Related papers: Rare baryonic decays $\Lambda_b \to \Lambda l^+ l^…
Rare $\Lambda_b\to\Lambda l^+l^-$ and $\Lambda_b\to\Lambda\gamma$ decays are investigated in the relativistic quark model based on the quark-diquark picture of baryons. The decay form factors are calculated with the account of all…
We investigate the rare baryonic exclusive decays of $\Lambda_b\to \Lambda l^+ l^- (l=e,\mu,\tau)$ with polarized $\Lambda $. Under the approximation of the heavy quark effective theory (HQET), in the standard model we derive the…
The form factors of the rare $\Lambda_b\to n l^+l^-$ decays are calculated in the framework of the relativistic quark-diquark picture of baryons with the consistent account of the relativistic effects. Their momentum transfer squared…
Rare decays $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda l^{+} l^{-}$ (l= e, $\mu$) are examined. We use QCD sum rules to calculate the hadronic matrix elements governing the decays. The $\Lambda$ polarization in the decays is…
We present a systematic analysis for the rare baryonic exclusive decays of $\Lambda_b\to\Lambda l^+ l^- (l=e,\mu,\tau)$. We study the differential decay rates and the di-lepton forward-backward, lepton polarization and various CP…
Using the most general, model independent form of the effective Hamiltonian, the exclusive, rare baryonic (Lambda_b -> Lambda l^+ l^- ~l=\mu,\tau) decay is analyzed. We study sensitivity of the branching ratio and lepton forward-backward…
We examine the rare decays $B_s\to l^+l^-$ and $B\to Kl^+l^-$ in the framework of the topcolor-assisted technicolor ($TC2$) model. The contributions of the new particles predicted by this model to these rare decay processes are evaluated.…
We present the first lattice QCD determination of the $\Lambda_b \to \Lambda$ transition form factors that govern the rare baryonic decays $\Lambda_b \to \Lambda l^+ l^-$ at leading order in heavy-quark effective theory. Our calculations…
Form factors of the rare $\Lambda_{b}(\Lambda_{b}^*)\to N\ell^{+}\ell^{-}$ decays are calculated in the framework of the light cone QCD sum rules by taking into account of the contributions from the negative parity baryons. Using the…
We investigate the rare baryonic ${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$ decays in a non-universal $Z'$ model, which is one of the well-motivated extensions of the standard model (SM). Considering the effects of $Z'$-mediated…
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…
Using the updated form factors within the light-cone QCD sum rule approach, we calculate the new physics contributions to rare semileptonic $\bar{B}_s \to \phi\mu^+\mu^-, \phi \tau^+\tau^-$ decays from the new particles appearing in the…
The relativistic quark model based on the quasipotential approach with the QCD-motivate potential is employed for the calculation of the form factors of the $\Lambda_c\to p$ rare weak transitions. Their momentum dependence is explicitly…
The rare baryonic decay $\Lambda_b\to \Lambda(\to p\pi^-)\mu^+\mu^-$ provides valuable complementary information compared to the corresponding mesonic $b\to s\mu^+\mu^-$ transition. In this paper, using the latest high-precision lattice QCD…
Recent experimental progress on baryonic rare decays has spurred a deeper investigation on flavor-changing neutral current transitions in the baryon sector. Within the framework of QCD sum rules, we derive a complete set of form factors for…
Using the covariant constituent quark model previously developed by us we calculate the differential rate and the forward-backward asymmetries on the lepton and hadron side for the rare baryon decays Lambda_b -> Lambda l+ l- (l=e, mu, tau)…
Measurements from the LHCb experiment and $B$ factories have revealed several discrepancies in angular observables of rare semileptonic $B$ decays involving the quark-level transition $b \to s \ell^+ \ell^-$. In this work, we conduct a…
A search for the rare decay $B^{+} \to \bar \Lambda p \mu^{+} \mu^{-}$ is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of $\sqrt{s}= 13$ TeV, corresponding to an integrated…
Within the Standard Model, we investigate the weak decays of $\Lambda_b \to \Lambda + \gamma$ and $\Lambda_b \to \Lambda + l^{+} l^{-}$ with the light-cone sum rules approach. The higher twist distribution amplitudes of $\Lambda$ baryon to…
We study the differential decay rate for the rare $\Lambda_b \to \Lambda (\to N \pi)\ell^+\ell^-$ transition, including a determination of the complete angular distribution, assuming unpolarized $\Lambda_b$ baryons. On the basis of a…