Discovery of SM Higgs boson in ATLAS experiment

The Large Hadron Collider (LHC) at CERN - the most expensive and complex instrument mankind has ever built to address some of the most fundamental questions of Nature - is colliding proton-on-proton at high energy since November 2009. The full data set delivered by the LHC over the last 4 years has been analyzed by the ATLAS and CMS experiments in their pursuit of the Higgs boson, the particle responsible for generating masses for the basic building blocks of matter. In this article I discuss in detail the building and commissioning of the detector, search strategy and results obtained by the two experiments with special emphasis on ATLAS. © 2013 Indian Academy of Sciences.