Related papers: Spin Sum Rules at Low $Q^2$
A description of the generalized Gerasimov-Drell-Hearn sum rules for proton, neutron and deuteron is suggested. The proton consideration confirms the earlier conjecture, that the structure function $g_T$ features a smooth $Q^2-$dependence,…
The generalized forward spin polarizabilities $\gamma_0$ and $\delta_{LT}$ of the neutron have been extracted for the first time in a $Q^2$ range from 0.1 to 0.9 GeV$^2$. Since $\gamma_0$ is sensitive to nucleon resonances and $\delta_{LT}$…
I discuss recent results from Jefferson Lab on the measurement of inclusive spin structure functions in the nucleon resonance region using polarized electron beams and polarized targets. Results on the first moment of the spin structure…
We propose a general method embedded in the ab initio nuclear framework to reconstruct linear response functions and calculate sum rules. Within our approach, based on the Gaussian integral transform, we consistently treat the groundstate…
We compare momentum sum rules from unpolarized electroproduction and the spin sum rule for $g_1$ in polarized electroproduction, and their $Q^2$ evolution in the framework of the operator product expansion. Second order effects in…
The Gerasimov-Drell-Hearn and Baldin-Lapidus sum rules are evaluated in the dressed K-matrix model for photon-induced reactions on the nucleon. For the first time the sum $\alpha+\beta$ of the electric and magnetic polarisabilities and the…
New experimental results on the spin dependent structure functions g_1 and g_2 which are determined from deep-inelastic scattering experiments at CERN, SLAC and DESY are reported. These results are used to evaluate the Bjorken sum rule and…
It is reviewed how Compton scattering sum rules relate low-energy nucleon structure quantities to the nucleon excitation spectrum. In particular, the GDH sum rule and recently proposed extensions of it will be discussed. These extensions…
In this short note the QED extension of the nucleon spin sum rule is considered. To this end, the leading-order (LO) QED evolution kernels for the quark/gluon helicity and orbital-angular-momentum (OAM) distributions are calculated, as well…
The spin structure functions of the proton and the deuteron were measured during the EG4 experiment at Jefferson Lab in 2006. Data were collected for longitudinally polarized electron scattering off longitudinally polarized NH$_3$ and…
Standard QCD sum-rule analyses of the nucleon mass give results that are inconsistent with chiral perturbation theory due to an overly simple continuum ansatz on the phenomenological side of the sum rule. We show that a careful treatment of…
Two new QCD sum rules for nucleon tensor charge are derived from a mixed correlator of spin-1/2 and spin-3/2 nucleon interpolating fields. These sum rules are analyzed along with a sum rule obtained from the usual correlator of a general…
The importance of the nonlinear corrections on the momentum sum rule is investigated on the initial scale $Q_{0}^2$. Nonlinear corrections are found to play an indispensable role in the singlet and gluon momentum sum rule in the high-order…
Recent results from Jefferson Lab on measurement of inclusive double polarization asymmetries in the nucleon resonance region are discussed. Preliminary results on the first moment of the structure function g_1(x,Q^2) for protons, and on…
Two new QCD sum rules for nucleons in nuclear matter are obtained from a mixed correlator of spin-1/2 and spin-3/2 interpolating fields. These new sum rules, which are insensitive to the poorly known four-quark condensates, provide…
We analyze polarized Compton scattering which provides information on the spin-structure of the nucleon. For scattering processes with photon energies up to 100 MeV the spin-structure dependence can be encoded into four independent…
Some higher twist corrections to the Bjorken sum rule are estimated in the framework of a quark-diquark model of the nucleon. The parameters of the model have been previously fixed by fitting the measured higher twist corrections to the…
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…
We present new data on the Bjorken sum $\overline \Gamma_1^{p-n}(Q^2)$ at 4-momentum transfer $ 0.021 \leq Q^2 \leq 0.496$ GeV$^2$. The data were obtained in two experiments performed at Jefferson Lab: EG4 on polarized protons and…
Infinite sets of sum rules involving the excitations of infinite nuclear matter are derived using only completeness, the current algebra implicit in QCD, and relativistic covariance. The sum rules can be used for isospin-asymmetric nuclear…