In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. The Standard Model presently recognizes seventeen distinct particles—twelve fermions and five bosons. As a consequence of flavor and color combinations and antimatter, the fermions and bosons are known to have 48 and 13 variations, respectively. Among the 61 elementary particles embraced by the Standard Model number: electrons and other leptons, quarks, and the fundamental bosons. Subatomic particles such as protons or neutrons, which contain two or more elementary particles, are known as composite particles.
Particle physics or high-energy physics is the study of fundamental particles and forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the scale of protons and neutrons, while the study of combination of protons and neutrons is called nuclear physics.
Supersymmetry is a theoretical framework in physics that suggests the existence of a symmetry between particles with integer spin (bosons) and particles with half-integer spin (fermions). It proposes that for every known particle, there exists a partner particle with different spin properties. There have been multiple experiments on supersymmetry that have failed to provide evidence that it exists in nature. If evidence is found, supersymmetry could help explain certain phenomena, such as the nature of dark matter and the hierarchy problem in particle physics.
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle accelerator. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundreds of universities and laboratories across more than 100 countries. It lies in a tunnel 27 kilometres (17 mi) in circumference and as deep as 175 metres (574 ft) beneath the France–Switzerland border near Geneva.
ATLAS is the largest general-purpose particle detector experiment at the Large Hadron Collider (LHC), a particle accelerator at CERN in Switzerland. The experiment is designed to take advantage of the unprecedented energy available at the LHC and observe phenomena that involve highly massive particles which were not observable using earlier lower-energy accelerators. ATLAS was one of the two LHC experiments involved in the discovery of the Higgs boson in July 2012. It was also designed to search for evidence of theories of particle physics beyond the Standard Model.
Lisa Randall is an American theoretical physicist and Frank B. Baird, Jr. Professor of Science at Harvard University. Her research includes the fundamental forces of nature and dimensions of space. She studies the Standard Model, supersymmetry, possible solutions to the hierarchy problem concerning the relative weakness of gravity, cosmology of dimensions, baryogenesis, cosmological inflation, and dark matter. She contributed to the Randall–Sundrum model, first published in 1999 with Raman Sundrum.
Jonathan Richard "John" Ellis is a British-Swiss theoretical physicist.
In theoretical physics, a dual resonance model arose during the early investigation (1968–1973) of string theory as an S-matrix theory of the strong interaction.
The history of string theory spans several decades of intense research including two superstring revolutions. Through the combined efforts of many researchers, string theory has developed into a broad and varied subject with connections to quantum gravity, particle and condensed matter physics, cosmology, and pure mathematics.
Carl Richard Hagen is a professor of particle physics at the University of Rochester. He is most noted for his contributions to the Standard Model and Symmetry breaking as well as the 1964 co-discovery of the Higgs mechanism and Higgs boson with Gerald Guralnik and Tom Kibble (GHK). As part of Physical Review Letters 50th anniversary celebration, the journal recognized this discovery as one of the milestone papers in PRL history. While widely considered to have authored the most complete of the early papers on the Higgs theory, GHK were controversially not included in the 2013 Nobel Prize in Physics.
Chris Quigg is an American theoretical physicist at the Fermi National Accelerator Laboratory (Fermilab). He graduated from Yale University in 1966 and received his Ph.D. in 1970 under the tutelage of J. D. Jackson at the University of California, Berkeley. He has been an associate professor at the Institute for Theoretical Physics, State University of New York, Stony Brook, and was head of the Theoretical Physics Department at Fermilab from 1977 to 1987.
Joseph David Lykken is an American theoretical physicist at the Fermi National Accelerator Laboratory and, from July 1, 2014 to Sept 6, 2022, he was the Deputy Director of Fermilab. He is currently Director of Fermilab's Quantum Division.
The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory. In the Standard Model, the Higgs particle is a massive scalar boson with zero spin, even (positive) parity, no electric charge, and no colour charge that couples to mass. It is also very unstable, decaying into other particles almost immediately upon generation.
Gordon Leon Kane is Victor Weisskopf Distinguished University Professor at the University of Michigan and director emeritus at the Leinweber Center for Theoretical Physics (LCTP), a leading center for the advancement of theoretical physics. He was director of the LCTP from 2005 to 2011 and Victor Weisskopf Collegiate Professor of Physics from 2002 - 2011. He received the Lilienfeld Prize from the American Physical Society in 2012, and the J. J. Sakurai Prize for Theoretical Particle Physics in 2017.
The search for the Higgs boson was a 40-year effort by physicists to prove the existence or non-existence of the Higgs boson, first theorised in the 1960s. The Higgs boson was the last unobserved fundamental particle in the Standard Model of particle physics, and its discovery was described as being the "ultimate verification" of the Standard Model. In March 2013, the Higgs boson was officially confirmed to exist.
Guido Tonelli is an Italian particle physicist who was involved with the discovery of the Higgs boson at the Large Hadron Collider. He is a professor of General Physics at the University of Pisa (Italy) and a CERN visiting scientist.
Sir Tejinder Singh Virdee,, is a Kenyan-born British experimental particle physicist and Professor of Physics at Imperial College London. He is best known for originating the concept of the Compact Muon Solenoid (CMS) with a few other colleagues and has been referred to as one of the 'founding fathers' of the project. CMS is a world-wide collaboration which started in 1991 and now has over 3500 participants from 50 countries.
Particle Fever is a 2013 American documentary film tracking the first round of experiments at the Large Hadron Collider (LHC) near Geneva, Switzerland. The film follows the experimental physicists at the European Organization for Nuclear Research (CERN) who run the experiments, as well as the theoretical physicists who attempt to provide a conceptual framework for the LHC's results. The film begins in 2008 with the first firing of the LHC and concludes in 2012 with the successful identification of the Higgs boson.
The Future Circular Collider (FCC) is a proposed particle accelerator with an energy significantly above that of previous circular colliders, such as the Super Proton Synchrotron, the Tevatron, and the Large Hadron Collider (LHC). The FCC project is considering three scenarios for collision types: FCC-hh, for hadron-hadron collisions, including proton-proton and heavy ion collisions, FCC-ee, for electron-positron collisions, and FCC-eh, for electron-hadron collisions.
Victoria Jane Martin is a Scottish physicist who is Professor of Collider Physics at the University of Edinburgh. She works on the ATLAS experiment on the Higgs boson.
