alternatives: beyond susy searches in cms dimitri bourilkov university of florida for the cms...
DESCRIPTION
D.Bourilkov Alternatives: Beyond SUSY Searches in CMS3 Introduction Alternatives: simple final states with no missing energy; can reconstruct invariant mass Early discovery ? “Easy” – resonances “Not-so-easy” – non-resonant OR just a resonance tail LHC is a di-{lepton, photon, jet} factory Test Standard Model to highest momentum transfers Signals for many new physics scenarios: compositeness, Z’, extra dimensions: Randall- Sundrum (RS) gravitons, ADD …TRANSCRIPT
![Page 1: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/1.jpg)
Alternatives: Beyond SUSY Searches in CMS
Dimitri BourilkovDimitri BourilkovUniversity of FloridaUniversity of Florida
For the CMS CollaborationFor the CMS Collaboration
SUSY06, June 2006, Irvine, CA, USASUSY06, June 2006, Irvine, CA, USA
![Page 2: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/2.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 2
Length : ~20 m Radius : ~7 m Weight : ~ 13000 tons
ECAL crystals
Barrel HCAL
CMS
Endcap Muon Chambers
Silicon tracker
Coil + inner vacuum tank
![Page 3: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/3.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 3
IntroductionAlternatives: simple final
states with no missing energy; can reconstruct invariant mass
Early discovery ?“Easy” – resonances“Not-so-easy” – non-resonant OR just a resonance tail
LHC is a di-{lepton, photon, jet} factory
Test Standard Model to highest momentum transfers
Signals for many new physics scenarios: compositeness, Z’, extra dimensions: Randall-Sundrum (RS) gravitons, ADD …
![Page 4: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/4.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 4
Dielectron ReconstructionCMS Physics TDR:
Full detector simulation / reconstructionDetailed backgrounds & systematic uncertainties
Saturation correction: above 1.7 TeV barrel, 3 TeV endcaps; mass resolution barrel 0.6 % (7%) without (with) saturation
Preshower, HCAL, energy corrections
KK Z boson SSM Z’ Graviton
![Page 5: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/5.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 5
Diphoton Reconstruction
Photon energy corrections as for electrons
![Page 6: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/6.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 6
Dimuon Efficiency/Resolution
Most important - misalignment:First data <~ 1 fb-1
Long term (with more data)
![Page 7: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/7.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 7
Dimuon Reconstruction
Input mass 4 TeVgenerated
reconstructed
![Page 8: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/8.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 8
Dijet Reconstruction
Combine triggers with prescaling
Z’
/M = 0.045 + 1.3/M
QCD radiation
![Page 9: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/9.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 9
Resonance Hunting with Dielectrons
5 discovery reach for KK Z bosons, 6 Z’ models, RS gravitons
![Page 10: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/10.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 10
Resonance Identification for Dielectrons(muons)
Use angular distributions: identify spin/distinguish between Z’ models
Graviton (blue); Drell-Yan (red)
Z’ (LR) (red)
![Page 11: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/11.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 11
Resonance Hunting with Diphotons
5 discovery reach for RS gravitons
![Page 12: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/12.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 12
Resonance Hunting with Dimuons5 discovery reach for 6 Z’ models, RS gravitons
(plots with systematic uncertainties e.g. misalignment)
C = 0.01
C = 0.1First data
Long term
![Page 13: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/13.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 13
Resonance Hunting with DijetsExclusion / 5 discovery reach: resonance cross
section compared to different models
![Page 14: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/14.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 14
Contact Interactions
general framework for new interactions:• scale s (virtual effects) or resonances if s • coupling g (convention g2 = 4)• we constrain g / • operators with canonical dimension N > 4 terms ~ 1/N-4
![Page 15: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/15.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 15
Double Ratio Method for Dileptons• Observed events N = L..• Use e.g. mass bin 250-500 GeV for normalization (SM valid;
Tevatron); prefer to use data above the Z due to the flavor composition / PDF
> At Z peak 32.1% of initiating partons are heavier flavors (not u & d quarks) with their own PDF uncertainties; more d than u quarks
> At 250-500 GeV u & d are “initiators” already in 85.6% of the cases> u & d are 96.3% above 1 TeV; the u / d ratio approaches 4:1
• For higher masses (bins 1 – n): Ri
DATA = NiD/N0
D = iD.i
D / 0D.0
D Ri
MC = NiMC/N0
MC = iMC.i
MC / 0MC.0
MC • Many things cancel in the ratios: luminosity, absolute
efficiency, K-factor etc.; absolute values are not important, only the shapesshapes as function of mass
• Double ratio aka a pion/nucleon PDF study and aka SuperKamiokande DRi = Ri
DATA / RiMC
• If theory understanding and detector modeling are both perfect DRi = 1
![Page 16: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/16.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 16
Example of Double Ratios (100 fb-1)
![Page 17: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/17.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 17
Systematic Effects for Dimuons• PDF uncertainties (LHAPDF) on ratios
• EW corrections change cross section by ~ 10 % (W.Hollik, U.Baur et al.); conservatively take ½ = 5 %
• QCD K-factors change cross section by ~ 8 %; conservatively take ½ = 4 % from K-functions
• In total < 11.5 % from theory• Experiment+theory: nominal <12 %, start-up <15%
Mass R(M/ 250-500) R(M/ Z)[GeV] PDF+ PDF- PDF+ PDF-500-600
+1.5% -1.5% +4.6% -4.2%
1000+ +5.2% -4.8% +7.8% -7.1% 2000+ +10.7% -7.8% +12.9% -9.4%
![Page 18: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/18.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 18
Contact Interactions with Dimuons
Up to 10 fb-1 (higher for +) we are dominated by statistical errors: even 30 % systematic errors have small impact
![Page 19: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/19.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 19
ADD Extra Dimensions with Dimuons
![Page 20: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/20.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 20
Contact Interactions with Dijets
Use dijet ratio N(|| < 0.5) / N(0.5 < || < 1) as function of dijet mass
![Page 21: Alternatives: Beyond SUSY Searches in CMS Dimitri Bourilkov University of Florida For the CMS Collaboration SUSY06, June 2006, Irvine, CA, USA](https://reader036.vdocuments.mx/reader036/viewer/2022062503/5a4d1b0a7f8b9ab05998a703/html5/thumbnails/21.jpg)
D.BourilkovD.Bourilkov Alternatives: Beyond SUSY Searches in CMS 21
Outlook
• CMS can measure cross sections / forward-backward asymmetries for di-{electron, photon, muon, jet} to the highest masses @ LHC
• Rich search field for early discoveries at the multi-TeV scale: resonances first; fix scale for new physics?
• Ratio methods for non-resonant searches developed and well understood (reduced systematic uncertainties; dependence mainly on shapes as function of invariant mass, not on absolute values)
• Be ready for first data: detector, data acquisition, software
• Other alternatives studied by CMS: single leptons / photons, black holes, technicolor, heavy Majorana neutrinos and right-handed bosons, little Higgs, same sign top