Dr. Marcel Froissart

Collège de France

Marcel Froissart (* 20 décembre 1934, Paris, France) is a french physicist, professor emeritus at Collège de France¹, mainly known for discovering the Froissart bound on the behaviour of cross sections of particles at high energy².

Biography

After studying at Lycée Louis-le-Grand, Marcel Froissart entered École polytechnique (Paris) in 1953, and then École nationale supérieure des mines (Paris) in 1955. He attends there one semester out of four, being sent in cooperation, in the Navy, to Algeria. He enters Commissariat à l'énergie atomique in 1957, and then goes to CERN (Geneva, 1957-1958), and then again to Algiers University in civil cooperation (1958-1959). He spends long times to University of California (Berkeley, 1960-1961), where he works notably with Geoffrey Chew, and to Princeton University (1961-62, 1965-66). In 1964, he is awarded the Paul Langevin Prize by the Société française de physique. He is elected in 1973 professor at Collège de France in the chair "Physique corpusculaire", until 2004¹.

He takes up into a single laboratory depending on his chair the biggest two labs at Collège de France then, those of Francis Perrin and of Louis Leprince-Ringuet. His first task consists in uniting these two labs, which considered themselves more as competitors. He makes then the Laboratoire de Physique Corpusculaire (LPC).

A long-term task is to diminish the size of this lab, whilst keeping an international activity and renown. The policy of Collège de France is to have on site only smaller teams, which can easily be moved if the subject of the chair disappears as its holder goes away.

So physicists of the Laboratory interested in working with LHC, which would start after the departure of Marcel Froissart, were asked jointly by Collège de France and their employer CNRS, to carry on their work on this facility in other labs. A majority of physicists turned towards astroparticle, and the lab took the name of Physique corpusculaire et cosmolgie (PCC).

When Marcel Froissart retires with the status of emeritus, PCC goes to Université Paris VII-Denis-Diderot where it makes the bulk of the new lab "Astroparticle and Cosmology" (APC).

Main works

• Study of the stability of relativistic polarized protons in a synchrotron³. This showed the existence of resonance energies leading to the reversal of the polarization.
• Works on scattering theory in the framework of the Mandelstam representation², ⁵.
• Search for a possible justification of Mandelstam's representation⁶.
• Generalisation of Bell's inequalities to several systems, and general algorithm to find such ones in other systems⁷.
• Application of the theory of analytic functions to the localisation of a point on a plane resistive surface⁸.
• Studies on various properties of light mesons⁹.

Bibliography

^{9 ^} Benayoun(1989). Some topics on light-flavour meson physics Nuclear Physics B 315(2): 295-360.

^{6 ^} Fotiadi, Dimitri; Froissart, Marcel; Lascoux, Jean and Pham, Frédéric (1965). Applications of an isotopy theorem Topology 4: 159-191.

^{3 ^} Froissart(1960). Dépolarisation d'un faisceau de protons polarisés dans un synchrotron Nuclear Instruments and Methods 7(3): 297-305.

^{2 ^a b} Froissart, Marcel (1961). Asymptotic Behavior and Subtractions in the Mandelstam Representation Physical Review 123(3): 1053-1057.

^{7 ^} Froissart, Marcel (1981). Constructive Generalization of Bell's Inequalities Il Nuovo Cimento B 64(2): 241-251.

^{5 ^} Omnès, Roland and Froissart, Marcel (1963). Mandelstam Theory and Regge Poles – An Introduction for Experimentalists W A Benjamin, New York & Amsterdam.

Patent

^{8 ^} 1988 : « A device for two-dimensional localization of current-generating events on a resistive surface » ; US patent No 4,788,384 (in coll. avec Roger Bruère-Dawson, Bernard M. Maréchal, Marcio N. DeSouza), in the name of Centre national de la recherche scientifique/CNRS.

External links

• ^{1 ^a b}Marcel Froissart page on the Collège de France site
• 1974 - 2004 : Public lectures and reports of Marcel Froissart, Collège de France (Chaire de physique corpusculaire)