1 00:00:02,790 --> 00:00:07,920 Okay, so now I can see your slides. Yeah, in full screen mode. Perfect. Okay. You 2 00:00:07,920 --> 00:00:08,760 are ready, you can start. 3 00:00:09,630 --> 00:00:13,290 And it's Michael, I'm very glad to be here, even virtually hope to be in Paris 4 00:00:13,290 --> 00:00:18,060 one day again. And really thank Allison all the coordinators for this opportunity. 5 00:00:18,780 --> 00:00:24,900 So, in TMS we're wedged in in understanding wide variety of systems. 6 00:00:26,790 --> 00:00:32,310 draw attention was brought to this possibility of, of understanding very 7 00:00:32,310 --> 00:00:33,930 small systems, whether they 8 00:00:35,880 --> 00:00:37,050 behave collectively. 9 00:00:38,460 --> 00:00:43,170 Our interest essentially came from the observation of the rich in high 10 00:00:43,170 --> 00:00:49,470 multiplicity PvP collisions. And this sort of really two aspects of this. One of them 11 00:00:49,500 --> 00:00:55,920 is is whether we do see some approach to hide dynamics when 100 Amex becomes 12 00:00:55,920 --> 00:01:01,170 applicable and they also the questions of what is the initial state There's a small 13 00:01:01,170 --> 00:01:02,070 system look like 14 00:01:03,689 --> 00:01:04,799 ah 15 00:01:06,870 --> 00:01:12,750 What is it? What is the power spectrum of fluctuations inside a small system. And so 16 00:01:12,900 --> 00:01:14,490 that's also what we're hoping to find 17 00:01:16,139 --> 00:01:18,779 from these studies. So 18 00:01:20,730 --> 00:01:28,170 so this this talk will focus on vn and cumulus measurements. And these sort of 19 00:01:28,170 --> 00:01:33,360 flow correlations have been very helpful in standing, the pressure that's in it in 20 00:01:33,420 --> 00:01:39,600 in heavier inclusions, and instead, we want to use these techniques to look for 21 00:01:39,600 --> 00:01:45,480 collectivity in smaller systems. So today, I'll pretty much focus on proton land and 22 00:01:45,480 --> 00:01:51,000 PvP and how we can try to subtract non flow effects 23 00:01:52,379 --> 00:01:53,879 in those in those small systems. 24 00:01:56,099 --> 00:01:58,319 So first timers, Chris TPP pled 25 00:02:00,000 --> 00:02:06,840 So, a basic measurement would be to look at the second moment the v2, and we can do 26 00:02:06,840 --> 00:02:12,030 this with just two particles four, six or eight or even all particles in the event 27 00:02:12,030 --> 00:02:21,570 using the NGS and zeros. And so here on the left we see proton proton versus 28 00:02:21,570 --> 00:02:28,320 proton lead versus lead lead. And we see this general rise of v2 with a number of 29 00:02:28,320 --> 00:02:42,720 tracks. Now, in lead lead period, we see a difference between the v2 with a just two 30 00:02:42,720 --> 00:02:48,300 particles and a larger PD cap, and then the higher order measurements of v2, and 31 00:02:48,300 --> 00:02:53,280 we believe that this is because of the these high order v four v 242. Six are 32 00:02:53,280 --> 00:03:01,980 better at subtracting non flow in Low multiplicity, these two sets of 33 00:03:01,980 --> 00:03:06,090 measurements tend to come together. And and potent, potent. We don't see such a 34 00:03:06,090 --> 00:03:06,960 difference between the two 35 00:03:08,760 --> 00:03:12,450 the different types of measurement. So 36 00:03:13,769 --> 00:03:22,229 let's look at another way of looking at this data. We can look at v2 v3 v4. And 37 00:03:22,349 --> 00:03:30,149 there's different ways of tackling this one is to try to subtract the very low 38 00:03:30,149 --> 00:03:36,209 multiplicity results from from the v2. And this by definition forces, v2 sub to go to 39 00:03:36,209 --> 00:03:42,779 zero at Denver tax was this year. But when we look at these measurements, we see non 40 00:03:42,779 --> 00:03:49,049 dual vetoes even down to very small values. Until again, this question of, of 41 00:03:49,319 --> 00:03:54,059 always seeing is this real collectivity and try to explore this more. 42 00:03:59,610 --> 00:04:04,830 So we've got also looked at different particles, and not just all hydrants. So 43 00:04:04,830 --> 00:04:12,120 here we have charged hydrants versus neutral counts versus lambdas, 90 lambdas. 