2022 Impact factor 2.5

EPJ H Highlight - The Quark Model: A Personal Perspective

George Zweig—father of the ‘Concrete Quark Model’. Photo courtesy G Zweig

The properties of hadrons - both protons and neutrons, and heavier short-lived particles - are explained by the quark model. This was introduced by André Petermann (whose 1963 paper, in French, went unnoticed for 50 years); Murray Gell-Mann (whose insistence that they are purely mathematical entities discouraged take-up of the idea); and George Zweig.

The idea that protons and neutrons were composed of even smaller particles, with non-integral electric charges, was proposed in 1963/64 by Andre Petermann, George Zweig and Murray Gell-Mann, who dubbed them ‘quarks’. It was not until the mid-1970s, however, that the quark model became widely accepted. Chris Llewellyn Smith, now an emeritus professor at the University of Oxford and formerly the Director-General of CERN who put together the proposal to build the Large Hadron Collider, has published a ‘personal perspective’ on the development of the quark model and of the theory of the force that holds them together (quantum chromodynamics or QCD) in EPJ H: Historical Perspectives on Contemporary Physics. He had a ringside seat as a student in theoretical particle physics at Oxford from 1964-7, as a post-doctoral Fellow at CERN and at the Stanford Linear Accelerator Center where experiments that confirmed the reality of quarks were performed.


EPJ H Highlight - Acquitting a Physicist Accused of “Obscurantism”

David Bohm (1917-1992) contributed an innovative interpretation of quantum theory. Credit: Unknown photographer https://en.wikipedia.org/wiki/David_ Bohm#/media/File:David_Bohm.jpg

A reanalysis of letters and publications show that David Bohm’s contemptuous contemporaries were misinformed and politically driven.

American-born British theoretical physicist David Bohm made many significant contributions to physics. But he’s most famous for challenging convention and interpreting quantum mechanics in terms of nonlocal or hidden variables. Several eminent contemporaries accused him of defending outdated ideals based in deterministic physics, rather than embracing his contemporaries’ non-deterministic views. In a study published in EPJ H: Historical Perspectives on Contemporary Physics, Andrea Oldofredi, of the University of Lisbon, Portugal, revisits Bohm’s private correspondences and academic works to reconstruct the evolution of his philosophical trajectory. The analysis indicates that bias against Bohm was mostly not based on scientific grounds, and instead underlines the originality of his ontological reflections.


EPJ H Highlight – Would Matrix Mechanics Win Recognition Today?

Max Born formulated the matrix mechanics interpretation of quantum theory. Public domain: https://commons.wikimedia. org/wiki/File:Max_Born.jpg

A re-evaluation of contributions to the development of quantum mechanics suggests that a belated Nobel Prize was a product of its times.

Albert Einstein, best known for his work in relativity, won the Nobel Prize for his formula for the photoelectric effect, which often surprises modern physicists. He’s not the only physicist whose Nobel award misaligns with the winner's modern claim-to-fame. In a study published in EPJ H: Historical Perspectives on Contemporary Physics, John Heilbron of the University of California, Berkeley, USA, and Carlo Rovelli of Western Ontario University, Canada, analyze why the Nobel Prize in 1954 recognized Max Born’s interpretation of the quantum mechanical wave function, while ignoring his leadership in the development of matrix mechanics. The researchers conclude that assessments made by historical actors can serve as a barometer of the changing consensus of interpretations of quantum mechanics.


EPJ H Highlight - Is the end of the “particle era” of physics upon us?

The completed standard model of particle physics. What shape will physics beyond this model take? Credit: Daniel Dominguez/CERN

New research looks at the potential for new discoveries in particle physics

The discovery of the Higgs Boson in 2012 represented a major turning point for particle physics marking the completion of what is known as the standard model of particle physics. Yet, the standard model can’t answer every question in physics, thus, since this discovery at the Large Hadron Collider (LHC) physicists have searched for physics beyond the standard model and to determine what shape future physics will take.

A new paper in EPJ H: Historical Perspectives on Contemporary Physics by Robert Harlander and Jean-Philippe Martinez of the Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Germany, and Gregor Schiemann from the Faculty of Humanities and Cultural Studies, Bergische Universität Wuppertal, Germany, considers the idea that particle physics may be on the verge of a new era of discovery and understanding in particle physics. The paper also considers the implications of the many possible scenarios for the future of high-energy physics.


EPJ H Highlight - Quarks and gluons: The JADE experiment at DESY

Illustration of an electron-positron annihilation event recorded with the JADE detector. The emergence of a separate, third “jet” of particle tracks from the central annihilation point was the first indicator for the existence of gluons. Credit: DESY.

