TOTEM experiment

Last updated
Large Hadron Collider
(LHC)
LHC.svg
Plan of the LHC experiments and the preaccelerators.
LHC experiments
ATLAS A Toroidal LHC Apparatus
CMS Compact Muon Solenoid
LHCb LHC-beauty
ALICE A Large Ion Collider Experiment
TOTEM Total Cross Section, Elastic Scattering and Diffraction Dissociation
LHCf LHC-forward
MoEDAL Monopole and Exotics Detector At the LHC
FASER ForwArd Search ExpeRiment
SND Scattering and Neutrino Detector
LHC preaccelerators
p and Pb Linear accelerators for protons (Linac 4) and lead (Linac 3)
(not marked) Proton Synchrotron Booster
PS Proton Synchrotron
SPS Super Proton Synchrotron


The TOTEM experiment (TOTal Elastic and diffractive cross section Measurement) is one of the nine detector experiments at CERN's Large Hadron Collider. The other eight are: ATLAS, ALICE, CMS, LHCb, LHCf, MoEDAL, FASER and SND@LHC. It shares an interaction point with CMS. The detector aims at measurement of total cross section, elastic scattering, and diffraction processes. The primary instrument of the detector is referred to as a Roman pot. In December 2020, the D0 and TOTEM Collaborations made public the odderon discovery based on a purely data driven approach in a CERN and Fermilab approved preprint that was later published in Physical Review Letters. [1] In this experimental observation, the TOTEM proton-proton data in the region of the diffractive minimum and maximum was extrapolated from 13, 8, 7 and 2.76 TeV to 1.96 TeV and compared this to D0 data at 1.96 TeV in the same t-range giving an odderon significance of 3.4 σ. When combined with TOTEM experimental data at 13 TeV at small scattering angles providing an odderon significance of 3.4 - 4.6 σ, the combination resulted in an odderon significance of at least 5.2 σ. [2]

Contents

TOTEM tunnel.jpg
TOTEM experiment in the LHC tunnel
TOTEM.jpg
The roman pot of TOTEM experiment.

See also

Related Research Articles

<span class="mw-page-title-main">CERN</span> European research centre based in Geneva, Switzerland

The European Organization for Nuclear Research, known as CERN, is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Geneva, on the France–Switzerland border. It comprises 23 member states. Israel, admitted in 2013, is the only non-European full member. CERN is an official United Nations General Assembly observer.

<span class="mw-page-title-main">Tevatron</span> Defunct particle accelerator at Fermilab in Illinois, USA (1983–2011)

The Tevatron was a circular particle accelerator in the United States, at the Fermi National Accelerator Laboratory, east of Batavia, Illinois, and is the second highest energy particle collider ever built, after the Large Hadron Collider (LHC) of the European Organization for Nuclear Research (CERN) near Geneva, Switzerland. The Tevatron was a synchrotron that accelerated protons and antiprotons in a 6.28 km (3.90 mi) ring to energies of up to 1 TeV, hence its name. The Tevatron was completed in 1983 at a cost of $120 million and significant upgrade investments were made during its active years of 1983–2011.

<span class="mw-page-title-main">Compact Muon Solenoid</span> One of the two general-purposes experiments at the CERNs Large Hadron Collider

<span class="mw-page-title-main">Large Hadron Collider</span> Particle accelerator at CERN, Switzerland

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, as well as 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.

<span class="mw-page-title-main">ATLAS experiment</span> CERN LHC experiment

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.

<span class="mw-page-title-main">H1 (particle detector)</span>

H1 was a particle detector operated at the HERA collider at the German national laboratory DESY in Hamburg. The first studies for the H1 experiment were proposed in 1981. The H1 detector began operating together with HERA in 1992 and took data until 2007. It consisted of several different detector components, measured about 12 m × 15 m × 10 m and weighed 2800 tons. It was one of four detectors along the HERA accelerator.

<span class="mw-page-title-main">Large Electron–Positron Collider</span> Particle accelerator at CERN, Switzerland

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.

<span class="mw-page-title-main">Glueball</span> Hypothetical particle composed of gluons

In particle physics, a glueball is a hypothetical composite particle. It consists solely of gluon particles, without valence quarks. Such a state is possible because gluons carry color charge and experience the strong interaction between themselves. Glueballs are extremely difficult to identify in particle accelerators, because they mix with ordinary meson states. In pure gauge theory, glueballs are the only states of the spectrum and some of them are stable.

<span class="mw-page-title-main">LHCb experiment</span> Experiment at the Large Hadron Collider

<span class="mw-page-title-main">ALICE experiment</span> Detector experiments at the Large Hadron Collider

The Roman pot is the name of a technique used in accelerator physics. Named after its implementation by the CERN-Rome collaboration in the early 1970s, it is an important tool to measure the total cross section of two particle beams in a collider. They are called pots because the detectors are housed in cylindrical vessels. The first generation of Roman pots was purpose-built by the CERN Central Workshops and used in the measurement of the total cross-section of proton-proton inter-actions in the ISR.

