STUDY OF K + → 𝝆 + 𝝆 0 DECAY QUYNH HUONG VUONG YAMANAKA GROUP YEAR-END PRESENTATIONS 2019 1
THE KOTO EXPERIMENT • Purpose: Search for New Physics that violates CP symmetry • Probe: K L → 𝝆 0 𝜉𝜉 • Signature: 2 photons with 𝝆 0 invariant mass and finite pT K L 𝝆 0 𝛿 𝛿 2
MOTIVATION • Want to know if there is K + contamination in K L beam • Major decay mode: K + → 𝝆 + 𝝆 0 (3 clusters: 2 photons from pi0 and 1 pseudo-photon pi+) • Main background: K L → 𝝆 + 𝝆 - 𝝆 0 (1 charged pion escapes detection) • Develop a new algorithm to reconstruct K + from 3 clusters • Kaon mass, chi2, PT, energy, etc are reconstructed and used to evaluate the performance of new algorithm using MC data • Different cut criteria are also studied 3
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