Abstract:

Measurements of the CKM matrix elements |Vcb| and |Vub| are needed to test the Standard Model's description of CP violation and quark flavor mixing. Precise determinations of |Vub| and |Vcb| are needed for tests of CKM unitarity, which could reveal new physics before it is directly observed at the energy frontier. Measurements of |Vub| and |Vcb| are currently limited by hadronic uncertainties, but progress has recently been made in using inclusive B meson decays to limit these uncertainties. I present recent measurements of Vcb and Vub at CLEO from both exclusive and inclusive techniques. I also discuss CLEO's measurement of the photon spectrum and how this is combined with measurements of spectra in inclusive semileptonic decay to improve |Vcb| and |Vub| determinations.