Searching for hidden-charm baryonium signals in QCD sum rules

Hua-Xing Chen,Dan Zhou,Xiang Liu,Shi-Lin Zhu,Wei Chen

doi:10.1140/epjc/s10052-016-4459-0

Abstract

We give an explicit QCD sum rule investigation to hidden-charm baryonium states with the quark content $u\bar u d\bar d c\bar c$, spin $J=0/1/2/3$, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. We find some of them can couple to hidden-charm baryonium states, using which we evaluate the masses of the lowest-lying hidden-charm baryonium states with quantum numbers $J^P=2^-/3^-/0^+/1^+/2^+$ to be around 5.0 GeV. We suggest to search for hidden-charm baryonium states, especially the one of $J=3^-$, in the $D$-wave $J/\psi \pi \pi$ and $P$-wave $J/\psi \rho$ and $J/\psi \omega$ channels in this energy region.

Highlights

In this letter we study one kind of hidden-charm hexaquark states, that is the hidden-charm baryonium states consisting of color-singlet heavy baryons and antibaryons
We find these currents can couple to various structures, including hidden-charm baryonium states [ccqqqq], charmonium states plus two pions [cc + π π ], and hiddencharm tetraquark states plus one pion [ccqq+π ], etc., which fact can be helpful to relevant studies, such as lattice QCD
To summarize the current letter, we use the method of QCD sum rule to investigate hidden-charm baryonium states with the quark content uuddcc, spin J = 0/1/2/3, and of both positive and negative parities

Summary

Introduction

In this letter we study one kind of hidden-charm hexaquark states, that is the hidden-charm baryonium states consisting of color-singlet heavy baryons and antibaryons. In this letter we perform an explicit QCD sum rule investigation to hidden-charm baryonium states with the quark content uuddcc, spin J = 0/1/2/3, and of both positive and negative parities. 2. We systematically construct the relevant local hidden-charm baryonium interpolating currents in Sect. We find these currents can couple to various structures, including hidden-charm baryonium states [ccqqqq], charmonium states plus two pions [cc + π π ], and hiddencharm tetraquark states plus one pion [ccqq+π ], etc., which fact can be helpful to relevant studies, such as lattice QCD. We do not know which structure these currents couple to at the beginning, but we try to perform sum rule analyses using them in Sect. This paper has a supplementary file “OPE.nb” containing all the spectral densities

Hidden-charm baryonium currents

QCD sum rule analyses

Summary