Larysa Didenko

© 2015 Macmillan Publishers Limited. All rights reserved.One of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider, where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton-antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton-proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.

Based on the etymological, historical and philosophical analysis, the author of the article examines the term «Nova Doba» and notes the positive and negative consequences of its use. Through the analysis of foreign language equivalents of this term, demarcation of the concepts of «chas» and «doba» and the word «novyy», the author reveals the incorrectness of the term «Novyy chas» (Modern age). The incorrectness of the concept is manifested in the discrepancy between the word «chas» and its foreign language analogues «Temps», «Age» and «Times». Also, according to the author, «chas» has the meaning of an indefinite sequential duration, unlike the concept of «doba», which postulates a specifically defined period of time. The author concludes that the concepts of «Novyy chas» and «Nova Doba» are incorrect due to the relativity of the word «novyy» (new). Instead of the analysed commonly used terms, in the author's opinion, it is more appropriate to use the term «prosvitnytstvo» (enlightenment) to characterise the relevant historical and philosophical epoch.