Sub-barrier fusion of the magic nuclei 40,48Ca+48Ca

Abstract

The fusion excitation functions of 40,48Ca+48Ca have been measured near and below the Coulomb barrier and the fusion barrier distributions have been extracted from the data. The cross sections for 48Ca+48Ca are well reproduced by coupled-channels (CC) calculations, including inelastic excitations to the 2+ and 3- states of both nuclei and using a standard potential. The cross sections of 40Ca+48Ca are significantly larger than previous data for the same system, especially near and above the barrier. While a much better agreement between present data and CC calculations is found in that energy range, the sub-barrier cross sections are still underpredicted

Examining the role of transfer coupling in sub-barrier fusion ofTi46,50+Sn124

“…8(a). It is worth noting that the coupling to the octupole state in 40 Ca also results in a barrier well below the uncoupled barrier for other reactions [31][32][33].…”

“…As an example, the sub-barrier fusion enhancement in 32 [37,38]. It is worth noting that 32 S has a very collective high-lying octupole state, like 40 Ca.…”

Breakup and n -transfer effects on the fusion reactions Li6,7+Sn120,Fisichella1, Shotter2, Фігуера3 et al. 2017Phys. Rev. C20030View full textAdd to dashboardCite

“…For example, enhanced fusion cross sections have been observed for 28 Si + 94 Zr [10], 32 S + 96 Zr, 110 Pd [11,12] and 40 Ca + 48 Ca, 96 Zr, 124,132 Sn [13][14][15][16] systems compared to their isotopic counterparts characterized by lower Q values for neutron transfer. However, the fusion excitation functions for systems like Sn+Ni, Te+Ni [17], O+Ge [18], and Ni+Mo [19] do not show significant differences, when different isotopes of the colliding nuclei are considered, even though the systems present very different Q values for multineutron transfer channels.…”

Sub-barrier fusion enhancement with radioactive134Te

“…However, the fusion probability is over an order of magnitude greater for the cross system, 40 Ca+ 48 Ca, at E c.m. /V C ∼ 0.94 (where V C is the * kohley@kohley@nscl.msu.edu Coulomb barrier) [15]. The most significant difference of the cross system compared to the symmetric systems is the presence of PQNT channels, which suggests that the enhanced sub-barrier fusion is related to the coupling to transfer channels.…”

“…A variety of experimental measurements have shown strong correlations between the presence of positive Q-value neutron transfer (PQNT) channels and enhanced sub-barrier fusion probabilities (see Refs. [1,[10][11][12][13][14][15][16][17][18][19][20] and references therein). For example, the fusion of the symmetric 40 Ca+ 40 Ca and 48 Ca+ 48 Ca systems show very similar excitation functions when taking into account the differences in the barrier height and nuclear radii.…”