Cosmic antimatter

As far as we can see into the Universe, we don t observe any primordial antimatter. Within the limits of our present observational horizon the Universe is seen to contain only matter and no antimatter. The presence of cosmic antimatter would lead to observable traces of annihilation however the measurements of the extragalactic 7 ray flux indicate an absence of annihilation radiation, and the microwave background spectrum lacks a corresponding distortion. These findings preclude the existence of a significant amount of antimatter within tens of Megaparsecs, which is the scale of super-clusters of galaxies. 

The matter - antimatter asymmetry in the Universe and its relation to the underlying symmetries of Nature is of such fundamental importance that a number of large-scale experiments have been undertaken to search for cosmic antimatter. 

Earth and the sun, and, as far as is kno wn, the stars and planets in the rest of the visible universe, are made of ordinai y matter. However, according to a theoi y fir.st proposed by Paul Dirac in 1928, for every kind of particle of ordinary matter that exists in nature, there can exist an antiparticle made of antimatter. Some antiparticles have been discovered for example, the antiparticle of the electron, called the positron, was discovered in 1932 in cosmic rays falling on earth and have also been created in experiments performed in the laboratory. Antimatter is very simi-... 

Big Bang nucleosynthesis (cosmic nucleosynthesis) Proton-proton cycle Triple He collisions Alpha capture CNO cycle Neutron capture High-energy photon collisions produce antimatter-matter pairs. This leads to H,D, He and some Li nuclei Hydrogen burning to produce He 12C production Addition of 4He to the nucleus Production of 13C, 13N, 14N and 150 Post-Fe nuclei... 

The hole theory was perceived as a Active mathematical construction and was initially rejected by prominent contemporary physicists such as Pauli and Bohr. The physical reality of antiparticles was not taken seriously even by Dirac himself. In 1931 he wrote about his anti-electron we should not expect to find it in Nature [2]. Surprisingly, the first anti-electrons were discovered already in 1932 by Anderson, who studied cosmic rays in Caltech s magnet cloud chamber. Anderson noticed abnormally bending trajectories indicating the presence of light positively charged particles and, as related by Fowler [3], "could not resist the devastating conclusion that they are caused by positive electrons The first piece of antimatter, a positron, made its physical appearance. 

Hence Eq. (3.6.15) is not merely an academic exercise Indeed, positron emission tomography (PET) is a known analytical technique used in medicine (the annihilation rate is subtly spindependent and varies, depending on the type of human body tissue traversed). When matter and antimatter collide in the universe, they annihilate each other in a cosmic version of Eq. (3.6.15). 

Not too many theories have been formulated from this point of view and some of the more interesting cases are at the speculative stage of development. Even so, it is remarkable how some of the most enigmatic of natural phenomena have no convincing explanation apart from broken-symmetry theories. Included are the initiation or nucleation of phase transitions, superconductivity (T4.5.1), the arrow of time (entropy) and the cosmic imbalance between matter and antimatter. The beauty of the world, indeed seems to lie in approximate symmetries. 

It is then both natural and even compelling to be able to explain the baryon asymmetry quantified by the baryon to the photon number density in the present universe. This ratio is the direct measure of the asymmetry prior to the cosmic disappearance of antimatter. This number is usually given in the form of the baryon to the entropy ratio ub/ns and is of order ft)-10, which seems too small at first one excess of baryon over 1010 B — B pairs led to the present B-dominated universe. But actually this number is often too large to be explained in theoretical models. With this large number the standard electroweak theory fails as the microscopic theory for the baryogenesis, as explained below. 

Keywords Antimatter, cosmic ray, dark matter, gamma ray, magnetic spectrometer, neu-... 

The origin of X-rays, 7-ray bursts and radiowaves that pervade the Galaxy is as mysterious as the cosmic-ray sources. Evidence is mounting that in most cases these phenomena are linked to violent explosions, thought to include neutron-star quakes, quark nuggets, supernovae, matter-antimatter annihilation, clumping of quasars and colliding stars. Of all space radiations radio phenomena have been studied in most detail. 

The most likely configuration must surely be a universe in equilibrium, but not necessarily static equilibrium. Furthermore, the assumption of imi-versally uniform distribution of matter is not necessarily correct, as it ignores the symmetry between matter and antimatter. The single most important mathematical difference between matter and antimatter is in their temporal response. Whatever the topology required to accommodate equal amoimts of matter and antimatter, it cannot contain a privileged cosmic time coordinate. 

As the plasma moves through the centre of maximum curvature it is forced through the vacumn interface into a space-time domain of inverted chirahty and decreasing pressme. New matter (antimatter) emerges beyond the interface as an equilibrimn mixture of cosmic rays, in a soup of a-particles, as it is squirted out from the black hole into free space. Some of the newly formed nuchdes decay radioactively on moving into regions of lower curvatme and a set of nuclides, characteristic of local cmvatme, smvives. In the solar system the set consists of the 264 stable isotopes of 81 elements described before. The closed periodic sytem of nuclides and anti-nuclides, related by inversion, is consistent with the proposed mode of cosmic circulation of mass. 

The imphed wave nature of elementary matter furthermore clarifies their mode of interaction through standing waves generated by the interference between advanced and retarded wave components. The negative-energy solutions of relativistic wave equations first indicated the existence of antimatter, as later confirmed experimentally. To avoid the annihilation of matter and antimatter on a cosmic scale an involuted structure of the vacuum, consistent with projective space-time, is inferred. 

Empirical evidence at variance with standard cosmology is, likewise, totally ignored. Even the most fundamental of empirical observations, known as universal CPT (charge conjugation-parity-time inversion) symmetry, which dictates equal amounts of matter and antimatter in the cosmos, is dismissed out-of-hand. Less well known, but of equal importance, cosmic self-similarity, is not considered at all. 

Primary electrons constitute about 1% of the cosmic ray beam. The positron to negative electron ratio is about 10% (J. M. Clem et al., 1995). Antimatter in the Primary cam... 

They debated the structure of the proton. Other topics they discussed may have seemed more far-reaching at the time. None would prove to be. On August 2, 1932, working with a carefully prepared cloud chamber, an American experimentalist at Caltech named Carl Anderson had discovered a new particle in a shower of cosmic rays. The particle was an electron with a positive instead of a negative charge, a positron, the first indication that the universe consists not only of matter but of antimatter as well. (Its discovery earned Anderson the 1936 Nobel Prize.) Physicists everywhere im-... 

The demonstration [1] that both Lorentz transformation and quantum spin are the direct result of quaternion rotation implies that aU relativistic and quantum structures must have the same symmetry. This is the basis of cosmic self-similarity. The observation that the golden mean features in many known self-similarities confirms that r represents a fundamental characteristic of space-time curvature. The existence of antimatter and the implied CPT symmetry of space-time favors... 

Antimatter. All known particles have antiparticles, with opposite properties in all measures, such as charge. The collision of a particle and its antiparticle always leads to a burst of radiation, when both particles are annihilated. In cosmic rays we observe antiprotons, and positrons, the antiparticles to electrons. The search for antinuclei has not been successful any detection of even a single antinucleus, such as antihelium, would provide extremely strong constraints on the physics of matter in the universe. 

Antimatter as observed today can all be produced in normal cosmic ray interactions. However, even the detection of a single antinucleus of an element such as helium would constitute proof that the universe contains antimatter regions and would radically change our perception of the matter-antimatter symmetries in our world. 

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