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- Babusci, D., et al.
(author)
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Upper limit on the eta -> pi(+)pi(-) branching fraction with the KLOE experiment
- 2020
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In: Journal of High Energy Physics (JHEP). - : SPRINGER. - 1126-6708 .- 1029-8479. ; :10
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Journal article (peer-reviewed)abstract
- Based on an integrated luminosity of 1.61 fb(-1)e(+)e(-) collision data collected with the KLOE detector at DA Phi NE, the Frascati phi -factory, a search for the P- and CP-violating decay eta -> pi (+)pi (-) has been performed. Radiative phi -> eta gamma decay is exploited to access the eta mesons. No signal is observed in the pi (+)pi (-) invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be B(eta -> pi (+)pi (-)) < 4.9 x 10(-6), which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get B( -> pi (+)pi (-)) < 4.4 x 10(-6) at 90% confidence level.
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