# Lepto-Hadronic Scenarios for TeV Extensions of Gamma-Ray Burst Afterglow Spectra

**Authors:** Marc Klinger, Chengchao Yuan, Andrew M. Taylor, Walter Winter  
**arXiv:** [2403.13902](https://arxiv.org/abs/2403.13902)  
**Date:** 2024-03-20  
**Summary page:** https://www.summarizepaper.com/fr/paper/2403.13902v1/

## Abstract

Recent multi-wavelength observations of gamma-ray burst afterglows observed in the TeV energy range challenge the simplest Synchrotron Self-Compton (SSC) interpretation of this emission, and are consistent with a single power-law component spanning over eight orders of magnitude in energy. To interpret this generic behaviour in the single-zone approximation without adding further free parameters, we perform an exhaustive parameter space study using the public, time-dependent, multi-messenger transport software AM3. This description accounts for the radiation from non-thermal protons and the lepto-hadronic cascade induced by pp- and p{\gamma}-interactions. We summarise the main scenarios which we have found (SSC, Extended-syn, Proton-syn, pp-cascade, and p{\gamma}-cascade), and discuss their advantages and limitations. We find that possible high-density environments, as may be typical for surrounding molecular cloud material, offer an alternative explanation for producing flat hard (source) spectra up to and beyond energies of 10 TeV.