On leptonic width of $X(4260)$

New measurements on cross sections in $e^+e^-\to J/ψπ^+π^-$, $h_cπ^+π^-$, $D^0D^{*-}π^++c.c.$, $ψ(2S)π^+π^-$, $ωχ_{c0}$ and $J/ψη$ channels have been carried out by BESIII, Belle and BABAR collaborations, and also in the $D_s^*\bar D_s^*$ channel. We perform extensive numerical analyses by combining all these data available, together with those in $D\bar D^*$ and $D^*\bar D^*$ channels. Though the latter show no evident peak around $\sqrt{s}=4.230$ GeV, the missing $X(4260)$ is explained as that it is concealed by the interference effects of the well established charmonia $ψ(4040)$, $ψ(4160)$ and $ψ(4415)$. Our analyses reveal that the leptonic decay width of $X(4260)$ ranges from $O(10^2)$ eV to $O(1)$ keV, and hence may be explained in the conventional quark model picture. That is, the $X(4260)$ may well be interpreted as a mixture of $4^3S_1$ and $3^3D_1$ states.

No reviews yet.

No comments yet.