Open charm-bottom axial-vector tetraquarks and their properties

Abstract

Abstract The charged axial-vector $$J^{P}=1^{+}$$ J P = 1 + tetraquarks $$Z_{q}=[cq][\bar{b} \bar{q} ]$$ Z q = [ c q ] [ b ¯ q ¯ ] and $$Z_{s}=[cs][\bar{b} \bar{s}]$$ Z s = [ c s ] [ b ¯ s ¯ ] with the open charm-bottom contents are studied in the diquark–antidiquark model. The masses and meson–current couplings of these states are calculated by employing a QCD two-point sum rule approach, where the quark, gluon and mixed condensates up to eight dimensions are taken into account. These parameters of the tetraquark states $$ Z_{q}$$ Z q and $$Z_{s}$$ Z s are used to analyze the vertices $$Z_q B_c \rho $$ Z q B c ρ and $$Z_s B_c \phi $$ Z s B c ϕ to determine the strong $$g_{Z_qB_c \rho }$$ g Z q B c ρ and $$g_{Z_sB_c \phi }$$ g Z s B c ϕ couplings. For these purposes, the QCD light-cone sum rule method and its soft-meson approximation are utilized. The couplings $$g_{Z_qB_c \rho }$$ g Z q B c ρ and $$ g_{Z_sB_c \phi }$$ g Z s B c ϕ , extracted from this analysis, are applied for evaluating the strong $$Z_q \rightarrow B_c \rho $$ Z q → B c ρ and $$Z_s \rightarrow B_c \phi $$ Z s → B c ϕ decays’ widths, which are essential results of the present investigation. Our predictions for the masses of the $$Z_{q}$$ Z q and $$Z_{s}$$ Z s states are confronted with similar results available in the literature.

Keywords

• Operator Product Expansion
• Charmonium State
• Tetraquark State
• Current Coupling
• Borel Parameter