Field-theoretic realization of heavy mesons as composite particles

We construct a covariant field-theoretic model for the structure of a heavy meson in the heavy quark limit. This model overcomes the limitations caused by non-covariance in the light-front quark model, thus it is very useful for studying hadronic matrix elements at arbitrary momentum transfers. Furthermore, the model satisfies heavy quark symmetry and provides a suitable framework for the systematic evaluation of heavy quark symmetry breaking effects caused by 1/m_Q corrections in the heavy quark effective theory of QCD. The Isgur-Wise function, the decay constant, and the axial-vector coupling constant are calculated, and physically realistic results are obtained.