Vector Component of Confinement Force and P-Wave Spectrum of D mesons

The mass spectrum and the pionic decay widths of the P-wave $D$ mesons are studied using the Dirac equation for the light quark. Our aim is to determine the Lorentz property of the confinement force. We find that the Lorentz scalar confinement is consistent with the mass spectrum, while a significant mixture of the Lorentz vector confinement is necessary to explain the decay widths.