Revisiting gauge invariance and Reggeization of pion exchange - Montaña, G.; Winney, D.; Bibrzycki, L.; Fernández-Ramírez, C.; Foti, G.; Hammoud, N.; Mathieu, V.; Perry, R.J.; Pilloni, A.; Rodas, A.; Shastry, V.; Smith, W.A.; et al. (Physical Review D, 2024)