Model-independent approach for incorporating interference effects in collider searches for new resonances

TL;DR

This paper introduces a model-independent method to incorporate interference effects in collider searches for new resonances, reducing theoretical bias and improving the accuracy of signal interpretation at the LHC.

Contribution

It proposes a physically-motivated, model-independent template functional form to model interference effects in resonance searches, applicable for both discoveries and null results.

Findings

Effective modeling of interference effects demonstrated with scalar resonance example

Reduces dependence on specific beyond Standard Model theories

Enhances accuracy of resonance signal characterization

Abstract

The presence of large-mass resonances in the data collected at the Large Hadron Collider would provide direct evidence of physics beyond the Standard Model. A key challenge in current resonance searches at the LHC is the modelling of signal--background interference effects, which can severely distort the shape of the reconstructed invariant mass distribution relative to the case where there is no interference. Such effects are strongly dependent on the beyond the Standard Model theory that must be considered as unknown if one aims to minimise any theoretical bias on the search results. In this paper, we describe a procedure which employs a physically-motivated, model-independent template functional form that can be used to model interference effects, both for the characterisation of positive discoveries, and in the presentation of null results. We illustrate the approach with the example of a scalar resonance decaying into a pair of photons.