Update on Search for Resonant Slepton Production

Transcription

1 Overview Update on Search for Resonant Slepton Production Christian Autermann III. Phys. Inst. A, RWTH Aachen Luminosity Di-µ Trigger Efficiency & Error QCD Estimation New Limits Supported by Christian Autermann New Phenomena Meeting, / 2

2 Luminosity Question: Why was the luminosity 347 pb -? I was not yet using the v3 data. Now: good recorded Luminosity: ± 24.5 pb - Now using all data until shutdown 24 Removed 2.76 bad runs Removed bad LBNs. Christian Autermann New Phenomena Meeting, / 2

3 2µ-Trigger Efficiency Question: Why is the trigger eff. error so large? Di-muon Trigger Efficiency ε trigger = 94 ± 6 % correction factor.8.6 mean.939 ± di-µ trigger eff. ± σ syst. error stat. uncertainty η µ 2 Christian Autermann New Phenomena Meeting, / 2

4 2µ Trigger Efficiency (top_trigger) η-dependency of L (muptxatxx) and L2 is parameterized by: f 2 A ( η A2 ) 2 ( η) = A + A e sin( η A ) 3 2 with the parameters: A A A 2 A 3 Level : muptxatxx 2-4 ± ±.3 3.2±.2.998±.5 Level 2: MUON(,med) -.3±.6.±.9 See the top group s Note 452 for detail! -.7±.9.98±.2 from latest top_trigger release Trigger uncertainty of σ is defined by the uncertainty of these parameters. (top_trigger methods set_sigma & EventWeight) Christian Autermann New Phenomena Meeting, / 2

5 MC weight (trigger efficiency) weight.9 2µ Trigger η-parameterisation MU trigger turnon L3 + max. error L3 + σ LL2L3 Total L3 - σ L3 - max error trigger efficiency all parameter errors chosen randomly inside their range maximal error (error propagation) this is what top_trigger does η Christian Autermann New Phenomena Meeting, / 2

6 Error on Trigger Efficiency Ok, the error of the trigger efficiency is (too) large: 94 ± 6 % The reason is probably, that σ deviation is not given by the maximal variation of the parameters inside their errors But the systematic error of the trigger efficiency on preselection with 2 jets is only: 4. % The trigger error is negligible to other errors: (JES:.5%, QCD 6.6%, Lumi 6.5%) Even though it is estimated very conservatively Christian Autermann New Phenomena Meeting, / 2

7 QCD Estimation Question: Why did the QCD events peak at the Z-resonance? Redid the QCD estimation, now: almost same isolation cuts on data/signal and QCD more statistics QCD Criteria: b-tag one of both muons must NOT be isolated with respect to - Σ E T in hollow cone R=.4, r=. OR - Σ p_ T (track) in cone R=.5 number of events /. GeV Reconstructed Z-mass DO RunII preliminary Data Signal, point #58 QCD from Data tt->ll tt->l+jet Y Y s 2 s WW->µνµν WZ incl. ZZ incl. 5-5GeV 5-6GeV 4 5-6GeV 5 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV 5-6GeV 5 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV inv. di-muon mass [GeV] Christian Autermann New Phenomena Meeting, / 2

8 In the last talk, not enough points were processed. The limit was increasing with the slepton mass, because the inter/extrapolation failed. [GeV] m /2 Now I have enough points (275), (at least for tan(β)=5, sign(µ)=-) Limits τ tan(β)=5, sign(µ)=- is the LSP D RunII preliminary χ = GeV χ =75 GeV λ Not allowed l=2 GeV l=3 GeV 95% CL Exclusion Contour Gen. points excl. (λ 2 =.7) Gen. points (not excluded) [GeV] m Christian Autermann New Phenomena Meeting, / 2

9 Limit vs. Neutralino mass Fixed parameters: A =, sign(µ)=, tan β = 5, λ 2 =.7 Slepton mass = 2 GeV Slepton mass = 3 GeV limit,σ [pb] 3 25 λ 2 =.8 D RunII preliminary σ tot, l=2gev, tan(β)=5 Limit 95% CL limit,σ [pb] 8 7 λ 2 =.9 D RunII preliminary σ tot, l=3gev, tan(β)=5 Limit 95% CL 6 2 λ 2 =.7 5 λ 2 = λ 2 =.6 λ 2 =.5 λ 2 =.4 λ 2 =.3 Excluded Not allowed Neutralino mass χ [GeV] λ 2 =.7 λ 2 =.6 λ 2 =.5 λ 2 =.4 λ 2 =.3 Excluded Not allowed Neutralino mass χ [GeV] Christian Autermann New Phenomena Meeting, / 2

