Semi-leptonic decays of heavy mesons and the Isgur-Wise function in quenched lattice QCD

TL;DR

This paper calculates semi-leptonic decay form factors of heavy mesons using quenched lattice QCD, providing insights into the Isgur-Wise function and comparing results with experimental data.

Contribution

It presents a non-perturbatively improved lattice QCD calculation of B->D and B->D* decay form factors at two couplings, including the slope of the Isgur-Wise function.

Findings

Slope of Isgur-Wise function: rho^2=0.83 with errors.

Form factor ratios are consistent with experimental data.

Results are obtained at two different lattice couplings.

Abstract

The form factors for the semi-leptonic B->D and B->D* decays are evaluated in quenched lattice QCD at two different values of the coupling, beta=6.0 and 6.2. The action and the operators are fully O(a) non-perturbatively improved. The slope of the Isgur-Wise function is evaluated, and found to be rho^2=0.83^{+15+24}_{-11-1} (quoted errors are statistical and systematic respectively). Ratios of form factors are evaluated and compared to experimental determinations.