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ID 19322
file
creator
KEK-PS E224 Collaboration
Ahn, J.K.
Aoki, S.
Chung, K. S.
Chung, M. S.
En'yo, H.
Fukuda, T.
Funahashi, H.
Goto, Y.
Higashi, A.
Ieiri, M.
Iijima, T.
Imai, K.
Itow, Y.
Lee, J. M.
Makino, S.
Masaike, A.
Matsuda, Y.
Matsuyama, Y.
Mihara, S.
Nagoshi, C.
Nomura, I.
Park, I. S.
Saito, N.
Sekimoto, M.
Shin, Y. M.
Sim, K. S.
Susukita, R.
Takashima, R.
Takeutchi, F.
Tlustý, P.
Weibe, S.
Yokkaichi, S.
Yoshida, K.
Yoshida, M.
Yoshida, T.
Yamashita, S.
abstract
Stopped-Ξ-12C reactions have been investigated with respect to H-dibaryon and hypernucleus formation with a scintillating fiber detector. Out of 5.5×103 tagged Ξ- particles via the (K-,K+) reaction we obtained 72 stopping Ξ- events with 6.7+1.1-1.4 background events after imposing kinematic constraints. Hypernuclear production has been studied by observing free Λ decays in the stopped-Ξ- reactions. From the observed Λ momentum spectrum, we have found the hypernuclear production rates to be 18±13, 65±6, and 17±12 % for double/twin-A hypernucleus, single-Λ hypernucleus, and no hypernucleus cases, respectively. With the same sample, we set upper limits on R (stopped-Ξ-12C→HX /stopped-Ξ-12C→ all) for H decaying into Λn, Σ-p, and Λpπ-, for H masses just below ΛΛ mass threshold and for H lifetime range 10-11≤τH≤10-8 s. The upper limits on R are ∼0.1-0.2, assuming all of the H decay into each decay mode. Our results give a tight constraint on the existence of the bound H, in comparison with the theoretical estimates of Aerts and Dover, albeit with different target nuclei.
journal title
Physical Review C - Nuclear Physics
volume
Volume 62
issue
Issue 5
start page
055201-1
end page
055201-12
date of issued
2000-10-02
publisher
American Physical Society
issn
0556-2813
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
Copyright (c) 2000 The American Physical Society.
relation url
department
Graduate School of Advanced Sciences of Matter