arXiv subjects
Publications and source records attributed to T. M. Aliev.
We calculate the "pi Sigma Lambda" and "pi Sigma Sigma" coupling constants in light cone QCD sum rules for the structure "sigma_{alpha beta} gamma_5 p^alpha q^beta". A comparison of our results on these coupling constants with prediction of the SU(3) symmetry is presented.
The "g_{Delta N gamma}" coupling for the "Delta -> N gamma" decay is calculated in framework of the light cone QCD sum rules and is found to be g_{Delta N gamma} = (1.6 pm 0.2) GeV^(-1). Using this value of g_{Delta N gamma} we estimate the branching ratio of the Delta^+ -> N gamma decay, which is in a very good agreement with the experimental result.
We study the b --> sγdecay including the next to leading QCD corrections in the two Higgs doublet model with flavor changing neutral currents at the tree level. We find the constraints to the flavor changing parameters of the model, using the experimental results on the branching ratio of B --> X_s γdecay, provided by the CLEO Collaboration, the restrictions coming from the ΔF=2 (F=K,D,B) mixing and the ρparameter.
The strong coupling constants g_{K LAMBDA N} and g_{K SIGMA N} for the structure (sigma_{mu,nu} gamma_5) are calculated within light cone QCD sum rules. A comparison of our results on these couplings with predictions from traditional QCD sum rules is presented.
We study the decay width, forward-backward asymmetry and the longitudinal lepton polarization for the exclusive decay B --> K^* l^+ l^- in the two Higgs doublet model with three level flavor changing neutral currents (model III) and analyse the dependencies of these quantities on the the selected parameters, ξ^{U,D}, of model III including the next to leading QCD corrections. It is found that to look for charged Higgs effects, the measurements of the branching ratio, forward-backward asymmetry and the longitudinal lepton polarization for the decay B --> K^* l^+ l^- are promising.
The form factors and the branching ratio of the "B -> a_1 l nu" decay are calculated in framework of QCD sum rules. A comparison of our results on form factors and branching ratio with the results from constituent quark model is presented.
We investigate the exclusive B -> pi e^+ e^- and B -> rho e^+ e^- decays in framework of the general two Higgs doublet model (model III), in which an extra phase angle in the charged--Higgs fermion coupling, i.e., a new source for CP violation exists. The CP violation for both decays are calculated and it is observed that the CP violating asymmetry in model III differs significantly than the one predicted by the standard model and model II which is a special case of model III. Furthermore, it is shown that the zero value of forward backward asymmetry A_{FB} is shifted when compared with the SM value, which can also serve as the efficiency tool for establishing new physics.
The strong coupling constant g_(Ko* K pi) of the scalar Ko* meson decay to (K pi) is calculated in light cone QCD sum rule. The predicted value of the coupling constant g_(Ko* K pi) is in a good agreement with the experimental result.
The radiative "B_c -> tau nu_tau gamma" decay is analyzed in the standard model. The branching ratio of this decay is calculated and the contributions of the Bremstrahlung and structure dependent parts are compared. It is shown that this decay can be detected at LHC.
Using the experimental result on b\to sγand theoretical result on b\to sg, a four -generation SM is analysed to constrain the rephasing-invariant combinations of the CKM matrix and masses of the fourth generation quarks.
We examine the possibility for precise determination of |V_{ts}| (and |V_{td}/V_{ts}|) from the exclusive decays, $B --> K \ell^+ \ell^-, B --> K^* \ell^+ \ell^-$ (and $B --> π\ell^+ \ell^-, B --> ρ\ell^+ \ell^-$). We show that the ratio |V_{ts}| can be extracted experimentally with a small theoretical uncertainty from hadronic form--factors, if we {\bf appropriately constrain} kinematical regions of $q^2$. We also give detailed analytical and numerical results on the differential decay width $dΓ(B --> K^* \ell^+ \ell^-)/dq^2$, and the ratios of integrated branching fractions, ${\cal B}(B --> ρ\ell^+ \ell^-)/{\cal B}(B --> K^* \ell^+ \ell^-)$. We estimate that one can determine the ratio |V_{ts}| from those decays within theoretical accuracy of $\sim 10%$.
