The J/ψp signals at 4380 MeV and 4450 MeV which were seen by the LHCb collaboration in the decay Λb0→K−J/ψp are discussed following the hypothesis of the existence of diquark-diquark-antiquark composite states. The discussed problems concern: (i) estimation of masses and mass splittings for low-lying states, (ii) determination of decay modes in the quark recombination scheme, (iii) unitarity and analyticity constrains for pentaquark propagators, (iv) hadronic deuteron-like components in the diquark-diquark-antiquark multiplet.
@article{arxiv.1711.10736,
title = {Diquark-diquark-antiquark model for pentaquarks with hidden charm: current status and problems},
author = {V. V. Anisovich and M. A. Matveev and J. Nyiri and A. V. Sarantsev and A. N. Semenova},
journal= {arXiv preprint arXiv:1711.10736},
year = {2017}
}