- M. J. Borchert et al. (BASE Collaboration) · Nature, 2022
- C. Smorra et al. (BASE Collaboration) · Nature, 2017
- M. M. Ter-Pogossian, M. E. Phelps, E. J. Hoffman & N. A. Mullani · Radiology, 1975
- UniversityALPHA antihydrogen experiment, ATHENA, antiproton radiotherapy research (ACE)
- Antiproton Cell ExperimentMeasure how effectively antiproton beams kill cells relative to protons, to assess antiprotons for cancer radiotherapy.
- Antihydrogen Experiment: Gravity, Interferometry, SpectroscopyMeasure Earth's gravitational acceleration on a pulsed, horizontally travelling beam of antihydrogen with a moiré deflectometer, aiming for 1% precision.
- A Large Ion Collider ExperimentStudy strongly interacting matter at extreme energy densities in LHC collisions, including measuring how light antinuclei and antihypernuclei form, interact and compare with their matter partners.
- Antihydrogen Laser Physics ApparatusTrap antihydrogen and compare its spectrum and its response to gravity with those of hydrogen, testing CPT symmetry and the weak equivalence principle.
- Alpha Magnetic SpectrometerMeasure charged cosmic rays above the atmosphere with particle-physics precision to search for antimatter and dark-matter signatures and to trace the origin of cosmic rays.
- Alpha Magnetic Spectrometer (AMS-02), International Space StationAMS Collaboration; hosted on the ISS by NASA; operated from CERN, Low Earth orbit aboard the ISS (operations from the AMS Payload Operations Control Centre, CERN Prévessin site)
- Theoretical physicist and human-rights activistSet out in 1967 the three conditions needed to explain the universe's excess of matter.
- What happens when a particle meets its antiparticle: their combined mass-energy reappears as photons or new particles.
- The simplest anti-atom, a positron bound to an antiproton; first made in 1995 and now trapped by the thousand.
- Matter built from antiparticles: the same masses as ordinary particles, opposite charges, and mutual annihilation on contact.
- Does antimatter fall like matter? Since 2023 we know it falls down; how precisely it matches matter is still being measured.
- Uses antihydrogensMatter–antimatter annihilation converts essentially all rest mass to energy: one gram of antimatter meeting one gram of matter releases about 1.8 × 10¹⁴ J, roughly 43 kilotons of TNT, and NASA cites about 10⁸ MJ per gram, ten orders of magnitude above chemical fuels.
- Rocket concepts that would harness annihilation, the densest energy source known, but need far more antimatter than exists.
- Using a few billion antiprotons not as fuel but as a spark to trigger fission and fusion in a small pellet.
- Uses antihydrogensSteven Howe and Gerald Jackson of Hbar Technologies proposed the antimatter-driven sail in a NASA NIAC study begun in 2002.
- CompanyAntiproton generation via particle physics, advanced accelerators and autonomous experimentation, High-inventory, transportable antiproton traps, Antiproton-based non-destructive measurement (asteroid assay, container verification, fissile-material detection)
- The neutron's antiparticle: electrically neutral, but with opposite baryon number and magnetic moment. Discovered in 1956.
- B. Cork, G. R. Lambertson, O. Piccioni & W. A. Wenzel · Physical Review, 1956
- Bound clusters of antiprotons and antineutrons, from the antideuteron of 1965 to antihelium-4 and antihyperhydrogen-4.
- The partner of a particle with identical mass and lifetime but opposite charge and other additive quantum numbers.
- The proton's antiparticle, with negative charge; discovered at Berkeley's Bevatron in 1955 and now studied one at a time in traps.
- Uses antiprotonsAntiprotons slow down in tissue much as protons do.
- How CERN turns hot, fast antiprotons from a target into slow, dense bunches that experiments can trap.
- Antiproton Decelerator (AD) and Extra Low ENergy Antiproton ring (ELENA), CERN Antimatter FactoryCERN, AD Hall (Building 193), CERN Meyrin site, Meyrin, Geneva
- Uses antiprotonsAn antiproton captured by an atom cascades down to the nucleus and annihilates on either a proton or a neutron near the nuclear surface.
- Uses antiprotonsAn antiproton stopping in matter annihilates on a nucleus, emitting energetic pions and gamma rays that escape the target.
