Measurement of the branching ratio and search for a CP violating asymmetry in the $\eta \to \pi^+ \pi^- e^+ e^-(\gamma)$ decay at KLOE - INSPIRE

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Measurement of the branching ratio and search for a CP violating asymmetry in the $\eta \to \pi^+ \pi^- e^+ e^-(\gamma)$ decay at KLOE

KLOE

Collaboration

•

F. Ambrosino
(
- Naples U. and
- INFN, Naples
)

Dec, 2008

12 pages

Published in:

Phys.Lett.B 675 (2009) 283-288

e-Print:

0812.4830 [hep-ex]

DOI:

10.1016/j.physletb.2009.04.013

PDG:

{{\mathit \eta}}

\rightarrow

{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit e}^{+}}{{\mathit e}^{-}}

{{\mathit \gamma}}

Experiments:

FRASCATI-DAFNE-KLOE

View in:

reference search58 citations

Citations per year

Abstract: (Elsevier)

We have studied the η→π+π−e+e−(γ) decay using about 1.7 fb−1 collected by the KLOE experiment at the DAΦNE ϕ -factory. This corresponds to about 72 millions η mesons produced in ϕ radiative decays. We have measured the branching ratio, inclusive of radiative effects, with 4% accuracy: BR(η→π+π−e+e−(γ))=(26.8±0.9Stat.±0.7Syst.)×10−5 . We have obtained the first measurement of the CP-odd ππ – ee decay planes angular asymmetry, Aϕ=(−0.6±2.5Stat.±1.8Syst.)×10−2 .

14.40.Aq
13.66.Bc
11.30.Er
e+e- collisions
rare eta decays
CP violation
e+e− collisions
Rare η decays
[formula omitted] collisions
CP: violation

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Figures(10)

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