X0,1 (2900) and (D- K+) invariant mass from QCD Laplace sum rules at NLO

We revisit, improve and complete some recent estimates of the 0(+) and 1(-) open charm (c over bar d over bar )(us) tetraquarks and the corresponding molecules masses and decay constants from QCD spectral sum rules (QSSR) by using QCD Laplace sum rule (LSR) within stability criteria where the factorised perturbative NLO corrections and the contributions of quark and gluon condensates up to dimension-6 in the OPE are included. We confront our results with the D-K+ invariant mass recently reported by LHCb from B+ -> D+(D-K+) decays. We expect that the bump near the D-K+ threshold can be originated from the 0(++)(D-K+) molecule and/or D-K+ scattering. The prominent X-0 (2900) scalar peak and the bump XJ (3150) (if J = 0) can emerge from a minimal mixing model, with a tiny mixing angle theta(0) similar or equal to (5.2 +/- 1.9)(0), between a scalar Tetramole (T-M0) (superposition of nearly degenerated hypothetical molecules and compact tetraquarks states with the same quantum numbers) having a mass M-TM0 = 2743(18) MeV and the first radial excitation of the D-K+ molecule with mass M-(DK)1 = 3678(310) MeV. In an analogous way, the X-1 (2900) and the X-J (3350) (if J = 1) could be a mixture between the vector Tetramole (T-M1) with a mass MTM1 = 2656(20) MeV and its first radial excitation having a mass M(T-M1)1 = 4592(141) MeV with an angle theta(1) similar or equal to (9.1 +/- 0.6)0. A (non)-confirmation of the previous minimal mixing models requires an experimental identification of the quantum numbers of the bumps at 3150 and 3350 MeV. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study revisits recent estimates of charm tetraquarks and molecules using QCD spectral sum rules (QSSR) with QCD Laplace sum rule (LSR), incorporating perturbative NLO corrections and contributions of quark and gluon condensates up to dimension-6 in OPE. Results are compared with experimental data, suggesting that the bump near the D-K+ threshold may come from interactions between molecules and scattering mechanisms.