Experimental Evidence of Free Neutron Antibunching

The experimental and theoretical study of the foundations of quantummechanics has been enriched by many seminal contribution on thermalneutrons, in particular by the results on the coherence properties andthe physical nature of the wave function describing a massive particle.We present a new contribution in this field: an experiment on thermalneutrons, bringing to light fermion antibunching in a beam of freeparticles. The theoretical analysis of the experiment is interesting andpaves the way towards the possibility of creating a two-neutron Bell state.