* Speaker : Prof. Seyong Kim (Sejong University)
* Abstract : Using Non-relativistic formulation of Euclidean lattice field theory, we calculate non-perturbatively the Sommerfeld enhancement factor associated with the heavy quark--anti-heavy co-annihilation in a thermal bath of quark-gluon plasma. We found a large enhancement in the color singlet channel and a modest suppresion in the color octet channel and suggest that this large enhancement comes from a bound state formation by considering a perturbative calculation of the Sommerfeld factor with/without a bound state formation. Similar consideration may be generalized to a class of dark matter models.