1 00:00:00,240 --> 00:00:06,390 Okay, thanks, Sam. So Hi, everybody. So, today I'm going to talk about the victor 2 00:00:06,390 --> 00:00:11,190 was on sketching at high luminosity. Let's see. So 3 00:00:12,990 --> 00:00:13,860 come on. 4 00:00:15,869 --> 00:00:21,569 Okay. So to give you a small introduction first vector was on scattering is the 5 00:00:21,869 --> 00:00:26,459 production of the divers on so as you can see from this Fineman diagram here along 6 00:00:26,459 --> 00:00:33,689 with the two forward jets, and within this blog here, you can have the production via 7 00:00:33,749 --> 00:00:39,809 electric vehicle, or quarter gauge couplings as highlighted in the blue here 8 00:00:39,809 --> 00:00:45,209 in the Fineman diagrams or via the Higgs boson exchange at the tree level as 9 00:00:45,299 --> 00:00:51,299 highlighted in the green in the Fineman diagrams below. So, this process is 10 00:00:51,299 --> 00:00:57,209 interesting because it provides a test of the electroweak symmetry breaking and we 11 00:00:57,209 --> 00:01:02,159 know that it is still to be proven that the presence of The discovered Higgs boson 12 00:01:02,159 --> 00:01:07,049 preserves the unitarity of the longitudinal polarized dives on 13 00:01:07,049 --> 00:01:16,859 scattering. And what this image shows you is the typical BBs topology, with the two 14 00:01:16,859 --> 00:01:23,099 bosons produced centrally and to forward jets with large digest invariant mass and 15 00:01:23,129 --> 00:01:33,149 large data. Gabby alijah it a gap between these two jets for the backgrounds. Strong 16 00:01:33,149 --> 00:01:38,279 plus electronic interaction interactions as shown in the Fineman diagrams here 17 00:01:38,909 --> 00:01:46,229 result in the irreducible background for this process. So, coming to the Heilmann 18 00:01:47,099 --> 00:01:52,439 LSC prospects for these measurements, I will not go through the details of this 19 00:01:52,979 --> 00:01:57,749 roadmap as it was already shown in the previous talk. What's important to take 20 00:01:57,749 --> 00:02:03,989 away from here is that the These projections were done with the assumption 21 00:02:03,989 --> 00:02:11,609 of 200 phyla, center of mass energy or 14 TV and integrated Leumi of up to three at 22 00:02:11,609 --> 00:02:18,719 Oban inverse at high luminosity LSC to of course, cope with the increase Domi 23 00:02:18,719 --> 00:02:25,349 radiation and the pile of challenges posed by the high luminosity LSC both Atlas and 24 00:02:25,349 --> 00:02:33,509 CMS detectors need upgrades. So in the next slide, this slide summarizes briefly 25 00:02:33,509 --> 00:02:39,629 the overview of both Atlas and CMS upgrades. Again, not going into details 26 00:02:39,629 --> 00:02:46,949 what's important for the in the view of the BBs perspective is the extended 27 00:02:46,949 --> 00:02:52,199 coverage of the silicon tracker on the or the inner detector with the Atlas is 28 00:02:52,199 --> 00:02:59,969 extended Ada coverage or the forward chloramine and the forward calorimeter. So 29 00:03:00,479 --> 00:03:08,279 Now coming to the overview of the VBS measurements. This slide shows you the 30 00:03:09,479 --> 00:03:16,079 measurements that have been explored with the high luminosity let's see so far, and 31 00:03:16,079 --> 00:03:23,639 the first three channels hair within the men in this table here with the same same 32 00:03:23,639 --> 00:03:31,739 www z and zz are the analysis that are done with the fully electronic DK modes 33 00:03:31,769 --> 00:03:38,189 via the simulate tonic decay mode was treated separately. And most of these 34 00:03:38,189 --> 00:03:43,949 analysis have been extrapolated from the 13 t v analysis with corrections for cross 35 00:03:43,949 --> 00:03:50,639 sections and parameterised efficiencies using fast simulation or the full detector 36 00:03:50,639 --> 00:03:56,429 simulation. These projections are of course done with the upgraded detector 37 00:03:56,429 --> 00:04:02,009 configurations as shown in the last slide and have been summarized in the yellow 38 00:04:02,009 --> 00:04:08,669 report. For the sake of completeness, I also put a summary of the run to results 39 00:04:08,669 --> 00:04:13,499 in the backup but for the detailed update on run to please see Christians talk on 40 