Path optimization in 0+1D QCD at finite density

We investigate the sign problem in 0+1D quantum chromodynamics at finite chemical potential by using the path optimization method. The SU(3) link variable is complexified to the SL(3,C) link variable, and the integral path is represented by a feedforward neural network. The integral path is then optimized to weaken the sign problem. The average phase factor is enhanced to be greater than 0.99 on the optimized path. Results with and without diagonalized gauge fixing are compared and proven to be consistent. This is the first step in applying the path optimization method to gauge theories.