Bc → Bs(d) form factors from lattice QCD

Cooper, L. J., Davies, C. T.H. , Harrison, J., Komijani, J. and Wingate, M. (2020) Bc → Bs(d) form factors from lattice QCD. Physical Review D, 102(1), 014513. (doi: 10.1103/PhysRevD.102.014513)

219719.pdf - Published Version
Available under License Creative Commons Attribution.



We present results of the first lattice QCD calculations of B c → B s and B c → B d weak matrix elements. Form factors across the entire physical q 2 range are then extracted and extrapolated to the physical-continuum limit before combining with Cabbibo-Kobayashi-Maskawa (CKM) matrix elements to predict the semileptonic decay rates Γ ( B + c → B 0 s ¯ ℓ ν ℓ ) = 52.4 ( 2.5 ) × 10 9     s − 1 and Γ ( B + c → B 0 ¯ ℓ ν ℓ ) = 3.10 ( 21 ) × 10 9     s − 1 . The lattice QCD uncertainty is comparable to the CKM uncertainty here. Results are derived from correlation functions computed on MILC Collaboration gauge configurations with a range of lattice spacings including 2 + 1 + 1 flavors of dynamical sea quarks in the highly improved staggered quark (HISQ) formalism. HISQ is also used for the propagators of the valence light, strange, and charm quarks. Two different formalisms are employed for the bottom quark: nonrelativistic QCD (NRQCD) and heavy-HISQ. Checking agreement between these two approaches is an important test of our strategies for heavy quarks on the lattice. From chained fits of NRQCD and heavy-HISQ data, we obtain the differential decay rates d Γ / d q 2 as well as integrated values for comparison to future experimental results.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Davies, Professor Christine and Komijani, Dr Javad and Harrison, Mr Judd
Authors: Cooper, L. J., Davies, C. T.H., Harrison, J., Komijani, J., and Wingate, M.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Physical Review D
Publisher:American Physical Society
ISSN (Online):2470-0029
Published Online:23 July 2020
Copyright Holders:Copyright © 2020 American Physical Society
First Published:First published in Physical Review D 102(1): 014513
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
173809Phenomenology from Lattice QCD and Collider PhysicsChristine DaviesScience and Technology Facilities Council (STFC)ST/P000746/1P&S - Physics & Astronomy