Observation of the rare η → e + e − e + e − decay with the KLOE experiment
نویسندگان
چکیده
F. Ambrosino d,e, A. Antonelli a, M. Antonelli a, F. Archilli i,j, I. Balwierz b, G. Bencivenni a, C. Bini g,h, C. Bloise a, S. Bocchetta k,l, F. Bossi a, P. Branchini l, G. Capon a, T. Capussela a, F. Ceradini k,l, P. Ciambrone a, E. Czerwiński a, E. De Lucia a, A. De Santis g,h, P. De Simone a, G. De Zorzi g,h, A. Denig c, A. Di Domenico g,h, C. Di Donato e, B. Di Micco k,l, M. Dreucci a, G. Felici a, S. Fiore g,h, P. Franzini g,h, C. Gatti a, P. Gauzzi g,h, S. Giovannella a,∗, E. Graziani l, M. Jacewicz a, J. Lee-Franzini a,m, M. Martemianov o, M. Martini a,f,1, P. Massarotti d,e, S. Meola d,e, S. Miscetti a, G. Morello a, M. Moulson a, S. Müller c, M. Napolitano d,e, F. Nguyen k,l, M. Palutan a, A. Passeri l, V. Patera a,f, I. Prado Longhi k,l, P. Santangelo a, B. Sciascia a, M. Silarski b, T. Spadaro a, C. Taccini k,l, L. Tortora l, G. Venanzoni a, R. Versaci a,f,∗,2, G. Xu a,n, J. Zdebik b
منابع مشابه
Results from the KLOE collaboration : study of the eta / eta ’ mesons
The KLOE experiment has successfully completed its data taking in March 2006 with a total integrated luminosity of about 2.5 pb −1. We report the results on the pseudoscalars η/η mesons, such as the η meson mass measurement, the dynamics of η → 3π, the η − η mixing angle, and the measurement of the rare Branching Ratio for the η → π + π − e + e − decay.
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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-od...
متن کاملMeasurement of the branching ratio and search for a CP violating asymmetry in the η → π + π − e + e − ( γ ) decay at KLOE The KLOE Collaboration
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-od...
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We have searched with the KLOE detector for the P and CP violating decay η → ππ in a sample of 1.55 × 10 η’s from the decay φ → ηγ of φ-mesons produced in ee annihilations at DAΦNE. No signal is found. We obtain the upper limit BR(η → ππ)< 1.3×10 at 90% confidence level.
متن کامل6 Measurement of the Branching Ratio of the K L → π + π − decay with the KLOE Detector
We present a measurement of the branching ratio of the CP violating decay KL→ ππ performed by the KLOE experiment at the φ factory DAΦNE. We use 328 pb of data collected in 2001 and 2002, corresponding to ∼ 150 million tagged KL mesons. We find BR(KL → ππ) = (1.963 ± 0.012stat. ± 0.017syst.) × 10. This branching ratio measurement is fully inclusive of final-state radiation. Using the above resu...
متن کامل2 Study of the Decay φ → ηπ 0 γ with the KLOE Detector
In a sample of 5.3× 10 φ-decays observed with the KLOE detector at the Frascati φ-factory DAΦNE we find 605 ηπγ events with η → γγ and 197 ηπγ events with η → πππ. The decay ηπγ is dominated by the process φ→a0γ. From a fit to the ηπ mass spectrum we find BR(φ→a0(980)γ)= (7.4± 0.7) × 10 .
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تاریخ انتشار 2011