Neutron electric dipole moment in left-right-symmetric models

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.45.259· OSTI ID:5083424

Frere, J ^[1]; Galand, J; Le Yaouanc, A; Oliver, L; Pene, O; Raynal, J ^[2]

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1. Service de Physique Theorique, Universite Libre de Bruxelles, Boulevard du Triomphe, 1050 Bruxelles (Belgium)
2. Laboratoire de Physique Theorique et Hautes Energies, Universite de Paris-Sud, Batiment 211, 91405 Orsay (France)

We discuss the neutron electric dipole moment in the SU(2){sub {ital L}}{times}SU(2){sub {ital R}}{times}U(1) model of {ital CP} violation. We compute the leading-logarithm QCD corrections to the quark electric dipole moment. To estimate the anomalous dimensions one needs to go to two loops, like in the controversial {ital b}{r arrow}{ital s}{gamma} transition in the standard model. Since fermion loops in chiral theories need a careful treatment of regularization, we expose in detail the calculation in various dimensional-regularization schemes (naive dimensional regularization, dimensional reduction, and the 't Hooft--Veltman prescription) and also in Pauli-Villars regularization. We do not find the kind of discrepancies claimed in the literature for {ital b}{r arrow}{ital s}{gamma}, and obtain the same result for all these regularizations. The QCD corrections to the dominant left-right ({ital LR}) exchange contribution are large and critically dependent on {mu} and {Lambda}{sub QCD}, making uncertain even its sign. We show that, in addition to the currently considered {ital N}{sup *} intermediate states, the nucleon and {Delta} also make a very large contribution. One has {l angle}{ital N}{vert bar}{ital H}{sub {ital L}{ital R}}{sup PV}{vert bar}{ital N}{r angle}, {l angle}{ital N}{vert bar}{ital H}{sub {ital L}{ital R}}{sup PV}{vert bar}{Delta}{r angle}{ne}0, in contrast with {l angle}{ital N}{vert bar}{ital H}{sub {ital L}{ital L}}{sup PV}{vert bar}{ital N}{r angle}=0 (Lee-Swift theorem) and {l angle}{ital N}{vert bar}{ital H}{sub {ital L}{ital L}}{sup PV}{vert bar}{Delta}{r angle}=0 (color wave-function antisymmetry).

• OSTI ID: 5083424
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 45:1; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
NEUTRONS
ELECTRIC DIPOLE MOMENTS
CP INVARIANCE
DECAY
FERMIONS
QUANTUM CHROMODYNAMICS
QUARKS
STANDARD MODEL
SU-2 GROUPS
U-1 GROUPS
BARYONS
DIPOLE MOMENTS
ELECTRIC MOMENTS
ELEMENTARY PARTICLES
FIELD THEORIES
HADRONS
INVARIANCE PRINCIPLES
LIE GROUPS
MATHEMATICAL MODELS
NUCLEONS
PARTICLE MODELS
POSTULATED PARTICLES
QUANTUM FIELD THEORY
SU GROUPS
SYMMETRY GROUPS
U GROUPS
UNIFIED GAUGE MODELS
662410* - Properties of Baryons & Baryon Resonances- (1992-)
662230 - Quantum Chromodynamics- (1992-)