SNP-CNS Summer School 2024

Likely existence of bound states and the Efimov effect in the triple-J/ψ system

Not scheduled

20m

Suzuki Umetaro Hall (RIKEN Wako campus)

Oral+Poster Aug. 6 afternoon

Speaker

Ya-Wen Pan

Description

The ground-breaking discovery of the first fully charmed
tetraquark state $X(6900)$ in the $J/\psi J/\psi$ invariant mass
distribution by the LHCb collaboration has inspired intensive
theoretical studies. Various interpretations, such as molecular
states, compact tetraquark states, and coupled-channel effects, have
been proposed for these states. Of particular interest is the ongoing
search for the triple-$J/\psi$ state--a fully-charmed hexaquark state.
To deepen our understanding of the triple-$J/\psi$ state and to guide
future experimental searches, we study the triple-$J/\psi$ system in
this work employing the Gaussian expansion method and with the $J/\psi J/\psi$ potential parameterized to yield a shallow bound state, as
suggested in several theoretical works. Our results support a
triple-$J/\psi$ bound state, even in cases where the attractive
interaction between the two $J/\psi$ mesons is very weak. Moreover,
our analysis implies the Efimov effect in the triple-$J/\psi$ system.
In addition, we extend our investigation to the triple-$\mathrm{{\rm Y}}(1S)$
system and obtain results similar to those for the triple-$J/\psi$
system.