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arXiv · 1609.06205

Identifying a new particle with jet substructures

Chengcheng Han·Doojin Kim·Minho Kim·Kyoungchul Kong·Sung Hak Lim·Myeonghun Park
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Abstract

We investigate a potential of measuring properties of a heavy resonance X, exploiting jet substructure techniques. Motivated by heavy higgs boson searches, we focus on the decays of X into a pair of (massive) electroweak gauge bosons. More specifically, we consider a hadronic Z boson, which makes it possible to determine properties of X at an earlier stage. For $m_X$ of O(1) TeV, two quarks from a Z boson would be captured as a "merged jet" in a significant fraction of events. The use of the merged jet enables us to consider a Z-induced jet as a reconstructed object without any combinatorial ambiguity. We apply a conventional jet substructure method to extract four-momenta of subjets from a merged jet. We find that jet substructure procedures may enhance features in some kinematic observables formed with subjets. Subjet momenta are fed into the matrix element associated with a given hypothesis on the nature of X, which is further processed to construct a matrix element method (MEM)-based observable. For both moderately and highly boosted Z bosons, we demonstrate that the MEM with current jet substructure techniques can be a very powerful discriminator in identifying the physics nature of X. We also discuss effects from choosing different jet sizes for merged jets and jet-grooming parameters upon the MEM analyses.

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Chengcheng Han, Doojin Kim, Minho Kim, Kyoungchul Kong, Sung Hak Lim, Myeonghun Park. 2016-09-20. Identifying a new particle with jet substructures. https://doi.org/10.1007/jhep01(2017)027

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