Matter antimatter interactions

In view of the current search for antimatter in outer space, the ongoing efforts to produce antihydrogen in laboratory, and the forthcoming experiments with cold antihydrogen we have undertaken the study of matter-antimatter interactions [26, 27, 28, 29, 30, 31, 32]. Such interactions are of interest both for CERN AD experiments on forming antihydrogen, and for the astrophysical search for the presence of antimatter in the Universe. 

A unique situation of the passage of positrons through an absorber is that as a positron loses its energy by interaction with electrons of the absorber atoms and comes to almost rest, it combines with an electron of an absorber atom. At this instant, both particles (/ + and e ) are annihilated as a result of matter-antimatter encounter to produce two photons of 511 keV, which are emitted in opposite directions ( 180°) (Fig. 1.6). This process is called the... 

After the discovery of parity violation the CP symmetry, i.e., the invariance of the physical laws against the simultaneous transformation of charge and space reflection, was still assumed to be exact. However, in 1964 Cronin and Fitch (Nobel Prize 1980) discovered (Christenson et al. 1964) that the weak interaction violates that as well, although this violation is tiny, not maximal, like that of the P invariance. CP violation makes it possible to differentiate between a world and an antiworld and may be related to the matter - antimatter asymmetry. 

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. 

An award-winning interactive web tour of quarks, neutrinos, antimatter, extra dimensions, dark matter, accelerators, and much more. 

In recent work [26, 29] we have investigated the question of the stability of antimatter in contact with matter. The fundamental collisional interaction between hydrogen H and antihydrogen H hits been considered as the prototype reaction. 

Three-dimensional chirality can likewise be resolved in four dimensions by transplantation in non-orientable projective space. This three-dimensional analog requires a four-dimensional twist that closes the three-dimensional universe onto itself and turns left-handed matter into right-handed antimatter. Considered as a single universe in three-dimensional space, chirality is preserved throughout. However, the interface created by the curvature separates regions of space with opposite chiralities. The interface cannot be crossed in three-dimensional motion, but allows interaction between entities near the interface to give rise to the quantum effects. 

One important clue to answering that question is that matter and antimatter do not get along very well with each other. When a particle comes into contact with its antiparticle, a reaction occurs in which both particles are annihilated. The products of that reaction are two gamma rays, a neutrino, and an antineutrino. For example, suppose that a proton and an antiproton interact with each other. The reaction that occurs is ... 

The reader who feels uneasy about the time-inversion symmetry is reminded that the simplest mathematical distinction between matter and antimatter relates to an inverted time parameter. This is the convention used in the analysis of interactions by Feynman diagrams (Gottfried Weisskopf, (1984). 

The result is a universe that consists of exactly fifty percent antimatter, which however, can never be detected in convential observations - only when the interface is penetrated. Although matter and antimatter therefore occupy the same space, there is no possibihty of direct interaction as the two antipodes of the double cover are at different time coordinates. It is important to realize that transportation along the double cover, through the involution, gradually converts matter into antimatter. 

Before one can seriously consider an alternative plasma cosmology the ideas of Alfven and others need to be integrated with a sensible alternative to universal expansion and the topology of space-time. Instead of chasing after non-baryonic dark matter the role of hydrogen in that regard should be explored and the interaction between matter and antimatter, an important argument in the current theories (Lerner, 1991), must be rationalized. 

As the source of all matter in the universe the big bang is an abject failure. By a series of convoluted assumptions and arguments it "predicts" that all matter came into being in the form of H and He, without interacting with an equivalent amoimt of antimatter in the mix, and overestimates the relative He/H ratio and the background temperature by an order of magnitude. 

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. 

The strong nuclear force is insensitive to the distinction between neutrons and protons. These can be treated as alternative states of a single particle called a nucleon, differing in isotopic spin or isospin. It is found, for example, that the nuclei and He have similar energy-level spectra. Isospin is, however, only an approximate symmetry. It is broken by electromagnetic interactions since protons have electric charge, while neutrons do not. Broken symmetry is a central theme in fundamental physics. An open question is how our universe evolved to break the symmetry between matter and antimatter, so that it is now dominated by matter. 

In the past few decades a new method for the examination of matter has developed from the study of positron annihilation. This method utilizes the interaction of matter and the antielectron, i.e., the positron, one of the elementary particles of antimatter most readily accessible under terrestrial conditions. Positron annihilation reacts sensitively to changes occurring in the physical and (as a consequence of the formation of positronium atoms, which behave as chemical elements) the chemical properties of the medium. 

One took three different gauge theories, supplied them with some free parameters, added an ad hoc Higgs mechanism to make it work, and the result seems to function properly. It is not known exactly why those three symmetries create the three interactions although the U(l) symmetry is clearly related to the electromagnetic charge, the SU(2) to the weak isospin, and SU(3) to the three colors. It is not clear why there are exactly three fermion families and how the fermions of a family are related to each other (apart from the sum of their charges). It is not known why there is no antimatter in the Universe, and there is the deep mystery of dark matter astronomical observations indicate that about 90% of the mass of the Universe is invisible, probably non-baryonic matter that cannot be explained within the framework of the Standard Model (Amsler et al. 2008). 

Quarks and antiquarks traverse the phase boundaries, which represent a potential barrier for them. As a consequence of the complex CP-violating phase in the Hamiltonian describing weak interactions, the reflection and transmission amplitudes for matter and antimatter turn out to be different leading to an asymmetry in the constitution of matter and antimatter inside the bubbles. 

Fig. 3.4. (a) The electric field dose to the proton (composed of three quarks) is so strong that it creates matter and antimatter (shown as electron-positron pairs). The three quarks visible in scattering experiments represent the valence quarks, (b) One of the radiative effects in the QED correction of the c order (see Table 3.1). The pictures show the sequence of the events from left to the right A photon (wavy line on the left) polarizes the vacuum and an electron-positron pair (solid lines) is created, and the photon vanishes. Then the created particles annihilate each other and a photon is created, (c) A similar event (of the order in QED), but during the existence of the electron-positron pair the two particles interact by exchange of a photon, (d) An electron (horizontal solid line) emits a photon, which creates an electron-positron pair, that annihilates producing another photon. Meanwhile the first electron emits a photon, then first absorbs the photon from the annihilation, and afterwards the photon emitted by itself earlier. This effect is of the order c in QED. 

These invariance relations, when treated literally and rigorously, are not of particular usefulness in theoretical chemistry. They may, however, open new possibilities when considered as some limiting cases. Chemical reaction mechanisms very often involve the interaction of molecular ions. Suppose we have a particular reaction mechanism. Now, let us make the charge conjugation of all the objects involved in the reaction (this would require the change of matter to antimatter). 

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