SM Higgs search at CMS 1. The Standard Model Higgs search strategies in CMS will be presented 2. The Higgs has been excluded at 95% CL to have a mass <114.4 GeV (by LEP direct search) and with amass between 160-170 GeV (by Tevtron direct search). Precision observable indicate a light Higgs. Theory allows a Higgs upto 1 TeV 3. Production cross sections are plotted and uncertainty on the crosssection is quoted. 4. Cross section in CMS are computed using M. Spira tools. gg is at NNLO. 5. The Branching Ratios of the Higgs are shown 6. The background is many orders of magnitude larger than the Higgs signal. LHC is a "factory" of top, W, Z, and we will get milions ofJ/psi. 7. A design of one slice in the transverse plane of the CMS experiment, to show how the different particles are identified. 8.The CMS detector is ready to take data: in this slide we show a cosmic muon crossing all the detectors, living energy deposition in the calorimeter as well and a "splash event" of the 10-Sep-2008. where one can see that all the detectors + on-line+off-line software were working properly! 9. The first data will allow the re-discovery of the StandardModel and the tuning of the MC andthe understanding of the detector 10. W and Z cross section can be measured at 10TeV with Lumi=10pb-1 11. Di-bosons (WWandZZ) can be observed at 10 TeV with Lumi=~100 pb-1 12. to-top production will be measured also with very little Lumi 13. Low mass higgs: is searched in bb and gammagamma final state and also in WW and ZZ. 14.h->bb: the background is dominating for the ttH,H->bb production mode. Others channel are under investigations 15. h->gammagamma 16. The mass resolution is the key parameter to distinguish a narrow peak from a huge background 17. The material in front of the calorimeter makes about 50% of photons convert into e+e-. 18. Diagrams of two photon background (irreducible -real gammas, reducible- jets mistag as gamma) The control of the background (normalization) is done using the "side-bands" around the higgs peak. 19. Two "final" plots for the cut based analysis and for the Neural Network one. 20. The performance plots: with Lumi=30fb-1 CMS will have a signifcance of more than 5 for the wide mass range. NN analysis gain almost a factor of 2. 21. The precision on the measurement of the mass is coming from the photons final state up to ~150 GeV, then it will be the 4 charged letpons final state that will contribute. 22. WW and ZZ final state can cover the full mass range. 23. Two nice event display of higgs events into 4 charged leptons. 24. The CMS performance in muon reconstruction is shown: very high efficiency (>98% for pt>10 GeV and >90% for pt>5 GeV) and good resolution up to TeV scale. 25. Caibration of the muon momentum scale will be done with j/psi, Y and Z. Resolution will also be measured using the Z line shape. 26. Electrons have similar performances. The loss in efficiency and in resolution is due to the material in front of the calorimeter. 27. H->ZZ->4 leptons : very clean final state: 4 leptons of high pt and isolated, coming from the primary vertex. Very high efficiency for the signal and good reduction of the reducible background (QCD, tt, Zbb,Zjets). 28. Isolation and impact parameter significance of the leptons are shown for signal and background, showing to be very good discriminant observables. 29. The mass of the 2 couples of leptons are also requested to be within certain ranges (loose cuts) 30. The invariant mass of the 4 leptons for 1fb-1 (top) and 9 fb-1 (bottom) for various Higgs masses and for background. The ZZ background is the only left, plus some traces of Zbb. 31. we are developing methods to control the background from data itself. We invert cuts in order to define a region where the signal is absent and only one (or more) background is present. Then we use the data itself tonormalize the background. Finally we rely on theory (or MC prediction) to compute changes in background when inverting cuts again going to the signal region 32. The Zbb background can be easily control with data thanks to a very clean separation between signal and background in the plane "the least isolated lepton variable VS pt(third lepton- when ordered in decreasing pt). In the "background" region of low pt and high isolation variable, the Zbb can be separated by the top-top by selecting the Z->ll. The systematic error can then be estimated running a psudo-experiment. 33. The dominant ZZ background can be control in 3 different ways, that have different performance. The idea is to normalize to the Z that has large cross-section and is well known. 34. The performance for 14 TeV and 1fb-1 are shown. For masses larger than 180 GeV the significance is enough to allow an eventual exclusion. 35. A ttbar event is shown: 2 high pt isolated muon and 2 high energy isolated electrons. 36 . H->WW->llvv : the mass of the Higgs cannot be reconstructed,thus we rely on counting the events. The background must be well under control, so we developed methodto control it from the data itself (see pag.31) .This channel it will be the first exclusion/discovery channel because of the large cross section. 37. The most discriminant variables for H->WW->lnln are shown. 38. Two of the data driven methods to control the background are shown: the measurement of the rate of jets faking a lepton, and the measurement of the ttbar background in a "control region". 39. two tables with the number of events expcted at 14 TeV with L=1fb-1, and with the systematics extracted all with data driven methods. 40. The significance after L= 1fb-1 at 14 TeV with a simple sequential cut analysis and with a multivariate analysis. The second gain a large factor in significance. 41. If taking data at 10 TeV, the cross sections are lower for signal and background and we need about twice the luminosity to reach the same performances. With L=1fb-1 we can exclude the region from 150 to 190 GeV. 42.The Vector Boson Fusion process holds the key to the symmetry breaking: if the Higgs exist,wewilloberve a resonance at M(VV)=M(H). If the Higgs does not exist then the sigma(VV) will deviate from the SM prediction for M(VV) >~ TeV 43. THE VBF signature is peculiar: 6 fermions in the final state. A rapidity gap between the tag jets and the decay of the Higgs bosons. Sparse jet activity in the central region, due to the absence of color exchange between the W/Z. 44. Results of the VBF H,H->tau tau for L=30fb-1. DIscovery possible only with Lumi>30fb-1. 45. Many ways to suppress the events with jetsactivity in the barrel. Data driven way to control the largest background, i.e. the Z->tautau events. 46. WIth L=1fb-1 the analysis is very difficult, but the control of the background can be studied. 47. There are many diagrams contributing a 6 fermion final state at the alpha_ew^6 order. They should be taken into account when studying VBF. 48. A dedicated study to the hgh mass M(VV) region can distinguish between the Higgs and No-Higgs scenario, 49. Ratio of cross section (higgs/no-higgs) up to 3 could be reach in some of the final states. 50. The performances of the Higgs search in CMS are shown as a function of the Higgs mass.