Bs →kν decay from lattice QCD

Fermilab Lattice and MILC Collaborations

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

We use lattice QCD to calculate the form factors f+(q2) and f0(q2) for the semileptonic decay Bs→Kν. Our calculation uses six MILC asqtad 2+1 flavor gauge-field ensembles with three lattice spacings. At the smallest and largest lattice spacing the light-quark sea mass is set to 1/10 the strange-quark mass. At the intermediate lattice spacing, we use four values for the light-quark sea mass ranging from 1/5 to 1/20 of the strange-quark mass. We use the asqtad improved staggered action for the light valence quarks, and the clover action with the Fermilab interpolation for the heavy valence bottom quark. We use SU(2) hard-kaon heavy-meson rooted staggered chiral perturbation theory to take the chiral-continuum limit. A functional z expansion is used to extend the form factors to the full kinematic range. We present predictions for the differential decay rate for both Bs→Kμν and Bs→Kτν. We also present results for the forward-backward asymmetry, the lepton polarization asymmetry, ratios of the scalar and vector form factors for the decays Bs→Kν and Bs→Dsν. Our results, together with future experimental measurements, can be used to determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |Vub|.

Original languageEnglish (US)
Article number034501
JournalPhysical Review D
Volume100
Issue number3
DOIs
StatePublished - Aug 1 2019

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Fingerprint Dive into the research topics of 'Bs →kν decay from lattice QCD'. Together they form a unique fingerprint.

  • Cite this

    Fermilab Lattice and MILC Collaborations (2019). Bs →kν decay from lattice QCD. Physical Review D, 100(3), [034501]. https://doi.org/10.1103/PhysRevD.100.034501