2025/04/01 by Goswami, Rakshanda, Talukdar, Pulak, Das, Bhoomika +2
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2504.00706
We present an improved evaluation of the two-photon exchange correction to the unpolarized lepton-proton elastic scattering process at very low-energies relevant to the MUSE experiment, where only the dominant intermediate elastic proton is considered. We employ the framework of heavy baryon chiral perturbation theory and invoke the soft-photon approximation in order to reduce the intricate 4-point loop-integrals into simpler 3-point loop-integrals. In the present work, we adopt a more robust methodology compared to an earlier work along the same lines for analytically evaluating the loop-integrations, and incorporate important corrections at next-to-next-to-leading order. These include the proton's structure effects which renormalize the proton-photon interaction vertices and the proton's propagator. Finally, our results allow a model-independent estimation of the charge asymmetry for the scattering of unpolarized massive leptons and anti-leptons.