178 research outputs found

    Direct photons measured by the PHENIX experiment at RHIC

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    Results from the PHENIX experiment at RHIC on direct photon production in p+p, d+Au, and Au+Au collisions at sqrt(s_NN) = 200 GeV are presented. In p+p collisions, direct photon production at high p_T behaves as expected from perturbative QCD calculations. The p+p measurement serves as a baseline for direct photon production in Au+Au collisions. In d+Au collisions, no effects of cold nuclear matter are found within the large uncertainty of the measurement. In Au+Au collisions, the production of high p_T direct photons scales as expected for particle production in hard scatterings. This supports jet quenching models, which attribute the suppression of high p_T hadrons to the energy loss of fast partons in the medium produced in the collision. Low p_T direct photons, measured via e+e- pairs with small invariant mass, are possibly related to the production of thermal direct photons.Comment: 5 pages, 5 figures, Proceedings of the Hot Quarks 2006 Workshop for young scientists on the physics of ultra-relativistic nucleus-nucleus collisions, Villasimius, Sardinia, Italy, May 15--20, 200

    Search for the Proton Decay Mode proton to neutrino K+ in Soudan 2

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    We have searched for the proton decay mode proton to neutrino K+ using the one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for occurrence of a visible K+ track which decays at rest into mu+ nu or pi+ pi0. We found one candidate event consistent with background, yielding a limit, tau/B > 4.3 10^{31} years at 90% CL with no background subtraction.Comment: 13 pages, Latex, 3 tables and 3 figures, Accepted by Physics Letters

    Effects of red grape, wild grape and black raspberry wines on ground pork during refrigerated storage

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    The effects of red grape, wild grape and black raspberry wines on the quality of ground pork during a 15 days refrigerated storage period were investigated. The levels of phenolic compounds were the highest in black raspberry wine (P0.05). The addition of 5% and 10% wine influenced the quality of ground pork by decreasing pH, inhibiting the progression of lipid oxidation and the formation of total volatile basic nitrogen (TVB-N), and stabilizing the red colour of the ground pork compared to control samples to which no wine was added. In ground pork, addition of red grape wine led to lower concentrations of thiobarbituric acid reactive substances (TBARS, 0.19–0.39 mg kg−1) and TVB-N values (69.1–119.9 mg kg−1) than wild grape (0.16–0.43 mg kg−1 and 72.0–194.1 mg kg−1, respectively) or black raspberry wine (0.33–0.58 mg kg−1 and 81.7–225.4 mg kg−1, respectively) up to 10 days of storage. Results from the present study suggested that the quality of ground pork was affected by wine type and storage period. These effects could be due to phenolic compounds as well as other chemical components of the wines

    Electromagnetic Probes

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    A review is presented of dilepton and real photon measurements in relativistic heavy ion collisions over a very broad energy range from the low energies of the BEVALAC up to the highest energies available at RHIC. The dileptons cover the invariant mass range \mll = 0 - 2.5 GeV/c2^2, i.e. the continuum at low and intermediate masses and the light vector mesons, ρ,ω,ϕ\rho, \omega, \phi. The review includes also measurements of the light vector mesons in elementary reactions.Comment: To be published in Landolt-Boernstein Volume 1-23A; 40 pages, 24 figures. Final version updated with small changes to the text, updated references and updated figure

    Pion contamination in the MICE muon beam

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    The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than \sim1\% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is fπ<1.4%f_\pi < 1.4\% at 90\% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.Department of Energy and National Science Foundation (U.S.A.), the Instituto Nazionale di Fisica Nucleare (Italy), the Science and Technology Facilities Council (U.K.), the European Community under the European Commission Framework Programme 7 (AIDA project, grant agreement no. 262025, TIARA project, grant agreement no. 261905, and EuCARD), the Japan Society for the Promotion of Science and the Swiss National Science Foundation, in the framework of the SCOPES programme

    Studies on Culture Communication of Confucius Institute

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    新世纪以来,随着中国经济发展、国际地位提升,全球掀起了“中国热”“汉语热”,学习汉语和了解中华文化成为世界风尚,孔子学院正是借鉴国外一些文化推广组织的成功经验,以教授汉语和传播中华文化为目的于2004年应运而生。它致力于世界各国人民对中国语言文化了解,加强中外文化交流,构建和谐世界。成立至今仅有8年,孔子学院在数量上的发展卓有成效,而实际传播效果却尚未达到理想。文化传播实践存在许多问题。学界关于孔子学院文化传播角度的研究不多,对影响孔子学院传播效果的具体因素甚少涉及。因此,为尽快达到孔子学院预期的对外文化传播效果,实现中华文化的有效传播,对孔子学院传播过程各环节、影响因素、存在问题进行研究非常...As China has been gaining power and influence, there arises a craze for the study of China and the Chinese language. The Confucius Institute, following the successful examples of the international culture promotion organizations, was set up in the year 2004, aiming to promote Chinese language and culture. The organization commits to bringing cultural understanding and communication between China a...学位:新闻与传播硕士院系专业:新闻传播学院广告学系_传播学学号:3192009115258
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