10 Limit vs. Slepton mass Fixed parameters: A =, sign(µ)=, tan β = 5, λ 2 =.7 Neutralino mass = 75 GeV Neutralino mass = GeV limit,σ [pb] D RunII preliminary σ tot, χ =75GeV, tan(β)=5 Limit 95% CL limit,σ [pb] 4 2 D RunII preliminary λ 2 =.8 σ tot, χ =GeV, tan(β)=5 λ 2 =.7 Limit 95% CL Not allowed λ 2 =.3 λ 2 =.7 λ 2 = Not allowed λ 2 =.5 λ 2 =.4 λ 2 =.3 5 Excluded Slepton mass l [GeV] 2 Excluded Slepton mass l [GeV] Christian Autermann New Phenomena Meeting, / 2

11 More limits (in progress ) [GeV] m /2 tan(β)=5, sign(µ)= τ is the LSP D RunII preliminary χ = GeV.4 λ χ =75 GeV.4 [GeV] m / tan(β)=5, sign(µ)=+ τ is the LSP l=2 GeV D RunII preliminary l=3 GeV χ = GeV χ =75 GeV 95% CL Exclusion Contour 5 Gen. points excl. (λ 2 =.7) Not allowed Gen. points (not excluded) m [GeV] λ 2 λ 95% CL Exclusion Contour 5 Gen. points excl. (λ 2 =.7) Not allowed Gen. points (not excluded) m [GeV] D RunII preliminary Christian Autermann New Phenomena Meeting, / 2 [GeV] m /2 tan(β)=5, sign(µ)= τ is the LSP l=2 GeV l=2 GeV l=3 GeV l=3 GeV χ = GeV χ =75 GeV 95% CL Exclusion Contour 5 Gen. points excl. (λ 2 =.7) Not allowed Gen. points (not excluded) [GeV] m λ

12 To Do Update note with limits for tan(β)=5, sign(µ)=+, tan(β)=5, sign(µ)=-, tan(β)=5, sign(µ)=+ Give limits more independent with respect to SUSY parameters (any suggestions welcome) Christian Autermann New Phenomena Meeting, / 2

13 Old Talk Christian Autermann New Phenomena Meeting, / 2

14 Overview Search for Resonant Slepton Production Christian Autermann III. Phys. Inst. A, RWTH Aachen Event Topology Data Selection and Efficiencies Control Plots Preliminary Exclusion Limits Outlook Supported by Christian Autermann New Phenomena Meeting, / 2

15 R-parity Violating Supersymmetry R - parity : W W R/ P = = W 2 MSSM ijk R P + i = ( ) W j R/ P k 3B+ L+ 2S ' λ L L E + λ L Q D + ijk i S is the particle spin, B is the baryon number, L is the lepton number j k '' λ ijk U i D j D k R-parity violating extension of the MSSM i,j,k =,2,3 generation indices R-parity conserving production associated/pair production of gauginos decay via λ ijk into 4 charged leptons require 3 charged leptons for analysis e e + X : Anne-Marie Magnan (λ 2 ) µ µ + X : Daniela Käfer (λ 22 ) τ + X : Anne-Catherine Le-Bihan (λ 33 ) Resonant production via λ 2 of smuon or sneutrino Cascade decay to LSP (neutralino) decay via λ 2 into 2 jets & lepton Chiral superfields: L: lepton doublet superfield E: lepton singlet superfield Q: quark doublet superfield D: down-like quark singlet superfield λ, λ`, λ``: Yukawa couplings Christian Autermann New Phenomena Meeting, / 2

16 Slepton Decay Channels Final State consists of 2 jets and up to two muons or missing E T Huge background from multi-jet processes Need to select events with at least 2 muons u u d µ µ d ν µ u 2 Muon Channels: Golden channel if l is a muon No ν, no missing E T Possible to reconstruct the neutralino and the slepton mass But only 25% branching ratio Other channels with MET and a second muon from cascade processes Not possible to reconstruct the slepton mass and not necessarily the neutralino mass. But higher branching ratio Christian Autermann New Phenomena Meeting, / 2

17 Signal Branching Ratios no muon one muon two muons ( golden channel ) Christian Autermann New Phenomena Meeting, / 2

18 Data Sample & Preselection Data from April 22 August 24 good recorded Luminosity: 347 pb - (preliminary) Preselection Sample Any Dimuon trigger has fired Veto against cosmic muons (Scintillator timings) 2 good muons with pt > 2 GeV, pt > 8 GeV central track match & isolation for both muons events, expected background: 2 984±67(stat)±54(syst) event Corrected for - Dimuon Trigger efficiency - Muon reconstruction efficiencies - Isolation efficiencies - Track finding & matching - Muon momentum smearing - Jet energy scale - Monte Carlo LO NNLO cross section Christian Autermann New Phenomena Meeting, / 2

