ATLAS Searches for SUSY Chris Young, CERN ATLAS Group What have we - PowerPoint PPT Presentation

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group What have we not looked for? 1 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group What have we not looked for? 2 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group This talk: Where/What have we looked for? 3 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group Outline ◮ Introduction ◮ Searches for strong production (RPC) ◮ Searches for stop/sbottom production (RPC) ◮ Searches for electo-weak production (RPC) ◮ Searches for RPV SUSY. ◮ Conclusions 4 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group Introduction ◮ There are searches for both RPC and RPV SUSY (although many more RPC). ◮ Experimentally we divide our searches into 3 categories driven by the production mode. ◮ This is motivated by the very different signatures that result from the decays. 10 σ tot [ pb ] : pp → SUSY √ S = 8 TeV 1 q ˜g ˜ -1 10 q ˜q ˜ ˜ * q ˜q -2 χ ˜ 2 o χ ˜ 1 + ˜ 2 χ o g ˜ ˜ 1 t t ˜ 1* g ˜g ˜ 10 ˜ e ν ν ˜ e* ˜ e l l ˜ e* -3 10 200 400 600 800 1000 1200 1400 1600 m average [ GeV ] 5 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group Searches For Strong Production (RPC) ◮ Strong production has the highest cross-section at a p-p collider → highest mass reach. ◮ For RPC SUSY we assume to have a neutralino (or gravitino) LSP such that there will be E miss T ◮ Strong decays will produce jets and then searches are split by the number of leptons also required. ◮ Most searches favour a strategy of cutting hard on the sum of transverse momenta of objects m eff and E miss to reduce the SM backgrounds. 1 T ◮ Background determination is then performed by performing a simultaneous fit in “control regions” which are rich in different SM background with similar kinematic cuts and the “signal region(s)”. Monte-Carlo is used to evaluate the ratios between regions. ◮ Fits are performed both for the background only hypothesis and for each point in the models used for interpretation such that signal contamination in the “control regions” is taken into account. 1 There are some exceptions to this. 6 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group Strong Production (RPC) : 0-lepton + ≥ 2-6 jets ATLAS-CONF-2013-047 ◮ Hard cuts on scalar sum of jets and E miss ( m eff ) and E miss / m eff . T T ◮ 10 signal regions covering a variety of jet multiplicities. 7 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group Strong Production (RPC) : 0-lepton + ≥ 2-6 jets ATLAS-CONF-2013-047 ◮ Background estimation comes from “control regions” which require a lepton and require/veto the presence of a b-jet (for t ¯ t and W +jets) or a high p T photon (for Z +jets). ◮ The Monte-Carlo is seen to describe the data well in these regions and a simultaneous fit gives the expectation in the SR. 4 events / 100 GeV events / 100 GeV events / 100 GeV 10 ATLAS ATLAS ATLAS ∫ ∫ ∫ Preliminary Preliminary Preliminary -1 -1 -1 L dt = 20.3 fb L dt = 20.3 fb L dt = 20.3 fb CRWC - 4 jets CRTC - 4 jets CRYC - 4 jets 10 3 3 10 Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) miss after cut: E /m (N ) > 0.25 T eff jets 3 10 SM Total SM Total SM Total γ +jets W+jets W+jets Multijet 2 2 10 10 t t & single top t t & single top W+jets 10 2 Z+jets Z+jets t & single top t Diboson Diboson Diboson 10 10 10 Cm Ct Cm Ct Ct Ct 1 1 1 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 2.5 2.5 2.5 2 2 2 m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] 1.5 1.5 1.5 eff eff eff 1 1 1 0.5 0.5 0.5 0 0 0 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] eff eff eff 8 / 37

