Axial-vector and pseudoscalar tetraquarks [ud][cs]

Abstract

Spectroscopic parameters and widths of the fully open-flavor axial-vector and pseudoscalar tetraquarks XAV and X-PS with content [ud][cs] are calculated by means of the QCD sum rule methods. Masses and current couplings of XAV and X-PS are found using two-point sum rule computations performed by taking into account various vacuum condensates up to dimension 10. The full width of the axial vector state XAV is evaluated by including into analysis S wave decay modes X-AV -> D*(2010)K--(+), D*(2007)0K0, D- K*(892)+, and D0 K*(892)0. In the case of XPS, we consider S-wave decay XPS -> D*0(2300)0 K0, and P-wave processes X-PS -> D-K*(892)+ and X-PS (->) D0K*(892)0. To determine partial widths of these decay modes, we employ the QCD light-cone sum rule method and soft-meson approximation, which are necessary to estimate strong couplings at tetraquark-meson-meson vertices X-AV D- D*(2010)(-) K+, etc. Our predictions for the mass m(AV) = (2800 +/- 75) MeV and width gamma(AV )= (58 +/- 10) MeV of the tetraquark XAV, as well as results m(PS) = (3000 +/- 60) MeV and M-PS = (65 +/- 12) MeV for the same parameters of X(PS )may be useful in future experimental studies of multiquark hadrons.