Λb→Λℓ+ℓ- form factors and differential branching fraction from lattice QCD

William Detmold, C. J.David Lin, Stefan Meinel, Matthew Wingate

Research output: Contribution to journalArticle

33 Scopus citations

Abstract

We present the first lattice QCD determination of the Λ b→Λ transition form factors that govern the rare baryonic decays Λb→Λℓ+- at leading order in heavy-quark effective theory. Our calculations are performed with 2+1 flavors of domain-wall fermions, at two lattice spacings and with pion masses down to 227 MeV. Three-point functions with a wide range of source-sink separations are used to extract the ground-state contributions. The form factors are extrapolated to the physical values of the light-quark masses and to the continuum limit. We use our results to calculate the differential branching fractions for Λb→Λℓ+- with ℓ=e, μ, τ within the standard model. We find agreement with a recent CDF measurement of the Λb→ Λμ+μ- differential branching fraction.

Original languageEnglish (US)
Article number074502
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume87
Issue number7
DOIs
StatePublished - Apr 5 2013
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)

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