1 00:00:00,000 --> 00:00:00,570 So 2 00:00:00,570 --> 00:00:02,130 procreate is in adolescent. 3 00:00:02,970 --> 00:00:07,290 Okay, so it started to show for making him have a full stop, but we'll start with 4 00:00:07,290 --> 00:00:11,550 that first and then have CMS on the same topic then. So I'm going to talk about top 5 00:00:11,550 --> 00:00:16,020 properties from from Atlas. So the top graph at the top here cross section at the 6 00:00:16,020 --> 00:00:23,580 LSE is very large, it's 830 Vika barns at 13 gb. So in room two, we've produced over 7 00:00:23,580 --> 00:00:28,380 100 million top 20 top pairs and the ATLAS experiment. This gives us a very large 8 00:00:28,380 --> 00:00:32,760 data set to study for different particle properties of the top, and the production 9 00:00:32,760 --> 00:00:37,230 mechanisms and the decay. So we study all the different parts of the top production, 10 00:00:37,500 --> 00:00:41,400 and the top Quark itself and the top Quark decay, and all the properties of the decay 11 00:00:41,400 --> 00:00:46,110 products as well. So firstly, we have properties related to production. So 12 00:00:46,110 --> 00:00:49,410 obviously, there's a cross section itself and the kinematics of the top and the anti 13 00:00:49,410 --> 00:00:54,330 top system. And for those, they're covered by the top by feature, and then there's 14 00:00:54,330 --> 00:00:58,560 spin correlations, which are induced by the production mechanism. And there's the 15 00:00:58,560 --> 00:01:03,720 charge asymmetry of those The top pair production, the top part polarization and 16 00:01:03,720 --> 00:01:07,920 then flavor changing neutral currents and many more. We then have the fundamental 17 00:01:07,920 --> 00:01:11,910 properties of the top part and which are the mass and the waves and which material 18 00:01:11,910 --> 00:01:16,440 we'll talk about later in the session. And there's a charge and the spin chain 19 00:01:16,440 --> 00:01:21,900 indirect measure. Then we have properties related to the decay of the top Quark, I 20 00:01:21,900 --> 00:01:25,890 mean these are things like the W Felicity measurements, and charge electron flavor 21 00:01:25,890 --> 00:01:29,670 violation and flavor changing neutral currents and various different decay 22 00:01:29,670 --> 00:01:34,590 channels will be talked about by curl, and then jet shaping curl, color flow and 23 00:01:34,590 --> 00:01:40,710 anomalous couplings and some more as well. And then finally, and because we produce w 24 00:01:40,710 --> 00:01:44,190 bosons and top Quark this case, we can look at the properties of the W goes on 25 00:01:44,190 --> 00:01:48,270 itself. And today, one of the analysis I'll talk about is the measurement of the 26 00:01:48,270 --> 00:01:52,620 universality of lepton couplings to W bosons, and looking at the branching 27 00:01:52,620 --> 00:01:58,680 ratios of W's and top events themselves. So there's far too many results to cover 28 00:01:58,710 --> 00:02:03,750 and frontlets say today I focused on three different results. So there's the charge a 29 00:02:03,750 --> 00:02:08,760 symmetry, and then the spin correlations between the top and the anti top. And 30 00:02:08,760 --> 00:02:13,290 there's new CMS Atlas comparison plots for this. And then there's the measurement of 31 00:02:13,290 --> 00:02:18,480 the inverse ality of electron couplings to the W boson. So firstly, the charging 32 00:02:18,480 --> 00:02:23,640 symmetry. So at leading order and you expect the Tiki Bar production is charged 33 00:02:23,640 --> 00:02:28,200 symmetric as a proton proton Collider. However, on higher orders, you get 34 00:02:28,200 --> 00:02:32,640 interference effects in the Quark glue on the Quark counterpart channels, and also 35 00:02:32,640 --> 00:02:38,430 electric contributions can lead to asymmetries. And so the main production 36 00:02:38,430 --> 00:02:43,290 diagram is shown on the left here and for Q bar production where you get a deal and 37 00:02:43,290 --> 00:02:47,700 on the S channel and then Tiki Bar and but there's also a box diagram and then when 38 00:02:47,700 --> 00:02:53,160 these interfere, you get a charging symmetry, and also the SMT physics can 39 00:02:53,160 --> 00:02:56,880 lead to large enhancements, and which makes this particularly interesting when 40 00:02:56,880 --> 00:02:59,970 you do it as a function of kinematic variables such as the mass of the teacher. 