Limits on Lorentz violation in neutral-Kaon decay

TL;DR

This paper interprets KLOE experiment results to set bounds on Lorentz violation in neutral kaon decay, using a theoretical framework that introduces a Lorentz-violating tensor into the W boson propagator.

Contribution

It develops a general framework to probe Lorentz violation in weak interactions and applies it to kaon decay data to constrain Lorentz-violating parameters.

Findings

Real part of Lorentz-violating tensor hi_{\u03bc u} is smaller than 10^-2

Derived decay asymmetry in a tree-level model

Discussed theoretical challenges in nonleptonic decays

Abstract

The KLOE collaboration recently reported bounds on the directional dependence of the lifetime of the short-lived neutral kaon K_S with respect to the cosmic microwave background dipole anisotropy. We interpret their results in a general framework developed to probe Lorentz violation in the weak interaction. In this approach a Lorentz-violating tensor \chi_{\mu\nu} is added to the standard propagator of the W boson. We derive the K_S decay rate in a naive tree-level model and calculate the asymmetry for the lifetime. By using the KLOE data the real vector part of \chi_{\mu\nu} is found to be smaller than 10^-2. We briefly discuss the theoretical challenges concerning nonleptonic decays.