"Two-proton radioactivity - status and perspectives"

Abstract:
Ground-state two-proton (2p) radioactivity is a characteristic decay mode for isotopes of even-Z elements located beyond the two-proton drip line. So far, this exotic process has been experimentally observed in a few light- and medium-mass nuclides with Z ≤ 36. In fact, ground-state, simultaneous two-proton emission is predicted to be observable for every even-Z element up to tellurium. Most of them, however, will be very difficult to reach in the near future. In the region between tellurium and lead the particle instability is expected to be manifested by sequential emission of two protons. In addition to the ongoing search for new 2p emitters, an important research direction aims at precision studies of this exotic decay mode. The interesting question in this context is to what extent details of nuclear structure can be inferred from 2p decay observables. It is expected that the momentum correlations between the emitted protons may reveal the composition of the initial wave function. Work is in progress to investigate whether the p−p correlations in the three classical cases ⁴⁵Fe, ⁴⁸Ni, and ⁵⁴Zn will shed light on the Z = 28 shell closure in this region of the nuclear chart.

In the talk, I will overview 2p radioactivity studies with a focus on recent experimental and theoretical developments.