The tau Lepton

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The tau Lepton. and. Flavour Violation. Mass Origin and Supersymmetry March 6 -8 2006 Tsukuba. Achim Stahl RWTH Aachen University. t -  m - n m n t. n  p e - n e. t -decays:. Lepton Number. L i = Σ # Leptons Gen i – # Antileptons Gen i. conserved in the Standard Model. - PowerPoint PPT Presentation

Transcript of The tau Lepton

  • Achim StahlRWTH AachenUniversityMass Origin and SupersymmetryMarch 6 -8 2006Tsukuba

  • Li = # LeptonsGen i # AntileptonsGen iconserved in the Standard ModelWolfgang Paulitoday: many examples

  • neutrinooscillationsviolateleptonnumber !

  • t-m-ntnmW-t- m- forbidden:nm nt

  • t-m-ntnmW-t- m- forbidden:nm ntbut: energy/momentum conservation

  • t-m-ntnmW-t- m- forbidden:nm ntbut: energy/momentum conservationg

  • t-m-ntnmW-t- m- m+ m- g/Zm+m-

  • t-m-ntnmW-t- m- r0 Zr0

  • t-m-ntnmW-t- m- g

  • t-m-niW-UtiUmi*br 10-40

  • Euro Phys J C8 (1999) 513, hep-ph/9810484for discussion see Tord Riemanns home-pagehttp://www-zeuthen.desy.de/~riemann/

  • new physics breaks GIM

  • new physics breaks GIM

  • Signal:Background:e+e- m+m- ge+e- t+t-e+e- q q_

  • currently best limits !approaching 109 t-pairst- m- g Belle 2004: < 3.1 10-7

    BaBar 2005: < 6.8 10-8BaBar

  • currently best limits !approaching 109 t-pairst- m- g Belle 2004: < 3.1 10-7

    BaBar 2005: < 6.8 10-8BaBarprel. 03 final 05(r/e-tag) 5.2 % 3.8 %

    (total) 9.4 %

    exp. BGD (r/e) 7.8 ev. 2.8 ev.

    (total) 6.2 ev.

    limit (10-8) < 200 < 6.8b-factories reaching the limits at x 10-8

  • t sources at the LHC:p p W t ntp p Z/g t tp p B0 t Xp p B t Xp p Bs t Xp p Ds t X1.7 1088.0 1084.0 10113.8 10117.9 10111.5 10121 year runninglow luminosityplenty of taus !no chance to seet- m- g

  • Try t- m- m+ m- Simulation with underlying eventlow luminosity

  • Source: W t ntTrigger: Single-Muon L1: pT > 14 GeV HLT: pT > 19 GeVTrigger: Di-Muon L1: pT > 3 GeV HLT: pT > 7 GeVLooks okay 1.7 108 t per year

  • DS - SourceTrigger: Single-Muon L1: pT > 14 GeV HLT: pT > 19 GeVTrigger: Di-Muon L1: pT > 3 GeV HLT: pT > 7 GeVTrigger-Eff. only 1% 1.5 1012 t per year

  • Background Problem with DS sourceDS F m nm1 % br.F m m (g)10-5 br.Does anybody know of a generator for this process ?

  • t-m-ntnmW-t- m- m+ m- g/Zm+m-

  • t-m-ntnmW-m- m+ t- m-g/Zm+m-

  • t+m-ntnmm- m+ m- t+g/Zm+m-

  • t+m-ntnmp p Z m- t+g/Zpp

  • t+m-ntnmp p Z m- t+g/ZppW

  • Can we improve a few channels at LHC ?Also look for LVF in Z-decays at LHC !LFV tau-decays Interesting search for physics beyond the S.M. (SUSY and others )b-factories will approach 10-8

    Title page; Lepton Flavor Violation Connection to SupersymmetryLepton Number in the SM. intro, definition, examplesLFV in neutrino oscillationsPaper von PHAM ?LFV beyond the SM; SUSY etc.LFV beyond the SM; SUSY etc.Perspectives at b-factoriesPerspectives at b-factoriesLFV-decays at the LHCSome plots from CMSConnection to Z tau muConnection to Z tau muConnection to Z tau muConnection to Z tau muConnection to Z tau muOutlook CMS: mu-ID, Vertex-Fit; Phi mu mu gamma background