4,146 research outputs found
Matrix Elements of Random Operators and Discrete Symmetry Breaking in Nuclei
It is shown that several effects are responsible for deviations of the
intensity distributions from the Porter-Thomas law. Among these are genuine
symmetry breaking, such as isospin; the nature of the transition operator;
truncation of the Hilbert space in shell model calculations and missing
transitionsComment: 8 pages, 3 figure
Nonlinear Schrodinger equation with chaotic, random, and nonperiodic nonlinearity
In this paper we deal with a nonlinear Schr\"{o}dinger equation with chaotic,
random, and nonperiodic cubic nonlinearity. Our goal is to study the soliton
evolution, with the strength of the nonlinearity perturbed in the space and
time coordinates and to check its robustness under these conditions. Comparing
with a real system, the perturbation can be related to, e.g., impurities in
crystalline structures, or coupling to a thermal reservoir which, on the
average, enhances the nonlinearity. We also discuss the relevance of such
random perturbations to the dynamics of Bose-Einstein Condensates and their
collective excitations and transport.Comment: 4 pages, 6 figure
Interference effects in the Coulomb dissociation of 15,17,19C
In this work the semiclassical model of pure Coulomb excitation was applied
to the breakup of 15,17,19C. The ground state wave functions were calculated in
the particle-rotor model including core excitation. The importance of
interference terms in the dipole strength arising after including core degrees
of freedom is analyzed for each isotope. It is shown that Coulomb interference
effects are important for the case of 17C.Comment: 17 pages, 5 figures accepted to Physical Review
A doorway to Borromean halo nuclei: the Samba configuration
We exploit the possibility of new configurations in three-body halo nuclei -
Samba type - (the neutron-core form a bound system) as a doorway to Borromean
systems. The nuclei Be, B, N and F are of such
nature, in particular N with a half-life of 37.7 s and a halo radius of
6.07 fm is an excellent example of Samba-halo configuration. The fusion below
the barrier of the Samba halo nuclei with heavy targets could reveal the so far
elusive enhancement and a dominance of one-neutron over two-neutron transfers,
in contrast to what was found recently for the Borromean halo nucleus He +
U.Comment: Accepted for publication in Modern Physics Letters
Inclusive Breakup Theory of Three-Body Halos
We present a recently developed theory for the inclusive breakup of
three-fragment projectiles within a four-body spectator model
\cite{CarPLB2017}, for the treatment of the elastic and inclusive non-elastic
break up reactions involving weakly bound three-cluster nuclei in
/ collisions. The four-body theory is an extension of the
three-body approaches developed in the 80's by Ichimura, Autern and Vincent
(IAV) \cite{IAV1985}, Udagawa and Tamura (UT) \cite{UT1981} and Hussein and
McVoy (HM) \cite{HM1985}. We expect that experimentalists shall be encouraged
to search for more information about the system in the elastic
breakup cross section and that also further developments and extensions of the
surrogate method will be pursued, based on the inclusive non-elastic breakup
part of the spectrum.Comment: 8 pages, 3 figures, Contribution to the Proceedings of Fusion17:
"International Conference on Heavy-Ion Collisions at Near-Barrier Energies",
20-24 February 2017 Hobart, Tasmania, Australi
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