1 00:00:32,600 --> 00:00:33,240 Hello, everybody, 2 00:00:33,240 --> 00:00:36,240 and welcome to early morning coffee at CERN. 3 00:00:36,680 --> 00:00:41,560 I'm Steven Goldfarb and we have a really I would say mind boggling show 4 00:00:41,720 --> 00:00:46,040 for you today because we're going to be talking about quantum mechanics. 5 00:00:46,040 --> 00:00:47,480 And that's a world that boggles I think everybody's mind. 6 00:00:47,480 --> 00:00:49,160 7 00:00:49,160 --> 00:00:52,400 I think as Richard Feynman said, if it doesn't, then you don't get it. 8 00:00:52,520 --> 00:00:52,880 Right. 9 00:00:52,880 --> 00:00:58,200 So, so I have here with me, Giulia Negro from the CMS experiment. 10 00:00:59,000 --> 00:01:03,440 Giulia, you work, for Purdue University. 11 00:01:03,800 --> 00:01:04,400 In beautiful Lafayette, Indiana. 12 00:01:04,400 --> 00:01:06,200 By the way, 13 00:01:06,200 --> 00:01:09,160 for my French friends, it doesn't mean that the university has been lost. 14 00:01:09,160 --> 00:01:10,160 Okay. 15 00:01:10,160 --> 00:01:11,840 It is actually a beautiful place. 16 00:01:11,840 --> 00:01:13,280 Lafayette, Indiana. 17 00:01:13,280 --> 00:01:17,840 And also, with me, to talk about quantum entanglement of top quarks 18 00:01:18,720 --> 00:01:21,840 I have one of my colleagues from the ATLAS Experiment, Yoav Afik. 19 00:01:22,120 --> 00:01:22,480 Yoav. 20 00:01:23,760 --> 00:01:24,720 And he is from 21 00:01:24,720 --> 00:01:28,280 as you can see from his cup, the Enrico Fermi Institute, 22 00:01:28,600 --> 00:01:31,520 at the University of Chicago in Chicago, Illinois. 23 00:01:31,520 --> 00:01:34,360 So actually, your institutes are not far from each other, 24 00:01:34,360 --> 00:01:37,360 but you guys are both far from your institutes 25 00:01:38,440 --> 00:01:39,640 We are both based here at CERN, actually. 26 00:01:39,640 --> 00:01:41,160 I beat you on that, though, because I actually work 27 00:01:41,160 --> 00:01:42,960 for the University of Melbourne in Australia. 28 00:01:42,960 --> 00:01:46,880 Okay, so this is a very typical thing, here at CERN. 29 00:01:47,000 --> 00:01:50,960 So we're here actually today we're going to be celebrating 30 00:01:51,480 --> 00:01:54,640 the International Day of Quantum Science and Technology 31 00:01:54,640 --> 00:01:58,880 as declared by the United Nations. 32 00:01:59,360 --> 00:02:02,400 UNESCO sponsors these special events. 33 00:02:03,240 --> 00:02:05,440 And we'll be talking 34 00:02:05,440 --> 00:02:08,800 about this really nice measurement that you guys have made, 35 00:02:09,640 --> 00:02:13,760 about the quantum entanglement of two top quarks 36 00:02:13,960 --> 00:02:18,040 in the Large Hadron Collider, both at ATLAS and at CMS. 37 00:02:18,400 --> 00:02:22,000 And I have to say, first of all, this is a measurement that was not previewed. 38 00:02:22,920 --> 00:02:25,680 We have these these books when we start these experiments. 39 00:02:25,680 --> 00:02:27,960 The yellow books, right? 40 00:02:27,960 --> 00:02:29,640 And I think they were not actually yellow for the LHC. 41 00:02:29,640 --> 00:02:31,880 But back in the day they were yellow 42 00:02:31,880 --> 00:02:34,640 they would they would sort of list all the different types of physics 43 00:02:34,640 --> 00:02:37,640 and things that we might discover, things and measurements, we might make. 44 00:02:38,280 --> 00:02:40,240 And you guys went beyond that. Right. 45 00:02:40,240 --> 00:02:41,560 So we're going to talk about that. 46 00:02:41,560 --> 00:02:45,240 But first I'd like to to get into quantum mechanics if we can. 47 00:02:45,600 --> 00:02:45,960 A little bit. 48 00:02:47,240 --> 00:02:50,000 Maybe you each have an opinion, but usually when UNESCO 49 00:02:50,000 --> 00:02:54,120 does something like this, it's because it's 100 years since something. 50 00:02:54,880 --> 00:02:56,120 So Giulia, 51 00:02:56,120 --> 00:02:58,520 What what do you what would you say happened a hundred years ago 52 00:02:58,520 --> 00:03:00,960 That launched this? 53 00:03:00,960 --> 00:03:01,280 Okay. 54 00:03:01,280 --> 00:03:05,000 Well, 100 years ago, there were a lot of, discoveries. 55 00:03:05,280 --> 00:03:06,800 There was, process. 56 00:03:06,800 --> 00:03:09,440 There were a lot of physicists, 57 00:03:09,440 --> 00:03:10,400 that had different ideas. 58 00:03:10,400 --> 00:03:10,680 Yeah. 59 00:03:10,680 --> 00:03:14,240 For example, Heisenberg with his matrix mechanics, 60 00:03:14,720 --> 00:03:17,720 and Schrödinger with the wave mechanics. 61 00:03:17,960 --> 00:03:20,320 So that was, what, 1925? 62 00:03:20,320 --> 00:03:23,320 Yes. It's the centennial this year, 63 00:03:24,520 --> 00:03:27,520 that's why it's considered the beginning, but, 64 00:03:27,920 --> 00:03:30,920 yeah, I think it's more of a process 65 00:03:31,240 --> 00:03:33,240 than a specific year of when this all started. That makes a lot of sense. 66 00:03:33,240 --> 00:03:34,600 Yuav, you have an opinion on this? 67 00:03:36,320 --> 00:03:38,200 Yeah. I see it as a process. 68 00:03:38,200 --> 00:03:41,360 I think what Giulia mentioned is where let's say the formalism 69 00:03:41,720 --> 00:03:45,680 has been designed for quantum mechanics, but in fact, 70 00:03:46,760 --> 00:03:48,200 I think it started 71 00:03:48,200 --> 00:03:51,520 even earlier when Einstein introduced the photoelectric effect. 72 00:03:52,080 --> 00:03:55,600 And so he didn't have the exact formalism 73 00:03:55,600 --> 00:03:57,640 of the quantum mechanics, of course, as we know it today. 74 00:03:57,640 --> 00:04:03,320 But he was able to show that light comes in quanta, which is exactly, 75 00:04:03,320 --> 00:04:07,960 you know, what is quantum mechanics is all about - discrete quantities. 76 00:04:08,160 --> 00:04:11,480 And I think at the time, I mean, he wasn't always a big fan, right? 77 00:04:12,040 --> 00:04:14,480 of quantum mechanics, he thought that there was something strange 78 00:04:14,480 --> 00:04:17,800 about not being deterministic. 79 00:04:18,440 --> 00:04:21,200 - I think it was hard for him that there are many concepts 80 00:04:21,200 --> 00:04:24,440 that weren't so let's say intuitive in quantum mechanics. 81 00:04:24,440 --> 00:04:25,560 I mean, as you mentioned before, right? 