(The 25th international conference on high-energy physics at Singapore)

The traveler attended the 25th International Conference on High-Energy Physics in Singapore, August 1--8, 1990. The conference was dominated by results from the new LEP accelerator at CERN. The precision of the data from LEP is impressive, and all results are consistent with the standard model. No new physics'' has emerged at LEP. The traveler presented a talk on CERN/SPS WA80 results and had several interesting, private discussions on both L* and WA80 topics

High energy nuclear collisions

This presentation covers three broad topics: a brief introduction to the field of nucleus-nucleus collisions at relativistic energies; a discussion of several topics illustrating what`s been learned after more than a decade of fixed target experiments; and an indication of what the future may bring at the Relativistic Heavy Ion Collider (RHIC) under construction at the Brookhaven National Laboratory (BNL) and at the Large Hadron Collider (LHC) planned at CERN

Thalhammerite, Pd9Ag2Bi2S4, a New Mineral from the Talnakh and Oktyabrsk Deposits, Noril'sk Region, Russia

This is an Open Access publicatiomThe file attached is the Published/publisher’s pdf version of the article

Kinetic energy—mass distributions from the fission of nuclei lighter than radium

The distributions in masses and total kinetic energies of fission fragments from a number of elements ranging from erbium to bismuth have been measured. The nuclei undergoing fission were produced by bombarding a variety of targets with projectiles ranging from He4 to O16. The energies of coincident fission fragments were measured using solid-state counters. The energy data were transformed to give mass-total kinetic energy density-of-events distributions. These distributions were compared with those calculated from an approximate version of the liquid-drop model which applies to this region of elements. General agreement in the shapes and widths of the distributions was found, particularly in the cases which involved small angular momenta and small nuclear temperatures. The dependence of the widths of the experimental distributions on the nuclear temperature was found to differ from that predicted by the theory, but uncertainties in the evaluation of nuclear temperatures for the reactions investigated may be large. Analysis of these uncertainties indicated that they were not large enough to alone account for the discrepancy, although this analysis was subject to some error. Angular momentum effects were studied by using certain combinations of targets and projectiles to give the compound nucleus Os186 at the same excitation energy but with different angular momenta. The effect of increasing angular momentum was to broaden and change the shape of the experimental distributions

Prospects for baryon instability search with long-lived isotopes

In this paper we consider the possibility of observation of baryon instability processes occurring inside nuclei by searching for the remnants of such processes that could have been accumulated in nature as mm long-lived isotopes. As an example, we discuss here the possible detection of traces of {sup 97}Tc, {sup 98}Tc, and {sup 99}Tc in deep-mined nonradioactive tin ores

Tau Be or not Tau Be? - A Perspective on Service Compatibility and Substitutability

One of the main open research issues in Service Oriented Computing is to propose automated techniques to analyse service interfaces. A first problem, called compatibility, aims at determining whether a set of services (two in this paper) can be composed together and interact with each other as expected. Another related problem is to check the substitutability of one service with another. These problems are especially difficult when behavioural descriptions (i.e., message calls and their ordering) are taken into account in service interfaces. Interfaces should capture as faithfully as possible the service behaviour to make their automated analysis possible while not exhibiting implementation details. In this position paper, we choose Labelled Transition Systems to specify the behavioural part of service interfaces. In particular, we show that internal behaviours (tau transitions) are necessary in these transition systems in order to detect subtle errors that may occur when composing a set of services together. We also show that tau transitions should be handled differently in the compatibility and substitutability problem: the former problem requires to check if the compatibility is preserved every time a tau transition is traversed in one interface, whereas the latter requires a precise analysis of tau branchings in order to make the substitution preserve the properties (e.g., a compatibility notion) which were ensured before replacement.Comment: In Proceedings WCSI 2010, arXiv:1010.233

Xcd - Modular, Realizable Software Architectures

Connector-Centric Design (Xcd) is centred around a new formal architectural description language, focusing mainly on complex connectors. Inspired by Wright and BIP, Xcd aims to cleanly separate in a modular manner the high-level functional, interaction, and control system behaviours. This can aid in both increasing the understandability of architectural specifications and the reusability of components and connectors themselves. Through the independent specification of control behaviours, Xcd allows designers to experiment more easily with different design decisions early on, without having to modify the functional behaviour specifications (components) or the interaction ones(connectors). At the same time Xcd attempts to ease the architectural specification by following (and extending) a Design-by-Contract approach, which is more familiar to software developers than process algebras like CSP or languages like BIP that are closer to synchronous/hardware specification languages. Xcd extends Design-by-Contract (i) by separating component contracts into functional and interaction sub-contracts, and (ii) by allowing service consumers to specify their own contractual clauses. Xcd connector specifications are completely decentralized, foregoing Wright’s connector glue, to ensure their realizability by construction

Attained energy densities and neutral pion spectra in nucleus-nucleus collisions at 200 GeV/nucleon

The main goal of the CERN heavy-ion experiments is the search for an indication that the predicted state of deconfined quarks and gluons, the quark-gluon plasma (QGP), has been produced. The quantity most crucial to the probability of QGP formation is the thermalized energy density attained during the heavy-ion reaction. The amount of energy radiated transverse to the beam direction is the experimental quantity which is believed to be a measure of the amount of energy deposition in the reaction, and hence to reflect the energy density attained. In this presentation we consider the systematics of transverse energy production at CERN SPS energies, and we use the results to make estimates, under various assumptions, of attained energy densities. 18 refs., 2 figs