41 00:03:00,000 --> 00:03:05,850 Our system the glue and glue and process remains charged symmetric to all orders. 42 00:03:05,880 --> 00:03:10,800 And this is the dominant production mechanism overall. So this dilutes the 43 00:03:10,800 --> 00:03:16,800 asymmetry significantly. And the quantity we try to measure is called AC. And so 44 00:03:16,800 --> 00:03:21,810 this is the number of the fraction of the time basically, where you have a top 45 00:03:21,810 --> 00:03:26,040 that's more forward from the ante top minus the number of times you get the 46 00:03:26,040 --> 00:03:30,390 answer top more forward from the top divided by that the total sets the 47 00:03:30,780 --> 00:03:37,110 essentially the fraction of times you get top more forward. And and positive values 48 00:03:37,110 --> 00:03:41,370 indicate that the top is more forwards on the top which is what we expect. So not to 49 00:03:41,370 --> 00:03:45,870 scale this is what we kind of expect you expect to see a slightly more and narrow 50 00:03:45,900 --> 00:03:49,710 empty top into distribution the top and therefore you get a slightly positive 51 00:03:49,710 --> 00:03:57,180 value of AC. The analysis as I mentioned, is done in different kinematic regions as 52 00:03:57,180 --> 00:04:02,580 well as inclusively. And so first There's a result analysis where boosted events are 53 00:04:02,580 --> 00:04:07,350 removed. And a BDT is used to assign the different checks to the two top systems, 54 00:04:07,560 --> 00:04:11,610 including Cale Fisher as a massive fan tronic top and W in various Angular 55 00:04:11,610 --> 00:04:15,840 variables to assign different jets to different top to the top and the anti top 56 00:04:15,840 --> 00:04:19,110 such that both the top and the anti top can be reconstructed and then they're 57 00:04:19,350 --> 00:04:24,120 calculated. The best combination is used and only events of good reconstruction 58 00:04:24,120 --> 00:04:25,980 according to the BDT which are attained. 59 00:04:27,240 --> 00:04:30,930 Secondly, there's this boosted channel which gives access to the highest kinetic 60 00:04:30,930 --> 00:04:36,420 regions particularly an empty bar and a high PT and the hydronic top so we're 61 00:04:36,420 --> 00:04:40,170 looking in some electronic events one electronic components are drawn. The 62 00:04:40,170 --> 00:04:45,150 hydronic top can be reconstructed with a single large radius jet and we require the 63 00:04:45,150 --> 00:04:51,150 PTS to be greater than 350 gV. We then use two variables the mass of the jet to 64 00:04:51,150 --> 00:04:55,710 distinguish it from HD and also this variable called tau three, two and a nice 65 00:04:55,710 --> 00:05:00,330 to flop show. Okay, three, two in a QC DJ selection on the right hand side And you 66 00:05:00,330 --> 00:05:05,520 can see that it peaked at high values. And then enter Tiki Bar and booster jet 67 00:05:05,520 --> 00:05:09,450 selection on the left hand side where you can see the white which is the Tiki Bar 68 00:05:09,450 --> 00:05:14,220 component has a large tail to low values of totally unusual events that you'd 69 00:05:14,220 --> 00:05:19,950 select using this tagging of hardrock tops for the electronic side and you can use 70 00:05:19,950 --> 00:05:23,850 the ETS and the leptons and an R equals naught point fortune to reconstruct the 71 00:05:23,850 --> 00:05:30,750 top under the assumption that the W is on show. So, results are presented for an 72 00:05:30,750 --> 00:05:35,880 inclusive volume AC and we find not not not sex with an error of not point naught 73 00:05:35,880 --> 00:05:40,680 naught one five and this is for sigma from zero. So this is first evidence of non 74 00:05:40,680 --> 00:05:47,370 