Strong decays of the newly observed $D(2550)$, $D(2600)$, $D(2750)$, and $D(2760)$

TL;DR

This paper investigates the strong decay properties of four newly observed D mesons using a constituent quark model, proposing specific quantum state assignments and explaining their overlapping resonances and decay behaviors.

Contribution

It provides a detailed analysis of the decay properties and quantum state identifications of the D(2550), D(2600), D(2750), and D(2760) mesons, including the suggestion of overlapping resonances.

Findings

D(2760) identified as $1^3D_3$ with $J^P=3^-$

D(2750) likely a high-mass mixed state $|1D_2'>_H$ ($J^P=2^-$)

D(2600) favors the mixed state $|(SD)_1>_L$ ($J^P=1^-$)

Abstract

The strong decay properties of the newly observed $D(2550)$, $D(2600)$, $D(2750)$ and $D(2760)$ are studied in a constituent quark model. It is predicted that the $D(2760)$ and $D(2750)$ seem to be two overlapping resonances. The $D(2760)$ could be identified as the $1^3D_3$ with $J^P=3^-$, while the $D(2750)$ is most likely to be the high-mass mixed state $|1{D_2}'>_H$ ($J^P=2^-$) via the $1^1D_2$-$1^3D_2$ mixing. The $D(2600)$ favors the low-mass mixed state $|(SD)_1>_L$ $(J^P=1^-)$ via the $1^3D_1$-$2^3S_1$ mixing. The $D(2550)$ as the $2^1S_0$ assignment bears controversies for its too broad width given in experiments.