1,721,337 research outputs found
Charged-hadron identification at Belle II
No full textAbstract The Belle II experiment’s ability to identify particles critically affects the sensitivity of its measurements. We describe Belle II’s algorithms for identifying charged particles and evaluate their performance in separating pions, kaons, and protons using 426 fb - 1 of data collected at the energy-asymmetric {\varvec{e}}^+{\varvec{e}}^- e + e - collider SuperKEKB in 2019–2022 at center-of-mass energies at and near the mass of the Υ (4S)
Measurement of Lepton Mass Squared Moments in Decays with the Belle II Experiment
No full textWe present measurements of the first to fourth moments of the lepton mass squared of \mbox{} decays for and with a hadronic system containing a charm quark. These results use a sample of electron-positron collisions at the resonance corresponding to of integrated luminosity and collected by the Belle II experiment in 2019 and 2020. To identify the system and reconstruct , one of the mesons from an decay is fully reconstructed in a hadronic decay mode using a multivariate tagging algorithm. We report raw and central moments for up to , probing up to 77% of the accessible \mbox{} phase space. This is the first measurement of moments in the experimentally challenging range of
Measurement of Lepton Mass Squared Moments in Decays with the Belle II Experiment
No full textWe present measurements of the first to fourth moments of the lepton mass
squared of \mbox{} decays for and with a hadronic system containing a charm quark. These
results use a sample of electron-positron collisions at the
resonance corresponding to of integrated luminosity
and collected by the Belle II experiment in 2019 and 2020. To identify the
system and reconstruct , one of the mesons from an decay is fully reconstructed in a
hadronic decay mode using a multivariate tagging algorithm. We report raw
and central moments for up to , probing up to 77\% of the accessible \mbox{} phase space. This is the first measurement of moments
in the experimentally challenging range of .Comment: Submitted to PR
Observation of inclusive decays in early Phase III data5 (untagged).
No full textThis note contains spectrum of b → (s, d)γ candidates selected in early Phase III data overlaidwith expectations for continuum events and background B ̄B events. The plot also shows thedifference between observed number of events and the background expectations
Belle II Analysis Software Framework (basf2)
No full textPublic repository of basf2 (Belle II Analysis Software Framework)If you use this software, please cite it using the metadata from this file and https://doi.org/10.1007/s41781-018-0017-9
Search for Axionlike Particles Produced in e + e − Collisions at Belle II
No full textAustralian Research Council http://dx.doi.org/10.13039/501100000923Austrian Federal Ministry of Education, Science and Research http://dx.doi.org/10.13039/501100013699Austrian Science Fund http://dx.doi.org/10.13039/501100002428Natural Sciences and Engineering Research Council of Canada http://dx.doi.org/10.13039/501100000038Compute Canada http://dx.doi.org/10.13039/100013020CANARIE http://dx.doi.org/10.13039/100008313Chinese Academy of Sciences http://dx.doi.org/10.13039/501100002367National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809Science and Technology Commission of Shanghai Municipality http://dx.doi.org/10.13039/501100003399CAS Center for Excellence in Particle Physics http://dx.doi.org/10.13039/501100015710Ministerstvo Školství, Mládeže a Tělovýchovy http://dx.doi.org/10.13039/501100001823Univerzita Karlova v Praze http://dx.doi.org/10.13039/100007397FP7 Ideas: European Research Council http://dx.doi.org/10.13039/100011199H2020 Marie Sklodowska-Curie Actions http://dx.doi.org/10.13039/100010665L’Institut National de Physique Nucléaire et de Physique des Particules http://dx.doi.org/10.13039/501100012441Centre National de la Recherche Scientifique http://dx.doi.org/10.13039/501100004794Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347Helmholtz-Gemeinschaft http://dx.doi.org/10.13039/501100001656Max-Planck-Gesellschaft http://dx.doi.org/10.13039/501100004189Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Department of Atomic Energy, Government of India http://dx.doi.org/10.13039/501100001502Department of Science and Technology, Ministry of Science and Technology http://dx.doi.org/10.13039/501100001409Israel Science Foundation http://dx.doi.org/10.13039/501100003977United States-Israel Binational Science Foundation http://dx.doi.org/10.13039/501100001742Instituto Nazionale di Fisica Nucleare http://dx.doi.org/10.13039/501100004007Japan Society for the Promotion of Science http://dx.doi.org/10.13039/501100001691Ministry of Education, Culture, Sports, Science and Technology http://dx.doi.org/10.13039/501100001700National Research Foundation of Korea http://dx.doi.org/10.13039/501100003725Korea Institute of Science and Technology Information http://dx.doi.org/10.13039/501100003708Universiti Malaya http://dx.doi.org/10.13039/501100004386Akademi Sains Malaysia http://dx.doi.org/10.13039/501100007110Ministry of Education Malaysia http://dx.doi.org/10.13039/501100015515Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional http://dx.doi.org/10.13039/501100008688Ministerstwo Nauki i Szkolnictwa Wyższego http://dx.doi.org/10.13039/501100004569University of Tabuk http://dx.doi.org/10.13039/100009391Javna Agencija za Raziskovalno Dejavnost RS http://dx.doi.org/10.13039/501100004329Generalitat Valenciana http://dx.doi.org/10.13039/501100003359Ministry of Science and Technology of the People’s Republic of China http://dx.doi.org/10.13039/501100002855Ministry of Education http://dx.doi.org/10.13039/100010002Thailand Center of Excellence in Physics http://dx.doi.org/10.13039/100012863Türkiye Bilimsel ve Teknolojik Araştirma Kurumu http://dx.doi.org/10.13039/501100004410Ministry of Education and Science of Ukraine http://dx.doi.org/10.13039/501100007684National Science Foundation http://dx.doi.org/10.13039/100000001U.S. Department of Energy http://dx.doi.org/10.13039/100000015National Foundation for Science and Technology Development http://dx.doi.org/10.13039/100007224Ministry of Science and Higher Education of the Russian Federation http://dx.doi.org/10.13039/501100003443Science Committee of the Republic of ArmeniaLiaoNing Revitalization Talents ProgramShanghai Pujiang ProgramAvH Foundation 100005156National Institute of Informatics, and Science Information NETwork 5Radiation Science Research InstituteForeign Large-size Research Facility Application Supporting projectGlobal Science Experimental Data Hub CenterKREONET/GLORIADFrontiers of Science ProgramNational Science CenterAgencia Estatal de Investigacion, Spai
Search for an Invisibly Decaying Z′ Boson at Belle II in e+e- →μ+μ- (e±μ) Plus Missing Energy Final States
No full textTheories beyond the standard model often predict the existence of an additional neutral boson, the Z′. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z′ in the process e+e-→μ+μ-Z′ and of a lepton-flavor-violating Z′ in e+e-→e±μZ′. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an Lμ-Lτ theory, into upper limits on the Z′ coupling constant at the level of 5×10-2-1 for MZ′≤6 GeV/c2
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