The JINR Directorate deeply regrets to announce that on 5 November 2020, an outstanding scientist, a wonderful teacher and man, Doctor of Physics and Mathematics, Professor Samoil Mikhelevich Bilenky passed away.

Samoil Mikhelevich Bilenky

23.05.1928 – 05.11.2020

Samoil Mikhelevich Bilenky was born on 23 May 1928 in Zhmerynka, Ukraine SSR. In1952, he graduated with honours from the Moscow Engineering Physics Institute and immediately after that came to work in Dubna, at the Institute of Nuclear Problems that was then transformed into JINR in 1956. Since then, his entire life was always linked with JINR where he defended Candidate and Doctor dissertations working on the issues of particle physics in various scientific groups, including those of Academician I. Ya. Pomeranchuk and Academician N. N. Bogoliubov.

Samoil Mikhelevich Bilenky was one of the first staff members of the Laboratory of Theoretical Physics organized after the creation of JINR. During his work, he greatly contributed to various branches of particle physics. His studies on polarization phenomena and finding out links between the effects of polarization and internal parity of particles were widely used in experiments and in the 1960s, they initiated the development of the technique of proton polarized targets. He studied the issue of parity violation in deep-inelastic scattering of polarized muons by nucleons, and it required a special experiment in CERN.

In 1970, he started a close cooperation with a leading Italian and Soviet physicist, Academician Bruno Maksimovich Pontecorvo who worked at DLNP JINR. From this moment on, the main focus of work of Samoil Mikhelevich was the theory and phenomenology of electroweak interactions and, first of all, heavy neutrino physics and their mixing. Jointly with Bruno Maksimovich Pontecorvo, he developed a general theory of neutrino mixing and neutrino oscillations basing on which he then considered possible options for testing these effects and made detailed proposals for oscillation experiments implemented later and conducted nowadays using accelerating, reactor, atmosphere and solar neutrinos. These studies with the use of oscillations as a precision tool opened a new field of neutrino physics which is one of the most promising areas of search for new phenomena.

Samoil Mikhelevich Bilenky had a long and fruitful life. About 40 out of more than 300 of his scientific papers have been published in recent years! Very few young and middle-aged physicists can boast of such scientific productivity. Two reviews of Bilenky written jointly with B. M. Pontecorvo (1978) and S. T. Petkov (1987) have approximately 500 citations, and most of them are of recent years: this is one more illustration of scientific longevity.

S. M. Bilenky’s monographs “Introduction to Feynman diagram technique”, “Lectures on physics of neutrino and lepton-nucleon processes”, “Introduction to the physics of electroweak interactions” have long been indispensable guides for everyone who wants to master the calculation technique. These books were especially popular among experimentalists who use them not only like textbooks but also like authoritative reference books on the main sections of “practical” field theory and particle physics.

S. M. Bilenky has made lectures for students of Dubna departments of the Moscow State University for more than 30 years. Many generations of physicists have been deeply impressed by his clear, open and unbiased discussions on modern physics. He also provided lecture courses on the standard model of electroweak interactions and neutrino physics for postgraduates and students of universities of Prague, Milan, Vienna, Valencia, Barcelona, at ICTP and SISSA in Trieste, Technion, and at many other international schools, including Pontecorvo Neutrino Physics School he has successfully organized for the past 20 years.

Samoil Mikhelevich Bilenky repeatedly received high awards for his outstanding scientific activities. These were the Pontecorvo International Prize, the Humboldt Prize, the second-degree medal of the order of the Russian Federation “For services to the Fatherland”, the MSU honorary diploma, the first-degree medal of the Faculty of Physics and Mathematics of Charles University, as well as numerous scientific awards of JINR and other achievements.

International science suffered a grievous loss with the passing of Samoil Mikhelevich Bilenky. His example of selfless service inspired and educated many generations of scientists who will always remember his scientific and human qualities.

His friends, students and colleagues will always remember his intelligence and modesty, openness, endless sociability and kindness, as well as his incredible performance and absolutely sincere wish to enjoy the success of others.

The Directorate and staff members of JINR express their deepest condolences to the family of Samoil Mikhelevich Bilenky.