Neutrino oscillations as two-slit experiments in momentum space

E. Kh. Akhmedov, A. Yu. Smirnov

Ciprian Pater

Harry J. Lipkin

The role of simple quantum mechanics in understanding neutrino oscillation experiments is pointed out by comparison with two-slit and Bragg scattering experiments. The importance of considering the beam and the detector as a correlated quantum system is emphasized. Quantum mechanics alone shows that the difference observed in the same neutrino detector at Super-Kamiokande between upward and downward going neutrinos requires the existence of a neutrino mass difference. The localization of the source and detector in space in the laboratory system for long times leads to an uncertainty in the momentum but not of the energy of the neutrino and to coherence between states having different momenta and the same energy and not between states with different energies.

Alisha Roberts

Carlo Giunti

Département de Physique Nucléaire et Corpusculaire, Université de Genève 24, quai Ernest-Ansermet CH-1211Genève 4., J.H. Field

Feynman path integral analyses of a two-neutrino-flavour electron appearence experiment and the Young double slit are compared.The comparison reveals a conceptual flaw in previous work of the present author that led to a false claim of the incorrectness of standard formulas for the oscillation phase.In both calculations, path amplitudes add coherently, but no putative 'neutrino flavour eigenstates' are invoked in the former case.It is shown that the coherent production of these eigenstates is incompatible with the measured values of Γ (π → eν)/Γ (π → µν) and the PMNS matrix elements.Applications of the path integral approach to other two-path quantum interference experiments are compared with neutrino oscillations, and other treatments of the latter in the literature are critically discussed.