Measurement of spin-dependent total cross-section difference $\hat{I}”\ddot{I}{ƒ}_T$ in neutron-proton scattering at 16 MeV

Abstract

A new measurement of $\hat{I}”\ddot{I}{ƒ}_T$ for polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. A polarized neutron beam was obtained from the ${}^3\mathrm{H}(\mathrm{d},\vec{\mathrm{n}}{)}^4\mathrm{He}$ reaction; proton polarization over 90\% was achieved in a frozen spin target of 20 cm${}^3$ volume. The measurement yielded the value $\hat{I}”\ddot{I}{ƒ}_T=(-126\pm 21\pm 14)$ mb. The result of a simple phase shift analysis for the ${}^3{S}_1{-}^3{D}_1$ mixing parameter $\hat{I}{\mu }_1$ 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