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We study the modification of Newton's second law, upto first order in the deformation parameter $a$, in the $\kappa$-space-time. We derive the deformed Hamiltonian, expressed in terms of the commutative phase space variables, describing the…

High Energy Physics - Theory · Physics 2010-12-09 E. Harikumar , A. K. Kapoor

Constraints on possible Lorentz symmetry violation (LV) of order E/M_Planck for electrons and photons in the framework of effective field theory (EFT) are discussed. Using (i) the report of polarized MeV emission from GRB021206 and (ii) the…

Astrophysics · Physics 2009-11-10 T. Jacobson , S. Liberati , D. Mattingly , F. W. Stecker

Lorentz invariance is a fundamental symmetry of spacetime and serves as the cornerstone of modern physics, supporting the constancy of the speed of light. A crucial implication of this principle is that no particle can propagate faster than…

High Energy Physics - Phenomenology · Physics 2025-06-26 Yu-Ming Yang , Xing-Jian Lv , Xiao-Jun Bi , Peng-Fei Yin

In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body tau decays. These parameters can be used to search for anomalous longitudinal-versus transverse…

High Energy Physics - Phenomenology · Physics 2009-10-30 Charles A. Nelson

Unambiguous isospin violation in the strong interaction sector is a key issue in low energy hadronic physics, both experimentally and theoretically. Bernstein has employed the Fermi-Watson theorem to demonstrate that pion photoproduction is…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Ananthanarayan

We study the dimensional reduction for a $(3+1)$-dimensional Lorentz Violating Lagrangian in the matter and gauge sectors in a Supersymmetric scenario. We thus obtain an effective model for photons induced by the effects of supersymmetry in…

High Energy Physics - Theory · Physics 2020-04-22 L. D. Bernal , Patricio Gaete , Y. P. M. Gomes , José A. Helayël-Neto

We construct models for first- and second-order Fermi acceleration of particles, incorporating generic frame transformations, dispersion relations, and conservation laws. Within this framework, we study deformations of Lorentz symmetry via…

General Relativity and Quantum Cosmology · Physics 2026-01-09 Erick Aguiar , A. A. Araújo Filho , Valdir B. Bezerra , Gilson A. Ferreira , Iarley P. Lobo

We give a progress report of our lattice calculation of direct and indirect CP violation in kaon decays, parametrized as $\epsilon'/\epsilon$ and $B_K$, which require non-perturbative calculation of the matrix elements of the Standard Model…

High Energy Physics - Lattice · Physics 2009-11-10 Junichi Noaki , RBC Collaboration

An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising…

High Energy Physics - Phenomenology · Physics 2009-09-25 Alan Kostelecky , Matthew Mewes

We construct the complete effective chiral pion-nucleon Lagrangian in the presence of virtual photons to one loop. As an application, we consider strong and electromagnetic isospin violation for scattering of neutral pions off nucleons. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ulf-G. Meißner , S. Steininger

The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions appear at O(p^4) in the small-momentum expansion, and the…

High Energy Physics - Phenomenology · Physics 2009-12-30 Randy Lewis , Nader Mobed

Nuclear parity violation is studied with polarized neutrons in the photodisintegration of the deuteron at low energies. A pionless effective field theory with di-baryon fields is used for the investigation. Hadronic weak interactions are…

Nuclear Theory · Physics 2015-05-30 J. W. Shin , S. -I. Ando , C. H. Hyun , S. W. Hong

A Regge model with absorptive corrections is employed in a global analysis of the world data on the reactions gamma p -> pi0 p and gamma n -> pi0 n for photon energies from 3 to 18 GeV. In this region resonance contributions are expected to…

High Energy Physics - Phenomenology · Physics 2009-07-22 A. Sibirtsev , J. Haidenbauer , S. Krewald , U. -G. Meißner , A. W. Thomas

We consider different renormalizable models of Lorentz invariance violation. We show that the limits on birefringence of the propagation of cosmic microwave background photons from the five year data of the Wilkinson microwave anisotropy…

Astrophysics · Physics 2009-01-08 Tina Kahniashvili , Ruth Durrer , Yurii Maravin

Lepton flavor violation (LFV) has been observed in neutrino oscillations. For charged lepton FV decays only upper limits are known, but sizable branching ratios are expected in many neutrino mass models. High scale models, such as the…

High Energy Physics - Phenomenology · Physics 2013-05-30 M. Hirsch , F. Staub , A. Vicente

We show that direct CP violation in semi-leptonic and leptonic decays can occur in multi-Higgs doublet extensions of the electroweak standard model with flavor changing neutral currents. For pion and lepton decays these $CP$ violating…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. Pleitez

In the minimal left-right symmetric model with spontaneous CP violation, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors. In addition, the left-and right-handed Majorana…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mu-Chun Chen , K. T. Mahanthappa

Lorentz violation (LV) is predicted by some quantum gravity (QG) candidates, wherein the canonical energy-momentum dispersion relation, $E^2=p^2+m^2$, is modified. Consequently, new phenomenons beyond the standard model are predicted.…

High Energy Physics - Phenomenology · Physics 2010-12-07 Lijing Shao , Bo-Qiang Ma

We consider an alternative explanation of newly found growth of neutral pion transition form factor with virtuality of one of photon. It is based on Sudakov suppression of quark-photon vertex. Some applications to scattering and…

High Energy Physics - Phenomenology · Physics 2011-03-31 E. A. Kuraev , A. N. Ilyichev , V. V. Bytev , Yu. M. Bystritskiy

We investigate the relativistic dynamics of a spin half particle in the presence of a Lorentz-violating background within the framework of effective field theory. A modified Dirac Hamiltonian is considered, arising from a CPT odd coupling…

High Energy Physics - Phenomenology · Physics 2026-04-10 E. Maciel , M. A. Anacleto , K. E. L. Farias , E. Passos