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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

Lee, Teck-Ghee, and Wong, Cheuk-Yin. Optical model potential analysis of n¯A and nA interactions. United States: N. p., Web. doi:10.1103/PhysRevC.97.054617.
Lee, Teck-Ghee, & Wong, Cheuk-Yin. Optical model potential analysis of n¯A and nA interactions. United States. doi:10.1103/PhysRevC.97.054617.
Lee, Teck-Ghee, and Wong, Cheuk-Yin. 2018. "Optical model potential analysis of n¯A and nA interactions". United States. doi:10.1103/PhysRevC.97.054617.
@article{osti_1439938,
title = {Optical model potential analysis of n¯A and nA interactions},
author = {Lee, Teck-Ghee and Wong, Cheuk-Yin},
abstractNote = {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 plab ≲ 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 plab 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.},
doi = {10.1103/PhysRevC.97.054617},
journal = {Physical Review C},
number = 5,
volume = 97,
place = {United States},
year = {2018},
month = {5}
}