We studied 93 asteroid pairs. We estimated times elapsed since separation of pair members that are between 7*10^3 and a few 10^6 yr. We derived the rotation periods for all the primaries and a sample ...of secondaries. We derived the absolute magnitude differences of the asteroid pairs that provide their mass ratios. We refined their WISE geometric albedos and estimated their taxonomic classifications. For 17 pairs, we determined their pole positions. In 2 pairs where we obtained the spin poles for both components, we saw the same sense of rotation for both components and constrained the angles between their original spin vectors at the time of their separation. We found that the primaries of 13 pairs are actually binary or triple systems, i.e., they have one or two bound secondaries (satellites). As by-product, we found 3 new young asteroid clusters (each of them consisting of three known asteroids on highly similar orbits). We compared the obtained asteroid pair data with theoretical predictions and discussed their implications. We found that 86 of the 93 studied pairs follow the trend of primary rotation period vs mass ratio that was found by Pravec et al. (2010). Of the 7 outliers, 3 appear insignificant (may be due to our uncertain or incomplete knowledge), but 4 are high mass ratio pairs that were unpredicted by the theory of asteroid pair formation by rotational fission. We discuss a (remotely) possible way that they could be created by rotational fission of flattened parent bodies followed by re-shaping of the formed components. The 13 pairs with binary primaries are particularly interesting systems that place important constraints on formation and evolution of asteroid pairs. We present two hypotheses for their formation: The pairs having both bound and unbound secondaries could be `failed asteroid clusters', or they could be formed by a cascade primary spin fission process.
Phi meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV beam energy. The data are compared with measurements at lower and higher ...energies and to microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies.
The latest NA49 results on event-by-event transverse momentum fluctuations are presented for central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV). Two different methods are ...applied: evaluating the \(\Phi_{p_{T}}\) fluctuation measure and studying two-particle transverse momentum correlations. The obtained results are compared to predictions of the UrQMD model. The results on the energy dependence are compared to the NA49 data on the system size dependence. The NA61 (SHINE, NA49-future) strategy of searching of the QCD critical end-point is also discussed.
Production of \(d\), \(t\), and \(^3\)He nuclei in central Pb+Pb interactions was studied at five collision energies (\(\sqrt{s_{NN}}=\) 6.3, 7.6, 8.8, 12.3, and 17.3 GeV) with the NA49 detector at ...the CERN SPS. Transverse momentum spectra, rapidity distributions, and particle ratios were measured. Yields are compared to predictions of statistical models. Phase-space distributions of light nuclei are discussed and compared to those of protons in the context of a coalescence approach. The coalescence parameters \(B_2\) and \(B_3\), as well as coalescence radii for \(d\) and \(^3\)He were determined as a function of transverse mass at all energies.
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