A search for resonances decaying into a Higgs boson and a new particle $X$ in the $XH\to qqbb$ final state with the ATLAS detector

Abstract

A search for heavy resonances decaying into a Higgs boson ($H$) and a new particle ($X$) is reported, utilizing 36.1 fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}=$ 13 TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle $X$ is assumed to decay to a pair of light quarks, and the fully hadronic final state $XH\to q{\bar{q}}^{\prime }b\bar{b}$ is analysed. The search considers the regime of high $XH$ resonance masses, where the $X$ and $H$ bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of $XH$ mass versus $X$ mass is scanned for evidence of a signal, over a range of $XH$ resonance mass values between 1 TeV and 4 TeV, and for $X$ particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of $XH$ and $X$ masses, on the production cross-section of the $XH\to q{\bar{q}}^{\prime }b\bar{b}$ resonance.

36 pages in total, author list starting page 20, 7 figures, 0 tables, published in PLB, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2017-04/

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Cited by in corpus (10)

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• Anomaly detection search for new resonances decaying into a Higgs boson and a generic new particle $X$ in hadronic final states using $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector
• Dedicated Strategies for Triboson Signals from Cascade Decays of Vector Resonances
• Properties of $g\to b\bar{b}$ at small opening angles in $pp$ collisions with the ATLAS detector at $\sqrt{s}=13$ TeV
• $U(1{)}^{\prime }$ extensions of the $\mu \nu$SSM
• Identifying the Quantum Properties of Hadronic Resonances using Machine Learning
• Reconstruction and identification of $H\to W{W}^{\ast }$ with high transverse momentum in the full hadronic final state