- Uses antiprotonsIn the 1990s Penn State researchers proposed using small numbers of antiprotons as a trigger for nuclear reactions rather than as the main fuel.
- Experimental particle physicistLed the CERN team that observed the antideuteron, the first antinucleus, in 1965.
- PhysicistImagined 'anti-atoms' and 'anti-matter' in a playful 1898 letter to Nature.
- Atomic Spectroscopy And Collisions Using Slow AntiprotonsTest CPT symmetry by laser spectroscopy of antiprotonic helium and in-flight hyperfine spectroscopy of an antihydrogen beam, and study antiproton collisions with atoms.
- Uses antiprotonsAntimatter, Inc.
- Antihydrogen Production and Precision ExperimentsProduce cold antihydrogen by mixing trapped antiprotons and positrons, as a first step toward precision comparison with hydrogen.
- Antihydrogen TrapProduce, trap and study cold antihydrogen for precise comparison with hydrogen.
- G. Gabrielse et al. (ATRAP Collaboration) · Physical Review Letters, 2002
- The unexplained excess of matter over antimatter in the universe, about one extra particle per billion antiparticles in the early universe.
- Baryon Antibaryon Symmetry ExperimentCompare the magnetic moments and charge-to-mass ratios of protons and antiprotons in cryogenic Penning traps to test CPT invariance in the baryon sector.
- BASE-STEP transportable antiproton trapMove trapped antiprotons by road from CERN's Antimatter Factory to low-noise laboratories, where CPT tests at least 100 times more precise should be possible.
- R. Akbari et al. (ALPHA Collaboration) · Nature Communications, 2025
- Balloon-borne Experiment with a Superconducting SpectrometerSearch cosmic rays for antihelium and measure low-energy antiprotons with a balloon-borne superconducting magnetic spectrometer.
- Laboratoryheavy-ion collisions (RHIC/STAR), antinuclei and antihypernuclei, antihydrogen (ALPHA participation)
- Experimental high-energy physicistLead author of the 1956 discovery of the antineutron at the Bevatron.
- Uses antiprotonsAntimatter, Inc.
- Experimental physicistDiscovered the positron in cosmic rays in 1932, the first antiparticle ever observed.
- Experimental particle physicistChampioned the proton–antiproton collider that found the W and Z bosons; Nobel Prize 1984.
- LaboratoryAntiproton Decelerator and ELENA, antihydrogen production and spectroscopy, antiproton precision measurements
- M. Ahmadi et al. (ALPHA Collaboration) · Nature, 2018
- Experimental physicistPrincipal investigator of BASE-STEP, the trap that first carried antiprotons by road.
- Experimental physicistCo-discoverer of the antiproton in 1955, left out of the Nobel Prize.
- B. M. Latacz et al. (BASE Collaboration) · Nature, 2025
- ALPHA Collaboration · Nature Physics, 2011
- Antiparticles arriving from space, from positrons and antiprotons to tentative antihelium, and what they reveal about the cosmos.
- A small difference between the behaviour of matter and antimatter, first seen in kaons in 1964 and in baryons in 2025.
- The combined reversal of charge, mirror image and time, which relativistic quantum field theory requires to be an exact symmetry.
- Paul Dirac's 1928 relativistic wave equation for the electron, whose negative-energy solutions foretold antimatter.
- Dirac's picture of the vacuum as a filled ocean of negative-energy electrons, whose vacancies, or holes, behave as antiparticles.
- Fermilab E862 – Observation of Antihydrogen AtomsProduce and detect fast antihydrogen atoms formed when circulating antiprotons capture positrons created in collisions with a hydrogen gas-jet target.
- Experimental physicistAntiprotonic-helium pioneer and ASACUSA physicist working on antihydrogen hyperfine spectroscopy.
- Cooling a beam or cloud of heavy charged particles by letting it share heat with a cold beam or cloud of electrons.
- Experimental physicistLed the Berkeley team that discovered the antiproton in 1955; Nobel Prize 1959.
- Theoretical physicistShowed in 1937 that a neutral fermion could be its own antiparticle.
