Testing effects of Lorentz invariance violation in the propagation of astroparticles with the Pierre Auger Observatory
P. Abreu, M. Aglietta, Justin M. Albury, I. Allekotte, Kévin Almeida Cheminant, A. Almela, Jaime Álvarez-Muñiz, Rafael Alves Batista, Gioacchino Alex Anastasi, Luis A. Anchordoqui, Belén Andrada, S. Andringa, C. Aramo, Paulo Ricardo Araújo Ferreira, Enrico Arnone, Juan Carlos Arteaga Velázquez, H. Asorey, P. Assis, G. Ávila, Alina Mihaela Badescu, Alena Bakalová, A. Balaceanu, Felicia Barbato, Jose A. Bellido, Corinne Bérat, M. E. Bertaina, X. Bertou, Gopal Bhatta, Peter L. Biermann, Virginia Binet, Kathrin Bismark, Teresa Bister, Jonathan Biteau, Jiří Blažek, C. Bleve, J. Blümer, M. Boháčová, Denise Boncioli, C. Bonifazi, Luan Bonneau Arbeletche, Nataliia Borodai, Ana Martina Botti, J. Brack, T. Bretz, P. Gabriel Brichetto Orchera, F. L. Briechle, P. Buchholz, A. Bueno, S. Buitink, Mario Buscemi, Max Büsken, K. S. Caballero‐Mora, Lorenzo Caccianiga, Fabrizia Canfora, Ioana Caracas, R. Caruso, A. Castellina, Fernando Catalani, G. Cataldi, Lorenzo Cazon, M. Cerda, J. A. Chinellato, J. Chudoba, L. Chytka, R. W. Clay, Agustín Cobos Cerutti, Roberta Colalillo, Alan Coleman, M. R. Coluccia, R. Conceição, Antonio Condorelli, Giovanni Consolati, F. Contreras, Fabio Convenga, Diego Correia dos Santos, C. E. Covault, S. Dasso, K. Daumiller, B. R. Dawson, J.A. Day, R. M. de Almeida, Joaquín de Jesús, S. J. de Jong, J.R.T. de Mello Neto, I. De Mitri, Jaime de Oliveira, Danelise de Oliveira Franco, F. de Palma, V. de Souza, Emanuele De Vito, Antonino Del Popolo, M. del Río, Olivier Deligny, L. Deval, Armando di Matteo, M. Dobre, C. Dobrigkeit, J. C. D’Olivo, Luis Miguel Domingues Mendes, R. C. dos Anjos
Abstract
Abstract Lorentz invariance violation (LIV) is often described by dispersion relations of the form E i 2 = m i 2 + p i 2 +δ i,n E 2+n with delta different based on particle type i , with energy E , momentum p and rest mass m . Kinematics and energy thresholds of interactions are modified once the LIV terms become comparable to the squared masses of the particles involved. Thus, the strongest constraints on the LIV coefficients δ i,n tend to come from the highest energies. At sufficiently high energies, photons produced by cosmic ray interactions as they propagate through the Universe could be subluminal and unattenuated over cosmological distances. Cosmic ray interactions can also be modified and lead to detectable fingerprints in the energy spectrum and mass composition observed on Earth. The data collected at the Pierre Auger Observatory are therefore possibly sensitive to both the electromagnetic and hadronic sectors of LIV. In this article, we explore these two sectors by comparing the energy spectrum and the composition of cosmic rays and the upper limits on the photon flux from the Pierre Auger Observatory with simulations including LIV. Constraints on LIV parameters depend strongly on the mass composition of cosmic rays at the highest energies. For the electromagnetic sector, while no constraints can be obtained in the absence of protons beyond 10 19 eV, we obtain δ γ,0 > -10 -21 , δ γ,1 > -10 -40 eV -1 and δ γ,2 > -10 -58 eV -2 in the case of a subdominant proton component up to 10 20 eV. For the hadronic sector, we study the best description of the data as a function of LIV coefficients and we derive constraints in the hadronic sector such as δ had,0 < 10 -19 , δ had,1 < 10 -38 eV -1 and δ had,2 < 10 -57 eV -2 at 5σ CL.