Deepak Kar

Jet substructure studies in ATLAS

WH11NE - Sunrise (Fermilab - LPC)

WH11NE - Sunrise

Fermilab - LPC

Abstract: Boosted objects, such as vector bosons or top quarks with very high transverse momentum, are useful to probe for new physics signals at the LHC. In events with one or more jets containing the decay products of a heavy particle that has been produced with a transverse momentum substantially larger than its mass, the decay products are all contained within a single large radius (or large-R) jet. Different techniques have been proposed using a large-R jet to distinguish and reconstruct the interesting physics signal over the background. Shower Deconstruction is one of the methods for this. In Shower Deconstruction method, the large-R jets are divided into into narrow subjets, which are termed microjets. The idea is to distinguish a jet that contains the decay products of a hadronically decaying top quark from a jet that does not contain decay products from a top quark. The advantage of this method lies in its use of a single signal-to-background discriminating analytic function by using most available information from underlying event, radiation and hard process. This method is seen to be robust against pileup, and performs better than the HEPTopTagger in discriminating a boosted top against a multijet in ATLAS.