Our dear colleague Roberto Petronzio passed away on 28 July at the age of 67. He was a CERN fellow from 1977 until 1979, and then a staff member in the Theory division from 1980 until 1986. He played a significant role in our field as Professor at the University of Tor Vergata, as President of the INFN (2004-2011), and as a member of the CERN Council.

Roberto was a major contributor to the development of QCD. He was involved, among other projects, in the first complete calculation of the NLO anomalous dimensions, and in the resummation of soft gluon emission in partonic processes. He was also involved in the non-perturbative analysis of the theory. In particular, along with Cabibbo and Parisi, he was one of the first members of the APE collaboration, which managed to construct the famous series of supercomputers for numerical simulations. Together with Cabibbo and Martinelli, he proposed the use of lattice simulations to compute weak amplitudes. These results are of great importance in flavour physics, e.g. for B-physics studies at B-factories and at CERN for similar work carried out by the LHCb, ATLAS and CMS collaborations.

Roberto was well anchored in the Standard Model but always looking for harbingers of new physics. He had an eclectic knowledge of particle physics and related subjects. His legacy is also represented by several generations of brilliant young physicists spread across different laboratories and universities throughout the world.

He had a charming and wonderful personality and was a great asset to our community. He will be dearly missed.