Review of SIS Experimental Results on Strangeness

>A review of meson emission in heavy ion collisions at incident energies around 1 -- 2 $A\cdot$GeV is presented. It is shown how the shape of the spectra and the various particle yields vary with system size, with centrality and with incident energy. A statistical model assuming thermal and chemical equilibrium and exact strangeness conservation (i.e. strangeness conservation per collision) explains most of the observed features. Emphasis is put onto the study of $K^+$ and $K^-$ emission. In the framework of this statistical model it is shown that the experimentally observed equality of $K^+$ and $K^-$ rates at threshold corrected energies $\sqrt{s} - \sqrt{s_{th}}$ is due to a crossing of two excitation functions. Furthermore, the independence of the $K^+$ to $K^-$ ratio on the number of participating nucleons observed between 1 and 10 $A\cdot$GeV is consistent with this model. The observed flow effects are beyond the scope of this model.Comment: 10 pages, 9 figures, Strangeness 2000, V International Conference on Strangeness in Quark Matter, July, 2000, Berkeley, Californi

Image retrieval by hypertext links

This paper presents a model for retrieval of images from a large World Wide Web based collection. Rather than considering complex visual recognition algorithms, the model presented is based on combining evidence of the text content and hypertext structure of the Web. The paper shows that certain types of query are amply served by this form of representation. It also presents a novel means of gathering relevance judgements

Multiplexed communication over a high-speed quantum channel

In quantum information systems it is of particular interest to consider the best way in which to use the non-classical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are amongst the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analogue bandwidth. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4 GHz comb of vacuum squeezing produced by a sub-threshold OPO, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel

The Role of Starbursts in the Formation of Galaxies & Active Galactic Nuclei

Starbursts are episodes of intense star-formation in the central regions of galaxies, and are the sites of roughly 25% of the high-mass star-formation in the local universe. In this contribution I review the role starbursts play in the formation and evolution of galaxies, the intergalactic medium, and active galactic nuclei. Four major conclusions are drawn. 1) Starburst galaxies are good analogues (in fact, the only plausible local analogues) to the known population of star-forming galaxies at high-redshift. 2) Integrated over cosmic time, supernova-driven galactic-winds (`superwinds') play an essential role in the evolution of galaxies and the inter-galactic medium. 3) Circumnuclear starbursts are an energetically-significant component of the Seyfert phenomenon. 4) The evolution of the population of the host galaxies of radio-quiet quasars is significantly different than that of powerful radio galaxies, and is at least qualitatively consistent with the standard picture of the hierarchical assembly of massive galaxies at relatively late times.Comment: 16 pages, 4 figures, Royal Society discussion meeting `The formation of galaxies

Highlights of the Beam Energy Scan from STAR

The first part of the beam energy scan (BES) program at RHIC was successfully completed in the years 2010 and 2011. First STAR results from particle yield measurements are in good agreement with previously published data from SPS and AGS experiments whereas other results like azimuthal HBT and $K/\pi$ event-by-event fluctuations differ at some energies. In addition, new observations like the centrality dependence of chemical freeze-out parameters ($T_{\rm{ch}}$ and $\mu_{B}$) or the smoothly increasing difference with decreasing energy in the elliptic flow $v_{2}$ between particles and corresponding anti-particles, are discussed.Comment: CPOD 2011 proceedings, 5 pages, 4 figure

Design concepts for bioreactors in space

Microbial food sources are becoming viable and more efficient alternatives to conventional food sources, especially in the context of closed ecological life support systems (CELSS) in space habitats. Two bioreactor design concepts presented represent two dissimilar approaches to grappling with the absence of gravity in space habitats and deserve to be tested for adoption as important components of the life support function aboard spacecraft, space stations and other extra-terrestrial habitats