On integrable directed polymer models on the square lattice

Understand

In a recent work Povolotsky provided a three-parameter family of stochastic particle systems with zero-range interactions in one dimension which are integrable by coordinate Bethe ansatz.

• Using these results we obtain the corresponding condition for integrability of a class of directed polymer models with random weights on the square lattice.
• Analyzing the solutions we find, besides known cases, a new two-parameter family of integrable DP model, which we call the Inverse-Beta polymer, and provide its Bethe ansatz solution.