Ultrahighenergy cosmicray bounds on nonbirefringent modified Maxwell theory
Abstract
A particularly simple Lorentzviolating modification of the Maxwell theory of photons maintains gauge invariance, CPT, and renormalization. This modified Maxwell theory, coupled to standard Dirac particles, involves 19 dimensionless “deformation parameters.” Ten of these parameters lead to birefringence and are already tightly constrained by astrophysics. New bounds on the remaining nine nonbirefringent parameters can be obtained from the absence of vacuum Cherenkov radiation for ultrahighenergy cosmic rays (UHECRs). Using selected UHECR events recorded at the Pierre Auger Observatory and assigning pseudorandom directions (i.e., assuming largescale isotropy), Cherenkov bounds are found at the 10^{18} level, which improve considerably upon current laboratory bounds. Future UHECR observations may reduce these Cherenkov bounds to the 10^{23} level.
 Publication:

Physical Review D
 Pub Date:
 January 2008
 DOI:
 10.1103/PhysRevD.77.016002
 arXiv:
 arXiv:0709.2502
 Bibcode:
 2008PhRvD..77a6002K
 Keywords:

 11.30.Cp;
 12.20.m;
 41.60.Bq;
 98.70.Sa;
 Lorentz and Poincare invariance;
 Quantum electrodynamics;
 Cherenkov radiation;
 Cosmic rays;
 High Energy Physics  Phenomenology;
 Astrophysics;
 High Energy Physics  Theory
 EPrint:
 16 pages, v6: included reference to a published Addendum