Scattering in the dual regime of Yang-Baxter deformed O(2N) sigma models

Abstract

We continue to explore the previously suggested dual regime of Yang-Baxter (YB) deformed $\mathrm{O}(2N)$ sigma models, which is a new one-parametric deformation of the $\mathrm{O}(2N)$ model. It can be obtained from the conventional YB deformed $\mathrm{O}(2N+2)$ sigma model by freezing two isometries. The scattering matrix in the non-deformed $\mathrm{O}(n)$ model is known to coincide with the rational $\mathfrak{so}_n$-invariant $R-$matrix. For $n = 2N$ this rational solution allows for two trigonometric deformations: the usual $D_N^{(1)}$ and the twisted $D_{N}^{(2)}$. The usual one is known to coincide with the scattering matrix of the conventional $\mathrm{YB-O}(2N)$ model. A natural question to ask is what sigma model corresponds to the twisted solution. In this work we claim that it is precisely our dual regime of $\mathrm{YB-O}(2N)$. We find the corresponding unitarizing function $F_N(\theta)$ explicitly, and, as a bonus, extract some physical properties of this system using the thermodynamic Bethe Ansatz technique.