Lorentz Violation in Fermion-Antifermion Decays of Spinless Particles

Abstract

If Lorentz and CPT violation exist, they could affect the decays of scalar and pseudoscalar particles. For a decay into a fermion and an antifermion (not necessarily of the same mass), both the total decay rate and the outgoing particle distribution may be modified, through interference between the conventional decay mechanism and a separate Lorentz-violating mechanism. The modifications are sensitive to forms of Lorentz violation that are otherwise rather difficult to study, since at tree level they do not affect particle propagation, but only interaction vertices. Using existing experimental data on charged pion decay, it is possible to constrain three parameters in the modified pion-muon-neutrino coupling at better than the $10^{-9}$ level; these are the first bounds on these quantities.

16 pages

References in corpus (13)

• Atom Interferometry tests of the isotropy of post-Newtonian gravity
• Preferred-Frame and CP-Violation Tests with Polarized Electrons
• Sensitive polarimetric search for relativity violations in gamma-ray bursts
• Rotating optical cavity experiment testing Lorentz invariance at the 10^{-17} level
• Lorentz-violating electrodynamics and the cosmic microwave background
• Relativity tests by complementary rotating Michelson-Morley experiments
• Testing for Lorentz Violation: Constraints on Standard-Model Extension Parameters via Lunar Laser Ranging
• Addendum: Ultrahigh-energy cosmic-ray bounds on nonbirefringent modified-Maxwell theory
• Ultrahigh-energy cosmic-ray bounds on nonbirefringent modified-Maxwell theory
• Limits on Lorentz Violation from Synchrotron and Inverse Compton Sources
• Eliminating the CPT-Odd f Coefficient from the Lorentz-Violating Standard Model Extension
• Contributions to Pion Decay from Lorentz Violation in the Weak Sector
• Astrophysical Limits on Lorentz Violation for Pions