相关论文: Rare $\Lambda_{b}\to \Lambda $ l$^{+}$ l$^{-}$ Dec…
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…
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…
In the framework of the top triangle moose $(TTM)$ model, we analyze the rare decays $\Lambda_{b}\rightarrow \Lambda l^{+}l^{-} (l=e,\mu,\tau)$ by using the form factors calculated in full $QCD$. We calculate the contributions of the new…
The rare exclusive dileptonic $\Lambda_{b}\to \Lambda\ell^{+}\ell^{-}$ $(\ell =\mu, \tau)$ decays are investigated in the general two-Higgs-doublet model of type III. A significant enhancement to the branching ratios, differential branching…
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 $\Lambda_b\to\Lambda l^+l^-$ 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…
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 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…
We investigate the decay of $\Lambda_b\to\Lambda\nu\bar{\nu}$ with the polarized baryons of $\Lambda_b$ and $\Lambda$. With the most general hadronic form factors, we first study the decay branching ratio and then derive the longitudinal,…
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 present the model independent analysis of $\Lambda$ baryon polarizations in the (Lambda_b -> Lambda l^+ l^-) decay. The sensitivity of the averaged 'Lambda' polarizations to the new Wilson coefficients is studied. It is observed that…
We study the rare decays $\Lambda_b \rightarrow \Lambda l^+ l^-~(l=e,\mu, \tau)$ in the Bethe-Salpeter equation approach. We find that depending on the values of parameters in our model the branching ratio $Br(\Lambda_b \rightarrow \Lambda…
We study the four-body semileptonic baryonic decay of $B^-\to \Lambda\bar p\nu\bar \nu$ in the standard model. We find that the decay branching ratio is $(7.9\pm 1.9)\times 10^{-7}$. Similar to the rare decays of $B^-\to K^{(*)-}\nu\bar…
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)…
We investigate the exclusive rare baryonic $\Lambda_{b}\to\Lambda\ell^{+}\ell^{-}$ in a family non-universal $Z^{\prime}$ model, which is one of the natural extension of standard model. Using transition form factors, calculated in the…
The recent anomalies in $b\to s\ell^+\ell^-$ transitions could originate from some New Physics beyond the Standard Model. Either to confirm or to rule out this assumption, more tests of $b\to s\ell^+\ell^-$ transition are needed. Polarized…
The rare decays mediated by flavor-changing neutral current processes, such as $b \to s \ell^{+}\ell^{-}$, provide powerful probes of the Standard Model and potential windows into new physics. Particularly, the angular observables in these…
We study the T violating effects in the baryonic decays of $\Lambda_b\to\Lambda l^+l^- (l=e ,\mu)$ with polarized $\Lambda$. We show that the transverse $\Lambda$ polarizations in these baryonic decays could be as large as 50% in CP…
Rare $b \to s\ell^+\ell^-$ flavour-changing-neutral-current processes provide important tests of the Standard Model of particle physics. Angular observables in exclusive $b \to s\ell^+\ell^-$ processes can be particularly powerful as they…
The independent helicity amplitudes in the (Lambda_b -> \Lambda l^+ l^-) decay in the standard model and its minimal extension, i.e., with the new vector type interactions, are calculated. We calculate various asymmetry parameters…