Search

We first give a short and elementary overview of standard-model phase transitions (electroweak and strong) with emphasis on how they generated the visible mass in the early universe. Subsequently, we focus on transitions associated with the strong interaction, in particular the mechanisms and observable consequences of spontaneous chiral symmetry breaking and its restoration. Recent advances in the interpretation of dilepton spectra in relativistic heavy-ion collisions, which provide the unique opportunity to study QCD phase changes in the laboratory, are discussed. [ABSTRACT FROM AUTHOR]

The chargino-neutralino production is one of the most promising SUSY processes that could be observed at the Tevatron. Cross sections of the order of 0.1 pb have not been excluded yet under the mSUGRA scenario, whereas the trilepton signature of the process is not contaminated by significant standard model backgrounds. We report on the status of CDF search for chargino-neutralino production at the Tevatron by presenting the results of five multilepton subanalyses as well as the result of their combination which leads to our current lower limit on the chargino mass of 127 GeV/c2 and upper limit on the production cross section times branching ratio to leptons of 0.25 pb at 95% confidence level. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

We present the discovery potential of heavy new resonances decaying into dilepton pairs with early LHC data using the ATLAS detector. The dilepton final states are robust channels to analyze because of the simplicity of the event topology. The unprecedented available center-of-mass energy will allow one to probe regions that were simply inaccessible at previous experiments even with modest amounts of data. After studying the Standard Model predictions and the associated uncertainties one can look for significant deviations as indications of Beyond the Standard Model physics (BSM). The focus is to study the prospects for discovering BSM physics in the dilepton final states with an assumed integrated luminosity ranging from 100 pb-1 to 1 fb-1. [ABSTRACT FROM AUTHOR]

The High Acceptance DiElectron Spectrometer (HADES) has been constructed at the SIS accelerator (GSI, Darmstadt) to investigate electron-positron pairs produced in proton, pion and heavy-ion induced reactions. The physics programme of HADES is focused on in-medium properties of light vector mesons. In this contribution the HADES experiment is outlined and first results obtained for 12C + 12C collisions at 2 AGeV are presented. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Direct photon production in Au+Au collisions at √sNN=200GeV has been measured. The result is compared to several theoretical calculations, and found that it is not inconsistent with ones including thermal radiation from QGP or jet-photon conversion process on top of a NLO pQCD expectation. The direct photon contribution in dilepton measurement is also evaluated. [ABSTRACT FROM AUTHOR]