相关论文: Spin effects in diffractive charmonia production
The leading-particle effect and the factorization property of the scattering amplitude in the impact parameter space are used to study semiclassical production of pions in the central region. The mechanism is related to the isospin-uniform…
We consider several single spin asymmetries in inclusive, transversely polarized proton(antiproton) - proton processes as higher twist QCD contributions, taking into account spin and intrinsic transverse momentum effects in the quark…
We extend our recent study of chiral magnetic effect in relativistic heavy ion collisions based on an anomalous transport model by including also the chiral vortical effect. We find that although vorticities in the chirally restored quark…
We investigate the prospects to observe effects of transverse polarization of top quarks in $pp,p\bar{p}\to t\bar{t}X$. QCD absorptive parts generate a polarization of top quarks and antiquarks transverse to the production plane in the…
We present a calculation for the polarizations of $J/\psi$ and $\psi'$ produced in the hadron collisions at the Fermilab Tevatron. Various color octet channels including ${}^1S_0^{(8)}$, ${}^3P_J^{(8)}$, and ${}^3S_1^{(8)}$ as well as…
We consider double spin asymmetries for longitudinally polarized leptons and transversally polarized protons in diffractive vector meson and $Q \bar Q$ production for the HERMES energy range on the basis of the two-gluon model. The…
The influence of the electron spin degree of freedom on nonperturbative electron-positron pair production by high-energy proton impact on an intense laser field of circular polarization is analyzed. Predictions from the Dirac and…
In order to extract the polarized strange quark density in proton, we studied the semi-inclusive $\Lambda_c$/$\bar{\Lambda}_c$ leptoproduction in charged current DIS at THERA energies. We indicate that measurements of the spin correlation…
We analyse spin effects in diffractive vector meson leptoproduction at small $x$ on the basis of the generalized parton distribution (GPD) approach. We take into account quark transverse degrees of freedom in the hard subprocess. We…
The model combined with unitarity and impact parameter picture provides simple mechanism for generation of hyperon polarization in collision of unpolarized hadrons. We concentrate on a particular problem of $\Lambda$-hyperon polarization…
A first theoretical study for neutrino-induced diffractive productions of heavy pseudoscalar-mesons, \eta_c and \eta_b, off a nucleon is performed based on factorization formalism in QCD. We evaluate the forward diffractive production cross…
We show that spin polarization of a fermion in a relativistic fluid at local thermodynamic equilibrium can be generated by the symmetric derivative of the four-temperature vector, defined as thermal shear. As a consequence, besides…
We show that hard-scattering factorization is violated in the production of high-p_T hadrons in hadron-hadron collisions, in the case that the hadrons are back-to-back, so that k_T factorization is to be used. The explicit counterexample…
We study the dependencies of spin asymmetries in diffractive leptoproduction on the spin structure of the pomeron coupling. It is shown that the $A_{ll}$ asymmetry in diffractive processes is proportional to the fraction of the initial…
It is shown that the $A_{ll}$ asymmetry in diffractive $Q \bar Q$ leptoproduction is not small at HERA energies and dependent on the structure of the pomeron couplings and on the masses of produced quarks. The connection of this asymmetry…
The recently developed quantum mechanical string+${}^3P_0$ model of polarized quark fragmentation with pseudoscalar and vector meson production has been implemented in a stand alone Monte Carlo program. The simulation enables the detailed…
The $\Upsilon(1S)$ meson production and polarization at high energies is studied in the framework of the $k_T$-factorization approach. Our consideration is based on the non-relativistic QCD formalism for a bound states formation and…
The $\Upsilon(2S)$ production and polarization at high energies is studied in the framework of $k_T$-factorization approach. Our consideration is based on the non-relativistic QCD formalism for bound states formation and off-shell…
Significant differences between transverse and longitudinal polarized parton distributions are found at low energies within a light-front covariant quark model of the nucleon. These differences are due to relativistic spin effects…
The consequences of CP- and CPT-invariance for production and subsequent decay of Majorana fermions are analytically studied. We derive general symmetry relations for the spin density matrix for production of Majorana fermions by polarized…