A search for directional violations of the Lorentz invariance through the study of a possible asymmetry of particle lifetimes

TL;DR

This study tests Lorentz invariance by examining potential asymmetries in K0S meson lifetimes relative to Earth's motion with respect to the CMB, finding no violation and setting a new stringent limit.

Contribution

It provides the most precise experimental limit on directional Lorentz invariance violation using K0S lifetime asymmetry measurements.

Findings

No observed lifetime asymmetry at 95% confidence level.

Set a new upper limit on asymmetry: A < 0.98 x 10^-3.

Limits constrain Lorentz-violating theories.

Abstract

From the study of a sample of about 62.3 million well reconstructed K0S decays recorded by the KLOE detector at the DAFNE accelerator in Frascati, the lifetimes of K0S mesons parallel and antiparallel to the direction of motion of the Earth with respect to the Cosmic Microwave Background reference frame have been studied. No difference has been found, and a limit on a possible asymmetry of the lifetime with respect to the CMB has been set at 95% C.L.: A < 0.98 x 10-3. This is presently the best experimental limit on such quantity, and it is smaller of the speed, expressed in natural units, of the Solar System with respect to the CMB. The present limit might constrain possible Lorentz-violating anisotropical theories.