Neutrino Decoherence via Modified Dispersion

TL;DR

This work analyzes quantum gravity–motivated decoherence in neutrino oscillations within an open quantum system framework. By modeling modified dispersion relations as an environmental interaction, the authors derive MDR-induced decoherence and master equations, revealing an energy-dependent damping controlled by a in [0,1]. They identify three decoherence rates in the three-flavour case and extend the study to a 3+1 sterile neutrino scenario, showing distinct signatures in oscillation probabilities and flavour compositions at neutrino telescopes. The results map detection prospects across astrophysical baselines and energy scales, and they propose using initial flux compositions at detectors to constrain the MDR parameter a, thereby linking quantum gravity effects to observable neutrino phenomenology.

Abstract

We study in detail the effect of quantum decoherence in neutrino oscillations. We adopt a phenomenological approach that allows us to parametrize the energy dependence of the decoherence effects resulting from the modification of the neutrino dispersion relation. Using the open quantum system framework we derive decoherence parameters, which are usually connected to quantum gravitational effects. Furthermore, we study the sensitivity of decoherence on high-energy astrophysical neutrinos among all possible initial source compositions. We find that variation in the flux composition at neutrino telescopes can be a good probe to test such effects. Additionally, we show that a simple extension with heavy sterile neutrino decoherence produces verifiable signatures.

Figures (8)

• Figure 1: The dependence of the decoherence strength parameter on propagation length with varying $a$ is shown.
• Figure 2: The dependence of coherence lengths on energy is shown. The bands represents energy ranges of neutrinos coming from a definite source.
• Figure 3: Damping signatures on neutrino transition probabilities over time, with $a = 2/3$ and neutrino energy $E_\nu = 100$ PeV.
• Figure 4: The variation of averaged neutrino oscillation probabilities with propagation length is shown with NH and IH taking $a=2/3$.
• Figure 5: (Top) We show the $\nu_e \rightarrow \nu_e$ survival probability witnessing decoherence. (Bottom-left) Here, $\nu_{\mu} \rightarrow \nu_{\mu}$ survival probability is shown. (Bottom-right) $\nu_{\tau} \rightarrow \nu_{\tau}$ survival probability is shown with $E_\nu=100$ PeV. All the plots are generated with NH.