Triangle singularity as the origin of X0(2900) and X1(2900) observed in B+→D+D-K+

The LHCb collaboration recently reported the observation of a narrow peak in the D-K+ invariant mass distributions from the B+-> D+D-K+ decay. The peak is parameterized in terms of two resonances X0(2900) and X1(2900) with the quark contents csud, and their spin-parity quantum numbers are 0+ and 1-, respectively. We investigate the rescattering processes which may contribute to the B+-> D+D-K+ decays. It is shown that the D-K+ rescattering via the chi c1K+D- loop and the D10K0 rescattering via the DsJ+D10K0 loop can simulate the X0(2900) and X1(2900) with consistent quantum numbers. Such phenomena are due to the analytical property of the scattering amplitudes with the triangle singularities located to the vicinity of the physical boundary.