arXiv subjects
Publications and source records attributed to K. Azizi.
The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-})\ellν$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors are obtained. The total decay width and branching ratio for these decays are also evaluated using the $q^2$ dependencies of these form factors.
The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-}) ellν$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors as well as $1/m_{b}$ corrections to those form factors are obtained. A comparison of the results for the ratio of form factors at zero recoil limit and other values of $q^{2}$ with the predictions of the subleading Isgur-Wise form factor application for $B\to D^{\ast}\ellν$ is presented. The total decay width and branching ratio for these decays are also evaluated using the $q^2$ dependencies of these form factors. The results are in good agreement with the constituent quark meson model and existing experimental data. The $q=s$ case can also be detected at LHC in the near future.
We study the double-lepton polarization asymmetries and single and double-lepton polarization forward backward asymmetries of the rare b \to s \ell^+ \ell^- mode within the Standard Model and in the Appelquist-Cheng-Dobrescu model, which is a new physics scenario with a single universal extra dimension. In particular, we examine the sensitivity of the observables to the radius R of the compactified extra-dimension, which is the new parameter in this new physics model.
Considering the gluon condensate corrections, the form factors relevant to the semileptonic rare $B_c \rar D,D_s(J^{P}=0^{-}) l^{+}l^{-}$ with $l=τ,μ,e$ and $B_c \rar D,D_s(J^{P}=0^{-})ν\barν$ transitions are calculated in the framework of the three point QCD sum rules. The heavy quark effective theory limit of the form factors are computed. The branching fraction of these decays are also evaluated and compared with the predictions of the relativistic constituent quark model. Analyzing of such type transitions could give useful information about the strong interactions inside the pseudoscalar $D_{s}$ meson and its structure.
The rare $B_c \to D_{s,d}^{*} l^+ l^-$ decays are investigated in the framework of the three point QCD sum rules approach. Considering the gluon condensate corrections to the correlation function, the form factors relevant to these transitions are calculated. The total decay width and branching ratio for these decays are also evaluated. The results for the branching ratios are in good agreement with the quark models.
The form factors of the semileptonic $B_{q}\to D_{q}(J^{P}=0^{-})\ellν$ with $q=s, u, d$ transitions are calculated in the framework of three point QCD sum rules. Using the $q^2$ dependencies of the relevant form factors, the total decay width and the branching ratio for these decays are also evaluated. A comparison of our results for the form factors of $B\to D\ellν$ with the lattice QCD predictions within heavy quark effective theory and zero recoil limit is presented. Our results of the branching ratio are in good agreement with the constituent quark meson model for ($q=s, u, d$) and experiment for ($q= u, d$). The result of branching ratio for $B_{s}\to D_{s}(1968)\ellν$ indicates that this transition can also be detected at LHC in the near future.
The magnetic moments of heavy $Ξ_{Q}$ baryons containing a single charm or bottom quark are calculated in the framework of light cone QCD sum rules method. A comparison of our results with the predictions of the quark models is presented.
Taking into account the gluon correction contributions to the correlation function, the form factors relevant to the rare $B_c \rar X ν\barν$ decays are calculated in the framework of the three point QCD sum rules, where $X$ stands for axial vector particle, $AV(D_{s1})$, and vector particles, $V(D^*,D^*_s)$. The total decay width as well as the branching ratio of these decays are evaluated using the $q^2$ dependent expressions of the form factors. A comparison of our results with the predictions of the relativistic constituent quark model is presented.
This study investigates the influence of the fourth generation quarks on the double lepton polarizations in B \rar K \ell^+ \ell^- decay. Taking |V_{t's}V_{t'b}|\sim \{0.01-0.03\} with phase about 100^\circ, which is consistent with the b\to s\ell^+\ell^- rate and the B_s mixing parameter Delta m_{B_s}$, we obtain that the double lepton(muon and tau) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to indirect search for the fourth generation quarks(t', b').
The nucleon electromagnetic form factors are calculated in light cone QCD sum rules framework using the most general form of the nucleon interpolating current. Using two forms of the distribution amplitudes (DA's), predictions for the form factors are presented and compared with existing experimental data. It is shown that our results describe remarkably well the existing experimental data.
Using three point QCD sum rules method, the form factors relevant to the semileptonic $B_{s}\to D_{sJ}(2460)\ellν$ decay are calculated. The $q^2$ dependencies of these form factors are evaluated. The dependence of the asymmetry parameter $α$, characterizing the polarization of $D_{sJ}$ meson, on $q^2$ is studied. This study gives useful information about the structure of the $D_{sJ}$ meson. Finally the branching ratio of this decay is also estimated and is shown that it can be easily detected at LHC.
The axial N-> Delta(1232) transition form factors are calculated within the light cone QCD sum rules method. A comparison of our results with predictions of lattice theory and quark model calculations is pre- sented.
In this work, the radiative Bc -> D*_s gamma decay is investigated in the framework of QCD sum rules. The transition form factors responsible for the decay are calculated. The branching ratio for this decay is estimated to be order of 10^-5 which can be measurable at LHC.
Form factors of rare (B -> K_0*(1430) l^+ l^-$ decay) decay are calculated within three-point QCD sum rules, with (K_0* (1430)) being the p-wave scalar meson. The branching ratios are estimated when only short, as well as short and long distance effects, are taken into account.It is obtained that the (B -> K_0*(1430) l^+ l^- (l=e,mu)) decay is measurable at LHC. Measurement of these branching ratios for the semileptonic rare (B -> K_0*(1430) l^+ l^-$ decay) can give valuable information about the nature of scalar meson (K_0* (1430)).
This study investigates the influence of the fourth generation quarks on the total branching ratio and the single lepton polarizations in Λ_b --> Λ\ell^+ \ell^- decay. Taking $|V_{t's}V_{t'b}| {0.01-0.03} with phase just below $90^\circ$, which is consistent with the b\to s\ell^+\ell^- rate and the B_s mixing parameter Δm_{B_s}, we obtain that the total branching ratio and the single lepton(μ, τ) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks(t', b').
Using three point QCD sum rules method, the form factors relevant to the semileptonic Bs ->DsJ (2460)l nu decay are calculated. The q2 dependence of these form factors is evaluated and compared with the heavy quark effective theory predictions. The dependence of the asymmetry parameter alpha, characterizing the polarization of DsJ meson, on q2 is studied .The branching ratio of this decay is also estimated and is shown that it can be easily detected at LHC.