Year: 2005
Type: conference-paper
Abstract: We study the Čerenkov effect in the context of the Maxwell-Chern-Simons (MCS) limit of the Standard Model Extension. We present a method to determine the exact radiation rate for a point charge. 1. The Čerenkov effect in the MCS model In recent years the so-called Standard-Model Extension (SME) 1 has provided a convenient framework for studying minute Lorentz and CPT violations that may be low-energy signatures for Planck-scale physics. 2 In this work we will study a subsector of the SME describing pure electrodynamics, where Maxwell theory has been modified with Chern–Simons-like term in the Lagrangian parametrized by dimensionful parameter (kAF) µ: LMCS = − 1 4 FµνF µν + (kAF)µAν ˜ F µν − Aµj µ. (1) The Chern–Simons term explicitly violates Lorentz invariance, as well as PT and CPT invariance. (For an explicit mechanism generating it see Ref. 3.) We have explicitly included a coupling to an external current j µ, which we take to satisfy ∂µj µ = 0. As will become clear below, the inclusion of the (kAF)µ term results in a modification of the photon dispersion relation, with the possibility of phase speeds smaller than the conventional speed of light in vacuum c. If realized in Nature, this opens up the possibility that ordinary charged matter could move with a velocity exceeding the phase velocity of radiation, and thus should emit Čerenkov radiation in vacuum. This effect is well established experimentally and theoretically in conventional macroscopic media. 4 Recently, some unexpected features have been encountered in observations involving lead ions 5 and in exotic condensed-matter systems. 6
Source: CPT and Lorentz Symmetry
Authors: R. LEHNERT, R. POTTING
Institution: University of Algarve
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1997331028