Mesons containing a heavy and a light quark in lattice quantum chromodynamics

The masses and decay constants of mesons composed of a heavy and a light quark are estimated in the SU(3) lattice gauge theory by a numerical simulation which excludes the effects of dynamic-fermion loops. In a mass region corresponding to the charmed $D$ mesons we find some evidence for a different ordering of the $P$-waves states compared to the equal-quark-mass case. An accurate determination of the mass of these states could provide another test of QCD.