Precise charm-quark mass from deep-inelastic scattering

TL;DR

This paper determines the charm-quark mass using deep-inelastic scattering data from HERA, employing a comprehensive global analysis that accounts for correlations with proton structure parameters, achieving competitive accuracy.

Contribution

It provides a precise charm-quark mass measurement in the MSbar scheme from HERA data, including correlations with proton structure and QCD parameters, at NLO and approximate NNLO accuracy.

Findings

Charm-quark mass at NLO: 1.15 GeV with 0.04 GeV experimental uncertainty.

Charm-quark mass at approximate NNLO: 1.24 GeV with combined uncertainties.

Analysis accounts for correlations with gluon distribution and alpha_s, improving precision.

Abstract

We present a determination of the charm-quark mass in the MSbar scheme using the data combination of charm production cross section measurements in deep-inelastic scattering at HERA. The framework of global analyses of the proton structure accounts for all correlations of the charm-quark mass with the other non-perturbative parameters, most importantly the gluon distribution function in the proton and the strong coupling constant alpha_s(M_Z). We obtain at next-to-leading order in QCD the value m_c(m_c) = 1.15 +- 0.04 (exp) +0.04/-0.00 (scale) GeV and at approximate next-to-next-to-leading order m_c(m_c) = 1.24 +- 0.03 (exp) +0.03/-0.02 (scale) +0.00/-0.07 (theory) GeV with an accuracy competitive with other methods.