Fully heavy pentaquark states

Jian-Rong Zhang

doi:10.1103/physrevd.103.074016

Abstract

Developing the calculation techniques to fivefold heavy hadrons, we perform the study of novel fully-heavy $QQQQ\bar{Q}$ pentaquark states by the QCD sum rule approach that is firmly based on the QCD basic theory. Numerically, masses of fully-heavy pentaquark states are calculated to be $7.41^{+0.27}_{-0.31}~\mbox{GeV}$ for $cccc\bar{c}$ and $21.60^{+0.73}_{-0.22}~\mbox{GeV}$ for $bbbb\bar{b}$, respectively. In experiment, these predicted all-heavy pentaquark states could be searched for in the $\Omega_{QQQ}\eta_{Q}$ invariant mass spectrum.

Highlights

In recent years, hunting for evidences of the multiquark states composed of more than three quarks have attracted one’s great interest
Making a synthetical consideration of all these observations, it seems very promising that pentaquark states consist of fully charmed quarks could be found in the Ωcccηc invariant mass spectrum experimentally
By way of parenthesis, involving those unascertained higher dimensional gluonic condensates, one technically has to accomplish a tremendous task since a number of multiloop massive propagator diagrams need to be treated for the present fully heavy pentaquark states for which could be taken into account in some further work

Summary

INTRODUCTION

In recent years, hunting for evidences of the multiquark states composed of more than three quarks have attracted one’s great interest. Making a synthetical consideration of all these observations, it seems very promising that pentaquark states consist of fully charmed quarks could be found in the Ωcccηc invariant mass spectrum experimentally. To probe a fully heavy pentaquark state, one inevitably has to confront the very intricate nonperturbative QCD problem. Referring to fully heavy pentaquark states, the related operator product expansion (OPE) calculations are quite complicated as one has to treat many multiloop massive propagator diagrams. Making the development of corresponding calculation techniques, we devote to investigating fully heavy pentaquark states with the help of trustworthy QCD sum rule method in this paper.

FULLY HEAVY PENTAQUARK STATES IN QCD SUM RULES

NUMERICAL ANALYSIS AND DISCUSSIONS

SUMMARY