ALEPH | Apparatus for LEPPHysics |
---|---|
DELPHI | DEtector with Lepton, Photon and Hadron Identification |
OPAL | Omni-Purpose Apparatus for LEP |
L3 | Third LEP experiment |
ALEPH was a particle detector at the Large Electron-Positron collider (LEP) at CERN. It was designed to explore the physics predicted by the Standard Model and to search for physics beyond it. [1] [2] [3]
The ALEPH detector was built to measure events created by electron positron collisions in LEP. It operated from 1989 to 1995 in the energy range of the Z particle (around 91 GeV) and later (1995 to 2000) above the threshold of W pair production (up to 200 GeV)[ citation needed ]. Typical events have many particles distributed in jets over the entire detector volume. The event rate ranged from around 1 Hz at the peak of the Z to at least a factor hundred smaller at the highest energies. The ALEPH detector was therefore designed to accumulate, for each event, as much information over as much solid angle as was practical.
This was achieved by a cylindrical arrangement around the beam pipe with the electron-positron interaction point in the middle. A magnetic field of 1.5 Tesla was created by a superconducting coil 6.4 m long and 5.3 m in diameter. The iron return yoke was a dodecagonal cylinder with two end-plates that left holes for a focusing magnet (quadrupole) of the LEP machine. The iron was 1.2 m thick and was subdivided into layers that left space for the insertion of layers of streamer tubes. In this way the iron yoke was a fully instrumented hadron calorimeter (HCAL), which was read out in 4608 projective towers. Outside the iron, there were two double layers of streamer tube chambers to record the position and angle of muons that had penetrated the iron. [4]
Inside the coil was the electron-photon calorimeter (ECAL), designed for the highest possible angular resolution and electron identification. It consisted of alternating layers of lead and proportional tubes read out in 73,728 projective towers, each subdivided into three depth zones. The central detector for charged particles was the time projection chamber (TPC), 4.4 m long and 3.6 m in diameter. It provided a three dimensional measurement of each track segment. In addition, it provided up to 330 ionisation measurements for a track; this was useful for particle identification. The TPC surrounded the inner track chamber (ITC); an axial-wire drift chamber with inner and outer diameters of 13 cm and 29 cm and a length of 2 m. It provided 8 track coordinates and a trigger signal for charged particles that came from the interaction point. Closest to the beam pipe, was a silicon strip vertex detector. For each track, this measured two pairs of coordinates, 6.3 cm and 11 cm away from the beam axis over a length of 40 cm along the beam line. The beam pipe, made out of beryllium, had a diameter of 16 cm. The vacuum inside was about 10−15 atm. [5] [6]
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.
The Large Electron–Positron Collider (LEP) was one of the largest particle accelerators ever constructed. It was built at CERN, a multi-national centre for research in nuclear and particle physics near Geneva, Switzerland.
A wire chamber or multi-wire proportional chamber is a type of proportional counter that detects charged particles and photons and can give positional information on their trajectory, by tracking the trails of gaseous ionization.
The Compact Linear Collider (CLIC) is a concept for a future linear particle accelerator that aims to explore the next energy frontier. CLIC would collide electrons with positrons and is currently the only mature option for a multi-TeV linear collider. The accelerator would be between 11 and 50 km long, more than ten times longer than the existing Stanford Linear Accelerator (SLAC) in California, USA. CLIC is proposed to be built at CERN, across the border between France and Switzerland near Geneva, with first beams starting by the time the Large Hadron Collider (LHC) has finished operations around 2035.
The Underground Area 2 (UA2) experiment was a high-energy physics experiment at the Proton-Antiproton Collider — a modification of the Super Proton Synchrotron (SPS) — at CERN. The experiment ran from 1981 until 1990, and its main objective was to discover the W and Z bosons. UA2, together with the UA1 experiment, succeeded in discovering these particles in 1983, leading to the 1984 Nobel Prize in Physics being awarded to Carlo Rubbia and Simon van der Meer. The UA2 experiment also observed the first evidence for jet production in hadron collisions in 1981, and was involved in the searches of the top quark and of supersymmetric particles. Pierre Darriulat was the spokesperson of UA2 from 1981 to 1986, followed by Luigi Di Lella from 1986 to 1990.
