|
Measurement of the Ratio $\Gamma(K_L \rightarrow \pi^+\pi^-) / \Gamma(K_L \rightarrow \pi^{\pm}e^{\mp}\nu)$ and Extraction of the CP Violation Parameter $|\eta_{+-}|$ (2006) |
- Lai, A,
- Anzivino, Giuseppina,
- Arcidiacono, R,
- Barr, G,
- Becker, H G,
- Bertanza, L,
- Bevan, A,
- Biino, C,
- Bizzeti, A,
- Bocquet, G,
- Calvetti, M,
- Carosi, R,
- Cartiglia, N,
- Ceccucci, A,
- Cenci, P,
- Cerri, C,
- Cheshkov, C,
- Chollet, J C,
- Chèze, J B,
- Cirilli, M,
- Cogan, J,
- Collazuo, G,
- Contalbrigo, M,
- Costantini, F,
- Cuhadar-Dnszelmann, T,
- Cundy, Donald C,
- D'Agostini, G,
- Dalpiaz, P,
- De Beer, M,
- Debu, P,
- Dibon, Heinz,
- Doble, N,
- Dosanjh, R S,
- Duclos, J,
- Eppard, K,
- Eppard, M,
- Falaleev, V,
- Fantechi, R,
- Fayard, L,
- Fischer, G,
- Formica, A,
- Fox, H,
- Frabetti, P L,
- Gaponenko, A N,
- Gatignon, L,
- Gershon, T J,
- Gianoli, A,
- Giudici, S,
- Gonidec, A,
- Gorini, B,
- Govi, G,
- Grafstrm, P,
- Graziani, G,
- Guida, R,
- Hay, B,
- Holder, M,
- Iacopini, E,
- Iconomidou-Fayard, L,
- Imbergamo, E,
- Jeitler, Manfred,
- Kalmus, George Ernest,
- Kalter, A,
- Kekelidze, V D,
- Khristov, P Z,
- Kleinknecht, K,
- Knowles, I,
- Koch, U,
- Kpke, L,
- Kubischta, Werner,
- Lacourt, A,
- Lazzeroni, C,
- Lenti, M,
- Litov, L,
- Lubrano, P,
- Madigozhin, D T,
- Maier, A,
- Mannelli, I,
- Marchetto, F,
- Markytan, Manfred,
- Marouelli, P,
- Marras, D,
- Martelli, F,
- Martin, V,
- Martini, M,
- Mazzucato, E,
- Menichetti, E,
- Mestvirishvili, A,
- Mikulec, I,
- Molokanova, N A,
- Munday, D J,
- Nappi, A,
- Nassalski, J P,
- Neuhofer, G,
- Norton, A,
- Ocariz, J,
- Olaiya, E,
- Palestini, S,
- Panzer-Steindel, B,
- Parker, M A,
- Pastrone, N,
- Pellmann, I,
- Pepé, M,
- Pernicka, M,
- Peters, A,
- Petrucci, F,
- Peyaud, B,
- Piccini, M,
- Pierazzini, G M,
- Potrebenikov, Yu K,
- Renk, B,
- Rondio, E,
- Sacco, R,
- Savrié, M,
- Schmidt, S A,
- Schönharting, V,
- Schué, Yu,
- Sozzi, M,
- Stoynev, S,
- Szleper, M,
- Tatishvili, G T,
- Taureg, H,
- Taurok, A,
- Tkatchev, A,
- Turlay, René,
- Unal, G,
- Vallage, B,
- Velasco, M,
- Veltri, M,
- Wah, H,
- Walker, A,
- Wanke, R,
- White, T O,
- Widhalm, L,
- Wingerter-Seez, I,
- Winhart, A,
- Wislicki, W,
- Wittgen, M,
- Wotton, S A,
- Wronka, S,
- Zinchenko, A I,
- Ziolkowski, M
|
Abstract |
|
We present a measurement of the ratio of the decay rates $\Gamma (K_L \rightarrow\pi^+\pi^-) / \Gamma(K_L \rightarrow\pi^{\pm}e^{\mp}\nu)$, denoted as $\Gamma_{K2\pi}/\Gamma_{Ke3}$. 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 47000 $K_{2\pi}$ and five million $K_{e3}$ decays, we find $\Gamma_{K2\pi}/\Gamma_{Ke3} = (4.835 \pm 0.022_{stat.} \pm 0.016_{syst.}) \times 10^{-3}$. From this we derive the branching ratio of the CP violating decay $K_L \rightarrow\pi^+\pi^-$ and the CP violation parameter $|\eta_{+-}|$. Excluding the CP conserving direct photon emission component $K_L \rightarrow \pi^+\pi^-\gamma$, we obtain the results BR$(K_L \rightarrow \pi^+\pi^-) = (1.941 \pm 0.019) \times 10^{-3}$ and $|\eta_{+-}| = (2.223 \pm 0.012) \times 10^{-3}$. |
Publication details |
|