82 00:04:25,560 --> 00:04:29,240 Feynman said, if you think you understand quantum mechanics means you understood nothing. 83 00:04:29,520 --> 00:04:32,080 Nothing. Yeah. And then we understand nothing. 84 00:04:32,080 --> 00:04:35,840 We're willing to say that as scientists. It's one of the things you find out 85 00:04:35,840 --> 00:04:39,080 when you're a scientist, especially at CERN, is how much you don't know 86 00:04:39,920 --> 00:04:41,720 Most of the universe we don't know. 87 00:04:41,720 --> 00:04:45,520 But we've learned a lot, and we're making a lot of progress, which is important. 88 00:04:46,760 --> 00:04:49,760 So our director, Chetna, 89 00:04:50,240 --> 00:04:53,240 always reminds me that there's a guy named (Satyendra) Bose 90 00:04:54,400 --> 00:04:56,320 who was very important in all of this as well. 91 00:04:56,320 --> 00:04:59,800 And I think it is interesting because some of 92 00:05:00,480 --> 00:05:03,360 the concepts of quantum mechanics 93 00:05:03,360 --> 00:05:06,320 came about somewhat by mistake. 94 00:05:06,320 --> 00:05:08,560 I think, you know, you mentioned, 95 00:05:08,560 --> 00:05:11,360 the photoelectric effect E equals Hv. 96 00:05:11,360 --> 00:05:14,360 And so there were quanta in, the energy, 97 00:05:14,840 --> 00:05:17,840 of a photon, which depends on its frequency. 98 00:05:18,760 --> 00:05:20,960 So you have to use these exact discreet 99 00:05:20,960 --> 00:05:22,640 quanta. 100 00:05:22,640 --> 00:05:24,320 There were also, 101 00:05:24,320 --> 00:05:27,600 even just before that, that the equation came from Max Planck, hence 102 00:05:28,800 --> 00:05:29,520 the Planck constant. 103 00:05:29,520 --> 00:05:31,960 When he was trying to understand (black body) radiation. 104 00:05:31,960 --> 00:05:35,120 And he found that using that mathematics, using 105 00:05:35,120 --> 00:05:38,120 this idea of these various frequencies, 106 00:05:38,120 --> 00:05:40,160 you got 107 00:05:40,160 --> 00:05:42,760 solutions to the problems that they were looking at. 108 00:05:42,760 --> 00:05:46,160 So the at the time, they were trying to measure the different discrete spectra 109 00:05:46,360 --> 00:05:47,000 of electrons 110 00:05:48,120 --> 00:05:51,080 orbiting around the proton. 111 00:05:51,080 --> 00:05:52,960 112 00:05:52,960 --> 00:05:56,120 And, and that's kind of cool, I think, because we're experimentalists. 113 00:05:56,280 --> 00:05:56,960 Yeah. 114 00:05:56,960 --> 00:06:00,200 You know, experiment led and 115 00:06:00,200 --> 00:06:03,720 they couldn't come up with a solution using classical mechanics. 116 00:06:04,200 --> 00:06:07,200 And so we got to this really, really cool world of quantum mechanics. 117 00:06:11,320 --> 00:06:13,720 Bose, he also made a mistake which was in counting, in the classroom. 118 00:06:13,720 --> 00:06:17,120 And he was talking about counting different states, we have two particles 119 00:06:17,560 --> 00:06:20,320 and they can be one spin up and one spin down. 120 00:06:20,320 --> 00:06:23,320 And you can try to count probabilities. 121 00:06:23,440 --> 00:06:27,200 And normally you say, okay, you can have them both up and both down. 122 00:06:27,240 --> 00:06:29,280 Or there's two different ways it can be up and down. 123 00:06:29,280 --> 00:06:32,640 And if you have something like electrons, where that's the correct way to count 124 00:06:32,640 --> 00:06:34,480 because you can differentiate between the two particles. 125 00:06:35,520 --> 00:06:38,520 But Bose those just said, okay, there's two up, 126 00:06:38,800 --> 00:06:41,800 two down, and then there's one with one up and one down. 127 00:06:42,040 --> 00:06:43,960 So three possibilities. 128 00:06:43,960 --> 00:06:47,320 It turned out that worked for bosons like photons. 129 00:06:47,840 --> 00:06:49,920 And then because they're called bosons right. 130 00:06:49,920 --> 00:06:51,280 Because of Bose. 131 00:06:51,280 --> 00:06:53,680 So it was a really good contribution. 132 00:06:53,680 --> 00:06:57,400 He realised it was a mistake, but then then he started using it. 133 00:06:57,400 --> 00:06:58,400 He said, this works. 134 00:06:58,400 --> 00:07:00,840 And he tried to publish. 135 00:07:00,840 --> 00:07:02,720 And due to various biases 136 00:07:02,720 --> 00:07:05,880 around the world, maybe just the bias of this we have never done before 137 00:07:06,280 --> 00:07:09,760 or could have been cultural knows, it wasn't accepted. 138 00:07:10,240 --> 00:07:11,600 But then he sent it to Einstein. 139 00:07:11,600 --> 00:07:15,800 and he said it was good, and it got accepted. 140 00:07:16,280 --> 00:07:20,440 So we always have to fight our biases, both from past, 141 00:07:21,600 --> 00:07:23,480 what we thought was true. 142 00:07:23,480 --> 00:07:24,320 And we have to draft those. 143 00:07:24,320 --> 00:07:26,480 But also there's still cultural biases. 144 00:07:26,480 --> 00:07:27,680 We always get. 145 00:07:27,680 --> 00:07:30,120 Having a place like CERN is a great place to battle that. 146 00:07:30,120 --> 00:07:30,400 Right? 147 00:07:30,400 --> 00:07:31,520 Because you know, 148 00:07:31,520 --> 00:07:34,960 when you get when you have lunch, you know, who knows who will be sitting next to you. 149 00:07:35,720 --> 00:07:38,560 So, okay, so no one asks the question. 150 00:07:38,560 --> 00:07:39,960 Quantum mechanics. 151 00:07:39,960 --> 00:07:42,040 It's a weird world, right? 152 00:07:42,040 --> 00:07:43,600 It's not like the world that we live in. 153 00:07:43,600 --> 00:07:45,760 The macroscopic. 154 00:07:45,760 --> 00:07:46,960 Giulia, tell me: 155 00:07:46,960 --> 00:07:49,960 What is your favourite effect? 156 00:07:50,920 --> 00:07:53,920 But of course, it's the quantum entanglement. 157 00:07:54,600 --> 00:07:56,440 We are speaking about that today. 158 00:07:56,440 --> 00:07:57,800 And you have 159 00:07:57,800 --> 00:08:01,000 to have to explain this because it's really difficult to comprehend. 161 00:08:02,400 --> 00:08:06,040 And and I suppose because she said that, you Yoav? 162 00:08:07,280 --> 00:08:09,760 which one? She took entanglement from me, 163 00:08:09,760 --> 00:08:10,720 so I would 164 00:08:10,720 --> 00:08:13,680 say Bell inequality 165 00:08:13,680 --> 00:08:16,080 or the violation of Bell inequality. 