• DOI:10.1051/epjconf/202225806001
• Corpus ID: 237485281

Electromagnetic finite-size effects beyond the point-like approximation

@article{Carlo2021ElectromagneticFE,
  title={Electromagnetic finite-size effects beyond the point-like approximation},
  author={Matteo Di Carlo and Maxwell T. Hansen and Nils Hermansson-Truedsson and Antonin Portelli},
  journal={EPJ Web of Conferences},
  year={2021}
}

• M. Carlo, M. Hansen, +1 author A. Portelli
• Published 10 September 2021
• Physics
• EPJ Web of Conferences

We present a model-independent and relativistic approach to analytically derive electromagnetic finite-size effects beyond the point-like approximation. The key element is the use of electromagnetic Ward identities to constrain vertex functions, and structure-dependence appears via physical form-factors and their derivatives. We apply our general method to study the leading finitesize structure-dependence in the pseudoscalar mass (at order 1/L3) as well as in the leptonic decay amplitudes of pions and kaons (at order 1/L2). Knowledge of the latter is essential for Standard Model precision tests in the flavour physics sector from lattice simulations.