Abs Calibr 1 Calorimeter energy calibration using the energy conservation law V. Morgunov DESY, Hamburg and ITEP, Moscow LCWS26, Bangalore, India, 26. The copy of this talk one can find at the http://www.desy.de/ morgunov Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 2 How to get calorimeter energy conversion coeffs? Easy: One should run muons in Monte Carlo, take whole energy in absorber and scintillator, and divide it by energy in the scintillator. The reason for this is: if one particle crosses one sampling layer it should deposit the whole energy, but we can measure the scintillator energy only. But: the cascade in matter consists of not only pure particles (track like) but rather dense electromagnetic showers and a mixture of the photoeffect s and compton scattered electrons together with pure track like energy deposition. This leads to the co called e/π ratio for the calorimeter response for different types of particles. The using of the complex calorimeter, which we have in LDC detector, leads to even more tricky procedure for the calibration, because it needs to define the coeffs for each part of the calorimeter with different samplings and then choose the correct ratio between that coeffs to get a correct whole measured energy. So, let us start from the coeffs defined by muon run in the simulation. C = E whole /E visible for each sampling structures, that are three of them in our case. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 3 How to get a whole event energy conservation? Hcal energy () 6 5 Old coeffs for t tbar to 6 jets, 5 The simple formula should give us an answer E Ecal + E Hcal = E CM but, we have no this see a picture. 4 So, let us rotate the black line to the position of the red one by rescaling the coefficient of 3 energy conversion (see previous slide). Rotation actually means of the affine trans- 2 formation of this 2 D space. (see next slide) 1 These rotated coeffs consist of all the properties of the whole LDC calorimeters as well as the flavor s containment of the jets! 1 2 3 4 5 6 Ecal energy () E-ECAL vs E-HCAL Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 4 The black line equation is: How to rotate? a E Ecal + E Hcal = a (c 1 E vis1 + c 2 E vis2 ) + c 3 H vis = E where: c 1, c 2 and c 3 is an initial energy conversion coeffs, a is the slope which give us the minimal energy width. E is some constant the line should come through the most probable value of the initial energy sum. By the way; if the initial coeffs were bad fitted to the intrinsic mutual calorimeter properties (bad inter calibration), one will never get the sharp top right edge of the energy distribution as well as the most probable line! The red line equation is: E calib ECAL + Ecalib HCAL = E CM energy conservation law. Then we got the new coeffs: where: f = E CM /E ; and Let us require E = E CM and a = 1 exactly. c calib 1 = fa c 1, c calib 2 = fa c 2 and c calib 3 = fc 3 ; c calib 1 E vis1 + c calib 2 E vis2 + c calib 3 H vis = E CM along the most probable line These three coeffs will be applied latter on to each hit in the particular sampling regions of the calorimeter. For any events you will see below. