Direct jet reconstruction in p + p and Cu + Cu collisions at PHENIX
Direct jet reconstruction in heavy ion collisions is an important probe for the in-medium parton energy loss and jet–medium interactions and reconstructed jets provide additional constraints to characterize the underlying mechanisms. However, traditional jet reconstruction algorithms operating in the large soft background at RHIC produce fake jets well above the intrinsic production rate of high- p T hard scattering, thus impeding the detection of the low cross section jet signal at RHIC energies. We developed a jet reconstruction algorithm that locates and reconstructs the jet energy using a Gaussian filter. This algorithm is combined with a fake jet rejection scheme that provides efficient jet reconstruction with acceptable fake rate in a background environment up to the central Au + Au collision at s NN = 200 GeV . We present results of its application in p + p and Cu + Cu collisions using data from the PHENIX detector, including jet spectrum up to 60 GeV/ c , nuclear modification factor, and fragmentation function.

title: sPHENIX: An Upgrade Concept from the PHENIX Collaboration
abstract: The PHENIX collaboration presents a concept for a major upgrade to the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). This upgrade, referred to as sPHENIX, brings exciting new capability to the RHIC program by opening new and important channels for experimental investigation and utilizing fully the luminosity of the recently upgraded RHIC facility. sPHENIX enables a compelling jet physics program that will address fundamental questions about the nature of the strongly coupled quark-gluon plasma discovered experimentally at RHIC to be a perfect fluid. The upgrade concept addresses specific questions whose answers are necessary to advance our understanding of the quark-gluon plasma: (1) How to reconcile the observed strongly coupled quark-gluon plasma with the asymptotically free theory of quarks and gluons? (2) What are the dynamical changes to the quark-gluon plasma in terms of quasiparticles and excitations as a function of temperature? (3) How sharp is the transition of the quark-gluon plasma from the most strongly coupled regime near Tc to a weakly coupled system of partons known to emerge at asymptotically high temperatures? In three Appendices, we detail the additional physics capabilities gained through further upgrades: (A) two midrapidity detector additions, (B) a forward rapidity upgrade, and (C) an evolution to an ePHENIX detector suitable for a future Electron Ion Collider at RHIC.

title: Measurement of the properties of a Higgs boson in the four-lepton final state
abstract: Austrian Federal Ministry of Science and Research and the Austrian Science Fund; the Belgian Fonds de la Recherche Scientifique and Fonds voor Wetenschappelijk Onderzoek; the Brazilian Funding Agencies (CNPq, CAPES, FAPERJ, and FAPESP); the Bulgarian Ministry of Education and Science; CERN; the Chinese Academy of Sciences, Ministry of Science and Technology, and National Natural Science Foundation of China; the Colombian Funding Agency (COLCIENCIAS); the Croatian Ministry of Science, Education and Sport, and the Croatian Science Foundation; the Research Promotion Foundation, Cyprus; the Ministry of Education and Research, Recurrent Financing Contract No. SF0690030s09 and European Regional Development Fund, Estonia; the Academy of Finland, Finnish Ministry of Education and Culture, and Helsinki Institute of Physics; the Institut National de Physique Nucleaire et de Physique des Particules/CNRS and Commissariat a l’Energie Atomique et aux Energies Alternatives/CEA, France; the Bundesministerium fur Bildung und Forschung, Deutsche Forschungsgemeinschaft, and Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germany; the General Secretariat for Research and Technology, Greece; the National Scientific Research Foundation and National Innovation Office, Hungary; the Department of Atomic Energy and the Department of Science and Technology, India; the Institute for Studies in Theoretical Physics and Mathematics, Iran; the Science Foundation, Ireland; the Istituto Nazionale di Fisica Nucleare, Italy; the Korean Ministry of Education, Science and Technology and the World Class University program of NRF, Republic of Korea; the Lithuanian Academy of Sciences; the Mexican Funding Agencies (CINVESTAV, CONACYT, SEP, and UASLP-FAI); the Ministry of Business, Innovation and Employment, New Zealand; the Pakistan Atomic Energy Commission; the Ministry of Science and Higher Education and the National Science Centre, Poland; the Fundacao para a Ciencia e a Tecnologia, Portugal; JINR, Dubna, the Ministry of Education and Science of the Russian Federation, the Federal Agency of Atomic Energy of the Russian Federation, Russian Academy of Sciences, and the Russian Foundation for Basic Research; the Ministry of Education, Science and Technological Development of Serbia; the Secretaria de Estado de Investigacion, Desarrollo e Innovacion and Programa Consolider-Ingenio 2010, Spain; the Swiss Funding Agencies (ETH Board, ETH Zurich, PSI, SNF, UniZH, Canton Zurich, and SER); the National Science Council, Taipei; the Thailand Center of Excellence in Physics, the Institute for the Promotion of Teaching Science and Technology of Thailand, Special Task Force for Activating Research and the National Science and Technology Development Agency of Thailand; the Scientific and Technical Research Council of Turkey and the Turkish Atomic Energy Authority; the Science and Technology Facilities Council, United Kingdom; the U.S. Department of Energy and the U.S. National Science Foundation.Individuals have received support from the Marie-Curie program and the European Research Council and EPLANET (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Science and Industrial Research, India; the Compagnia di San Paolo (Torino); the HOMING PLUS programme of Foundation for Polish Science, cofinanced by EU, Regional Development Fund; and the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF.

