Highlights of Recent CMS Results. Dmytro Kovalskyi (UCSB)

Transcription

1 Highlights of Recent CMS Results Dmytro Kovalskyi (UCSB)

2 Introduction Number of CMS publication is over 0 already It is very hard to review all the recent results in one talk This talk concentrates on a few topics: Higgs Searches Dark Matter Searches Searches for Physics Beyond the Standard Model Complete information about all CMS results: May 8, 0

3 Standard Model at 7 TeV Standard Model is explored in details Higgs is next... May 8, 0

4 Higgs Search Results 95% CL limit on!/! SM CMS Preliminary Observed Expected (68%) s = 7 TeV Expected (95%) L = fb LEP excluded CMS excluded Best fit!/! SM CMS Preliminary s = 7 TeV L = fb 68% CL band Higgs boson mass (GeV) Higgs boson mass (GeV) Only narrow range is still allowed: [47.5] GeV Largest deviation from background: 5GeV -.σ global significance for 45 GeV window Consistent with the excess in ATLAS Phys.Lett. B7 (0) 6-48 top cited physics result from CMS May 8, 0 4

5 Higgs Search in Different Channels ) Events / ( GeV/c CMS preliminary s = 7 TeV L = 4.76 fb All Categories Combined Data Bkg Model ± " ± " xsm m H =0 GeV Relative Contribution at 5GeV H γγ H ZZ H ττ H bb (GeV/c ) m!! H WW weight is defined as /μ, i.e. inverse expected signal strength squared Currently not a single channel has sensitivity to see Higgs at ~5 GeV H γγ and H WW have same sensitivity in the region of interest H ZZ 4 is close and can improve in future Convenient mass to measure all couplings H ττ and H bb while contribute less, will soon provide unique information about couplings May 8, 0 5

6 Main Contributors at 5 GeV H WW ν H ZZ 4 H γγ e+ e - ) Events / ( 0.5 GeV/c Simulation Parametric Model =.8 GeV/c " eff FWHM =.9 GeV/c CMS preliminary Simulation All Categories Combined Missing Energy (neutrinos) (GeV/c m!! ) HWW highest event yield No mass - background estimation is critical Excess is wide (mass resolution ~0GeV) HZZ4L is far off-shell Leptons pt: 0//5/5 Very few events Beside mass it allows to determine spin Main challenge - mass resolution to reduce large SM background Main discovery channel May 8, 0 6

7 Expectations for Exclusion in 0 5/fb(0) + 5/fb (0) 5/fb(0) + 5/fb (0) Projections take into account observed 0 results By ICHEP 0 we may have ~ 5/fb If Higgs doesn t exist we should exclude it at 95% CL with ~60% probability By the end of 0 if LHC performs CMS will have enough sensitivity to certainly exclude Higgs in low mass range May 8, 0 7

8 Expectations for Discovery in 0 5/fb(0) + 5/fb (0) 5/fb(0) + 5/fb (0) Projections take into account observed 0 results By ICHEP 0 we may have ~ 5/fb If Higgs exist and its mass is around 5 GeV the local significance is likely to increase from ~σ to 4σ By the end of 0 CMS should be able to discover Higgs at 5σ for Higgs masses above 0GeV May 8, 0 8

9 Dark Matter

10 Dark Matter at Collider Dark matter existence is well established based on gravitational effects We don t know what it is, but in the best case it s weakly interacting In the detector it s undetectable as neutrinos Large amount of dark matter in the Universe suggests that it can have reasonably high interaction rate with Standard Model particles LHC can produce Dark Matter via the same process that is used in direct (dark matter-nucleon scattering) and indirect (dark matter annihilation) searches May 8, 0

11 Dark Matter Production May 8, 0

12 Dark Matter Search Mono-jet MET+Lep Mono-photon Events / 5 GeV 5 4 CMS Preliminary L dt = 4.7 fb at s=7 TeV Z W lν tt QCD + - Z l l Data ν DM-AVd m=gev ADD M D δ Events /GeV CMS, s 5.0 fb = 7 TeV DATA Total uncertainty on Bkg Z!# ""! W# e" MisID-! (QCD)!+jets, W! Beam Halo SM+ADD(M = TeV, n=) D E miss T [GeV] E T [GeV] Data is consistent with Standard Model prediction Dominant background is Z νν+x May 8, 0

13 Dark Matter Production at LHC Direct Detection Mono-jet partonic production For heavy mediator (M>0GeV), mono-jet production is ~ 00 larger than direct-detection one For light mediator, mono-jet production is smaller than the direct-detection one If DM is observed in direct-detection experiments and not at LHC it can suggest existence of a light mediator May 8, 0

