In Memoriam

Stanislav Mikheyev, an outstanding experimentalist in the field of neutrino and underground physics, died suddenly of a heart attack on 23 April in Moscow.

Mikheyev was a close collaborator of ICTP scientist Alexei Smirnov of the Centre's High Energy, Cosmology and Astroparticle Physics section. The two, along with American physicist Lincoln Wolfenstein, co-discovered the MSW (Mikheyev-Smirnov-Wolfenstein) effect related to neutrino oscillations in matter. Mikheyev and Smirnov's work in 1985 uncovered the resonance enhancement of neutrino oscillations and adiabatic flavor conversion. The latter has been established as an explanation of the "deficit" of solar neutrinos arriving at Earth from the Sun, after confirmation by underground neutrino observatories.

Mikheyev continued collaboration with Smirnov in the 1990s and visited ICTP in 2001 and 2002. In 2006, Mikheyev, Smirnov and Wolfenstein were awarded the Bruno Pontecorvo Prize, and in 2008 Smirnov and Mikheyev shared the American Physical Society's J.J. Sakurai Prize for Theoretical Particle Physics "for pioneering and influential work on the enhancement of neutrino oscillations in matter, which is essential to a quantitative understanding of the solar neutrino flux."