Kyungpook National University

About: Kyungpook National University is a education organization based out in Daegu, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 20497 authors who have published 42107 publications receiving 834608 citations.

Suppression of non-prompt J/ψ, prompt J/ψ, and Y(1S) in PbPb collisions at √s NN = 2.76 TeV

Abstract: Yields of prompt and non-prompt J/psi, as well as Y(1S) mesons, are measured by the CMS experiment via their dimuon decays in PbPb and pp collisions at sqrt(sNN) = 2.76 TeV for quarkonium rapidity |y|<2.4. Differential cross sections and nuclear modification factors are reported as functions of y and transverse momentum pt, as well as collision centrality. For prompt J/psi with relatively high pt (6.5

Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes

Abstract: A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a $b\bar{b}$ quark pair. The searches use the 8 TeV pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.7 inverse femtobarns. Certain channels include data from 7 TeV collisions corresponding to an integrated luminosity of 4.9 inverse femtobarns. The searches are sensitive to non-standard-model invisible decays of the recently observed Higgs boson, as well as additional Higgs bosons with similar production modes and large invisible branching fractions. In all channels, the observed data are consistent with the expected standard model backgrounds. Limits are set on the production cross section times invisible branching fraction, as a function of the Higgs boson mass, for the vector boson fusion and ZH production modes. By combining all channels, and assuming standard model Higgs boson cross sections and acceptances, the observed (expected) upper limit on the invisible branching fraction at $m_H$=125 GeV is found to be 0.58 (0.44) at 95% confidence level. We interpret this limit in terms of a Higgs-portal model of dark matter interactions.