Study of Higgsinvisible using kinematic fit method applied jet - PowerPoint PPT Presentation

Study of Higgs→invisible using kinematic fit method applied jet energy resolution of ILD Yu Kato The Univ. of Tokyo Asian Physics and Software Meeting Jan. 19, 2018

Goal of this study 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 2 Improve analysis performance kinematic fit apply jet energy resolution method

Flow of study Evaluate jet energy resolution ILD model : ILD_l(s)5_v02 evaluate jet angle resolution → apply to kinematic fit kinematic fit use MarlinKinfit - fitter engine : OPALFitter apply jet resolution Improve analysis performance [ BSM search using Higgs→invisible ] 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 3 Ø jet energy ＆ cosθ dependence Ø check effect & accuracy of fit

Evaluate JER 9k 350 400 500 l5 [events] 10k 10k 10k 10k 10k 10k 10k 10k 9k 10k 10k 240 s5 [events] 10k 10k 10k 10k 9k 10k 10k 9k 10k 10k 10k 10k Update. use jet clustering: Durham 300 200 160 120 91 60 40 30 √s [GeV] Setting of Evaluation JER 4 Study of Jet Resolution 2018/1/19 � 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 (/hsm/ilc/grid/storm/prod/ilc/mc-opt.dsk/ild/dst/calib/uds/*) l jet resolution definition ◦ use RMS 90 method ◦ Energy 𝐹 = RMS90 𝐹 RMS90 𝐹 𝜏 " * ** = 2 𝑛𝑓𝑏𝑜 /0 𝐹 𝑛𝑓𝑏𝑜 /0 𝐹 * ** (J. S. Marshall and M. A. Thomson, ”Pandora Particle Flow Algorithm”, arXiv:1308.4537 [physics.ins-det]) ◦ Angle 𝜀𝜚 = RMS90(𝜚 678 − 𝜚 :8 ) 𝜀𝜄 = RMS90(𝜄 678 − 𝜄 :8 )

ILD model Detailed Baseline Design 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 5 Endcap Barrel θ ILD_l5_v02 ILD_s5_v02 Evaluate JER

Result：Energy dependence 6 2018/1/19 Evaluate JER using kin-fit applied JER of ILD Study of Higgs→invisible sv01-19-05.mILD_l5_o1_v02_nobg 7 ) [%] σ /E = 3.5% E σ /E = 30%/ E E j 6 Overall : (E 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 0 50 100 150 200 250 E [GeV] j

Result : energy & angle dependence 2018/1/19 apply this result to kinematic fit Evaluate JER 7 using kin-fit applied JER of ILD Study of Higgs→invisible sv01-19-05.mILD_l5_o1_v02_nobg 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 |

Anglar resolution azimuth angle use jet clustering. For evaluation of angular resolution, Evaluate JER Durham algorithm 2018/1/19 apply this result to kinematic fit polar angle Study of Higgs→invisible using kin-fit applied JER of ILD 8 𝜀𝜄 = 𝑆𝑁𝑇 /0 (𝜄 678 − 𝜄 :8 ) 𝜀𝜚 ∗ 𝑡𝑗𝑜𝜄 = 𝑆𝑁𝑇 /0 { 𝜚 678 − 𝜚 :8 𝑡𝑗𝑜𝜄} sv01-19-05.mILD_l5_o1_v02_nobg sv01-19-05.mILD_l5_o1_v02_nobg 0.08 0.08 15GeV 15GeV MC θ *sin 20GeV 20GeV θ - 30GeV 30GeV φ 0.06 0.06 REC 45.5GeV 45.5GeV δ 60GeV 60GeV θ 80GeV = 80GeV 0.04 0.04 100GeV 100GeV θ δ 120GeV 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 |

Principle of kinematic fit 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 9 seek minimum of under kinematic constraints method of Lagrange multipliers d.o.f.： kinematic fit

MarlinKinfit : OPALFitter 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 10 For iterative solution : Taylor-expansion of the constraints Convergence condition or kinematic fit ü 𝜀𝜓 F < 0.01% ∩ 𝜀𝐺 N < 10 OP N < 10 OF Q 𝜓 F ∩ 𝐺 S < 10 OT ∩ 𝜀 𝜃, 𝜊, 𝜇 < 10 OT ü all 𝑔

ZH processor 11 invisible X X q q kinematic fit using kin-fit applied JER of ILD Study of Higgs→invisible 2018/1/19 sv01-19-05.mILD_l5_o1_v02_nobg 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 !" H → XX ~???% θ |cos | sv01-19-05.mILD_l5_o1_v02_nobg 0.08 15GeV MC 20GeV p Z mass constraint θ - 30GeV 0.06 REC 45.5GeV 60GeV θ 80GeV = 0.04 100GeV θ δ 120GeV 150GeV p jet mass constraint 0.02 175GeV 200GeV 250GeV 0 0 0.2 0.4 0.6 0.8 1 θ |cos | p Implement of jet resolution sv01-19-05.mILD_l5_o1_v02_nobg 0.3 15GeV MC 20GeV φ 0.25 - 30GeV REC 45.5GeV 0.2 60GeV p degrees of freedom φ 80GeV = 0.15 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 |