167 00:08:17,680 --> 00:08:19,360 And I can explain, shortly, what this all means. 168 00:08:19,360 --> 00:08:21,760 Yeah, you should explain, because Bell is from CERN. 169 00:08:21,760 --> 00:08:24,040 So as we spoke before about Einstein. 170 00:08:24,040 --> 00:08:26,560 So, Einstein, not only Einstein, but 172 00:08:28,320 --> 00:08:32,520 he had a bit of a problem with entanglement, right? 173 00:08:32,520 --> 00:08:36,040 So let me let me try and explain the concept of entanglement. 174 00:08:36,320 --> 00:08:40,840 So entanglement tells you ... let's say that you have two particles. 175 00:08:41,440 --> 00:08:42,680 You cannot describe them 176 00:08:42,680 --> 00:08:45,680 within quantum mechanics independently from each other. 177 00:08:46,480 --> 00:08:47,680 What does it mean. 178 00:08:47,680 --> 00:08:50,040 Let's say that we have two particles, two electrons, for example, 179 00:08:50,040 --> 00:08:53,680 in two parts of the universe. These electrons, 180 00:08:54,160 --> 00:08:57,280 they have a property which is called spin, which we can measure. 181 00:08:57,800 --> 00:09:00,760 So it turns out that if we measure, 182 00:09:01,960 --> 00:09:02,600 if they are coming 183 00:09:02,600 --> 00:09:05,600 from the same source which we call as singlet, 184 00:09:05,760 --> 00:09:07,760 and we measure the spin of one of the electrons 185 00:09:07,760 --> 00:09:10,760 on one side of the universe, we would immediately know the outcome 186 00:09:11,080 --> 00:09:12,600 on the other one. 187 00:09:12,600 --> 00:09:15,520 Immediately? So not with time for it to go around the WWW? 188 00:09:15,520 --> 00:09:17,400 And this is mind blowing, right. 189 00:09:17,400 --> 00:09:21,160 And it can tell you, for example, it implies that the information 190 00:09:21,160 --> 00:09:24,160 travels faster than the speed of light, which contradicts, 191 00:09:24,600 --> 00:09:27,120 Einstein's theory of relativity. 192 00:09:27,120 --> 00:09:29,280 So this is why, in the 30's, Einstein 193 00:09:29,280 --> 00:09:32,280 together with, with Podolsky and Rosen came up with the 194 00:09:33,280 --> 00:09:39,040 famous paper of the EPR paradox, the Einstein, Podolsky and Rosen paradox, 196 00:09:39,520 --> 00:09:42,640 which basically claims that quantum mechanics is an incomplete theory. 197 00:09:42,920 --> 00:09:46,560 We have a set of hidden variables within the theory, which tells us 198 00:09:46,720 --> 00:09:50,560 before the measurement itself, the outcome of the measurement of one electron and the other one. 199 00:09:52,760 --> 00:09:53,440 And we need more variables 200 00:09:53,440 --> 00:09:55,720 in order to describe this theory. 201 00:09:55,720 --> 00:09:57,360 Okay. 202 00:09:57,360 --> 00:10:00,360 Now, in the 60's came John Stewart Bell, 203 00:10:00,480 --> 00:10:03,480 and showed that if these theories exist, 204 00:10:03,600 --> 00:10:05,160 it means that they have to fulfil 205 00:10:05,160 --> 00:10:08,160 this, very famous Bell inequality. 206 00:10:08,560 --> 00:10:11,680 So you can actually exclude these theories 207 00:10:11,680 --> 00:10:14,680 with additional local hidden variables 208 00:10:15,400 --> 00:10:17,280 as claimed by Einstein, Podolsky and Rosen. 209 00:10:17,280 --> 00:10:23,160 by breaking the Bell inequality. 212 00:10:25,400 --> 00:10:28,240 So it so it's broken then. 213 00:10:28,240 --> 00:10:31,240 It has been measured to be violated 214 00:10:31,600 --> 00:10:33,400 many times already. Yes. 215 00:10:33,400 --> 00:10:34,480 And there was, 216 00:10:34,480 --> 00:10:38,080 there was a Nobel Prize recently for that a couple of years ago, yes. 217 00:10:38,080 --> 00:10:41,880 If I remember somewhere around here, 2022, 218 00:10:41,920 --> 00:10:44,920 the winners of the 2022 Nobel Prize were Aspect, Clauser and Zeilinger 219 00:10:45,240 --> 00:10:48,240 Exactly, Aspect, Clauser and Zeilinger. 220 00:10:48,400 --> 00:10:49,600 Very good. 221 00:10:49,600 --> 00:10:51,760 Yes, exactly. For testing this concept. 222 00:10:51,760 --> 00:10:53,200 And that's important, I think, Bell was at CERN actually. 223 00:10:53,200 --> 00:10:56,160 Yes he was. 224 00:10:57,120 --> 00:10:59,520 So we have we have some smart people here, 225 00:10:59,520 --> 00:11:02,280 On occasion, there are some smart people here. 226 00:11:02,280 --> 00:11:04,160 So as long as we're talking about 227 00:11:04,160 --> 00:11:07,160 quantum entanglement here, 228 00:11:08,040 --> 00:11:12,080 you guys both independently did measurements of quantum entanglement. 229 00:11:12,280 --> 00:11:12,800 Of course. 230 00:11:12,800 --> 00:11:15,400 That's why we have different experiments, right? 231 00:11:15,400 --> 00:11:18,400 You know, and CMS and Atlas are beautiful experiments. 232 00:11:19,160 --> 00:11:20,800 They both enormous. 233 00:11:20,800 --> 00:11:25,880 They both have a lot of people, like 5000 or 6000 people on CMS, right? 234 00:11:25,880 --> 00:11:26,560 5000 or 6000 on ATLAS. 235 00:11:26,560 --> 00:11:30,520 There's 3000 authors, I think 236 00:11:31,120 --> 00:11:31,480 Yeah, almost 237 00:11:31,480 --> 00:11:33,640 You know that that means that I've written less. 238 00:11:33,640 --> 00:11:36,400 I've been on ATLAS with you. 239 00:11:36,400 --> 00:11:39,400 Even before you, 240 00:11:39,640 --> 00:11:42,480 Yeah, because I think, I've been around since 1998 241 00:11:42,480 --> 00:11:45,320 and I still haven't written a total of one paper. 242 00:11:45,320 --> 00:11:45,640 Right. 243 00:11:45,640 --> 00:11:51,280 Because if you take and divide by 3000, we have to write more papers, I think. 245 00:11:54,880 --> 00:11:58,040 So you've independently done this, I think, the story, 246 00:11:58,040 --> 00:12:01,520 of how you came up with the idea of looking 247 00:12:01,760 --> 00:12:04,720 for quantum entanglement, 248 00:12:04,720 --> 00:12:07,920 in the LHC, because just like I said, this is never too far before. 249 00:12:07,920 --> 00:12:09,720 I think you have the story. - We came up with the idea. 250 00:12:11,200 --> 00:12:14,400 So together with, Juan Ramón Muñoz de Nova 251 00:12:14,920 --> 00:12:19,240 when I was in my Ph.D., we were in the same institute. 252 00:12:19,680 --> 00:12:22,440 He's actually coming from the field of condensed matter physics. 