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

Abstract

We study the production of the exotic charged charmonium-like state $Z_c^{\pm }(3900)$ in $p\bar{p}$ collisions through the sequential process $\psi (4260)\to Z_c^{\pm }(3900){\pi }^{\mp }$, $Z_c^{\pm }(3900)\to J/\psi {\pi }^{\pm }$. 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 $M=3902.6_{-5.0}^{+5.2}{(\mathrm{stat})}_{-1.4}^{+3.3}(\mathrm{syst})$ MeV and $\Gamma =32_{-21}^{+28}{(\mathrm{stat})}_{-7}^{+26}(\mathrm{syst})$ MeV, respectively. We search for prompt production of the $Z_c^{\pm }(3900)$ 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 $10.4\mathrm{f}{\mathrm{b}}^{-1}$ of $p\overline{p}$ collision data collected by the D0 experiment at the Fermilab Tevatron collider.

10 pages, 5 figures. Accepted by Phys. Rev. D