(Lambda_b -> Lambda l^+ l^-) decay in universal extra dimensions

Abstract

We study the exclusive (Lambda_b -> \Lambda l^+ l^-) decay in the Appelquist, Chang, Dobrescu model within one universal extra dimension. We investigate the sensitivity of the branching ratio, lepton polarization and forward-backward asymmetry A_{FB} to the compactification parameter (1/R) We obtain that the branching ratio changed about 50% compared to the SM value, when (1/R=200 GeV) and zero position of the forward-backward asymmetry is shifted to the left compared to the SM result. Therefore measurement of the branching ratio of (Lambda_b -> Lambda l^+ l^-) decay and determination of zero position of A_{FB} are very useful in looking for new physics in the framework of the UED models.