zero charge asymmetry in Tiki Bar. A PP collider is in good agreement with an nll 75 00:05:47,370 --> 00:05:54,510 calculation. And additionally, we unfold into bins in in the mass of the TT bar 76 00:05:54,510 --> 00:05:59,040 system and also in the longitudinal boost of the TT bar system. So these two blocks 77 00:05:59,040 --> 00:06:04,140 here, the left hand block Gerry's AC on the y axis as a function of five different 78 00:06:04,140 --> 00:06:09,360 variants of the mass of the Tiki Bar system. And you can see the asymmetry grow 79 00:06:09,360 --> 00:06:13,800 slightly as you move to higher tiki bar and the green is the next next leading 80 00:06:13,800 --> 00:06:18,900 order prediction plus another one electroweak and the data agrees Well, the 81 00:06:18,900 --> 00:06:21,750 right hand block says the same thing, but because along the tutorial groups and 82 00:06:21,750 --> 00:06:26,580 again for the Korean to see. So, having seen good agreement with the standard 83 00:06:26,580 --> 00:06:31,380 model, we go to set limits in an effective field theory and based on both the 84 00:06:31,380 --> 00:06:38,430 inclusive and the left hand side plot here and so, now you should see the variable C 85 00:06:38,490 --> 00:06:42,750 and which is one of the linear combination of the Wilson coefficients and which 86 00:06:42,750 --> 00:06:49,800 affect the charge a symmetry under a flavor symmetric couplings scenario and 87 00:06:49,800 --> 00:06:55,830 you can see near the just you can see at the bottom to previous results and then 88 00:06:55,830 --> 00:07:00,510 the inclusive results and then the different MTT bargains included Results 89 00:07:00,510 --> 00:07:06,870 provide very strong limits as to the 1000 to 1500 gd, then and higher volumes of 90 00:07:06,870 --> 00:07:13,830 mats we start to run up statistics and lower volumes or lessons. Moving on to 91 00:07:13,830 --> 00:07:18,240 spin correlations. The standard model predicts the top Quark pair should be 92 00:07:18,240 --> 00:07:21,750 produced without polarization, but with some correlation between their spin 93 00:07:21,750 --> 00:07:26,640 states. As the top part lifetime is much shorter than the spin D correlation time 94 00:07:26,640 --> 00:07:31,680 the spin information is directly transferred to the decay products. And the 95 00:07:31,680 --> 00:07:36,690 analysis done with a simple electronic Tiki Bar selection requiring one electron 96 00:07:36,690 --> 00:07:41,730 one neuron and greater than one greater than or equal to one reject. And we then 97 00:07:41,730 --> 00:07:45,750 look at the angle between the leptons in both eater and phi, but delta phi is the 98 00:07:45,750 --> 00:07:50,250 most sensitive. And this is sensitive to the spin correlations and this is seen in 99 00:07:50,250 --> 00:07:55,740 this plot. And so if we just look at the two lines, the blue and the red line, so 100 00:07:55,740 --> 00:07:59,580 the red line shows the delta phi distribution that you'd expect if you had 101 00:07:59,580 --> 00:08:05,040 noticed correlations between the top and the anti top. And the blue line shows if 102 00:08:05,040 --> 00:08:10,620 you had the standard model and correlation between the two. And so, you can see that 103 00:08:10,620 --> 00:08:16,470 this variable is highly sensitive to the spin correlations. So results are unfolded 104 00:08:16,500 --> 00:08:21,210 to both parts on level and also particle level distributions are really leading 105 00:08:21,210 --> 00:08:24,210 uncertainties on the inclusive measurements come from generator modeling, 106 00:08:24,270 --> 00:08:28,890 mainly radiation and scale. The data didn't show slightly higher spin 107 00:08:28,890 --> 00:08:33,120 correlations on the predictions, and this is quantified by fitting templates of the 108 00:08:33,120 --> 00:08:40,290 fraction of the Standard Model spin correlation, and one minus by a fraction 109 00:08:40,290 --> 00:08:44,790 of the Standard Model correlation and no correlation and using the perfect next 110 00:08:44,790 --> 00:08:50,610 leading