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

TL;DR

This paper investigates the potential impact of triangle singularities on the decay width of the $T^+_{cc}$ particle, concluding that a tree-level approximation suffices given current experimental precision.

Contribution

It demonstrates that triangle logarithmic singularities may influence the decay process but that a tree approximation remains adequate for current measurements.

Findings

Triangle singularities could affect decay widths.

Tree approximation is sufficient for current data.

Final state interactions are significant in decay analysis.

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.