A search is presented for long-lived particles decaying into an oppositely charged lepton pair, μ+μ−, e+e−, or e ± μ ∓, that form a vertex within the inner tracking system of the ATLAS detector at the Large Hadron Collider, displaced from the primary proton–proton interaction region. The analysis uses the 140 fb−1 of Run-2 data collected at s=13 TeV by the ATLAS experiment in 2015–2018. The results of the analysis are interpreted in the context of three benchmark models covering masses from 0.1 to 2.2 TeV and a range of mean proper lifetimes times the speed of light from 1 to 10 000 mm. The first model is a generic Z ′ boson pair-produced by a new heavy scalar, with the Z ′ decaying into lepton pairs. The remaining two models are R -parity violating supersymmetric models in which the lightest neutralino χ˜10 decays into ℓ+ℓ[email protected]@535bc5b1ν (ℓ,ℓ′=e, μ). The models differ by the mode of production of the χ˜10, which can be produced via the decay of pairs of gluinos or of pairs of charginos and neutralinos (χ˜1±χ˜10, χ˜1±χ˜20, or χ˜20χ˜10). Although each benchmark sample includes pair-produced LLPs, only a single vertex is required to be reconstructed. No dilepton displaced vertex candidate is observed and the results are presented as upper limits on the production cross-sections. This analysis sets leading limits on the production cross-sections for multiple models, including parameter space that has never been directly probed.

Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N.J., et al. (2026). Search for long-lived particles using displaced vertices of oppositely charged leptons in 140fb−1 of pp collisions at sqrt(s)=13 TeV with the ATLAS detector. PHYSICS LETTERS. SECTION B, 878 [10.1016/j.physletb.2026.140497].

Search for long-lived particles using displaced vertices of oppositely charged leptons in 140fb−1 of pp collisions at sqrt(s)=13 TeV with the ATLAS detector

Di Micco, B.;Di Nardo, R.;Montereali, F.;Orestano, D.;Orlandini, R.;
2026-01-01

Abstract

A search is presented for long-lived particles decaying into an oppositely charged lepton pair, μ+μ−, e+e−, or e ± μ ∓, that form a vertex within the inner tracking system of the ATLAS detector at the Large Hadron Collider, displaced from the primary proton–proton interaction region. The analysis uses the 140 fb−1 of Run-2 data collected at s=13 TeV by the ATLAS experiment in 2015–2018. The results of the analysis are interpreted in the context of three benchmark models covering masses from 0.1 to 2.2 TeV and a range of mean proper lifetimes times the speed of light from 1 to 10 000 mm. The first model is a generic Z ′ boson pair-produced by a new heavy scalar, with the Z ′ decaying into lepton pairs. The remaining two models are R -parity violating supersymmetric models in which the lightest neutralino χ˜10 decays into ℓ+ℓ[email protected]@535bc5b1ν (ℓ,ℓ′=e, μ). The models differ by the mode of production of the χ˜10, which can be produced via the decay of pairs of gluinos or of pairs of charginos and neutralinos (χ˜1±χ˜10, χ˜1±χ˜20, or χ˜20χ˜10). Although each benchmark sample includes pair-produced LLPs, only a single vertex is required to be reconstructed. No dilepton displaced vertex candidate is observed and the results are presented as upper limits on the production cross-sections. This analysis sets leading limits on the production cross-sections for multiple models, including parameter space that has never been directly probed.
2026
Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N.J., et al. (2026). Search for long-lived particles using displaced vertices of oppositely charged leptons in 140fb−1 of pp collisions at sqrt(s)=13 TeV with the ATLAS detector. PHYSICS LETTERS. SECTION B, 878 [10.1016/j.physletb.2026.140497].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/561099
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