Searches for Majoron production and other processes associated with<i>π→eν</i>decay

Abstract

Data from a new study of the decay \ensuremath{\pi}\ensuremath{\rightarrow}e\ensuremath{\nu} are used to place bounds on Majoron-neutrino couplings and to obtain inclusive branching-ratio limits for \ensuremath{\pi}\ensuremath{\rightarrow}e\ensuremath{\nu}M, where M is a new particle with a mass in the range 0 to 125 MeV. A limit for the process ${\ensuremath{\pi}}^{+}$\ensuremath{\rightarrow}${e}^{+}$\ensuremath{\nu}\ensuremath{\nu}\ensuremath{\nu}\ifmmode\bar\else\textasciimacron\fi{} is also obtained.