Prediction of hidden charm strange molecular baryon states with heavy quark spin symmetry

• Main Authors: C.W. Xiao, J. Nieves, E. Oset
• Format: Article
• Language: English
• Published: Elsevier 2019-12-01
• Series: Physics Letters B
• Online Access: http://www.sciencedirect.com/science/article/pii/S0370269319307737

We have studied the meson-baryon S−wave interaction in the isoscalar hidden-charm strange sector with the coupled-channels, ηcΛ, J/ψΛ, D¯Ξc, D¯sΛc, D¯Ξc′, D¯⁎Ξc, D¯s⁎Λc, D¯⁎Ξc′, D¯⁎Ξc⁎ in JP=1/2−, J/ψΛ, D¯⁎Ξc, D¯s⁎Λc, D¯⁎Ξc′, D¯Ξc⁎, D¯⁎Ξc⁎ in 3/2− and D¯⁎Ξc⁎ in 5/2−. We impose constraints of heavy quark spin symmetry in the interaction and obtain the non vanishing matrix elements from an extension of the local hidden gauge approach to the charm sector. The ultraviolet divergences are renormalized using the same meson-baryon-loops regulator previously employed in the non-strange hidden charm sector, where a good reproduction of the properties of the newly discovered pentaquark states is obtained. We obtain five states of 1/2−, four of 3/2− and one of 5/2−, which could be compared in the near future with forthcoming LHCb experiments. The 5/2−, three of the 3/2− and another three of the 1/2− resonances are originated from isoscalar D¯(⁎)Ξc′ and D¯(⁎)Ξc⁎ interactions. They should be located just few MeV below the corresponding thresholds (4446, 4513, 4588 and 4655 MeV), and would be SU(3)-siblings of the isospin 1/2 D¯(⁎)Σc(⁎) quasi-bound states previously found, and that provided a robust theoretical description of the Pc(4440), Pc(4457) and Pc(4312) LHCb exotic states. The another two 1/2− and 3/2− states obtained in this work are result of the D¯(⁎)Ξc−Ds(⁎)Λc coupled-channels isoscalar interaction, are significantly broader than the others, with widths of the order of 15 MeV, being D¯s(⁎)Λc the dominant decay channel.