This paper is dedicated to the study of the running coupling constant of meson and protons from and interactions at 4.2 GeV/c. It is a well known fact that the more correct value of the cut parameter in the formula of plays a very important role in obtaining the right values of this strong coupling constant . In calculations, the value of obtained previously by the authors [1], was used: The values of obtained with this cut parameter are compared to the QCD predictions.
The isospin violation in the strong decays of the spin-2 exotic charmonium-like state has been studied within the framework of the covariant confined quark model. We have interpreted the exotic hadron as a four-quark state with a molecular-type interpolating quark current and computed the leading-order strong decay widths at the level of two-petal quark-loop diagrams. The partial widths of the decay modes into channels and , and their branching ratio recently discussed in literature have been calculated and analyzed. In the comparison of our approach to the recent molecular scenarios, we have shown the explicit appearance of the threshold effect in the latter models. The calculated partial strong decay widths and their branching ratio are in reasonable agreement with the latest experimental data.
In this paper we have calculated the values of the running coupling constants of mesons and protons from and interactions at . The value of the cut parameter obtained previously by the authors [1], was used: The results have been compared with QCD predictions.
This paper presents an analysis of the running coupling constant using data from interactions at and interactions at . It is known that choosing the correct value for the cut parameter is very important for calculating the right values of the strong coupling constant . In our study, we used the value , which was obtained in our previous work [3, 4]. Finally, the results for are compared with theoretical QCD predictions.
We study model dependence of strange hadron spectra (, , , ) on transverse momentum, rapidity, and collision centrality in Au + Au collisions in the range of energies GeV using the UrQMD model. The results are compared with the data from RHIC Beam Energy Scan (BES) program. While the model shows reasonable agreement for spectra, it systematically underestimates the yields of strange and multi-strange hadrons over the entire energy range, with the discrepancy increasing with the strangeness content. The antibaryon-to-baryon and hadron-to-pion ratios are qualitatively reproduced, but significant quantitative deviations persist. These results demonstrate that, in its present form, the UrQMD model does not provide a satisfactory description of strange hadron observables at GeV, indicating the need for additional physical mechanisms beyond hadronic rescattering to account for strangeness production in high-density nuclear matter.
