1. Summary of the Electroweak Symmetry Breaking working group Part 1: Experiments Dhiman Chakraborty Northern Illinois University WIN07, Kolkata, India 15-20 January, 2007

2. WIN07 EWSB expt summaryDhiman Chakraborty2 Informative, stimulating, engaging talks from collider experiment collaborations Reports from the LHC, Tevatron, HERA: – Experiment status and commissioning (2) – Electroweak measurements (3) – Studies of the top quark (2) – Higgs searches (1) – Searches for physics beyond the Standard Model (3)

3. WIN07 EWSB expt summaryDhiman Chakraborty3 CMS status, commissioning and early physics prospects (L. Malgeri)

4. WIN07 EWSB expt summaryDhiman Chakraborty4 CMS physics roadmap 100 fb /yr 1000 fb /yr 3000 300 30 10-20 fb /yr First physics run: O(1fb -1 ) SUSY@1TeV SUSY@3TeV Z ﾁfﾁf@6TeV ADD X-dim@9TeV Compositeness@40TeV H(120GeV)    100 fb /yr 1000 fb /yr 200 fb /yr 3000 300 30 10-20 fb /yr SUSY@1TeV SUSY@3TeV Z ﾁfﾁf@6TeV ADD X-dim@9TeV Compositeness@40TeV H(120GeV)   

5. L. Malgeri - CMS status - 16/1/07 - WIN07 - Kolkata 5 Summary CMS assembling and commissioning is going full speed No major obstacles foreseen on the road Recent MTCC, software challenges have proven that: CMS can work with full magnetic field CMS sub-detectors can work as a single detector The DAQ and (new!) software is ready for prime-time CMS started to be lowered in the pit A full physics commissioning plan is setup: alignment and calibration re-discover SM possible early discoveries Initial CMS will be ready for collisions in 2007

6. WIN07 EWSB expt summaryDhiman Chakraborty6 Inner Tracking (|  |<2.5, B=2T) : Silicon pixels and strips Transition Radiation Detector (+e/  separation) Solenoid B=2T Calorimetry (|  |<5) : EM : Pb-LAr with Accordion shape HAD: Fe/scintillator (central), Cu/W-LAr (fwd) Muon Spectrometer (|  |<2.7) : Air-core toroids with muon chambers (Trigger + Precise measurements) ATLAS detector status and early physics (S. Tanaka) Length : ~45 m Height : ~25 m Weight : ~ 7000 tons Electronic channels : ~ 10 8 ~ 3000 km of cables

7. WIN07 EWSB expt summaryDhiman Chakraborty7 ATLAS physics roadmap With early 14 TeV run, (~10pb -1 ) Study minimum-bias, di-jet, pile-up events (~100pb -1 ) Missing E T,, Jet Energy calibration (-> SUSY, Higgs) Top, W, Z, QCD b-jet (SM processes) (~ few fb -1 ) Early Higgs search (H->W + W -,ZZ) SUSY, BSM search (Miss E T, Di-Jet, Di-Lepton…..) End of 2008 : will be record few fb -1 data.

8. WIN07 EWSB expt summaryDhiman Chakraborty8 ATLAS summary The ATLAS detector is well on its way to be ready in 2007. Magnets : Solenoid, Barrel Toroid : operation OK. End-cap Toroid: will be install but some delay Inner Tracker: SCT+TRT : Barrel installed (Cosmic ray test independently) : End-cap will be install in Feb 2007. PXCEL: will be install in April 2007. (Schedule is tight) Calorimeter: Barrel LAr+ Tile : Installed and start cosmic run End-cap will start cold operation from April 2007. Muon: Barrel parts (MDT+RPC) installed (some segments start cosmic run) End-Cap : 1 TGC Big Wheel (need 6 wheels) has installed MDT Wheel is now installing (will be install before beam closing) From autumn 2007, we will start to record 900 GeV data and calibrate detector response for preparing 14 TeV run. ATLAS will be ready to enter the new high energy scale in 2008.

