We study the exclusive flavor changing neutral current process [Formula: see text] in the leptophobic Z′ model, where charged leptons do not couple to the extra Z′ boson. The branching ratio, as well as, the longitudinal, transversal and normal polarizations are calculated. It has been shown that all these physical observables are very sensitive to the existence of new physics beyond the standard model and their experimental measurements can give valuable information about it.

We investigate the B → K * 0 (1430)l + l − transition in the Applequist-Cheng-Dobrescu model in the presence of a universal extra dimension. In particular, we calculate double lepton polarization asymmetries and branching ratio related to this channel and compare the obtained results with the predictions of the standard model. Our analysis of the considered observables in terms of radius R of the compactified extra-dimension as the new parameter of the model show a considerable discrepancy between the predictions of two models in low

We study the radiative dileptonic B → γl + l − transition in the presence of a universal extra dimension in the Applequist-Cheng-Dobrescu model. In particular, using the corresponding form factors calculated via light cone QCD sum rules, we analyze the branching ratio and double lepton polarization asymmetries related to this channel and compare the results with the predictions of the standard model. We show how the results deviate from predictions of the standard model at lower values of the compactification factor (1/R) of extra dimension.

Using the most general model independent form of the effective Hamiltonian, the rare B s → γ ℓ + ℓ − decays are studied by taking into account the polarization of the photon. The total and the differential branching ratios for these decays, when photon is in the positive and negative helicity states, are presented. Dependence of these observables on the new Wilson coefficients are studied. It is also investigated the sensitivity of "photon polarization asymmetry" in B s → γ ℓ + ℓ − decays to the new Wilson coefficients. It has been shown that all these physical observables are very sensitive to the existence of new physics beyond SM and their experimental measurements can give valuable information about it.

Double-lepton polarization asymmetries for the exclusive decay B → K 1 l + l − in the Universal Extra Dimension (UED) Model is studied. It is obtained that double-lepton polarization asymmetries are very sensitive to the UED model parameters. Experimental measurements of double lepton polarizations can give valuable information on the physics beyond the Standard Model (SM).