44 00:04:12,930 --> 00:04:19,980 And we see different distributions, but when we scale by these numbers by the 45 00:04:19,980 --> 00:04:24,390 number of quarks and look like the kinetic energy divided by the number of quarks, we 46 00:04:24,390 --> 00:04:28,710 see this sort of universal scaling which has also been seen, especially in in heavy 47 00:04:28,710 --> 00:04:36,510 hand collisions. And when we look at this in P, P, again, we see the same thing it's 48 00:04:36,510 --> 00:04:41,040 clear difference in v2. For different product features a functional PT, 49 00:04:41,190 --> 00:04:43,950 functional particles, we would express 50 00:04:45,329 --> 00:04:47,819 expect this in a hydrogen amical situation. 51 00:04:50,759 --> 00:04:57,329 But when we scale by the number of quarks, we get similar kinds of distributions for 52 00:04:57,329 --> 00:05:02,879 the different add ons in proton lead and lead, lead, lead lead. Now hold on and 53 00:05:02,879 --> 00:05:06,869 lead lead this agreement is better, of course, and see that there's some 54 00:05:06,869 --> 00:05:12,929 deviation in the product lead for the two zeros. It's still the fact that the 55 00:05:12,929 --> 00:05:16,679 particles are so nicely like the Omega so right on looks suggestive. 56 00:05:18,089 --> 00:05:23,369 So let's go to slide number nine. So 57 00:05:24,779 --> 00:05:28,709 here we're going to compare v2 and v3. And in 58 00:05:30,149 --> 00:05:35,489 total on that and the lead, again, versus the number of tracks. And again, we're 59 00:05:35,489 --> 00:05:42,029 we're doing different numbers of higher order correlations, both in v2 and v3. And 60 00:05:42,029 --> 00:05:48,899 again, we see the the higher order correlations seem to cut down v2, which is 61 00:05:49,019 --> 00:05:54,089 can we expect to be getting rid of non flow, but it all methods seem to converge 62 00:05:54,359 --> 00:06:04,229 below about 100 tracks. So, another way of looking at these data is to try to look at 63 00:06:04,229 --> 00:06:12,959 these ratios of v4 to v2. This is believed to be sensitive to the ratios of the 64 00:06:12,959 --> 00:06:14,549 geometrical eccentricities. 65 00:06:16,230 --> 00:06:18,990 And when we look at this ratio for over v. 66 00:06:22,709 --> 00:06:28,049 So, v n for particle correlations of a VM from two particle correlations, we see a 67 00:06:28,079 --> 00:06:36,569 gradual decrease with this is enough agreement with what we expect from the 68 00:06:36,569 --> 00:06:40,379 scaling eccentricities. So, that that is very 69 00:06:46,560 --> 00:06:52,260 here we see even higher order we see if we compare different ratios now, like we have 70 00:06:52,260 --> 00:06:59,100 p 26324 and v two eight, a v2 six as a ratio v2 for the future 71 00:07:02,040 --> 00:07:04,050 fy Two, two, we 72 00:07:06,990 --> 00:07:13,200 were pretty nice height. with very high an ATV, we're very high statistics data, a 73 00:07:13,200 --> 00:07:17,220 slight increase with these trends and the prediction is a reasonable agreement with 74 00:07:17,250 --> 00:07:25,860 with the ratio of geometrical eccentricity. So that's nice. So, we 75 00:07:25,860 --> 00:07:31,050 suddenly we've been trying to move towards using their cumulant methods to subtract 76 00:07:31,050 --> 00:07:37,230 non flow contributions. And so we have these cumulative four particles, which of 77 00:07:37,230 --> 00:07:44,460 two orders and an M, and they can be, they come as a ratio of the average cosine of 78 00:07:44,460 --> 00:07:50,580 these, this column here, which can be broken down into n times the difference of 79 00:07:50,580 --> 00:07:56,070 two particles, multiplied by m times a difference of four particles of two other 80 00:07:56,070 --> 00:07:56,700 particles. 