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arXiv · 2511.22568

New Physics Searches via Beam Normal Spin Asymmetry in Bhabha Scattering

Aleksandr Pustyntsev·Muthubharathi S. Ramasamy·Marc Vanderhaeghen
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Abstract

We examine the sensitivity of the beam normal spin asymmetry in Bhabha scattering to beyond the Standard Model (BSM) mediators, in the context of the JLab polarized positron program. A key property of this observable is that the Standard Model contribution exhibits a zero crossing at a fixed scattering angle, providing a clean, effectively background-free point for these searches. We consider scalar, vector, and axial vector mediators and present projected bounds, finding that scalar and vector scenarios allow a significant extension of the search ranges beyond existing constraints.

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Aleksandr Pustyntsev, Muthubharathi S. Ramasamy, Marc Vanderhaeghen. 2025-11-27. New Physics Searches via Beam Normal Spin Asymmetry in Bhabha Scattering. https://doi.org/10.1103/w2zp-7mdr

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