Torleif Ericson

Torleif Erik Oskar Ericson (born November 2, 1930) is a Swedish nuclear theoretical physicist. He is known for 'Ericson fluctuations' under the supervision of Ben Mottelson at the Nordic Institute for Theoretical Physics (Nordita), in 1958.

Ericson held positions as a postdoctoral researcher and an instructor at MIT and as Visiting scientist at Berkeley from 1959 to 1960.

Following he joined CERN’s Theory Division, first as a fellow, and then as a staff member in 1962. He was recruited by the Director-General, V. F. Weisskopf, as the theoretical interface between particle and nuclear physics. but still emeritus (honorary member of the personnel).

Research contributions Moving from MIT to Berkeley he wrote two papers Initially the idea was met with resistance. However, the prediction stimulated in a large number of nuclear reaction studies, as reviewed a few years later with Mayer-Kuckuk, and Ericson continued to develop the consequences in depth in a series of articles.

In 1963, Ericson, after an initiative by A. de-Shalit and V.F. Weisskopf, organised an international conference on high-energy physics and nuclear structure. The meeting turned out to be of significant importance both for Ericson's own career and the development of this field, as a new branch of nuclear physics. The conference series, later generally referred to as PANIC, was the start of the field interfacing nuclear and particle physics and has developed into a triennial event. The series is sponsored by the International Union of Pure and Applied Physics and has been going on since then.

In the 1960's much information in this field came from exotic atoms. This was limited but precise information. In this context Ericson studied how nuclei and particles manifest dielectric constants and magnetic susceptibilities in external fields. Furthermore, Ericson, together with his wife Magda Ericson, were among the first to focus on the interaction of pions with nuclei and to study a regime that was intermediate between the low energies of traditional nuclear physics and elementary particles of higher energies. In particular the Ericsons realized that the pion behavior in nuclei is changed and that this produces major effects. This became known as the 'Ericson-Ericson Lorentz-Lorenz effect' and has later influenced other areas of many-body physics.

He took interest in many different areas of physics. Together with J. Bernabeu and C. Jarlskog, he realized that neutral currents imply parity violations, which are strongly enhanced in certain muonic atoms. He also developed an accurate test of T-violation in nuclei based on fluctuations,

The activity on the interface between nuclear and particle physics led to that CERN set up various scientific committees, in which Ericson was deeply involved.

Administrative activities In his role as chairman of the Nuclear Structure Committee, Ericson proposed in 1964, to build an on-line isotope separator, which later has become known as ISOLDE. CERN eventually established its ultrarelativistic heavy-ion programme that over the years has attracted a large number of experimental physicists to the laboratory.

In addition to carry out his research, Ericson has taken on a series of managerial tasks. For several periods he filled the role as deputy leader for the CERN Theory Division, he chaired the CERN Nuclear Structure Committee, served as a member of the CERN Physics III Committee, Swedish Program Committee for Physics and in the IUPAP body International Committee for High Intensity Accelerators (ICHIA). Since 1991 he is one of the general editors of the series Cambridge Monographs on Particle Physics, Nuclear Physics and Cosmology. Ericson has also been editor for a large number of conference proceedings.

Awards and honors

1976: Title of Professor (Swedish: Professors namn) awarded by the Government of Sweden 1990: Foreign member of the Finnish Society of Sciences and Letters 1990: Honorary professor, Shanghai Advanced Research Institute, Chinese Academy of Sciences 1994: Member of the Royal Society of Sciences in Uppsala

Private life Ericson is married to the French physicist Magda Ericson since 1957. Together they have two adult children. The Ericsons reside in Geneva, Switzerland.