학술논문
The cross-section measurement for the $^3{\textrm H}(e,e'K^+)nn\Lambda$ reaction
Document Type
Working Paper
Author
Suzuki, K. N.; Gogami, T.; Pandey, B.; Itabashi, K.; Nagao, S.; Okuyama, K.; Nakamura, S. N.; Tang, L.; Abrams, D.; Akiyama, T.; Androic, D.; Aniol, K.; Gayoso, C. Ayerbe; Bane, J.; Barcus, S.; Barrow, J.; Bellini, V.; Bhatt, H.; Bhetuwal, D.; Biswas, D.; Camsonne, A.; Castellanos, J.; Chen, J-P.; Chen, J.; Covrig, S.; Chrisman, D.; Cruz-Torres, R.; Das, R.; Fuchey, E.; Gnanvo, K.; Garibaldi, F.; Gautam, T.; Gomez, J.; Gueye, P.; Hague, T. J.; Hansen, O.; Henry, W.; Hauenstein, F.; Higinbotham, D. W.; Hyde, C. E.; Kaneta, M.; Keppel, C.; Kutz, T.; Lashley-Colthirst, N.; Li, S.; Liu, H.; Mammei, J.; Markowitz, P.; McClellan, R. E.; Meddi, F.; Meekins, D.; Michaels, R.; Mihovilovič, M.; Moyer, A.; Nguyen, D.; Nycz, M.; Owen, V.; Palatchi, C.; Park, S.; Petkovic, T.; Premathilake, S.; Reimer, P. E.; Reinhold, J.; Riordan, S.; Rodriguez, V.; Samanta, C.; Santiesteban, S. N.; Sawatzky, B.; Širca, S.; Slifer, K.; Su, T.; Tian, Y.; Toyama, Y.; Uehara, K.; Urciuoli, G. M.; Votaw, D.; Williamson, J.; Wojtsekhowski, B.; Wood, S. A.; Yale, B.; Ye, Z.; Zhang, J.; Zheng, X.
Source
Prog. Theor. Exp. Phys. 2022, 013D01 (2022)
Subject
Language
Abstract
The small binding energy of the hypertrition leads to predictions of non-existence of bound hypernuclei for isotriplet three-body systems such as $nn\Lambda$. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound $nn\Lambda$ state. The $nn\Lambda$ 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 $nn\Lambda$-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 $^3{\rm{H}}(\gamma^{*},K^+)\textrm{X}$ reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well ($|\delta p/p| < 4\%$), 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 $nn\Lambda$ state were obtained to be $21$ and $31~\rm{nb/sr}$ at the $90\%$ confidence level when theoretical predictions of $(-B_{\Lambda}, \Gamma) = (0.25,0.8)$ and $(0.55, 4.7)$ MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of $nn\Lambda$.
Comment: 27 pages, 12 figures
Comment: 27 pages, 12 figures