Interactive cutting path analysis programs

The operation of numerically controlled machine tools is interactively simulated. Four programs were developed to graphically display the cutting paths for a Monarch lathe, Cintimatic mill, Strippit sheet metal punch, and the wiring path for a Standard wire wrap machine. These programs are run on a IMLAC PDS-ID graphic display system under the DOS-3 disk operating system. The cutting path analysis programs accept input via both paper tape and disk file

Goldstone Gauginos

Models of supersymmetry with Dirac gauginos provide an attractive scenario for physics beyond the standard model. The "supersoft" radiative corrections and suppressed SUSY production at colliders provide for more natural theories and an understanding of why no new states have been seen. Unfortunately, these models are handicapped by a tachyon which is naturally present in existing models of Dirac gauginos. We argue that this tachyon is absent, with the phenomenological successes of the model preserved, if the right handed gaugino is a (pseudo-)Goldstone field of a spontaneously broken anomalous flavor symmetry.Comment: 5 pages, 1 figure. v2: minor changes to text, references added and update

Models of Goldstone Gauginos

Models with Dirac gauginos provide appealing scenarios for physics beyond the standard model. They have smaller radiative corrections to the Higgs mass, a suppression of certain SUSY production processes, and ameliorated flavor constraints. Unfortunately, they also generally have tachyons, the solutions to which typically spoil these positive features. The recently proposed "Goldstone Gaugino" mechanism provides a simple solution that eliminates these tachyonic states. We provide details on this mechanism and explore models for its origin. In particular, we find SUSY QCD models that realize this idea simply, and discuss scenarios for unification.Comment: 33 pages, 4 figure

Transform-limited pulses are not optimal for resonant multiphoton transitions

Maximizing nonlinear light-matter interactions is a primary motive for compressing laser pulses to achieve ultrashort transform limited pulses. Here we show how, by appropriately shaping the pulses, resonant multiphoton transitions can be enhanced significantly beyond the level achieved by maximizing the pulse's peak intensity. We demonstrate the counterintuitive nature of this effect with an experiment in a resonant two-photon absorption, in which, by selectively removing certain spectral bands, the peak intensity of the pulse is reduced by a factor of 40, yet the absorption rate is doubled. Furthermore, by suitably designing the spectral phase of the pulse, we increase the absorption rate by a factor of 7.Comment: 4 pages, 3 figure

Unitary representations of the W3-algebra with c ≥ 2

We prove unitarity of the vacuum representation of the W_3-algebra for all values of the central charge c ≥ 2.We do it by modifying the free field realization of Fateev and Zamolodchikov resulting in a representation which, by a nontrivial argument, can be shown to be unitary on a certain invariant subspace, although it is not unitary on the full space of the two currents needed for the construction. These vacuum representations give rise to simple unitary vertex operator algebras. We also construct explicitly unitary representations for many positive lowest weight values. Taking into account the known form of the Kac determinants, we then completely clarify the question of unitarity of the irreducible lowest weight representations of the W_3-algebra in the 2 ≤ c ≤ 98 region

Accumulated Earnings Tax and Stock Redemptions - Further Thoughts on the Reasonable Business Needs Test

Few penalty taxes have been imposed with the frequency of the tax on unreasonable accumulations of corporate earnings and profits. Any corporation formed or availed of for the purpose of avoiding income tax with respect to its shareholders by permitting earnings and profits to accumulate instead of being divided or distributed is subject to the tax. However, the tax is not properly imposed where the accumulations are for the reasonable business needs of the corporation. Accordingly, the question of what constitutes reasonable business needs is critical. This article considers one aspect of the reasonable business needs question: Under what circumstances should a redemption of corporate stock or the funding of a proposed redemption be considered a reasonable business need