Light particle emission inCl35+Mg24fusion reactions at high excitation energy and angular momentum

Abstract

In-plane and out-of-plane correlations of light charged particles and neutrons emitted in the $^{35}\mathrm{Cl}\phantom{\rule{0.3em}{0ex}}(260\phantom{\rule{0.3em}{0ex}}\text{MeV})+^{24}\mathrm{Mg}$ complete fusion reaction have been measured to investigate deformation and angular momentum effects upon the decay of $^{59}\mathrm{Cu}$ compound nucleus. An array of $21\phantom{\rule{0.3em}{0ex}}{\text{BaF}}_{2}$ crystals has been used to identify the light charged particles $(Z\ensuremath{\leqslant}4)$ and neutrons emitted in coincidence with heavy fragments $(Z\ensuremath{\geqslant}5)$ detected in six ionization chamber telescopes. Coincident energy spectra and angular distributions of neutrons, protons, and $\ensuremath{\alpha}$-particles have been described by the statistical-model calculations with nuclear level densities tuned to take account of deformation effects in the emitters. This spin-dependent approach suggests the onset of large nuclear deformation in $^{59}\mathrm{Cu}$ at high spin. This conclusion is consistent with the recent observation of a superdeformed band in the $^{59}\mathrm{Cu}$ nucleus.