- Tytuł:
- Measurement of $\eta \to \pi^{0}\gamma \gamma$ branching fraction with the KLOE detector
- Autorzy:
-
Fiore, S.
Domenici, D.
Kang, X.
Moskal, Paweł
Wolke, M.
Gajos, Aleksander
Babusci, D.
Gauzzi, P.
Martini, M.
D’Uffizi, A.
Wiślicki, W.
Venanzoni, G.
Giovannella, S.
Passeri, A.
Miscetti, S.
Schioppa, M.
Selce, A.
De Lucia, E.
Czerwiński, Eryk
Branchini, P.
Perez del Rio, Elena
Fantini, G.
Cotrozzi, L.
Teubner, T.
Ceradini, F.
Mandaglio, G.
Sborzacchi, F.
Ciambrone, P.
Berlowski, M.
Punzi, L.
Ignatov, F.
Silarski, Michał
Solodov, E. P.
Vestergaard, N.
Gamrat, Szymon
Bloise, C.
Graziani, E.
Patera, V.
De Leo, V.
Curciarello, F.
Bossi, F.
Kupsc, A.
D’Amico, R.
De Santis, A.
Beltrame, P.
Cao, B.
Sirghi, F.
Di Domenico, A.
D’Agostini, G.
Danè, E.
Diociaiuti, E.
Zaid, E.
De Simone, P. - Opis:
- We present a measurement of the doubly radiative decay $\eta \to \pi^{0}\gamma \gamma$ based on a sample of 82 million $\eta$ mesons produced in the $e^{+}e^{-} \to \phi \to \eta\gamma$ process at the Frascati $\phi$-factory DAΦNE. From the data analysis, 1246 ± 133 signal events were observed. By normalising the signal to the well-known $\eta \to 3\pi^{0}$ decay the branching fraction $\mathcal{B}(\eta \to \pi^{0}\gamma \gamma)$ is measured to be (0.98 ± 0.11$_{stat}$ ± 0.14$_{syst}$) $\times$ 10$^{−4}$. This result agrees with a preliminary KLOE measurement, but is a factor of two smaller than the current world average. Results for $d\Gamma(\eta \to \pi^{0}\gamma \gamma)/dM^{2}(\gamma\gamma)$ are also presented and compared with the latest theoretical predictions.
- Dostawca treści:
- Repozytorium Uniwersytetu Jagiellońskiego
Artykuł