| Autor: |
The KLOE Collaboration, Ambrosino, F., Antonelli, A., Antonelli, M., Archilli, F., Balwierz, I., Bencivenni, G., Bini, C., Bloise, C., Bocchetta, S., Bossi, F., Branchini, P., Capon, G., Capussela, T., Ceradini, F., Ciambrone, P., Czerwiski, E., De Lucia, E., De Santis, A., De Simone, P., De Zorzi, G., Denig, A., Di Domenico, A., Di Donato, C., Di Micco, B., Dreucci, M., Felici, G., Fiore, S., Franzini, P., Gatti, C., Gauzzi, P., Giovannella, S., Graziani, E., Jacewicz, M., Lee-Franzini, J., Martemianov, M., Martini, M., Massarotti, P., Meola, S., Miscetti, S., Morello, G., Moulson, M., Muller, S., Napolitano, M., Nguyen, F., Palutan, M., Passeri, A., Patera, V., Longhi, I. Prado, Santangelo, P., Sciascia, B., Silarski, M., Spadaro, T., Taccini, C., Tortora, L., Venanzoni, G., Versaci, R., Xu, G., Zdebik, J., collaboration, as members of the KLOE-2, Babusci, D., Badoni, D., Bocci, V., Budano, A., Bulychjev, S. A., Campana, P., Dané, E., De Robertis, G., Domenici, D., Erriquez, O., Fanizzi, G., Gonnella, F., Happacher, F., Höistad, B., Iarocci, E., Johansson, T., Kulikov, V., Kupsc, A., Loddo, F., Matsyuk, M., Messi, R., Moricciani, D., Moskal, P., Ranieri, A., Sarra, I., Schioppa, M., Sciubba, A., Wiślicki, W., Wolke, M. |
| Rok vydání: |
2011 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| Popis: |
We report the measurement of the ratio $\Gamma(\eta \to \pi^+\pi^-\gamma)/\Gamma(\eta \to \pi^+\pi^-\pi^0)$ analyzing a large sample of $\phi \to \eta \gamma$ decays recorded with the KLOE experiment at the DA$\Phi$NE $e^+ e^-$ collider, corresponding to an integrated luminosity of 558 pb$^{-1}$. The $\eta \to \pi^+\pi^-\gamma$ process is supposed to proceed both via a resonant contribution, mediated by the $\rho$ meson, and a non resonant direct term, connected to the box anomaly. The presence of the direct term affects the partial width value. Our result $R_{\eta}=\Gamma(\eta \to \pi^+ \pi^- \gamma)/\Gamma(\eta \to \pi^+ \pi^- \pi^0)= 0.1838\pm 0.0005_{stat} \pm 0.0030_{syst}$ is in agreement with a recent CLEO measurement, which differs by more 3 $\sigma$ from the average of previous results. |
| Databáze: |
arXiv |
| Externí odkaz: |
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