30 August 2026 to 4 September 2026
Asia/Tokyo timezone

Secondary Electron-Positron Pairs as a Key Component of the Solar Disk TeV Emission

Not scheduled
20m
Oral Gamma-rays

Speaker

wenyu cao

Description

The Sun exhibits a TeV flux that significantly exceeds theoretical expectations, challenging conventional particle interaction models. In this Letter, we demonstrate that secondary electron-positron ($e^{\pm}$) pairs constitute a crucial and irreducible component of the observed solar signal. Due to their Extensive Air Shower (EAS) morphology being virtually indistinguishable from that of gamma rays in ground-based arrays, this leptonic component has been overlooked in current interpretations. By employing the \textsc{G4Solar} framework with a data-driven Outward Cosmic Ray'' (OCR) injection model, we successfully reproduce the broadband spectra measured by Fermi-LAT and HAWC. Our results show that escaping secondary $e^{\pm}$ contribute approximately 20\% of the total signal in the TeV regime, with a fraction that exhibits a 2--3$\times$ anti-correlation with the solar cycle. We propose aShadow-Center'' reference frame analysis to mitigate magnetic smearing, providing a vital diagnostic tool for future experiments like LHAASO and SWGO to identify this leptonic component.

Primary authors

Chingam Fong (The Chinese University of Hong Kong) Kenny C. Y. Ng (The Chinese University of Hong Kong) Zhe Li (Institute of High Energy Physics) wenyu cao

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