Impact of the heavy-quark matching scales in PDF fits
Authors:
- V. Bertone,
- D. Britzger,
- S. Camarda,
- A. Cooper-Sarkar,
- A. Geiser,
- F. Giuli,
- A. Glazov,
- E. Godat,
- A. Kusina,
- A. Luszczak,
- F. Lyonnet,
- F. Olness,
- R. Plačakytė,
- V. Radescu,
- I. Schienbein,
- O. Zenaiev
Abstract
We investigate the impact of displaced heavy-quark matching scales in a global fit. The heavy-quark matching scale μm determines at which energy scale μ the QCD theory transitions from NF to NF+1 in the variable flavor number scheme (VFNS) for the evolution of the parton distribution functions (PDFs) and strong coupling αS(μ) . We study the variation of the matching scales, and their impact on a global PDF fit of the combined HERA data. As the choice of the matching scale μm effectively is a choice of scheme, this represents a theoretical uncertainty, ideally, we would like to see minimal dependence on this parameter. For the transition across the charm quark (from NF=3 to 4), we find a large μm=μc dependence of the global fit χ2 at NLO, but this is significantly reduced at NNLO. For the transition across the bottom quark (from NF=4 to 5), we have a reduced μm=μb dependence of the χ2 at both NLO and NNLO as compared to the charm. This feature is now implemented in xFitter 2.0.0, an open source QCD fit framework.
- Record ID
- CUT0ec00922cac84d1a818be6b1e0dbcf66
- Publication categories
- ;
- Author
- Journal series
- European Physical Journal C, ISSN 1434-6044, e-ISSN 1434-6052
- Issue year
- 2017
- Vol
- 77
- No
- 12
- Pages
- 1-14
- Article number
- 837
- Other elements of collation
- rys.; tab.; wykr.; Bibliografia (na s.) - 13-14; Bibliografia (liczba pozycji) - 49; Oznaczenie streszczenia - Abstr.; Numeracja w czasopiśmie - Vol. 77, Iss. 12
- Keywords in English
- heavy quark, parton distribution function, HERA data, the matching scales
- DOI
- DOI:10.1140/epjc/s10052-017-5407-3 Opening in a new tab
- URL
- https://link.springer.com/article/10.1140/epjc/s10052-017-5407-3 Opening in a new tab
- Related project
- wyjazd do zagranicznego ośrodka naukowego w Niemczech w celu realizacji projektu pt. "Wyznaczenie nowych rozkładów partonowych w nukleonach i jądrach w ramach chromodynamiki kwantowej". . Project leader at PK: , ,
Projekty finansowane przez MNiSW - Language
- eng (en) English
- License
- Score (nominal)
- 40
- Additional fields
- Indeksowana w: Web of Science, Scopus
- Uniform Resource Identifier
- https://cris.pk.edu.pl/info/article/CUT0ec00922cac84d1a818be6b1e0dbcf66/
- URN
urn:pkr-prod:CUT0ec00922cac84d1a818be6b1e0dbcf66
* presented citation count is obtained through Internet information analysis, and it is close to the number calculated by the Publish or PerishOpening in a new tab system.