NA48/2 studies of rare decays

Raggi, M. (2015) NA48/2 studies of rare decays. Il nuovo cimento C, 38 (4). pp. 1-9. ISSN 1826-9885

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The first observation of about 2000 candidates, with a background contamination below 3%, of the rare decay K± → π±π0e+e− is reported by the NA48/2 experiment. The preliminary branching ratio in the full kinematic region is obtained to be: B(K± → π±π0e+e−) = (4.06 ± 0.17) · 10−6 by analyzing the data collected in 2003. A sample of 4.687×106 K± → π±π0 D, decay candidates with a negligible background contamination collected in 2003–04 is analyzed to search for the dark photon (A ) via the decay chain K± → π±π0, π0 → γA , A → e+e−. No signal is observed, and preliminary limits in the plane dark photon mixing parameter ε2 vs. its mass mA are reported.

Item Type: Article
Subjects: 500 Scienze naturali e Matematica > 530 Fisica
Depositing User: Marina Spanti
Date Deposited: 05 Jun 2020 13:34
Last Modified: 05 Jun 2020 13:34

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