The measurement of the matter/antimatter asymmetry in the leptonic sector is one of the highest priority of the particle physics community in the next decades. The ESSnuSB collaboration proposes to design a long baseline experiment based on the European Spallation Source at Lund in Sweden. This experiment will be able to measure the delta_CP parameter with an unprecedent sensitivity thanks to a very intense neutrino superbeam and to the observation of the nu_mu to nu_e oscillation at the second oscillation maximum. To reach this goal, the European Spallation Source facility will be upgraded to provide an additional 5 MW proton beam by doubling the linac pulse frequency from 14 Hz to 28 Hz. The pulse time width will be reduced thanks to an accumulator ring from 2.86 ms to 1.3 microseconds and shared in four parts by a beam switchyard before entering into the target station. The produced neutrino superbeam will be sent to a large 538kt fiducial mass Far Detector based on water Cherenkov technology.
The global overview of the project with its physics potentials will be reviewed and additional possibilities offered by this high intensity facility for complementary R&D activities will also be discussed.