b-tagging in boosted topologies

As the LHC explores a new energy regime, searches for physics beyond the Standard Model at high mass scale will probe objects produced with a momentum considerably higher than their mass, modifying in a very appreciable way the event topology. The decay products of boosted objects will be collimated into a smaller area such that they could be merged within a single \emph{fat} jet. Highly boosted objects represent a challenge to the standard jet algorithm, object identification and isolation criteria, developed for decaying particles approximately at rest in the laboratory frame. For larger boosts above order of $p_T>$200 GeV, the final state from the $H\rightarrow b\bar{b}$ or $t\rightarrow bW$ decay can merge into a single jet and the approach to reconstruct the Higgs boson or top quark in this environment should change drastically. Rather than attempting to resolve jets individually, the decaying object is reconstructed as a single fat jet. Then, the composite nature of the jet is revealed by analyzing its substructure. Besides subjet btagging also a dedicated approach to identify both B hadrons in the same fat jet for $H\rightarrow b\bar{b}$ has been studied.