Related papers: Polarization properties of diffractively produced …
The contributions of direct knockout processes, in addition to the diffractive production and one-pion-exchange processes associated with the phi-rho-pi and phi-gamma-pi couplings, to the polarization observables of the phi photoproduction…
The Lambda polarization in muon neutrino charged current interactions has been measured in the NOMAD experiment. We observe negative polarization along the W - boson direction which is enhanced in the target fragmentation region: Px (xF <…
The polarization of Lambda, Anti-Lambda, Xi, and Anti-Xi hyperons along the angular momentum of the system has been measured in isobar collisions of Ru+Ru and Zr+Zr at $\sqrt{s_{NN}}$ = 200 GeV with the STAR detector at RHIC. The…
The double-helicity asymmetries ($A_{LL}$) of $\pi^{+}$ and $\pi^{-}$ production in polarized proton proton collisions are specially interesting probes of the gluon's polarization. Relative differences among $A_{LL}$ of positive, neutral,…
Within the context of flux tube models, heavy quark fragmentation takes place through the breaking of flux tubes with the production of a (di)quark-anti(di)quark pair. It is found that the (di)quark produced are more likely to be found in…
Several fixed-target experiments reported J/$\psi$ and $\Upsilon$ polarization measurements, as functions of Feynman $x$ ($x_{\rm F}$) and transverse momentum ($p_{\rm T}$), in three different polarization frames, using different…
We calculate polarization asymmetries in photoproduction of high transverse momentum mesons, focusing on charged pions, considering the direct, fragmentation, and resolved photon processes. The results at very high meson momentum measure…
The momentum distribution of Lambda^0 hyperons produced from the quark-gluon plasma (QGP) in ultra-relativistic heavy-ion collisions is calculated in dependence on their polarization. The momentum distribution of Lambda^0 hyperons is…
We calculate the inclusive production of a polarized $\Lambda$ or $\bar{\Lambda}$ hyperon from the single longitudinally polarized proton and proton ($pp$) collision at RHIC. By comparing the data reported by the STAR Collaboration, we find…
Little information is known about the polarization of gluons inside a longitudinally polarized proton. I report on the sensitivity of photoproduction experiments to it. Both jet and heavy quark production are considered.
Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality…
An important observable to understand the properties of the matter produced in heavy-ion collisions is its strangeness content. Recent experimental results show that in semi-central collisions, the $\Lambda$ and $\bar{\Lambda}$ global…
We propose a qualitatively new mechanism for quarkonium production, motivated by the global features of the experimental data and by the successes/failures of existing models. In QCD, heavy quarks are created in conjunction with a…
The $\Lambda$ ($\bar{\Lambda}$) hyperon polarization along the beam direction has been measured for the first time in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. The polarization dependence on the hyperons' emission angle relative to…
Starting from the Feynman diagram representation of multiple scattering we consider the polarized $\chi_c$(1P)-charmonia production in antiproton-nucleus reactions close to the threshold ($p_{\rm lab}=5-7$ GeV/c). The rescattering and…
The amplitude of diffractive $\rho$ (and open quark) leptoproduction on a polarized target is calculated in the leading log approximation of pQCD using the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in terms of…
We use the recombination and the Thomas Precession Model to obtain a prediction for the $\Lambda _0$ polarization in the $p+p \to \Lambda_0+X$ reaction. We study the effect of the recombination function on the $\Lambda_0$ polarization.
The polarization of the $\Lambda$ and $\overline{\Lambda}$ hyperons along the beam direction has been measured in proton-lead (pPb) collisions at a center-of-mass energy per nucleon pair of 8.16 TeV. The data were obtained with the CMS…
We show that, in $\nu_\mu N\to \mu^-\Lambda X$ at the NOMAD energies, it is impossible to separate the products of the fragmentation of the struck quark from those of the nucleon remnant. The latter has a large contribution even in the…
We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the…