Few-body correlations in the QCD phase diagram

From the viewpoint of statistical physics, nuclear matter is a strongly correlated many-particle system. Several regimes of the QCD phase diagram should exhibit strong correlations. Here I focus on three- and four-body correlations that might be important in the phase diagram.Comment: 3 pages, 4 figures, contribution to QNP200

Three- and Four-body correlations in nuclear matter

Few-nucleon correlations in nuclear matter at finite densities and temperatures are explored. Using the Dyson equation approach leads to effective few-body equations that include self energy corrections and Pauli blocking factors in a systematic way. Examples given are the nucleon deuteron in-medium reaction rates, few-body bound states including the \ga-particle, and \ga-particle condensation.Comment: 7 pages, 4 figures, uses Few-Body Systems style file

Formation of Few-Body Clusters in Nuclear Matter

Starting from a suitably modified three-body equation to include dominant medium effects such as self energy corrections and Pauli blocking I present results on several observables relevant for the formation of light clusters in a heavy ion collision at moderate energies. Properly taking into account the medium leads to the Mott effect, larger reaction rates, in turn, faster time scales for the deuteron life time and chemical relaxation time. Within a Boltzmann-Uehling-Uhlenbeck approach to simulate the heavy ion reactions, also the total number of deuterons and the energy spectrum are significantly changed due to medium effects in the elementary cross sections entering into the collision integrals.Comment: 3 pages, uses Elsevier package CRC, talk at XVI International Conference on Few-Body Problems in Physics, Taipei, Taiwan, March 6-10 200

Dissociation of hadrons in quark matter within finite temperature field theory approach on the light front

We present a relativistic three-body equation to investigate the properties of nucleons in hot and dense nuclear/quark matter. Within the light front approach we utilize a zero-range interaction to study the three-body dynamics. The relativistic in-medium equation is derived within a systematic Dyson equation approach that includes the dominant medium effects due to Pauli blocking and self energy corrections. We present the in-medium nucleon mass and calculate the dissociation of the three-body system.Comment: 4 pages, 2 figures. Presented by S. Mattiello at Light-Cone 2004, Amsterdam, 16 - 20 Augus

The alpha-particle in nuclear matter

Among the light nuclear clusters the alpha-particle is by far the strongest bound system and therefore expected to play a significant role in the dynamics of nuclei and the phases of nuclear matter. To systematically study the properties of the alpha-particle we have derived an effective four-body equation of the Alt-Grassberger-Sandhas (AGS) type that includes the dominant medium effects, i.e. self energy corrections and Pauli-blocking in a consistent way. The equation is solved utilizing the energy dependent pole expansion for the sub system amplitudes. We find that the Mott transition of an alpha-particle at rest differs from that expected from perturbation theory and occurs at approximately 1/10 of nuclear matter densities.Comment: 9 pages RevTex file, 1 figure, submitted to Phys. Lett.

Deuteron formation in nuclear matter

We investigate deuteron formation in nuclear matter at finite temperatures within a systematic quantum statistical approach. We consider formation through three-body collisions relevant already at rather moderate densities because of the strong correlations. The three-body in-medium reaction rates driven by the break-up cross section are calculated using exact three-body equations (Alt-Grassberger-Sandhas type) that have been suitably modified to consistently include the energy shift and the Pauli blocking. Important quantities are the lifetime of deuteron fluctuations and the chemical relaxation time. We find that the respective times differ substantially while using in-medium or isolated cross sections. We expect implications for the description of heavy ion collisions in particular for the formation of light charged particles at low to intermediate energies.Comment: 19 pages, 5 figure