Probing the standard model and its extensions in rare exclusive b -> sl(+)l(-) decays

Long-distance effects on the forward-backward and longitudinal lepton polar isation asymmetries in rare B --> (K, K*)l(+)l(-) decays are investigated. The lepton asymmetries are found to be largely unaffected by the theoretica l uncertainties in the long-distance contributions, induced both by the lon g-range charming penguins in the l(+)l(-) channel and by the transition for m factors in the meson channels, while they are mainly determined by the sh ort-distance Wilson coefficients, providing in this way a test of the possi ble presence of New Physics. We also show that within left-right models one can expect a strong enhancement of the right-handed K* production in B --> K*l(+)l(-) decays compared to models including only left-handed quark curr ents. Hence an experimental study of the transverse asymmetry of the produc ed K* mesons provides a dean possibility to discriminate between the MSSM a nd LR extensions of the SM.