36 research outputs found
--Dependence of Bond Energies in Double--- Hypernuclei
The -dependence of the bond energy of the
hypernuclear ground states is calculated in a three-body
model and in the Skyrme-Hartree-Fock approach.
Various and -nucleus or potentials
are used and the sensitivity of to the interactions
is discussed. It is shown that in medium and heavy
hypernuclei, is a linear function of
, where is rms radius of the hyperon orbital. It
looks unlikely that it will be possible to extract
interaction from the double- hypernuclear energies only, the
additional information about the -core interaction, in particular, on
is needed.Comment: 11 pages, LaTex, 3 figure
Strangeness production in antiproton-nucleus collisions
Antiproton annihilations on nuclei provide a very interesting way to study
the behaviour of strange particles in the nuclear medium. In low energy annihilations, the hyperons are produced mostly by strangeness exchange
mechanisms. Thus, hyperon production in interactions is very
sensitive to the properties of the antikaon-nucleon interaction in nuclear
medium. Within the Giessen Boltzmann-Uehling-Uhlenbeck transport model (GiBUU),
we analyse the experimental data on and production in collisions at GeV/c. A satisfactory overall agreement is
reached, except for the production in Ne collisions at
MeV/c, where we obtain substantially larger
production rate. We also study the hyperon production, important in view
of the forthcoming experiments at FAIR and J-PARC.Comment: 8 pages, 4 figures, invited talk given by A.B. Larionov at the 10th
International Conference on Low Energy Antiproton Physics (LEAP2011),
Vancouver, Canada, Apr 27 - May 1, 2011, Hyperfine Interact. in pres
Semi-phenomenological neutron density distributions
The simple algebraic form for the nuclear densities designed to incorporate correctly, the two physical requirements, namely, the asymptotic behaviour and the behaviour near the centre, is used to calculate the neutron distributions in several nuclei. Sample neutron densities for Ni-58,Ni-64, Sn-116 and Pb-208 are presented. The calculation reveals an excellent agreement with the experiment as well as with the relativistic and nonrelativistic microscopic mean field calculations. The use of this algebraic form of the densities in the analytic studies is strongly advocated
Temperature dependent relativistic mean field for highly excited hot nuclei
The temperature dependent relativistic mean field (RMF-T) results obtained by using nonlinear Lagrangian parameter set NL3 are presented for a few selected representative spherical and deformed nuclei. The calculated total binding energy (entropy) decrease (increase) as temperature (T) increases. The depths of the potentials and the single particle (sp) energies change very little with temperature. The density slightly spreads out; as a result the radius increases as temperature rises. For well deformed nuclei the shell effects disappear at around T similar to 3 MeV. This value of T is relatively higher as compared to the corresponding value of T (similar to 1.8 MeV) obtained in the Strutinsky-type calculations. This difference in the value of T is shown to be due to the use of the effective nucleon mass (< the bare mass) appearing in the Skyrme III interaction or emerging from the RMF Lagrangian