Energy Distribution of the Leptons in Top Decay to Charged Higgs

We analyze the energy distribution of the leptons coming from the top decay t\ra b\hc,\ bW^+\ra bl^+\nu. The correlation between the lepton energy distribution and the top spin may be useful for distinguishing the \hc signature from the $W$ background. Such a correlation can also be useful for disentangling the two different \hc \bar tb couplings and determining the experimental value of $\tan\beta$.Comment: talk given at the Workshop on Physics at Current Accelerators and the Supercollider, Argonne, Illinois, June, 1993, 5 pages (LATEX) + 3 figures (not included but available on request) SLAC-PUB-6354, SCIPP 93/2

Emigre Anti-Imperialists and America\u27s Philippines, 1898-1899

This thesis considers similarities between key members of the American Anti-Imperialist League who, born in the Old World, emigrated to the United States and became luminaries in their adopted country. The American Anti-Imperialist League formed in 1898 to oppose America’s annexation of the Philippines after the Spanish-American War. Anti-war activists had not prevented the conflict itself, but members of the new League hoped to effect a real protest against the United States taking far-flung Pacific colonies. The League drew support from a vast array of Americans. With diverse branches in several major American cities, its members included writers, businessmen, philosophers, lawyers, social activists, peace activists, Henry George-style single taxers, and everything in between. It was not short on luminaries: Mark Twain, former President Grover Cleveland, Ambrose Bierce, William James, Jane Addams and William Graham Sumner were just some of its members. But it was short on cohesiveness. Other than generally opposing Philippine annexation, its members’ reasons and beliefs differed on subjects from economics to racism to political preferences to pacifism. As fractured as its membership was, the Anti-Imperialist League notably had several key members who were born in Europe and emigrated to America later in life. Their beginnings varied in the details, but there are four key Anti-Imperialists who all came from European beginnings to become prominent men in the United States of the late 19th century. Carl Schurz (Germany), Edwin Lawrence Godkin (then-British Ireland), Andrew Carnegie (Scotland), and Samuel Gompers (England) all left Western Europe and became U.S. citizens, constructing an identity consistent with their vision of America. And all four vigorously opposed annexing the Philippines. This thesis considers whether these men have a more cohesive ideology than the rest of the League. Were they outliers or squarely in the middle of the spectrum of beliefs present in the League? How much of an impact were they able to exert on the issue, compared to each other and to the rest of the League? And how exactly did their backgrounds provoke their opposition to an imperial foreign policy for America? Research consisted of the extensive use of primary and secondary materials from the physical and electronic collections at Syracuse University, as well as Wheaton College (Wheaton, IL). There was also a research trip to the Library of Congress in Washington DC, made possible by a generous grant from the History Department’s Wortman-Ellman fund. Many thanks to the History Department of the Maxwell School. The general conclusion of the thesis is that the émigré anti-imperialists, due to their émigré backgrounds, were all essentially anti-statists, agreeing on a wide array of libertarian principles, and were also powerfully idealistic men. This was why they, unlike a great many Americans, were consistently and fervently anti-imperialistic

The Washburn-Crosby Company: Cadwallader Washburn’s Vision for Minneapolis Flour Milling

In the late nineteenth century, Minneapolis underwent a dramatic transformation and became known as the flour milling center of the world. Powered by the Falls of St. Anthony on the the Mississippi River, aided by technological advancements, and promoted by the expansion of railroads, dozens of flour mills were built, including those of the Washburn Crosby Company. This company, under the leadership of Governor Cadwallader Washburn of Wisconsin, exemplified many of the developments that had brought the Minneapolis industry to renown. Several historians such as William Edgar, Lucile Kane, Robert Frame, and Charles Kuhlmann have published works on the significance of flour milling in Minneapolis. These publications have established a number of factors behind the flour milling industry’s success in Minneapolis including the effects of hydropower, technological innovations, and progressive ideologies. However, the influence of the leading company in the city, the Washburn Crosby Company, has only marginally been discussed in these works. This then raises an important question: How did Cadwallader Washburn, as the head of the Washburn Crosby Company, impact the growth and success of the Minneapolis flour milling industry? To answer this question, I analyzed the papers of Governor Washburn and other leading figures in the flour industry in addition to the issues of two nineteenth century trade journals, the Northwestern Miller and the American Miller. I conclude that Washburn profoundly influenced the Minneapolis flour milling industry in three primary ways: the implementation of modern milling technology in his company, the organization of railroads in Minneapolis, and the expansion of flour export markets in Europe. This analysis of Washburn’s visionary influence on the industry is important in that both Washburn and his mills played a significant role in the rise and development of early Minneapolis as a city and as an international flour milling center

