High-energy cosmic neutrinos as a probe of the vector mediator scenario in light of the muon $g-2$ anomaly and Hubble tension

TL;DR

This paper explores how high-energy cosmic neutrinos can test a $L_{\mu}-L_{ au}$ gauge boson model that addresses the muon $g-2$ anomaly and Hubble tension, using IceCube data and future telescope prospects.

Contribution

It provides a detailed analysis of the $L_{\mu}-L_{ au}$ model's parameter space in light of IceCube data and shows how future neutrino telescopes can further probe this scenario.

Findings

No evidence for secret interactions in current IceCube data.

Preferred $Z'$ mass around 10 MeV and coupling near 0.1.

Future telescopes can test the model and measure neutrino mass.

Abstract

In light of the recent Muon $g-2$ experiment data from Fermilab, we investigate the implications of a gauged $L_{\mu} - L_{\tau}$ model for high energy neutrino telescopes. It has been suggested that a new gauge boson at the MeV scale can both account for the Muon $g-2$ data and alleviate the tension in the Hubble parameter measurements. It also strikes signals at IceCube from the predicted resonance scattering between high-energy neutrinos and the cosmic neutrino background. We revisit this model based on the latest IceCube shower data, and perform a four-parameter fit to find a preferred region. We do not find evidence for secret interactions. The best-fit points of $m_{Z'}$ and $g_{\mu\tau}$ are $\sim10$~MeV and $\sim0.1$, respectively, depending on assumptions regarding the absolute neutrino masses, and the secret interaction parameter space allowed by the observed IceCube data overlaps with the regions of the parameter space that can explain the muon $g-2$ anomaly and Hubble tension as well. We demonstrate that future neutrino telescopes such as IceCube-Gen2 can probe this unique parameter space, and point out that successful measurements would infer the neutrino mass with $0.06~{\rm eV}\lesssim \Sigma m_\nu\lesssim 0.3~{\rm eV}$.