Beauty mesons in lattice QCD with exact chiral symmetry

TL;DR

This paper reports the first lattice QCD study of b, c, and s quarks as Dirac fermions with exact chiral symmetry, calculating meson spectra, decay constants, and quark masses.

Contribution

It introduces a novel approach to treat heavy quarks as Dirac fermions in lattice QCD with exact chiral symmetry, providing new mass spectra and decay constants.

Findings

Determined meson mass spectra for b_bbar, c_bbar, s_bbar, and c_cbar.

Calculated b and c quark masses in MS_bar scheme.

Provided decay constants for pseudoscalar mesons.

Abstract

We present the first study of treating b, c, and s quarks as Dirac fermions in lattice QCD with exact chiral symmetry. For 100 gauge configurations generated with single-plaquette action at beta = 7.2 on the 32^3 x 60 lattice, we compute point-to-point quark propagators for 33 quark masses in the range 0.01 < m_q a < 0.85, and measure the time-correlation function of (pseudo-)scalar, (pseudo-)vector, and tensor mesons, for symmetric and asymmetric quark masses respectively. The lowest-lying mass spectra of mesons with quark contents b_bbar, c_bbar, s_bbar, and c_cbar are determined, together with the pseudoscalar decay constants. Our results are sumarized in Tables 1-5. Furthermore, we also determine the b and c quark masses in the MS_bar scheme, m_b = 4.65(5) GeV, and m_c = 1.16(4) GeV.