From the lineshape of the $X(3872)$ to its structure

Abstract

From a study of the lineshape of the $X(3872)$, the LHCb collaboration measures a sizeable negative effective range. This cannot be reconciled with a shallow $D{\bar{D}}^{\ast }$ bound state hypothesis. Based on Weinberg's compositeness criterion, together with a theorem by Smorodinsky, it follows that the $X$ has to have a compact hidden charm structure, most likely a tetraquark, interacting with unbound $D{\bar{D}}^{\ast }$ pairs via short-distance color forces. This conclusion is strengthened by the general pattern recently emerging for exotic mesons.

6 pages. Updated version including the evaluation of the error on the effective range. Discussion and conclusions unchanged. To appear as a Letter in Physical Review D

References in corpus (10)

• Multiquark Resonances
• Is the X(3872) Production Cross Section at Tevatron Compatible with a Hadron Molecule Interpretation?
• Observation of new resonances decaying to $J/\psi K^{+}$ and $J/\psi \varphi$
• Observation of a near-threshold structure in the $K^{+}$ recoil-mass spectra in $e^{+}{e}^{-}\to K^{+}(D_s^{-}{D}^{\ast 0}+D_s^{\ast -}{D}^0)$
• Reconciling the X(3872) with the near-threshold enhancement in the D^0\bar{D}^{*0} final state
• Comprehensive analysis of the wave function of a hadronic resonance and its compositeness
• Nature of X(3872) from data
• Production of doubly charmed tetraquarks with exotic color configurations in electron-positron collisions
• Observation of multiplicity-dependent prompt ${\chi }_{c1}(3872)$ and $\psi (2S)$ production in $pp$ collisions
• Constraints from precision measurements on the hadron-molecule interpretation of X,Y,Z resonances

Cited by in corpus (27)

• An updated review of the new hadron states
• Chiral perturbation theory for heavy hadrons and chiral effective field theory for heavy hadronic molecules
• 50 Years of Quantum Chromodynamics
• The ALICE experiment: a journey through QCD
• Effective range expansion for narrow near-threshold resonances
• Novel approaches in Hadron Spectroscopy
• Compositeness of S-wave weakly-bound states from next-to-leading order Weinberg's relations
• Four-quark states with charm quarks in a two-body Bethe-Salpeter approach
• Heavy- and light-flavor symmetry partners of the $T_{cc}^{+}(3875)$, the $X(3872)$ and the $X(3960)$ from light-meson exchange saturation
• Compositeness of $T_{cc}$ and $X(3872)$ by considering decay and coupled-channels effects
• Charmonium ${\chi }_{c0}$ and ${\chi }_{c2}$ resonances in coupled-channel scattering from lattice QCD
• The role of the pion in the lineshape of the $X(3872)$
• Probing the nature of the ${\chi }_{c1}(3872)$ state using radiative decays
• The nature of ${\chi }_{c1}\left(3872\right)$ and $T_{cc}^{+}\left(3875\right)$
• Study of exotic hadrons with machine learning
• Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
• Towards the understanding of heavy quarks hadronization: from leptonic to heavy-ion collisions
• Compositeness of hadrons, nuclei, and atomic systems
• Electromagnetic properties of the $T_{cc}^{+}$ molecular states
• ${\bar{B}}^0\to {\bar{K}}^{(\ast )0}X$, $B^{-}\to K^{(\ast )-}X$, ${\bar{B}}_s^0\to \eta ({\eta }^{\prime },\varphi )X$ from the $X(3872)$ molecular perspective
• Role of the short-range dynamics in the formation of $D^{(\ast )}{\bar{D}}^{(\ast )}/B^{(\ast )}{\bar{B}}^{(\ast )}$ hadronic molecules
• A short review on the compositeness of the $X(3872)$
• Charge-conjugation asymmetry and molecular content: the $D_{s0}^{\ast }(2317{)}^{\pm }$ in matter
• New reaction approach to reflect exotic structure of hadronic molecular state
• ${\chi }_{c1}(2p)$: an overshadowed charmoniumlike resonance
• Hadronic molecules and multiquark states
• The general propagator for S-wave threshold states