Related papers: Spin physics with antiprotons
We review the density matrix formalism and the positivity conditions for general multiple spin asymmetries, taking as an example the case antiproton + proton -> antiLambda + Lambda, in which one, two or three spins are analyzed. Some…
The high energy and large p_T inclusive polarized process, (A, S_A) + (B, S_B) --> C + X, is considered under the assumption of a generalized QCD factorization scheme. For the first time all transverse motions, of partons in hadrons and of…
We present a detailed study, performed in the framework of LO perturbative QCD with the inclusion of spin and k_T effects, of unpolarized cross sections for the Drell-Yan process and for inclusive pion and photon production in hadronic…
I review what is known about the quark and gluon spin distributions in the nucleon. I discuss in some detail (a) the existence of sum rules for angular momentum; (b) the interpretation and possible measurement of the nucleon's transversity…
Although the proton was discovered about 100 years ago, its spin structure still remains a mystery. Recent studies suggest that the orbital angular momentum of sea quarks could significantly contribute to the proton's spin. The SeaQuest…
We investigate Drell-Yan pair production in a QCD inspired model, which takes into account all relevant hard processes up to $O(\alpha_s)$. To address the known shortfalls of such a fixed order calculation we introduce phenomenological…
We explore the electromagnetic gauge invariance of the hadron tensor of the Drell-Yan process with one transversely polarized hadron. Due to the special role of the contour gauge for gluon fields, the prescription for the gluonic pole in…
We review how RHIC is expected to deepen our understanding of the spin structure of longitudinally and transversely polarized nucleons. After briefly outlining the current status of spin-dependent parton densities and pointing out open…
We discuss possible studies of parton distributions at the proposed 50-GeV PS facility. First, comments are given in general on the importance of large-x physics for finding new physics. Second, polarized deuteron reactions are discussed in…
A system of quarks interacting with chiral fields is shown to provide a physical realization of a "non-standard" time reversal for particle multiplets which mixes the multiplet components. We argue that, if the internal structure of the…
We discuss transversity distributions and transverse spin asymmetries. First, $Q^2$ evolution results are shown for transversity and longitudinally polarized distributions. Second, the antiquark flavor asymmetry $\Delta_{_T} \bar…
The azimuthal single target-spin asymmetries for pi^{+} production in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons are evaluated using two main approaches available in the literature. It is shown…
PROZA-M experiment results as well the proposal of a new spin program with the use of a polarized proton beam are presented. Significant asymmetries were observed in inclusive $\pi^0$ production. The new program proposes to study a wealth…
Exploration of transverse spin structure of the nucleon via study of the spin (in)dependent azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS) and Drell-Yan (DY) reactions is one of the main aspects of the broad…
We discuss techniques and results for the extraction of the nucleon's spin-dependent parton distributions and their uncertainties from data for polarized deep-inelastic lepton-nucleon and proton-proton scattering by means of a global QCD…
The observation of the quark transversity distribution requires another soft object sensitive to the quark's transverse spin. Dihadron fragmentation functions represent a convenient tool to analyze partonic spin, which can influence the…
The physics case is summarised for the investigation of high energy spin phenomena by placing an internal polarised target into HERA's unpolarised proton beam. The luminosity and experimental sensitivity are discussed. Estimating the…
We calculate the double-spin transverse asymmetries for the Drell-Yan lepton pair production in p-p and p-anti p collisions. We assume the transverse and the longitudinal polarization densities to be equal at a very small scale, as it is…
We discuss bounds on the distribution and fragmentation functions that appear at leading order in deep inelastic 1-particle inclusive leptoproduction or in Drell-Yan processes. These bounds simply follow from positivity of the quark-hadron…
Model-independent identities and inequalities relating the various spin observables of a reaction are reviewed in a unified formalism, together with their implications for dynamical models, their physical interpretation, and the quantum…