Form factors in the massless coset models su(2)k+1⊗su(2)k/su(2)2k+1: Part II

Massless flows from the coset model su(2)k+1⊗su(2)k/su(2)2k+1 to the minimal model Mk+2 are studied from the viewpoint of form factors. These flows include in particular the flow from the tricritical Ising model to the Ising model. By analogy with the magnetization operator in the flow TIM→IM, we construct all form factors of an operator that flows to Φ1,2 in the IR. We make a numerical estimation of the difference of conformal weights between the UV and the IR thanks to the Δ-sum rule; the results are consistent with the conformal weight of the operator Φ2,2 in the UV. By analogy with the energy operator in the flow TIM → IM, we construct all form factors of an operator that flows to Φ2,1. We propose to identify the operator in the UV with σ1Φ1,2.