Transition b to sl+l-

Searches for physics beyond the Standard Model (BSM) through the low energy flavor physics experiments could provide us with an indirect tool for identifying the new particles that will hopefully be directly detected at LHC. Flavor changing neutral currents are known to be particularly revealing in that respect, and the b to s transitions are known to be particularly interesting. In this work we discussed the transition b to sl+l-, in particular we studied the exclusive decays B to Kl+ l- and B to K*l+l-. We collected the decay amplitude formulas of these two rare B-decays, based on the OPE. For both decay modes we collected different sets of form factors, obtained with different methods, and we discussed the hadronic uncertainties related to these quantities. This phenomenological study was completely model-independent: we constructed observables protected against QCD uncertainties and we searched for a way to identify, according to the experimental results, the Wilson coefficients where the new physics enters. In the case of B to K*l+l- decay, we studied the effects of the right-handed currents, i.e. the C'_{7,9,10} Wilson coefficients, analyzing the low q2-region. We discussed the three independent asymmetries, AT(2)(q2), AT(im)(q2) and AT(re)(q2). Studying their low q2-dependence can be helpful in discerning among various possible new physics scenarios. In particular from the shapes of these three transverse asymmetries at low q2's and the point at which the three asymmetries can change the sign, one can tell which operators receive contributions from BSM physics. In the case of B to Kl+l-, we considered the scenarios in which there are non-SM Dirac structure, (pseudo-)scalar and (pseudo-)tensor type interactions, i.e. , i.e. the C_{S,P,T,T5} Wilson coefficients. We studied the current constraints on the scalar and tensor Wilson coefficients and we used them to discuss the A_FB(q2) in this decay. We showed that at high q2, nearly the end point, a huge enhancement appears in certain scenarios