Lev Borisovich Okun (1929 - 2015)

Soviet and Russian theoretical physicist Lev Borisovich Okun passed away on 23 November, 2015, after a long illness.



Lev Okun was born in 1929, in western Russia and graduated from the Moscow Institute for Physics and Engineering in the early 1950s under the supervision of Arkady Migdal. Lev Okun came to the Institute of Theoretical and Experimental Physics (ITEP) in 1954 as a graduate student of Isaac Pomeranchuk, the head of the ITEP Theory Department. In 1956 he was instrumental in the proof of the Okun–Pomeranchuk theorem, establishing the asymptotic equality of cross sections of certain scattering processes.

A number of Okun’s pioneering works were devoted to weak interactions of elementary particles. In particular, he was among the first to explain the special features of CP preserving neutral kaon decays, and his results on the false vacuum decay and domain walls in cosmology are of paramount importance. His many textbooks on physics are well-known and cherished worldwide.

For many years Lev Okun was the heart of the ITEP Theory Department. He was devoted to physics beyond limits, believing that there can be nothing more noble in the world than theoretical physics. He taught his students to be as committed to physics as he was himself. Many of them became outstanding theorists, now scattered all over the world.

Lev was also a great supporter of the CERN programme. He regularly visited the Theory Division for many years, and was a member of the Scientific Policy Committee. His advice was always extremely valuable. We will miss the great scientist and also the kind, warm and wonderful friend.

His colleagues and friends