity to entropy density ratio $\eta/s$. We also find that a good agreement between these two approaches requires a Knudsen number $Kn < 1/2$.
hep-ph/9804254
Robert Fleischer
Amol Dighe (ICTP), Isard Dunietz (Fermilab), Robert Fleischer (CERN)
Resolving a Discrete Ambiguity in the CKM Angle $\beta$ through $B_{u,d} \to J/\psi K^\ast$ and $B_s \to J/\psi \phi$ Decays
5 pages, LaTeX, no figures
Phys.Lett. B433 (1998) 147-149
10.1016/S0370-2693(98)00680-7
CERN-TH/98-123, FERMILAB-PUB-98/101-T, IC/98/34
hep-ph
null
It is well known that $\sin(2\beta)$, where $\beta$ is one of the angles of the unitarity triangle of the CKM matrix, can be determined in a theoretically clean way by measuring mixing-induced CP violation in the decay $B_d \to J/\psi K_S$. Another clean extraction of this CKM angle is provided by the time-dependent angular distribution for the decay products of $B_d \to J/\psi(\to l^+l^-) K^{\ast0}(\to \pi^0 K_S)$, where we have more observables at our disposal than in the case of $B_d \to J/\psi K_S$, so that in addition to $\sin(2\beta)$ also $\cos(2\beta)$ can be probed in a direct way. Unfortunately a sign ambiguity remains in $\cos(2\beta)$. If it could be resolved, a discrete ambiguity in the extraction of the CKM angle $\beta$ could be resolved as well, which would allow a more incisive test of the CKM model of CP violation. This note shows that detailed time-dependent studies of $B_{u,d} \to J/\psi K^{\ast}$ and $B_s \to J/\psi \phi$ decay processes can determine the sign of $\cos(2\beta)$, thereby removing the corresponding ambiguity in the extraction of the CKM angle $\beta$.
[ { "created": "Wed, 8 Apr 1998 07:49:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Dighe", "Amol", "", "ICTP" ], [ "Dunietz", "Isard", "", "Fermilab" ], [ "Fleischer", "Robert", "", "CERN" ] ]
It is well known that $\sin(2\beta)$, where $\beta$ is one of the angles of the unitarity triangle of the CKM matrix, can be determined in a theoretically clean way by measuring mixing-induced CP violation in the decay $B_d \to J/\psi K_S$. Another clean extraction of this CKM angle is provided by the time-dependent angular distribution for the decay products of $B_d \to J/\psi(\to l^+l^-) K^{\ast0}(\to \pi^0 K_S)$, where we have more observables at our disposal than in the case of $B_d \to J/\psi K_S$, so that in addition to $\sin(2\beta)$ also $\cos(2\beta)$ can be probed in a direct way. Unfortunately a sign ambiguity remains in $\cos(2\beta)$. If it could be resolved, a discrete ambiguity in the extraction of the CKM angle $\beta$ could be resolved as well, which would allow a more incisive test of the CKM model of CP violation. This note shows that detailed time-dependent studies of $B_{u,d} \to J/\psi K^{\ast}$ and $B_s \to J/\psi \phi$ decay processes can determine the sign of $\cos(2\beta)$, thereby removing the corresponding ambiguity in the extraction of the CKM angle $\beta$.
1502.06508
Rome Samanta
Rome Samanta, Mainak Chakraborty, Ambar Ghosal
Evaluation of the Majorana Phases of a General Majorana Neutrino Mass Matrix: Testability of hierarchical Flavour Models
27 pages, 16 figures, 4 tables, to appear in NPB
null
10.1016/j.nuclphysb.2016.01.001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the Majorana phases for a general $3\times3$ complex symmetric neutrino mass matrix on the basis of Mohapatra-Rodejohann's phase convention using the three rephasing invariant quantities $I_{12}$, $I_{13}$ and $I_{23}$ proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses ($\Sigma_im_i$) and the neutrinoless double beta decay ($\beta\beta_{0\nu}$) parameter $|m_{11}|$. This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted hierarchy section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub case following the normal hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.
[ { "created": "Mon, 23 Feb 2015 17:03:49 GMT", "version": "v1" }, { "created": "Sat, 2 Jan 2016 15:25:09 GMT", "version": "v2" } ]
2016-02-17
[ [ "Samanta", "Rome", "" ], [ "Chakraborty", "Mainak", "" ], [ "Ghosal", "Ambar", "" ] ]
We evaluate the Majorana phases for a general $3\times3$ complex symmetric neutrino mass matrix on the basis of Mohapatra-Rodejohann's phase convention using the three rephasing invariant quantities $I_{12}$, $I_{13}$ and $I_{23}$ proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses ($\Sigma_im_i$) and the neutrinoless double beta decay ($\beta\beta_{0\nu}$) parameter $|m_{11}|$. This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted hierarchy section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub case following the normal hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.
1907.00011
Harikrishnan Ramani
Maxim Pospelov, Surjeet Rajendran, Harikrishnan Ramani
Metastable Nuclear Isomers as Dark Matter Accelerators
13 pages, 6 figures
Phys. Rev. D 101, 055001 (2020)
10.1103/PhysRevD.101.055001
null
hep-ph astro-ph.CO hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inelastic dark matter and strongly interacting dark matter are poorly constrained by direct detection experiments since they both require the scattering event to deliver energy from the nucleus into the dark matter in order to have observable effects. We propose to test these scenarios by searching for the collisional de-excitation of meta-stable nuclear isomers by the dark matter particles. The longevity of these isomers is related to a strong suppression of $\gamma$- and $\beta$-transitions, typically inhibited by a large difference in the angular momentum for the nuclear transition. The collisional de-excitation by dark matter is possible since heavy dark matter particles can have a momentum exchange with the nucleus comparable to the inverse nuclear size, hence lifting tremendous angular momentum suppression of the nuclear transition. This de-excitation can be observed either by searching for the direct effects of the decaying isomer, or through the re-scattering or decay of excited dark matter states in a nearby conventional dark matter detector setup. Existing nuclear isomer sources such as naturally occurring $^{180m}$Ta, $^{137m}$Ba produced in decaying Cesium in nuclear waste, $^{177m}$Lu from medical waste, and $^{178m}$Hf from the Department of Energy storage can be combined with current dark matter detector technology to search for this class of dark matter.
[ { "created": "Fri, 28 Jun 2019 18:00:04 GMT", "version": "v1" }, { "created": "Fri, 10 Jul 2020 18:24:23 GMT", "version": "v2" } ]
2020-07-14
[ [ "Pospelov", "Maxim", "" ], [ "Rajendran", "Surjeet", "" ], [ "Ramani", "Harikrishnan", "" ] ]
Inelastic dark matter and strongly interacting dark matter are poorly constrained by direct detection experiments since they both require the scattering event to deliver energy from the nucleus into the dark matter in order to have observable effects. We propose to test these scenarios by searching for the collisional de-excitation of meta-stable nuclear isomers by the dark matter particles. The longevity of these isomers is related to a strong suppression of $\gamma$- and $\beta$-transitions, typically inhibited by a large difference in the angular momentum for the nuclear transition. The collisional de-excitation by dark matter is possible since heavy dark matter particles can have a momentum exchange with the nucleus comparable to the inverse nuclear size, hence lifting tremendous angular momentum suppression of the nuclear transition. This de-excitation can be observed either by searching for the direct effects of the decaying isomer, or through the re-scattering or decay of excited dark matter states in a nearby conventional dark matter detector setup. Existing nuclear isomer sources such as naturally occurring $^{180m}$Ta, $^{137m}$Ba produced in decaying Cesium in nuclear waste, $^{177m}$Lu from medical waste, and $^{178m}$Hf from the Department of Energy storage can be combined with current dark matter detector technology to search for this class of dark matter.
hep-ph/0203196
Rishikesh Vaidya
Rishikesh Vaidya
Constraining R Violation from Anomalous Abelian Family Symmetry
7 pages, talk given at 7th Workshop on High Energy Particle Phenomenology, HRI, Allahabad, India and XIV DAE Symposium, Hyderabad, India few references added
null
null
null
hep-ph
null
The patterns of R violation resulting from imposition of a gauged U(1) horizontal symmetry, on the minimal supersymmetric standard model are systematically analyzed. We concentrate on a class of models with integer U(1) charges chosen to reproduce the quark masses and mixings as well as charged lepton masses exactly or approximately. The U(1) charges are further restricted from the requirement that very large bilinear lepton number violating terms should not be allowed in the super-potential. It is shown that all the trilinear $\lambda'_{ijk}$ and all but at most two trilinear $\lambda_{ijk}$ couplings vanish or are enormously suppressed.
[ { "created": "Wed, 20 Mar 2002 12:57:15 GMT", "version": "v1" }, { "created": "Tue, 9 Jul 2002 18:47:55 GMT", "version": "v2" } ]
2007-05-23
[ [ "Vaidya", "Rishikesh", "" ] ]
The patterns of R violation resulting from imposition of a gauged U(1) horizontal symmetry, on the minimal supersymmetric standard model are systematically analyzed. We concentrate on a class of models with integer U(1) charges chosen to reproduce the quark masses and mixings as well as charged lepton masses exactly or approximately. The U(1) charges are further restricted from the requirement that very large bilinear lepton number violating terms should not be allowed in the super-potential. It is shown that all the trilinear $\lambda'_{ijk}$ and all but at most two trilinear $\lambda_{ijk}$ couplings vanish or are enormously suppressed.
1903.04975
Nelly Sagidova
S.Belostotski, N.Sagidova, A.Vorobyev
Proton radius reconstruction from simulated electron-proton elastic scattering cross sections at low transfer momenta
null
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This note is motivated by preparations of a new $ep$ elastic scattering experiment in the low transfer momentum region to be carried out in the 720 MeV electron beam of the Mainz Microtron MAMI. This experiment will use an innovative method allowing for detection of recoil protons in coincidence with the scattered electrons. The goal is to measure the $ep$ differential cross sections in the $Q^2$ range from 0.001 GeV$^2$ to 0.04 GeV$^2$ and to determine the proton charge radius with sub-percent precision.
[ { "created": "Tue, 12 Mar 2019 15:05:30 GMT", "version": "v1" }, { "created": "Thu, 14 Mar 2019 13:06:22 GMT", "version": "v2" }, { "created": "Mon, 18 Mar 2019 21:39:59 GMT", "version": "v3" } ]
2019-03-20
[ [ "Belostotski", "S.", "" ], [ "Sagidova", "N.", "" ], [ "Vorobyev", "A.", "" ] ]
This note is motivated by preparations of a new $ep$ elastic scattering experiment in the low transfer momentum region to be carried out in the 720 MeV electron beam of the Mainz Microtron MAMI. This experiment will use an innovative method allowing for detection of recoil protons in coincidence with the scattered electrons. The goal is to measure the $ep$ differential cross sections in the $Q^2$ range from 0.001 GeV$^2$ to 0.04 GeV$^2$ and to determine the proton charge radius with sub-percent precision.
