[PDF] Search For Excited Leptons Using The Aleph Detector At Lep eBook

Author : Brigitte Marie Christine Vachon
Publisher :
Page : pages
File Size : 47,64 MB
Release : 2002
Category :
ISBN :

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A search for evidence that fundamental particles are made of smaller subconstituents is performed. The existence of excited states of fundamental particles would be an unambiguous indication of their composite nature. Experimental signatures compatible with the production of excited states of charged leptons in electron-positron collisions are studied. The data analysed were collected by the OPAL detector at the LEP collider. No evidence for the existence of excited states of charged leptons was found. Upper limits on the product of the cross-section and the electromagnetic branching fraction are inferred. Using results from the search for singly produced excited leptons, upper limits on the ratio of the excited lepton coupling constant to the compositeness scale are calculated. From pair production searches, 95% confidence level lower limits on the masses of excited electrons, muons and taus are determined to be 103.2 GeV.

Author : Zygmunt Ajduk
Publisher : World Scientific
Page : 1878 pages
File Size : 33,61 MB
Release : 1997-04-11
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ISBN : 9814547107

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The 28th conference from the Rochester series was the major high energy physics conference in 1996. Volume one contains short reports on new theoretical and experimental results. Volume two consists of the review talks presented in the plenary sessions.

Author : Alan Astbury
Publisher : World Scientific
Page : 618 pages
File Size : 28,53 MB
Release : 1997-04-01
Category : Electronic books
ISBN : 9814546488

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The week-long Lake Louise Winter Institute starts with three days of pedagogical lectures by invited speakers, and the remainder of the time is for short presentations on current research topics. This year, the theme of the Institute was 'Topics in Electroweak Physics'. The invited lecturers were Drs E G Adelberger, G Altarelli, J Ellis, J-M Poutissou, B Sadoulet and S Wojcicki.

Author :
Publisher :
Page : 54 pages
File Size : 37,9 MB
Release : 2016
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ISBN :

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Our search for compositeness of electrons and muons is presented using a data sample of proton-proton collisions at a center-of-mass energy of √(s) = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. Excited leptons (l*) produced via contact interactions in conjunction with a standard model lepton are considered, and a search is made for their gauge decay modes. The decays considered are l* →l? and l* → lZ, which give final states of two leptons and a photon or, depending on the Z-boson decay mode, four leptons or two leptons and two jets. The number of events observed in data is consistent with the standard model prediction. Exclusion limits are set on the excited lepton mass, and the compositeness scale L. For the case Ml* = L the existence of excited electrons (muons) is excluded up to masses of 2.45 (2.47) TeV at 95% confidence level. The neutral current decays of excited leptons are considered for the first time, and limits are extended to include the possibility that the weight factors f and f ', which determine the couplings between standard model leptons and excited leptons via gauge mediated interactions, have opposite sign.