Observation of a (6)(LambdaLambda)He double hypernucleus.

Authors :: Takahashi H
Ahn JK
Akikawa H
Aoki S
Arai K
Bahk SY
Baik KM
Bassalleck B
Chung JH
Chung MS
Davis DH
Fukuda T
Hoshino K
Ichikawa A
Ieiri M
Imai K
Iwata YH
Iwata YS
Kanda H
Kaneko M
Kawai T
Kawasaki M
Kim CO
Kim JY
Kim SJ
Kim SH
Kondo Y
Kouketsu T
Lee YL
McNabb JW
Mitsuhara M
Nagase Y
Nagoshi C
Nakazawa K
Noumi H
Ogawa S
Okabe H
Oyama K
Park HM
Park IG
Parker J
Ra YS
Rhee JT
Rusek A
Shibuya H
Sim KS
Saha PK
Seki D
Sekimoto M
Song JS
Takahashi T
Takeutchi F
Tanaka H
Tanida K
Tojo J
Torii H
Torikai S
Tovee DN
Ushida N
Yamamoto K
Yasuda N
Yang JT
Yoon CJ
Yoon CS
Yosoi M
Yoshida T
Zhu L
Source :: Physical review letters [Phys Rev Lett] 2001 Nov 19; Vol. 87 (21), pp. 212502. Date of Electronic Publication: 2001 Nov 02.
Publication Year :: 2001
Abstract: A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.