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Related papers: Determination of $\alpha_s$ and the Nucleon Spin D…

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The recent series of experiments on polarized lepton-nucleon scattering have provided a strange new twist in the story of the nucleon, some of whose aspects are reviewed in these lectures. In the first lecture, we review some issues arising…

High Energy Physics - Phenomenology · Physics 2007-05-23 John Ellis , Marek Karliner

We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. De Roeck , A. Deshpande , V. W. Hughes , J. Lichtenstadt , G. Radel

This paper contains three parts relating to the nucleon spin structure in a simple picture of the nucleon: (i) The polarized gluon distribution in the proton is dynamically predicted starting from a low scale by using a nonlinear QCD…

High Energy Physics - Phenomenology · Physics 2015-10-14 Wei Zhu , Jianhong Ruan

We extract polarized parton distribution functions (PPDFs), referred to as "KTA17," together with the highly correlated strong coupling $\alpha_s$ from recent and up-to-date $g_1$ and $g_2$ polarized structure functions world data at…

High Energy Physics - Phenomenology · Physics 2017-04-07 Hamzeh Khanpour , Sara Taheri Monfared , S. Atashbar Tehrani

The QCD coupling $\alpha_s$ is extracted from the energy evolution of the first two moments (multiplicity and mean) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. Comparisons of the experimental…

High Energy Physics - Phenomenology · Physics 2015-05-20 David d'Enterria , and Redamy Pérez-Ramos

Quantum statistical distributions for the partons provide a fair description of deep inelastic scattering data at $Q^2 = 3$ and $10 (GeV/c)^2$. The study of the polarized structure functions seems to suggest an alternative possible solution…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. Buccella , G. Miele , N. Tancredi

The status of Compton scattering by the nucleon at energies of the first and second resonance is summarized. In addition to a general test of dispersion theories and a precise determination of polarizabilities, the validities of four…

Nuclear Experiment · Physics 2013-06-26 Martin Schumacher

We compute the order $\alpha_s$ QCD corrections to the density matrix for the decay of a neutral Higgs boson $\phi$ with (in)definite CP parity into a quark antiquark pair, respectively the QED corrections for the decay into a pair of…

High Energy Physics - Phenomenology · Physics 2016-08-24 W. Bernreuther , A. Brandenburg , M. Flesch

We propose a novel method to determine the strong coupling of quantum chromodynamics (QCD) and fix its running behavior at all scales by using the Bjorken sum rules (BSR). The BSR defines an effective coupling $\alpha^{g_1}_s(Q)$ which…

High Energy Physics - Phenomenology · Physics 2025-01-28 Qing Yu , Xing-Gang Wu , Hua Zhou , Jian-Ming Shen

The review of current experimental situation in the measurements of the first moment $\Gamma_{p,n}$ of spin dependent nucleon structure functions $g_{1;p,n}(x,Q^2)$ is presented. The results of the calculations of twist-4 corrections to…

High Energy Physics - Phenomenology · Physics 2015-06-25 B. L. Ioffe

New QCD sum rules for nucleons in nuclear matter are derived from a mixed correlation function of spin-1/2 and spin-3/2 interpolating fields. These sum rules allow a determination of the scalar self-energy of the nucleon independent of the…

Nuclear Theory · Physics 2007-05-23 Derek B. Leinweber , Xuemin Jin , R. J. Furnstahl

The decomposition of the nucleon spin into that of quarks and gluons is related to twist-two GPDs according to Ji sum rule. Further decomposition into the helicity and the orbital angular momentum inevitably requires twist-three GPDs. In…

High Energy Physics - Phenomenology · Physics 2015-06-05 Yoshitaka Hatta , Shinsuke Yoshida

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 experiment E155 at SLAC measured the spin structure functions g_1 and g_2 of the proton and deuteron. The experiment used deep inelastic scattering of 48.3 GeV longitudinally polarized electrons incident on polarized solid ^{15}NH_3 and…

High Energy Physics - Experiment · Physics 2007-05-23 Gregory S. Mitchell

We report on a precision measurement of the neutron spin structure function $g^n_1$ using deep inelastic scattering of polarized electrons by polarized ^3He. For the kinematic range 0.014<x<0.7 and 1 (GeV/c)^2< Q^2< 17 (GeV/c)^2, we obtain…

High Energy Physics - Experiment · Physics 2012-08-03 The SLAC E154 Collaboration , K. Abe

An analytic calculation of the differential cross section for elastic Compton scattering on the deuteron at photon energies \omega in the range of 25-50 MeV is presented to next-to-next-to-leading order, i.e. to an accuracy of \sim 3%. The…

Nuclear Theory · Physics 2009-11-06 Harald W. Griesshammer , Gautam Rupak

The QCD coupling alpha_s is determined at NLO*+NMLLA accuracy from the comparison of experimental jet data to theoretical predictions of the energy-evolution of the parton-to-hadron fragmentation function moments (multiplicity, peak, width,…

High Energy Physics - Phenomenology · Physics 2014-10-20 David d'Enterria , Redamy Pérez-Ramos

We review the potential impact of neutrino data on the determination of the spin structure of the nucleon. We show that a flavour decomposition of the parton structure of the nucleon as required by present-day precision phenomenology could…

High Energy Physics - Phenomenology · Physics 2017-08-23 Stefano Forte

The QCD sum rules for spin-dependent nucleon-nucleon interactions are formulated and their physical implications are studied. The basic object of the study is the correlation function of the nucleon interpolating field, where the matrix…

Nuclear Theory · Physics 2009-10-31 Y. Kondo , O. Morimatsu

We report on measurements of the neutron spin asymmetries $A_{1,2}^n$ and polarized structure functions $g_{1,2}^n$ at three kinematics in the deep inelastic region, with $x=0.33$, 0.47 and 0.60 and $Q^2=2.7$, 3.5 and 4.8 (GeV/c)$^2$,…

Nuclear Experiment · Physics 2009-09-29 X. Zheng