English
Related papers

Related papers: Spin-Dependent Twist-Four Matrix Elements from g_1…

200 papers

We present a measurement of the deuteron spin-dependent structure function g1d based on the data collected by the COMPASS experiment at CERN during the years 2002-2004. The data provide an accurate evaluation for Gamma_1^d, the first moment…

High Energy Physics - Experiment · Physics 2008-11-26 The COMPASS Collaboration , V. Yu. Alexakhin

Higher-twist effects in the low-order moments of the longitudinal and transverse structure functions of proton and deuteron have been analyzed using available phenomenological fits of existing data in the Q**2 range between 1 and 20…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Ricco , S. Simula

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

We discuss the QCD effects of the higher-twist operators in the nucleon spin-dependent structure functions measured by the polarized deep inelastic leptoproduction. We particularly study the renormalization of the twist-3 and twist-4…

High Energy Physics - Phenomenology · Physics 2016-09-01 Tsuneo Uematsu

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

The structure functions g1p and g1n have been measured over the range 0.014 < x < 0.9 and 1 < Q2 < 40 GeV2 using deep-inelastic scattering of 48 GeV longitudinally polarized electrons from polarized protons and deuterons. We find that the…

High Energy Physics - Phenomenology · Physics 2016-09-06 The E155 Collaboration , P. L. Anthony

We present the first measurement of the Q^2-dependence of the neutron spin structure function g_2^n at five kinematic points covering 0.57 (GeV/c)^2 <= Q^2 <= 1.34 (GeV/c)^2 at x~0.2. Though the naive quark-parton model predicts g_2=0,…

Nuclear Experiment · Physics 2008-11-26 K. Kramer

Nuclear effects in the spin-dependent structure function $g_1$ of the deuteron are studied in the kinematics of future experiments at CEBAF, ($\nu \leq 3~GeV, ~Q^2 \leq 2~GeV^2$). The magnitude of nuclear effects is found to be…

Nuclear Theory · Physics 2015-06-26 C. Ciofi degli Atti , S. Scopetta , A. Yu. Umnikov , L. P. Kaptari

The higher twist corrections $h^N(x)/Q^2$ to the spin dependent proton and neutron $g_1$ structure functions are extracted from the world data on $g_1(x,Q^2)$ in a model independent way and found to be non-negligible. Their role in…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Leader , A. V. Sidorov , D. B. Stamenov

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q^2 = 1.3 GeV^2. Using the Jefferson Lab polarized electron beam, a spectrometer,…

The spin dependent structure function, g2ww(x,Q^2), is calculated in the valon model. A simple approach is given for the determination of the twist-3 part of the g2(x, Q^2) in Mellin space; thus, enabling us to obtain the full transverse…

High Energy Physics - Phenomenology · Physics 2015-08-13 Z. Alizadeh Yazdi , A. Tahamtan , F. Taghavi-Shahri , F. Arash , M. E. Zomorrodian

The nuclear effects in the spin-dependent structure function $g_1$ of the deuteron are studied in the kinematics of future experiments at CEBAF, ($\nu \leq 3~GeV, ~Q^2 \leq 2~GeV^2$). The magnitude of the nuclear effects is found to be…

Nuclear Theory · Physics 2007-05-23 C. Ciofi degli Atti , S. Scopetta , A. Yu. Umnikov , L. P. Kaptari

The spin-structure functions $g_1$ and $g_2$, and the spin-dependent partial cross-section $\sigma_\mathrm{TT}$ have been extracted from the polarized cross-sections differences, $\Delta…

We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer ($Q^2$ = 0.27 -- 1.3 (GeV/c)$^2$) and final hadronic state mass in the nucleon resonance region ($W$ = 1.08…

High Energy Physics - Experiment · Physics 2019-08-15 J. Yun , S. E. Kuhn , G. E. Dodge , T. A. Forest , M. Taiuti

In this paper, we show what we can learn from the CEBAF experiments on spin-structure functions, and the transition from the Drell-Hearn-Gerasimov sum rule in the real photon limit to the spin dependent sum rules in the deep inelastic…

High Energy Physics - Phenomenology · Physics 2009-10-28 Zhenping Li , Zhujun Li

Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)**2. We compute for the first time low-order…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Osipenko , S. Simula , W. Melnitchouk , P. Bosted , V. Burkert , E. Christy , K. Griffioen , C. Keppel , S. Kuhn , G. Ricco

We compute the nucleon matrix elements of QCD operators of twist 3 and 4 in the instanton vacuum. We consider the operators determining 1/Q^2-power corrections to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. The nucleon is…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Balla , M. V. Polyakov , C. Weiss

We calculate the spin dependent structure functions g_{1}(x) and g_{2}(x) of the proton and neutron. Our calculation uses the meson cloud model of nucleon structure, which has previously given a good description of the HERMES data on…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. Bissey , F. G. Cao , A. I. Signal

We present a precise measurement of the deuteron longitudinal spin asymmetry A_1^d and of the deuteron spin-dependent structure function g_1^d at Q^2 < 1 GeV^2 and 4*10^-5 < x < 2.5*10^-2 based on the data collected by the COMPASS…

High Energy Physics - Experiment · Physics 2008-11-26 The Compass Collaboration , E. S. Ageev

The spin dependent deuteron structure functions are investigated in the relativistic model of deuteron. It is shown that the deuteron structure function $g_{2}(X)$ can be considered properly only in the infinite momentum frame where the…

High Energy Physics - Phenomenology · Physics 2009-10-28 N. L. Ter-Isaakyan