Optical Model by co-operation between

China Nuclear Data Center &Tuebingen University

Ruirui Xu,* Zhongyu Ma, Yue Zhang, and Yuan Tian

China Nuclear Data Center, China Institute of Atomic Energy

E. N. E. van Dalen and H. Müther

Institutfür Theoretische Physik, Universität Tübingen, Germany


Introduction of CTOM:

The optical model is a crucial component in such nuclear reaction studies, mainly because it determines the cross section for nuclear scattering and the formation of compound nuclei in the initial stage of a reaction and supplies the transmission coefficients for branching into the various final states. During the past few decades, considerable effort has been made to explore such nuclear reactions based on fundamental microscopic nuclear theories to obtain reliable predictions to nuclear data with sparse or lacking experimental data completely .

CTOM provides an isospin dependent microscopic nucleon-nucleus optical potentials in a Dirac-Brueckner-Hartree-Fock approach. In this work, the DBHF approach is used to evaluate the relativistic structure of the nucleon self-energies in nuclear matter at various densities and asymmetries. The Schrödinger equivalent potentials of finite nuclei are derived from these Dirac components by a local density approximation (LDA). The density distributions of finite nuclei are taken from the Hartree-Fock-Bogoliubov approach with Gogny D1S force. An improved LDA approach (ILDA) is employed to get a better prediction of the scattering observables. A χ2 assessment system based on the global simulated annealing algorithm is developed to optimize the very few free components in this study.

Results with the present relativistic MOP reproduce the n,p + A scattering observables with good accuracy over a broad range of targets and a large region of energies fitting only the free-range factor t in ILDA and minor adjustments of the scalar and vector potentials in the low-density region.

More descriptions of CTOM are obtained in the following references:

[1] Relativistic nucleon optical potentials with isospin dependence

in a Dirac-Brueckner-Hartree-Fock approach, PHYSICAL REVIEW C 85, 034613 (2012);

[2] Global analysis of isospin dependent microscopic nucleon-nucleus optical potentials Global analysis of isospin dependent microscopic nucleon-nucleus optical potentials, PHYSICAL REVIEW C 94, 034606 (2016);

[3] The relativistic Dirac–Brueckner approach to asymmetric nuclear matter, Nuclear Physics A 744 (2004) 227–248.

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