1 00:00:00,299 --> 00:00:05,399 Okay, so I will just give you a brief report on the most recent multiple, 2 00:00:05,429 --> 00:00:11,249 multiple measurements done by CMS experiment. myself with that, just a very 3 00:00:11,249 --> 00:00:16,499 brief introduction. Before I go into more details of the two most recent multi 4 00:00:16,499 --> 00:00:22,169 button analyses performed by CMS, which are the W plus W minus and they try both 5 00:00:22,169 --> 00:00:28,949 and analysis, I will not talk about vector scattering in this talk. So, if you're 6 00:00:28,949 --> 00:00:36,179 interested in that, you can follow Mario talk on Friday afternoon. So, just a brief 7 00:00:36,179 --> 00:00:40,349 introduction and motivation while it's important to perform multiple 8 00:00:40,379 --> 00:00:46,349 measurements, while the normal structure of the standard model allows for 9 00:00:46,979 --> 00:00:52,289 interrupts telling directionality vector by zone, which can be principal triple and 10 00:00:52,289 --> 00:00:58,169 courting any number of zones to connect it to the vertex and a procedural measurement 11 00:00:58,199 --> 00:01:04,019 of the strength of this coupling is You put on tests of the electric sector from 12 00:01:04,019 --> 00:01:11,279 the model itself. Moreover, as we already are in the previous talks, the indirect 13 00:01:11,279 --> 00:01:17,219 sales for new features can be performed with these analogies because if we see a 14 00:01:17,549 --> 00:01:21,779 difference between the predicted cabling and what we measure which which which we 15 00:01:21,779 --> 00:01:26,549 call anomalous coupling, could hint to the prevalence of new physics. Another 16 00:01:26,549 --> 00:01:32,039 important motivation to do these analogies, of course, that many multiples 17 00:01:32,039 --> 00:01:38,429 on prophecies, actually backgrounds in the study of new physics, or for example, in 18 00:01:38,879 --> 00:01:46,439 exit searches how these measurements are very challenging because as you can see 19 00:01:46,439 --> 00:01:52,619 from the blog, the cross section four is processing very low, generally smaller 20 00:01:52,619 --> 00:01:58,859 than peak about what to say. And so this is why we need to use the full power of 21 00:01:58,859 --> 00:02:05,639 the full CMS atlases around two statistics, which is about 114% of them. 22 00:02:06,569 --> 00:02:12,149 These are complex final state, because we have a higher high particle multiplicity. 23 00:02:12,179 --> 00:02:17,279 And as I said before, these are high precision measurements. So we need to have 24 00:02:17,279 --> 00:02:23,969 a good control on detector effects, kill factors and so on to the precision 25 00:02:23,969 --> 00:02:29,639 measurements that we really want to the basic idea of all the analysis is to 26 00:02:29,639 --> 00:02:35,279 measure the critical section, and hopefully find in our significant seven 27 00:02:35,279 --> 00:02:40,379 evidence for an observation of prophecies that have never been mentioned before. So, 28 00:02:40,799 --> 00:02:46,109 I will now talk about the first one to focus on which is the W plus W minus 29 00:02:46,109 --> 00:02:52,319 analysis which has been published by CMS experiments using the data collected in 30 00:02:52,319 --> 00:02:58,319 2016. So disease, an important background source in searches for new particles but 31 00:02:58,319 --> 00:03:06,539 also, for example, indicating to WW. The production comes mainly from tiki bar or 32 00:03:06,959 --> 00:03:13,229 intrusion if you consider higher order interactions. And this analysis has been 33 00:03:13,229 --> 00:03:17,279 performed by CMS following two different approaches. One which is the sequential 34 00:03:17,279 --> 00:03:21,989 cap one, which is let's say the usual way to do the analysis, and the other one that 35 00:03:22,019 --> 00:03:26,639 exploits a random forest classifier and I will show you why these two approaches 36 00:03:27,209 --> 00:03:33,869 somewhat somewhat complimentary and why they can be different results. In the 37 00:03:33,869 --> 00:03:38,609 sequential exceptionalities. The selection is pretty much the standard one. He wants 38 00:03:38,609 --> 00:03:42,599 to opposite charges related electronic work since you have to do both on the cane 39 00:03:42,989 --> 00:03:47,129 and you want a trunk does not make a big transformation coming from the neutrinos. 