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1110.5908
Jian Tang
Jian Tang, Walter Winter
Requirements for a New Detector at the South Pole Receiving an Accelerator Neutrino Beam
34 pages, 15 figures. Minor changes and accepted in JHEP
null
10.1007/JHEP02(2012)028
IDS-NF-031; EURONU-WP6-11-42
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There are recent considerations to increase the photomultiplier density in the IceCube detector array beyond that of DeepCore, which will lead to a lower detection threshold and a huge fiducial mass for the neutrino detection. This initiative is known as "Phased IceCube Next Generation Upgrade" (PINGU). We discuss the possibility to send a neutrino beam from one of the major accelerator laboratories in the Northern hemisphere to such a detector. Such an experiment would be unique in the sense that it would be the only neutrino beam where the baseline crosses the Earth's core. We study the detector requirements for a beta beam, a neutrino factory beam, and a superbeam, where we consider both the cases of small theta_13 and large theta_13, as suggested by the recent T2K and Double Chooz results. We illustrate that a flavor-clean beta beam best suits the requirements of such a detector, in particular, that PINGU may replace a magic baseline detector for small values of theta_13 -- even in the absence of any energy resolution capability. For large theta_13, however, a single-baseline beta beam experiment cannot compete if it is constrained by the CERN-SPS. For a neutrino factory, because of the missing charge identification possibility in the detector, a very good energy resolution is required. If this can be achieved, especially a low energy neutrino factory, which does not suffer from the tau contamination, may be an interesting option for large theta_13. For the superbeam, where we use the LBNE beam as a reference, electron neutrino flavor identification and statistics are two of the main limitations. Finally, we demonstrate that, at least in principle, neutrino factory and superbeam can measure the density of the Earth's core to the sub-percent level for sin^2 2theta_13 larger than 0.01.
[ { "created": "Wed, 26 Oct 2011 20:00:02 GMT", "version": "v1" }, { "created": "Mon, 23 Jan 2012 12:32:40 GMT", "version": "v2" } ]
2015-05-30
[ [ "Tang", "Jian", "" ], [ "Winter", "Walter", "" ] ]
There are recent considerations to increase the photomultiplier density in the IceCube detector array beyond that of DeepCore, which will lead to a lower detection threshold and a huge fiducial mass for the neutrino detection. This initiative is known as "Phased IceCube Next Generation Upgrade" (PINGU). We discuss the possibility to send a neutrino beam from one of the major accelerator laboratories in the Northern hemisphere to such a detector. Such an experiment would be unique in the sense that it would be the only neutrino beam where the baseline crosses the Earth's core. We study the detector requirements for a beta beam, a neutrino factory beam, and a superbeam, where we consider both the cases of small theta_13 and large theta_13, as suggested by the recent T2K and Double Chooz results. We illustrate that a flavor-clean beta beam best suits the requirements of such a detector, in particular, that PINGU may replace a magic baseline detector for small values of theta_13 -- even in the absence of any energy resolution capability. For large theta_13, however, a single-baseline beta beam experiment cannot compete if it is constrained by the CERN-SPS. For a neutrino factory, because of the missing charge identification possibility in the detector, a very good energy resolution is required. If this can be achieved, especially a low energy neutrino factory, which does not suffer from the tau contamination, may be an interesting option for large theta_13. For the superbeam, where we use the LBNE beam as a reference, electron neutrino flavor identification and statistics are two of the main limitations. Finally, we demonstrate that, at least in principle, neutrino factory and superbeam can measure the density of the Earth's core to the sub-percent level for sin^2 2theta_13 larger than 0.01.
hep-ph/0308200
Elsayed Lashin Dr.
E. I. Lashin
CP conserved nonleptonic $K \to \pi \pi \pi $ decays in the Chiral Quark Model
28 pages, 5 figurs, 6 tables
Int.J.Mod.Phys. A21 (2006) 3699-3726
10.1142/S0217751X06029405
null
hep-ph
null
The CP conserved non leptonic $K\to \pi \pi \pi$ decays are discussed within the chiral quark model, including chiral perturbation theory corrections. All amplitudes are parameterized in terms of quark and gluon condensate and the constituent quark mass. The same values for these parameters that can be obtained by a fit of the $\Delta I = 1/2$ rule in $K\to 2 \pi$ give a reasonably good fit in the $K\to 3 \pi$ case. We compare with the work of other groups.
[ { "created": "Tue, 19 Aug 2003 21:25:53 GMT", "version": "v1" }, { "created": "Mon, 7 Aug 2006 13:32:51 GMT", "version": "v2" } ]
2009-11-10
[ [ "Lashin", "E. I.", "" ] ]
The CP conserved non leptonic $K\to \pi \pi \pi$ decays are discussed within the chiral quark model, including chiral perturbation theory corrections. All amplitudes are parameterized in terms of quark and gluon condensate and the constituent quark mass. The same values for these parameters that can be obtained by a fit of the $\Delta I = 1/2$ rule in $K\to 2 \pi$ give a reasonably good fit in the $K\to 3 \pi$ case. We compare with the work of other groups.
1910.11224
Maxim Malyshev
A.V. Lipatov, M.A. Malyshev, H. Jung
On relation between Parton Branching Approach and CCFM evolution
15 pages, 8 figures
Phys. Rev. D 101, 034022 (2020)
10.1103/PhysRevD.101.034022
DESY 19-183
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the associated production of electroweak gauge bosons and charm or beauty quark jets at the LHC using the $k_T$-factorization framework. We apply the transverse momentum dependent (TMD) parton distributions in a proton obtained from the Parton Branching (PB) method as well as from the Catani-Ciafaloni-Fiorani-Marchesini (CCFM) evolution equation. For the PB approach, our prescription merges the standard leading order ${\cal O}(\alpha \alpha_s)$ $k_T$-factorization calculations with several tree-level next-to-leading order ${\cal O}(\alpha \alpha_s^2)$ off-shell production amplitudes. For the CCFM scenario, our consideration is based on the ${\cal O}(\alpha \alpha_s^2)$ off-shell gluon-gluon fusion subprocess $g^* g^* \to Z/W + Q\bar Q$ and some subleading ${\cal O}(\alpha \alpha_s^2)$ subprocesses involving quark interactions, taken into account in conventional (collinear) QCD factorization. We find that the $W + c$ and $Z + b$ cross sections, calculated within the PB and CCFM-based schemes with the proper choice of leading and next-to-leading subprocesses, are in good agreement with each other, thus establishing a correspondence between these two scenarios. A comparison with the latest LHC experimental data is given and the necessity for the proper off-shell treatment of the production amplitudes in determination of the parameters of the TMD parton density is demonstrated.
[ { "created": "Thu, 24 Oct 2019 15:27:27 GMT", "version": "v1" } ]
2020-02-26
[ [ "Lipatov", "A. V.", "" ], [ "Malyshev", "M. A.", "" ], [ "Jung", "H.", "" ] ]
We consider the associated production of electroweak gauge bosons and charm or beauty quark jets at the LHC using the $k_T$-factorization framework. We apply the transverse momentum dependent (TMD) parton distributions in a proton obtained from the Parton Branching (PB) method as well as from the Catani-Ciafaloni-Fiorani-Marchesini (CCFM) evolution equation. For the PB approach, our prescription merges the standard leading order ${\cal O}(\alpha \alpha_s)$ $k_T$-factorization calculations with several tree-level next-to-leading order ${\cal O}(\alpha \alpha_s^2)$ off-shell production amplitudes. For the CCFM scenario, our consideration is based on the ${\cal O}(\alpha \alpha_s^2)$ off-shell gluon-gluon fusion subprocess $g^* g^* \to Z/W + Q\bar Q$ and some subleading ${\cal O}(\alpha \alpha_s^2)$ subprocesses involving quark interactions, taken into account in conventional (collinear) QCD factorization. We find that the $W + c$ and $Z + b$ cross sections, calculated within the PB and CCFM-based schemes with the proper choice of leading and next-to-leading subprocesses, are in good agreement with each other, thus establishing a correspondence between these two scenarios. A comparison with the latest LHC experimental data is given and the necessity for the proper off-shell treatment of the production amplitudes in determination of the parameters of the TMD parton density is demonstrated.
1404.7096
Gudrun Heinrich
G. Cullen, H. van Deurzen, N. Greiner, G. Heinrich, G. Luisoni, P. Mastrolia, E. Mirabella, G. Ossola, T. Peraro, J. Schlenk, J.F. von Soden-Fraunhofen, F. Tramontano
GoSam-2.0: a tool for automated one-loop calculations within the Standard Model and beyond
replaced by published version and reference added
Eur.Phys.J. C74 (2014) 8, 3001
10.1140/epjc/s10052-014-3001-5
DESY 14-061, MPP-2014-145
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the version 2.0 of the program package GoSam for the automated calculation of one-loop amplitudes. GoSam is devised to compute one-loop QCD and/or electroweak corrections to multi-particle processes within and beyond the Standard Model. The new code contains improvements in the generation and in the reduction of the amplitudes, performs better in computing time and numerical accuracy, and has an extended range of applicability. The extended version of the "Binoth-Les-Houches-Accord" interface to Monte Carlo programs is also implemented. We give a detailed description of installation and usage of the code, and illustrate the new features in dedicated examples.
[ { "created": "Mon, 28 Apr 2014 19:02:47 GMT", "version": "v1" }, { "created": "Thu, 25 Jun 2015 12:49:31 GMT", "version": "v2" } ]
2015-06-26
[ [ "Cullen", "G.", "" ], [ "van Deurzen", "H.", "" ], [ "Greiner", "N.", "" ], [ "Heinrich", "G.", "" ], [ "Luisoni", "G.", "" ], [ "Mastrolia", "P.", "" ], [ "Mirabella", "E.", "" ], [ "Ossola", "G.", "" ], [ "Peraro", "T.", "" ], [ "Schlenk", "J.", "" ], [ "von Soden-Fraunhofen", "J. F.", "" ], [ "Tramontano", "F.", "" ] ]
We present the version 2.0 of the program package GoSam for the automated calculation of one-loop amplitudes. GoSam is devised to compute one-loop QCD and/or electroweak corrections to multi-particle processes within and beyond the Standard Model. The new code contains improvements in the generation and in the reduction of the amplitudes, performs better in computing time and numerical accuracy, and has an extended range of applicability. The extended version of the "Binoth-Les-Houches-Accord" interface to Monte Carlo programs is also implemented. We give a detailed description of installation and usage of the code, and illustrate the new features in dedicated examples.
hep-ph/9705395
B. F. L. Ward
S. Jadach, W. Placzek and B. F. L. Ward
e^+ (Anti)Quark Scattering in the Presence of the Anomalous HERA Positron-Jet Event Phenomenon
9 pages, 3 figures, Latex and bbl files
null
null
UTHEP-97-0103
hep-ph
null
We discuss the leptoquark interpretation of the anomalous HERA positron-jet events in the context of the YFS exponentiated Monte Carlo event generator treatment of the attendant multiple photon radiative effects for both the would-be signal and the SM background, wherein finite-$p_T$ photon effects are properly taken into account and wherein infrared singularities are cancelled to all orders in $\alpha$. We show that H1 and ZEUS data are consistent with such an interpretation for a leptoquark coupling $\lesssim 0.3g_W$, mass $\sim 200$ GeV, and width $\lesssim 2$GeV. Possible future tests are proposed.
[ { "created": "Thu, 22 May 1997 16:07:41 GMT", "version": "v1" }, { "created": "Fri, 23 May 1997 00:28:26 GMT", "version": "v2" } ]
2008-02-03
[ [ "Jadach", "S.", "" ], [ "Placzek", "W.", "" ], [ "Ward", "B. F. L.", "" ] ]
We discuss the leptoquark interpretation of the anomalous HERA positron-jet events in the context of the YFS exponentiated Monte Carlo event generator treatment of the attendant multiple photon radiative effects for both the would-be signal and the SM background, wherein finite-$p_T$ photon effects are properly taken into account and wherein infrared singularities are cancelled to all orders in $\alpha$. We show that H1 and ZEUS data are consistent with such an interpretation for a leptoquark coupling $\lesssim 0.3g_W$, mass $\sim 200$ GeV, and width $\lesssim 2$GeV. Possible future tests are proposed.
2003.04478
Xiangdong Ji
Xiangdong Ji
Fundamental Properties of the Proton in Light-Front Zero Modes
5 pages, no figure
null
10.1016/j.nuclphysb.2020.115181
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For a proton in the infinite momentum frame, its wave function contains a zero-momentum part (light-front zero-modes) originated from the modification of the QCD vacuum in the presence of the valence quarks, exhibiting a light-front long-range order in the quantum state. This ``non-travelling'' component of the proton contributes to its fundamental properties, including the mass and spin, as well as the naive-time-reversal-odd correlations between transverse momentum and spin. The large momentum effective theory (LaMET) provides a theoretical approach to study the physical properties of the proton's zero-mode ``condensate'' through lattice simulations.
[ { "created": "Tue, 10 Mar 2020 00:45:37 GMT", "version": "v1" } ]
2020-10-28
[ [ "Ji", "Xiangdong", "" ] ]
For a proton in the infinite momentum frame, its wave function contains a zero-momentum part (light-front zero-modes) originated from the modification of the QCD vacuum in the presence of the valence quarks, exhibiting a light-front long-range order in the quantum state. This ``non-travelling'' component of the proton contributes to its fundamental properties, including the mass and spin, as well as the naive-time-reversal-odd correlations between transverse momentum and spin. The large momentum effective theory (LaMET) provides a theoretical approach to study the physical properties of the proton's zero-mode ``condensate'' through lattice simulations.
2104.04494
Tong Li
Tong Li, Michael A. Schmidt, Chang-Yuan Yao, Man Yuan
Charged lepton flavor violation in light of the muon magnetic moment anomaly and colliders
21 pages, 4 figures, 4 tables. version accepted by EPJC
null
10.1140/epjc/s10052-021-09569-9
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Any observation of charged lepton flavor violation (CLFV) implies the existence of new physics beyond the SM in charged lepton sector. CLFV interactions may also contribute to the muon magnetic moment and explain the discrepancy between the SM prediction and the recent muon $g-2$ precision measurement at Fermilab. We consider the most general SM gauge invariant Lagrangian of $\Delta L=0$ bileptons with CLFV couplings and investigate the interplay of low-energy precision experiments and colliders in light of the muon magnetic moment anomaly. We go beyond previous work by demonstrating the sensitivity of the LHC, the MACE experiment, a proposed muonium-antimuonium conversion experiment, and a muon collider. Currently-available LHC data is already able to probe unexplored parameter space via the CLFV process $pp\to\gamma^*/Z^*\to \ell_1^\pm \ell_1^\pm \ell_2^\mp \ell_2^\mp$.
[ { "created": "Fri, 9 Apr 2021 17:22:38 GMT", "version": "v1" }, { "created": "Tue, 24 Aug 2021 07:22:53 GMT", "version": "v2" } ]
2021-09-29
[ [ "Li", "Tong", "" ], [ "Schmidt", "Michael A.", "" ], [ "Yao", "Chang-Yuan", "" ], [ "Yuan", "Man", "" ] ]
Any observation of charged lepton flavor violation (CLFV) implies the existence of new physics beyond the SM in charged lepton sector. CLFV interactions may also contribute to the muon magnetic moment and explain the discrepancy between the SM prediction and the recent muon $g-2$ precision measurement at Fermilab. We consider the most general SM gauge invariant Lagrangian of $\Delta L=0$ bileptons with CLFV couplings and investigate the interplay of low-energy precision experiments and colliders in light of the muon magnetic moment anomaly. We go beyond previous work by demonstrating the sensitivity of the LHC, the MACE experiment, a proposed muonium-antimuonium conversion experiment, and a muon collider. Currently-available LHC data is already able to probe unexplored parameter space via the CLFV process $pp\to\gamma^*/Z^*\to \ell_1^\pm \ell_1^\pm \ell_2^\mp \ell_2^\mp$.
hep-ph/9501303
Michael Eides
Michael I. Eides and Valery A. Shelyuto
CORRECTIONS OF ORDER $\alpha^2(Z\alpha)^5$ TO HYPERFINE SPLITTING AND LAMB SHIFT
22 pages, LaTeX, 2 figures, 6 tables
Phys.Rev.A52:954,1995
10.1103/PhysRevA.52.954
PSU/TH/155
hep-ph
null
Corrections to hyperfine splitting and Lamb shift of order $\alpha^2(Z\alpha)^5$ induced by the diagrams with radiative photon insertions in the electron line are calculated in the Fried-Yennie gauge. These contributions are as large as $-7.725(3)\alpha^2(Z\alpha)^5/(\pi n^3)(m_r/m)^3m$ and $-0.6711(7)\alpha^2(Z\alpha)/(\pi n^3)E_F$ for the Lamb shift and hyperfine splitting, respectively. Phenomenological implications of these results are discussed with special emphasis on the accuracy of the theoretical predictions for the Lamb shift and experimental determination of the Rydberg constant. New more precise value of the Rydberg constant is obtained on the basis of the improved theory and experimental data.
[ { "created": "Sun, 15 Jan 1995 19:53:47 GMT", "version": "v1" } ]
2016-09-01
[ [ "Eides", "Michael I.", "" ], [ "Shelyuto", "Valery A.", "" ] ]
Corrections to hyperfine splitting and Lamb shift of order $\alpha^2(Z\alpha)^5$ induced by the diagrams with radiative photon insertions in the electron line are calculated in the Fried-Yennie gauge. These contributions are as large as $-7.725(3)\alpha^2(Z\alpha)^5/(\pi n^3)(m_r/m)^3m$ and $-0.6711(7)\alpha^2(Z\alpha)/(\pi n^3)E_F$ for the Lamb shift and hyperfine splitting, respectively. Phenomenological implications of these results are discussed with special emphasis on the accuracy of the theoretical predictions for the Lamb shift and experimental determination of the Rydberg constant. New more precise value of the Rydberg constant is obtained on the basis of the improved theory and experimental data.
1210.5154
Mohammad Athar SAJJAD
M. Sajjad Athar, M. Honda, T. Kajita, K. Kasahara and S. Midorikawa
Atmospheric neutrino flux at INO, South Pole and Pyh\"asalmi
12Pages,9Figs
null
10.1016/j.physletb.2012.12.016
null
hep-ph astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the calculation of the atmospheric neutrino fluxes for the neutrino experiments proposed at INO, South Pole and Pyh\"asalmi. Neutrino fluxes have been obtained using ATMNC, a simulation code for cosmic ray in the atmosphere. Even using the same primary flux model and the interaction model, the calculated atmospheric neutrino fluxes are different for the different sites due to the geomagnetic field. The prediction of these fluxes in the present paper would be quite useful in the experimental analysis.
[ { "created": "Thu, 18 Oct 2012 15:06:09 GMT", "version": "v1" } ]
2015-06-11
[ [ "Athar", "M. Sajjad", "" ], [ "Honda", "M.", "" ], [ "Kajita", "T.", "" ], [ "Kasahara", "K.", "" ], [ "Midorikawa", "S.", "" ] ]
We present the calculation of the atmospheric neutrino fluxes for the neutrino experiments proposed at INO, South Pole and Pyh\"asalmi. Neutrino fluxes have been obtained using ATMNC, a simulation code for cosmic ray in the atmosphere. Even using the same primary flux model and the interaction model, the calculated atmospheric neutrino fluxes are different for the different sites due to the geomagnetic field. The prediction of these fluxes in the present paper would be quite useful in the experimental analysis.
hep-ph/9810237
Chung-I. Tan
Chung-I Tan
Diffractive Production at Collider Energies and Factorization
LateX, 35 pages, 4 EPS figures, to be published in a special volume of Physics Report in honor of Richard Slansky
Phys.Rept. 315 (1999) 175-198
10.1016/S0370-1573(99)00020-4
null
hep-ph
null
The most important consequence of Pomeron being a pole is the factorization property. However, due to Pomeron intercept being greater than 1, the extrapolated single diffraction dissociation cross section based on a classical triple-Pomeron formula is too large leading to a potential unitarity violation at Tevatron energies, which has been referred to as "Dino's paradox". We review our resolution which involves a proper implementation of final-state screening correction, with "flavoring" for Pomeron as the primary dynamical mechanism for setting the relevant energy scale. In this approach, factorization remains intact, and unambiguous predictions for double Pomeron exchange, doubly diffraction dissociation, etc., both at Tevatron and at LHC energies, can be made.
[ { "created": "Sat, 3 Oct 1998 17:26:20 GMT", "version": "v1" } ]
2015-06-25
[ [ "Tan", "Chung-I", "" ] ]
The most important consequence of Pomeron being a pole is the factorization property. However, due to Pomeron intercept being greater than 1, the extrapolated single diffraction dissociation cross section based on a classical triple-Pomeron formula is too large leading to a potential unitarity violation at Tevatron energies, which has been referred to as "Dino's paradox". We review our resolution which involves a proper implementation of final-state screening correction, with "flavoring" for Pomeron as the primary dynamical mechanism for setting the relevant energy scale. In this approach, factorization remains intact, and unambiguous predictions for double Pomeron exchange, doubly diffraction dissociation, etc., both at Tevatron and at LHC energies, can be made.
hep-ph/9908400
Hyun-Chul Kim
Mario Franz, Hyun-Chul Kim, and Klaus Goeke
$\Delta S=1,2$ Effective Weak Chiral Lagrangian from the Instanton Vacuum
26 pages. RevTex is used. 9 postscript figures. Submitted to Nucl. Phys. A. The errors and typos corrected
Nucl.Phys. A699 (2002) 541-561
10.1016/S0375-9474(01)01275-1
PNU-NTG-01/99, RUB-TPII-09/99
hep-ph
null
We study the effective weak chiral Lagrangian within the framework of the instanton vacuum. We incorporate the $\Delta S=1,2$ effective weak Hamiltonian into the effective low-energy QCD partition function defining the chiral symmetric quark-Goldstone boson interactions with the momentum-dependent dynamical quark mass. Employing the derivative expansion, we derive the corresponding weak effective Lagrangian in leading order with the low energy constants to be used e.g. in chiral perturbation theory. We find that the momentum-dependent dynamical quark mass plays an essential role in improving the low energy constants and their ratio $g_{8}/g_{27}$.
[ { "created": "Wed, 18 Aug 1999 14:51:56 GMT", "version": "v1" }, { "created": "Tue, 24 Jul 2001 09:12:30 GMT", "version": "v2" } ]
2009-10-31
[ [ "Franz", "Mario", "" ], [ "Kim", "Hyun-Chul", "" ], [ "Goeke", "Klaus", "" ] ]
We study the effective weak chiral Lagrangian within the framework of the instanton vacuum. We incorporate the $\Delta S=1,2$ effective weak Hamiltonian into the effective low-energy QCD partition function defining the chiral symmetric quark-Goldstone boson interactions with the momentum-dependent dynamical quark mass. Employing the derivative expansion, we derive the corresponding weak effective Lagrangian in leading order with the low energy constants to be used e.g. in chiral perturbation theory. We find that the momentum-dependent dynamical quark mass plays an essential role in improving the low energy constants and their ratio $g_{8}/g_{27}$.
1803.07575
Mae Teo
Gustavo Marques-Tavares, Mae Teo
Light axions with large hadronic couplings
8 pages, 3 figures; v2: references added, minor clarifications
null
10.1007/JHEP05(2018)180
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present models in which axions have large couplings to hadrons while remaining naturally light. By assigning $U(1)_{PQ}$ charges to Standard Model quarks such that $U(1)_{PQ}$ is not anomalous under QCD, the derivative couplings naturally arise while no potential is generated for the axion upon QCD confinement. We present simple models that implement this idea both for an axion-like particle and for the QCD axion. We show that both models lead to sizable flavor violations that could be probed by future experiments. Our construction shows that the axion coupling to hadrons can be essentially independent from its mass and thus motivates experimental searches in a wide range of axion parameter space.
[ { "created": "Tue, 20 Mar 2018 18:00:38 GMT", "version": "v1" }, { "created": "Tue, 10 Apr 2018 22:20:28 GMT", "version": "v2" } ]
2018-07-04
[ [ "Marques-Tavares", "Gustavo", "" ], [ "Teo", "Mae", "" ] ]
We present models in which axions have large couplings to hadrons while remaining naturally light. By assigning $U(1)_{PQ}$ charges to Standard Model quarks such that $U(1)_{PQ}$ is not anomalous under QCD, the derivative couplings naturally arise while no potential is generated for the axion upon QCD confinement. We present simple models that implement this idea both for an axion-like particle and for the QCD axion. We show that both models lead to sizable flavor violations that could be probed by future experiments. Our construction shows that the axion coupling to hadrons can be essentially independent from its mass and thus motivates experimental searches in a wide range of axion parameter space.
