Thousands of particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. Electrically charged particles are discernable by the curves they trace in the detector's magnetic field.

Particle physics is a branch of physics that studies the elementary constituents of matter and radiation, and the interactions between them. It is also called "high energy physics", because many elementary particles do not occur under normal circumstances in nature, but can be created and detected during energetic collisions of other particles, as is done in particle accelerators. Download high resolution version (1226x946, 452 KB)First Gold Beam-Beam Collision Events at RHIC at 100 - 100 GeV/c per beam recorded by the STAR detector. ... Download high resolution version (1226x946, 452 KB)First Gold Beam-Beam Collision Events at RHIC at 100 - 100 GeV/c per beam recorded by the STAR detector. ... A GEV (or Ground Effect Vehicle) is vehicle that takes advantage of the aerodynamic principle of ground effect (or Wing-in-ground). ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... The STAR detector [1] is one of the four experiments at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratry. ... The Relativistic Heavy Ion Collider at Brookhaven National Laboratory. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not made up of smaller particles. ... This article is about matter in physics and chemistry. ... Radiation as used in physics, is energy in the form of waves or moving subatomic particles. ... “Natural” redirects here. ... For other uses, see Collision (disambiguation). ... For the DC Comics Superhero also called Atom Smasher, see Albert Rothstein. ...

Subatomic particles

Modern particle physics research is focused on subatomic particles, which have less structure than atoms. These include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), particles produced by radiative and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles. Helium atom (schematic) Showing two protons (red), two neutrons (green) and two electrons (yellow). ... For other uses, see Atom (disambiguation). ... For other uses, see Electron (disambiguation). ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... This article or section does not adequately cite its references or sources. ... For other uses, see Quark (disambiguation). ... In this Feynman diagram, electrons annihilate and become a quark-antiquark pair. ... Scattering is a general physical process whereby some forms of radiation, such as light, sound or moving particles, for example, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which it passes. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... Neutrinos are elementary particles denoted by the symbol ν. Travelling close to the speed of light, lacking electric charge and able to pass through ordinary matter almost undisturbed, they are extremely difficult to detect. ... The muon (from the letter mu (μ)--used to represent it) is an elementary particle with negative electric charge and a spin of 1/2. ... An exotic particle is a kind of theoretical particle said to exist by some areas of modern physics whose alleged properties are extremely unusual. ...

Strictly speaking, the term particle is a misnomer because the dynamics of particle physics are governed by quantum mechanics. As such, they exhibit wave-particle duality, displaying particle-like behavior under certain experimental conditions and wave-like behavior in others (more technically they are described by state vectors in a Hilbert space; see quantum field theory). Following the convention of particle physicists, we will use "elementary particles" to refer to objects such as electrons and photons, with the understanding that these "particles" display wave-like properties as well. For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ... In physics, wave-particle duality holds that light and matter exhibit properties of both waves and of particles. ... A wave is a disturbance that propagates through space or spacetime, transferring energy and momentum and sometimes angular momentum. ... The mathematical formulation of quantum mechanics is the body of mathematical formalisms which permits a rigorous description of quantum mechanics. ... The mathematical concept of a Hilbert space (named after the German mathematician David Hilbert) generalizes the notion of Euclidean space in a way that extends methods of vector algebra from the plane and three-dimensional space to spaces of functions. ... Quantum field theory (QFT) is the quantum theory of fields. ... For other uses, see Electron (disambiguation). ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ...

All the particles and their interactions observed to date can be described by a quantum field theory called the Standard Model. The Standard Model has 40 species of elementary particles (24 fermions, 12 vector bosons, and 4 scalars), which can combine to form composite particles, accounting for the hundreds of other species of particles discovered since the 1960s. The Standard Model has been found to agree with almost all the experimental tests conducted to date. However, most particle physicists believe that it is an incomplete description of Nature, and that a more fundamental theory awaits discovery. In recent years, measurements of neutrino mass have provided the first experimental deviations from the Standard Model. Quantum field theory (QFT) is the quantum theory of fields. ... The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... In particle physics, fermions are particles with half-integer spin, such as protons and electrons. ... In particle physics, bosons, named after Satyendra Nath Bose, are particles having integer spin. ... The concept of a scalar is used in mathematics and physics. ... Neutrinos are elementary particles denoted by the symbol ν. Travelling close to the speed of light, lacking electric charge and able to pass through ordinary matter almost undisturbed, they are extremely difficult to detect. ... This article or section is in need of attention from an expert on the subject. ...

