Eur. Phys. J. C (2011) 71: 1764
https://doi.org/10.1140/epjc/s10052-011-1764-5

Regular Article - Theoretical Physics

Study of B _s →φℓ ⁺ ℓ ⁻ decay in a single universal extra dimension model

Department of Physics, Yantai University, Yantai, 264-005, China

^* e-mail: liying@ytu.edu.cn

Received: 31 July 2011
Revised: 8 September 2011
Published online: 28 September 2011

Abstract

Using form factors derived from the light-cone sum rules, we investigate B _s →φℓ ⁺ ℓ ⁻ (ℓ=e,μ,τ) in a single universal extra dimension model (UED). In UED, there is only one new parameter with respect to the Standard Model (SM), which is the inverse of the compactification radius R of the extra dimension. In this work, the branching ratios, the dilepton invariant mass spectra, the forward–backward asymmetries, and the lepton polarization asymmetries of B _s →φℓ ⁺ ℓ ⁻ are calculated. For a lower value of 1/R, there are some considerable discrepancies between the UED and SM. However, with the increase of 1/R, the effect of UED tends to diminish; in particular for 1/R≥1000 GeV, two models have approximately the same predictions. Compared with data from CDF for B _s →φμ ⁺ μ ⁻, we find that the 1/R tends to be larger than 350 GeV. We also find that the zero crossing point of the forward–backward asymmetry of B _s →φμ ⁺ μ ⁻ becomes smaller, which would be an important platform for probing the UED effect. These results could be tested in the Large Hadron Collider (LHC) at CERN and the future super-B factory.