The High Luminosity Large Hadron Collider is an upgrade to the Large Hadron Collider, operated by the European Organization for Nuclear Research (CERN), located at the French-Swiss border near Geneva. From 2011 to 2020, the project was led by Lucio Rossi. In 2020, the lead role was taken up by Oliver Brüning.

<span class="mw-page-title-main">LHCf experiment</span>

The LHCf is a special-purpose Large Hadron Collider experiment for astroparticle physics, and one of nine detectors in the LHC accelerator at CERN. LHCf is designed to study the particles generated in the forward region of collisions, those almost directly in line with the colliding proton beams.

In particle physics, the odderon corresponds to an elusive family of odd-gluon states, dominated by a three-gluon state. When protons collide elastically with protons or with anti-protons at high energies, even or odd numbers of gluons are exchanged. Exchanging an even number of gluons is a crossing-even part of elastic proton–proton and proton–antiproton scattering, while odderon exchange, i.e. exchange of odd number of gluons, corresponds to a crossing-odd term in the elastic scattering amplitude. It took about 48 years to find a definite signal of odderon exchange.

<span class="mw-page-title-main">Search for the Higgs boson</span> Effort to prove the existence or non-existence of the Higgs boson

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.

<span class="mw-page-title-main">750 GeV diphoton excess</span> 2015 anomaly in the Large Hadron Collider

The 750 GeV diphoton excess in particle physics was an anomaly in data collected at the Large Hadron Collider (LHC) in 2015, which could have been an indication of a new particle or resonance. The anomaly was absent in data collected in 2016, suggesting that the diphoton excess was a statistical fluctuation. In the interval between the December 2015 and August 2016 results, the anomaly generated considerable interest in the scientific community, including about 500 theoretical studies. The hypothetical particle was denoted by the Greek letter Ϝ in the scientific literature, owing to the decay channel in which the anomaly occurred. The data, however, were always less than five standard deviations (sigma) different from that expected if there was no new particle, and, as such, the anomaly never reached the accepted level of statistical significance required to announce a discovery in particle physics. After the August 2016 results, interest in the anomaly sank as it was considered a statistical fluctuation. Indeed, a Bayesian analysis of the anomaly found that whilst data collected in 2015 constituted "substantial" evidence for the digamma on the Jeffreys scale, data collected in 2016 combined with that collected in 2015 was evidence against the digamma.

<span class="mw-page-title-main">David B. Cline</span> American particle physicist

]

<span class="mw-page-title-main">FASER experiment</span> 2022 particle physics experiment at the Large Hadron Collider at CERN

FASER is one of the nine particle physics experiments in 2022 at the Large Hadron Collider at CERN. It is designed to both search for new light and weakly coupled elementary particles, and to detect and study the interactions of high-energy collider neutrinos. In 2023, FASER reported the first observation of collider neutrinos.

<span class="mw-page-title-main">Kamal Benslama</span> Moroccan-Swiss Experimental Particle physicist

Kamal Benslama is a Moroccan-Swiss experimental particle physicist. He is a professor of physics at Drew University, a visiting experimental scientist at Fermilab, and a guest scientist at Brookhaven National Laboratory. He worked on the ATLAS experiment, at the Large Hadron Collider (LHC) at CERN in Switzerland, which is considered the largest experiment in the history of physical science. At present, he is doing research at Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago. Fermilab is a United States Department of Energy national laboratory specializing in high-energy particle physics.

<span class="mw-page-title-main">Scattering and Neutrino Detector</span>

The Scattering and Neutrino Detector (SND) at the Large Hadron Collider (LHC), CERN, is an experiment built for the detection of the collider neutrinos. The primary goal of SND is to measure the p+p --> +X process and search for the feebly interacting particles. It will be operational from 2022, during the LHC-Run 3 (2022-2024). SND will be installed in an empty tunnel- TI18 that links the LHC and Super Proton Synchrotron, 480m away from the ATLAS experiment interaction point in the fast forward region and along the beam collision axis.

References

  1. Abazov, V. M.; et al. (4 August 2021). "Odderon Exchange from Elastic Scattering Differences between pp and ppbar Data at 1.96 TeV and from pp Forward Scattering Measurements". Physical Review Letters. 127 (6): 062003. arXiv: 2012.03981 . Bibcode:2021PhRvL.127f2003A. doi:10.1103/PhysRevLett.127.062003. PMID   34420329. S2CID   227737845.
  2. "Odderon discovered". CERN Courier. 2021-03-09. Retrieved 2022-02-11.

Further reading

46°18′35″N6°04′35″E / 46.30972°N 6.07639°E / 46.30972; 6.07639