{"paper":{"title":"$B\\to\\pi\\ell\\nu$ semileptonic form factors from unquenched lattice QCD and determination of $|V_{ub}|$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-lat","authors_text":"A. Bazavov, A. S. Kronfeld, A. X. El-Khadra, C. Bernard, C. Bouchard, C. DeTar, D. Du, D. Toussaint, E. D. Freeland, E. Gamiz, E. T. Neil, J. A. Bailey, J. Foley, J. Laiho, J. N. Simone, L. Levkova, P. B. Mackenzie, R. L. Sugar, R. S. Van de Water, R. Zhou, S. Qiu, Steven Gottlieb, U. M. Heller, Y. Meurice, Yuzhi Liu","submitted_at":"2014-11-21T21:59:51Z","abstract_excerpt":"We compute the $B\\to\\pi\\ell\\nu$ semileptonic form factors and update the determination of the CKM matrix element $|V_{ub}|$. We use the MILC asqtad ensembles with $N_f=2+1$ sea quarks at four different lattice spacings in the range $a \\approx 0.045$~fm to $0.12$~fm. The lattice form factors are extrapolated to the continuum limit using SU(2) staggered chiral perturbation theory in the hard pion limit, followed by an extrapolation in $q^2$ to the full kinematic range using a functional $z$-parameterization. The extrapolation is combined with the experimental measurements of the partial branchin"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1411.6038","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}