Why was silcrete heat-treated in the Middle Stone Age? An early transformative technology in the context of raw material use at Mertenhof Rock Shelter, South Africa

People heat treated silcrete during the Middle Stone Age (MSA) in southern Africa but the spatial and temporal variability of this practice remains poorly documented. This paucity of data in turn makes it difficult to interrogate the motive factors underlying the application of this technique. In this paper we present data on heat treatment of silcrete through the Howiesons Poort and post-Howiesons Poort of the rock shelter site Mertenhof, located in the Western Cape of South Africa. In contrast to other sites where heat treatment has been documented, distance to rock source at Mertenhof can be reasonably well estimated, and the site is known to contain high proportions of a diversity of fine grained rocks including silcrete, hornfels and chert at various points through the sequence. Our results suggest the prevalence of heat treatment is variable through the sequence but that it is largely unaffected by the relative abundance of silcrete prevalence. Instead there is a strong inverse correlation between frequency of heat treatment in silcrete and prevalence of chert in the assemblage, and a generally positive correlation with the proportion of locally available rock. While it is difficult to separate individual factors we suggest that, at Mertenhof at least, heat treatment may have been used to improve the fracture properties of silcrete at times when other finer grained rocks were less readily available. As such, heat treatment appears to have been a component of the MSA behavioural repertoire that was flexibly deployed in ways sensitive to other elements of technological organisation

A single ion as a shot noise limited magnetic field gradient probe

It is expected that ion trap quantum computing can be made scalable through protocols that make use of transport of ion qubits between sub-regions within the ion trap. In this scenario, any magnetic field inhomogeneity the ion experiences during the transport, may lead to dephasing and loss of fidelity. Here we demonstrate how to measure, and compensate for, magnetic field gradients inside a segmented ion trap, by transporting a single ion over variable distances. We attain a relative magnetic field sensitivity of \Delta B/B_0 ~ 5*10^{-7} over a test distance of 140 \micro m, which can be extended to the mm range, still with sub \micro m resolution. A fast experimental sequence is presented, facilitating its use as a magnetic field gradient calibration routine, and it is demonstrated that the main limitation is the quantum shot noise.Comment: 5 pages, 3 figure

Statistical Properties of Exciton Fine Structure Splittings and Polarization Angles in Quantum Dot Ensembles

We propose an effective model to describe the statistical properties of exciton fine structure splitting (FSS) and polarization angle of quantum dot ensembles (QDEs). We derive the distributions of FSS and polarization angle for QDEs and show that their statistical features can be fully characterized using at most three independent measurable parameters. The effective model is confirmed using atomistic pseudopotential calculations as well as experimental measurements for several rather different QDEs. The model naturally addresses three fundamental questions that are frequently encountered in theories and experiments: (I) Why the probability of finding QDs with vanishing FSS is generally very small? (II) Why FSS and polarization angle differ dramatically from QD to QD? and (III) Is there any direct connection between FSS, optical polarization and the morphology of QDs? The answers to these fundamental questions yield a completely new physical picture for understanding optical properties of QDEs.Comment: 6 pages, 3 figures, 1 tabl

Experimental and theoretical investigation of a multi-mode cooling scheme using multiple EIT resonances

We introduce and demonstrate double-bright electromagnetically induced transparency (D-EIT) cooling as a novel approach to EIT cooling. By involving an additional ground state, two bright states can be shifted individually into resonance for cooling of motional modes of frequencies that may be separated by more than the width of a single EIT cooling resonance. This allows three-dimensional ground state cooling of a $^{40}$Ca$^+$ ion trapped in a linear Paul trap with a single cooling pulse. Measured cooling rates and steady-state mean motional quantum numbers for this D-EIT cooling are compared with those of standard EIT cooling as well as concatenated standard EIT cooling pulses for multi-mode cooling. Experimental results are compared to full density matrix calculations. We observe a failure of the theoretical description within the Lamb-Dicke regime that can be overcome by a time-dependent rate theory. Limitations of the different cooling techniques and possible extensions to multi-ion crystals are discussed.Comment: 18 pages, 13 figures. We have decided to merge the contents of our submission arXiv:1711.00738 with this paper into one comprehensive work. New titl