2009.01809
Gael Alguero
Ga\"el Alguero, Sabine Kraml, Wolfgang Waltenberger
A SModelS interface for pyhf likelihoods
11 pages, 3 figures
Comput. Phys. Comm. 264, July 2021, 107909
10.1016/j.cpc.2021.107909
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
SModelS is an automatized tool enabling the fast interpretation of simplified model results from the LHC within any model of new physics respecting a $\mathbb{Z}_2$ symmetry. We here present a new version of SModelS that can use the full likelihoods now provided by ATLAS in the form of pyhf JSON files. This much improves the statistical evaluation and therefore also the limit setting on new physics scenarios.
[ { "created": "Thu, 3 Sep 2020 17:15:26 GMT", "version": "v1" } ]
2021-03-17
[ [ "Alguero", "Gaël", "" ], [ "Kraml", "Sabine", "" ], [ "Waltenberger", "Wolfgang", "" ] ]
SModelS is an automatized tool enabling the fast interpretation of simplified model results from the LHC within any model of new physics respecting a $\mathbb{Z}_2$ symmetry. We here present a new version of SModelS that can use the full likelihoods now provided by ATLAS in the form of pyhf JSON files. This much improves the statistical evaluation and therefore also the limit setting on new physics scenarios.
1204.1016
Pietro Slavich
G. Degrassi, S. Di Vita, P. Slavich
On the NLO QCD corrections to the production of the heaviest neutral Higgs scalar in the MSSM
18 pages, 4 figures
Eur.Phys.J. C72 (2012) 2032
10.1140/epjc/s10052-012-2032-z
RM3-TH/12-5
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a calculation of the two-loop top-stop-gluino contributions to Higgs production via gluon fusion in the MSSM. By means of an asymptotic expansion in the heavy particle masses, we obtain explicit and compact analytic formulae that are valid when the Higgs and the top quark are lighter than stops and gluino, without assuming a specific hierarchy between the Higgs mass and the top mass. Being applicable to the heaviest Higgs scalar in a significant region of the MSSM parameter space, our results complement earlier ones obtained with a Taylor expansion in the Higgs mass, and can be easily implemented in computer codes to provide an efficient and accurate determination of the Higgs production cross section.
[ { "created": "Wed, 4 Apr 2012 17:57:18 GMT", "version": "v1" } ]
2012-06-08
[ [ "Degrassi", "G.", "" ], [ "Di Vita", "S.", "" ], [ "Slavich", "P.", "" ] ]
We present a calculation of the two-loop top-stop-gluino contributions to Higgs production via gluon fusion in the MSSM. By means of an asymptotic expansion in the heavy particle masses, we obtain explicit and compact analytic formulae that are valid when the Higgs and the top quark are lighter than stops and gluino, without assuming a specific hierarchy between the Higgs mass and the top mass. Being applicable to the heaviest Higgs scalar in a significant region of the MSSM parameter space, our results complement earlier ones obtained with a Taylor expansion in the Higgs mass, and can be easily implemented in computer codes to provide an efficient and accurate determination of the Higgs production cross section.
hep-ph/0009033
Mikolaj Misiak
Mikolaj Misiak
Status of theoretical B -> X_s gamma and B -> X_s l^+ l^- analyses
Talk at the 30th International Conference on High Energy Physics, Osaka, July 27 - August 2, 2000. Two pages, no figures
null
null
null
hep-ph
null
Status of the theoretical B -> X_s gamma and B -> X_s l^+ l^- analyses is reviewed. Recently completed perturbative calculations are mentioned. The level at which non-perturbative effects are controlled is discussed.
[ { "created": "Mon, 4 Sep 2000 13:38:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Misiak", "Mikolaj", "" ] ]
Status of the theoretical B -> X_s gamma and B -> X_s l^+ l^- analyses is reviewed. Recently completed perturbative calculations are mentioned. The level at which non-perturbative effects are controlled is discussed.
2011.03529
Thomas Rueter
Thomas D. Rueter, Thomas G. Rizzo
Building Kinetic Mixing From Scalar Portal Matter
32 pages, 16 figures
null
null
SLAC-PUB-17566
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nature of dark matter (DM) and how it might interact with the particles of the Standard Model (SM) is an ever-growing mystery. It is possible that the existence of new `dark sector' forces, yet undiscovered, are the key to solving this fundamental problem. In this paper, we construct a model in which a dark photon mediates interactions with the SM via kinetic mixing. Unlike traditional models, in which the dark photon, which couples to a dark charge, $Q_D$, mixes with the hypercharge boson, our model effectively mixes the dark photon directly with the photon after electroweak symmetry is broken, but remains unmixed until the symmetry breaks. The kinetic mixing is generated at one loop by fields which satisfy $\sum Q_D Q_{em} = 0$, a condition which guarantees a finite result at one loop. In the literature, this has been traditionally obtained via heavy fermions, which may lie out of the reach of current accelerators. In this model, by contrast, this process is mediated by scalar `portal matter' fields, which are charged under the $SU(2)_L \times U(1)_Y$ of the standard model as well as the dark gauge group $U(1)_D$ and acquire GeV-scale vevs which give mass to the dark Higgs and dark photon. The additional scalar fields are relatively light, at or below the weak scale, yet may remain undetected by current experiments since their couplings to SM fermions come only through percent level mixing with the SM Higgs. At colliders, these models are typified by relatively low MET due the BSM states decaying into MET and SM bosons, with MET which is balanced by the decay of the associated production object. Nevertheless, the higher statistics of HL-LHC may be able to probe the entirety of the model space.
[ { "created": "Fri, 6 Nov 2020 18:57:05 GMT", "version": "v1" }, { "created": "Wed, 18 Nov 2020 19:23:41 GMT", "version": "v2" } ]
2020-11-20
[ [ "Rueter", "Thomas D.", "" ], [ "Rizzo", "Thomas G.", "" ] ]
The nature of dark matter (DM) and how it might interact with the particles of the Standard Model (SM) is an ever-growing mystery. It is possible that the existence of new `dark sector' forces, yet undiscovered, are the key to solving this fundamental problem. In this paper, we construct a model in which a dark photon mediates interactions with the SM via kinetic mixing. Unlike traditional models, in which the dark photon, which couples to a dark charge, $Q_D$, mixes with the hypercharge boson, our model effectively mixes the dark photon directly with the photon after electroweak symmetry is broken, but remains unmixed until the symmetry breaks. The kinetic mixing is generated at one loop by fields which satisfy $\sum Q_D Q_{em} = 0$, a condition which guarantees a finite result at one loop. In the literature, this has been traditionally obtained via heavy fermions, which may lie out of the reach of current accelerators. In this model, by contrast, this process is mediated by scalar `portal matter' fields, which are charged under the $SU(2)_L \times U(1)_Y$ of the standard model as well as the dark gauge group $U(1)_D$ and acquire GeV-scale vevs which give mass to the dark Higgs and dark photon. The additional scalar fields are relatively light, at or below the weak scale, yet may remain undetected by current experiments since their couplings to SM fermions come only through percent level mixing with the SM Higgs. At colliders, these models are typified by relatively low MET due the BSM states decaying into MET and SM bosons, with MET which is balanced by the decay of the associated production object. Nevertheless, the higher statistics of HL-LHC may be able to probe the entirety of the model space.
0809.1209
Mihoko Nojiri
Mihoko M. Nojiri
The Night before the LHC
5 pages, 5 figures, a plenary talk in SUSY08
AIP Conf.Proc.1078:79-83,2009
10.1063/1.3052055
KEK TH-1273, IPMU 08-0051
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review recent developments on the use of mT2 variables for SUSY parameter study, which might be useful for the data analysis in the early stage of the LHC experiments. I also review some of recent interesting studies. Talk in SUSY08.
[ { "created": "Sun, 7 Sep 2008 06:12:58 GMT", "version": "v1" } ]
2009-04-06
[ [ "Nojiri", "Mihoko M.", "" ] ]
I review recent developments on the use of mT2 variables for SUSY parameter study, which might be useful for the data analysis in the early stage of the LHC experiments. I also review some of recent interesting studies. Talk in SUSY08.
hep-ph/9808470
Lawrence M. Krauss
Sheldon L. Glashow (1), Peter J. Kernan (2) and Lawrence M. Krauss (2) ((1) Harvard University, (2) Case Western Reserve University)
"Just So" Neutrino Oscillations Are Back
4 pages, revtex, 4 ps figs: new refs added, and Super-K energy resolution function incorporated
Phys.Lett. B445 (1999) 412-418
10.1016/S0370-2693(98)01449-X
CWRU-P27-98
hep-ph astro-ph
null
Recent evidence for oscillations of atmospheric neutrinos at Super-Kamiokande suggest, in the simplest see-saw interpretation, neutrino masses such that `just so' vacuum oscillations can explain the solar neutrino deficit. Super-K solar neutrino data provide preliminary support for this interpretation. We describe how the just-so signal---an energy dependent seasonal variation of the event rate, might be detected within the coming years and provide general arguments constraining the sign of the variation. The expected variation at radiochemical detectors may be below present sensitivity, but a significant modulation in the $^7$Be signal could shed light on the physics of the solar core---including a direct measure of the solar core temperature.
[ { "created": "Fri, 28 Aug 1998 21:40:37 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 1998 22:34:00 GMT", "version": "v2" } ]
2009-10-31
[ [ "Glashow", "Sheldon L.", "", "Harvard University" ], [ "Kernan", "Peter J.", "", "Case Western Reserve University" ], [ "Krauss", "Lawrence M.", "", "Case Western Reserve University" ] ]
Recent evidence for oscillations of atmospheric neutrinos at Super-Kamiokande suggest, in the simplest see-saw interpretation, neutrino masses such that `just so' vacuum oscillations can explain the solar neutrino deficit. Super-K solar neutrino data provide preliminary support for this interpretation. We describe how the just-so signal---an energy dependent seasonal variation of the event rate, might be detected within the coming years and provide general arguments constraining the sign of the variation. The expected variation at radiochemical detectors may be below present sensitivity, but a significant modulation in the $^7$Be signal could shed light on the physics of the solar core---including a direct measure of the solar core temperature.
1205.4756
Skokov Vladimir
V. Skokov, B. Friman, and K. Redlich
Volume fluctuations and higher order cumulants of the net baryon number
5 pages, 3 figures; version published in 2013
Phys. Rev. C 88, 034911 (2013)
10.1103/PhysRevC.88.034911
BNL-98044-2012-JA
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the effect of volume fluctuations on cumulants of the net baryon number. Based on a general formalism, we derive universal expressions for the net baryon number cumulants in the presence of volume fluctuations with an arbitrary probability distribution. The relevance of these fluctuations for the baryon-number cumulants and in particular for the ratios of cumulants is assessed in the Polyakov loop extended quark-meson model within the functional renormalization group. We show that the baryon number cumulants are generally enhanced by volume fluctuations and that the critical behavior of higher order cumulants may be modified significantly.
[ { "created": "Mon, 21 May 2012 21:31:50 GMT", "version": "v1" }, { "created": "Wed, 2 Mar 2016 14:15:53 GMT", "version": "v2" } ]
2016-03-03
[ [ "Skokov", "V.", "" ], [ "Friman", "B.", "" ], [ "Redlich", "K.", "" ] ]
We consider the effect of volume fluctuations on cumulants of the net baryon number. Based on a general formalism, we derive universal expressions for the net baryon number cumulants in the presence of volume fluctuations with an arbitrary probability distribution. The relevance of these fluctuations for the baryon-number cumulants and in particular for the ratios of cumulants is assessed in the Polyakov loop extended quark-meson model within the functional renormalization group. We show that the baryon number cumulants are generally enhanced by volume fluctuations and that the critical behavior of higher order cumulants may be modified significantly.
