A QCD sum rule calculation of the X±(5568)→Bs0π± decay width

Abstract

To understand the nature of the X(5568), recently observed in the mass spectrum of the Bs0π± system by the D0 Collaboration, we have investigated, in a previous work, a scalar tetraquark (diquak–antidiquark) structure for it, within the two-point QCD sum rules method. We found that it is possible to obtain a stable value of the mass compatible with the D0 result, although a rigorous QCD sum rule constrained analysis led to a higher value of mass. As a continuation of our investigation, we calculate the width of the tetraquark state with same quark content as X(5568), to the channel Bs0π±, using the three-point QCD sum rule. We obtain a value of (20.4±8.7) MeV for the mass ∼ 5568 MeV, which is compatible with the experimental value of 21.9±6.4(sta)−2.5+5.0(syst) MeV/c2. We find that the decay width to Bs0π± does not alter much for a higher mass state.