Michail Petrovich Rekalo 1938-2004
Michail Petrovich Rekalo was a leading scientific researcher at the Institute for Theoretical Physics of the National Science Center Kharkov Institute of Physics and Technology, in the Ukraine. Rekalo was born on 11 July 1938 in the Ukrainian town of Konstantinovka. He graduated in 1960 from Kharkov State University, with a thesis on polarization phenomena in pion and photon scattering on nucleons, a subject in which he was to become a world expert. This marked the beginning of his intensive work in the theoretical physics department, and he later obtained his doctorate at the Joint Institute of Nuclear Research (JINR), Dubna, with a thesis on hadron interaction theory.
In 1974 Rekalo was appointed head of the theoretical physics at Kharkov. His main research work, and that of his team of scientists, focused on the study of hadron electrodynamics. The "Kharkov school" pioneered the understanding and analysis of polarization observables in different processes, such as the electro-disintegration of the deuteron and photo- and electro-production of pions on deuterons.
Rekalo wrote several monographs, text books and popular books on physics. He co-authored more than 300 works on topics in the physics of elementary particles, and he inspired and suggested many others to his students and colleagues. His article on "Polarization phenomena in electron scattering by protons at high energies" (written with A I Akhiezer) showed for the first time that the elastic scattering of longitudinally polarized electrons by polarized protons or the measurement of the polarization of protons scattered by polarized electrons contains all the necessary information for an efficient separation of proton electromagnetic form factors.
Other work was devoted to the photo- and electro-production of particles containing s and c quarks. He suggested a theory of vector meson production in nucleon-nucleon scattering, and also developed a relativistic theory of polarization effects in the disintegration of deuterons by high-energy electrons. Within this theory an effective method for the measurement of the neutron charge form factor was proposed.
In the 1990s, Rekalo was able to join various international scientific collaborations, leading joint research with physicists from JINR (Russia), Bratislava (Slovakia), Ankara (Turkey), Saclay and Orsay (France), Jefferson Laboratory (US) and CERN. When he first came to France, he was invited to the Saturne National Laboratory. Although his main interest was in quantum electrodynamics, he was very enthusiastic about contact with experimentalists in a different field and found a real pleasure in understanding and interpreting the experiments there.
When given any complex problem he could extract the essential properties from general principles, and only afterwards rely on some model, if necessary. In particular he developed a general model-independent formalism to calculate polarization phenomena for meson production at threshold. This formalism is so general that it applies to light, strange and charmed mesons as well. In this context he suggested experiments that should be done to determine unambiguously the parity of strange and charm particles and the pentaquark.
With the advent of high-intensity polarized electron machines, he could enjoy the realization of the physics that had been his main interest: elastic and inelastic electron-deuteron scattering, parity-violation experiments and especially the measurement of the elastic form factor of the proton. His contacts with the experimentalists of these collaborations were always very stimulating and constructive. He always brought original ideas and deep understanding, as his knowledge was extremely profound, in many fields of physics.
Rekalo was also a dedicated teacher, and for more than 25 years he lectured at the Physical and Technical Department of Kharkov State University. He was recently appointed as visiting professor at the Middle East Technical University (METU), Ankara, where he taught courses on fundamental physics. He typically gave lectures without notes or books; armed with chalk and a blackboard, he could create immediate contact and a lively interaction with his students.
Extremely creative and full of ideas, Rekalo was always ready to interact with people. Very generous in scientific discussions, he had a deep sense of humour, which was sometimes very sharp. He was able to think deeply and to concentrate on physics, where he could focus very quickly on the essential aspects of a problem: complicated and difficult questions were suddenly made very simple and solvable.
Michail Petrovich Rekalo died on 27 August 2004 at Saint-Cloud in France - an invaluable loss for our community. He is remembered by his students and colleagues both as a talented physicist and as a person who sincerely loved science and dedicated his life to it.
Ivan M Neklyudov, Nikolai F Shul'ga and Alexey P Rekalo, NSC-KIPT, Kharkov; Egle Tomasi-Gustafsson CEA, Saclay; Jacques Arvieux and Boris Tatischeff, IPN, Orsay, on behalf of his colleagues and friends.