1806.05566
Toyokazu Sekiguchi Ph.D
Masahiro Kawasaki, Toyokazu Sekiguchi, Masahide Yamaguchi and Jun'ichi Yokoyama
Long-term dynamics of cosmological axion strings
12 pages, 5 figures; accepted for publication in PTEP letters
Prog Theor Exp Phys (2018)
10.1093/ptep/pty098
RESCEU-8/18
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results of new field-theoretic simulation of cosmological axion strings, which are eight times longer than previous ones. We have upgraded our simulation of physical strings in Hiramatsu et al. (2011) in terms of the number of grids as well as the suite of analysis methods. These improvements enable us to monitor a variety of quantities characterizing the dynamics of the physical string network for the longest term ever. Our extended simulations have revealed that global strings do not evolve according to the scaling solution but its scaling parameter, or the number of long strings per horizon, increases logarithmically in time. In addition, we have also found that the scaling parameter shows nontrivial dependence on the breaking scale of the Peccei-Quinn symmetry.
[ { "created": "Thu, 14 Jun 2018 14:10:23 GMT", "version": "v1" }, { "created": "Mon, 20 Aug 2018 07:07:20 GMT", "version": "v2" } ]
2019-12-06
[ [ "Kawasaki", "Masahiro", "" ], [ "Sekiguchi", "Toyokazu", "" ], [ "Yamaguchi", "Masahide", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
We present results of new field-theoretic simulation of cosmological axion strings, which are eight times longer than previous ones. We have upgraded our simulation of physical strings in Hiramatsu et al. (2011) in terms of the number of grids as well as the suite of analysis methods. These improvements enable us to monitor a variety of quantities characterizing the dynamics of the physical string network for the longest term ever. Our extended simulations have revealed that global strings do not evolve according to the scaling solution but its scaling parameter, or the number of long strings per horizon, increases logarithmically in time. In addition, we have also found that the scaling parameter shows nontrivial dependence on the breaking scale of the Peccei-Quinn symmetry.
hep-ph/0105308
David London
Michael Gronau, David London, Nita Sinha and Rahul Sinha
Improving Bounds on Penguin Pollution in B -> pi pi
10 pages, LaTeX, 3 figures. Abstract modified slightly. Submitted to Physics Letters
Phys.Lett.B514:315-320,2001
10.1016/S0370-2693(01)00818-8
TECHNION-PH-2001-27, UdeM-GPP-TH-01-89, IMSc-2001/05/27
hep-ph hep-ex
null
In the presence of penguin contributions, the indirect CP asymmetry in B0(t) -> pi+ pi- measures sin(2\alpha + 2\theta), where 2\theta parametrizes the size of the penguin ``pollution.'' We derive a new upper bound on |2\theta|, requiring the measurement of of BR(B+ -> pi+ pi0) and an upper bound on B00 \equiv {1\over 2} [BR(B0 -> pi0 pi0) + BR(B0bar -> pi0 pi0)]. The new bound is stronger than those previously discussed in the literature. We also present a lower bound on B00. Current data may suggest that it is not very small, in which case \theta can be determined using a complete isospin analysis.
[ { "created": "Tue, 29 May 2001 17:13:10 GMT", "version": "v1" }, { "created": "Fri, 1 Jun 2001 12:32:17 GMT", "version": "v2" } ]
2014-11-17
[ [ "Gronau", "Michael", "" ], [ "London", "David", "" ], [ "Sinha", "Nita", "" ], [ "Sinha", "Rahul", "" ] ]
In the presence of penguin contributions, the indirect CP asymmetry in B0(t) -> pi+ pi- measures sin(2\alpha + 2\theta), where 2\theta parametrizes the size of the penguin ``pollution.'' We derive a new upper bound on |2\theta|, requiring the measurement of of BR(B+ -> pi+ pi0) and an upper bound on B00 \equiv {1\over 2} [BR(B0 -> pi0 pi0) + BR(B0bar -> pi0 pi0)]. The new bound is stronger than those previously discussed in the literature. We also present a lower bound on B00. Current data may suggest that it is not very small, in which case \theta can be determined using a complete isospin analysis.
2003.11823
Hyun Min Lee
Soo-Min Choi, Jinsu Kim, Hyun Min Lee, Bin Zhu
Connecting between inflation and dark matter in models with gauged $Z_3$ symmetry
40 pages, 9 figures, Accepted to JHEP, Discussion on heavy degrees of freedom during inflation added
null
10.1007/JHEP06(2020)135
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility of unifying the inflation and dark matter physics in the minimal model for a complex scalar dark matter with gauged $Z_3$ symmetry. The dark local $U(1)$ symmetry is broken spontaneously into the $Z_3$ symmetry by the dark Higgs mechanism. As compared to dark matter models with $Z_2$ parity, the dark matter cubic self-interaction restricts the inflation with non-minimal couplings to take place beyond the pure dark matter direction and plays an important role in the loop corrections for the inflationary predictions as well as determining the correct dark matter relic density. Considering either of $2\rightarrow 2$, $3\rightarrow 2$ or forbidden channels to be a dominant production mechanism for dark matter, we show the viable parameter space of the model that is consistent with the theoretical and phenomenological constraints combined from inflation and dark matter.
[ { "created": "Thu, 26 Mar 2020 10:37:50 GMT", "version": "v1" }, { "created": "Sun, 7 Jun 2020 19:59:45 GMT", "version": "v2" } ]
2020-07-15
[ [ "Choi", "Soo-Min", "" ], [ "Kim", "Jinsu", "" ], [ "Lee", "Hyun Min", "" ], [ "Zhu", "Bin", "" ] ]
We investigate the possibility of unifying the inflation and dark matter physics in the minimal model for a complex scalar dark matter with gauged $Z_3$ symmetry. The dark local $U(1)$ symmetry is broken spontaneously into the $Z_3$ symmetry by the dark Higgs mechanism. As compared to dark matter models with $Z_2$ parity, the dark matter cubic self-interaction restricts the inflation with non-minimal couplings to take place beyond the pure dark matter direction and plays an important role in the loop corrections for the inflationary predictions as well as determining the correct dark matter relic density. Considering either of $2\rightarrow 2$, $3\rightarrow 2$ or forbidden channels to be a dominant production mechanism for dark matter, we show the viable parameter space of the model that is consistent with the theoretical and phenomenological constraints combined from inflation and dark matter.
hep-ph/9410201
Apostolos Pilaftsis
Z. Gagyi-Palffy, A. Pilaftsis, and K. Schilcher
Heavy-Neutrino Chirality Enhancement of the Decay $K_L -> e\mu $ in Left-Right Symmetric Models
16 pages (4 figs appended as a ps file), LaTeX, RAL/94-090 and MZ-TH/94-22
Phys.Lett. B343 (1995) 275-281
10.1016/0370-2693(94)01432-C
null
hep-ph
null
We study the decay $K_L -> e\mu$ in minimal extensions of the Standard Model based on the gauge groups $SU(2)_L x U(1)_Y$ and $SU(2)_R x SU(2)_L x U(1)_{B-L}$, in which heavy Majorana neutrinos are present. In $SU(2)_L x U(1)_Y$ models with chiral neutral singlets, $B(K_L -> e\mu )$ cannot be much larger than $5 x 10^{-15}$ without violating other low-energy constraints. In $SU(2)_L x SU(2)_R x U(1)_{B-L}$ models, we find that heavy-neutrino-chirality enhancements due to the presence of left-handed and right- handed currents can give rise to a branching ratio close to the present experimental limit $B(K_L -> e \mu)< 3.3 x 10^{-11}$.
[ { "created": "Mon, 3 Oct 1994 10:31:09 GMT", "version": "v1" } ]
2009-10-28
[ [ "Gagyi-Palffy", "Z.", "" ], [ "Pilaftsis", "A.", "" ], [ "Schilcher", "K.", "" ] ]
We study the decay $K_L -> e\mu$ in minimal extensions of the Standard Model based on the gauge groups $SU(2)_L x U(1)_Y$ and $SU(2)_R x SU(2)_L x U(1)_{B-L}$, in which heavy Majorana neutrinos are present. In $SU(2)_L x U(1)_Y$ models with chiral neutral singlets, $B(K_L -> e\mu )$ cannot be much larger than $5 x 10^{-15}$ without violating other low-energy constraints. In $SU(2)_L x SU(2)_R x U(1)_{B-L}$ models, we find that heavy-neutrino-chirality enhancements due to the presence of left-handed and right- handed currents can give rise to a branching ratio close to the present experimental limit $B(K_L -> e \mu)< 3.3 x 10^{-11}$.
1110.1825
Schoeffel Laurent
Krzysztof Golec-Biernat (INP Polish Academy of Sciences, Krakow, University of Rzeszow), Christophe Royon (CEA Saclay), Laurent Schoeffel (CEA Saclay), Rafal Staszewski (INP Polish Academy of Sciences, Krakow)
Electroweak vector boson production at the LHC as a probe of mechanisms of diffraction
9 pages, 6 figures (submitted to Phys. Rev. D)
null
10.1103/PhysRevD.84.114006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the double diffractive electroweak vector boson production in the $pp$ collisions at the LHC is an ideal probe of QCD based mechanisms of diffraction. Assuming the resolved Pomeron model with flavor symmetric parton distributions, the $W$ production asymmetry in rapidity equals exactly zero. In other approaches, like the soft color interaction model, in which soft gluon exchanges are responsible for diffraction, the asymmetry is non-zero and equal to that in the inclusive $W$ production. In the same way, the ratio of the $W$ to $Z$ boson production is independent of rapidity in the models with resolved Pomeron in contrast to the predictions of the soft color interaction model.
[ { "created": "Sun, 9 Oct 2011 11:56:53 GMT", "version": "v1" }, { "created": "Tue, 24 Sep 2013 15:14:50 GMT", "version": "v2" } ]
2015-05-30
[ [ "Golec-Biernat", "Krzysztof", "", "INP Polish Academy of Sciences, Krakow,\n University of Rzeszow" ], [ "Royon", "Christophe", "", "CEA Saclay" ], [ "Schoeffel", "Laurent", "", "CEA\n Saclay" ], [ "Staszewski", "Rafal", "", "INP Polish Academy of Sciences, Krakow" ] ]
We show that the double diffractive electroweak vector boson production in the $pp$ collisions at the LHC is an ideal probe of QCD based mechanisms of diffraction. Assuming the resolved Pomeron model with flavor symmetric parton distributions, the $W$ production asymmetry in rapidity equals exactly zero. In other approaches, like the soft color interaction model, in which soft gluon exchanges are responsible for diffraction, the asymmetry is non-zero and equal to that in the inclusive $W$ production. In the same way, the ratio of the $W$ to $Z$ boson production is independent of rapidity in the models with resolved Pomeron in contrast to the predictions of the soft color interaction model.
hep-ph/0307334
Sechul Oh
C. S. Kim and Sechul Oh
Remarks on the recently observed B decays into $f_X(1300) K$ and $J/\psi K_X^*(1430)$
11 pages, no figure, Revtex; Some comments added; to appear in Physics Letters B
Phys.Lett. B576 (2003) 165-172
10.1016/j.physletb.2003.10.007
KEK-TH-906
hep-ph
null
In light of the recent experimental results on decays $B^+ \to f_X(1300) K^+$ and $B^{\pm(0)} \to J/\psi K_X^{*\pm(0)}(1430)$ from Belle, we study the $B \to P(V) S$ type decays, $B^{\pm(0)} \to f_0(1370) K^{\pm(0)}$ and $B^{\pm(0)} \to J/\psi K_0^{*\pm(0)}(1430)$, in comparison with the $B \to P(V) T$ type decays, $B^{\pm(0)} \to f_2(1270) K^{\pm(0)}$ and $B^{\pm(0)} \to J/\psi K_2^{*\pm(0)}(1430)$. We calculate the BRs for these decays by using the form factors obtained in the ISGW2 model [the improved version of the original Isgur-Scora-Grinstein-Wise (ISGW) model], as well as the ISGW model for comparison. The ratios of ${\cal B}(B \to P(V)S) / {\cal B}(B \to P(V)T)$ are also presented.
[ { "created": "Mon, 28 Jul 2003 12:59:49 GMT", "version": "v1" }, { "created": "Fri, 3 Oct 2003 14:37:22 GMT", "version": "v2" } ]
2010-04-05
[ [ "Kim", "C. S.", "" ], [ "Oh", "Sechul", "" ] ]
In light of the recent experimental results on decays $B^+ \to f_X(1300) K^+$ and $B^{\pm(0)} \to J/\psi K_X^{*\pm(0)}(1430)$ from Belle, we study the $B \to P(V) S$ type decays, $B^{\pm(0)} \to f_0(1370) K^{\pm(0)}$ and $B^{\pm(0)} \to J/\psi K_0^{*\pm(0)}(1430)$, in comparison with the $B \to P(V) T$ type decays, $B^{\pm(0)} \to f_2(1270) K^{\pm(0)}$ and $B^{\pm(0)} \to J/\psi K_2^{*\pm(0)}(1430)$. We calculate the BRs for these decays by using the form factors obtained in the ISGW2 model [the improved version of the original Isgur-Scora-Grinstein-Wise (ISGW) model], as well as the ISGW model for comparison. The ratios of ${\cal B}(B \to P(V)S) / {\cal B}(B \to P(V)T)$ are also presented.
hep-ph/9503214
Nir Polonsky-3C13-949
Paul Langacker and Nir Polonsky
The strong coupling, unification, and recent data
12 pages, LaTex + RevTex, uuencoded postscript file (including 13 figures) is attached. Also available at ftp://dept.physics.upenn.edu/pub/Nir
Phys.Rev. D52 (1995) 3081-3086
10.1103/PhysRevD.52.3081
UPR-642T
hep-ph
null
The prediction of the strong coupling assuming (supersymmetric) coupling constant unification is reexamined. We find, using the new electroweak data, $\alpha_{s}(M_{Z}) \approx 0.129 \pm 0.010$. The implications of the large $\alpha_{s}$ value are discussed. The role played by the $Z$ beauty width is stressed. It is also emphasized that high-energy (but not low-energy) corrections could significantly diminish the prediction. However, unless higher-dimension operators are assumed to be suppressed, at present one cannot place strong constraints on the super-heavy spectrum. Non-leading electroweak threshold corrections are also discussed.
[ { "created": "Thu, 2 Mar 1995 17:53:08 GMT", "version": "v1" } ]
2016-09-01
[ [ "Langacker", "Paul", "" ], [ "Polonsky", "Nir", "" ] ]
The prediction of the strong coupling assuming (supersymmetric) coupling constant unification is reexamined. We find, using the new electroweak data, $\alpha_{s}(M_{Z}) \approx 0.129 \pm 0.010$. The implications of the large $\alpha_{s}$ value are discussed. The role played by the $Z$ beauty width is stressed. It is also emphasized that high-energy (but not low-energy) corrections could significantly diminish the prediction. However, unless higher-dimension operators are assumed to be suppressed, at present one cannot place strong constraints on the super-heavy spectrum. Non-leading electroweak threshold corrections are also discussed.
hep-ph/9307306
Tilo Wettig
A.D. Jackson, T. Wettig and N.L. Balazs
High--Energy Multiparticle Distributions and a Generalized Lattice Gas Model
4 pages, REVTEX 3.0, NORDITA preprint 93/50
null
null
null
hep-ph nucl-th
null
A simple lattice gas model in one dimension is constructed in which each site can be occupied by at most one particle of any one of $D$ species. Particles interact with a randomly drawn nearest neighbor interaction. This model is capable of reproducing the factorial moments observed in high--energy scattering. In the limit $D \rightarrow \infty$, the factorial moments of the negative binomial distribution are obtained naturally.
[ { "created": "Tue, 20 Jul 1993 11:48:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jackson", "A. D.", "" ], [ "Wettig", "T.", "" ], [ "Balazs", "N. L.", "" ] ]
A simple lattice gas model in one dimension is constructed in which each site can be occupied by at most one particle of any one of $D$ species. Particles interact with a randomly drawn nearest neighbor interaction. This model is capable of reproducing the factorial moments observed in high--energy scattering. In the limit $D \rightarrow \infty$, the factorial moments of the negative binomial distribution are obtained naturally.
hep-ph/0201078
U. Meissner
Ulf-G. Mei{\ss}ner
Chiral dynamics with strange quarks: Mysteries and opportunities
26 pp, LaTeX2e, 14 figs (uses epsf,epsfig), contribution to the ``Eta Physics Handbook'', Workshop on Eta Physics, Uppsala, Sweden, Oct. 2001, 2 figs replaced, references added
Phys.Scripta T99:68-83,2002
10.1238/Physica.Topical.099a00068
FZJ-IKP(TH)-2002-01
hep-ph nucl-th
null
Recent developments and open issues in chiral dynamics with strange quarks are reviewed. Topics include: Order parameters of chiral symmetry breaking, the flavor dependence of these order parameters, speculations about the phase structure of QCD with varying number of flavors, OZI violation and its natural emergence in case of a small strange quark condensate, heavy kaon chiral perturbation theory, an update on pion-pion, pion-kaon and pion-nucleon sigma terms, the dynamics and nature of scalar mesons, the role of the scalar pion and kaon form factors, attempts to describe some strange baryons employing coupled channel dynamics tied to unitarity and chiral perturbation theory, and the role of final state interactions in Goldstone boson pair production in proton-proton collisions.
[ { "created": "Thu, 10 Jan 2002 17:19:59 GMT", "version": "v1" }, { "created": "Wed, 23 Jan 2002 13:07:43 GMT", "version": "v2" }, { "created": "Tue, 5 Feb 2002 14:01:59 GMT", "version": "v3" } ]
2014-11-17
[ [ "Meißner", "Ulf-G.", "" ] ]
Recent developments and open issues in chiral dynamics with strange quarks are reviewed. Topics include: Order parameters of chiral symmetry breaking, the flavor dependence of these order parameters, speculations about the phase structure of QCD with varying number of flavors, OZI violation and its natural emergence in case of a small strange quark condensate, heavy kaon chiral perturbation theory, an update on pion-pion, pion-kaon and pion-nucleon sigma terms, the dynamics and nature of scalar mesons, the role of the scalar pion and kaon form factors, attempts to describe some strange baryons employing coupled channel dynamics tied to unitarity and chiral perturbation theory, and the role of final state interactions in Goldstone boson pair production in proton-proton collisions.
2207.04190
Shan Cheng
Jian Chai, Shan Cheng, Yao-hui Ju, Da-cheng Yan, Cai-Dian L\"u and Zhen-Jun Xiao
Charmless two-body $B$ meson decays in perturbative QCD factorization approach
52 pages, 4 figures, 11 tables
Chin.Phys.C 46 (2022) 12, 123103
10.1088/1674-1137/ac88bd
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The perturbative QCD (PQCD) approach based on $k_T$ factorization has made a great achievement for the QCD calculation of the hadronic B decays. Regulating the endpoint divergence by the transverse momentum of quarks in the propagators, one can do the perturbation calculation for kinds of diagrams including the annihilation type diagrams. In this paper, we review the current status of PQCD factorization calculation of two-body charmless $B\to PP, PV, VV$ decays up to the next-to-leading order (NLO) QCD corrections. two new power suppressed terms in decaying amplitudes are also taken into account. By using the universal input (non-perturbative) parameters, we collected the branching ratios and ${\bf CP}$ asymmetry parameters for all the charmless two body $B$ decays, calculated in the PQCD approach up to the NLO, including some power suppressed terms in decaying amplitudes. The results are compared with the ones from QCD factorization approach, soft-collinear effective theory approach and the current experimental measurements. For most considered B meson decays, the PQCD results for branching ratios agree well with other approaches and the experimental data. The PQCD predictions for the ${\bf CP}$ asymmetry parameters for many of the decay channels do not agree with other approaches, but have a better agreement with the experimental data. The longstanding $K \pi $ puzzle about the pattern of the direct CP asymmetries of the penguin-dominated $B \to K \pi $ decays can be understood after the inclusion of the NLO contributions in PQCD. The NLO corrections and power suppressed terms play an important role in the color suppressed and pure annihilation type $B$ decay modes. These rare decays are more sensitive to different types of corrections, providing opportunity to examine the factorization approach with the more precise experimental measurements.
[ { "created": "Sat, 9 Jul 2022 04:21:09 GMT", "version": "v1" }, { "created": "Mon, 18 Jul 2022 06:23:15 GMT", "version": "v2" }, { "created": "Mon, 19 Dec 2022 01:54:02 GMT", "version": "v3" } ]
2022-12-20
[ [ "Chai", "Jian", "" ], [ "Cheng", "Shan", "" ], [ "Ju", "Yao-hui", "" ], [ "Yan", "Da-cheng", "" ], [ "Lü", "Cai-Dian", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
The perturbative QCD (PQCD) approach based on $k_T$ factorization has made a great achievement for the QCD calculation of the hadronic B decays. Regulating the endpoint divergence by the transverse momentum of quarks in the propagators, one can do the perturbation calculation for kinds of diagrams including the annihilation type diagrams. In this paper, we review the current status of PQCD factorization calculation of two-body charmless $B\to PP, PV, VV$ decays up to the next-to-leading order (NLO) QCD corrections. two new power suppressed terms in decaying amplitudes are also taken into account. By using the universal input (non-perturbative) parameters, we collected the branching ratios and ${\bf CP}$ asymmetry parameters for all the charmless two body $B$ decays, calculated in the PQCD approach up to the NLO, including some power suppressed terms in decaying amplitudes. The results are compared with the ones from QCD factorization approach, soft-collinear effective theory approach and the current experimental measurements. For most considered B meson decays, the PQCD results for branching ratios agree well with other approaches and the experimental data. The PQCD predictions for the ${\bf CP}$ asymmetry parameters for many of the decay channels do not agree with other approaches, but have a better agreement with the experimental data. The longstanding $K \pi $ puzzle about the pattern of the direct CP asymmetries of the penguin-dominated $B \to K \pi $ decays can be understood after the inclusion of the NLO contributions in PQCD. The NLO corrections and power suppressed terms play an important role in the color suppressed and pure annihilation type $B$ decay modes. These rare decays are more sensitive to different types of corrections, providing opportunity to examine the factorization approach with the more precise experimental measurements.
hep-ph/9211243
null
R.V. Gavai, R.M. Godbole and K. Sridhar
Looking for the gluonic EMC effect in associated $J/\psi$ + $\gamma $ production
10 pages, 4 Figures (not included, available only by p-mail), LaTeX, CERN-TH.6679/92, TIFR/TH/92-59, BU-TH-92/3, Minor revision. Replaced version has the style file equation.sty appended for easy processing, which is the only change
Phys.Lett.B299:157-164,1993
10.1016/0370-2693(93)90897-Q
null
hep-ph
null
We study the associated production of $ J/\psi\ + \gamma $ in fixed-target experiments with nuclear targets as well as at the relativistic heavy-ion collider (RHIC). We find that this process affords a very clean probe of $\rho_g$, the ratio of gluon density in a heavy nucleus to that of a proton. The combined $x$ range thus available can be used to discriminate between the predictions of different models of the EMC effect for $\rho_g$.
[ { "created": "Fri, 13 Nov 1992 08:01:32 GMT", "version": "v1" }, { "created": "Wed, 18 Nov 1992 08:25:56 GMT", "version": "v2" } ]
2011-07-19
[ [ "Gavai", "R. V.", "" ], [ "Godbole", "R. M.", "" ], [ "Sridhar", "K.", "" ] ]
We study the associated production of $ J/\psi\ + \gamma $ in fixed-target experiments with nuclear targets as well as at the relativistic heavy-ion collider (RHIC). We find that this process affords a very clean probe of $\rho_g$, the ratio of gluon density in a heavy nucleus to that of a proton. The combined $x$ range thus available can be used to discriminate between the predictions of different models of the EMC effect for $\rho_g$.
1903.02275
Simone Marzani
Andrew J. Larkoski, Simone Marzani, and Chang Wu
Theory Predictions for the Pull Angle
6 pages, 1 figure
Phys. Rev. D 99, 091502 (2019)
10.1103/PhysRevD.99.091502
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pull is a jet observable that is sensitive to color flow between dipoles. It has seen wide use for discrimination of particles with similar decay topologies but carrying different color representations and has been measured on W bosons from top quark decays by the D$\emptyset$ and ATLAS experiments. In this paper, we present the first theoretical predictions of pull, focusing on a color-singlet decaying in two jets. The pull angle observable is particularly sensitive to color flow, but is not infrared and collinear safe and so cannot be calculated in fixed-order perturbation theory. Nevertheless, all-orders resummation renders its distribution finite, a property referred to as Sudakov safety. In our prediction of the pull angle we also include an estimation of the effects from hadronization, and directly compare our results to simulation and experimental data.
