Asiye Tuğba Olgun

Constraint on compactification scale via recently observed baryonic Λb → Λℓ+ℓ− channel and analysis of the Σb → Σℓ+ℓ− transition in SM and UED scenario

We obtain a lower limit on the compactification scale of extra dimension via comparison of the branching ratio in the baryonic Λb → Λμ+μ− decay channel recently measured by CDF collaboration and our previous theoretical study. We also use the newly available form factors calculated via light cone QCD sum rules in full theory to analyze the flavour changing neutral current process of the Σb → Σl+l− in universal extra dimension scenario in the presence of a single extra compact dimension. We calculate various physical quantities like branching ratio, forward-backward asymmetry, baryon polarizations and double lepton polarization asymmetries defining the decay channel under consideration. We also compare the obtained predictions with those of the standard model. PACS number(s): 12.60-i, 13.30.-a, 13.30.Ce, 14.20.Mr e-mail: kazizi@dogus.edu.tr e-mail: sehban@istanbul.edu.tr e-mail: nkatirci@dogus.edu.tr e-mail: a.t.olgun@gmail.com.tr e-mail: z.tavukoglu@gmail.com.trA bstractWe obtain a lower limit on the compactification scale of extra dimension via comparison of the branching ratio in the baryonic Λb → Λμ+μ− decay channel recently measured by CDF collaboration and our previous theoretical study. We also use the newly available form factors calculated via light cone QCD sum rules in full theory to analyze the flavour changing neutral current process of the Σb → Σℓ+ℓ− in universal extra dimension scenario in the presence of a single extra compact dimension. We calculate various physical quantities like branching ratio, forward-backward asymmetry, baryon polarizations and double lepton polarization asymmetries defining the decay channel under consideration. We also compare the obtained predictions with those of the standard model.

Comparative analysis of the

We comparatively analyze the rare

\Lambda_b \rightarrow \Lambda \ell^+ \ell^-

\Lambda _b\rightarrow \Lambda \ell^+ \ell^-

decay in the SM, SUSY and RS model with custodial protection

channel in standard model, supersymmetry and Randall-Sundrum model with custodial protection (RS

Analysis of the semileptonic

_c

\Lambda_b\rightarrow \Lambda \ell^+ \ell^-

). Using the parametrization of the matrix elements entering the low energy effective Hamiltonian in terms of form factors, we calculate the corresponding differential decay width and lepton forward-backward asymmetry in these models. We compare the results obtained with the most recent data from LHCb as well as lattice QCD results on the considered quantities. It is obtained that the standard model, with the form factors calculated in light-cone QCD sum rules, can not reproduce some experimental data on the physical quantities under consideration but the supersymmetry can do it. The RS

transition in the topcolor-assisted technicolor model

_c

Analysis of the semileptonic Λ b → Λ ℓ + ℓ − transition in the topcolor-assisted technicolor model

model predictions are roughly the same as the standard model and there are no considerable differences between the predictions of these two models. In the case of differential decay rate, the data in the range

Comparative analysis of the semileptonic Λ b → Λℓ + ℓ − transition in SM and different SUSY scenarios using form factors from full QCD

4

Radiative Σb→Σγ decay in SM and BSM

GeV