Observation and study of the decay J /ψ →φηη′

Date Issued
18-06-2019
Author(s)
Ablikim, M.
Achasov, M. N.
Ahmed, S.
Albrecht, M.
Alekseev, M.
Amoroso, A.
An, F. F.
An, Q.
Bai, J. Z.
Bai, Y.
Bakina, O.
Baldini Ferroli, R.
Ban, Y.
Begzsuren, K.
Bennett, D. W.
Bennett, J. V.
Berger, N.
Bertani, M.
Bettoni, D.
Bianchi, F.
Boger, E.
Boyko, I.
Briere, R. A.
Cai, H.
Cai, X.
Cakir, O.
Calcaterra, A.
Cao, G. F.
Cetin, S. A.
Chai, J.
Chang, J. F.
Chelkov, G.
Chen, G.
Chen, H. S.
Chen, J. C.
Chen, M. L.
Chen, P. L.
Chen, S. J.
Chen, X. R.
Chen, Y. B.
Cheng, W.
Chu, X. K.
Cibinetto, G.
Cossio, F.
Dai, H. L.
Dai, J. P.
Dbeyssi, A.
Dedovich, D.
Deng, Z. Y.
Denig, A.
Denysenko, I.
Destefanis, M.
De Mori, F.
Ding, Y.
Dong, C.
Dong, J.
Dong, L. Y.
Dong, M. Y.
Dou, Z. L.
Du, S. X.
Duan, P. F.
Fang, J.
Fang, S. S.
Fang, Y.
Farinelli, R.
Fava, L.
Fegan, S.
Feldbauer, F.
Felici, G.
Feng, C. Q.
Fioravanti, E.
Fritsch, M.
Fu, C. D.
Gao, Q.
Gao, X. L.
Gao, Y.
Gao, Y. G.
Gao, Z.
Garillon, B.
Garzia, I.
Gilman, A.
Goetzen, K.
Gong, L.
Gong, W. X.
Gradl, W.
Greco, M.
Gu, M. H.
Gu, Y. T.
Guo, A. Q.
Guo, R. P.
Guo, Y. P.
Guskov, A.
Haddadi, Z.
Han, S.
Hao, X. Q.
Harris, F. A.
He, K. L.
He, X. Q.
Heinsius, F. H.
Held, T.
DOI
Abstract
We report the observation and study of the decay J/ψ→φηη′ using 1.3×109 J/ψ events collected with the BESIII detector. Its branching fraction, including all possible intermediate states, is measured to be (2.32±0.06±0.16)×10-4. We also report evidence for a structure, denoted as X, in the φη′ mass spectrum in the 2.0-2.1 GeV/c2 region. Using two decay modes of the η′ meson (γπ+π- and ηπ+π-), a simultaneous fit to the φη′ mass spectra is performed. Assuming the quantum numbers of the X to be JP=1-, its significance is found to be 4.4σ, with a mass and width of (2002.1±27.5±21.4) MeV/c2 and (129±17±9) MeV, respectively, and a product branching fraction B(J/ψ→ηX)×B(X→φη′)=(9.8±1.2±1.7)×10-5. Alternatively, assuming JP=1+, the significance is 3.8σ, with a mass and width of (2062.8±13.1±7.2) MeV/c2 and (177±36±35) MeV, respectively, and a product branching fraction B(J/ψ→ηX)×B(X→φη′)=(9.6±1.4±2.0)×10-5. The angular distribution of J/ψ→ηX is studied and the two JP assumptions of the X cannot be clearly distinguished due to the limited statistics. In all measurements the first uncertainties are statistical and the second systematic.
Volume
99