Repositorio
Institucional

Balart, Leonardo

Reyes, Carlos M.#Ossandon, Sebastian#Reyes, Camilo

Perturbative unitarity and higher-order Lorentz symmetry breaking

AMER PHYSICAL SOC

PHYSICAL REVIEW D

en

We study perturbative unitarity in the scalar sector of the Myers-Pospelov model. The model introduces a preferred four-vector n which breaks Lorentz symmetry and couples to a five-dimension operator. When the preferred four-vector is chosen in the pure timelike or lightlike direction, the model becomes a higher time derivative theory, leading to a cubic dispersion relation. Two of the poles are shown to be perturbatively connected to the standard ones, while a third pole, which we call the Lee-Wick-like pole, is associated to a negative metric in Hilbert space, threatening the preservation of unitarity. The pure spacelike case is a normal theory in the sense that it has only two solutions, both being small perturbations over the standard ones. We analyze perturbative unitarity for purely spacelike and timelike cases using the optical theorem and considering a quartic self-interaction term. By computing discontinuities in the loop diagram, we arrive at a pinching condition which determines the propagation of particles and Lee-Wick-like particles through the cut. We find that the contribution for Lee-Wick-like particles vanishes for any external momenta, leaving only the contribution of particles, thus preserving one-loop unitarity in both cases.

Artículo original

L. B. is supported by DIUFRO through the Project No. DI16-0075 by supported by Direccion de Investigacion de la Universidad de La Frontera (DIUFRO) through the Grant No. DI16-0075. C. M. R. acknowledges partial support by the research project Fondecyt Regular 1140781 and GI172309/C UBB by partial support by Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDECYT) Grant No. 1140781 and Direccion de Investigacion de la Universidad del Bio-Bio (DIUB) Grant No. GI172309/C.

L. B. cuenta con el apoyo de DIUFRO a través del Proyecto No. DI16-0075 con el apoyo de la Dirección de Investigación de la Universidad de La Frontera (DIUFRO) a través de la Subvención No. DI16-0075. C. M. R. reconoce el apoyo parcial del proyecto de investigación Fondecyt Regular 1140781 y GI172309/C UBB mediante el apoyo parcial del Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) Beca No. 1140781 y la Dirección de Investigación de la Universidad del Bio-Bio (DIUB) Beca No. GI172309/C.

10.1103/PhysRevD.98.035035

pdf

http://dx.doi.org/10.1103/PhysRevD.98.035035

Astronomy & Astrophysics# Physics, Particles & Fields

Física de Partículas y Campos

Otras Especialidades de la Física

WOS:000442670200008

Perturbative unitarity and higher-order Lorentz symmetry breaking

Artículo original

version publicada

AMER PHYSICAL SOC

PHYSICAL REVIEW D

Astronomía y Astrofísica# Física, Partículas y Campos

2470-0010

en

UFRO DI16-0075#ANID 1140781# UBB GI172309/C

UFRO DI16-0075

ANID FONDECYT 1140781

ANID FONDECYT GI172309/C UBB

UBB DIUB GI172309/C

L. B. is supported by DIUFRO through the Project No. DI16-0075 by supported by Direccion de Investigacion de la Universidad de La Frontera (DIUFRO) through the Grant No. DI16-0075. C. M. R. acknowledges partial support by the research project Fondecyt Regular 1140781 and GI172309/C UBB by partial support by Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDECYT) Grant No. 1140781 and Direccion de Investigacion de la Universidad del Bio-Bio (DIUB) Grant No. GI172309/C.

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