Lattice QCD Matrix Elements for the B_{s}^{0}-B[over ¯]_{s}^{0} Width Difference beyond Leading Order.

Area of Science:

• High Energy Physics
• Quantum Chromodynamics
• Particle Physics

Background:

• Predicting the B_{s}^{0}-B[over ¯]_{s}^{0} width difference (ΔΓ_{s}) is crucial for understanding particle physics beyond the Standard Model.
• This prediction relies on the heavy quark expansion and hadronic matrix elements of ΔB=2 operators.

Purpose of the Study:

• To present the first lattice QCD results for dimension-7 operators (R_{2,3} and R[over ˜]_{2,3}).
• To perform the first Standard Model determination of ΔΓ_{s} using lattice QCD results for all hadronic matrix elements through O(1/m_{b}).

Main Methods:

• Utilized nonrelativistic QCD for the bottom quark and a highly improved staggered quark (HISQ) action for the strange quark.
• Employed MILC Collaboration ensembles with 2+1+1 flavors of sea quarks and HISQ discretization.
• Analyzed uncertainties from series truncation, discretization, and quark mass dependence.

Main Results:

• Calculated the 1/m_{b} contribution to ΔΓ_{s} as ΔΓ_{1/m_{b}} = -0.022(10) ps^{-1}.
• Determined the Standard Model prediction for ΔΓ_{s} to be 0.092(14) ps^{-1} after adding the leading order contribution.

Conclusions:

• The study provides crucial lattice QCD calculations for dimension-7 operators.
• The results offer a precise Standard Model prediction for ΔΓ_{s}, enhancing our understanding of B meson physics.