Title: Statistical tools for a better optical model

Journal Article · · Physical Review. C
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [1]
  1. Michigan State Univ., East Lansing, MI (United States)
  2. Michigan State Univ., East Lansing, MI (United States); Washington Univ., St. Louis, MO (United States)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
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Background: Modern statistical tools provide the ability to compare the information content of observables and provide a path to explore which experiments would be most useful to give insight into and constrain theoretical models. Purpose: Here we study three such tools in the context of nuclear reactions with the goal of constraining the optical potential. Method: The three statistical tools examined are (i) the principal component analysis, (ii) the sensitivity analysis based on derivatives, and (iii) the Bayesian evidence. We first apply these tools to a toy-model case, comparing the form of the imaginary part of the optical potential. Then we consider two different reaction observables, elastic angular distributions and polarization data for reactions on 48Ca and 208Pb at two different beam energies. Results: For the toy-model case, we find significant discrimination power in the sensitivities and the Bayesian evidence, showing clearly that the volume imaginary term is more useful to describe scattering at higher energies. When comparing between elastic cross sections and polarization data using realistic optical models, sensitivity studies indicate that both observables are roughly equally sensitive but the variability of the optical model parameters is strongly angle dependent. The Bayesian evidence shows some variability between the two observables, but the Bayes factor obtained is not sufficient to discriminate between angular distributions and polarization. Conclusions: From the cases considered, we conclude that, in general, elastic scattering angular distributions have similar impact in constraining the optical potential parameters compared with the polarization data. The angular ranges for the optimum experimental constraints can vary significantly with the observable considered.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC), Nuclear Physics (NP)
Grant/Contract Number:
89233218CNA000001; SC0021422
OSTI ID:
1864993
Report Number(s):
LA-UR-20-28425
Journal Information:
Physical Review. C, Journal Name: Physical Review. C Journal Issue: 6 Vol. 104; ISSN 2469-9985
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (25)

3D preoperative planning and patient specific instrumentation for treatment of malunions of the forearm text January 2016
Bayesian averaging of computer models with domain discrepancies: a nuclear physics perspective preprint January 2019
A global nucleon optical model potential journal March 1991
Nuclear sizes in 40, 44, 48Ca journal June 1972
Local and global nucleon optical models from 1 keV to 200 MeV journal January 2003
Efficient emulators for scattering using eigenvector continuation journal October 2020
Toward emulating nuclear reactions using eigenvector continuation journal December 2021
Bayes in the sky: Bayesian inference and model selection in cosmology journal March 2008
Characterizing the Formation History of Milky way like Stellar Halos with Model Emulators journal November 2012
Bayesian parameter estimation for effective field theories journal May 2016
Statistical aspects of nuclear mass models journal July 2020
Recent advances in the quantification of uncertainties in reaction theory journal December 2020
Nucleon-Nucleus Optical-Model Parameters, A > 40 , E < 50 MeV journal June 1969
Proton elastic scattering on calcium isotopes from chiral nuclear optical potentials journal July 2019
Exploring experimental conditions to reduce uncertainties in the optical potential journal December 2019
Uncertainty quantification of an empirical shell-model interaction using principal component analysis journal May 2020
Determining fundamental properties of matter created in ultrarelativistic heavy-ion collisions journal March 2014
Toward a deeper understanding of how experiments constrain the underlying physics of heavy-ion collisions journal February 2016
Optical potential from first principles journal February 2017
Ab initio translationally invariant nonlocal one-body densities from no-core shell-model theory journal February 2018
Constraining transfer cross sections using Bayes' theorem journal June 2018
Microscopic optical potentials for calcium isotopes journal October 2018
Direct Comparison between Bayesian and Frequentist Uncertainty Quantification for Nuclear Reactions journal June 2019
Global Sensitivity Analysis of Bulk Properties of an Atomic Nucleus journal December 2019
Nuclear theory and science of the facility for rare isotope beams journal April 2014

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
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models and methods for nuclear reactions
nuclear induced nuclear reactions
nuclear reactions
nucleon elastic scattering
optical potential
optical
coupled-channel and distorted wave models
transfer nuclear reactions
uncertainty quantification