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High-resolution Hypernuclear Spectroscopy Electron Scattering at JLab, Hall A
Garibaldi, F. ; Cisbani, E. ; Cusanno, F. ; Frullani, S. ; Iodice, M. ; Urciuoli, G.M. ; De Leo, R. ; Lagamba, L. ; Marrone, S. ; LeRose, J. J. ; de Jager, C.W. ; Feuerbach, R. J. ; Higinbotham, D. W. ; Reitz, B. ; Acha, A. ; Markowitz, P. ; Bydžovský, Petr ; Sotona, Miloslav ; Chang, C. C. ; Millener, J.
The characteristics of the Jefferson LAB electron beam, together with those of the experimental equipments, offer a unique opportunity to study hypernuclear spectroscopy via electromagnetic induced reactions. Experiment 94-107 started a systematic study on 1p-shell targets, C-12, Be-9 and O-16. We present the results from C-12, O-16 and very preliminary results from Be-9. For C-12 for the first time measurable strength in the core-excited part of the spectrum between the ground state and the p(Lambda) state was shown in B-12(Lambda) for the first time. A high-quality N-16(Lambda) spectrum was produced for the first time with sub-MeV Energy resolution. A very precise B-Lambda value for N-16(Lambda), calibrated against the elementary (e,e'K+) reaction on hydrogen, has also been obtained. Final data on Be-9 will be available soon. The missing energy resolution is the best ever obtained in hypernuclear production experiments.
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Neutral Kaon Photoproduction at LNS, Tohoku University
Kaneta, M. ; Chiga, N. ; Beckford, B. ; Ejima, M. ; Fujii, T. ; Fujii, Y. ; Fujibayashi, T. ; Gogami, T. ; Futatsukawa, K. ; Hashimoto, O. ; Hosomi, K. ; Hirose, K. ; Iguchi, A. ; Kameoka, S. ; Kanda, H. ; Kawama, D. ; Kawasaki, T. ; Kimura, C. ; Kiyokawa, S. ; Koike, T. ; Kon, T. ; Ma, Y. ; Maeda, K. ; Maruyama, N. ; Matsumura, A. ; Miyagi, Y. ; Miura, Y. ; Miwa, K. ; Nakamura, S. N. ; Nomura, H. ; Okuyama, A. ; Ohtani, A. ; Otani, T. ; Sato, M. ; Shichijo, A. ; Shirotori, K. ; Takahashi, T. ; Tamura, H. ; Taniya, N. ; Tsubota, H. ; Tsukada, K. ; Terada, N. ; Ukai, M. ; Uchida, D. ; Watanabe, T. ; Yamamoto, T. ; Yamauchi, H. ; Yokota, K. ; Ishikawa, T. ; Kinoshita, T. ; Miyahara, H. ; Nakabayashi, T. ; Shimizu, H. ; Suzuki, K. ; Tamae, T. ; Terasawa, T. ; Yamazaki, H. ; Han, Y. C. ; Wang, T. S. ; Sasaki, A. ; Konno, O. ; Bydžovský, Petr ; Sotona, Miloslav
The elementary photo-strangeness production process has been intensively studied based on the high-quality data of the charged kaon channel, gamma + p -> K+ + Lambda(Sigma(0)). However, there had been no reliable data for the neutral kaon channel gamma + n -> K-0 Lambda(Sigma(0)) and the theoretical investigations suffer seriously from the lack of the data. In order to have reliable data for the neutral kaon photo-production data, substantial effort has been made to measure the gamma + n -> K-0 + A process in the pi(+)pi(-) decay channel, using a liquid deuterium target and a tagged photon beam (E-gamma = 0.8-1.1 GeV) in the threshold region at the Laboratory of Nuclear Science (LNS), Tohoku University. We have taken exploratory data quite successfully with the use of Neutral Kaon Spectrometer (NKS) at LNS-Tohoku in 2003 and 2004. The data is compared to theoretical models and it indicates a hint that the K-0 differential cross section has a backward peak in the energy region. The second generation of the experiment, NKS2, is designed to extend the NKS experiment by considerably upgrading the original neutral kaon spectrometer, fully replacing the spectrometer magnet, tracking detectors and all the trigger counters. The new spectrometer NKS2 has significantly larger acceptance for neutral kaons compared with NKS, particularly covering forward angles and much better invariant mass resolution. The estimated acceptance of NKS2 is three (ten) times larger for K-S(0)(Lambda) than that of NKS. The spectrometer is newly constructed and installed at the Laboratory of Nuclear Science, Tohoku University in 2005. The deuterium target data was taken with tagged photon beam in 2006-2007. We will report recent results of NKS2 in this paper. Additionally, a status of the upgrade project that gives us larger acceptance and capability of K-0 + A coincidence measurement will be presented.
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