order prediction, and we get about 25% more correlation than we'd expect in 111 00:08:50,610 --> 00:08:56,130 the standard model using this thing. So this is the distribution of the delta phi 112 00:08:56,130 --> 00:09:01,020 that's been unfolded normalized cross section on the left hand side You can see 113 00:09:01,020 --> 00:09:05,700 that the data is consistently high at low values of delta phi and consistently low 114 00:09:06,030 --> 00:09:09,210 at high values of delta phi showing a slightly stronger correlation in the 115 00:09:09,210 --> 00:09:13,380 spins. And then the predicted by the next leading order Monte Carlo shown in this 116 00:09:13,380 --> 00:09:13,680 plot 117 00:09:15,150 --> 00:09:19,350 the right hand plot and shows the same thing. So it's the ratio to power a 118 00:09:19,350 --> 00:09:25,110 Bezier. And on the y axis, and the data is the same as the left hand plot. But this 119 00:09:25,110 --> 00:09:29,130 time, we've added in a next to next leading order prediction. And you can see 120 00:09:29,130 --> 00:09:34,740 that some of the, the discrepancy is reduced, but it's not entirely solved by 121 00:09:34,740 --> 00:09:40,950 this and there's work on going on more accurate calculations and comparisons and 122 00:09:40,950 --> 00:09:47,790 to the theory in this area. So as a discrepancy was seen, and this is not 123 00:09:47,910 --> 00:09:52,530 completely understood. And it's interesting to compare to see if CMS see 124 00:09:52,530 --> 00:09:57,270 the same thing. So CMS has also produced measurements of the delta phi distribution 125 00:09:57,270 --> 00:10:03,780 from 2015 and 2016. And you can see on these blocks and red, there's the CMS 126 00:10:03,780 --> 00:10:09,660 data. And in blue, there's the Atlas data. And you can see that the CMS and the Atlas 127 00:10:09,660 --> 00:10:15,540 data agree very well. And we also check that the two simulations that we use agree 128 00:10:15,540 --> 00:10:19,890 very well, and these two as well. And so we've produced, these are not 129 00:10:19,890 --> 00:10:23,850 combinations, but these are more comparisons, showing that the two, the two 130 00:10:23,850 --> 00:10:29,730 collaborations are producing very similar results in these distributions. Moving on 131 00:10:29,730 --> 00:10:35,370 to the third analysis, and this is the electron universality in w two leptons in 132 00:10:35,370 --> 00:10:40,530 TT parlance. So the universality of the coupling of the different generations of 133 00:10:40,530 --> 00:10:45,390 leptons to the gauge bosons is the fundamental axiom of a standard model. The 134 00:10:45,390 --> 00:10:49,440 large number of Tiki Bar events produced at the LSE give us an excellent sample of 135 00:10:49,440 --> 00:10:55,260 W bosons to test this. So this analysis looks to measure the ratio of the 136 00:10:55,260 --> 00:11:01,140 branching ratio of W's to toes divided by the branching ratio of W's to means And 137 00:11:01,140 --> 00:11:06,240 the motivation for this is that we want to test this fundamental axiom, but also that 138 00:11:06,270 --> 00:11:12,450 in previous measurements and discrepancy has been observed. So, the left and four 139 00:11:12,450 --> 00:11:16,950 experiments did a combination of their different results and their combined value 140 00:11:16,950 --> 00:11:23,640 is 2.7 sigma Hi, in this in this in this body. So this plot here shows a comparison 141 00:11:23,640 --> 00:11:27,900 of different previous experiments measurements. So, the bottom panel plot 142 00:11:27,900 --> 00:11:32,490 shows who retires divided by the least means, the middle panel who retires 143 00:11:32,490 --> 00:11:37,140 divided by w two electrons, and the left points in red show high for both of these. 