Possible effect of mixed phase and deconfinement upon spin correlations in the pairs generated in relativistic heavy-ion collisions

Valery V Lyuboshitz,Vladimir L Lyuboshitz

doi:10.1088/1742-6596/668/1/012130

Abstract

Spin correlations for the ΛΛ and pairs, generated in relativistic heavy-ion collisions, and related angular correlations at the joint registration of hadronic decays of two hyperons, in which space parity is not conserved, are analyzed. The correlation tensor components can be derived from the double angular distribution of products of two decays by the method of “moments”. The properties of the “trace” of the correlation tensor (a sum of three diagonal components), determining the relative fractions of the triplet states and singlet state of respective pairs, are discussed. Spin correlations for two identical particles (ΛΛ) and two non-identical particles () are considered from the viewpoint of the conventional model of one-particle sources. In the framework of this model, correlations vanish at sufficiently large relative momenta. However, under these conditions, in the case of two non-identical particles () a noticeable role is played by two-particle annihilation (two-quark, two-gluon) sources, which lead to the difference of the correlation tensor from zero. In particular, such a situation may arise when the system passes through the “mixed phase”.

Highlights

Spin correlations for and pairs, generated in relativistic heavy ion collisions, and respective angular correlations at joint registration of hadronic decays of two hyperons, in which space parity is not conserved, give important information on the character of multiple processes
; is determined only by the “trace" of the correlation tensor T = W t 3Ws ( Ws and Wt are relative fractions of the singlet state and triplet states, respectively ), and it does not depend on the polarization vectors
The angular correlation between the proton and antiproton momenta in the rest frames of the and particles is described by the expression: d w(cos

Summary

Introduction

Spin correlations for and pairs, generated in relativistic heavy ion collisions, and respective angular correlations at joint registration of hadronic decays of two hyperons, in which space parity is not conserved, give important information on the character of multiple processes. C T ; P P = tensor with components ik ik 1i 2k describes the spin correlations of two particles . P is the polarization vector of the particle, n is the unit vector along the direction of proton momentum in the rest frame of the particle, is the coefficient of P -odd angular asymmetry ( = 0:642 ).

Results

Conclusion