Search for hadronic decays of feebly-interacting particles at NA62

TL;DR

This paper reports a search for feebly-interacting particles decaying into hadrons at the NA62 experiment, setting new constraints on dark photons, scalars, and axion-like particles using proton beam-dump data.

Contribution

First search for hadronic decays of feebly-interacting particles at NA62 in beam-dump mode, extending constraints on multiple New Physics models.

Findings

No evidence of New Physics signals was observed.

Excluded new regions of parameter space for dark photons, scalars, and axion-like particles.

Analyzed $1.4 imes 10^{17}$ protons on dump from 2021 data.

Abstract

The NA62 experiment at CERN has the capability to collect data in a beam-dump mode, where 400 GeV protons are dumped on an absorber. In this configuration, New Physics particles, including dark photons, dark scalars, and axion-like particles, may be produced in the absorber and decay in the instrumented volume beginning approximately 80 m downstream of the dump. A search for these particles decaying in flight to hadronic final states is reported, based on an analysis of a sample of $1.4 \times 10^{17}$ protons on dump collected in 2021. No evidence of a New Physics signal is observed, excluding new regions of parameter spaces of multiple models.