Expectation value analysis of wave packet solutions for the quantum bouncer: short-term classical and long-term revival behavior

We discuss the time development of Gaussian wave packet solutions of the quantum bouncer' (a quantum mechanical particle subject to a uniform downward force, above an impermeable flat surface). We focus on the evaluation and visualization of the expectation values and uncertainties of position and momentum variables during a single quasi-classical period as well as during the long term collapsed phase and several revivals. This approach complements existing analytic and numerical analyses of this system, as well as being useful for comparison with similar results for the harmonic oscillator and infinite well cases.Comment: 20 pages, 7 separate .ps figure

Measurement of tan beta in associated t H^\pm Production in gamma gamma Collisions

The ratio of neutral Higgs field vacuum expectation values, tan beta, is one of the most important parameters to determine in type-II Two-Higgs Doublet Models (2HDM), specifically the Minimal Supersymmetric Standard Model (MSSM). Assuming the energies and integrated luminosity of a future high energy e^+e^- linear collider of sqrt{s}=500, 800, 1000, and 1500 GeV and L=1 ab^{-1} we show that associated t H^+/- production in gamma gamma collisions can be used to make an accurate determination of tan beta for low and high tan beta by precision measurements of the gamma gamma -> H^+/- t + X cross section.Comment: 7 pages, 11 figures, uses REVTEX

What Can We Learn About Leptoquarks At LEP200?

We investigate the discovery potential for first generation leptoquarks at the LEP200 $e^+e^-$ collider. We consider direct leptoquark searches using single leptoquark production via resolved photon contributions which offers a much higher kinematic limit than the more commonly considered leptoquark pair production process. Depending on the coupling strength of the leptoquark, search limits can be obtained to within a few GeV of $\sqrt{s}$. We also consider LQ limits that can be obtained from t-channel interferences effects in $e^+e^- \to hadrons$.Comment: Latex file uses revtex version 3, epsfig, and rotate, 5 postscript figures are attache