Speaker
Description
Above the chiral restoration crossover some cumulants
of quark (baryon) number and charge fluctuations approach
a free quark gas value already at T ~ 200-250 MeV and
are considered sometimes as evidence of deconfinement.
At the same time at these temperatures very clear patterns
of chiral spin symmetry, which is a symmetry of the color
charge and electric interactions, and which is not a symmetry
of free quark gas, are observed. This symmetry suggests that
degrees of freedom are chirally symmetric quarks connected
by electric field into color singlet objects ("long strings").
The cumulants of conserved charge fluctuations are given
by integrals of spatial correlators of conserved charge.
If quarks are free these correlators demonstrate on a
finite lattice remarkable diffractive patterns that are
induced by quarks that are separated by a large distance.
In full QCD these diffractive patterns are absent which
indicates that a confining interaction does not allow
quarks to be separated by a large distance. These effects
are clearly visible in the correlators in a region where
the correlators are suppressed by a few orders of magnitude.
Hence the cumulants of conserved charge fluctuations are
simply insensitive to the deep infrared region where
confinement is manifest.
