Knockout reactions from ${}^{14}\mathrm{O}$ at 305 MeV/nucleon

The cross section for one-proton knockout from ${}^{14}\mathrm{O}$ on a carbon target at 305 MeV/nucleon was measured to be ${\sigma }_{-p}({}^{14}\mathrm{O}\to {}^{13}\mathrm{N})=35\left(5\right)\mathrm{mb}$. The one-proton one-neutron ($pn$) removal cross section ${\sigma }_{-p-n}({}^{14}\mathrm{O}\to {}^{12}\mathrm{N})=30\left(6\right)\mathrm{mb}$ and two-proton one-neutron ($2pn$) removal cross section ${\sigma }_{-2p-n}({}^{14}\mathrm{O}\to {}^{11}\mathrm{C})=41\left(6\right)\mathrm{mb}$ were also obtained. The deduced reduction factor, the ratio of the experimental and theoretical cross sections, is close to unity for one-proton knockout from ${}^{14}\mathrm{O}$, consistent with the systematics as well as the result obtained at a much lower beam energy. The indirect reaction process, which involves a one-neutron knockout plus proton(s) evaporation mechanism, is expected to contribute much to the $pn$ and $2pn$ removal.

Figure 1

Schematic of the layout of (a) the RIBLL2 and (b) the External Target Facility (ETF).

Figure 2

The particle identification spectrum of the incoming cocktail beams.

Figure 3

The charge number $Z$ identification spectrum of the particles after the reaction target.

Figure 4

The mass number $A$ identification spectra of the particles after the reaction target. The particles are already charge selected for (a) $Z=7$ and (b) $Z=6$.