RUcore Resource Object
RUcore Resource Object
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TitleEnergy spectrum measured by the telescope array surface detector
NameIvanov, Dmitri (author), Lath, Amitabh (chair), Chou, John Paul (internal member), Gawiser, Eric (internal member), Thomas, Scott (internal member), Thomson, Gordon B. (outside member), Rutgers University, Graduate School - New Brunswick,
Degree Date2012-10
Date Created2012
SubjectPhysics and Astronomy,
Particles (Nuclear physics),
Cosmic rays,
Cosmic ray variations
DescriptionTwo conflicting measurements of the ultra high energy cosmic ray (UHECR) flux have been reported by the Akeno Giant Air Shower Array (AGASA) and the High Resolution Fly's Eye (HiRes) experiments. HiRes observes a $sim$5$sigma$ suppression at $E=10^{19.75}$ eV, which is in agreement with the prediction of Greisen-Zatsepin-Kuz'min (GZK) theory. AGASA, in contrast, sees the flux extended well beyond $E=10^{20}$ eV with no visible break, suggesting that the flux is limited only by the rate at which the sources can produce the UHECR and not by interaction of energetic particles with the cosmic microwave background, thus challenging the relativistic invariance principle. In response to this discrepancy, a new experiment named the Telescope Array (TA) has been deployed, which combines the detection elements used separately by HiRes and AGASA. We describe the TA surface detector (SD) analysis using a technique new to the field, which consists of a detailed Monte-Carlo (MC) simulation of the SD response to the natural cosmic rays, validating the MC by comparing its distributions with the data, and calculation of the SD aperture from the MC. We will also describe our reconstruction procedure, based solely upon the data, and its application to both data and the MC. Finally, we will describe the energy spectrum resulting from this analysis, which is found to be in excellent agreement with the HiRes result, and as such, is the first confirmation of the GZK effect by a ground array of scintillation counters.
NotePh. D.
NoteIncludes bibliographical references
Noteby Dmitri Ivanov
Genretheses
Persistent URLhttp://hdl.rutgers.edu/1782.1/rucore10001600001.ETD.000066829
Languageeng
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.