BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:1 UID:UW-Physics-Event-8265 DTSTART:20230508T190000Z DTEND:20230508T203000Z DTSTAMP:20260409T005356Z LAST-MODIFIED:20230417T144841Z LOCATION:4274 Chamberlin SUMMARY:Higgs production with a top quark pair in the diphoton channel \, di-Higgs production in the bb-diphoton channel\, and Inner Tracker upgrade with the ATLAS detector at the Large Hadron Collider\, Graduat e Program Event\, Alex Zeng Wang\, Physics Graduate Student DESCRIPTION:Since the discovery of the Higgs boson in 2012\, the dipho ton (γγ) decay channel of the Higgs boson has been one of the most p otent channels due to the contrast between the smoothly falling backgr ound and sharply peaked signal in the diphoton invariant mass.
\n< br> \nIn 2018\, with up to 80 fb−1 of data at √s = 13 TeV\, ATLAS observed Higgs boson production in association with a pair of top quar ks (ttH) with a significance of 5.8σ by combining measurements in the γγ\, bb\, ZZ\, and multi-lepton Higgs decay channels. The ttH produ ction cross-section was measured to be 670 ± 90 (stat) +110 -100 (sys t) fb. The diphoton channel was one of the main contributors to this r esult\, alone providing a significance of 4.1σ.
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\nWith 140 fb−1\, a search for non-resonant Higgs pair production in the bbγΠ³ final state was performed. No significant signal was observed and up per limits at 95% confidence level were set. The observed limit on the SM cross-section was 130fb\, or 4.2 times the predicted value. The ob served Higgs trilinear coupling modifier was constrained to be between [-1.5\, 6.7].
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\nBoth the ttH (H → γγ) and HH → bbγΠ³ analyses will benefit tremendously from the increased statistics exp ected from the High-Luminosity LHC (HL-LHC). To ensure the continued e fficiency of the detector in the harsh HL-LHC environment\, ATLAS will install a new Inner Tracker (ITk) consisting of silicon pixel sensors in its innermost layer. At SLAC National Accelerator Laboratory\, a v ariety of electrical tests are performed for the construction of a pro totype integrated pixel system\, in order to provide early feedback an d validation of the ITk design. URL:https://www.physics.wisc.edu/events/?id=8265 END:VEVENT END:VCALENDAR