This is the first report on the scientific activities of the Department of Mathematics and Physics "Ennio De Giorgi" and of the Lecce division of the National Institute of Nuclear Physics (INFN); it is also the fourth scientific report of the "old" Department of Physics and Lecce division of INFN.
During the last year, the former Departments of Mathematics and Physics joined to give birth to the bigger Department of Mathematics and Physics, entitled to the memory of the great mathematician "Ennio De Giorgi" who strongly contributed to many scientific researches in Lecce. Almost all the mathematicians and physicists of the Salento University are members of this new Department. All universitary courses in Informatics, Mathematics and Physics are assumed and organized by the Department. The deep changes of the university legislation in 2012 forced our university to reorganize its departments on a disciplinary basis. Mathematicians an Physicists decided to to start a route together, based on an ancient hystory which shows their common features, rather than their differences. A century ago a distinction between these two categories of scientists  would appear artificial.
The annual report already shows fields where we work together. I hope and believe that such a collaboration will improve in the future.

The Director of the
Dipartimento di Matematica e Fisica "Ennio De Giorgi"
Prof. Giorgio Metafune

One of the strategic choices of the Istituto Nazionale di Fisica Nucleare is the tight collaboration with Universities, and in particular with the University Departments to which physicists belong.
2012 was the first year of activity of the new Department of Mathematics and Physics and a reorganization of the services managed jointly by the University and INFN was necessary, especially of the computing and networking service.
The last year was a year of great achievements in the field of high energy physics, with the stable data taking of LHC, which lead to the discovery of the Higgs boson. The biggest research group of the INFN Lecce section was involved in the ATLAS experiment at LHC with many important contributions.
Looking to the future, another achievement was the approval of the upgrade of the MEG experiment, in which the Lecce section is involved with a reinforced contribution, mainly for the construction of the drift chamber.
Meanwhile, the participation to well established experiments continues (just to mention the biggest ones, AUGER and ARGO) as well as the study of a new big experiment in the field of the neutrino physics. Nessie.

The Director of the
INFN sezione di  Lecce
Prof. Giovanni Mancarella

G. Co', F. Paparella and D. Dell'Anna Editors