Measurement of the magnetic moments of the ${\mathrm{\Sigma }}^{+}$ and Σ${\mathrm{¯}}^{\mathrm{-}}$ hyperons

We have measured the magnetic moments of the ${\mathrm{\Sigma }}^{+}$ and Σ¯ ${}_{}{}^{\mathrm{-}}{}_{}{}^{}$ hyperons produced by 800-GeV protons incident on a Cu target. We determine the ${\mathrm{\Sigma }}^{+}$ magnetic moment to be (2.4613±0.0034±0.0040)${\mathrm{\mu }}_{\mathit{N}}$ where the uncertainties are statistical and systematic, respectively. In this first measurement we determine the magnetic moment of the Σ¯ ${}_{}{}^{\mathrm{-}}{}_{}{}^{}$ to be -(2.428±0.036±0.007)${\mathrm{\mu }}_{\mathit{N}}$. The magnetic moments of the ${\mathrm{\Sigma }}^{+}$ and Σ¯ ${}_{}{}^{\mathrm{-}}{}_{}{}^{}$ are consistent with each other in magnitude but opposite in sign as required by CPT invariance.