¹⁶O + ¹⁶O cluster states and their fusion to ³²S: A non-monotonic potential description

Abstract

Nonmonotonic (NM) nucleus-nucleus potential families rooted in the Pauli-compliant Energy Density Functional (EDF) theory and especially their behavior at higher energies, have been investigated using experimental data for $^{16}$O+$^{16}$O elastic scattering in the range $25 \leq E_{lab} \leq 1120$ MeV. At $E_{lab}= 75$ MeV, the $^{16}$O+$^{16}$O NM potentials, in a simple optical model (OM) are found to support five rotational bands of $^{16}$O+$^{16}$O bound and quasimolecular states in $^{32}$S with cluster global quantum numbers $G = 24$, 26, 28, 30 and 32. The lowest band in the experimental spectrum starting at $E_x = 7.5357$ MeV, and having $I^{\pi}$ = 0$^+$, 2$^+$, 4$^+$, 6$^+$ and 8$^+$, has been located for the first time. In the simple OM, the NM potentials are found to reproduce the experimental $^{16}$O+$^{16}$O fusion cross sections in the energy range 12 - 31 MeV. The present work shows that both the $^{16}$O+$^{16}$O cluster-bands and fusion cross sections in the Coulomb-barrier region can be reproduced using NM potentials.

Comparison of non-monotonic and monotonic potentials for cross-sections and analyzing powers of ⁶Li elastic scattering on ¹²C at 30 MeV

“…The best choice of the nuclear interaction potential between two nuclei is a long-standing and challenging problem (Brandan and Satchler, 1997). The study of nucleus-nucleus (NN) potentials is essential not only to understand the structure of the nucleus (Basak et al, 2022) but also for the burning of stars (Duarte et al, 2015) and dynamics of the nucleosynthesis for astrophysics (Thomas, 2020).…”

“…The microscopic NM potential with a repulsive core derived from the EDF theory of (Brueckner et al, 1968a;Brueckner et al, 1969) (BCD) which incorporates appropriately the Pauli principle enjoyed several successes in recent years which include: (i) the alpha-elastic scattering (Tariq et al, 1999), (ii) alpha-inelastic scattering (Basak et al, 2001), (iii) one- (Das et al, 1999), two- (Das et. al., 2000a;Das et al, 2001), three-nucleon (Das et al, 2000b) transfer reactions, (iv) band-mixing of band heads and in the Nilsson model (Hossain et al, 2005), (v) verification of the Goldberg criterion (Goldberg and Smith, 1972) of the 16 O+ 16 O (Islam et al, 2021a) and 12 C+ 12 C (Islam et al, 2021b) elastic scattering with discussion on the intriguing aspect at potential families at lower energies, (vi) 16 O+ 16 O cluster states and their fusion to 32 S (Basak et al, 2022), (vii) a novel method (Hossain et al, 2015) for determining the nuclear incompressibility K for cold nuclear matter using the 16 O+ 16 O elastic scattering. (viii) The opposite signs of the vector analyzing power (VAP) of 6,7 Li elastic scattering by 58 Ni at 20 MeV (Basak et al, 2011) and 120 Sn at 44 MeV (Basak et al, 2011) are reproduced successfully using NM potentials in the OM.…”