Test of parity-conserving time-reversal invariance using polarized neutrons and nuclear spin aligned holmium

A test of parity-conserving, time-reversal noninvariance (PC TRNI) has been performed in 5.9MeV polarized neutron transmission through nuclear spin aligned holmium. The experiment searches for the {ital T}-violating fivefold correlation via a double modulation technique{emdash}flipping the neutron spin while rotating the alignment axis of the holmium. Relative cross sections for spin-up and spin-down neutrons are found to be equal to within 1.2{times}10{sup {minus}5} (80{percent} confidence). This is a 2 orders of magnitude improvement compared to traditional detailed balance studies of time reversal, and represents the most precise test of PC TRNI in a dynamical process. {copyright} {ital 1996 The American Physical Society.}