Status of heavy quark physics on the lattice

Abstract

The status of lattice calculations of some phenomenology of heavy quarks is presented. Emphasis is on progress made in calculating those quantities relevant to estimating parameters of the quark mixing matrix, namely leptonic decay constants, the bag parameter of neutral B mixing, and semileptonic form factors. New results from studies of quarkonia are highlighted.

Standard model matrix elements for neutralB-meson mixing and associated decay constants

“…The same is true of our results for the decay constants, which are compatible with other modern, quenched determinations [32-36, 38, 39] and the world averages of [17,[42][43][44][45][46][47].…”

“…They are compatible with other recent calculations in the quenched approximation [32][33][34][35][36]38,39], as reviewed in Refs. [44,46,47]. A very recent, non-perturbatively O (a)-improved calculation by the UKQCD Collaboration [37] yields f Bs and f B which are over two statistical standard deviations higher than our results.…”

B0-B0bar mixing and decay constants from Lattice QCD

“…Note that our results, obtained with large statistics and a highly improved action are compatible with recent world averages [5,18,19,20]. …”

Studies of B_s and B_d mixing at SLD

“…Currently, lattice QCD calculations [1] give a 20 − 30% uncertainty. It is advantageous to extract the ratio V ts /V td from the ratio ∆ms ∆m d…”