2017 Theses Doctoral

A Search for Squarks and Gluinos with Recursive Jigsaw Reconstruction

Smith, Russell Woods

A search for squarks and gluinos in all hadronic final states in \sqrt(s) = 13 TeV proton-proton collisions using an integrated luminosity of 13.3 fb⁻¹ collected by the ATLAS detector at the LHC is presented. The search is the first to use Recursive Jigsaw Reconstruction, a technique to impose a particular decay tree interpretation on events. The decay tree is resolved using jigsaw rules, which define boosts between the relevant reference frames to define an uncorrelated basis of variables to describe the decay. The Recursive Jigsaw Reconstruction variables are used to define a set of selections with sensitivity to pair produced squarks and gluinos.

No excess is observed over the Standard Model background. Results are interpreted in simplified models where squarks and gluinos are pair produced and decay to jets and the lightest supersymmetric particle. These limits substantially extend the region of supersymmetric phase space excluded by previous searches.