CDF Logo Search for Randall-Sundrum Gravitons in the Diphoton Channel at CDF Exotics Logo

This page summarizes a search for Randall-Sundrum model gravitons performed in the diphoton channel using 5.4 fb-1 Run II data collected in the CDF detector. 95% confidence limits on the production cross-section times branching ratio for Randall-Sundrum model gravitons decaying to diphotons are obtained, from which lower limits on the graviton mass for various width parameters are derived.

Plots and Tables

Signal shape EPS GIF
Graviton selection efficiency EPS GIF
Graviton event rate systematics EPS GIF
Diphox mass spectrum and fit EPS GIF
Residual of Diphox fit EPS GIF
Efficiency of selecting QCD diphoton events EPS GIF
Systematics on QCD diphoton background EPS GIF
Diphoton mass spectrum binned by detector resolution EPS GIF
Diphoton mass spectrum with background fit overlaid EPS GIF
Integral of diphoton mass spectrum EPS GIF
Residual of background fit EPS GIF
A bump around 200 GeV EPS GIF
95% C.L. cross section limits EPS GIF
95% C.L. cross section limits with theoretical cross section calculations overlaid EPS GIF
K-factor for G->γγ cross section EPS GIF
Lower limit on graviton mass as a function of k/MPl EPS GIF
Probability of background to fluctuate to the level of data in the range between 150 GeV and 650 GeV EPS GIF


Table 1: Total efficiency and systematic error for RS graviton events decaying to two photons as a function of graviton mass.
Graviton mass (GeV/c2) Total efficiency and systematic error
200 0.118±0.013
300 0.175±0.019
400 0.224±0.023
500 0.258±0.024
600 0.284±0.024
700 0.299±0.023
800 0.312±0.019
900 0.321±0.021
1000 0.330±0.018
1100 0.334±0.016


Table 2: The 95% C.L. lower limits on the RS graviton mass for various values of k/MPl.
k/MPl Lower mass limit (GeV/c2)
0.1 963
0.07 899
0.05 838
0.025 704
0.01 459

Update on Dec. 10, 2010

We discovered a minor issue about how we derived limits on the RS model. Our theoretical cross section curves did not have good granularity, the consequence is that the extracted limits on the RS model were not as precise as we intended. With improved granularity for the theoretical cross section curves, the limits on the RS model changed slightly. For some values of k/Mpl, the new limits were 10-20 GeV lower than before. This issue doesn't affect our observed limits on the RS production cross section. It only makes the limits on RS model more precise. This public page has been updated to reflect this change. The old page can be found here.
Tingjun Yang
Last modified: Tue Feb 1 13:19:22 CST 2011