Related papers: Spin-Orbit Dynamics from the Gluon Asymmetry
The STAR collaboration at the Relativistic Heavy Ion Collider is using polarized proton beams at sqrt{s} = 200 GeV to study the spin structure of the proton. The first results for the double spin helicity dependence of inclusive jet…
The gluon polarization contribution to the proton spin is an integral part to solve the longstanding proton spin puzzle. At the Relativistic Heavy Ion Collider (RHIC), the STAR experiment has measured jets produced in mid-pseudo-rapidity,…
The constituent quarks are interpreted as bound states, which have an internal structure. The quark distributions of the proton are related to those of the constituent quarks. The experiments support this hypothesis. Likewise the spin…
Using the equations of motion of QCD and Lorentz invariance relations, we show a new, more direct way of obtaining the decomposition of the proton's quark transverse angular momentum into its spin and orbital components. The new…
The notion of the spin is shown to have two constituents, as exemplified by the spin of the electron. The first one is related to the form of the wave equation and determines the fermion or boson particle type. This implies the spin taking…
Similarities between nuclear structure study with many-body theory approach and nucleon structure calculations with lattice QCD are pointed out. We will give an example of how to obtain the connected sea partons from a combination of the…
The study of two spin asymmetries in hadron-hadron collisions probes the details of fundamental particle interactions in ways infeasible to machines with unpolarized collisions. Within reach is how the proton spin is distributed among its…
How do the quark and gluon share the nucleon momentum? How does the nucleon spin distribute among its constituents? What means the quark and gluon momentum, spin and orbital angular momentum? These problems are analyzed and a solution is…
The proton spin puzzle has inspired a vast programme of experiments and theoretical work challenging our understanding of QCD and its role in the structure of hadrons.The proton's internal spin structure is connected to chiral symmetry and,…
Employing the experimental electro-weak interactions between quarks and leptons, the spin of the proton may easily be understood in terms of the spins of the constituent quarks.
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…
At the low energy, {\sl hadronic}, scale we calculate Orbital Angular Momentum (OAM) twist-two parton distributions for the relativistic MIT bag model and for non-relativistic quark models. We reach the scale of the data by leading order…
The question how the spin of the nucleon is distributed among its quark and gluon constituents is still a subject of intense investigations. Lattice QCD has progressed to provide information about spin fractions and orbital angular momentum…
An action with unconventional supersymmetry was introduced in an earlier paper. Here it is shown that this action leads to standard physics for fermions and gauge bosons at low energy, but to testable extensions of standard physics for…
I use the formalism of skewed parton distributions (SPD) to describe elastic form factors of the nucleon. The results are consistent with approximate dipole behavior of $G_{Mp}(Q^2)$ and recent JLab data for the ratio of the proton form…
This contribution presents the most recent mid-rapidity inclusive jet results from 3 pb^-1 of data collected from longitudinally polarized proton collisions at sqrt(s)=200 GeV during the 2005 RHIC run. The inclusive jet asymmetry, a_LL,…
We report a complete calculation of the quark and glue momenta and angular momenta in the proton. These include the quark contributions from both the connected and disconnected insertions. The calculation is carried out on a $16^3 \times…
Based on a sumrule for the nucleon spin we expand quark and gluon orbital angular momentum operators and derive an evolution matrix for higher moments of the corresponding distributions. In combination with the spin-dependent DGLAP-matrix…
We present a calculation of the proton momentum and angular momentum decompositions using overlap fermions on a $2+1$-flavor RBC/UKQCD domain-wall lattice at 0.143 fm with a pion mass of 171 MeV which is close to the physical one. A…
Effects of the spin-dependent gluon distributions on J/$\psi$ productions in polarized ep and pp collisions are investigated. These productions serve as a very clean probe of the spin-dependent gluon distributions in a proton.