Speaker
Description
Since the discovery of the Higgs boson in 2012, a priority of the ATLAS and CMS Collaborations has been to better understand its properties and couplings. Understanding the Higgs self-coupling is vital, since it provides a direct probe to the electroweak symmetry breaking and constitutes a precision test of the electroweak theory. A direct probe of the trilinear coupling is possible via Higgs boson pair production, making di-Higgs analyses particularly interesting. In addition, 𝐻𝐻 production via vector boson fusion, the second-leading 𝐻𝐻 production process, has a unique sensitivity to the interaction of two Higgs bosons and two vector bosons. Furthermore, enhancements to the di-Higgs production rate and kinematics would point to new physics beyond the Standard Model (BSM), making this analyses sensitive to such effects.
In the 𝐻𝐻 → 𝑏𝑏𝛾𝛾 channel. The 𝑏𝑏𝛾𝛾 state benefits from the high branching ratio for the 𝐻 → 𝑏𝑏 decay (59% for a SM Higgs boson), while the low branching ratio for the 𝐻 → 𝛾𝛾 decay (0.23%) is compensated by the excellent trigger and reconstruction efficiency for photons with the ATLAS detector and the excellent resolution of the invariant mass of the photon pair (1-2 GeV), thus resulting in a distinctly clear signature.
This is the first HH → bb𝛾𝛾 analysis result using the Run 2 and partial Run 3 dataset from 2022 to 2024. With 308 fb-1, this analysis achieves an observed significance of 0.84$\sigma$(1$\sigma$ expected). The observed results are in agreement with the Standard Model (SM). An overall deficit (excess) is observed in the Run 2 (Run 3) categories, but the measurements are compatible between Run 2 and Run 3.
| 请选择分会 | TeV物理和超出标准模型新物理 |
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