9. WIN07 EWSB expt summaryDhiman Chakraborty9 Electroweak results from the Tevatron (C. Hays) New CDF measurement of W mass is world's most precise Central value up by 6 MeV to 80398 MeV World avg uncertainty reduced by ~15% SM Higgs mass constrained to 80 +36 -26 GeV

10. WIN07 EWSB expt summaryDhiman Chakraborty10 Tevatron electroweak summary High-luminosity data samples are opening new physics windows. Most precise determination of W mass (CDF) – Expect <25 MeV precision with 1.5 fb-1 data already collected. First observation of WZ production – Expect most sensitive probes to anomalous WWZ couplings. First hint of W  radiation amplitude zero – Expect to observe this quantum interference effect. Many other measurements of W and Z boson properties constraining couplings and PDFs.

11. WIN07 EWSB expt summaryDhiman Chakraborty11 Electroweak results from HERA (E. Rizvi) Direct measurement of parity violation in neutral current interactions

12. WIN07 EWSB expt summaryDhiman Chakraborty12 HERA electroweak summary ● Many interesting results coming from HERA experiments ● NC & CC measurements at EW scale ● Improvement of statistical precision through H1 & ZEUS combination ● Clear observation of parity violation in NC channel ● Simultaneous QCD & EW fits performed on HERA data ● Determination of spacelike propagator mass in CC interactions ● Polarised CC date give direct sensitivity to W R  limit set ● Extraction of light quark couplings to Z 0 ● The Standard Model holds up extremely well ● Last six months of HERA operation ● Final analysis of complete HERA dataset will follow...

13. WIN07 EWSB expt summaryDhiman Chakraborty13 EW physics at the LHC (K. Mazumdar) Precision measurements can be done with early data. Stat. uncertainties will be negligible, thanks to huge cross sections. Final precision will be limited by understanding of physics and detector response. Knowledge of total luminosity will drive cross section measurements. Excellent momentum and energy resolution for leptons (all flavors) and jets (both light and heavy) will be crucial: requires accurate and precise alignment of detector elements (<1  m for inner tracking). High potential for tests of the SM through precision EW measurements.

14. WIN07 EWSB expt summaryDhiman Chakraborty14 Studies of the top quark at Tevatron (E. Aguilo)

15. WIN07 EWSB expt summaryDhiman Chakraborty15 Top mass measurement at the Tevatron Many analyses

16. WIN07 EWSB expt summaryDhiman Chakraborty16 Evidence of single top production (via electroweak processes) at the Tevatron EVIDENCE!!!

17. WIN07 EWSB expt summaryDhiman Chakraborty17 Tevatron top quark summary Rich program at Tevatron leading into the LHC era. July 2006 Tevatron combined top mass: m t = 171.4 ± 1.2 ± 1.7 GeV dominated by the CDF lepton+jets measurement: m t = 170.9 ± 1.6 ± 2.0 GeV The precision is better than expected! CDF combined top pair production cross section:  tt) = 7.3 ± 0.5 ± 0.7 pb Evidence of electroweak single top production has been found at DØ with the Decision Trees analysis. Measured cross section:  t) = 4.9 ± 1.4 pb(3.4  ) And a first direct measurement of |V tb | has been made: 0.68 < |V tb | < 1 @ 95% CL

18. WIN07 EWSB expt summaryDhiman Chakraborty18 Top physics at the LHC (G. Steinbrück) Pair production cross section: ~870 pb (NLO), i.e. ~120x tevatron Run 2. ~87% via gluon fusion, ~13% via quark annihilation Rate ~ 1Hz at 10 33 cm -2 s -1  LHC is a top factory unlike the Tevatron.  Differential x-sec become more powerful! Single production rate enhanced similarly Many detailed studies have been done by ATLAS and CMS to determine the physics potential and the challenges for (top) physics. Top mass measurement is expected to reach the precision of 1 GeV. Tests of the SM through spin correlation, production kinematics Searches for new physics through deviations from SM predictitons

