Properties of $Z_c^{\pm}(3900)$ produced in $p \bar p$ collisions

Abstract

We study the production of the exotic charged charmonium-like state Zc±(3900) in pp¯ collisions through the sequential process ψ(4260)→Zc±(3900)π∓, Zc±(3900)→J/ψπ±. Using the subsample of candidates originating from semi-inclusive weak decays of b-flavored hadrons, we measure the invariant mass and natural width to be M=3902.6−5.0+5.2(stat)−1.4+3.3(syst) MeV and Γ=32−21+28(stat)−7+26(syst) MeV, respectively. We search for prompt production of the Zc±(3900) through the same sequential process. No significant signal is observed, and we set an upper limit of 0.66 at the 95% credibility level on the ratio of prompt production to the production via b-hadron decays. The study is based on 10.4 fb−1 of pp¯ collision data collected by the D0 experiment at the Fermilab Tevatron collider.