Progress of Theoretical and Experimental Physics
The small binding energy of the hypertriton leads to predictions of the non-existence of bound hypernuclei for isotriplet three-body systems such as nnΛ. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound nnΛ state. The nnΛ state was sought by missing-mass spectroscopy via the (e, e′K+) reaction at Jefferson Lab’s experimental Hall A. The present experiment has higher sensitivity to the nnΛ-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the 3H(γ*, K+)X reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well (ƍp/p⎮ < 4%), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the nnΛ state were obtained to be 21 and 31nbsr-1 at the 90% confidence level when theoretical predictions of (−BΛ, Γ) = (0.25, 0.8) MeV and (0.55, 4.7) MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of nnΛ.
Original Publication Citation
Suzuki, K.N. Gogami, T., Pandey, B. ... Ye, Z. Zhang, J. & Zheng, X. (2022). The cross-section measurement for the 3H (e, e', K+) nnΛ reaction. Progress of Theoretical and Experimental Physics, 2022(1), 1-19, Article 013D01. https://doi.org/10.1093/ptep/ptab158
Suzuki, K. N.; Gogami, T.; Pandey, B.; Hauenstein, Florian; Hyde, Charles E.; Ye, Z.; Zhang, J.; Zheng, X.; and Et al., "The Cross-Section Measurement for the 3H (e, e', K+) nnΛ Reaction" (2022). Physics Faculty Publications. 576.