Radiation of a Massless Closed String from Interacting D$p$-branes with Background Fields in the Superstring Theory

In the context of the superstring theory, we calculate the radiation amplitude of a general massless closed string from the interaction of two parallel D$p$-branes. The background field is the constant antisymmetric tensor $B_{\mu\nu}$, and the branes have been equipped with the different $U(1)$ gauge fields. For the large distance of the branes, the Kalb-Ramond emission will be investigated.