81 00:07:58,170 --> 00:07:59,970 And then it could be talked about in the ratio of the 82 00:08:01,800 --> 00:08:02,340 of 83 00:08:03,720 --> 00:08:05,580 products of Viet. 84 00:08:07,290 --> 00:08:13,470 Also we can use sub event methods to try to break down our acceptance and then also 85 00:08:13,470 --> 00:08:19,620 try to get rid of short range correlations to the effect of sub sub event. So here we 86 00:08:19,620 --> 00:08:23,700 see data from proton, proton, proton lead and lead lead as a function of the number 87 00:08:23,700 --> 00:08:29,040 of tracks for these different order correlators. And if we start perhaps on 88 00:08:29,040 --> 00:08:35,340 the on the right, you see the two three correlator going down with multiplicity 89 00:08:35,640 --> 00:08:45,750 two for color going up. And so that change occurring around about 100 tracks. We see 90 00:08:45,750 --> 00:08:49,800 in code on lead we see again this rapid drop below 100 and then a flattening 91 00:08:50,160 --> 00:08:57,180 doesn't rise like that, but it is it flattens, and then the PS two data looks a 92 00:08:57,180 --> 00:08:58,590 different kind of shape. 93 00:09:00,539 --> 00:09:02,849 Above 100 so not so, 94 00:09:05,339 --> 00:09:12,209 not quite the same as as I suppose a lead and the lead lead I should say that the 95 00:09:12,209 --> 00:09:18,809 poteau lead clip access is somewhat compressed in multiplicity. So, now we can 96 00:09:18,839 --> 00:09:27,389 another technique is to normalize these key words by the RMS of the v2 and the v3 97 00:09:28,319 --> 00:09:31,709 and here we see proton proton proton lead. 98 00:09:34,470 --> 00:09:36,720 This rapidity between point three to three gv 99 00:09:37,980 --> 00:09:44,430 and this is the second third correlator can see a nice agreement between proton 100 00:09:44,430 --> 00:09:54,420 lead and lead lead. That's not such a good agreement with with PGP. And again for the 101 00:09:54,420 --> 00:09:59,310 two for a moment again we see pulled on ladder poaching lead ladder high 102 00:09:59,310 --> 00:10:10,650 multiplicity But somewhat different in pp. So, if we sort of qualify this, this 103 00:10:10,650 --> 00:10:18,030 defense as a, we can add to this the scale scale accumulates we can try to cut harder 104 00:10:18,030 --> 00:10:26,580 by using the sub event method to suppress non flow even further. And we see again 105 00:10:27,120 --> 00:10:34,230 that we have these cumulants seem to have got rid of non flow above about 100 below 106 00:10:34,230 --> 00:10:46,110 100 D no sub event method shoots up. So, this is s two three and a similar 107 00:10:46,860 --> 00:10:54,240 situation we've seen in the s document two four. I've wanted to for work in the know 108 00:10:54,240 --> 00:11:00,780 some event method shoots up, whereas the higher multiple sub event methods Much 109 00:11:00,780 --> 00:11:06,480 more flat. So this is suggested that the killer math, the suburban method is 110 00:11:06,480 --> 00:11:07,650 helping to get rid of modular. 111 00:11:12,660 --> 00:11:15,810 We can quantify this by looking at the difference between the three and two 112 00:11:15,810 --> 00:11:20,760 suburban methods as a function of two sub event. And we see for the two, three 113 00:11:20,760 --> 00:11:24,720 correlator, almost no difference. So it's doing a very good job of suppressing non 114 00:11:24,720 --> 00:11:27,360 flow, there is a difference in 115 00:11:29,160 --> 00:11:31,560 for the two for correlator. Between 116 00:11:34,020 --> 00:11:38,340 and we, this this might be possible because we may be seeing an effect of the 117 00:11:38,940 --> 00:11:43,890 event plan t correlation today. Not sure why there's this difference in the two 118 00:11:43,890 --> 00:11:47,520 four correlated but event plan D correlation may be reason. 119 00:11:49,050 --> 00:11:50,910 So finally, to our conclusions. 120 00:11:52,590 --> 00:11:58,560 We've been trying to explain that the wide acceptance of CMS and ISIS two data sets 121 00:11:59,490 --> 00:12:07,680 to Canada in multiple ways to try to suppress non flow. The data seem to be 122 00:12:07,680 --> 00:12:12,540 suggesting that collectivities present in PP and perhaps p systems PNP systems with 123 00:12:12,750 --> 00:12:19,740 tracks of the order of 100. It's, it's still, I'd certainly agree with the last 124 00:12:19,740 --> 00:12:25,050 speaker that its situation in PvP is not clear. In the future, we will have a 125 00:12:25,050 --> 00:12:29,520 larger tracker and we will try to push to 126 00:12:31,020 --> 00:12:32,220 even smaller systems. 127 00:12:34,080 --> 00:12:35,310 Thank you everybody for your attention. 128 00:12:36,720 --> 00:12:42,750 Okay, thank you, Michael, for a very nice talk. So now we have time for discussion. 