Axial charge segregation and CP violation during the electroweak phase transition with hypermagnetic fields

Abstract

We study the scattering of fermions off the true vacuum bubbles nucleated during a first order electroweak phase transition in the presence of a background hypermagnetic field. By considering the limit of an infinitely thin bubble wall, we derive and analytically solve the Dirac equation in three spatial dimensions for left and right chirality modes and compute reflection and transmission coefficients for the case when the fermions move from the symmetric toward the broken symmetry phase. Given the chiral nature of the fermion coupling with the background field in the symmetric phase, an axial asymmetry is generated during the scattering processes. This mechanism is thus shown to provide an additional source of CP violation within the standard model. We discuss possible implications for baryon number generation.

9 pages, 4 EPS figures, uses ReVTeX4. Three references added

References in corpus (8)

• Magnetic Fields in the Early Universe
• A Limit on Primordial Small-Scale Magnetic Fields from CMB Distortions
• Tensor Microwave Anisotropies from a Stochastic Magnetic Field
• Primordial Hypermagnetic Knots
• Hypermagnetic Knots, Chern-Simons Waves and the Baryon Asymmetry
• Cosmological magnetic fields
• Fermion scattering off electroweak phase transition kink walls with hypermagnetic fields
• Axially asymmetric fermion scattering off electroweak phase transition bubble walls with hypermagnetic fields

Cited by in corpus (8)

• The Magnetized Universe
• Effective potential at finite temperature in a constant magnetic field I: Ring diagrams in a scalar theory
• Effective potential at finite temperature in a constant hypermagnetic field: Ring diagrams in the Standard Model
• Symmetry restoration at finite temperature with weak magnetic fields
• Electroweak baryogenesis via chiral gravitational waves
• Baryogenesis and CP-Violating Domain Walls in the Background of a Magnetic Field
• Chiral fermion mass and dispersion relations at finite temperature in the presence of hypermagnetic fields
• Fermion Scattering off a CP-violating Bubble Wall in the Background of a Uniform Magnetic Field