Top Partners at the LHC: Spin and Mass Measurement

If one takes naturalness seriously and also assumes a weakly coupled extension of the Standard Model (SM) then there are predictions for phenomenology that can be inferred in a model independent framework. The first such prediction is that there must be some colored particle with mass O(TeV) that cancels the top loop contribution to the quadratic divergence of the Higgs mass. In this paper we begin a model independent analysis of the phenomenology of this "top partner," t'. We make one additional assumption that it is odd under a parity which is responsible for the stability of a WIMP dark matter candidate, N. We focus on three questions to be explored at the LHC: discovery opportunities, mass determination, and spin determination of this top partner. We find that within a certain region of masses for the t' and N, t'\bar{t'} is easily discovered in the t\bar{t}+2N decay with the tops decaying fully hadronically. We show that without having to rely on other channels for new physics that for a a given t' spin the masses of t' and N can be measured using kinematic information (e.g. average MET or H_T) and total cross section. A degeneracy due to the spin remains, but with several hundred inverse fb of luminosity we demonstrate potentially useful new methods for determining the t' spin over a wide range of masses. Our methods could be useful for distinguishing supersymmetric and non-supersymmetric models.Comment: 28 pages, 5 figure

Dry Etch of Shadow Trench Isolation

Shallow trench isolation (STI) planarized with chemical mechanical polishing (CMP) has replaced local oxidation of silicon (LOCOS) as the conventional isolation technique for sub-micron devices. STI increases transistor-packing density, allowing for more functionality and speed per unit area. STI offer superior latch-up immunity, smaller channel-width encroachment and better planarity. The implementation and feasibility of STI has been examined for device fabrication at RIT previously. The process utilized was etching of shallow trenches using SF6-02 dry chemistry and trench fill by TEOS (tetraethylorthosilicate) oxide deposition. The etch chemistry used did not yield anisotropic etching and appreciable undercutting was observed. In the present study, STI process used includes 60 nm of thermal pad oxide and 160 nm of LPCVD nitride as the hard mask. To create the shallow trenches, Si is etched using SF6-CHF3 chemistry for dry etching. The objective is to etch the trenches of depth — 0.5 μm - 0.8 μm deep without undercutting and with high selectivity on resist. A series of experiments have been done to study the Si trench etching using SF6-CHF3 chemistry in the DryTek Quad tool by varying process parameters. The results will be presented at the conference

Modulation of experimental autoimmune myocarditis with cytokine-myosin fusion proteins and novel cardiac peptides

Infectious agents that induce cross-reactive myocarditic T cell responses may cause autoimmune inflammation of the heart, dilated cardiomyopathy (DCM), and heart failure. The purpose of this study was to evaluate the efficacy of GMCSF-Myosin fusion proteins as tolerogenic vaccines capable of inhibiting experimental autoimmune myocarditis (EAM). The fusion proteins were comprised of an N-terminal granulocyte macrophage-colony stimulating factor (GM-CSF) domain and a C-terminal cardiac myosin antigen domain. The antigenic domains Myosin 1052-1076 and Myosin 614-643 were chosen based on epitopes known to cause EAM in Lewis rats and BALB/c mice, respectively. Bioactivity of the cytokine domains for GMCSF-Myo1052 and GMCSF-Myo614 were confirmed with bone marrow proliferation assays. Enhanced antigen presentation was confirmed for GMCSF-Myo1052. Both fusion proteins were found to inhibit disease progression when given as a pretreatment before EAM induction. When administered after disease induction, GMCSF-Myo614 reduced the incidence of EAM. To investigate the mechanisms of these tolerogenic vaccines, a model of EAM was developed in C57BL/6 mice by evaluating a peptide (myosin 718-736) derived from the murine cardiac alpha myosin heavy chain and theorized to bind to H2-I-Ab. EAM was successfully induced in Interferon gamma receptor knockout (Ifgr1-/- ) mice on the C57BL/6 background. Defining the mechanisms by which Interferon-gamma (IFN-[gamma]) inhibits EAM on the C57BL/6 background is beyond the scope of this project, but it is hypothesized that T cell apoptosis or induction of T regulatory cells is involved. In conclusion, this study demonstrated the feasibility of using GMCSF-Myosin fusion proteins to inhibit EAM, and provides a new model of EAM on C57BL/6 background to explore the mechanisms by which GMCSF-Myosin fusion proteins mediate tolerance

