Speaker
Syuhei Iguro
(KEK/IAR/KMI)
Description
Lepton flavor universality violations in semileptonic b→c transitions have garnered attention over a decade. For RH_c=BR(H_b→H_cτν)/BR(H_b→H_cℓν) with ℓ being e, μ, a sum rule among RD, RD∗ and RΛc was proposed to check consistency in the experimental results independently of new physics models. We revisit this relation from the perspective of the heavy quark symmetry. We derive a sum rule holding exactly in the heavy quark limit and clarify how model-dependent corrections are introduced in a realistic situation.