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 5 The results of rotation/rescaling are Hcal energy () 1 8 New coeffs for t tbar to 6 jets, 1 Hcal energy () 5 45 4 New coeffs for t tbar to 6 jets, 5 Hcal energy () 5 45 4 New coeffs for e+ e- to heavy quarks, 5 35 35 6 3 3 25 25 4 2 2 15 15 2 1 1 5 5 2 4 6 8 1 Ecal energy () E-ECAL vs E-HCAL 5 1 15 2 25 3 35 4 45 5 Ecal energy () E-ECAL vs E-HCAL 5 1 15 2 25 3 35 4 45 5 Ecal energy () E-ECAL vs E-HCAL Hcal energy () 1 8 New coeffs for W+ W- to everything, 1 Hcal energy () 5 45 4 New coeffs for W+ W- to everything, 5 Hcal energy () 5 45 4 New coeffs for e+ e- to light quarks, 5 35 35 6 3 3 25 25 4 2 2 15 15 2 1 1 5 5 2 4 6 8 1 Ecal energy () E-ECAL vs E-HCAL 5 1 15 2 25 3 35 4 45 5 Ecal energy () E-ECAL vs E-HCAL 5 1 15 2 25 3 35 4 45 5 Ecal energy () E-ECAL vs E-HCAL Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 6 Calorimeter energy sum 12 New coeffs for t tbar to 6 jets, 1 Constant 15.8 Mean 982.5 Sigma 24.64 14 New coeffs for t tbar to 6 jets, 5 Constant 111.9 Mean 488.8 Sigma 16.9 14 New coeffs for e+ e- to heavy quarks, 5 Constant 14.5 Mean 495. Sigma 14.78 1 12 12 8 1 1 8 8 6 6 6 4 4 4 2 2 2 2 4 6 8 1 12 1 2 3 4 5 6 7 1 2 3 4 5 6 7 7 New coeffs for W+ W- to everything, 1 Constant 64.38 Mean 992.6 Sigma 25.47 8 New coeffs for W+ W- to everything, 5 Constant 71.89 Mean 496.6 Sigma 14.52 16 New coeffs for e+ e- to light quarks, 5 Constant 139.9 Mean 497.9 Sigma 14.9 6 7 14 5 6 12 4 5 1 4 8 3 3 6 2 2 4 1 1 2 2 4 6 8 1 12 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 7 about Available Energy Events for all these plots were generated without luminosity curve and without ISR, so, the whole sum of energy in HEP record is equal of the center mass energy exactly. To calculate available energy for calorimeters one should subtract the neutrino energies, as well as the energy of particles which go to the beam tube (acceptance detector inefficiency); and also subtract the muons energies but with leaving of the energy which deposited by any muon in the calorimeter, which is about 1.6 per muon. So, the estimated energy to be measured by calorimeters for each event is: E available = E CM E neutrinos E to tube E muons + N muons 1.6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 8 Check plots 12 1 Check quality, t tbar to 6 jets, 1 Constant 13. Mean.1879 Sigma 18.69 1 Check quality, t tbar to 6 jets, 5 Constant 87.81 Mean 1.22 Sigma 12.62 1 Check quality, e+ e- to heavy quarks, 5 Constant 79.47 Mean -.4959 Sigma 12.84 8 8 8 6 6 6 4 4 4 2 2 2-1 -75-5 -25 25 5 75 1-6 -4-2 2 4 6-6 -4-2 2 4 6 18 16 Check quality, W+ W- to everything, 1 Constant 11.8 Mean 2.684 Sigma 17.37 14 12 Check quality, W+ W- to everything, 5 Constant 16.7 Mean 3.16 Sigma 8.934 9 8 Check quality, e+ e- to light quarks, 5 Constant 72.4 Mean -1.73 Sigma 14.14 14 1 7 12 6 1 8 5 8 6 4 6 4 3 4 2 2 2 1-1 -75-5 -25 25 5 75 1-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 9 For reference Z pole reaction Hcal energy () 1 8 Z to everything, 91.2 18 16 14 Z to everything, 91.2 Constant 152.3 Mean 9.44 Sigma 4.67 12 6 1 8 4 6 2 4 2 2 4 6 8 1 Ecal energy () E-ECAL vs E-HCAL 2 4 6 8 1 12 All decay channels are allowed. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 1 Check plot 12 1 Check quality, Z to everything, 91.2 Constant 99.7 Mean -.5865E-1 Sigma 4.247 Sigma = 44.5 % 8 6 4 2-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 11 Marlin Reco also knows about this LDC (tile HCal), 4T 4 35 3 χ 2 / ndf 139.8 / 63 Prob 1.517e-8 Normalisation 369.5 Mean -.8576 Sigma Central Part 3.399 Sigma Left Tail 9.77 Sigma Right Tail 7.756 Fraction Central Part.7956 25 2 15 1 5-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 12 Summary Table, model LDC Whole calorimeter sum Check plots e+ e- into, at energy Mean [] Sigma [] Mean [] Estimated energy resolution [] t tbar, 1 982.3 24.6.19 18.7 W+ W-, 1 992.6 25.5 2.7 17.4 t tbar, 5 488.8 16.9 1.8 12.6 W+ W-, 5 496.6 14.5 1.6 1.9 heavy quarks, 5 495. 14.8 -.5 12.8 light quarks, 5 497.9 14.9-1.1 14.3 t tbar, 36 356.4 14. 5.5 1. Z pole, 91.2 9.4 4.67 -.6 4.25 Any reconstruction program should give us these resolutions, at least. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 13 Detector models comparison, 4 Tesla, W+ W-, 5 8 7 e+ e- to W+ W-, 5 42.84 / 22 Constant 65.83 Mean 499.2 Sigma 14.46 8 7 e+ e- to W+ W-, 5 3.93 / 22 Constant 68.17 Mean 53.1 Sigma 15.31 6 6 5 5 4 4 3 3 2 2 1 1 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 14 Attempt of Optimization Shift of the most probable peak of energy from the center of mass energy. 3 Tesla 4 Tesla LDC1 LDC LDC1 LDC e+ e- into, at energy -2-2 + + + +2 +2-2-2 + + + + +2 +2 W+ W-, 5-3.4-2.1 +3.1 +2.4 -.8 -.4 +4.2 +3.1 t tbar, 5-6.9-7. -3.1-4.6-6.2-5. -1.9-3. t tbar, 36-6.7-6.3-3.6-4.6-5.8-6.5-3.2-5. Tendency is visible, BUT, to make any decision on these numbers is too hard, they are around one percent of whole energy. All detector models are good from the point of view of the energy consistence in the calorimeter. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 15 Conclusion Let us use the energy conservation law with its full power. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 16 After the conclusion (ZEUS data) For HERA experiments this feature also can be used but at the more complex way. The relative calibration can be done using E P z = 2 E e beam equation. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 17 Support slides Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 18 Once chosen coeffs work for any energy Hcal energy () 1 8 New coeffs for t tbar to 6 jets, 1 12 1 New coeffs for t tbar to 6 jets, 1 Constant 15.8 Mean 982.5 Sigma 24.64 6 8 6 4 4 2 2 2 4 6 8 1 Ecal energy () E-ECAL vs E-HCAL 2 4 6 8 1 12 e + e t t 6 jets, semileptonic decay channels for W ± were prohibited. Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 19 Let us check the result again 12 1 Check quality, t tbar to 6 jets, 1 Constant 13. Mean.1879 Sigma 18.69 8 6 4 2-1 -75-5 -25 25 5 75 1 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 2 And any reactions Hcal energy () 1 8 New coeffs for W+ W- to everything, 1 7 6 New coeffs for W+ W- to everything, 1 Constant 64.38 Mean 992.6 Sigma 25.47 6 5 4 4 3 2 2 1 2 4 6 8 1 Ecal energy () E-ECAL vs E-HCAL 2 4 6 8 1 12 e + e W + W, all decay channels for W ± are allowed. HEP record has cut: Cos(W ) <.9 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 21 And again, let us check the result 18 16 Check quality, W+ W- to everything, 1 Constant 11.8 Mean 2.684 Sigma 17.37 14 12 1 8 6 4 2-1 -75-5 -25 25 5 75 1 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 22 As for light quarks Hcal energy () 5 45 4 New coeffs for e+ e- to light quarks, 5 16 14 New coeffs for e+ e- to light quarks, 5 Constant 139.9 Mean 497.9 Sigma 14.9 35 12 3 1 25 8 2 15 6 1 4 5 2 5 1 15 2 25 3 35 4 45 5 Ecal energy () E-ECAL vs E-HCAL 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 23 Let us check the result 9 8 Check quality, e+ e- to light quarks, 5 Constant 72.4 Mean -1.73 Sigma 14.14 7 6 5 4 3 2 1-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 24 As for heavy quarks Hcal energy () 5 45 4 New coeffs for e+ e- to heavy quarks, 5 14 12 New coeffs for e+ e- to heavy quarks, 5 Constant 14.5 Mean 495. Sigma 14.78 35 1 3 25 8 2 6 15 4 1 5 2 5 1 15 2 25 3 35 4 45 5 Ecal energy () E-ECAL vs E-HCAL 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 25 Let us check the result 1 Check quality, e+ e- to heavy quarks, 5 Constant 79.47 Mean -.4959 Sigma 12.84 8 6 4 2-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 26 Detector models comparison, 4 Tesla, W+ W-, 5 8 7 e+ e- to W+ W-, 5 42.84 / 22 Constant 65.83 Mean 499.2 Sigma 14.46 8 7 e+ e- to W+ W-, 5 23.97 / 22 Constant 64.97 Mean 499.6 Sigma 15.24 6 6 5 5 4 4 3 3 2 2 1 1 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 e+ e- to W+ W-, 5 15.95 / 22 Constant 71.5 Mean 54.2 Sigma 14.93 8 7 e+ e- to W+ W-, 5 3.93 / 22 Constant 68.17 Mean 53.1 Sigma 15.31 7 6 6 5 5 4 4 3 3 2 2 1 1 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 27 Detector models comparison, 3 Tesla, W+ W-, 5 8 e+ e- to W+ W-, 5 22.26 / 22 Constant 67.63 Mean 496.6 Sigma 14.36 9 8 e+ e- to W+ W-, 5 21.1 / 22 Constant 68.26 Mean 497.9 Sigma 14.44 7 7 6 6 5 5 4 4 3 3 2 2 1 1 1 2 3 4 5 6 7 1 2 3 4 5 6 7 1 8 e+ e- to W+ W-, 5 28.51 / 22 Constant 7.15 Mean 53.1 Sigma 14.6 8 7 e+ e- to W+ W-, 5 33.74 / 22 Constant 68.24 Mean 52.4 Sigma 15.8 6 6 5 4 4 3 2 2 1 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 28 Detector models comparison, 4 Tesla, t tbar, 5 12 1 e+ e- to t tbar, 5 24.83 / 22 Constant 18.6 Mean 493.8 Sigma 15.49 12 e+ e- to t tbar, 5 38.3 / 22 Constant 17.8 Mean 495. Sigma 14.83 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 12 e+ e- to t tbar, 5 14.8 / 22 Constant 19.8 Mean 498.1 Sigma 15.99 12 e+ e- to t tbar, 5 36.91 / 22 Constant 17.7 Mean 497. Sigma 15.97 1 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 29 Detector models comparison, 3 Tesla, t tbar, 5 12 e+ e- to t tbar, 5 28.93 / 22 Constant 13. Mean 493.1 Sigma 15.73 12 e+ e- to t tbar, 5 22.52 / 22 Constant 112.1 Mean 493. Sigma 15.4 1 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 14 12 e+ e- to t tbar, 5 21.4 / 22 Constant 114.7 Mean 496.9 Sigma 15.14 12 e+ e- to t tbar, 5 33.59 / 22 Constant 11.4 Mean 495.4 Sigma 16.25 1 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 3 Detector models comparison, 4 Tesla, t tbar, 36 14 e+ e- to t tbar, 36 15.59 / 18 Constant 136.1 Mean 354.2 Sigma 13.38 16 14 e+ e- to t tbar, 36 26.58 / 18 Constant 139.5 Mean 353.5 Sigma 13.4 12 12 1 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 16 14 e+ e- to t tbar, 36 17.19 / 18 Constant 141.9 Mean 356.8 Sigma 13.7 16 14 e+ e- to t tbar, 36 23.59 / 18 Constant 137.8 Mean 355. Sigma 13.69 12 12 1 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 31 Detector models comparison, 3 Tesla, t tbar, 36 16 14 e+ e- to t tbar, 36 13.76 / 18 Constant 135.5 Mean 353.3 Sigma 13.37 16 14 e+ e- to t tbar, 36 16.35 / 18 Constant 14.2 Mean 353.7 Sigma 12.87 12 12 1 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 16 14 e+ e- to t tbar, 36 27.66 / 18 Constant 137.5 Mean 356.4 Sigma 14.3 12 e+ e- to t tbar, 