@article{cf5b18bec23b4b95aeeaad91d1a4a9e9,
title = "| Vus | from K3 decay and four-flavor lattice QCD",
abstract = "Using highly improved staggered quark (HISQ) Nf=2+1+1 MILC ensembles with five different values of the lattice spacing, including four ensembles with physical quark masses, we perform the most precise computation to date of the K→πν vector form factor at zero momentum transfer, f+K0π-(0)=0.9696(15)stat(12)syst. This is the first calculation that includes the dominant finite-volume effects, as calculated in chiral perturbation theory at next-to-leading order. Our result for the form factor provides a direct determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vus|=0.22333(44)f+(0)(42)exp, with a theory error that is, for the first time, at the same level as the experimental error. The uncertainty of the semileptonic determination is now similar to that from leptonic decays and the ratio fK+/fπ+, which uses |Vud| as input. Our value of |Vus| is in tension at the 2-2.6σ level both with the determinations from leptonic decays and with the unitarity of the CKM matrix. In the test of CKM unitarity in the first row, the current limiting factor is the error in |Vud|, although a recent determination of the nucleus-independent radiative corrections to superallowed nuclear β decays could reduce the |Vud|2 uncertainty nearly to that of |Vus|2. Alternative unitarity tests using only kaon decays, for which improvements in the theory and experimental inputs are likely in the next few years, reveal similar tensions and could be further improved by taking correlations between the theory inputs. As part of our analysis, we calculated the correction to f+Kπ(0) due to nonequilibrated topological charge at leading order in chiral perturbation theory, for both the full-QCD and the partially quenched cases. We also obtain the combination of low-energy constants in the chiral effective Lagrangian [C12r+C34r-(L5r)2](Mρ)=(2.92±0.31)×10-6.",
author = "{(Fermilab Lattice and MILC Collaborations)} and A. Bazavov and C. Bernard and C. Detar and Daping Du and El-Khadra, {A. X.} and Freeland, {E. D.} and E. G{\'a}miz and Steven Gottlieb and Heller, {U. M.} and J. Komijani and Kronfeld, {A. S.} and J. Laiho and Mackenzie, {P. B.} and Neil, {E. T.} and T. Primer and Simone, {J. N.} and R. Sugar and D. Toussaint and {Van De Water}, {R. S.}",
note = "Funding Information: We thank Matthew Moulson for useful discussions and Bipasha Chakraborty for participating in an early stage of this analysis. We thank Johan Bijnens for making his isospin-breaking NLO partially quenched ChPT and isospin-breaking NNLO full QCD codes available to us, and Bijnens and Johan Relefors for making their FV ChPT code available to us. We thank Zechariah Gelzer for discussions on autocorrelations in the MILC ensembles. Computations for this work were carried out with resources provided by the USQCD Collaboration, the National Energy Research Scientific Computing Center, the Argonne Leadership Computing Facility, the Blue Waters sustained-petascale computing project, the National Institute for Computational Science, the National Center for Atmospheric Research, and the Texas Advanced Computing Center. USQCD resources are acquired and operated thanks to funding from the Office of Science of the U.S. Department of Energy. The National Energy Research Scientific Computing Center is a Department of Energy Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. An award of computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. This research used resources of the Argonne Leadership Computing Facility, which is a Department of Energy Office of Science User Facility supported under Contract No. DE-AC02-06CH11357. The Blue Waters sustained-petascale computing project is supported by the National Science Foundation (Grants No. OCI-0725070 and No. ACI-1238993) and the State of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications. This work is also part of the “Lattice QCD on Blue Waters” and “High Energy Physics on Blue Waters” PRAC allocations supported by the National Science Foundation (Grants No. 0832315 and No. 1615006) and used an allocation received under the “Blue Waters for Illinois faculty” program. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1548562 [161]. Allocations under the Teragrid and XSEDE programs included resources at the National Institute for Computational Sciences (NICS) at the Oak Ridge National Laboratory Computer Center, the Texas Advanced Computing Center and the National Center for Atmospheric Research, all under NSF teragrid allocation TG-MCA93S002. Computer time at the National Center for Atmospheric Research was provided by NSF MRI Grant No. CNS-0421498, NSF MRI Grant No. CNS-0420873, NSF MRI Grant No. CNS-0420985, NSF sponsorship of the National Center for Atmospheric Research, the University of Colorado, and a grant from the IBM Shared University Research (SUR) program. This work was supported in part by the U.S. Department of Energy under Grants No. DE-FG02-91ER40628 (C. B.), No. DE-FC02-12ER41879 (C. D.), No. DE-SC0010120 (S. G.), No. DE-FG02-91ER40661 (S. G.), No. DE-FG02-13ER42001 (A. X. K.), No. DE-SC0015655 (A. X. K.), No. DE-SC0010005 (E. T. N.), No. DE-FG02-13ER41976 (D. T.); by the U.S. National Science Foundation under Grants No. PHY14-14614 and No. PHY17-19626 (C. D.), No. PHY14-17805 (J. L.), and No. PHY13-16748 and No. PHY16-20625 (R. S.); by the MINECO (Spain) under Grants No. FPA2013-47836-C-1-P and No. FPA2016-78220-C3-3-P (E. G.); by the Junta de Andaluc{\'i}a (Spain) under Grant No. FQM-101 (E. G.); by the European Commission (EC) under Grant No. PCIG10-GA-2011-303781 (E. G.); by the U.K. Science and Technology Facilities Council (J. K.); by the German Excellence Initiative and the European Union Seventh Framework Program under Grant No. 291763 as well as the European Union Marie Curie COFUND program (J. K., A. S. K.). Brookhaven National Laboratory is supported by the United States Department of Energy, Office of Science, Office of High Energy Physics, under Contract No. DE-SC0012704. Fermilab is operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy, Office of Science, Office of High Energy Physics. Publisher Copyright: {\textcopyright} 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP.",
year = "2019",
month = jun,
day = "24",
doi = "10.1103/PhysRevD.99.114509",
language = "English (US)",
volume = "99",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Physical Society",
number = "11",
}