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R. Khosravi

Publications and source records attributed to R. Khosravi.

24 records · Page 2Linked to original sources
arXiv2009

Analysis of the $B_q\to D_q(D_q^*) P$ and $B_q\to D_q(D_q^*) V$ decays within the factorization approach in QCD

Using the factorization approach and considering the contributions of the current-current, QCD penguin and electroweak penguin operators at the leading approximation, the decay amplitudes and decay widths of $B_q\to D_q(D_q^*) P$ and $B_q\to D_q(D_q^*) V$ transitions, where $q=u,d,s$ and P and V are pseudoscalar and vector mesons, are calculated in terms of the transition form factors of the $B_q\to D_{q}$ and $B_q\to D^{*}_{q}$. Having computed those form factors in three-point QCD sum rules, the branching fraction for these decays are also evaluated. A comparison of our results with the predictions of the perturbative QCD as well as the existing experimental data is presented.

hep-ph↗
arXiv2009

Investigation of the $D_{s1}$ structure via $B_c$ to $D_{s1} l^+l^-/ν\barν$ transitions in QCD

We investigate the structure of the $D_{s1}(2460,2536) (J^P=1^+)$ mesons via analyzing the semileptonic $B_{c}\to D_{s1}l^+l^-$, $l=τ, μ, e$ and $B_{c}\to D_{s1}ν\barν$ transitions in the framework of the three--point QCD sum rules. We consider the $D_{s1}$ meson in two ways, the pure $|c\bar{s}>$ state and then as a mixture of two $|^3P_1>$ and $|^1P_1>$ states. Such type rare transitions take place at loop level by electroweak penguin and weak box diagrams in the standard model via the flavor changing neutral current transition of $b \to s$. The relevant form factors are calculated taking into account the gluon condensate contributions. These form factors are numerically obtained for $|c\bar s>$ case and plotted in terms of the unknown mixing angle $θ_s$, when the $D_{s1}$ meson are considered as mixture of two $|^3P_1>$ and $|^1P_1>$ states. The obtained results for the form factors are used to evaluate the decay rates and branching ratios. Any future experimental measurement on these form factors as well as decay rates and branching fractions and their comparison with the obtained results in the present work can give considerable information about the structure of this meson and the mixing angle $θ_s$.

hep-ph↗
arXiv2009

Semileptonic $D_{q}\to K_{1}\ell ν$ and nonleptonic $D\to K_1 π$ decays in three--point QCD sum rules and factorization approach

We analyze the semileptonic $D_{q}\to K_1 \ellν$ transition with $q=u, d, s$, in the framework of the three--point QCD sum rules and the nonleptonic $D\to K_1 π$ decay within the QCD factorization approach. We study $D_{q}$ to $K_1(1270)$ and $K_1(1400)$ transition form factors by separating the mixture of the $K_1(1270)$ and $K_1(1400)$ states. Using the transition form factors of the $D\to K_1 $, we analyze the nonleptonic $D\to K_1 π$ decay. We also present the decay amplitude and decay width of these decays in terms of the transition form factors. The branching ratios of these channel modes are also calculated at different values of the mixing angle $θ_{K_1}$ and compared with the existing experimental data for the nonleptonic case.

hep-ph↗
arXiv2008

Semileptonic $B_{c}^{-}\to D^{*0}\ellν$ transition in three--point QCD sum rules and HQET with gluon condensate corrections

Taking into account the gluon condensate contributions, the form factors of the semileptonic $B_c^- \to D^{*0}\ellν$ transition with $l=τ, e$ are calculated in the framework of the three point QCD sum rules. The heavy quark effective theory limit of the form factors are also computed. The relevant total decay width as well as the branching ratio are evaluated and compared with the predictions of the other non-perturbative approaches.

hep-ph↗
arXiv2008

Analysis of the rare semileptonic $B_c \rar P(D,D_s) l^{+}l^{-}/ν\barν$ decays within QCD sum rules

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.

hep-ph↗
arXiv2008

QCD sum rules analysis of the rare $B_c \rar Xν\barν$ decays

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.

hep-ph↗