Measurement of top quark pairs production cross-section in the semi-leptonic channel with the ATLAS experiment

This thesis is about three major aspects of the identification of top quarks. First comes the understanding of their production mechanism, their decay channels and how to translate theoretical formulae into programs that can simulate such physical processes using Monte Carlo techniques. In particular, the author has been involved in the introduction of the POWHEG generator in the framework of the ATLAS experiment. POWHEG is now fully used as the benchmark program for the simulation of ttbar pairs production and decay, along with MC@NLO and AcerMC: this will be shown in chapter one. The second chapter illustrates the ATLAS detectors and its sub-units, such as calorimeters and muon chambers. It is very important to evaluate their efficiency in order to fully understand what happens during the passage of radiation through the detector and to use this knowledge in the calculation of final quantities such as the ttbar production cross section. The last part of this thesis concerns the evaluation of this quantity deploying the so-called "golden channel" of ttbar decays, yielding one energetic charged lepton, four particle jets and a relevant quantity of missing transverse energy due to the neutrino. The most important systematic errors arising from the various part of the calculation are studied in detail. Jet energy scale, trigger efficiency, Monte Carlo models, reconstruction algorithms and luminosity measurement are examples of what can contribute to the uncertainty about the cross-section.

Razor Thin Win: The 1972 Constitution Ballot, Campaign, Ratification & the Courts -- Mae Nan (Robinson) Ellingson & Mick McKeon “In the Crucible of Change”

