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 Summary, DIS 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

April 10, 2008Electroweak Summary, DIS 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!

April 10, 2008Electroweak Summary, DIS The Electroweak Theory Before symmetry breaking: SU(2) L x U(1) Y gauge symmetry gauge term fermion term Higgs term Yukawa term After symmetry breaking: U(1) EM gauge symmetry kinetic neutral current charged current Trilinear gauge interaction Higgs Higgs-gauge interaction Quartic gauge interaction Yukawa

April 10, 2008Electroweak Summary, DIS Trilinear Gauge Couplings Probe WW  vertex with W  production at the Tevatron t- and u-channels dominate cross section –How do you see the s-channel? 2.6  “dip” significance Interference effectsCompare data to non-SM trilinear-gauge-coupling predictions Y. Maravin’s talk arXiv:

April 10, 2008Electroweak Summary, DIS Trilinear Gauge Couplings Tevatron only place to separately probe WWZ and WW  vertices CDF has observed WZ production at the 6  level D. Waters’ talk PRL 98, PRD 76, (R)

April 10, 2008Electroweak Summary, DIS 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: D. Waters’ talk arXiv: CDF: first measurement of ZZ production 4.4  significance

April 10, 2008Electroweak Summary, DIS Neutral Current HERA can probe electron and quark neutral current couplings ZEUS: New measurements of quark couplings with global fit K. Nagano’s talk

April 10, 2008Electroweak Summary, DIS Neutral and Charged Currents NuTeV extracts sin 2  W 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, m c,... K. McFarland's talk

April 10, 2008Electroweak Summary, DIS Charged Current NA48/62 at CERN tests universality of e and  CC couplings x 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 ± →  ± ):

April 10, 2008Electroweak Summary, DIS Charged Current HERA probes V-A structure of the charged current with polarized electron beam K. Nagano’s talk

April 10, 2008Electroweak Summary, DIS Charged Current Tevatron probes Wtb vertex by measuring W helicity C. Potter’s talk

April 10, 2008Electroweak Summary, DIS Charged Current Tevatron directly constrains V tb with single top production CDF:  t+s = 2.2 ± 0.7 pb (3.7  significance), |V tb | > 0.66 DØ:  t+s = 4.7 ± 1.3 pb (3.6  significance), |V tb | > 0.68 D. Hirschbühl’s talk LHC: |V tb | to 5% with 10 fb -1 R. Hawkings' talk

April 10, 2008Electroweak Summary, DIS Yukawa Couplings Top Yukawa coupling suspiciously close to 1 –CDF & DØ have updated their measurements with 2 fb -1 P. Mehtälä's talk LHC: m t to 1 GeV with 1 fb -1 N. Besson's talk

April 10, 2008Electroweak Summary, DIS Yukawa Couplings Independently determine top mass from production cross section m t = 170 ± 7 GeV D. Cho's talk

April 10, 2008Electroweak Summary, DIS Kinetic Terms Indirectly constrain Higgs mass using Electroweak parameters –Higgs loop corrections to the W mass New top mass improves consistency with SM m H = GeV, m H < 160 (190) GeV Assuming  m t ~ 1 GeV and  m W ~ 10 MeV (LHC projections) N. Besson's talk

April 10, 2008Electroweak Summary, DIS Kinetic Terms 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 WH ZH VBF H B. Tuchming's talk D. Hidas' talk

April 10, 2008Electroweak Summary, DIS Kinetic Terms LHC experiments have determined combined Higgs sensitivity D. Fortin's talk Discovery Exclusion

April 10, 2008Electroweak Summary, DIS 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?

April 10, 2008Electroweak Summary, DIS 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.”

April 10, 2008Electroweak Summary, DIS Backup

April 10, 2008Electroweak Summary, DIS Tevatron Higgs Sensitivity Recent improvements and projections