Impact of jet energy resolution on Higgs invisible decays Yu Kato - PowerPoint PPT Presentation

Impact of jet energy resolution on Higgs invisible decays Yu Kato The University of Tokyo ILD Meeting 2018 in Ichinoseki Feb. 22, 2018 katou@icepp.s.u-tokyo.ac.jp

Outline Evaluate jet energy resolution & jet angle resolution ILD models: large/small Ø check jet energy ＆ cos θ dependence Study impact on physics analysis [ Higgs invisible decays with hadronic recoil ] use kinematic fit (MarlinKinfit) fit variables : mass constraint : apply jet energy/angle resolution Impact of jet energy resolution on 2018/2/22 2 Higgs invisible decays

Mark Thomson ILD meeting 2014 in Oscu Impact of jet energy resolution on 2018/2/22 3 Higgs invisible decays

Outline Evaluate jet energy resolution & jet angle resolution ILD models: large/small Ø check jet energy ＆ cos θ dependence Study impact on physics analysis [ Higgs invisible decays with hadronic recoil ] use kinematic fit (MarlinKinfit) fit variables : mass constraint : apply jet energy/angle resolution Impact of jet energy resolution on 2018/2/22 4 Higgs invisible decays

Evaluate JER Setup of Evaluating JER l ILCSoft : v01-19-05 (gcc49) l ILDConfig : v01-19-05-p01 l ILD models : ILD_l5_o1_v02, (ILD_s5_o1_v02) l Samples: Z → uds (w/o overlay) [ /ilc/prod/ilc/mc-opt.dsk/ild/dst/calib/uds/… ] 30 40 60 91 120 160 200 240 300 350 400 500 √ s [GeV] l5 [events] 10k 10k 10k 10k 10k 10k 10k 10k 9k 10k 9k 10k s5 [events] 10k 10k 10k 10k 9k 10k 10k 9k 10k 10k 10k 10k l Jet resolution definition ◦ use RMS 90 method ◦ Energy (J. S. Marshall and M. A. Thomson, ”Pandora Particle Flow Algorithm”, arXiv:1308.4537 [physics.ins-det]) ◦ Angle 𝜀𝜚 = RMS90(𝜚 <=> − 𝜚 @> ) use jet clustering: Durham 𝜀𝜄 = RMS90(𝜄 <=> − 𝜄 @> ) Impact of jet energy resolution on 2018/2/22 5 Higgs invisible decays

Evaluate JER JER: Comparison Barrel/Endcap JER was evaluated separately for barrel and endcap regions. Barrel sv01-19-05.mILD_l5_o1_v02_nobg Endcap 7 ) [%] σ Endcap /E = 3.5% θ E σ Overall /E = 30%/ E E j 6 Overall : (E Barrel 31.3/ E -1.97 +0.200 E 90 j j ) / Mean θ Barrel : |cos | < 0.7 5 28.9/ E -1.91 +0.195 E j j θ ≥ Endcap : |cos | 0.7 33.6/ E -1.66 +0.184 E 4 j j j (E 90 RMS 3 α β 0 50 100 150 200 250 Overall 31.3 -1.97+0.200 √ E E [GeV] j Barrel 28.9 -1.91+0.195 √ E Endcap 33.6 -1.66+0.184 √ E Impact of jet energy resolution on 2018/2/22 6 Higgs invisible decays

Evaluate JER JER: Comparison Large/Small The two detector models (large/small) were evaluated for comparison. θ sv01-19-05 |cos |<0.7 7 ) [%] σ /E = 3.5% E σ /E = 30%/ E j 6 E (E mILD_l5_o1_v02_nobg α β 90 28.9/ E -1.91 +0.195 E ) / Mean j j Small 28.9 -1.91+0.195 √ E 5 mILD_s5_o1_v02_nobg Large 27.6 -1.59+0.199 √ E 27.6/ E -1.59 +0.199 E j j 4 j (E Small 90 Large 3 RMS 0 50 100 150 200 250 E [GeV] j Impact of small detector seen for large jet energy • JER goal (ILC TDR) satisfied for both models • Impact of jet energy resolution on 2018/2/22 7 Higgs invisible decays

