Vector resonance $X_1(2900)$ and its structure

Abstract

The new vector resonance $X_1(2900)$ observed recently by LHCb in the $D^{-}{K}^{+}$ invariant mass distribution in the decay $B^{+}\to D^{+}{D}^{-}{K}^{+}$ is studied to uncover internal structure of this state, and calculate its physical parameters. In the present paper, the resonance $X_1(2900)$ is modeled as an exotic vector state, $J^P=1^{-}$, built of the light diquark $u^{T}C{\gamma }_{5}d$ and heavy antidiquark $\overline{c}{\gamma }_{\mu }{\gamma }_{5}C{\overline{s}}^T$. The mass and current coupling of $X_1(2900)$ are computed using the QCD two-point sum rule approach by taking into account various vacuum condensates up to dimension $10$. The width of the resonance $X_1(2900)$ is saturated by two decay channels $X_1\to D^{-}{K}^{+}$ and $X_1\to {\overline{D}}^0{K}^0$. The strong couplings $g_1$ and $g_2$ corresponding to the vertices $X_1{D}^{-}{K}^{+}$ and $X_1{\overline{D}}^0{K}^0$ are evaluated in the context of the QCD light-cone sum rule method and technical tools of the soft-meson approximation. Results for the mass of the resonance $X_1(2900)$ $m=(2890\pm 122)\mathrm{MeV}$, and for its full width ${\Gamma }_{\mathrm{full}}=(93\pm 13)\mathrm{MeV}$ are smaller than their experimental values reported by the LHCb collaboration. Nevertheless, by taking into account theoretical and experimental errors of investigations, interpretation of the state $X_1(2900)$ as the vector tetraquark does not contradict to the LHCb data. We also point out that analysis of the invariant mass distribution $D^{+}{K}^{+}$ in the same decay $B^{+}\to D^{+}{D}^{-}{K}^{+}$ may reveal doubly charged four-quark structures $[uc][\overline{s}\overline{d}]$.

8 Pages, 1 Figure and 1 Table

References in corpus (1)

• Four-quark exotic mesons

Cited by in corpus (17)

• An updated review of the new hadron states
• First observation of a doubly charged tetraquark and its neutral partner
• Amplitude analysis of $B^0\to {\overline{D}}^0{D}_s^{+}{\pi }^{-}$ and $B^{+}\to D^{-}{D}_s^{+}{\pi }^{+}$ decays
• Spectroscopy behavior of fully heavy tetraquarks
• On the structures of new scalar resonances $T_{cs0}^a(2900{)}^{++}$ and $T_{cs0}^a(2900{)}^0$
• Modeling the resonance $T_{cs0}^a(2900{)}^{++}$ as a hadronic molecule $D^{\ast +}{K}^{\ast +}$
• Color flux-tube nature of the states $T_{cs}(2900)$ and $T_{c\bar{s}}^a(2900)$
• Diagrammatic analysis of hidden- and open-charm tetraquark production in $B$ decays
• Magnetic moment of the $X_1(2900)$ state in the diquark-antidiquark picture
• Searching for $X_0(2900)$ and $X_1(2900)$ through the kaon induced reactions
• Is the resonance $X_0(2900)$ a ground-state or radially excited scalar tetraquark $[ud][\overline{c}\overline{s}]$?
• Axial-vector and pseudoscalar tetraquarks $[ud][\bar{c}\bar{s}]$
• Observation of the open-charm tetraquark candidate $T_{cs0}^{\ast }(2870{)}^0$ in the $B^{-}\to D^{-}{D}^0{K}_{\mathrm{S}}^0$ decay
• $D_1(2420)$ and its interactions with a kaon: open charm states with strangeness
• Pole analysis for the $D^{\ast }\bar{K}$-$D\overline{K^{\ast }}$ coupled-channel system
• Exotic hadrons associated with $b$-quark
• Investigation of $T_{cs0}^{\ast }(2870{)}^0$ in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the PACIAE model