144 00:11:37,890 --> 00:11:42,450 And the top panel shows and whether a much more accurate measurements that ratio of 145 00:11:42,450 --> 00:11:49,860 the two light laptop generations and there's now Atlas and ALEKS TV and lab 146 00:11:49,860 --> 00:11:55,080 results and ch CDF or have a very high precision here. So, this is generally 147 00:11:55,080 --> 00:11:55,440 Well, 148 00:11:56,069 --> 00:11:57,029 Mark better understood 149 00:11:58,680 --> 00:12:03,780 So, events are selected and with the Thai jets and electrons, and this is triggered 150 00:12:03,780 --> 00:12:09,390 by an electron or Mian. And with a second leptons, which is always a meal, the 151 00:12:09,390 --> 00:12:14,070 branching ratio of times to neurons is very well known so that we can easily 152 00:12:14,070 --> 00:12:19,080 extrapolate from the number of events where we see a W going to a time going to 153 00:12:19,080 --> 00:12:24,540 a Mian and divided by the dope branching ratio of W straight to me ons to the 154 00:12:24,540 --> 00:12:29,040 branching rate to the quantity we're interested in, we're w k times divided by 155 00:12:29,040 --> 00:12:35,640 w, because the the second part of this sophistication is very well known. So 156 00:12:35,640 --> 00:12:39,480 events with new ones from time to case are distinguished but those were the mediums 157 00:12:39,480 --> 00:12:44,910 are produced directly from the W by their softer PT spectrum and the displacement of 158 00:12:44,910 --> 00:12:48,210 the decay. And the displacement is characterized through the transverse 159 00:12:48,210 --> 00:12:52,710 distance of closest approach to the track and which is d zero. So this plot here 160 00:12:52,710 --> 00:12:58,440 shows the zero and millimeters on the x axis and the events and you can see in 161 00:12:58,560 --> 00:13:03,630 light green In the case where they have a prompt neon, Adobe, neon coming directly 162 00:13:03,630 --> 00:13:08,220 from Adobe, and then dark green we have where the tires that came to me obviously 163 00:13:08,220 --> 00:13:13,020 we have a W two. You can see there's a clear distinction between the two the two 164 00:13:13,020 --> 00:13:18,780 cases. to model this distribution well the D zero distribution for the prompt me on 165 00:13:18,780 --> 00:13:22,830 just taken from templates created from said to die new events and so you have 166 00:13:22,830 --> 00:13:27,510 prompt new ones that decays and therefore you can take the distributions from data. 167 00:13:28,320 --> 00:13:32,040 And the distribution for nonprofit beyond service immune from tires and wheels from 168 00:13:32,040 --> 00:13:36,090 heavy hug on the case is corrected for using the measure of resolution of t zero 169 00:13:36,390 --> 00:13:37,410 in the same selection. 170 00:13:38,520 --> 00:13:39,990 You have two minutes. 171 00:13:40,260 --> 00:13:44,490 Yep. So the main backgrounds to the analysis are said to dine yawns plus 172 00:13:44,490 --> 00:13:49,080 Jetsam the diamond on channel and we will indicate a nuance from hadron to case. And 173 00:13:49,080 --> 00:13:53,790 so for the diamond background effect of the diamond and the mass spectrum is used 174 00:13:53,790 --> 00:13:59,040 to normalize this background with the same check requirements and for the new ones 175 00:13:59,040 --> 00:14:03,840 from hadron the case. Same sign and chart selection is used to normalize the 176 00:14:03,840 --> 00:14:08,010 background of neurons from hadron the case. And and then a simulation is used to 177 00:14:08,010 --> 00:14:12,060 extrapolate from the same sign to the different sign and selections. And the 178 00:14:12,060 --> 00:14:15,900 right hand block shown here shows the same sign selection of this D zero variable 179 00:14:16,110 --> 00:14:21,780 showing that as well model in the same time region. effect is then performed in 180 00:14:21,780 --> 00:14:27,060 three bins and PT and multiplied by eight bins and D zero and the two channels so 181 00:14:27,060 --> 00:14:32,160 it's a tag electron or a type neuron and an appropriate arms in both cases. Good 182 00:14:32,160 --> 00:14:35,250 agreement is seen in the fitted distributions and you can see four of the 183 00:14:35,250 --> 00:14:43,800 PT bands here. And whereas is that to to lower PT ones on the top panel and then to 184 00:14:43,800 --> 00:14:49,980 higher PT ones on the bottom panel and