Search for dark matter in proton-proton collisions at 8 TeV with missing transverse momentum and vector boson tagged jets

TL;DR

This study searches for dark matter signals in proton-proton collisions at 8 TeV by analyzing missing transverse momentum and vector boson tagged jets, setting new limits on mediator masses with no observed excess.

Contribution

It introduces jet substructure techniques for identifying hadronically decaying vector bosons, improving sensitivity in dark matter searches at the LHC.

Findings

Excluded mediator masses between 80 and 400 GeV for scalar and pseudoscalar models.

Excluded mediator masses up to 1.5 TeV for vector and axial vector models.

Achieved 80% improvement in exclusion limits over previous CMS analysis.

Abstract

A search is presented for an excess of events with large missing transverse momentum in association with at least one highly energetic jet, in a data sample of proton-proton collisions at a centre-of-mass energy of 8 TeV. The data correspond to an integrated luminosity of 19.7 inverse femtobarns collected by the CMS experiment at the LHC. The results are interpreted using a set of simplified models for the production of dark matter via a scalar, pseudoscalar, vector, or axial vector mediator. Additional sensitivity is achieved by tagging events consistent with the jets originating from a hadronically decaying vector boson. This search uses jet substructure techniques to identify hadronically decaying vector bosons in both Lorentz-boosted and resolved scenarios. This analysis yields improvements of 80% in terms of excluded signal cross sections with respect to the previous CMS analysis using the same data set. No significant excess with respect to the standard model expectation is observed and limits are placed on the parameter space of the simplified models. Mediator masses between 80 and 400 GeV in the scalar and pseudoscalar models, and up to 1.5 TeV in the vector and axial vector models, are excluded.