Explicit Derivation of New Hyper-Kahler metric

Using the harmonic superspace techniques in D=2 N=4, we present an explicit derivation of a new hyper-Kahler metric associated to the Toda like self interaction $H ^{4+}(\omega, u)= (\frac{\xi^{++}}{\lambda})^{2}\exp(2\lambda \omega)$. Some important features are also discussed.