1996/03/10 by Andrzej Czarnecki · 3 citations
Physics and Astronomy · #Charm (quantum number) #Electroweak interaction #High-Energy Particle Collisions Research #Mathematical physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #hep-ph
paper · pdf · doi:10.1103/physrevlett.76.4124
published as Phys. Rev. Lett. 76, 4124 (1996) · 8 pages, Revtex, one figure included
arxiv created 1996/03/10 · openalex publication_date 1996/05/27 · arxiv updated 2016/08/24 · openalex created_date 2020/05/13 · openalex updated_date 2026/08/05
Complete two-loop QCD corrections to b\ensuremath→c transitions are presented in the limit of zero recoil. Vector and axial-vector coefficients \ensuremathηA,V are calculated analytically in the limit of equal beauty and charm masses, and a series appoximation is obtained for the general mass case. \ensuremathηA is crucial for the determination of the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element Vcb. The two-loop effects enhance the one-loop corrections by 22%, removing a major theoretical uncertainty in the value of |Vcb|. Including two-loop QCD effects and previously neglected electroweak corrections we find |Vcb|\phantom\rule0ex0ex=\phantom\rule0ex0ex0.0383\ifmmode±\else\textpm\fi0.0021(stat)\ifmmode±\else\textpm\fi0.0025(syst)\ifmmode±\else\textpm\fi0.0011(theory).