Detecting photons in radiative Bhabha interaction with Si-strip and LYSO crystals at future e+e- colliders

Chentao Bao; Hai Chen; Wang Chen; Zhujun Fang; Jiading Gong; Suen Hou; Xiaolin Kang; Mingyi Liu; Ming Qi; Liqing Qin; Weimin Song; Jie Wang; Yadi Wang; Lei Zhang; Linghua Zhang

arXiv · 2610.15036

Detecting photons in radiative Bhabha interaction with Si-strip and LYSO crystals at future e+e- colliders

Chentao Bao·Hai Chen·Wang Chen·Zhujun Fang·Jiading Gong·Suen Hou·Xiaolin Kang·Mingyi Liu·Ming Qi·Liqing Qin·Weimin Song·Jie Wang·Yadi Wang·Lei Zhang·Linghua Zhang

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Abstract

Next-generation e+e-colliders have been proposed for the Super Tau Charm Facility covering center-of-mass energies sqrt(s) = 2-7 GeV, and for the Higgs Factories optimized for Z-pole physics and for HZ production. Luminosity can be determined by measuring forward Bhabha scattering. The QED cross-section calculation has reached a precision of better than 10^-3. Detecting radiative photons in Bhabha events provides a tool for validating higher-order corrections in theory. We propose the Forward Detector for detecting Bhabha scattering events at the STCF. The design uses high-resolution silicon detectors and finely segmented LYSO crystals to discriminate radiative photons from closely associated electrons. Bhabha scattering events are simulated with the BHLUMI and BHWIDE programs, and the detector is modeled using GEANT. Systematic uncertainties due to multiple scattering and bremsstrahlung in the beam pipe were evaluated. The potential for achieving precise measurements of radiative processes in Bhabha events is investigated.

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Chentao Bao, Hai Chen, Wang Chen, Zhujun Fang, Jiading Gong, Suen Hou, Xiaolin Kang, Mingyi Liu, Ming Qi, Liqing Qin, Weimin Song, Jie Wang, Yadi Wang, Lei Zhang, Linghua Zhang. 2026-10-10. Detecting photons in radiative Bhabha interaction with Si-strip and LYSO crystals at future e+e- colliders. https://arxiv.org/abs/2610.15036

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