Polarised neutron scattering is the method of choice to study magnetism in
condensed matter. Polarised neutrons are yet typically very low in flux and
complex experimental configurations further reduce the count rate, neutron
polarisation corrections would therefore be needed. Here we analytically derive
formulae of the corrected partial differential scattering cross sections. The
analytical method is designed for the longitudinal polarisation analysis, and
the correction generally holds for time-independent polarised neutrons with a
triple-axis spectrometer. We then applied the correction to recent results of
our Pxβ experiment on Y3βFe5βO12β. Although there is a difficulty
with experimental determination of inefficiency parameters of neutron spin
polarisers and flippers, the correction appears to work properly.Comment: 6 pages, 2 figure