1908.08803
Wolfgang Lucha
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Tetraquark-Adequate QCD Sum Rules
6 pages, 6 figures, contributed to the "European Physical Society Conference on High Energy Physics - EPS-HEP 2019" (10 - 17 July 2019, Ghent, Belgium)
null
null
HEPHY-PUB 1017/19 (2019)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the experimental observation of several credible candidates for multiquark hadrons, the latter states re-entered the focus of interest of theoretical strong-interaction physics. Proper treatment of hadronic bound states by quantum chromodynamics, QCD, the quantum field theory governing all strong interactions, necessitates a nonperturbative approach. A well-established framework of this kind is provided by QCD sum rules relating hadron features to the parameters of QCD. Conceptual reconsideration, however, reveals that, in order to really match the peculiarities of multiquarks, the long-standing conventional QCD sum-rule techniques evidently must be subjected to considerable modification. The so far overlooked necessity for such adaptations is most easily demonstrated for the case of least complexity, that is, for tetraquarks, bound states of two quarks and two antiquarks.
[ { "created": "Fri, 23 Aug 2019 13:01:56 GMT", "version": "v1" } ]
2019-08-26
[ [ "Lucha", "Wolfgang", "" ], [ "Melikhov", "Dmitri", "" ], [ "Sazdjian", "Hagop", "" ] ]
With the experimental observation of several credible candidates for multiquark hadrons, the latter states re-entered the focus of interest of theoretical strong-interaction physics. Proper treatment of hadronic bound states by quantum chromodynamics, QCD, the quantum field theory governing all strong interactions, necessitates a nonperturbative approach. A well-established framework of this kind is provided by QCD sum rules relating hadron features to the parameters of QCD. Conceptual reconsideration, however, reveals that, in order to really match the peculiarities of multiquarks, the long-standing conventional QCD sum-rule techniques evidently must be subjected to considerable modification. The so far overlooked necessity for such adaptations is most easily demonstrated for the case of least complexity, that is, for tetraquarks, bound states of two quarks and two antiquarks.
1811.09957
Kim Siyeon
C. H. Jang, B. J. Kim, Y. J. Ko, and K. Siyeon
Neutrinoless Double Beta Decay and Light Sterile Neutrino
5 figures
null
10.3938/jkps.73.1625
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent neutrino experiment results show a preference for the normal neutrino mass ordering. The global efforts to search for neutrinoless double beta decays undergo a broad gap with the approach to the prediction in the three-neutrino framework based on the normal ordering. This research is intended to show that it is possible to find a neutrinoless double beta decay signal even with normal ordered neutrino masses. We propose the existence of a light sterile neutrino as a solution to the higher effective mass of the electron neutrino expected by the current experiments. A few short-baseline oscillation experiments gave rise to a limit on the mass of the sterile neutrino and its mixing with the lightest neutrino. We demonstrate that the results of neutrinoless double beta decays can also narrow down the range of the mass and the mixing angle of the light sterile neutrino.
[ { "created": "Sun, 25 Nov 2018 06:23:06 GMT", "version": "v1" } ]
2019-01-30
[ [ "Jang", "C. H.", "" ], [ "Kim", "B. J.", "" ], [ "Ko", "Y. J.", "" ], [ "Siyeon", "K.", "" ] ]
Recent neutrino experiment results show a preference for the normal neutrino mass ordering. The global efforts to search for neutrinoless double beta decays undergo a broad gap with the approach to the prediction in the three-neutrino framework based on the normal ordering. This research is intended to show that it is possible to find a neutrinoless double beta decay signal even with normal ordered neutrino masses. We propose the existence of a light sterile neutrino as a solution to the higher effective mass of the electron neutrino expected by the current experiments. A few short-baseline oscillation experiments gave rise to a limit on the mass of the sterile neutrino and its mixing with the lightest neutrino. We demonstrate that the results of neutrinoless double beta decays can also narrow down the range of the mass and the mixing angle of the light sterile neutrino.
0912.3440
Bastian Kubis
Bastian Kubis
Cusp effects in meson decays
12 pages, 14 figures; plenary talk at the 19th International IUPAP Conference on Few-Body Problems in Physics, Bonn, Germany, August 31 - September 5, 2009
EPJ Web Conf.3:01008,2010
10.1051/epjconf/20100301008
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The pion mass difference generates a pronounced cusp in the pi0 pi0 invariant mass distribution of K+ --> pi0 pi0 pi+ decays. As originally pointed out by Cabibbo, an accurate measurement of the cusp may allow one to pin down the S-wave pion-pion scattering lengths to high precision. We present the non-relativistic effective field theory framework that permits to determine the structure of this cusp in a straightforward manner, including the effects of radiative corrections. Applications of the same formalism to other decay channels, in particular eta and eta' decays, are also discussed.
[ { "created": "Thu, 17 Dec 2009 16:03:01 GMT", "version": "v1" } ]
2014-11-20
[ [ "Kubis", "Bastian", "" ] ]
The pion mass difference generates a pronounced cusp in the pi0 pi0 invariant mass distribution of K+ --> pi0 pi0 pi+ decays. As originally pointed out by Cabibbo, an accurate measurement of the cusp may allow one to pin down the S-wave pion-pion scattering lengths to high precision. We present the non-relativistic effective field theory framework that permits to determine the structure of this cusp in a straightforward manner, including the effects of radiative corrections. Applications of the same formalism to other decay channels, in particular eta and eta' decays, are also discussed.
hep-ph/0004073
Francesco Vissani
Francesco Vissani (Gran Sasso)
Charm Production by Cosmic Muons
9 pages, 1 figure
Astropart.Phys.15:217,2001
10.1016/S0927-6505(00)00146-8
null
hep-ph
null
Narrow muon bundles in underground detectors permit to study muoproduction reactions that take place in the surrounding rock. We analyze the relevance of a QED+QCD reaction, muoproduction of "open charm". The contribution to double muon events is estimated to be 4-8 % of the one due to QED "trident" process, for an ideal detector located under a rock depth of 3 km water equivalent, and an observation threshold of 1 GeV.
[ { "created": "Fri, 7 Apr 2000 16:15:55 GMT", "version": "v1" }, { "created": "Sat, 8 Apr 2000 07:13:29 GMT", "version": "v2" }, { "created": "Wed, 28 Feb 2001 16:25:06 GMT", "version": "v3" } ]
2011-05-23
[ [ "Vissani", "Francesco", "", "Gran Sasso" ] ]
Narrow muon bundles in underground detectors permit to study muoproduction reactions that take place in the surrounding rock. We analyze the relevance of a QED+QCD reaction, muoproduction of "open charm". The contribution to double muon events is estimated to be 4-8 % of the one due to QED "trident" process, for an ideal detector located under a rock depth of 3 km water equivalent, and an observation threshold of 1 GeV.
hep-ph/9411248
Per Osland
Bjarte Kileng and Per Osland
Light-Gluino Production at LEP
8 pages, LaTex 2.09, 4 figures, uuencoded ps files Full ps file available via anonymous ftp at ftp://vsfys1.fi.uib.no/anonymous/kileng/NORDITA_9460.ps (Figures now tar-compressed according to party line.)
null
null
NORDITA - 94/60 P
hep-ph
null
If gluinos are light, they will be produced in electron-positron annihilation at LEP, not only by radiation in pairs off quarks and antiquarks, but also without accompanying quark and antiquark jets. We here discuss the latter process, pair production of gluinos, in a model with soft supersymmetry breaking, allowing for mixing between the squarks. In much of the parameter space of the Minimal Supersymmetric Model (MSSM) the cross section corresponds to a $Z$ branching ratio above $10^{-5}$, even up to $10^{-4}$. A non-observation of gluinos at this level restricts the allowed MSSM parameter space.
[ { "created": "Tue, 8 Nov 1994 15:32:17 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 1994 07:21:36 GMT", "version": "v2" } ]
2008-02-03
[ [ "Kileng", "Bjarte", "" ], [ "Osland", "Per", "" ] ]
If gluinos are light, they will be produced in electron-positron annihilation at LEP, not only by radiation in pairs off quarks and antiquarks, but also without accompanying quark and antiquark jets. We here discuss the latter process, pair production of gluinos, in a model with soft supersymmetry breaking, allowing for mixing between the squarks. In much of the parameter space of the Minimal Supersymmetric Model (MSSM) the cross section corresponds to a $Z$ branching ratio above $10^{-5}$, even up to $10^{-4}$. A non-observation of gluinos at this level restricts the allowed MSSM parameter space.
2209.06578
Wolfgang Sch\"afer
Anna Cisek, Wolfgang Sch\"afer, Antoni Szczurek
Exclusive production of $\rho$ meson in gamma-proton collisions: $d \sigma/dt$ and the role of helicity flip processes
18 pages, 8 figures
null
10.1016/j.physletb.2022.137595
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We calculate the differential cross section $d\sigma/dt$ for the diffractive photoproduction process $\gamma p \to \rho p$ and compare to recent data extracted by the CMS collaboration from ultraperipheral proton-lead collisions. Our model is based on two-gluon exchange in the nonperturbative domain. We take into account both helicity conserving and often neglected helicity-flip amplitudes in the $\gamma \to V$ transition. The letter can contribute at finite $t$. The shape of the differential cross section as well as the role of helicity flip processes is strongly related to the dependence of the unintegrated gluon distribution on transverse momenta in the nonperturbative region.
[ { "created": "Wed, 14 Sep 2022 12:00:42 GMT", "version": "v1" } ]
2022-11-30
[ [ "Cisek", "Anna", "" ], [ "Schäfer", "Wolfgang", "" ], [ "Szczurek", "Antoni", "" ] ]
We calculate the differential cross section $d\sigma/dt$ for the diffractive photoproduction process $\gamma p \to \rho p$ and compare to recent data extracted by the CMS collaboration from ultraperipheral proton-lead collisions. Our model is based on two-gluon exchange in the nonperturbative domain. We take into account both helicity conserving and often neglected helicity-flip amplitudes in the $\gamma \to V$ transition. The letter can contribute at finite $t$. The shape of the differential cross section as well as the role of helicity flip processes is strongly related to the dependence of the unintegrated gluon distribution on transverse momenta in the nonperturbative region.
hep-ph/9912361
Xiaofeng Guo
Xiaofeng Guo, Jianwei Qiu, and Xiaofei Zhang
Nuclear dependence coefficient $\alpha(A,q_T)$ for the Drell-Yan and J/$\psi$ production
latex, 28 pages, 10 figures, updated two figures, and add more discussions
Phys.Rev. D62 (2000) 054008
10.1103/PhysRevD.62.054008
UK/TP 99-19
hep-ph nucl-th
null
Define the nuclear dependence coefficient $\alpha(A,q_T)$ in terms of ratio of transverse momentum spectrum in hadron-nucleus and in hadron-nucleon collisions: $\frac{d\sigma^{hA}}{dq_T^2}/ \frac{d\sigma^{hN}}{dq_T^2}\equiv A^{\alpha(A,q_T)}$. We argue that in small $q_T$ region, the $\alpha(A,q_T)$ for the Drell-Yan and J/$\psi$ production is given by a universal function:\ $a+b q_T^2$, where parameters a and b are completely determined by either calculable quantities or independently measurable physical observables. We demonstrate that this universal function $\alpha(A,q_T)$ is insensitive to the A for normal nuclear targets. For a color deconfined nuclear medium, the $\alpha(A,q_T)$ becomes strongly dependent on the A. We also show that our $\alpha(A,q_T)$ for the Drell-Yan process is naturally linked to perturbatively calculated $\alpha(A,q_T)$ at large $q_T$ without any free parameters, and the $\alpha(A,q_T)$ is consistent with E772 data for all $q_T$.
