The Belle Collaboration recently reported a promising candidate for the spin-2 D*D¯* partner of the X(3872), called the X2 for short, having a mass of (4014.3±4.0±1.5) MeV and a width of (4±11±6) MeV. Assuming the X2 as a pure molecule of the D*D¯*, we calculated in detail the hidden charmonium decays of the X2→J/ψV and X2→ηcP via the intermediate meson loops, where V=ρ0,ω and P=π0,η,η′. The results indicate that the decay widths are strongly dependent on the X2 mass. At present center value of the mass 4014.3 MeV, the width for the X2→J/ψρ0 is predicted to be a few tens of keV, while it is on the order of 102−3 keV for the X2→J/ψω; the predicted width for the X2→ηcπ0 is about a few keV, while the widths for X2→ηcη and ηcη′ are around a few tens and tenths of keV, respectively. We also investigated the dependence of the ratios between these widths on the X2 mass and on the η−η′ mixing angle, which may be good quantities for experiments. We hope that the present calculations will be checked experimentally in the future.
Published by the American Physical Society
2024