Determination of |Vcb| and m_b from Inclusive B -> X_c l nu and B -> X_s gamma Decays at Belle

TL;DR

This paper extracts the CKM matrix element |Vcb| and the b-quark mass from inclusive B decay measurements at Belle using theoretical models, providing precise values in two different schemes.

Contribution

It presents a novel analysis combining Belle data with theoretical expressions in 1S and kinetic schemes to determine |Vcb| and m_b with improved precision.

Findings

|Vcb| in 1S scheme: (41.49 +/- 0.52) x 10^-3

|Vcb| in kinetic scheme: (41.93 +/- 0.65) x 10^-3

b-quark mass in 1S scheme: (4.729 +/- 0.048) GeV

Abstract

We present an analysis of the Belle measured moments of the lepton energy and hadronic mass spectra in B -> X_c l nu decays and the photon energy spectrum in B -> X_s gamma decays using theoretical expressions derived in the 1S and kinetic schemes. The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb, the b-quark mass and other non-perturbative parameters are extracted. In the 1S scheme analysis we find |Vcb|=(41.49 +/- 0.52(fit) +/- 0.20(tau_B)) x 10^-3 and m_b^{1S}=(4.729 +/- 0.048) GeV. In the kinetic scheme, we obtain |Vcb|=(41.93 +/- 0.65(fit) +/- 0.07(alpha_s) +/- 0.63(th)) x 10^-3 and m_b^{kin}=4.564 +/- 0.076(fit) +/- 0.003(alpha_s) GeV.