title: Multiplicity and transverse momentum dependence of two- and four-particle correlations in pPb and PbPb collisions
abstract: Measurements of two- and four-particle angular correlations for charged particles emitted in pPb collisions are presented over a wide range in pseudorapidity and full azimuth. The data, corresponding to an integrated luminosity of approximately 31 nb^(−1), were collected during the 2013 LHC pPb run at a nucleon–nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. The results are compared to 2.76 TeV semi-peripheral PbPb collision data, collected during the 2011 PbPb run, covering a similar range of particle multiplicities. The observed correlations are characterized by the near-side (|Δϕ|≈0) associated pair yields and the azimuthal anisotropy Fourier harmonics (v_n). The second-order (v_2) and third-order (v_3) anisotropy harmonics are extracted using the two-particle azimuthal correlation technique. A four-particle correlation method is also applied to obtain the value of v_2 and further explore the multi-particle nature of the correlations. Both associated pair yields and anisotropy harmonics are studied as a function of particle multiplicity and transverse momentum. The associated pair yields, the four-particle v_2, and the v_3 become apparent at about the same multiplicity. A remarkable similarity in the v_3 signal as a function of multiplicity is observed between the pPb and PbPb systems. Predictions based on the color glass condensate and hydrodynamic models are compared to the experimental results.

title: Searches for light- and heavy-flavour three-jet resonances in pp collisions at $s = 8$ TeV
abstract: A search for three-jet hadronic resonance production in pp collisions at a centre-of-mass energy of 8 TeV has been conducted by the CMS Collaboration at the LHC with a data sample corresponding to an integrated luminosity of 19.4 fb−119.4 fb−1. The search method is model independent, and events are selected that have high jet multiplicity and large values of jet transverse momenta. The signal models explored assume R-parity-violating supersymmetric gluino pair production and have final states with either only light-flavour jets or both light- and heavy-flavour jets. No significant deviation is found between the selected events and the expected standard model multijet and View the MathML sourcett¯ background. For a gluino decaying into light-flavour jets, a lower limit of 650 GeV on the gluino mass is set at a 95% confidence level, and for a gluino decaying into one heavy- and two light-flavour jets, gluino masses between 200 and 835 GeV are, for the first time, likewise excluded.

title: Direct Jet Reconstruction in Proton–Proton and Copper–Copper at $\sqrt{s_{NN}}$ = 200 GeV

title: Search for the rare decays J/psi ---> D-(s) e+ nu(e), J/psi ---> anti-D0 e+ e-
abstract: We report on a search for the decays J / ψ → D s − e + ν e + c.c. , J / ψ → D − e + ν e + c.c. , and J / ψ → D 0 ¯ e + e − + c.c. in a sample of 5.8 × 10 7 J / ψ events collected with the BESII detector at the BEPC. No excess of signal above background is observed, and 90% confidence level upper limits on the branching fractions are set: B ( J / ψ → D s − e + ν e + c.c. ) 4.9 × 10 −5 , B ( J / ψ → D − e + ν e + c.c. ) 1.2 × 10 −5 , and B ( J / ψ → D 0 ¯ e + e − + c.c. ) 1.1 × 10 −5 .