Two-proton decay from alpha-cluster states in C-10 and N-11

Two-proton decay from excited states in 10C and 11N has been characterized from an analysis of the 2p + 2 alpha and 3p + 2 alpha exit channels. Data from four previously published invariant-mass studies associated with inelastic excitation, multinucleon knockout, and neutron pickup reactions have been considered. A rotational band in 10C was identified built on the second 0+ state which has strong alpha-cluster molecular structure. The members of this band were tentatively identified up to J pi = 4+ and all identified states have a prompt 2p decay branch. The spins of the 0+ and 2+ members were deduced from comparisons of the momentum correlations in their 2p branches to those from known 2p emitters. The 2+ and the tentative 4+ members are both above the alpha threshold and exhibit large reduced decay widths for alpha emission. This band exhibits a similar moment of inertia to its analog in the mirror nucleus 10Be. Evidence is also presented fora molecular band in 11N built on the second 3/2- state which 2p decays. Tentative members of this band have been assigned up to J pi = 9/2- and their excitation energies also match their likely analogs in the mirror nucleus 11Be.