# Recent results on entangled neutral kaons at KLOE-2

- Institution: CERN
- Department: EP Seminar
- Speaker: Antonio Di Domenico
- Year: 2022
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3001256)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

The entanglement of $K^0\bar{K^0}$ pairs produced in $\phi$-meson decays, in combination

with the unique properties of the neutral kaon system – such as flavour oscillations, charge-parity (CP)

and time-reversal (T ) violation – opens up new horizons in testing the basic principles

of quantum mechanics and its fundamental discrete symmetries T , CP, CPT.

The KLOE and KLOE-2 experiments at the Frascati Laboratories of INFN

collected at the DA$\Phi$NE collider an integrated luminosity of about 8 fb$^{-1}$,

corresponding to $\simeq 8 \times 10^{9}$ $K_SK_L$ entangled pairs produced.

This is the world largest available data sample of this kind

and represents a unique tool to improve the precision on these studies.

The seminar will illustrate the most recent KLOE-2 results, including:

(i) an improved search for decoherence and CPT violation effects that exploits EPR correlations

in the process $\phi\rightarrow K_S K_L \rightarrow\pi^+\pi^-\pi^+\pi^-$, and constraints

the parameters of various phenomenological models with a precision that reaches - for some of them -

the interesting level at which – in the most optimistic scenarios – quantum gravity effects might show up.

(ii) the first direct test of the T and CPT symmetries in neutral kaon transitions between flavor and CP eigenstates,

by studying the processes $\phi\rightarrow K_S K_L \rightarrow \pi^+\pi^- \, \pi e \nu$ and

$\phi\rightarrow K_S K_L \rightarrow \pi e \nu \, 3\pi^0$~;

(iii) a new measurement of the $K_S \rightarrow \pi e \nu $ branching fraction, that in combination

with the previous KLOE result improves the total precision by almost a factor of two, and allows

a new derivation of $f_+(0)|V_{us}|$.

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## Lectures

1. [Recent results on entangled neutral kaons at KLOE-2](https://invisiblenetwork.ai/learn/cern/3001256/26d2d2829cfa), 1 h 16 min (CERN's player)