Torleif Erik Oskar Ericson | |
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![]() Torleif Ericson | |
Born | November 2, 1930 93) Lund, Sweden | (age
Alma mater | Lund University |
Known for | Ericson-Ericson Lorentz-Lorenz correction Ericson fluctuations |
Spouse | Magda Ericson |
Awards | Professors namn (Title of Professor), Sweden, 1976 Foreign member of the Finnish Society of Sciences and Letters, 1990 Contents
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Scientific career | |
Fields | Nuclear physics Particle physics |
Institutions | Lund University Nordita Massachusetts Institute of Technology (MIT) UC Berkeley European Organization for Nuclear Research (CERN) Uppsala University |
Torleif Erik Oskar Ericson (born November 2, 1930) is a Swedish nuclear theoretical physicist. [1] [2] He is known for 'Ericson fluctuations' [3] [4] and the 'Ericson-Ericson Lorentz-Lorenz effect'. [5] His research has nurtured the link between nuclear and particle physics.
Ericson studied physics at Lund University, from where he obtained his PhD, [6] 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 [4] [3] [7] and as Visiting scientist at Berkeley [3] [8] from 1959 to 1960.
Following he joined CERN’s Theory Division, [9] first as a fellow, and then as a staff member in 1962. [10] He was recruited by the Director-General, V. F. Weisskopf, as the theoretical interface between particle and nuclear physics. [2]
Sabbatical year 1969/70 at MIT.
Invited guest professor at Geneva, Lausanne, Louvain, Tokyo and Uppsala.
Adjunct professor at Uppsala University from 1993 within the framework of CERN's collaboration with Member States.
Official retirement from CERN in 1995, [11] but still emeritus (honorary member of the personnel). [12]
Moving from MIT to Berkeley he wrote two papers [3] [4] in which he predicted what later became known as 'Ericson fluctuations' and today is considered a prime example of quantum chaos. [8] [13] 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, [14] and Ericson continued to develop the consequences in depth in a series of articles. [15]
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. [16] 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. [1] [15] [17] 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. [18]
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. [5] 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. [15]
His interest in the quantitatively limits of pion physics in nuclei produced some of the most accurate and parameter-free descriptions of observables in the entire nuclear physics. [15] [19]
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. [20] [21] He also developed an accurate test of T-violation in nuclei based on fluctuations, [3] as well as an accurate empirical bound for anti-gravity. [22]
The activity on the interface between nuclear and particle physics led to that CERN set up various scientific committees, [23] in which Ericson was deeply involved.
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. [24] [25] [26] CERN eventually established its ultrarelativistic heavy-ion programme [27] that over the years has attracted a large number of experimental physicists to the laboratory. [28] [29]
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). [15] Furthermore, Ericson was associated editor in the journal Nuclear Physics A, with responsibility for intermediate energy, from 1976 to 2000. [30] [31] Since 1991 he is one of the general editors of the series Cambridge Monographs on Particle Physics, Nuclear Physics and Cosmology. [32] [33] Ericson has also been editor for a large number of conference proceedings.
Ericson is married to the French physicist Magda Ericson since 1957. Together they have two adult children. The Ericsons reside in Geneva, Switzerland. [37]
The European Muon Collaboration (EMC) was formed in 1973 to study the interactions of high energy muons at CERN. These experiments were motivated by the interest in determining the quark structure of the nucleon following the discovery of high levels of deep inelastic scattering at SLAC.
The ISOLDE Radioactive Ion Beam Facility, is an on-line isotope separator facility located at the centre of the CERN accelerator complex on the Franco-Swiss border. Created in 1964, the ISOLDE facility started delivering radioactive ion beams (RIBs) to users in 1967. Originally located at the Synchro-Cyclotron (SC) accelerator, the facility has been upgraded several times most notably in 1992 when the whole facility was moved to be connected to CERN's ProtonSynchroton Booster (PSB). ISOLDE is currently the longest-running facility in operation at CERN, with continuous developments of the facility and its experiments keeping ISOLDE at the forefront of science with RIBs. ISOLDE benefits a wide range of physics communities with applications covering nuclear, atomic, molecular and solid-state physics, but also biophysics and astrophysics, as well as high-precision experiments looking for physics beyond the Standard Model. The facility is operated by the ISOLDE Collaboration, comprising CERN and sixteen (mostly) European countries. As of 2019, close to 1,000 experimentalists around the world are coming to ISOLDE to perform typically 50 different experiments per year.
Rolf Hagedorn was a German theoretical physicist who worked at CERN. He is known for the idea that hadronic matter has a "melting point". The Hagedorn temperature is named in his honor.
The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory near Geneva. It was built from the Antiproton Collector (AC) to be a successor to the Low Energy Antiproton Ring (LEAR) and started operation in the year 2000. Antiprotons are created by impinging a proton beam from the Proton Synchrotron on a metal target. The AD decelerates the resultant antiprotons to an energy of 5.3 MeV, which are then ejected to one of several connected experiments.
Quark–gluon plasma is an interacting localized assembly of quarks and gluons at thermal and chemical (abundance) equilibrium. The word plasma signals that free color charges are allowed. In a 1987 summary, Léon Van Hove pointed out the equivalence of the three terms: quark gluon plasma, quark matter and a new state of matter. Since the temperature is above the Hagedorn temperature—and thus above the scale of light u,d-quark mass—the pressure exhibits the relativistic Stefan-Boltzmann format governed by temperature to the fourth power and many practically massless quark and gluon constituents. It can be said that QGP emerges to be the new phase of strongly interacting matter which manifests its physical properties in terms of nearly free dynamics of practically massless gluons and quarks. Both quarks and gluons must be present in conditions near chemical (yield) equilibrium with their colour charge open for a new state of matter to be referred to as QGP.
