Discrete symmetry in epithermal neutron optics
Neutrons with the kinetic energy of 0.1eV to 1keV are called as epithermal neutrons. Epithermal neutrons interact with nuclei via the nuclear potential scattering and well-resolved and narrow resonant absorptions via compound nuclear states. Some of the compound states are known to exhibit extremely large parity violating effects as a result of enhancement of the tiny contribution of weak interaction included in effective nucleon-nucleon interaction. The enhancement mechanism is expected to magnify possible time-reversal-violating effects if the compound states have “preferable” conditions and consequently applicable for the search for large T-violation beyond the standard model. The reaction mechanism of the compound nuclear process and “preferable” conditions will be discussed. An overview of the application of neutron optics to fundamental physics will be also shown.