Computation of the spectral density of two-point functions: Complex masses, cut rules, and beyond
Computation of the spectral density of two-point functions: Complex masses, cut rules, and beyond
We present a steepest descent calculation of the Kallen-Lehmann spectral density of two-point functions involving complex conjugate masses in Euclidean space. This problem occurs in studies of (gauge) theories with Gribov-like propagators. As the presence of complex masses and the use of Euclidean space brings the theory outside of the …