相关论文: Polarization phenomena for heavy meson production …
We establish the model-independent spin structure of the matrix elements for the near-threshold scalar meson production in $pp-$ and $np$-collisions, when the final particles are emitted in S-state. Polarization phenomena are derived in a…
The threshold region for processes of hadronic and nuclear interactions is very interesting for a theoretical as well as an experimental point of view. In this region one can apply different physical methods, starting from classical current…
We study the threshold $\phi$-meson production in the process $\Delta+N\to N+N+\phi$, which appears as a possible important mechanism in high energy nuclei-nuclei collisions. The isotopic invariance of the strong interaction and the…
Using the symmetry properties of the strong interaction, such as the Pauli principle, the P-invariance, the conservation of the total angular momentum and isotopic invariance, we establish the spin structure of the threshold matrix elements…
The strongly interacting system created in ultrarelativistic nuclear collisions behaves almost as an ideal fluid with rich patterns of the velocity field exhibiting strong vortical structure. Vorticity of the fluid, via spin-orbit coupling,…
We analyze polarization phenomena for pseudoscalar and vector mesons production in nucleon-nucleon collisions. We identify three energy regions corresponding to different physics and different approaches in the analysis of polarization…
We analyze $J/\psi-$ production in nucleon-nucleon collisions near threshold in the framework of a general model independent formalism, which can be applied to any reaction $N+N\to N+N+V^0$, where $V^0=\omega$, $\phi$, or $J/\psi$. Such…
Polarization and spin effects are useful for probing the Standard Model, in both the electroweak sector and the strong sector, where the spin decomposition of the nucleon is still a hot topic, with important new data on the net…
We develop polarization observables for the processes $\gamma N\to\pi\pi N$ and $\pi N\to\pi\pi N$, using both a helicity and hybrid helicity-transversity basis. Such observables are crucial if processes that produce final states consisting…
We analyze the production of $\phi$ mesons in $\pi N$ and NN reactions in the near-threshold region, using throughout the conventional ``non-strange'' dynamics based on such processes which are allowed by the non-ideal $\omega-\phi$ mixing.…
Pion production at threshold from nucleon-deuteron collisions is considered, with reference to the outgoing channel where the three-nucleon system is bound. The available experimental data are compared with calculations using accurate…
We propose to extend the investigations of the eta meson production in nucleon-nucleon collisions by studying single and double polarization observables. Over the last years, the eta meson has been studied at several different experiments…
We discuss the information that can be deduced from a measurement of particle (hyperon or vector meson) polarization in ultrarelativistic nuclear collisions. We describe the sensitivity of polarization to initial conditions, hydrodynamic…
After a brief introduction into the general importance of polarization observables for the analysis of a reaction, the basic density matrix formalism for the description of polarization phenomena is outlined and illustrated by explicit…
We established important relationships between entanglement measures and the order parameter (spin polarization) in nuclear spin systems controlled by the nuclear magnetic resonance (NMR) technique. Since spin polarization can be easily…
Intermediate-energy heavy-ion collisions can produce a spin polarization of the projectile-like species. Spin polarization has been observed for both nucleon removal and nucleon pickup processes. Qualitative agreement with measured spin…
We discuss two aspects of polarisation in hard exclusive meson production: the leading-twist selection rule for the meson helicity, and the different partial waves of a (pi pi)-pair which may or may not be due to the decay of a rho.
Accurate knowledge of cross sections for pion production in proton-proton collisions finds wide application in particle physics, astrophysics, cosmic ray physics and space radiation problems, especially in situations where an incident…
We propose a new mechanism of generating spin polarization in heavy-ion collisions dominated by nucleon degree of freedom. By incorporating the spin change in nucleon-nucleon scatterings based on the phase shift data together with the…
The polarization observables in phi photoproduction are suggested for probing the nucleon strangeness. Based on models for phi photoproduction, some double polarization observables are shown to be very sensitive to the strangeness content…