MESON2026

Comments on eta' nuclei and on the hypertriton binding energy

26 Jun 2026, 16:25

25m

Medium lecture hall (B) (Auditorium Maximum)

Invited parallel Hadron-hadron interactions Parallel session B3

Speaker

Avraham Gal (Hebrew University)

Description

I briefly discuss two apparent puzzles: (i) is the observation of eta'(958) meson bound
states in 11C [1] compatible with near-zero values of the eta'-N scattering length [2]?,
and (ii) is the Lambda binding energy of the hypertriton (L3H) small, 63(+38/-31) keV
(J-PARC E73 [3]), or large, 523+/-76 keV (A1@MAMI [4])?

For good background on searches for eta' nuclei, see Volker Metag's concluding talk here.
As for B_L(L3H), my suggestion is that MAMI's observed weak-decay pion momentum peak originates from L7He, not from L3H [5].

[1] R. Sekiya, et al., PRL 136 (2026) 142501
[2] E. Friedman, A. Gal, PLB 870 (2025) 139916
[3] T. Akaishi, et al., PLB 873 (2026) 140163
[4] R. Kino, et al., PRL 136 (2026) 152301
[5] A. Gal, arXiv:2604.18259, submitted to PLB

Presentation materials

gal_meson26_v2.pdf