Speaker
Description
Searches for di-photon resonances at the ATLAS experiment in the intermediate mass range of $130-200\,\mathrm{GeV}$ remain largely unexplored, with previous studies primarily focusing on the low-mass $66-110\,\mathrm{GeV}$ and high-mass $200-3000\,\mathrm{GeV}$ regions. In this work, we investigate the $\gamma\gamma + 1\tau^{\mathrm{had}}$ final state in the intermediate-mass region, performing a detailed background characterisation and validation using early to mid-phase Run 3 ATLAS data collected between 2022 and 2024, corresponding to an integrated luminosity of $164\,\mathrm{fb}^{-1}$ at a centre-of-mass energy of $\sqrt{s} = 13.6\,\mathrm{TeV}$. The dominant background contributions considered include $V\gamma\gamma$, Single Higgs production, $t\bar{t}\gamma\gamma$, and $\gamma\gamma + \mathrm{jets}$, which are compared to data to assess the accuracy of Monte Carlo modelling both before and after event selection. Following the application of analysis selections, an optimisation of the hadronic tau identification is performed by comparing different recurrent neural network (RNN)-based working points, namely $\mathrm{RNN}$ Loose, Loose with electron rejection, Medium, and Tight. The performance of each working point is evaluated using the Asimov significance, allowing for a quantitative determination of the optimal working point that maximises signal sensitivity in this channel.
| Apply for student award at which level: | PhD |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |