Enigmatic Neutrons

Abstract

Neutrons are well known entities used as a tool in condensed matter and nuclear physics research. Their properties are well known with great precision but only one problem has remained unsolved for more than 25 years - the problem of extralosses of ultracold neutrons in traps. These losses are small, but they are two orders of magnitude larger than the theoretically predicted ones. To solve this enigma an excursion into the fundamental principles of quantum mechanics was undertaken. The wave function of free particles was supposed to be a singular wave packet. Because of high energy components of the packet the neutron can penetrate deeply into the potential barrier and even overcome it by nontunneling way. It is shown here that these considerations do not contradict the essence of quantum mechanics and lead to some experimentally observable consequences: one is the weak temperature dependence of the loss coefficient and at the same time the second one is the strong temperature dependence of the UCN inelastic scattering on the walls. The investigation of these wavepackets shows that the uncertainty relations have nothing to do with the essence of quantum mechanics, and a particle can have precisely mathematically defined position and momentum simultaneously. It is shown that a different definition of a bound state can be provided.