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               <dc:title>Observation of the B0s→η′η′ Decay</dc:title>
               <dc:creator>Badalov, Alexey</dc:creator>
               <dc:creator>Calvo Gómez, Míriam</dc:creator>
               <dc:creator>Casanova Mohr, Raimon</dc:creator>
               <dc:creator>Garrido Beltrán, Lluís</dc:creator>
               <dc:creator>Gascón Fora, David</dc:creator>
               <dc:creator>Graciani Díaz, Ricardo</dc:creator>
               <dc:creator>Graugés Pous, Eugeni</dc:creator>
               <dc:creator>Marin Benito, Carla</dc:creator>
               <dc:creator>Picatoste Olloqui, Eduardo</dc:creator>
               <dc:creator>Rives Molina, Vicente José</dc:creator>
               <dc:creator>Ruiz, Hugo (Ruiz Pérez)</dc:creator>
               <dc:creator>Vilasis-Cardona, Xavier</dc:creator>
               <dc:creator>LHCb Collaboration</dc:creator>
               <dc:subject>Física de partícules</dc:subject>
               <dc:subject>Experiments</dc:subject>
               <dc:subject>Particle physics</dc:subject>
               <dc:subject>Experiments</dc:subject>
               <dc:description>The first observation of the B 0 s → η ′ η ′ decay is reported. The study is based on a sample of proton-proton collisions corresponding to 3.0     fb − 1 of integrated luminosity collected with the LHCb detector. The significance of the signal is 6.4 standard deviations. The branching fraction is measured to be [ 3.31 ± 0.64 ( stat ) ± 0.28 ( syst ) ± 0.12 ( norm ) ] × 10 − 5 , where the third uncertainty comes from the B ± → η ′ K ± branching fraction that is used as a normalization. In addition, the charge asymmetries of B ± → η ′ K ± and B ± → ϕ K ± , which are control channels, are measured to be ( − 0.2 ± 1.3 ) % and ( + 1.7 ± 1.3 ) % , respectively. All results are consistent with theoretical expectations.</dc:description>
               <dc:date>2019-05-09T09:51:53Z</dc:date>
               <dc:date>2019-05-09T09:51:53Z</dc:date>
               <dc:date>2015-07-28</dc:date>
               <dc:date>2019-05-09T09:51:53Z</dc:date>
               <dc:type>info:eu-repo/semantics/article</dc:type>
               <dc:type>info:eu-repo/semantics/publishedVersion</dc:type>
               <dc:relation>Reproducció del document publicat a: https://doi.org/10.1103/PhysRevLett.115.051801</dc:relation>
               <dc:relation>Physical Review Letters, 2015, vol. 115, num. 5, p. 051801</dc:relation>
               <dc:relation>https://doi.org/10.1103/PhysRevLett.115.051801</dc:relation>
               <dc:rights>cc by (c) CERN; LHCb Collaboration, 2015</dc:rights>
               <dc:rights>http://creativecommons.org/licenses/by/3.0/es/</dc:rights>
               <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
               <dc:publisher>American Physical Society</dc:publisher>
               <dc:source>Articles publicats en revistes (Física Quàntica i Astrofísica)</dc:source>
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