Semileptonicbdecay at intermediate recoil

Matthew Dowling, Alexey Pak, Andrzej Czarnecki
2008 Physical Review D  
We compute the O(α_s^2) corrections to the differential rate of the semileptonic decay b -> clv at the "intermediate recoil" point, where the c-quark mass and the invariant mass of the leptons are equal. The calculation is based on an expansion around two opposite limits of the quark masses m_b,c: m_c m_b and m_c << m_b. The former case was previously studied; we correct and extend that result. The latter case is new. The smooth matching of both expansions provides a check of both. We clarify
more » ... e discrepancy between the recent determinations of the full NNLO QCD correction to the semileptonic b -> c rate, and its earlier estimate.
doi:10.1103/physrevd.78.074029 fatcat:x2n6cynvsfbhbmvdloprdula4y