Using heavy meson chiral perturbation theory, we consider the light quark mass and spatial volume dependence of the matrix elements of ΔB=2 and ΔC=2 four-quark operators relevant for B(s)0-B̄(s)0 and D0-D̄0 mixing, and the Bs meson width difference. Our results for these matrix elements are obtained in the Nf=2+1 partially quenched theory, which becomes full QCD in the limit where sea and valence quark masses become equal. They can be used in extrapolation of lattice calculations of these matrix elements to the physical light quark masses and to infinite volume. An important conclusion of this paper is that the chiral extrapolations for matrix elements of heavy-light meson mixing beyond the standard model, and those relevant for the Bs width difference are more complicated than that for the standard model mixing matrix elements.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - 2 Jul 2007|