So-called antimatter in the form of elementary particles such as positive electrons (antielectrons alias positrons) and negative protons (antiprotons) has for long been investigated by physicists. However, atoms or molecules of this exotic kind are conspicuously absent from nature. Since antimatter is believed to be symmetric with ordinary matter, the flagrant asymmetry constitutes a problem that still worries physicists and cosmologists. As first suggested by Paul Dirac in 1933, in distant parts of the universe there might be entire stars (...) and galaxies made of antiparticles alone. Why not? This paper examines how the concepts of antiparticles and antimatter slowly migrated from particle physics to astronomy and cosmology. At around 1970 a few physicists speculated about an anti-universe separate from ours while others looked for the charge asymmetry in quantum processes in the early big-bang explosion of the universe. Others again proposed a ‘plasma cosmology’ that kept our world and the hypothetical world of antimatter apart. Soviet physicists and astronomers were no less interested in the problem than their colleagues in the West. The paper details the development up to the late 1970s, paying attention not only to mainstream scientific works but also to more speculative ideas, some of them very speculative. By that time the antimatter mystery remained mysterious – which is still the situation. (shrink)

CDF (the acronym stands for Collider Detector at Fermilab) is the experiment that in 1994 and 1995 suggested and then confirmed the discovery of the top quark, using 1.8 TeV collisions of protons with antiprotons at the Fermilab Tevatron. To assemble convincing evidence for the top quark, the CDF group collected data from a large number of proton-antiproton collisions during the 1992-93 running period. Then, with the top quark safely salted away, the CDF group has been examining their accumulated (...) data for other aspects of the p+p-bar collisions. One such study of the CDF group focuses on "jets" from the p+p-bar collisions. "Jet" is high-energy physics jargon for a cluster of high energy particles emitted in the same direction. Free unattached quarks are not permitted by the rules of QCD. Within the colliding protons, the constituent quarks are tied together with gluons that form "color strings" connecting the quarks. If a quark strikes another quark in a head-on collision and is ejected from its surrounding proton, its attempted escape from this confinement stretches the string until it breaks, with a new quark and anti-quark forming at the broken string ends. The resulting multitude of new quarks combine to form a multitude of new particles, all moving in the same direction as the original quark, thereby forming a "jet". When a very high energy quark is ejected from a collision, a jet is what actually reaches the detector. (shrink)

Cooper has claimed to have found evidence for faster-than-light particles by reanalyzing the data of Chamberlain et al. in their paper reporting the discovery of the antiproton. A careful reanalysis of this same data gives no evidence to support Cooper's claim.

A reexamination of the Nobel-prize-winning experiment in which the antiproton was discovered reveals that the associated antimesons might be traveling faster than light. The time-of-flight experiment should be repeated with a view toward more accurate measurement of distance and time of flight to discredit or to confirm this tentative conclusion.

Franklin's underrating the importance of the time-of-flight measurements contradicts Segrè's account of the experiment in two journals and Chamberlain's Nobel Prize acceptance speech. Franklin further fails to understand that Segrè's velocity selector method of determining antiproton and proton mass also depends upon measuring the S1-to-S2 flight distance. Franklin's conclusion that there is no evidence that the Segrè mesons are traveling faster than light is based on a faulty premise about the average antiproton velocity.