Antihyperon Polarization in High-Energy Inclusive Processes

Abstract

We propose a model for the antihyperon polarization in high-energy proton-nucleus inclusive reactions, based on the final-state interactions between the antihyperons and other produced particles (predominantly pions). To formulate this idea, we use the previously obtained low-energy pion-(anti-)hyperon interaction using effective chiral Lagrangians, and a hydrodynamic parametrization of the background matter, which expands and decouples at a certain freezeout temperature.1.

Low energy kaon-hyperon interaction

“…In high energy physics this kind of interaction is very important also. When studying hyperon polarization, produced in proton-nucleus and nucleus-nucleus collisions [9]- [18], in [19]- [21] the final interactions of the hyperons and antihyperons with the produced pions is a central ingredient in order to explain the final polarizations. As it has been shown, the effect of the hyperon interactions with the surrounding hot medium, composed predominantly of pions, is very important.…”

Global Λ polarization in high energy collisions

“…Afterwards, more experimental research was launched continuously, including nucleon collisions and heavy ion collisions [3][4][5][6][7][8][9]. Theoretical studies have also been under way synchronously with the experiments [10][11][12][13][14][15][16][17][18][19].…”

Low energy pion–$$\Lambda _b$$ interaction

“…6, we may see that in general, the polarization is not so large, except near the b and * b masses. If this polarization is considered in mechanisms such as the ones presented in [16][17][18], that take into account the final-state interactions of the b , a relatively small value of the polarization 1% − 2% (or even smaller) should remain when the average is computed. Obviously in order to determine the exact value, the calculations must be made, that is a task for a future work.…”

“…In [16][17][18] the polarization of hyperons and antihyperons produced in high energy collisions have been calculated taking into account the final-state interactions and was successful in explaining the polarization of antihyperons that should be produced unpolarized if this effect was not considered. In the proposed model, based on relativistic hydrodynamics, during the collision a hot expanding medium is formed, and inside this medium the hyperons are produced.…”