Experimental resolution and density-matrix reconstruction for neutrino coherence

Determine the experimental resolution required to observe damping-induced changes in Hellinger-distance coherence and establish how the neutrino density matrix can be reconstructed from experimental data.

Background

The paper compares the response of Hellinger-distance coherence and other quantum-information quantifiers to the same neutrino decoherence parameter, finding a nonanalytic square-root response for Hellinger coherence in the weak-damping, pure-state limit. However, the comparison is explicitly theoretical and does not establish whether the predicted changes can be resolved experimentally.

The authors also do not specify a procedure for reconstructing the flavor-basis density matrix from measured neutrino data. Both the experimental observability of the effect and the practical inverse problem of density-matrix reconstruction are therefore left unresolved.