Direct experimental evidence of free fermion antibunching
  Fermion antibunching was observed on a beam of free noninteracting neutrons. A monochromatic beam of thermal neutrons was first split by a graphite single crystal, then fed to two detectors, displaying a reduced coincidence rate. The result is a fermionic complement to the Hanbury Brown and Twiss effect for photons. 
M. Iannuzzi, A. Orecchini, F. Sacchetti, P. Facchi, S. Pascazio