Probing the Hadronic Weak Interaction using Polarized Slow Neutron Spin Rotation in L4He

The NSR collaboration proposes to search for parity violation in n-4He by searching for a rotation of the plane of polarization of transversely polarized neutrons moving through the liquid. This observable is sensitive to a linear combination of weak amplitudes in the hadronic weak interaction which is orthogonal to previous measurements. An earlier measurement conducted at NIST reported $ d\theta/dz=[+1.7\pm9.1(\mathrm{stat})\pm1.4(\mathrm{sys.})]\times10^{-7}\sim$rad/m [1]. We will briefly discuss progress towards a $ 1\times10^{-8}$ sensitivity measurement.\\[4pt] [1] W.M. Snow et al, Phys. Rev. C \textbf{83} 2 2501 (2010).