6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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Background studies and Performance Evaluation of Tau Identification Working Points in the Diphoton–Hadronic Tau Final State with ATLAS Data in the mass range 130 – 200 GeV

8 Jul 2026, 11:20
20m
Lecture Hall GH3 (University of the Western Cape)

Lecture Hall GH3

University of the Western Cape

Oral Presentation Track B - Nuclear, Particle and Radiation Physics Nuclear, Particle and Radiation Physics -2

Speaker

Mr Vuyolwethu Happyboy Kakancu (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa)

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.

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Author

Mr Vuyolwethu Happyboy Kakancu (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa)

Co-authors

Prof. Bruce Mellado (Institute of High Energy Physics of the Chinese Academy of Sciences, 19 Yuquan Rd, Shijingshan District, Beijing, China, 100039 and School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Mr Chinedu Jude Nnaji (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Dr Francesco Curcio (Institute of High Energy Physics of the Chinese Academy of Sciences, 19 Yuquan Rd, Shijingshan District, Beijing, China, 100039) Mr Karabo Mosala (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Mr Kgothatso Ntumbe (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Dr Mukesh Kumar (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Mr Njokweni Mbuyiswa (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Mr Paballo Ndhlovu (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Dr Phuti Rapheeha (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Dr Rachid Mazini (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa) Dr Sijing Zhang (Institute of High Energy Physics of the Chinese Academy of Sciences, 19 Yuquan Rd, Shijingshan District, Beijing, China, 100039) Mr Thapelo Leboho (School of Physics and Institute for Collider Particle Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa)

Presentation materials