Exclusive B-> M ν\barν (M= π, K, ρ, K^*) Decays and Leptophobic Z^\prime Model

Abstract

We consider the exclusive flavor changing neutral current processes B -> M ν\barν (M= π, K, ρ, K^*) in the leptophobic Z^\prime model, in which the charged leptons do not couple to the extra Z^\prime boson. We find that these exclusive modes are very effective to constrain the leptophobic Z^\prime model. In the leptophobic Z^\prime model, additional right-handed neutrinos are introduced and they can contribute to the missing energy signal in B -> M + E_missing decays. Through the explicit calculations, we obtain quite stringent bounds on the model parameters, |U_{sb}^{Z^\prime}| \leq 0.29 and |U_{db}^{Z^\prime}| \leq 0.61, from the already existing experimental data. We also briefly discuss an interesting subject of massive right-handed neutrinos, which might be connected with the dark matter problem.

17 pages, 3 figures, minor corrections, version to appear in PLB