The excitations of the sympletic integrable models and their applications

The Bethe ansatz equations of the fundamental Sp(2N) integrable model are solved by a peculiar configuration of roots leading us to determine the nature of the excitations. They consist of N elementary generalized spinons and N-1 composite excitations made by special convolutions between the spinons. This fact is essential to determine the low-energy behaviour which is argued to be described in terms of 2N Majorana fermions. Our results have practical applications to spin-orbital systems and also shed new light to the connection between integrable models and Wess-Zumino-Witten field theories.