1.5 Previous p + -> p 0 e+ n measurements
Two previous precise measurements of the p + -> p 0
e+ n decay rate have been made. The first, which used a
stopped pion beam, was done in 1968 by Depommier et al. and is described
in section 1.3.2.1. The second, which used in-flight pion decays, was done by
McFarlane et al. and is described in section 1.3.2.2.
Figure 1.3: Positron energy spectrum for early times (<30 ns) from [Bri
94]. The two low energy peaks are the zero energy pedestal and the 0.511 MeV
g spectrum from the annihilation of low energy positrons outside of
TINA.