# A 96 GeV scalar tagged to dark matter models

## TL;DR

This paper explores a potential 96 GeV scalar resonance observed in diphoton events, examining its implications within dark matter models and constraining their parameter space through experimental and theoretical considerations.

## Contribution

It proposes models linking the 96 GeV scalar to dark matter extensions, analyzing how this resonance constrains model parameters and affects dark matter phenomenology.

## Key findings

- Scalar resonance can be incorporated via UV complete or effective models.
- Parameter space becomes more constrained with the scalar, aiding model tractability.
- Constraints from LHC, dark matter searches, and theoretical bounds are significant.

## Abstract

Recently, the CMS Collaboration observed the hint of a resonance decaying to two photons at about 96 GeV with a local significance of $2.8\sigma$. While it is too early to say whether this will stand the test of time, such a resonance can easily be accommodated in many extensions of the Standard Model (SM). The more challenging part is to tune such an extension so that the required number of diphoton events is reproduced. Assuming that the new resonance is a scalar, we propose that the signal may come either from an ultraviolet complete model with vectorial quarks, or a model involving gluon-scalar and photon-scalar effective operators. We then incorporate this portal to several extensions of the SM that include one or more cold dark matter candidates, and try to investigate how the existence of such a scalar resonance affects the parameter space of such models. As expected, we find that with such a scalar, the parameter space gets more constrained and hence, more tractable. We show how significant constraints can be placed on the parameter space, not only from direct dark matter searches or LHC data but also from theoretical considerations like scattering unitarity or stability of the potential, and discuss some novel features of the allowed parameter space.