Quantum correlations and the neutrino mass degeneracy problem

Abstract

Many facets of nonclassicality are probed in the context of three flavour neutrino oscillations including matter effects and CP violation. The analysis is carried out for parameters relevant to two ongoing experiments NOνA and T2K, and also for the upcoming experiment DUNE. The various quantum correlations turn out to be sensitive to the masshierarchy problem in neutrinos. This sensitivity is found to be more prominent in DUNE experiment as compared to NOνA and T2K experiments. This can be attributed to the large baseline and high energy of the DUNE experiment. Further, we find that to probe these correlations, the neutrino (antineutrino) beam should be preferred if the sign of mass square difference Δ 31 turns out to be positive (negative).

Effects of nonstandard interaction on temporal and spatial correlations in neutrino oscillations

“…Moreover, this measure can be considered as an absolute entanglement measure for a tripartite system since its nonzero value ensures the existence of the nonzero entanglement at least in one bipartition. For the three flavour neutrino oscillation system we name it flavour entanglement entropy and can write it as a concave function of transition probabilities [26,27],…”

“…Genuine tripartite entanglement Another measure of tripartite entanglement, in the genuine sense, can be defined as cube of the geometric mean of von Neumann entropies of each bipartite section and can be expressed as following [27]…”

“…: V,-vol experimental set-ups. These spatial correlations can also be quantified in terms of flavour entropy [26,27] and genuine tripartite entanglement [27]. These are basically measures of entanglement embedded in the system.…”

Coherence and mixedness of neutrino oscillations in a magnetic field

“…Neutrinos host dichotomic left-right helicity and different lepton flavour (electron, muon, and tau) and, when propagating, they can change their type, or oscillate. Neutrino oscillations is an inherently quantum mechanical phenomenon [12][13][14][15][16][17][18] that exhibits such essentially quantum features as entanglement [19][20][21][22][23][24][25] and can be interpreted in terms of quantum resource theory. An interesting case of this phenomenon is expected when neutrinos propagate in the presence of a magnetic field: neutrinos can change both their flavour and helicity (see, for instance, Refs.…”

“…[30][31][32]). Using the occupation number representation for flavour and massive modes (see [15]), the neutrino state can be presented in the form…”