The Hubble tension and a renormalizable model of gauged neutrino self-interactions
Maximilian Berbig, Sudip Jana, Andreas Trautner
Abstract
We present a simple extension of the Standard Model that leads to renormalizable long-range vector-mediated neutrino self-interactions. This model can resolve the Hubble tension by delaying the onset of neutrino free-streaming during recombination, without conflicting with other measurements. The extended gauge, scalar, and neutrino sectors lead to observable signatures, including invisible Higgs and $Z$ decays, thereby relating the Hubble tension to precision measurements at the LHC and future colliders. The model has a new neutrinophilic gauge boson with ${m}_{{Z}^{\ensuremath{'}}}\ensuremath{\sim}\mathcal{O}(10\text{ }\text{ }\mathrm{eV})$ and charged Higgses at a few 100 GeV. It requires hidden neutrinos with active-hidden mixing angles larger than $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and masses in the range $1\textdiv{}300\text{ }\text{ }\mathrm{eV}$, which could also play a role for short baseline neutrino oscillation anomalies.