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Related papers: Polarized Parton Densities

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To obtain improved parton densities of the proton, we present a new global analysis of deep-inelastic and related hard scattering data including, in particular, the recent measurements of F2 at HERA, of the asymmetry of the rapidity…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. D. Martin , R. G. Roberts , W. J. Stirling

The prospects for a determination of the strong coupling constant $\alpha_s$ via scaling violations of fragmentation functions in deeply inelastic scattering are studied. The statistical error in the case of an integrated luminosity of $250…

High Energy Physics - Phenomenology · Physics 2016-09-06 Dirk Graudenz

We present a new set of parton distributions obtained at NNLO. These differ from the previous sets available at NNLO due to improvements in the theoretical treatment. In particular we include a full treatment of heavy flavours in the region…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Martin , W. J. Stirling , R. S. Thorne , G. Watt

The jet parton correlation has been studied for different cut scenarios and various jet algorithms. These migrations are getting important for measuring the strong coupling constant alpha_s and the NLO gluon density g(xi,Q^2) from jet rates…

High Energy Physics - Experiment · Physics 2007-05-23 Thomas Hadig

I present a determination of longitudinally-polarized parton distribution functions of the proton from inclusive deep-inelastic scattering data: NNPDFpol1.0+. This determination, based on the NNPDF methodology, upgrades a previous analysis,…

High Energy Physics - Phenomenology · Physics 2016-02-17 Emanuele R. Nocera

We study an influence of precise data on uncertainty of polarized parton distribution functions. This analysis includes the SLAC-E155 proton target data which are precise measurements. Polarized PDF uncertainties are estimated by using the…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Hirai

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 present parton distribution functions which include a quantitative estimate of its uncertainties. The parton distribution functions are optimized with respect to deep inelastic proton data, expressing the uncertainties as a density…

High Energy Physics - Phenomenology · Physics 2007-05-23 Walter T. Giele , Stephane A. Keller , David A. Kosower

We report the value of $\alpha_{\rm s}$ obtained from QCD analysis of existing data on deep-inelastic scattering of charged leptons off proton and deuterium and estimate its theoretical uncertainties with particular attention paid to impact…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Alekhin

The main goals of `spin physics' are recalled, and some theoretical and phenomenological aspects of longitudinally polarized deep inelastic scattering and other hard processes are reviewed. The spin dependent parton densities of protons and…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Stratmann

The strong coupling alpha_s(M_Z^2) has been measured using hadronic decays of Z^0 bosons collected by the SLD experiment at SLAC. The data were compared with QCD predictions both at fixed order, O(alpha_s^2), and including resummed analytic…

High Energy Physics - Experiment · Physics 2008-11-26 K. Abe

A next-to-leading order QCD analysis of spin asymmetries and structure functions in polarized deep inelastic lepton nucleon scattering is presented within the framework of the radiative parton model. A consistent NLO formulation of the…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Gluck , E. Reya , M. Stratmann , W. Vogelsang

We use the recent estimates of NNLO splitting functions, made by van Neerven and Vogt, to perform exploratory fits to deep inelastic and related hard scattering data. We investigate the hierarchy of parton distributions obtained at LO, NLO…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

In the past year, polarized deep inelastic scattering experiments at CERN and SLAC have obtained structure function measurements off proton, neutron and deuteron targets at a level of precision never before achieved. The measurements can be…

High Energy Physics - Phenomenology · Physics 2010-04-06 T. Gehrmann , W. J. Stirling

We discuss uncertainties in the extraction of parton distributions from global analyses of DIS and related data. We present conservative sets of partons, at both NLO and NNLO, which are stable to x,Q^2,W^2 cuts on the data. We give the…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. D. Martin , R. G. Roberts , W. J. Stirling , R. S. Thorne

We investigate the uncertainty in the value of the strong coupling $\alpha_S(M_Z^2)$ when allowing it to be a free parameter in the recent MMHT global analyses of deep-inelastic and related hard scattering data that was undertaken to…

High Energy Physics - Phenomenology · Physics 2015-10-28 L. A. Harland-Lang , A. D. Martin , P. Motylinski , R. S. Thorne

The impact of the recent very precise CLAS and COMPASS g_1/F_1 data on polarized parton densities and higher twist effects is discussed. We demonstrate that the low Q^2 CLAS data improve essentially our knowledge of higher twist corrections…

High Energy Physics - Phenomenology · Physics 2007-07-12 Elliot Leader , Aleksander V. Sidorov , Dimiter B. Stamenov

Deep inelastic scattering data on $F_2$ structure function obtained by BCDMS, SLAC and NMC collaborations in fixed-target experiments were analyzed in the non-singlet approximation with next-to-next-to-leading-order accuracy. The strong…

High Energy Physics - Phenomenology · Physics 2015-09-02 A. V. Kotikov , V. G. Krivokhizhin , B. G. Shaikhatdenov

The $\rho$ meson polarized generalized parton distribution functions, its structure functions $g_1$ and $g_2$ and its axial form factors ${\tilde G}_{1,2}$ are studied based on a light-front quark model for the first time. Comparing our…

High Energy Physics - Phenomenology · Physics 2019-02-06 Bao-Dong Sun , Yu-Bing Dong

We present a determination of a set of polarized parton distributions (PDFs) of the nucleon, at next-to-leading order, from a global set of longitudinally polarized deep-inelastic scattering data: NNPDFpol1.0. The determination is based on…

High Energy Physics - Phenomenology · Physics 2013-04-01 The NNPDF Collaboration , Richard D. Ball , Stefano Forte , Alberto Guffanti , Emanuele R. Nocera , Giovanni Ridolfi , Juan Rojo
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