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Very preliminary look at sparticle mass measurements through end-points. Massimiliano Chiorboli Alessia Tricomi Università and INFN Catania. p. b. b. p. Sparticle mass peaks.
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Very preliminary look at sparticle mass measurements through end-points Massimiliano Chiorboli Alessia Tricomi Università and INFN Catania
p b b p Sparticle mass peaks • Last CPT week we showed that it is possible to reconstruct sparticle mass peaks combining jets and leptons arising from their decays
p b b p 10 fb-1 sbottom Sbottom reconstruction At the end-point:
p b b p 10 fb-1 sbottom chain Gluino Reconstruction
How can we do that without depending on M(c10)? These peaks are built assuming M(c10) known p b b p Kinematical peculiarities can be exploited Fundamental question
SUSY events generated with ISAJET 7.51 + PYTHIA 6.158 Detector simulated with CMSJET 4.801 Point B: m0 = 100, m1/2=250, tanb=10, A0=0, m>0 Integrated luminosity 30 fb-1 2 isolated leptons, pT>10 GeV, |h|<2.5 2 jets, pT1>150 GeV, pT2>100 GeV, pT3,4>50 GeV ETmiss > 150 GeV SM bkg not yet considered Signal selection
Dilepton edge Result of the fit:
llq edge 4 jet 2 jet
llq edge Result of the fit:
lq edges • We cannot distinguish the two leptons
lq edge separation hep-ph/0007009
lqmin edge Result of the fit:
lqmax edge Result of the fit:
How to distinguish the two leptons? • We tried the solution proposed by Luc, but the scatter plot doesn’t seem to show particular structures. • However, a deep study has to be performed to optimize cuts
Mass determination • We solved the system analitically and get M(c10), M(c20), M(slepton) • Sizeable difference from nominal values to be understood. • The solutions are very sensitive to small variations of the input parameters. • We would need theoretical shapes of the end-points in order to perform reasonable fits.
Conclusions & Future Plans • Use of edges looks promising but still a lot of work needed • Optimization of cuts • Theoretical shape of the edges • SM bkg • Better estimate of errors