The comparison of the OM results given by the calculable R-matrix method with those given by other methods confirms that the calculable R-matrix method is an efficient tool for the OM study of the elastic nucleon-nucleus scattering using a nonlocal nucleon OP. | Communications in Physics, Vol. 28, No. 4 (2018), pp. 323-336 DOI: R-MATRIX METHOD AND THE NONLOCAL NUCLEON OPTICAL POTENTIAL DOAN THI LOAN† , NGUYEN HOANG PHUC, DAO TIEN KHOA Institute for Nuclear Science and Technology, VINATOM, 179 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam † E-mail: loandoan87@ Received 13 July 2018 Accepted for publication 08 September 2018 Published 15 December 2018 Abstract. The calculable R-matrix method is applied to solve the Schr¨odinger equation in the optical model (OM) analysis of the elastic nucleon-nucleus scattering using a nonlocal nucleon optical potential (OP). The phenomenological nonlocal nucleon OP proposed by Perey and Buck (PB), and the two recent versions of the PB parametrization were used in the present OM study of the elastic nucleon scattering on 27 Al, 40 Ca, 48 Ca, 90 Zr, and 208 Pb targets at different energies. The comparison of the OM results given by the calculable R-matrix method with those given by other methods confirms that the calculable R-matrix method is an efficient tool for the OM study of the elastic nucleon-nucleus scattering using a nonlocal nucleon OP. Keywords: Nonlocality, nucleon optical potential, R-matrix method. Classification numbers: ; . I. INTRODUCTION The nucleon-nucleus scattering remains an important experiment of the modern nuclear physics to investigate the nucleon-nucleus interaction as well as the structure of the target nucleus. In particular, the elastic and inelastic scattering of the short-lived, unstable nuclei on proton target, or proton scattering in the inverse kinematics, is now extensively carried out with the secondary beams of unstable nuclei to investigate the unknown structure of unstable nuclei under study. The key quantity needed for the description of the nucleon-nucleus scattering at both low and high energies is the nucleon optical potential (OP), which determines the scattering wave function of the scattered
