Past electron-positron g-2 experiments yielded sharpest bound on CPT violation for point particles

TL;DR

This paper reanalyzes past electron-positron g-2 experiments to establish a new, highly sensitive limit on CPT violation for point particles, surpassing previous bounds for composite particles like kaons.

Contribution

It introduces a novel figure of merit for CPT violation based on g-2 data, providing the most stringent bound for leptons to date.

Findings

New CPT violation limit of <3(12)×10^-22 from g-2 data

Compared CPT violation bounds for leptons to those for kaons

Demonstrates the sensitivity of g-2 measurements for fundamental symmetry tests

Abstract

In our past experiments on a single electron and positron we measured the cyclotron and spin-cyclotron difference frequencies omega_c and omega_a and the ratios a = omega_a/ omega_c at omega_c = 141 Ghz for e^- and e^+ and later, only for e^-, also at 164 Ghz. Here, we do extract from these data, as had not done before, a new and very different figure of merit for violation of CPT symmetry, one similar to the widely recognized impressive limit |m_Kaon - m_Antikaon|/m_Kaon < 10^-18 for the K-mesons composed of two quarks. That expression may be seen as comparing experimental relativistic masses of particle states before and after the C, P, T operations had transformed particle into antiparticle. Such a similar figure of merit for a non-composite and quite different lepton, found by us from our Delta a = a^- - a^+ data, was even smaller, h_bar |omega_a^- - omega_a^+|/2m_0 c^2 = |Delta a| h_bar omega_c/2m_0 c^2) < 3(12) 10^-22.