A new paper in EPJ H describes the JADE experiment at DESY in Hamburg, in which high-energy electron-positron collisions led to the discovery of the particle that holds quarks together to form protons and neutrons: the gluon.

The DESY research centre in Hamburg has been at the centre of German physical science research since the 1960s, leading to important discoveries about the fundamental structure of matter. One experiment at DESY, known as JADE, recorded data on electron-positron collisions between 1979 and 1986. Siggi Bethke from the Max Planck Institute of Physics in Munich and Albrecht Wagner from DESY have now reviewed the history of JADE in the journal EPJ H: Historical Perspectives on Contemporary Physics.


EPJ H Highlight - Mid-twentieth-century physics in the home of Galileo

Credit: Department of Physics and Astronomy, Scientific and Technological Hub, University of Florence.

Breakthroughs made at the Institute of Physics near Florence before 1950 include Fermi statistics and the first electronic coincidence circuits

Florence was a flourishing centre for fundamental physics research throughout most of the twentieth century. Roberto Casalbuoni, Daniele Dominici and Massimo Mazzoni – all physicists currently working there – have reviewed the history of the city’s Institute of Physics for the journal EPJ H: Historical Perspectives on Contemporary Physics, concentrating on the important decades of the 1920s to 1960s.


EPJ H Editor Jürgen Renn receives 2023 Abraham Pais Prize for History of Physics

Prof. Jürgen Renn

The prestigious Abraham Pais Prize for History of Physics, awarded each year by the American Physical Society, recognizes outstanding scholarly achievements in the history of physics. Professor Jürgen Renn, Editor of EPJH: Historical Perspectives on Contemporary Physics and Archive for History of Exact Sciences receives the 2023 Abraham Pais Prize for History of Physics "for contributions to the historiography of modern and early modern science, in particular, studies of Albert Einstein; and for contributing scholarship and taking public stances that directly raise the social relevance of science historiography."


EPJ H Highlight - Legacy of a molecular dynamics trailblazer

Chemists Martin Karplus (L) and J. Andrew McCammon (R) in Sweden in 1982

Computer simulations meet biochemistry

Life is motion. And so, to understand how living organisms function, one must understand the movement and reorganisation of the atoms and molecules that compose them. The approach called “molecular dynamics simulation” enables scientists to use computer programmes to simulate the dynamic motion of all the atoms in a molecular system as a function of time.

In a new paper in EPJ H: Historical Perspectives on Contemporary Physics, Daniele Macuglia from Peking University in Beijing, China, Benoît Roux from the University of Chicago, USA, and Giovanni Ciccotti from the University of Rome, Italy, explain how the theoretical chemist Martin Karplus and his team carried out the first molecular dynamics simulation of a large biological molecule, a protein, deeply impacting biology and the physical sciences in the 20th and 21st centuries. Currently, machine learning researchers are using biomolecular simulations to better understand their time-dependent motions and the function that governs the forces between them.


EPJ H Highlight - Fermi’s ground-breaking figure

Fermi’s radial wave function

How the radial wave function transformed physics

One way to better understand an atom is to shoot a particle at it and infer the atom’s properties based on how the particle bounces off it. In the mid-1930s, the physicist Enrico Fermi showed that one measurable number – the scattering length – illuminated everything that could be known about an electron scattering off an atom, or a neutron scattering off a nucleus. In a new paper in EPJ H: Historical Perspectives on Contemporary Physics, Chris Gould from North Carolina State University in Raleigh, USA, explains how Fermi’s simple sketch of a radial wave function laid the groundwork for a better understanding of low energy scattering phenomena, and led in turn to the concept of the pseudopotential, widely used in many areas of physics, including ultracold atom research and studies of qubits in realisations of quantum computers.


EPJ H Highlight - A step towards quantum gravity

Representation of the Earth affecting the curvature of spacetime. https://commons.wikimedia.org/wiki/ File:Spacetime_lattice_analogy.svg Mysid, CC BY-SA 3.0.

Resolving the problem of time

In Einstein’s theory of general relativity, gravity arises when a massive object distorts the fabric of spacetime the way a ball sinks into a piece of stretched cloth. Solving Einstein’s equations by using quantities that apply across all space and time coordinates could enable physicists to eventually find their ‘white whale’: a quantum theory of gravity. In a new article in EPJ H: Historical Perspectives on Contemporary Physics, Donald Salisbury from Austin College in Sherman, USA, explains how Peter Bergmann and Arthur Komar first proposed a way to get one step closer to this goal by using Hamilton-Jacobi techniques. These arose in the study of particle motion in order to obtain the complete set of solutions from a single function of particle position and constants of the motion.


Pere Roca i Cabarrocas
and Jean-Louis Lazzari
ISSN: 2105-0716 (Electronic Edition)

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