Triangle singularities in the $T^+_{cc}\to D^{*+}D^0\to\pi^+D^0D^0$ decay width

Abstract

The values of the masses of the particles involved in the decay of $T^+_{cc}\to D^{*+}D^0\to\pi^+D^0D^0$ suggest that due to the final state interactions in the transition vertex $T^+_{cc}\to D^{*+}D^0 $ there may be triangle logarithmic singularities. We discuss their possible role and show that the tree approximation for calculating the decay widths $T^+_{cc}\to(D^{*+}D^0+D^{*0}D^+)\to\pi^+D^0D^0$, $\pi^0D^0 D^+$, $\gamma D^0D^+$ is quite sufficient at the current level of measurement accuracy.