Double-lepton polarization asymmetries and branching ratio of the B -> gamma l(+)l(-) transition in universal extra dimension

We study the double-lepton polarization asymmetries and single and double-lepton polarization forward-backward asymmetries of the rare b ! s‘þ‘ mode within the standard model and in the Appelquist-Cheng-Dobrescu model, which is a new physics scenario with a single universal extra dimension. In particular, we examine the sensitivity of the observables to the radius R of the compactified extra dimension, which is the new parameter in this new physics model