19 Data Consistency: Preselection () number of events /.8 GeV Reconstructed Z-mass Statistics Data Signal, point # QCD from Data inv. di-muon mass [GeV] tt->ll tt->l+jet Y Y s 2 s WW->µνµν WZ incl. ZZ incl. 5-5GeV 5-6GeV 4 5-6GeV 5 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV 5-6GeV 5 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV Dominant SM MC is Z/γ µµ QCD is estimated from Data by a) using data events with like-sign, nearly isolated muons b) data events with b-tag Best agreement with method (b). Signal x (m χ =9GeV, m µ =263GeV) Other considered but negligible SM backgrounds: ttbar ll, ttbar l jet Z ττ Y(s), Y(2s) W µν ZZ, WZ, WW Christian Autermann New Phenomena Meeting, / 2

20 Data Consistency: Preselection (2) Preselection & jet p T > 5 GeV Transverse Momentum of jet Transverse Momentum of jet number of events /.5 GeV data Statistics Data Signal, point # QCD from Data signal x tt->ll tt->l+jet 5-5GeV Z/γ GeV 4 5-6GeV 5 6-3GeV 4 Z/γ 5-6 GeV Z/γ ->µµ 6-3GeV GeV 25-5GeV Z/γ ->µµ 5-GeV QCD, b-tag data 5-6GeV 5 tt ll 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV jet p T [GeV] Ys 2 Ys WW->µνµν WZ incl. ZZ incl. number of events /.5 GeV data signal x Statistics Data Signal, point #56 SM ± syst. ± stat. sytematic uncertainty jet p T [GeV] Signal x (m χ =9GeV, m µ =263GeV) Christian Autermann New Phenomena Meeting, / 2

21 Data Consistency: Preselection (3) number of events / 8. GeV Preselection & jet p T > 5 GeV & jet 2 p T > 5 GeV Reconstructed χ nd Mass with 2 data signal x Statistics Data Signal, point # QCD from Data inv. mass of µ 2, jet, jet 2 [GeV] tt->ll tt->l+jet Z/γ ->µµ 5-6GeV 4 Z/γ GeV 5 6-3GeV 4 Z/γ ->µµ 6-3GeV GeV Ys 2 Ys WW->µνµν WZ incl. ZZ incl. 25-5GeV 5-GeV 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV µ Z/γ 5-6 GeV QCD tt ll number of events / 8. GeV Reconstructed χ Mass with st µ Statistics Data Signal, point #56 SM ± syst. ± stat. data signal x sytematic uncertainty inv. mass of µ 2, jet, jet 2 [GeV] Signal unscaled (m χ =9GeV, m µ =263GeV) Christian Autermann New Phenomena Meeting, / 2

22 Constant Corrections () MC eff. Data eff. correction Muon Reconstruction.938±..93±.2.973±.27 MURECOEFF skim, Z/DY6-3 Muon central track finding & matching.972±..988±..6±.6 2MU skim, Z/DY6-3 Muon track isolation.956±..944±.2.989±. 2MU skim, Z/DY6-3 Medium Muon.956±..97±..6±.6 2MU skim, Z/DY6-3 All Pass 2 Data Method: Tag & Probe Data eff. / MC eff. is flat for p T, η, φ and inv. µ-mass Christian Autermann New Phenomena Meeting, / 2

23 Constant Corrections (2) reconstruction isolation track matching η µ reco correction.8.6 mean.973 ±.27 µ isolation correction.8.6 mean.989 ±. µ track correction.8.6 mean.27 ±.27 φ p T µ reco correction µ reco correction mean.973 ±.27 murecoeff Data / Z/γ (6-3 GeV) mean.973 ±.27 murecoeff Data / Z/γ (6-3 GeV) φ.4 η µ isolation correction MU Data / Z/γ (6-3 GeV) µ isolation correction mean.989 ±. 2MU Data / Z/γ (6-3 GeV) φ η mean.989 ±. µ track correction µ track correction mean.29 ±.29 2MU Data / Z/γ (6-3 GeV) MU Data / Z/γ (6-3 GeV) φ η mean.29 ± murecoeff Data / Z/γ (6-3 GeV) 2MU Data / Z/γ (6-3 GeV) 2MU Data / Z/γ (6-3 GeV) p T [GeV] p T [GeV] p T [GeV] Christian Autermann New Phenomena Meeting, / 2

24 Other Corrections Data eff. MC correction factor 2µ Trigger (top_dq) 92.8 ± 6.8 % f( p T, η, φ, jet, ME T ) Jet energy scale jet jet jet jet jet jet f(p T,η,φ, ME T ) f(p T,η,φ, ME T, ) Muon p T smearing NNLO MC x-sec. corr. f(p T muon ) f( inv. µ mass ) Corrections depend on event kinematics, like p T, η, φ, MET Systematic uncertainties are derived by varying corrections by ± σ. Total muon efficiency: 8 ± 5 % Christian Autermann New Phenomena Meeting, / 2

