Latest results from the searches for ultra-high-energy photons and neutrinos at the Pierre Auger Observatory
Marcus Niechciol, Adila Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, Kévin Almeida Cheminant, Alejandro Almela, Roberto Aloisio, Jaime Álvarez-Muñiz, Juan Ammerman Yebra, Gioacchino Alex Anastasi, Luis A. Anchordoqui, Belén Andrada, S. Andringa, C. Aramo, Paulo Ricardo Araújo Ferreira, Enrico Arnone, Juan Carlos Arteaga Velázquez, Hernán Gonzalo Asorey, P. Assis, Gualberto Avila, Emanuele Avocone, Alina Mihaela Badescu, Alena Bakalová, Alexandru Balaceanu, Felicia Barbato, Adriel Bartz Mocellin, Jose A. Bellido, Corinne Bérat, М. Бертаина, Gopal Bhatta, Marta Bianciotto, Peter L. Biermann, Virginia Binet, Kathrin Bismark, Teresa Bister, Jonathan Biteau, Jiří Blažek, C. Bleve, Johannes Blümer, Martina Boháčová, Denise Boncioli, C. Bonifazi, Luan Bonneau Arbeletche, Nataliia Borodai, J. Brack, P. Gabriel Brichetto Orchera, Florian Lukas Briechle, A. Bueno, S. Buitink, Mario Buscemi, Max Büsken, Anthony Bwembya, K. S. Caballero‐Mora, Sergio Cabana-Freire, Lorenzo Caccianiga, Ioana Caracas, R. Caruso, A. Castellina, Fernando Catalani, G. Cataldi, Lorenzo Cazon, Marcos Cerda, Alessandro Cermenati, J. A. Chinellato, J. Chudoba, L. Chytka, R. W. Clay, Agustín Cobos Cerutti, Roberta Colalillo, Alan Coleman, Maria Rita Coluccia, R. Conceição, Antonio Condorelli, Giovanni Consolati, Matteo Conte, Fabio Convenga, Diego Correia dos Santos, Pedro J. Costa, C. E. Covault, M. Cristinziani, Carlo Salvattore Cruz Sanchez, S. Dasso, K. Daumiller, B. R. Dawson, Rogerio M. de Almeida, Joaquin de Jesus, S. J. de Jong, João de Mello Neto, I. De Mitri, Jaime de Oliveira, Danelise de Oliveira Franco, Francesco de Palma, Vitor de Souza, Emanuele De Vito, Antonino Del Popolo, Olivier Deligny, Nikolas Denner, Luca Deval, Armando di Matteo
Abstract
The Pierre Auger Observatory is the largest air-shower experiment in the world, offering an unprecedented exposure not only to ultra-high-energy (UHE, $E > 10^{17}$ eV}) cosmic rays, but also to UHE neutral particles, specifically photons and neutrinos. Since the beginning of data taking almost 20 years ago, a number of searches for UHE photons and neutrinos using the different detector systems of the Observatory have been carried out. These searches led to some of the most stringent upper limits on the diffuse—i.e., direction-independent, unresolved—fluxes of photons and neutrinos in the UHE regime. These limits severely constrain current models for the origin of UHE cosmic rays and underline the capabilities of the Pierre Auger Observatory and its leading role in the context of multimessenger astronomy at the highest energies. In this contribution, we give an overview of the current activities concerning searches for UHE photons and neutrinos in the data from the Pierre Auger Observatory. The latest results of the searches for diffuse fluxes of photons and neutrinos will be shown. Furthermore, the follow- up searches for UHE photons and neutrinos in association with transient events, such as gravitational wave events, will be summarized. In addition, future perspectives in view of the ongoing $\textit{AugerPrime}$ detector upgrade will be discussed, which will further improve the sensitivity of the Pierre Auger Observatory to neutral particles at the highest energies.