[ { "created": "Wed, 15 Dec 1999 17:36:32 GMT", "version": "v1" }, { "created": "Tue, 11 Apr 2000 18:40:14 GMT", "version": "v2" } ]
2009-10-31
[ [ "Guo", "Xiaofeng", "" ], [ "Qiu", "Jianwei", "" ], [ "Zhang", "Xiaofei", "" ] ]
Define the nuclear dependence coefficient $\alpha(A,q_T)$ in terms of ratio of transverse momentum spectrum in hadron-nucleus and in hadron-nucleon collisions: $\frac{d\sigma^{hA}}{dq_T^2}/ \frac{d\sigma^{hN}}{dq_T^2}\equiv A^{\alpha(A,q_T)}$. We argue that in small $q_T$ region, the $\alpha(A,q_T)$ for the Drell-Yan and J/$\psi$ production is given by a universal function:\ $a+b q_T^2$, where parameters a and b are completely determined by either calculable quantities or independently measurable physical observables. We demonstrate that this universal function $\alpha(A,q_T)$ is insensitive to the A for normal nuclear targets. For a color deconfined nuclear medium, the $\alpha(A,q_T)$ becomes strongly dependent on the A. We also show that our $\alpha(A,q_T)$ for the Drell-Yan process is naturally linked to perturbatively calculated $\alpha(A,q_T)$ at large $q_T$ without any free parameters, and the $\alpha(A,q_T)$ is consistent with E772 data for all $q_T$.
1906.08685
Nicol\'as Mileo
Julien Alcaide and Nicol\'as I. Mileo
LHC sensitivity to singly-charged scalars decaying into electrons and muons
15 pages, 8 figures
Phys. Rev. D 102, 075030 (2020)
10.1103/PhysRevD.102.075030
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
Current LHC searches for non-supersymmetric singly-charged scalars, based on Two-Higgs-Doublet models, in general focus the analysis on third-generation fermions in the final state. However, singly-charged scalars in alternative extensions of the scalar sector involve Yukawa couplings not proportional to the mass of the fermions. Assuming the scalar decays into electrons and muons, it can manifest cleaner experimental signatures. In this paper we suggest that a singly-charged scalar singlet, with electroweak production, can start to be probed in the near future with dedicated search strategies. Depending on the strength of the Yukawa couplings, two independent scenarios are considered: direct pair-production (small couplings) and single-production via virtual neutrino exchange (large couplings). We show that, up to a mass as large as 500 GeV, most of the parameter space could be excluded at the 95% C.L. in a high-luminosity phase of the LHC. Our results also apply to other frameworks, provided the singly-charged scalar exhibits similar production patterns and dominant decay modes.
[ { "created": "Thu, 20 Jun 2019 15:17:14 GMT", "version": "v1" } ]
2020-10-28
[ [ "Alcaide", "Julien", "" ], [ "Mileo", "Nicolás I.", "" ] ]
Current LHC searches for non-supersymmetric singly-charged scalars, based on Two-Higgs-Doublet models, in general focus the analysis on third-generation fermions in the final state. However, singly-charged scalars in alternative extensions of the scalar sector involve Yukawa couplings not proportional to the mass of the fermions. Assuming the scalar decays into electrons and muons, it can manifest cleaner experimental signatures. In this paper we suggest that a singly-charged scalar singlet, with electroweak production, can start to be probed in the near future with dedicated search strategies. Depending on the strength of the Yukawa couplings, two independent scenarios are considered: direct pair-production (small couplings) and single-production via virtual neutrino exchange (large couplings). We show that, up to a mass as large as 500 GeV, most of the parameter space could be excluded at the 95% C.L. in a high-luminosity phase of the LHC. Our results also apply to other frameworks, provided the singly-charged scalar exhibits similar production patterns and dominant decay modes.
2007.10978
Fedor Bezrukov
Fedor Bezrukov and Chris Shepherd
A heatwave affair: mixed Higgs-$R^2$ preheating on the lattice
21 pages 11 figures
null
10.1088/1475-7516/2020/12/028
MAN/HEP/2020/009
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use lattice methods to perform the first nonlinear study of preheating in $R^2$-healed Higgs inflation for "$R^2$-like" parameters $1.1\times 10^9$ and $1.8\times 10^9$ where the curvature-squared coupling $\beta$ and nonminimal coupling $\xi$ of the Higgs field contribute similarly to the CMB scalar perturbations. Preheating occurs first through tachyonic production of Higgs bosons, and later scattering off the homogeneous inflaton field. We generalise our results to "Higgs-like" parameters with smaller $\beta$, where observables saturate the bound of instantaneous preheating. All predictions for the spectral index and tensor-to-scalar ratio lie within the $1\sigma$ region of measurements by the Planck satellite, but a future ground-based experiment optimised for 21 cm tomography may be able to discriminate the mixed Higgs-curvature inflation from the pure Higgs and $R^2$ theories.
[ { "created": "Tue, 21 Jul 2020 17:56:50 GMT", "version": "v1" } ]
2021-01-06
[ [ "Bezrukov", "Fedor", "" ], [ "Shepherd", "Chris", "" ] ]
We use lattice methods to perform the first nonlinear study of preheating in $R^2$-healed Higgs inflation for "$R^2$-like" parameters $1.1\times 10^9$ and $1.8\times 10^9$ where the curvature-squared coupling $\beta$ and nonminimal coupling $\xi$ of the Higgs field contribute similarly to the CMB scalar perturbations. Preheating occurs first through tachyonic production of Higgs bosons, and later scattering off the homogeneous inflaton field. We generalise our results to "Higgs-like" parameters with smaller $\beta$, where observables saturate the bound of instantaneous preheating. All predictions for the spectral index and tensor-to-scalar ratio lie within the $1\sigma$ region of measurements by the Planck satellite, but a future ground-based experiment optimised for 21 cm tomography may be able to discriminate the mixed Higgs-curvature inflation from the pure Higgs and $R^2$ theories.
1006.5593
Paola Ferrario
Paola Ferrario and German Rodrigo
Charge asymmetry of top quarks
Proceedings of XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects, April 19 -23, 2010, Firenze
PoS DIS2010:191,2010
null
IFIC/10-21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHC is a promising machine to discover new physics in the top sector. There are several models that predict the existence of heavy colored resonances decaying to top quarks in the TeV energy range. The production of such resonances might generate a sizable charge asymmetry of top versus antitop quarks. At the Tevatron, a 2 sigma discrepancy with the SM prediction for the forward--backward asymmetry has been found, boosting a renewed interest for this kind of models. We consider a toy model with general flavour dependent couplings of the resonance to quarks, of both vector and axial-vector kind and investigate the possible constraints on the coupling space from the measurement of the asymmetry and the invariant mass distribution at the Tevatron. Then, we define a central asymmetry in a specific kinematic region and investigate its signature at the LHC as well as its statistical significance, for exclusive processes.
[ { "created": "Tue, 29 Jun 2010 12:35:01 GMT", "version": "v1" } ]
2010-11-19
[ [ "Ferrario", "Paola", "" ], [ "Rodrigo", "German", "" ] ]
The LHC is a promising machine to discover new physics in the top sector. There are several models that predict the existence of heavy colored resonances decaying to top quarks in the TeV energy range. The production of such resonances might generate a sizable charge asymmetry of top versus antitop quarks. At the Tevatron, a 2 sigma discrepancy with the SM prediction for the forward--backward asymmetry has been found, boosting a renewed interest for this kind of models. We consider a toy model with general flavour dependent couplings of the resonance to quarks, of both vector and axial-vector kind and investigate the possible constraints on the coupling space from the measurement of the asymmetry and the invariant mass distribution at the Tevatron. Then, we define a central asymmetry in a specific kinematic region and investigate its signature at the LHC as well as its statistical significance, for exclusive processes.
1211.4507
Peter Watson
Peter Watson and Hugo Reinhardt (Tuebingen U.)
Bethe-Salpeter equation at leading order in Coulomb gauge
23 pages, 8 figures
null
10.1103/PhysRevD.86.125030
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bethe-Salpeter equation and leptonic decay constants for pseudoscalar and vector quark-antiquark mesons with arbitrary quark masses are studied in Coulomb gauge, under a leading order truncation. As input, we use a pure linear rising potential, supplemented by a contact term arising from the conservation of total color charge. It is shown how the equations can be written in terms of manifestly finite functions, despite the infrared singular interaction. The resulting equations are solved numerically. Both the pattern of dynamical chiral symmetry breaking and the leading order heavy quark limit are visible.
[ { "created": "Mon, 19 Nov 2012 17:17:07 GMT", "version": "v1" } ]
2013-05-30
[ [ "Watson", "Peter", "", "Tuebingen U." ], [ "Reinhardt", "Hugo", "", "Tuebingen U." ] ]
The Bethe-Salpeter equation and leptonic decay constants for pseudoscalar and vector quark-antiquark mesons with arbitrary quark masses are studied in Coulomb gauge, under a leading order truncation. As input, we use a pure linear rising potential, supplemented by a contact term arising from the conservation of total color charge. It is shown how the equations can be written in terms of manifestly finite functions, despite the infrared singular interaction. The resulting equations are solved numerically. Both the pattern of dynamical chiral symmetry breaking and the leading order heavy quark limit are visible.
1304.2334
Shun Zhou
Ji-Yuan Liu and Shun Zhou
Hybrid Textures of Majorana Neutrino Mass Matrix and Current Experimental Tests
29 pages, 6 figures, more discussions and references added, to appear in Phys. Rev. D
Phys. Rev. D 87 (2013) 093010
10.1103/PhysRevD.87.093010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by recent measurements of a relatively large \theta_{13} in the Daya Bay and RENO reactor neutrino experiments, we carry out a systematic analysis of the hybrid textures of Majorana neutrino mass matrix $M_\nu$, which contain one texture zero and two equal nonzero matrix elements. We show that three neutrino masses (m_1, m_2, m_3) and three leptonic CP-violating phases (\delta, \rho, \sigma) can fully be determined from two neutrino mass-squared differences (\delta m^2, \Delta m^2) and three flavor mixing angles (\theta_{12}, \theta_{23}, \theta_{13}). Out of sixty logically possible patterns of $M_\nu$, thirty-nine are found to be compatible with current experimental data at the 3\sigma level. We demonstrate that the texture zero of $M_\nu$ is stable against one-loop quantum corrections, while the equality between two independent elements not. Phenomenological implications of $M_\nu$ for the neutrinoless double-beta decay and leptonic CP violation are discussed, and a realization of the texture zero and equality by means of discrete flavor symmetries is illustrated.
