Luscher's mu-term and finite volume bootstrap principle for scattering states and form factors

Understand

We study the leading order finite size correction (Luscher's mu-term) associated to moving one-particle states, arbitrary scattering states and finite volume form factors in 1+1 dimensional integrable models.

• Our method is based on the idea that the mu-term is intimately connected to the inner structure of the particles, ie.
• their composition under the bootstrap program.
• We use an appropriate analytic continuation of the Bethe-Yang equations to quantize bound states in finite volume and obtain the leading mu-term (associated to symmetric particle fusions) by calculating the deviations from the predictions of the ordinary Bethe-Yang quantization.