An exact formula for default swaptions' pricing in the SSRJD stochastic   intensity model
  We develop and test a fast and accurate semi-analytical formula for single-name default swaptions in the context of a shifted square root jump diffusion (SSRJD) default intensity model. The model can be calibrated to the CDS term structure and a few default swaptions, to price and hedge other credit derivatives consistently. We show with numerical experiments that the model implies plausible volatility smiles. 
Damiano Brigo and Naoufel El-Bachir