Marek Gaździcki is a Polish high-energy nuclear physicist, and the initiator and spokesperson of the NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS).
The Pandya theorem is a good illustration of the richness of information forthcoming from a judicious use of subtle symmetry principles connecting vastly different sectors of nuclear systems. It is a tool for calculations regarding both particles and holes.
Hot spots in subatomic physics are regions of high energy density or temperature in hadronic or nuclear matter.
In high-energy nuclear physics, strangeness production in relativistic heavy-ion collisions is a signature and diagnostic tool of quark–gluon plasma (QGP) formation and properties. Unlike up and down quarks, from which everyday matter is made, heavier quark flavors such as strange and charm typically approach chemical equilibrium in a dynamic evolution process. QGP is an interacting localized assembly of quarks and gluons at thermal (kinetic) and not necessarily chemical (abundance) equilibrium. The word plasma signals that color charged particles are able to move in the volume occupied by the plasma. The abundance of strange quarks is formed in pair-production processes in collisions between constituents of the plasma, creating the chemical abundance equilibrium. The dominant mechanism of production involves gluons only present when matter has become a quark–gluon plasma. When quark–gluon plasma disassembles into hadrons in a breakup process, the high availability of strange antiquarks helps to produce antimatter containing multiple strange quarks, which is otherwise rarely made. Similar considerations are at present made for the heavier charm flavor, which is made at the beginning of the collision process in the first interactions and is only abundant in the high-energy environments of CERN's Large Hadron Collider.
The NA49 experiment was a particle physics experiment that investigated the properties of quark–gluon plasma. The experiment's synonym was Ions/TPC-Hadrons. It took place in the North Area of the Super Proton Synchrotron (SPS) at CERN from 1991-2002.
Total absorption spectroscopy is a measurement technique that allows the measurement of the gamma radiation emitted in the different nuclear gamma transitions that may take place in the daughter nucleus after its unstable parent has decayed by means of the beta decay process. This technique can be used for beta decay studies related to beta feeding measurements within the full decay energy window for nuclei far from stability.
Magda Galula Ericson (born 1929) is a French-Algerian physicist of Tunisian origin. Her experimental pioneering PhD work changed the understanding of critical phenomena near the Curie point and later in her career she has become known for her theoretical development of the Ericson-Ericson Lorentz-Lorenz correction.
The Synchro-Cyclotron, or Synchrocyclotron (SC), built in 1957, was CERN’s first accelerator. It was in circumference and provided for CERN's first experiments in particle and nuclear physics. It accelerated particles to energies up to 600 MeV. The foundation stone of CERN was laid at the site of the Synchrocyclotron by the first Director-General of CERN, Felix Bloch. After its remarkably long 33 years of service time, the SC was decommissioned in 1990. Nowadays it accepts visitors as an exhibition area in CERN.
Emanuele Quercigh is an Italian particle physicist who works since 1964 at CERN, most known for the discovery of quark-gluon plasma (QGP). Quercigh moved as a child to Friuli with his mother and his younger brother after the early death of his father. Quercigh studied physics at the University of Milan in Italy, where he became assistant of professor Giuseppe Occhialini in 1959.
Ericson fluctuations constitute one of the most characteristic features of quantum chaotic scattering in the regime of strongly overlapping resonances such as a compound nucleus. These fluctuations were predicted in 1960 by Torleif Ericson in two seminal articles, further developed in 1963, based on the same statistical assumptions as those used by E. Wigner, C. E. Porter and R. G. Thomas to describe generic properties of resonances in long-lived compound nuclear systems. In the present case the fluctuations occur in the "continuum" regime for which a large number of such resonances overlap coherently, owing to the short lifetime of the compound nucleus. At the time it was believed that this would lead to a structure-less behavior. Ericson realized that the opposite was the case with strong, random fluctuations.
Ericson-Ericson Lorentz-Lorenz correction, also called the Ericson-Ericson Lorentz-Lorenz effect (EELL), refers to an analogy in the interface between nuclear, atomic and particle physics, which in its simplest form corresponds to the well known Lorentz-Lorenz equation for electromagnetic waves and light in a refractive medium.
David Maurice Brink was an Australian-British nuclear physicist. He is known for the Axel-Brink hypothesis.
The LUCRECIA experiment is a permanent experimental setup at the ISOLDE facility at CERN. The purpose of LUCRECIA is to analyse nuclear structure and use this to confirm theoretical models and make stellar predictions. The experiment is based on a Total Absorption gamma Spectrometer (TAS) designed to measure beta ray feeding.
The Miniballexperiment is a gamma-ray spectroscopy setup regularly located in the ISOLDE facility at CERN, along with other locations including GSI, Cologne, PSI and RIKEN (HiCARI). Miniball is a high-resolution germanium detector array, specifically designed to work with low-intensity radioactive ion beams post-accelerated by HIE-ISOLDE, to analyse gamma radiation emitted by short-lived nuclei. Due to six-fold detector segmentation, Miniball offers a superior Doppler-correction capability with respect to conventional gamma-ray spectrometers using unsegmented detectors. The array has been used for successful Coulomb-excitation and transfer-reaction experiments with exotic beams. Results from Miniball experiments have been used to determine and probe nuclear structure.
The Scattering Experiments Chamber (SEC) experiment is a permanent experimental setup located in the ISOLDE facility at CERN. The station facilitates diversified reaction experiments, especially for studying low-lying resonances in light atomic nuclei via transfer reactions. SEC does not detect gamma radiation, and therefore is complementary to the ISOLDE Solenoidal Spectrometer (ISS) and Miniball experiments.
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