Puzzles of excited charm meson masses

TL;DR

This paper analyzes the masses of low-lying charm mesons, using theoretical predictions to address discrepancies with experimental data and emphasizing the need for new measurements.

Contribution

It applies heavy hadron chiral perturbation theory to predict non-strange excited charm meson masses, highlighting inconsistencies with experimental values.

Findings

Predicted masses are smaller than experimental measurements.

Critical assessment of current experimental data.

Calls for new experimental investigations.

Abstract

We attempt a comprehensive analysis of the low lying charm meson states which present several puzzles, including the poor determination of masses of several non-strange excited mesons. We use the well-determined masses of the ground states and the strange first excited states to `predict' the mass of the non-strange first excited state in the framework of heavy hadron chiral perturbation theory, an approach that is complementary to the well-known analysis of Mehen and Springer. This approach points to values for the masses of these states that are smaller than the experimental determinations. We provide a critical assessment of these mass measurements and point out the need for new experimental information.