New experimental tests of sum rules for charmed baryon masses

TL;DR

This paper uses new experimental data to test sum rules for charmed baryon masses, confirming some predictions while highlighting discrepancies that challenge existing quark models.

Contribution

It provides updated tests of model-independent sum rules for charmed baryons and offers improved mass predictions, revealing significant isospin breaking issues.

Findings

Sum rules for medium-strong mass differences are well satisfied.

New measurements improve the prediction of the $ ext{Omega}_c^{*0}$ mass.

Significant disagreement in isospin breaking sum rule for $ ext{Sigma}_c$ mass splittings.

Abstract

New experimental measurements are used to test model independent sum rules for charmed baryon masses. Sum rules for medium-strong mass differences are found to be reasonably well satisfied with increasing accuracy, and the new measurements permit an improved prediction of $2778\pm 9$ MeV for the mass of the $\Omega_c^{*0}$. But an isospin breaking sum rule for the $\Sigma_c$ mass splittings is still in significant disagreement posing a serious problem for the quark model of charmed baryons. Individual $\Sigma_c$ mass splittings are investigated, using the new CLEO measurement of the $\Xi_c^\prime$ mass splitting, but the accuracy is not yet sufficient for a good test.