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Title: Optical model potential analysis of n ¯ A and n A interactions

In this study, we use a momentum-dependent optical model potential to analyze the annihilation cross sections of the antineutron $$\overline{n}$$ on C, Al, Fe, Cu, Ag, Sn, and Pb nuclei for projectile momenta p lab ≲ 500 MeV / c . We obtain a good description of annihilation cross section data of Barbina et al. [Nucl. Phys. A 612, 346 (1997)] and of Astrua et al. [Nucl. Phys. A 697, 209 (2002)] which exhibit an interesting dependence of the cross sections on p lab as well as on the target mass number A. We also obtain the neutron (n) nonelastic reaction cross sections for the same targets. Comparing the $nA$ reaction cross sections σ$$nA\atop{rec}$$ to the $$\overline{n}A$$ annihilation cross sections σ $$\overline{n}A$$ ann, we find that σ $$\overline{n}A$$ ann is significantly larger than σ$$nA\atop{rec}$$, that is, theσ $$\overline{n}A$$ ann / σ$$nA\atop{rec}$$ cross section ratio lies between the values of about 1.5 to 4.0 in the momentum region where comparison is possible. The dependence of the $$\overline{n}$$ annihilation cross section on the projectile charge is also examined in comparison with the antiproton $$\overline{p}$$. Here we predict the $$\overline{p}A$$ annihilation cross section on the simplest assumption that both $$\overline{p}A$$ and $$\overline{n}A$$ interactions have the same nuclear part of the optical potential but differ only in the electrostatic Coulomb interaction. Finally, deviation from a such simple model extrapolation in measurements will provide new information on the difference between $$\overline{n}A$$ and $$\overline{p}A$$ potentials.
Authors:
 [1] ;  [2]
  1. Auburn Univ., AL (United States). Department of Physics
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Physics Division
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 97; Journal Issue: 5; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
OSTI Identifier:
1439938
Alternate Identifier(s):
OSTI ID: 1439138