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Electroweak Summary. Chris Hays, Oxford University for the EWK/BSM session conveners: Michael Kramer Dave South Filip Zarnecki XVI th Workshop on Deep Inelastic Scattering London, England April 10, 2008. Electroweak and Beyond-the-Standard-Model Session. 42 talks
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Electroweak Summary Chris Hays, Oxford University for the EWK/BSM session conveners: Michael Kramer Dave South Filip Zarnecki XVIth Workshop on Deep Inelastic Scattering London, England April 10, 2008
Electroweak and Beyond-the-Standard-Model Session • 42 talks • 17 in this summary, 25 in BSM summary • 10 additional talks in joint sessions with HFS, SF • 4 in this summary, 6 in HFS/SF summaries • Many new results shown • Impossible to show all, or to give those shown justice • 420 minutes in 20 slides • Apologies to those missed Electroweak Summary, DIS 2008
The Experiments in a Nutshell • CMS & ATLAS • Looking forward to data! • ZEUS & H1 & NuTeV • Look at all our data! • CDF & DØ & NA48/62 • Looking forward to more data! Electroweak Summary, DIS 2008
The Electroweak Theory • Before symmetry breaking: SU(2)Lx U(1)Y gauge symmetry Higgs term gauge term fermion term Yukawa term • After symmetry breaking: U(1)EM gauge symmetry kinetic Higgs-gauge interaction Quartic gauge interaction Yukawa charged current neutral current Higgs Trilinear gauge interaction Electroweak Summary, DIS 2008
Trilinear Gauge Couplings • Probe WW vertex with W production at the Tevatron Y. Maravin’s talk • t- and u-channels dominate cross section • How do you see the s-channel? Interference effects Compare data to non-SM trilinear-gauge-coupling predictions 2.6 “dip” significance arXiv:0803.0030 Electroweak Summary, DIS 2008
Trilinear Gauge Couplings • Tevatron only place to separately probe WWZ and WW vertices D. Waters’ talk • CDF has observed WZ production at the 6 level PRL 98, 161801 PRD 76, 111104(R) Electroweak Summary, DIS 2008
Trilinear Gauge Couplings • No neutral trilinear couplings in the SM • Tevatron experiments test this prediction with measurements of Z and ZZ production Y. Maravin’s talk arXiv:0712.0599 CDF: first measurement of ZZ production 4.4 significance D. Waters’ talk arXiv:0801.4806 Electroweak Summary, DIS 2008
Neutral Current • HERA can probe electron and quark neutral current couplings ZEUS: New measurements of quark couplings with global fit K. Nagano’s talk Electroweak Summary, DIS 2008
Neutral and Charged Currents • NuTeV extracts sin2W using ratio of NC to CC: Update with fit of s/s asymmetry, K+e3 BR, d/u PDF uncertainties Additional effects still to be included: EWK PDF corrections, mc, ... K. McFarland's talk Electroweak Summary, DIS 2008
Charged Current • NA48/62 at CERN tests universality of e and CC couplings 2.477 x 10-5 in SM trigger dominated background dominated Analysis progressing with 2007 data: use data to constrain → e backgrounds E. Goudzovski's talk Preparing for 2011 run to measure BR(K± → ±): Electroweak Summary, DIS 2008
Charged Current • HERA probes V-A structure of the charged current with polarized electron beam K. Nagano’s talk Electroweak Summary, DIS 2008
Charged Current • Tevatron probes Wtb vertex by measuring W helicity C. Potter’s talk Electroweak Summary, DIS 2008
Charged Current CDF: t+s = 2.2 ± 0.7 pb (3.7 significance), |Vtb| > 0.66 • Tevatron directly constrains Vtb with single top production DØ: t+s = 4.7 ± 1.3 pb (3.6 significance), |Vtb| > 0.68 D. Hirschbühl’s talk LHC: |Vtb| to 5% with 10 fb-1 R. Hawkings' talk Electroweak Summary, DIS 2008
Yukawa Couplings • Top Yukawa coupling suspiciously close to 1 • CDF & DØ have updated their measurements with 2 fb-1 P. Mehtälä's talk LHC: mt to 1 GeV with 1 fb-1 N. Besson's talk Electroweak Summary, DIS 2008
Yukawa Couplings • Independently determine top mass from production cross section mt = 170 ± 7 GeV D. Cho's talk Electroweak Summary, DIS 2008
Kinetic Terms • Indirectly constrain Higgs mass using Electroweak parameters • Higgs loop corrections to the W mass Assuming mt ~ 1 GeV and mW ~ 10 MeV (LHC projections) New top mass improves consistency with SM mH = 87+36-27 GeV, mH < 160 (190) GeV N. Besson's talk Electroweak Summary, DIS 2008
Kinetic Terms B. Tuchming's talk • Higgs searches heating up at the Tevatron • Low-mass searches focus on WH, ZH, with H → bb; New: VBF H → • High-mass searches focus on H → WW ZH WH VBF H D. Hidas' talk Electroweak Summary, DIS 2008
Kinetic Terms • LHC experiments have determined combined Higgs sensitivity Discovery Exclusion D. Fortin's talk Electroweak Summary, DIS 2008
The Experiments Revisited • CMS & ATLAS • Wish we had collision data… • ZEUS & H1 & NuTeV • Too bad we won’t get any more data… • CDF & DØ & NA 48/62 • Will we get enough data? Electroweak Summary, DIS 2008
Summary • New results test Electroweak theory at unprecedented level • Input parameters growing ever more precise • Rapidly approaching the last piece of the Electroweak puzzle: The Higgs Boson “Well, either we’ve found the Higgs boson, or Fred’s just put the kettle on.” Electroweak Summary, DIS 2008
Backup Electroweak Summary, DIS 2008
Tevatron Higgs Sensitivity • Recent improvements and projections Electroweak Summary, DIS 2008