13,826 research outputs found
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
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