[ { "created": "Wed, 6 Mar 2019 10:00:50 GMT", "version": "v1" } ]
2019-05-22
[ [ "Larkoski", "Andrew J.", "" ], [ "Marzani", "Simone", "" ], [ "Wu", "Chang", "" ] ]
Pull is a jet observable that is sensitive to color flow between dipoles. It has seen wide use for discrimination of particles with similar decay topologies but carrying different color representations and has been measured on W bosons from top quark decays by the D$\emptyset$ and ATLAS experiments. In this paper, we present the first theoretical predictions of pull, focusing on a color-singlet decaying in two jets. The pull angle observable is particularly sensitive to color flow, but is not infrared and collinear safe and so cannot be calculated in fixed-order perturbation theory. Nevertheless, all-orders resummation renders its distribution finite, a property referred to as Sudakov safety. In our prediction of the pull angle we also include an estimation of the effects from hadronization, and directly compare our results to simulation and experimental data.
2406.13468
Zhao-Huan Yu
Jun-Yu Tong, Zhao-Huan Yu, Hong-Hao Zhang
Leptogenesis assisted by scalar decays
18 pages, 8 figures; minor revisions, references added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a pragmatic approach to lower down the mass scale of right-handed neutrinos in leptogenesis by introducing a scalar decaying to right-handed neutrinos. The key point of our proposal is that the out-of-equilibrium decays of the scalar provide an additional source for right-handed neutrinos and hence the lepton asymmetry. This mechanism works well at low temperatures when the washout of the generated lepton asymmetry is suppressed. Thus, the lepton asymmetry can be effectively produced despite the washout effect is strong or not. Through a comprehensive analysis, we demonstrate that such a scalar-assisted leptogenesis can typically decrease the viable right-handed neutrino mass scale by two to four orders of magnitude.
[ { "created": "Wed, 19 Jun 2024 11:50:06 GMT", "version": "v1" }, { "created": "Thu, 27 Jun 2024 13:00:29 GMT", "version": "v2" } ]
2024-06-28
[ [ "Tong", "Jun-Yu", "" ], [ "Yu", "Zhao-Huan", "" ], [ "Zhang", "Hong-Hao", "" ] ]
We present a pragmatic approach to lower down the mass scale of right-handed neutrinos in leptogenesis by introducing a scalar decaying to right-handed neutrinos. The key point of our proposal is that the out-of-equilibrium decays of the scalar provide an additional source for right-handed neutrinos and hence the lepton asymmetry. This mechanism works well at low temperatures when the washout of the generated lepton asymmetry is suppressed. Thus, the lepton asymmetry can be effectively produced despite the washout effect is strong or not. Through a comprehensive analysis, we demonstrate that such a scalar-assisted leptogenesis can typically decrease the viable right-handed neutrino mass scale by two to four orders of magnitude.
hep-ph/0410173
Muriel Pivk
Muriel Pivk
CP violation and the CKM matrix: impact of the asymmetric B Factories
4 pages, 8 figures, Contributed to 32nd International Conference on High-Energy Physics (ICHEP 04), Beijing, China, 16-22 Aug 2004
null
10.1142/9789812702227_0176
null
hep-ph
null
An up-to-date profile of the CKM matrix is presented, with emphasis on the interpretation of recent CP-violation results from the $B$ factories. The apex of the Unitarity Triangle is determined by a global CKM fit. A study is performed to probe the dynamics of B decays into $\pi\pi$, $K\pi$, $\rho\pi$ and $\rho\rho$ within two theoretical frameworks. A model-independent investigation of New Physics effects in $\Bz\Bzb$ mixing is given.
[ { "created": "Tue, 12 Oct 2004 18:07:10 GMT", "version": "v1" }, { "created": "Wed, 13 Oct 2004 23:35:51 GMT", "version": "v2" } ]
2017-08-23
[ [ "Pivk", "Muriel", "" ] ]
An up-to-date profile of the CKM matrix is presented, with emphasis on the interpretation of recent CP-violation results from the $B$ factories. The apex of the Unitarity Triangle is determined by a global CKM fit. A study is performed to probe the dynamics of B decays into $\pi\pi$, $K\pi$, $\rho\pi$ and $\rho\rho$ within two theoretical frameworks. A model-independent investigation of New Physics effects in $\Bz\Bzb$ mixing is given.
1002.0830
Alex Bernardini E
Alex E. Bernardini, O. Bertolami
Naturalness and stability of the generalized Chaplygin gas in the seesaw cosmon scenario
24 pages, 6 figures
Phys.Rev.D81:123013,2010
10.1103/PhysRevD.81.123013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The seesaw mechanism is conceived on the basis that a mass scale, $\xi$, and a dimensionless scale, $s$, can be fine-tuned in order to control the dynamics of active and sterile neutrinos through cosmon-type equations of motion: the seesaw cosmon equations. This allows for sterile neutrinos to be a dark matter candidate. In this scenario, the dynamical masses and energy densities of active and sterile neutrinos can be consistently embedded into the generalized Chaplygin gas (GCG), the unified dark sector model. In addition, dark matter adiabatically coupled to dark energy allows for a natural decoupling of the (active) mass varying neutrino (MaVaN) component from the dark sector. Thus MaVaN's turn into a secondary effect. Through the scale parameters, $\xi$ and $s$, the proposed scenario allows for a convergence among three distinct frameworks: the cosmon scenario, the seesaw mechanism for mass generation and the GCG model. It is found that the equation of state of the perturbations is the very one of the GCG background cosmology so that all the results from this approach are maintained, being smoothly modified by active neutrinos. Constrained by the seesaw relations, it is shown that the mass varying mechanism is responsible for the stability against linear perturbations and is indirectly related to the late time cosmological acceleration.
[ { "created": "Wed, 3 Feb 2010 20:25:29 GMT", "version": "v1" }, { "created": "Mon, 5 Apr 2010 21:27:05 GMT", "version": "v2" } ]
2011-06-03
[ [ "Bernardini", "Alex E.", "" ], [ "Bertolami", "O.", "" ] ]
The seesaw mechanism is conceived on the basis that a mass scale, $\xi$, and a dimensionless scale, $s$, can be fine-tuned in order to control the dynamics of active and sterile neutrinos through cosmon-type equations of motion: the seesaw cosmon equations. This allows for sterile neutrinos to be a dark matter candidate. In this scenario, the dynamical masses and energy densities of active and sterile neutrinos can be consistently embedded into the generalized Chaplygin gas (GCG), the unified dark sector model. In addition, dark matter adiabatically coupled to dark energy allows for a natural decoupling of the (active) mass varying neutrino (MaVaN) component from the dark sector. Thus MaVaN's turn into a secondary effect. Through the scale parameters, $\xi$ and $s$, the proposed scenario allows for a convergence among three distinct frameworks: the cosmon scenario, the seesaw mechanism for mass generation and the GCG model. It is found that the equation of state of the perturbations is the very one of the GCG background cosmology so that all the results from this approach are maintained, being smoothly modified by active neutrinos. Constrained by the seesaw relations, it is shown that the mass varying mechanism is responsible for the stability against linear perturbations and is indirectly related to the late time cosmological acceleration.
hep-ph/9910231
Piotr Chankowski
P.H. Chankowski (CERN, Warsaw), W. Krolikowski (Warsaw), S. Pokorski (Warsaw)
Fixed points in the evolution of neutrino mixings
17 pages, 2 figures. References added and comments concerning the two-flavour case changed
Phys.Lett.B473:109-117,2000
10.1016/S0370-2693(99)01465-3
CERN-TH/99-269, IFT-99/22
hep-ph
null
We derive the renormalization group equations for the neutrino masses and mixing angles in explicit form and discuss the possible classes of their solutions. We identify fixed points in the equations for mixing angles, which can be reached during the evolution for several mass patterns and give $\sin^22\theta_{sol}=\sin^22\theta_{atm}\sin^2\theta_3/ (\sin^2\theta_{atm}\cos^2\theta_3 + \sin^2\theta_3)^2$, consistently with the present experimental information. Further experimental test of this relation is of crucial interest. Moreover, we discuss the stability of quantum corrections to neutrino mass squared differences. Several interesting mass patterns show stability in the presence of fixed point solutions for the angles.
[ { "created": "Tue, 5 Oct 1999 00:00:04 GMT", "version": "v1" }, { "created": "Wed, 6 Oct 1999 21:56:02 GMT", "version": "v2" }, { "created": "Fri, 12 Nov 1999 12:53:10 GMT", "version": "v3" } ]
2010-04-06
[ [ "Chankowski", "P. H.", "", "CERN, Warsaw" ], [ "Krolikowski", "W.", "", "Warsaw" ], [ "Pokorski", "S.", "", "Warsaw" ] ]
We derive the renormalization group equations for the neutrino masses and mixing angles in explicit form and discuss the possible classes of their solutions. We identify fixed points in the equations for mixing angles, which can be reached during the evolution for several mass patterns and give $\sin^22\theta_{sol}=\sin^22\theta_{atm}\sin^2\theta_3/ (\sin^2\theta_{atm}\cos^2\theta_3 + \sin^2\theta_3)^2$, consistently with the present experimental information. Further experimental test of this relation is of crucial interest. Moreover, we discuss the stability of quantum corrections to neutrino mass squared differences. Several interesting mass patterns show stability in the presence of fixed point solutions for the angles.
2203.02859
Hidefumi Matsuda Mr
Hidefumi Matsuda, Teiji Kunihiro, Akira Ohnishi and Toru T. Takahashi
Entropy production in longitudinally expanding Yang-Mills field with use of Husimi function$-$semiclassical approximation
28 pages, 15 figures
null
null
YITP-22-24
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possible thermalization process of the highly occupied and weakly coupled Yang-Mills fields expanding along the beam axis through an evaluation of the entropy, particle number, and pressure anisotropy. The time evolution of the system is calculated by solving the equation of motion for the Wigner function in the semiclassical approximation with initial conditions mimicking the glasma. For the evaluation of the entropy, we adopt the Husimi-Wehrl (HW) entropy, which is obtained by using the Husimi function, a positive semidefinite quantum distribution function given by smearing the Wigner function. By numerical calculations at $g=0.1$ and $0.2$, the entropy production is found to occur together with the particle creation in two distinct stages: In the first stage, the particle number and the entropy at low longitudinal momenta grow rapidly. In the second stage, the particle number and the entropy of higher longitudinal momentum modes show slower increase. The pressure anisotropy remains in our simulation and implies that the system is still out-of-equilibrium.
[ { "created": "Sun, 6 Mar 2022 02:48:58 GMT", "version": "v1" }, { "created": "Wed, 16 Mar 2022 07:53:48 GMT", "version": "v2" }, { "created": "Mon, 6 Jun 2022 23:55:03 GMT", "version": "v3" } ]
2022-06-08
[ [ "Matsuda", "Hidefumi", "" ], [ "Kunihiro", "Teiji", "" ], [ "Ohnishi", "Akira", "" ], [ "Takahashi", "Toru T.", "" ] ]
We investigate the possible thermalization process of the highly occupied and weakly coupled Yang-Mills fields expanding along the beam axis through an evaluation of the entropy, particle number, and pressure anisotropy. The time evolution of the system is calculated by solving the equation of motion for the Wigner function in the semiclassical approximation with initial conditions mimicking the glasma. For the evaluation of the entropy, we adopt the Husimi-Wehrl (HW) entropy, which is obtained by using the Husimi function, a positive semidefinite quantum distribution function given by smearing the Wigner function. By numerical calculations at $g=0.1$ and $0.2$, the entropy production is found to occur together with the particle creation in two distinct stages: In the first stage, the particle number and the entropy at low longitudinal momenta grow rapidly. In the second stage, the particle number and the entropy of higher longitudinal momentum modes show slower increase. The pressure anisotropy remains in our simulation and implies that the system is still out-of-equilibrium.
1206.2977
Amelia Brennan
Nicole F. Bell, Amelia J. Brennan and Thomas D. Jacques
Neutrino signals from electroweak bremsstrahlung in solar WIMP annihilation
18 pages, 5 figures. Discussion expanded; matches published version
null
10.1088/1475-7516/2012/10/045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bremsstrahlung of $W$ and $Z$ gauge bosons, or photons, can be an important dark matter annihilation channel. In many popular models in which the annihilation to a pair of light fermions is helicity suppressed, these bremsstrahlung processes can lift the suppression and thus become the dominant annihilation channels. The resulting dark matter annihilation products contain a large, energetic, neutrino component. We consider solar WIMP annihilation in the case where electroweak bremsstrahlung dominates, and calculate the resulting neutrino spectra. The flux consists of primary neutrinos produced in processes such as $\chi\chi\rightarrow \bar{\nu}\nu Z$ and $\chi\chi\rightarrow \bar{\nu}\ell W$, and secondary neutrinos produced via the decays of gauge bosons and charged leptons. After dealing with the neutrino propagation and flavour evolution in the Sun, we consider the prospects for detection in neutrino experiments on Earth. By comparing our signal with that for annihilation to $W^+W^-$, we show that the detection prospects for the bremsstrahlung annihilation channel are favourable.
[ { "created": "Thu, 14 Jun 2012 00:48:49 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2012 03:21:47 GMT", "version": "v2" } ]
2015-06-05
[ [ "Bell", "Nicole F.", "" ], [ "Brennan", "Amelia J.", "" ], [ "Jacques", "Thomas D.", "" ] ]
Bremsstrahlung of $W$ and $Z$ gauge bosons, or photons, can be an important dark matter annihilation channel. In many popular models in which the annihilation to a pair of light fermions is helicity suppressed, these bremsstrahlung processes can lift the suppression and thus become the dominant annihilation channels. The resulting dark matter annihilation products contain a large, energetic, neutrino component. We consider solar WIMP annihilation in the case where electroweak bremsstrahlung dominates, and calculate the resulting neutrino spectra. The flux consists of primary neutrinos produced in processes such as $\chi\chi\rightarrow \bar{\nu}\nu Z$ and $\chi\chi\rightarrow \bar{\nu}\ell W$, and secondary neutrinos produced via the decays of gauge bosons and charged leptons. After dealing with the neutrino propagation and flavour evolution in the Sun, we consider the prospects for detection in neutrino experiments on Earth. By comparing our signal with that for annihilation to $W^+W^-$, we show that the detection prospects for the bremsstrahlung annihilation channel are favourable.
hep-ph/9704244
Giulia de Divitiis
G. M. de Divitiis, R. Petronzio and L. Silvestrini
Flavour changing top decays in supersymmetric extensions of the standard model
18 pages, latex files, text + 8 eps files of figures
Nucl.Phys.B504:45-60,1997
10.1016/S0550-3213(97)00476-8
ROM2F-97-08
hep-ph
null
Flavour changing top decays $t \to c Z^0, t \to c g$ and $t \to c \gamma$ are predicted with invisible rates within the standard model and may represent a window on new physics. We consider these processes in supersymmetric extensions of the standard model and we show that observable rates can be obtained only if the SUSY breaking is non universal and flavour dependent.
[ { "created": "Sat, 5 Apr 1997 13:09:23 GMT", "version": "v1" } ]
2009-07-09
[ [ "de Divitiis", "G. M.", "" ], [ "Petronzio", "R.", "" ], [ "Silvestrini", "L.", "" ] ]
Flavour changing top decays $t \to c Z^0, t \to c g$ and $t \to c \gamma$ are predicted with invisible rates within the standard model and may represent a window on new physics. We consider these processes in supersymmetric extensions of the standard model and we show that observable rates can be obtained only if the SUSY breaking is non universal and flavour dependent.
hep-ph/0410062
Yannis K. Semertzidis
William M. Morse
Is the Difference Between the Pion Form Factor Measured in e+e- Annihilations and tau- Decays Due to an H- Propagator?
4 pages, 2 figures
null
null
null
hep-ph
null
We discuss how a charged Higgs propagator would modify the form factor in tau- -> pi- pi0 nu_tau decays.
[ { "created": "Mon, 4 Oct 2004 20:18:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Morse", "William M.", "" ] ]
We discuss how a charged Higgs propagator would modify the form factor in tau- -> pi- pi0 nu_tau decays.
hep-ph/0411382
Xiangdong Ji
Xiangdong Ji, Jian-Ping Ma, and Feng Yuan
Factorization of Large-x Quark Distributions in a Hadron
7 pages, 2 figures included
Phys.Lett. B610 (2005) 247-252
10.1016/j.physletb.2005.02.019
UM-PP#05-027
hep-ph
null
We present a factorization formula for valence quark distributions in a hadron in x-->1 limit. For the example of pion, we arrive at the form of factorization by analyzing momentum flow in the leading and high-order Feynman diagrams. The result confirms the well-known 1-x scaling rule to all orders in perturbation theory, providing the non-perturbative matrix elements for the infrared-divergence factors. We comment on re-summation of perturbative single and double logarithms in 1-x.
[ { "created": "Tue, 30 Nov 2004 00:19:44 GMT", "version": "v1" } ]
2010-04-05
[ [ "Ji", "Xiangdong", "" ], [ "Ma", "Jian-Ping", "" ], [ "Yuan", "Feng", "" ] ]
We present a factorization formula for valence quark distributions in a hadron in x-->1 limit. For the example of pion, we arrive at the form of factorization by analyzing momentum flow in the leading and high-order Feynman diagrams. The result confirms the well-known 1-x scaling rule to all orders in perturbation theory, providing the non-perturbative matrix elements for the infrared-divergence factors. We comment on re-summation of perturbative single and double logarithms in 1-x.
hep-ph/9604239
Daijiro Suematsu
Daijiro Suematsu
Flavor Structure of Soft SUSY Breaking Parameters
19 pages, latex, a version published in Phys. Rev. D, minor corrections
Phys.Rev. D54 (1996) 5715-5722
10.1103/PhysRevD.54.5715
Kanazawa-96-03
hep-ph
null
Flavor structure of soft supersymmetry breaking parameters is studied in a certain type of effective supergravity theory derived from moduli/dilaton dominated supersymmetry breaking. Some interesting sum rules for soft scalar masses are presented. They constrain their flavor structure and predict some interesting patterns appeared in soft scalar masses in the non-universal case. We also study the alignment phenomena in the flavor space of soft breaking parameters due to Yukawa couplings and discuss their phenomenological consequences.
[ { "created": "Thu, 4 Apr 1996 07:01:46 GMT", "version": "v1" }, { "created": "Wed, 10 Apr 1996 02:53:23 GMT", "version": "v2" }, { "created": "Mon, 19 Aug 1996 05:12:00 GMT", "version": "v3" } ]
2009-10-28
[ [ "Suematsu", "Daijiro", "" ] ]
Flavor structure of soft supersymmetry breaking parameters is studied in a certain type of effective supergravity theory derived from moduli/dilaton dominated supersymmetry breaking. Some interesting sum rules for soft scalar masses are presented. They constrain their flavor structure and predict some interesting patterns appeared in soft scalar masses in the non-universal case. We also study the alignment phenomena in the flavor space of soft breaking parameters due to Yukawa couplings and discuss their phenomenological consequences.
hep-ph/0110303
Masaki Yasue
Teruyuki Kitabayashi and Masaki Yasue
Large Solar Neutrino Mixing and Radiative Neutrino Mechanism
RevTex, 10 pages including one figure. In Ref.[25], the cited page number is corrected
Phys.Lett.B524:308-318,2002
10.1016/S0370-2693(01)01368-5
TOKAI-HEP/TH-0106
hep-ph
null
We find that the presence of a global $L_e-L_\mu-L_\tau$ ($\equiv L^\prime$) symmetry and an $S_2$ permutation symmetry for the $\mu$- and $\tau$-families supplemented by a discrete $Z_4$ symmetry naturally leads to almost maximal atmospheric neutrino mixing and large solar neutrino mixing, which arise, respectively, from type II seesaw mechanism initiated by an $S_2$-symmetric triplet Higgs scalar $s$ with $L^\prime=2$ and from radiative mechanism of the Zee type initiated by two singly charged scalars, an $S_2$-symmetric $h^+$ with $L^\prime=0$ and an $S_2$-antisymmetric $h^{\prime +}$ with $L^\prime=2$. The almost maximal mixing for atmospheric neutrinos is explained by the appearance of the democratic coupling of $s$ to neutrinos ensured by $S_2$ and $Z_4$ while the large mixing for solar neutrinos is explained by the similarity of $h^+$- and $h^{\prime +}$-couplings described by $f^h_+\sim f^h_-$ and $\mu_+\sim\mu_-$, where $f^h_+$ ($f^h_-$) and $\mu_+$ ($\mu_-$) stand for $h^+$ ($h^{\prime +}$)-couplings, respectively, to leptons and to Higgs scalars.
[ { "created": "Wed, 24 Oct 2001 15:24:29 GMT", "version": "v1" }, { "created": "Thu, 15 Nov 2001 03:47:07 GMT", "version": "v2" }, { "created": "Fri, 21 Dec 2001 02:32:17 GMT", "version": "v3" } ]
2008-11-26
[ [ "Kitabayashi", "Teruyuki", "" ], [ "Yasue", "Masaki", "" ] ]
We find that the presence of a global $L_e-L_\mu-L_\tau$ ($\equiv L^\prime$) symmetry and an $S_2$ permutation symmetry for the $\mu$- and $\tau$-families supplemented by a discrete $Z_4$ symmetry naturally leads to almost maximal atmospheric neutrino mixing and large solar neutrino mixing, which arise, respectively, from type II seesaw mechanism initiated by an $S_2$-symmetric triplet Higgs scalar $s$ with $L^\prime=2$ and from radiative mechanism of the Zee type initiated by two singly charged scalars, an $S_2$-symmetric $h^+$ with $L^\prime=0$ and an $S_2$-antisymmetric $h^{\prime +}$ with $L^\prime=2$. The almost maximal mixing for atmospheric neutrinos is explained by the appearance of the democratic coupling of $s$ to neutrinos ensured by $S_2$ and $Z_4$ while the large mixing for solar neutrinos is explained by the similarity of $h^+$- and $h^{\prime +}$-couplings described by $f^h_+\sim f^h_-$ and $\mu_+\sim\mu_-$, where $f^h_+$ ($f^h_-$) and $\mu_+$ ($\mu_-$) stand for $h^+$ ($h^{\prime +}$)-couplings, respectively, to leptons and to Higgs scalars.
hep-ph/9510380
Ivanyi Bela
B. Iv\'anyi, Zs. Schram, K. Sailer and W. Greiner
Time evolution of the two-jet events $e^+-e^- \to hadrons$ in the Dynamical String Model
5 pages in LaTex format, 11 Postscript figures available by e-mailing to bela@dtp.atomki.hu
null
10.1007/BF03053631
null
hep-ph
null
The time dependent pion emission rate and the mean life time of the pion source in the center of mass frame of the two-jet events have been determined for $e^+-e^- \to hadrons$ at $\sqrt{s} = 20 - 50$ GeV by the Dynamical String Model. It was established that the time needed for the creation of the pion source is $5$ fm/c, whereas its life time is $\tau_0 \approx 7 - 13$ fm/c for energies $\sqrt{s} = 20 - 50$ GeV, respectively.
[ { "created": "Tue, 24 Oct 1995 10:51:58 GMT", "version": "v1" } ]
2022-02-23
[ [ "Iványi", "B.", "" ], [ "Schram", "Zs.", "" ], [ "Sailer", "K.", "" ], [ "Greiner", "W.", "" ] ]
The time dependent pion emission rate and the mean life time of the pion source in the center of mass frame of the two-jet events have been determined for $e^+-e^- \to hadrons$ at $\sqrt{s} = 20 - 50$ GeV by the Dynamical String Model. It was established that the time needed for the creation of the pion source is $5$ fm/c, whereas its life time is $\tau_0 \approx 7 - 13$ fm/c for energies $\sqrt{s} = 20 - 50$ GeV, respectively.
hep-ph/9611302
Zack Sullivan
Zack Sullivan (U. of Illinois)
Supersymmetric QCD correction to top-quark production at the Tevatron
To appear Phys. Rev. D, added discussion of some references, two figures replaced with one, 15 pages, 7 ps figures included
Phys.Rev. D56 (1997) 451-457
10.1103/PhysRevD.56.451
ILL-(TH)-96-13
hep-ph
null
We calculate the supersymmetric QCD correction to top-quark production at the Fermilab Tevatron, allowing for arbitrary left-right mixing of the squarks. We find that the correction is significant for several combinations of gluino and squark masses, e.g. +33% for m_{\tilde g}=200 GeV, m_{\tilde t} = m_{\tilde q} =75 GeV.
