The radial distributions of a heavy-light meson on a lattice

TL;DR

This study measures the radial distributions of heavy-light mesons on a lattice, improving previous work by using dynamical fermions, more data, and analyzing excited states, revealing decay patterns consistent with known meson masses.

Contribution

The paper introduces enhanced lattice simulations with dynamical fermions and extensive data analysis, including excited states, to better understand meson radial distributions.

Findings

Exponential decay characterized by meson masses 0.9 and 1.5 GeV.

Distributions measured at many off-axis points.

Results align with vector and scalar qqbar-states.

Abstract

In an earlier work, the charge (vector) and matter (scalar) radial distributions of heavy-light mesons were measured in the quenched approximation on a 16^3 times 24 lattice with a quark-gluon coupling of 5.7, a lattice spacing of 0.17 fm, and a hopping parameter corresponding to a light quark mass about that of the strange quark. Several improvements are now made: 1) The configurations are generated using dynamical fermions with a quark-gluon coupling of 5.2 (a lattice spacing of 0.14 fm); 2) Many more gauge configurations are included (78 compared with the earlier 20); 3) The distributions at many off-axis, in addition to on-axis, points are measured; 4) The data-analysis is much more complete. In particular, distributions involving excited states are extracted. The exponential decay of the charge and matter distributions can be described by mesons of mass 0.9+-0.1 and 1.5+-0.1 GeV respectively - values that are consistent with those of vector and scalar qqbar-states calculated directly with the same lattice parameters.