Related papers: Who discovered positron annihilation?
Observations of soft gamma rays emanating from the Milky Way from SPI/\textit{INTEGRAL} reveal the annihilation of $\sim2\times10^{43}$ positrons every second in the Galactic bulge. The origin of these positrons, which annihilate to produce…
In October 1934 Fermi discovered that neutrons became particularly effective in rendering the elements radioactive after being slowed down by hydrogenous substances. His was described as an absolutely unpredictable scientific discovery. In…
The ionization losses -- the losses of energy by fast charged particles traveling through a matter -- have been under study for more than 100 years. The theoretical explanation of this process spans similar period. About 75 years ago, Lev…
$\gamma$ spectra for positron annihilation in noble-gas atoms are calculated using many-body theory for positron momenta up to the positronium-formation threshold. This data is used, together with time-evolving positron-momentum…
Raoul Gatto and Bruno Touschek's collaboration in the establishment of electron positron colliders as a fundamental discovery tool in particle physics will be illustrated. In particular, we will tell the little-known story of how Gatto and…
Cosmic rays were discovered by Victor Hess in 1912 through their effect on the conductivity of the atmosphere. It took several decades of research to understand their nature and composition. The photographic method of particle detection,…
The discovery of the Higgs boson in 2012 was one of the most significant developments of science in the last half century. A simplified history has Peter Higgs positing it in the mid-1960s followed by a long wait while experimentalists…
We retrace the first steps towards understanding neutrinos, particles predicted by Pauli in 1930 to avoid a supposed violation of time-translation symmetry. Despite the tendency to reduce the whole story to his intuition and the skill of…
In this article, we present a brief review of the discoveries of kinds of antimatter particles, including positron, antiproton, antideuteron and antihelium-3. Special emphasis is put on the discovery of the antihypertriton and antihelium-4…
We compare data of antineutron and antiproton annihilation cross sections on different targets at very low energies. After subtracting Coulomb effects, we observe that the ratio between the antineutron proton and antiproton proton…
The precise measurements of the Compton scatterings of photons originating from the decay of positronium atoms can reveal information about their polarizations. J-PET detector is constructed of 192 plastic scintillators and is unique to…
Currently, thirty-nine astatine, thirty-nine radon, thirty-five francium, and thirty-four radium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed…
The photoelectric effect has been discovered by H. Hertz, and studied experimentally by P. Lenard. First theoretical explanation has been done by A. Einstein who suggested the corpuscular theory of light introducing the "photons" which are…
We review the derivation of Planck's Radiation Formula on the light of recent studies in its centenary. We discuss specially the issue of discreteness, Planck's opinion on his discovery, and the critical analysis on the contributions by…
This is a pedagogical overview of neutrino physics from the invention of neutrino by Pauli in 1930 to the precise measurement of neutrino mass and mixing parameters via neutrino oscillation experiments in recent years. I have tried to pitch…
The positronium molecule (Ps$_2$) has not been experimentally observed yet because its tiny (4.5 eV) binding energy cannot be detected when the molecule annihilates by emitting two photons with energy of 0.51 MeV each. It is shown in this…
Positronium (the bound state of electron and positron) has been thought to be formed after proton decay ($>10^{34}$yr) through collisional recombination and then decays by pair annihilation, thereby changing the matter content of the…
The first detected gamma-ray line originating from outside the solar system is the 511 keV emission from the center of our Galaxy. The widely accepted explanation attributes this signal to electron-positron annihilation. However, despite…
Since their "discovery" by Pauli in 1930, neutrinos have plaed a key part in confirmation of the structure of the standard model of strong and electroweak interactions. After reviewing ways in which this has been manifested in the past, we…
The present study shows that the new TOTEM datum $\rho^{pp} = 0.098 \pm 0.01$ can be considered as the first experimental discovery of the Odderon, namely in its maximal form.