No enhancement of the localization length for two interacting particles in a random potential

We study two interacting particles in a random potential chain by means of the transfer matrix method. The dependence of the two-particle localization length $\lambda_2$ on disorder and interaction strength is investigated. Our results demonstrate that the recently proposed enhancement of $\lambda_2$ as compared to the results for single particles is entirely due to the finite size of the systems considered. This is shown for a Hubbard-like onsite interaction and also a long-range interaction.