[ { "created": "Mon, 11 Nov 1996 21:07:07 GMT", "version": "v1" }, { "created": "Mon, 14 Apr 1997 19:41:42 GMT", "version": "v2" } ]
2009-10-30
[ [ "Sullivan", "Zack", "", "U. of Illinois" ] ]
We calculate the supersymmetric QCD correction to top-quark production at the Fermilab Tevatron, allowing for arbitrary left-right mixing of the squarks. We find that the correction is significant for several combinations of gluino and squark masses, e.g. +33% for m_{\tilde g}=200 GeV, m_{\tilde t} = m_{\tilde q} =75 GeV.
hep-ph/9504254
Gregory Poulis
G.I Poulis (NIKHEF) and P.J. Mulders (NIKHEF and Amsterdam Free University)
On the Dirac quantization condition
5 pages, uuencoded Z-compressed tar file, includes RevTeX source and two postscript figures
null
null
NIKHEF 95-007
hep-ph
null
We revisit the Dirac quantization condition for string-like and string-less (but multi-valued) magnetic monopole potentials. In doing so we allow for an {\it a priori} different coupling ${\tilde e}$ associated with the longitudinal components of the gauge potential. By imposing physical criteria in the choice of the longitudinal--transverse decomposition we show that -in contrast to some recent claims- the `unphysical' coupling $\tilde e$ does not appear in the quantization condition.
[ { "created": "Fri, 7 Apr 1995 12:40:59 GMT", "version": "v1" }, { "created": "Mon, 10 Apr 1995 09:22:00 GMT", "version": "v2" } ]
2008-02-03
[ [ "Poulis", "G. I", "", "NIKHEF" ], [ "Mulders", "P. J.", "", "NIKHEF and Amsterdam Free\n University" ] ]
We revisit the Dirac quantization condition for string-like and string-less (but multi-valued) magnetic monopole potentials. In doing so we allow for an {\it a priori} different coupling ${\tilde e}$ associated with the longitudinal components of the gauge potential. By imposing physical criteria in the choice of the longitudinal--transverse decomposition we show that -in contrast to some recent claims- the `unphysical' coupling $\tilde e$ does not appear in the quantization condition.
1805.03295
Ernest Ma
Ernest Ma (UC Riverside)
Leptonic Dark Matter with Scalar Dilepton Mediator
12 pages, 4 figures (published version)
null
10.1142/S0217732318502267
UCRHEP-T591 (May 2018)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A simple and elegant mechanism is proposed to resolve the problem of having a light scalar mediator for self-interacting dark matter and the resulting disruption to the cosmic microwave background (CMB) at late times by the former's enhanced Sommerfeld production and decay. The crucial idea is to have Dirac neutrinos with the conservation of U(1) lepton number extended to the dark sector. The simplest scenario consists of scalar or fermion dark matter with unit lepton number accompanied by a light scalar dilepton mediator, which decays to two neutrinos.
[ { "created": "Tue, 8 May 2018 21:27:48 GMT", "version": "v1" }, { "created": "Tue, 15 May 2018 20:54:40 GMT", "version": "v2" }, { "created": "Sat, 5 Jan 2019 19:00:08 GMT", "version": "v3" } ]
2019-01-08
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
A simple and elegant mechanism is proposed to resolve the problem of having a light scalar mediator for self-interacting dark matter and the resulting disruption to the cosmic microwave background (CMB) at late times by the former's enhanced Sommerfeld production and decay. The crucial idea is to have Dirac neutrinos with the conservation of U(1) lepton number extended to the dark sector. The simplest scenario consists of scalar or fermion dark matter with unit lepton number accompanied by a light scalar dilepton mediator, which decays to two neutrinos.
2006.16002
Samina S. Masood
Samina Masood
QED Plasma at Extremely High Temperature and Density
12 pages. arXiv admin note: substantial text overlap with arXiv:1801.07835
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the renormalization scheme of QED (Quantum Electrodynamics) in real-time formalism to calculate the effective parameters of the theory, indicating the existence of relativistic QED plasma at extremely high temperatures and extremely high densities. High-density plasma is found inside the stellar cores and high temperature QED plasma could only exist, right after the neutrino decoupling temperature in the early universe, before the nucleosynthesis is complete. Radiation couples with the medium through the vacuum polarization in a hot and dense medium. Calculating the vacuum polarization tensor in a medium, the effect of radiation on matter is investigated in such a medium. We explicitly compute the parameters of QED plasma such as plasma frequency, Debye shielding length and the propagation frequency in terms of temperature and density of the superhot and superdense medium, respectively. This study helps to understand short term existence of QED plasma in the superhot and superdense systems.
[ { "created": "Thu, 25 Jun 2020 16:01:04 GMT", "version": "v1" } ]
2020-06-30
[ [ "Masood", "Samina", "" ] ]
We use the renormalization scheme of QED (Quantum Electrodynamics) in real-time formalism to calculate the effective parameters of the theory, indicating the existence of relativistic QED plasma at extremely high temperatures and extremely high densities. High-density plasma is found inside the stellar cores and high temperature QED plasma could only exist, right after the neutrino decoupling temperature in the early universe, before the nucleosynthesis is complete. Radiation couples with the medium through the vacuum polarization in a hot and dense medium. Calculating the vacuum polarization tensor in a medium, the effect of radiation on matter is investigated in such a medium. We explicitly compute the parameters of QED plasma such as plasma frequency, Debye shielding length and the propagation frequency in terms of temperature and density of the superhot and superdense medium, respectively. This study helps to understand short term existence of QED plasma in the superhot and superdense systems.
hep-ph/0608223
Jin Min Yang
Peiying Li, Gongru Lu, Jin Min Yang, Huanjun Zhang
Probing R-parity Violating Interactions from Top Quark Polarization at LHC
more comments added (7 pages, 5 figs)
Eur.Phys.J.C51:163-168,2007
10.1140/epjc/s10052-007-0290-y
null
hep-ph hep-ex
null
In minimal supersymmetric standard model the R-parity violating interactions can induce anomalous top pair productions at the LHC through the t-channel process d_R \bar d_R -> t_L \bar t_L by exchanging a slepton or u-channel process d_R \bar d_R -> t_R \bar t_R by exchanging a squark. Such top pair productions with certain chirality cause top quark polarization in the top pair events. We found that at the LHC, due to the large statistics, the statistical significance of the polarization observable and thus the probing ability for the corresponding R-parity violating couplings are much higher than at the Tevatron upgrade.
[ { "created": "Sun, 20 Aug 2006 06:42:59 GMT", "version": "v1" }, { "created": "Sat, 24 Feb 2007 13:37:33 GMT", "version": "v2" } ]
2008-11-26
[ [ "Li", "Peiying", "" ], [ "Lu", "Gongru", "" ], [ "Yang", "Jin Min", "" ], [ "Zhang", "Huanjun", "" ] ]
In minimal supersymmetric standard model the R-parity violating interactions can induce anomalous top pair productions at the LHC through the t-channel process d_R \bar d_R -> t_L \bar t_L by exchanging a slepton or u-channel process d_R \bar d_R -> t_R \bar t_R by exchanging a squark. Such top pair productions with certain chirality cause top quark polarization in the top pair events. We found that at the LHC, due to the large statistics, the statistical significance of the polarization observable and thus the probing ability for the corresponding R-parity violating couplings are much higher than at the Tevatron upgrade.
hep-ph/9412222
PostDoc Its
N. Deshpande, Xiao-Gang He and Josip Trampetic
Long Distance Contributions to Penguin Processes $b\rightarrow s\gamma$ and $b\rightarrow d \gamma$
13 pages, Revtex. Some numerical errors in the calculation of $b\rightarrow d \gamma$ are corrected. The long distance contribution to $b\rightarrow d \gamma$ is smaller than stated in the earlier version. New estimate due to u and c loop contributions to the short distance $b\rightarrow d\gamma$ amplitude are included
Phys.Lett. B367 (1996) 362-368
10.1016/0370-2693(95)01364-4
OITS-564
hep-ph
null
We consider the long distance contributions to inclusive penguin processes through processes like $b\rightarrow s V$ and $b\rightarrow d V$ where $V$ are $^3S_1(c\bar c)$ states $\psi_i$ in the former case and include $\rho$, $\omega$ for the latter case. We carefully examine vector dominance for $\bar c c$ states, and conclude that there is a large suppression of $\psi\sim \gamma$ transition when $\psi$ is at $q^2 = 0$. The long distance effects can be at most 10\% in both the amplitudes for $b\rightarrow s\gamma$ and $b\rightarrow d \gamma$. Although the long distance contributions are small, the ratio $BR(b\rightarrow d\gamma)/BR(b \rightarrow s \gamma) = |V_{td}/V_{ts}|^2$ does not hold due to significant $u$ and $c$ loop contributions to the short distance $b\rightarrow d\gamma$ amplitudes .
[ { "created": "Fri, 2 Dec 1994 23:26:55 GMT", "version": "v1" }, { "created": "Fri, 23 Dec 1994 23:38:47 GMT", "version": "v2" }, { "created": "Mon, 23 Jan 1995 22:29:11 GMT", "version": "v3" } ]
2009-10-28
[ [ "Deshpande", "N.", "" ], [ "He", "Xiao-Gang", "" ], [ "Trampetic", "Josip", "" ] ]
We consider the long distance contributions to inclusive penguin processes through processes like $b\rightarrow s V$ and $b\rightarrow d V$ where $V$ are $^3S_1(c\bar c)$ states $\psi_i$ in the former case and include $\rho$, $\omega$ for the latter case. We carefully examine vector dominance for $\bar c c$ states, and conclude that there is a large suppression of $\psi\sim \gamma$ transition when $\psi$ is at $q^2 = 0$. The long distance effects can be at most 10\% in both the amplitudes for $b\rightarrow s\gamma$ and $b\rightarrow d \gamma$. Although the long distance contributions are small, the ratio $BR(b\rightarrow d\gamma)/BR(b \rightarrow s \gamma) = |V_{td}/V_{ts}|^2$ does not hold due to significant $u$ and $c$ loop contributions to the short distance $b\rightarrow d\gamma$ amplitudes .
hep-ph/9406324
null
S. Dawson and G. Valencia
Bounds on $g_5^Z$ from Precision LEP Measurements
Phys. Lett. B333 (1994) 207. A few minor errors in the table are corrected and updated experimental and theoretical numbers are used. The conclusions are unchanged. These changes will appear in an erratum to the published paper
Phys.Lett. B333 (1994) 207-211
10.1016/0370-2693(94)91031-6
null
hep-ph
null
The parity violating but CP conserving anomalous three-gauge-boson coupling $g_5^Z$ induces a universal contribution to the left-handed coupling of the $Z$ boson to fermions. We find that the LEP measurements of the partial $Z$ widths and lepton forward-backward asymmetries are sufficiently precise to place a bound of order $|g_5^Z|$ less than $\sim~10\%$. This bound is significantly better than what can be obtained at present from rare $K$ and $B$ meson decays.
[ { "created": "Thu, 16 Jun 1994 22:35:32 GMT", "version": "v1" }, { "created": "Fri, 28 Oct 1994 15:56:52 GMT", "version": "v2" } ]
2009-10-28
[ [ "Dawson", "S.", "" ], [ "Valencia", "G.", "" ] ]
The parity violating but CP conserving anomalous three-gauge-boson coupling $g_5^Z$ induces a universal contribution to the left-handed coupling of the $Z$ boson to fermions. We find that the LEP measurements of the partial $Z$ widths and lepton forward-backward asymmetries are sufficiently precise to place a bound of order $|g_5^Z|$ less than $\sim~10\%$. This bound is significantly better than what can be obtained at present from rare $K$ and $B$ meson decays.
1211.7261
Sourav Mandal
Biplob Bhattacherjee, Sourav K. Mandal and Mihoko Nojiri
Top Polarization and Stop Mixing from Boosted Jet Substructure
Corresponds to published version
JHEP 1303 (2013) 105
10.1007/JHEP03(2013)105
IPMU12-0200
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top polarization is an important probe of new physics that couples to the top sector, and which may be discovered at the 14 TeV LHC. Taking the example of the MSSM, we argue that top polarization measurements can put a constraint on the soft supersymmetry breaking parameter A_t. In light of the recent discovery of a Higgs-like boson of mass ~125 GeV, a large A_t is a prediction of many supersymmetric models. To this end, we develop a *detector level* analysis methodology for extracting polarization information from hadronic tops using boosted jet substructure. We show that with 100 fb^(-1) of data, left and right 600 GeV stops can be distinguished to 4\sigma, and 800 GeV stops can be distinguished to 3\sigma.
[ { "created": "Fri, 30 Nov 2012 14:06:45 GMT", "version": "v1" }, { "created": "Sun, 24 Mar 2013 11:38:45 GMT", "version": "v2" } ]
2013-03-28
[ [ "Bhattacherjee", "Biplob", "" ], [ "Mandal", "Sourav K.", "" ], [ "Nojiri", "Mihoko", "" ] ]
Top polarization is an important probe of new physics that couples to the top sector, and which may be discovered at the 14 TeV LHC. Taking the example of the MSSM, we argue that top polarization measurements can put a constraint on the soft supersymmetry breaking parameter A_t. In light of the recent discovery of a Higgs-like boson of mass ~125 GeV, a large A_t is a prediction of many supersymmetric models. To this end, we develop a *detector level* analysis methodology for extracting polarization information from hadronic tops using boosted jet substructure. We show that with 100 fb^(-1) of data, left and right 600 GeV stops can be distinguished to 4\sigma, and 800 GeV stops can be distinguished to 3\sigma.
1012.2875
Marco Serone
Giuliano Panico, Mahmoud Safari and Marco Serone
Simple and Realistic Composite Higgs Models in Flat Extra Dimensions
30 figures, 9 figures; v2: minor improvements, one reference added, version to appear in JHEP
JHEP 1102:103,2011
10.1007/JHEP02(2011)103
SISSA-85/2010/EP
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct new composite Higgs/gauge-Higgs unification (GHU) models in flat space that overcome all the difficulties found in the past in attempting to construct models of this sort. The key ingredient is the introduction of large boundary kinetic terms for gauge (and fermion) fields. We focus our analysis on the electroweak symmetry breaking pattern and the electroweak precision tests and show how both are compatible with each other. Our models can be seen as effective TeV descriptions of analogue warped models. We point out that, as far as electroweak TeV scale physics is concerned, one can rely on simple and more flexible flat space models rather than considering their unavoidably more complicated warped space counterparts. The generic collider signatures of our models are essentially undistinguishable from those expected from composite Higgs/warped GHU models, namely a light Higgs, colored fermion resonances below the TeV scale and sizable deviations to the Higgs and top coupling.
[ { "created": "Mon, 13 Dec 2010 21:05:29 GMT", "version": "v1" }, { "created": "Tue, 15 Feb 2011 08:37:30 GMT", "version": "v2" } ]
2011-03-18
[ [ "Panico", "Giuliano", "" ], [ "Safari", "Mahmoud", "" ], [ "Serone", "Marco", "" ] ]
We construct new composite Higgs/gauge-Higgs unification (GHU) models in flat space that overcome all the difficulties found in the past in attempting to construct models of this sort. The key ingredient is the introduction of large boundary kinetic terms for gauge (and fermion) fields. We focus our analysis on the electroweak symmetry breaking pattern and the electroweak precision tests and show how both are compatible with each other. Our models can be seen as effective TeV descriptions of analogue warped models. We point out that, as far as electroweak TeV scale physics is concerned, one can rely on simple and more flexible flat space models rather than considering their unavoidably more complicated warped space counterparts. The generic collider signatures of our models are essentially undistinguishable from those expected from composite Higgs/warped GHU models, namely a light Higgs, colored fermion resonances below the TeV scale and sizable deviations to the Higgs and top coupling.
1612.00643
Jeremie Quevillon
J\'er\'emie Quevillon
Searching for New Physics in Scalar Top-Pair Resonance
Talk given at the 9th International Workshop on Top Quark Physics (TOP 2016), 19-23 September 2016, Olomouc, Czech Republic, to appear in the proceedings
null
null
KCL-PH-TH/2016-67
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the effects in the production via gluon fusion in LHC collisions of one or two spin-zero new resonant particles $\Phi$ that decay into a top quark pair. We revisit previous analyses of the interferences between the heavy-fermion loop-induced $gg \rightarrow \Phi \rightarrow t\bar{t}$ signal and the continuum QCD background $gg \rightarrow t\bar{t}$. We show that in the presence of standard model fermions only in the $gg \rightarrow \Phi$ loops, the interference effect is destructive causing a dip in the $t \bar t$ mass distribution. Including New Physics such as additional vector-like quarks leads to a totally different picture as the line-shape can be distorted by peaks and dips. For the time being, the absence of such effects in ATLAS and CMS data constrain models of the production and decays of the $\Phi$ state(s).
[ { "created": "Fri, 2 Dec 2016 11:46:47 GMT", "version": "v1" } ]
2016-12-05
[ [ "Quevillon", "Jérémie", "" ] ]
We consider the effects in the production via gluon fusion in LHC collisions of one or two spin-zero new resonant particles $\Phi$ that decay into a top quark pair. We revisit previous analyses of the interferences between the heavy-fermion loop-induced $gg \rightarrow \Phi \rightarrow t\bar{t}$ signal and the continuum QCD background $gg \rightarrow t\bar{t}$. We show that in the presence of standard model fermions only in the $gg \rightarrow \Phi$ loops, the interference effect is destructive causing a dip in the $t \bar t$ mass distribution. Including New Physics such as additional vector-like quarks leads to a totally different picture as the line-shape can be distorted by peaks and dips. For the time being, the absence of such effects in ATLAS and CMS data constrain models of the production and decays of the $\Phi$ state(s).
hep-ph/0609072
Pietro Colangelo
P. Colangelo, F. De Fazio, R. Ferrandes
Two topics for a discussion on the $b \bar s$ and $b \bar q$ systems
6 pages, 1 figure. Invited talk at the First Workshop on Theory, Phenomenology and Experiments in Heavy Flavour Physics, Anacapri, Italy, May 29-31, 2006 - v2: two misprints corrected
null
10.1016/j.nuclphysbps.2006.09.005
BARI-TH/06-540
hep-ph
null
The analysis of the $b \bar s$ system is an important issue in the Physics programs of the hadron colliders. We discuss two different topics: the structure of the orbitally excited states and prediction of the rates of a class of non leptonic $B_s$ decays.
[ { "created": "Thu, 7 Sep 2006 09:23:52 GMT", "version": "v1" }, { "created": "Wed, 27 Dec 2006 11:09:11 GMT", "version": "v2" } ]
2009-11-11
[ [ "Colangelo", "P.", "" ], [ "De Fazio", "F.", "" ], [ "Ferrandes", "R.", "" ] ]
The analysis of the $b \bar s$ system is an important issue in the Physics programs of the hadron colliders. We discuss two different topics: the structure of the orbitally excited states and prediction of the rates of a class of non leptonic $B_s$ decays.
hep-ph/9305233
Jan Willem Bos
J.W. Bos and J.H. Koch
The off-Shell Electromagnetic Vertex of the Nucleon in Chiral Perturbation Theory
12 pages (LaTeX), 1 figure (available upon request), NIKHEF 93-P1
Nucl.Phys. A563 (1993) 539-548
10.1016/0375-9474(93)90054-2
null
hep-ph
null
We study the electromagnetic vertex of a nucleon in next-to-leading order chiral perturbation theory (CPT). We consider the case where one of the nucleons at the $\gamma$NN vertex is off its mass shell. We define relevant measures for the off-shell dependence in the limited kinematical range allowed, and analyze their expansion in the pion mass. The leading nonanalytic contributions are calculated to estimate their size.
[ { "created": "Mon, 10 May 1993 11:15:41 GMT", "version": "v1" } ]
2009-10-22
[ [ "Bos", "J. W.", "" ], [ "Koch", "J. H.", "" ] ]
We study the electromagnetic vertex of a nucleon in next-to-leading order chiral perturbation theory (CPT). We consider the case where one of the nucleons at the $\gamma$NN vertex is off its mass shell. We define relevant measures for the off-shell dependence in the limited kinematical range allowed, and analyze their expansion in the pion mass. The leading nonanalytic contributions are calculated to estimate their size.
1803.11127
Vasily Sotnikov
F. R. Anger, V. Sotnikov
On the Dimensional Regularization of QCD Helicity Amplitudes With Quarks
Some minor changes regarding the presentation of the relation to the FDF approach
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study QCD helicity amplitudes with an arbitrary number of (massive) quarks, keeping unobserved (loop) particles in fixed integer $D_s$ dimensions. We find a suitable embedding of external four-dimensional fermion states into higher dimensional spaces. This allows to identify the $D_s$ dependence of amplitudes with external quarks at one and two loops, permitting an analytic continuation in $D_s$. Explicitly we focus on 't Hooft-Veltman and four-dimensional helicity schemes for which we provide a compact prescription for the computation of one- and two-loop amplitudes amenable for numerical implementation.
[ { "created": "Thu, 29 Mar 2018 15:57:23 GMT", "version": "v1" }, { "created": "Fri, 13 Apr 2018 17:11:53 GMT", "version": "v2" } ]
2018-04-16
[ [ "Anger", "F. R.", "" ], [ "Sotnikov", "V.", "" ] ]
We study QCD helicity amplitudes with an arbitrary number of (massive) quarks, keeping unobserved (loop) particles in fixed integer $D_s$ dimensions. We find a suitable embedding of external four-dimensional fermion states into higher dimensional spaces. This allows to identify the $D_s$ dependence of amplitudes with external quarks at one and two loops, permitting an analytic continuation in $D_s$. Explicitly we focus on 't Hooft-Veltman and four-dimensional helicity schemes for which we provide a compact prescription for the computation of one- and two-loop amplitudes amenable for numerical implementation.
1608.01673
Venus Keus
A. Cordero-Cid, J. Hern\'andez-S\'anchez, V. Keus, S. F. King, S. Moretti, D. Rojas, D. Soko{\l}owska
CP violating scalar Dark Matter
42 pages, 22 figures
null
10.1007/JHEP12(2016)014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an extension of the Standard Model (SM) in which two copies of the SM scalar $SU(2)$ doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are \textit{inert}, are added to the scalar sector. We allow for CP-violation in the \textit{inert} sector, where the lightest \textit{inert} state is protected from decaying to SM particles through the conservation of a $Z_2$ symmetry. The lightest neutral particle from the \textit{inert} sector, which has a mixed CP-charge due to CP-violation, is hence a Dark Matter (DM) candidate. We discuss the new regions of DM relic density opened up by CP-violation, and compare our results to the CP-conserving limit and the Inert Doublet Model (IDM). We constrain the parameter space of the CP-violating model using recent results from the Large Hadron Collider (LHC) and DM direct and indirect detection experiments.
[ { "created": "Thu, 4 Aug 2016 20:00:00 GMT", "version": "v1" } ]
2016-12-21
[ [ "Cordero-Cid", "A.", "" ], [ "Hernández-Sánchez", "J.", "" ], [ "Keus", "V.", "" ], [ "King", "S. F.", "" ], [ "Moretti", "S.", "" ], [ "Rojas", "D.", "" ], [ "Sokołowska", "D.", "" ] ]
We study an extension of the Standard Model (SM) in which two copies of the SM scalar $SU(2)$ doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are \textit{inert}, are added to the scalar sector. We allow for CP-violation in the \textit{inert} sector, where the lightest \textit{inert} state is protected from decaying to SM particles through the conservation of a $Z_2$ symmetry. The lightest neutral particle from the \textit{inert} sector, which has a mixed CP-charge due to CP-violation, is hence a Dark Matter (DM) candidate. We discuss the new regions of DM relic density opened up by CP-violation, and compare our results to the CP-conserving limit and the Inert Doublet Model (IDM). We constrain the parameter space of the CP-violating model using recent results from the Large Hadron Collider (LHC) and DM direct and indirect detection experiments.
