PISIN CHEN2018-09-102018-09-102012-02http://inspirehep.net/record/1086982http://scholars.lib.ntu.edu.tw/handle/123456789/371983First observation of $B_s^0\\to J/\\psi\\eta$ and $B_s^0\\to J/\\psi\\eta'$journal article10.1103/PhysRevLett.108.181808