HEP/Astro Seminar, Thursday 16th April 1998

MODEL INDEPENDENT EXTRACTION OF |V(CB)| USING DISPERSION RELATIONS

Ben Grinstein (U. California, San Diego)

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Abstract

We present a method for parametrizing heavy meson semileptonic form
factors using dispersion relations, and from it produce a
two-parameter description of the B -> B elastic form factor. We use
heavy quark symmetry to relate this function to B->D* l \nu form
factors, and extract |V_{cb}|=0.037^{+0.003}_{-0.002} from
experimental data with a least squares fit. Our method eliminates
model-dependent uncertainties inherent in choosing a parametrization
for the extrapolation of the differential decay rate to threshold. The
method also allows a description of B -> D l nu form factors accurate
to 1% in terms of two parameters.

Thursday, 3:30pm, Smith Lab 4079