0708.3731
Andreas Vogt
S. Moch, M. Rogal (DESY, Zeuthen), A. Vogt (Liverpool Univ.)
Differences between charged-current coefficient functions
20 pages, LaTeX, 4 eps-figures
Nucl.Phys.B790:317-335,2008
10.1016/j.nuclphysb.2007.09.022
DESY 07-048, SFT/CPP-07-13, LTH 756
hep-ph
null
Second- and third-order results are presented for the structure functions of charged-current deep-inelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding crossing-even and -odd coefficient functions, including those for the longitudinal structure function not covered in the literature so far. At three loops we compute the lowest five moments of these differences for all three structure functions and provide approximate expressions in Bjorken-$x$ space. Also calculated is the related third-order coefficient-function correction to the Gottfried sum rule. We confirm the conjectured suppression of these quantities if the number of colours is large. Finally we derive the second- and third-order QCD contributions to the Paschos-Wolfenstein ratio used for the determination of the weak mixing angle from neutrino-nucleon deep-inelastic scattering. These contributions are found to be small.
[ { "created": "Tue, 28 Aug 2007 09:01:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Moch", "S.", "", "DESY, Zeuthen" ], [ "Rogal", "M.", "", "DESY, Zeuthen" ], [ "Vogt", "A.", "", "Liverpool Univ." ] ]
Second- and third-order results are presented for the structure functions of charged-current deep-inelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding crossing-even and -odd coefficient functions, including those for the longitudinal structure function not covered in the literature so far. At three loops we compute the lowest five moments of these differences for all three structure functions and provide approximate expressions in Bjorken-$x$ space. Also calculated is the related third-order coefficient-function correction to the Gottfried sum rule. We confirm the conjectured suppression of these quantities if the number of colours is large. Finally we derive the second- and third-order QCD contributions to the Paschos-Wolfenstein ratio used for the determination of the weak mixing angle from neutrino-nucleon deep-inelastic scattering. These contributions are found to be small.
hep-ph/9705250
Jim Huang
Zheng Huang, Hung Jung Lu and Ina Sarcevic
Partonic Picture of Nuclear Shadowing at Small x
15 two-column pages in RevTeX with 9 eps figures
Nucl.Phys. A637 (1998) 79-106
10.1016/S0375-9474(98)00210-3
AZPH-TH/97-07
hep-ph nucl-th
null
We investigate the nuclear shadowing mechanism in the context of perturbative QCD and the Glauber multiple scattering model. Using recent HERA data on nucleon structure function at small $x$, we put stringent constrains on the nucleon gluon density in the double-logarithm approximation. We suggest that the scaling violation of the nucleon structure function in the region of small $x$ and semihard scale $Q^2$ can be reliably described by perturbative QCD which is a central key to the understanding of the scale dependence of the nuclear shadowing effect. Our results indicate that while the shadowing of the quark density arises from an interplay between the ``soft'' and semihard QCD processes, the gluon shadowing is largely driven by a perturbative shadowing mechanism. We demonstrate that the gluon shadowing is a robust phenomenon at large $Q^2$ and can be unambiguously predicted by perturbative QCD.
[ { "created": "Tue, 6 May 1997 20:26:14 GMT", "version": "v1" } ]
2009-10-30
[ [ "Huang", "Zheng", "" ], [ "Lu", "Hung Jung", "" ], [ "Sarcevic", "Ina", "" ] ]
We investigate the nuclear shadowing mechanism in the context of perturbative QCD and the Glauber multiple scattering model. Using recent HERA data on nucleon structure function at small $x$, we put stringent constrains on the nucleon gluon density in the double-logarithm approximation. We suggest that the scaling violation of the nucleon structure function in the region of small $x$ and semihard scale $Q^2$ can be reliably described by perturbative QCD which is a central key to the understanding of the scale dependence of the nuclear shadowing effect. Our results indicate that while the shadowing of the quark density arises from an interplay between the ``soft'' and semihard QCD processes, the gluon shadowing is largely driven by a perturbative shadowing mechanism. We demonstrate that the gluon shadowing is a robust phenomenon at large $Q^2$ and can be unambiguously predicted by perturbative QCD.
2204.07511
Kei Yagyu
Shinya Kanemura, Kei Yagyu
Implication of the $W$ boson mass anomaly at CDF II in the Higgs triplet model with a mass difference
Version accepted for publication in PLB
null
10.1016/j.physletb.2022.137217
OU-HET-1141
hep-ph
http://creativecommons.org/licenses/by/4.0/
A new report for the measurement of the W boson mass has been provided by the CDF II experiment. The measured value of the W boson mass is given to be $m_W^{\text{CDF II}} = 80.4335 \pm 0.0094$ GeV which shows $7\sigma$ deviation from the standard model prediction, while the other groups of high energy experiments, e.g., ATLAS and D0 II, show consistent results with the latter. Assuming that the measurement at CDF II is correct, we discuss the possibility to explain the anomaly in the Higgs triplet model. We find that the anomaly can be explained under the constraints from the electroweak rho parameter, the effective weak mixing angle, the partial width of the leptonic $Z$ decay and current direct searches at LHC when non-zero mass differences among the triplet-like Higgs bosons and the vacuum expectation value of the triplet Higgs field are taken to be ${\cal O}(100)$ GeV and ${\cal O}(1)$ GeV, respectively.
[ { "created": "Fri, 15 Apr 2022 15:13:29 GMT", "version": "v1" }, { "created": "Tue, 31 May 2022 01:39:45 GMT", "version": "v2" } ]
2022-06-08
[ [ "Kanemura", "Shinya", "" ], [ "Yagyu", "Kei", "" ] ]
A new report for the measurement of the W boson mass has been provided by the CDF II experiment. The measured value of the W boson mass is given to be $m_W^{\text{CDF II}} = 80.4335 \pm 0.0094$ GeV which shows $7\sigma$ deviation from the standard model prediction, while the other groups of high energy experiments, e.g., ATLAS and D0 II, show consistent results with the latter. Assuming that the measurement at CDF II is correct, we discuss the possibility to explain the anomaly in the Higgs triplet model. We find that the anomaly can be explained under the constraints from the electroweak rho parameter, the effective weak mixing angle, the partial width of the leptonic $Z$ decay and current direct searches at LHC when non-zero mass differences among the triplet-like Higgs bosons and the vacuum expectation value of the triplet Higgs field are taken to be ${\cal O}(100)$ GeV and ${\cal O}(1)$ GeV, respectively.
0806.1751
Arkady Vainshtein
S.G. Karshenboim, V.A. Shelyuto, and A.I. Vainshtein
Hadronic Light-by-Light Scattering in the Muonium Hyperfine Splitting
16 pages, 7 figures, a reference added
Phys.Rev.D78:065036,2008
10.1103/PhysRevD.78.065036
FTPI-MINN-08/21, UMN-TH-2609/07, CERN-PH-TH/2008-126
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an impact of hadronic light-by-light scattering on the muonium hyperfine structure. A shift of the hyperfine interval $\Delta \nu({\rm Mu}) _{\rm\tiny HLBL}$ is calculated with the light-by-light scattering approximated by exchange of pseudoscalar and pseudovector mesons. Constraints from the operator product expansion in QCD are used to fix parameters of the model similar to the one used earlier for the hadronic light-by-light scattering in calculations of the muon anomalous magnetic moment. The pseudovector exchange is dominant in the resulting shift, $\Delta \nu({\rm Mu})_{\rm\tiny HLBL}= -0.0065(10) {Hz}$. Although the effect is tiny it is useful in understanding the level of hadronic uncertainties.
[ { "created": "Tue, 10 Jun 2008 20:36:21 GMT", "version": "v1" }, { "created": "Wed, 9 Jul 2008 22:45:00 GMT", "version": "v2" } ]
2008-11-26
[ [ "Karshenboim", "S. G.", "" ], [ "Shelyuto", "V. A.", "" ], [ "Vainshtein", "A. I.", "" ] ]
We consider an impact of hadronic light-by-light scattering on the muonium hyperfine structure. A shift of the hyperfine interval $\Delta \nu({\rm Mu}) _{\rm\tiny HLBL}$ is calculated with the light-by-light scattering approximated by exchange of pseudoscalar and pseudovector mesons. Constraints from the operator product expansion in QCD are used to fix parameters of the model similar to the one used earlier for the hadronic light-by-light scattering in calculations of the muon anomalous magnetic moment. The pseudovector exchange is dominant in the resulting shift, $\Delta \nu({\rm Mu})_{\rm\tiny HLBL}= -0.0065(10) {Hz}$. Although the effect is tiny it is useful in understanding the level of hadronic uncertainties.
hep-ph/0311176
Alexander Studenikin
Maxim Dvornikov, Alexander Studenikin
There is no mass squared term in neutrino electric charge
null
null
null
null
hep-ph
null
We claim that the neutrino mass squared term cannot appear in the expansion of the neutrino electric charge over the neutrino mass parameter at the one-loop level of the standard model supplied with $\mathrm{SU}(2)$-singlet right-handed neutrino.
[ { "created": "Thu, 13 Nov 2003 18:36:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dvornikov", "Maxim", "" ], [ "Studenikin", "Alexander", "" ] ]
We claim that the neutrino mass squared term cannot appear in the expansion of the neutrino electric charge over the neutrino mass parameter at the one-loop level of the standard model supplied with $\mathrm{SU}(2)$-singlet right-handed neutrino.
0908.2197
Simonetta Liuti
Simonetta Liuti and Gary R. Goldstein
Accessing Generalized Transversity Distributions with Exclusive $\pi^o$ Electroproduction
5 pages, 3 figures, to appear in the proceedings of DIS 2009, 26-30 April 2009, Madrid
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exclusive $\pi^0$ electroproduction from nucleons at large $Q^2$ can be described by Generalized Parton Distributions (GPDs), particularly the chiral odd subset related to transversity. These GPDs can be accessed experimentally from various cross sections and asymmetries. We calculate these GPDs in a spectator model, constrained by boundary functions. Alternatively, in a hadronic picture the meson production amplitudes correspond to C-odd Regge exchanges with final state interactions. The helicity structure provides relations between the partonic and the hadronic, Regge description of C-odd, chiral-odd processes. Calculations show how the tensor charge and other transversity parameters can be
[ { "created": "Sat, 15 Aug 2009 20:51:17 GMT", "version": "v1" } ]
2009-08-18
[ [ "Liuti", "Simonetta", "" ], [ "Goldstein", "Gary R.", "" ] ]
Exclusive $\pi^0$ electroproduction from nucleons at large $Q^2$ can be described by Generalized Parton Distributions (GPDs), particularly the chiral odd subset related to transversity. These GPDs can be accessed experimentally from various cross sections and asymmetries. We calculate these GPDs in a spectator model, constrained by boundary functions. Alternatively, in a hadronic picture the meson production amplitudes correspond to C-odd Regge exchanges with final state interactions. The helicity structure provides relations between the partonic and the hadronic, Regge description of C-odd, chiral-odd processes. Calculations show how the tensor charge and other transversity parameters can be
hep-ph/9603367
null
Fuguang Cao (ITP) and T. Huang (BIHEP)
Perturbative QCD study on the photonic penguin contributions to the decay $B\to K^* \gamma$
13 pages, latex, 2 PostScript figures, more meson wave function models are employed in numerical calculation, the text is revised substantially, to be published in Z. Phys. C
Eur.Phys.J.C4:277-281,1998
10.1007/s100520050205
null
hep-ph
null
Including corrections of order $O(m_{K^*}/m_B)$, we present an analysis of photonic penguin contributions to the decay $B\to K^* \gamma$ in the perturbative QCD framework. Employing several models of the meson wave functions, we demonstrate that the corrections of $O(m_{K^*}/m_B)$ are enhanced and will providesubstantial contributions to the decay because of the B meson wave function being sharply peaked (bound state effect). The numerical predictions for the corrections are about $30%\sim 60%$ which depend on the non-perturbative inputs such as the meson wave functions and the $b$-quark mass.
[ { "created": "Thu, 21 Mar 1996 23:41:02 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 1997 08:41:00 GMT", "version": "v2" } ]
2011-09-13
[ [ "Cao", "Fuguang", "", "ITP" ], [ "Huang", "T.", "", "BIHEP" ] ]
Including corrections of order $O(m_{K^*}/m_B)$, we present an analysis of photonic penguin contributions to the decay $B\to K^* \gamma$ in the perturbative QCD framework. Employing several models of the meson wave functions, we demonstrate that the corrections of $O(m_{K^*}/m_B)$ are enhanced and will providesubstantial contributions to the decay because of the B meson wave function being sharply peaked (bound state effect). The numerical predictions for the corrections are about $30%\sim 60%$ which depend on the non-perturbative inputs such as the meson wave functions and the $b$-quark mass.
hep-ph/9507455
Manuel Perez-Victoria
F. del Aguila, M. Masip and M. Perez-Victoria
Physical Parameters and Renormalization of U(1)_a x U(1)_b Models
24 pages, tex, 1 figure
Nucl.Phys. B456 (1995) 531-549
10.1016/0550-3213(95)00511-6
UG-FT-46/94
hep-ph
null
We analize the structure of models with unbroken and spontaneously broken U(1)_a x U(1)_b gauge symmetry. We show that the quantum corrections to the 2N gauge charges, with N = #fermions + #scalars, can be absorbed in the redefinition of three independent gauge couplings (g_a,g_b and g_ab). We establish the (one-loop) conditions on the matter cotent for g_ab= = 0 (a value usually assumed in the literature) and we show that in the minimal extensions of the Standard Model with an extra U(1) symmetry the choice g_ab = 0 is not stable under radiative corrections induced by the standard Higgs fields. Moreover, g_ab = 0 to all orders seems to require an exact symmetry. The spontaneous breaking of the gauge symmetry induces further mixing between the two gauge bosons and introduces a fourth independent physical parameter. A consequence of our analysis is that the usual tree-level description with only three physical parameters (i.e., two gauge couplings and one gauge boson mixing angle) is not in general a justified zero order limit of the treatment including radiative corrections.
[ { "created": "Mon, 31 Jul 1995 11:09:26 GMT", "version": "v1" }, { "created": "Tue, 1 Aug 1995 10:21:10 GMT", "version": "v2" } ]
2009-10-28
[ [ "del Aguila", "F.", "" ], [ "Masip", "M.", "" ], [ "Perez-Victoria", "M.", "" ] ]
We analize the structure of models with unbroken and spontaneously broken U(1)_a x U(1)_b gauge symmetry. We show that the quantum corrections to the 2N gauge charges, with N = #fermions + #scalars, can be absorbed in the redefinition of three independent gauge couplings (g_a,g_b and g_ab). We establish the (one-loop) conditions on the matter cotent for g_ab= = 0 (a value usually assumed in the literature) and we show that in the minimal extensions of the Standard Model with an extra U(1) symmetry the choice g_ab = 0 is not stable under radiative corrections induced by the standard Higgs fields. Moreover, g_ab = 0 to all orders seems to require an exact symmetry. The spontaneous breaking of the gauge symmetry induces further mixing between the two gauge bosons and introduces a fourth independent physical parameter. A consequence of our analysis is that the usual tree-level description with only three physical parameters (i.e., two gauge couplings and one gauge boson mixing angle) is not in general a justified zero order limit of the treatment including radiative corrections.
hep-ph/0101326
Roberto Casalbuoni
R. Casalbuoni, R. Gatto, M. Mannarelli and G. Nardulli
Effective Field Theory for the Crystalline Colour Superconductive Phase of QCD
Latex, 17 pages, Modifications in the effective goldstone boson description
Phys.Lett.B511:218-228,2001
10.1016/S0370-2693(01)00645-1
null
hep-ph astro-ph hep-th nucl-th
null
We present an effective field theory for high density, low temperature QCD in the crystalline colour superconductive phase (LOFF phase). This interesting phase of QCD is characterized by a gap parameter with a crystalline pattern, breaking traslational and rotational invariance, and could have astrophysical applications. In the effective theory the fermions have a Majorana mass, which, besides colour, breaks translation and rotation symmetries. Fermions couple to the three phonons arising from the breaking of rotation and translation invariance. Integrating out the fermions leads eventually to an effective lagrangian in terms of the phonon fields only, which satisfies an anisotropic dispersion relation.
[ { "created": "Mon, 29 Jan 2001 16:23:41 GMT", "version": "v1" }, { "created": "Mon, 12 Mar 2001 09:05:37 GMT", "version": "v2" }, { "created": "Sun, 20 May 2001 20:34:13 GMT", "version": "v3" } ]
2010-11-19
[ [ "Casalbuoni", "R.", "" ], [ "Gatto", "R.", "" ], [ "Mannarelli", "M.", "" ], [ "Nardulli", "G.", "" ] ]
We present an effective field theory for high density, low temperature QCD in the crystalline colour superconductive phase (LOFF phase). This interesting phase of QCD is characterized by a gap parameter with a crystalline pattern, breaking traslational and rotational invariance, and could have astrophysical applications. In the effective theory the fermions have a Majorana mass, which, besides colour, breaks translation and rotation symmetries. Fermions couple to the three phonons arising from the breaking of rotation and translation invariance. Integrating out the fermions leads eventually to an effective lagrangian in terms of the phonon fields only, which satisfies an anisotropic dispersion relation.
1608.06945
Tim Stefaniak
Stefano Profumo, Tim Stefaniak
Alignment without Decoupling: the Portal to Light Dark Matter in the MSSM
9 pages, 2 figures, 3 tables; v2: minor changes, added discussion of dominant annihilation final states, matches published version in PRD
Phys.Rev. D94 (2016) no.9, 095020
10.1103/PhysRevD.94.095020
SCIPP 16/12
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study light, thermal neutralino dark matter in the sub-GeV to 65 GeV mass range in the Minimal Supersymmetric extension of the Standard Model (MSSM). We consider realizations of the limit of alignment without decoupling in the Higgs sector where the heavier CP-even Higgs impersonates the observed Higgs state at 125 GeV, while the lighter CP-even Higgs is the mediator of dark matter annihilation. We single out three distinct and novel possibilities for light dark matter: (i) a neutralino with mass around half the light Higgs mass, in the sub-GeV to 30 GeV mass range; (ii) a neutralino with a mass around half the pseudoscalar Higgs boson mass, in our examples around 60 to 65 GeV; (iii) a very light neutralino with mass around the light Higgs mass, pair-annihilating to Higgs pairs. We discuss the implications of all these possibilities for indirect and direct dark matter detection experiments, and we demonstrate that all scenarios will be tested by next generation direct detection experiments. We also emphasize that the unique Higgs phenomenology of these scenarios warrants a dedicated search program at the LHC.
[ { "created": "Wed, 24 Aug 2016 20:00:46 GMT", "version": "v1" }, { "created": "Mon, 19 Dec 2016 19:15:42 GMT", "version": "v2" } ]
2016-12-20
[ [ "Profumo", "Stefano", "" ], [ "Stefaniak", "Tim", "" ] ]
We study light, thermal neutralino dark matter in the sub-GeV to 65 GeV mass range in the Minimal Supersymmetric extension of the Standard Model (MSSM). We consider realizations of the limit of alignment without decoupling in the Higgs sector where the heavier CP-even Higgs impersonates the observed Higgs state at 125 GeV, while the lighter CP-even Higgs is the mediator of dark matter annihilation. We single out three distinct and novel possibilities for light dark matter: (i) a neutralino with mass around half the light Higgs mass, in the sub-GeV to 30 GeV mass range; (ii) a neutralino with a mass around half the pseudoscalar Higgs boson mass, in our examples around 60 to 65 GeV; (iii) a very light neutralino with mass around the light Higgs mass, pair-annihilating to Higgs pairs. We discuss the implications of all these possibilities for indirect and direct dark matter detection experiments, and we demonstrate that all scenarios will be tested by next generation direct detection experiments. We also emphasize that the unique Higgs phenomenology of these scenarios warrants a dedicated search program at the LHC.
hep-ph/0608099
Ayres Freitas
M. Awramik, M. Czakon, A. Freitas
Electroweak two-loop corrections to the effective weak mixing angle
28 pages; added numerical formulae for form factors Delta-r and Delta-kappa, and few minor corrections, version to appear in JHEP
JHEP0611:048,2006
10.1088/1126-6708/2006/11/048
DESY 06-108, ZH-TH 17/06
hep-ph
null
Recently exact results for the complete electroweak two-loop contributions to the effective weak mixing angle were published. This paper illustrates the techniques used for this computation, in particular the methods for evaluating the loop diagrams and the proper definition of Z-pole observables at next-to-next-to-leading order. Numerical results are presented in terms of simple parametrization formulae and compared in detail with a previous result of an expansion up to next-to-leading order in the top-quark mass. Finally, an estimate of the remaining theoretical uncertainties from unknown higher-order corrections is given.
[ { "created": "Wed, 9 Aug 2006 15:06:56 GMT", "version": "v1" }, { "created": "Tue, 21 Nov 2006 08:41:05 GMT", "version": "v2" } ]
2009-11-11
[ [ "Awramik", "M.", "" ], [ "Czakon", "M.", "" ], [ "Freitas", "A.", "" ] ]
Recently exact results for the complete electroweak two-loop contributions to the effective weak mixing angle were published. This paper illustrates the techniques used for this computation, in particular the methods for evaluating the loop diagrams and the proper definition of Z-pole observables at next-to-next-to-leading order. Numerical results are presented in terms of simple parametrization formulae and compared in detail with a previous result of an expansion up to next-to-leading order in the top-quark mass. Finally, an estimate of the remaining theoretical uncertainties from unknown higher-order corrections is given.
1912.08211
Christopher Lepenik
Christopher Lepenik, Vicent Mateu
NLO Massive Event-Shape Differential and Cumulative Distributions
37 pages + appendices, 21 figures; v2: journal version
null
10.1007/JHEP03(2020)024
IFT-UAM/CSIC-19-149, UWThPh-2019-34
hep-ph
http://creativecommons.org/licenses/by/4.0/
We provide a general method to effectively compute differential and cumulative event-shape distributions to $\mathcal{O}(\alpha_s)$ precision for massive quarks produced primarily at an $e^+e^-$ collider. In particular, we show that at this order, due to the screening of collinear singularities by the quark mass, for all event shapes linearly sensitive to soft dynamics, there appear only two distributions at threshold: a Dirac delta function and a plus distribution. Furthermore, we show that the coefficient of the latter is universal for any infra-red and collinear safe event shape, and provide an analytic expression for it. Likewise, we compute a general formula for the coefficient of the Dirac delta function, which depends only on the event-shape measurement function in the soft limit. Finally, we present an efficient algorithm to compute the differential and cumulative distributions, which does not rely on Monte Carlo methods, therefore achieving a priory arbitrary precision even in the extreme dijet region. We implement this algorithm in a numeric code and show that it agrees with analytic results on the distribution for 2-jettiness, heavy jet mass and a massive generalization of C-parameter.
[ { "created": "Tue, 17 Dec 2019 19:00:02 GMT", "version": "v1" }, { "created": "Fri, 28 Feb 2020 22:58:57 GMT", "version": "v2" } ]
2020-03-17
[ [ "Lepenik", "Christopher", "" ], [ "Mateu", "Vicent", "" ] ]
We provide a general method to effectively compute differential and cumulative event-shape distributions to $\mathcal{O}(\alpha_s)$ precision for massive quarks produced primarily at an $e^+e^-$ collider. In particular, we show that at this order, due to the screening of collinear singularities by the quark mass, for all event shapes linearly sensitive to soft dynamics, there appear only two distributions at threshold: a Dirac delta function and a plus distribution. Furthermore, we show that the coefficient of the latter is universal for any infra-red and collinear safe event shape, and provide an analytic expression for it. Likewise, we compute a general formula for the coefficient of the Dirac delta function, which depends only on the event-shape measurement function in the soft limit. Finally, we present an efficient algorithm to compute the differential and cumulative distributions, which does not rely on Monte Carlo methods, therefore achieving a priory arbitrary precision even in the extreme dijet region. We implement this algorithm in a numeric code and show that it agrees with analytic results on the distribution for 2-jettiness, heavy jet mass and a massive generalization of C-parameter.
0911.4875
Rachid Benbrik
Abdesslam Arhrib, Rachid Benbrik, Chuan-Hung Chen
Forward-backward asymmetry of top quark in diquark models
12 pages, 5 figures. Discussion and figures improved. Version accepted for publication in PRD
Phys.Rev.D82:034034,2010
10.1103/PhysRevD.82.034034
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the recent unexpected large forward-backward asymmetry (FBA) of the top quark observed by D$\O$ and CDF at the Tevatron, we investigate a possible explanation for the anomaly within the framework of diquark models. Unlike other mechanisms induced by s-channel or t-channel, the top-quark pair production in the diquark models is dictated by the u-channel diagram. We find that the color-triplet diquark can generate the FBA of 20% when the constraint from the cross section of the top-quark pair production is taken into account.
