XYZ-SU3 Breakings from Laplace Sum Rules at Higher Orders

Understand

We present new compact integrated expressions of SU3 breaking corrections to QCD spectral functions of heavy-light molecules and four-quark XYZ-like states at lowest order (LO) of perturbative (PT) QCD and up to d=8 condensates of the OPE.

• Including N2LO PT corrections in the chiral limit and NLO SU3 PT corrections, which we have estimated by assuming the factorization of the four-quark spectral functions, we improve previous LO results for the XYZ-like masses and decay constants from QCD spectral sum rules.
• Systematic errors are estimated from a geometric growth of the higher order PT corrections and from some partially known d=8 non-perturbative contributions.
• Our optimal results, based on stability criteria, are summarized in Tables 18 to 21 and compared with some LO results in Table 22.