40 00:03:47,999 --> 00:03:55,229 The two main backgrounds come from Julian and teba are single top events. And as 41 00:03:55,229 --> 00:04:00,539 usual, the single topic toolbar can be reduced by providing a beachhead laser 42 00:04:00,869 --> 00:04:07,769 lights will Ditalion background and will be used to discriminate between signal and 43 00:04:07,769 --> 00:04:14,579 background. As I said before, the analysis used is also another approach which is the 44 00:04:14,579 --> 00:04:19,499 one of the run the first classifier. And random forest classifier is basically an 45 00:04:19,499 --> 00:04:27,179 aggregate of boosting decision trees which each percentage entry does not use the 46 00:04:27,179 --> 00:04:33,539 whole set of kinematic parameters, but a subset of them. And in this way the 47 00:04:33,539 --> 00:04:39,059 overall results that it is you can get from all the trees together mitigates the 48 00:04:39,059 --> 00:04:43,409 problem of overfitting. You can every single BDT 49 00:04:45,180 --> 00:04:50,310 as before, it would mean backgrounds. Jolyon and tiki bar to run the first 50 00:04:50,310 --> 00:04:54,660 classifier and been built for this analysis. And as you can see from the 51 00:04:54,660 --> 00:04:59,970 blocks on the bottom left in the single region, which is the one in the orange box 52 00:05:00,000 --> 00:05:07,080 So, you have a very high contribution from WWF signal and a very low contribution of 53 00:05:07,080 --> 00:05:12,090 the Tiki Bar and this is after applying both the score of the random forest 54 00:05:12,090 --> 00:05:19,470 classifier for the Julian and for the top backgrounds. It has been shown that the 55 00:05:19,470 --> 00:05:24,360 random forest classifier analysis as a signal efficiency impurity higher is 56 00:05:24,360 --> 00:05:32,040 compared to the center frequency counts anomalies. The backgrounds are the Tiki 57 00:05:32,040 --> 00:05:37,050 Bar, the tread yacht and also the non prom events which are basically from these 58 00:05:37,050 --> 00:05:43,980 analogies w plus Jessica and when one where one jet is reconstructed as electron 59 00:05:44,460 --> 00:05:50,130 will not go into high detail, but basically for all of these contour contour 60 00:05:50,130 --> 00:05:56,130 regions built in both the sequential account or random forest and these 61 00:05:56,130 --> 00:06:00,720 backgrounds are obtained by normalizing the contribution in the Conservation 62 00:06:00,720 --> 00:06:07,140 before estimate what is the contribution in the signal region. This is semantics 63 00:06:07,170 --> 00:06:12,570 the telephone for the sequential caption you can see on the table below the 64 00:06:13,230 --> 00:06:17,340 greatest uncertainty comes from the analyzation of the backgrounds. So, this 65 00:06:17,340 --> 00:06:22,380 is the most delicate part of the analysis, while there is also a contribution from 66 00:06:22,380 --> 00:06:28,290 the theoretical side coming from mainly from Halo the QED calculation of 67 00:06:28,290 --> 00:06:32,730 certainty, the total systematic efficient is about 6% while the statistical one is 68 00:06:32,730 --> 00:06:42,540 1%. So, this is a systematic dominated analysis. So, the first measurements that 69 00:06:42,540 --> 00:06:46,200 came out from this analysis is the measurement of the topic resection with 70 00:06:46,230 --> 00:06:52,290 the two different methods. So, from the sequential data analysis, all the 71 00:06:52,290 --> 00:06:58,200 different possible channels are studying separately and then put it all together 72 00:06:58,530 --> 00:07:03,900 where you can see The signal strength are measured separately for Vito jet one jet 73 00:07:04,050 --> 00:07:08,820 sync same flavor or differently or channels and all the signal strength and 74 00:07:08,820 --> 00:07:13,920 in agreement with each other with one face or with the Standard Model prediction and 75 00:07:13,950 --> 00:07:18,900 this proves that there was a good consistency of the model and the overall 76 00:07:19,170 --> 00:07:24,330 cross section is in agreement with the theoretical prediction. random forest 77 00:07:24,330 --> 00:07:32,970 classifier is more sensitive to their weighting of the debug on spectrum tables 78 00:07:32,970 --> 00:07:37,830 in terms of momentum spectrum that is used to take into account higher the QC D 79 00:07:37,830 --> 00:07:44,880 calculation. And as a result, these sensitivity to this correction is what you 80 00:07:44,880 --> 00:07:51,060 can see in the plot, which is that random forest classifier