Measurement of theΣ+Magnetic Moment

Abstract

Approximately 370 000 pictures of slow ${K}^{\ensuremath{-}}$ interactions were taken in the Michigan-Argonne propane bubble chamber at the Argonne National Laboratory Zero-Gradient Synchrotron. They were scanned for the reaction ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ produced by ${K}^{\ensuremath{-}}$ in the momentum range 250-550 MeV/c. A 45-kG magnetic field applied perpendicular to the incident beam precessed the spin of the ${\ensuremath{\Sigma}}^{+}$ through an average angle of 9\ifmmode^\circ\else\textdegree\fi{}. The final sample, after cuts, consisted of 2651 events with an average time of flight of 1.5 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}10}$ sec and an average polarization of 0.37. A maximum-likelihood analysis yielded 2.7 \ifmmode\pm\else\textpm\fi{} 0.9 nuclear magnetons for the ${\ensuremath{\Sigma}}^{+}$ magnetic moment.