Related papers: Transverse Spin Structure Function g2(x, Q2 ) in t…
The spin structure function $g_1^p$ of the proton is studied in a two component framework, where the perturbative evolution of parton distributions and nonperturbative vector meson dominance model are used. We predict the $g_1^p$ asymmetric…
Using recently derived relations between spin-dependent nuclear and nucleon g_1 and g_2 structure functions at finite Q^2, we study nuclear effects in 3He in the nucleon resonance and deep inelastic regions. Comparing the finite-Q^2 results…
We consider the one-loop factorization of the simplest twist-three process: inclusive deep-inelastic scattering of longitudinally-polarized leptons on a transversely-polarized nucleon target. By studying the Compton amplitudes for certain…
We measured the $g_1$ spin structure function of the deuteron at low $Q^{2}$, where QCD can be approximated with chiral perturbation theory ($\chi$PT). The data cover the resonance region, up to an invariant mass of $W\approx1.9$~GeV. The…
We compute the contribution of twist-2 and twist-3 parton distribution functions to the small-$b$ expansion for transverse momentum dependent (TMD) distributions at all powers of $b$. The computation is done by the twist-decomposition…
We analyse the proton and deutron data on spin dependent asymmetry $A_1(x,Q^2)$ supposing the DIS structure functions $g_1(x,Q^2)$ and $F_3(x,Q^2)$ have the similar $Q^2$-dependence.
We present preliminary results on the leading-twist transverse-momentum-dependent (TMD) gluon linearity function, which is directly connected to nucleon transverse-spin asymmetries originating from the density of linearly-polarized gluons.…
We have measured the spin-dependent structure function $g_1^p$ in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003 < x < 0.7$ and $1 GeV^2 < Q^2 < 60 GeV^2$. A next-to-leading order…
Quark mass effects are clarified in the parton model approach to the transversely polarized nucleon structure function. The special propagator technique is employed to obtain manifestly gauge invariant results and extract the buried…
We show that the transverse momentum dependent transversity function is proportional to the longitudinal polarization of a quark in a transversely polarized proton. This result suggests an alternative, convenient method for determining…
We report progresses on leading-twist transverse-momentum-dependent (TMD) gluon distributions, calculated in a spectator-model framework for the parent nucleon. We encode in our formalism a fit-based parameterization for the spectator-mass…
We perform an extensive study of the scale dependence of flavor-singlet contributions to the structure function g_2(x,Q^2) in polarized deep-inelastic scattering. We find that the mixing between quark-antiquark-gluon and three-gluon twist-3…
Spin-1 hadrons contain different aspects of spin physics from the ones of the spin-1/2 nucleon because of the existence of tensor-polarized structure functions. In the charged-lepton deep inelastic scattering from a spin-1 hadron or…
We have measured the spin structure functions $g_1$ and $g_2$ of $^3$He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.07 GeV off a polarized $^3$He target at a 15.5$^{\circ}$…
The twist-2 contributions to the polarized structure functions in deep inelastic lepton--hadron scattering are calculated including the exchange of weak bosons and using both the operator product expansion and the covariant parton model. A…
The spin structure functions g_1 for the proton and the deuteron have been measured over a wide kinematic range in x and Q2 using 1.6 and 5.7 GeV longitudinally polarized electrons incident upon polarized NH_3 and ND_3 targets at Jefferson…
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…
We show that the first moment of the spin-dependent structure function $g_1^{\gamma}(x,Q^2)$ of a real photon vanishes independent of the momentum transfer $Q^2$ it is probed with. This result is non-perturbative: it holds to all orders in…
We study the $Q^2$ variation of the first moment of the nucleon's spin-dependent structure function $G_1$. As $Q^2 \rightarrow 0$ the moment is determined by the low energy theorem for Compton scattering. In the deep-inelastic region the…
We investigate the dependence of the deep inelastic proton structure function $F_L(x, Q^2)$ on different forms of the transverse momentum dependent (TMD, or unintegrated) gluon distribution. We present a comparison of theoretical results…