Bounds on Heavy-to-Heavy Weak Decay Form Factors

Abstract

We provide upper and lower bounds on the semileptonic weak decay form factors for $B\to D^{(}\ast )$ and ${\Lambda }_b\to {\Lambda }_c$ decays by utilizing inclusive heavy quark effective theory sum rules. These bounds are calculated to second order in ${\Lambda }_{QCD}/m_Q$ and first order in ${\alpha }_s$. The $O({\alpha }_s^2{\beta }_0)$ corrections to the bounds at zero recoil are also presented.

3 pages, talk given at DPF 2000, Columbus, OH, August 9, 2000; reference added