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Title: Defect structures in Lorentz and CPT violating scenarios

Abstract

We investigate models described by real scalar fields, searching for defect structures in the presence of interactions which explicitly violate Lorentz and CPT symmetries. We first deal with a single field, and we investigate a class of models which supports traveling waves that violate Lorentz invariance. This scenario is then generalized to the case of two (or more) real scalar fields. In the case of two fields, in particular, we introduce another class of models, which supports topological structures that attain a Bogomol'nyi bound, although violating both Lorentz and CPT symmetries. An example is considered, for which we construct the Bogomol'nyi bound and find some explicit solutions. We show that violation of both Lorentz and CPT symmetries induces the appearance of an asymmetry between defects and antidefects, including the presence of linearly stable solutions with negative energy density in their outer side.

Authors:
;  [1];  [1];  [2]
  1. Departamento de Fisica, Universidade Federal da Paraiba, 58051-970 Joao Pessoa, Paraiba (Brazil)
  2. (Portugal)
Publication Date:
OSTI Identifier:
20782686
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevD.73.065015; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; CPT THEOREM; DEFECTS; ENERGY DENSITY; LORENTZ INVARIANCE; MATHEMATICAL SOLUTIONS; SCALAR FIELDS; SYMMETRY; SYMMETRY BREAKING; TOPOLOGY; TRAVELLING WAVES

Citation Formats

Barreto, M.N., Bazeia, D., Menezes, R., and Centro de Fisica e Departamento de Fisica, Universidade do Porto, Porto. Defect structures in Lorentz and CPT violating scenarios. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.065015.
Barreto, M.N., Bazeia, D., Menezes, R., & Centro de Fisica e Departamento de Fisica, Universidade do Porto, Porto. Defect structures in Lorentz and CPT violating scenarios. United States. doi:10.1103/PHYSREVD.73.065015.
Barreto, M.N., Bazeia, D., Menezes, R., and Centro de Fisica e Departamento de Fisica, Universidade do Porto, Porto. Wed . "Defect structures in Lorentz and CPT violating scenarios". United States. doi:10.1103/PHYSREVD.73.065015.
@article{osti_20782686,
title = {Defect structures in Lorentz and CPT violating scenarios},
author = {Barreto, M.N. and Bazeia, D. and Menezes, R. and Centro de Fisica e Departamento de Fisica, Universidade do Porto, Porto},
abstractNote = {We investigate models described by real scalar fields, searching for defect structures in the presence of interactions which explicitly violate Lorentz and CPT symmetries. We first deal with a single field, and we investigate a class of models which supports traveling waves that violate Lorentz invariance. This scenario is then generalized to the case of two (or more) real scalar fields. In the case of two fields, in particular, we introduce another class of models, which supports topological structures that attain a Bogomol'nyi bound, although violating both Lorentz and CPT symmetries. An example is considered, for which we construct the Bogomol'nyi bound and find some explicit solutions. We show that violation of both Lorentz and CPT symmetries induces the appearance of an asymmetry between defects and antidefects, including the presence of linearly stable solutions with negative energy density in their outer side.},
doi = {10.1103/PHYSREVD.73.065015},
journal = {Physical Review. D, Particles Fields},
number = 6,
volume = 73,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • We calculate, by the method of dimensional regularization and derivative expansion, the one-loop effective action for a Dirac fermion with a Lorentz-violating and CPT-odd kinetic term in the background of a gauge field. We show that this term induces a Chern-Simons modification to Maxwell theory. Some related issues are also discussed. [copyright] [ital 1999] [ital The American Physical Society]
  • We examine the nonperturbative structure of the radiatively induced Chern-Simons term in a Lorentz- and CPT-violating modification of QED. Although the coefficient of the induced Chern-Simons term is in general undetermined, the nonperturbative theory appears to generate a definite value. However, the CPT-even radiative corrections in this same formulation of the theory generally break gauge invariance. We show that gauge invariance may yet be preserved through the use of a Pauli-Villars regulator, and, contrary to earlier expectations, this regulator does not necessarily give rise to a vanishing Chern-Simons term. Instead, two possible values of the Chern-Simons coefficient are allowed, onemore » zero and one nonzero. This formulation of the theory therefore allows the coefficient to vanish naturally, in agreement with experimental observations.« less
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  • We discuss the possibility to perform and use the exact Foldy-Wouthuysen transformation (EFWT) for the Dirac spinor coupled to different CPT and Lorentz violating terms. The classification of such terms is performed, selecting those of them which admit EFWT. For the particular example of an axial vector field, which can be associated with the completely antisymmetric torsion, we construct an explicit EFWT in the case when only a timelike component of this axial vector is present. In the cases when EFWT is not possible, one can still use the corresponding technique for deriving the perturbative Foldy-Wouthuysen transformation, as is illustratedmore » in a particular example in the Appendix.« less