2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/200671K^0 \to pi^- e^+ nu_e e^+ e^- decay is studied up to the next-to-leading order O^4 in chiral perturbation theory. It is found that the O^4 terms appreciably modifiy the shape of the invariant mass distribution of the leptons and the energy spectrum of the neutrino.17 pages, 7 figures, figures and formula are addedHigh Energy Physics - PhenomenologyStudy of K^0 \to pi^- e^+ nu_e e^+ e^- in chiral perturbation theorytext