Abstract
We report the results of a lattice quantum chromodynamics calculation of FK/Fπ using Möbius domain-wall fermions computed on gradient-flowed Nf=2+1+1 highly improved staggered quark (HISQ) ensembles. The calculation is performed with five values of the pion mass ranging from 130 400 MeV, four lattice spacings of a∼0.15, 0.12, 0.09 and 0.06 fm and multiple values of the lattice volume. The interpolation/extrapolation to the physical pion and kaon mass point, the continuum, and infinite volume limits are performed with a variety of different extrapolation functions utilizing both the relevant mixed-action effective field theory expressions as well as discretization-enhanced continuum chiral perturbation theory formulas. We find that the a∼0.06 fm ensemble is helpful, but not necessary to achieve a subpercent determination of FK/Fπ. We also include an estimate of the strong isospin breaking corrections and arrive at a final result of FK+/Fπ+=1.1942(45) with all sources of statistical and systematic uncertainty included. This is consistent with the Flavour Lattice Averaging Group average value, providing an important benchmark for our lattice action. Combining our result with experimental measurements of the pion and kaon leptonic decays leads to a determination of |Vus|/|Vud|=0.2311(10).
| Original language | English |
|---|---|
| Article number | 034507 |
| Journal | Physical Review D |
| Volume | 102 |
| Issue number | 3 |
| DOIs | |
| State | Published - Aug 15 2020 |
| Externally published | Yes |
Funding
We would like to thank V. Cirigliano, S. Simula, J. Simone, and T. Kaneko for helpful correspondence and discussions regarding the strong isospin breaking corrections to . We would like to thank J. Bijnens for helpful correspondence on and a c ++ interface to chiron that we used for the analysis presented in this work. We thank the MILC Collaboration for providing some of the HISQ configurations used in this work, and A. Bazavov, C. Detar, and D. Toussaint for guidance on using their code to generate the new HISQ ensembles also used in this work. We would like to thank P. Lepage for enhancements to gvar and lsqfit that enable the pickling of lsqfit . nonlinear _ fit objects. We also thank C. Bernard for useful correspondence concerning higher order extrapolation analysis and R. Sommer for comments on the leading asymptotic scaling violations. Computing time for this work was provided through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program and the LLNL Multiprogrammatic and Institutional Computing program for Grand Challenge allocations on the LLNL supercomputers. This research utilized the NVIDIA GPU-accelerated Titan and Summit supercomputers at Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725 as well as the Surface, RZHasGPU, Pascal, Lassen, and Sierra supercomputers at Lawrence Livermore National Laboratory. The computations were performed utilizing lalibe which utilizes the chroma software suite with quda solvers and HDF5 for I/O . They were efficiently managed with metaq and status of tasks logged with EspressoDB . The hybrid Monte Carlo was performed with the milc Code , and for the ensembles new in this work, running on GPUs using quda . The final extrapolation analysis utilized gvar v11.2 and lsqfit v11.5.1 and chiron v0.54 . This work was supported by the NVIDIA Corporation (M. A. C.), the Alexander von Humboldt Foundation through a Feodor Lynen Research Fellowship (C. K.), the DFG and the NSFC Sino-German CRC110 (E. B.), the RIKEN Special Postdoctoral Researcher Program (E. R.), the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Awards No. DE-AC02-05CH11231 (C. C. C., C. K., B. H., A. W. L.), No. DE-AC52-07NA27344 (D. A. B., D. H., A. S. G., P. V.), No. DE-FG02-93ER-40762 (E. B.), No. DE-AC05-06OR23177 (B. J., C. M., K. O.), No. DE-FG02-04ER41302 (K. O.); the Office of Advanced Scientific Computing (B. J.); the Nuclear Physics Double Beta Decay Topical Collaboration (D. A. B., H. M. C., A. N., A. W. L.); and the DOE Early Career Award Program (C. C. C., A. W. L.).
| Funders | Funder number |
|---|---|
| Nuclear Physics Double Beta Decay Topical Collaboration | |
| Office of Advanced Scientific Computing | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Alexander von Humboldt-Stiftung | |
| Office of Science | |
| Nuclear Physics | DE-FG02-93ER-40762, DE-AC02-05CH11231, DE-FG02-04ER41302, DE-AC52-07NA27344, DE-AC05-06OR23177 |
| NVIDIA | |
| Deutsche Forschungsgemeinschaft | |
| National Natural Science Foundation of China | |
| RIKEN |