Search for pair production of long-lived heavy charged stau particles with LHCb

The conference note is available here (LHCb-CONF-2014-001)

More detailed information: ANA note 2013-081

Abstract

The minimal Gauge Mediated Supersymmetry Breaking (mGMSB) model predicts that the next-to-lightest Supersymmetric Particle is the stau, the charged, massive, and long-lived bosonic super-partner to the tau. We have analysed data collected at the LHCb experiment in 2011 and 2012 corresponding to a total integrated luminosity of 3 fb-1 , searching for pairs of particles which can be identified as staus with masses between 124 and 309 GeV/c2. A neural network was used to distinguish staus from muons. No evidence is observed for the production of such long-lived states. Limits on the di-stau production cross-section are set.

Figures

(Note, eps versions are available under attachments).

Caption Figure
Figure 1: Distributions of the number of candidates (N) as a function of the four variables used as inputs to the NN. The black dots with error bars are the 2012 data. The dashed red line is the expected shape from 124 GeV/c2 staus and the blue histogram shows the background from Z0/γ decays into muons. The first bin of histogram (b) (about 40% of the number of candidates) is not displayed: it corresponds to depositions which are below the readout threshold of the ECAL. Fig1a.pngFig1b.pngFig1c.pngFig1d.png
Figure 2: The number of candidates (N) as a function of the pair significance of the muon and the stau pairs. The left and right figures correspond to the stau masses of 124 and 309 GeV/c2 respectively. The black dots with their statistical error bars are the 2012 data set. The red dashed histogram is the expected shape from staus and the blue histogram the background. The arrows indicate the chosen threshold. Fig2_left.pngFig2_right.png
Figure 3: 95 % CL upper limits on the cross-sections for stau pair production (black squares) and corresponding theoretical predictions (red dots) for pp collisions as a function of the stau mass at √s = 7 and 8 TeV. Fig3_left.pngFig3_right.png

-- KatharinaMueller - 2014-11-06

Topic attachments
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Unknown file formateps Fig1a.eps r1 manage 6621.9 K 2014-11-06 - 15:09 KatharinaMueller  
PDFpdf Fig1a.pdf r1 manage 8.2 K 2014-11-06 - 15:09 KatharinaMueller  
PNGpng Fig1a.png r1 manage 62.6 K 2014-11-06 - 15:09 KatharinaMueller  
Unknown file formateps Fig1b.eps r1 manage 6833.8 K 2014-11-06 - 15:09 KatharinaMueller  
PDFpdf Fig1b.pdf r1 manage 10.9 K 2014-11-06 - 15:09 KatharinaMueller  
PNGpng Fig1b.png r1 manage 73.3 K 2014-11-06 - 15:09 KatharinaMueller  
Unknown file formateps Fig1c.eps r1 manage 6833.8 K 2014-11-06 - 15:09 KatharinaMueller  
PDFpdf Fig1c.pdf r1 manage 11.9 K 2014-11-06 - 15:09 KatharinaMueller  
PNGpng Fig1c.png r1 manage 84.2 K 2014-11-06 - 15:09 KatharinaMueller  
Unknown file formateps Fig1d.eps r1 manage 6699.4 K 2014-11-06 - 15:11 KatharinaMueller  
PDFpdf Fig1d.pdf r1 manage 6.9 K 2014-11-06 - 15:11 KatharinaMueller  
PNGpng Fig1d.png r1 manage 54.5 K 2014-11-06 - 15:11 KatharinaMueller  
Unknown file formateps Fig2_left.eps r1 manage 6581.7 K 2014-11-06 - 15:11 KatharinaMueller  
PDFpdf Fig2_left.pdf r1 manage 8.0 K 2014-11-06 - 15:11 KatharinaMueller  
PNGpng Fig2_left.png r1 manage 60.0 K 2014-11-06 - 15:11 KatharinaMueller  
Unknown file formateps Fig2_right.eps r1 manage 6581.7 K 2014-11-06 - 15:11 KatharinaMueller  
PDFpdf Fig2_right.pdf r1 manage 7.9 K 2014-11-06 - 15:11 KatharinaMueller  
PNGpng Fig2_right.png r1 manage 59.6 K 2014-11-06 - 15:11 KatharinaMueller  
Unknown file formateps Fig3_left.eps r1 manage 4427.9 K 2014-11-06 - 15:12 KatharinaMueller  
PDFpdf Fig3_left.pdf r1 manage 8.3 K 2014-11-06 - 15:12 KatharinaMueller  
PNGpng Fig3_left.png r1 manage 57.0 K 2014-11-06 - 15:12 KatharinaMueller  
Unknown file formateps Fig3_right.eps r1 manage 4427.9 K 2014-11-06 - 15:12 KatharinaMueller  
PDFpdf Fig3_right.pdf r1 manage 8.3 K 2014-11-06 - 15:12 KatharinaMueller  
PNGpng Fig3_right.png r1 manage 57.6 K 2014-11-06 - 15:12 KatharinaMueller  
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