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Mass Origin and Supersymmetry
The tau Lepton and Flavour Violation Title page; Lepton Flavor Violation Connection to Supersymmetry Achim Stahl RWTH Aachen University Mass Origin and Supersymmetry March Tsukuba
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Lepton Number Li = Σ # LeptonsGen i – # AntileptonsGen i t-decays:
conserved in the Standard Model n p e- ne today: many examples Lepton Number in the SM. intro, definition, examples t- m- nm nt t-decays: Wolfgang Pauli
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Neutrino Oscillations
nm nt Neutrino Oscillations LFV in neutrino oscillations neutrino oscillations violate lepton number !
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Leptonic tau-Decay t- m- t- m- nm nt nm nt nt nm annihilation W-
forbidden: nm nt
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Leptonic tau-Decay t- m- t- m- nm nt nt nm nm neutrino oscillation
W- m- t- m- forbidden: nm nt but: energy/momentum conservation
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LFV-Decay t- m- t- m- nm nt possible decay nt nm nm g g
neutrino oscillation nm t- nm g W- m- t- m- g forbidden: nm nt but: energy/momentum conservation
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LFV-Decay possible decays nt t- nm m- W- g/Z m+ m- t- m- m+ m-
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LFV-Decay possible decays nt r0 Z t- nm W- m- t- m- r0
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GIM-Mechanism nt neutrino oscillation nm t- nm g W- m- t- m- g
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GIM-Mechanism t- m- t- m- ni g g = Uti W- Umi = unitarity condition
Ue1 Ue2 Ue3 Um1 Um2 Um3 Ut1 Ut2 Ut3 n1 n2 n3 ne nm nt = t- Uti g W- Umi * m- Ue1 Ue2 Ue3 Um1 Um2 Um3 Ut1 Ut2 Ut3 Ue1 Um1 Ut1 Ue2 Um2 Ut2 Ue3 Um3 Ut3 = * * * unitarity condition t- m- g A S Uti Umi f(mi2) ≈ 0 * A S Uti Umi = 0 * A S Uti Umi = ? * br ≈ 10-40
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for discussion see Tord Riemanns home-page
The Paper of X.-Y. Pham Is this true ? Paper von PHAM ? Euro Phys J C8 (1999) 513, hep-ph/ for discussion see Tord Riemanns home-page
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Beyond the S.M. LFV beyond the SM; SUSY etc. new physics breaks GIM
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Beyond the S.M. Some theoretical estimates new physics breaks GIM
mg mmm SUSY SO(10) NPB649(2003)189 PRD68(2003) SUSY HIGGS PLB549(2002)159 PLB566(2003) mSUGRA EPJC14(2000)319 PRD66(2002) non-universal Z´ PLB547(2002) Heavy Maj. NR PRD66(2002) Some theoretical estimates LFV beyond the SM; SUSY etc. new physics breaks GIM
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Experimental Searches
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Experimental Searches
Signal: t- m- g Background: e+e- m+m- g e+e- t+t- t- m- nm nt g _ e+e- q q
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LVF @ b-factories t- m- g currently best limits ! BaBar
approaching 109 t-pairs t- m- g Belle 2004: < BaBar 2005: < Perspectives at b-factories
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LVF @ b-factories t- m- g currently best limits ! BaBar
approaching 109 t-pairs prel. ’03 final ‘05 t- m- g (r/e-tag) % % (total) % exp. BGD (r/e) ev ev. (total) ev. limit (10-8) < < 6.8 Belle 2004: < BaBar 2005: < Perspectives at b-factories b-factories reaching the limits at x 10-8
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LVF @ LHC t sources at the LHC: t- m- g 1 year running
low luminosity p p W t nt p p Z/g t t p p B0 t X p p B± t X p p Bs t X p p Ds t X plenty of taus ! LFV-decays at the LHC no chance to see t- m- g
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Simulation with underlying event
LHC Try t- m- m+ m- Some plots from CMS Simulation with underlying event low luminosity
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LVF @ LHC Source: W t nt Trigger: Single-Muon L1: pT > 14 GeV
HLT: pT > 19 GeV Trigger: Di-Muon L1: pT > 3 GeV HLT: pT > 7 GeV Looks okay t per year
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LVF @ LHC DS - Source Trigger: Single-Muon L1: pT > 14 GeV
HLT: pT > 19 GeV Trigger: Di-Muon L1: pT > 3 GeV HLT: pT > 7 GeV Trigger-Eff. only 1% t per year
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LVF @ LHC F m m (g) 10-5 br. Background Problem with DS source
DS F m nm 1 % br. F m m (g) br. Does anybody know of a generator for this process ?
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LVF Z-Decays m+ m- t- m- t- m- m+ m- g/Z nt nm W-
Connection to Z tau mu t- m- m+ m-
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LVF Z-Decays m- m+ t- m- m- m+ t- m- g/Z nt nm W-
Connection to Z tau mu m- m+ t- m-
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LVF Z-Decays m- m+ m- m- m+ m- t+ t+ g/Z nt nm
Connection to Z tau mu m- m+ m- t+ t+
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LVF Z-Decays m- t+ g/Z nt nm p p p p Z m- t+
Connection to Z tau mu p p Z m- t+ t+
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LVF Z-Decays m- t+ nm g/Z nt p p p p Z m- t+ W
Connection to Z tau mu p p Z m- t+
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Summary Outlook CMS: mu-ID, Vertex-Fit; Phi mu mu gamma background
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Conclusions LFV tau-decays
Interesting search for physics beyond the S.M. (SUSY and others ) b-factories will approach 10-8 Can we improve a few channels at LHC ? Also look for LVF in Z-decays at LHC !
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