by Barbara Erazmus & Jurgen Schukraft. Published: 18 December 2012

During the recent ALICE Physics week in Puebla ALICE colleagues and friends celebrated Guy Paic's 75th Birthday along with a special symposium on Heavy-Ion Physics that was organized to honour his birthday. We asked two of Guy's colleagues, Barbara Erazmus and Jurgen Schukraft, to share their thoughts from the time they spent with him and their wishes through the pages of A.M. The ALICE MATTERS team warmly wishes to Guy: Happy Birthday!

"Keep your great curiosity for the secrets of matter..."

by Barbara Erazmus

The first time I met Guy was in Nantes in 1994. At the time he had a visitor’s position and was involved in the NA44 collaboration at CERN dedicated to particle correlations measurements. Originally, we were both low energy nuclear physicists. Guy was so enthusiastic that he easily convinced me to join the NA44 experiment. Guy was also at the core of a small group formed in Nantes. We participated in the complex data analysis and in challenging technical developments. Engineers from Nantes still remember it today: the process for introducing a mixture of gases into an enclosure, as well as the step of maintaining it at a constant temperature of 32 degrees C in order to avoid its liquefaction.

Guy Paic always excites curiosity - in the photo with Paolo Giubellino who is announcing Guy´s Birthday Party by blowing an original Mexican Caracol.

Guy left Nantes in 1996 and joined the ALICE team at CERN. At that time the Nantes laboratory was already involved in ALICE. We have continued to move forward together discussing about the quark gluon plasma, physics observables and first beam… one day in the future. Guy joked that I would already be grandmother when the ALICE experiment starts.

In 2003 Guy left CERN for Mexico and I left ALICE for a couple of years. We met again last year at the time of new exciting physics results.
Guy, I am not yet grandmother and you did not change at all!
Keep your great curiosity and the same infectious enthusiasm for the mystery of life and for the secrets of matter. Stay with us and continue enjoying all you are doing, energizing and inspiring people around you !

Happy Birthday Guy Paic!

Guy and ALICE

by Jurgen Schukraft

The physics of high-energy heavy-ion collisions is still a very young field which started some 30 years ago at the SPS and AGS. Guy is one of the lucky few who have participated, and indeed shaped, this program from modest beginning to a thriving pillar of modern nuclear physics with over 2000 scientists working today on state-of-the-art experiments at the top energy accelerators RHIC and LHC.

Already one year after the first heavy ion run at the SPS (which actually used Oxygen, more of a ‘light ion’), in 1987, the possibility of using both ions as well as protons was mentioned during a workshop to choose CERN’s next accelerator project, the machine which was to become the LHC. The idea lingered for a few years but was finally taken up in 1990 during the ECFA sponsored LHC workshop in Aachen. The same year, a group of some 50 physicists, amongst them Guy, met for the first time to ponder the prospects for a general purpose heavy ion detector: ALICE was born (but not yet christened, it started life as HIPC or ‘Heavy Ion Proto Collaboration’!).

Designing a heavy ion experiment in the early 90’s for use at the LHC some 20 years later posed some daunting challenges: In a field still in its infancy, it required extrapolating the conditions to be expected by a factor of 300 in energy and a factor of seven in beam mass.

Guy took up this challenge with his characteristic energy and enthusiasm and quickly became one of the strongest and most active members of the emerging ALICE Collaboration. By the time the Letter of Intend was submitted in 1993, the Collaboration had grown to slightly above 200 people from about 40 Institutes, with Guy in charge of the novel CsI based fast RICH detector which he was developing with his long time close collaborator Francois Piuz. The next year, when ALICE adopted a more formal internal organisation, Guy was elected to the newly formed executive body, the Management Board, as one of its first three members (the others being Reinhard Stock/Frankfurt and Lodovico Riccati/Torino). In this influential role, at the heart of ALICE, he was instrumental in guiding the experiment through numerous heated discussions, strategic decision, internal and external reviews for almost a decade until his formal retirement and departure overseas to Mexico.

Guy Paic in front of the ALICE detector

His impact was by far not limited to managing, he was equally (if not more) active in defining the physics, first as Convenor of the Particle Identification Physics Working Group during the preparation of the Technical proposal (1994 - 1996), then as Physics Coordinator (1997 - 2003) and later as member of the Physics Board and editor of the two volume (and voluminous) Physics Performance Reports (2003, 2005). And last but not least, Guy stayed at the head and center of the HMPID RICH detector (together with F. Piuz and E. Nappi), pushing forward technological development as well as funding, organisation and construction. Thus the HMPID became the poster child of ALICE’s many detector systems, the first ready with a large proto-type (proto-2, ready in 1997), the first ready with its Technical Design Report (ALICE TDR #1 in 1998, the latest being TDR # 14 in 2008), and the first detector to complete construction in early 2006. There was even time to spare, an opportunity Guy did not leave unused, and so proto-2 was sent on a sabbatical to Brookhaven in 1999, installed in the STAR experiment at RICH, and brought to good use producing the first physics results of any Alice detector, some 10 years before the LHC would eventually start operating!

Having seen ALICE grow from a sketch on paper to a 10,000 ton giant, retiring was not an option for Guy. After joining the Instituto de Ciencias Nucleares in Mexico in 2003, he sets up a new research group and participates in yet more projects, from trigger counters (V0, ACORDE, both critical in time and for the performance of ALICE) to new R&D for potential upgrades (extending the momentum range for particle identification with the VHMPID). Clearly, neither age nor distance have kept this ‘founding father’ from caring about the present wellbeing and future prospects of his growing little ALICE.


Happy Birthday

It was a pleasure to share with Guy this exciting Alice adventure for such a long time. And it is not yet over !