a new channels and new channels. The fitted 185 00:14:49,980 --> 00:14:58,410 value of r is found to be naught point nine nine to plus or minus 1.3%. And so 186 00:14:58,410 --> 00:15:03,690 this is in good agreement with one is the most precise measurement to date by a 187 00:15:03,690 --> 00:15:08,070 factor of two. And it's after the error of the of the lead measurement and the 188 00:15:08,070 --> 00:15:13,230 Standard Model seems to prevail. So now we can look at look at our universality plot 189 00:15:13,230 --> 00:15:17,460 again. And we can see in the bottom panel, we now have our new Atlas results, sitting 190 00:15:17,460 --> 00:15:23,520 sitting nicely on one, and showing that the Standard Model postulation of equal 191 00:15:23,520 --> 00:15:26,370 couplings seems to work well. And then 192 00:15:28,470 --> 00:15:30,600 the old results as well, so shown from this book. 193 00:15:32,400 --> 00:15:36,180 So in conclusion, Atlas has measured many different properties of top quarks, and 194 00:15:36,180 --> 00:15:41,250 now w Verizon's and Tiki Bar lamps. We've heard many different kinematic and 195 00:15:41,250 --> 00:15:45,600 fundamental properties in the sector. And so far that standard model has described 196 00:15:45,600 --> 00:15:49,800 the data extremely well. More results with the wrong two data sets are in the 197 00:15:49,800 --> 00:15:54,930 pipeline, and wrong three and beyond promise even larger data sets. And so 198 00:15:54,930 --> 00:15:59,640 there's many more exciting top physics results still to come. And then As with 199 00:15:59,640 --> 00:16:04,680 the previous Speaker I've set up a private Zoom Room in case there are more detailed 200 00:16:04,680 --> 00:16:06,510 questions at the end of the session. 201 00:16:09,360 --> 00:16:11,880 A lot, Chris, any questions? 202 00:16:19,980 --> 00:16:23,490 Ask one quick curiosity question. 203 00:16:26,670 --> 00:16:34,350 If you go to slide 15, you didn't mentioned you estimate volumes that come 204 00:16:34,350 --> 00:16:40,470 from attorney case. But I was wondering whether how much of your sensitivity Yeah, 205 00:16:40,470 --> 00:16:47,250 if you go to previous slide still 15 Yeah. How much of this STP comes from the last 206 00:16:47,250 --> 00:16:51,480 thing because you seem to either run out of statistics predict your background in 207 00:16:51,480 --> 00:17:00,810 the last thing for me. And I would increase to expect that it's not So 208 00:17:00,810 --> 00:17:07,380 quickly diminishing because, you know, these are heavy flavored decays, and they 209 00:17:07,380 --> 00:17:08,520 would have large impact. 210 00:17:11,460 --> 00:17:13,680 In the next slide, a data driven 211 00:17:17,279 --> 00:17:24,209 Yes, so this plot here is the high PT Ben. So maybe if I go to slide 17, then we see 212 00:17:24,239 --> 00:17:30,089 the middle and high PT ranges. And so the top plots here show 10 to 20, gv, and then 213 00:17:30,089 --> 00:17:35,879 the bottom flops are higher than 20 gV. So the hadron decay background is mostly 214 00:17:35,879 --> 00:17:40,109 important at low PT and it becomes increasingly less significant as you move 215 00:17:40,109 --> 00:17:44,369 to high PT and then you end up simply running out of statistics and the towers 216 00:17:44,369 --> 00:17:49,829 and that becomes the the uncertainty. And so the hadron decay background is very 217 00:17:49,829 --> 00:17:54,509 important and it's particularly important in the five to 10 gV benefit chain, which 218 00:17:54,509 --> 00:17:59,099 I don't show here. And in those cases, we do have statistics open to the Heidi zero 219 00:17:59,099 --> 00:18:05,099 tell and we can that both the simulation and the simulation is modeling the shape 220 00:18:05,099 --> 00:18:10,319 of this right and we can normalize the distribution in our control regions in 221 00:18:10,319 --> 00:18:10,799 this case. 222 00:18:13,139 --> 00:18:13,829 Okay, thank you. 223 00:18:18,180 --> 00:18:19,980 Any other agent question? 224 00:18:24,150 --> 00:18:26,880 If not, let's thank Chris again.