相关论文: Lambda_b-Polarization from its Inclusive Semilepto…
The physics interpretation of the recent measurements of the spin polarization of $\Lambda$ hyperons produced in relativistic heavy-ion collisions is discussed. We suggest that the polarization measured in the $\Lambda$ rest frame should be…
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…
This review addresses the question of the chirality of $b$ quark weak couplings from a theoretical and from a purely phenomenological point of view. Due to their small magnitude $b$ decay couplings are subject to possible large corrections…
We analyze the baryonic semilepton decay $\Lambda_{b} \rightarrow$ $\Lambda \mu^{+} \mu^{-}$ in the scalar leptoquark models with $X(3,2,7/6)$ and $X(3,2,1/6)$ states, respectively. We also discuss the effects of this two NP models on some…
The flavor and spin structure for the quark distributions of the $\Lambda$-baryon is studied in a perturbative QCD (pQCD) analysis and in the SU(6) quark-diquark model, and then applied to calculate the $\Lambda$-polarization of…
The increasing number of flavour anomalies motivates the investigation of new processes where tensions similar to the observed ones may emerge. It is necessary to identify observables sensitive to physics beyond the Standard Model. The…
We study the semileptonic decays of the lowest-lying bc baryons to the lowest-lying cc baryons (Xi_{bc}^{(\prime*)}--> Xi_{cc}^{(*)} and Omega_{bc}^{(\prime*)}--> Omega_{cc}^{(*)}), in the limit m_b, m_c >> Lambda_{QCD} and close to the…
The polarization properties of the charmed Lambda^+_c baryon are investigated in weak non-leptonic four-body Lambda^+_c -> p + K^- + pi^+ + pi^0 decay. The probability of this decay and the angular distribution of the probability are…
We study the measurement of the quark fragmentation functions for spin-1/2 baryon production ($\Lambda$ and $\bar \Lambda$, in particular) in unpolarized $e^+e^-$ annihilation. The spin-dependent fragmentation functions $\hat g_1(z)$ and…
Polarization and spin correlations have been explored very little for quarks other than the top. Utilizing the partial preservation of the quark's spin information in baryons in the jet produced by the quark, we examine possible analysis…
Data on the nucleon spin structure suggests that the $u$ (and $d$) quark distributions in the $\Lambda$ hyperon may be polarized. If this correlation carries over into fragmentation, then the study of polarized $\Lambda$'s in the current…
A measurement of the photon polarization in radiative penguin $B$ decays provides a test of the Standard Model and a probe for New Physics, that can lead to a deviation from the Standard Model prediction of left-handed photons in $b\to s…
We analyze the tauonic semileptonic baryon decays $\Lambda^0_b \to \Lambda^+_c + \tau^{-} +\bar \nu_{\tau}$ with particular emphasis on the lepton helicity flip contributions which vanish for zero lepton masses. We calculate the total rate,…
We have developed a new technique for inclusive reconstruction of the energy of B hadrons. The excellent efficiency and resolution of this technique allow us to make the most precise determination of the b-quark fragmentation function,…
The baryon decay modes of B,bar{B}-> N_{1}bar{N}_{2}(f), bar{N}_{1}N_{2}(bar{f}) provide a frame work to test CP-invariance in baryon sector. It is shown that in the rest frame of B, N_{1} and bar{N}_{2} come out with longitudnal…
The polarization of $\Lambda$ hyperons is preserved in the angular distribution of their decay products. This property allows one to study the spin structure of the $\Lambda$. In Semi-Inclusive Deep Inelastic Scattering where a high energy…
We give a general parameterization of the Lambda_b --> Lambda(1520) gamma decay amplitude, applicable to any strange isosinglet spin-3/2 baryon, and calculate the branching fraction and helicity amplitudes. Large-energy form factor…
This paper presents an analysis of the $\Lambda^0_b\rightarrow J/\psi\Lambda$ angular distribution and the transverse production polarisation of $\Lambda^0_b$ baryons in proton-proton collisions at centre-of-mass energies of 7, 8 and 13…
We study the scalar leptoquark effects on the rare semileptonic decays of $\Lambda_b$ baryon, governed by the quark level transition $b \to s l^+ l^-$. We estimate the branching ratios, forward-backward asymmetries, lepton polarization…
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…