XYZ - SU3 Breakings from Laplace Sum Rule at Higher Orders: Summary

Abstract

This talk reviews and summarizes some of our results in [1] on XYZ- SU3 Breakings obtained from QCD Laplace Sum Rules (LSR) at next-to-next-leading order (N2LO) of perturbative (PT) theory and including next-to-leading order (NLO) SU3 breaking corrections and leading order (LO) contributions of dimensions d< (6 - 8) non-perturbative condensates. We conclude that the observed X states are good candidates for being 1^++ and 0^++ molecules states. We find that the SU3 breakings are relatively small for the masses (< 10 (resp. 3) %) for the charm (resp. bottom) channels while they are large (< 20 %) for the couplings. Like in the chiral limit case, the couplings decrease faster: 1/m_b^3/2 than 1/m_b^1/2 of HQET. Our approach cannot clearly separate ( within the errors ) some molecule states from the four-quark ones with the same quantum numbers.

Comments: Part of a review presented by S. Narison @ QCD17 (3-7july 2017, Montpellier-FR) and Talks given by D. Rabetiarivony and G. Randriamanatrika @ HEPMAD17 (21 - 26 September, Antananarivo - MG). To appear in Nucl. Part. Phys. Proc. 8 pages, 6 figures and 7 tables