[ { "created": "Mon, 8 Apr 2013 19:52:15 GMT", "version": "v1" }, { "created": "Fri, 17 May 2013 08:32:15 GMT", "version": "v2" } ]
2013-05-30
[ [ "Liu", "Ji-Yuan", "" ], [ "Zhou", "Shun", "" ] ]
Motivated by recent measurements of a relatively large \theta_{13} in the Daya Bay and RENO reactor neutrino experiments, we carry out a systematic analysis of the hybrid textures of Majorana neutrino mass matrix $M_\nu$, which contain one texture zero and two equal nonzero matrix elements. We show that three neutrino masses (m_1, m_2, m_3) and three leptonic CP-violating phases (\delta, \rho, \sigma) can fully be determined from two neutrino mass-squared differences (\delta m^2, \Delta m^2) and three flavor mixing angles (\theta_{12}, \theta_{23}, \theta_{13}). Out of sixty logically possible patterns of $M_\nu$, thirty-nine are found to be compatible with current experimental data at the 3\sigma level. We demonstrate that the texture zero of $M_\nu$ is stable against one-loop quantum corrections, while the equality between two independent elements not. Phenomenological implications of $M_\nu$ for the neutrinoless double-beta decay and leptonic CP violation are discussed, and a realization of the texture zero and equality by means of discrete flavor symmetries is illustrated.
hep-ph/0111215
Kaladi Babu
K.S. Babu (Oklahoma State University) and S.M. Barr (Bartol Research Institute)
Bimaximal Neutrino Mixings from Lopsided Mass Matrices
12 pages in LaTeX, no figures
Phys.Lett.B525:289-296,2002
10.1016/S0370-2693(01)01455-1
OSU-HEP-01-09, BA-01-49
hep-ph
null
Current solar and atmospheric neutrino oscillation data seem to favor a bimaximal pattern for neutrino mixings where the matrix elements U_{e2} and U_{\mu 3} are of order one, while U_{e3} is much smaller. We show that such a pattern can be obtained quite easily in theories with ``lopsided'' mass matrices for the charged leptons and the down type quarks. A relation connecting the solar and atmospheric neutrino mixing angles is derived, \tan^2\theta_{atm} \simeq 1+ \tan^2\theta_{sol}, which predicts \sin^2 2\theta_{atm} \simeq 0.97 corresponding to the best fit LMA solution for solar neutrinos. Predictive schemes in SO(10) realizing these ideas are presented. A new class of SO(10) models with lopsided mass matrices is found which makes use of an adjoint VEV along the I_{3R} direction, rather than the traditional B-L direction.
[ { "created": "Fri, 16 Nov 2001 21:04:13 GMT", "version": "v1" } ]
2011-05-12
[ [ "Babu", "K. S.", "", "Oklahoma State University" ], [ "Barr", "S. M.", "", "Bartol Research\n Institute" ] ]
Current solar and atmospheric neutrino oscillation data seem to favor a bimaximal pattern for neutrino mixings where the matrix elements U_{e2} and U_{\mu 3} are of order one, while U_{e3} is much smaller. We show that such a pattern can be obtained quite easily in theories with ``lopsided'' mass matrices for the charged leptons and the down type quarks. A relation connecting the solar and atmospheric neutrino mixing angles is derived, \tan^2\theta_{atm} \simeq 1+ \tan^2\theta_{sol}, which predicts \sin^2 2\theta_{atm} \simeq 0.97 corresponding to the best fit LMA solution for solar neutrinos. Predictive schemes in SO(10) realizing these ideas are presented. A new class of SO(10) models with lopsided mass matrices is found which makes use of an adjoint VEV along the I_{3R} direction, rather than the traditional B-L direction.
hep-ph/9607284
Joao Soares
Joao M. Soares
Form factor relations for heavy-to-heavy and heavy-to-light meson transitions
13 pages, LaTex, 2 figures
Phys.Rev. D54 (1996) 6837-6841
10.1103/PhysRevD.54.6837
UMHEP-430
hep-ph
null
Relations between the form factors that parametrize the hadronic matrix elements, in spectator decays of heavy mesons, have been derived by Stech within the constituent quark model. In here, we examine these relations using a slightly modified description of the meson states. We find new and very general relations for some of the form factors. For the other form factors, we obtain small modifications to the relations previously derived by Stech, in the case of heavy-to-light transitions.
[ { "created": "Wed, 10 Jul 1996 19:03:58 GMT", "version": "v1" } ]
2009-10-28
[ [ "Soares", "Joao M.", "" ] ]
Relations between the form factors that parametrize the hadronic matrix elements, in spectator decays of heavy mesons, have been derived by Stech within the constituent quark model. In here, we examine these relations using a slightly modified description of the meson states. We find new and very general relations for some of the form factors. For the other form factors, we obtain small modifications to the relations previously derived by Stech, in the case of heavy-to-light transitions.
1912.02034
Kai Urban
Martin Beneke, Caspar Hasner, Kai Urban, Martin Vollmann
Precise yield of high-energy photons from Higgsino dark matter annihilation
30 pages, 5 figures, v2: matches published version + typo in (C.23) fixed
null
10.1007/JHEP03(2020)030
TUM-HEP-1240/19
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The impact of electroweak Sudakov logarithms on the endpoint of the photon spectrum for wino dark matter annihilation was studied intensively over the last several years. In this work, we extend these results to Higgsino dark matter $\chi_1^0$. We achieve NLL' resummation accuracy for narrow and intermediate spectral energy resolutions, of order $m_W^2 / m_\chi$ and $m_W$, respectively. This is the most accurate prediction to date for the yield of high-energy $\gamma$-rays from $\chi_1^0 \chi_1^0 \to \gamma + X$ annihilation for the energy resolutions realized by current and next-generation telescopes. We also discuss for the first time the effect of power corrections in $m_W/m_\chi$ in this context and argue why they are not sizeable.
[ { "created": "Wed, 4 Dec 2019 15:00:20 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 2020 09:26:38 GMT", "version": "v2" } ]
2020-12-17
[ [ "Beneke", "Martin", "" ], [ "Hasner", "Caspar", "" ], [ "Urban", "Kai", "" ], [ "Vollmann", "Martin", "" ] ]
The impact of electroweak Sudakov logarithms on the endpoint of the photon spectrum for wino dark matter annihilation was studied intensively over the last several years. In this work, we extend these results to Higgsino dark matter $\chi_1^0$. We achieve NLL' resummation accuracy for narrow and intermediate spectral energy resolutions, of order $m_W^2 / m_\chi$ and $m_W$, respectively. This is the most accurate prediction to date for the yield of high-energy $\gamma$-rays from $\chi_1^0 \chi_1^0 \to \gamma + X$ annihilation for the energy resolutions realized by current and next-generation telescopes. We also discuss for the first time the effect of power corrections in $m_W/m_\chi$ in this context and argue why they are not sizeable.
1910.07076
HoSeong La
HoSeong La
Neutrino Oscillations and Energy-Momentum Conservation
4 pages
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is proposed that the energy-momentum expectation values of flavor states should be identified with the missing energy-momentum of neutrino processes so that the conservation of energy-momentum can be strictly imposed. It is also observed that there is a plausible condition to express neutrino mixing angles in terms of neutrino masses without invoking symmetries.
[ { "created": "Tue, 15 Oct 2019 22:19:01 GMT", "version": "v1" } ]
2019-10-17
[ [ "La", "HoSeong", "" ] ]
It is proposed that the energy-momentum expectation values of flavor states should be identified with the missing energy-momentum of neutrino processes so that the conservation of energy-momentum can be strictly imposed. It is also observed that there is a plausible condition to express neutrino mixing angles in terms of neutrino masses without invoking symmetries.
1709.03921
Gabriela Pomery Miss
Thomas Blake, Ulrik Egede, Patrick Owen, Gabriela Pomery, Konstantinos Alexandros Petridis
An empirical model of the long-distance contributions to $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ transitions
24 pages, 6 figures in main text, 2 figures in appendix, version accepted by journal
Eur. Phys. J. C (2018) 78: 453
10.1140/epjc/s10052-018-5937-3
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
A method for analysing the hadronic resonance contributions in $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ decays is presented. This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving $J^{PC}=1^{--}$ resonances, relative to the short-distance component, across the full dimuon mass spectrum of $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ transitions. The model is in good agreement with existing calculations of hadronic non-local effects. The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the $q^{2}$ spectrum provide a dramatic enhancement to $CP$-violating effects in the short-distance amplitude. Finally, a study of the hadronic resonance effects on lepton universality ratios, $R_{K^{(*)}}$, in the presence of new physics is presented.
[ { "created": "Tue, 12 Sep 2017 15:49:41 GMT", "version": "v1" }, { "created": "Wed, 13 Sep 2017 13:20:01 GMT", "version": "v2" }, { "created": "Thu, 7 Jun 2018 09:56:10 GMT", "version": "v3" } ]
2018-06-08
[ [ "Blake", "Thomas", "" ], [ "Egede", "Ulrik", "" ], [ "Owen", "Patrick", "" ], [ "Pomery", "Gabriela", "" ], [ "Petridis", "Konstantinos Alexandros", "" ] ]
A method for analysing the hadronic resonance contributions in $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ decays is presented. This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving $J^{PC}=1^{--}$ resonances, relative to the short-distance component, across the full dimuon mass spectrum of $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ transitions. The model is in good agreement with existing calculations of hadronic non-local effects. The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the $q^{2}$ spectrum provide a dramatic enhancement to $CP$-violating effects in the short-distance amplitude. Finally, a study of the hadronic resonance effects on lepton universality ratios, $R_{K^{(*)}}$, in the presence of new physics is presented.
hep-ph/9608411
W. James Stirling
W. J. Stirling (University of Durham)
DIS96 - Summary
39 pages, LATEX, 26 Postscript figures, uses procl.sty
null
null
DTP/96/68
hep-ph
null
Some of the new experimental results and theoretical developments presented at the Workshop on Deep Inelastic Scattering and Related Phenomena (Rome, April 1996) are reviewed.
[ { "created": "Thu, 22 Aug 1996 18:45:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Stirling", "W. J.", "", "University of Durham" ] ]
Some of the new experimental results and theoretical developments presented at the Workshop on Deep Inelastic Scattering and Related Phenomena (Rome, April 1996) are reviewed.
1402.1817
Hao Sun
Hao Sun
Probe Anomalous $tq\gamma$ couplings through Single Top Photoproduction at the LHC
37pages, 10 figures, 6 tables, to appear in Nuclear Physics B
Nuclear Physics B 886 (2014) 691-711
10.1016/j.nuclphysb.2014.07.012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the constraints on the anomalous $tq\gamma$ ($q=u$, $c$) couplings by photon-produced leading single top production and single top jet associated production through the main reaction $pp\rightarrow p\gamma p\rightarrow pt\rightarrow pW(\rightarrow\ell \nu_\ell) b+X$ and $pp\rightarrow p\gamma p\rightarrow ptj\rightarrow pW(\rightarrow\ell \nu_\ell) bj+X$ assuming a typical LHC multipurpose forward detectors in a model independent effective lagrangian approach. Our results show that: for the typical detector acceptance $0.0015<\xi_1<0.5$, $0.1<\xi_2<0.5$ and $0.0015<\xi_3<0.15$ with a luminosity of 2 $\rm{fb}^{-1}$, the lower bounds of $\kappa_{tq\gamma}$ through leading single top channel (single top jet channel) are 0.0096 (0.0115), 0.0162 (0.0152) and 0.0098 (0.0122), respectively, correspond to $\rm{Br}(t\rightarrow q\gamma)\sim 3\times 10^{-5}$. With a luminosity of 200 $\rm{fb}^{-1}$, the lower bounds of $\kappa_{tq\gamma}$ are 0.0031 (0.0034), 0.0051 (0.0047) and 0.0031(0.0038), respectively, correspond to $\rm{Br}(t\rightarrow q\gamma)\sim 4\times 10^{-6}$. We conclude that both channels can be used to detect such anomalous $tq\gamma$ couplings and the detection sensitivity on $\kappa_{tq\gamma}$ can be improved.
