6533b862fe1ef96bd12c735e

RESEARCH PRODUCT

Axial current in extended systems

subject

description

We establish a connection between the nuclear axial current and pionic properties in the medium. As a strict consequence of PCAC alone, the time component has its matrix elements determined by a wave pion absorption to leading order in the momentum transfer. The properties of the system are governed by scale parameters associated both with its size and with the local interaction structure. Based on this observation we suggest a locality condition for the part of the axial current which has no pion pole. It follows that the full axial current can be explicitly constructed from the local s and p wave pion source functions. A model illustration is presented. Our approach unifies in a model independent way axial β-decay and μ capture with pion processes, so that they all reflect the same phenomenon.