Beyond the challenge of crafting a new state Constitution that empowered the people and modernized and opened up state and local government in Montana, the Constitutional Convention delegates, as they signed the final document, looked forward to the arduous task of getting it ratified by the electorate in a short ten week period between the end of the convention on March 24 and the ratification election of June 6, 1972. While all 100 delegates signed the draft Constitution, not all supported its adoption. But the planning about how to get it adopted went back to the actions of the Convention itself, which carefully crafted a ballot that kept “hot political issues” from potentially killing the entire document at the polls. As a result, three side issues were presented to the electorate on the ballot. People could vote for or against those side issues and still vote to ratify the entire document. Thus, the questions of legalizing gambling, having a unicameral legislature and retaining the death penalty were placed separately on the ballot (gambling passed, as did the retention of the death penalty, but the concept of a one-house legislature was defeated). Once the ballot structure was set, delegates who supported the new Constitution organized a grassroots, locally focused effort to secure ratification – thought hampered by a MT Supreme Court decision on April 28 that they could not expend $45,000 in public monies that they had set aside for voter education. They cobbled together about $10,000 of private money and did battle with the established political forces, led by the MT Farm Bureau, MT Stockgrowers’ Assn. and MT Contractors Assn., on the question of passage. Narrow passage of the main document led to an issue over certification and a Montana Supreme Court case challenging the ratification vote. After a 3-2 State Supreme Court victory, supporters of the Constitution then had to defend the election results again before the federal courts, also a successful effort. Montana finally had a new progressive State Constitution that empowered the people, but the path to it was not clear and simple and the win was razor thin. The story of that razor thin win is discussed in this chapter by the two youngest delegates to the 1972 Constitutional Convention, Mae Nan Ellingson of Missoula and Mick McKeon, then of Anaconda. Both recognized “Super Lawyers in their later professional practices were also significant players in the Constitutional Convention itself and actively participated in its campaign for ratification. As such, their recollections of the effort provide an insider’s perspective of the struggle to change Montana for the better through the creation and adoption of a new progressive state Constitution “In the Crucible of Change.” Mae Nan (Robinson) Ellingson was born Mae Nan Windham in Mineral Wells, TX and graduated from Mineral Wells High School in 1965 and Weatherford College in Weatherford, TX in 1967. Mae Nan was the youngest delegate at the 1972 Convention from Missoula. She moved to Missoula in 1967 and received her BA in Political Science with Honors from the University of MT in 1970. She was a young widow known by her late husband’s surname of Robinson while attending UM graduate school under the tutelage of noted Professor Ellis Waldron when he persuaded her to run for the Constitutional Convention. Coming in a surprising second in the delegate competition in Missoula County she was named one of the Convention’s “Ten Outstanding Constitutional Convention Delegates,” an impressive feat at such a young age. She was 24 at the time, the youngest person to serve at the ConCon, and one of 19 women out of 100 delegates. In the decade before the Convention, there were never more than three women Legislators in any session, usually one or two. She was a member of the American Association of University Women, a Pi Sigma Alpha political science honorary, and a Phi Alpha Theta historical honorary. At the Convention, she led proposals for the state's bill of rights, particularly related to equal rights for women. For years, Ellingson kept a copy of the preamble to the Constitution hanging in her office; while all the delegates had a chance to vote on the wording, she and delegate Bob Campbell are credited with the language in the preamble. During the convention, she had an opportunity that opened the door to her later career as an attorney. A convention delegate suggested to her that she should go to law school. Several offered to help, but at the time she couldn't go to school. Her mom had died in Texas, and she ended up with a younger brother and sister to raise in Missoula. She got a job teaching, but about a year later, intrigued with the idea of pursuing the law as a career, she called the man back to ask about the offer. Eventually another delegate, Dave Drum of Billings, sponsored her tuition at the UM School of Law. After receiving her JD with Honors (including the Law Review and Moot Court) from the UM Law School Ellingson worked for the Missoula city attorney's office for six years (1977-83), and she took on landmark projects. During her tenure, Missoula became the first city to issue open space bonds, a project that introduced her to Dorsey & Whitney. The city secured its first easement on Mount Sentinel, and it created the trail along the riverfront with a mix of playing fields and natural vegetation. She also helped develop a sign ordinance for the city of Missoula. She ended up working as bond counsel for Dorsey & Whitney, and she opened up the firm's full-fledged Missoula office after commuting a couple of years to its Great Falls office. She was a partner at Dorsey Whitney, working there from 1983 until her retirement in 2012. The area of law she practiced there is a narrow specialty - it requires knowledge of constitutional law, state and local government law, and a slice of federal tax law - but for Ellingson it meant working on great public projects – schools, sewer systems, libraries, swimming pools, ire trucks. At the state level, she helped form the Montana Municipal Insurance Authority, a pooled insurance group for cities. She's shaped MT’s tax increment law, and she was a fixture in the MT Legislature when they were debating equal rights. As a bond lawyer, though, Ellingson considers her most important work for the state to be setting up the Intercap Program that allowed local governments to borrow money from the state at a low interest rate. She has been a frequent speaker at the League of Cities and Towns, the Montana Association of Counties, and the Rural Water Users Association workshops on topics related to municipal finance, as well as workshops sponsored by the DNRC, the Water and Sewer Agencies Coordination Team, and the Montana State University Local Government Center. In 2002, she received an outstanding service award from the Montana Rural Water Users Association. In addition to being considered an expert on Montana state and constitutional law, local government law and local government finance, she is a frequent teacher at the National Association of Bond Lawyers (NABL) Fundamentals of Municipal Bond Law Seminar and the NABL Bond Attorney’s Workshop. For over 30 years Mae Nan has participated in the drafting of legislation in Montana for state and local finance matters. She has served on the Board of Directors of NABL, as Chairman of its Education Committee, was elected as an initial fellow in 1995 to the American College of Bond Counsel, and was recognized as a Super Lawyer in the Rocky Mountain West. Mae Nan was admitted to practice before the MT and US Supreme Courts, was named one of “America’s Leading Business Lawyers” by Chambers USA (Rank 1), a Mountain States Super Lawyer in 2007 and is listed in Best Lawyers in America; she is a member and former Board Member of NABL, a Fellow of the American College of Bond Counsel and a member of the Board of Visitors of the UM Law School. Mae Nan is also a philanthropist who serves on boards and applies her intelligence to many organizations, such as the Missoula Art Museum. [Much of this biography was drawn from a retirement story in the Missoulian and the Dorsey Whitney web site.] Mick McKeon, born in Anaconda in 1946, is a 4th generation Montanan whose family roots in this state go back to the 1870’s. In 1968 he graduated from Notre Dame with a BA in Communications and received a Juris Doctorate degree from the University of Montana Law School in 1971. Right after graduating from law school, Mick was persuaded by his father, longtime State Senator Luke McKeon, and his uncle, Phillips County Attorney Willis McKeon, to run for delegate to Montana’s Constitutional Convention and was elected to represent Deer Lodge, Philipsburg, Powell, and part of Missoula Counties. Along with a coalition of delegates from Butte and Anaconda, he fought through the new Constitution to eliminate the legal strangle hold, often called “the copper collar,” that corporate interests -- the Anaconda Company and its business & political allies -- had over state government for nearly 100 years. The New York Times called Montana’s Constitutional Convention a “prairie revolution.” After helping secure the ratification of the new Constitution, Mick began his practice of law in Anaconda where he engaged in general practice for nearly 20 years. Moving to Butte in 1991, Mick focused has practice in personal injury law, representing victims of negligence and corporate wrongdoing in both Montana district courts and federal court. As such, he participated in some of the largest cases in the history of the state. In 1992 he and his then law partner Rick Anderson obtained a federal court verdict of $11.5 million -- the largest verdict in MT for many years. Mick’s efforts on behalf of injured victims have been recognized by many legal organizations and societies. Recently, Mick was invited to become a member of the International Academy of Trial Lawyers - 600 of the top lawyers in the world. Rated as an American Super Lawyer, he has continuously been named one of the Best Lawyers in America, and an International Assn. of Trial Lawyers top 100 Trial Lawyer. In 2005, he was placed as one of Montana’s top 4 Plaintiff’s lawyers by Law Dragon. Mick is certified as a civil trial specialist by the National Board of Trial Advocacy and has the highest rating possible from Martindale-Hubble. Mick was awarded the Montana Trial Lawyers Public Service Award and provided pro bono assistance to needy clients for his entire career. Mick’s law practice, which he now shares with his son Michael, is limited to representing individuals who have been injured in accidents, concentrating on cases against insurance companies, corporations, medical providers and hospitals. Mick resides in Butte with his wife Carol, a Butte native. Mick, Carol, Michael and another son, Matthew, who graduated from Dartmouth College and was recently admitted to the Montana bar, enjoy as much of their time together in Butte and at their place on Flathead Lake.