Evaluate JER JER: Angular Dependence [used as input for kinematic fit] sv01-19-05.mILD_s5_o1_v02_nobg sv01-19-05.mILD_l5_o1_v02_nobg 15 15GeV 15 ) [%] 15GeV ) [%] ILD_s5_v02 ILD_l5_v02 20GeV 20GeV 30GeV 30GeV j (E j (E 45.5GeV 45.5GeV 90 10 90 60GeV 10 60GeV ) / Mean ) / Mean 80GeV 80GeV 100GeV 100GeV 120GeV 120GeV 5 150GeV 5 150GeV j (E j 175GeV (E 175GeV 90 200GeV 90 200GeV RMS 250GeV RMS 250GeV 0 0 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 θ |cos | θ |cos | JER worse for forward jets as expected • Angular dependence has same tendency for large/small • Impact of jet energy resolution on 2018/2/22 8 Higgs invisible decays

Evaluate JAR Angular Resolution [used as input for kinematic fit] 𝜀𝜄 = 𝑆𝑁𝑇 FG (𝜄 <=> − 𝜄 @> ) sv01-19-05.mILD_s5_o1_v02_nobg sv01-19-05.mILD_l5_o1_v02_nobg 0.08 15GeV 0.08 15GeV MC ILD_s5_v02 MC ILD_l5_v02 20GeV 20GeV θ θ - 30GeV - 30GeV 0.06 REC 45.5GeV 0.06 REC 45.5GeV 60GeV 60GeV θ θ 80GeV = 80GeV = 0.04 100GeV 0.04 100GeV θ θ δ 120GeV δ 120GeV 150GeV 150GeV 0.02 175GeV 0.02 175GeV 200GeV 200GeV 250GeV 250GeV 0 0 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 θ θ |cos | |cos | 𝜀𝜚 = 𝑆𝑁𝑇 FG (𝜚 <=> − 𝜚 @> ) sv01-19-05.mILD_s5_o1_v02_nobg sv01-19-05.mILD_l5_o1_v02_nobg 0.3 0.3 15GeV 15GeV MC MC ILD_s5_v02 ILD_l5_v02 20GeV 20GeV φ φ 0.25 0.25 - - 30GeV 30GeV REC REC 45.5GeV 45.5GeV 0.2 0.2 60GeV 60GeV φ φ 80GeV 80GeV = = 0.15 0.15 100GeV 100GeV φ φ δ δ 120GeV 120GeV 0.1 0.1 150GeV 150GeV 175GeV 175GeV 0.05 0.05 200GeV 200GeV 250GeV 250GeV 0 0 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 θ θ |cos | |cos | Impact of jet energy resolution on 2018/2/22 9 Higgs invisible decays

Outline Evaluate jet energy resolution & jet angle resolution ILD models: large/small Ø check jet energy ＆ cos θ dependence Study impact on physics analysis [ Higgs invisible decays with hadronic recoil ] use kinematic fit (MarlinKinfit) fit variables : mass constraint : apply jet energy/angle resolution Impact of jet energy resolution on 2018/2/22 10 Higgs invisible decays

ν q ν ν ν q q Z X X Z q Higgs → invisible Motivation l In SM, Higgs decays invisibly through Previous study (A. Ishikawa) (95% CL, 250fb -1 ) H → ZZ ∗ → 4𝜉 (BR(H → 𝑗𝑜𝑤.)~0.1%) left pol. : right pol. 0.95% : 0.69% l If BR(H → 𝑗𝑜𝑤.) exceeds SM prediction , it signifies new physics beyond SM (BSM) l We estimate upper limit of BR(H → 𝑗𝑜𝑤.) in SM Dark Matter… SUSY… l Compare result between 𝑄 = Z , 𝑄 = \ = −0.8, +0.3 , (+0.8, −0.3) invisible invisible BSM 𝐶𝑆 H → ZZ ∗ → 4𝜉 ~0.1% 𝐶𝑆 H → XX ~? ? ? % visible visible Ø A. Ishikawa (Tohoku Univ.), ”Search for Invisible Higgs Decays at the ILC” LCWS2014@Belgrade Impact of jet energy resolution on 2018/2/22 11 Higgs invisible decays

q q X X Higgs → invisible Signal invisible ü ２ jet & missing E ü 𝑁 `` ≈ 𝑁 b : 𝐶𝑆 Z → 𝑟𝑟 ~70% ü 𝑁 <=>efg ≈ 𝑁 hfiij 𝐶𝑆 H → XX ~? ? ? % ü s channel process Main background ZZ semi-leptonic WW semi-leptonic νν Z semi-leptonic Impact of jet energy resolution on 2018/2/22 12 Higgs invisible decays

