A review of naturalness and dark matter prediction for the Higgs mass in MSSM and beyond

Within a two-loop leading-log approximation, we review the prediction for the lightest Higgs mass (m_h) in the framework of constrained MSSM (CMSSM), derived from the naturalness requirement of minimal fine-tuning (Delta) of the electroweak scale and dark matter consistency. As a result, the Higgs mass is predicted to be just above the LEP2 bound, m_h=115.9\pm 2 GeV, corresponding to a minimal Delta=17.8, value obtained from consistency with electroweak and WMAP (3\sigma) constraints, but without the LEP2 bound. Due to quantum corrections (largely QCD ones for m_h above LEP2 bound), Delta grows \approx exponentially on either side of the above value of m_h, which stresses the relevance of this prediction. A value m_h>121 (126) GeV cannot be accommodated within the CMSSM unless one accepts a fine-tuning cost worse than Delta>100 (1000), respectively. We review how the above prediction for m_h and Delta changes under the addition of new physics beyond the MSSM Higgs sector, parametrized by effective operators of dimensions d=5 and d=6. For d=5 operators, one can obtain values m_h\leq 130 GeV for Delta<10. The size of the supersymmetric correction that each individual operator of d=6 brings to the value of m_h for points with Delta<100, is found to be small, of few (<4) GeV for M=8 TeV, where M is the scale of new physics. This value decreases (increases) by approximately 1 GeV for a 1 TeV increase (decrease) of the scale M. The relation of these results to the Atlas/CMS supersymmetry exclusion limits is presented together with their impact for the CMSSM regions of lowest fine-tuning.Comment: 27 pages, 19 figures; (new figures and references added; improved presentation

Naturalness of electroweak physics within minimal supergravity

Low energy supersymmetry is motivated by its use as a solution to the hierarchy problem of the electroweak scale. Having motivated this model with naturalness arguments, it is then necessary to check whether the experimentally allowed parameter space permits realisations of the model with low fine tuning. The scope of this thesis is a study of naturalness of the electroweak physics in the minimal supergravity model. The latest experimental constraints are applied, and the fine tuning is quantitatively evaluated for a scan across the parameter space. The fine tuning of the electroweak scale is evaluated at 2-loop order, and the fine tuning of the neutralino dark matter thermal relic energy density is also determined. The natural regions of the parameter space are identified and the associated phenomenology relevant for detection discussed. Naturalness limits are also found for the parameter space and spectrum. The minimum fine tuning found is 1 part in 9 when dark matter constraints are neglected, and 1 part in 15 when dark matter constraints are satisfied. For both cases, the minimum fine tuning is found for a Higgs mass of 115 GeV irrespective of whether the Higgs mass constraint is applied or not. The most natural spectrum includes light superpartner fermions, and heavy superpartner scalars. Minimal supergravity currently remains viable with respect to naturalness and a natural realisation may be discovered within the next couple of years.Comment: 148 pages, D. Phil. Thesis, Oxford Universit

The effect of hydrologic connectivity on benthic macroinvertebrate communities and heavy metal concentrations in oxbow lakes along the Wabash River, Indiana

Access to thesis permanently restricted to Ball State community onlyThe Wabash River in the Midwest United States flows through Indiana then flows along the Indiana and Illinois border until it reaches the confluence with the Ohio River. In the most southern stretch of the Lower Wabash River three lentic oxbow lakes reconnect to the river during flood events. Hydrologic reconnection can affect physiochemical parameters and heavy metals in the upper layer of sediment and throughout the water column. Benthic macroinvertebrates communities can also be affected by flooding events through scouring of the benthic layer and changes in physiochemical parameters. This study shows that flooding events influenced physiochemical parameters and caused a decrease in heavy metal concentrations (Co, Cu, Pb, and Mn). Flooding events also caused a decrease in benthic macroinvertebrate abundance, taxonomic richness, and Shannon diversity. Further, the relative abundance and spatial trends of benthic macroinvertebrates were influenced by flooding events. This shows that hydrologic reconnection can influence the ecology of lentic oxbow lakes.Department of BiologyThesis (M.S.