Result：accuracy of fit fit probability Mean > Ndof Ndof ：１ Mean：14.5 a possibility of underestimating parameter error →normal distributed between 0 and 1 fit with well-estimated errors ←peak around０ 2018/1/19 kinematic fit 12 Study of Higgs→invisible using kin-fit applied JER of ILD sv01-19-05.mILD_o1_v05.eL.pR sv01-19-05.mILD_o1_v05.eL.pR Events / 2.00 4 OPALFitter 10 fit success : 99.85 % mean = 14.453 sigma = 46.970 3 10 2 10 sv01-19-05.mILD_o1_v05.eL.pR sv01-19-05.mILD_o1_v05.eL.pR 10 Events / 0.01 4 10 OPALFitter fit success : 99.85 % mean = 0.278 1 sigma = 0.313 0 500 1000 1500 2000 χ 2 3 10 χ 2 distribution 2 10 0 0.2 0.4 0.6 0.8 1 Fit Probability

Result：Recoil mass 2018/1/19 improve recoil mass resolution ~20% ↓ISR effect kinematic fit Study of Higgs→invisible using kin-fit applied JER of ILD 13 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 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

Problems : Z mass distribution 2018/1/19 Error??? kinematic fit 14 Study of Higgs→invisible using kin-fit applied JER of ILD sv01-19-05.mILD_o1_v05.eL.pR OPALFitter success : 99.85 % Events / 0.50 GeV MC: before fit: 4 10 mean = 90.9 mean = 90.7 sigma = 5.338 sigma = 10.091 3 10 after fit: mean = 91.3 2 10 sigma = 1.271 10 1 70 80 90 100 110 120 M [GeV] Z

0.95% : 0.69% q Z Z ν ν ν X X ν q q 15 Study of Higgs->invisible using kinematic fit 2018/1/19 Motivation Previous study (A.Ishikawa) (95% CL, 250fb -1 ) it signifies new physics beyond SM (BSM) left pol. : right pol. q l In SM, Higgs decays invisibly through H → ZZ ∗ → 4𝜉 (BR(H → 𝑗𝑜𝑤.)~0.1%) l If BR(H → 𝑗𝑜𝑤.) exceeds SM prediction , l We estimate SM upper limit of BR(H → 𝑗𝑜𝑤.) Dark Matter… SUSY… l Compare between left & right polarization at the ILC invisible BSM invisible 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

Cut table 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 16 w/o kinematic fit w/ kinematic fit Higgs→invisible 7 e , 𝑄 7 f = −0.8, +0.3 𝑄

Cut table 2018/1/19 Study of Higgs→invisible using kin-fit applied JER of ILD 17 w/o kinematic fit w/ kinematic fit Higgs→invisible 7 e , 𝑄 7 f = +0.8, −0.3 𝑄

Higgs→invisible 2018/1/19 w/ kinematic fit w/o kinematic fit significance=16.26 significance=19.72 significance=20.81 significance=15.54 Result：Recoil mass distribution using kin-fit applied JER of ILD Study of Higgs→invisible Right polarization Left polarization 18 ∫ ∫ - - + -1 w/o kinematic fit + -1 s = 250 GeV, (Pe ,Pe ) = (-0.8,+0.3), L dt = 250 fb , Cut: No.1~No.9 s = 250 GeV, (Pe ,Pe ) = (-0.8,+0.3), L dt = 250 fb , Cut: No.1~No.9 w/ kinematic fit Events / 2.00 GeV Events / 2.00 GeV → → H inv. H inv. 2500 2500 BR = 10% BR = 10% qqH,SM qqH,SM 2000 2000 ZZ ZZ 1500 WW 1500 WW ν ν ν ν Z Z 1000 other bkg 1000 other bkg 500 500 0 0 100 110 120 130 140 150 160 100 110 120 130 140 150 160 kf M [GeV] M [GeV] recoil recoil ∫ ∫ - + -1 w/o kinematic fit - s = 250 GeV, (Pe ,Pe ) = (+0.8,-0.3), L dt = 250 fb , Cut: No.1~No.9 + -1 s = 250 GeV, (Pe ,Pe ) = (+0.8,-0.3), L dt = 250 fb , Cut: No.1~No.9 w/ kinematic fit Events / 2.00 GeV Events / 2.00 GeV → → H inv. H inv. BR = 10% BR = 10% 800 800 qqH,SM qqH,SM ZZ ZZ 600 600 WW WW ν ν ν ν Z Z 400 400 other bkg other bkg 200 200 0 0 100 110 120 130 140 150 160 100 110 120 130 140 150 160 M [GeV] kf M [GeV] recoil recoil