- J. H. Christenson, J. W. Cronin, V. L. Fitch & R. Turlay · Physical Review Letters, 1964
- T. Massam, Th. Muller, B. Righini, M. Schneegans & A. Zichichi · Il Nuovo Cimento, 1965
- Uses antiprotonsA trapped antiproton is lost only when it meets residual gas, so its storage lifetime sets an upper bound on gas density far below the range of conventional gauges.
- Facility for Antiproton and Ion ResearchFAIR GmbH with GSI Helmholtzzentrum für Schwerionenforschung, GSI/FAIR campus, Darmstadt, Hesse
- Laboratoryantiproton production and stochastic cooling, Tevatron proton–antiproton collider (1985–2011), antiproton storage rings
- Fermilab Antiproton Source (Target Station, Debuncher and Accumulator rings, with the Recycler)Fermi National Accelerator Laboratory, Batavia, Illinois (AP-0 target hall and Antiproton Source rings)
- G. Gabrielse et al. · Physical Review Letters, 1986
- Uses antiprotonsAntiprotons annihilating on heavy nuclei can induce fission, releasing neutrons and fission fragments whose yields depend on the target; experiments in the early 1990s measured large fission and neutron yields from antiprotons annihilating at rest in uranium.
- R. Akbari et al. (ALPHA Collaboration) · Nature, 2026
- UniversityTRAP and ATRAP experiments, antiproton mass and magnetic moment, antihydrogen
- General Antiparticle SpectrometerSearch for low-energy cosmic-ray antideuterons and antihelium, and measure low-energy antiprotons, as signatures of dark matter.
- Gravitational Behaviour of Antihydrogen at RestTime the free fall of ultracold antihydrogen, obtained by cooling and photodetaching positive antihydrogen ions, to test the weak equivalence principle.
- Experimental particle physicist and antimatter propulsion researcherLed Penn State's antiproton propulsion work, from portable traps to the ICAN and AIMStar concepts.
- Experimental physicistFirst trapped antiprotons in 1986 and led ATRAP's cold-antihydrogen work.
- Accelerator and plasma physicistInvented electron cooling, the technique that tames antiproton beams at low energy.
- Experimental physicistCo-discovered electron–positron pair production with Blackett and, later, the charged pion.
- LaboratoryFAIR antiproton and ion facility, PANDA antiproton physics, Penning-trap physics (BASE)
- Experimental atomic physicistPioneered the Penning trap for single particles; compared electron and positron magnetism.
- Companyantimatter-driven sail propulsion, antiproton production and commercialization, antimatter harvesting in space
- UniversityBASE and BASE-STEP, transportable antiproton traps, proton–antiproton CPT tests
- Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility, muon sectionJ-PARC Center (KEK and Japan Atomic Energy Agency), Tokai, Ibaraki Prefecture
- Experimental particle physicistCo-discovered CP violation in 1964, the first sign that matter and antimatter behave differently.
- Experimental physicistFounder and spokesperson of ALPHA, which trapped, laser-cooled and dropped antihydrogen.
- Slow Positron Facility, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)KEK Institute of Materials Structure Science (IMSS), Test Hall, Electron-Positron Injector Linac building, KEK Tsukuba Campus, Tsukuba, Ibaraki
- C. J. Baker et al. (ALPHA Collaboration) · Nature, 2021
- Laboratorydiscovery of the antiproton (1955), Bevatron, accelerator physics
- Experimental particle physicistCo-discovered the antideuteron at Brookhaven in 1965; Nobel laureate and Fermilab director.
- Large Hadron ColliderCERN, CERN, Geneva (France–Switzerland border)
- Large Hadron Collider beauty experimentMeasure the small differences between matter and antimatter, chiefly CP violation in decays of hadrons containing beauty and charm quarks.
- Laboratoryantiproton gravity (PS200 at LEAR), Penning-trap antiproton capture, nuclear physics
- Low Energy Antiproton RingCERN, Proton Synchrotron South Hall (Building 150), CERN Meyrin site, Meyrin, Geneva
- A trap for neutral atoms, such as antihydrogen, built around a point of minimum magnetic field strength.
- Spin-½ particles that are their own antiparticles. Whether neutrinos are Majorana fermions is one of physics' open questions.
- Experimental physicistALPHA founding scientist and spokesperson of ALPHA-Canada at TRIUMF.
