Spectroscopic parameters and decays of the resonance $$Z_b(10610)$$ Z b ( 10610 )

Abstract

Abstract The resonance $$Z_b(10610)$$ Z b ( 10610 ) is investigated as the diquark–antidiquark $$ Z_b=[bu][\overline{bd}]$$ Z b = [ b u ] [ bd ¯ ] state with spin–parity $$J^{P}=1^{+}$$ J P = 1 + . The mass and current coupling of the resonance $$Z_b(10610)$$ Z b ( 10610 ) are evaluated using QCD two-point sum rule and taking into account the vacuum condensates up to ten dimensions. We study the vertices $$Z_b\Upsilon (nS)\pi \ (n=1,2,3)$$ Z b Υ ( n S ) π ( n = 1 , 2 , 3 ) by applying the QCD light-cone sum rule to compute the corresponding strong couplings $$g_{Z_b\Upsilon (nS)\pi }$$ g Z b Υ ( n S ) π and widths of the decays $$Z_b \rightarrow \Upsilon (nS)\pi $$ Z b → Υ ( n S ) π . We explore also the vertices $$Z_b h_{b}(mP)\pi \ (m=1,2)$$ Z b h b ( m P ) π ( m = 1 , 2 ) and calculate the couplings $$g_{Z_b h_{b}(mP)\pi }$$ g Z b h b ( m P ) π and the widths of the decay channels $$Z_b \rightarrow h_{b}(mP)\pi $$ Z b → h b ( m P ) π . To this end, we calculate the mass and decay constants of the $$h_b(1P)$$ h b ( 1 P ) and $$h_b(2P) $$ h b ( 2 P ) mesons. The results obtained are compared with experimental data of the Belle Collaboration.