Particle physics has had a large impact on the philosophy of science. Some particle physicists adhere to reductionism, a point of view that has been criticized and defended by philosophers and scientists. Part of the debate is described below.

History

The idea that all matter is composed of elementary particles dates to at least the 6th century BC. The philosophical doctrine of atomism was studied by ancient Greek philosophers such as Leucippus, Democritus, and Epicurus. In the 19^th century John Dalton, through his work on stoichiometry, concluded that each element of nature was composed of a single, unique type of particle. Dalton and his contemporaries believed these were the fundamental particles of nature and thus named them atoms, after the Greek word atomos, meaning "indivisible". However, near the end of the century, physicists discovered that atoms were not, in fact, the fundamental particles of nature, but conglomerates of even smaller particles. This article is about matter in physics and chemistry. ... Concern has been expressed that this article or section is missing information about: discussions of existence of atoms among prominent physicists up to the end of 19th century. ... Ancient Greece is the term used to describe the Greek-speaking world in ancient times. ... A philosopher is a person who thinks deeply regarding people, society, the world, and/or the universe. ... This article is about the philosopher. ... ‎ Democritus (Greek: ) was a pre-Socratic Greek philosopher (born at Abdera in Thrace ca. ... Epicurus (Greek ) (341 BC, Samos – 270 BC, Athens) was an ancient Greek philosopher and the founder of Epicureanism, a popular school of thought in Hellenistic Philosophy that spanned about 600 years. ... It has been suggested that Stoichiometric coefficient and Gas stoichiometry be merged into this article or section. ...

The early 20th century explorations of nuclear physics and quantum physics culminated in proofs of nuclear fission in 1939 by Lise Meitner (based on experiments by Otto Hahn), and nuclear fusion by Hans Bethe in the same year. These discoveries gave rise to an active industry of generating one atom from another, even rendering possible (although not profitable) the transmutation of lead into gold. They also led to the development of nuclear weapons. Nuclear physics is the branch of physics concerned with the nucleus of the atom. ... Fig. ... An induced nuclear fission event. ... Lise Meitner ca. ... Otto Hahn and Lise Meitner, 1913, at the KWI for Chemistry in Berlin Otto Hahn (March 8, 1879 – July 28, 1968) was a German chemist and received the 1944 Nobel Prize in Chemistry. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... Hans Albrecht Bethe (pronounced bay-tuh; July 2, 1906 – March 6, 2005), was a German-American physicist who won the Nobel Prize in Physics in 1967 for his work on the theory of stellar nucleosynthesis. ... For other uses, see Alchemy (disambiguation). ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the epicenter. ...

Throughout the 1950s and 1960s, a bewildering variety of particles was found in scattering experiments. This was referred to as the "particle zoo". This term was deprecated after the formulation of the Standard Model during the 1970s in which the large number of particles was explained as combinations of a (relatively) small number of fundamental particles. The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ...

The Standard Model

Main article: Standard Model

The current state of the classification of elementary particles is the Standard Model. It describes the strong, weak, and electromagnetic fundamental forces, using mediating gauge bosons. The species of gauge bosons are the gluons, W^- and W⁺ and Z bosons, and the photons, respectively. The model also contains 24 fundamental particles, which are the constituents of matter. Finally, it predicts the existence of a type of boson known as the Higgs boson, which has yet to be discovered. The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... Gauge bosons are bosonic particles which act as carriers of the fundamental forces of Nature. ... In particle physics, gluons are subatomic particles that cause quarks to interact, and are indirectly responsible for the binding of protons and neutrons together in atomic nuclei. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... In physics, the photon (from Greek φως, phōs, meaning light) is the quantum of the electromagnetic field; for instance, light. ... In particle physics, an elementary particle is a particle of which other, larger particles are composed. ... This article is about matter in physics and chemistry. ... In particle physics, bosons, named after Satyendra Nath Bose, are particles having integer spin. ... The Higgs boson is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model of particle physics. ...