[ { "created": "Wed, 25 Nov 2009 15:16:54 GMT", "version": "v1" }, { "created": "Tue, 22 Dec 2009 03:17:34 GMT", "version": "v2" }, { "created": "Mon, 30 Aug 2010 18:56:13 GMT", "version": "v3" } ]
2014-11-20
[ [ "Arhrib", "Abdesslam", "" ], [ "Benbrik", "Rachid", "" ], [ "Chen", "Chuan-Hung", "" ] ]
Motivated by the recent unexpected large forward-backward asymmetry (FBA) of the top quark observed by D$\O$ and CDF at the Tevatron, we investigate a possible explanation for the anomaly within the framework of diquark models. Unlike other mechanisms induced by s-channel or t-channel, the top-quark pair production in the diquark models is dictated by the u-channel diagram. We find that the color-triplet diquark can generate the FBA of 20% when the constraint from the cross section of the top-quark pair production is taken into account.
hep-ph/0412046
Alessandro Mirizzi
G.L.Fogli, E.Lisi (Bari U. & INFN, Bari), A.Mirizzi (Bari U. & INFN, Bari & Munich, Max Planck Inst.), D.Montanino (Lecce U. & INFN, Lecce)
Probing supernova shock waves and neutrino flavor transitions in next-generation water-Cherenkov detectors
Revised version (27 pages, 13 eps figures), to appear in JCAP. Includes revised numerical estimates and figures. In particular: calculations of inverse beta decay event rates improved by using the differential cross section by Vissani and Strumia (astro-ph/0302055); supernova relic neutrino flux calculations updated by using recent GALEX Mission data (astro-ph/0411424) on the star formation rate (SFR). References added. Conclusions unchanged
JCAP 0504:002,2005
10.1088/1475-7516/2005/04/002
null
hep-ph astro-ph hep-ex
null
Several current projects aim at building a large water-Cherenkov detector, with a fiducial volume about 20 times larger than in the current Super-Kamiokande experiment. These projects include the Underground nucleon decay and Neutrino Observatory (UNO) in the Henderson Mine (Colorado), the Hyper-Kamiokande (HK) detector in the Tochibora Mine (Japan), and the MEgaton class PHYSics (MEMPHYS) detector in the Frejus site (Europe). We study the physics potential of a reference next-generation detector (0.4 Mton of fiducial mass) in providing information on supernova neutrino flavor transitions with unprecedented statistics. After discussing the ingredients of our calculations, we compute neutrino event rates from inverse beta decay ($\bar\nu_e p\to e^+ n $), elastic scattering on electrons, and scattering on oxygen, with emphasis on their time spectra, which may encode combined information on neutrino oscillation parameters and on supernova forward (and possibly reverse) shock waves. In particular, we show that an appropriate ratio of low-to-high energy events can faithfully monitor the time evolution of the neutrino crossing probability along the shock-wave profile. We also discuss some background issues related to the detection of supernova relic neutrinos, with and without the addition of gadolinium.
[ { "created": "Fri, 3 Dec 2004 13:06:14 GMT", "version": "v1" }, { "created": "Thu, 10 Mar 2005 13:31:58 GMT", "version": "v2" } ]
2009-10-07
[ [ "Fogli", "G. L.", "", "Bari U. & INFN, Bari" ], [ "Lisi", "E.", "", "Bari U. & INFN, Bari" ], [ "Mirizzi", "A.", "", "Bari U. & INFN,\n Bari & Munich, Max Planck Inst." ], [ "Montanino", "D.", "", "Lecce U. & INFN, Lecce" ] ]
Several current projects aim at building a large water-Cherenkov detector, with a fiducial volume about 20 times larger than in the current Super-Kamiokande experiment. These projects include the Underground nucleon decay and Neutrino Observatory (UNO) in the Henderson Mine (Colorado), the Hyper-Kamiokande (HK) detector in the Tochibora Mine (Japan), and the MEgaton class PHYSics (MEMPHYS) detector in the Frejus site (Europe). We study the physics potential of a reference next-generation detector (0.4 Mton of fiducial mass) in providing information on supernova neutrino flavor transitions with unprecedented statistics. After discussing the ingredients of our calculations, we compute neutrino event rates from inverse beta decay ($\bar\nu_e p\to e^+ n $), elastic scattering on electrons, and scattering on oxygen, with emphasis on their time spectra, which may encode combined information on neutrino oscillation parameters and on supernova forward (and possibly reverse) shock waves. In particular, we show that an appropriate ratio of low-to-high energy events can faithfully monitor the time evolution of the neutrino crossing probability along the shock-wave profile. We also discuss some background issues related to the detection of supernova relic neutrinos, with and without the addition of gadolinium.
hep-ph/9212305
Mariano Quiros
J.R. Espinosa and M. Quir\'os
Upper Bounds on the Lightest Higgs Boson Mass in General Supersymmetric Standard Models
13 pages, latex, IEM-FT-64/92 (5 postscript figures availables upon request)
Phys.Lett. B302 (1993) 51-58
10.1016/0370-2693(93)90634-T
null
hep-ph
null
In a general supersymmetric standard model there is an upper bound $m_h$ on the tree level mass of the $CP=+1$ lightest Higgs boson which depends on the electroweak scale, $\tan \beta$ and the gauge and Yukawa couplings of the theory. When radiative corrections are included, the allowed region in the $(m_h,m_t)$ plane depends on the scale $\Lambda$, below which the theory remains perturbative, and the supersymmetry breaking scale $\Lambda_s$, that we fix to $1\ TeV$. In the minimal model with $\Lambda=10^{16}\ GeV$: $m_h<130\ GeV$ and $m_t<185\ GeV$. In non-minimal models with an arbitrary number of gauge singlets and $\Lambda=10^{16}\ GeV$: $m_h<145\ GeV$ and $m_t<185\ GeV$. We also consider supersymmetric standard models with arbitrary Higgs sectors. For models whose couplings saturate the scale $\Lambda=10^{16}\ GeV$ we find $m_h<155\ GeV$ and $m_t<190\ GeV$. As one pushes the saturation scale $\Lambda$ down to $\Lambda_s$, the bounds on $m_h$ and $m_t$ increase. For instance, in models with $\Lambda=10\ TeV$, the upper bounds for $m_h$ and $m_t$ go to $415\ GeV$ and $385\ GeV$, respectively.
[ { "created": "Tue, 22 Dec 1992 20:02:36 GMT", "version": "v1" } ]
2009-10-22
[ [ "Espinosa", "J. R.", "" ], [ "Quirós", "M.", "" ] ]
In a general supersymmetric standard model there is an upper bound $m_h$ on the tree level mass of the $CP=+1$ lightest Higgs boson which depends on the electroweak scale, $\tan \beta$ and the gauge and Yukawa couplings of the theory. When radiative corrections are included, the allowed region in the $(m_h,m_t)$ plane depends on the scale $\Lambda$, below which the theory remains perturbative, and the supersymmetry breaking scale $\Lambda_s$, that we fix to $1\ TeV$. In the minimal model with $\Lambda=10^{16}\ GeV$: $m_h<130\ GeV$ and $m_t<185\ GeV$. In non-minimal models with an arbitrary number of gauge singlets and $\Lambda=10^{16}\ GeV$: $m_h<145\ GeV$ and $m_t<185\ GeV$. We also consider supersymmetric standard models with arbitrary Higgs sectors. For models whose couplings saturate the scale $\Lambda=10^{16}\ GeV$ we find $m_h<155\ GeV$ and $m_t<190\ GeV$. As one pushes the saturation scale $\Lambda$ down to $\Lambda_s$, the bounds on $m_h$ and $m_t$ increase. For instance, in models with $\Lambda=10\ TeV$, the upper bounds for $m_h$ and $m_t$ go to $415\ GeV$ and $385\ GeV$, respectively.
0810.5266
Kai Wang
Zongguo Si and Kai Wang
GeV Majorana Neutrinos in Top-quark Decay at the LHC
15 pages, 8 figures
Phys.Rev.D79:014034,2009
10.1103/PhysRevD.79.014034
MADPH 08-1524,IPMU 08-0068,CAS-KITPC/ITP-072
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the \Delta L=2 same-sign dilepton signal from top-quark decay via a Majorana neutrino at the LHC in the top anti-top pair production samples. The signature is same-sign dilepton plus multi-jets with no significant missing energy. The most optimistic region lies where the Majorana neutrino mass is between 15-65 GeV. For 300 fb^-1 integrated luminosity, it is possible to probe S_{ij}, the effective mixing parameter, to order of 10^-5.
[ { "created": "Wed, 29 Oct 2008 12:59:50 GMT", "version": "v1" } ]
2010-04-21
[ [ "Si", "Zongguo", "" ], [ "Wang", "Kai", "" ] ]
We explore the \Delta L=2 same-sign dilepton signal from top-quark decay via a Majorana neutrino at the LHC in the top anti-top pair production samples. The signature is same-sign dilepton plus multi-jets with no significant missing energy. The most optimistic region lies where the Majorana neutrino mass is between 15-65 GeV. For 300 fb^-1 integrated luminosity, it is possible to probe S_{ij}, the effective mixing parameter, to order of 10^-5.
hep-ph/0610186
Takayuki Matsuki
Takayuki Matsuki, Toshiyuki Morii, and Kazutaka Sudoh
Radial Excitations of Heavy Mesons
3 pages, 1 figure, QNP06 conference report
Eur.Phys.J.A31:701-704,2007
10.1140/epja/i2006-10287-1
null
hep-ph hep-ex
null
Recent discovery of D_s states suggests existence of radial excitations. Our semirelativistic quark potential model succeeds in reproducing these staes within one to two percent of accuracy compared with the experiments, D_s0(2860) and D_s^*(2715), which are identified as 0^+ and 1^- radial excitations (n=2). We also present calculations of radial excitations for B/B_s heavy mesons. Relation between our formulation and the modified Goldberger-Treiman relation is also described.
[ { "created": "Mon, 16 Oct 2006 05:52:53 GMT", "version": "v1" }, { "created": "Mon, 23 Oct 2006 00:52:24 GMT", "version": "v2" }, { "created": "Thu, 8 Feb 2007 00:56:15 GMT", "version": "v3" } ]
2008-11-26
[ [ "Matsuki", "Takayuki", "" ], [ "Morii", "Toshiyuki", "" ], [ "Sudoh", "Kazutaka", "" ] ]
Recent discovery of D_s states suggests existence of radial excitations. Our semirelativistic quark potential model succeeds in reproducing these staes within one to two percent of accuracy compared with the experiments, D_s0(2860) and D_s^*(2715), which are identified as 0^+ and 1^- radial excitations (n=2). We also present calculations of radial excitations for B/B_s heavy mesons. Relation between our formulation and the modified Goldberger-Treiman relation is also described.
hep-ph/0703154
S. Descotes-Genon
S. Descotes-Genon (LPT Orsay)
Low-energy pi-pi and pi-K scatterings revisited in three-flavour resummed chiral perturbation theory
35 pages, 3 figures, accepted for publication in Eur. Phys. J. C
Eur.Phys.J.C52:141-158,2007
10.1140/epjc/s10052-007-0359-7
LPT-ORSAY/07-12
hep-ph
null
Chiral symmetry breaking may exhibit significantly different patterns in two chiral limits: N_f=2 massless flavours (m_u=m_d=0, m_s physical) and N_f=3 massless flavours (m_u=m_d=0=m_s=0). Such a difference may arise due to vacuum fluctuations of s-bar{s} pairs related to the violation of the Zweig rule in the scalar sector, and could yield a numerical competition between contributions counted as leading order and next-to-leading in the chiral expansions of observables. We recall and extend Resummed Chiral Perturbation Theory (ReChPT), a framework that we introduced previously to deal with such instabilities: it requires a more careful definition of the relevant observables and their one-loop chiral expansions. We analyse the amplitudes for low-energy pi-pi and pi-K scatterings within ReChPT, which we match in subthreshold regions with dispersive representations obtained from the solutions Roy and Roy-Steiner equations. Using a frequentist approach, we constrain the quark mass ratio as well as the quark condensate and the pseudoscalar decay constant in the N_f=3 chiral limit. The results mildly favour significant contributions of vacuum fluctuations suppressing the N_f=3 quark condensate compared to its N_f=2 counterpart.
[ { "created": "Wed, 14 Mar 2007 16:59:33 GMT", "version": "v1" }, { "created": "Thu, 21 Jun 2007 08:16:57 GMT", "version": "v2" } ]
2008-11-26
[ [ "Descotes-Genon", "S.", "", "LPT Orsay" ] ]
Chiral symmetry breaking may exhibit significantly different patterns in two chiral limits: N_f=2 massless flavours (m_u=m_d=0, m_s physical) and N_f=3 massless flavours (m_u=m_d=0=m_s=0). Such a difference may arise due to vacuum fluctuations of s-bar{s} pairs related to the violation of the Zweig rule in the scalar sector, and could yield a numerical competition between contributions counted as leading order and next-to-leading in the chiral expansions of observables. We recall and extend Resummed Chiral Perturbation Theory (ReChPT), a framework that we introduced previously to deal with such instabilities: it requires a more careful definition of the relevant observables and their one-loop chiral expansions. We analyse the amplitudes for low-energy pi-pi and pi-K scatterings within ReChPT, which we match in subthreshold regions with dispersive representations obtained from the solutions Roy and Roy-Steiner equations. Using a frequentist approach, we constrain the quark mass ratio as well as the quark condensate and the pseudoscalar decay constant in the N_f=3 chiral limit. The results mildly favour significant contributions of vacuum fluctuations suppressing the N_f=3 quark condensate compared to its N_f=2 counterpart.
1604.01305
Marcin Bury
Marcin Bury, Michal Deak, Krzysztof Kutak and Sebastian Sapeta
Single and double inclusive forward jet production at the LHC at $\sqrt{s}$ = 7 and 13 TeV
14 pages, 5 figures, version accepted for PLB
Physics Letters B, Volume 760, 10 September 2016, Pages 594-601
10.1016/j.physletb.2016.07.041
IFJPAN-IV-2016-6; CERN-TH-2016-077
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a description of the transverse momentum spectrum of single inclusive forward jets produced at the LHC, at the center-of-mass energies of 7 and 13 TeV, using the high energy factorization (HEF) framework. We subsequently study double inclusive forward jet production and, in particular, we calculate contributions to azimuthal angle distributions coming from double parton scattering. We also compare our results for double inclusive jet production to those obtained with the Pythia Monte Carlo generator. This comparison confirms that the HEF resummation acts like an initial state parton shower. It also points towards the need to include final state radiation effects in the HEF formalism.
[ { "created": "Tue, 5 Apr 2016 15:45:50 GMT", "version": "v1" }, { "created": "Thu, 14 Apr 2016 17:38:14 GMT", "version": "v2" }, { "created": "Thu, 11 Aug 2016 13:34:47 GMT", "version": "v3" } ]
2016-08-12
[ [ "Bury", "Marcin", "" ], [ "Deak", "Michal", "" ], [ "Kutak", "Krzysztof", "" ], [ "Sapeta", "Sebastian", "" ] ]
We provide a description of the transverse momentum spectrum of single inclusive forward jets produced at the LHC, at the center-of-mass energies of 7 and 13 TeV, using the high energy factorization (HEF) framework. We subsequently study double inclusive forward jet production and, in particular, we calculate contributions to azimuthal angle distributions coming from double parton scattering. We also compare our results for double inclusive jet production to those obtained with the Pythia Monte Carlo generator. This comparison confirms that the HEF resummation acts like an initial state parton shower. It also points towards the need to include final state radiation effects in the HEF formalism.
2204.11893
Risto Paatelainen
Tyler Gorda, Aleksi Kurkela, Juuso \"Osterman, Risto Paatelainen, Saga S\"appi, Philipp Schicho, Kaapo Sepp\"anen, Aleksi Vuorinen
Degenerate fermionic matter at N$^3$LO: Quantum Electrodynamics
6 pages (main text), 6 pages (supplemental material) and 3 figures
null
10.1103/PhysRevD.107.L031501
HIP-2022-9/TH
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the pressure of a cold and dense electron gas to a nearly complete next-to-next-to-next-to-leading order (N$^3$LO) in the fine-structure constant $\alpha_e$, utilizing a new result for the two-loop photon self-energy from a companion paper. Our result contains all infrared-sensitive contributions to the pressure at this order, including the coefficient of the $O(\alpha_e^3 \ln \alpha_e^{ })$ term, and leaves only a single coefficient associated with the contributions of unresummed hard momenta undetermined. Moreover, we explicitly demonstrate the complete cancellation of infrared divergences according to the effective field theory paradigm by determining part of the hard contributions at this order. Our calculation provides the first improvement to a 45-year-old milestone result and demonstrates the feasibility of the corresponding N$^3$LO calculation for cold and dense quark matter.
[ { "created": "Mon, 25 Apr 2022 18:01:10 GMT", "version": "v1" } ]
2023-03-01
[ [ "Gorda", "Tyler", "" ], [ "Kurkela", "Aleksi", "" ], [ "Österman", "Juuso", "" ], [ "Paatelainen", "Risto", "" ], [ "Säppi", "Saga", "" ], [ "Schicho", "Philipp", "" ], [ "Seppänen", "Kaapo", "" ], [ "Vuorinen", "Aleksi", "" ] ]
We determine the pressure of a cold and dense electron gas to a nearly complete next-to-next-to-next-to-leading order (N$^3$LO) in the fine-structure constant $\alpha_e$, utilizing a new result for the two-loop photon self-energy from a companion paper. Our result contains all infrared-sensitive contributions to the pressure at this order, including the coefficient of the $O(\alpha_e^3 \ln \alpha_e^{ })$ term, and leaves only a single coefficient associated with the contributions of unresummed hard momenta undetermined. Moreover, we explicitly demonstrate the complete cancellation of infrared divergences according to the effective field theory paradigm by determining part of the hard contributions at this order. Our calculation provides the first improvement to a 45-year-old milestone result and demonstrates the feasibility of the corresponding N$^3$LO calculation for cold and dense quark matter.
hep-ph/9707318
Matthias Neubert
A.G. Grozin (Novosibirsk), M. Neubert (CERN)
Higher-order estimates of the chromomagnetic moment of a heavy quark
16 pages, 3 figures embedded
Nucl.Phys. B508 (1997) 311-326
10.1016/S0550-3213(97)00615-9
CERN-TH/97-102, Budker INP 97-60
hep-ph
null
The leading beta_0^(n-1) alpha_s^n terms in the Wilson coefficient and anomalous dimension of the chromomagnetic operator in the heavy-quark effective Lagrangian are summed to all orders of perturbation theory. The perturbation series for the anomalous dimension is well behaved, while that for the Wilson coefficient exhibits a divergent behaviour already in low orders, caused by a nearby infrared renormalon singularity. The resulting ambiguity is commensurate with terms of order 1/m^2 in the effective Lagrangian, whose corresponding ultraviolet renormalons are identified. An excellent approximation for the scheme-invariant Wilson coefficient at next-to-next-to-leading order in renormalization-group improved perturbation theory is obtained.
[ { "created": "Fri, 11 Jul 1997 09:01:39 GMT", "version": "v1" } ]
2009-10-30
[ [ "Grozin", "A. G.", "", "Novosibirsk" ], [ "Neubert", "M.", "", "CERN" ] ]
The leading beta_0^(n-1) alpha_s^n terms in the Wilson coefficient and anomalous dimension of the chromomagnetic operator in the heavy-quark effective Lagrangian are summed to all orders of perturbation theory. The perturbation series for the anomalous dimension is well behaved, while that for the Wilson coefficient exhibits a divergent behaviour already in low orders, caused by a nearby infrared renormalon singularity. The resulting ambiguity is commensurate with terms of order 1/m^2 in the effective Lagrangian, whose corresponding ultraviolet renormalons are identified. An excellent approximation for the scheme-invariant Wilson coefficient at next-to-next-to-leading order in renormalization-group improved perturbation theory is obtained.
1602.07099
Pouya Bakhti
Pouya Bakhti and Yasaman Farzan
CP-Violation and Non-Standard Interactions at the MOMENT
15 pages, 6 figures
null
10.1007/JHEP07(2016)109
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To measure the last unknown $3\nu$ oscillation parameter ($\delta$), several long baseline neutrino experiments have been designed or proposed. Recently it has been shown that turning on neutral current Non-Standard Interactions (NSI) of neutrinos with matter can induce degeneracies that may even hinder the proposed state-of-the-art DUNE long baseline experiment from measuring the value of $\delta$. We study how the result of the proposed MOMENT experiment with a baseline of 150 km and $200~{\rm MeV}<E_\nu<600~{\rm MeV}$ can help to solve the degeneracy induced by NSI and determine the true value of $\delta$.
[ { "created": "Tue, 23 Feb 2016 09:34:25 GMT", "version": "v1" }, { "created": "Wed, 7 Dec 2016 14:35:05 GMT", "version": "v2" } ]
2016-12-08
[ [ "Bakhti", "Pouya", "" ], [ "Farzan", "Yasaman", "" ] ]
To measure the last unknown $3\nu$ oscillation parameter ($\delta$), several long baseline neutrino experiments have been designed or proposed. Recently it has been shown that turning on neutral current Non-Standard Interactions (NSI) of neutrinos with matter can induce degeneracies that may even hinder the proposed state-of-the-art DUNE long baseline experiment from measuring the value of $\delta$. We study how the result of the proposed MOMENT experiment with a baseline of 150 km and $200~{\rm MeV}<E_\nu<600~{\rm MeV}$ can help to solve the degeneracy induced by NSI and determine the true value of $\delta$.
hep-ph/0506239
Mustafa Savci
T. M. Aliev, V. Bashiry and M. Savci
Double-lepton polarization asymmetries in the Exclusive (B -> rho l^+ l^-) decay beyond the Standard Model
28 pages, 16 figures, LaTeX formatted
Phys.Rev. D72 (2005) 034031
10.1103/PhysRevD.72.034031
metu-phys-hep-06-15
hep-ph
null
The double-lepton polarization asymmetries in (B -> rho l^+ l^-) decay is analyzed in a model independent framework. The general expressions for nine double-polarization asymmetries are calculated. It is shown that the study of the double-lepton polarization asymmetries proves to be very useful tool in looking for new physics beyond the standard model.
[ { "created": "Thu, 23 Jun 2005 19:30:28 GMT", "version": "v1" } ]
2009-11-11
[ [ "Aliev", "T. M.", "" ], [ "Bashiry", "V.", "" ], [ "Savci", "M.", "" ] ]
The double-lepton polarization asymmetries in (B -> rho l^+ l^-) decay is analyzed in a model independent framework. The general expressions for nine double-polarization asymmetries are calculated. It is shown that the study of the double-lepton polarization asymmetries proves to be very useful tool in looking for new physics beyond the standard model.
hep-ph/0405041
Mikhail Ryskin G.
S.B. Nurushev and M.G. Ryskin
Experimental data on the single spin asymmetry and their interpretations by the chromo-magnetic string model
17 pages, 3 figures
Phys.Atom.Nucl. 69 (2006) 133-141
10.1134/S1063778806010170
null
hep-ph
null
An attempt is made to interpret the various existing experimental data on the single spin asymmetries in inclusive pion production by the polarized proton and antiproton beams. As the basis of analysis the chromo-magnetic string model is used. A whole measured kinematic region is covered. The successes and fails of such approach are outlined. The possible improvements of model are discussed.
[ { "created": "Wed, 5 May 2004 15:33:08 GMT", "version": "v1" } ]
2015-06-25
[ [ "Nurushev", "S. B.", "" ], [ "Ryskin", "M. G.", "" ] ]
An attempt is made to interpret the various existing experimental data on the single spin asymmetries in inclusive pion production by the polarized proton and antiproton beams. As the basis of analysis the chromo-magnetic string model is used. A whole measured kinematic region is covered. The successes and fails of such approach are outlined. The possible improvements of model are discussed.
