A possible signature of new physics at BES-III

Abstract

The recent observations of the purely leptonic decay $\Ds \to μ^+ ν_μ$ and ${\tau }^{+}{\nu }_{\tau }$ at CLEO-c and $B$ factory may allow a possible contribution from a charged Higgs boson. One such measurement of the decay constant $f_{D_s}$ differs from the most precise unquenched lattice QCD calculation by 4 $\sigma$ level. Meanwhile, the measured ratio, ${\cal BR}(\Ds \to μ^+ ν_μ)$ / ${\cal BR}(\Dp \to μ^+ ν_μ)$, is larger than the standard model prediction at 2.0$\sigma$ level. We discuss that the precise measurement of the ratio ${\cal BR}(\Ds \to μ^+ ν_μ)$ / ${\cal BR}(\Dp \to μ^+ ν_μ)$ at BES-III will shed light on the presence of new intermediate particles by comparing the theoretical predictions, especially, the predictions of high precise unquenched lattice QCD calculation.

5 pages, 3 figures, mini-review, accepted by Chinese Physics C (HEP & NP)

References in corpus (2)

• Effect of H^\pm on B^\pm\to τ^\pmν_τand D^\pm_s\to μ^\pmν_μ,τ^\pmν_τ
• Decay constants of charm and beauty pseudoscalar heavy-light mesons on fine lattices