Experiment

In particle physics, the major international laboratories are:

• Brookhaven National Laboratory, located on Long Island, USA. Its main facility is the Relativistic Heavy Ion Colliderwhich collides heavy ions such as gold ions (it is the first heavy ion collider) and protons.

• Budker Institute of Nuclear Physics [1] (Novosibirsk, Russia)]

• CERN, located on the French-Swiss border near Geneva. Its main project is now LHC, or the Large Hadron Collider, which is currently under construction. The LHC will be in operation in 2007 and will be the world's most energetic collider upon completion. Earlier facilities include LEP, the Large Electron Positron collider, which was stopped in 2001 and which is now dismantled to give way for LHC; and SPS, or the Super Proton Synchrotron.

• DESY, located in Hamburg, Germany. Its main facility is HERA, which collides electrons or positrons and protons.

• Fermilab, located near Chicago, USA. Its main facility is the Tevatron, which collides protons and antiprotons and is presently the highest energy particle collider in the world.

• KEK The High Energy Accelerator Research Organization of Japan located in Tsukuba, Japan. It is the home of a number of interesting experiments such as K2K, a neutrino oscillation experiment and Belle, an experiment measuring the CP-symmetry violation in the B-meson.

• SLAC, located near Palo Alto, USA. Its main facility is PEP-II, which collides electrons and positrons.

Many other particle accelerators exist. ≠ Aerial view of Brookhaven National Laboratory. ... Heavy-ion refers to ion of atom which is usually heavier than carbon. ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... The Budker Institute in Winter The Budker Institute of Nuclear Physics is one of the major centres of advanced study of nuclear physics in Russia. ... Location of Novosibirsk in Russia and the Oblast Coordinates: Oblast Novosibirsk  - Mayor Vladimir Gorodetskiy Area    - City 447. ... CERN logo The European Organization for Nuclear Research (French: ), commonly known as CERN (see Naming), pronounced (or in French), is the worlds largest particle physics laboratory, situated just northwest of Geneva on the border between France and Switzerland. ... Geneva (pronunciation //; French: Genève //, German:   //, Italian: Ginevra //, Romansh: Genevra) is the second most populous city in Switzerland (after Zürich), and is the most populous city of Romandy (the French-speaking part of Switzerland). ... The Large Hadron Collider (LHC) is a particle accelerator and collider located at CERN, near Geneva, Switzerland (). Currently under construction, the LHC is scheduled to begin operation in May 2008. ... A hadron, in particle physics, is a subatomic particle which experiences the nuclear force. ... A collider is a type of a particle accelerator with two opposite beams of the particles. ... The Large Electron-Positron Collider (usually called LEP for short. ... For other uses, see Electron (disambiguation). ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... The abbreviation SPS can stand for: IATA airport code for Wichita Falls Municipal Airport St. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... Synchrotrons are now mostly used for producing monochromatic high intensity X-ray beams; here, the synchrotron is the circular track, off which the beamlines branch. ... The DESY (Deutsches Elektronen Synchrotron, German Electron Synchrotron) is the biggest German research center for particle physics, with sites in Hamburg and Zeuthen. ... This article is about the city in Germany. ... HERA (Hadron-Elektron-Ringanlage, or Hadron-Electron Ring Accelerator) is a particle accelerator at DESY in Hamburg. ... For other uses, see Electron (disambiguation). ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... Aerial view of the Fermilab site. ... Tevatron is a circular particle accelerator (or synchrotron) at the Fermi National Accelerator Laboratory in Batavia, Illinois. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... High Energy Accelerator Research Organization (高エネルギー加速器研究機構 Kō EnerugÄ« Kasokuki KenkyÅ« Kikō), commonly known as KEK, is the high-energy physics research organization in Tsukuba, Ibaraki Prefecture, Japan. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... The Stanford Linear Accelerator Center (SLAC) is a U.S. national laboratory operated by Stanford University for the U.S. Department of Energy. ... For other uses, see Electron (disambiguation). ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... For the DC Comics Superhero also called Atom Smasher, see Albert Rothstein. ...

