A recent report on 7Li(e,e′K+) electroproduction runs by the A1 collaboration at the Mainz Microtron (MAMI) assigns a sharp pion-momentum line at pπ−≈113.8±0.1 MeV/c to Λ3H→π−+3He weak decay, resulting in exceptionally large Λ3H binding-energy BΛ(Λ3H)=0.523±0.013±0.075 MeV. Here I suggest an alternative interpretation of the observed sharp line in terms of Λ7Heg.s.→π−+7Li(Ex=478 keV) weak decay, discussing also the model dependence of BΛ(Λ7He).
Cite
@article{arxiv.2604.18259,
title = {Questioning MAMI's recent determination of $B_{\Lambda}({_{\Lambda}^3}{\rm H})$},
author = {Avraham Gal},
journal= {arXiv preprint arXiv:2604.18259},
year = {2026}
}
Comments
v1: 9 pages, 2 figures, 2 tables, to be submitted for publication, comments are welcome! v2: very slight changes, version submitted for publication