Comeback Measurement of the CKM Matrix Element |V_cb| From B⁰ → D^*- at Belle

Author(s)

E. Waheed
P. Urquijo
D. Ferlewicz
I. Adachi
K. Adamczyk
H. Aihara
S. Al Said
D.M. Asner
H. Atmacan
T. Aushev
R. Ayad
V. Babu
I. Badhrees
P. Behera
C. Beleño
F. Bernlochner
B. Bhuyan
T. Bilka
J. Biswal
A. Bobrov
Milind Purohit, University of South CarolinaFollow
Et. Al.

Document Type

Article

Abstract

We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| from B⁰ → D^*-ℓ _vℓ decays, reconstructed with the full Belle data set of 711 fb⁻¹ integrated luminosity. Two form factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product F(1)η_EW||V_cb| and the decay form factors, where F(1) is the normalization factor and η_EW is a small electroweak correction. In the CLN parametrization we find F(1)η_EW||Vcb|=(35.06 ± 0.15 ± 0.56) × 10⁻³, ρ² =1.106 ± 0.031± 0.007, R₁(1) ¼ 1.229 ± 0.028 ± 0.009, R₂(1) = 0.852 ± 0.021 ± 0.006. For the BGL parametrization we obtain F(1)η_EW|Vcb|=(34.93 ± 0.23 ± 0.59) × 10⁻³, which is consistent with the world average when correcting for F(1) η_EW. The branching fraction of B0 → D−lþνl is measured to be B(B⁰ → D−lþνlÞ¼ð4.90 0.02 0.16Þ%. We also present a new test of lepton flavor universality violation in semileptonic B decays, BðB0→D−eþνÞ BðB0→D−μþνÞ ¼ 1.01 0.01 0.03. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of Fð1ÞηEWjVcbj and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement.

Digital Object Identifier (DOI)

https://doi.org/10.1103/PhysRevD.100.052007

Publication Info

Published in Physical Review D, Volume 100, Issue 5, 2019.

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

Rights

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

APA Citation

Waheed, E., Urquijo, P., Ferlewicz, D., Adachi, I., Adamczyk, K., Aihara, H., Al Said, S., Asner, D. M., Atmacan, H., Aushev, T., Ayad, R., Babu, V., Badhrees, I., Bansal, V., Behera, P., Beleño, C., Bernlochner, F., Bhuyan, B., Bilka, T., … Zhukova, V. (2019). Measurement of the CKM matrix element . Physical Review D, 100(5). https://doi.org/10.1103/physrevd.100.052007