Speaker
Mrs.
Maiken Pedersen
(University of Oslo)
Description
Sharing ATLAS data and research with young students
Maiken Pedersen, Farid Ould-Saada, on behalf of the ATLAS Collaboration and IPPOG International Masterclasses
In recent years the International Masterclasses (IMC) featured the use of real experimental data as produced by the LHC and collected by the detectors. We present ATLAS-based educational material using these data allowing high-school students to learn about properties of known particles and search for new phenomena. The ambition to bring to the “classrooms” important LHC discoveries is realised using the recent discovery of the Higgs boson. About 10% of the ATLAS discovery data are made available for students to search for the Higgs boson: 2fb-1 at 8 TeV for the Z-path, and 1 fb-1 at 7 TeV for the Wpath, in the 2014 version of IMC. The Higgs study samples constitute one third of the total sample including Z, W and other low mass resonances.
The goal of the Zpath measurement is to rely on the invariant mass concept to identify and measure properties of known particles, such as the Z boson, inferred from the decay products, pairs of leptons. When a heavy gauge boson Z´ with mass 1 TeV is mixed with the real data, the simulated signal shows up in the di-lepton mass distribution, to the surprise of students, who realize that they have mastered a discovery tool. They go on and apply the same technique to di-photons and pairs of di-leptons to search for the Higgs boson. To help the buildup and display of the invariant mass distributions, we developed OPloT, a scalable, php-based web-plotting tool for submission and automatic combination of all measurements performed. This allows for prompt access of results for further discussion within institutes and during videoconferences. The W-Path deals, with the structure of the proton, by comparing the numbers of W+ and W-, and search for the Higgs into a pair of W bosons, by measuring the angle between the leptons stemming from the W bosons. Event-display files are read using Hypathia (Zpath) or Minerva (Wpath).
The educational material is tuned and expanded to follow LHC “heartbeats”. In the future we hope to bring new discoveries to the public. Among new features being implemented in the Zpath, a signal of graviton resonances in di-lepton, di-photon mass distributions, and the exploiting of missing transverse energy to study di-lepton invariant mass endpoints of supersymmetric particles. Finally, a script is available for more advanced university students to loop through all events.
Primary author
Mrs.
Maiken Pedersen
(University of Oslo)
Co-author
Prof.
Farid Ould-Saada
(University of Oslo)