253 00:12:22,440 --> 00:12:27,360 So this already tells us something about the interdisciplinary nature of this idea. 254 00:12:28,120 --> 00:12:29,720 And we were friends. 255 00:12:29,720 --> 00:12:32,720 And we met for coffee breaks at the TECHNION where I did my PhD. 256 00:12:35,120 --> 00:12:36,200 And we chatted. 257 00:12:36,200 --> 00:12:39,200 Also, sometimes about physics, of course. 258 00:12:39,400 --> 00:12:40,000 Yeah, yeah. 259 00:12:40,000 --> 00:12:42,400 Well, more than sometimes. Yeah. 260 00:12:42,400 --> 00:12:44,640 And then he asked me 261 00:12:44,640 --> 00:12:47,640 if I think that we can measure entanglement at the LHC. 262 00:12:48,000 --> 00:12:51,320 I said, okay, that's a very interesting question. 263 00:12:52,080 --> 00:12:53,440 And I started to, 264 00:12:54,840 --> 00:12:55,320 to do some 265 00:12:55,320 --> 00:12:58,320 research and to see the possibilities. 266 00:12:58,320 --> 00:13:01,000 Then I saw this, 267 00:13:01,000 --> 00:13:03,040 very unique particle, 268 00:13:03,040 --> 00:13:06,040 which is the top quark, which I assume we will discuss about soon. 269 00:13:06,200 --> 00:13:06,960 Yeah. 270 00:13:06,960 --> 00:13:09,960 And this seemed to me also by the previous measurements 272 00:13:10,160 --> 00:13:14,840 that I saw were done using top quarks as the perfect system. 273 00:13:15,520 --> 00:13:17,840 to try and measure quantum entanglement at the LHC 274 00:13:17,840 --> 00:13:19,600 And that is what we did. 275 00:13:19,600 --> 00:13:20,920 Someone had thought about that idea 276 00:13:20,920 --> 00:13:23,440 that you could use the top quark. 277 00:13:23,440 --> 00:13:27,520 So we thought about it together, you know, Juan and myself together. 278 00:13:27,520 --> 00:13:33,320 And this led to a paper published about a year after we chatted about it. 279 00:13:33,720 --> 00:13:36,400 This was basically the baseline 280 00:13:36,400 --> 00:13:37,120 for both of the measurements. 281 00:13:37,120 --> 00:13:41,040 And you were a student at the time? - Yes, I was a PhD student back then. 282 00:13:42,680 --> 00:13:44,320 That's actually our workforce. 283 00:13:45,280 --> 00:13:46,120 People don't realise that. 284 00:13:46,120 --> 00:13:51,280 But like more than a third of the authors on our experiments are PhD students. 285 00:13:51,440 --> 00:13:54,960 and they're also the people you'll find on shifts a lot. 286 00:13:54,960 --> 00:13:59,120 Postdocs are also okay, The rest of us 287 00:13:59,120 --> 00:14:00,320 are kind of useless. 288 00:14:00,320 --> 00:14:03,240 but we have fun anyhow! 289 00:14:03,240 --> 00:14:05,520 So you asked about it. 290 00:14:05,520 --> 00:14:07,800 Maybe Giulia can explain a little bit more 291 00:14:07,800 --> 00:14:10,080 Why is the top quark 292 00:14:10,080 --> 00:14:12,520 something that we can look at 293 00:14:12,520 --> 00:14:14,080 in this case. 294 00:14:14,080 --> 00:14:16,840 So the top quark is very special because, 295 00:14:16,840 --> 00:14:19,840 a difference with respect to the other quarks is that 296 00:14:20,200 --> 00:14:23,200 it decays before it can hadronise. 297 00:14:23,760 --> 00:14:26,760 So the information, for example, the spin information, of the 298 00:14:26,880 --> 00:14:29,880 the top quark is transferred, to its decay products. 299 00:14:32,720 --> 00:14:35,240 Interesting that you bring up hadronise, so quarks are very special. 300 00:14:35,240 --> 00:14:37,280 Yes, they are fundamental particles 301 00:14:37,280 --> 00:14:38,240 They're fundamental, 302 00:14:38,240 --> 00:14:40,440 when we talk about 303 00:14:40,440 --> 00:14:42,080 doing particle physics at CERN, 304 00:14:42,080 --> 00:14:44,200 So we talked about looking at the elementary 305 00:14:44,200 --> 00:14:47,880 or fundamental particles those things you can't cut a top quark in half. 306 00:14:48,120 --> 00:14:49,280 Right. 307 00:14:49,280 --> 00:14:52,360 So we have 6 of these quarks. 308 00:14:52,880 --> 00:14:54,760 Two of them are stable because they're really light. 309 00:14:57,080 --> 00:14:59,320 The up and the down. The other ones, they appear for short times. 310 00:14:59,320 --> 00:15:02,440 And then I guess the the more massive they are, 311 00:15:02,960 --> 00:15:06,360 the quicker they decay. Indeed, 312 00:15:06,720 --> 00:15:10,560 the top quark is the one with the highest mass 313 00:15:10,560 --> 00:15:13,800 it is 40 times, larger than the bottom quark. 314 00:15:13,810 --> 00:15:17,560 It's about 180 times the mass of the proton. 316 00:15:18,400 --> 00:15:19,120 And a proton is made up 317 00:15:19,120 --> 00:15:20,760 of quarks. 318 00:15:20,760 --> 00:15:22,400 Right. So yeah. 319 00:15:22,400 --> 00:15:25,360 The top quark is super massive. 320 00:15:25,360 --> 00:15:28,480 It's the most massive of any of the, any of the elementary particles. 321 00:15:28,480 --> 00:15:29,680 Even the bosons, like 322 00:15:29,680 --> 00:15:33,200 the W and the Z, even the Higgs even more massive than the Higgs. 323 00:15:34,240 --> 00:15:36,360 So it doesn't have a chance 324 00:15:36,360 --> 00:15:39,360 like the other quarks have this wonderful life because 325 00:15:39,840 --> 00:15:44,360 as soon as they're born, they find a partner or a couple partners, right. 326 00:15:44,760 --> 00:15:46,280 And they hang out with them, 327 00:15:46,280 --> 00:15:49,720 and it takes a huge amount of effort to pull them apart. 328 00:15:50,080 --> 00:15:52,200 It's the strong nuclear force. 329 00:15:53,480 --> 00:15:56,240 And when you do when you finally get these two 330 00:15:56,240 --> 00:16:00,680 quark and antiquark and you pull them apart, suddenly out of, out of nowhere 331 00:16:01,880 --> 00:16:04,600 out of the vacuum, a couple other quarks appear. 333 00:16:05,640 --> 00:16:09,080 they can't get to, they get divorced and they immediately got new partners. 334 00:16:09,680 --> 00:16:13,040 But the poor top quark is all alone. 335 00:16:13,480 --> 00:16:16,040 and it disintegrates, it transforms 336 00:16:16,040 --> 00:16:16,880 to other 337 00:16:16,880 --> 00:16:18,680 I don't like using decays, 338 00:16:18,680 --> 00:16:20,600 I agree, my wife tells me that more massive you get 339 00:16:20,600 --> 00:16:22,360 the quicker you'll decay, 340 00:16:22,360 --> 00:16:24,720 And I agree that like, 341 00:16:24,720 --> 00:16:27,000 you know, I don't like this word because when you think of decays, 342 00:16:27,000 --> 00:16:28,600 you think of the breaking into parts 343 00:16:28,600 --> 00:16:32,480 and the top quark doesn't break into parts, it transforms into energy. 