相关论文: Model independent analysis of 'Lambda' baryon pola…
We present the explicit form of the expressions of the 'Lambda' baryon polarizations in (Lambda_b -> Lambda l^+ l^-) decay for the massive lepton case as a complementary to our previous work prep: hep--ph/0211447.
Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the…
Following updated and extended measurements of the full angular distribution of the decay $\Lambda_b\to \Lambda(\to p\,\pi^-)\mu^+\mu^-$ by the LHCb collaborations, as well as a new measurement of the $\Lambda \to p \pi^-$ decay asymmetry…
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 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 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 dilepton forward-backward and the longitudinal, normal and transverse lepton polarization asymmetries in the heavy baryon decays of $\Lambda_b\to\Lambda l^+l^-$. We show that the asymmetries have a less dependence on 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…
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…
We discuss the Lambda_b-polarization of the bottom baryon Lambda_b in its production and in its decay. Standard Model predictions for b-quark polarization on the Z-peak are reviewed, including beam-quark orientation effects and O(as)…
General expressions for the double-lepton polarizations in the (B -> K l^+ l^-) decay are obtained, using model independent effective Hamiltonian, including all possible interactions. Correlations between the averaged double-lepton…
In the Standard Model, b quarks produced in e^+e^- annihilation at the Z^0 peak have a large average longitudinal polarization of -0.94. Some fraction of this polarization is expected to be transferred to b-flavored baryons during…
Possible manifestation of the family non-universal Z' boson effects in lepton polarization in rare, exclusive baryonic "Lambda_b -> Lambda l+l-" decay is examined. It is observed that the double lepton polarizations P_TT and P_NN are…
We study the exclusive (Lambda_b -> \Lambda l^+ l^-) decay in the Appelquist, Chang, Dobrescu model within one universal extra dimension. We investigate the sensitivity of the branching ratio, lepton polarization and forward-backward…
We study unparticle physics effects in (Lambda_b -> Lambda + missing energy) decay with polarized $\Lambda_b$ and $\Lambda$ baryons. The sensitivity of the branching ratio of this decay and polarizations of (Lambda_b) and (Lambda) baryons…
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…
Inspired by various updated tantalizing results of LHCb on baryonic sector we study the {\Lambda}_b decays into {\Lambda}^* (1520)l^+ l^- decay in non-universal Z^' model. We present the four-fold angular distributions of the decay in terms…
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…
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 calculate various P-odd asymmetries appearing in the differential decay width for the cascade decay (Lambda_b -> Lambda(-> a+b) V^* (-> l^+ l^-)) with polarized and unpolarized heavy baryons including new vector type interactions and…