25 2D Cuts Final selection Final signal selection on Preselection & with di-jets: slepton neutralino mass plane channel separation several other 2D cuts in planes with -di-µ mass - missing E T - R(µ µ 2 ) -µ p T +µ p T - inv. di-jet mass - sum of jet p T - R(jet jet 2 ) Each 2D cut is done when the signal efficiency purity is larger than a certain limit. [GeV] inv. mass of µ 2, jet, jet 2 Reconstructed Slepton & Neutralino Mass inv. mass of µ, µ 2, jet, jet 2 [GeV] Christian Autermann New Phenomena Meeting, / 2 5 Statistics Data Signal, point # QCD from Data Signal (mχ=9gev, mµ=263gev) channel with MET High signal purity can be achieved Strong dependence on msugra point Optimize all cut parameters for each 2D cut and each msugra point tt->ll tt->l+jet 5-6GeV 4 5-6GeV 5 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV 6-3GeV 4 6-3GeV GeV 25-5GeV 5-GeV Ys 2 Ys WW->µνµν WZ incl. ZZ incl. golden channel

26 Data Consistency (3) Cut Flow An exemplary cutflow for the SUSY point m =2 GeV, m /2 =243 GeV: Jet cuts 2D cuts Christian Autermann New Phenomena Meeting, / 2

27 Preliminary Results msugra points ready analyzed ( tan β = 5, µ/ µ = - ) 49 points reconstructed 27 generated Scans for tan β = 5 and 2.5M signal events positive µ in progress Christian Autermann New Phenomena Meeting, / 2

28 Exclusion Contours A =, tanβ=5, sign(µ)= [GeV] m / τ is the LSP D RunII preliminary DØ RunII preliminary l=2 GeV l=3 GeV χ = GeV χ =65 GeV 95% CL Exclusion Contour 5 Gen. points excl. (λ 2 =.7) Not allowed Gen. points (not excluded) [GeV] m.4 λ mass [GeV] l DØ RunII preliminary Not allowed 95% CL Exclusion Contour Gen. points excl. (λ 2 =.7) Gen. points (not excluded) χ mass [GeV].4 λ m m /2 plane slepton neutralino mass plane Christian Autermann New Phenomena Meeting, / 2

29 Limit vs. neutralino mass Fixed parameters: A =, sign(µ)=, tan β = 5, λ 2 =.7 Slepton mass = 2 GeV Slepton mass = 3 GeV limit,σ [pb] 3 25 λ 2 =.8 D RunII preliminary σ tot, l=2gev, tan(β)=5 σ ( l χ +l), λ =.7 2 Limit 95% CL limit,σ [pb] λ 2 =.9 D RunII preliminary σ tot, l=3gev, tan(β)=5 σ ( l χ +l), λ =.7 2 Limit 95% CL 2 λ 2 =.7 5 λ 2 = λ 2 =.6 λ 2 =.5 λ 2 =.4 λ 2 =.3 Excluded Not allowed Neutralino mass χ [GeV] λ 2 =.7 λ 2 =.6 λ 2 =.5 λ 2 =.4 λ 2 =.3 Excluded Not allowed Neutralino mass χ [GeV] Christian Autermann New Phenomena Meeting, / 2

30 Limit vs. slepton mass Fixed parameters: A =, sign(µ)=, tan β = 5, λ 2 =.7 Neutralino mass = 65 GeV Neutralino mass = GeV limit,σ [pb] 3 25 D RunII preliminary σ tot, χ =65GeV, tan(β)=5 σ ( l χ +l), λ =.7 2 Limit 95% CL limit,σ [pb] 4 2 D RunII preliminary λ 2 =.8 σ tot, χ =GeV, tan(β)=5 λ 2 =.7 l χ σ ( +l), λ 2 =.7 Limit 95% CL Not allowed λ 2 =.4 λ 2 =.3 2 =.8 λ =.7 λ 2 Excluded Slepton mass l [GeV] Not allowed λ 2 =.5 λ 2 =.4 λ 2 =.3 Excluded Slepton mass l [GeV] Christian Autermann New Phenomena Meeting, / 2

31 Conclusions Search for RPV SUSY through the LQD coupling λ 2 2 muon preselection sample is well described by SM incl. QCD All efficiencies and systematic errors measured Efficient 2D final selection cuts Improved limits compared to DØ Run I Continuously generating more signal points: Publish Results Christian Autermann New Phenomena Meeting, / 2