ATLAS Searches for SUSY Chris Young, CERN ATLAS Group Strong Production (RPC) : 0-lepton + ≥ 2-6 jets ATLAS-CONF-2013-047 ◮ No significant excess is seen. events / 100 GeV events / 100 GeV events / 100 GeV events / 100 GeV ATLAS ATLAS ATLAS ATLAS 5 Preliminary ∫ Preliminary ∫ Preliminary ∫ Preliminary ∫ 10 -1 -1 -1 -1 L dt = 20.3 fb L dt = 20.3 fb L dt = 20.3 fb L dt = 20.3 fb 10 4 SRA - 2 jets SRA - 2 jets 10 4 SRB - 3 jets SRB - 3 jets Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) SM Total SM Total SM Total SM Total 4 ∼ ∼ ∼ 10 3 ∼ 10 ~ ~ ~ χ ~ ~ ~ χ ~ ~ ~ ~ χ ~ ~ ~ ~ χ q q m( q )=850,m( 0 )=100 q q m( q )=850,m( 0 )=100 q g m( g )=1.04 m( × q )=1425,m( 0 )=525 q g m( g )=1.04 m( × q )=1425,m( 0 )=525 1 ∼ ∼ 1 ∼ 1 ∼ 1 ~ ~ ~ χ ~ ~ ~ χ ~ ~ ~ ~ χ ~ ~ ~ ~ χ q q m( q )=450,m( 0 )=400 10 3 q q m( q )=450,m( 0 )=400 3 q g m( g )=1.04 m( × q )=1612,m( 0 )=37 q g m( g )=1.04 m( × q )=1612,m( 0 )=37 1 1 10 1 1 Multijet Multijet Multijet Multijet 10 3 Z+jets Z+jets Z+jets Z+jets 10 2 W+jets W+jets W+jets W+jets 2 10 10 2 t t & single top t & single top t t & single top t t t & single top 2 10 Diboson Diboson Diboson Diboson 10 10 10 10 Bt Al Am Bm 1 1 1 1 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 2.5 DATA / MC 2.5 DATA / MC 2.5 DATA / MC 2.5 m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] 2 eff 2 eff 2 eff 2 eff 1.5 1.5 1.5 1.5 1 1 1 1 0.5 0.5 0.5 0.5 0 0 0 0 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] eff eff eff eff events / 100 GeV events / 100 GeV events / 150 GeV events / 150 GeV ATLAS ∫ ATLAS ∫ ATLAS ∫ ATLAS ∫ Preliminary 10 3 Preliminary Preliminary Preliminary L dt = 20.3 fb -1 L dt = 20.3 fb -1 L dt = 20.3 fb -1 L dt = 20.3 fb -1 SRC - 4 jets SRD - 5 jets SRE - 6 jets SRE - 6 jets Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) Data 2012 ( s = 8 TeV) 10 2 Data 2012 ( s = 8 TeV) 3 SM Total SM Total 2 SM Total SM Total 10 ∼ 10 ∼ ∼ ∼ ∼ CMSSM m =1000,m =700 ~ ~ ~ χ 0 ~ ~ ~ χ ± χ 0 ~ ~ ~ χ ± χ 0 0 g g m( g )=1162,m( )=337 g g m( g )=1065,m( )=785,m( )=505 g g m( g )=1065,m( )=785,m( )=505 ∼ 1/2 ∼ 1 ∼ 1 ∼ 1 ∼ 1 1 ∼ ~ ~ ~ χ 0 ~ ~ ~ χ 0 ~ ~ ~ χ ± χ 0 ~ ~ ~ χ ± χ 0 g g m( g )=700,m( )=550 2 g g m( g )=1250,m( )=50 g g m( g )=1265,m( )=865,m( )=465 g g m( g )=1265,m( )=865,m( )=465 1 10 1 1 1 1 1 Multijet Multijet Multijet Multijet Z+jets Z+jets Z+jets Z+jets 10 2 W+jets W+jets W+jets W+jets 10 t t & single top t & single top t 10 t & single top t t & single top t Diboson Diboson Diboson Diboson 10 Em 10 El Cm Ct Dt 1 1 1 1 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 4500 DATA / MC 0 500 1000 1500 2000 2500 3000 3500 4000 4500 2.5 2.5 2.5 2.5 m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] eff eff eff eff 2 2 2 2 1.5 1.5 1.5 1.5 1 1 1 1 0.5 0.5 0.5 0.5 0 0 0 0 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 3500 4000 4500 0 500 1000 1500 2000 2500 3000 3500 4000 4500 m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] m (incl.) [GeV] eff eff eff eff 9 / 37