Spin Physics @ FAIR

Our knowledge on the nucleonic structure is still uncomplete. A transverse momentum dependent description of the nucleon structure is a crucial milestone of several forthcoming studies in a wide range of experimental scenarios. The physics program of the future FAIR facility includes the investigation of the nucleon structure by mean of antiproton beams, eventually polarised, with a beam momentum up to 15 GeV/c, in kinematic regions where perturbative QCD could not yet completely hold. The Drell-Yan production of lepton pairs in antiproton-proton scattering is a unique tool to access the spin depending properties of the nucleon, and in particular its transverse degrees of freedom, by mean of experimental asymmetries leading to Transverse Momentum Dependent (TMD) Parton Distribution Functions (PDF’s). The spin physics program that could be accomplished at FAIR, and in particular by mean of the PANDA spectrometer, will be discussed in details.