344 00:16:32,480 --> 00:16:33,880 Plus the 345 00:16:35,640 --> 00:16:36,720 W and the bottom quark 346 00:16:36,720 --> 00:16:37,400 Exactly. 347 00:16:37,400 --> 00:16:40,120 So you have these decay products, you know, 348 00:16:40,120 --> 00:16:43,120 and then you can look at 349 00:16:44,240 --> 00:16:47,000 their energy, their momentum, their angles 350 00:16:47,000 --> 00:16:49,400 and then you can 351 00:16:49,400 --> 00:16:51,160 figure things out from that? 352 00:16:51,160 --> 00:16:54,640 In our case for the entanglement, 353 00:16:54,680 --> 00:16:58,400 we measured that the angular correlation between these decay products, 354 00:16:58,400 --> 00:17:01,840 So in this case with the leptons, that decay from the top quark. 355 00:17:02,560 --> 00:17:03,120 Okay. 356 00:17:03,120 --> 00:17:05,960 So you have you have a couple leptons. 357 00:17:05,960 --> 00:17:08,960 It's complicated when they decay right? 358 00:17:08,960 --> 00:17:13,280 Top quarks have a few possibilities to decay, we look specifically at, 359 00:17:13,280 --> 00:17:21,640 we need to say that the top quarks are created in a pair of the top quark and its antimatter counterpart, the antitop 360 00:17:21,640 --> 00:17:24,640 And between these two, we actually measured the entanglement 360 00:17:25,040 --> 00:17:27,840 the spin entanglement between the top of the antitop. 361 00:17:27,840 --> 00:17:28,440 Both of them can decay, 362 00:17:29,400 --> 00:17:30,880 so they can 363 00:17:30,880 --> 00:17:34,120 have a few possibilities to decay. 364 00:17:34,560 --> 00:17:38,840 One of the possibilities to decay to final states with charged leptons. 365 00:17:38,840 --> 00:17:41,840 So, for example, electron or positron 366 00:17:42,320 --> 00:17:47,360 or the heavier twin of the electron 367 00:17:48,520 --> 00:17:50,480 not exactly the twin, 368 00:17:50,480 --> 00:17:52,840 the muon or the antimuon 369 00:17:52,840 --> 00:17:53,800 why we do this? 370 00:17:53,800 --> 00:17:57,280 Because the in our detectors, we measure 371 00:17:58,320 --> 00:18:01,880 the charged leptons in very good precision. 372 00:18:02,440 --> 00:18:06,640 And we need to have the tracks being measured very precisely. 373 00:18:07,000 --> 00:18:08,560 Because, as Giulia said before, 374 00:18:08,560 --> 00:18:12,040 in the end, we need to measure the angular separations between one charged lepton from one top, 375 00:18:12,040 --> 00:18:15,840 to the other charged lepton from the antitop. 376 00:18:16,360 --> 00:18:18,920 And this way we can deduce something about their spin correlations 377 00:18:18,920 --> 00:18:21,920 and about the entanglement between the top and anti top. 378 00:18:22,160 --> 00:18:24,520 So it tells you that they are correlated. Yes. 379 00:18:25,960 --> 00:18:26,840 That's interesting. 380 00:18:26,840 --> 00:18:29,840 And you came up with this over coffee, 381 00:18:31,200 --> 00:18:34,200 during a conference in, more or less. 382 00:18:34,920 --> 00:18:40,560 Yeah, a regular coffee break in the office. 383 00:18:41,000 --> 00:18:42,880 Oh, yeah. Okay. 384 00:18:42,880 --> 00:18:44,720 Coffee is very important, by the way. 385 00:18:47,240 --> 00:18:49,240 So Chetna wants to know. 387 00:18:50,560 --> 00:18:51,920 What exactly does it mean? 388 00:18:51,920 --> 00:18:54,880 So under certain circumstances, 389 00:18:54,880 --> 00:18:57,880 they're entangled you measure that they are entangled 390 00:18:58,360 --> 00:19:03,000 So how are they entangled, what is the meaning behind this? 391 00:19:03,080 --> 00:19:05,120 So, as Yoav said before, that 392 00:19:05,120 --> 00:19:12,440 means that you cannot describe, the spin state of one quark independently from the other 393 00:19:12,480 --> 00:19:13,800 in quantum mechanics, 394 00:19:13,800 --> 00:19:17,160 we use, just for example, the wave function 395 00:19:17,160 --> 00:19:20,640 to describe the state of a given particle or a given system. 396 00:19:21,440 --> 00:19:24,960 we can also use what, what is called the density matrix, 397 00:19:24,960 --> 00:19:27,960 which gives us the density to be in some specific states. 398 00:19:30,480 --> 00:19:34,560 And the idea behind entanglement is that if 399 00:19:34,560 --> 00:19:37,960 we have this density matrix which describes the quantum state of the system, 400 00:19:38,120 --> 00:19:41,120 and we have defined this for the top and the antitop. 401 00:19:41,520 --> 00:19:43,680 for the system of the two, 402 00:19:43,680 --> 00:19:46,680 we cannot describe this just by a combination 403 00:19:46,880 --> 00:19:51,000 of the individual spin density matrix of each one of the top 404 00:19:51,520 --> 00:19:52,680 or the antitop. 405 00:19:52,680 --> 00:19:55,200 This tells us that the state is not separable. 406 00:19:55,200 --> 00:20:00,720 We cannot describe the state of the top and antitop independently from the other. 407 00:20:02,440 --> 00:20:05,440 You know, if you're listening 408 00:20:06,480 --> 00:20:09,600 and you don't completely get this it's normal, right? 409 00:20:09,600 --> 00:20:11,880 This is a world that we don't live in. 410 00:20:11,880 --> 00:20:15,120 It's like the electrons that were mentioned before, right? 411 00:20:15,120 --> 00:20:18,800 Because we know the outcome of the measurement of 412 00:20:18,800 --> 00:20:21,800 one electron 413 00:20:22,960 --> 00:20:25,400 after we did the measurement on the other one, it tells us 414 00:20:25,400 --> 00:20:29,120 that basically we cannot describe the quantum state 415 00:20:29,120 --> 00:20:33,480 of both of the electrons, sorry, as an independent combination 416 00:20:33,480 --> 00:20:34,880 of the states of both of them, 417 00:20:34,880 --> 00:20:38,560 just because the correlations look so strong, there's so much affect each other. 418 00:20:39,000 --> 00:20:42,000 And so you have to describe the system as a whole. 419 00:20:43,800 --> 00:20:44,600 So I understand this 420 00:20:44,600 --> 00:20:48,360 was not simple to do, there were some hallenges in doing the analysis. 