Related papers: The Study of Rare $B_c\rightarrow D^{(*)}_{s,d}l\b…

In this paper, we study the rare radiative processes $B_c\to D_{sJ} ^{(*)}\gamma$ within the Standard Model, where $D_{sJ}^{(*)}$ stands for the meson $D_s^*$,~$D_{s1}(2460,2536)$ or ~$D_{s2}^*(2573)$. During the investigations, we consider…

We study the rare decays of $B_c^+\to D_{q}^{(*)+}l\bar{l}$ ($q=d,s$ and $l=\nu_l,e,\mu,\tau)$ in the standard model. The form factors are evaluated in the light front and constituent quark models, respectively. We find that the decay…

Applying the perturbative QCD ( PQCD ) method, we study the decay $B_c\rightarrow D_s^*\gamma$ in the standard model and multiscale walking technicolor model. In the SM, we find that the contribution of weak annihilation is more important…

The rare processes $B_c\to D_{(s)J} ^{(*)}\mu\bar{\mu}$, where $D_{(s)J}^{(*)}$ stands for the final meson $D_{s0}^*(2317)$, $D_{s1}(2460,2536)$,~$D_{s2}^*(2573)$, $D_0^*(2400)$, $D_{1}(2420,2430)$ or~$D_{2}^*(2460)$, are studied within the…

Rare $B$, $D$ and $K$ decays provide interesting probes of the Standard Model (SM), with a potential sensitivity to New Physics (NP) higher than other, more common, decays. Their experimental measurement is challenging, and their…

We present first theoretical predictions for various observables related to the $\bar B_d \to \mu^+ \mu^- e^+ e^-$ decay within the framework of the Standard Model. Our study encompasses the branching ratios, differential distributions, and…

We analyze the rare semileptonic decays $B_{c}^+ \to D^{\ast+}(\to P_1 P_2)\ell^{+}\ell^{-}$, with $P_1 P_2 = D^+ \pi^0$ or $D^0 \pi^+$, and $\ell=\mu, \tau$. We focus on the impact of weak annihilation contributions alongside penguin, box,…

Systematic analysis of the high recoil decay channels of the B-meson, two body mesonic decay channels in particular. For decays involving D-mesons, all experimentally observed rates are in reasonable accord with our calculations. Noticeable…

In the framework of the Standard Model we present new theoretical predictions for the branching ratios, double and single differential distributions and forward -- backward leptonic asymmetries for the $\bar B_s \to \mu^+ \mu^- e^+ e^-$…

We study the decay $B_c \rightarrow D_s^* \gamma$. There are two mechanisms contributing to the process. One proceeds through the short distance $b{\rightarrow}s\gamma$ transition and the other occurs through weak annihilation accompanied…

In perturbative QCD approach, we investigate the $B(B_{s})\rightarrow D_{(s)}(\bar{D}_{(s)})\,T$ and $D_{(s)}^{*}(\bar{D}_{(s)}^{*})\,T$ decays, which include the Cabibbo-Kobayashi-Maskawa (CKM) favored decays and the…

We calculate the contributions to the rare decays $B \to X_{s,d} \nu \bar \nu$ and $B_{s,d} \to l^+l^-$ from one-loop $Z^0$-penguin diagrams in the framework of Topcolor-assisted Technicolor Model. Within the parameter space, we find that:…

Motivated by the recent measurement of $D^0\to\rho^0\gamma$ improved standard model (SM) predictions for branching ratios and CP asymmetries of radiative charm decay are given. Weak annihilation induced decays are probes of non-perturbative…

We study the loop induced rare decays $B_s(B_d)\to\gamma\nu\bar\nu$ within the standard model. Both constituent quark model and pole model are used and the branching ratios turn out to be of the orders of $10^{-8}$ for $B_s\to \gamma \nu…

The rare Bc->Ds l^+ l^- decay is investigated by using the most general model independent effective Hamiltonian. The general expressions of longitudinal, normal and transversal polarization asymmetries for l^- and l^+ and the combined…

In these lectures we give, first, the model-independent analysis of the exclusive rare decays B -> K l(bar) l and B_c -> D(D*) l(bar) l with special emphasis on the cascade decay B_c -> D(*)(-> D pi) l(bar) l. We derive a four-fold angular…

The rare decay b -> s s bar{d} is studied in the supersymmetric standard model by considering the contribution from the chargino box diagrams. We find that this contribution amounts to 10^{-9} in the branching ratio.

In this work, we use the QCD sum rule method to study the radiative decays of the vector and axial-vector $B_c$ mesons to each of three charmed strange mesons, $D_s$, $D^*_s$ and $D_{s1}$, through their dominant weak annihilation channels.…

The general analysis of the rare Bc->D^*_s l^+ l^- decay is presented by using the most general, model independent effective Hamiltonian. The dependencies of the branching ratios, longitudinal, normal and transversal polarization…

We calculate the contributions of penguin diagrams with internal u or c quarks to various inclusive charmless B-decay rates. Further we analyze the influence of the chromomagnetic dipole operator Q_8 on these rates. We find that the rates…