An effective look at right-handed currents and quark flavour mixing

Abstract

We present an effective theory approach for a model with a left-right symmetric flavour group broken only by the Yukawa couplings. An underlying SU(2)_L x SU(2)_R x U(1)_{B-L} global symmetry is assumed without specifying the fundamental theory. The model is motivated by the fact that the |V_{ub}| problem can be solved by assuming the existence of right-handed (RH) currents. In this framework the flavour mixing in the RH sector is given by a new mixing matrix. After a short introduction of the model, we show how this RH mixing matrix can be determined by theory, experimental data and phenomenological constraints. We summarize the results of the RH contribution to flavour mixing in Delta F=2 processes. Furthermore we briefly discuss Z -> b bbar and the rare decays B_{s,d} -> mu+ mu-, B -> {X_s,K,K*} nu nubar and K -> pi nu nubar with corresponding correlations.