Abstract
A search for weakly interacting massive dark-matter particles produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and missing transverse momentum are considered. The analysis uses 36.1fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s=13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are interpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour-neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross-section of 300 times the predicted rate for mediators with masses between 10 and 50GeV and assuming a dark-matter mass of 1GeV and unitary coupling. Constraints on colour-charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35GeV , mediator particles with mass below 1.1TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements.
Original language | English |
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Article number | 18 |
Number of pages | 36 |
Journal | European Physical Journal C |
Volume | 78 |
Issue number | 1 |
DOIs | |
Publication status | Published - 11 Jan 2018 |
Bibliographical note
52 pages in total, author list starting page 36, 8 figures, 9 tables, submitted to EPJC, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-18/Keywords
- hep-ex