Two-Body Correlations in Pionic Systems

Abstract

In close analogy to fermionic many-body theory the truncation of the bosonic BBGKY density matrix hierarchy on the two-body level leads to a coupled set of nonlinear equations of motion for the one-body density matrix and the two-body correlation function. These equations provide a nonperturbative description of the nonequilibrium time evolution of particle number conserving bosonic many-body systems including the dynamical resummation of parquet-like diagrams. Within this framework we study the properties of a pionic system as a function of temperature and density with focus on two-body quantities. For each temperature we find a related pion density for which the relative strength of the two-body correlation function assumes a maximum and the pionic system is far from the mean-field limit. Since these correlated phases up to $T$=200 MeV only appear at rather low pion density, the hot and dense pion gas as generated in ultrarelativistic nucleus-nucleus collisions should be well described within mean-field theory; i.e. the HBT analysis of pion sources from $\pi -\pi$ correlations should remain valid even in the case of strongly interacting pions.

30 pages, LATEX, figures are available as one postscript file via ftp from the directory ugi-94-12 of [email protected], UGI-94-12

References in corpus (4)

• Correlation Dynamics of Green's Functions
• Vibrations versus collisions and the iterative structure of two-body dynamics
• Pion Properties in a Hot $\Pi N\Delta$ Gas
• Microscopic analysis of two-body correlations in light nuclei

Cited by in corpus (4)

• Connected Green function approach to ground state symmetry breaking in ${\Phi }_{1+1}^4$-theory
• New Source Term for QGP Formation in the Background-Field Model
• The BBGKY hierarchy for ultracold bosonic systems: II. Applications
• Convergence properties of the equal-time connected Green function approach for temporal gauge SU(2)_{2+1} Yang-Mills theory