Axial-vector and pseudoscalar tetraquarks $$[ud][{\overline{c}}{\overline{s}}]$$

Abstract

AbstractSpectroscopic parameters and widths of the fully open-flavor axial-vector and pseudoscalar tetraquarks $$X_{\textrm{AV}}$$ X AV and $$X_{\textrm{PS}}$$ X PS with content $$[ud][{\overline{c}}{\overline{s}}]$$ [ u d ] [ c ¯ s ¯ ] are calculated by means of the QCD sum rule methods. Masses and current couplings of $$X_{\textrm{AV}}$$ X AV and $$X_{\textrm{PS}}$$ 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 $$X_{\textrm{AV}}$$ X AV is evaluated by including into analysis S-wave decay modes $$X_{\textrm{AV}}\rightarrow D^{*}(2010)^{-}K^{+}$$ X AV → D ∗ ( 2010 ) - K + , $${\overline{D}}^{*}(2007)^{0}K^{0}$$ D ¯ ∗ ( 2007 ) 0 K 0 , $$D^{-}K^{*}(892)^{+}$$ D - K ∗ ( 892 ) + , and $${\overline{D}}^{0}K^{*}(892)^{0}$$ D ¯ 0 K ∗ ( 892 ) 0 . In the case of $$X_{\textrm{PS}}$$ X PS , we consider S-wave decay $$X_{\textrm{PS}}\rightarrow {\overline{D}} _{0}^{*}(2300)^{0}K^{0}$$ X PS → D ¯ 0 ∗ ( 2300 ) 0 K 0 , and P-wave processes $$X_{\textrm{PS}}\rightarrow D^{-}K^{*}(892)^{+}$$ X PS → D - K ∗ ( 892 ) + and $$X_{\textrm{PS}}\rightarrow {\overline{D}} ^{0}K^{*}(892)^{0}$$ X PS → D ¯ 0 K ∗ ( 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 $$X_{\textrm{AV}}D^{-}D^{*}(2010)^{-}K^{+} $$ X AV D - D ∗ ( 2010 ) - K + , etc. Our predictions for the mass $$m_{\textrm{AV}}=(2800 \pm 75)~\text {MeV}$$ m AV = ( 2800 ± 75 ) MeV and width $$\Gamma _{\textrm{AV}}=(58 \pm 10)~\text {MeV}$$ Γ AV = ( 58 ± 10 ) MeV of the tetraquark $$X_{ \textrm{AV}}$$ X AV , as well as results $$m_{\textrm{PS}}=(3000 \pm 60)~\text {MeV} $$ m PS = ( 3000 ± 60 ) MeV and $$\Gamma _{\textrm{PS}}=(65 \pm 12)~\text {MeV}$$ Γ PS = ( 65 ± 12 ) MeV for the same parameters of $$X_{\textrm{PS}}$$ X PS may be useful in future experimental studies of multiquark hadrons.