Enhanced Nonperturbative Effects in Z Decays to Hadrons

We use soft collinear effective field theory (SCET) to study nonperturbative strong interaction effects in Z decays to hadronic final states that are enhanced in corners of phase space. These occur, for example, in the jet energy distribution for two jet events near E_J=M_Z/2, the thrust distribution near unity and the jet invariant mass distribution near zero. The extent to which such nonperturbative effects for different observables are related is discussed.Comment: 17 pages. Paper reorganized, and more discussion and results include

Energy Flow in Interjet Radiation

We study the distribution of transverse energy, Q_Omega, radiated into an arbitrary interjet angular region, Omega, in high-p_T two-jet events. Using an approximation that emphasizes radiation directly from the partons that undergo the hard scattering, we find a distribution that can be extrapolated smoothly to Q_Omega=Lambda_QCD, where it vanishes. This method, which we apply numerically in a valence quark approximation, provides a class of predictions on transverse energy radiated between jets, as a function of jet energy and rapidity, and of the choice of the region Omega in which the energy is measured. We discuss the relation of our approximation to the radiation from unobserved partons of intermediate energy, whose importance was identified by Dasgupta and Salam.Comment: 26 pages, 8 eps figures. Revised to include a discussion of non-global logarithm

Perspectives on the Evolution of Hip-Hop Music through Themes of Race, Crime, and Violence

This thesis examines the role or race, crime, and violence as major themes in hip-hop music through existing academic literature. Utilizing the three major themes, this paper discusses the inherent ties of race, crime, and violence to the production of hip-hop music which can reflect broader social issues existing in American society over the time period from 1970-present day. Furthermore, these themes will be assessed for their activist oriented ability to suggest change in society for the primary groups affected by the issues contained in hip-hop lyrics. Over time, hip-hop, much like any artistic form, has undergone an evolution, producing new sounds, subgenres, and content that may also reflect changes in American society. To explore the alterations that have occurred in the hip-hop genre, this thesis analyzes lyrics from the top 100 songs of the most recent decade of popular hip-hop music through a content analysis. Lastly, interviews with professionals in various fields relevant to the research are discussed to show connections between the empirical data resulting from the analysis and the professional knowledge available on the subject

BRCA1 and BRCA2 mutations in a population-based study of male breast cancer

Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear. Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk. Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives. Conclusion: These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found

Far from Home: A Qualitative Analysis of Altered Social and Familial Interactions by Students Attending College Significant Distances from Home

This study explored the necessary modifications for students’ relationships with their home contexts (social and familial) as they acclimated to college life. We specifically targeted students living over 1,000 miles from their present school setting. Thirty undergraduate students at a private Midwest university participated in this qualitative phenomenological research study through semistructured interviews. While numerous dynamics surfaced, repeated themes included feelings of homesickness, desiring to go home, weakening of peer relationships established at home, and gradual strengthening of familial relationships

Delayed Emergence of Trachykele blondeli blondeli (Coleoptera: Buprestidae)

Prolonged emergence of Trachykele blondeli blondeli Marseul (Coleoptera: Buprestidae) is reported from kiln-dried and subsequently painted wood in this report. The specimen emergence is a new record for Florida. Because the specimen did not emerge from host plant material grown in Florida, it is likely that its origin was exterior to Florida. Because of delayed and prolonged emergence capability in Buprestidae, as well as specimen survival of wood preservation processes like kiln drying, the current report does indicate a concern for redistribution of non-indigenous buprestid species to new areas

Event Shape/Energy Flow Correlations

We introduce a set of correlations between energy flow and event shapes that are sensitive to the flow of color at short distances in jet events. These correlations are formulated for a general set of event shapes, which includes jet broadening and thrust as special cases. We illustrate the method for electron-positron annihilation dijet events, and calculate the correlation at leading logarithm in the energy flow and at next-to-leading-logarithm in the event shape.Comment: 43 pages, eight eps figures; minor changes, references adde

Scaling Rule for Nonperturbative Radiation in a Class of Event Shapes

We discuss nonperturbative radiation for a recently introduced class of infrared safe event shape weights, which describe the narrow-jet limit. Starting from next-to-leading logarithmic (NLL) resummation, we derive an approximate scaling rule that relates the nonperturbative shape functions for these weights to the shape function for the thrust. We argue that the scaling reflects the boost invariance implicit in NLL resummation, and discuss its limitations. In the absence of data analysis for the new event shapes, we compare these predictions to the output of the event generator PYTHIA.Comment: 23 pages, 3 figures, uses JHEP3.cls (included); v2 - version to appear in JHE

Event shapes in e+e- annihilation and deep inelastic scattering

This article reviews the status of event-shape studies in e+e- annihilation and DIS. It includes discussions of perturbative calculations, of various approaches to modelling hadronisation and of comparisons to data.Comment: Invited topical review for J.Phys.G; 40 pages; revised version corrects some nomenclatur

Probing quark gluon plasma with jets

We study multiple scatterings of jets on constituents of quark gluon plasma and introduce energy--energy correlations to quantify their effects. The effects from a longitudinally expanding plasma on medium as well as high energy jets are found to be significant at both RHIC and LHC energies. Because jets escape from the plasma long before the completion of mixed phase, these effects are free from complications of final state hadronic interactions and decays. These suggest that jets can be used to probe the plasma that might be created in future high energy heavy ion collisions.Comment: 15 pages, 6 figures in 5 ps files included, McGill/94-1