Speaker
Description
High-altitude balloon-borne detectors offer a unique perspective on the extensive air showers induced by very high-energy cosmic rays. By placing a detector on the edge of the atmosphere (33 km altitude), fluorescence and Cherenkov light produced by high-altitude horizontal air showers (HAHAS) can be observed. These HAHAS develop in a rarefied atmosphere resulting in the shower’s energy being deposited over a larger spatial distance. This spatial separation makes small features of the longitudinal profile more pronounced, and impact the development of the shower. This may allow for a more precise event-by-event classification of primary masses or help address some remaining issues related to the shower physics. POEMMA balloon with radio (PBR), an ultra-long duration mission planned to launch in 2027 will be the first payload to house a fluorescence detector which can point towards the limb of the Earth and be sensitive to such HAHAS. Additionally, PBR will fly both a Cherenkov and a radio detector, allowing for complementary observations of lower energy events. In this contribution we explore the possibility of these novel observation techniques and their potential interest, both from a theoretical and phenomenological point of view.
