A description is given of a new experiment to measure the muon electric dipole moment (EDM) to between sigma = 10(-24) e-cm and 10(-25) e-cm, which would be 5 to 6 orders of magnitude improvement over the current world average. Muons are stored in a magnetic ring. Precession due to Thomas precession and the magnetic moment are canceled with the proper combination of applied E and B fields. Only precession due to a non-vanishing EDM remains, resulting in a large amplification of the EDM signal. The method has general applicability to charged particles.

We report on results of a dedicated search for the CP-violating decay ${\mathit{K}}_{\mathit{L}}$\ensuremath{\rightarrow}${\mathrm{\ensuremath{\pi}}}^{0}$${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$. We have found no evidence for this decay mode and obtain a 90%-confidence upper limit of 5.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}9}$ for its branching ratio.

We report on measurements of the ${\mathit{K}}_{\mathit{L}}$ Dalitz decay ${\mathit{K}}_{\mathit{L}}$\ensuremath{\rightarrow}${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\gamma}. The results are based on a sample of 919 events. Through an evaluation of the form factor, we have established evidence for a nonvanishing contribution due to the ${\mathit{KK}}^{\mathrm{*}}$\ensuremath{\gamma} coupling. We have determined the branching ratio to be B(${\mathit{K}}_{\mathit{L}}$\ensuremath{\rightarrow}${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\gamma})=(9.1\ifmmode\pm\else\textpm\fi{}0.${4}_{\mathrm{\ensuremath{-}}0.5}^{+0.6}$)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}6}$.

A search for the vector boson ($W$ particle), postulated as the mediator of the weak interaction, has been carried out by determining the intensity and polarization of muons originating very near the point of interaction of 28-GeV protons with nucleons. Bosons were not observed and the upper limit on the production cross section for $W$'s with masses between 2.0 and 4.5 $\frac{\mathrm{GeV}}{{c}^{2}}$ is $B{\ensuremath{\sigma}}_{W}\ensuremath{\lesssim}6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}36}$ ${\mathrm{cm}}^{2}$, where $B$ is the branching ratio for the $W$ decay to a muon and a neutrino. A comparison between the measured flux of muon pairs and the flux expected on the basis of a plausible model for the production and decay of both $W$'s and heavy virtual $\ensuremath{\gamma}$'s suggests that the experiment may not have been sensitive to $W$'s, if they exist in this mass region. The flux of high-energy muons produced directly by an unknown process, an $X$ process, is determined to be no greater than ${10}^{\ensuremath{-}6}$ times the pion flux.