- LaboratoryASACUSA antihydrogen hyperfine spectroscopy, atomic hydrogen beams, exotic atoms
- Experimental physicistWeighs the antiproton by laser spectroscopy of antiprotonic helium; ASACUSA co-spokesperson.
- LaboratoryPenning-trap precision measurements, BASE collaboration, CPT symmetry tests
- Experimental particle physicistFounder of CERN's AEgIS antimatter-gravity experiment and an ATHENA veteran.
- Agencyadvanced propulsion concepts, antimatter propulsion studies, space antiparticle harvesting
- NEutron induced POsitron source MUniCh at the FRM II research reactorTechnical University of Munich and Universität der Bundeswehr München, at the Heinz Maier-Leibnitz Zentrum (MLZ), FRM II research neutron source, Garching near Munich, Bavaria
- Experimental physicistALPHA co-founder and deputy spokesperson; leads Swansea University's antimatter group.
- D. E. Dorfan, J. Eades, L. M. Lederman, W. Lee & C. C. Ting · Physical Review Letters, 1965
- O. Chamberlain, E. Segrè, C. Wiegand & T. Ypsilantis · Physical Review, 1955
- LHCb Collaboration · Nature, 2025
- M. Ahmadi et al. (ALPHA Collaboration) · Nature, 2017
- STAR Collaboration · Nature, 2011
- STAR Collaboration · Nature, 2024
- E. K. Anderson et al. (ALPHA Collaboration) · Nature, 2023
- Experimental physicistCo-discovered the antineutron in 1956 and contested credit for the antiproton.
- Experimental physicistCo-discovered the antiproton at the Bevatron in 1955; Nobel Prize 1959.
- The creation of a particle and its antiparticle from energy, as when a gamma ray becomes an electron and a positron near a nucleus.
- Payload for Antimatter Matter Exploration and Light-nuclei AstrophysicsMeasure cosmic-ray antiprotons and positrons from orbit over a wide energy range and search for antinuclei, to probe dark matter and cosmic-ray propagation.
- Experimental particle physicistETH Zurich physicist working on positronium, muonium and GBAR's first antihydrogen.
- Experimental particle physicistInitiator and spokesperson of GBAR, which aims to measure antihydrogen's free fall.
- Experimental physicistWith Occhialini, photographed electron–positron pair creation and confirmed the positron in 1933.
- Theoretical physicistWrote the relativistic equation of the electron and predicted the anti-electron, the first antiparticle.
- A device that holds charged particles with a strong uniform magnetic field and a weak electric quadrupole field.
- An elongated Penning trap built from a stack of cylindrical electrodes, used to accumulate and shape large clouds of antiprotons and positrons.
- Universityantiproton-catalysed microfission/fusion (ICAN), antimatter-initiated microfusion (AIMStar), portable Penning traps
- The antielectron: same mass as the electron, positive charge. The first antiparticle ever observed, by Carl Anderson in 1932.
- Uses positronsPositrons implanted in a solid are trapped at open-volume defects such as vacancies, where the local electron density is lower.
- Companyradioisotope positron sources, positron moderation, positron-catalysed fusion propulsion
- PET: medical imaging that follows a positron-emitting tracer by detecting the paired gamma rays from each annihilation.
- Uses positronsIn PET, a patient receives a radiopharmaceutical labelled with a positron-emitting isotope.
- An exotic atom made of an electron and a positron orbiting each other, which annihilates in nanoseconds or less.
- Uses positronsDuring a PET scan, some positrons form positronium, a short-lived bound state with an electron, in the molecular voids of tissue.
- Chirp laser cooling of positronium, University of Tokyo with KEK and AISTLaser-cool positronium, the bound state of an electron and a positron, as a step toward precision tests of bound-state QED and Bose–Einstein condensation of a matter–antimatter system.
- L. T. Glöggler et al. (AEgIS Collaboration) · Physical Review Letters, 2024
- M. Amoretti et al. (ATHENA Collaboration) · Nature, 2002
- G. Baur et al. (PS210) · Physics Letters B, 1996
- M. Leonhardt et al. (BASE Collaboration) · Nature, 2025
- Exotic atoms in which an antiproton replaces an electron, either orbiting a proton (protonium) or a helium nucleus.