Bugs After the Bomb: Insect Representations in Postatomic American Fiction and Film.

As cold-blooded invertebrates which more often provoke disgust than delight, insect tend to be overlooked within animal studies in favor of warm-blooded beings in whom it is easier to perceive expression of emotion more “like ours.” Since insects and other arthropods are often conceived of as smaller, “lower,” and more “simple” forms of life, they are thought of as more like machines than animals, lifeless automatons that react to the world with blind instinct rather than agential beings who respond to the world with proclivities and inclinations all their own. This dissertation examines how such a view of insects and other bug-like creatures embodied cultural anxieties about postatomic life in 20th century North American literature, film, and culture. I coin the term “insectoid figuration” to expand beyond Linnaean classification to account for the more affectively motivated layperson’s categorical understanding of “bugs” in order to argue that insectoid figuration became a powerful political register for articulating concerns about American social order, language, dehumanization, and xenophobia. I bridge critical animal studies, materialist feminism, affect theory, and posthumanism to reveal how humanism depends upon abjection of animality by espousing exceptionalist views of human affective capacities. The various insectoid figurations which I explore in this dissertation—the bevy of mutated, big bugs which stomped across the celluloid screen in the 1950s; the centipede as an agent of viral control in William S. Burroughs’s Naked Lunch and other cut-up experimentations; the femme fatale gynoid modeled on insect mimicry and praying mantises in Philip K. Dick’s dystopic Do Androids Dream of Electric Sheep?; the Oankali, an insectoid alien species which seeks genetic trade with humans in Octavia E. Butler’s speculative trilogy Lilith’s Brood—shuttle between the literal and figurative, the material and semiotic, encompass a range of affects and anxieties, and ultimately form a signifying constellation which lays bare shifts in how American social order was conceptualized after the chaos of World War II and in the aftermath of atomic potentiality especially in response to severe environmental degradation.PhDEnglish and Women's StudiesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133284/1/cscassel_1.pd

Fine-tuning implications for complementary dark matter and LHC SUSY searches

The requirement that SUSY should solve the hierarchy problem without undue fine-tuning imposes severe constraints on the new supersymmetric states. With the MSSM spectrum and soft SUSY breaking originating from universal scalar and gaugino masses at the Grand Unification scale, we show that the low-fine-tuned regions fall into two classes that will require complementary collider and dark matter searches to explore in the near future. The first class has relatively light gluinos or squarks which should be found by the LHC in its first run. We identify the multijet plus E_T^miss signal as the optimal channel and determine the discovery potential in the first run. The second class has heavier gluinos and squarks but the LSP has a significant Higgsino component and should be seen by the next generation of direct dark matter detection experiments. The combined information from the 7 TeV LHC run and the next generation of direct detection experiments can test almost all of the CMSSM parameter space consistent with dark matter and EW constraints, corresponding to a fine-tuning not worse than 1:100. To cover the complete low-fine-tuned region by SUSY searches at the LHC will require running at the full 14 TeV CM energy; in addition it may be tested indirectly by Higgs searches covering the mass range below 120 GeV.Comment: References added. Version accepted for publication in JHE

Tuning supersymmetric models at the LHC: A comparative analysis at two-loop level

