Understanding Pentaquark States in QCD

Abstract

We estimate the mass of the pentaquark state with QCD sum rules and find that pentaquark states with isospin $I=0,1,2$ lie close to each other around $(1.55\pm 0.15)$ GeV. The experimentally observed baryon resonance ${\Theta }^{+}(1540)$ with $S=+1$ can be consistently identified as a pentaquark state if its $J^P={\frac{1}{2}}^{-}$. Such a state is expected in QCD. If its parity is positive, this pentaquark state is really exotic. Now the outstanding issue is to determine its quantum numbers experimentally.

Cited by in corpus (2)

• Heavy and Light Pentaquark Chiral Lagrangian
• Mass spectrum of the J^P=1/2^- and 3/2^- pentaquark antidecuplets in the perturbative chiral quark model