Final state interactions inD0→K0K0

It is believed that the production rate of $D^0\to K^0{K}^0$ is almost solely determined by final state interactions (FSIs) and hence provides an ideal place to test FSI models. Here we examine model calculations of the contributions from s-channel resonance $f_J\mathrm{}\left(1710\right)\mathrm{}$ and t-channel exchange to FSI effects in $D^0\to K^0{K}^0$. The contribution from s-channel $f_0\mathrm{}\left(1710\right)\mathrm{}$ is small. For the t-channel FSI evaluation, we employ the one-particle-exchange model and Regge model, respectively. The results from the two methods are roughly consistent with each other and can reproduce the large rate of $D^0\to K^0{K}^0$ reasonably well.