TY - JOUR
T1 - Λb → Λ∗ (1520)ℓ+ℓ- form factors from lattice QCD
AU - Meinel, Stefan
AU - Rendon, Gumaro
N1 - Funding Information:
We thank Marzia Bordone, Danny van Dyk, and Sébastien Descotes-Genon for discussions, and the RBC and UKQCD Collaborations for making their gauge field ensembles available. S. M. is supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award No. DE-SC0009913. G. R. is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-SC0012704 (BNL). The computations for this work were carried out on facilities at the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH1123, and on facilities of the Extreme Science and Engineering Discovery Environment (XSEDE) , which is supported by National Science Foundation Grant No. ACI-1548562.
Publisher Copyright:
© 2021 authors. Published by the American Physical Society.
PY - 2021/4/15
Y1 - 2021/4/15
N2 - We present the first lattice QCD determination of the Λb→Λ∗(1520) vector, axial vector, and tensor form factors that are relevant for the rare decays Λb→Λ∗(1520)ℓ+ℓ-. The lattice calculation is performed in the Λ∗(1520) rest frame with nonzero Λb momenta, and is limited to the high-q2 region. An interpolating field with covariant derivatives is used to obtain good overlap with the Λ∗(1520). The analysis treats the Λ∗(1520) as a stable particle, which is expected to be a reasonable approximation for this narrow resonance. A domain-wall action is used for the light and strange quarks, while the b quark is implemented with an anisotropic clover action with coefficients tuned to produce the correct Bs kinetic mass, rest mass, and hyperfine splitting. We use three different ensembles of lattice gauge-field configurations generated by the RBC and UKQCD collaborations, and perform extrapolations of the form factors to the continuum limit and physical pion mass. We give Standard-Model predictions for the Λb→Λ∗(1520)ℓ+ℓ- differential branching fraction and angular observables in the high-q2 region.
AB - We present the first lattice QCD determination of the Λb→Λ∗(1520) vector, axial vector, and tensor form factors that are relevant for the rare decays Λb→Λ∗(1520)ℓ+ℓ-. The lattice calculation is performed in the Λ∗(1520) rest frame with nonzero Λb momenta, and is limited to the high-q2 region. An interpolating field with covariant derivatives is used to obtain good overlap with the Λ∗(1520). The analysis treats the Λ∗(1520) as a stable particle, which is expected to be a reasonable approximation for this narrow resonance. A domain-wall action is used for the light and strange quarks, while the b quark is implemented with an anisotropic clover action with coefficients tuned to produce the correct Bs kinetic mass, rest mass, and hyperfine splitting. We use three different ensembles of lattice gauge-field configurations generated by the RBC and UKQCD collaborations, and perform extrapolations of the form factors to the continuum limit and physical pion mass. We give Standard-Model predictions for the Λb→Λ∗(1520)ℓ+ℓ- differential branching fraction and angular observables in the high-q2 region.
UR - http://www.scopus.com/inward/record.url?scp=85104582161&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85104582161&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.103.074505
DO - 10.1103/PhysRevD.103.074505
M3 - Article
AN - SCOPUS:85104582161
SN - 2470-0010
VL - 103
JO - Physical Review D
JF - Physical Review D
IS - 7
M1 - 074505
ER -