RIGHT-HANDED CURRENTS IN B-DECAY REEXAMINED - ART. NO. 055009

We critically re-examine the case for and against a sizeable right-han ded component in the b-->c charged current coupling with a strength xi relative to the conventional left-handed current. Using data from CLE O on the decay B-->Dl nu, as well as our knowledge of V-cb extracted from both inclusive and exclusive processes, we are able to determine the presently allowed parameter space for xi via HQET. We then identif y several observables which could be measured at B factories to either strengthen these constraints or otherwise observe right-handed curren ts. This parameter space region is found to be consistent with the low degree of Lambda(b) polarization as determined by ALEPH as well as th e measurements of the charged lepton and neutrino energy spectra from b decay made by L3. We discuss how future measurements of semileptonic decay distributions may distinguish between exotic Lambda(b) depolari zation mechanisms and the existence of right-handed currents. Within t he parameter space allowed by CLEO, using the left-right symmetric mod el as a guide, we perform a detailed search for specific sub-regions w hich can lead to a reduction in both the B semileptonic branching frac tion as well as the the average yield of charmed quarks in B decay. Th e results provide a concrete realization of an earlier suggestion by V oloshin, but may lead to potential difficulties with certain penguin m ediated decay processes. [S0556-2821(98)00119-2].