We provide a comparative study of the fine tuning amount (Delta) at the two-loop leading log level in supersymmetric models commonly used in SUSY searches at the LHC. These are the constrained MSSM (CMSSM), non-universal Higgs masses models (NUHM1, NUHM2), non-universal gaugino masses model (NUGM) and GUT related gaugino masses models (NUGMd). Two definitions of the fine tuning are used, the first (Delta_{max}) measures maximal fine-tuning wrt individual parameters while the second (Delta_q) adds their contribution in "quadrature". As a direct result of two theoretical constraints (the EW minimum conditions), fine tuning (Delta_q) emerges as a suppressing factor (effective prior) of the averaged likelihood (under the priors), under the integral of the global probability of measuring the data (Bayesian evidence p(D)). For each model, there is little difference between Delta_q, Delta_{max} in the region allowed by the data, with similar behaviour as functions of the Higgs, gluino, stop mass or SUSY scale (m_{susy}=(m_{\tilde t_1} m_{\tilde t_2})^{1/2}) or dark matter and g-2 constraints. The analysis has the advantage that by replacing any of these mass scales or constraints by their latest bounds one easily infers for each model the value of Delta_q, Delta_{max} or vice versa. For all models, minimal fine tuning is achieved for M_{higgs} near 115 GeV with a Delta_q\approx Delta_{max}\approx 10 to 100 depending on the model, and in the CMSSM this is actually a global minimum. Due to a strong ($\approx$ exponential) dependence of Delta on M_{higgs}, for a Higgs mass near 125 GeV, the above values of Delta_q\approx Delta_{max} increase to between 500 and 1000. Possible corrections to these values are briefly discussed.Comment: 23 pages, 46 figures; references added; some clarifications (section 2

Chronic idiopathic thrombocytopenia in the Bantu

No Abstract

Testing SUSY

If SUSY provides a solution to the hierarchy problem then supersymmetric states should not be too heavy. This requirement is quantified by a fine tuning measure that provides a quantitative test of SUSY as a solution to the hierarchy problem. The measure is useful in correlating the impact of the various experimental measurements relevant to the search for supersymmetry and also in identifying the most sensitive measurements for testing SUSY. In this paper we apply the measure to the CMSSM, computing it to two-loop order and taking account of current experimental limits and the constraint on dark matter abundance. Using this we determine the present limits on the CMSSM parameter space and identify the measurements at the LHC that are most significant in covering the remaining parameter space. Without imposing the LEP Higgs mass bound we show that the smallest fine tuning (1:13) consistent with a relic density within the WMAP bound corresponds to a Higgs mass of 114$\pm$2 GeV. Fine tuning rises rapidly for heavier Higgs.Comment: 12 pages, 7 figures; references added, figures updated for extended parameter space sca

Testing SUSY at the LHC: Electroweak and Dark matter fine tuning at two-loop order

In the framework of the Constrained Minimal Supersymmetric Standard Model (CMSSM) we evaluate the electroweak fine tuning measure that provides a quantitative test of supersymmetry as a solution to the hierarchy problem. Taking account of current experimental constraints we compute the fine tuning at two-loop order and determine the limits on the CMSSM parameter space and the measurements at the LHC most relevant in covering it. Without imposing the LEPII bound on the Higgs mass, it is shown that the fine tuning computed at two-loop has a minimum $\Delta=8.8$ corresponding to a Higgs mass $m_h=114\pm 2$ GeV. Adding the constraint that the SUSY dark matter relic density should be within present bounds we find $\Delta=15$ corresponding to $m_h=114.7\pm 2$ GeV and this rises to $\Delta=17.8$ ($m_h=115.9\pm 2$ GeV) for SUSY dark matter abundance within 3$\sigma$ of the WMAP constraint. We extend the analysis to include the contribution of dark matter fine tuning. In this case the overall fine tuning and Higgs mass are only marginally larger for the case SUSY dark matter is subdominant and rises to $\Delta=28.7$ ($m_h=116.98\pm 2$ GeV) for the case of SUSY dark matter saturates the WMAP bound. For a Higgs mass above these values, fine tuning rises exponentially fast. The CMSSM spectrum that corresponds to minimal fine tuning is computed and provides a benchmark for future searches. It is characterised by heavy squarks and sleptons and light neutralinos, charginos and gluinos.Comment: 36 pages, 24 figure