  We consider the scaling Lee-Yang model. It corresponds to the unique
perturbation of the minimal CFT model M(2,5). This is not a unitary model. We
used known expression for form factors in order to obtain a closed expression
for a correlation function of a trace of energy-momentum tensor. This
expression is a determinant of an integral operator. Similar determinant
representation were proven to be useful not only for quantum correlation
functions but also in matrix models.
