Do we have enough evidence to invalidate the mean-field approximation adopted to model collective neutrino oscillations?

Understand

Recent body of work points out that the mean-field approximation, widely employed to mimic the neutrino field within a neutrino-dense source, might give different results in terms of flavor evolution with respect to the correspondent many-body treatment.

• In this paper, we investigate whether such conclusions derived within a constrained framework should hold in an astrophysical context.
• We show that the plane waves, commonly adopted in the many-body literature to model the neutrino field, provide results that are crucially different with respect to the ones obtained using wavepackets of finite size streaming with a non-zero velocity.
• The many-body approach intrinsically includes coherent and incoherent scatterings.