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M. Savci

Publications and source records attributed to M. Savci.

At least 91 records · Page 5Linked to original sources

Double-lepton polarization asymmetries in (Lambda_b -> Lambda l^+ l^-) decay in universal extra dimension model

Double-lepton polarization asymmetries in (Lambda_b -> Lambda l^+ l^-) decay are calculated in universal extra dimension (UED) model. It is obtained that numerous double-lepton polarization asymmetries are very sensitive to the UED model and therefore can be very useful tool for establishing new physics predicted by the UED model.establishing new physics predicted by the UED model.

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(Lambda_b -> Lambda l^+ l^-) decay in universal extra dimensions

We study the exclusive (Lambda_b -> Λl^+ l^-) decay in the Appelquist, Chang, Dobrescu model within one universal extra dimension. We investigate the sensitivity of the branching ratio, lepton polarization and forward-backward asymmetry A_{FB} to the compactification parameter (1/R) We obtain that the branching ratio changed about 50% compared to the SM value, when (1/R=200 GeV) and zero position of the forward-backward asymmetry is shifted to the left compared to the SM result. Therefore measurement of the branching ratio of (Lambda_b -> Lambda l^+ l^-) decay and determination of zero position of A_{FB} are very useful in looking for new physics in the framework of the UED models.

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Analysis of exclusive (B_s -> D_{s_0} (2317) l nu_l) decay in "full" QCD

The transition form factors of the semileptonic decay B_s into scalar D_{s_0}(2317) meson is calculated in the framework of 3-point QCD sum rule. The branching ratio is found to be ~10^(-3) for the (B_s -> D_{s_0}(2317) l nu_l) (l=e,mu) decay, and 10^(-4) for the (B_s -> D_{s_0}(2317) tau nu_tau) decay, respectively.

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Analysis of the semileptonic (B_c -> B_u* l+ l-) decay from QCD sum rules

We analyze the semileptonic (B_c -> B_u* l+ l-) decay in the frame work of the Standard Model. We calculate the (B_c) to (B_u*) transition form factors in QCD sum rules. Analytical expressions for the spectral densities and gluon condensates are presented. The branching ratio of the (B_c -> B_u* l+ l-) decay is calculated, and it is obtained that this decay can be detectable at forthcoming LHC machines.

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Polarization effects in exclusive semileptonic (Lambda_b -> Lambda l^+ l^-) decay

The independent helicity amplitudes in the (Lambda_b -> Λl^+ l^-) decay in the standard model and its minimal extension, i.e., with the new vector type interactions, are calculated. We calculate various asymmetry parameters characterizing the angular dependence of the differential decay width for the cascade decay (Lambda_b -> Lambda(-> a+b) V^* (-> l^+ l^-)) with polarized and unpolarized heavy baryons. The sensitivity of the asymmetry parameters to the new Wilson coefficients are analyzed.

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P-odd asymmetries in polarized (Lambda_b -> Lambda l^+ l^-) decay

We calculate various P-odd asymmetries appearing in the differential decay width for the cascade decay (Lambda_b -> Lambda(-> a+b) V^* (-> l^+ l^-)) with polarized and unpolarized heavy baryons including new vector type interactions and using the helicity amplitudes. It is obtained that the study of P-odd asymmetries can serve a good test for establishing new physics beyond the SM.

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Exclusive (B -> rho l^+ l^-) decay and Polarized lepton pair forward--backward asymmetries

The polarized lepton pair forward-backward asymmetries in (B -> rho l^+ l^-) decay using a general, model independent form of the effective Hamiltonian is studied. The general expression for nine double-polarization forward-backward asymmetries are calculated. The study of the forward-backward asymmetries of the doubly-polarized lepton pair proves to be very useful tool in looking for new physics beyond the standard model.

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Polarized forward-backward asymmetries of leptons in (B_s -> l^+ l^- gamma) decay

Polarized forward-backward asymmetries in the (B_s -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian, including all possible forms of interactions. The dependencies of the asymmetries on new Wilson coefficients are investigated. The detectability of the asymmetries at LHC is discussed.

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Double-lepton polarization asymmetries in Lambda_b -> Lambda l^+ l^- decay

Double-lepton polarization asymmetries in (Lambda_b -> Lambda l^+ l^-) decay are calculated using a general, model independent form of the effective Hamiltonian. The sensitivities of these asymmetries to the new Wilson coefficients are studied in detail. Furthermore, the correlations between averaged double-lepton polarization asymmetry and branching ratio are analyzed. It is shown that there exist certain regions of the new Wilson coefficients where new physics can be established by measuring the double-lepton polarization asymmetries only.

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Forward-backward asymmetries in (Lambda_b -> Lambda l^+ l^-) decay beyond the standard model

We study the doubly-polarized lepton pair forward-backward asymmetries in (Lambda_b -> Lambda l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine double-polarization forward-backward asymmetries. It is observed that, the study of the forward-backward asymmetries of the doubly-polarized lepton pair is a very useful tool for establishing new physics beyond the standard model. Moreover, the correlation between forward-backward asymmetry and branching ratio is investigated. It is shown that there exist certain certain regions of the new Wilson coefficients where new physics can be established by measuring the polarized forward-backward asymmetry only.

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Polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay beyond the standard model

We study the polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine double-polarization forward-backward asymmetries. It is shown that, the study of the forward-backward asymmetries of the doubly-polarized lepton pair is a very useful tool for establishing new physics beyond the standard model.

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Electromagnetic form factors of the (rho) meson in light cone QCD sum rules

We investigate the electromagnetic form factors of the (rho) meson in light cone QCD sum rules. We find that the ratio of the magnetic and charge form factors is larger than two at all values of Q^2, (Q^2 >= 0.5 GeV^2). The values of the individual form factors at fixed values of Q^2 predicted by the light cone QCD sum rules are quite different compared to the results of other approaches. These results can be checked in future, when more precise data on (rho) meson form factors is available.

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Double-lepton polarization asymmetries in the (B -> K l^+ l^-) decay beyond the Standard Model

General expressions for the double-lepton polarizations in the (B -> K l^+ l^-) decay are obtained, using model independent effective Hamiltonian, including all possible interactions. Correlations between the averaged double-lepton polarization asymmetries and the branching ratio, as well as, the averaged single-lepton polarization asymmetry are studied. It is observed that, study of the double-lepton polarization asymmetries can serve as a good test for establishing new physics beyond the Standard Model.

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Magnetic moment of the (rho) meson in light cone QCD

The magnetic moment $μ$ of the "rho" meson is studied in QCD light cone sum rules, and it is found that "mu = (2.3 pm 0.5)". A comparison of our result on the magnetic moment of the "rho" meson with the predictions of the other approaches, is presented.

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Fourth generation effects in processes induced by "b -> s" transition

We study the effects of sequential fourth quark generation in rare "B -> K(K*) l^+ l^-" decays induced by "b -> s" transition and in "B_s^0 - bar{B}_s^0" mixing. Using the experimental values on branching ratios of the "B -> X_s gamma" and "B -> K(K*) l^+ l^-" decays, the allowed regions for $\vel V_{tb} V_{ts}^\ast\ver$ and "|V_{t'b} V_{t's}*| are determined as a function of the (t') quark mass.

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