Anomalous coupling of scalars to gauge fields

Abstract

We study the transformation properties of a scalar-tensor theory, coupled to fermions, under the Weyl rescaling associated with a transition from the Jordan to the Einstein frame. We give a simple derivation of the corresponding modification to the gauge couplings. After changing frame, this gives rise to a direct coupling between the scalar and the gauge fields.

Comments: 5 pages. v2: minor changes, matches version published in PLB