Phase space factors for β+β+ decay and competing modes of double-β decay

A complete and improved calculation of phase space factors (PSF) for 2 nu beta(+)beta(+) and 0 nu beta(+)beta(+) decay, as well as for the competing modes 2 nu EC beta(+), 0 nu EC beta(+), and 2 nu ECEC, is presented. The calculation makes use of exact Dirac wave functions with finite nuclear size and electron screening and includes life-times, single and summed positron spectra, and angular positron correlations. DOI: 10.1103/PhysRevC.87.024313