-
J.J. Thomson discovers the electron
J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup." -
Paul Dirac's dirac equation
Formulates the Dirac equation, predicting the existence of antimatter.Dirac interpreted the equation to mean that for every particle there exists a corresponding antiparticle, exactly matching the particle but with opposite charge. For example, for the electron there should be an "antielectron", or "positron", identical in every way but with a positive electric charge. -
Carl D. Anderson's discovery of positron
The first known antimatter particle.An experiment on Cosmic rays performed by Carl D Anderson led to the accidental discovery of the
positron in 1932. The discovery was a turning point in particle physics which led to numerous other
theories and has been discussed by scientists all over the world. Anderson had photographed a 63
MeV, upward moving electron. The possible origin of such a positron has never before been
discussed and is what this report will aim to explain -
Emilio Segrè discover the antiproton
Antiprotons were first produced and identified in 1955 by Emilio Segrè, Owen Chamberlain (for which they received the Nobel Prize for Physics in 1959), and coworkers by bombarding a copper target with high-energy protons from the proton synchrotron at the University of California at Berkeley. -
Andrei Sakharov proposes the concept of baryon asymmetry
Andrei Sakharov proposed a set of three necessary conditions that a baryon-generating interaction must satisfy to produce matter and antimatter at different rates. These conditions were inspired by the recent discoveries of the cosmic background radiation and CP violation in the neutral kaon system. -
ATHENA experiment
The Athena (AnTiHydrogEN Apparatus) experiment has the goal of producing antihydrogen atoms at low energies, capturing these atoms in a magnetic trap, and comparing the energy levels of antihydrogen with those of hydrogen, in view of testing CPT invariance. The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter. -
The BaBar experiment
The BaBar experiment at SLAC confirms CP violation in the decay of B mesons, a phenomenon that could explain the matter-antimatter asymmetry. -
The ALPHA experiment
The ALPHA experiment is a successor of an earlier antimatter experiment, ATHENA. Set up in late 2005 with similar overall research goals as its predecessor, ALPHA makes, captures and studies atoms of antihydrogen and compares these with hydrogen atoms.The ALPHA experiment at CERN traps antihydrogen atoms for the first time. -
The LHCb experiment
The Large Hadron Collider beauty (LHCb) experiment specializes in investigating the slight differences between matter and antimatter by studying a type of particle called the "beauty quark", or "b quark". Instead of surrounding the entire collision point with an enclosed detector as do ATLAS and CMS, the LHCb experiment uses a series of subdetectors to detect mainly forward particles – those thrown forwards by the collision in one direction. -
The T2K experiment
T2K provided the first and the strongest yet constraint on δCP, rejecting at the 3σ (99.7%) significance level almost half of the possible values, ruling out the both CP conserving points at the significance level of 95% and giving a strong hint that CP violation may be large in the neutrino sector. -
The discovery of the Higgs boson
Existence of this field could be verified by discovery of its associated particle – the Higgs boson. On 4 July 2012, the ATLAS and CMS experiments at CERN announced that they had independently observed a new particle in the mass region of around 125 GeV: a particle consistent with the Higgs boson. -
The LHCb experiment decay of charm mesons.
The existence of CP violation in the decays of strange and beauty mesons is well established experimentally by numerous measurements. By contrast, CP violation in the decays of charmed particles has escaped observation. During the first two runs of the LHC, the LHCb collaboration has collected a sample of charmed hadrons of unprecedented size. This sample enables some of the most sensitive searches for CP violation ever performed. -
The Belle II experiment
The Belle II experiment is a particle physics experiment designed to study the properties of B mesons (heavy particles containing a beauty quark) and other particles. Belle II is the successor to the Belle experiment, and commissioned at the SuperKEKB accelerator complex at KEK in Tsukuba, Ibaraki prefecture, Japan. -
The T2K experiment reports further evidence of neutrino oscillations
This kind of experiment could provide the definitive proof of neutrino oscillations, as the neutrino source is man-made and can be accurately controlled in terms of neutrino flux and energy. The relevant neutrino oscillation length was estimated to be of the order of 1000 km for neutrinos of 1 GeV. -
The GBAR experiment
The Gravitational Behaviour of Antimatter at Rest experiment’s acronym refers to the fact that it measures the freefall acceleration under gravity of antimatter, which is denoted by g (pronounced g-bar). It operates in the Antiproton Decelerator (AD) Hall, using antiprotons slowed down by the ELENA facility.GBAR first combines the antiprotons with two antielectrons to form antihydrogen ions with a positive charge. -
2022;2023;2024;2025;2027
2022: Scientists continue to study the properties of antimatter to understand its role in the universe.2023: Research on antimatter continues to advance with new experiments and discoveries. 2024: The search for antimatter in space and its implications for cosmology intensifies.2025: Scientists make progress in understanding the matter-antimatter asymmetry in the universe. 2027: The study of antimatter continues to be a key focus in particle physics research worldwide.