392 research outputs found
Quasifission at extreme sub-barrier energies
With the quantum diffusion approach the behavior of the capture cross-section
is investigated in the reactions Mo + Mo, Ru +
Ru, Pd + Pd, and Kr + Sn at deep
sub-barrier energies which are lower than the ground state energies of the
compound nuclei. Because the capture cross section is the sum of the complete
fusion and quasifission cross sections, and the complete fusion cross section
is zero at these sub-barrier energies, one can study experimentally the unique
quasifission process in these reactions after the capture.Comment: 3 pages, 3 figure
Non-Markovian dynamics with fermions
Employing the quadratic fermionic Hamiltonians for the collective and
internal subsystems with a linear coupling, we studied the role of fermionic
statistics on the dynamics of the collective motion. The transport coefficients
are discussed as well as the associated fluctuation-dissipation relation. Due
to different nature of the particles, the path to equilibrium is slightly
affected. However, in the weak coupling regime, the time-scale for approaching
equilibrium is found to be globally unchanged. The Pauli-blocking effect can
modify the usual picture in open quantum system. In some limits, contrary to
boson, this effect can strongly hinder the influence of the bath by blocking
the interacting channels.Comment: 13 pages, 6 figures. Submitted to PR
Neutron pair transfer in sub-barrier capture process
The sub-barrier capture reactions following the neutron pair transfer are
proposed to be used for the indirect study of neutron-neutron correlation in
the surface region of nucleus. The strong effect of the dineutron-like clusters
transfer stemming from the surface of magic and non-magic nuclei O,
Ca, Ni, Mo, Ru, Pd, and
Sn is demonstrated. The dominance of
two-neutron transfer channel at the vicinity of the Coulomb barrier is further
supported by time-dependent mean-field approaches.Comment: 17 pages, 7 figures, accepted in PR
Disagreement between capture probabilities extracted from capture and quasi-elastic backscattering excitation functions
Experimental quasi-elastic backscattering and capture (fusion) excitation
functions are usually used to extract the s-wave capture probabilities for the
heavy-ion reactions. We investigated the
O+Sn,Sm,Pb systems at energies near and below
the corresponding Coulomb barriers and concluded that the probabilities
extracted from quasi-elastic data are much larger than the ones extracted from
fusion excitation functions at sub and deep-sub barrier energies. This seems to
be a reasonable explanation for the known disagreement observed in literature
for the nuclear potential diffuseness derived from both methods.Comment: 9 pages, 3 figure
Sub-barrier capture reactions with O and Ca beams
Various sub-barrier capture reactions with beams O and Ca
are treated within the quantum diffusion approach. The role of neutron transfer
in these capture reactions is discussed. The quasielastic and capture barrier
distributions are analyzed and compared with the recent experimental data.Comment: 8 pages, 9 figures, will be published in EPJA. arXiv admin note:
substantial text overlap with arXiv:1211.433
Sub-barrier capture reactions with O beams
Various sub-barrier capture reactions with beams O are treated
within the quantum diffusion approach. The role of neutron transfer in these
capture reactions is discussed.Comment: 3 pages, 4 figure
Threshold energy for sub-barrier fusion hindrance phenomenon
The relationship between the threshold energy for a deep sub-barrier fusion
hindrance phenomenon and the energy at which the regime of interaction changes
(the turning-off of the nuclear forces and friction) in the sub-barrier capture
process, is studied within the quantum diffusion approach. The quasielastic
barrier distribution is shown to be a useful tool to clarify whether the slope
of capture cross section changes at sub-barrier energies.Comment: 4 pages, 4 figures (accepted in Eur. Phys. J. A
Production of exotic isotopes in complete fusion reactions with radioactive beams
The isotopic dependence of the complete fusion (capture) cross section is
analyzed in the reactions
Xe+Ca with stable and
radioactive beams. It is shown for the first time that the very neutron-rich
nuclei W can be reached with relatively large cross sections by
complete fusion reactions with radioactive ion beams at incident energies near
the Coulomb barrier. A comparison between the complete fusion and fragmentation
reactions for the production of neutron-rich W and neutron-deficient Rn
isotopes is performed.Comment: 13 pages, 6 figures, accepted in PR
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