Phenomenological Constraints on $\bar{\Lambda }$ and ${\lambda }_1$

Abstract

Combining the experimental data on the inclusive decays $D\to Xe\nu$, $B\to Xe\nu$ and $B\to X\tau \nu$, we find severe constraints on the $\bar{\Lambda }$ and ${\lambda }_1$ parameters of the Heavy Quark Effective Theory. In particular, we get $\bar{\Lambda }<0.7$GeV. Our constraints further imply $m_c\ge 1.43$GeV and $m_b\ge 4.66$GeV. We discuss future prospects of improving these bounds and their phenomenological implications.

Comments: 8pages RevTeX + 1 postscript figure included, WIS-94/2/Jan-PH