In physics, a time projection chamber (TPC) is a type of particle detector that uses a combination of electric fields and magnetic fields together with a sensitive volume of gas or liquid to perform a three-dimensional reconstruction of a particle trajectory or interaction.
DELPHI was one of the four main detectors of the Large Electron–Positron Collider (LEP) at CERN, one of the largest particle accelerators ever made. Like the other three detectors, it recorded and analyzed the result of the collision between LEP's colliding particle beams. The specific focus of DELPHI was on particle identification, three-dimensional information, high granularity (detail), and precise vertex determination.
The Collider Detector at Fermilab (CDF) experimental collaboration studies high energy particle collisions from the Tevatron, the world's former highest-energy particle accelerator. The goal is to discover the identity and properties of the particles that make up the universe and to understand the forces and interactions between those particles.
The DØ experiment was a worldwide collaboration of scientists conducting research on the fundamental nature of matter. DØ was one of two major experiments located at the Tevatron Collider at Fermilab in Batavia, Illinois. The Tevatron was the world's highest-energy accelerator from 1983 until 2009, when its energy was surpassed by the Large Hadron Collider. The DØ experiment stopped taking data in 2011, when the Tevatron shut down, but data analysis is still ongoing. The DØ detector is preserved in Fermilab's DØ Assembly Building as part of a historical exhibit for public tours.
T2K is a particle physics experiment studying the oscillations of the accelerator neutrinos. The experiment is conducted in Japan by the international cooperation of about 500 physicists and engineers with over 60 research institutions from several countries from Europe, Asia and North America and it is a recognized CERN experiment (RE13). T2K collected data within its first phase of operation from 2010 till 2021. The second phase of data taking (T2K-II) is expected to start in 2023 and last until commencement of the successor of T2K – the Hyper-Kamiokande experiment in 2027.
OPAL was one of the major experiments at CERN's Large Electron–Positron Collider. OPAL studied particles and their interactions by collecting and analysing electron-positron collisions. There were over three-hundred physicists from 32 institutions involved in the collaboration.
The L3 experiment was one of the four large detectors on the Large Electron–Positron Collider (LEP). The detector was designed to look for the physics of the Standard Model and beyond. It started up in 1989 and stopped taking data in November 2000 to make room for construction of the Large Hadron Collider (LHC). Now, the ALICE detector sits in the cavern that L3 used to occupy, reusing L3's characteristic red octagonal magnet.
The NA62 experiment is a fixed-target particle physics experiment in the North Area of the SPS accelerator at CERN. The experiment was approved in February 2007. Data taking began in 2015, and the experiment is expected to become the first in the world to probe the decays of the charged kaon with probabilities down to 10−12. The experiment's spokesperson is Cristina Lazzeroni. The collaboration involves 333 individuals from 30 institutions and 13 countries around the world.
The Beijing Spectrometer III is a particle physics experiment at the Beijing Electron–Positron Collider II at the Institute of High Energy Physics (IHEP). It is designed to study the physics of charm, charmonium, and light hadron decays. It also performs studies of the tau lepton, tests of QCD, and searches for physics beyond the Standard Model. The experiment started collecting data in the summer of 2008.
The LEP Pre-Injector (LPI) was the initial source that provided electrons and positrons to CERN's accelerator complex for the Large Electron–Positron Collider (LEP) from 1989 until 2000.
The AMY detector was used by particle physicists at the TRISTAN electron-positron collider at KEK in Japan between 1984 and 1995 to search for new particles and perform precision studies of the strong and electroweak forces.
The Underground Area 7 (UA7) experiment was a high-energy physics experiment at the Proton-Antiproton Collider, a modification of the Super Proton Synchrotron (SPS), at CERN. The purpose of the experiment was to measure the invariant cross section of photons and neutral pions (π0) emitted close to zero degrees, by using silicon shower detectors. The experiment data taking ran from 1985 to 1986, and the final analysis was completed in 1996.