A lattice study of spin interactions between heavy quarks in the quark gluon plasma.

by Dr Swagatam Tah (IMSC)

Thursday 24 Sept 2026, 14:30 → 15:30 Asia/Kolkata

A304 and on Zoom

I will talk about the extraction of the spin-dependent relativistic correction to the non-perturbative potential between a heavy quark-antiquark pair in the quark gluon plasma using lattice techniques. We first analytically derive the spin-dependent potential in terms of Wilson-line correlators with color-magnetic field insertions and show that it contains an imaginary part in the hard-thermal loop approximation. Next, we calculate the same in quenched QCD on a lattice with a spatial extent $N_s=68$ and temporal size $N_\tau=16, 20$ respectively, deep in the deconfined phase at a temperature 470 MeV. After performing a continuum estimate and subsequent renormalization, the physical spin-dependent potential thus obtained allows us to reconstruct the spectral functions for different quarkonium states. We observe that spin-dependent interactions enhance the thermal decay widths more so in the vector compared to pseudo-scalar states, manifestly more pronounced in the charmonium rather than bottomonium states.