The UA1 experiment (an abbreviation of Underground Area 1 ) was a high-energy physics experiment that ran at CERN 's Proton-Antiproton Collider ( Sp p S ), a modification of the one-beam Super Proton Synchrotron ( SPS ). The data was recorded between 1981 and 1990. The joint discovery of the W and Z bosons by this experiment and the UA2 experiment in 1983 led to the Nobel Prize for physics being awarded to Carlo Rubbia and Simon van der Meer in 1984. Peter Kalmus and John Dowell , from the UK groups working on the project, were jointly awarded the 1988 Rutherford Medal and Prize from the Institute of Physics for their outstanding roles in the discovery of the W and Z particles.
20-550: It was named as the first experiment in a CERN "Underground Area" (UA), i.e. located underground, outside of the two main CERN sites, at an interaction point on the SPS accelerator, which had been modified to operate as a collider . The UA1 central detector was crucial to understanding the complex topology of proton-antiproton collisions. It played a most important role in identifying a handful of W and Z particles among billions of collisions. After
40-412: A reaction occurs that transforms the particles into other particles. Detecting these products gives insight into the physics involved. To do such experiments there are two possible setups: The collider setup is harder to construct but has the great advantage that according to special relativity the energy of an inelastic collision between two particles approaching each other with a given velocity
60-592: A dozen future particle collider projects of various types - circular and linear, colliding hadrons (proton-proton or ion-ion), leptons (electron-positron or muon-muon), or electrons and ions/protons - are currently under consideration for detail exploration of the Higgs/electroweak physics and discoveries at the post-LHC energy frontier. Sources: Information was taken from the website Particle Data Group . Midwestern Universities Research Association The Midwestern Universities Research Association ( MURA )
80-542: A group at the Midwestern Universities Research Association (MURA). This group proposed building two tangent radial-sector FFAG accelerator rings. Tihiro Ohkawa , one of the authors of the first paper, went on to develop a radial-sector FFAG accelerator design that could accelerate two counterrotating particle beams within a single ring of magnets. The third FFAG prototype built by the MURA group
100-798: A much lower flux. The first electron - positron colliders were built in late 1950s-early 1960s in Italy, at the Istituto Nazionale di Fisica Nucleare in Frascati near Rome, by the Austrian-Italian physicist Bruno Touschek and in the US, by the Stanford-Princeton team that included William C.Barber, Bernard Gittelman, Gerry O’Neill, and Burton Richter . Around the same time, the VEP-1 electron-electron collider
120-526: Is a type of particle accelerator that brings two opposing particle beams together such that the particles collide . Compared to other particle accelerators in which the moving particles collide with a stationary matter target, colliders can achieve higher collision energies. Colliders may either be ring accelerators or linear accelerators . Colliders are used as a research tool in particle physics by accelerating particles to very high kinetic energy and letting them impact other particles. Analysis of
140-474: Is not just 4 times as high as in the case of one particle resting (as it would be in non-relativistic physics); it can be orders of magnitude higher if the collision velocity is near the speed of light. In the case of a collider where the collision point is at rest in the laboratory frame (i.e. p → 1 = − p → 2 {\displaystyle {\vec {p}}_{1}=-{\vec {p}}_{2}} ),
160-409: Is the total energy of a particle from each beam. For a fixed target experiment where particle 2 is at rest, E c m 2 = m 1 2 + m 2 2 + 2 m 2 E 1 {\displaystyle E_{\mathrm {cm} }^{2}=m_{1}^{2}+m_{2}^{2}+2m_{2}E_{1}} . The first serious proposal for a collider originated with
180-584: The 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced. The UA1 detector was conceived and designed in 1978/9, with the proposal submitted in mid-1978. Since the end of running, the magnet used in the UA1 experiment has been used for other high energy physics experiments, notably the NOMAD and T2K neutrino experiments. CERN-UA-01 experiment record on INSPIRE-HEP Collider A collider
200-565: The MURA machine and laboratory. In its formative years, Donald Kerst was the director of MURA. At this institution, Keith Symon invented the FFAG accelerator , independently to Tihiro Ohkawa , which combines several concepts of cyclotrons and synchrotrons . FFAG concepts were extensively developed in MURA. The proposed MURA accelerators were scaling FFAG synchrotrons , meaning that orbits of any momentum are photographic enlargements of those of any other momentum. The concept of FFAG acceleration
220-503: The byproducts of these collisions gives scientists good evidence of the structure of the subatomic world and the laws of nature governing it. These may become apparent only at high energies and for extremely short periods of time, and therefore may be hard or impossible to study in other ways. In particle physics one gains knowledge about elementary particles by accelerating particles to very high kinetic energy and guiding them to colide with other particles. For sufficiently high energy,
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#1732852634328240-458: The center of mass energy E c m {\displaystyle E_{\mathrm {cm} }} (the energy available for producing new particles in the collision) is simply E c m = E 1 + E 2 {\displaystyle E_{\mathrm {cm} }=E_{1}+E_{2}} , where E 1 {\displaystyle E_{1}} and E 2 {\displaystyle E_{2}}
260-466: The discovery of the W and Z boson, the UA1 collaboration went on to search for the top quark . Physicists had anticipated its existence since 1977, when its partner — the bottom quark — was discovered. It was felt that the discovery of the top quark was imminent. In June 1984, Carlo Rubbia at the UA1 experiment expressed to the New York Times that evidence of the top quark "looks really good". Over
280-571: The first proton - antiproton collisions were recorded at a center of mass energy of 1.6 TeV, making it the highest energy collider in the world, at the time. The energy had later reached 1.96 TeV and at the end of the operation in 2011 the collider luminosity exceeded 430 times its original design goal. Since 2009, the most high-energetic collider in the world is the Large Hadron Collider (LHC) at CERN. It currently operates at 13 TeV center of mass energy in proton-proton collisions. More than
300-442: The next months it became clear that UA1 had overlooked a significant source of background. The top quark was ultimately discovered in 1994–1995 by physicists at Fermilab with a mass near 175 GeV. The UA1 was a huge and complex detector for its day. It was designed as a general-purpose detector. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded
320-440: The tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon - ethane gas mixture filling the chambers were ionised by the passage of charged particles . The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of
340-427: Was a 50 MeV electron machine built in 1961 to demonstrate the feasibility of this concept. Gerard K. O'Neill proposed using a single accelerator to inject particles into a pair of tangent storage rings . As in the original MURA proposal, collisions would occur in the tangent section. The benefit of storage rings is that the storage ring can accumulate a high beam flux from an injection accelerator that achieves
360-468: Was a collaboration between 15 universities with the goal of designing and building a particle accelerator for the Midwestern United States . It existed between 1953–1967, but could not achieve its goal in this time and lost funding. It was thought that President John F. Kennedy would have supported the MURA machine, while one of President Lyndon B. Johnson 's first actions was the shutdown of
380-580: Was a pair of storage rings that accumulated and collided protons injected by the CERN Proton Synchrotron . This was the first hadron collider, as all of the earlier efforts had worked with electrons or with electrons and positrons . In 1968 construction began on the highest energy proton accelerator complex at Fermilab . It was eventually upgraded to become the Tevatron collider and in October 1985
400-583: Was independently developed and built under supervision of Gersh Budker in the Institute of Nuclear Physics in Novosibirsk , USSR . The first observations of particle reactions in the colliding beams were reported almost simultaneously by the three teams in mid-1964 - early 1965. In 1966, work began on the Intersecting Storage Rings at CERN , and in 1971, this collider was operational. The ISR
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