421 00:20:53,640 --> 00:20:55,320 Where to start? 422 00:20:55,320 --> 00:20:58,160 Well, one challenge is that we had to deal 423 00:20:58,160 --> 00:21:00,960 with the modelling of the t-tbar 424 00:21:00,960 --> 00:21:03,040 production threshold region 425 00:21:03,040 --> 00:21:06,040 So, close to 426 00:21:06,240 --> 00:21:09,040 two times the mass of the top quark 427 00:21:09,040 --> 00:21:09,480 And 428 00:21:09,480 --> 00:21:12,480 this region is not very well modelled yet, 429 00:21:12,880 --> 00:21:15,200 So we had to come up with a 430 00:21:15,200 --> 00:21:18,200 simplified model, and then we introduced this 431 00:21:19,120 --> 00:21:23,040 pseudoscalar resonance, that is a bound state of a top quark and a top antiquark, 432 00:21:25,800 --> 00:21:28,200 So this is called toponium. 433 00:21:28,200 --> 00:21:30,040 and then this improves 434 00:21:30,040 --> 00:21:33,040 our modelling of this region. 435 00:21:33,560 --> 00:21:36,560 Including this was not an easy process 436 00:21:37,240 --> 00:21:39,360 and, in our measurements 437 00:21:39,360 --> 00:21:40,800 we managed to do it. 438 00:21:40,800 --> 00:21:45,720 So in ATLAS they came out first but they didn't include this in the model. 439 00:21:45,760 --> 00:21:50,320 Yeah, we were able to show that our measurement 440 00:21:51,360 --> 00:21:54,360 is not affected by this effect. 441 00:21:54,640 --> 00:21:57,640 But nevertheless, this is actually a super interesting point 442 00:21:57,640 --> 00:21:59,920 because this is a very cool effect. 443 00:21:59,920 --> 00:22:02,920 The idea behind this is that 444 00:22:03,040 --> 00:22:07,000 close to the production threshold where the top and anti-top are slow, 445 00:22:07,840 --> 00:22:10,840 there are some non-relativistic effects that enters 446 00:22:11,680 --> 00:22:14,320 this is the so-called toponium. 447 00:22:14,320 --> 00:22:17,480 It's funny, this is not included by default 448 00:22:18,040 --> 00:22:20,320 in our Monte Carlo simulations. 449 00:22:20,320 --> 00:22:23,600 It's a non-perturbative effect. 450 00:22:24,640 --> 00:22:27,640 Actually, the tools we used and that were used in CMS, 451 00:22:30,440 --> 00:22:33,800 let's say give a better and better 452 00:22:33,800 --> 00:22:37,120 grasp of this specific effect 453 00:22:37,640 --> 00:22:40,640 and perhaps also the possibility to measure it 454 00:22:41,120 --> 00:22:44,120 and to develop some observables which are more sensitive to this state 455 00:22:44,680 --> 00:22:48,040 because this state brings an enhancement 456 00:22:48,040 --> 00:22:51,840 of the more entangled events to a cross section. 457 00:22:51,840 --> 00:22:54,280 So it basically means that we should see more entangled events than 458 00:22:54,280 --> 00:22:58,360 than expected from Monte Carlo simulations that we use. 459 00:23:00,640 --> 00:23:02,000 So you mentioned a few things in there. 460 00:23:02,000 --> 00:23:05,000 I'm not sure if we're going to go into details, but now, 461 00:23:05,600 --> 00:23:09,800 QCD is very complicated. 462 00:23:10,120 --> 00:23:13,120 So you you have these different realms, right? 463 00:23:13,520 --> 00:23:16,600 the perturbative and the non perturbative, which has to do 464 00:23:16,600 --> 00:23:19,160 with relativity effects? Yes. 465 00:23:22,320 --> 00:23:29,480 The nice thing is that actually these measurement of entanglement, beyond being 466 00:23:30,400 --> 00:23:32,680 these measurements of entanglement, beyond 467 00:23:32,680 --> 00:23:35,680 being just, you know, being a very nice 468 00:23:36,880 --> 00:23:39,360 and cool interdisciplinary thing to measure, they actually brought a lot of benefits 469 00:23:39,360 --> 00:23:42,360 to high-energy physics, to measure processes of high-energy physics. 471 00:23:43,000 --> 00:23:46,360 So, so tell me a little bit more about this. What are the benefits that come from this. 472 00:23:47,360 --> 00:23:48,680 So besides the 473 00:23:48,680 --> 00:23:51,680 possibility to have a better grasp of toponym, 474 00:23:52,640 --> 00:23:54,520 mentioned before by Giulia, 475 00:23:54,520 --> 00:23:57,520 So for example, if you look at the measurement by CMS, 476 00:23:57,600 --> 00:24:01,680 you can see that the data agrees better with the existence of this toponium. 477 00:24:02,320 --> 00:24:05,840 Which is quite nice, because if we look at our 478 00:24:06,800 --> 00:24:11,080 resolution in the detector to reconstruct the invariant mass 479 00:24:11,520 --> 00:24:13,680 of the top and the anti top, 480 00:24:13,680 --> 00:24:15,680 We can never see this because it's 481 00:24:15,680 --> 00:24:18,880 a lot more narrow than our t-tbar resolution. 482 00:24:18,880 --> 00:24:21,880 But with the spin correlation effects and entanglement observables, 483 00:24:22,880 --> 00:24:25,880 it's possible to see some signs of this, 484 00:24:25,900 --> 00:24:31,920 It also gave a push to theorists, to investigate a bit more. 485 00:24:31,920 --> 00:24:35,000 And this also came up in a few other measurements 486 00:24:35,640 --> 00:24:38,640 by CMS, these effects, 487 00:24:40,440 --> 00:24:43,320 In addition, I have to say that 488 00:24:43,320 --> 00:24:47,760 there are many new techniques to search for physics 489 00:24:47,760 --> 00:24:51,480 beyond the Standard Model that has been developed based on the quantum observables 490 00:24:52,000 --> 00:24:56,280 that we thought about and that we looked at in our measurements. 491 00:24:57,520 --> 00:24:58,840 Physics beyond the Standard Model 492 00:24:58,840 --> 00:25:03,040 is something we all want because this is what makes our careers here 493 00:25:04,000 --> 00:25:06,840 as experimentalists is forever 494 00:25:06,840 --> 00:25:09,840 trying to find out what's wrong with theory. 495 00:25:10,640 --> 00:25:12,480 We love theorists. We love theorists. 496 00:25:12,480 --> 00:25:16,360 But they only explain 5% of the universe. 497 00:25:16,520 --> 00:25:19,160 Or less, we don't even know gravity. 498 00:25:19,160 --> 00:25:22,480 Okay, so there are a lot of things, a lot of big questions out there. 499 00:25:22,800 --> 00:25:26,120 And so we're always looking to see where the model can break. 500 00:25:26,760 --> 00:25:27,840 And that gives us hints. 