Measurement of spin-dependent total cross-section difference $Δσ_T$ in neutron-proton scattering at 16 MeV

Abstract

A new measurement of $Δσ_T$ for polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. A polarized neutron beam was obtained from the $^{3}\rm{H}(d,\vec n)^{4}\rm{He}$ reaction; proton polarization over 90\% was achieved in a frozen spin target of 20 cm$^3$ volume. The measurement yielded the value $Δσ_T=(-126\pm21\pm14)$ mb. The result of a simple phase shift analysis for the $^3S_1-^3D_1$ mixing parameter $ε_1$ is presented and compared with the theoretical potential model predictions.

17 pages, 8 ps figures, available at http://www.troja.mff.cuni.cz/~dolezal/dstprep.html