Graham Garland Ross (1944 – 31 October 2021) was a Scottish

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experim ...

who was the Emeritus Professor of

Physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...

at the

University of Oxford The University of Oxford is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the world's second-oldest university in contin ...

and Emeritus Fellow of Wadham College.

Career

Ross was known for constructing models of

fundamental interaction In physics, the fundamental interactions, also known as fundamental forces, are the interactions that do not appear to be reducible to more basic interactions. There are four fundamental interactions known to exist: the gravitational and electr ...

s and verifying them by experimentation. With others, while at the European Organization for Nuclear Research (CERN) in

Geneva Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaking part of Switzerland. Situ ...

, he predicted that

gluon A gluon ( ) is an elementary particle that acts as the exchange particle (or gauge boson) for the strong force between quarks. It is analogous to the exchange of photons in the electromagnetic force between two charged particles. Gluons bi ...

radiation would generate

collimated A collimated beam of light or other electromagnetic radiation has parallel rays, and therefore will spread minimally as it propagates. A perfectly collimated light beam, with no divergence, would not disperse with distance. However, diffraction ...

jets of particles in electron–positron annihilation, which subsequently established the existence of the gluon. He made contributions to the foundation of the

perturbative In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for wh ...

treatment of

quantum chromodynamics In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a ty ...

, applying it to high-energy processes and developing connections with the low-energy

quark A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All common ...

model. He developed predictions of unified models of the fundamental forces for polarised

lepton In particle physics, a lepton is an elementary particle of half-integer spin (spin (physics), spin ) that does not undergo strong interactions. Two main classes of leptons exist: electric charge, charged leptons (also known as the electron-li ...

scattering Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including ...

, for sin²''θ''_W, for

proton decay In particle physics, proton decay is a hypothetical form of particle decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron. The proton decay hypothesis was first formulated by Andrei Sakha ...

, and for

inflationary cosmology In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from seconds after the conjectured Big Bang singulari ...

. He discovered that in

supersymmetric In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theorie ...

models, the

electroweak symmetry In particle physics, the electroweak interaction or electroweak force is the unified description of two of the four known fundamental interactions of nature: electromagnetism and the weak interaction. Although these two forces appear very differe ...

can be broken by quantum effects, and he was among the first researchers to develop models based on this idea. One or more of the preceding sentences may incorporate text from the royalsociety.org website where "all text published under the heading 'Biography' on Fellow profile pages is available under Creative Commons Attribution 4.0 International License." , "Intellectual property rights"

Personal life

Ross died suddenly on 31 October 2021.

Awards and honours

Ross was elected a Fellow of the Royal Society (FRS) in 1991. In 2012, he was given the

Dirac Medal The Dirac Medal is the name of four awards in the field of theoretical physics, computational chemistry, and mathematics, awarded by different organizations, named in honour of Professor Paul Dirac, one of the great theoretical physicists of the 2 ...

by the

Institute of Physics The Institute of Physics (IOP) is a UK-based learned society and professional body that works to advance physics education, research and application. It was founded in 1874 and has a worldwide membership of over 20,000. The IOP is the Physica ...

''for his theoretical work in developing both the Standard Model of fundamental particles and forces and theories beyond the Standard Model that have led to many new insights into the origins and nature of the universe''.

References

{{DEFAULTSORT:Ross, Graham 1944 births 2021 deaths People from Aberdeen Scottish physicists 20th-century British physicists 21st-century British physicists Theoretical physicists People associated with CERN Fellows of Wadham College, Oxford Fellows of the Royal Society Department of Physics, University of Oxford Alumni of Durham University Graduate Society