A Search for Heavy Resonances Decaying to HH → bb̄bb̄ with the ATLAS Detector

• Main Author: Emerman, Alexander Zack
• Language: English
• Published: 2021
• Subjects: Particles (Nuclear physics); Higgs bosons; Proton-proton interactions; Gluons; Large Hadron Collider (France and Switzerland); Hadrons > Decay
• Online Access: https://doi.org/10.7916/d8-vt62-4w03

A search for Higgs boson pairs produced in the decay of high mass exotic resonances is presented. The search uses the bb̄bb̄ final state, analyzing 139 fb⁻¹ of proton–proton collision data at √s = 13 TeV collected with the ATLAS detector. Spin-0 and spin-2 benchmark signal models are considered and no significant deviation from the Standard Model prediction is observed. The search is combined with a complementary analysis for lower mass resonances to set upper limits on the production cross-section times HH branching ratio of new resonances in the mass range of 251 GeV to 5 TeV. In addition, the methodology for the in-situ calibration of a novel double-b-tagging algorithm (Xbb2020) using gluon to bb̄ decays is presented. Preliminary scale factors for Monte-Carlo simulation are computed using 139 fb⁻¹ of √s = 13 TeV pp collision data collected with the ATLAS detector. The completed calibration will allow the Xbb2020 algorithm to be used in future ATLAS searches for H → bb̄ decays.