Search for Supersymmetry in Events with Photons and Missing Energy

Abstract

We have performed a search for beyond the standard model physics with photons and missing transverse energy. The data sample corresponds to an integrated luminosity of 4.04~\fbinv of $pp$~collisions at $\sqrt{s}=8~\TeV$, recorded by the CMS experiment at the LHC. We compare the missing transverse energy distribution in events containing either at least two photons plus at least one hadronic jet or at least one photon plus at least two hadronic jets to the spectra expected from standard model processes. No excess of events at high missing transverse energy is observed, and results are interpreted in the context of General Gauge Mediated SUSY with the next to lightest SUSY particle being either a bino and wino-like neutralino. 95\% confidence level upper limits on the signal production cross sections for different composition and decay modes of the SUSY particles are determined for a range of squark and gluino masses.

PAS

This analysis is documented in This CDS Entry.

PAS Plots

Figure	Caption
	Figure 1: \MET spectrum of data compared to QCD prediction together with the small EWK background for events with at least one jet. The red hatched areas indicate the total background uncertainties. Two example GGM points on either side of our exclusion boundary ( in GeV) are also shown.
	Figure 2a: 95\% C.L. upper limits on the signal cross section (left) and corresponding exclusion contours (right) in gluino-squark mass space for a 375 GeV bino-like neutralino in the diphoton analysis.
	Figure 2b: 95\% C.L. upper limits on the signal cross section (left) and corresponding exclusion contours (right) in gluino-squark mass space for a 375 GeV bino-like neutralino in the diphoton analysis. The shaded uncertainty band around the exclusion contours correspond to the NLO renormalization and PDF uncertainties of the signal cross section.
	Figure 2c: 95\% C.L. upper limits on the signal cross section (left) and corresponding exclusion contours (right) in gluino-squark mass space for a 375 GeV wino-like neutralino in the diphoton analysis.
	Figure 2d: 95\% C.L. upper limits on the signal cross section (left) and corresponding exclusion contours (right) in gluino-squark mass space for a 375 GeV wino-like neutralino in the diphoton analysis. The shaded uncertainty band around the exclusion contours correspond to the NLO renormalization and PDF uncertainties of the signal cross section.
	Figure 3: Total standard model background prediction compared to the number of single-photon events, including two GGM benchmark signal benchmark points as examples where masses () are given in GeV.
	Figure 4a: 95\% C.L. upper limits on the signal cross section in gluino-squark mass space for a 375 GeV bino-like neutralino for the single photon analysis.
	Figure 4a: 95\% C.L. exclusion contours on the signal cross section in gluino-squark mass space for a 375 GeV bino-like neutralino for the single photon analysis. The shaded uncertainty band around the exclusion contours correspond to the NLO renormalization and PDF uncertainties of the signal cross section.
	Figure 4a: 95\% C.L. upper limits on the signal cross section in gluino-squark mass space for a 375 GeV wino-like neutralino for the single photon analysis.
	Figure 4a: 95\% C.L. exclusion contours on the signal cross section in gluino-squark mass space for a 375 GeV wino-like neutralino for the single photon analysis. The shaded uncertainty band around the exclusion contours correspond to the NLO renormalization and PDF uncertainties of the signal cross section.

Additional Public Plots

Figure	Caption
	MET spectrum of data compared to QCD prediction together with the small EWK background for events without a jet requirement. The red hatched areas indicate the total background uncertainties. Two example GGM points on either side of our exclusion boundary ( in GeV) are also shown.
	The pT of the two EM objects in the 3 samples used in the diphoton analysis before reweighting. The distribution is in black, the ff in blue, and ee in red.
	The pT of the two EM objects in the 3 samples used in the diphoton analysis after reweighting. The distribution is in black, the ff in blue, and ee in red.
	The di-electron mass spectrum used to determine the electron misidentification rate . The signal yield is determined from a Crystal Ball x Breit Wigner with a RooCMSShape background assumption.
	The $e-\gamma$ mass spectrum used to determine the electron misidentification rate $f_{e\to\gamma}$ The signal yield is determined from a Crystal Ball x Breit Wigner with a RooCMSShape background assumption.
	Event display from the diphoton analysis. The missing transverse energy of the event is indicated by the blue arrow and is 142.8 GeV. The two photons indicated as green bars at the top and bottom of the display had energy 132.5 GeV and 132.1 GeV respectively. (black background version)
	Event display from the diphoton analysis. The missing transverse energy of the event is indicated by the blue arrow and is 142.8 GeV. The two photons indicated as green bars at the top and bottom of the display had energy 132.5 GeV and 132.1 GeV respectively. (white background version)
	Leading photon pT ratio between candidate photon and fakeable objects used to correct the pT dependence in the hadronic system in the single photon analysis. Note, this figure is for illustration purpose taken from the 2011 analysis with 4.6/fb of CMS data taken at sqrt(s) = 7 TeV.
	MC Closure demonstration for the single photon analysis in QCD and Photon Jet Monte Carlo. Note, this figure on MC closure is for illustration purpose taken from the 2011 analysis with 4.6/fb of CMS data at sqrt(s) = 7 TeV.
	Example high MET event display from the single photon analysis. Missing transverse energy is 379 GeV, the photon transverse energy is 94.4 GeV, and two jets are present with transverse energy 208.4 and 172.86 GeV respectively.