2002.08315
Sarira Sahu
Jos\'e F. Nieves and Sarira Sahu
Neutrino decoherence in an electron and nucleon background
27 Pages, 2 Figures, Typographical errors in Eqs. (6.5) and (6.11) of the PRD published version have been corrected. arXiv admin note: text overlap with arXiv:1909.11271
Phys. Rev. D 102, 056007 (2020)
10.1103/PhysRevD.102.056007
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the decoherence effects in the propagation of active neutrinos due to the non-forward neutrino scattering processes in a matter background composed of electrons and nucleons. We calculate the contribution to the imaginary part of the neutrino self-energy arising from such processes. Since the initial neutrino state is depleted but does not actually disappear (the initial neutrino transitions into a neutrino of a different flavor but does not decay) those processes should be associated with decoherence effects that cannot be described in terms of the coherent evolution of the state vector. Based on the formalism developed in our previous work for treating the non-forward scattering processes using the notion of the stochastic evolution of the state, we identify the jump operators, as used in the context of the master or Lindblad equation, in terms of the results of the the calculation of the non-forward neutrino scattering contribution to the imaginary part of the neutrino self-energy. As a guide to estimating the decoherence effects in situations of practical interest we give explicit formulas for the decoherence terms for different background conditions, and point out some of the salient features in particular the neutrino energy dependence. To establish contact wih previous works in which the decoherence terms are treated as phenomenological parameters, we consider the solution to the evolution equation in the two-generation case. We give formulas that are useful for estimating the effects of the decoherence terms under various conditions and environments, including the typical conditions applicable to long baseline experiments, where matter effects are important. In those contexts the effects appear to be small, and indicative that if significant decoherence effects were to be found they would be due to non-standard contributions to the decoherence terms.
[ { "created": "Mon, 17 Feb 2020 20:02:27 GMT", "version": "v1" }, { "created": "Wed, 9 Sep 2020 05:01:07 GMT", "version": "v2" }, { "created": "Mon, 15 Mar 2021 01:31:38 GMT", "version": "v3" }, { "created": "Sat, 10 Apr 2021 01:27:50 GMT", "version": "v4" }, { "created": "Tue, 6 Jul 2021 11:36:17 GMT", "version": "v5" } ]
2021-07-07
[ [ "Nieves", "José F.", "" ], [ "Sahu", "Sarira", "" ] ]
We consider the decoherence effects in the propagation of active neutrinos due to the non-forward neutrino scattering processes in a matter background composed of electrons and nucleons. We calculate the contribution to the imaginary part of the neutrino self-energy arising from such processes. Since the initial neutrino state is depleted but does not actually disappear (the initial neutrino transitions into a neutrino of a different flavor but does not decay) those processes should be associated with decoherence effects that cannot be described in terms of the coherent evolution of the state vector. Based on the formalism developed in our previous work for treating the non-forward scattering processes using the notion of the stochastic evolution of the state, we identify the jump operators, as used in the context of the master or Lindblad equation, in terms of the results of the the calculation of the non-forward neutrino scattering contribution to the imaginary part of the neutrino self-energy. As a guide to estimating the decoherence effects in situations of practical interest we give explicit formulas for the decoherence terms for different background conditions, and point out some of the salient features in particular the neutrino energy dependence. To establish contact wih previous works in which the decoherence terms are treated as phenomenological parameters, we consider the solution to the evolution equation in the two-generation case. We give formulas that are useful for estimating the effects of the decoherence terms under various conditions and environments, including the typical conditions applicable to long baseline experiments, where matter effects are important. In those contexts the effects appear to be small, and indicative that if significant decoherence effects were to be found they would be due to non-standard contributions to the decoherence terms.
1403.2555
Gorazd Cvetic
Gorazd Cvetic, C. S. Kim, Jilberto Zamora-Saa
CP violation in lepton number violating semihadronic decays of $K, D, D_s, B, B_c$
19 pages, 8 figures; v2: a new Table (I); minor changes in the text; new references [5,31,32]; ref.[19] extended; to appear in Phys.Rev.D
Phys. Rev. D 89, 093012 (2014)
10.1103/PhysRevD.89.093012
USM-TH-321
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the CP violation in lepton number violating meson decays $M^{\pm} \to \ell_1^{\pm} \ell_2^{\pm} M^{' \mp}$, where $M$ and $M^{'}$ are pseudoscalar mesons, $M=K, D, D_s, B, B_c$ and $M^{'}=\pi, K, D, D_s$, and the charged leptons are $\ell_1, \ell_2 = e, \mu$. It turns out that the CP-violating difference $S_{-}(M) \equiv [\Gamma(M^- \to \ell_1^- \ell_2^- M^{' +})-\Gamma(M^+ \to \ell_1^+ \ell_2^+ M^{' -})]$ can become appreciable when two intermediate on-shell Majorana neutrinos $N_j$ ($j=1,2$) participate in these decays. Our calculations show that the asymmetry becomes largest when the masses of $N_1$ and $N_2$ are almost degenerate, i.e., when the mass difference $\Delta M_N$ becomes comparable with the (small) decay widths $\Gamma_N$ of these neutrinos: $\Delta M_N \not\gg \Gamma_N$. We show that in such a case, the CP ratio ${\cal A}_{CP}(M) \equiv [\Gamma(M^- \to \ell_1^- \ell_2^- M^{' +})-\Gamma(M^+ \to \ell_1^+ \ell_2^+ M^{' -})]/[\Gamma(M^- \to \ell_1^- \ell_2^- M^{' +})+\Gamma(M^+ \to \ell_1^+ \ell_2^+ M^{' -})]$ becomes a quantity $\sim 1$. The observation of CP violation in these decays would be consistent with the existence of the well-motivated $\nu$MSM model with two almost degenerate heavy neutrinos in the mass range between $M_N \sim 0.1$-$10^1$ GeV.
[ { "created": "Tue, 11 Mar 2014 12:39:50 GMT", "version": "v1" }, { "created": "Mon, 12 May 2014 17:13:41 GMT", "version": "v2" } ]
2014-05-21
[ [ "Cvetic", "Gorazd", "" ], [ "Kim", "C. S.", "" ], [ "Zamora-Saa", "Jilberto", "" ] ]
We study the CP violation in lepton number violating meson decays $M^{\pm} \to \ell_1^{\pm} \ell_2^{\pm} M^{' \mp}$, where $M$ and $M^{'}$ are pseudoscalar mesons, $M=K, D, D_s, B, B_c$ and $M^{'}=\pi, K, D, D_s$, and the charged leptons are $\ell_1, \ell_2 = e, \mu$. It turns out that the CP-violating difference $S_{-}(M) \equiv [\Gamma(M^- \to \ell_1^- \ell_2^- M^{' +})-\Gamma(M^+ \to \ell_1^+ \ell_2^+ M^{' -})]$ can become appreciable when two intermediate on-shell Majorana neutrinos $N_j$ ($j=1,2$) participate in these decays. Our calculations show that the asymmetry becomes largest when the masses of $N_1$ and $N_2$ are almost degenerate, i.e., when the mass difference $\Delta M_N$ becomes comparable with the (small) decay widths $\Gamma_N$ of these neutrinos: $\Delta M_N \not\gg \Gamma_N$. We show that in such a case, the CP ratio ${\cal A}_{CP}(M) \equiv [\Gamma(M^- \to \ell_1^- \ell_2^- M^{' +})-\Gamma(M^+ \to \ell_1^+ \ell_2^+ M^{' -})]/[\Gamma(M^- \to \ell_1^- \ell_2^- M^{' +})+\Gamma(M^+ \to \ell_1^+ \ell_2^+ M^{' -})]$ becomes a quantity $\sim 1$. The observation of CP violation in these decays would be consistent with the existence of the well-motivated $\nu$MSM model with two almost degenerate heavy neutrinos in the mass range between $M_N \sim 0.1$-$10^1$ GeV.
hep-ph/0010231
Alexander Friedland
Alexander Friedland (Princeton, Inst. for Advanced Study & Berkeley, LBNL)
On the Evolution of the Neutrino State inside the Sun
34 pages, 8 figures
Phys.Rev.D64:013008,2001
10.1103/PhysRevD.64.013008
LBNL-46980, IASSNS-AST-00/55
hep-ph
null
We reexamine the conventional physical description of the neutrino evolution inside the Sun. We point out that the traditional resonance condition has physical meaning only in the limit of small values of the neutrino mixing angle, theta<<1. For large values of theta, the resonance condition specifies neither the point of the maximal violation of adiabaticity in the nonadiabatic case, nor the point where the flavor conversion occurs at the maximal rate in the adiabatic case. The corresponding correct conditions, valid for all values of theta including theta>pi/4, are presented. An adiabaticity condition valid for all values of theta is also described. The results of accurate numerical computations of the level jumping probability in the Sun are presented. These calculations cover a wide range of Delta m^2, from the vacuum oscillation region to the region where the standard exponential approximation is good. A convenient empirical parametrization of these results in terms of elementary functions is given. The matter effects in the so-called "quasi-vacuum oscillation regime" are discussed. Finally, it is shown how the known analytical results for the exponential, 1/x, and linear matter distributions can be simply obtained from the formula for the hyperbolic tangent profile. An explicit formula for the jumping probability for the distribution N_e ~ (coth(x/l) +- 1) is obtained.
[ { "created": "Thu, 19 Oct 2000 23:15:01 GMT", "version": "v1" }, { "created": "Sat, 21 Oct 2000 04:10:04 GMT", "version": "v2" }, { "created": "Fri, 26 Jan 2001 16:44:23 GMT", "version": "v3" } ]
2014-11-17
[ [ "Friedland", "Alexander", "", "Princeton, Inst. for Advanced Study & Berkeley,\n LBNL" ] ]
We reexamine the conventional physical description of the neutrino evolution inside the Sun. We point out that the traditional resonance condition has physical meaning only in the limit of small values of the neutrino mixing angle, theta<<1. For large values of theta, the resonance condition specifies neither the point of the maximal violation of adiabaticity in the nonadiabatic case, nor the point where the flavor conversion occurs at the maximal rate in the adiabatic case. The corresponding correct conditions, valid for all values of theta including theta>pi/4, are presented. An adiabaticity condition valid for all values of theta is also described. The results of accurate numerical computations of the level jumping probability in the Sun are presented. These calculations cover a wide range of Delta m^2, from the vacuum oscillation region to the region where the standard exponential approximation is good. A convenient empirical parametrization of these results in terms of elementary functions is given. The matter effects in the so-called "quasi-vacuum oscillation regime" are discussed. Finally, it is shown how the known analytical results for the exponential, 1/x, and linear matter distributions can be simply obtained from the formula for the hyperbolic tangent profile. An explicit formula for the jumping probability for the distribution N_e ~ (coth(x/l) +- 1) is obtained.
1110.2375
Massimiliano Grazzini
Stefano Catani, Leandro Cieri, Daniel de Florian, Giancarlo Ferrera and Massimiliano Grazzini
Diphoton production at hadron colliders: a fully-differential QCD calculation at NNLO
Numerical error at NNLO corrected and corresponding results updated. Reference added to numerical code 2gNNLO
null
10.1103/PhysRevLett.108.072001
ZU-TH 18/11, IFUM-984-FT
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider direct diphoton production in hadron collisions, and we compute the next-to-next-to-leading order (NNLO) QCD radiative corrections at the fully-differential level. Our calculation uses the $q_T$ subtraction formalism and it is implemented in a parton level Monte Carlo program. The program allows the user to apply arbitrary kinematical cuts on the final-state photons and the associated jet activity, and to compute the corresponding distributions in the form of bin histograms. We present selected numerical results related to Higgs boson searches at the LHC and corresponding results at the Tevatron.
[ { "created": "Tue, 11 Oct 2011 13:48:49 GMT", "version": "v1" }, { "created": "Fri, 24 Jun 2016 07:38:53 GMT", "version": "v2" } ]
2016-06-27
[ [ "Catani", "Stefano", "" ], [ "Cieri", "Leandro", "" ], [ "de Florian", "Daniel", "" ], [ "Ferrera", "Giancarlo", "" ], [ "Grazzini", "Massimiliano", "" ] ]
We consider direct diphoton production in hadron collisions, and we compute the next-to-next-to-leading order (NNLO) QCD radiative corrections at the fully-differential level. Our calculation uses the $q_T$ subtraction formalism and it is implemented in a parton level Monte Carlo program. The program allows the user to apply arbitrary kinematical cuts on the final-state photons and the associated jet activity, and to compute the corresponding distributions in the form of bin histograms. We present selected numerical results related to Higgs boson searches at the LHC and corresponding results at the Tevatron.
1401.3284
Ernest Ma
Ernest Ma (UC Riverside)
Vanishing Higgs Quadratic Divergence in the Scotogenic Model and Beyond
6 pages, 2 figures
null
10.1016/j.physletb.2014.03.047
UCRHEP-T539 (January 2014)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the inherent quadratic divergence of the Higgs mass renormalization of the standard model may be avoided in the well-studied scotogenic model of radiative neutrino mass as well as other analogous extensions.
[ { "created": "Tue, 14 Jan 2014 18:55:15 GMT", "version": "v1" } ]
2015-06-18
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
It is shown that the inherent quadratic divergence of the Higgs mass renormalization of the standard model may be avoided in the well-studied scotogenic model of radiative neutrino mass as well as other analogous extensions.
2301.00231
Miguel Levy
Dipankar Das, Miguel Levy, Palash B. Pal, Anugrah M. Prasad, Ipsita Saha, Ayushi Srivastava
Democratic three Higgs-doublet models: the custodial limit and wrong-sign Yukawa
22 pages, 3 captioned figures. Version accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.107.055035
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study two novel aspects of democratic 3HDMs -- the custodial limit and the possibility of wrong-sign Yukawa couplings. In the custodial limit, the democratic 3HDMs can easily negotiate the constraints from the electroweak $T$-parameter. We also uncover the possibility of having wrong-sign Yukawa couplings in democratic 3HDMs, as in the case of 2HDMs. We show that a democratic 3HDM encompasses all the wrong-sign possibilities entertained by 2HDMs, and has considerably more leeway in the wrong-sign limit as compared to the 2HDM case. Our study underscores the importance of reporting analysis in the kappa-formalism without any implicit assumptions on the signs of the kappas.
[ { "created": "Sat, 31 Dec 2022 15:51:34 GMT", "version": "v1" }, { "created": "Thu, 2 Mar 2023 14:03:13 GMT", "version": "v2" } ]
2023-04-05
[ [ "Das", "Dipankar", "" ], [ "Levy", "Miguel", "" ], [ "Pal", "Palash B.", "" ], [ "Prasad", "Anugrah M.", "" ], [ "Saha", "Ipsita", "" ], [ "Srivastava", "Ayushi", "" ] ]
We study two novel aspects of democratic 3HDMs -- the custodial limit and the possibility of wrong-sign Yukawa couplings. In the custodial limit, the democratic 3HDMs can easily negotiate the constraints from the electroweak $T$-parameter. We also uncover the possibility of having wrong-sign Yukawa couplings in democratic 3HDMs, as in the case of 2HDMs. We show that a democratic 3HDM encompasses all the wrong-sign possibilities entertained by 2HDMs, and has considerably more leeway in the wrong-sign limit as compared to the 2HDM case. Our study underscores the importance of reporting analysis in the kappa-formalism without any implicit assumptions on the signs of the kappas.
hep-ph/0012195
Michael Melles
Michael Melles
The Standard Model Higgs in $\gamma \gamma$ Collisions
contribution to LCWS2000 at Fermilab
null
10.1063/1.1394330
null
hep-ph
null
For a Higgs boson below the $W^\pm$ threshold, the $\gamma \gamma$ collider option of a future linear $e^+ e^-$ machine is compelling. In this case one can measure the ``gold-plated'' loop induced $\Gamma (H \longrightarrow \gamma \gamma)$ partial width to high precision, testing various extensions of the Standard Model. With recent progress in the expected $\gamma \gamma$ luminosity at TESLA, we find that for a Higgs of 115 GeV a statistical accuracy of the two photon partial width of 1.4 % is possible. The total width depends thus solely on the accuracy of $BR(H \longrightarrow \gamma \gamma)$ and is of ${\cal O} (10 %)$.
[ { "created": "Fri, 15 Dec 2000 16:37:19 GMT", "version": "v1" } ]
2009-10-31
[ [ "Melles", "Michael", "" ] ]
For a Higgs boson below the $W^\pm$ threshold, the $\gamma \gamma$ collider option of a future linear $e^+ e^-$ machine is compelling. In this case one can measure the ``gold-plated'' loop induced $\Gamma (H \longrightarrow \gamma \gamma)$ partial width to high precision, testing various extensions of the Standard Model. With recent progress in the expected $\gamma \gamma$ luminosity at TESLA, we find that for a Higgs of 115 GeV a statistical accuracy of the two photon partial width of 1.4 % is possible. The total width depends thus solely on the accuracy of $BR(H \longrightarrow \gamma \gamma)$ and is of ${\cal O} (10 %)$.
2301.07439
Junichiro Kawamura
Yoshihiko Abe, Tetsutaro Higaki, Junichiro Kawamura and Tatsuo Kobayashi
Quark masses and CKM hierarchies from $S_4^\prime$ modular flavor symmetry
13 pages, 3 tables; ver2 comments on CP violation added
null
null
CTPU-PTC-23-01, EPHOU-23-002
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose models to explain the hierarchies of the quark masses and mixing by utilizing the $S_4^\prime$ modular flavor symmetry. The hierarchy is realized by the modulus $\tau$ stabilized at $\mathrm{Im}\,\tau \gg 1$, where the residual $Z_4^T$ symmetry is approximately unbroken and the Froggatt-Nielsen mechanism works. It is found that the quark hierarchies are realized only in a few cases of quark representations. We study two models with assigning the modular weights, so that the observed quark hierarchies are explained in the cases of both small and large ratios of the top to bottom Yukawa couplings. We also argue that $\mathcal{O}({0.1})$ hierarchies of the $\mathcal{O}({1})$ coefficients can be explained by imposing another $S_3$ modular symmetry.
[ { "created": "Wed, 18 Jan 2023 11:20:29 GMT", "version": "v1" }, { "created": "Thu, 26 Jan 2023 07:37:23 GMT", "version": "v2" } ]
2023-01-27
[ [ "Abe", "Yoshihiko", "" ], [ "Higaki", "Tetsutaro", "" ], [ "Kawamura", "Junichiro", "" ], [ "Kobayashi", "Tatsuo", "" ] ]
We propose models to explain the hierarchies of the quark masses and mixing by utilizing the $S_4^\prime$ modular flavor symmetry. The hierarchy is realized by the modulus $\tau$ stabilized at $\mathrm{Im}\,\tau \gg 1$, where the residual $Z_4^T$ symmetry is approximately unbroken and the Froggatt-Nielsen mechanism works. It is found that the quark hierarchies are realized only in a few cases of quark representations. We study two models with assigning the modular weights, so that the observed quark hierarchies are explained in the cases of both small and large ratios of the top to bottom Yukawa couplings. We also argue that $\mathcal{O}({0.1})$ hierarchies of the $\mathcal{O}({1})$ coefficients can be explained by imposing another $S_3$ modular symmetry.
hep-ph/0107121
Ulrich Nierste
Gabriela Barenboim, Martin Gorbahn, Ulrich Nierste and Martti Raidal
Higgs Sector of the Minimal Left-Right Symmetric Model
brief discussion of non-minimal Higgs sectors added, journal version
Phys.Rev.D65:095003,2002
10.1103/PhysRevD.65.095003
FERMILAB-Pub-01/213-T, TUM-HEP-384-01, CERN-TH/2001-181
hep-ph
null
We perform an exhaustive analysis of the most general Higgs sector of the minimal left-right symmetric model (MLRM). We find that the CP properties of the vacuum state are connected to the Higgs spectrum: if CP is broken spontaneously, the MLRM does not approach the Standard Model in the limit of a decoupling left-right symmetry breaking scale. Depending on the size of the CP phases scenarios with extra non-decoupling flavor-violating doublet Higgses or very light SU(2) triplet Higgses emerge, both of which are ruled out by phenomenology. For zero CP phases the non-standard Higgses decouple only if a very unnatural fine-tuning condition is fulfilled. We also discuss generalizations to a non-minimal Higgs sector.
[ { "created": "Tue, 10 Jul 2001 21:35:49 GMT", "version": "v1" }, { "created": "Wed, 11 Jul 2001 01:37:04 GMT", "version": "v2" }, { "created": "Fri, 1 Mar 2002 23:00:19 GMT", "version": "v3" } ]
2014-11-17
[ [ "Barenboim", "Gabriela", "" ], [ "Gorbahn", "Martin", "" ], [ "Nierste", "Ulrich", "" ], [ "Raidal", "Martti", "" ] ]
We perform an exhaustive analysis of the most general Higgs sector of the minimal left-right symmetric model (MLRM). We find that the CP properties of the vacuum state are connected to the Higgs spectrum: if CP is broken spontaneously, the MLRM does not approach the Standard Model in the limit of a decoupling left-right symmetry breaking scale. Depending on the size of the CP phases scenarios with extra non-decoupling flavor-violating doublet Higgses or very light SU(2) triplet Higgses emerge, both of which are ruled out by phenomenology. For zero CP phases the non-standard Higgses decouple only if a very unnatural fine-tuning condition is fulfilled. We also discuss generalizations to a non-minimal Higgs sector.
hep-ph/0002079
Sreerup Raychaudhuri fc phy
Prasanta Das, Sreerup Raychaudhuri, Saswati Sarkar (IIT, Kanpur)
HERA Constraint on Warped Quantum Gravity
13 pages, LaTeX, 2 ps figures; reference added and minor errors corrected
JHEP 0007 (2000) 050
10.1088/1126-6708/2000/07/050
IITK-HEP-00-01
hep-ph
null
We study recent data on deep inelastic e^+ p scattering at HERA to constrain the parameters of a Randall-Sundrum-type scenario of quantum gravity with a small extra dimension and a non-factorable geometry.
[ { "created": "Mon, 7 Feb 2000 21:35:09 GMT", "version": "v1" }, { "created": "Thu, 10 Feb 2000 16:15:23 GMT", "version": "v2" } ]
2009-10-31
[ [ "Das", "Prasanta", "", "IIT, Kanpur" ], [ "Raychaudhuri", "Sreerup", "", "IIT, Kanpur" ], [ "Sarkar", "Saswati", "", "IIT, Kanpur" ] ]
We study recent data on deep inelastic e^+ p scattering at HERA to constrain the parameters of a Randall-Sundrum-type scenario of quantum gravity with a small extra dimension and a non-factorable geometry.
hep-ph/9807246
Konstantin
Hsin-Chia Cheng, Bogdan A. Dobrescu and Konstantin T. Matchev (Fermilab)
A Chiral Supersymmetric Standard Model
13 pages, 1 figure, LaTeX
Phys.Lett.B439:301-308,1998
10.1016/S0370-2693(98)01052-1
FERMILAB-PUB-98/205-T
hep-ph
null
We propose a supersymmetric extension of the Standard Model with an extra U(1) gauge symmetry, so that all supersymmetric mass terms, including the $\mu$-term, are forbidden by the gauge symmetries. Supersymmetry is broken dynamically which results in U(1) breaking and generation of realistic $\mu$ term and soft breaking masses. The additional fields required to cancel the U(1) anomalies are identified with the messengers of supersymmetry breaking. The gaugino masses arise as in the usual gauge mediated scenario, while squarks and sleptons receive their masses from both the U(1) $D$-term and the two-loop gauge mediation contributions. The scale of supersymmetry breaking in this model can be below $10^6$ GeV, yielding collider signatures with decays to goldstinos inside the detector.
[ { "created": "Fri, 3 Jul 1998 21:05:21 GMT", "version": "v1" } ]
2009-10-09
[ [ "Cheng", "Hsin-Chia", "", "Fermilab" ], [ "Dobrescu", "Bogdan A.", "", "Fermilab" ], [ "Matchev", "Konstantin T.", "", "Fermilab" ] ]
We propose a supersymmetric extension of the Standard Model with an extra U(1) gauge symmetry, so that all supersymmetric mass terms, including the $\mu$-term, are forbidden by the gauge symmetries. Supersymmetry is broken dynamically which results in U(1) breaking and generation of realistic $\mu$ term and soft breaking masses. The additional fields required to cancel the U(1) anomalies are identified with the messengers of supersymmetry breaking. The gaugino masses arise as in the usual gauge mediated scenario, while squarks and sleptons receive their masses from both the U(1) $D$-term and the two-loop gauge mediation contributions. The scale of supersymmetry breaking in this model can be below $10^6$ GeV, yielding collider signatures with decays to goldstinos inside the detector.
0705.4493
Francesco D'Eramo
Francesco D'Eramo (Scuola Normale Superiore)
Dark matter and Higgs boson physics
17 pages, 7 figures. v3: published version (small corrections)
Phys.Rev.D76:083522,2007
10.1103/PhysRevD.76.083522
null
hep-ph
null
A vector-like colorless fermion doublet and a singlet added to the Standard Model allow a consistent interpretation of dark matter in terms of the lightest neutral particle, as they may help in obtaining successful gauge coupling unification. We analyze in detail the mass range of the lightest neutral particle below the W mass, i.e. in a range of the parameters where the physics of the Standard Model Higgs boson may be substantially affected either directly or indirectly.
