SUSY Thresholds at a Muon Collider

One of the useful features of muon colliders is the naturally narrow spread in beam energies. Measurements of threshold cross sections then become a prime candidate for precision measurements of particle masses, widths, and couplings as well as determining particle spin. We describe the potential for measuring cross sections near threshold in supersymmetric theories.Comment: 6 pages, To appear in the Proceedings of the 5th International Conference on Physics Potential and Development of $\mu^+\mu^-$ Colliders (MuMu99), San Francisco, CA, 15-17 December 199

Superfield Realizations of Lorentz Violation

Lorentz-violating extensions of the Wess-Zumino model have been formulated in superspace. The models respect a supersymmetry algebra and can be understood as arising from suitably modified superspace transformations.Comment: 7 page

Abelian family symmetries and Leptogenesis

We study the impact of a set of horizontal symmetries on the requirements for producing the baryon asymmetry of the universe via leptogenesis. We find that Abelian horizontal symmetries lead to a simple description of the parameters describing leptogenesis in terms of the small expansion parameter that arises from spontaneous symmetry breaking. If the family symmetry is made discrete, then an enhancement in the amount of leptogenesis can result.Comment: 11 pages, 2 figures, version to appear in Physical Review

Precision W-Boson and Higgs Boson Mass Determinations at Muon Colliders

Precise determinations of the masses of the $W$ boson and of the top quark could stringently test the radiative structure of the Standard Model (SM) or provide evidence for new physics. We analyze the excellent prospects at a muon collider for measuring $M_W$ and $m_t$ in the $W^+W^-$ and $ZH$ threshold regions. With an integrated luminosity of 10 (100) fb$^{-1}$, the W-boson mass could be measured to a precision of 20 (6) MeV, provided that theoretical and experimental systematics are understood. A measurement of $\Delta M_W=6$ MeV would constrain the mass of a $\sim 100$ GeV Higgs to about $\pm 10$ GeV. We demonstrate that a measurement at future colliders of the Bjorken process. With an integrated luminosity of 100\fbi it is possible to measure the Standard Model Higgs mass to within 45\mev at a $\mu^+\mu^-$ collider for \mh=100\gev.Comment: 6 pages, 4 figure

Muon Collider Physics at Very High Energies

Muon colliders might greatly extend the energy frontier of collider physics. One can contemplate circular colliders with center-of-mass energies in excess of 10 TeV. Some physics issues that might be relevant at such a machine are discussed.Comment: 6 page

A Note on the High Stability of Happiness: The Minimal Effects of a Nuclear Catastrophe on Life Satisfaction

Using life satisfaction as a direct measure of individual utility has become popular in the empirical economic literature. In this context, it is crucial to know what circumstances or changes the measure is sensitive to. Is life satisfaction a volatile concept that is affected by minor changes in life circumstances? Or is it a reliable measure of personal happiness? This paper will analyze the impact of a catastrophe, namely the nuclear catastrophe of Chernobyl, on life satisfaction. I use longitudinal data from the German Socio-Economic Panel Study and especially information collected on a monthly basis which allows the researcher to study calendar effects. The following clear-cut results are found. While concern about the environment rose immediately after the nuclear incident, life satisfaction changed little. This suggests that although people were aware of the severity of the catastrophe, they did not feel that their individual well-being had been affected. This finding is highly relevant to the life satisfaction literature as it shows that the life satisfaction measure is very stable and robust against societal and global events. It is shown to predominantly reflect personal life circumstances like health, employment, income, and the family situation and this relationship is apparently not disturbed by global events. Thus, my results reinforce previous findings on the relationship between life satisfaction and individual life characteristics as the stability of their outcome measure is approved.Subjective Well-Being, Happiness, Environmental Protection, Household Panel, SOEP

The Power of Monthly Data in the GSOEP: How the Chernobyl Catastrophe Affected People's Life Satisfaction and Environmental Concerns

Subjective well-being, happiness, Environmental protection, household panel, SOEP