- Antihydrogen Production in p̄–Z InteractionsProduce antihydrogen atoms in flight by passing antiprotons circulating in LEAR through a xenon gas-jet target.
- Intense Slow Positron Beam Facility, PULSTAR Reactor, North Carolina State UniversityNC State University Nuclear Reactor Program, Burlington Engineering Laboratories, NC State University, Raleigh, North Carolina
- antiProton Unstable Matter AnnihilationTrap antiprotons at ELENA and carry them by truck to ISOLDE to measure neutron-to-proton annihilation ratios on short-lived nuclei, probing neutron skins and halos.
- P. A. M. Dirac · Proceedings of the Royal Society A, 1931
- Uses positronsPositron Dynamics proposed a propulsion system that needs no stored antimatter.
- B. Lee et al. (GBAR Collaboration) · arXiv (preprint), 2026
- Relativistic Heavy Ion ColliderBrookhaven National Laboratory (US DOE Office of Science user facility), Brookhaven National Laboratory, Upton, New York
- C. Amole et al. (ALPHA Collaboration) · Nature, 2012
- LaboratoryBASE collaboration leadership, proton–antiproton CPT tests, Penning-trap techniques
- M. Leonhardt et al. (BASE Collaboration) · Nature, 2026
- Physicist, aerospace engineer and science-fiction authorLeading advocate of antimatter propulsion and author of 'Mirror Matter'.
- Experimental particle physicistSpokesperson of ATHENA, which made the first cold antihydrogen atoms in 2002.
- Experimental physicistLed the discovery of long-lived antiprotonic helium and co-founded CERN's ASACUSA experiment.
- Three ingredients any theory needs to create more matter than antimatter: baryon-number violation, C and CP violation, and non-equilibrium.
- Experimental particle physicistAntideuteron co-discoverer, Nobel laureate, and principal investigator of the AMS antimatter detector in space.
- Accelerator physicist and engineerInvented stochastic cooling, which made dense antiproton beams and the W and Z discoveries possible.
- P. M. S. Blackett & G. P. S. Occhialini · Proceedings of the Royal Society A, 1933
- Solenoidal Tracker at RHICStudy quark-gluon plasma in heavy-ion collisions, including discovering and characterising the antinuclei these collisions produce.
- Experimental physicistFounder and spokesperson of BASE, which compares protons and antiprotons with record precision.
- Nuclear engineer and physicistAntimatter propulsion researcher, author of the antimatter-driven sail, and Chief Scientist of Antimatter, Inc.
- Simon van der Meer's feedback method for squeezing a beam: sense its fluctuations at one point, correct them at another.
- Universitypositron physics, antihydrogen (ATHENA, ALPHA), charged-particle trapping and imaging
- Tokai to KamiokaCompare neutrino and antineutrino oscillations to determine whether leptons violate CP symmetry, a possible source of the universe's matter–antimatter imbalance.
- E. Majorana · Il Nuovo Cimento, 1937
- C. D. Anderson · Physical Review, 1933
- P. A. M. Dirac · Proceedings of the Royal Society A, 1928
- Experimental particle physicistYoungest co-discoverer of the antiproton; later co-invented ring-imaging Cherenkov detectors.
- Precision Comparison of Antiproton and Proton Masses in a Penning TrapCapture antiprotons in a Penning trap and compare the antiproton's charge-to-mass ratio with the proton's.
- G. B. Andresen et al. (ALPHA Collaboration) · Nature, 2010
- LaboratoryALPHA and ALPHA-g, antimatter gravity, HAICU quantum techniques
- Universityantihydrogen (ALPHA), plasma physics, history: antiproton discovery
- Experimental particle physicistCo-discovered CP violation in neutral kaon decays in 1964; Nobel Prize 1980.
- A. D. Sakharov · JETP Letters (English reprint: Soviet Physics Uspekhi, 1991), 1967
- Uses positronsAntimatter, Inc.
- Experimental nuclear and hadron physicistLed PS210, which made the first atoms of antihydrogen at CERN in 1995.
- Making antimatter wastes almost all the energy spent: CERN's entire output would light a bulb only briefly.
- Experimental plasma and accelerator physicistALPHA deputy spokesperson, formerly its technical coordinator, at the University of Manchester.