Search for supersymmetry in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $$\sqrt{s}=8$$ s = 8  TeV pp collisions with the ATLAS detector

Two searches for supersymmetric particles in final states containing a same-flavour opposite-sign lepton pair, jets and large missing transverse momentum are presented.The proton-proton collision data used in these searches were collected at a centre-of-mass energy √ s = 8 TeV by the ATLAS detector at the Large Hadron Collider and corresponds to an integrated luminosity of 20.3 fb -1 .Two leptonic production mechanisms are considered: decays of squarks and gluinos with Z bosons in the final state, resulting in a peak in the dilepton invariant mass distribution around the Z -boson mass; and decays of neutralinos (e.g.χ 0 2 → ℓ + ℓ -χ 0 1 ), resulting in a kinematic endpoint in the dilepton invariant mass distribution.For the former, an excess of events above the expected Standard Model background is observed, with a significance of three standard deviations.In the latter case, the data are well-described by the expected Standard Model background.The results from each channel are interpreted in the context of several supersymmetric models involving the production of squarks and gluinos. The ATLAS detectorATLAS is a multi-purpose detector consisting of a tracking system, electromagnetic and hadronic calorimeters and a muon system.The tracking system comprises an inner detector (ID) immersed in a 2 T axial field supplied by the central solenoid magnet surrounding it.This sub-detector provides position and momentum measurements of charged particles over the pseudorapidity 1 range |η| < 2.5.The electromagnetic calorimetry is provided by liquid argon (LAr) sampling calorimeters using lead absorbers, covering the central region (|η| < 3.2).Hadronic calorimeters in the barrel region (|η| < 1.7) use scintillator tiles with steel absorbers, while the pseudorapidity range 1.5 < |η| < 4.9 is covered using LAr technology with copper or tungsten absorbers.The muon spectrometer (MS) has coverage up to |η| < 2.7 and is built around the three superconducting toroid magnet systems.The MS uses various technologies to provide muon tracking and identification as well as dedicated muon triggering for the range |η| < 2.4.The trigger system [27] comprises three levels.The first of these (L1) is a hardware-based trigger that uses only a subset of calorimeter and muon system information.Following this, both the second level (L2) and event filter (EF) triggers, constituting the software-based high-level trigger, include fully reconstructed event information to identify objects.At L2, only the regions of interest in η-φ identified at L1 are scrutinised, whereas complete event information from all detector sub-systems is available at the EF.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.