Speaker
Description
KLOE and KLOE-2 collected the largest dataset (about 8 fb$^{-1}$) at an electron-positron collider operating at the peak of the $\phi(1020)$ resonance, corresponding to the production of about 24 billions of $\phi$ mesons, namely 8 billion pairs of neutral $K$ mesons and 300 millions of $\eta$ mesons. A wide hadron physics program, investigating fundamental symmetries, rare meson decays, and dark forces is carried on by the KLOE-2 Collaboration.
The entanglement in the neutral kaon pairs produced at the DA$\Phi$NE $\phi$-factory is a unique tool to test discrete symmetries. The final result of the first direct test of CPT and T in neutral kaon transitions is presented.
The $\eta\to\pi^0\gamma\gamma$ decay is a test bench for various models and effective theories, like VMD (Vector Meson Dominance) or ChPT (Chiral Perturbation Theory. KLOE-2 performed a new precise measurement of the branching ratio, by using its highly pure $\eta$ sample produced in $\phi\to\eta\gamma$ process.
KLOE-2 is currently probing a complementary model to the U boson or "dark photon", where the dark force mediator is a hypothetical leptophobic $B$-boson that could show up in the $\phi\to\eta B\to\eta\pi^0\gamma$ channel. The preliminary upper limit on the coupling constant of such a particle to ordinary matter will be shown.
The KLOE-2 High Energy Tagger detectors allow the possibility to investigate the single $\pi^0$ production in $\gamma\gamma$ collisions by tagging the scattered electrons from $e^+e^-\to e^+e^-\gamma^*\gamma^*\to
e^+e^-\pi^0$ in coincidence with the $\pi^0$ in the barrel calorimeter. A preliminary measurement of the $\gamma^*\gamma^*\to\pi^0$ counting obtained by using single tagged events will be reported.
| Parallel Session | Invited Plenary Talk |
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