Wednesday 11 April 2018 

Speaker: Todd Huffman (University of Oxford)


Title: "The "Multiplicity Jump!" - Finding B's in multi-TeV jets without tracks”

Abstract: The performance of standard tagging algorithms begins to fall in the case of highly boosted
B hadrons (γβ >200). This work uses the jump in hit multiplicity among the pixel layers of an ATLAS 
or CMS-like detector when a B hadron decays within the detector volume. Consequently, tracking is not 
required. The problem is outlined and stage is set. Then the details of the simulations used to uncover 
whether this idea, in fact, stands a chance of working. Indications that relatively simple neural networks 
can use this information to make substantial gains over a simple cut-based approach are presented. Evidence
that a "multiplicity jump counter" does work on high energy jets will be shown as well as the speaker's 
assessment of the progress of implementing these algorithms in the ATLAS experiment.