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We report on the first direct measurement of the proton separation energy for the proton-unbound nucleus (69)Br. Bypassing the (68)Se waiting point in the rp process is directly related to the 2p-capture rate through (69)Br, which depends exponentially on the proton separation energy. We find a proton separation energy for (69)Br of Sp((69)Br )= -785(-40)(+34) keV; this is less bound compared to previous predictions which have relied on uncertain theoretical calculations. The influence of the extracted proton separation energy on the rp process occurring in type I x-ray bursts is examined within the context of a one-zone burst model.

An exclusive proton-proton bremsstrahlung measurement has been performed with polarized protons of 190 MeV. Absolute cross sections and analyzing powers have been measured with unprecedented accuracy in a large part of the phase space. The data are compared with state-of-the-art theoretical calculations including higher-order off-shell effects, like the D isobar and meson-exchange currents. Surprisingly, the calculations are unable to describe the data in detail.

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Resonance-decay spectroscopy is used to study particle-unbound excited states produced in interactions of E/A = 50 MeV 12 Be on polyethylene and carbon targets. The particle-unbound states are produced in a variety of reaction mechanisms, ranging from projectile fragmentation to proton pickup. New proton-decaying excited states are observed in 9 Li(E * = 14.1 ± 0.1 MeV, = 207 ± 49 keV) and 10 Be(E * = 20.4 ± 0.1 MeV, = 182 ± 74 keV). In addition a new α-decaying state is observed in 13 B(E * = 13.6 ± 0.1 MeV, 320 keV). Also found was a 8 Be state with E * = 23 MeV, = 616 ± 30 keV, which decays to the p + 3 H + α channel. Correlation between the fragments indicates that the decay is initiated by a proton emission to the 4.63-MeV state of 7 Li and the spin of the state is J > 2. A second T = 2 state was confirmed in 12 B at 14.82 MeV, which decays to the p + 11 Be, 3 H + 9 Be, and α + 8 Li channels. Its width was found to be 100 keV and its spin is consistent with J π = 2 + .