[ { "created": "Sat, 8 Feb 2014 04:01:35 GMT", "version": "v1" }, { "created": "Thu, 17 Jul 2014 00:33:36 GMT", "version": "v2" } ]
2014-07-29
[ [ "Sun", "Hao", "" ] ]
In this work we study the constraints on the anomalous $tq\gamma$ ($q=u$, $c$) couplings by photon-produced leading single top production and single top jet associated production through the main reaction $pp\rightarrow p\gamma p\rightarrow pt\rightarrow pW(\rightarrow\ell \nu_\ell) b+X$ and $pp\rightarrow p\gamma p\rightarrow ptj\rightarrow pW(\rightarrow\ell \nu_\ell) bj+X$ assuming a typical LHC multipurpose forward detectors in a model independent effective lagrangian approach. Our results show that: for the typical detector acceptance $0.0015<\xi_1<0.5$, $0.1<\xi_2<0.5$ and $0.0015<\xi_3<0.15$ with a luminosity of 2 $\rm{fb}^{-1}$, the lower bounds of $\kappa_{tq\gamma}$ through leading single top channel (single top jet channel) are 0.0096 (0.0115), 0.0162 (0.0152) and 0.0098 (0.0122), respectively, correspond to $\rm{Br}(t\rightarrow q\gamma)\sim 3\times 10^{-5}$. With a luminosity of 200 $\rm{fb}^{-1}$, the lower bounds of $\kappa_{tq\gamma}$ are 0.0031 (0.0034), 0.0051 (0.0047) and 0.0031(0.0038), respectively, correspond to $\rm{Br}(t\rightarrow q\gamma)\sim 4\times 10^{-6}$. We conclude that both channels can be used to detect such anomalous $tq\gamma$ couplings and the detection sensitivity on $\kappa_{tq\gamma}$ can be improved.
1910.04170
Ennio Salvioni
Maximilian Ruhdorfer, Ennio Salvioni and Andreas Weiler
A Global View of the Off-Shell Higgs Portal
12 pages + appendices and references, 10 figures; v2: minor revisions and a few additions, including extra references; v3: new figure comparing VBF reach to parameter regions compatible with first-order EW phase transition (Figure 9), additional references. This version is more up to date than the published one
SciPost Phys. 8, 027 (2020)
10.21468/SciPostPhys.8.2.027
TUM-HEP-1231-19
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study for the first time the collider reach on the derivative Higgs portal, the leading effective interaction that couples a pseudo Nambu-Goldstone boson (pNGB) scalar Dark Matter to the Standard Model. We focus on Dark Matter pair production through an off-shell Higgs boson, which is analyzed in the vector boson fusion channel. A variety of future high-energy lepton colliders as well as hadron colliders are considered, including CLIC, a muon collider, the High-Luminosity and High-Energy versions of the LHC, and FCC-hh. Implications on the parameter space of pNGB Dark Matter are discussed. In addition, we give improved and extended results for the collider reach on the marginal Higgs portal, under the assumption that the new scalars escape the detector, as motivated by a variety of beyond the Standard Model scenarios.
[ { "created": "Wed, 9 Oct 2019 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 2 Jan 2020 13:13:20 GMT", "version": "v2" }, { "created": "Fri, 15 Jan 2021 19:59:13 GMT", "version": "v3" } ]
2021-01-19
[ [ "Ruhdorfer", "Maximilian", "" ], [ "Salvioni", "Ennio", "" ], [ "Weiler", "Andreas", "" ] ]
We study for the first time the collider reach on the derivative Higgs portal, the leading effective interaction that couples a pseudo Nambu-Goldstone boson (pNGB) scalar Dark Matter to the Standard Model. We focus on Dark Matter pair production through an off-shell Higgs boson, which is analyzed in the vector boson fusion channel. A variety of future high-energy lepton colliders as well as hadron colliders are considered, including CLIC, a muon collider, the High-Luminosity and High-Energy versions of the LHC, and FCC-hh. Implications on the parameter space of pNGB Dark Matter are discussed. In addition, we give improved and extended results for the collider reach on the marginal Higgs portal, under the assumption that the new scalars escape the detector, as motivated by a variety of beyond the Standard Model scenarios.
2405.14309
Jun Guo
Jun Guo, Zhaofeng Kang, Ji-Gang Zhao
Gamma-ray Signal from $Z_{N\geq 3}$ Dark Matter-Companion Models
14 pages, 3 figures
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
In Ref.~\cite{Guo:2021rre}, we proposed to replace the final dark matter (DM) particle in the semi-annihilation mode $\rm DM+DM\to antiDM+Higgs~boson$ with its $Z_{N\geq 3}$ companion, thus reducing DM number density without DM-nucleon scattering. In this work, we study the indirect detection signals from DM annihilation, the Higgs boson pair with one of them from the companion decay being on- or off- shell, depending on the DM-companion mass splitting. We generate the photon spectrum by using PYTHIA8 and study the properties of the spectrum, to find that the hard part of the spectrum in our model is mainly shaped by the direct Higgs boson and thus does not differ much from that of the conventional semi-annihilation mode. Using the Fermi-LAT data of white dwarfs, we derive the current limit of the DM annihilation cross section for ${\rm DM+DM\to companion^*+Higgs~ boson}$, and for the relatively light DM, it reaches the typical thermal cross section. However, for the TeV scale DM, we have to rely on the Cherenkov Telescope Array, which is able to rule out the whole parameter space except for the coannihilation region.
[ { "created": "Thu, 23 May 2024 08:29:52 GMT", "version": "v1" } ]
2024-05-24
[ [ "Guo", "Jun", "" ], [ "Kang", "Zhaofeng", "" ], [ "Zhao", "Ji-Gang", "" ] ]
In Ref.~\cite{Guo:2021rre}, we proposed to replace the final dark matter (DM) particle in the semi-annihilation mode $\rm DM+DM\to antiDM+Higgs~boson$ with its $Z_{N\geq 3}$ companion, thus reducing DM number density without DM-nucleon scattering. In this work, we study the indirect detection signals from DM annihilation, the Higgs boson pair with one of them from the companion decay being on- or off- shell, depending on the DM-companion mass splitting. We generate the photon spectrum by using PYTHIA8 and study the properties of the spectrum, to find that the hard part of the spectrum in our model is mainly shaped by the direct Higgs boson and thus does not differ much from that of the conventional semi-annihilation mode. Using the Fermi-LAT data of white dwarfs, we derive the current limit of the DM annihilation cross section for ${\rm DM+DM\to companion^*+Higgs~ boson}$, and for the relatively light DM, it reaches the typical thermal cross section. However, for the TeV scale DM, we have to rely on the Cherenkov Telescope Array, which is able to rule out the whole parameter space except for the coannihilation region.
2207.06928
Raghuveer Garani
Raghuveer Garani, Michel H.G. Tytgat and J\'er\^ome Vandecasteele
Condensed dark matter with a Yukawa interaction
10+19 pages, 6+8 figures
null
10.1103/PhysRevD.106.116003
null
hep-ph astro-ph.CO hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
We explore the possible phases of a condensed dark matter (DM) candidate taken to be in the form of a fermion with a Yukawa coupling to a scalar particle, at zero temperature but at finite density. This theory essentially depends on only four parameters, the Yukawa coupling, the fermion mass, the scalar mediator mass, and the DM density. At low fermion densities we delimit the Bardeen-Cooper-Schrieffer (BCS), Bose-Einstein Condensate (BEC) and crossover phases as a function of model parameters using the notion of scattering length. We further study the BCS phase by consistently including emergent effects such as the scalar density condensate and superfluid gaps. Within the mean field approximation, we derive the consistent set of gap equations, retaining their momentum dependence, and valid in both the non-relativistic and relativistic regimes. We present numerical solutions to the set of gap equations, in particular when the mediator mass is smaller and larger than the DM mass. Finally, we discuss the equation of state (EoS) and possible astrophysical implications for asymmetric DM.
[ { "created": "Thu, 14 Jul 2022 13:50:33 GMT", "version": "v1" } ]
2022-12-21
[ [ "Garani", "Raghuveer", "" ], [ "Tytgat", "Michel H. G.", "" ], [ "Vandecasteele", "Jérôme", "" ] ]
We explore the possible phases of a condensed dark matter (DM) candidate taken to be in the form of a fermion with a Yukawa coupling to a scalar particle, at zero temperature but at finite density. This theory essentially depends on only four parameters, the Yukawa coupling, the fermion mass, the scalar mediator mass, and the DM density. At low fermion densities we delimit the Bardeen-Cooper-Schrieffer (BCS), Bose-Einstein Condensate (BEC) and crossover phases as a function of model parameters using the notion of scattering length. We further study the BCS phase by consistently including emergent effects such as the scalar density condensate and superfluid gaps. Within the mean field approximation, we derive the consistent set of gap equations, retaining their momentum dependence, and valid in both the non-relativistic and relativistic regimes. We present numerical solutions to the set of gap equations, in particular when the mediator mass is smaller and larger than the DM mass. Finally, we discuss the equation of state (EoS) and possible astrophysical implications for asymmetric DM.
hep-ph/9405326
null
Harry J. Lipkin
How to Use Weak Decays in Analyses of Data on Nucleon Spin Structure Functions
10 pages, Weizmann Report WIS-94/24/May-PH, Tel Aviv Report TAUP 2165-94
Phys.Lett. B337 (1994) 157-162
10.1016/0370-2693(94)91461-3
null
hep-ph
null
The use of weak decays to determine proton spin structure is examined in view of possible violations of the Bjorken and Gottfried Sum rules, flavor symmetry breaking and flavor asymmetry in the sea. The use of the neutron decay is found to be unaffected by all these. A method for including these effects in analyses of hyperon decays shows that a flavor-asymmetric sea produced by SU(3) symmetry breaking has only a small effect on results for the total spin carried by quarks. However the strange quark contribution cannot be reliably obtained from charged lepton scattering and weak decay data alone, and requires additional model-dependent input relating nucleon and hyperon wave functions.
[ { "created": "Thu, 19 May 1994 11:40:00 GMT", "version": "v1" } ]
2009-10-28
[ [ "Lipkin", "Harry J.", "" ] ]
The use of weak decays to determine proton spin structure is examined in view of possible violations of the Bjorken and Gottfried Sum rules, flavor symmetry breaking and flavor asymmetry in the sea. The use of the neutron decay is found to be unaffected by all these. A method for including these effects in analyses of hyperon decays shows that a flavor-asymmetric sea produced by SU(3) symmetry breaking has only a small effect on results for the total spin carried by quarks. However the strange quark contribution cannot be reliably obtained from charged lepton scattering and weak decay data alone, and requires additional model-dependent input relating nucleon and hyperon wave functions.
