Spin Physics – Experimental Overview Original Research Article

Over the last decade, second generation polarised high energy experiments at CERN, DESY, JLAB and RHIC have addressed all aspects in studying the spin structure of the nucleon. Novel and pioneering results on the spin structure of the nucleon are presented which illustrate the new trends in the field. We concentrate here on the quark spin flavour decomposition of the nucleon spin, the extraction of the gluon polarisation and on novel transverse spin phenomena. The new formalism of Generalised Parton Distributions and their investigation in hard exclusive processes is discussed elsewhere at this conference [M. Guidal, Generalised Parton Distributions, proceedings to this conference]. Although exciting new information has been obtained on the nucleon structure, a detailed decomposition of its spin remains elusive.