A New State of Baryonium

The recent discovery of a narrow resonance in the decay $J/\psi \to \gamma p \bar{p}$ is described as a zero baryon number, ``deuteron-like singlet ${}^1S_0$'' state. The difference in binding energy of the deuteron (-2.225 MeV) and of the new state (-17.5 MeV) can be accounted for in a simple potential model with a $\lambda \cdot \lambda$ confining interaction.Comment: 7 page

Charmless B Decays to Final States with Radially Excited Vector Mesons

We consider the weak decays of a B meson to final states that contain a S-wave radially excited vector meson. We consider vector-pseudoscalar final states and calculate ratios of the type $B \to \rho^{\prime} \pi/B \to \rho \pi$, $B \to \omega^{\prime} \pi/B \to \omega \pi$ and $B \to \phi^{\prime} \pi/B \to \phi \pi$ where $\rho^{\prime}$, $\omega^{\prime}$ and $\phi^{\prime}$ are higher $\rho$, $\omega$ and $\phi$ S-wave radial excitations. We find such decays to have larger or similar branching ratios compared to decays where the final state $\rho$, $\omega$ and $\phi$ are in the ground state. We also study the effect of radial mixing in the vector system generated from hyperfine interaction and the annihilation term.Comment: Latex, 12 pages, one figur

Malaria and National Income: Examining a Two Way Causal Relationship

Simple plots of data show that malaria has a negative correlation with national income per capita, whether looking across countries at a point in time, or looking at a single country over time. Some countries have been able to move from an equilibrium characterized by low income and high malaria, to a new equilibrium with higher income and lower rates of malaria. This study develops and estimates a simultaneous equations model to explain these changes. We distinguish three potential causal chains: (a) the ability for decreases in malaria to increase income, (b) the ability for increases in income to reduce malaria (reverse causality), and (c) external factors that may lead to both higher income and lower malaria (incidental association). We find that changes in income have a much stronger effect on malaria than the other way around. While a 1% rise in the number of malaria cases per million decreases income per capita by less than 0.01%, a 1% rise in income per capita decreases the number of malaria cases per million by more than 1.1%. If income were just 1% higher in the 100 countries of the sample, 603,189 cases of malaria could be averted annually.antipoverty, GDP, health, economic growth, malaria, simultaneous equations, Health Economics and Policy, International Development, Labor and Human Capital, I1, I3, O1, O2,

Constitutive modelling of Sandvik 1RK91

A physically based constitutive equation is being developed for the maraging\ud stainless steel Sandvik 1RK91. The steel is used to make precision parts. These parts are formed through multistage forming operations and heat treatments from cold rolled and annealed sheets. The specific alloy is designed to be thermodynamically unstable, so that deformation even at room temperatures can bring about a change in the phase of face centred cubic austenite to either hexagonal closed packed martensite and/or, body centred cubic martensite. This solid state phase change is a function of the strain path, strain, strain rate and temperature. Thus, the fraction of the new phase formed depends on the state of stress at a given location in the part being formed. Therefore a set of experiments is being conducted in order to quantify the stress-strain behavior of this steel under various stress states, strain, strain rate as well as temperature. A magnetic sensor records the fraction of ferromagnetic martensite formed from paramagnetic austenite. A thermocouple as well as an infra red thermometer is used to log the change in temperature of the steel during a mechanical test. The force-displacement data are converted to stress-strain data after correcting for the changes in strain rate and temperature. These data are then cast into a general form of constitutive equation and the transformation equations are derived from Olson-Cohen type functions