5 33.59 / 22 Constant 11.4 Mean 495.4 Sigma 16.25 1 12 1 8 8 6 6 4 4 2 2 1 2 3 4 5 6 7 1 2 3 4 5 6 7 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 32 Detector models comparison, 4 Tesla, W+ W-, 5 25 Check quality, e+ e- to W+ W-, 5 37.14 / 14 Constant 199.8 Mean 2.94 Sigma 1.18 25 Check quality, e+ e- to W+ W-, 5 31. / 14 Constant 21.6 Mean 3.29 Sigma 9.916 2 2 15 15 1 1 5 5-6 -4-2 2 4 6-6 -4-2 2 4 6 225 2 175 Check quality, e+ e- to W+ W-, 5 19.52 / 14 Constant 2.8 Mean 7.21 Sigma 1.48 25 2 Check quality, e+ e- to W+ W-, 5 31.17 / 14 Constant 23.9 Mean 7.3 Sigma 9.854 15 15 125 1 1 75 5 5 25-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 33 Detector models comparison, 3 Tesla, W+ W-, 5 25 Check quality, e+ e- to W+ W-, 5 3.15 / 14 Constant 24.5 Mean.182 Sigma 1.12 25 Check quality, e+ e- to W+ W-, 5 3.64 / 14 Constant 26. Mean 1.275 Sigma 9.828 2 2 15 15 1 1 5 5-6 -4-2 2 4 6-6 -4-2 2 4 6 25 Check quality, e+ e- to W+ W-, 5 21.56 / 14 Constant 215.8 Mean 6.8 Sigma 9.376 25 Check quality, e+ e- to W+ W-, 5 29.17 / 14 Constant 213.5 Mean 5.985 Sigma 9.444 2 2 15 15 1 1 5 5-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 34 Detector models comparison, 4 Tesla, t tbar, 5 2 175 Check quality, e+ e- to t tbar, 5 18.3 / 14 Constant 174.4 Mean 2.721 Sigma 12.35 2 175 Check quality, e+ e- to t tbar, 5 12.55 / 14 Constant 177.3 Mean 4.18 Sigma 11.88 15 15 125 125 1 1 75 75 5 5 25 25-6 -4-2 2 4 6-6 -4-2 2 4 6 2 175 Check quality, e+ e- to t tbar, 5 11.63 / 14 Constant 171.9 Mean 7.964 Sigma 13.19 2 Check quality, e+ e- to t tbar, 5 19.39 / 14 Constant 174.4 Mean 6.747 Sigma 12.21 175 15 15 125 125 1 1 75 75 5 5 25 25-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 35 Detector models comparison, 3 Tesla, t tbar, 5 2 175 Check quality, e+ e- to t tbar, 5 17.41 / 14 Constant 168.9 Mean 2.417 Sigma 12.8 225 2 175 Check quality, e+ e- to t tbar, 5 15.81 / 14 Constant 174.2 Mean 2.44 Sigma 12.77 15 15 125 125 1 1 75 75 5 5 25 25-6 -4-2 2 4 6-6 -4-2 2 4 6 2 175 Check quality, e+ e- to t tbar, 5 12.2 / 14 Constant 184. Mean 6.526 Sigma 11.62 2 175 Check quality, e+ e- to t tbar, 5 12.77 / 14 Constant 182.3 Mean 5.967 Sigma 11.41 15 15 125 125 1 1 75 75 5 5 25 25-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 36 Detector models comparison, 4 Tesla, t tbar, 36 25 225 2 Check quality, e+ e- to t tbar, 36 13.21 / 18 Constant 217.7 Mean 3.138 Sigma 1.54 25 2 Check quality, e+ e- to t tbar, 36 19.91 / 18 Constant 218.2 Mean 2.85 Sigma 1.4 175 15 15 125 1 1 75 5 5 25-6 -4-2 2 4 6-6 -4-2 2 4 6 25 Check quality, e+ e- to t tbar, 36 28.36 / 18 Constant 224. Mean 5.53 Sigma 1.2 25 Check quality, e+ e- to t tbar, 36 21.95 / 18 Constant 216.7 Mean 4.654 Sigma 1.44 2 2 15 15 1 1 5 5-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26
Abs Calibr 37 Detector models comparison, 3 Tesla, t tbar, 36 25 2 Check quality, e+ e- to t tbar, 36 11.84 / 18 Constant 219.5 Mean 2.244 Sigma 1.36 225 2 Check quality, e+ e- to t tbar, 36 15.37 / 18 Constant 215. Mean 2.289 Sigma 1.73 175 15 15 125 1 1 75 5 5 25-6 -4-2 2 4 6-6 -4-2 2 4 6 25 Check quality, e+ e- to t tbar, 36 16.26 / 18 Constant 218. Mean 5.952 Sigma 1.5 2 Check quality, e+ e- to t tbar, 5 12.77 / 14 Constant 182.3 Mean 5.967 Sigma 11.41 2 175 15 15 125 1 1 75 5 5 25-6 -4-2 2 4 6-6 -4-2 2 4 6 Vasiliy Morgunov LCWS26, Bangalore, India, 9-13 March 26