B{sup +}{r_arrow}D{sub s}{sup {asterisk}+}{gamma} and B{sup +}{r_arrow}D{sup {asterisk}+}{gamma} as probes of V{sub ub}

The decays B{sup +}{r_arrow}D{sub s}{sup {asterisk}+}{gamma} and B{sup +}{r_arrow}D{sup {asterisk}+}{gamma} can be used for an extraction of {vert_bar}V{sub ub}{vert_bar}. When the {ital b} and {ital c} quarks are nearly degenerate, the rate for these modes can be determined in terms of other observed rates, namely B{bar B} mixing and D{sup {asterisk}}{r_arrow}D{gamma} decay. To this end, we introduce a novel application of heavy quark and flavor symmetries. Although somewhat unrealistic, this limit provides us with a first estimate of these rates. {copyright} {ital 1999} {ital The American Physical Society}