The Hubble tension and a renormalizable model of gauged neutrino self-interactions

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 $m_{Z^{\prime }}\sim \mathcal{O}(10\mathrm{eV})$ and charged Higgses at a few $100\mathrm{GeV}$. It requires hidden neutrinos with active-hidden mixing angles larger than $5\times 10^{-4}$ and masses in the range $1÷300\mathrm{eV}$, which could also play a role for short baseline neutrino oscillation anomalies.

Comments: 9 pages, 2 figures, 1 table; v2: matches published version