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Nuclear Theory·nucl-th

Friday·July 18, 2025

8 papers—2 primary·6 cross-listed

All8Primary2Cross-lists6
  1. 01

    Systematic study of the propagation of uncertainties to transfer observables

    Chloë Hebborn🇫🇷 · Filomena M. Nunes🇺🇸

    A systematic study of parametric uncertainties in transfer reactions is performed using the recently developed uncertainty quantified global optical potential (KDUQ). We consider reactions on the doubly-magic spherical nucleus Ca and explore the dependence of the predicted angular distribution uncertainties at different beam energies and for different properties of the final single-particle state populated by the reaction. Our results show that correlations between the uncertainties associated with the bound state potential and with the optical potentials may be important for correctly determining the uncertainty in the transfer cross sections (in our case, these do not add in quadrature). In general, we find small uncertainties in the predicted transfer observables: half-width of the 68% credible interval is roughly %, which is comparable to the experimental error on the transfer data. Finally, our results show that the relative magnitude of the parametric uncertainty in transfer observables increases with the beam energy and does not depend strongly on the properties of the final state.

    nucl-thFront.in Phys.(2025)·2 citations
  2. 02

    Systematic study of the validity of the eikonal model including uncertainties

    Daniel Shiu🇺🇸 · Chloë Hebborn🇺🇸 · Filomena M. Nunes🇺🇸

    Nuclear reactions at intermediate beam energies are often interpreted using the eikonal model. In the analysis of complex reaction probes, where few-body reaction methods are needed, the eikonal method may be used as an efficient way for describing the fragment-target reaction process. In this work, we perform a systematic study to test the validity of the eikonal approximation for nucleon-nucleus reactions. We also quantify uncertainties due to the nucleon optical potential on reaction observables. We inspect the validity of the eikonal model and its semiclassical correction by comparing it to exact solutions (obtained from solving the optical model equation with a finite differences method) for a wide range of reactions. We also study the effect of relativistic corrections, both kinematic and dynamic, by effectively incorporating the relativistic effects at intermediate energies. The uncertainties from a Bayesian global optical potential (KDUQ) are propagated to the observables of interest. Our study includes neutron and proton reactions on Al, Ca, Zr and Pb, for a wide range of energies MeV. Our results show that for the proton absorption cross section, the eikonal model can be used down to around MeV and the semiclassical correction extends its use to MeV. However, the validity of the eikonal model for the neutron total cross section only goes down to MeV, a range extended to MeV when using the semiclassical correction. We find the semi-classical correction to the eikonal model to be less effective in describing the angular distributions. The uncertainty intervals on the observables we studied is less than % for most of the energies considered, but increases rapidly for higher energies, namely energies outside the range of KDUQ ( MeV).

    nucl-thPRC(2025)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE