The Properties of $D^{*}_{s1}(2700)^{+}$

TL;DR

This paper analyzes the properties of the $D^{*}_{s1}(2700)^{+}$ particle and proposes it is better described as two overlapping resonances, a $2^3S_1$ state and a 1D state, rather than a single state.

Contribution

It introduces a new interpretation of $D^{*}_{s1}(2700)^{+}$ as two overlapping resonances, based on mass, decay modes, and experimental data comparison.

Findings

$D^{*}_{s1}(2700)^{+}$ may be two resonances, not one.

Both states are around 2700 MeV with broad decay widths.

Current experiments cannot distinguish the two overlapping states.

Abstract

The new particle $D^{*}_{s1}(2700)^{+}$ has stimulated many attentions. There are different assignments of its inherent properties. It may be a $2^3S_1$, $1^3D_1$ or the mixture of $2^3S_1-1^3D_1$ $c\bar s$ $1^-$ state. By considering its mass, decay modes, full width, production rate, and comparing with current experimental data, we point out that there is another more reasonable assignment: $D^{*}_{s1}(2700)^{+}$ could be identified as two resonances, one of which is a $2^3S_1$ state, another is a 1D state, and both are $c\bar s$ $1^-$ states. The two states have very close masses, which are around 2700 MeV, and both have broad decay widths. So in experiments, the overlapping of $DK$ or $D^*K$ invariant mass distribution coming from their decays is found, but the current experiments could not distinguish these two resonances and reported one particle.