Abstract
Predicting the width difference relies on the heavy quark expansion and on hadronic matrix elements of operators. We present the first lattice QCD results for matrix elements of the dimension-7 operators and linear combinations using nonrelativistic QCD for the bottom quark and a highly improved staggered quark (HISQ) action for the strange quark. Computations use MILC Collaboration ensembles of gauge field configurations with flavors of sea quarks with the HISQ discretization, including lattices with physically light up or down quark masses. We discuss features unique to calculating matrix elements of these operators and analyze uncertainties from series truncation, discretization, and quark mass dependence. Finally we report the first standard model determination of using lattice QCD results for all hadronic matrix elements through . The main result of our calculations yields the contribution . Adding this to the leading order contribution, the standard model prediction is .
- Received 3 October 2019
- Accepted 22 January 2020
DOI:https://doi.org/10.1103/PhysRevLett.124.082001
Published by the American Physical Society under the terms of the 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 SCOAP3.
Published by the American Physical Society