We confirm our previous prediction of a d∗ state with I(JP)=0(3+) [Phys. Rev. C 60, 045203 (1999)] and report for the first time based on a microscopic calculation that d∗ is a hexaquark dominated exotic state as it has about 2/3 hidden color (CC) configurations. By performing a more elaborate dynamical coupled-channels investigation of the ΔΔ-CC system within the framework of resonating group method (RGM) in a chiral quark model, we found that the d∗ state has a mass of about 2.38-2.42 GeV, a root-mean-square radius (RMS) of 0.76-0.88 fm, and a CC fraction of 66%-68%. The last ensures that the d∗ has a rather narrow width which, together with the quantum numbers and our calculated mass, is consistent with the newly observed resonance-like structure (M≈2380 MeV, Γ≈70 MeV) in double-pionic fusion reactions reported by WASA-at-COSY Collaboration.
@article{arxiv.1408.0458,
title = {Is $d^*$ a candidate of hexaquark-dominated exotic state?},
author = {F. Huang and Z. Y. Zhang and P. N. Shen and W. L. Wang},
journal= {arXiv preprint arXiv:1408.0458},
year = {2015}
}