Revealing timid pseudo-scalars with taus at the LHC

TL;DR

This paper proposes a new search strategy for light pseudo-scalars at the LHC using boosted di-tau resonances, effectively probing models that evade current detection methods.

Contribution

It introduces a novel boosted di-tau resonance search method to detect light pseudo-scalars in composite Higgs models, expanding the experimental reach.

Findings

Most models can be probed with less than 300 fb$^{-1}$ of data.

The lower mass window below 65 GeV can be effectively tested.

Current di-photon searches do not cover the entire parameter space.

Abstract

A light pseudo-scalar that is copiously produced at the LHC may still be allowed by present searches. While masses above 65 GeV are effectively covered by di-photon searches, the lower mass window can be tested by a new search for boosted di-tau resonances. We test this strategy on a set of composite Higgs models with top partial compositeness, where most models can be probed with an integrated luminosity below 300 fb$^{-1}$.