ELPH研究会C033「ハドロン分光に迫る反応と構造の物理」

Spectrum of the fully-charmed tetraquark state

Dec 6, 2022, 2:15 PM

20m

オンライン

Speaker

Guang Juan Wang (Japan Atomic Energy Agency)

Description

In this talk, I will present our calculation of the mass spectrum of the S-wave fully-charmed tetraquark resonant states $cc\overline{c}\overline{c}$ in the nonrelativistic quark model, which successfully describes the charmonium spectrum.
The four-body system is solved with the Gaussian expansion method. The complex scaling technique is used to identify the genuine resonances. With the nonrelativistic quark model, our results show the existence of two $cc\overline{c}\overline{c}$ resonances in each of the $J^{PC}=$ $0^{++}$, $1^{+-}$ and $2^{++}$ sectors, respectively. In the S-wave sector, no resonance is found at the energy region of the $X(6200)$ and $X(6600)$ states. The lower $0^{++}$ and $2^{++}$ resonances are located around $100$ MeV higher than the $X(6900)$ state observed in experiments but have the decay widths consistent with the experiment. The higher $0^{++}$ and $2^{++}$ resonances are found at around $7.2$ GeV with the widths of $60.6$ MeV and $91.2$ MeV, respectively, and they may be good candidates for the $X(7200)$ state.

Presentation materials

ELPH_wgj.pdf