Heavy axial-vector structures bb(cc)

Abstract

The fully heavy axial-vector diquark-antidiquark structures bb(cc) are explored by means of the QCD sum rule method. They are modeled as four-quark mesons T-1 and T-2 composed of b(T)C sigma(mu nu)gamma(5)b, cgamma(nu)Cc(T) and b(T)C gamma(mu)gamma(5)b, cCc(T) diquarks, respectively. The spectroscopic parameters of the tetraquarks T-1 and T-2 are determined in the context of the QCD two-point sum rule method. Results obtained for masses of these states m(1) = (12715 +/- 86) MeV and m(2) = (13383 +/- 92) MeV are used to fix their strong decay channels. The full width Gamma(T-1) of the diquark-antidiquark state T-1 is estimated by considering the processes T-1 -> Bc-Bc & lowast;- and T-1 -> Bc & lowast;-Bc & lowast;-. The decays to mesons Bc-Bc & lowast;-, B-c(-)(2S)B-c(& lowast;-) and Bc & lowast;-Bc & lowast;- are employed to evaluate Gamma(T-2). Results obtained for the widths Gamma(T-1) = (44.3 +/- 8.8) MeV and Gamma(T-2)=(82.5 +/- 13.7) MeV of these tetraquarks in conjunction with their masses are useful for future experimental studies of fully heavy resonances.