00:04:13,499 --> 00:04:21,239 Thursday. So, before going on to the details of the analysis, few words of the 41 00:04:21,239 --> 00:04:29,249 systematic assumptions that were used for the high luminosity, let's see studies. So 42 00:04:29,279 --> 00:04:36,569 broadly two scenarios were used. One was ran to scenario where the systematics for 43 00:04:36,569 --> 00:04:43,799 a given analysis were taken as it is from the run to and use as it is for high 44 00:04:43,799 --> 00:04:50,459 luminosity galaxy. While there was another scenario referred to as yellow report 45 00:04:50,519 --> 00:04:55,139 scenario, where the theoretical uncertainties were reduced by a factor of 46 00:04:55,169 --> 00:05:01,919 two compared to the current situation and experimental uncertainty These go as one 47 00:05:02,069 --> 00:05:08,759 by square root of l until they hit the detector capabilities of the 48 00:05:10,380 --> 00:05:11,790 Atlas or CMS. 49 00:05:12,570 --> 00:05:21,030 So now, finally coming to the analysis. First, let's start with the same same ww 50 00:05:21,120 --> 00:05:27,870 analysis. So the first goal of the analysis here is to extract the cross 51 00:05:27,870 --> 00:05:37,650 section uncertainty and see how it varies with the luminosity. So to do this board 52 00:05:37,650 --> 00:05:44,370 analysis and CMS in close, use 1d Bank maximum likelihood fit to the invariant 53 00:05:44,370 --> 00:05:53,310 mass distribution as shown here for CMS to extract the uncertainty on the cross 54 00:05:53,310 --> 00:05:59,970 section measurement so what you see on the these two plots, like the middle plot 55 00:06:00,510 --> 00:06:07,560 Right plot the cross section uncertainty as a function of integrated Lumi. For the 56 00:06:07,560 --> 00:06:16,260 systematic assumptions, Atlas uses return to scenario except that the rate 57 00:06:16,260 --> 00:06:24,570 uncertainties on the backgrounds were half vital for the CMS, it is using the yellow 58 00:06:24,570 --> 00:06:34,080 report scenario and in the plots here, you see the uncertainties going beyond 3000 59 00:06:35,430 --> 00:06:44,400 time to bond invoice this is just to show what we can achieve if if we can we try to 60 00:06:44,430 --> 00:06:52,470 combine the results from both CMS and Atlas. So, coming to the next slide and 61 00:06:52,920 --> 00:06:58,260 there and talking about longitudinal scattering measurement from the same sign 62 00:06:58,260 --> 00:07:05,820 ww So, we know that That total BBs cross section can be decomposed into the 63 00:07:05,820 --> 00:07:12,600 polarized components where vo w was on scan longitudinally or transversely 64 00:07:13,110 --> 00:07:19,200 polarized or it can as well be the mixture of longitudinal or data source polarized 65 00:07:20,520 --> 00:07:28,440 component. So, this analysis is challenging because this Ll component is 66 00:07:28,440 --> 00:07:35,970 only about six to 7% of the total VBS cross section, the PT of the jet to be 67 00:07:35,970 --> 00:07:43,830 greater than 50 gb. And to do this measurement, we used delta phi between the 68 00:07:43,830 --> 00:07:51,030 two jets to discriminate between the longitudinal component from the mixture of 69 00:07:51,030 --> 00:08:01,380 the two for both CMS and Atlas, and what is shown is in these two plots delta phi 70 00:08:01,380 --> 00:08:09,420 distribution of the two jets for signal and the big ground, but only in the in the 71 00:08:09,420 --> 00:08:19,020 brain of where the invariant mass between the two jets is greater than 1100 gV. So, 72 00:08:20,070 --> 00:08:28,800 to summarize the desert on this, it was I mean, it was extracted using a 73 00:08:28,800 --> 00:08:34,830 simultaneous fate of to the delta phi distribution that I showed up in the 74 00:08:34,830 --> 00:08:41,700 previous slide and in the Tomas regions of invariant mass of two jets and the 75 00:08:41,700 --> 00:08:46,920 significance that we obtain is shown in the plots below for CMS in Atlas 76 00:08:46,920 --> 00:08:54,120 respectively. And for CMS, we can see that at 3005 to one inverse, we have about 2.7 77 00:08:54,120 --> 00:09:03,180 sigma and if we combine the results from Atlas and CMS, it can Go above three sigma 78 00:09:05,220 --> 00:09:07,380 if you try to combine beyond 79 00:09:08,670 --> 00:09:15,840 to