Experiment to observe the spin precession of channeled relativistic Σ+ hyperons

Abstract

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