The high energy behavior of fermion-meson and meson-meson scattering in a supersymmetric field theory

A review of the general methods of high energy calculations within the framework of field theory is given. These include Feynman parameter methods, the infinite momentum frame, and Mellin transform methods. A general discussion of supersymmetry is also presented. The basic aspects of the Wess-Zumino model are given. This includes a proof of renormalizability through one-loop, and a derivation of the Feynman rules. The general supersymmetry algebra is presented. The method of generating representations of this algebra through the concept of superfields is discussed. The high energy behavior of fermion-boson and boson-boson scattering amplitudes of a supersymmetric field theory containing a spin-/sup 1///sub 2/ fermion field, a scalar field, and a pseudoscalar field is investigated. The results can be easily modified to apply to the Yukawa model and the neutral version of the linear sigma model. The results are also compared to those of fermion-fermion scattering in the same model. In the leading logarithm approximation, ladders with fermions running along the sides in the t channel and mesons as rungs dominate in each order of two classes of diagrams. The sums of the dominant series give rise to fixed Regge cuts for all amplitudes in each of the three theories. All amplitudes in the supersymmetric theory possess a definite signature factor, while the amplitudes for fermion-fermion and fermion-antifermion scattering in the Y model and the sigma model lack it. The results of the supersymmetric theory are also compared to the results of the spontaneously broken non-Abelian gauge theory

Lapdogs, Attack Dogs, or Watchdogs? News Media's Role in State Government and Politics

What is the news media’s role in influencing political engagement, participation, and polarization at the state level? This thesis reviews existing literature on the history of journalism in the United States, the relationship between media consumption and political behavior, and the relationship between media consumption and political polarization. Case studies examine three states selected by a formula measuring population, length of legislative session, and political diversity in presidential elections. The first chapter studies the relationship between the size of statehouse press corps and voter participation in Massachusetts, Oklahoma, and Wisconsin, finding no significant effect on turnout. The second examines the influence of partisan news on political attitudes in the same three states. Findings support existing theories that increased availability of partisan news is connected to heightened political engagement, along with heightened polarization. The final chapter brings a sharp focus to the state of Wisconsin—ranked by several measures as one of the most polarized states in the country—assessing a set of factors that have contributed to deepening divisions in an effort to better understand media’s role in polarization. Findings indicate that a changing media landscape does influence polarization, but its effects are intertwined with other factors. Government-based and industry-based solutions are recommended to build trust in news media and bridge political divides

Pulsations in M dwarf stars

We present the results of the first theoretical non-radial non-adiabatic pulsational study of M dwarf stellar models with masses in the range 0.1 to 0.5M_solar. We find the fundamental radial mode to be unstable due to an \epsilon mechanism caused by deuterium (D-) burning for the young 0.1 and 0.2M_solar models, by non-equilibrium He^3 burning for the 0.2 and 0.25M_solar models of 10^4Myr, and by a flux blocking mechanism for the partially convective 0.4 and 0.5M_solar models once they reach the age of 500Myr. The periods of the overstable modes excited by the D-burning are in the range 4.2 to 5.2h for the 0.1M_solar models and is of order 8.4h for the 0.2M_solar models. The periods of the modes excited by He^3 burning and flux blocking are in the range 23 to 40min. The more massive and oldest models are more promising for the observational detection of pulsations, as their ratio of instability e-folding time to age is more favourable.Comment: 5 pages, 4 figures, 2 tables. Accepted for publication in MNRAS Letters on 2011 October 11 Version 2 is the accepted manuscript with changes in boldfac