The real-rootedness and log-concavities of coordinator polynomials of Weyl group lattices

It is well-known that the coordinator polynomials of the classical root lattice of type A _n and those of type C _n are real-rooted. They can be obtained, either by the Aissen-Schoenberg-Whitney theorem, or from their recurrence relations. In this paper, we develop a trigonometric substitution approach which can be used to establish the real-rootedness of coordinator polynomials of type D _n. We also find the coordinator polynomials of type B _n are not real-rooted in general. As a conclusion, we obtain that all coordinator polynomials of Weyl group lattices are log-concave.