Related papers: Spin Observables in Transition-Distribution-Amplit…
Exclusive production of $\rho^0$ mesons was studied at the COMPASS experiment by scattering 160 GeV/$c$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured as a function of…
COMPASS is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron investigating the structure and spectrum of hadrons. One primary goal is the search for new hadronic states, in particular spin-exotic mesons and…
The lepton pair production in collisions of antiproton beam (E_beam = 14 GeV) with proton target is studied on the basis of event samples simulated with PYTHIA6 generator. Two types of quark level subprocesses are considered. The first one…
We calculate the longitudinal polarizations of hyperons in high $p_\perp$ jets in $pp$ collisions in which one of the protons is longitudinally polarized at RHIC energies using different models for the spin transfer in fragmentation…
We consider top-antitop quark ($t{\bar t}$) production at the Large Hadron Collider (LHC) with subsequent decay into dileptonic and lepton plus jets final states. We present a set of leptonic angular correlations and distributions with…
We investigate the joint $\Lambda \bar{\Lambda}$ decay in the reaction $e^+ e^- \rightarrow \gamma \Lambda(\rightarrow p\pi^-) \bar{\Lambda}(\rightarrow \bar{p}\pi^+)$. This reaction may provide information on the electromagnetic form…
The collider experiments at the Tevatron and the LHC will allow for detailed investigations of the properties of the top quark. This requires precise predictions of the hadronic production of $t\bar t$ pairs and of their subsequent decays.…
The study of transverse spin effects is part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS. COMPASS investigates the transversity PDFs in semi-inclusive DIS, using a longitudinally polarized muon beam of…
Pion photoproduction is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by…
In this paper we present recent results from the NA49 experiment for $\Lambda$ and $\bar{\Lambda}$ hyperons produced in central Pb+Pb collisions at 40, 80 and 158 A$\cdot$GeV. Transverse mass spectra and rapidity distributions for $\Lambda$…
The shapes of invariant differential cross section for identified pi,K, p and pbar production as function of transverse momentum measured in pp collisions by the PHENIX detector are analyzed. Simultaneous fit of these data to the sum of…
Spin observables may reveal much deeper properties of non perturbative hadronic physics than unpolarized quantities. We discuss here possible origins of single spin asymmetries in DIS, absent in the elementary lepton-quark interactions, and…
The production and propagation of mesons ($\pi, \eta, \rho, \omega, \Phi, K, \bar{K}, J/\Psi$) in proton-nucleus and nucleus-nucleus collisions from 1 - 200 GeV/u is studied within the covariant transport approach HSD, which explicitly…
The production and dynamics of strange and antistrange hadrons in heavy-ion reactions from $\sqrt{s_{NN}} \approx$ 3 GeV to 200 GeV is analyzed within the Parton-Hadron-String-Dynamics (PHSD) transport model. The PHSD results for strange…
We study the single longitudinal-spin asymmetries in lepton-pair production with large transverse-momentum at RHIC and J-PARC experiments. The asymmetries in the azimuthal angular distribution of a lepton can arise from an absorptive part…
A set of measurements of azimuthal asymmetries in the production of pairs of identified hadrons in deep-inelastic scattering of muons on transversely polarised $^6$LiD (deuteron) and NH$_3$ (proton) targets is presented. All available data…
We extend the classical phase-space distribution function to include the spin and electromagnetic fields coupling and derive the modified constitutive relations for charge current, energy-momentum tensor, and spin tensor. Because of the…
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 study the twist-2 double-spin asymmetries for the 2-jets and large-$p_T$ hadron ($\pi$, $\Lambda$ etc) production in semi-inclusive deep inelastic scattering to $O(\alpha_s)$ in perturbative QCD. After deriving the complete set of the…
Since the first surprising results on the spin structure of the proton by the EMC experiment in the late 1980s, much progress has been made in understanding the origin of the proton spin. However, the sea quark contribution to the proton…