Measurement of the ratio Γ (KL → π+ π-) / Γ (KL → π± e∓ ν) and extraction of the CP violation parameter | η+ - |

We present a measurement of the ratio of the decay rates Γ (KL → π+ π-) / Γ (KL → π± e∓ ν), denoted as ΓK 2 π / ΓK e 3. The analysis is based on data taken during a dedicated run in 1999 by the NA48 experiment at the CERN SPS. Using a sample of 47 000 K2 π and five million Ke 3 decays, we find ΓK 2...

Täydet tiedot

Bibliografiset tiedot
Päätekijät: Lai, A, Marras, D, Bevan, A, Dosanjh, R, Gershon, T, Hay, B, Kalmus, G, Lazzeroni, C, Munday, D, Olaiya, E, Parker, M, White, T, Wotton, SA, Barr, G, Bocquet, G, Ceccucci, A, Cuhadar-Dönszelmann, T, Cundy, D, D'Agostini, G, Doble, N, Falaleev, V, Gatignon, L, Gonidec, A, Gorini, B, Govi, G
Aineistotyyppi: Journal article
Kieli:English
Julkaistu: 2007
Kuvaus
Yhteenveto:We present a measurement of the ratio of the decay rates Γ (KL → π+ π-) / Γ (KL → π± e∓ ν), denoted as ΓK 2 π / ΓK e 3. The analysis is based on data taken during a dedicated run in 1999 by the NA48 experiment at the CERN SPS. Using a sample of 47 000 K2 π and five million Ke 3 decays, we find ΓK 2 π / ΓK e 3 = (4.835 ± 0.022stat . ± 0.016syst .) × 10-3. From this we derive the branching ratio of the CP violating decay KL → π+ π- and the CP violation parameter | η+ - |. Excluding the CP conserving direct photon emission component KL → π+ π- γ, we obtain the results BR (KL → π+ π-) = (1.941 ± 0.019) × 10-3 and | η+ - | = (2.223 ± 0.012) × 10-3. © 2006 Elsevier B.V. All rights reserved.