Towards nature of the X(3872) resonance

Abstract

We construct spectra of decays of the resonance X(3872) with good analytical and unitary properties which allows to define the branching ratio of the X(3872) \to D^{*0}\bar D^0 + c.c. decay studying only one more decay, for example, the X(3872)\to\pi^+\pi^- J/\psi(1S) decay, and show that our spectra are effective means of selection of models for the resonance X(3872). Then we discuss the scenario where the X(3872 resonance is the c\bar c = \chi_{c1}(2P) charmonium which "sits on" the D^{*0}\bar D^0 threshold. We explain the shift of the mass of the X(3872) resonance with respect to the prediction of a potential model for the mass of the \chi_{c1}(2P) charmonium by the contribution of the virtual D^*\bar D+c.c. intermediate states into the self energy of the X(3872) resonance. This allows us to estimate the coupling constant of the X(7872) resonance with the D^{*0}\bar D^0 channel, the branching ratio of the X(3872) \to D^{*0}\bar D^0 + c.c. decay, and the branching ratio of the X(3872) decay into all non-D^{*0}\bar D^0 + c.c. states. We predict a significant number of unknown decays of X(3872) via two gluons:X(3872)\to gluons\ gluon\to hadrons.