Hyperon physics at BESIII

TL;DR

This paper reports on hyperon-antihyperon pair production at BESIII, measuring polarization, decay parameters, and CP conservation observables to test the Standard Model with large data samples.

Contribution

It presents the first precise measurements of hyperon decay parameters and CP observables using quantum entangled pairs at BESIII.

Findings

Hyperon polarization observed in entangled pairs

Decay parameters measured with high precision

CP conservation observables estimated

Abstract

Using the largest $J/\psi$ and $\psi(3686)$ data samples collected at the BESIII experiment, the hyperon anti-hyperon pairs are generated in their quantum entangle system. The polarization of hyperon has been observed, which makes it possible to measure the decay parameters of hyperon and anti-hyperon precisely. The CP conservation observables have been estimated which is important to test the Standard Model. In the meanwhile, the branching fractions and angular distributions related to hyperon pair production have been measured.