Spectrum of the doubly charmed molecular pentaquarks in chiral effective field theory

Abstract

We perform a systematic study on the interactions of the ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$ systems within the framework of chiral effective field theory. We introduce the contact term, one-pion-exchange and two-pion-exchange contributions to describe the short-, long-, and intermediate-range interactions. The low energy constants of the ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$ systems are estimated from the $N\bar{N}$ scattering data by introducing a quark level Lagrangian. With three solutions of LECs, all the ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$ systems with isospin $I=1/2$ can form bound states, in which different inputs of LECs may lead to distinguishable mass spectra. In addition, we also investigate the interactions of the charmed-bottom ${\Sigma }_c^{(\ast )}{\bar{B}}^{(\ast )}$, ${\Sigma }_b^{(\ast )}{D}^{(\ast )}$, and ${\Sigma }_b^{(\ast )}{\bar{B}}^{(\ast )}$ systems. Among the obtained bound states, the bindings become deeper when the reduced masses of the corresponding systems are heavier.

Comments: 12 pages, 8 figures, 9 tables. Happy Spring Festival!