The possibility of using a spin sum-rule to extract from the first moments of the transversity PDF's the contribution of the parton orbital angular momentum to the nucleon spin is of great importance for the understanding of the "spin puzzle" . In 2004 B.L.G. Bakker, E. Leader and T.L. Trueman have published a "transverse spin sum rule". The interpretation of this sum-rule is the subject of a one-day workshop which will be held in the meeting room of the Padriciano building of the Trieste Section of INFN on November 24, 2006, starting at 9 a.m.
Specific seminars on the subject will be given by
prof. A. Efremov, DUBNA, Mosca, RU
prof. E. Leader, Imperial College,London,U.K.
prof. P. Mulders, NIKHEF, Amsterdam, N.L.