Four-Charm-Quark Matter from the CMS Collaboration as a Witness of the Development of High-Precision Hadron Spectroscopy

Abstract

Recent CMS observations in the di-$J/\psi$ invariant mass spectrum reveal new structures at 6638 MeV ($X(6600)$)) and 7134 MeV, and confirm the $X(6900)$ at 6847 MeV. These findings provide crucial insights into four-charm-quark matter. The CMS Collaboration's result serves as a testament to the progress in exploring exotic hadronic matter.

2 pages and 1 figure. Accepted by Science Bulletin as Research Highlight

References in corpus (3)

• Fully-heavy structures in the invariant mass spectrum of $J/\psi \psi (3686)$, $J/\psi \psi (3770)$, $\psi (3686)\psi (3686)$, and $J/\psi {\rm Y}(1S)$ at hadron colliders
• Improved understanding of the peaking phenomenon existing in the new di-$J/\psi$ invariant mass spectrum from the CMS Collaboration
• The $X(6900)$ peak could be a molecular state

Cited by in corpus (1)

• Experimental Review of the Quarkonium Physics at the LHC