Light-Front Heavy Quark Effective Theory and Heavy Meson Bound States

The heavy quark effective theory is developed on the light-front. Based on this effective theory, a light-front heavy meson bound state with definite spin and parity is constructed. Within the effective theory, the Isgur-Wise function is derived in terms of the asymptotic light-front bound state amplitudes in the limit $m_Q\to \mathrm{\infty }$; the result is a general expression for arbitrary recoil velocities. With the asymptotic form of the BSW amplitudes, the Isgur-Wise function is given by $\xi (v\cdot v^{\mathrm{\prime }})=1\mathrm{/}v\cdot v^{\mathrm{\prime }}$. The slope at the zero-recoil point is ${\rho }^2=-{\xi }^{\mathrm{\prime }}(1)=1$, in excellent agreement with the recent CLEO result of ${\rho }^2=1.01\pm 0.15\pm 0.09$.