6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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Probing Axion-Like Particle Couplings to the Top Quark at the Future $e^- p$ Collider

7 Jul 2026, 11:00
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

Karabo Mosala (University of the Witwatersrand)

Description

Future electron-proton ($e^- p$) colliders offer a clean and sensitive environment to probe Axion-Like Particle (ALP) interactions with the top quark via single anti-top production in association with an ALP, $e^- p \to \bar{t}~a_x~\nu_e$. We investigate the precision with which the ALP-top quark coupling $C_{a\bar{t}}/f_{a}$ and the ALP-photon coupling $C_{a\gamma}/f_{a}$ can be constrained, considering the ALP decaying to a diphoton pair ($ a_x \to \gamma\gamma$). Focusing on both the hadronic and leptonic decay channels of the anti-top quark, $\bar{t} \to \bar{b} j j$ and $\bar{t} \to \bar{b}\,\ell^-\bar{\nu}_\ell$ respectively. Using a one-parameter multi-bin $\chi^2$ analysis of the most sensitive distribution, we derive $95\%$ confidence level bounds on the ALP couplings as a function of integrated luminosity in the range $10-1000~ {\rm fb}^{-1}$. Throughout, we assume a systematic uncertainty of $\delta_s = 5\%$ in all analysis. Our projected constraints are compared against existing constraints.

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Author

Karabo Mosala (University of the Witwatersrand)

Co-authors

Mr Katlego Machethe (iThemba LABS, National Research Foundation, Somerset West, South Africa) Dr Mukesh Kumar (University of the Witwatersrand)

Presentation materials