Clinical Impact of Couch Top and Rails on IMRT and Arc Therapy

Purpose: To evaluate the clinical impact of the Varian Exact Couch on dose and volume coverage to targets and critical structures and tumor control probability (TCP) for 6-MV IMRT and Arc Therapy. Methods: Five clinical prostate patients were planned with both, 6-MV 8-field IMRT and 6-MV 2-field RapidArc using the Eclipse treatment planning system (TPS). These plans neglected treatment couch attenuation, as is standard clinical practice. Dose distributions were then recalculated in Eclipse with the inclusion of the Varian Exact Couch (imaging couch top) and the rails in varying configurations. The changes in dose and coverage were evaluated using the DVHs from each plan iteration. We used a tumor control probability (TCP) model to calculate losses in tumor control resulting from not accounting for the couch top and rails. We also verified dose measurements in a phantom. Results: Failure to account for the treatment couch and rails resulted in clinically unacceptable dose and volume coverage losses to the target for both IMRT and RapidArc. The couch caused average dose losses (relative to plans that ignored the couch) to the prostate of 4.2% and 2.0% for IMRT with the rails out and in, respectively, and 3.2% and 2.9% for RapidArc with the rails out and in, respectively. On average, the percentage of the target covered by the prescribed dose dropped to 35% and 84% for IMRT (rails out and in, respectively) and to 18% and 17% for RapidArc (rails out and in, respectively). The TCP was also reduced by as much as 10.5% (6.3% on average). Dose and volume coverage losses for IMRT plans were primarily due to the rails, while the imaging couch top contributed most to losses for RapidArc. Both the couch top and rails contribute to dose and coverage losses that can render plans clinically unacceptable. A follow-up study we performed found that the less attenuating unipanel mesh couch top available with the Varian Exact couch does not cause a clinically impactful loss of dose or coverage for IMRT but still causes an unacceptable loss for RapidArc. Conclusions: Both the imaging couch top and rails contribute to dose and coverage loss to a degree that, if included, would prevent the plan from meeting clinical planning criteria. Therefore, the imaging and mesh couch tops and rails should be accounted for in Arc Therapy and the imaging couch and rails only in IMRT treatment planning.

Hydrography and water chemistry of the open Mediterranean Sea

On a cruise from the eastern into western Mediterranean Sea in November/December 1978 a total of 126 samples were collected from 8 vertical profiles and 7 coastal stations for trace metal analysis. The sampling, processing and analysis was performed under strict "clean room" conditions. The concentration of the open-sea samples are close to oceanic results gathered under similar conditions. The grand averages from all profiles (± st. dev. of the individual samples) of 0.40 ± 0.16 µg/l Zn, 17.4 ± 7.4 ng/l Cd, 0.21 ± 0.07 µg/l Cu, 0.21 ± 0.13 µg/l Mn and 0.25 ± 0.09 µg/l Fe indicate that a "metal problem" does not exist in the open Mediterranean. A biologically mediated deplition in surface waters or correlation with nutrients have not been observed under the conditions established on this cruise. This is probably due top low primary production and seasonal advection processes prevailing in this sea. The data for manganese show generally higher values in the surface layer (0-75 m) than in deep waters. This could evidently proved in the nearshore profile indicating a terrigenous source for manganese.

