Spin correlations of strongly interacting massive fermion pairs as a test of Bell's inequality.
We report the results of the first-time test of the local hidden variable theories (Bell-Clauser-Horne-Shimony-Holt) involving strongly interacting pairs of massive spin 1/2 hadrons from the decay of short-lived (tau<10;-21sec) 2He spin-singlet state, populated in the nuclear reaction 2H+;1H-->;2He+n. The novel features of this experiment are (a) the use of an 'event-ready' [corrected] detector of nearly 100% efficiency to prepare an unbiased sample and (b) a focal-plane polarimeter of full 2pi sr acceptance with a random "post selection" of the reference axes. The spin-correlation function is deduced to be S[exp](pi/4)=2.83+/-0.24stat+/-0.07sys. This result is in agreement with nonlocal quantum mechanical prediction and it violates the Bell-CHSH inequality of |S|<or=2 at a confidence level of 99.3%.
Sakai
H
H
Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033, Japan.
Saito
T
T
Ikeda
T
T
Itoh
K
K
Kawabata
T
T
Kuboki
H
H
Maeda
Y
Y
Matsui
N
N
Rangacharyulu
C
C
Sasano
M
M
Satou
Y
Y
Sekiguchi
K
K
Suda
K
K
Tamii
A
A
Uesaka
T
T
Yako
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K