Monojet signatures from heavy colored particles: future collider sensitivities and theoretical uncertainties

Chakraborty, Amit; Kuttimalai, Silvan; Lim, Sung Hak; Nojiri, Mihoko M.; Ruiz, Richard

Abstract

In models with colored particle Q that can decay into a dark matter candidate X, the relevant collider process pp → QQ¯ → X X¯ + jets gives rise to events with significant transverse momentum imbalance. When the masses of Q and X are very close, the relevant signature becomes monojetlike, and Large Hadron Collider (LHC) search limits become much less constraining. In this paper, we study the current and anticipated experimental sensitivity to such particles at the High-Luminosity LHC at √s = 14 TeV with L = 3 ab−1 of data and the proposed High-Energy LHC at √s = 27 TeV with L = 15 ab−1 of data. We estimate the reach for various Lorentz and QCD color representations of Q. Identifying the nature of Q is very important to understanding the physics behind the monojet signature. Therefore, we also study the dependence of the observables built from the pp → QQ¯ + j process on Q itself. Using the state-of-theart Monte Carlo suites MadGraph5_aMC@NLO+Pythia8 and Sherpa, we find that when these observables are calculated at NLO in QCD with parton shower matching and multijet merging, the residual theoretical uncertainties are comparable to differences observed when varying the quantum numbers of Q itself. We find, however, that the precision achievable with NNLO calculations, where available, can resolve this dilemma.

Citation

Chakraborty, A., Kuttimalai, S., Lim, S. H., Nojiri, M. M., & Ruiz, R. (2018). Monojet signatures from heavy colored particles: future collider sensitivities and theoretical uncertainties. The European Physical Journal C, 78(8), Article 679. https://doi.org/10.1140/epjc/s10052-018-6149-6

• Journal Article Type: Article
• Acceptance Date: Aug 10, 2018
• Online Publication Date: Aug 25, 2018
• Publication Date: Aug 25, 2018
• Deposit Date: Sep 6, 2018
• Publicly Available Date: Sep 6, 2018
• Journal: European Physical Journal C: Particles and Fields
• Print ISSN: 1434-6044
• Electronic ISSN: 1434-6052
• Publisher: SpringerOpen
• Peer Reviewed: Peer Reviewed
• Volume: 78
• Issue: 8
• Article Number: 679
• DOI: https://doi.org/10.1140/epjc/s10052-018-6149-6
• Public URL: https://durham-repository.worktribe.com/output/1320872