as a higher efficiency 81 00:07:51,210 --> 00:07:58,470 at the low values of the momentum offers a voting system and this means that it is 82 00:07:58,470 --> 00:08:06,090 more sensitive to Jessie banks and this is why the devalue the central value of the 83 00:08:06,090 --> 00:08:11,580 measured cross sectionally leaking the differential prior to the sequential 84 00:08:11,610 --> 00:08:16,380 Katelyn, it has taken to be taken into account that also this radical uncertainty 85 00:08:16,380 --> 00:08:23,100 entire situation for the same reason for these analogies, also the new show and 86 00:08:23,100 --> 00:08:26,280 differentiate perfection and be measured and these numbers are just there for 87 00:08:26,280 --> 00:08:30,990 reference. And as you can see from the prop on the top right, there is a very 88 00:08:30,990 --> 00:08:34,260 good agreement. For example, this is differential perfection in the dialect in 89 00:08:34,260 --> 00:08:38,970 math, there is a very good agreement between data and simulation. And the 90 00:08:38,970 --> 00:08:44,340 random forest classifier allows a lot over to the measurement of just multiplicity. 91 00:08:44,670 --> 00:08:48,630 And it is very important because it's a probe of theoretical calculation that 92 00:08:48,870 --> 00:08:55,530 ultimately go into the event generator. And so it's important to know how the just 93 00:08:55,530 --> 00:09:00,780 multiplicity is precisely and as you can see from the block on the bottom left Also 94 00:09:00,780 --> 00:09:07,020 you're going to live by the computer simulation and the data and the lasting 95 00:09:07,020 --> 00:09:12,900 results with analysis also, believe it or not most coupling have been measured. And 96 00:09:12,960 --> 00:09:19,620 as you can see from the block the highest sensitivity is the highest value of the 97 00:09:19,620 --> 00:09:22,890 time with myself today electrons and 98 00:09:24,360 --> 00:09:29,940 limits on triple gauge Captain are measured for the values because at the one 99 00:09:29,940 --> 00:09:35,940 presented on the Fineman diagram, and the plus on the left represent a scam when 100 00:09:35,940 --> 00:09:40,980 you, Barney, just one parameter or capital of them together. And the table on the 101 00:09:40,980 --> 00:09:45,900 bottom presented the results obtained by this analysis for the limits on the 102 00:09:45,900 --> 00:09:52,800 anomalous capital. We talked about about the other analysis. That is the most 103 00:09:52,800 --> 00:09:57,930 recent one we published, which is the tribalism analysis that is done with the 104 00:09:57,930 --> 00:10:03,630 fool around to that effect. The goal of these analogies was to measure both the 105 00:10:03,630 --> 00:10:09,030 inclusive tribalism production protection and the the single line for the all the 106 00:10:09,030 --> 00:10:15,930 different processes. So, types mainly, yes, thank you. Mainly There are of 107 00:10:15,930 --> 00:10:23,970 course, all the possible combination of W's and D and the w w w production has 108 00:10:23,970 --> 00:10:29,040 been divided into two channels depending on the chain. So if two of the W SDK 109 00:10:29,040 --> 00:10:35,340 electronically one and radically or all three of them decay electronically, and 110 00:10:35,340 --> 00:10:39,990 for the flexion. The main backgrounds come from what is called the last lesson. So 111 00:10:40,020 --> 00:10:44,970 three lesson processes, where one lesson is not ever constructed for exception or 112 00:10:44,970 --> 00:10:51,540 efficiency problems, and the non prompter background that I already described, while 113 00:10:52,020 --> 00:10:58,470 on the processes where at least one debit spread in the background is lower, because 114 00:10:58,470 --> 00:11:04,560 it's possible to constrain The simpler approach to electron mass within the value 115 00:11:04,560 --> 00:11:11,340 of the set mass and basically on the WWE channel that main backbone comes from that 116 00:11:11,340 --> 00:11:16,650 production while on the other two channels the backs on each individual even though 117 00:11:16,950 --> 00:11:22,530 the cross section and rushing ratio for these processes are very, very low. So, as 118 00:11:22,530 --> 00:11:27,120 I said before, you know complex from background is one of the main sources and 119 00:11:27,120 --> 00:11:35,700 has been estimated from data to boosting decision trees have been used to better 120 00:11:35,700 --> 00:11:41,310 discriminate