N=2 Supersymmetric QCD and Integrable Spin Chains: Rational Case N_f < 2N_c

The form of the spectral curve for $4d$ $N=2$ supersymmetric Yang-Mills theory with matter fields in the fundamental representation of the gauge group suggests that its $1d$ integrable counterpart should be looked for among (inhomogeneous) $sl(2)$ spin chains with the length of the chain being equal to the number of colours $N_c$. For $N_f < 2N_c$ the relevant spin chain is the simplest $XXX$-model, and this identification is in agreement with the known results in Seiberg-Witten theory.