Λ[subscript b] → pℓ[superscript -][bar over v]ℓ and Λ[subscript b] → Λ[subscript c]ℓ[superscript -][bar over v]ℓ form factors from lattice QCD with relativistic heavy quarks
Name
PhysRevD.92.034503.pdf
Size
1.44 MB
Format
Adobe PDF
Checksum (MD5)
620901118cb2cc73bcdc75e4ae239af4
Author(s)
Detmold, William
Lehner, Christoph
Meinel, Stefan
Date Issued
August 2015
Journal
Physical Review D
Publisher
American Physical Society
Citation
Detmold, William, Christoph Lehner, and Stefan Meinel. "Λ[subscript b] → pℓ[superscript -][bar over v]ℓ and Λ[subscript b] → Λ[subscript c]ℓ[superscript -][bar over v]ℓ form factors from lattice QCD with relativistic heavy quarks." Phys. Rev. D 92, 034503 (August 2015). © 2015 American Physical Society
Version
Final published version
Abstract
Measurements of the Λ[subscript b] → pℓ[superscript -][bar over v]ℓ and Λ[subscript b] → Λ[subscript c]ℓ[superscript -][bar over v]ℓ decay rates can be used to determine the magnitudes of the Cabibbo-Kobayashi-Maskawa matrix elements V[subscript ub] and V[subscript cb], provided that the relevant hadronic form factors are known. Here we present a precise calculation of these form factors using lattice QCD with 2+1 flavors of dynamical domain-wall fermions. The b and c quarks are implemented with relativistic heavy-quark actions, allowing us to work directly at the physical heavy-quark masses. The lattice computation is performed for six different pion masses and two different lattice spacings, using gauge-field configurations generated by the RBC and UKQCD Collaborations. The b → u and b → c currents are renormalized with a mostly nonperturbative method. We extrapolate the form factor results to the physical pion mass and the continuum limit, parametrizing the q[superscript 2] dependence using z expansions. The form factors are presented in such a way as to enable the correlated propagation of both statistical and systematic uncertainties into derived quantities such as differential decay rates and asymmetries. Using these form factors, we present predictions for the Λ[subscript b] → pℓ[superscript -][bar over v]ℓ and Λ[subscript b] → Λ[subscript c]ℓ[superscript -][bar over v]ℓ differential and integrated decay rates. Combined with experimental data, our results enable determinations of |V[subscript ub]|, |V[subscript cb]|, and |V[subscript ub]/V[subscript cb]| with theory uncertainties of 4.4%, 2.2%, and 4.9%, respectively.
MIT Department
Massachusetts Institute of Technology. Center for Theoretical Physics
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevD.92.034503