Implications of a 125 GeV Higgs for the MSSM and Low-Scale SUSY Breaking

Recently, the ATLAS and CMS collaborations have announced exciting hints for a Standard Model-like Higgs boson at a mass of approximately 125 GeV. In this paper, we explore the potential consequences for the MSSM and low scale SUSY-breaking. As is well-known, a 125 GeV Higgs implies either extremely heavy stops (>~ 10 TeV), or near-maximal stop mixing. We review and quantify these statements, and investigate the implications for models of low-scale SUSY breaking such as gauge mediation where the A-terms are small at the messenger scale. For such models, we find that either a gaugino must be superheavy or the NLSP is long-lived. Furthermore, stops will be tachyonic at high scales. These are very strong restrictions on the mediation of supersymmetry breaking in the MSSM, and suggest that if the Higgs truly is at 125 GeV, viable models of gauge-mediated supersymmetry breaking are reduced to small corners of parameter space or must incorporate new Higgs-sector physics.Comment: 6 pages, 6 figure

EC85-198 Nebraska Poisonous Range Plants

Extension Circular 85-198: Nebraska Poisonous Range Plants. This circular helps people identify plants that grow in Nebraska that may be poisonous

EC85-198 Nebraska Poisonous Range Plants

Extension Circular 85-198: Nebraska Poisonous Range Plants. This circular helps people identify plants that grow in Nebraska that may be poisonous

EC00-153 Selecting Alfalfa Varieties for Nebraska

Yield potential, pest resistance and seed price should be considered when selecting alfalfa varieties in Nebraska. The most important variety decision on many farms and ranches is the selection of alfalfa. The choice of alfalfa variety affects production for three to 10 or more years, whereas varieties of annual crops can be change every year. This extension circular lists the alfalfa varieties that have been tested in Nebraska with commercial seed for two or more years since 1997 and marketed in the state. These are the 2000 results

Genotype and Genotype x Environment Interaction Effects on Forage Yield and Quality of Intermediate Wheatgrass in Swards

Genetic differences among cultivars or strains for specific traits can be significantly reduced or increased by differential genotypic responses to environments. The objective of this study was to determine the relative magnitude of genotype and genotype x environment interaction effects, which are due to differential responses, on forage yield and quality of intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey] when grown in seeded swards in the central Great Plains. Thirty-four strains (genotypes), which included cultivars, experimental strains, and PI lines, were grown in replicated trials at Mead, North Platte, and Alliance, NE. The three sites differed markedly in precipitation and length of growing season. There were significant differences among strains for all evaluated traits. Genotype x location and genotype x year interaction effects were not significant for in vitro dry matter digestibility (IVDMD), indicating that this trait is quite stable across environments. Genotype x location interaction effects were significant for forage yield and protein concentration; genotype x year effects were significant for forage yield. Spearman rank correlations, used to test for consistency of ranking of the strains across environments, were high and significant for IVDMD, but were low and usually not significant for forage yield. Improving IVDMD should be emphasized in intermediate wheatgrass breeding programs, since there is substantial genetic variation for IVDMD, it is stable across environments, and it can improve livestock production per hectare

TEACHING MARKETING AND MANAGEMENT TO AN EXTENSION AUDIENCE IN AN INTER-DISCIPLINARY SETTING

This paper discusses how economists utilize an inter-disciplinary workshop to teach marketing and management concepts to beef cattle producers and beef industry advisors. Range and animal scientists along with economists teach concepts in the classroom and then demonstrate these concepts with hands-on field activities in an 8-day Ranch Practicum, spread over an 8-month period.Teaching/Communication/Extension/Profession,