320 research outputs found
Phase Space Representation for Open Quantum Systems within the Lindblad Theory
The Lindblad master equation for an open quantum system with a Hamiltonian
containing an arbitrary potential is written as an equation for the Wigner
distribution function in the phase space representation. The time derivative of
this function is given by a sum of three parts: the classical one, the quantum
corrections and the contribution due to the opening of the system. In the
particular case of a harmonic oscillator, quantum corrections do not exist.Comment: 19 pages, Latex, accepted for publication in Int. J. Mod. Phys.
Dissipative tunneling through a parabolic potential in the Lindblad theory of open quantum systems
By using the Lindblad theory for open quantum systems, an analytical
expression of the tunneling probability through an inverted parabola is
obtained. This penetration probability depends on the environment coefficients.
It is shown that the tunneling probability increases with the dissipation and
the temperature of the thermal bath.Comment: 16 pages, 6 figure
Cluster radioactivity of Th isotopes in the mean-field HFB theory
Cluster radioactivity is described as a very mass asymmetric fission process.
The reflection symmetry breaking octupole moment has been used in a mean field
HFB theory as leading coordinate instead of the quadrupole moment usually used
in standard fission calculations. The procedure has been applied to the study
of the ``very mass asymmetric fission barrier'' of several even-even Thorium
isotopes. The masses of the emitted clusters as well as the corresponding
half-lives have been evaluated on those cases where experimental data exist.Comment: Contribution to XIV Nuclear Physics Workshop at Kazimierz Dolny,
Poland, Sept. 26-29, 200
On scission configuration in ternary fission
A static scission configuration in cold ternary fission has been considered
in the framework of two mean field approaches. The virial theorems has been
suggested to investigate correlations in the phase space, starting from a
kinetic equation. The inverse mean field method is applied to solve
single-particle Schredinger equation, instead of constrained selfconsistent
Hartree-Fock equations. It is shown, that it is possible to simulate
one-dimensional three-center system via inverse scattering method in the
approximation of reflectless single-particle potentialsComment: 11 pages, 1 figure, Fusion Dynamics at the Extremes, Int. Workshop,
Dubna, Russia, May 2000. To be published in World Scientifi
Pairing and continuum effects in nuclei close to the drip line
The Hartree-Fock-Bogoliubov (HFB) equations in coordinate representation are
solved exactly, i.e., with correct asymptotic boundary conditions for the
continuous spectrum. The calculations are preformed with effective Skyrme
interactions. The exact HFB solutions are compared with HFB calculations based
on box boundary conditions and with resonant continuum Hartree-Fock-BCS
(HF-BCS) results. The comparison is done for the neutron-rich Ni isotopes. It
is shown that close to the drip line the amount of pairing correlations depends
on how the continuum coupling is treated. On the other hand, the resonant
continuum HF-BCS results are generally close to those of HFB even in
neutron-rich nuclei.Comment: 9 figures, corrected ref.
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