How large can the branching ratio of B-s -%26gt; tau(+)tau(-) be?

作者：Dighe Amol^*; Ghosh Diptimoy

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 86(5): 054023.

DOI：10.1103/PhysRevD.86.054023

Motivated by the large like-sign dimuon charge asymmetry observed recently, whose explanation would require an enhanced decay rate of B-s -%26gt; tau(+)tau(-), we explore how large a branching ratio of this decay mode is allowed by the present constraints. We use bounds from the lifetimes of B-d and B-s, constraints from the branching ratios of related b -%26gt; s tau(+)tau(-) modes, as well as measurements of the mass difference, width difference and CP-violating phase in the B-s-(B) over bar (s) system. Using an effective field theory approach, we show that a branching ratio as high as 15% may be allowed while being consistent with the above constraints. The measurement of this decay, therefore, may be within the reach of current experiments and can point toward a specific class of new physics models. We also explore the possible enhancement of this decay in models with leptoquarks and Z%26apos; and find that, in the latter case, the branching ratio may be as much as 5%, which can alleviate the dimuon anomaly to some extent.

• 出版日期2012-9-25