Neutron electric dipole moment in left-right-symmetric models

Journal Article · Wed Jan 01 04:00:00 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), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 45:1; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

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