ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004...

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Transcript of ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004...

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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 GLOBAL ELECTROWEAK FITS AND CONSTRAINTS ON THE HIGGS MASS Pete Renton University of Oxford LEP Electroweak Working Group status of precision Z and W boson properties top quark mass, (M Z ) and other SM parameters agreement of data with SM ? global electroweak fits and Higgs mass Emphasis on new results since EPS Aachen Summer 2003
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Z boson properties: LEP + SLD (f=l,c,b) (f=c,b) f results (almost!) final f Z -
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 CDFD0 new Run 1 improved M t measurement from D0 ~100 pb-1 Run 2 prelim M t measurements from CDF & D0 from ~160 pb -1 new combinations (Run 1 only) by Tevatron Electroweak Working Group 19th year!
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Precision (pseudo-)observables tau polarisation - A e (1) left-right asymm -A e (1) Z lineshape (5) Z (b,c) properties (6) W properties (2) top quark mass (1) Total of 17 at high Q 2 (assuming lepton universality) from > 1000 measurements with (correlated) uncertainties
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Electroweak Corrections 40 th anniversary of Peter Higgs papers Standard Model parameters:& top-quark mass predicted by electroweak corrections prior to direct discovery plus unknown does this work for the Higgs ? eg LP 1995 Beijing SM: TOPAZ0 and ZFITTER 6.40 new sin 2 eff fermion 2-loop: M W full 2 (& leading 3)-loop
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Z boson other measurements LEP lineshape results derived quantities leptons favour low Higgs mass lepton couplings
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Combined LEP/SLD Z heavy flavour results (F/B asymmetries are statistics dominated) new updates from SLD -all results & combination (almost) final Z- b (and c) asymmetries favour high Higgs mass
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 W boson mass Run 2: CDF,D0 coming soon! LEP2 Tevatron M W favours low Higgs mass final analyses still in progress
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 W boson width new final results from ALEPH & L3 W branching ratios
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 top quark mass: Run 1 D0: improved Run 1 value new
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 top quark mass Run 2 (prelim) CDF D0 new not yet included in world average new
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 (M Z ) EWWG default value data driven - no significant change using latest re-analysed CMD-2 and KLOE data (LAPP EXP 2004-4) also use a more theory driven value
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 long standing (and a-posteriori) observation of difference between: leptons hadrons essentially from difference of prob = 8.4%
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 THE BLUE BAND PLOT Global electroweak fit high Q 2 data Since Aachen EPS Summer 2003 new top mass increases m H by ~20 GeV new 2-loop terms etc increase m H by ~6 GeV new Awramik,Czakon,Freitas,Weiglein hep-ph/0311148,0407317 &refs therein Faisst,Kuhn,Seidensticker,Veretin N Phys B665,649(2003) + many more!
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Higgs mass from individual measurements pulls direct search limit
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 m t, m w direct vs indirect direct m t and m w indirect m t and m w reasonable degree of overlap powerful test of SM
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 progress since Lepton Photon 95 in Beijing 2004 indirect m t and m w 2004 direct m t and m w 1995 direct m t and m w 1995 indirect m t and m w 68% cl
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 Moller scattering E158 SLAC polarised e - beam measure right-left parity violating asymm. A PV (accuracy ~3 10 -8 ) Atomic Parity Violation (APV) (SM -72.93) Woods et al, Sci. 275 (1997) 1759; Ginges & Flambaum, physics/0309054 Measurement of weak charge in 133 Cs hep-ex/ 0312035, 0403010 & E158 website Q2 ~.03 GeV 2 (prelim) Q 2 ~ 5 10 -5 GeV 2 new (SM 0.2310) new
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 NuTeV experiment Measure R = NC CC - Q 2 ~ 15 GeV 2 for m t = 175, m H = 150 GeV New physics? : Z, contact int., lepto-quarks, new fermions, neutrino oscillations. or old physics ?: pdfs uncertainties in LO, isospin violation, s-sea asymm., shadowing, QED corrections (hep-ph/0310364) fit also including low Q 2 data SM m H 128 GeV ( +14 GeV) prob of fit 5.4 % pull (NuTeV) = 2.9
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  • ICHEP04 Beijing Global Electroweak fits and constraints on the Higgs mass Pete Renton Aug 2004 summary steady progress on both experiment & theory fronts although still issues with A FB (b) and NuTeV results (both ~3sigma effects) SM gives satisfactory fit to large amount of data. Clarification desirable but how & when? fits favour relatively light Higgs (