0902.2525
Pankaj Jain
Pankaj Jain and Subhadip Mitra
One Loop Calculation of Cosmological Constant in a Scale Invariant Theory
13 pages, 6 figures
Mod.Phys.Lett.A24:2069-2079,2009
10.1142/S0217732309031351
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the cosmological constant in a scale invariant scalar field theory. The gravitational action is also suitably modified to respect scale invariance. Due to scale invariance the theory does not admit a cosmological constant term. The scale invariance is broken by a recently introduced mechanism called cosmological symmetry breaking. This leads to a nonzero cosmological constant. We compute the one loop corrections to the cosmological constant and show that it is finite.
[ { "created": "Sun, 15 Feb 2009 07:30:18 GMT", "version": "v1" } ]
2010-11-15
[ [ "Jain", "Pankaj", "" ], [ "Mitra", "Subhadip", "" ] ]
We compute the cosmological constant in a scale invariant scalar field theory. The gravitational action is also suitably modified to respect scale invariance. Due to scale invariance the theory does not admit a cosmological constant term. The scale invariance is broken by a recently introduced mechanism called cosmological symmetry breaking. This leads to a nonzero cosmological constant. We compute the one loop corrections to the cosmological constant and show that it is finite.
0805.2435
Hisakazu Minakata
Hisakazu Minakata
Probing Non-Standard Neutrino Physics at Neutrino Factory and T2KK
Written version of a talk presented at the ``Fourth International Workshop on Neutrino Oscillations in Venice --Ten Years after the Neutrino Oscillations--'', (NO-VE 2008) Venice, Italy. 15-18, April 2008. 20 pages, 9 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss ways to explore non-standard interactions (NSI) which neutrinos may possess by expressing them as effective four Fermi operators with coefficient of the order of (M_{W} / M_{NP})^2 ~0.01 (0.0001) for energy scales of new physics as M_{NP} ~1 (10) TeV. Neutrino Factory is a prime candidate for such apparatus that can reach to the extreme precision. I describe a two detector setting, one at baseline L~3000 km and the other at L~7000 km, which is able to solve the notorious theta_{13}-NSI confusion, and possibly also the two-phase confusion. The resultant sensitivities to off-diagonal NSI elements \epsilon's are excellent, |\epsilon_{e tau}| \simeq a few \times10^{-3} and |\epsilon_{e mu}| \simeq a few \times10^{-4}. Our results suggest a new picture of neutrino factory as a hunting machine for NSI while keeping its potential of precision measurement of lepton mixing parameters. Sensitivities to NSI by T2KK and the related settings are also discussed.
[ { "created": "Fri, 16 May 2008 04:20:37 GMT", "version": "v1" } ]
2008-05-19
[ [ "Minakata", "Hisakazu", "" ] ]
We discuss ways to explore non-standard interactions (NSI) which neutrinos may possess by expressing them as effective four Fermi operators with coefficient of the order of (M_{W} / M_{NP})^2 ~0.01 (0.0001) for energy scales of new physics as M_{NP} ~1 (10) TeV. Neutrino Factory is a prime candidate for such apparatus that can reach to the extreme precision. I describe a two detector setting, one at baseline L~3000 km and the other at L~7000 km, which is able to solve the notorious theta_{13}-NSI confusion, and possibly also the two-phase confusion. The resultant sensitivities to off-diagonal NSI elements \epsilon's are excellent, |\epsilon_{e tau}| \simeq a few \times10^{-3} and |\epsilon_{e mu}| \simeq a few \times10^{-4}. Our results suggest a new picture of neutrino factory as a hunting machine for NSI while keeping its potential of precision measurement of lepton mixing parameters. Sensitivities to NSI by T2KK and the related settings are also discussed.
hep-ph/0210428
Kerry Whisnant
V. Barger, D. Marfatia, K. Whisnant
How two neutrino superbeam experiments do better than one
18 pages, 6 PS figures, added references and revised discussion
Phys.Lett.B560:75-86,2003
10.1016/S0370-2693(03)00334-4
MAD-PH-1311
hep-ph
null
We examine the use of two superbeam neutrino oscillation experiments with baselines $\lsim 1000$ km to resolve parameter degeneracies inherent in the three-neutrino analysis of such experiments. We find that with appropriate choices of neutrino energies and baselines two experiments with different baselines can provide a much better determination of the neutrino mass ordering than a single experiment alone. Two baselines are especially beneficial when the mass scale for solar neutrino oscillations $\delta m^2_{\rm sol}$ is $\gsim 5\times10^{-5}$ eV$^2$. We also examine CP violation sensitivity and the resolution of other parameter degeneracies. We find that the combined data of superbeam experiments with baselines of 295 and 900 km can provide sensitivity to both the neutrino mass ordering and CP violation for $\sin^22\theta_{13}$ down to 0.03 for $|\delta m^2_{\rm atm}| \simeq 3\times10^{-3}$ eV$^2$. It would be highly advantageous to have a 10% determination of $|\delta m^2_{\rm atm}|$ before the beam energies and baselines are finalized, although if $|\delta m^2_{\rm atm}|$ is not that well known, the neutrino energies and baselines can be chosen to give fairly good sensitivity for a range of $|\delta m^2_{\rm atm}|$.
[ { "created": "Wed, 30 Oct 2002 18:46:50 GMT", "version": "v1" }, { "created": "Mon, 18 Nov 2002 22:12:28 GMT", "version": "v2" } ]
2009-09-15
[ [ "Barger", "V.", "" ], [ "Marfatia", "D.", "" ], [ "Whisnant", "K.", "" ] ]
We examine the use of two superbeam neutrino oscillation experiments with baselines $\lsim 1000$ km to resolve parameter degeneracies inherent in the three-neutrino analysis of such experiments. We find that with appropriate choices of neutrino energies and baselines two experiments with different baselines can provide a much better determination of the neutrino mass ordering than a single experiment alone. Two baselines are especially beneficial when the mass scale for solar neutrino oscillations $\delta m^2_{\rm sol}$ is $\gsim 5\times10^{-5}$ eV$^2$. We also examine CP violation sensitivity and the resolution of other parameter degeneracies. We find that the combined data of superbeam experiments with baselines of 295 and 900 km can provide sensitivity to both the neutrino mass ordering and CP violation for $\sin^22\theta_{13}$ down to 0.03 for $|\delta m^2_{\rm atm}| \simeq 3\times10^{-3}$ eV$^2$. It would be highly advantageous to have a 10% determination of $|\delta m^2_{\rm atm}|$ before the beam energies and baselines are finalized, although if $|\delta m^2_{\rm atm}|$ is not that well known, the neutrino energies and baselines can be chosen to give fairly good sensitivity for a range of $|\delta m^2_{\rm atm}|$.
1009.1053
Berndt Muller
Berndt M\"uller and Andreas Sch\"afer
Charge Fluctuations from the Chiral Magnetic Effect in Nuclear Collisions
A numerical error in an earlier version of the manuscript is corrected
Phys.Rev.C82:057902,2010
10.1103/PhysRevC.82.057902
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a nonlocal effective Lagrangian for the chiral magnetic effect. An electric field is generated by winding number fluctuations of the nonabelian gauge field in the presence of a strong magnetic field. We estimate the magnitude of charge asymmetry fluctuations with respect to the reaction plane induced by the chiral magnetic effect in relativistic heavy ion collisions to be less than $10^{-6}$, several orders of magnitude smaller than the signal observed in the STAR experiment.
[ { "created": "Mon, 6 Sep 2010 13:24:37 GMT", "version": "v1" }, { "created": "Tue, 21 Sep 2010 11:04:08 GMT", "version": "v2" } ]
2010-12-23
[ [ "Müller", "Berndt", "" ], [ "Schäfer", "Andreas", "" ] ]
We derive a nonlocal effective Lagrangian for the chiral magnetic effect. An electric field is generated by winding number fluctuations of the nonabelian gauge field in the presence of a strong magnetic field. We estimate the magnitude of charge asymmetry fluctuations with respect to the reaction plane induced by the chiral magnetic effect in relativistic heavy ion collisions to be less than $10^{-6}$, several orders of magnitude smaller than the signal observed in the STAR experiment.
hep-ph/0402095
Lawrence Gibbons
M. Battaglia and L. Gibbons
Determination of |Vub|
16 pages, requires mtexsis, to appear in Review of Particle Properties, 2004 ed
null
null
CLNS 04/1864, LBNL-54491
hep-ph
null
The element Vub of the CKM mixing matrix is the smallest of the quark couplings and is crucial in understanding CP violation in the B system. In this review, we discuss the present status of the determination of its magnitude, which involves a significant effort both experimentally and theoretically. Decisive progress has been achieved in recent years, thanks in part to the large data sets that have become available at the B factories. Based on these data we propose an average |Vub| value of (3.67 \pm 0.47)x10^{-3}, which has an uncertainty of 13%. With the experimental and theoretical progress expected in the next few years a determination to an accuracy of 10%, or better, seems feasible.
[ { "created": "Mon, 9 Feb 2004 21:16:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Battaglia", "M.", "" ], [ "Gibbons", "L.", "" ] ]
The element Vub of the CKM mixing matrix is the smallest of the quark couplings and is crucial in understanding CP violation in the B system. In this review, we discuss the present status of the determination of its magnitude, which involves a significant effort both experimentally and theoretically. Decisive progress has been achieved in recent years, thanks in part to the large data sets that have become available at the B factories. Based on these data we propose an average |Vub| value of (3.67 \pm 0.47)x10^{-3}, which has an uncertainty of 13%. With the experimental and theoretical progress expected in the next few years a determination to an accuracy of 10%, or better, seems feasible.
1103.3270
Jason Kumar
Jason Kumar, John G. Learned, Michinari Sakai and Stefanie Smith
Dark Matter Detection With Electron Neutrinos in Liquid Scintillation Detectors
5 pages, 4 figures, PDFLaTeX; v2: references added, figures updated, more detailed comparison of liquid scintillation and water Cerenkov detectors (journal version)
null
10.1103/PhysRevD.84.036007
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the prospects for liquid scintillation experiments (with a focus on KamLAND) to detect the flux of electron neutrinos arising from dark matter annihilation in the core of the sun. We show that, with data already taken, KamLAND can provide the greatest sensitivity to the dark matter-proton spin-dependent scattering cross-section for dark matter lighter than 20 GeV. It is also possible to probe the dark matter-nucleon spin-independent scattering cross-section for isospin-violating dark matter lighter than 10 GeV. KamLAND can thus potentially confirm the dark matter interpretation of the DAMA and CoGeNT signals, utilizing data already taken.
