Speaker
Description
Heavy quarkoinium QQ̄ states created (together with hot hadron/quark-gluon matter) in high
energy hadron-hadron/ion-ion collisions can be used as a thermometer. This is one of the motiva-
tion to study the heavy quarks dynamics in a broad range of temperatures T . On the other hand,
not only light but also heavy quarks physics is sensitive to one of the properties of QCD vacuum
– instantons.
In the present talk we discuss various applications of the instanton liquid model (ILM) at non-zero T:
1. Different scenarios for the T -dependence of the mean instanton size ρ̄(T ) and density n(T ).
2. Direct contribution of the instantons to the central QQ̄ potential, which might be essential at
the distances of the order of the mean instanton size ρ̄(T ).
3. Modification of the gluon properties in ILM, affects the perturbative one-gluon exchange con-
tribution, important for to the QQ̄ potential. We found that in ILM the gluons acquire a dynam-
ical ”electric” gluon mass M el (q, T ), which depends on temperature. At typical ρ̄(0) = 1/3 f m
and n(0) = 1 f m −4 gluons acquire mass M el (0, 0) ≈ 362 MeV, which decreases with T . The
T -dependence of the mass strongly correlates with the temperature dependence of the instanton
vacuum parameters ρ̄(T ), n(T ). The inclusion of one-loop thermal gluon corrections leads to a
rising with temperature contribution M pert,el (0, T ) ∼ T and allows to reproduce the lattice results
for the dynamical gluon mass.
