Speaker
子航 贾
(Nanjing University)
Description
Searches are performed for non-resonant and resonant di-Higgs boson production in the 𝑏𝑏 ̄𝛾𝛾 final state. The data set used corresponds to an integrated luminosity of 139 fb−1 of proton–proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No excess with respect to background expectations is found and upper limits on the di-Higgs boson production cross sections are set. A 95% confidence level upper limit of 130 fb is set on the 𝑝𝑝 → 𝐻𝐻 non-resonant production, where the expected limit is 180 fb. The observed (expected) limit corresponds to 4.1 (5.5) times the cross section predicted by the Standard Model. The observed (expected) limit on the Higgs boson trilinear coupling modifier 𝜅𝜆 is extracted to be [-1.5, 6.7] ([-2.4, 7.7]) at 95% confidence level. The constraints on 𝜅𝜆 are obtained over an expected background hypothesis excluding 𝑝𝑝 → 𝐻𝐻 production. For the resonant production of a new hypothetical scalar particle 𝑋 (𝑋 → 𝐻𝐻 → 𝑏𝑏 ̄𝛾𝛾), limits on the cross section 𝑝𝑝 → 𝑋 → 𝐻𝐻 are presented for the narrow-width approximation as a function of 𝑚𝑋 in the range 251 GeV ≤ 𝑚𝑋 ≤ 1000 GeV. The observed (expected) limits on the cross section 𝑝𝑝 → 𝑋 → 𝐻𝐻 range from 610 fb to 47 fb (360–43 fb) over the considered mass range.
Primary author
子航 贾
(Nanjing University)
