Charmonium resonances in the 3.9 GeV/$c^2$ energy region and the $X(3915)/X(3930)$ puzzle

Abstract

An interesting controversy has emerged challenging the widely accepted nature of the $X(3915)$ and the $X(3930)$ resonances, which had initially been assigned to the ${\chi }_{c0}(2P)$ and ${\chi }_{c2}(2P)$ $c\bar{c}$ states, respectively. To unveil their inner structure, the properties of the $J^{PC}=0^{++}$ and $J^{PC}=2^{++}$ charmonium states in the energy region of these resonances are analyzed in the framework of a constituent quark model. Together with the bare $q\bar{q}$ states, threshold effects due to the opening of nearby meson-meson channels are included in a coupled-channels scheme calculation. We find that the structure of both states is dominantly molecular with a probability of bare $q\bar{q}$ states lower than $45\%$. Our results favor the hypothesis that $X(3915)$ and $X(3930)$ resonances arise as different decay mechanisms of the same $J^{PC}=2^{++}$ state. Moreover we found an explanation for the recently discovered $M=3860$ MeV$/c^2$ as a $J^{PC}=0^{++}$ $2P$ state and rediscovery the lost $Y(3940)$ as an additional state in the $J^{PC}=0^{++}$ family.

6 pages, 3 tables

References in corpus (8)

• Constituent quark model study of the meson spectra
• Quark-model study of few-baryon systems
• Decay channels and charmonium mass-shifts
• Where is the χ_{c0}(2P)?
• Interplay of quark and meson degrees of freedom in a near-threshold resonance
• Could the $X(3915)$ and the $X(3930)$ Be the Same Tensor State?
• Is the X(3915) the chi_{c0}(2P)?
• Radiative decays of the Y(3940), Z(3930) and the X(4160) as dynamically generated resonances

Cited by in corpus (28)

• Threshold cusps and triangle singularities in hadronic reactions
• Spectroscopy of ${\mathbf{B}}_{\mathbf{c}}$ mesons and the possibility of finding exotic ${\mathbf{B}}_{\mathbf{c}}$-like structures
• Doubly Charmed Pentaquarks
• The $\mathbf{sQ}\bar{\mathbf{q}}\bar{\mathbf{q}}$ $(\mathbf{q}=\mathbf{u},\mathbf{d};\mathbf{Q}=\mathbf{c},\mathbf{b})$ tetraquarks in the chiral quark model
• $QQ\bar{s}\bar{s}$ tetraquarks in the chiral quark model
• Towards the discovery of novel $B_c$ states: radiative and hadronic transitions
• Understanding the $0^{++}$ and $2^{++}$ charmonium(-like) states near 3.9 GeV
• Scalar and tensor charmonium resonances in coupled-channel scattering from QCD
• Radiative decays of the spin-$2$ partner of $X(3872)$
• Two-Body Strong Decay of the 2P and 3P Charmonium states
• Charmonium states in a coupled-channel model
• The scalar exotic resonances X(3915), X(3960), X(4140)
• Diabatic description of charmoniumlike mesons II: mass corrections and strong decay widths
• The $Z_b$ structures in a constituent quark model coupled-channels calculation
• Production of the $X(4014)$ as the spin-2 partner of $X(3872)$ in $e^{+}{e}^{-}$ collisions
• $P$-wave charmonium contribution to hidden-charm states from reanalysis of lattice QCD data
• Does the $J^{PC}=1^{+-}$ counterpart of the $X(3872)$ exist?
• The role of electromagnetic interaction in the $X(3872)$ and its analogs
• Bottomonium-like tetraquarks in a chiral quark model
• The two-channel exotic charmonium-like resonances in the mass region $(3900-4700)$ MeV
• Cross sections for 2-to-1 meson-meson scattering
• Shedding light on charmonium
• Hidden-Charm Tetraquarks in a Mixture Model: Coupled-Channel Analysis with $c\bar{c}$ and Hadronic Molecular Components
• ${\chi }_{c1}(2p)$: an overshadowed charmoniumlike resonance
• Study of conventional and non-conventional scalar and vector mesons
• Production of $\psi (4040)$, $\psi (4160)$, and $\psi (4415)$ mesons in strong interactions
• Coupled-channel meson-meson scattering in the diabatic framework
• Dissociation cross sections of $\psi (3770)$, $\psi (4040)$, $\psi (4160)$, and $\psi (4415)$ mesons with nucleons