Two proton emission and other exotic decays in the 48Ni region with ACTAR TPC

Abstract

Since the first indirect measurements of the two proton radioactivity in 2002 [1], some theoretical descriptions have been able to reproduce experimental results until the 2-proton radioactivity was established for 67Kr at RIKEN [2], with a lifetime about 20 times lower than expected. New theory inputs have recently been developed [3][4], predicting angular distributions of the emitted protons for some of the two proton emitters, that need to be confirmed experimentally. An experiment at GANIL/LISE3 facility was performed in May 2021 aiming to produce one of the 2 proton emitters (48Ni) and measure the angular distribution of the emitted protons. We used the ACTAR TPC detector to implant the ions and perform the tracking of their proton decays. In addition, other exotic nuclei in the 48Ni region were produced. For several of them we have found a first evidence of exotic decays such as β delayed 3- and 2-proton emission or low energy proton branches for β delayed single proton emission. The analysis of this decays will provide helpful experimental information about the structure and the partial decay schemes of these unstable nuclei.