The techniques required to do modern experimental particle physics are quite varied and complex, constituting a subspecialty nearly completely distinct from the theoretical side of the field. See Category:Experimental particle physics for a partial list of the ideas required for such experiments.

Theory

Theoretical particle physics attempts to develop the models, theoretical framework, and mathematical tools to understand current experiments and make predictions for future experiments. See also theoretical physics. There are several major efforts in theoretical particle physics today and each includes a range of different activities. The efforts in each area are interrelated. Theoretical physics employs mathematical models and abstractions of physics, as opposed to experimental processes, in an attempt to understand nature. ...

One of the major activities in theoretical particle physics is the attempt to better understand the standard model and its tests. By extracting the parameters of the standard model from experiments with less uncertainty, this work probes the limits of the standard model and therefore expands our understanding of nature. These efforts are made challenging by the difficult nature of calculating many quantities in quantum chromodynamics. Some theorists making these efforts refer to themselves as phenomenologists and may use the tools of quantum field theory and effective field theory. Others make use of lattice field theory and call themselves lattice theorists. The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... Quantum chromodynamics (abbreviated as QCD) is the theory of the strong interaction (color force), a fundamental force describing the interactions of the quarks and gluons found in hadrons (such as the proton, neutron or pion). ... Particle physics phenomenology is the part of theoretical particle physics that deals with the application of theory to high energy particle physics experiments. ... Quantum field theory (QFT) is the quantum theory of fields. ... In physics, an effective field theory is an approximate theory (usually a quantum field theory) that contains the appropriate degrees of freedom to describe physical phenomena occurring at a chosen length scale, but ignores the substructure and the degrees of freedom at shorter distances (or, equivalently, higher energies). ... It has been suggested that Lattice gauge theory be merged into this article or section. ...

Another major effort is in model building where model builders develop ideas for what physics may lie beyond the standard model (at higher energies or smaller distances). This work is often motivated by the hierarchy problem and is constrained by existing experimental data. It may involve work on supersymmetry, alternatives to the Higgs mechanism, extra spatial dimensions (such as the Randall-Sundrum models), Preon theory, combinations of these, or other ideas. It has been suggested that this article or section be merged with model builder. ... In theoretical physics, a hierarchy problem occurs when the fundamental parameters (couplings or masses) of some Lagrangian are vastly different (usually larger) than the parameters measured by experiment. ... This article or section is in need of attention from an expert on the subject. ... The Higgs mechanism or Anderson-Higgs mechanism, originally proposed by the British physicist Peter Higgs based on a suggestion by Philip Anderson, is the mechanism that gives mass to all elementary particles in particle physics. ... In physics, Randall-Sundrum models imagine that the real world is a higher-dimensional Universe described by warped geometry. ... In particle physics, preons are postulated point-like particles, conceived to be subcomponents of quarks and leptons. ...

A third major effort in theoretical particle physics is string theory. String theorists attempt to construct a unified description of quantum mechanics and general relativity by building a theory based on small strings, and branes rather than particles. If the theory is successful, it may be considered a "Theory of Everything". Interaction in the subatomic world: world lines of pointlike particles in the Standard Model or a world sheet swept up by closed strings in string theory String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects called strings, rather than the zero-dimensional point... For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ... For a less technical and generally accessible introduction to the topic, see Introduction to general relativity. ... P-branes or branes are terms from quantum superstring theory used to refer to membrane-like structures of one to eleven dimensions that arise in equations of this heavily mathematical theory. ... This article or section is in need of attention from an expert on the subject. ...

There are also other areas of work in theoretical particle physics ranging from particle cosmology to loop quantum gravity. Loop quantum gravity (LQG), also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the seemingly incompatible theories of quantum mechanics and general relativity. ...

This divide of efforts in particle physics is reflected in the names of categories on the preprint archive [2]: hep-th (theory), hep-ph (phenomenology), hep-ex (experiments), hep-lat (lattice gauge theory). arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and quantitative biology which can be accessed via the Internet. ... In physics, lattice gauge theory is the study of the behaviour of lattice model gauge theories. ...

