The Compressed Baryonic Matter Experiment at FAIR: Progress with feasibility studies and detector developments

The Compressed Baryonic Matter (CBM) experiment is being planned at the international research center FAIR, under realization next to the GSI laboratory in Darmstadt, Germany. Its physics programme addresses the QCD phase diagram in the region of highest net baryon densities. Of particular interest are the expected first order phase transition from partonic to hadronic matter, ending in a critical point, and modifications of hadron properties in the dense medium as a signal of chiral symmetry restoration. Laid out as a fixed-target experiment at the heavy-ion synchrotrons SIS-100/300, the detector will record both proton-nucleus and nucleus-nucleus collisions at beam energies between 10 and 45$A$ GeV. Hadronic, leptonic and photonic observables have to be measured with large acceptance. The interaction rates will reach 10 MHz to measure extremely rare probes like charm near threshold. Two versions of the experiment are being studied, optimized for either electron-hadron or muon identification, combined with silicon detector based charged-particle tracking and micro-vertex detection. The CBM physics requires the development of novel detector sytems, trigger and data acquisition concepts as well as innovative real-time reconstruction techniques. Progress with feasibility studies of the CBM experiment and the development of its detector systems are reported.Comment: 4 pages, 3 figures - FINAL - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

The Cauchy Problem for the Wave Equation in the Schwarzschild Geometry

The Cauchy problem is considered for the scalar wave equation in the Schwarzschild geometry. We derive an integral spectral representation for the solution and prove pointwise decay in time.Comment: 33 page

Topological superconductivity in the extended Kitaev-Heisenberg model

We study superconducting pairing in the doped Kitaev-Heisenberg model by taking into account the recently proposed symmetric off-diagonal exchange $\Gamma$. By performing a mean-field analysis, we classify all possible superconducting phases in terms of symmetry, explicitly taking into account effects of spin-orbit coupling. Solving the resulting gap equations self-consistently, we map out a phase diagram that involves several topologically nontrivial states. For $\Gamma<0$, we find a competition between a time-reversal symmetry breaking chiral phase with Chern number $\pm1$ and a time-reversal symmetric nematic phase that breaks the rotational symmetry of the lattice. On the other hand, for $\Gamma \geq 0$ we find a time-reversal symmetric phase that preserves all the lattice symmetries, thus yielding clearly distinguishable experimental signatures for all superconducting phases. Both of the time-reversal symmetric phases display a transition to a $\mathbb{Z}_2$ non-trivial phase at high doping levels. Finally, we also include a symmetry-allowed spin-orbit coupling kinetic energy and show that it destroys a tentative symmetry protected topological order at lower doping levels. However, it can be used to tune the time-reversal symmetric phases into a $\mathbb{Z}_2$ non-trivial phase even at lower doping

Better Higgs-CP Tests Through Information Geometry

Measuring the CP symmetry in the Higgs sector is one of the key tasks of the LHC and a crucial ingredient for precision studies, for example in the language of effective Lagrangians. We systematically analyze which LHC signatures offer dedicated CP measurements in the Higgs-gauge sector, and discuss the nature of the information they provide. Based on the Fisher information measure, we compare the maximal reach for CP-violating effects in weak boson fusion, associated ZH production, and Higgs decays into four leptons. We find a subtle balance between more theory-independent approaches and more powerful analysis channels, indicating that rigorous evidence for CP violation in the Higgs-gauge sector will likely require a multi-step process.Comment: 27 pages, 8 figure

Beware of the Small-World neuroscientist!

The SW has undeniably been one of the most popular network descriptors in the neuroscience literature. Two main reasons for its lasting popularity are its apparent ease of computation and the intuitions it is thought to provide on how networked systems operate. Over the last few years, some pitfalls of the SW construct and, more generally, of network summary measures, have widely been acknowledged

IS AGRICULTURAL SECTOR GROWTH A PRECONDITION FOR ECONOMIC GROWTH? THE CASE OF SOUTH AFRICA

In this paper a simple growth model is adapted to explain the effect of the agricultural sectors' growth on the non-agricultural sector. The empirical results suggest that for a 1% growth in the agricultural sector, the non-agricultural sector responds by more than 1%. The results also confirm that productivity difference exists, the non-agricultural sector being more efficient in terms of input use. The empirical results support the argument of President T. Mbeki, that South Africa should follow an "agricultural-led" growth strategy for successful development.International Development,

Inter-sectoral Water Use in South Africa: Efficiency Versus Equity

While water supply sources are dwindling in South Africa, the demand for the scarce water resource is increasing. This situation requires a switch from supply to demand management of water in the country. The study updates the 1999 social accounting matrix for South Africa, using the Trade and Industrial Policy Strategies (TIPS) time series data, STATSA's 2001 census report and 2000 water accounts, the 2002 national income accounts, published by the South African Reserve Bank (SARB) and the Water Resource Management Strategy (WRMS) registration data. Using the updated SAM, the contribution of water to economic development in South Africa is estimated through the traditional SAM multiplier analysis. The paper then investigates the impact of reallocating water among the production sectors, on the basis of economic efficiency, on output growth, factor remuneration and households' income generation. The computational and simulation results show that, though agriculture is among the sectors that have the least marginal value of water, water reallocation based on marginal values will reduce the incomes of the poorest households, and put at stake the livelihoods of the most vulnerable population. Scenario analyses suggest that this effect will be minimal if marginal productivity consideration for inter-sectoral water reallocation is reduced to 30%, while intra-sectoral water reallocation on the basis of efficiency is currently viewed as the most viable option.SAM multipliers, output growth, factor remuneration, income generation, efficiency, equity, R20, Resource /Energy Economics and Policy, C67, D57, L60, Q25,