Because of the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV). Superluminal LIV enables the decay of photons at high energy. The high altitude water Cherenkov (HAWC) observatory is among the most sensitive gamma-ray instruments currently operating above 10 TeV. HAWC finds evidence of 100 TeV photon emission from at least four astrophysical sources. These observations exclude, for the strongest of the limits set, the LIV energy scale to 2.2×1031 eV, over 1800 times the Planck energy and an improvement of 1 to 2 orders of magnitude over previous limits.
Bibliographical noteFunding Information:
The authors are grateful to Alan Kostelecký and Ralf Lehnert for helpful discussions. We acknowledge the support from the U.S. National Science Foundation (NSF); the U.S. Department of Energy Office of High-Energy Physics; the Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory; Consejo Nacional de Ciencia y Tecnología (CONACyT), México, Grants No. 271051, No. 232656, No. 260378, No. 179588, No. 254964, No. 258865, No. 243290, No. 132197, No. A1-S-46288, No. A1-S-22784, cátedras 873, 1563, 341, 323, Red HAWC, México; DGAPA-UNAM Grants No. AG100317, No. IN111315, No. IN111716-3, No. IN111419, No. IA102019, No. IN112218; VIEP-BUAP; PIFI, PROFOCIE; FAPESP Support No. 2015/15897-1 and 2017/03680-3, and the LNCC/MCTI, Brazil; the University of Wisconsin Alumni Research Foundation; the Institute of Geophysics, Planetary Physics, and Signatures at Los Alamos National Laboratory; Polish Science Centre Grants No. DEC-2018/31/B/ST9/01069, No. DEC-2017/27/B/ST9/02272; Coordinación de la Investigación Científica de la Universidad Michoacana; Royal Society—Newton Advanced Fellowship 180385. Thanks to Scott Delay, Luciano Díaz, and Eduardo Murrieta for technical support.
© 2020 American Physical Society.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)