Reductionism

Throughout the development of particle physics, there have been many objections to the extreme reductionist (or greedy reductionist) approach of attempting to explain everything in terms of elementary particles and their interaction. These objections have been raised by people from a wide array of fields, including many modern particle physicists, solid state physicists, chemists, biologists, and metaphysical holists. While the Standard Model itself is not challenged, it is contended that the properties of elementary particles are no more (or less) fundamental than the emergent properties of atoms and molecules, and especially statistically large ensembles of those. Some critics of reductionism claim that even a complete knowledge of the underlying elementary particles will not lend a thorough understanding of more complicated natural processes, while others doubt that a complete knowledge of particle behavior (as part of a larger process) could even be attained, thanks to quantum indeterminacy. The term scientific reductionism has been used to describe various reductionist ideas about science. ... Greedy reductionism is a term coined by Daniel Dennett, in the book Darwins Dangerous Idea, to distinguish between acceptable and erroneous forms of reductionism. ... Solid-state physics, the largest branch of condensed matter physics, is the study of rigid matter, or solids. ... For other uses, see Chemistry (disambiguation). ... Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek: βίος, bio, life; and λόγος, logos, knowledge), also referred to as the biological sciences, is the study of living organisms utilizing the scientific method. ... Whole redirects here. ... In science, fundamental science is the part of science that describes the most basic objects, forces, relations between them and laws governing them, such that all other phenomena may be in principle derived from them, following the logic of scientific reductionism. ... A termite cathedral mound produced by a termite colony: a classic example of emergence in nature. ... Quantum indeterminacy is the apparent necessary incompleteness in the description of a physical system, that has become one of the characteristics of the standard description of quantum physics. ...

Reductionists typically claim that all progress in the sciences has involved reductionism to some extent.

Public policy

Experimental results in particle physics are often obtained using enormous particle accelerators which are very expensive (typically several billion US dollars) and require large amounts of government funding. Because of this, particle physics research involves issues of public policy. For the DC Comics Superhero also called Atom Smasher, see Albert Rothstein. ...

Many have argued that the potential advances do not justify the money spent, and that in fact particle physics takes money away from more important research and education efforts. In 1993, the US Congress stopped the Superconducting Super Collider (SSC) because of similar concerns, after US$2 billion had already been spent on its construction. Many scientists, both supporters and opponents of the SSC, believe that the decision to stop construction of the SSC was due in part to the end of the Cold War which removed scientific competition with the Soviet Union as a rationale for spending large amounts of money on the SSC. The Superconducting Super Collider (SSC) was a ring particle accelerator which was planned to be built in the area around Waxahachie, TX. It was planned to have a ring circumference of 87 km (54 miles) and an energy of 20 TeV per beam, potentially enough energy to create a Higgs... For other uses, see Cold War (disambiguation). ...

Some within the scientific community believe that particle physics has also been adversely affected by the aging population. The belief is that the aging population is much more concerned with immediate issues of their health and their parents' health and that this has driven scientific funding away from physics toward the biological and health sciences. In addition, many opponents question the ability of any single country to support the expense of particle physics results and fault the SSC for not seeking greater international funding.

Proponents of particle accelerators hold that the investigation of the most basic theories deserves adequate funding, and that this funding benefits other fields of science in various ways. They point out that all accelerators today are international projects and question the claim that money not spent on accelerators would then necessarily be used for other scientific or educational purposes.

The future

Particle physicists internationally agree on the most important goals of particle physics research in the near and intermediate future. The overarching goal, which is pursued in several distinct ways, is to find and understand what physics may lie beyond the standard model. There are several powerful experimental reasons to expect new physics, including dark matter and neutrino mass. There are also theoretical hints that this new physics should be found at accessible energy scales. Most importantly, though, there may be unexpected and unpredicted surprises which will give us the most opportunity to learn about nature. The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... In astrophysics and cosmology, dark matter refers to hypothetical matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter. ... The neutrino is an elementary particle. ...

Much of the efforts to find this new physics are focused on new collider experiments. A (relatively) near term goal is the completion of the Large Hadron Collider (LHC) in 2007 which will continue the search for the Higgs boson, supersymmetric particles, and other new physics. An intermediate goal is the construction of the International Linear Collider (ILC) which will complement the LHC by allowing more precise measurements of the properties of newly found particles. A decision for the technology of the ILC has been taken in August 2004, but the site has still to be agreed upon. The Large Hadron Collider (LHC) is a particle accelerator and collider located at CERN, near Geneva, Switzerland (). Currently under construction, the LHC is scheduled to begin operation in May 2008. ... The Higgs boson is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model of particle physics. ... In particle physics, supersymmetry is a hypothetical symmetry that relates bosons and fermions. ... The International Linear Collider is a proposed linear particle accelerator. ...

