Time reversal and the neutron

We have measured the triple correlation D⟨J⃗_n⟩/J_n· (β⃗_e×p̂_ν) with a polarized cold-neutron beam (Mumm et al., Phys Rev Lett 107:102301, 2011 ; Chupp et al., Phys Rev C 86:035505, 2012 ). A non-zero value of D can arise due to parity-even-time-reversal-odd interactions that imply CP violation. Final-state effects also contribute to D at the level of 10 − 5 and can be calculated with precision of 1