Role of neutron transfer on fusion barrier distributions of the ${}^{28,30}\mathrm{Si}$ + ${}^{124}\mathrm{Sn}$ systems

The fusion barrier distributions for ${}^{28,30}\mathrm{Si}$ + ${}^{124}\mathrm{Sn}$ systems were extracted from quasielastic excitation function measurements at backward angles. The experimental barrier distributions were then compared with coupled-channel (CC) calculations. The fusion barrier distribution for the ${}^{30}\mathrm{Si}$ + ${}^{124}\mathrm{Sn}$ reaction was well reproduced by the CC calculations with the inclusion of projectile and target inelastic couplings and only one possible positive $Q$-value 2$n$-transfer channel coupling using the ccfull code. However, CC calculations with similar coupling schemes for inelastic excitation of target and projectile with the 4$n$-transfer channel corresponding to the highest positive $Q$ value failed to reproduce the barrier distribution for the ${}^{28}\mathrm{Si}$ + ${}^{124}\mathrm{Sn}$ reaction, because it has many positive $Q$-value multi-neutron transfer channels. A better agreement between the experimental fusion barrier distribution for the ${}^{28}\mathrm{Si}$ + ${}^{124}\mathrm{Sn}$ system and the prediction of semiempirical CC calculations based on the Zagrebaev framework [V. I. Zagrebaev, Phys. Rev. C 67, 061601(R) (2003)] was obtained only after considering positive $Q$-value multi-neutron transfer couplings. The sensitivity of the fusion barrier distribution to the hexadecapole deformation parameter ${\beta }_4$ of the projectile was also discussed.

Figure 1

Typical PLF spectra in $\Delta E$ detector at ${\theta }_{\mathrm{lab}}$=160${}^{\circ }$.

Figure 2

Ratios of the quasielastic to the Rutherford scattering cross section at ${\theta }_{\mathrm{lab}}={160}^{\circ }$.

Figure 3

$D^{\mathrm{qel}}\left(E\right)$ for the ${}^{28,30}$Si + ${}^{124}$Sn systems along with the predictions of ccfull calculations.

Figure 4

$D^{\mathrm{qel}}\left(E\right)$ for the ${}^{28,30}$Si + ${}^{124}$Sn systems along with the predictions of NRV and ccfull calculations.