TY - JOUR

T1 - Λb → Λℓ+ℓ- form factors, differential branching fraction, and angular observables from lattice QCD with relativistic b quarks

AU - Detmold, William

AU - Meinel, Stefan

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Using (2+1)-flavor lattice QCD, we compute the 10 form factors describing the Λb→Λ matrix elements of the b→s vector, axial vector, and tensor currents. The calculation is based on gauge field ensembles generated by the RBC and UKQCD Collaborations with a domain-wall action for the u, d, and s quarks and the Iwasaki gauge action. The b quark is implemented using an anisotropic clover action, tuned nonperturbatively to the physical point, and the currents are renormalized with a mostly nonperturbative method. We perform simultaneous chiral, continuum, and kinematic extrapolations of the form factors through modified z expansions. Using our form factor results, we obtain precise predictions for the Λb→Λ(→p+π-)μ+μ- differential branching fraction and angular observables in the Standard Model.

AB - Using (2+1)-flavor lattice QCD, we compute the 10 form factors describing the Λb→Λ matrix elements of the b→s vector, axial vector, and tensor currents. The calculation is based on gauge field ensembles generated by the RBC and UKQCD Collaborations with a domain-wall action for the u, d, and s quarks and the Iwasaki gauge action. The b quark is implemented using an anisotropic clover action, tuned nonperturbatively to the physical point, and the currents are renormalized with a mostly nonperturbative method. We perform simultaneous chiral, continuum, and kinematic extrapolations of the form factors through modified z expansions. Using our form factor results, we obtain precise predictions for the Λb→Λ(→p+π-)μ+μ- differential branching fraction and angular observables in the Standard Model.

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U2 - 10.1103/PhysRevD.93.074501

DO - 10.1103/PhysRevD.93.074501

M3 - Article

AN - SCOPUS:84963704479

VL - 93

JO - Physical review D: Particles and fields

JF - Physical review D: Particles and fields

SN - 0556-2821

IS - 7

M1 - 074501

ER -