Final Activity Report Summary - HIGH-DENSITY-QCD@LHC (Hard probes of high-density Quantum Chromo Dynamics in high-energy hadronic collisions at CERN-LHC) The Large Hadron Collider (LHC), in its final construction phase at the CERN laboratory in Geneva, will make possible the study of the particles and forces of nature at energies never explored before. By colliding protons and heavy nuclei against each other at energies of 5-14 Tera-electron-volts, one expects to recreate locally the conditions that existed in the universe a fraction of billionth of a second after the Big Bang. By detecting the products of such reactions in complex detector systems, the high-energy physicists aim at finding new particles theoretically predicted but never observed before (such as the Higgs boson or super-symmetric particles) as well as at studying the phase transitions that took place in the primordial universe. The Fellowship project has focused on the preparation of the physics programme of one of the big experiments at the LHC, the Compact Muon Solenoid (CMS). The most important achievements of the project are: 1. The preparation of the physics programme and the construction of three new detector systems of the CMS experiment: the (i) CASTOR and the (ii) ZDC forward electromagnetic and hadronic calorimeters, and the (iii) FP420 proton taggers. Those three new detectors will allow the measurement of particles produced at angles very close to the beam in proton-proton and nucleus-nucleus collisions at the LHC. The possibility to have such instrumentation at very small angles will open access to a rich programme of study of the properties of the strong interaction that binds quarks and gluons together, and also will allow one to identify more efficiently the collisions that may have produced a Higgs boson. 2. The coordination within the CMS experiment of all the physics studies related to nucleus-nucleus collisions. The Fellow has acted as coordinator of about 100 people from 25 institutions all over the world who are interested in the study of the quark-gluon plasma state of matter, and has been the editor of a 150-pages publication that summarises the capabilities of the CMS experiment to carry out such a research programme. By measuring the particles issuing from the very hot and dense 'soup' of quarks and gluons produced in head-on collisions of heavy-ions at the LHC, one will be able to analyse the properties of the strong interaction in a regime of temperatures and pressures never reached before in the laboratory. 3. The organisation of a few workshops, the participation in numerous international conferences, the redaction of various review papers and the supervision of students, all activities related to fore-front physics at the LHC.