Sensitivity of β4 values extracted from quasi elastic barrier distribution to the 2n transfer channel

Abstract

In recent times, the Fusion Barrier Distributions (FBD) determined from quasi-elastic scattering measurements have been employed to determine the hexadecapole deformation parameter β4 value precisely. In reactions where transfer channels are favourable, coupling due to transfer may affect the determination of β4 . In order to study the role of transfer channels while determining β4 from barrier distribution, the quasi-elastic scattering measurements have been carried out in 16 O + 176 Yb. Quasi-elastic scattering excitation function has been measured at backward angles with respect to the beam direction and barrier distribution Dqel(E) has been derived. Experimentally obtained barrier distribution has been compared with coupled channel calculations using CCFULL code. The effect of two neutron transfer and hexadecapole deformation has been studied using coupled channel calculation. χ2 was calculated in a two dimensional space of β4 and neutron transfer strength Ptr . Without considering neutron transfer, χ2 minimization of Dqel(E) was not possible and the best-fit was found over a small range of β4 and Ptr . At Ptr= 0.37 , corresponding to minimum χ2 , the β4 of 176 Yb is determined to be 0.00 ± 0.015 . This value of β4 is in agreement with that obtained from Coulomb excitation measurement. © 2023, The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.