501 00:25:27,840 --> 00:25:30,840 And so to see this it gives us some more tools. 502 00:25:31,480 --> 00:25:36,200 I should mention toponium is only one of the oniums right? 503 00:25:36,400 --> 00:25:38,600 There are others that have been measured 504 00:25:38,600 --> 00:25:41,720 bottomonium, charmonium, 505 00:25:42,040 --> 00:25:44,960 meaning that you have a charm quark and an anti charm, 506 00:25:44,960 --> 00:25:50,200 bottom, or anti bottom, but these we can measure more directly. 507 00:25:51,360 --> 00:25:52,320 Yes, but 508 00:25:52,320 --> 00:25:55,720 with the top it's not so easy. 509 00:25:55,720 --> 00:25:57,320 Also, 510 00:25:57,320 --> 00:26:01,000 it's not exactly the same thing because the tops really decay before 511 00:26:01,000 --> 00:26:04,600 they can form like a particle a bound state, a meson, 512 00:26:04,840 --> 00:26:08,360 So maybe toponium is a bit of a misleading name. 513 00:26:08,480 --> 00:26:10,040 So they haven't really formed, 514 00:26:10,040 --> 00:26:13,040 They exchange a few gluons before they decay. 515 00:26:13,880 --> 00:26:17,360 Gluons being the carriers of the strong nuclear force, 516 00:26:18,160 --> 00:26:21,160 like photons, we have photons coming through us right now. 517 00:26:21,920 --> 00:26:24,920 That's what's inside these protons. 518 00:26:25,960 --> 00:26:27,200 The gluons, great name. 519 00:26:27,200 --> 00:26:29,440 Keeps it all glued. 520 00:26:29,440 --> 00:26:32,360 So my next question for you is, what's next? 521 00:26:32,360 --> 00:26:35,600 I mean, if you you guys learn off from each other, this is very common 522 00:26:36,360 --> 00:26:41,440 for experiments. We go to conferences or we have discussions or seminars. 523 00:26:41,440 --> 00:26:44,080 That's when we share information. 524 00:26:45,560 --> 00:26:47,160 Of course, you know, 525 00:26:47,160 --> 00:26:50,160 some information gets shared during coffee breaks, 526 00:26:50,960 --> 00:26:53,560 As we've learned, 527 00:26:53,560 --> 00:26:54,960 But now, I mean, 528 00:26:54,960 --> 00:26:58,000 will ATLAS, for example, do a measurement with toponium 529 00:26:59,200 --> 00:27:02,200 included, or, 530 00:27:02,480 --> 00:27:05,480 you found that it's an effect that doesn't we don't know. 531 00:27:05,640 --> 00:27:06,960 Can't say. 532 00:27:06,960 --> 00:27:07,720 Oh, yeah. 533 00:27:07,720 --> 00:27:10,720 We can't always say these things. 534 00:27:14,600 --> 00:27:18,600 In general, how do you see us going forward with these measurements? 535 00:27:19,560 --> 00:27:22,560 Well there is not only quantum entanglement that we can measure, 536 00:27:22,800 --> 00:27:26,320 there are also lots of other quantum correlations, 537 00:27:26,640 --> 00:27:30,480 like Bell's inequality, as we mentioned before. 538 00:27:30,920 --> 00:27:33,480 So for sure, one of the next 539 00:27:33,480 --> 00:27:35,120 point will be to also discover 540 00:27:36,840 --> 00:27:38,560 these new quantum effects. 541 00:27:38,560 --> 00:27:40,840 I want to give maybe a number. 542 00:27:40,840 --> 00:27:41,920 Just to give you an idea. 543 00:27:41,920 --> 00:27:43,920 Why is it interesting to do these measurements 544 00:27:43,920 --> 00:27:47,080 So we mentioned before the Nobel Prize in physics. 545 00:27:47,520 --> 00:27:48,120 Right. 546 00:27:48,120 --> 00:27:51,120 And it was done by testing 547 00:27:51,960 --> 00:27:54,200 the entanglement and the Bell inequality with photons. 548 00:27:54,200 --> 00:27:56,640 What we do here at the LHC, the measurement 549 00:27:56,640 --> 00:27:57,720 that both CMS and ATLAS did 550 00:27:57,720 --> 00:28:02,840 with top quarks, is about 12 orders of magnitude higher in energy than 551 00:28:03,000 --> 00:28:07,120 all of these extremely important laboratory experiments. 552 00:28:07,840 --> 00:28:10,360 So when you go so much higher in the scale, 553 00:28:10,360 --> 00:28:13,880 there is already a fundamental interest of why we do this. 554 00:28:14,520 --> 00:28:17,400 And what CMS and ATLAS did, 555 00:28:17,400 --> 00:28:19,920 at least to me, is a proof of concept 556 00:28:19,920 --> 00:28:24,560 that we can actually perform such measurements using collider physics, 557 00:28:25,240 --> 00:28:28,000 using collider experiments, 558 00:28:28,000 --> 00:28:30,800 and there is so much room for doing more. So many other proposals, 559 00:28:30,800 --> 00:28:31,920 to measure many other things. 560 00:28:33,480 --> 00:28:36,040 A lot has come up 561 00:28:36,040 --> 00:28:36,640 since then. 562 00:28:36,640 --> 00:28:40,080 And we think we can say both in CMS and ATLAS we are 563 00:28:40,720 --> 00:28:45,400 now working on performing these other measurements in some other parts of phase space with top quarks, 564 00:28:45,440 --> 00:28:49,040 or, for example, with the Higgs boson decay. 565 00:28:49,640 --> 00:28:53,320 And so there is a lot to do. 566 00:28:53,720 --> 00:28:56,640 This is the first time this is being done in collider research. 567 00:28:56,640 --> 00:28:59,840 It was the measurement with the highest energy ever performed. 568 00:29:00,840 --> 00:29:03,160 At the LHC it was the first time. 569 00:29:03,160 --> 00:29:06,160 It was done before 570 00:29:06,200 --> 00:29:09,480 in colliders with mesons 571 00:29:10,320 --> 00:29:14,440 at lower energies, in particular with B mesons, 572 00:29:15,240 --> 00:29:19,400 but it's a different type of entanglement. 573 00:29:20,080 --> 00:29:25,320 It's more flavour entanglement it's related to other properties of particles. 574 00:29:26,040 --> 00:29:28,440 But never at the LHC, 575 00:29:28,440 --> 00:29:30,880 never with quarks 576 00:29:30,880 --> 00:29:33,240 which are fundamental particles, 577 00:29:33,240 --> 00:29:37,520 It's pure quantum entanglement because it's a fundamental particle 578 00:29:38,680 --> 00:29:41,360 Remember the example that I gave with 579 00:29:41,360 --> 00:29:44,360 both of the electrons at other parts of the Universe. 580 00:29:44,480 --> 00:29:47,240 Yeah. This was never done actually. 582 00:29:48,040 --> 00:29:48,200 Yeah. 583 00:29:48,200 --> 00:29:50,840 That would take some effort to go to different parts of the universe. 584 00:29:50,840 --> 00:29:51,760 Well yes. 585 00:29:51,760 --> 00:29:54,760 But in general between two what we call free electrons. 