Solar Abundance of Elements from Neutron-Capture Cross Sections

Excess lightweight products of slow neutron capture in the photosphere, over the mass range of 25 to 207 amu, confirm the solar mass separation recorded by excess lightweight isotopes in the solar wind, over the mass range of 3 to 136 amu [Solar Abundance of the Elements, Meteoritics, volume 18, 1983, pages 209 to 222]. Both measurements show that major elements inside the Sun are Fe, O, Ni, Si and S, like those in rocky planets.Comment: 2 pages with 4 figures, submitted for oral presentation in the Genesis Mission Special Session, 36th Lunar and Planetary Science Conference, Houston, TX, 14-18 March 200

Supersymmetric Higgs Boson Decays in the MSSM with Explicit CP Violation

Decays into neutralinos and charginos are among the most accessible supersymmetric decay modes of Higgs particles in most supersymmetric extensions of the Standard Model. In the presence of explicitly CP--violating phases in the soft breaking sector of the theory, the couplings of Higgs bosons to charginos and neutralinos are in general complex. Based on a specific benchmark scenario of CP violation, we analyze the phenomenological impact of explicit CP violation in the Minimal Supersymmetric Standard Model on these Higgs boson decays. The presence of CP--violating phases could be confirmed either directly through the measurement of a CP--odd polarization asymmetry of the produced charginos and neutralinos, or through the dependence of CP--even quantities (branching ratios and masses) on these phases.Comment: 14 pages, latex, 4 eps figure

Pedagogy in diverse secondary school classes: Legacies for higher education

As university teachers we find ourselves grappling with the increasingly diverse legacies of students’ prior pedagogic experiences – some of which seem to work against the quality intellectual outcomes now demanded from higher education. In this context, this paper reports a descriptive study of pedagogy created for Chinese students in a mainstream Australian secondary school with a high level of tertiary entry. An influential literature on student learning in higher education has pointed to the constraining effects of bothWestern and Chinese secondary schooling on university students’ learning. In the case of Chinese students who enter Western universities from Western secondary schools, the picture is complicated by research indicating that students of English as a Second Language (ESL) receive even more constraining forms of pedagogy than their native-English-speaking peers. A framework of Bernsteinian sociological concepts and discourse analytic concepts was employed in the study reported here to explore this possibility. Implications are drawn for managing the transition of ESL students to university contexts, and for reflecting on our own responses to linguistic and cultural diversity in the tutorial room

Abundance of Cosmological Relics in Low-Temperature Scenarios

We investigate the relic density n_\chi of non-relativistic long-lived or stable particles \chi in cosmological scenarios in which the temperature T is too low for \chi to achieve full chemical equilibrium. The case with a heavier particle decaying into \chi is also investigated. We derive approximate solutions for n_\chi(T) which accurately reproduce numerical results when full thermal equilibrium is not achieved. If full equilibrium is reached, our ansatz no longer reproduces the correct temperature dependence of the \chi number density. However, it does give the correct final relic density, to an accuracy of about 3% or better, for all cross sections and initial temperatures.Comment: 26 pages, 8 figures, comments added, to appear in Phys. Rev.