between signal and background. And for example, in www and 121 00:11:41,310 --> 00:11:47,010 actually this one was a decision tree is used to enhance the discrimination between 122 00:11:47,010 --> 00:11:52,770 signal and non from background and one for all the other backgrounds. And you can see 123 00:11:52,770 --> 00:11:56,820 the result of the BDP score on the plot on the bottom left you can see that in the 124 00:11:56,820 --> 00:12:03,210 signal region, there is a higher signal to noise ratio was for the full electron 125 00:12:03,840 --> 00:12:08,640 factory, the main background contribution comes from the dead end. Of course 126 00:12:08,640 --> 00:12:12,900 background especially in the case where it's well known that electrons are 127 00:12:12,960 --> 00:12:18,360 opposite side fine. And as you can see from the plot of the transistor, the 128 00:12:18,360 --> 00:12:24,210 mission transfers momentum. This is a good viable where place a cap to get a higher 129 00:12:24,750 --> 00:12:29,460 sensitivity to the signal. They may systematic uncertainty as for the previous 130 00:12:29,460 --> 00:12:34,080 analysis come from the background estimation and the limited statistics in 131 00:12:34,080 --> 00:12:41,970 the control region estimation. This is the results of the analysis but there's a lot 132 00:12:41,970 --> 00:12:49,290 of information. But basically this is these are all the categories for all the 133 00:12:49,290 --> 00:12:54,990 different channels and the decay and the decay mode or all of them. And as you can 134 00:12:54,990 --> 00:13:02,610 see, there are some channels that have a very high significance that is The plot in 135 00:13:02,610 --> 00:13:07,980 the middle the brownish one. And as I said before, the main background for the www 136 00:13:07,980 --> 00:13:13,680 channel comes from the last lesson, while for the WWE that comes from the 137 00:13:14,520 --> 00:13:18,270 background, you can see that there are many channels where the sensitivity is 138 00:13:18,270 --> 00:13:25,620 very high to the presence of these presence of these processes. So, these are 139 00:13:25,620 --> 00:13:30,840 the results of this analysis, all the production as we mentioned, and you can 140 00:13:30,840 --> 00:13:34,770 see them on the table on the left and so, both the 141 00:13:36,059 --> 00:13:41,459 signal cross section and the big red one, and they are in agreement with the 142 00:13:41,849 --> 00:13:47,429 Standard Model prediction. And you can see on the table on the bottom right, what is 143 00:13:47,429 --> 00:13:51,269 the significance of obtaining with the two different methods for getting counts and 144 00:13:51,269 --> 00:13:55,709 the boosting decision tree. And you see that usually that was the decision to 145 00:13:55,739 --> 00:14:00,119 hire. I think music as compared to the cutting count one and another thing The 146 00:14:00,119 --> 00:14:06,119 test to be noticed is that the sensitivity for a company www Chanel is much higher 147 00:14:06,119 --> 00:14:10,079 when using the full run to that effect, it has been done for this analysis compared 148 00:14:10,079 --> 00:14:17,639 to the 2016 only data Finally, going to add slightly older analysis which is the 149 00:14:17,639 --> 00:14:24,089 www analysis potential statistics 16 with turning 16 data Sorry, I wanted to include 150 00:14:24,089 --> 00:14:29,909 this because besides the limits on almost cabling, it started also the craving of a 151 00:14:30,449 --> 00:14:35,009 possible action like political production in associate in association with the W 152 00:14:35,009 --> 00:14:38,909 boson, which is another thing that can be done in multiple alizee cities, which is 153 00:14:39,029 --> 00:14:43,709 test precise models. And as you can see from the Brazilian plot on the bottom 154 00:14:43,709 --> 00:14:48,389 right, these production the progress of this particular has been included up to 155 00:14:48,389 --> 00:14:55,709 480 gb approximately. So, this is my summary. With the LLC run to data 156 00:14:56,609 --> 00:15:02,009 properties are accessible even though they are rayar the perfection of the measure 157 00:15:02,009 --> 00:15:06,539 for many processes, not just the two represented here, but for many others, and 158 00:15:06,539 --> 00:15:10,619 the limits on the animal's capital is becoming more and more stringent. Also, in 159 00:15:10,619 --> 00:15:16,469 the better buttons capturing processes, some efficient models can be tested. And 160 00:15:16,469 --> 00:15:22,709 also another thing is that information of prophecy that critical level, for example, 161 00:15:22,709 --> 00:15:27,689 they want to prevent obesity can be extracted from the internet. Thank you. 162 00:15:29,639 --> 00:15:33,239 Thank you, Alison, for this very 163 00:15:34,620 --> 00:15:38,100 concise summary. So we have time for some questions. 