Abstract
In previous work, we identified an anomalous number of events in the LHC jets+MET searches characterized by low jet multiplicity and low-to-moderate transverse energy variables. Here, we update this analysis with results from a new ATLAS search in the monojet channel which also shows a consistent excess. As before, we find that this “monojet excess” is well-described by the resonant production of a heavy colored state decaying to a quark and a massive invisible particle. In the combined ATLAS and CMS data, we now find a local (global) preference of 3.3σ (2.5σ) for the new physics model over the Standard Model-only hypothesis. As the signal regions containing the excess are systematics-limited, we consider additional cuts to enhance the signal-to-background ratio. We show that binning finer in HT and requiring the jets to be more central can increase S/B by a factor of ∼1.5.
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References
P. Asadi, M.R. Buckley, A. DiFranzo, A. Monteux and D. Shih, Digging Deeper for New Physics in the LHC Data, JHEP 11 (2017) 194 [arXiv:1707.05783] [INSPIRE].
CMS collaboration, Search for supersymmetry in multijet events with missing transverse momentum in proton-proton collisions at 13 TeV, Phys. Rev. D 96 (2017) 032003 [arXiv:1704.07781] [INSPIRE].
CMS collaboration, Search for new phenomena with the M T2 variable in the all-hadronic final state produced in proton-proton collisions at \( \sqrt{s}=13 \) TeV, Eur. Phys. J. C 77 (2017) 710 [arXiv:1705.04650] [INSPIRE].
R. Barbieri and A. Masiero, Supersymmetric Models with Low-Energy Baryon Number Violation, Nucl. Phys. B 267 (1986) 679 [INSPIRE].
ATLAS collaboration, Search for squarks and gluinos in final states with jets and missing transverse momentum using 36 fb −1 of \( \sqrt{s}=13 \) TeV pp collision data with the ATLAS detector, arXiv:1712.02332 [INSPIRE].
CMS collaboration, Search for new physics in final states with an energetic jet or a hadronically decaying W or Z boson and transverse momentum imbalance at \( \sqrt{s}=13 \) TeV, arXiv:1712.02345 [INSPIRE].
ATLAS collaboration, Search for dark matter and other new phenomena in events with an energetic jet and large missing transverse momentum using the ATLAS detector, JHEP 01 (2018) 126 [arXiv:1711.03301] [INSPIRE].
CMS, ATLAS collaborations, Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at \( \sqrt{s}=7 \) and 8 TeV, CMS-PAS-HIG-15-002 (2015).
J. Alwall et al., The automated computation of tree-level and next-to-leading order differential cross sections and their matching to parton shower simulations, JHEP 07 (2014) 079 [arXiv:1405.0301] [INSPIRE].
T. Sjöstrand et al., An Introduction to PYTHIA 8.2, Comput. Phys. Commun. 191 (2015) 159 [arXiv:1410.3012] [INSPIRE].
DELPHES 3 collaboration, J. de Favereau et al., DELPHES 3, A modular framework for fast simulation of a generic collider experiment, JHEP 02 (2014) 057 [arXiv:1307.6346] [INSPIRE].
CMS collaboration, Simplified likelihood for the re-interpretation of public CMS results, CMS-NOTE-2017-001 (2017).
G. Cowan, K. Cranmer, E. Gross and O. Vitells, Asymptotic formulae for likelihood-based tests of new physics, Eur. Phys. J. C 71 (2011) 1554 [Erratum ibid. C 73 (2013) 2501] [arXiv:1007.1727] [INSPIRE].
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ArXiv ePrint: 1712.04939
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Asadi, P., Buckley, M.R., DiFranzo, A. et al. An update on the LHC monojet excess. J. High Energ. Phys. 2018, 130 (2018). https://doi.org/10.1007/JHEP03(2018)130
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DOI: https://doi.org/10.1007/JHEP03(2018)130