Precise charm-quark mass from deep-inelastic scattering

We present a determination of the charm-quark mass in the MS^¯ 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 α_s(M_Z). We obtain at next-to-leading order in QCD the value m_c(m_c)=1.15±0.04(exp)_−0.00^+0.04(scale) GeV and at approximate next-to-next-to-leading order m_c(m_c)=1.24±0.03(exp)_−0.02^+0.03(scale)_−0.07^+0.00(theory) GeV with an accuracy competitive with other methods