14 Dark Matter Search Results Collider results dominate in spin dependent searches Cover low mass range for spin independent searches May 8, 0 4

15 Searches for Physics Beyond Standard Model

16 W Searches Events / 0 GeV Events / 0 GeV 5 s = 7 TeV W " e! CMS % L dt = 5.0 fb W' " e! W " µ! W " #! Dibosons CMS Top DY " ll Multijet $ +Jets Data W' (m =. TeV) W' W " µ! s = 7 TeV 6 W " #! L dt = 5.0 fb $ W' " µ! Background Prediction M T Dibosons M T [GeV] Top DY " ll Multijet Data W' (m =. TeV) W' Background Prediction [GeV] overflow bin overflow bin +!) [fb] e / µ BR(W' " #. 4 95% Observed Limit (Electron) 95% Observed Limit (Muon) 95% Observed (Combined) 95% Expected (Combined) Theoretical Cross Section SSM W' with K-factor Theoretical Cross Section SSM W' without K-factor Theoretical Cross Section for W KK (µ = TeV) Theoretical Cross Section for W KK (µ = 0.05 TeV) CMS s = 7 TeV L dt = 5.0 fb W' mass [GeV] Sequential Standard Model W is excluded below.5 TeV $ arxiv: May 8, 0 6

17 Z Searches Events / GeV CMS preliminary s = 7 TeV DATA + - Z/#*"µ µ tt + other prompt leptons jets $ L dt = 4.9 fb R! -4 CMS preliminary ee(4.7fb )+µ + µ (4.9fb ) - median expected 68% expected 95% expected Z' SSM Events / GeV ! CMS preliminary s = 7 TeV DATA + - Z/#*"e e -! m(µ + µ ) [GeV] tt + other prompt leptons jets (data) $ L dt = 4.7 fb -5-6 Z' " G KK k/m Pl =0. G KK k/m Pl =0.05 Z' Stu #= 0.0 Z' Stu #= 0.0 Z' Stu #= 0.04 Z' Stu #= 0.05 Z' Stu #= % C.L. limit M [GeV] !! m(ee) [GeV] Sequential Standard Model Z is excluded below. TeV May 8, 0 7

18 t Searches t t bw + bw b + ν b ν ) Events/(4 GeV/c 4 CMS, 5.0 fb at s=7 TeV Events with ee/µµ/eµ Data tt (dileptonic) Other backgrounds t't', M = 450 GeV/c t' Signal Region " (pp! t't') (pb) CMS, 5.0 fb at s=7 TeV Theory (HATHOR) [5] 95% CL expected limits 95% CL observed limits Expected limits ± " Expected limits ± " min M lb (GeV/c ) M t' (GeV/c ) t excluded below 550GeV May 8, 0 8

19 b Searches b b tw tw + Look for leptons or leptons of same charge Events / 00 GeV data t t W/Z/VV/Single Top CMS L=4.9 fb at s = 7 TeV Same-charge dilepton events M b' 500 GeV/c tt+w(z) S T [GeV] "(pp! b'b') [pb] CMS L = 4.9 fb at s = 7 TeV observed limit expected limit Theory (HATHOR) " " Events / 00 GeV data t t W/Z/VV/Single Top CMS L=4.9 fb at s = 7 TeV Trilepton events M b' 500 GeV/c tt+w(z) - M b' < 6 GeV/c is excluded at 95% CL M b' [GeV/c ] S T [GeV] b excluded below 6 GeV May 8, 0 9

20 SUSY (all hadronic) jets H T = p T,i i jets MH T = p T,i i May 8, 0 Observations are consistent with Standard Model 0

21 d Generation SUSY Same-sign leptons + MET + b-jets For SUSY to remain natural with Higgs ~ 0GeV s-top/bottom < 400 GeV gluino < 500 GeV Gluon mitigated s-top and s-bottom production Direct s-top and s-bottom production searches are in the pipeline May 8, 0

22 Bs μμ Rare FCNC helicity suppressed process Sensitive to new physics via loop effects Long history of searches SM Predictions: B(Bs μμ) = (.±0.)x -9 B(B μμ) = (0.±0.0)x -9 LHCb results: B(Bs μμ) < 4.5x -9 95% CL B(B μμ) <.0x -9 95% CL CMS can benefit from rapid increase in data in 0 May 8, 0

23 Conclusion Higgs searches narrowed the allowed region to [4,7] GeV We see an excess at ~5GeV with a global significance of.σ In 0 we should know for sure if Higgs exists CMS dark matter search results compete successfully with direct detection experiments Searches for Physics Beyond the Standard Model cover many possible scenarios We see nothing new so far May 8, 0