Heavy-Light Exotics from QCD Laplace Sum Rules at N2LO in the chiral limit
Résumé
These talks review and summarize our results in [1, 2] on XYZ -like spectra obtained from QCD Laplace Sum Rule in the chiral limit at next-to-next-leading order (N2LO) of perturbation theory (PT) and including leading order (LO) contributions of dimensions d≤6−8 non-perturbative condensates. We conclude that the observed XZ states are good candidates for 1+ and 0+ molecules or / and four-quark states while the predictions for 1− and 0− states are about 1.5 GeV above the Yc,b experimental candidates and hadronic thresholds. We (numerically) find that these exotic molecules couple weakly to the corresponding interpolating currents than ordinary D , B heavy-light mesons while we observe that these couplings decrease faster [ 1/mb3/2 (resp. 1/mb ) for the 1+ , 0+ (resp. 1− , 0− ) states] than 1/mb1/2 . results do not also confirm the existence of the X (5568) state in agreement with LHCb findings.
Mots clés
Perturbative and Non-perturbative QCD
QCD spectral sum rules
Exotic hadrons
Masses and Decay constants
quantum chromodynamics: sum rule
sum rule: Laplace
sum rule: spectral
quantum chromodynamics: perturbation theory: higher-order
higher-order: 2
perturbation theory: chiral
X(5568)
bottom meson: mass
bottom meson: decay constant