ATLAS SUSY meeting - MET signatures subgroup, 24 Sept’08 - Jets+MET @ 10TeV Alan Barr, Claire...

ATLAS SUSY meeting- MET signatures subgroup, 24 Sept’08 -

Jets+MET @ 10TeV

Alan Barr, Claire Gwenlan (Oxford)

- initial look at the two- and three-jets+MET (CSC-style) analyses with 10pb-1 -

Outline MC samples/selection cuts initial results summary/future work

Jets+MET at 10TeV with 10pb-1 24 Sept'08 2

MC samples/selection cuts

Cuts: [two-/three-jet+MET analyses @ 10TeV, with 10pb-1]• look at “loose”, “medium” and “tight” phase space cuts (see below)

– [as proposed by S. Caron: http://indico.cern.ch/conferenceDisplay.py?confId=38731]

• [other cuts as in CSC note 5 (for now; see backups for full list) ]

tight medium loosetwo-jet pT > 200,80 GeV pT > 180,50 GeV pT > 120,40 GeV

three-jet

pT > 100,50,50 GeV

pT > 100,40,40 GeV

pT > 80,40,40 GeV

MC samples:

• v12 fullsim samples, as used in CSC note 5 (full list in backups)• these samples generated at 14TeV -> reweight PDFs to 10TeV

[as described: http://indico.cern.ch/conferenceDisplay.py?confId=33528 (C. Gwenlan) ]

MET>80 GeV in all cases


Results (i): Meff

two-jet+MET [all cuts incl. J70_XE70 trigger]

S/sqrt(B) [max.]

S/sqrt(S+B)

[max.]loose 21 12

medium 19 10tight 18 9

10TeV, 10pb-

1


Results (ii): Meff

S/sqrt(B) [max.]

S/sqrt(S+B)

[max.]loose 26 13

medium 26 12tight 25 12

10TeV, 10pb-

1three-jet+MET [all cuts incl. J70_XE70 trigger]


Results (iii): MT2


Results (iv): MT2


summary/future work

in principle, light SUSY discoverable with 10pb-1 at 10TeV

… IF enough statistics (and sufficient understadning of the detector!) to determine backgrounds to resonable precision

Next steps:

- background determinations

- trigger studies


Extras


MC samples (backgrounds)QCD J4 trig1_misal1_mc12.008090.pythia_J4_Nj2_FMET100.recon.AOD.v12000601

QCD J5 trig1_misal1_mc12.008091.pythia_J5_Nj2_FMET100.recon.AOD.v12000601




Zee trig1_misal1_mc12.008094.pythia_Zee_qg_ckin80_Nj2.recon.AOD.v12000601

Zmumu trig1_misal1_mc12.008095.pythia_Zmumu_qg_ckin80_Nj2.recon.AOD.v12000601

Ztautau

trig1_misal1_mc12.008091.pythia_Ztautau_qg_ckin80_Nj2.recon.AOD.v12000601

Znunu trig1_misal1_mc12.008090.pythia_Znunu_qg_ckin80_Nj2.recon.AOD.v12000601

Wenu trig1_misal1_mc12.008270.pythia_Wenu_qg_ckin80_Nj2.recon.AOD.v12000601

Wmunu trig1_misal1_mc12.008271.pythia_Wmunu_qg_ckin80_Nj2.merge.AOD.v12000605

Wtaunu trig1_misal1_mc12.008271.pythia_Wtaunu_qg_ckin80_Nj2.merge.AOD.v12000605

TTbar trig1_misal1_mc12.005204.TTbar_FullHad_McAtNlo_Jimmy.recon.AOD.v12000601

T1 trig1_misal1_mc12.005200.T1_McAtNlo_Jimmy.recon.AOD.v12000601

WW trig1_misal1_mc12.005985.WW_Herwig.recon.AOD.v12000601

ZZ trig1_misal1_mc12.005986.ZZ_Herwig.recon.AOD.v12000601

WZ trig1_misal1_mc12.005987.WZ_Herwig.recon.AOD.v12000601


MC samples (signal)

SU1 trig1_misal1_csc11.005401.SU1_jimmy.susy.recon.AOD.v12000601





SU8.1 trig1_misal1_csc11.005406.SU81_jimmy.susy.recon.AOD.v12000601


• hadronic cross section given by:

for a particular kinematic configuration with s, t, u, should just need to change the probability that incoming partons *had* that configuration i.e. just a PDF re-weight

Reminder: PDF reweighting

( )ˆ α∑∫1

2 2 2 21 2 1 1 2 2 1 2 s

flav 0

ó= dx dx PDF(x ,Q ,flav ) ? PDF(x ,Q ,flav ) ? ó p,p , (Q ),Q

Re-weight MC to 10 TeV using:

xi : x of parton i at 14TeV; x i’: x of parton i at 10TeV

proton PDFs

hard subprocess cross section

pTJet,1,2 >150,100

GeV


selection cuts

two-jet three-jetCut1 pT

jet1 pTjet1

Cut2 pTjet2 pT

jet3

Cut3 MET>80GeV MET>80GeV

Cut4 MET/Meff>0.3 MET/Meff>0.25

Cut5 dphi(jet1-MET)>0.2 dphi(jet1-MET)>0.2

Cut6 dphi(jet2-MET)>0.2 dphi(jet2-MET)>0.2

Cut7 dphi(jet3-MET)>0.2

Cut8 no isolated leptons no isolated leptons

as in CSC5 (for now)

Cuts: [two-/three-jet+MET analyses @ 10TeV, 10pb-1]

“loose”, “medium” or “tight” (as given below)

tight medium loosetwo-jet pT > 200,80 GeV pT > 180,50 GeV pT > 120,40 GeV

three-jet

pT > 100,50,50 GeV

pT > 100,40,40 GeV pT > 80,40,40 GeV


Results (extras):

Two-Jet+MET [Meff analysis]various SUX signal MC compared to total SM background


Results (extras):

Three-Jet+MET [Meff analysis]various SUX signal MC compared to total SM background


Results (i): Meff 10TeV, 10pb-

1two-jet+MET [all cuts except trigger]


Results (ii): Meff 10TeV, 10pb-

1three-jet+MET [all cuts except trigger]


Results (iii): MT2

two-jet+MET [jet-pT, lepton veto cuts only]

10TeV, 10pb-

1


Results (iv): MT2 10TeV, 10pb-

1two-jet+MET [jet-pT, lepton-veto, MET cuts only]


Results (v): MT2 10TeV, 10pb-

1two-jet+MET [jet-pT, lepton-veto, MET cuts and J70_XE70 trigger]


Results (vi): MT2 10TeV, 10pb-

1three-jet+MET [jet-pT, and lepton-veto cuts only]


Results (vii): MT2 10TeV, 10pb-

1three-jet+MET [jet-pT, lepton-veto, MET cuts only]


Results (viii): MT2 10TeV, 10pb-

1three-jet+MET [jet-pT, lepton-veto, MET cuts and J70_XE70 trigger]

ATLAS SUSY meeting - MET signatures subgroup, 24 Sept’08 - Jets+MET @ 10TeV Alan Barr, Claire...

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