6,110 research outputs found
Inclusion of Quantum Fluctuations in Wave Packet Dynamics
We discuss a method by which quantum fluctuations can be included in
microscopic transport models based on wave packets that are not energy
eigenstates. By including the next-to-leading order term in the cumulant
expansion of the statistical weight, which corresponds to the wave packets
having Poisson energy distributions, we obtain a much improved global
description of the quantum statistical properties of the many-body system. In
the case of atomic nuclei, exemplified by 12C and 40Ca, the standard
liquid-drop results are reproduced at low temperatures and a phase
transformation to a fragment gas occurs as the temperature is raised. The
treatment can be extended to dynamical scenarios by means of a Langevin force
emulating the transitions between the wave packets. The general form of the
associated transport coefficients is derived and it is shown that the
appropriate microcanonical equilibrium distribution is achieved in the course
of the time evolution. Finally, invoking Fermi's golden rule, we derive
specific expressions for the transport coefficients and verify that they
satisfy the fluctuation-dissipation theorem.Comment: uuencoded revtex body and 8 ps figures (16 pages total
Phase diagram at finite temperature and quark density in the strong coupling region of lattice QCD for color SU(3)
We study the phase diagram of quark matter at finite temperature (T) and
chemical potential (mu) in the strong coupling region of lattice QCD for color
SU(3). Baryon has effects to extend the hadron phase to a larger mu direction
relative to Tc at low temperatures in the strong coupling limit. With the 1/g^2
corrections, Tc is found to decrease rapidly as g decreases, and the shape of
the phase diagram becomes closer to that expected in the real world.Comment: 4 pages, 4 figures. To appear in the proceedings of the 19th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions,
Shanghai, China, Nov. 14-20, 2006 (Quark Matter 2006
Brown-Rho Scaling in the Strong Coupling Lattice QCD
We examine the Brown-Rho scaling for meson masses in the strong coupling
limit of lattice QCD with one species of staggered fermion. Analytical
expression of meson masses is derived at finite temperature and chemical
potential. We find that meson masses are approximately proportional to the
equilibrium value of the chiral condensate, which evolves as a function of
temperature and chemical potential.Comment: Prepared for Chiral Symmetry in Hadron and Nuclear Physics
(Chiral07), Nov. 13-16, 2007, Osaka, Japa
INCORPORATION OF QUANTUM STATISTICAL FEATURES IN MOLECULAR DYNAMICS
We formulate a method for incorporating quantum fluctuations into molecular-
dynamics simulations of many-body systems, such as those employed for energetic
nuclear collision processes. Based on Fermi's Golden Rule, we allow spontaneous
transitions to occur between the wave packets which are not energy eigenstates.
The ensuing diffusive evolution in the space of the wave packet parameters
exhibits appealing physical properties, including relaxation towards quantum-
statistical equilibrium.Comment: 8 latex pages + 1 uuencoded ps figur
Existence of Density Functionals for Excited States and Resonances
We show how every bound state of a finite system of identical fermions,
whether a ground state or an excited one, defines a density functional.
Degeneracies created by a symmetry group can be trivially lifted by a
pseudo-Zeeman effect. When complex scaling can be used to regularize a
resonance into a square integrable state, a DF also exists.Comment: 4 pages, no figure
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