A model solving the PVLAS-CAST puzzle

Abstract

Axion physics has received a boost with the recent claim of the PVLAS collaboration. Their results can be interpreted as due to a new axionlike particle but the CAST collaboration has not found trace of it. While the axionlike particle interpretation of the PVLAS signal is going to be probed by dedicated laboratory experiments, it is mandatory to find either alternatives to it or models in which the astrophysical bounds could be evaded. In this communication one of such models is presented. The new physics involved appears at a low energy scale $<$ eV.