Related papers: Global hyperon polarization and effects of decay f…
In these proceedings, measurements of J/psi polarization in p+p collisions at 200 and 500 GeV via the dielectron decay channel at mid-rapidity with the STAR experiment are discussed. At 200 GeV the polarization parameter,…
We discuss Lambda polarization in semi-inclusive proton-proton collisions, with one of the protons longitudinally polarized. The hyperfine interaction responsible for the $\Delta$-$N$ and $\Sigma$-$\Lambda$ mass splittings gives rise to…
The longitudinal or transverse spin transfer to Lambda and anti-Lambda hyperons in polarized proton-proton collisions is expected to be sensitive to the helicity or transversity distributions of strange and anti-strange quarks of the…
An observable to measure the polarity of lambda that caused by source global angular momentum in peripheral AU-AU collision at RHIC is proposed.This observable's capacity of measurement is tested by Monte Carlo method.And the main factors…
Lepton flavor violated processes are strongly suppressed in the Standard Model, but can be sizable in some extended models. The current experimental bounds on decay modes $\ell'^{\pm} \to a \ell^{\pm}$ are much weaker than the other…
Recently the STAR Collaboration discovered the "subatomic swirls", that is, the most vortical fluid flow structures in the quark-gluon plasma produced via the AuAu collisions at the Relativistic Heavy Ion Collider (RHIC). Published in…
We report measurements of the ratios of identified hadrons (pi,K,p,Lambda) in Au+Au collisions at sqrt(s_NN) = 200 GeV as a function of both collision centrality and transverse momentum (p_T). Ratios of anti-baryon to baryon yields are…
This study investigates the influence of the fourth generation quarks on the double lepton polarizations in \Lambda_b --> \Lambda \ell^+ \ell^- decay by taking |V^\ast_{t's}V_{t'b}|= 0.005,0.01,0.02,0.03 with phase…
Mid-rapidity Omega and anti-Omega production in Au+Au collisions at RHIC is studied with the STAR experiment. We report preliminary results on yields and spectra at $\sqrt{s_{NN}}$ = 130 and 200 GeV. Production relative to negatively…
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 most general model-independent analysis of the lepton polarization asymmetries in the rare B decay, $\Bstt$, is presented. We present the longitudinal, normal and transverse polarization asymmetries for the $\tau^+ $ and $\tau^-$, and…
Despite decades of studies of the photoproduction of hyperons, both their production mechanisms and their spectra of excited states are still largely unknown. While the parity-violating weak decay of hyperons offers a means of measuring…
We report on STAR analyses of p-lambda, p_bar-lambda_bar, p-lambda_bar, p_bar-lambda, p-p_bar and pi-Xi correlations in Au+Au collisions at sqrt(S_NN)=62 and 200 GeV. Measured source sizes in p(p_bar)-lambda(lambda_bar) and p-p_bar are…
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…
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…
Based on the formalism presented in [1], we make a systematic study of spin polarizations of hadrons with different spins including vector mesons, spin-1/2 and spin-3/2 hyperons and spin correlations of hadron-hadron such as…
The $\tau$ lepton arising from the scalar tau ($\st$) decay is naturally polarized. $\ptau$ depends on the left--right mixing of the $\st$ and the gaugino--higgsino mixing of the neutralino. The polarization $\ptau$ could be measured from…
A measurement of the polarization of Lambda and Anti-Lambda baryons produced in pC and pW collisions at sqrt(s)=41.6 GeV has been performed with the HERA-B spectrometer. The measurements cover the kinematic range of 0.6 GeV/c < p_T<1.2…
The concept of a common local spin equilibrium for both spin-1/2 and spin-1 particles is incorporated into a thermal model of particle production in heavy-ion collisions at the top RHIC energies. We show that an effective spin polarization…
We analyse the muon longitudinal polarization asymmetry \Delta_long in the decay K^+ --> \pi^+ \mu^+ mu^-. It is stressed that, since the muon helicities are not Lorentz-invariant quantities, the magnitude of \Delta_long depends in general…