586 00:29:54,880 --> 00:29:55,440 Yeah. 587 00:29:55,440 --> 00:29:58,680 I mean it was done with a bit more complicated systems. 588 00:29:58,680 --> 00:30:04,440 Here, we actually measured the entanglement between two quarks which are 589 00:30:04,440 --> 00:30:07,440 let's say quasi-free particles. 590 00:30:09,480 --> 00:30:11,400 So, you have theorists 591 00:30:11,400 --> 00:30:15,280 coming to you, saying, I got some ideas now, right? 592 00:30:15,280 --> 00:30:18,280 I guess you have both been approached by theorists 593 00:30:18,280 --> 00:30:20,760 and different things in quantum mechanics that can be measured. 594 00:30:20,760 --> 00:30:25,160 Also though, what we have coming up in a few years, 595 00:30:26,040 --> 00:30:28,640 we're going to tear our experiments apart 596 00:30:28,640 --> 00:30:31,560 and we're going to go to a High-Luminosity LHC. 597 00:30:31,560 --> 00:30:34,080 So actually, we have, a year and a half or so 598 00:30:34,080 --> 00:30:37,840 of running and then nothing for 3 and a half to 4 years. 599 00:30:37,840 --> 00:30:41,520 And then we start up with brand new beautiful detectors 600 00:30:42,360 --> 00:30:45,360 made to be able to go at a much higher rate, so we'll have much higher statistics, 601 00:30:46,200 --> 00:30:46,800 will that help? 602 00:30:47,320 --> 00:30:48,880 Will that be of use to you? 603 00:30:48,880 --> 00:30:52,360 We will have more data so we can get measurements more precisely. 604 00:30:53,760 --> 00:30:57,800 So, for example, I mean, as was mentioned before by Giulia, 605 00:30:57,800 --> 00:31:02,440 we have a lot more concepts of quantum correlations that we can measure. 606 00:31:02,920 --> 00:31:06,280 If you look, for example at Bell state, or Bell inequality, 607 00:31:07,680 --> 00:31:09,680 if we look at the measurement, 608 00:31:09,680 --> 00:31:12,960 in t-tbar, we have to go to a lot more extreme 609 00:31:12,960 --> 00:31:16,200 parts of phase space, to perform these measurements. 610 00:31:16,680 --> 00:31:19,680 And if we have more data in order to do it, 611 00:31:20,000 --> 00:31:24,240 it means that we have more events and more statistics to actually be able to 612 00:31:25,280 --> 00:31:27,640 do these measurements because, 613 00:31:27,640 --> 00:31:30,280 of course, we need statistics to make 614 00:31:30,280 --> 00:31:34,200 precise measurements So extreme parts of phase space. 615 00:31:34,200 --> 00:31:35,400 Sounds like a great place to go. 616 00:31:36,760 --> 00:31:37,080 But it is 617 00:31:37,080 --> 00:31:40,080 sort of those things which are rare. 618 00:31:40,160 --> 00:31:43,480 It's rare to find something that has this momentum, 619 00:31:43,480 --> 00:31:44,320 this energy, 620 00:31:44,320 --> 00:31:47,320 this mass, whatever. 621 00:31:47,400 --> 00:31:48,840 Those are what we consider phase space. 622 00:31:48,840 --> 00:31:51,560 And yeah, with more statistics. 623 00:31:51,560 --> 00:31:54,320 Even if we're not going to increase energy, because the LHC won't increase 624 00:31:54,320 --> 00:31:55,800 much more, 625 00:31:55,800 --> 00:31:58,080 we are about as high as we can go, 626 00:31:58,080 --> 00:32:02,240 having much more data is a way of also going up in energy 627 00:32:02,240 --> 00:32:05,240 because we can produce those things the more rare things you will see there. 628 00:32:08,240 --> 00:32:08,640 Okay. 629 00:32:08,640 --> 00:32:11,400 Well, I'm looking forward to seeing new results. 630 00:32:11,400 --> 00:32:13,760 I think it's going to be a lot of fun. I think especially because 631 00:32:13,760 --> 00:32:16,960 you've gone into an area that we haven't been in before. 632 00:32:17,000 --> 00:32:20,000 So congratulations on doing that. 633 00:32:20,560 --> 00:32:21,920 So thank you. 634 00:32:21,920 --> 00:32:24,280 I want you to thank Giulia Negro 635 00:32:24,280 --> 00:32:28,360 From Purdue University, in the CMS experiment. 636 00:32:28,800 --> 00:32:33,480 And also Yoav Afik from the ATLAS experiment and from 637 00:32:33,840 --> 00:32:37,440 Enrico Fermi Institute, as shown on his cup 638 00:32:37,880 --> 00:32:39,360 and you have your beautiful CMS cup here. 639 00:32:39,360 --> 00:32:41,080 And I celebrate outreach. 640 00:32:41,080 --> 00:32:43,200 with my IPPOG cup here. 641 00:32:43,200 --> 00:32:46,840 This has been early morning coffee at CERN. 642 00:32:47,360 --> 00:32:50,360 It's a podcast by the scientists of CERN 643 00:32:50,440 --> 00:32:53,360 about the science of CERN. 644 00:32:53,360 --> 00:32:56,760 You can find all of our episodes on CERN's YouTube channel. 645 00:32:57,040 --> 00:33:00,240 And if you don't want to look at our lovely faces, you can also listen to us 646 00:33:00,240 --> 00:33:03,440 anywhere where you get a podcast Early Morning Coffee at CERN. 647 00:33:04,240 --> 00:33:05,400 Anywhere. 648 00:33:05,400 --> 00:33:08,400 Our editor and producer is Chetna Krishna. 649 00:33:08,400 --> 00:33:11,640 Our executive producer is Jacques Fichet Studio. 650 00:33:11,640 --> 00:33:14,080 Ron Suykerbuyk is our technical lead. 651 00:33:14,080 --> 00:33:18,680 Our studio manager is Max Brice, sound engineer by Piotr Traczyk. 652 00:33:18,920 --> 00:33:21,760 Our original theme comes from the Canettes Blues Band 653 00:33:21,760 --> 00:33:24,960 with piano by Wojt "Play it in any key" Krajewski. 654 00:33:25,040 --> 00:33:29,760 Many thanks to Paola Catapano, Matthew Chalmers and Arnaud Marsollier 655 00:33:30,000 --> 00:33:33,120 for all of their great advice and strategic planning, and a big 656 00:33:33,120 --> 00:33:37,120 thanks to the entire ECO team (that's not the Ecological team, by the way) 657 00:33:38,040 --> 00:33:42,840 Rather, the Education, Communication and Outreach team at CERN for providing us with access 658 00:33:42,840 --> 00:33:47,240 to Wire Chamber Studio and all the help that comes along with it. 659 00:33:47,760 --> 00:33:52,440 Opinions expressed here are our own and do not necessarily reflect 660 00:33:52,440 --> 00:33:56,440 those of CERN or our colleagues, even though we think they ought to. 661 00:33:57,040 --> 00:34:00,400 My name is Steven Goldfarb, and this has been Early Morning Coffee at CERN. 662 00:34:00,440 --> 00:34:01,800 We'll see you again next month.