39 research outputs found
Probing Matter Radii of Neutron-Rich Nuclei by Antiproton Scattering
We propose to use antiprotons to investigate the sizes of stable and
neutron-rich exotic nuclei by measurements of the \pbar A absorption cross
section along isotopic chains in inverse kinematics. The expected effects are
studied theoretically in a microscopic model. The \pbar U optical potentials
are obtained by folding free space \pbar N scattering amplitudes with HFB
ground state densities and solving the scattering equations by direct
integration. The mass dependence of absorption cross sections is found to
follow closely the nuclear root-mean-square radii. The total absorption cross
section is shown to be a superposition of cross sections describing partial
absorption on neutrons and protons, respectively. Thus measuring the
differential cross sections for absorption on neutrons and protons will give
information on their respective distributions. In neutron-rich nuclei the outer
neutron layer shields the absorption on the protons giving access to
investigations of antiproton-neutron interactions in matter.Comment: 8 pages, 4 figure
How Deep is the Antinucleon Optical Potential at FAIR energies
The key question in the interaction of antinucleons in the nuclear medium
concerns the deepness of the antinucleon-nucleus optical potential. In this
work we study this task in the framework of the non-linear derivative (NLD)
model which describes consistently bulk properties of nuclear matter and Dirac
phenomenology of nucleon-nucleus interactions. We apply the NLD model to
antinucleon interactions in nuclear matter and find a strong decrease of the
vector and scalar self-energies in energy and density and thus a strong
suppression of the optical potential at zero momentum and, in particular, at
FAIR energies. This is in agreement with available empirical information and,
therefore, resolves the issue concerning the incompatibility of G-parity
arguments in relativistic mean-field (RMF) models. We conclude the relevance of
our results for the future activities at FAIR.Comment: 13 pages, 5 figures, accepted version to appear in Phys. Lett.
Mise au point de detecteurs a emission secondaire
SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Diffusion elastique et inelastique d'antiprotons de 50 et 180 MeV sur des noyaux
SIGLECNRS RP 148 (684) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc