501 research outputs found
Nuclear Model of Binding alpha-particles
The model of binding alpha-particles in nuclei is suggested. It is shown good
(with the accuracy of 1-2%) description of the experimental binding energies in
light and medium nuclear systems. Our preliminary calculations show enhancement
of the binding energy for super heavy nuclei with Z~120.Comment: 4 pages, 2 figures, Will be puplished in World Scientific as Procs.
Int. Symposium on Exotic Nuclei, "EXON - 2004", July 5 - 12, 2004, Peterhof,
Russi
Proof that the Hydrogen-antihydrogen Molecule is Unstable
In the framework of nonrelativistic quantum mechanics we derive a necessary
condition for four Coulomb charges ,
where all masses are assumed finite, to form the stable system. The obtained
stability condition is physical and is expressed through the required minimal
ratio of Jacobi masses. In particular this provides the rigorous proof that the
hydrogen-antihydrogen molecule is unstable. This is the first result of this
sort for four particles.Comment: Submitted to Phys.Rev.Let
On stability of the neutron rich Oxygen isotopes
Stability with respect to neutron emission is studied for highly
neutron-excessive Oxygen isotopes in the framework of Hartree-Fock-Bogoliubov
approach with Skyrme forces Sly4 and Ska. Our calculations show increase of
stability around 40O.Comment: 5 pages, 3 figure
Dynamic ferromagnetic proximity effect in photoexcited semiconductors
The spin dynamics of photoexcited carriers in semiconductors in contact with
a ferromagnet is treated theoretically and compared with time-dependent Faraday
rotation experiments. The long time response of the system is found to be
governed by the first tens of picoseconds in which the excited plasma interacts
strongly with the intrinsic interface between semiconductor and ferromagnet in
spite of the existence of a Schottky barrier in equilibrium
Stochastic Approach to Enantiomeric Excess Amplification and Chiral Symmetry Breaking
Stochastic aspects of chemical reaction models related to the Soai reactions
as well as to the homochirality in life are studied analytically and
numerically by the use of the master equation and random walk model. For
systems with a recycling process, a unique final probability distribution is
obtained by means of detailed balance conditions. With a nonlinear
autocatalysis the distribution has a double-peak structure, indicating the
chiral symmetry breaking. This problem is further analyzed by examining
eigenvalues and eigenfunctions of the master equation. In the case without
recycling process, final probability distributions depend on the initial
conditions. In the nonlinear autocatalytic case, time-evolution starting from a
complete achiral state leads to a final distribution which differs from that
deduced from the nonzero recycling result. This is due to the absence of the
detailed balance, and a directed random walk model is shown to give the correct
final profile. When the nonlinear autocatalysis is sufficiently strong and the
initial state is achiral, the final probability distribution has a double-peak
structure, related to the enantiomeric excess amplification. It is argued that
with autocatalyses and a very small but nonzero spontaneous production, a
single mother scenario could be a main mechanism to produce the homochirality.Comment: 25 pages, 6 figure
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