Energy dependence of nonlocal optical potentials

Journal Article · 29 November 2017 · Physical Review C

DOI: https://doi.org/10.1103/PhysRevC.96.051601 · OSTI ID:1463323

Lovell, A. E. ^[1]; Bacq, P. -L. ^[2]; Capel, P. ^[3]; Nunes, F. M. ^[1]; Titus, L. J. ^[1]

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1. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab. (NSCL) and Dept. of Physics and Astronomy
2. Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab. (NSCL) and Dept. of Physics and Astronomy; Free Univ. of Brussels (Belgium). Dept. of Nuclear and Quantum Physics
3. Free Univ. of Brussels (Belgium). Dept. of Nuclear and Quantum Physics; Technical Univ. of Darmstadt (Germany). Inst. of Nuclear Physics

Recently, a variety of studies have shown the importance of including nonlocality in the description of reactions. The goal of this work is to revisit the phenomenological approach to determining nonlocal optical potentials from elastic scattering. We perform a χ² analysis of neutron elastic scattering data off ⁴⁰Ca, ⁹⁰Zr, and ²⁰⁸Pb at energies E ≈ 5–40 MeV, assuming a Perey and Buck [Nucl. Phys. 32, 353 (1962)] or Tian et al. [Int. J. Mod. Phys. E 24, 1550006 (2015)] nonlocal form for the optical potential. We introduce energy and asymmetry dependencies in the imaginary part of the potential and refit the data to obtain a global parametrization. Independently of the starting point in the minimization procedure, an energy dependence in the imaginary depth is required for a good description of the data across the included energy range. We then present two parametrizations, both of which represent an improvement over the original potentials for the fitted nuclei as well as for other nuclei not included in our fit. Our results show that, even when including the standard Gaussian nonlocality in optical potential, a significant energy dependence is required to describe elastic-scattering data.

• Research Organization: Michigan State Univ., East Lansing, MI (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF); German Research Foundation (DFG); European Union (EU)
• Grant/Contract Number: NA0002132; PHY-1068571; PHY-1403906; NA0002135; FG52-08NA28552; 654002
• OSTI ID: 1463323
• Alternate ID(s): OSTI ID: 1410589
• Journal Information: Physical Review C, Vol. 96, Issue 5; ISSN 2469-9985
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English