TY - JOUR
T1 - Λc → Λl+νl Form Factors and Decay Rates from Lattice QCD with Physical Quark Masses
AU - Meinel, Stefan
N1 - Funding Information:
I thank Christoph Lehner for computing the perturbative renormalization and improvement coefficients, and Sergey Syritsyn for help with the generation of the domain-wall propagators on the physical-pion-mass ensemble. I am grateful to the RBC and UKQCD Collaborations for making their gauge field ensembles available. This work was supported by National Science Foundation Grant No.PHY-1520996 and by the RHIC Physics Fellow Program of the RIKEN BNL Research Center. High-performance computing resources were provided by the Extreme Science and Engineering Discovery Environment (XSEDE), supported by National Science Foundation Grant No.ACI-1053575, as well as 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-AC02-05CH11231. The chroma [44] and qlua [45] software systems were used in this work.
Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/2/21
Y1 - 2017/2/21
N2 - The first lattice QCD calculation of the form factors governing Λc→Λℓ+νℓ decays is reported. The calculation was performed with two different lattice spacings and includes one ensemble with a pion mass of 139(2) MeV. The resulting predictions for the Λc→Λe+νe and Λc→Λμ+νμ decay rates divided by Vcs2 are 0.2007(71)(74) and 0.1945(69)(72) ps-1, respectively, where the two uncertainties are statistical and systematic. Taking the Cabibbo-Kobayashi-Maskawa (CKM) matrix element Vcs from a global fit and the Λc lifetime from experiments, this translates to branching fractions of B(Λc→Λe+νe)=0.0380(19)LQCD(11)τΛc and B(Λc→Λμ+νμ)=0.0369(19)LQCD(11)τΛc. These results are consistent with, and two times more precise than, the measurements performed recently by the BESIII Collaboration. Using instead the measured branching fractions together with the lattice calculation to determine the CKM matrix element gives Vcs=0.949(24)LQCD(14)τΛc(49)B.
AB - The first lattice QCD calculation of the form factors governing Λc→Λℓ+νℓ decays is reported. The calculation was performed with two different lattice spacings and includes one ensemble with a pion mass of 139(2) MeV. The resulting predictions for the Λc→Λe+νe and Λc→Λμ+νμ decay rates divided by Vcs2 are 0.2007(71)(74) and 0.1945(69)(72) ps-1, respectively, where the two uncertainties are statistical and systematic. Taking the Cabibbo-Kobayashi-Maskawa (CKM) matrix element Vcs from a global fit and the Λc lifetime from experiments, this translates to branching fractions of B(Λc→Λe+νe)=0.0380(19)LQCD(11)τΛc and B(Λc→Λμ+νμ)=0.0369(19)LQCD(11)τΛc. These results are consistent with, and two times more precise than, the measurements performed recently by the BESIII Collaboration. Using instead the measured branching fractions together with the lattice calculation to determine the CKM matrix element gives Vcs=0.949(24)LQCD(14)τΛc(49)B.
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U2 - 10.1103/PhysRevLett.118.082001
DO - 10.1103/PhysRevLett.118.082001
M3 - Article
C2 - 28282163
AN - SCOPUS:85014454746
SN - 0031-9007
VL - 118
JO - Physical review letters
JF - Physical review letters
IS - 8
M1 - 082001
ER -