Hadron-hadron Correlation And Interaction from Heavy-ion Collisions

Abstract

We investigate the ΛΛ, ΝΩ and Κ⁻p momentum correlations in high-energy heavy-ion collisions and their relevance to the hadron-hadron interactions. For R/a₀0, <|R/a₀| ≪1 and R/a₀ > 1, where R and a₀ denote the source size and scattering length, the correlation functions at small relative momenta are enhanced, strongly enhanced and suppressed, respectively, by the interaction when the interaction range is short and the single channel treatment is justified. The recently observed ΛΛ correlation function is found to be enhanced by the interaction from that by the quantum statistics and feed-down effects, provided that the pair purity is as large as the statistical model estimate. The scattering length of the ΛΛ interaction is constrained to be 1/a₀ < -0.8 fm⁻¹ by the correlation data. For the Ω⁻p correlation, we propose to introduce an "SL (small-to-large) ratio" of the correlation functions for different source sizes in order to evade the contamination by the Coulomb interaction.In the SL ratios, the above characteristic interaction dependence is found to be recovered. Then the SL ratio is useful to judge the sign and strength of the scattering length and consequently the existence of the S = -3 dibaryon state. The coupling effects of the Κ⁻p and Κ⁻ºn channels are found to be important for the Κ⁻p correlation. The outgoing wave function in the Κ⁻p channnel differs from the complex conjugate of that in the Κ⁻p scattering due to the coupled-channel effects. Then we may find peak and dip structures different from those in the Κ⁻p scattering cross section, and it would be possible to examine the interference of the Ι = 0 and Ι = 1 amplitudes.