Effect of nuclear interactions of neutral kaons on CP asymmetry measurements

TL;DR

This paper investigates how differences in nuclear interactions of neutral kaons can significantly affect CP asymmetry measurements at electron-positron colliders, with potential impacts up to 0.3%.

Contribution

It quantifies the impact of neutral kaon nuclear interaction differences on CP asymmetry measurements, highlighting a previously underappreciated systematic effect.

Findings

Nuclear interaction differences can cause up to 0.3% shift in CP asymmetry measurements.

The effect is significant for interpreting CP violation in charm and B-meson experiments.

Neutral kaons' nuclear interactions must be carefully considered in CP asymmetry analyses.

Abstract

We examine the effect of the difference in nuclear interactions of ${K}^0$ and $\bar{K}^0$ mesons on the measurement of CP asymmetry for experiments at $e^+e^-$ colliders - charm and $B$-meson factories. We find that this effect on CP asymmetry can be as large as 0.3%, and therefore sufficiently significant in interpreting measurements of CP asymmetry when neutral kaons are present in the final state.