Study of semileptonic decays $B\to \pi l^{+}{l}^{-}$ and $B\to \rho l^{+}{l}^{-}$ in non-universal Z' model

Abstract

Semileptonic B meson decays induced by $b\to s(d)l^{+}{l}^{-}$ flavour changing neutral current (FCNC) transitions are very important to probe the quark-flavour sector of the standard model (SM) and also offer a probe to test new physics (NP). Although there exists a lot of precise results on $b\to s{l}^{+}{l}^{-}$ induced processes, there is lack of sufficient data for $b\to d{l}^{+}{l}^{-}$ induced decays. Here, we are interested to study $B\to \pi l^{+}{l}^{-}$ and $B\to \rho l^{+}{l}^{-}$ decays which proceed via $b\to d{l}^{+}{l}^{-}$ transition at the quark level. In this work, we investigate the differential branching ratio, forward-backward asymmetry, CP violation asymmetry and lepton polarization asymmetry in these two decay channels in a non-universal Z' model. We find a significant deviation from the SM value of these physical observables for these decays which provide a clear conjecture for NP arising from Z' gauge boson.

Comments: 28 pages, 7 figures