Previous Pierre Auger Collaboration Spokespersons
Giorgio Matthiae (Spokesperson 2006-2010).
Giorgio Matthiae received his Degree in Physics from the University of Rome in 1960. He was CERN fellow and
staff member in the Experimental Physics Division of CERN. He became Professor of Physics at the University of
Naples in 1980. Since 1985 he is Professor of Physics at the University of Roma II "Tor Vergata". In the period
1996-2002 he was Director of the Sezione INFN (Istituto Nazionale di Fisica Nucleare) of Roma II.
His principal activity has been experimental physics at high-energy accelerators. Amongst his scientific
achievements are the measurements of proton-proton and proton-nucleus interactions at the CERN Proton
Synchrotron (1964-1970) and the study of proton-proton elastic scattering and total cross section (1970-1975)
at the CERN Intersecting Storage Rings (CERN-Rome group). In these experiments it was discovered that the total
cross section increases with energy in the high-energy domain. Then he studied dimuon production in high-energy
collisions (experiment NA3, 1975-1980). In the period 1980-1988 he was spokesman of experiment UA4 at the
CERN SPS collider, which measured the proton-antiproton total cross section, elastic scattering and processes
of diffraction dissociation. From 1988 to 1999, as leader of the Rome group involved in the DELPHI collaboration,
he contributed to the construction of the calorimeters and to the analysis on the search of the Higgs particles,
on b quark physics and on the measurement of the W mass.
In 1997 he joined the Auger project, acting as country representative of Italy in the collaboration.
He has given important contributions to the design and construction of the fluorescence telescopes and is
currently responsible for the cameras of the telescopes.
Paul Sommers (Co-Spokesperson 2006-2010).
Paul Sommers is professor of physics at Penn State where he holds a
joint appointment in the department of astronomy and astrophysics. He
is the associate director of the Institute for Gravitation and the
Sommers got his PhD in physics at the University of Texas, Austin, in
1973 with a specialty in general relativity. His attention turned to
cosmic ray physics in 1983 at the University of Utah. He has worked
on the Auger Observatory since the inception of the project in 1992.
He served as task leader for fluorescence detectors 1995-2001 and
co-chair of the Auger Collaboration Board 2001-2006.
From left to right: Jim Cronin (Spokesperson emeritus), and
Alan Watson (Spokesperson emeritus).
James W. Cronin, professor of physics at the University of Chicago, received a Ph.D. in physics from the
University of Chicago in 1955. He served as assistant physicist at Brookhaven National Laboratory from 1955
until 1958, when he accepted an appointment as assistant professor of physics at Princeton University.
He became professor of physics at Princeton in 1964. In 1971, he returned to the University of Chicago as
professor of physics. Dr. Cronin's many awards include the Nobel Prize, which he received in 1980 with physicist
Val L. Fitch, for their discovery of charge conjugation/parity violation, the asymmetry in the behavior of
matter and antimatter. Dr. Cronin is a member of the National Academy of Science and the American Academy of
Arts and Science; he is a fellow of the American Physical Society.
Alan A. Watson, professor of physics and pro-vice-chancellor at the University of Leeds in the United Kingdom,
received a Ph.D. in physics from the University of Edinburgh in 1964. He accepted a lectureship in physics at
Leeds in 1964, doing research on ultrahigh-energy cosmic rays as a member of the Haverah Park group. In 1976,
he became director of the research program on extensive air showers of the Leeds University group at Haverah Park
and, beginning in 1986, at the South Pole. Dr. Watson accepted an appointment as professor of physics at Leeds
in 1984, and served as chairman of the Physics Department from 1989 to 1993. His 150 published papers, articles,
and conference reports reflect his lifelong research interest in ultrahigh-energy cosmic rays, high-energy
gamma rays, and high-energy astrophysics.