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Standard Model CP-violation and baryon asymmetry; 1, zero temperature

We consider quantum effects in a world with two coexisting symmetry phases, unbroken and spontaneously broken, as a result of a first order phase transition. The discrete symmetries of the problem are discussed in general. We compute the exact two-point Green function for a free fermion, when a thin...

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Detalles Bibliográficos
Autores principales: Gavela-Legazpi, Maria Belen, Lozano, M, Orloff, J, Pène, O
Lenguaje:eng
Publicado: 1994
Materias:
Acceso en línea:https://dx.doi.org/10.1016/0550-3213(94)00409-9
http://cds.cern.ch/record/264361
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author Gavela-Legazpi, Maria Belen
Lozano, M
Orloff, J
Pène, O
author_facet Gavela-Legazpi, Maria Belen
Lozano, M
Orloff, J
Pène, O
author_sort Gavela-Legazpi, Maria Belen
collection CERN
description We consider quantum effects in a world with two coexisting symmetry phases, unbroken and spontaneously broken, as a result of a first order phase transition. The discrete symmetries of the problem are discussed in general. We compute the exact two-point Green function for a free fermion, when a thin wall separates the two phases. The Dirac propagator displays both massive and massless poles, and new CP-even phases resulting from the fermion reflection on the wall. We discuss the possible quark-antiquark CP asymmetries produced in the Standard Model(SM) for the academic T=0 case. General arguments indicate that an effect first appears at order \alpha_W in the reflection amplitude, as the wall acts as a source of momentum and the on-shell one-loop self-energy cannot be renormalized away. The asymmetries stem from the interference of the SM CP-odd couplings and the CP-even phases in the propagator. We perform a toy computation that indicates the type of GIM cancellations of the problem. The behaviour can be expressed in terms of two unitarity triangles.
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institution Organización Europea para la Investigación Nuclear
language eng
publishDate 1994
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spelling cern-2643612019-09-30T06:29:59Zdoi:10.1016/0550-3213(94)00409-9http://cds.cern.ch/record/264361engGavela-Legazpi, Maria BelenLozano, MOrloff, JPène, OStandard Model CP-violation and baryon asymmetry; 1, zero temperatureParticle Physics - TheoryWe consider quantum effects in a world with two coexisting symmetry phases, unbroken and spontaneously broken, as a result of a first order phase transition. The discrete symmetries of the problem are discussed in general. We compute the exact two-point Green function for a free fermion, when a thin wall separates the two phases. The Dirac propagator displays both massive and massless poles, and new CP-even phases resulting from the fermion reflection on the wall. We discuss the possible quark-antiquark CP asymmetries produced in the Standard Model(SM) for the academic T=0 case. General arguments indicate that an effect first appears at order \alpha_W in the reflection amplitude, as the wall acts as a source of momentum and the on-shell one-loop self-energy cannot be renormalized away. The asymmetries stem from the interference of the SM CP-odd couplings and the CP-even phases in the propagator. We perform a toy computation that indicates the type of GIM cancellations of the problem. The behaviour can be expressed in terms of two unitarity triangles.hep-ph/9406288CERN-TH-7262-94FAMNSE-94-12HD-THEP-94-19LPTHE-94-48NSF-ITP-94-64oai:cds.cern.ch:2643611994
spellingShingle Particle Physics - Theory
Gavela-Legazpi, Maria Belen
Lozano, M
Orloff, J
Pène, O
Standard Model CP-violation and baryon asymmetry; 1, zero temperature
title Standard Model CP-violation and baryon asymmetry; 1, zero temperature
title_full Standard Model CP-violation and baryon asymmetry; 1, zero temperature
title_fullStr Standard Model CP-violation and baryon asymmetry; 1, zero temperature
title_full_unstemmed Standard Model CP-violation and baryon asymmetry; 1, zero temperature
title_short Standard Model CP-violation and baryon asymmetry; 1, zero temperature
title_sort standard model cp-violation and baryon asymmetry; 1, zero temperature
topic Particle Physics - Theory
url https://dx.doi.org/10.1016/0550-3213(94)00409-9
http://cds.cern.ch/record/264361
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