The Highest Energy Astroparticle Physics

University Of Chicago, Chicago IL

Investigators

Abstract

The origin of Ultra-High Energy Cosmic Rays (UHECR) is a long-standing mystery. These extraordinary particles, with energies up to ten-millions times higher than those achieved in particle accelerators, are so rare that their detection required the construction of the Pierre Auger Observatory, covering 3000 square kilometers in Argentina. The world’s largest cosmic ray detector has recently completed an upgrade, which will be exploited in this award by the University of Chicago group. Making progress on the puzzles of UHECR may radically change our understanding of the most extreme astrophysical objects in the Universe, of the magnetic fields which permeate it, or of particle physics. Immersive research experiences and engagement of the local community and partnerships will bring UHECR science to both formal and informal audiences. These activities include engaging high school students in a stimulating research environment, reaching out and communicating science to older adults, and partnering with Planetariums. Data from the Auger Observatory are publicly available to a broad community – comprising both professional and citizen scientists – encouraging exploration for educational and outreach purposes, fostering scientific literacy and collaboration. The large statistics collected to date by the Pierre Auger Observatory, along with new data from its upgrade, provides unique scientific opportunities and the world-leading precision measurements of the ultra-high energy (UHE) cosmic ray spectrum, composition, and arrival directions. The next operating period for the observatory is set to tackle a number of key questions including the origin of the observed features in the energy spectrum, the sources of UHE cosmic rays and the search for new physics at particle energies above 100 TeV. The observatory has recently completed an upgrade, AugerPrime, and combined with larger statistic data sets and planned improvements in the analysis methods, significant enhancement in the ability to address the above questions is anticipated. The research supported by this award will exploit these data through novel analysis methods – including Machine Learning - to advance composition reconstruction and further composition-assisted anisotropy studies. In addition, the installation and operation at the Auger Observatory of low-cost Fluorescence telescopes of new design will validate a concept for next-generation observatories and allow for cross-calibration of the energy scale of the measured UHECRs. This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.