Physics at ELSA, achievements and future

At ELSA interesting results on baryon resonances have been obtained by the CB-ELSA, the CBELSA/TAPS and the SAPHIR collaborations. New resonances were found, in particular a new $\rm D_{15}(2070)$ decaying into $p\eta$, was recently observed by the CB-ELSA experiment. The availability of a polarized beam and a polarized target did allow to measure the GDH sum rule up to 2.9 GeV. In the future double polarization experiments will be performed using the Crystal Barrel detector together with new forward detector components. These polarization observables will provide important additional information for the partial wave analyses performed to extract the contributing resonances and their parameters from the data.Comment: Prepared for the MENU 2004 conference proceedings, 7 pages, 6 eps-figure

Is Underconfidence Favored over Overconfidence? An Experiment on the Perception of a Biased Self-Assessment

This paper reports findings of a laboratory experiment, which explores how elfassessment regarding the own relative performance is perceived by others. In particular, I investigate whether overconfident subjects or underconfident subjects are considered as more likable by others, and who of the two is expected to achieve a higher performance in a real effort task. I observe that underconfidence beats overconfidence in both respects. Underconfident subjects are rewarded significantly more often than overconfident subjects, and are significantly more often expected to win the competitive real-effort task. It seems as if subjects being less convinced of their performance are taken as more congenial and are expected to be more ambitious to improve, whereas overconfident subjects are rather expected to rest on their high beliefs. While subjects do not anticipate the stronger performance signal of underconfidence, they anticipate its higher sympathy value. The comparison to a non-strategic setting shows that men strategically deflate their self-assessment to be rewarded by others. Women, in contrast, either do not deflate their self-assessment or do so even in non-strategic situations, a behavior that might be driven by nonmonetary image concerns of women

Traveling the Distances of Karen Tei Yamashita\u27s Fiction: A Review Essay on Yamashita Scholarship and Transnational Studies

This essay provides an analysis of scholarly works on the fiction of Karen Tei Yamashita, contextualizing them within major shifts taking place in a number academic disciplines and fields that are addressing transnationalism

Strongly Coupled Plasmas in High-Energy Physics

One of the main activities in high-energy and nuclear physics is the search for the so-called quark-gluon plasma, a new state of matter which should have existed a few microseconds after the Big Bang. A quark-gluon plasma consists of free color charges, i.e. quarks and gluons, interacting by the strong (instead of electromagnetic) force. Theoretical considerations predict that the critical temperature for the phase transition from nuclear matter to a quark-gluon plasma is about 150 - 200 MeV. In the laboratory such a temperature can be reached in a so-called relativistic heavy-ion collision in accelerator experiments. Using the color charge instead of the electric charge, the Coulomb coupling parameter of such a system is of the order 10 - 30. Hence the quark-gluon plasma is a strongly coupled, relativistic plasma, in which also quantum effects are important. In the present work the experimental and theoretical status of the quark-gluon plasma physics will be reviewed, emphasizing the similarities and differences with usual plasma physics. Furthermore, the mixed phase consisting of free quarks and gluons together with hadrons (e.g. pions) will be discussed, which can be regarded as a complex plasma due to the finite extent of the hadrons.Comment: 5 pages, 5 figures, to be published in the Proceedings of the 10th Workshop on the Physics of Dusty Plasmas (St. Thomas, US Virgin Islands

Van Hove Singularities in the Quark-Gluon Plasma

General arguments as well as different approximations for the in-medium quark propagator in a quark-gluon plasma lead to quark dispersion relations that exhibit a minimum in one branch (plasmino). This minimum causes Van Hove singularities in the dilepton production rate and mesonic correlators, which might have observable consequences.Comment: 9 pages, LaTex, 5 PostScript figures and style file included, to be published in the proceedings of the conference "New Frontiers in Soft Physics and Correlations on the Threshold of the Third Millenium" (12-17 June 2000, Torino, Italy

Absence of Thermophoretic Flow in Relativistic Heavy-Ion Collisions as an Indicator for the Absence of a Mixed Phase

If a quark-gluon plasma is formed in relativistic heavy-ion collisions, there may or may not be a mixed phase of quarks, gluons and hadronic clusters when the critical temperature is reached in the expansion of the fireball. If there is a temperature gradient in the fireball, the hadronic clusters, embedded in the heat bath of quarks and gluons, are subjected to a thermophoretic force. It is shown that even for small temperature gradients and short lifetimes of the mixed phase, thermophoresis would lead to a flow essentially stronger than the observed one. The absence of this strong flow provides support for a rapid or sudden hadronization mechanism without a mixed phase.Comment: 3 pages, 1 figure, revised version to be published in Phys. Rev. Let