We presented the first evidence for the existence of the interesting charmonium-like state X(3872) within lattice QCD. We found the state using the dinamical simulation of the DD* scattering the the channel JPC=1++ with isospin 0. The pole in the scattering matrix was found just below DD* threshold which was related the shallow bound state X(3872).
COBISS.SI-ID: 2613348
Previous lattice QCD simulations rendered too large value for the mass of the meson Ds0(2317). Our hypothesis was that this was due to the omission of the DK threshold effect. The hypothesis turned out correct. We took the effect of the threshold into account by simulating DK scattering and we found a pole in the scattering matrix below the threshold. The pole was related to Ds0 meson and the mass turned out finally in agreement with experiment.
COBISS.SI-ID: 2631780
We have presented the first lattice simulation of a charmonium resonance, taking into account its strong decay. The mass and decay width of the vector resonance psi(3770) was determined by simulating DD scattering in p-wave. The resulting mass and width are in fair agreement with experiment. The channel which should host yet unidentified scalar resonances was examined by simulating DD scatering in s-wave.
COBISS.SI-ID: 2847588
We determined the discrete energy spectrum in the channel JPG=1+- where the exotic experimental peaks called Zc+ were discovered. These peaks are interesting since they could indicate the existence of shortlived state charmonium-like Zc+ with quark structure ccud. A large number of interpolating fields with structure meson-meson and diquark-antidiquark were used. We searched the energy region up to 4.2 GeV. All expected two-meson eigenstates were found, while the energy eigenstate related to Zc+(3900) was not found. Our result seems in agreement with the result of HALQCD collaboration which indicate that a peak Zc+(3900) is not related to resonance pole but to the coupling of channels DD* and J/psi pi.
COBISS.SI-ID: 2775652
This was a more detailed study of X(3872), which was evidenced in our earlier simulation. For this purpose we implemented a much larger number of interpolating fields with strucutre cc, meson/meson and diquark-antidiquark. From the coupling of the X(3872) eigenstate to the various interpolating fields we concluded that cc and DD* Fock componbents are more cricial for this state than the diquark-antidiquark ones.
COBISS.SI-ID: 2834788