Charmoniumlike tetraquarks in a chiral quark model

Gang Yang; Jialun Ping; Jorge Segovia

doi:10.1140/epjc/s10052-023-11945-6

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2023) 83: 772
https://doi.org/10.1140/epjc/s10052-023-11945-6

Regular Article -Theoretical Physics

Charmoniumlike tetraquarks in a chiral quark model

Gang Yang¹, Jialun Ping² and Jorge Segovia³^c

¹ Department of Physics, Zhejiang Normal University, 321004, Jinhua, People’s Republic of China
² Department of Physics, Nanjing Normal University, 210023, Nanjing, People’s Republic of China
³ Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, 41013, Seville, Spain

^c jsegovia@upo.es

Received: 26 May 2023
Accepted: 21 August 2023
Published online: 31 August 2023

Abstract

The lowest-lying charmonium-like tetraquarks $c \bar{c} q \bar{q}$ $c{\bar{c}}q{\bar{q}}$ $(q = u, d)$ $(q=u,\,d)$ and $c \bar{c} s \bar{s}$ $c{\bar{c}}s{\bar{s}}$ , with spin-parity $J^{P} = 0^{+}$ $$J^P=0^+$$ , $1^{+}$ $$1^+$$ and $2^{+}$ $$2^+$$ , and isospin $I = 0$ $$I=0$$ and 1, are systematically investigated within the theoretical framework of complex-scaling range for a chiral quark model that has already been successfully applied in former studies of various tetra- and penta-quark systems. A four-body S-wave configuration which includes meson–meson, diquark–antidiquark and K-type arrangements of quarks, along with all possible color wave functions, is comprehensively considered. Several narrow resonances are obtained in each tetraquark channel when a fully coupled-channel computation is performed. We tentatively assign theoretical states to experimentally reported charmonium-like signals such as X(3872), $Z_{c} (3900)$ $$Z_c(3900)$$ , X(3960), X(4350), X(4685) and X(4700). They can be well identified as hadronic molecules; however, other exotic components which involve, for instance, hidden-color channels or diquark–antidiquark structures play a considerable role. Meanwhile, two resonances are obtained at 4.04 GeV and 4.14 GeV which may be compatible with experimental data in the energy interval 4.0–4.2 GeV. Furthermore, the X(3940) and X(4630) may be identified as color compact tetraquark resonances. Finally, we also find few resonance states in the energy interval from 4.5 to 5.0 GeV, which would be awaiting for discovery in future experiments.

© The Author(s) 2023

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