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At least 37 records · Page 2

Search for cosmic-ray antimatter

It appears probable that some fraction of the cosmic rays has extragalactic origin. A search for antimatter nuclei was conducted with the aid of a balloon-borne superconducting magnetic spectrometer. The investigation made use of the fact that matter and antimatter nuclei, because of their opposite signs of charge, would be deflected in opposite directions when passing through a magnetic field. The antimatter flux limits set by the experiments are discussed.

Smoot, G. F.↗

The need for expanded exploration of matter-antimatter annihilation for propulsion application

The use of matter-antimatter annihilation as a propulsion application for interstellar travel is discussed. The physical basis for the superior energy release in such a system is summarized, and the problems associated with antimatter production, collection and storage are assessed. Advances in devising a workable propulsion system are reported, and the parameters of an antimatter propulsion system are described.

Massier, P. F.↗

Antimatter applied for Earth protection from asteroid collision

An Earth protection system against asteroids and meteorites in colliding orbit is proposed. The system consists of detection and deorbiting systems. Analyses are given for the resolution of microwave optics, the detectability of radar, the orbital plan of intercepting operation, and the antimatter mass require for totally or partially blasting the asteroid. Antimatter of 1 kg is required for deorbiting an asteroid 200 m in diameter. An experimental simulation of antimatter cooling and storage is planned. The facility under construction is discussed.

Satori, Shin↗

Antimatter Production at a Potential Boundary

Current antiproton production techniques rely on high-energy collisions between beam particles and target nuclei to produce particle and antiparticle pairs, but inherently low production and capture efficiencies render these techniques impractical for the cost-effective production of antimatter for space propulsion and other commercial applications. Based on Dirac's theory of the vacuum field, a new antimatter production concept is proposed in which particle-antiparticle pairs are created at the boundary of a steep potential step formed by the suppression of the local vacuum fields. Current antimatter production techniques are reviewed, followed by a description of Dirac's relativistic quantum theory of the vacuum state and corresponding solutions for particle tunneling and reflection from a potential barrier. The use of the Casimir effect to suppress local vacuum fields is presented as a possible technique for generating the sharp potential gradients required for particle-antiparticle pair creation.

LaPointe, Michael R.↗

Possible evidence for the existence of antimatter on a cosmological scale in the universe.

Initial results of a detailed calculation of the cosmological gamma-ray spectrum from matter-antimatter annihilation in the universe. The similarity between the calculated spectrum and the present observations of the gamma-ray background spectrum above 1 MeV suggests that such observations may be evidence of the existence of antimatter on a large scale in the universe.

Stecker, F. W.↗

Matter-antimatter Cosmology

The possible existence of antimatter on a large scale in the universe is evaluated. As a starting point, an attempt was made to understand the origin of matter as being essentially analogous to the origin of backgound thermal radiation. Several theories and models are examined, with particular emphasis on nucleon-antinucleon interactions at intermediate energies. Data also cover annihilation interaction with the matter-antimatter boundary to produce the essential fluid motion known as coalesence.

Omnes, R.↗

Cosmic matter-antimatter asymmetry and gravitational force

Cosmic matter-antimatter asymmetry due to the gravitational interaction alone is discussed, considering the gravitational coupling of fermion matter related to the Yang-Mills (1954) gauge symmetry with the unique generalization of the four-dimensional Poincare group. Attention is given to the case of weak static fields which determines the space-time metric where only large source terms are retained. In addition, considering lowest-order Feynman diagrams, there are presented gravitational potential energies between fermions, between antifermions, and between a fermion and an antifermion. It is concluded that the gravitational force between matter is different from that between antimatter; implications from this concerning the evolution of the universe are discussed.

Hsu, J. P.↗

Gravitational matter-antimatter asymmetry and four-dimensional Yang-Mills gauge symmetry

A formulation of gravity based on the maximum four-dimensional Yang-Mills gauge symmetry is studied. The theory predicts that the gravitational force inside matter (fermions) is different from that inside antimatter. This difference could lead to the cosmic separation of matter and antimatter in the evolution of the universe. Moreover, a new gravitational long-range spin-force between two fermions is predicted, in addition to the usual Newtonian force. The geometrical foundation of such a gravitational theory is the Riemann-Cartan geometry, in which there is a torsion. The results of the theory for weak fields are consistent with previous experiments.

Hsu, J. P.↗

Cosmic ray neutrino tests for heavier weak bosons and cosmic antimatter

A program for using high energy neutrino astronomy with large neutrino detectors to directly test for the existence of heavier weak intermediate vector bosons (ivb) and cosmic antimatter is described. Such observations can provide a direct test of baryon symmetric cosmologies. Changes in the total cross section for nu(N) yields mu(X) due to additional propagators are discussed and higher mass resonances in the annihilation channel bar-nu sub e e(-) yields X are analyzed. The annihilation channel is instrumental in the search for antimatter, partcularly if heavier IVB's exist.

Brown, R. W.↗

Can we detect antimatter from other galaxies

A novel particle detection technique employing well established principles of high order quantum electrodynamics for searching for antimatter in cosmic rays is described, and shown to have both collecting power and resolution superior to conventional alternatives. By taking into account various estimates of the metagalactic cosmic-ray energy density, and the possible modulation of metagalactic cosmic rays by a galactic wind within the framework of the dynamical halo model, it is shown that the experiment proposed would be the first to be sensitive to the presence of extragalactic antimatter.

Ahlen, S. P.↗

Balloon test project: Cosmic Ray Antimatter Calorimeter (CRAC)

Cosmic ray observations from balloon flights are discussed. The cosmic ray antimatter calorimeter (CRAC) experiment attempts to measure the flux of antimatter in the 200-600 Mev/m energy range and the isotopes of light elements between 600 and 1,000 Mev/m.

Christy, J. C.↗

The Matter-Antimatter Asymmetry of the Universe

I will give here an overview of the present observational and theoretical situation regarding the question of the matter-antimatter asymmetry of the universe and the related question of the existence of antimatter on a cosmological scale. I will also give a simple discussion of the role of CP (charge conjugation parity) violation in this subject.

Stecker, F. W.↗

Radio Frequency (RF) Trap for Confinement of Antimatter Plasmas Using Rotating Wall Electric Fields

Perturbations associated with a rotating wall electric field enable the confinement of ions for periods approaching weeks. This steady state confinement is a result of a radio frequency manipulation of the ions. Using state-of-the-art techniques it is shown that radio frequency energy can produce useable manipulation of the ion cloud (matter or antimatter) for use in containment experiments. The current research focuses on the improvement of confinement systems capable of containing and transporting antimatter.

Sims, William Herbert, III↗

The Search for Cosmological Antimatter

For more than 40 years, experimentalists have searched in the cosmic radiation for evidence of antimatter which may have been created in the early Universe. The experimental evidence for cosmologically significant amounts of antimatter in the Universe is reviewed. There is no compelling evidence, either theoretical of experimental. However, the possibility is not completely ruled out.

Streitmatter, Robert E.↗

The study of the journey of cosmic antimatter

A potential observation of low-energy antihelium-3 nuclei would have profound impacts on our understanding of the Galaxy. Here, experiments at particle colliders help us understand how cosmic antimatter travels over long distances before reaching Earth.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