First observation of magnetic moment precession of channeled particles in bent crystals

Spin precession of channeled particles in bent crystals has been observed for the first time. Polarized ${\mathrm{\Sigma }}^{+}$ were channeled using bent Si crystals. These crystals provided an effective magnetic field of 45 T which resulted in a measured spin precession of 60±17°. This agrees with the prediction of 62±2° using the world average of ${\mathrm{\Sigma }}^{+}$ magnetic moment measurements. This new technique gives a ${\mathrm{\Sigma }}^{+}$ magnetic moment of (2.40±0.46±0.40)${\mathrm{\mu }}_{\mathit{N}}$, where the quoted uncertainties are statistical and systematic, respectively. We see no evidence of depolarization in the channeling process.