Limits on Lorentz violation from the highest energy cosmic rays
Abstract
We place several new limits on Lorentz violating effects, which can modify particles' dispersion relations, by considering the highest energy cosmic rays observed. Since these are hadrons, this involves considering the partonic content of such cosmic rays. We get a number of bounds on differences in maximum propagation speeds, which are typically bounded at the 10^{21} level, and on momentum dependent dispersion corrections of the form v=1±p^{2}/Λ^{2}, which typically bound Λ>10^{21} GeV, well above the Planck scale. For (CPT violating) dispersion correction of the form v=1+p/Λ, the bounds are up to 15 orders of magnitude beyond the Planck scale.
 Publication:

Physical Review D
 Pub Date:
 September 2004
 DOI:
 10.1103/PhysRevD.70.065002
 arXiv:
 arXiv:hepph/0404196
 Bibcode:
 2004PhRvD..70f5002G
 Keywords:

 11.30.Cp;
 11.10.Nx;
 13.85.Tp;
 Lorentz and Poincare invariance;
 Noncommutative field theory;
 Cosmicray interactions;
 High Energy Physics  Phenomenology;
 Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 24 pages, no figures. Added references, very slight changes. Version published in Physical Review D