164 00:15:43,799 --> 00:15:45,749 Are the question on page 11? 165 00:15:48,450 --> 00:15:48,960 Yes, 166 00:15:49,830 --> 00:15:55,290 so it's not your villain talking. So here's what you have on the top, top left, 167 00:15:55,290 --> 00:16:01,140 you have the signature where you have to send sign leptons and then To neutrino to 168 00:16:01,140 --> 00:16:09,210 jets. So actually this final status exactly vector wasn't catalysts inside. So 169 00:16:09,210 --> 00:16:15,750 I'm wondering how do you track it echoes and scattering contributions? Because in 170 00:16:15,750 --> 00:16:19,500 principle you cannot distinguish an experiment. So they also contributed to 171 00:16:19,500 --> 00:16:25,650 the same order. Yes. Do you treat a signal or background or you checks it is 172 00:16:25,680 --> 00:16:27,180 irrelevant into space space. 173 00:16:28,409 --> 00:16:33,689 There are some cats that did not report here which are that the nGj mark is 174 00:16:33,689 --> 00:16:38,759 required to be below 500 gV. And data preparation is more than 2.5 which is 175 00:16:38,759 --> 00:16:43,439 basically the opposite of what you do for a vector both an analysis has been done to 176 00:16:43,439 --> 00:16:47,009 reduce the contributions as much as possible. 177 00:16:50,370 --> 00:16:52,920 And then in this case, this is the technical 178 00:16:54,330 --> 00:16:59,250 sorry. And in this first case, to set tripod on Facebook, this is the critical 179 00:16:59,250 --> 00:17:02,400 channel. You could Do just consider this as background though. 180 00:17:06,120 --> 00:17:09,840 I think the contribution is very small compared to the 181 00:17:11,639 --> 00:17:17,939 the picture by production text 182 00:17:20,879 --> 00:17:22,259 question on slide eight 183 00:17:26,550 --> 00:17:33,300 don't understand correctly this plot on the right that at the low PT, random 184 00:17:33,300 --> 00:17:37,710 forest gives you better performance, but at the high PT is your worst performance. 185 00:17:39,750 --> 00:17:42,960 Yes, so did the IPT of the WWE system. Yes. 186 00:17:43,680 --> 00:17:47,790 Yeah. Can you can you describe a bit how do you construct uncertainty when you 187 00:17:47,790 --> 00:17:51,510 train BDT in one region and you apply it in another region? What are the 188 00:17:51,510 --> 00:17:56,100 uncertainties? What are the contributions don't say? How do you estimate 189 00:17:59,070 --> 00:17:59,610 okay. 190 00:18:01,500 --> 00:18:05,520 Noticing person so I don't know if someone is connected again answer to this question 191 00:18:06,480 --> 00:18:10,200 because this is beyond what I know about this. 192 00:18:17,940 --> 00:18:18,450 Sorry. 193 00:18:19,500 --> 00:18:21,780 Can you point me to the reference in the talk when 194 00:18:22,650 --> 00:18:28,500 it's on like to leave a link to the documentation is clickable. 195 00:18:30,840 --> 00:18:36,150 I can I can tell them a little bit on this if you want. I think this is, um, 196 00:18:36,840 --> 00:18:41,340 shouldn't necessarily be interpreted as where the random forest is better 197 00:18:41,340 --> 00:18:47,730 performing. It's simply showing which events it selects. So while the while in 198 00:18:47,730 --> 00:18:54,480 principle, the random forest is trained on on inclusive events, because it tries to 199 00:18:54,480 --> 00:19:00,990 find regions, but it's most sensitive to separating the WW from the teeth. bar, it 200 00:19:00,990 --> 00:19:07,230 ends up selecting the lower PT events. So this is just showing where the events come 201 00:19:07,230 --> 00:19:12,030 from. And then as to how the uncertainty is calculated. The biggest impact of the 202 00:19:12,030 --> 00:19:19,320 uncertainty in the random forest is when you look at the PG rating of the WWE 203 00:19:19,320 --> 00:19:22,980 system that comes from the higher order calculations, and its most sensitive to 204 00:19:22,980 --> 00:19:25,140 this topic collectivities 205 00:19:38,190 --> 00:19:44,310 Okay, if there are no more questions, let's thank Alessandra again. Thank you