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arXiv · 2404.16690

Neutrino many-body flavor evolution: the full Hamiltonian

Vincenzo Cirigliano·Srimoyee Sen·Yukari Yamauchi
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Abstract

We study neutrino flavor evolution in the quantum many-body approach using the full neutrino-neutrino Hamiltonian, including the usually neglected terms that mediate non-forward scattering processes. Working in the occupation number representation with plane waves as single-particle states, we explore the time evolution of simple initial states with up to $N=10$ neutrinos. We discuss the time evolution of the Loschmidt echo, one body flavor and kinetic observables, and the one-body entanglement entropy. For the small systems considered, we observe `thermalization' of both flavor and momentum degrees of freedom on comparable time scales, with results converging towards expectation values computed within a microcanonical ensemble. We also observe that the inclusion of non-forward processes generates a faster flavor evolution compared to the one induced by the truncated (forward) Hamiltonian.

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Vincenzo Cirigliano, Srimoyee Sen, Yukari Yamauchi. 2024-04-25. Neutrino many-body flavor evolution: the full Hamiltonian. https://arxiv.org/abs/2404.16690

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