Exact electron addition spectrum in 1D supersymmetric t-J model with 1/r2 interaction

The electron addition spectrum A+(k,ω) is obtained analytically for the one-dimensional supersymmetric t-J model with 1/r2 interaction. The spectral function A+(k,ω) has a simple analytic form with contributions from one spinon, one holon and one antiholon all of which obey fractional statistics. The upper edge of A+(k,ω) in the (k,ω) plane includes a delta-function peak which reduces to that of the single-electron band in the low-density limit. This peak is interpreted as a result of spin-charge recombination. Our derivation relies on the ideas of Yangian highest weight states and Jack polynomials adapted to the SU(1,1) supersymmetry