Charm and Beauty Production Cross-Section Measurements in Deep Inelastic Electron-Proton Scattering at HERA

The open charm and beauty production cross-sections in the deep inelastic ep scattering (DIS) at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross-sections are obtained in the kinematic range of negative four-momentum transfer squared of a photon 2.5≤ Q2 ≤2000 GeV2 and the Bjorken scaling variable 3×10¬5 ≤ xBj ≤5×10¬2. The different charm- and beauty-tagging methods are used for the heavy-flavor production study in DIS. The combined method accounts for the correlations of systematic uncertainties, as well as statistical uncertainties among the different datasets. Perturbative QCD (pQCD) calculations are compared to the measured combined data. A NLO QCD analysis is performed using these data together with the combined inclusive deep inelastic scattering cross-sections from HERA. The running charm- and beauty-quark masses are determined as mc(mc) = 1,290+0,046−0,041(exp /fit)+0,062−0,014(model)+0,03−0,031(parametrization) GeV and mb(mb) = 4,049+0,104−0,109(exp /fit)+0,090−0,032(model)+0,001−0,031(parametrization) GeV.

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Precision QCD measurements in DIS at HERA

Modern Physics Letters A ◽

10.1142/s0217732316300251 ◽

2016 ◽

Vol 31 (28) ◽

pp. 1630025

Author(s):

Daniel Britzger

Keyword(s):

Cross Sections ◽

Production Cross ◽

Distribution Functions ◽

Coupling Constants ◽

Charged Current ◽

Heavy Flavor ◽

Parton Distribution Functions ◽

Quark Masses ◽

Insight Into

New and recent results on QCD measurements from the H1 and ZEUS experiments at the HERA ep collider are reviewed. The final results on the combined deep-inelastic neutral and charged current cross-sections are presented and their role in the extractions of parton distribution functions (PDFs) is studied. The PDF fits give insight into the compatibility of QCD evolution and heavy flavor schemes with the data as a function of kinematic variables such as the scale Q2. Measurements of jet production cross-sections in ep collisions provide direct proves of QCD and extractions of the strong coupling constants are performed. Charm and beauty cross-section measurements are used for the determination of the heavy quark masses. Their role in PDF fits is investigated. In the regime of diffractive DIS and photoproduction, dijet and prompt photon production cross-sections provide insights into the process of factorization and the nature of the diffractive exchange.

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Heavy-flavor hadro-production with heavy-quark masses renormalized in the $$ \overline{\mathrm{MS}} $$, MSR and on-shell schemes

Journal of High Energy Physics ◽

10.1007/jhep04(2021)043 ◽

2021 ◽

Vol 2021 (4) ◽

Author(s):

M. V. Garzelli ◽

L. Kemmler ◽

S. Moch ◽

O. Zenaiev

Keyword(s):

Heavy Quark ◽

Cross Sections ◽

Top Quark ◽

Quark Mass ◽

Production Cross ◽

Hadron Collider ◽

Distribution Functions ◽

Heavy Flavor ◽

Parton Distribution Functions ◽

Heavy Quark Mass

Abstract We present predictions for heavy-quark production at the Large Hadron Collider making use of the $$ \overline{\mathrm{MS}} $$ MS ¯ and MSR renormalization schemes for the heavy-quark mass as alternatives to the widely used on-shell renormalization scheme. We compute single and double differential distributions including QCD corrections at next-to-leading order and investigate the renormalization and factorization scale dependence as well as the perturbative convergence in these mass renormalization schemes. The implementation is based on publicly available programs, MCFM and xFitter, extending their capabilities. Our results are applied to extract the top-quark mass using measurements of the total and differential $$ t\overline{t} $$ t t ¯ production cross-sections and to investigate constraints on parton distribution functions, especially on the gluon distribution at low x values, from available LHC data on heavy-flavor hadro-production.

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