Correlation functions of descendants in the scaling Lee-Yang model

Correlation functions of the composite field TT̄ in the scaling Lee-Yang model are studied. Using the analytic expression for form factors of this operator recently proposed by Delfino and Niccoli hep-th/0407142 [1], we show numerically that the constraints on the TT̄ expectation values obtained by Zamolodchikov hep-th/0401146 [2] and the additional requirement of asymptotic behavior lead to a perfect agreement with the ultraviolet asymptotic predicted by conformal perturbation theory.