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Measurement of differential distributions of B. D l.l and implications on Vcb

Publication at Faculty of Mathematics and Physics |
2023

Abstract

We present a measurement of the differential shapes of exclusive B -D*l & nu; over bar l (B = B-; B over bar 0 and l = e, is) decays with hadronic tag-side reconstruction for the full 711 fb-1 Belle dataset. We extract the Caprini-Lellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) form factor parameters and use an external input for the absolute branching fractions to determine the Cabibbo-Kobayashi-Maskawa matrix element and find IVcbICLN = (40.2 & PLUSMN; 0.9) x 10-3 and IVcbIBGL = (40.7 & PLUSMN; 1.0) x 10-3 with the zero-recoil lattice QCD point F(1) = 0.906 & PLUSMN; 0.013.

We also perform a study of the impact of beyond zero-recoil lattice QCD calculations on the IVcbI determinations. Additionally, we present the lepton-flavor universality ratio Reis = B(B -D*e & nu; over bar e)=B(B -D*is & nu; over bar is) = 0.993 & PLUSMN; 0.023 & PLUSMN; 0.023, the electron and muon forward -backward asymmetry and their difference & UDelta;AFB = 0.028 & PLUSMN; 0.028 & PLUSMN; 0.008, and the electron and muon D* longitudinal polarization fraction and their difference & UDelta;FD*L = 0.030 & PLUSMN; 0.025 & PLUSMN; 0.007.

The uncertainties quoted correspond to the statistical and systematic uncertainties, respectively.