Spin physics and polarized structure functions

摘要: Abstract A review on the theoretical aspects and experimental results of polarized deep inelastic scattering other hard processes is presented. The longitudinally structure functions are introduced cross section fromulae given for case photon as well W± Z0 exchange. Results from SLAC CERN polarization experiments shown compared with each their implications integrated g 1 (x, Q 2 ) reviewed. More recent presently underway (like HERMES at DESY) future projects RHIC BNL, HERA- N → a HERA collider discussed too. QCD interpretation LO NLO Q2-evolution g1, i.e. parton densities, in great detail, particular role gluon density, expectations x→0. Particular emphasis placed first moment function various factorization schemes, which related to axial anomaly, its relevance understanding origin proton spin. Sum rules (i.e. relations between moments functions) derived results. Various phenomenological applications well, parametrizations densities obtained data evolution Q2. Furthermore, jet, heavy quark direct production reviewed sensitive probe physics prospects ( p e studied. DIS semi-inclusive asymmetries elastic neutrino–proton reviewed, will help disentangle flavor nucleon. status single- double-spin asymmetries, observation handedness final state, well. Structure higher spin hadrons nuclei defined possible nuclear effects high energy concept spin-dependent distributions presented possibilities measuring them briefly discussed. nonperturbative approaches understand such isosinglet UA(1) Goldberger–Treiman relation, lattice calculations chiral soliton model physical transverse g2 presented, twist-3 measurements thereof, Burkhardt–Cottingham sum rule revisited. Finally, chiral-odd ‘transversity’ described delineating be important complete leading twist-2 sector nucleon's structure. In appendix full two-loop anomalous dimensions Altarelli–Parisi splitting governing g1 given.