Measurement of the Magnetic Moment of theΛ0Hyperon

Abstract

A measurement of the magnetic moment of the ${\ensuremath{\Lambda}}^{0}$ hyperon carried out at the Brookhaven Cosmotron gives the value ${\ensuremath{\mu}}_{{\ensuremath{\Lambda}}^{0}}=\ensuremath{-}1.5\ifmmode\pm\else\textpm\fi{}0.5$ Bohr nucleon magnetons. Polarized ${\ensuremath{\Lambda}}^{0}$ hyperons were produced by 1.02\ifmmode\pm\else\textpm\fi{}0.03 BeV/c ${\ensuremath{\pi}}^{+}$ mesons incident on a Be target in the reaction ${\ensuremath{\pi}}^{+}+n\ensuremath{\rightarrow}{\ensuremath{\Lambda}}^{0}+{K}^{+}$. After passing through a strong magnetic field, the ${\ensuremath{\Lambda}}^{0}$ were observed to decay in a parallel plate spark chamber which was triggered by an electronic counter logic. The asymmetry of the ${\ensuremath{\pi}}^{\ensuremath{-}}$ from the decay ${\ensuremath{\Lambda}}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}+p$ provided the method for determining the axis of polarization. The magnetic field and flight path were such that a magnetic moment of one Bohr nucleon magneton would precess 16.5\ifmmode^\circ\else\textdegree\fi{} in a plane perpendicular to the ${\ensuremath{\Lambda}}^{0}$ trajectory. Measurement of the angle of rotation of the decay pattern with field on, off, and reversed gave the magnitude of the moment; the sense of rotation yielded the sign.

Related Papers

• → Hyperon semileptonic decay constants with flavor SU(3) symmetry breaking(2015)42 cited
• → $\Lambda$ - anomaly in the hadron chemical freeze-out(2014)1 cited
• → A Search for cp violation in xi-minus / anti-xi-minus and lambda / anti-lambda hyperon decays(2003)
• Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV(2010)