KeywordsHeavy Hadron Chiral Perturbation Theory
Laser Effective Field Theory
Soft Collinear Effective Theory
Effective Field Theory
AdvisorFleming, Sean P.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractEffective field theories (EFTs) provide frameworks to systematically improve perturbation expansions in quantum field theory. This improvement is essential in quantum chromodynamics (QCD) predictions, both at low energy in the description of low momentum hadron-hadron scattering and at high energy in the description of electron-positron, proton-proton, proton-electron collisions. It is also important in quantum electrodynamics (QED), when electrons interact with a high-intensity, long-wavelength classical field. I introduce the principles and methods of effective field theory and describe my work in three EFTs: First, in the perturbative QCD region, I use soft collinear effective theory (SCET) to prove that strong interaction soft radiation is universal and to increase the QCD accuracy to next-to-next-to-next-to leading logarithm order for new particle searches in hadron colliders. I also compute a new class of non-perturbative, large logarithmic enhancement arising near the elastic limits of deep inelastic scattering and Drell-Yan processes. Second, in the QCD confinement region, I use heavy hadron chiral perturbation theory to study near-threshold enhancements in the scattering of 𝐷 and 𝜋 mesons near the threshold for the excited 𝐷-meson state, 𝐷*, as well as in the scattering of 𝐷 and 𝐷* mesons near the threshold for the exotic hadron X(3872). This work provides a clear picture of the hadronic molecule X(3872) and more profound understanding of the nuclear force between hadrons. Finally, inspired by SCET, I construct a new electron-laser effective field theory to describe highly-relativistic electrons traveling in strong laser fields, extract the universal distribution of electrons in strong electromagnetic backgrounds and its evolution in energy from the separated momentum scales of emitted photons and classical radiation, and predict the rate of wide angle photon emission. I conclude with limitations of EFT methods and some perspectives on what new work may be achieved with these EFTs.
Degree ProgramGraduate College
Degree GrantorUniversity of Arizona
Showing items related by title, author, creator and subject.
Understanding the Role of Emotions in Mediated Intergroup Threat: A Cultivation and Appraisal Theory ApproachMastro, Dana; Seate, Anita; Segrin, Chris; Harwood, Jake; Mastro, Dana (The University of Arizona., 2012)This investigation sought to extend research in mediated intergroup communication by examining the role of emotion in producing intergroup bias. Two studies were guided by social identity theory, appraisal-based theories of emotion, and cultivation theory. Study 1 surveyed 254 adults, recruited through student referrals. Drawing insight from previous content analytic research and cultivation theory, results indicated that the media plays an important role in cultivating emotional reactions toward racial minorities. Overall daily television consumption was associated with experiencing anxiety-related emotions and distrust-related emotions toward Blacks. Television news consumption was associated with experiencing anger towards Blacks. Overall daily television consumption was associated with experiencing anger and anxiety-related emotions toward Latinos and Asians. Television news consumption was associated with experiencing distrust-related emotions toward Asians. In Study 2 a 2 (Immigration: Threat/No-Threat) X 2 (Ingroup Emotional Norm Endorsement: Present/Absent) plus 1 (Control) experiment examined the impact of mediated intergroup threat on attitudes toward immigration, collective self-esteem, information sharing and seeking behaviors, and policy support, in the context of illegal immigration. This study also examined whether experimental condition indirectly influenced the above-specified outcomes through intergroup emotions. Previous news consumption was examined as a potential moderator of the mediational relationship between experimental condition and intergroup outcomes via intergroup emotions. Results indicate that exposure to intergroup threat via the media directly influence attitudes toward immigrants' human rights and information sharing. Exposure to intergroup threat indirectly influences immigration attitudes through feelings of anxiety. Moreover, exposure to intergroup threat via the media indirectly influences information sharing and support for English-only legislation through feelings of disgust. Conditional indirect effects were found for immigration attitudes, information sharing, and support for English-only legislation. Exposure to threatening intergroup information neither directly, nor indirectly information seeking or emailing congressperson to reduce the number of immigrants allowed in the United States. Results are discussed in light of social identity theory, intergroup threat theory, intergroup emotions theory, and BIAS map research. Taken together, results suggest that the current study's social identity appraisal-based approach provides insight into the role of media in intergroup processes.
Autoethnographic Art; Transformative Explorations of Self within a University Art ClassroomShin, Ryan; Cook, Victoria Hyne; Shin, Ryan; Hochtritt, Lisa; DiCindio, Carissa (The University of Arizona., 2017)Through this research study my aim was to critically examine the ways in which multimodal, autoethnographic art can enhance and expand educational experiences in general education art classrooms. The study investigates how participants’ perceptions of self and others within culture transform over a semester-long qualitative arts-based study. The study’s goal was to uncover teaching and learning strategies that help to disrupt traditional academic boundaries using autoethnography to create an engaged, cooperative university classroom environment. The participants for this study included 77 students in a general education art and culture course and myself as the co-teacher and researcher. Autoethnographic data were collected throughout the course in the forms of art research journals, pre-and post course questionnaires, researcher field notes, recorded class discussions, on-line discussion boards, notes from one-on-one student/researcher communications and field notes from participants’ final multimodal, autoethnographic art pieces and presentations. The methods used for the study were a modified version of arts-based and grounded theoretical research models. A heavy emphasis was placed on the participants art-making and sharing their work with others in the study. The findings from the study indicated most of, many of participants experienced advancement in their understanding of self within culture and developments of new insights into the experiences and perceptions of others in the study. Results from the study confirm a steady growth in participant engagement and development of cooperative class environment throughout the semester. This study contributes to existing scholarship on the generation of new knowledge from arts-based research models, multimodal autoethnograpy as method, teacher/student relationships in academia, and risk-taking in teacher professional development. The findings from the study might provide support and encouragement for meaningful discussions about the significance of exploring self through art making and art sharing in academic settings. By highlighting the achievements of the use of autoethnography as a method of inquiry, this study will add to the larger discussion of teacher and student identity in art education classrooms.
ENTROPY AND INFORMATION IN THE DESIGN AND ANALYSIS OF IMAGING SYSTEMS.Frieden, Roy; SABET-PEYMAN, FARHANG. (The University of Arizona., 1982)The main thrust of this dissertation is the application of statistics and information theory to design, analysis and estimation pertaining to image-forming systems. This study explores the application of Shannon's information in pupil design, the characterization of noise, and study of its behavior in a specific electro-optical system, and estimation of the degraded spread function in atmospherical imagery using the maximum entropy method. Our study shows that a pupil designed to maximize Shannon's information throughput is an apodizer, resulting in resolution and contrast enhancement when compared to the diffraction-limited case. The Strehl ratio is about 0.55. Investigation of statistical and spectral properties as a function of gray level in an electro-optical tracking system indicates that the noise is "white," having a wide band and a close-to-Gaussian distribution. Estimating the spread function via maximum entropy technique has revealed some remarkable results. Using an edge as the object, simulation studies predict a superior estimate in the mean squared error sense to those of the least squares in the presence of three types of noise (signal-dependent Gaussian and Poisson, and signal-independent Gaussian noise). Information theory, linear systems theory, sampling theory and more particularly, statistics and the Fast Fourier Transform are used to derive our results.