Dergi makalesi Açık Erişim

Study of the decay $J/\psi \to \varphi {\pi }^{0}\eta $

2024    CERN İşbirliği

Based on $\left(10.09±0.04\right)×{10}^{9}\text{}\text{}J/\psi $ events collected with the BESIII detector operating at the BEPCII collider, a partial wave analysis of the decay $J/\psi \to \varphi {\pi }^{0}\eta $ is performed. We observe for the first time two new structures on the $\varphi \eta $ invariant mass distribution, with significances exceeding $27\sigma $ and $13\sigma $; the first with ${J}^{\mathrm{PC}}={1}^{+-}$, mass $M=\left(1908±6\left(\mathrm{stat}\right){\text{}}_{-4}^{+8}\left(\mathrm{sys}\right)\right)\text{}\text{}\mathrm{MeV}/{c}^{2}$, and width $\Gamma =\left(175±13\left(\mathrm{stat}\right){\text{}}_{-16}^{+7}\left(\mathrm{sys}\right)\right)\text{}\text{}\mathrm{MeV}$, the second with ${J}^{\mathrm{PC}}={1}^{--}$, mass $M=\left(1992±12\left(\mathrm{stat}\right){\text{}}_{-6}^{+15}\left(\mathrm{sys}\right)\right)\text{}\text{}\mathrm{MeV}/{c}^{2}$, and width $\Gamma =\left(132±\phantom{\rule{0ex}{0ex}}22\left(\mathrm{stat}\right){\text{}}_{-4}^{+17}\left(\mathrm{sys}\right)\right)\text{}\text{}\mathrm{MeV}$. These measurements provide important input for the strangeonium spectrum. In addition, the ${f}_{0}\left(980\right)-{a}_{0}\left(980{\right)}^{0}$ mixing signal in $J/\psi \to \varphi {f}_{0}\left(980\right)\to \varphi {a}_{0}\left(980{\right)}^{0}$ and the corresponding electromagnetic decay $J/\psi \to \varphi {a}_{0}\left(980{\right)}^{0}$ are measured with improved precision, providing crucial information to understand the nature of ${a}_{0}\left(980{\right)}^{0}$ and ${f}_{0}\left(980\right)$.