Neutral B Mixing in Staggered Chiral Perturbation Theory

Abstract

I calculate, at one loop in staggered chiral perturbation theory, the matrix elements of the complete set of five local operators that may contribute to B mixing both in the Standard Model and in beyond-the-Standard-Model theories. Lattice computations of these matrix elements by the Fermilab Lattice/MILC collaborations (and earlier by the HPQCD collaboration) convert a light staggered quark into a naive quark, and construct the relevant 4-quark operators as local products of two local bilinears, each involving the naive light quark and the heavy quark. This particular representation of the operators turns out to be important in the chiral calculation, and it results in the presence of "wrong-spin" operators, whose contributions however vanish in the continuum limit. If the matrix elements of all five operators are computed on the lattice, then no additional low energy constants are required to describe wrong-spin chiral effects.

33 pages, 9 figures. v2: An appendix giving results for B-parameters has been added. Minor additional updates for clarity, to fix typos, and to get hyperrefs to work. Version to be published in Phys. Rev. D

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Cited by in corpus (8)

• FLAG Review 2019
• $B_{(s)}^0$-mixing matrix elements from lattice QCD for the Standard Model and beyond
• Neutral B-meson mixing from full lattice QCD at the physical point
• Short-distance matrix elements for $D^0$-meson mixing for $N_f=2+1$ lattice QCD
• Update on a short-distance D^0-meson mixing calculation with $N_f=2+1$ flavors
• Matrix Elements for $D$- and $B$-Mixing from 2+1 Flavor Lattice QCD
• Neutral B-meson mixing parameters in and beyond the SM with 2+1 flavor lattice QCD
• D-Meson Mixing in 2+1-Flavor Lattice QCD