Search for low-mass dilepton resonances in Higgs boson decays to four-lepton final states in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper searches for low-mass dilepton resonances in Higgs boson decays to four-lepton final states using CMS data at 13 TeV, setting limits on new physics models like dark photons and axion-like particles.

Contribution

It introduces a novel search for low-mass dilepton resonances in Higgs decays, providing the first constraints on such processes at 13 TeV with CMS data.

Findings

No significant deviation from the standard model observed.

Set upper limits on Higgs decay branching fractions to new particles.

Provided constraints on dark photon and axion-like particle production.

Abstract

A search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a Z boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 fb$^{-1}$, at a center-of-mass energy $\sqrt{s} =$ 13 TeV. No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle production, based on two specific models, are reported.