Elastic, inelastic, and one-neutron transfer angular distributions of ${}^6\mathrm{Li}+{}^{120}\mathrm{Sn}$ at energies near the Coulomb barrier

The elastic scattering, first $2^{+}$ and $3^{-}$ target inelastic excitation and one neutron pickup angular distributions for the ${}^6\mathrm{Li}+{}^{120}\mathrm{Sn}$ reaction have been measured for three bombarding energies (19, 24, and 27 MeV). Data have been analyzed through coupled-channel calculations and continuum-discretized coupled-channel calculations extended to include target excitation. In general, both theoretical models give a reasonable description of the data. For the elastic and inelastic angular distributions taken at $E_{\mathrm{lab}}=24$ and 27 MeV, the continuum-discretized coupled-channel results are slightly better in comparison to the coupled-channel predictions. For the elastic and inelastic angular distributions measured at $E_{\mathrm{lab}}=19$ MeV, the effect of the break-up channel seems to be quite important. At this energy, the elastic scattering data can be well explained by coupled channel calculations in which a strong absorptive optical imaginary potential is considered. In particular, the continuum-discretized coupled-channel theoretical results provided the best description of the $3^{-}$ excitation data at 19 MeV.

Figure 1

Single-channel spectrum taken with a detector at ${\theta }_{\mathrm{lab}}$ = ${105}^{\circ }$ placed on the SATURN array. The corresponding bombarding energy is 24 MeV. Elastic scattering yields from tin and gold nuclei may be seen in the right side of the figure. In the inset, it is possible to better visualize the inelastic and one-neutron transfer processes. See text for further details.

Figure 2

($\mathrm{\Delta }E\text{−}{E}_T$) spectrum for $E_{\mathrm{lab}}=24$ MeV and scattering angle of ${\theta }_{\mathrm{lab}}=150.1^{\circ }$. The colored solid lines represent theoretical calculations of energy loss in function of the total energy. The black circle of the inset shows $1n$-transfer events occurring in the ${}^{197}\mathrm{Au}$ backing. See text for further details. The energy loss calculations followed the method explained in Ref. [34].

Figure 3

Elastic scattering for the ${}^6\mathrm{Li}+{}^{120}\mathrm{Sn}$ reaction at 19, 24, and 27 MeV bombarding energies. The SATURN data are represented by the yellow circles and the STAR data are represented by the blue squares. The microscopical CC theoretical results obtained with the internal WS imaginary potential are presented as solid black lines. The dashed red lines correspond to CC calculations with strong surface absorption ($N_i=1.2$). The dotted-dashed green lines show the results of the CDCC calculations.

Figure 4

The inelastic scattering angular distributions for the ${}^{120}\mathrm{Sn}{2}^{+}(E^{*}=1.171$ MeV) excitation at $E_{\mathrm{lab}}=19$, 24, and 27 MeV. The SATURN and STAR data are represented by the yellow circles and blue squares, respectively. The lines represent the results of the theoretical CC (internal WS and $N_i=1.2$ imaginary potentials) and CDCC calculations.

Figure 5

The same as Fig. 4, for the excitation of the ${}^{120}\mathrm{Sn}{3}^{-}(E^{*}=2.400$ MeV) state.

Figure 6

One-neutron pickup transfer cross section for the ${}^6\mathrm{Li}+{}^{120}\mathrm{Sn}$ reaction at $E_{\mathrm{lab}}=19$ MeV. The SATURN and STAR data are represented by the yellow circles and blue squares, respectively. The solid black line in the figure was obtained from the CRC calculations as the sum of the states of ejectile and recoil nuclei labeled as Peak 1 in Table 1.

Figure 7

The same as Fig. 6 but for 24 MeV. The upper panel shows the cross sections related to the first three low-lying states of ${}^{119}\mathrm{Sn}$ (labeled as Peak 1 in Table 1). The lower panel presents the cross sections obtained from the yields of the second peak observed on the spectra (labeled as Peak 2 in Table 1).

Figure 8

The same as Fig. 7 for 27 MeV.