19. WIN07 EWSB expt summaryDhiman Chakraborty19 (SM) Higgs physics at the LHC (L. Feligioni) ● Gluon Gluon fusion: – Dominant production mode – NLO correction important ● K = 1.7 ● Main contribution is gluon radiation – many events with at least one jet – NNLO cross section known ● Sig(NNLO)/Sig(NLO) = 1.3 ● Vector Boson Fusion: – small K factor ~ 1.1 ● Small jet multiplicity in final state – No color exchange between quarks ● large energetic jets at small p T ● Low hadronic activity in central region from hard event – a part from Higgs decay ● Production with Gauge boson: – Known NNLO for QCD and EW corrections ● Production with heavy quarks: – More complicated final state – More than 10 diagrams, known at NLO

20. WIN07 EWSB expt summaryDhiman Chakraborty20 (SM) Higgs decay Light Higgs (110<m H (GeV)<130) – Dominant mode is H  bb (75-50%) – H    and cc with 3-7% – Higgs decay to    through top loop – H   VV (*) rises close to M H = 130 GeV Intermediate Higgs (130<m H (GeV)<180) – H  VV (*) most important decay mode Heavy Higgs (180<m H (GeV)<1000) – H  VV – For m H ~400 GeV the decay in two top quarks also plays a role ● All BR calculated at NLO, error within few %

21. WIN07 EWSB expt summaryDhiman Chakraborty21 LHC sensitivity to (SM) Higgs CMS studies based on NLO calculations, ATLAS on LO (NLO studies in progress)

22. WIN07 EWSB expt summaryDhiman Chakraborty22 LHC Higgs summary – Early discoveries (~10 fb -1 ) could be possible for H   VV at large mass – Low mass region more challenging: ● optimized H    analyses predict discovery after 3 years – other channels can be exploited: ttH, VBF – Good understanding of detector needed to assess performances and understand background shapes – Less than one year to first collisions! ● getting ready for data

23. WIN07 EWSB expt summaryDhiman Chakraborty23 Searches at Tevatron for beyond-SM physics (S. Banerjee) – Both D0 and CDF have been conducting searches for numerous new physics scenarios: ● SUSY (mSUGRA, GMSB, RPV,...) ● Extra dimensions ● Leptoquarks, heavy gauge bosons,... – No significant departure from SM predictions found yet, but continuing to analyze more data and reduce systematics in order to improve sensitivity Sorry, I could not extract any material from the talk - my laptop refuses to open the file!!!

24. WIN07 EWSB expt summaryDhiman Chakraborty24 Searches at the LHC for beyond-SM physics (R. Ströhmer) ● ATLAS & CMS have significant discovery potential for physics beyond the standard model. Much effort is invested in estimating and maximizing these. ● New physics could already show up in early data. ● In order to claim a discovery on needs to understand the background – detector performance – standard model processes ● discovery of “something” is only first step, the second is to distinguish between models and determine parameters.

25. WIN07 EWSB expt summaryDhiman Chakraborty25 Searches at HERA for beyond-SM physics (A. Raval) Model dependent searches Leptoquarks ● Lepton flavor violation Excited fermions ● Single top production ● Doubly charged Higgs Supersymmetry Model independent searches Events with isolated leptons and missing E T Tau production Multi-lepton production Magnetic monopoles General searches Limits from precision measurements NC DIS: CI, LEDs, quark radius CC DIS: Right-handed weak currents

26. WIN07 EWSB expt summaryDhiman Chakraborty26 Summary of HERA searches for BSM physics ● New results on – Leptoquarks –Compositeness –Large Extra Dimensions –Excited fermions –Supersymmetry ● HERA results competitive in most areas and complementary in others … ● Interesting excess/fluctuations (H1 excess in high-p T multiilepton events not confirmed by ZEUS) !? ● Still more HERA II data to come (until March 07)…

27. WIN07 EWSB expt summaryDhiman Chakraborty27 Summary – This summer HERA will conclude 14 years of successful studies of lepton-neucleon scattering at the highest energies – Tevatron is going strong, expected to run till 2009 (20 years!). Exciting results have been emerging steadily. Many more are expected. SM is still holding its ground. Search for the Higgs and new physics are on - more data than current have yet to come. – LHC experiments are on course to start taking data this year. Revolutionary discoveries of new physics are expected in the coming years. – For details, see the many excellent talks at this conference - thanks to all the speakers. – Thanks to the organizers for hosting this fruitful and enjoyable event, and to the participants for making it a success.