Search for the anomalous events detected by ANITA using the Pierre Auger Observatory.
HALIM, Adila Binti Abdul; CATALANI, Fernando; SOUZA, Vitor de; OLIVEIRA, Cainã de; ARMAND, Johnnier Perez; SANTOS, Edivaldo Moura; PEIXOTO, Carlos Jose Todero.
HALIM, Adila Binti Abdul; CATALANI, Fernando; SOUZA, Vitor de; OLIVEIRA, Cainã de; ARMAND, Johnnier Perez; SANTOS, Edivaldo Moura; PEIXOTO, Carlos Jose Todero.
Abstract: A dedicated search for upward-going air showers at zenith angles exceeding 110° and energies ??>0.1 EeV has been performed using the Fluorescence Detector of the Pierre Auger Observatory. The search is motivated by two ?anomalous? radio pulses observed by the ANITA flights I and III that appear inconsistent with the standard model of particle physics. Using simulations of both regular cosmic-ray showers and upward-going events, a selection procedure has been defined to separate potential upward-going candidate events and the corresponding exposure has been calculated in the energy range [0.1-33] EeV. One event has been found in the search period between January 1, 2004, and December 31, 2018, consistent with an expected background of 0.27 ±0.12 events from misreconstructed cosmic-ray showers. This translates to an upper bound on the integral flux of (7.2±0.2)×10-21 cm-2 sr-1 y-1 and (3.6±0.2)×10-20 cm-2 sr-1 y-1 for an ??-1 and ??-2 spectrum, respectively. An upward-going flux of showers normalized to the ANITA observations is shown to predict over 34 events for an ??-3 spectrum and over 8.1 events for a conservative ??-5 spectrum, in strong disagreement with the interpretation of the anomalous events as upward-going showers.
@article={003242970,author = {HALIM, Adila Binti Abdul; CATALANI, Fernando; SOUZA, Vitor de; OLIVEIRA, Cainã de; ARMAND, Johnnier Perez; SANTOS, Edivaldo Moura; PEIXOTO, Carlos Jose Todero.},title={Search for the anomalous events detected by ANITA using the Pierre Auger Observatory},journal={Physical Review Letters},note={v. 134, n. 12, p. 121003-1-121003-10},year={2025}}