Julian Heeck Heidelberg

Gauged L_mu-L_tau symmetry and its effect on neutrino phenomenology (pdf)

Promoting the anomaly-free (accidental) L_mu-L_tau symmetry of the standard model to a local gauge symmetry introduces an additional neutral vector boson with generation-dependent couplings. First generation particles are affected only through mass mixing with the Z boson and kinetic mixing with the hypercharge generator. We discuss current constraints on the model parameters for the ultralight case (fifth force) from electroweak precision data to cosmology and especially the effect on neutrino phenomenology. The sensitivity of future long-baseline experiments to the parameters will be discussed and compared. We will also mention the bounds on a higher breaking scale corresponding to a gauge boson with mass in the electroweak range.