Speaker
Description
Motivated by persistent Run-1 and Run-2 anomalies, including an excess near $m_{\gamma\gamma}\approx152\pm1~$GeV with combined ATLAS and CMS significance of 5.5$\sigma$ (5.3$\sigma$ global), this analysis searches for scalar resonances in diphoton final states with leptons using 2022–2024 ATLAS $pp$ data corresponding to 164 fb$^{-1}$ at $\sqrt{s}=13.6~$TeV. To support this search, a dedicated Monte Carlo generation campaign has been prepared to study final states containing diphotons in association with leptons, specifically $\gamma\gamma+1\ell$ $(\ell=e/\mu/\tau^{\mathrm{had}})$ and $\gamma\gamma+2\ell$, where $\tau^{\mathrm{had}}$ denotes hadronic tau decays. These final states are particularly sensitive to the presence of additional scalar resonances predicted in models with extended Higgs sectors. The signal production is modeled using two theoretical frameworks, a simplified Two-Higgs-Doublet Model extended with a scalar singlet (2HDM+S) and the Real Higgs Triplet Model (RHTM). In the simplified 2HDM+S scenario, heavy scalar resonances are produced predominantly via gluon–gluon fusion and subsequently decay through cascades involving additional scalar states that yield diphoton signatures accompanied by leptonic activity. The RHTM provides complementary phenomenology through extended Higgs sectors containing singly charged and neutral scalar states, leading to final states with photons and leptons arising from electroweak production and scalar decays. The generated samples enable detailed kinematic characterization of the targeted channels and support reconstruction and event selection optimization, object working point optimization studies, and sensitivity evaluations for scalar resonances within the explored mass range.
| Apply for student award at which level: | PhD |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |