STRINGS WITH INTERACTING ENDS

At the classical level we study open bosonic strings. A generic descri ption of string self-interactions localized at string ends is given. S elf-interactions are characterized by two dimensionless coupling const ants. The model is rewritten using complex Liouville fields. Using the se Lorentz and reparametrization invariant variables, equations of mot ion get greatly simplified and reduce to some boundary problem for Lio uville equation. Henceforth, the Nambu-Goto string model is proved to be still mathematically tractable if we attach finite masses and inter actions at string end points. With the help of semiclassical quantizat ion, we indicate several encouraging points for hadronic strings.