[ { "created": "Thu, 31 May 2007 01:21:29 GMT", "version": "v1" }, { "created": "Tue, 17 Jul 2007 13:07:55 GMT", "version": "v2" }, { "created": "Thu, 25 Oct 2007 21:42:17 GMT", "version": "v3" } ]
2008-11-26
[ [ "D'Eramo", "Francesco", "", "Scuola Normale Superiore" ] ]
A vector-like colorless fermion doublet and a singlet added to the Standard Model allow a consistent interpretation of dark matter in terms of the lightest neutral particle, as they may help in obtaining successful gauge coupling unification. We analyze in detail the mass range of the lightest neutral particle below the W mass, i.e. in a range of the parameters where the physics of the Standard Model Higgs boson may be substantially affected either directly or indirectly.
1105.3786
Milton Slaughter
Milton Dean Slaughter
$\Omega^-$, $\Xi^{*-}$, $\Sigma^{*-}}$ and $\Delta^-}$ decuplet baryon electric charge form factor $F_1(q^2)$
corrected typos in Eqs. (2) and (10)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The magnetic moment---a function of the electric charge form factor $F_{1}(q^{2})$ and the magnetic dipole form factor $F_{2}(q^{2})$ at zero four-momentum transfer $q^{2}$---of the ground-state $U$-spin =3/2 baryon decuplet $\Delta^{-}$, $\Xi^{*\,-}$, $\Sigma^{*\,-}$ and $\Omega^{-}$ and their ground-state spin 1/2 cousins $p$, $n$, $\Lambda$, $\Sigma^{+}$, $\Sigma^{0}$, $\Sigma^{-}$, $\Xi^{+}$, and $\Xi^{-}$ have been studied for many years with a modicum of success---only the magnetic moment of the $\Omega^{-}$ has been accurately determined. In a recent study by us utilizing the infinite momentum frame, we calculated the magnetic moments of the \emph{physical} decuplet $U$-Spin =3/2 quartet members in terms of that of the $\Omega^{-}$ without ascribing any specific form to their quark structure or intra-quark interactions. That study determined $F_{2}(q^{2})$ and was conducted nonperturbatively where the decuplet baryon momenta were all collinear. In this follow-up research---again utilizing the infinite momentum frame but now allowing for non-collinear momenta---we are able to determine $F_{1}(q^{2})$ where $q^{2}\leq 0$. We relate the electric charge form factor $F_{1}(q^{2})$ of the \emph{physical} decuplet $S\neq -3$, $U$-spin =3/2 quartet members to that of the $\Omega^{-}$ ($S=-3$).
[ { "created": "Thu, 19 May 2011 03:35:47 GMT", "version": "v1" }, { "created": "Fri, 19 Aug 2011 21:17:38 GMT", "version": "v2" } ]
2011-08-23
[ [ "Slaughter", "Milton Dean", "" ] ]
The magnetic moment---a function of the electric charge form factor $F_{1}(q^{2})$ and the magnetic dipole form factor $F_{2}(q^{2})$ at zero four-momentum transfer $q^{2}$---of the ground-state $U$-spin =3/2 baryon decuplet $\Delta^{-}$, $\Xi^{*\,-}$, $\Sigma^{*\,-}$ and $\Omega^{-}$ and their ground-state spin 1/2 cousins $p$, $n$, $\Lambda$, $\Sigma^{+}$, $\Sigma^{0}$, $\Sigma^{-}$, $\Xi^{+}$, and $\Xi^{-}$ have been studied for many years with a modicum of success---only the magnetic moment of the $\Omega^{-}$ has been accurately determined. In a recent study by us utilizing the infinite momentum frame, we calculated the magnetic moments of the \emph{physical} decuplet $U$-Spin =3/2 quartet members in terms of that of the $\Omega^{-}$ without ascribing any specific form to their quark structure or intra-quark interactions. That study determined $F_{2}(q^{2})$ and was conducted nonperturbatively where the decuplet baryon momenta were all collinear. In this follow-up research---again utilizing the infinite momentum frame but now allowing for non-collinear momenta---we are able to determine $F_{1}(q^{2})$ where $q^{2}\leq 0$. We relate the electric charge form factor $F_{1}(q^{2})$ of the \emph{physical} decuplet $S\neq -3$, $U$-spin =3/2 quartet members to that of the $\Omega^{-}$ ($S=-3$).
1910.10160
Gowri Kurup
Sungwoo Hong, Gowri Kurup and Maxim Perelstein
Conformal Freeze-In of Dark Matter
6 + 2 pages, 3 figures. Minor changes; version to be published in PRD
null
10.1103/PhysRevD.101.095037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the conformal freeze-in (COFI) scenario for dark matter production. At high energies, the dark sector is described by a gauge theory flowing towards a Banks-Zaks fixed point, coupled to the standard model via a non-renormalizable portal interaction. At the time when the dark sector is populated in the early universe, it is described by a strongly coupled conformal field theory. As the universe cools, cosmological phase transitions in the standard model sector, either electroweak or QCD, induce conformal symmetry breaking and confinement in the dark sector. One of the resulting dark bound states is stable on the cosmological time scales and plays the role of dark matter. With the Higgs portal, the COFI scenario provides a viable dark matter candidate with mass in a phenomenologically interesting 0.1-1 MeV range. With the quark portal, a dark matter candidate with mass around 1 keV is consistent with observations. Conformal bootstrap puts a non-trivial constraint on model building in this case.
[ { "created": "Tue, 22 Oct 2019 18:00:02 GMT", "version": "v1" }, { "created": "Mon, 27 Apr 2020 03:02:29 GMT", "version": "v2" } ]
2020-06-24
[ [ "Hong", "Sungwoo", "" ], [ "Kurup", "Gowri", "" ], [ "Perelstein", "Maxim", "" ] ]
We present the conformal freeze-in (COFI) scenario for dark matter production. At high energies, the dark sector is described by a gauge theory flowing towards a Banks-Zaks fixed point, coupled to the standard model via a non-renormalizable portal interaction. At the time when the dark sector is populated in the early universe, it is described by a strongly coupled conformal field theory. As the universe cools, cosmological phase transitions in the standard model sector, either electroweak or QCD, induce conformal symmetry breaking and confinement in the dark sector. One of the resulting dark bound states is stable on the cosmological time scales and plays the role of dark matter. With the Higgs portal, the COFI scenario provides a viable dark matter candidate with mass in a phenomenologically interesting 0.1-1 MeV range. With the quark portal, a dark matter candidate with mass around 1 keV is consistent with observations. Conformal bootstrap puts a non-trivial constraint on model building in this case.
1009.5137
Bill Dalton
Bill Dalton
Absence of Right-Handed Neutrino in Weak Interactions: Explanation via Nonlinear Electroweak Model
null
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nonlinear SU(2) electroweak model is used to explain the absence of the right-handed neutrino in weak interactions. Two covariant eigenvalue constraints which affect the transformation lead to two classes of right-handed leptons, and make possible invariant mass terms without the Higgs doublet. A covariant picture of neutrinos with mass is presented. A new invariant form for the boson potentials is described in which the boson mass terms arises via the adjoint field. This model also indicates a different region of matter involving coupled leptons that are "blind" to the massless electromagnetic field but "see" four massive potentials that are themselves blind to the electromagnetic field. We argue that these more difficult to detect "dark" fields provide a possible contribution to the missing mass.
[ { "created": "Mon, 21 Jun 2010 21:04:07 GMT", "version": "v1" } ]
2010-09-28
[ [ "Dalton", "Bill", "" ] ]
The nonlinear SU(2) electroweak model is used to explain the absence of the right-handed neutrino in weak interactions. Two covariant eigenvalue constraints which affect the transformation lead to two classes of right-handed leptons, and make possible invariant mass terms without the Higgs doublet. A covariant picture of neutrinos with mass is presented. A new invariant form for the boson potentials is described in which the boson mass terms arises via the adjoint field. This model also indicates a different region of matter involving coupled leptons that are "blind" to the massless electromagnetic field but "see" four massive potentials that are themselves blind to the electromagnetic field. We argue that these more difficult to detect "dark" fields provide a possible contribution to the missing mass.
0906.1904
Maxim Konyushikhin
Maxim Konyushikhin
Four-point vector correlators and AdS/QCD correspondence
7 pages, 1 figure
JETP Lett.91:441-446,2010
10.1134/S002136401009002X
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the four-point vector correlators in QCD from AdS/QCD correspondence. It is shown that meson poles are correctly reproduced. The final expression also suggests a nonzero amplitude in the limit of zero virtuality of two longitudinal gluons. This fact does not mean that one can produce, absorb or scatter real longitudinal gluons.
[ { "created": "Wed, 10 Jun 2009 10:40:13 GMT", "version": "v1" }, { "created": "Sun, 28 Jun 2009 12:14:50 GMT", "version": "v2" }, { "created": "Mon, 26 Apr 2010 12:50:29 GMT", "version": "v3" } ]
2014-11-20
[ [ "Konyushikhin", "Maxim", "" ] ]
We derive the four-point vector correlators in QCD from AdS/QCD correspondence. It is shown that meson poles are correctly reproduced. The final expression also suggests a nonzero amplitude in the limit of zero virtuality of two longitudinal gluons. This fact does not mean that one can produce, absorb or scatter real longitudinal gluons.
1202.1368
Renata Jora
Renata Jora
Do we need Feynman diagrams for higher orders perturbation theory?
version published in Phys. Lett. B
null
10.1016/j.physletb.2012.05.047
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the two and three loop corrections to the beta function for Yang-Mills theories in the background gauge field method and using the background gauge field as the only source. The calculations are based on the separation of the one loop effective potential into zero and positive modes and are entirely analytical. No two or three loop Feynman diagrams are considered in the process.
[ { "created": "Tue, 7 Feb 2012 08:14:02 GMT", "version": "v1" }, { "created": "Wed, 23 May 2012 14:08:46 GMT", "version": "v2" }, { "created": "Thu, 24 May 2012 04:33:17 GMT", "version": "v3" }, { "created": "Tue, 5 Jun 2012 05:43:06 GMT", "version": "v4" } ]
2015-06-04
[ [ "Jora", "Renata", "" ] ]
We compute the two and three loop corrections to the beta function for Yang-Mills theories in the background gauge field method and using the background gauge field as the only source. The calculations are based on the separation of the one loop effective potential into zero and positive modes and are entirely analytical. No two or three loop Feynman diagrams are considered in the process.
0708.3804
Xiao-Ming Xu
Xiao-Ming Xu, Ru Peng
Free Quarks and Antiquarks versus Hadronic Matter
9 pages, 3 figures
Chin. Phys. C33 (2009) 748
10.1088/1674-1137/33/9/007
null
hep-ph nucl-th
null
Meson-meson reactions A(q_1 \bar{q}_1) + B(q_2 \bar{q}_2) to q_1 + \bar{q}_1 + q_2 + \bar{q}_2 in high-temperature hadronic matter are found to produce an appreciable amount of quarks and antiquarks freely moving in hadronic matter and to establish a new mechanism for deconfinement of quarks and antiquarks in hadronic matter.
[ { "created": "Tue, 28 Aug 2007 14:04:09 GMT", "version": "v1" } ]
2015-05-13
[ [ "Xu", "Xiao-Ming", "" ], [ "Peng", "Ru", "" ] ]
Meson-meson reactions A(q_1 \bar{q}_1) + B(q_2 \bar{q}_2) to q_1 + \bar{q}_1 + q_2 + \bar{q}_2 in high-temperature hadronic matter are found to produce an appreciable amount of quarks and antiquarks freely moving in hadronic matter and to establish a new mechanism for deconfinement of quarks and antiquarks in hadronic matter.
hep-ph/0207285
Fazal-e-Aleem
Fazal-e-Aleem and Sohail Afzal Tahir
Recent Results For Rho And Odderon Picture
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This has critical errors
[ { "created": "Tue, 23 Jul 2002 17:12:11 GMT", "version": "v1" }, { "created": "Mon, 4 Jan 2010 06:27:53 GMT", "version": "v2" } ]
2010-01-04
[ [ "Fazal-e-Aleem", "", "" ], [ "Tahir", "Sohail Afzal", "" ] ]
This has critical errors
2304.13999
Muzi Hong
Muzi Hong, Kohei Kamada, Jun'ichi Yokoyama
Baryogenesis from sphaleron decoupling
16 pages, 5 figures
Phys.Rev.D 108 (2023) 6, 063502
10.1103/PhysRevD.108.063502
RESCEU-9/23
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The electroweak sphaleron process breaks the baryon number conservation within the realms of the Standard Model of particle physics (SM). Recently, it is pointed out that its decoupling may provide the out-of-equilibrium condition required for baryogenesis. In this paper, we study such a scenario taking into account the baryon-number wash-out effect of the sphaleron itself to improve the estimate. We clarify the amount of CP violation required for this scenario to explain the observed asymmetry.
[ { "created": "Thu, 27 Apr 2023 07:37:41 GMT", "version": "v1" } ]
2024-06-18
[ [ "Hong", "Muzi", "" ], [ "Kamada", "Kohei", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
The electroweak sphaleron process breaks the baryon number conservation within the realms of the Standard Model of particle physics (SM). Recently, it is pointed out that its decoupling may provide the out-of-equilibrium condition required for baryogenesis. In this paper, we study such a scenario taking into account the baryon-number wash-out effect of the sphaleron itself to improve the estimate. We clarify the amount of CP violation required for this scenario to explain the observed asymmetry.
1207.1128
Encieh Erfani
Athanasios Chatzistavrakidis, Encieh Erfani, Hans Peter Nilles, Ivonne Zavala
Axiology
21 pages, 1 figure, one ref. added, version published in JCAP
JCAP09(2012)006
10.1088/1475-7516/2012/09/006
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axions might play a crucial role for the solution of the strong CP-problem and explanation of cold dark matter in the universe. In addition they may find applications in the formulation of inflationary models for the early universe and can serve as candidates for quintessence. We show that all these phenomena can be described within a single framework exhibiting a specific pattern of mass scales: the axionic see-saw. We also discuss the role of supersymmetry (susy) in this axionic system in two specific examples: weak scale susy in the (multi) TeV range and tele-susy with a breakdown scale coinciding with the decay constant of the QCD axion: $f_a\sim 10^{11}-10^{12}$ GeV.
[ { "created": "Wed, 4 Jul 2012 21:23:36 GMT", "version": "v1" }, { "created": "Wed, 5 Sep 2012 19:26:18 GMT", "version": "v2" } ]
2012-09-06
[ [ "Chatzistavrakidis", "Athanasios", "" ], [ "Erfani", "Encieh", "" ], [ "Nilles", "Hans Peter", "" ], [ "Zavala", "Ivonne", "" ] ]
Axions might play a crucial role for the solution of the strong CP-problem and explanation of cold dark matter in the universe. In addition they may find applications in the formulation of inflationary models for the early universe and can serve as candidates for quintessence. We show that all these phenomena can be described within a single framework exhibiting a specific pattern of mass scales: the axionic see-saw. We also discuss the role of supersymmetry (susy) in this axionic system in two specific examples: weak scale susy in the (multi) TeV range and tele-susy with a breakdown scale coinciding with the decay constant of the QCD axion: $f_a\sim 10^{11}-10^{12}$ GeV.
1711.06087
Rados{\l}aw Kycia
R. A. Kycia, J. Turnau, J. J. Chwastowski, R. Staszewski, M. Trzebi\'nski
The adaptive Monte Carlo toolbox for phase space integration and generation
18 pages, 4 figures, 5 tables
Commun. Comput. Phys., 25 (2019), pp. 1547-1563
10.4208/cicp.OA-2018-0028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An implementation of the Monte Carlo (MC) phase space generators coupled with adaptive MC integration/simulation program FOAM is presented. The first program is a modification of the classic phase space generator GENBOD interfaced with the adaptive sampling integrator/generator FOAM. On top of this tool the algorithm suitable for generation of the phase space for an reaction with two leading particles is presented (double-peripheral process with central production of particles). At the same time it serves as an instructive example of construction of a self-adaptive phase space generator/integrator with a modular structure for specialized particle physics calculations.
[ { "created": "Thu, 16 Nov 2017 13:53:51 GMT", "version": "v1" } ]
2019-04-02
[ [ "Kycia", "R. A.", "" ], [ "Turnau", "J.", "" ], [ "Chwastowski", "J. J.", "" ], [ "Staszewski", "R.", "" ], [ "Trzebiński", "M.", "" ] ]
An implementation of the Monte Carlo (MC) phase space generators coupled with adaptive MC integration/simulation program FOAM is presented. The first program is a modification of the classic phase space generator GENBOD interfaced with the adaptive sampling integrator/generator FOAM. On top of this tool the algorithm suitable for generation of the phase space for an reaction with two leading particles is presented (double-peripheral process with central production of particles). At the same time it serves as an instructive example of construction of a self-adaptive phase space generator/integrator with a modular structure for specialized particle physics calculations.
hep-ph/0212266
Enrico Nardi
Enrico Nardi
On the neutrino vector and axial vector charge radius
8 pages, 3 eps figures. Talk given in the X Mexican School of Particles and Fields, Playa del Carmen, Mexico, October 30 - November 6, 2002. Based in part on hep-ph/0210137 written in collaboration with M. Hirsch and D. A. Restrepo
AIP Conf.Proc. 670 (2003) 118-131
10.1063/1.1594325
null
hep-ph
null
A Majorana neutrino is characterized by just one flavor diagonal electromagnetic form factor: the anapole moment, that in the static limit corresponds to the axial vector charge radius <r^2_A>. As is the case for the vector charge radius of a Dirac neutrino, proving that this is a well defined physical quantity is non trivial. I will first describe briefly the origin of the long standing controversy about the physical or non physical nature of the neutrino charge radius. Then I will argue that, in contrast to Dirac neutrino electromagnetic form factors, for Majorana neutrinos cosmological and astrophysical arguments do not provide useful informations on <r^2_A>, and therefore this quantity has to be studied by means of terrestrial experiment. Finally, I will discuss the constraints that can be derived on <r^2_A> for the tau neutrino from a comprehensive analysis of the data on single photon production off Z-resonance, and I will conclude with a few comments on $\nu_\mu$ scattering data from the NuTeV, E734, CCFR and CHARM-II collaborations and on the limits implied for <r^2_A> for the muon neutrino.
[ { "created": "Wed, 18 Dec 2002 17:46:26 GMT", "version": "v1" } ]
2009-11-07
[ [ "Nardi", "Enrico", "" ] ]
A Majorana neutrino is characterized by just one flavor diagonal electromagnetic form factor: the anapole moment, that in the static limit corresponds to the axial vector charge radius <r^2_A>. As is the case for the vector charge radius of a Dirac neutrino, proving that this is a well defined physical quantity is non trivial. I will first describe briefly the origin of the long standing controversy about the physical or non physical nature of the neutrino charge radius. Then I will argue that, in contrast to Dirac neutrino electromagnetic form factors, for Majorana neutrinos cosmological and astrophysical arguments do not provide useful informations on <r^2_A>, and therefore this quantity has to be studied by means of terrestrial experiment. Finally, I will discuss the constraints that can be derived on <r^2_A> for the tau neutrino from a comprehensive analysis of the data on single photon production off Z-resonance, and I will conclude with a few comments on $\nu_\mu$ scattering data from the NuTeV, E734, CCFR and CHARM-II collaborations and on the limits implied for <r^2_A> for the muon neutrino.
hep-ph/0601054
Cecilia Lunardini
Cecilia Lunardini
The diffuse neutrino flux from supernovae: upper limit on the electron neutrino component from the non-observation of antineutrinos at SuperKamiokande
LaTeX, 5 pages, 1 figure. Paper is modified in the presentation (Fig. 1 was replaced with a different plot and Table 1 was expanded), with unchanged results. References added and corrected
Phys.Rev. D73 (2006) 083009
10.1103/PhysRevD.73.083009
null
hep-ph astro-ph hep-ex
null
I derive an upper bound on the electron neutrino component of the diffuse supernova neutrino flux from the constraint on the antineutrino component at SuperKamiokande. The connection between antineutrino and neutrino channels is due to the similarity of the muon and tau neutrino and antineutrino fluxes produced in a supernova, and to the conversion of these species into electron neutrinos and antineutrinos inside the star. The limit on the electron neutrino flux is 5.5 cm^-2 s^-1 above 19.3 MeV of neutrino energy, and is stronger than the direct limit from Mont Blanc by three orders of magnitude. It represents the minimal sensitivity required at future direct searches, and is intriguingly close to the reach of the Sudbury Neutrino Observatory (SNO) and of the ICARUS experiment. The electron neutrino flux will have a lower bound if the electron antineutrino flux is measured. Indicatively, the first can be smaller than the second at most by a factor of 2-3 depending on the details of the neutrino spectra at production.
[ { "created": "Sun, 8 Jan 2006 19:02:13 GMT", "version": "v1" }, { "created": "Tue, 25 Apr 2006 18:37:39 GMT", "version": "v2" } ]
2009-11-11
[ [ "Lunardini", "Cecilia", "" ] ]
I derive an upper bound on the electron neutrino component of the diffuse supernova neutrino flux from the constraint on the antineutrino component at SuperKamiokande. The connection between antineutrino and neutrino channels is due to the similarity of the muon and tau neutrino and antineutrino fluxes produced in a supernova, and to the conversion of these species into electron neutrinos and antineutrinos inside the star. The limit on the electron neutrino flux is 5.5 cm^-2 s^-1 above 19.3 MeV of neutrino energy, and is stronger than the direct limit from Mont Blanc by three orders of magnitude. It represents the minimal sensitivity required at future direct searches, and is intriguingly close to the reach of the Sudbury Neutrino Observatory (SNO) and of the ICARUS experiment. The electron neutrino flux will have a lower bound if the electron antineutrino flux is measured. Indicatively, the first can be smaller than the second at most by a factor of 2-3 depending on the details of the neutrino spectra at production.
1512.01560
Fabrizio Senia
Riccardo Barbieri, Gino Isidori, Andrea Pattori, Fabrizio Senia
Anomalies in $B$-decays and $U(2)$ flavour symmetry
16 pages, 4 figures
null
10.1140/epjc/s10052-016-3905-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The collection of a few anomalies in semileptonic $B$-decays invites to speculate about the emergence of some strikingly new phenomena. Here we offer a possible interpretation of these anomalies in the context of a weakly broken $U(2)^5$ flavour symmetry and lepto-quark mediators.
[ { "created": "Fri, 4 Dec 2015 21:02:23 GMT", "version": "v1" } ]
2016-03-23
[ [ "Barbieri", "Riccardo", "" ], [ "Isidori", "Gino", "" ], [ "Pattori", "Andrea", "" ], [ "Senia", "Fabrizio", "" ] ]
The collection of a few anomalies in semileptonic $B$-decays invites to speculate about the emergence of some strikingly new phenomena. Here we offer a possible interpretation of these anomalies in the context of a weakly broken $U(2)^5$ flavour symmetry and lepto-quark mediators.
1912.05900
Mario W. Barela
Mario W. Barela and V. Pleitez
Trimuon production at the LHC
4 pages, 4 figures. Version matches with the published version
Phys. Rev. D 101, 015024 (2020)
10.1103/PhysRevD.101.015024
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
No process without a standard model (SM) background has been observed so far. As a tool in the study of a class of models containing doubly charged vector bileptons, we propose one such process that, violating lepton flavor number conservation, has no contribution from the SM: $pp\to \mu^+\mu^+\mu^- e^-$. By carefully isolating the parameters to keep them free, we are able to acquire a notion of how a possible PMNS-like matrix present in the relevant charged current parametrization could affect the observables. We find that an interesting section of the space of parameters can be explored at the current LHC in the specified conditions.
[ { "created": "Thu, 12 Dec 2019 12:48:17 GMT", "version": "v1" }, { "created": "Mon, 27 Jan 2020 02:04:48 GMT", "version": "v2" }, { "created": "Wed, 29 Jan 2020 02:24:09 GMT", "version": "v3" } ]
2020-02-05
[ [ "Barela", "Mario W.", "" ], [ "Pleitez", "V.", "" ] ]
No process without a standard model (SM) background has been observed so far. As a tool in the study of a class of models containing doubly charged vector bileptons, we propose one such process that, violating lepton flavor number conservation, has no contribution from the SM: $pp\to \mu^+\mu^+\mu^- e^-$. By carefully isolating the parameters to keep them free, we are able to acquire a notion of how a possible PMNS-like matrix present in the relevant charged current parametrization could affect the observables. We find that an interesting section of the space of parameters can be explored at the current LHC in the specified conditions.