TY - JOUR
T1 - Semileptonic form factors for B→ D∗ℓν at nonzero recoil from 2 + 1 -flavor lattice QCD
T2 - Fermilab Lattice and MILC Collaborations
AU - Bazavov, A.
AU - DeTar, C. E.
AU - Du, D.
AU - El-Khadra, A. X.
AU - Gámiz, E.
AU - Gelzer, Z.
AU - Gottlieb, S.
AU - Heller, U. M.
AU - Kronfeld, A. S.
AU - Laiho, J.
AU - Mackenzie, P. B.
AU - Simone, J. N.
AU - Sugar, R.
AU - Toussaint, D.
AU - Van de Water, R. S.
AU - Vaquero, A.
N1 - Funding Information:
We thank Claude Bernard for early contributions to this project, in particular for laying the foundations for the chiral-continuum extrapolations employed in this analysis. We thank Biplab Dey, Danny van Dyk, Paolo Gambino, Martin Jung, Laurent Lellouch, William Marciano, Christoph Schwanda, Phillip Urquijo, and Eiasha Waheed for useful discussions. We thank Biplab Dey especially for providing additional information on the BaBar analysis [], and Martin Jung for his careful reading of the manuscript. We thank Jon Bailey and Chris Bouchard for generating some of the correlator data. Computations for this work were carried out with resources provided by the USQCD Collaboration, the National Energy Research Scientific Computing Center, and the Argonne Leadership Computing Facility, which are funded by the Office of Science of the U.S. Department of Energy; and with resources provided by the National Institute for Computational Science and the Texas Advanced Computing Center, which are funded through the National Science Foundation’s Teragrid/XSEDE Program. This work was supported in part by the U.S. Department of Energy under Awards No. DE-FG02-13ER41976 (D.T.), No. DE-SC0009998 (J.L.), No. DE-SC0010120 (S.G.), and No. DE-SC0015655 (A.X.K.,Z.G.); by the U.S. National Science Foundation under Grants No. PHY17-19626 (C.D., A.V.), and No. PHY14-17805 (J.L.); by SRA (Spain) under Grant No. PID2019-106087GB-C21/10.13039/501100011033 (E.G.); by the Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (Spain) under Grants No. FQM- 101, A-FQM-467-UGR18, and P18-FR-4314 (FEDER) (E.G.); by the Fermilab Distinguished Scholars Program (A.X.K.). This document was prepared by the Fermilab Lattice and MILC Collaborations using the resources of the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - We present the first unquenched lattice-QCD calculation of the form factors for the decay B→ D∗ℓν at nonzero recoil. Our analysis includes 15 MILC ensembles with Nf= 2 + 1 flavors of asqtad sea quarks, with a strange quark mass close to its physical mass. The lattice spacings range from a≈ 0.15 fm down to 0.045 fm, while the ratio between the light- and the strange-quark masses ranges from 0.05 to 0.4. The valence b and c quarks are treated using the Wilson-clover action with the Fermilab interpretation, whereas the light sector employs asqtad staggered fermions. We extrapolate our results to the physical point in the continuum limit using rooted staggered heavy-light meson chiral perturbation theory. Then we apply a model-independent parametrization to extend the form factors to the full kinematic range. With this parametrization we perform a joint lattice-QCD/experiment fit using several experimental datasets to determine the CKM matrix element | Vcb|. We obtain | Vcb| = (38.40 ± 0. 68 th± 0. 34 exp± 0. 18 EM) × 10 - 3. The first error is theoretical, the second comes from experiment and the last one includes electromagnetic and electroweak uncertainties, with an overall χ2/dof = 126 / 84 , which illustrates the tensions between the experimental data sets, and between theory and experiment. This result is in agreement with previous exclusive determinations, but the tension with the inclusive determination remains. Finally, we integrate the differential decay rate obtained solely from lattice data to predict R(D∗) = 0.265 ± 0.013 , which confirms the current tension between theory and experiment.
AB - We present the first unquenched lattice-QCD calculation of the form factors for the decay B→ D∗ℓν at nonzero recoil. Our analysis includes 15 MILC ensembles with Nf= 2 + 1 flavors of asqtad sea quarks, with a strange quark mass close to its physical mass. The lattice spacings range from a≈ 0.15 fm down to 0.045 fm, while the ratio between the light- and the strange-quark masses ranges from 0.05 to 0.4. The valence b and c quarks are treated using the Wilson-clover action with the Fermilab interpretation, whereas the light sector employs asqtad staggered fermions. We extrapolate our results to the physical point in the continuum limit using rooted staggered heavy-light meson chiral perturbation theory. Then we apply a model-independent parametrization to extend the form factors to the full kinematic range. With this parametrization we perform a joint lattice-QCD/experiment fit using several experimental datasets to determine the CKM matrix element | Vcb|. We obtain | Vcb| = (38.40 ± 0. 68 th± 0. 34 exp± 0. 18 EM) × 10 - 3. The first error is theoretical, the second comes from experiment and the last one includes electromagnetic and electroweak uncertainties, with an overall χ2/dof = 126 / 84 , which illustrates the tensions between the experimental data sets, and between theory and experiment. This result is in agreement with previous exclusive determinations, but the tension with the inclusive determination remains. Finally, we integrate the differential decay rate obtained solely from lattice data to predict R(D∗) = 0.265 ± 0.013 , which confirms the current tension between theory and experiment.
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U2 - 10.1140/epjc/s10052-022-10984-9
DO - 10.1140/epjc/s10052-022-10984-9
M3 - Article
AN - SCOPUS:85144182797
SN - 1434-6044
VL - 82
JO - European Physical Journal C
JF - European Physical Journal C
IS - 12
M1 - 1141
ER -