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Related papers: A Variable Flavour Number Scheme at NNLO

200 papers

New, radiatively generated, NLO quark (u,d,s,c,b) and gluon densities in a real, unpolarized photon are presented. We perform three global fits, based on the NLO DGLAP evolution equations for Q^2>1 GeV^2, to all the available structure…

High Energy Physics - Phenomenology · Physics 2014-11-17 F. Cornet , P. Jankowski , M. Krawczyk

We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in…

High Energy Physics - Phenomenology · Physics 2015-06-05 H. Khanpour , Ali N. Khorramian , S. Atashbar Tehrani

We perform a global fit of parton distribution functions (PDFs) together with the strong coupling constant $\alpha_s$ and the quark masses $m_c$, $m_b$ and $m_t$ at next-to-leading order (NLO) in QCD. The analysis applies the…

High Energy Physics - Phenomenology · Physics 2018-09-10 S. Alekhin , J. Blümlein , S. Moch

We discuss a variable flavor number scheme (VFNS) for final state jets which can account for the effects of arbitrary finite quark masses in inclusive jet observables. The scheme is a generalization of the VFNS scheme for PDFs applied to…

High Energy Physics - Phenomenology · Physics 2015-01-05 Andre H. Hoang , Piotr Pietrulewicz , Daniel Samitz

The matching relations in the unpolarized and polarized variable flavor number scheme at three-loop order are presented in the single-mass case. They describe the process of massive quarks becoming light at large virtualities $Q^2$. In this…

High Energy Physics - Phenomenology · Physics 2025-10-03 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

We report on an update of the next-to-next-to-leading order (NNLO) ABKM09 parton distributions functions. They are obtained with the use of the combined HERA collider Run I inclusive deep-inelastic scattering (DIS) data and the partial NNLO…

High Energy Physics - Phenomenology · Physics 2010-11-19 S. Alekhin , J. Blumlein , S. Moch

Where appropriate, the abbreviation 'VFNS' is replaced by 'CSN' to indicate the scheme using massive heavy quark coefficient functions proposed in this paper. The text below Eq. (2.13) and between Eqs. (2.33) and (2.36) has been…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Chuvakin , J. Smith , W. L. van Neerven

We present the CTEQ6HQ parton distribution set which is determined in the general variable flavor number scheme which incorporates heavy flavor mass effects; hence, this set provides advantages for precision observables which are sensitive…

High Energy Physics - Phenomenology · Physics 2015-06-25 Stefan Kretzer , Fredrick I. Olness

We address quarkonium formation at moderate to large transverse momenta, where the single-parton collinear fragmentation prevails over the short-distance emission, directly from the hard sub-scattering, of the constituent heavy-quark pair.…

High Energy Physics - Phenomenology · Physics 2024-05-15 Francesco Giovanni Celiberto

I review the various methods for taking account of finite quark masses in DIS and related processes. I pay particular attention to the so-called variable flavour number schemes (VFNS) which are designed to extrapolate smoothly from the…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. S. Thorne

We determine a new set of parton distribution functions (ABMP16), the strong coupling constant $\alpha_s$ and the quark masses $m_c$, $m_b$ and $m_t$ in a global fit to next-to-next-to-leading order (NNLO) in QCD. The analysis uses the…

High Energy Physics - Phenomenology · Physics 2017-07-26 S. Alekhin , J. Blümlein , S. Moch , R. Placakyte

We discuss the heavy-quark contribution to deep inelastic scattering in the scheme with $n_f=3,4,5$ fixed flavors. Based on the recent ABM11 PDF analysis of world data for deep-inelastic scattering and fixed-target data for the Drell-Yan…

High Energy Physics - Phenomenology · Physics 2015-06-04 S. Alekhin , J. Bluemlein , S. Moch

We determine the parton distribution functions (PDFs) in a next-to-next-to-leading order (NNLO) QCD-analysis of the inclusive neutral-current deep-inelastic-scattering (DIS) world data combined with the neutri{-}no-nucleon DIS di-muon data…

High Energy Physics - Phenomenology · Physics 2010-05-25 S. Alekhin , J. Blümlein , S. Klein , S. Moch

We compare the results of the fixed-flavor scheme calculation of Laenen, Riemersma, Smith and van Neerven with the variable-flavor scheme calculation of Aivazis, Collins, Olness and Tung for the case of neutral-current (photon-mediated)…

High Energy Physics - Phenomenology · Physics 2011-01-25 Fredrick I. Olness , Stephan T. Riemersma

We discuss massive quark effects in the endpoint region $x \to 1$ of inclusive deep inelastic scattering, where the hadronic final state is collimated and thus represents a jet. In this regime heavy quark pairs are generated via secondary…

High Energy Physics - Phenomenology · Physics 2016-03-02 Andre H. Hoang , Piotr Pietrulewicz , Daniel Samitz

We present a determination of parton distribution functions (ABM11) and the strong coupling constant alpha_s at next-to-leading order and next-to-next-to-leading order (NNLO) in QCD based on world data for deep-inelastic scattering and…

High Energy Physics - Phenomenology · Physics 2015-06-04 S. Alekhin , J. Blumlein , S. Moch

We discuss some theoretical uncertainties in the calculation of the cross section for charm production in charged current deep inelastic neutrino scattering related to ambiguities in the treatment of terms which are singular in the limit of…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. Kramer , B. Lampe , H. Spiesberger

We compare the results of the fixed-flavor scheme calculation of Laenen, Riemersma, Smith and van Neerven with the variable-flavor scheme calculation of Aivazis, Collins, Olness and Tung for neutral-current (photon-mediated) heavy-flavor…

High Energy Physics - Phenomenology · Physics 2007-05-23 Fredrick I. Olness , Stephan T. Riemersma

The structure of the phase diagram of strongly interacting matter at moderate densities is calculated within a 3-flavor NJL-type quark model with realistic quark masses. We focus on the influence of the selfconsistently determined effective…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Oertel , M. Buballa

We evaluate the neutrino nucleon charged current cross section at next-to-leading order in quantum chromodynamic corrections in the variable flavor number scheme and the fixed flavor number scheme, taking into account quark masses. The…

High Energy Physics - Phenomenology · Physics 2014-11-20 Yu Seon Jeong , M. H. Reno