Dark sector searches with the CMS experiment

TL;DR

This paper reviews recent CMS experiment searches for dark sector particles, mediators, and long-lived particles, providing new results and interpretations that enhance understanding of dark matter beyond standard models.

Contribution

It presents the latest experimental searches for dark sector particles and mediators at the LHC, including novel results and comprehensive comparisons with direct detection experiments.

Findings

Constraints on dark matter models from CMS data

Discovery of new signatures for long-lived particles

Enhanced limits on dark-sector mediators

Abstract

Astrophysical observations provide compelling evidence for gravitationally interacting dark matter in the universe that cannot be explained by the standard model of particle physics. The extraordinary amount of data from the CERN LHC presents a unique opportunity to shed light on the nature of dark matter at unprecedented collision energies. This Report comprehensively reviews the most recent searches with the CMS experiment for particles and interactions belonging to a dark sector and for dark-sector mediators. Models with invisible massive particles are probed by searches for signatures of missing transverse momentum recoiling against visible standard model particles. Searches for mediators are also conducted via fully visible final states. The results of these searches are compared with those obtained from direct-detection experiments. Searches for alternative scenarios predicting more complex dark sectors with multiple new particles and new forces are also presented. Many of these models include long-lived particles, which could manifest themselves with striking unconventional signatures with relatively small amounts of background. Searches for such particles are discussed and their impact on dark-sector scenarios is evaluated. Many results and interpretations have been newly obtained for this Report.