[NT/RBRC seminar] Structure of Non-perturbative High Temperature QCD and the onset of Dimensional Reduction picture from 4D -> 3D

by Mr Swagatam Tah (The Institute of Mathematical Sciences, India.)

Friday 28 Jun 2024, 11:00 → 13:00 US/Eastern

Large seminar room (https://bnl.zoomgov.com/j/1614715193?pwd=WkwxODVWdzZzb29zQnZRVGp3VTBDQT09)

At high temperatures the spatial correlation functions in QCD can be 
described in terms of dimensionally reduced effective theory. In 
dimensional reduced effective theory we have $SU(3)$ gauge fields 
$A_i$ coupled to scalar $A_0$ field in adjoint representation and the   
massive fermions are already integrated out. Observables which are 
dependent on magnetic($g^2T$) scale remains non-perturbative even at 
very high temperatures due to matsubara zero modes in the gauge 
sector. Spatial Wilson loop (or spatial Wilson line correlator) which 
is sensitive to magnetic d.o.f can be calculated in lattice 
non-perturbatively. The spatial Wilson loops obey area law at all 
temperatures, and this is characterized by the spatial string tension. 
We extract the spatial string tension for $2+1$ flavour QCD with HISQ 
action at temperatures $T\equiv[T_c:4T_c]$ for $N_t=8,10$ lattices. 
The calculations shows the dimensional reduction picture becomes valid 
at $T\geq1.5~T_c$ ($T > 240$ MeV), while for
$T<240$ MeV the spatial string tension is equal to the zero 
temperature (vacuum) string tension.