The ATLAS collaboration has built and is now operating the world’s largest particle physics experiment at the 27 km long particle accelerator called the Large Hadron Collider at the CERN laboratory.
The purpose is to explore the highest energy proton collisions that are available under controlled conditions in the laboratory. Through these studies one can increase the knowledge about the basic forces that have shaped our universe since the beginning of time and that will determine its fate.
The Standard Model is a theoretical model that can describe the fundamental particles that build up the world around us and their interactions. It can explain most of the different observations that have been made so far in particle physics experiments. A major part of the Standard Model that had not been verified by experiments prior to ATLAS was the Higgs theory. This theory predicts that there is a Higgs field everywhere in the universe and that matter gets its mass by interacting with it. With the discovery of the Higgs boson by the ATLAS experiment this theory has been proven correct and the parameters of the theory are now being measured.
The focus is increasingly to search for what is beyond the so-called Standard Model. There are different theories describing such ideas, and one look for the predicted signatures that they would give in the ATLAS experiment, to see if those theories can be verified or falsified. ATLAS also searches in more general ways for deviations from the predictions of the Standard Model as a way to find new physics that no theories have predicted.
An enormous amount of computer power is needed in order to reconstruct and predict what happens when protons collide at high energy. The Lund ATLAS group has contributed to the development of so-called e-science in which the traditional computing infrastructures are optimized and developed in order to meet the ever increasing requirements. The group has also been involved in designing and building parts of detectors such as the TRT tracker, the muon spectrometer and the LUCID luminometer as well as the trigger system which selects which collisions to study.