Conveners
Parallel session B5
- Paweł Moskal (Jagiellonian University)
Bound systems composed of matter-antimatter are known to provide substantial testing ground for fundamental symmetries and decay dynamics. For example the lightest quark-antiquark system, the neutral pion $\pi_0$, which decays predominantly into two photons ($\sim$ 98.82$\%$). Due to Charge conjugation (C) symmetry $\pi_0$ cannot decay into three photons. However, if calculated the branching...
The possibility for the existence of a leptophobic $U(1)$ gauge boson associated to baryon symmetry is scrutinized in the MeV-GeV mass range by means of an exhaustive analysis of the corresponding golden channels $\eta\to\pi^{0}\gamma\gamma$ and $\phi\to\pi^{0}\eta\gamma$.
Using the latest experimental data on these two processes and taking also into account the Standard Model contributions...
The $K^{+}\rightarrow\pi^{+}\nu\bar{\nu}$ decay is a golden mode for flavour physics. Using data collected in 2016--2022, NA62 announced the first observation of this decay with a signal significance above $5\sigma$ and the measurement $B(K^{+}\rightarrow\pi^{+}\nu\bar{\nu}) = \left( 13.0^{+ 3.3}_{- 3.0} \right)\times10^{-11} $. New results from the analysis of the 2023--2024 dataset are...
Precision measurements of simple leptonic systems offer a powerful approach to testing fundamental symmetries and exploring physics beyond the Standard Model. This study focuses on the ortho-positronium (o-Ps) state, which predominantly decays into three photons. Owing to the absence of hadronic effects,positronium provides a uniquely clean system for precise tests of Quantum...