Fatty acid and stable isotope composition of calanoid copepods in the open eastern Atlantic Ocean during POLARSTERN cruise ANT-XXIX/1

The majority of global ocean production and total export production is attributed to oligotrophic oceanic regions due to their vast regional expanse. However, energy transfers, food-web structures and trophic relationships in these areas remain largely unknown. Regional and vertical inter- and intra-specific differences in trophic interactions and dietary preferences of calanoid copepods were investigated in four different regions in the open eastern Atlantic Ocean (38°N to 21°S) in October/November 2012 using a combination of fatty acid (FA) and stable isotope (SI) analyses. Mean carnivory indices (CI) based on FA trophic markers generally agreed with trophic positions (TP) derived from d15N analysis. Most copepods were classified as omnivorous (CI ~0.5, TP 1.8 to ~2.5) or carnivorous (CI >=0.7, TP >=2.9). Herbivorous copepods showed typical CIs of <=0.3. Geographical differences in d15N values of epi- (200-0 m) to mesopelagic (1000-200 m) copepods reflected corresponding spatial differences in baseline d15N of particulate organic matter from the upper 100 m. In contrast, species restricted to lower meso- and bathypelagic (2000-1000 m) layers did not show this regional trend. FA compositions were species-specific without distinct intra-specific vertical or spatial variations. Differences were only observed in the southernmost region influenced by the highly productive Benguela Current. Apparently, food availability and dietary composition were widely homogeneous throughout the oligotrophic oceanic regions of the tropical and subtropical Atlantic. Four major species clusters were identified by principal component analysis based on FA compositions. Vertically migrating species clustered with epi- to mesopelagic, non-migrating species, of which only Neocalanus gracilis was moderately enriched in lipids with 16% of dry mass (DM) and stored wax esters (WE) with 37% of total lipid (TL). All other species of this cluster had low lipid contents (< 10% DM) without WE. Of these, the tropical epipelagic Undinula vulgaris showed highest portions of bacterial markers. Rhincalanus cornutus, R. nasutus and Calanoides carinatus formed three separate clusters with species-specific lipid profiles, high lipid contents (>=41% DM), mainly accumulated as WE (>=79% TL). C. carinatus and R. nasutus were primarily herbivorous with almost no bacterial input. Despite deviating feeding strategies, R. nasutus clustered with deep-dwelling, carnivorous species, which had high amounts of lipids (>=37% DM) and WE (>=54% TL). Tropical and subtropical calanoid copepods exhibited a wide variety of life strategies, characterized by specialized feeding. This allows them, together with vertical habitat partitioning, to maintain high abundance and diversity in tropical oligotrophic open oceans, where they play an essential role in the energy flux and carbon cycling.

Draft of law related to the settling of chambers after Commencement, 1742

One-page handwritten draft of a law created by the president and tutors requiring juniors to inform the Faculty of their intent to stay in dormitory rooms following Commencement. The document is undated and unsigned, but appears to be in the hand of President Edward Holyoke, and has a note in shorthand in the left margin. The text is included in College Book IV and was presented at a meeting of the Harvard Corporation on September 6, 1742.

Open Season for Data Fishing on the Web: The Challenges of the US PRISM Programme for the EU. CEPS Policy Brief No. 293, 18 June 2013

The revelation of the top-secret US intelligence-led PRISM Programme has triggered wide-ranging debates across Europe. Press reports have shed new light on the electronic surveillance ‘fishing expeditions’ of the US National Security Agency and the FBI into the world’s largest electronic communications companies. This Policy Brief by a team of legal specialists and political scientists addresses the main controversies raised by the PRISM affair and the policy challenges that it poses for the EU. Two main arguments are presented: First, the leaks over the PRISM programme have undermined the trust that EU citizens have in their governments and the European institutions to safeguard and protect their privacy; and second, the PRISM affair raises questions regarding the capacity of EU institutions to draw lessons from the past and to protect the data of its citizens and residents in the context of transatlantic relations. The Policy Brief puts forward a set of policy recommendations for the EU to follow and implement a robust data protection strategy in response to the affair.

The open gate An original domestic drama, in one act,

Mode of access: Internet.