� Higgs → invisible Analysis Setup l Simulation ◦ ILCSoft: v01-19-05 ◦ Samples: DBD sample + Dirac sample ( e l e m → qqH, H → ZZ ∗ → 4ν ) ◦ Detector: ILD full simulation (ILD_o1_v05) “Left” “Right” = 250 GeV, ∫ 𝑀𝑒𝑢 = 250 fb -1 , 𝑄 ◦ 𝑡 = Z , 𝑄 = \ = −0.8, +0.3 , (+0.8, −0.3) l Flow of analysis 1. Particle flow reconstruction (PandoraPFA) 2. Isolated lepton finder (veto) 3. Durham jet finder (forced 2 jets) 4. Kinematic fit with MarlinKinfit (OPALFitter) 5. Event selection ◦ Optimized assuming signal BR(H → invisible) = 10% 6. Estimate upper limit of BR (95% CL) ◦ Evaluated for BR(H → invisible) = [1,2,…10%] Impact of jet energy resolution on 2018/2/22 13 Higgs invisible decays

invisible X X q q kinematic fit sv01-19-05.mILD_l5_o1_v02_nobg ZH processor 15 15GeV ) [%] 20GeV 30GeV j (E 45.5GeV 90 10 60GeV ) / Mean 80GeV 100GeV 120GeV 5 150GeV j (E 175GeV 90 200GeV RMS 250GeV 0 0 0.2 0.4 0.6 0.8 1 θ |cos | !" H → XX ~???% sv01-19-05.mILD_l5_o1_v02_nobg 0.08 15GeV MC 20GeV θ - 30GeV 0.06 REC 45.5GeV 60GeV p Observables (to fit) θ 80GeV = 0.04 100GeV θ δ 120GeV 150GeV 0.02 175GeV 200GeV p Z mass constraint: Hard Constraint 250GeV 0 0 0.2 0.4 0.6 0.8 1 θ |cos | sv01-19-05.mILD_l5_o1_v02_nobg p Jet mass assumption 0.3 15GeV MC 20GeV φ 0.25 - 30GeV REC 45.5GeV 0.2 60GeV φ 80GeV = 0.15 p Use parametrized jet resolution 100GeV φ δ 120GeV 0.1 150GeV 175GeV 0.05 200GeV 250GeV 0 0 0.2 0.4 0.6 0.8 1 θ |cos | Impact of jet energy resolution on 2018/2/22 14 Higgs invisible decays

kinematic fit Kinematic fit: Recoil mass (signal only) sv01-19-05.mILD_o1_v05.eL.pR sv01-19-05.mILD_o1_v05.eL.pR OPALFitter success : 99.85 % Events / 0.50 GeV 4000 MC: mode = 125.2 sigma = 6.379 3000 2000 1000 ↓ ISR effect improve recoil mass resolution ~20% 0 100 110 120 130 140 150 160 Recoil Mass [GeV] sv01-19-05.mILD_o1_v05.eL.pR sv01-19-05.mILD_o1_v05.eL.pR sv01-19-05.mILD_o1_v05.eL.pR OPALFitter success : 99.85 % OPALFitter success : 99.85 % Events / 0.50 GeV Events / 0.01 before fit: before fit: 1200 600 mean = 130.1 mean = 8.4e-03 sigma = 12.076 sigma = 8.8e-02 1000 after fit: after fit: 800 400 mean = 129.0 mean = -3.3e-04 sigma = 10.496 sigma = 6.9e-02 600 400 200 200 0 0 − − 100 110 120 130 140 150 160 1 0.5 0 0.5 1 Recoil Mass [GeV] Recoil Mass Relative Error Impact of jet energy resolution on 2018/2/22 15 Higgs invisible decays