[ { "created": "Wed, 16 Mar 2011 20:00:01 GMT", "version": "v1" }, { "created": "Tue, 26 Jul 2011 09:08:48 GMT", "version": "v2" } ]
2015-03-19
[ [ "Kumar", "Jason", "" ], [ "Learned", "John G.", "" ], [ "Sakai", "Michinari", "" ], [ "Smith", "Stefanie", "" ] ]
We consider the prospects for liquid scintillation experiments (with a focus on KamLAND) to detect the flux of electron neutrinos arising from dark matter annihilation in the core of the sun. We show that, with data already taken, KamLAND can provide the greatest sensitivity to the dark matter-proton spin-dependent scattering cross-section for dark matter lighter than 20 GeV. It is also possible to probe the dark matter-nucleon spin-independent scattering cross-section for isospin-violating dark matter lighter than 10 GeV. KamLAND can thus potentially confirm the dark matter interpretation of the DAMA and CoGeNT signals, utilizing data already taken.
hep-ph/0410256
Roberto Pittau
F. del Aguila (Granada U. & CAFPE, Granada) and R. Pittau (Granada U. & CAFPE, Granada)
Physics beyond the Standard Model and its Minimal Supersymmetric extension at large colliders
Bibliography updated, 17 pages, talk presented by F. del Aguila at the final meeting of the European Network ``Physics at Colliders'', Montpellier, France, September 26--27, 2004
Acta Phys.Polon. B35 (2004) 2767-2780
null
UG-FT-173/04 and CAFPE-43/04
hep-ph
null
New large colliders will probe scales up to few TeV, indicating the way Nature has chosen to extend the Standard Model. We review alternative scenarios to the traditional Minimal Supersymmetric Standard Model: the little Higgs model, split supersymmetry and extra dimensional models with low energy signals.
[ { "created": "Tue, 19 Oct 2004 09:31:45 GMT", "version": "v1" }, { "created": "Wed, 15 Dec 2004 11:09:46 GMT", "version": "v2" } ]
2007-05-23
[ [ "del Aguila", "F.", "", "Granada U. & CAFPE, Granada" ], [ "Pittau", "R.", "", "Granada U.\n & CAFPE, Granada" ] ]
New large colliders will probe scales up to few TeV, indicating the way Nature has chosen to extend the Standard Model. We review alternative scenarios to the traditional Minimal Supersymmetric Standard Model: the little Higgs model, split supersymmetry and extra dimensional models with low energy signals.
1106.2193
Jeremy Price
Jeremy Price
Randall-Sundrum Models and Holography
Master's thesis. 61 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This Master's thesis will introduce the Randall-Sundrum RSI model and overview its general features and basic phenomenology, with the goal of understanding its 5-dimensional geometric structure in terms of its 4-dimensional AdS/CFT dual theory. We discuss mode expansions, boundary terms, field content, and supersymmetry, leading up to a discussion of the AdS/CFT correspondence in RSI models. Low-energy 4d Yukawa hierarchies and gauge couplings are understood in terms of the bulk 5d theory. A few simple Standard Model and MSSM-like constructions are considered, and their 4d dual theories are discussed. One new result is presented: the 5d bulk interpretation of the Nelson-Strassler mechanism of generating Yukawa hierarchies through renormalization group flow.
[ { "created": "Sat, 11 Jun 2011 03:27:06 GMT", "version": "v1" } ]
2011-06-14
[ [ "Price", "Jeremy", "" ] ]
This Master's thesis will introduce the Randall-Sundrum RSI model and overview its general features and basic phenomenology, with the goal of understanding its 5-dimensional geometric structure in terms of its 4-dimensional AdS/CFT dual theory. We discuss mode expansions, boundary terms, field content, and supersymmetry, leading up to a discussion of the AdS/CFT correspondence in RSI models. Low-energy 4d Yukawa hierarchies and gauge couplings are understood in terms of the bulk 5d theory. A few simple Standard Model and MSSM-like constructions are considered, and their 4d dual theories are discussed. One new result is presented: the 5d bulk interpretation of the Nelson-Strassler mechanism of generating Yukawa hierarchies through renormalization group flow.
1612.05492
Yohei Ema
Yohei Ema, Koichi Hamaguchi, Takeo Moroi, Kazunori Nakayama
Flaxion: a minimal extension to solve puzzles in the standard model
23 pages, 1 figure; v2: version published in JHEP
null
10.1007/JHEP01(2017)096
UT-16-36, IPMU16-0189
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a minimal extension of the standard model which includes only one additional complex scalar field, flavon, with flavor-dependent global U(1) symmetry. It not only explains the hierarchical flavor structure in the quark and lepton sector (including neutrino sector), but also solves the strong CP problem by identifying the CP-odd component of the flavon as the QCD axion, which we call flaxion. Furthermore, the flaxion model solves the cosmological puzzles in the standard model, i.e., origin of dark matter, baryon asymmetry of the universe, and inflation. We show that the radial component of the flavon can play the role of inflaton without isocurvature nor domain wall problems. The dark matter abundance can be explained by the flaxion coherent oscillation, while the baryon asymmetry of the universe is generated through leptogenesis.
[ { "created": "Fri, 16 Dec 2016 14:48:20 GMT", "version": "v1" }, { "created": "Tue, 24 Jan 2017 04:52:00 GMT", "version": "v2" } ]
2017-03-08
[ [ "Ema", "Yohei", "" ], [ "Hamaguchi", "Koichi", "" ], [ "Moroi", "Takeo", "" ], [ "Nakayama", "Kazunori", "" ] ]
We propose a minimal extension of the standard model which includes only one additional complex scalar field, flavon, with flavor-dependent global U(1) symmetry. It not only explains the hierarchical flavor structure in the quark and lepton sector (including neutrino sector), but also solves the strong CP problem by identifying the CP-odd component of the flavon as the QCD axion, which we call flaxion. Furthermore, the flaxion model solves the cosmological puzzles in the standard model, i.e., origin of dark matter, baryon asymmetry of the universe, and inflation. We show that the radial component of the flavon can play the role of inflaton without isocurvature nor domain wall problems. The dark matter abundance can be explained by the flaxion coherent oscillation, while the baryon asymmetry of the universe is generated through leptogenesis.
1301.6764
Martin Spinrath
Stefan Antusch, Stephen F. King, Martin Spinrath
Spontaneous CP violation in A4xSU(5) with Constrained Sequential Dominance 2
25 pages, 6 figures; version to be published in PRD
Phys. Rev. D 87, 096018 (2013)
10.1103/PhysRevD.87.096018
MPP-2013-13, SISSA 04/2013/FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit a two right-handed neutrino model with two texture zeros, namely an indirect model based on A4 with the recently proposed new type of constrained sequential dominance (CSD2), involving vacuum alignments along the (0,1,-1)^T and (1,0,2)^T directions in flavour space, which are proportional to the neutrino Dirac mass matrix columns. In this paper we construct a renormalizable and unified indirect A4xSU(5) model along these lines and show that, with spontaneous CP violation and a suitable vacuum alignment of the phases, the charged lepton corrections lead to a reactor angle in good agreement with results from Daya Bay and RENO. The model predicts a right-angled unitarity triangle in the quark sector and a Dirac CP violating oscillation phase in the lepton sector of delta approximately 130 degrees, while providing a good fit to all quark and lepton masses and mixing angles.
[ { "created": "Mon, 28 Jan 2013 21:00:32 GMT", "version": "v1" }, { "created": "Mon, 13 May 2013 13:46:39 GMT", "version": "v2" } ]
2013-06-04
[ [ "Antusch", "Stefan", "" ], [ "King", "Stephen F.", "" ], [ "Spinrath", "Martin", "" ] ]
We revisit a two right-handed neutrino model with two texture zeros, namely an indirect model based on A4 with the recently proposed new type of constrained sequential dominance (CSD2), involving vacuum alignments along the (0,1,-1)^T and (1,0,2)^T directions in flavour space, which are proportional to the neutrino Dirac mass matrix columns. In this paper we construct a renormalizable and unified indirect A4xSU(5) model along these lines and show that, with spontaneous CP violation and a suitable vacuum alignment of the phases, the charged lepton corrections lead to a reactor angle in good agreement with results from Daya Bay and RENO. The model predicts a right-angled unitarity triangle in the quark sector and a Dirac CP violating oscillation phase in the lepton sector of delta approximately 130 degrees, while providing a good fit to all quark and lepton masses and mixing angles.
1402.6887
Kazem Azizi
K. Azizi, Y. Sarac, H. Sundu
Analysis of the strong $D_{2}^{*}(2460)^{0}\rightarrow D^+ \pi^- $ and $D_{s2}^{*}(2573)^{+}\rightarrow D^{+} K^{0}$ transitions via QCD sum rules
13 Pages and 7 Tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strong $D_{2}^{*}(2460)^{0}\rightarrow D^+ \pi^- $ and $D_{s2}^{*}(2573)^{+}\rightarrow D^{+} K^{0}$ transitions are analyzed via three point QCD sum rules. First, we calculate the corresponding strong coupling constants $g_{D_2^*D\pi}$ and $g_{D_{s2}^*DK}$. Then, we use them to calculate the corresponding decay widths and branching ratios. Making use of the existing experimental data on the ratio of the decay width in the pseudoscaler $D$ channel to that of the vector $D^*$ channel, finally, we estimate the decay width and branching ratio of the strong $D_2^*(2460)^0 \rightarrow D^*(2010)^+\pi^-$ transition.
[ { "created": "Thu, 27 Feb 2014 12:35:14 GMT", "version": "v1" }, { "created": "Fri, 26 Sep 2014 13:33:57 GMT", "version": "v2" } ]
2014-09-29
[ [ "Azizi", "K.", "" ], [ "Sarac", "Y.", "" ], [ "Sundu", "H.", "" ] ]
The strong $D_{2}^{*}(2460)^{0}\rightarrow D^+ \pi^- $ and $D_{s2}^{*}(2573)^{+}\rightarrow D^{+} K^{0}$ transitions are analyzed via three point QCD sum rules. First, we calculate the corresponding strong coupling constants $g_{D_2^*D\pi}$ and $g_{D_{s2}^*DK}$. Then, we use them to calculate the corresponding decay widths and branching ratios. Making use of the existing experimental data on the ratio of the decay width in the pseudoscaler $D$ channel to that of the vector $D^*$ channel, finally, we estimate the decay width and branching ratio of the strong $D_2^*(2460)^0 \rightarrow D^*(2010)^+\pi^-$ transition.
hep-ph/0002232
Hitoshi Murayama
Hitoshi Murayama (UC Berkeley, LBNL)
Supersymmetry Phenomenology
40 pages, uses psfig
null
null
UCB-PTH-00/05
hep-ph
null
This is a very pedagogical review of supersymmetry phenomenology, given at ICTP Summer School in 1999, aimed mostly at students who had never studied supersymmetry before. It starts with an analogy that the reason why supersymmetry is needed is similar to the reason why the positron exists. It introduces the construction of supersymmetric Lagrangians in a practical way. The low-energy constraints, renormalization-group analyses, collider phenomenology, and frameworks of mediating supersymmetry breaking are briefly discussed.
[ { "created": "Wed, 23 Feb 2000 01:12:51 GMT", "version": "v1" }, { "created": "Sat, 4 Mar 2000 05:21:56 GMT", "version": "v2" } ]
2007-05-23
[ [ "Murayama", "Hitoshi", "", "UC Berkeley, LBNL" ] ]
This is a very pedagogical review of supersymmetry phenomenology, given at ICTP Summer School in 1999, aimed mostly at students who had never studied supersymmetry before. It starts with an analogy that the reason why supersymmetry is needed is similar to the reason why the positron exists. It introduces the construction of supersymmetric Lagrangians in a practical way. The low-energy constraints, renormalization-group analyses, collider phenomenology, and frameworks of mediating supersymmetry breaking are briefly discussed.