EXO-10-019 < Main

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---+ Search for Randall-Sundrum Gravitons in the Diphoton Channel in pp Collisions at sqrt(s) = 7 TeV
---++ Summary

This note describes the search for Randall-Sundrum gravitons decaying in the di-photon channel at the CMS experiment, with 36.1 pb&minus;1of &radic;s = 7TeVproton-proton collision data. We find the spectrum to agree with Standard Model expectations, and find no evidence for a resonance. We therefore derive limits on the cross-section for the production of RS-gravitons, and hence on the parameters of the warped extra dimension model. For values of the coupling parameter ranging from 0.01 to 0.1, we find that at 95% C.L., graviton masses below 368 to 952GeV/c2 are excluded.

<img alt="h_FakeRate_minv_log_data_36.1pb.pdf" src="https://twiki.cern.ch/twiki/pub/CMSPublic/PhysicsResultsEXO10019/h_FakeRate_minv_log_data_36.1pb.png" />

Our diphoton spectrum with data driven backgrounds using Jet/Photon fake rates, and SM diphoton Monte Carlo. From this we extrapolate limits on our high mass signal region:

<img alt="CLall_CMSprelim361.pdf" src="https://twiki.cern.ch/twiki/pub/CMSPublic/PhysicsResultsEXO10019/CLall_CMSprelim361.png" />

These cross section limits are translated into mass limits for each value of the coupling constant:

<img alt="cLimit.pdf" src="https://twiki.cern.ch/twiki/pub/CMSPublic/PhysicsResultsEXO10019/cLimit.png" />
---++ Caltech contributions:

   * Analysis/Ntuple production - weekly analysis of data during 2010 run
   * data driven background estimate with templates - cross check of fake rate function estimates of each type of background, using template shapes for photons/jets
   * beam halo systematics removal - An important sytematic on the fake rate estimates, which was originally missed by the Extra Dimensions analysis
   * limit extraction from data - We will soon be competitive with Tevatron limits, using the data taken in 2011 up to the summer.
---++ References

[[http://cms.cern.ch/iCMS/jsp/db_notes/showNoteDetails.jsp?noteID=CMS%20AN-2010/405][AN-2010/405]]

[[http://cms.cern.ch/iCMS/analysisadmin/get?analysis=EXO-10-019-pas-v7.pdf][PAS-EXO-10-019]]

[[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsEXO10019][Public results twiki]]

-- Main.yma - 2011-04-06

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Topic revision: r2 - 2011-04-08 - yma
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