2006/11/06 by JiJi Fan, Walter D. Goldberger, Witold Skiba · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Noncommutative and Quantum Gravity Theories #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1016/j.physletb.2007.03.055
published as Phys.Lett.B649:186-190,2007 · 6 pages
arxiv created 2006/11/06 · openalex publication_date 2007/04/05 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Recently, Cohen and Glashow pointed out that all known experimental tests of relativistic kinematics are consistent with invariance of physics under the four-parameter subgroup Sim(2) of the Lorentz group. The massive one-particle irreducible representations of ISim(2), that is Sim(2) times spacetime translations, are all one-dimensional, labeled by spin along a preferred axis. Consequently particle theories based on this symmetry can accomodate lepton number conserving masses for left-handed neutrinos without the need to introduce sterile states. The same property of massive particle representations, however, also leads to the possibility that particle masses may be split within the diffferent spins of a representation of the ordinary Poincare group. In this article we investigate the low-energy structure of theories with spin dependent masses and comment on the bounds on such effects.