Physical Review Letters, cilt.119, sa.7, 2017 (SCI-Expanded, Scopus)
The spin and parity of the Zc(3900)± state are determined to be JP=1+ with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the process e+e-→π+π-J/ψ. We use a data sample of 1.92 fb-1 accumulated at s=4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Zc(3900)± with a Flatté-like formula, we determine its pole mass Mpole=(3881.2±4.2stat±52.7syst) MeV/c2 and pole width Γpole=(51.8±4.6stat±36.0syst) MeV. We also measure cross sections for the process e+e-→Zc(3900)+π-+c.c.→J/ψπ+π- and determine an upper limit at the 90% confidence level for the process e+e-→Zc(4020)+π-+c.c.→J/ψπ+π-.