Additionally, there are important non-collider experiments which also attempt to find and understand physics beyond the standard model. One important non-collider effort is the determination of the neutrino masses since these masses may arise from neutrinos mixing with very heavy particles. In addition, cosmological observations provide many useful constraints on the dark matter, although it may be impossible to determine the exact nature of the dark matter without the colliders. Finally, lower bounds on the very long life time of the proton put constraints on Grand Unification Theories at energy scales much higher than collider experiments will be able to probe any time soon. Neutrinos are elementary particles denoted by the symbol ν. Travelling close to the speed of light, lacking electric charge and able to pass through ordinary matter almost undisturbed, they are extremely difficult to detect. ... This article is about the physics subject. ... In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, usually a neutral pion and a positron. ... Grand unification, grand unified theory, or GUT is a theory in physics that unifies the strong interaction and electroweak interaction. ...

See also

• Atomic physics
• Beyond the Standard Model
• Introduction to quantum mechanics
• Fundamental particle
• List of particles
• List of accelerators in particle physics
• Standard model (basic details)
• Subatomic particle
• High pressure physics
• Rochester conference

Atomic physics (or atom physics) is the field of physics that studies atoms as isolated systems comprised of electrons and an atomic nucleus. ... This article or section seems not to be written in the formal tone expected of an encyclopedia entry. ... Quantum mechanics (QM, or quantum theory) is a physical science dealing with the behaviour of matter and energy on the scale of atoms and subatomic particles / waves. ... In particle physics, an elementary particle is a particle of which other, larger particles are composed. ... This is a list of particles in particle physics, including currently known and hypothetical elementary particles, as well as the composite particles that can be built up from them. ... A list of particle accelerators used for particle physics experiments. ... This is a detailed description of the standard model (SM) of particle physics. ... Helium atom (schematic) Showing two protons (red), two neutrons (green) and two electrons (yellow). ... High pressure physics is a specialized field in physics that involves the science and technology challenges of basic and applied materials at high pressures and temperatures. ... ICHEP or International Conference on High Energy Physics is the most prestigious international scientific conference in the field of particle physics, bringing together leading theorists and experimentalists of the world. ...

External links

• Particle Physics News and Resources
• ARXIV.ORG preprint server
• The Particle Adventure - educational project sponsored by the Particle Data Group of the Lawrence Berkeley National Laboratory (LBNL)
• History of particle physics
• symmetry magazine
• Introduction to Particle Physics by Matthew Nobes (published on Kuro5hin):
  • Part 1
  • Part 2
  • Part 3a
  • Part 3b
• SPIRES: High-Energy Physics Literature Database
• CERN Courier - International Journal of High-Energy Physics
• Particle physics in 60 seconds
• overinflation.org Particle Physics News and Rumors

The Particle Data Group is an international collaboration of particle physicists that compiles and reanalyzes published results related to the properties of particles and fundamental interactions. ... The Berkeley Lab is perched on a hill overlooking the Berkeley central campus and San Francisco Bay. ... Kuro5hin (K5) (pronounced corrosion) is a community discussion website (sometimes known as an example of Commons-based peer production) focused on technology and culture. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Classical mechanics (commonly confused with Newtonian mechanics, which is a subfield thereof) is used for describing the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... Thermodynamics (from the Greek θερμη, therme, meaning heat and δυναμις, dynamis, meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ... Statistical mechanics is the application of probability theory, which includes mathematical tools for dealing with large populations, to the field of mechanics, which is concerned with the motion of particles or objects when subjected to a force. ... For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ... Two-dimensional analogy of space-time curvature described in General Relativity. ... Condensed matter physics is the field of physics that deals with the macroscopic physical properties of matter. ... Atomic, molecular, and optical physics is the study of matter-matter and light-matter interactions on the scale of single atoms or structures containing a few atoms. ...