The radiative B_c -> l nu gamma decay is investigated in the Standard Model in framework of the light cone QCD. The transition form factors and decay width are calculated. A comparison of light cone QCD and constituent quark model predictions on these quantities is presented.
We investigate the radiative B_c -> rho^+ gamma and B_c -> K^{*+} gamma decays in the standard model. The transition form factors are calculated in the framework of the light cone QCD sum rules method. We estimate the branching ratios of the B_c -> rho^+ gamma and B_c -> K^{*+} gamma decays.
We calculate the leading logarithmic QCD corrections to the decay B_{s} -->γγin the two Higgs doublet model with tree level flavor changing currents (model III) including O_7 type long distance effects. Further, we analyse the dependencies of the branching ratio Br(B_{s} --> γγ)$ and the ratio of CP-even and CP-odd amplitude squares, R=|A^{+}|^2/|A^{-}|^2, on the charged Higgs mass m_{H^{\pm}} and the selected model III parameters ξ^{U,D} including the leading logarithmic QCD corrections. It is found that to look for charged Higgs effects, the measurement of the branching ratio Br(B_{s} --> γγ)$ is promising.
We calculate the leading logarithmic QCD corrections to the decay B_s --> γγin the two Higgs doublet model (2HDM) including O_7 type long distance effects and estimate the restrictions of the 2HDM parameters, tanβand m_H, using the experimental data of B --> X_s γdecay provided by the CLEO collaboration. A lower bound for the charged Higgs mass m_H as a function of the renormalization scale μis given for 2HDM model II. We further present the dependencies of the branching ratio Br(B_s --> γγ) and the ratio |A^{+}|^2/|A^{-}|^2 on m_H and tanβincluding leading logarithmic QCD corrections. The dependence on the renormalization scale is found to be strong for both ratios. An additional uncertainty arises from the variation of the parameters of the bound state model, (m_b, \barΛ_s). We see, that to look for charged Higgs effects the measurement of the branching ratio Br(B_s --> γγ) is promising.
We propose a new method for precise determination of |V_{td} / V_{ub}| from the ratios of branching ratios BR(B -> ρν\bar ν) / BR(B ->ρl ν) and BR(B -> πν\bar ν) / BR(B -> πl ν). These ratios depend only on the ratio of the Cabibbo-Kobayashi-Maskawa (CKM) elements |V_{td} / V_{ub}|$ with little theoretical uncertainty, when very small isospin breaking effects are neglected. As is well known, |V_{td} / V_{ub}| equals to (\sin γ) / (\sin β) for the CKM version of CP-violation within the Standard Model. We also give in detail analytical and numerical results on the differential decay width dΓ(B -> K^* ν\bar ν) / dq^2 and the ratio of the differential rates dBR(B -> ρν\bar ν)/dq^2 / dBR(B -> K^* ν\bar ν)/dq^2 as well as BR(B -> ρν\bar ν) / BR(B -> K^* ν\bar ν) and BR(B -> πν\bar ν) / BR(B -> K ν\bar ν).
The radiative B -> tau^+ tau^- gamma decay is investigated in the framework of the Standard Model. When only short (short and long together) distance contributions are taken into account, the Branching Ratio is found as 9.54x10^(-9) (1.52x10^(-8)), for the value of the cut delta = 0.01 imposed on the photon energy.
The decay width, forward-backward asymmetry and tau lepton longitudinal and transversal polarization for the exclusive (B -> K tau^+ tau^-) decay in a two Higgs doublet model are computed. It is shown that the forward-backward asymmetry and longitudinal polarization of the tau lepton are very effective tools for establishing new physics.