Eur. Phys. J. C (2012) 72: 1996
https://doi.org/10.1140/epjc/s10052-012-1996-z

Regular Article - Theoretical Physics

χ _QJ →ℓ ⁺ ℓ ⁻ within and beyond the Standard Model

College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing, 100049, China

^* e-mail: yangds@gucas.ac.cn

Received: 15 March 2012
Revised: 9 April 2012
Published online: 28 April 2012

Abstract

We revisit χ _QJ →ℓ ⁺ ℓ ⁻ (with J=0,1,2 and Q=b,c) within the Standard Model (SM). The electromagnetic contributions are given in the color-singlet model with non-vanishing lepton masses at the leading order of v. Numerically, the branching ratios of χ _QJ →ℓ ⁺ ℓ ⁻ predicted within the SM are so small that such decays are barely possible to be detected at future BESIII and SuperB experiments, but may be possible to be observed at the LHC. We investigate χ _b0→ℓ ⁺ ℓ ⁻ in Type-II 2HDM with large tanβ, and χ _b2→ℓ ⁺ ℓ ⁻ in the Randall–Sundrum model, to see their chance to be observed in future experiments.