Ising Field Theory in a magnetic field: ${\phi }^3$ coupling at $T>T_c$

Hao-Lan Xu, Alexander Zamolodchikov

We study the "three particle coupling" ${\Gamma }_{11}^1(\xi )$, in $2d$ Ising Field Theory in a magnetic field, as the function of the scaling parameter $\xi :=h/(-m{)}^{15/8}$, where $m \sim T…