Resonant, direct, and transfer breakup of ${}^6\mathrm{Li}$ by ${}^{112}\mathrm{Sn}$

Projectile breakup cross sections in the ${}^6\mathrm{Li}+{}^{112}\mathrm{Sn}$ reaction have been measured at two beam energies, 30 and 22 MeV. Cross sections for sequential breakup of ${}^6\mathrm{Li}$ into $\alpha +d$ via its resonant state of $1^{+}$ (5.65 MeV) in the continuum have been measured for the first time along with two other dominant resonant states of $3^{+}$ (2.18 MeV) and $2^{+}$ (4.31 MeV) at $E_{\mathrm{beam}}=30$ MeV. However, at 22 MeV, the $\alpha +d$ breakup is found to be only due to direct breakup process. Cross sections measured for sequential breakup via two transfer channels, $\left({}^6\mathrm{Li},{}^5\mathrm{Li}\right)$ and $\left({}^6\mathrm{Li},{}^8\mathrm{Be}\right)$, into $\alpha +p$ and $\alpha +\alpha$, respectively, and the above $\alpha +d$ breakup channels compared with the results of coupled-channels calculations unravel the reaction mechanisms involving a weakly bound projectile and different processes leading to large inclusive $\alpha$-particle production.

Figure 1

A typical two-dimensional raw spectrum of a vertical strip placed at ${51}^{\circ }$.

Figure 2

Comparison of the yield distributions of $\alpha -d,\alpha -p$, and $\alpha \text{−}\alpha$ breakup as a function of $Q$ value and relative energy at two different beam energies, i.e., 22 and 30 MeV.

Figure 3

Sequential $\alpha +d$ breakup cross section in center-of-mass frame measured at 30 MeV. See text for details.

Figure 4

Differential cross sections for direct breakup of ${}^6\mathrm{Li}\to \alpha +d$ in center-of-mass frame measured at $E_{\mathrm{beam}}$ of (a) 30 MeV and (b) 22 MeV. (c), (d) Measured elastic scattering angular distribution (diamonds) at respective energies along with the result of CDCC calculations (dash-dot-dot lines). See text for details.

Figure 5

Differential cross sections in center-of-mass frame for sequential breakup of (a) ${}^6\mathrm{Li}\to {}^5\mathrm{Li}\to \alpha +p$, and (b) ${}^6\mathrm{Li}\to {}^8\mathrm{Be}\to \alpha +\alpha$ measured at $E_{\mathrm{beam}}=30$ MeV and 22 MeV. Lines represent CRC calculations (see text for details).