We discuss how the spectral changes of quarkonia at Tc can reflect the 'critical' behaviour of QCD phase transition. Starting from the temperature dependencies of the energy density and pressure from lattice QCD calculation, we extract the temperature dependencies of the scalar and spin-2 gluon condensates near Tc. We also parametrize these changes into the electric and magnetic condensate near Tc. While the magnetic condensate hardly changes across Tc, we find that the electric condensate increases abruptly above Tc. Similar abrupt change is also seen in the scalar condensate. Using the QCD second-order Stark effect and QCD sum rules, we show that these sudden changes induce equally abrupt changes in the mass and width of J/ψ, both of which are larger than 100 MeV at slightly above Tc,
Bibliographical noteFunding Information:
This work was supported by the BK21 Program of the Korean Ministry of Education, and by the Korean Research Foundation KRF-2006-C00011.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)