$\hat{I}{\text{c◯}}_c$ excited states: a molecular approach with heavy-quark spin symmetry

Abstract

The LHCb Collaboration has recently discovered five excited $\hat{I}{\text{c◯}}_c$ states with masses between 3 and 3.1 GeV, four of them corroborated by the Belle Collaboration. We analyse the dynamical generation of these states within a molecular baryon-meson model that is consistent with both chiral and heavy-quark spin symmetries. Earlier predictions within this model found five $\hat{I}{\text{c◯}}_c$ states with masses below 3 GeV. Thus, in order to study the possible identification of any of these states with the experimental ones in the correct energy region, we explore two different regularization schemes, that is, a modified regularization subtraction method and a cutoff regularization scheme. We find that at least three of the dynamically generated states can be identified with the experimental ones and have spin-parity $J=1/2^{-}$ or $J=3/2^{-}$

6 pages, 3 tables, 1 figure, contribution based on a keynote parallel talk of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), November 13-17, 2018, Tsukuba (Japan)