Speaker
Dr
Si-Hong Zhou
(Inner Mongolia University)
Description
We extend the QED factorization effects on the leptonic B decays with light muon leptons to tauonic final states $ \tau^+\, \tau^-$ using soft-collinear effective theory (SCET). This extension is necessary owing to the appearance of the large $\tau$ mass, which will lead to a different power counting in SCET and also different results. The enhanced electromagnetic effect from hard collinear contribution on $B_{d,s} \to \mu^+\, \mu^-$ found before will not exist. Only about $0.04\%$ power-enhanced correction changes the branching fraction compared with $0.4\%$ to $B_{d,s} \to \mu^+\, \mu^-$. In addition to hard collinear contribution, we provide a complete NLO electromagnetic corrections below the bottom mass scale $\mu_b$ to $B_{d,s} \to \tau^+\, \tau^-$ including one loop hard corrections. The one loop hard corrections are actually antisymmetric under the exchange of the hard collinear and hard anti-collinear sectors in the final states. In fact, the symmetry of higher-order hard QED corrections are not always valid beyond tree level. They depend on the number of vertex of $\mathcal{L}_{\mathrm{QED}}$ attached to lepton sector.
| Presentation type | Oral |
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Primary author
Dr
Si-Hong Zhou
(Inner Mongolia University)
