@article{e08d81d7e6054bd3a947c19f91574fb7,

title = "Observation of ψ (3686) →n n{\= } and improved measurement of ψ (3686) →p p{\= }",

abstract = "We observe the decay ψ(3686)→n{\=n} for the first time and measure ψ(3686)→p{\=p} with improved accuracy by using 1.07×108 ψ(3686) events collected with the BESIII detector. The measured branching fractions are B(ψ(3686)→n{\=n})=(3.06±0.06±0.14)×10-4 and B(ψ(3686)→p{\=p})=(3.05±0.02±0.12)×10-4. Here, the first uncertainties are statistical, and the second ones are systematic. With the hypothesis that the polar angular distributions of the neutron and proton in the center-of-mass system obey 1+αcos2θ, we determine the α parameters to be αn{\=n}=0.68±0.12±0.11 and αp{\=p}=1.03±0.06±0.03 for ψ(3686)→n{\=n} and ψ(3686)→p{\=p}, respectively.",

keywords = "BARYON-ANTIBARYON PAIRS, J/PSI DECAYS, AMPLITUDES, BESIII, ANNIHILATION, TESTS, PHASE",

author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and S. Ahmed and M. Albrecht and Ambrose, {D. J.} and A. Amoroso and An, {F. F.} and Q. An and Bai, {J. Z.} and O. Bakina and {Baldini Ferroli}, R. and Y. Ban and Bennett, {D. W.} and Bennett, {J. V.} and N. Berger and M. Bertani and D. Bettoni and Bian, {J. M.} and F. Bianchi and E. Boger and I. Boyko and Briere, {R. A.} and H. Cai and X. Cai and O. Cakir and A. Calcaterra and Cao, {G. F.} and Cetin, {S. A.} and J. Chai and Chang, {J. F.} and G. Chelkov and G. Chen and Chen, {H. S.} and Chen, {J. C.} and Chen, {M. L.} and Chen, {P. L.} and Chen, {S. J.} and Chen, {X. R.} and Chen, {Y. B.} and Chu, {X. K.} and G. Cibinetto and Dai, {H. L.} and Dai, {J. P.} and A. Dbeyssi and D. Dedovich and Deng, {Z. Y.} and A. Denig and I. Denysenko and Muchnoi, {N. Yu} and Nikolaev, {I. B.}",

year = "2018",

month = aug,

day = "10",

doi = "10.1103/PhysRevD.98.032006",

language = "English",

volume = "98",

journal = "Physical Review D",

issn = "2470-0010",

publisher = "AMER PHYSICAL SOC",

number = "3",

}