at Oban inverse, but experiment, so, again here one can possibly improve the 80 00:09:15,840 --> 00:09:23,130 results using multi variate based analysis. So, now coming to the WC 81 00:09:23,130 --> 00:09:31,170 analysis here to extract the cross section uncertainty Atlas uses the cut on the dial 82 00:09:31,260 --> 00:09:40,410 in where the invariant mass of two jets at 600 gV or multivariate based analysis 83 00:09:40,410 --> 00:09:48,720 where they I mean where the distribution can be seen from the top right plot for 84 00:09:48,720 --> 00:09:54,900 the signal and the backgrounds. However, CMS uses a two dimensional distribution of 85 00:09:54,900 --> 00:10:02,490 the digit in variant mass in the bins of the digit Angular seven variation and the 86 00:10:02,490 --> 00:10:10,680 result on the cross section uncertainty is shown in the bottom guide plot. And we see 87 00:10:10,680 --> 00:10:17,190 that we have similar same sensitivity also from Atlas at the level of 5%, which is 88 00:10:17,190 --> 00:10:24,780 feasible from both detectors. So, coming to the longitudinal scattering measurement 89 00:10:25,620 --> 00:10:31,770 for this Atlas explore the cost data distribution shown here in the left for 90 00:10:31,800 --> 00:10:39,510 obtaining the significance on the single longitudinal polarization factor fraction 91 00:10:39,510 --> 00:10:45,630 and it was found to be around two to three sigma based on the different selections 92 00:10:45,630 --> 00:10:54,090 that they studied to improve the signal clarity, and CMS used distribution which 93 00:10:54,090 --> 00:11:01,020 is very similar to what I showed here in this slide for distinguishing Between the 94 00:11:01,350 --> 00:11:09,660 LL component and the LL section significance here from CMS is shown in the 95 00:11:09,660 --> 00:11:18,690 right plot and is found to be 1.6 sigma around 3000 to one inverse, again one can 96 00:11:19,170 --> 00:11:24,660 use multivariate analysis to better discriminate against background, which 97 00:11:24,660 --> 00:11:27,240 could possibly improve the results here. 98 00:11:28,500 --> 00:11:34,500 So, now, coming to the Z channel here 99 00:11:35,880 --> 00:11:44,100 this analysis is most challenging because it has height heretical uncertainty based 100 00:11:44,100 --> 00:11:52,500 on the QC these easy process. To deal with this Atlas use three different assumptions 101 00:11:52,500 --> 00:11:59,190 on the systematic biases CMS use both run to and yellow report scenarios with the 102 00:11:59,190 --> 00:12:09,510 additional answer 20 10% on global z, big z big on yield. And Atlas uses this nGj 103 00:12:09,900 --> 00:12:15,990 distribution by CMS uses multivariate analysis to differentiate between the 104 00:12:15,990 --> 00:12:25,200 electroweak and kcd background processes. And when can see that this particular 105 00:12:25,200 --> 00:12:31,440 process can be observed with the significance of about 13 sigma for both 106 00:12:32,250 --> 00:12:40,260 around two or the yellow report scenario. At 3000 femto burn inverse and the 107 00:12:40,260 --> 00:12:47,340 precision we reach to observe the significance describes the process. This 108 00:12:47,460 --> 00:12:55,050 process is about 20% with the 5% theoretical uncertainty that was 109 00:12:55,050 --> 00:13:01,920 considered from Atlas and about 8.5% for right There are four yellow reports in Are 110 00:13:01,920 --> 00:13:02,220 you 111 00:13:03,809 --> 00:13:05,099 at the CMS detector 112 00:13:05,670 --> 00:13:11,460 then what's shown in this right plot is the expected significance of this z 113 00:13:11,460 --> 00:13:18,060 longitudinal affection as a function of Noemi. And we can see again for this 114 00:13:18,060 --> 00:13:24,510 particular process, we have the significance of 1.4 sigma at 3000 frame to 115 00:13:24,510 --> 00:13:36,360 burn inverse for CMS such as tanks and so, coming to the semi electronic decades of 116 00:13:36,360 --> 00:13:41,850 this channel, this analysis is of course different as it deals with diatonic the 117 00:13:41,850 --> 00:13:48,630 case here we have BD DS that are chosen as discriminates to distinguish between the 118 00:13:49,260 --> 00:13:58,950 signal versus the backgrounds and this BD DS are used to extract the results for the 119 00:13:58,980 --> 00:14:05,610 expected significant gains on the Standard Model BBs process and what you see as a 120 00:14:05,610 --> 00:14:12,870 result is shown in the right plot here. And we can see again from here that we 121 00:14:12,870 --> 00:14:23,100 reach about 5.7 sigma at 370 upon inverse, and as far as the cross section 122 00:14:23,100 --> 00:14:33,150 uncertainties are concerned, we reach about 6.5% at 3000 to one inverse. So, to 123 00:14:33,150 --> 00:14:39,480 summarize, measurement on VBS production are presented for phase two Atlas and CMS 124 00:14:39,480 --> 00:14:47,970 detector at high luminosity LLC. We expect expected cross section uncertainties are 125 00:14:48,000 --> 00:14:55,650 at the level of 10% or mostly less than 5%. Also for especially for the same sign 126 00:14:55,650 --> 00:15:04,770 ww or WC analysis for integrating Romeo Juliet Oban inverse and then we also 127 00:15:04,770 --> 00:15:11,100 explored the protec for the potential for establishing the longitudinal vv 128 00:15:11,100 --> 00:15:17,730 scattering and it will be showed that it is still challenging that even with the 129 00:15:17,730 --> 00:15:24,720 combination of Atlas and CMS. It's a very challenging analysis. So we need more 130 00:15:24,720 --> 00:15:28,230 sophisticated analysis and techniques like multivariate 131 00:15:30,030 --> 00:15:31,530 analysis to 132 00:15:31,650 --> 00:15:32,370 do better. 133 00:15:33,150 --> 00:15:33,660 Yeah. 134 00:15:33,780 --> 00:15:36,450 So that's all from my side. 135 00:15:37,319 --> 00:15:41,819 Thank you very much. The floor is open for questions. Please raise your hand if you 136 00:15:41,819 --> 00:15:42,239 have one. 137 00:15:53,490 --> 00:15:57,060 Okay. I don't see a question here. 138 00:15:59,100 --> 00:16:01,110 So was wondering, 139 00:16:02,580 --> 00:16:09,540 on slide 13, but that might be more a question for the Atlas folks here. I see 140 00:16:09,540 --> 00:16:16,350 this PDT distribution and I'm wondering why even for the signal, it's cut off 141 00:16:16,350 --> 00:16:23,340 sharply at 0.6. Something to hear. Do you know why this could be? 142 00:16:26,280 --> 00:16:28,290 I don't know this actually. 143 00:16:29,820 --> 00:16:31,020 It's a good question. 144 00:16:32,340 --> 00:16:34,320 Someone from the audience knows. 145 00:16:38,760 --> 00:16:41,070 Okay. Seems to be a tough question. 146 00:16:42,300 --> 00:16:43,620 We should follow up. So. 147 00:16:44,339 --> 00:16:51,569 So then then I have have another one. And I mean, if you have the results are a bit 148 00:16:51,569 --> 00:16:55,559 different between Atlas and CMS and you said partially, the uncertainty 149 00:16:55,559 --> 00:17:02,909 assumptions are also different and you emphasized a lot That using MBAs might 150 00:17:02,909 --> 00:17:09,329 help. But can we maybe learn anything already from the projections we are 151 00:17:09,329 --> 00:17:13,739 having? We have right now where CMS does better Outlast us better with with similar 152 00:17:13,739 --> 00:17:17,909 and uncertainty assumptions. What's the what is there already a takeaway message 153 00:17:17,909 --> 00:17:19,079 that we can add on top of that? 154 00:17:23,220 --> 00:17:24,570 Well, I mean, 155 00:17:25,890 --> 00:17:32,880 the best I can say is that for the I mean, the uncertainties that we measure, 156 00:17:33,180 --> 00:17:34,290 we could reach 157 00:17:34,680 --> 00:17:38,910 up to the level which is less than 5%. 158 00:17:39,330 --> 00:17:46,770 Okay, for the integrated NUMMI of 3000 came to bond inverse, which is quite good 159 00:17:46,770 --> 00:17:57,840 for observing me on these processes. And for the the longitude nodes, scattering 160 00:17:57,840 --> 00:18:06,270 cross section measurements. I mean, it ultimately will depend on the the various 161 00:18:06,270 --> 00:18:13,320 aspects of the analysis how they take place, but I think I've What I can say is 162 00:18:13,320 --> 00:18:16,200 that it remains very challenging at the end. 163 00:18:20,670 --> 00:18:22,050 Last chance for a question. 164 00:18:26,280 --> 00:18:31,650 All right, I don't see any race tense. So thanks a lot again Sandhya for for this 165 00:18:31,650 --> 00:18:32,580 nice overview 166 00:18:34,590 --> 00:18:36,990 and for answering my my questions.