A search for an unexpected asymmetry in the production of e+μ− and e−μ+ pairs in proton–proton collisions recorded by the ATLAS detector at s=13 TeV

Summary, in English

This search, a type not previously performed at ATLAS, uses a comparison of the production cross sections for e+μ− and e−μ+ pairs to constrain physics processes beyond the Standard Model. It uses 139fb−1 of proton–proton collision data recorded at s=13 TeV at the LHC. Targeting sources of new physics which prefer final states containing e+μ− to e−μ+, the search contains two broad signal regions which are used to provide model-independent constraints on the ratio of cross sections at the 2% level. The search also has two special selections targeting supersymmetric models and leptoquark signatures. Observations using one of these selections are able to exclude, at 95% confidence level, singly produced smuons with masses up to 640 GeV in a model in which the only other light sparticle is a neutralino when the R-parity-violating coupling λ231′ is close to unity. Observations using the other selection exclude scalar leptoquarks with masses below 1880 GeV when g1Reu=g1Rμc=1, at 95% confidence level. The limit on the coupling reduces to g1Reu=g1Rμc=0.46 for a mass of 1420 GeV. © 2022 The Author(s)

• Author: G. Aad; T.P.A. Åkesson; E.E. Corrigan; C. Doglioni; J. Geisen; E. Hansen; V. Hedberg; G. Jarlskog; B. Konya; E. Lytken; K.H. Mankinen; C. Marcon; J.U. Mjörnmark; G.A. Mullier; R. Poettgen; N.D. Simpson; E. Skorda; O. Smirnova; L. Zwalinski
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2022
• Language: English
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 830
• Links: http://dx.doi.org/10.1016/j.physletb.2022.137106
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693