Boosted objects and jet substructure at the LHC. Report of BOOST2012, held at IFIC Valencia, 23rd–27th of July 2012

Abstract

This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of firstprinciple QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-ofthe-art Monte Carlo tools. Limitations of the experiments' ability to resolve substructure are evaluated, with a focus on the impact of additional (pile-up) proton proton collisions on jet substructure performance in future LHC operating scenarios. A final section summarizes the lessons learnt from jet substructure analyses in searches for new physics in the production of boosted top quarks.

Pileup per particle identification

“…in phenomenological studies, larger jets receive more pileup contamination and are commonplace in substructure studies where correcting more than only a jet's p T becomes important [34][35][36]. We choose R = 0.7 as a compromise between these applications.…”

“…Here we show results for jet mass which is considered a reasonable proxy for generic jet shapes and is used in many applications such as boosted object tagging (see [34][35][36] and references therein). First we look at jet mass for central jets with 100 GeV < p T < 200 GeV.…”

LHC τ -rich tests of lepton-specific 2HDM for (g − 2) μ

“…In that region, we have to think of how to capture the kinematic features of the boosted A → τ + τ − . We may be able to take the overlapping τ problem as an advantage by utilizing jet substructure study, which is already proven useful [52][53][54]. For example, using di-tau tagging as proposed in ref.…”

Deep-learning top taggers or the end of QCD?

“…Their jet substructure allows us to search for hadronic decays for example of Higgs bosons [1], weak gauge bosons [2][3][4], or top quarks [5][6][7][8][9][10][11][12][13][14][15] in a shower evolution otherwise described by QCD radiation [16][17][18][19]. Given this success, a straightforward question to ask is whether we can analyze the same jet substructure patterns without relying on advanced QCD algorithms.…”