Axion results: what is new?
  The PVLAS collaboration has obtained results that may be interpreted in terms of a light axion-like particle, while the CAST collaboration has not found any signal of such particles. Moreover, the PVLAS results are in gross contradiction with astrophysical bounds. We develop a particle physics model with two paraphotons and with a low energy scale in which these apparent inconsistencies are circumvented. 
Eduard Masso and Javier Redondo