Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions and bosons. There are three generations of fermions, although ordinary matter is made only from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons, and electrons and electron neutrinos. The three fundamental interactions known to be mediated by bosons are electromagnetism, the weak interaction, and the strong interaction.
A quark star is a hypothetical type of compact, exotic star, where extremely high core temperature and pressure has forced nuclear particles to form quark matter, a continuous state of matter consisting of free quarks.
The charm quark, charmed quark, or c quark is an elementary particle of the second generation. It is the third-most-massive quark with a mass of 1.27±0.02 GeV/c2 as measured in 2022 and a charge of +2/3e. It carries charm, a quantum number. Charm quarks are found in hadrons such as the J/psi meson and the charmed baryons. Several bosons, including the W and Z bosons and the Higgs boson, can decay into charm quarks.
A pentaquark is a human-made subatomic particle, consisting of four quarks and one antiquark bound together; they are not known to occur naturally, or exist outside of experiments specifically carried out to create them.
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. 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.
Martinus Justinus Godefriedus "Tini" Veltman was a Dutch theoretical physicist. He shared the 1999 Nobel Prize in physics with his former PhD student Gerardus 't Hooft for their work on particle theory.
The
J/ψ
(J/psi) meson is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium" or psions. The
J/ψ
is the most common form of charmonium, due to its spin of 1 and its low rest mass. The
J/ψ
has a rest mass of 3.0969 GeV/c2, just above that of the
η
c, and a mean lifetime of 7.2×10−21 s. This lifetime was about a thousand times longer than expected.
The Joint Institute for Nuclear Research, in Dubna, Moscow Oblast, Russia, is an international research center for nuclear sciences, with 5500 staff members including 1200 researchers holding over 1000 Ph.Ds from eighteen countries. Most scientists are scientists of Russian Federation.
In quantum field theory, penguin diagrams are a class of Feynman diagrams which are important for understanding CP violating processes in the standard model. They refer to one-loop processes in which a quark temporarily changes flavor, and the flavor-changed quark engages in some tree interaction, typically a strong one. For the interactions where some quark flavors have much higher interaction amplitudes than others, such as CP-violating or Higgs interactions, these penguin processes may have amplitudes comparable to or even greater than those of the direct tree processes. A similar diagram can be drawn for leptonic decays.
Jonathan Richard Ellis is a British theoretical physicist who is currently Clerk Maxwell Professor of Theoretical Physics at King's College London.
Helen Rhoda Arnold Quinn is an Australian-born particle physicist and educator who has made major contributions to both fields. Her contributions to theoretical physics include the Peccei–Quinn theory which implies a corresponding symmetry of nature and contributions to the search for a unified theory for the three types of particle interactions. As Chair of the Board on Science Education of the National Academy of Sciences, Quinn led the effort that produced A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas—the basis for the Next Generation Science Standards adopted by many states. Her honours include the Dirac Medal of the International Center for Theoretical Physics, the Oskar Klein Medal from the Royal Swedish Academy of Sciences, appointment as an Honorary Officer of the Order of Australia, the J. J. Sakurai Prize for Theoretical Particle Physics from the American Physical Society, the Karl Taylor Compton Medal for Leadership in Physics from the American Institute of Physics, and the 2018 Benjamin Franklin Medal in Physics from the Franklin Institute.
The timeline of particle physics lists the sequence of particle physics theories and discoveries in chronological order. The most modern developments follow the scientific development of the discipline of particle physics.
Gerson Goldhaber was a German-born American particle physicist and astrophysicist. He was one of the discoverers of the J/ψ meson which confirmed the existence of the charm quark. He worked at Lawrence Berkeley National Laboratory with the Supernova Cosmology Project, and was a professor of physics at the University of California, Berkeley as well as a professor at Berkeley's graduate school in astrophysics.
Luciano Maiani is a Sammarinese physicist best known for his prediction of the charm quark with Sheldon Glashow and John Iliopoulos.
John (Jean) Iliopoulos is a Greek physicist. He is the first person to present the Standard Model of particle physics in a single report. He is best known for his prediction of the charm quark with Sheldon Glashow and Luciano Maiani. Iliopoulos is also known for demonstrating the cancellation of anomalies in the Standard model. He is further known for the Fayet-Iliopoulos D-term formula, which was introduced in 1974. He is currently an honorary member of Laboratory of theoretical physics of École Normale Supérieure, Paris.
Kurt Gottfried was an Austrian-born American physicist who was professor emeritus of physics at Cornell University. He was known for his work in the areas of quantum mechanics and particle physics and was also a co-founder with Henry Way Kendall of the Union of Concerned Scientists. He wrote extensively in the areas of physics and arms control.
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.
Sau Lan Wu is a Chinese American particle physicist and the Enrico Fermi Distinguished Professor of Physics at the University of Wisconsin-Madison. She made important contributions towards the discovery of the J/psi particle, which provided experimental evidence for the existence of the charm quark, and the gluon, the vector boson of the strong force in the Standard Model of physics. Recently, her team located at the European Organization for Nuclear Research (CERN), using data collected at the Large Hadron Collider (LHC), was part of the international effort in the discovery of a boson consistent with the Higgs boson.
Vera G. Lüth is an experimental particle physicist and professor emerita at Stanford Linear Accelerator Center (SLAC), Stanford University, in the United States. A senator of the Helmholtz Association, she has worked in particle physics at SLAC since 1974. She is a fellow of the American Physical Society.
“One woman’s journey in physics”, Mary K Gaillard, June 1, 2016, CERN.