A stochastic model solvable without integrability
We introduce a model with diffusive and evaporation/condensation processes, depending on 3 parameters obeying some inequalities. The model can be solved in the sense that all correlation functions can be computed exactly without the use of integrability. We show that the mean field approximation is not exact in general. This can be shown by looking at the analytical expression of the two-point correlation functions, that we provide. We confirm our analysis by numerics based on direct diagonalisation of the Markov matrix (for small values of the number of sites) and also by Monte-Carlo simulations (for a higher number of sites). Although the model is symmetric in its diffusive rates, it exhibits a left / right asymmetry driven by the evaporation/condensation processes. We also argue that the model can be taken as a one-dimensional model for catalysis or fracturing processes.