Resonance $X(4630)$

Abstract

We investigate the structure $X(4630)$ discovered by the LHCb collaboration in the process $B^{+}\rightarrow J/\psi \phi K^{+}$ as a resonance in the $ J/\psi \phi $ mass distribution. We explore this resonance as a diquark-antidiquark state $X=[cs][\overline{c}\overline{s}]$ with spin-parities $J^{\mathrm{PC}}=1^{-+}$. Its mass and current coupling are calculated using the QCD two-point sum rule method by taking into account vacuum condensates up to dimension $10$. We also study decays of this tetraquark to mesons $J/\psi\phi $, $\eta _{c}\eta ^{(\prime )}$, and $\chi _{c1}\eta ^{(\prime )}$, and compute partial widths of these channels. To this end, we employ the light-cone sum rule approach and technical methods of soft-meson approximation to extract strong coupling at relevant tetraquark-meson-meson vertices. Our predictions for the mass $m=(4632\pm 60)~\mathrm{MeV}$ and width $\Gamma=(159\pm 31)~\mathrm{MeV}$ of $X$ are in a very nice agreement with recent measurements of the LHCb collaboration. These results allow us to interpret the resonance $X(4630)$ as the tetraquark $X$ with spin-parities $J^{\mathrm{PC}}=1^{-+}$.