129 00:12:45,720 --> 00:12:52,590 If you have a question, please press the right hand button. Okay, so we have one 130 00:12:53,940 --> 00:12:55,350 bye you. 131 00:12:56,850 --> 00:12:59,520 Okay, so now you are unmuted please ask your question. 132 00:13:02,429 --> 00:13:05,399 Hello, very nice results from CMS. I hope you can hear me. 133 00:13:06,029 --> 00:13:07,589 Yes, I have questions. 134 00:13:07,799 --> 00:13:13,139 Yes. Oh, great. I have a small question slide elevens. So this this results are 135 00:13:13,139 --> 00:13:18,239 really beautiful with the position man is from CMS in Chula ATV. However, I guess 136 00:13:18,239 --> 00:13:23,249 the conclusion really depends on the correlation between V and eccentricity 137 00:13:23,249 --> 00:13:27,749 coefficient, because we know that the empty lead, we might not have a strong 138 00:13:27,749 --> 00:13:31,739 correlation or linear correlation between the two. Therefore, these conclusion might 139 00:13:31,739 --> 00:13:35,489 be a little bit a little bit too strong. If you compare initial state to the final 140 00:13:35,489 --> 00:13:36,149 state. Yeah. 141 00:13:36,780 --> 00:13:42,570 So I do hope set that inventory we can have some smaller systems where we can 142 00:13:42,570 --> 00:13:48,900 control we have we have more variation in the geometry. I think that has been an 143 00:13:48,900 --> 00:13:50,250 advantage to the rep program. 144 00:13:51,660 --> 00:13:52,560 And hopefully, 145 00:13:54,600 --> 00:14:01,050 we can we can have that more inventory. I agree with you that it's It might be nice 146 00:14:01,050 --> 00:14:03,450 to have an oxygen oxygen on this plot perhaps. 147 00:14:05,910 --> 00:14:07,500 That would be very interesting. 148 00:14:08,490 --> 00:14:13,590 Yeah. So I, I agree with you that this is rather theoretical dependent. 149 00:14:19,980 --> 00:14:23,880 Do we have more questions? Sorry, I couldn't respond. I have a question on 150 00:14:23,880 --> 00:14:29,700 slide eight. I want to know what is the variable on the x axis? 151 00:14:31,560 --> 00:14:38,640 Oh, so what is it is the kinetic energy. So what you do is you take the total 152 00:14:38,640 --> 00:14:46,710 energy of the particle and you subtract the transverse, the mass of the system. So 153 00:14:46,710 --> 00:14:52,980 it's, it's, it's the kinetic kinetic transverse energy, which is p x the square 154 00:14:52,980 --> 00:14:59,430 root of p x squared plus p y squared minus m squared. I'm sorry. I apologize. I 155 00:14:59,430 --> 00:15:04,080 apologize for that. To find, and then it's divided by the number of cooks. So you 156 00:15:04,080 --> 00:15:09,990 divide by two for me zones, and you divide by FIFA barians. So I apologize that 157 00:15:09,990 --> 00:15:13,320 wasn't introduced to the problem. Thank you. 158 00:15:14,910 --> 00:15:18,510 All right, do we have time for one more question to this presentation? 159 00:15:23,550 --> 00:15:29,700 Okay, I don't see any. Okay. There's another one here. 160 00:15:31,320 --> 00:15:33,360 Yeah, please go on 161 00:15:33,570 --> 00:15:37,470 version one, slide nine. I don't know if there's new development in understanding 162 00:15:37,500 --> 00:15:42,150 of the low morphism region, while we see v two four is higher than v two two. 163 00:15:43,950 --> 00:15:44,790 It's like mine 164 00:15:46,710 --> 00:15:50,910 because from from the Federation, corner view, it's very hard to understand if v 165 00:15:50,910 --> 00:15:52,320 two four is higher than the two to 166 00:15:55,620 --> 00:16:00,000 eight Yeah, I would. You You You mean the lead lead placed here? 167 00:16:01,620 --> 00:16:09,000 Give me this point. I wouldn't. I would bet that it's the tie with it. I think 168 00:16:09,000 --> 00:16:16,500 within the systematic, it's consistent. I agree. I agree with you. But I think we 169 00:16:16,500 --> 00:16:21,870 have the data in tables and I can look to see if it's statistically. It there's 170 00:16:21,870 --> 00:16:25,650 actually a significant difference, but I don't think so. This so i 171 00:16:26,940 --> 00:16:29,940 i wouldn't I would base that on done and the one point there. 172 00:16:36,570 --> 00:16:42,510 All right. Thank you, Michael. I think we have to switch to the last presentation.