2026/07/15 by Sofia Lonardi, Manuel Ettengruber, Philipp Eller
#hep-ph #hep-ex
We present the first experimental search for the N-naturalness tower of neutrinos using a global analysis of publicly available neutrino data. As a potential solution to the hierarchy problem, the N-naturalness model employs a varying Higgs mass parameter among N dark sectors and encodes the required fine-tuning of the placement of the sectors in a parameter r. We report exclusion limits on the parameter space (r, N), for normal and inverted ordering and in case the neutrino is Majorana or Dirac. In the case of a Majorana neutrino, we can rule out N≤ 104 sectors with r≥ 0.1. This is particularly exciting as it shows that a gauge and gravitational unification around MGUT, which is a benchmark scenario of the N-naturalness framework with N=104 without fine-tuning, is ruled out by neutrino experiments.