Thermodynamics from the S-matrix reloaded: emergent thermal mass
摘要
The formalism of Dashen, Ma and Bernstein (DMB) expresses the thermal partition function of a system in terms of the S-matrix operator, roughly Z(β) ∝ ∫dEe−βE Tr ln S(E), where S denotes the full scattering operator on the asymptotic Fock space — i.e. including all multi-particle sectors — defined via the Lippmann-Schwinger equation. Recently we have employed this formalism to compute the free energy of flux tubes (essentially a two-dimensional theory of derivatively coupled scalars) and the two-loop O(αs) QCD thermal free energy.
Moving to higher orders, it is well known that at