NLO Effects for Doubly Heavy Baryon in QCD Sum Rules

TL;DR

This paper uses QCD sum rules to calculate NLO effects on the mass of the doubly heavy baryon $ ext{Xi}_{cc}^{++}$, improving theoretical accuracy and aligning predictions with experimental data.

Contribution

It provides the first NLO calculation of the perturbative contribution for the doubly heavy baryon in QCD sum rules, reducing theoretical uncertainties.

Findings

NLO correction improves scheme and scale dependence.

Estimated baryon mass aligns with LHCb measurements.

Theoretical uncertainties are better controlled at NLO.

Abstract

With the QCD sum rules approach, we study the newly discovered doubly heavy baryon $\Xi_{cc}^{++}$. We analytically calculate the next-to-leading order (NLO) contribution to the perturbative part of $J^{P} = \frac{1}{2}^{+}$ baryon current with two identical heavy quarks, and then reanalyze the mass of $\Xi_{cc}^{++}$ at the NLO level. We find that the NLO correction significantly improves both scheme dependence and scale dependence, whereas it is hard to control these theoretical uncertainties at leading order. With the NLO contribution, the baryon mass is estimated to be $m_{\Xi_{cc}^{++}} = 3.66_{-0.10}^{+0.08} \text{~GeV}$, which is consistent with the LHCb measurement.