WEBVTT 00:00:04.000 --> 00:00:08.000 No, we have. 00:00:08.000 --> 00:00:11.000 Okay. Okay. 00:00:11.000 --> 00:00:17.000 So it's our pleasure to have Melissa Diamond. 00:00:17.000 --> 00:00:21.000 Coming from McGill, to give a talk. 00:00:21.000 --> 00:00:29.000 So, today we have a downward fluctuation of grad students, but an upper fluctuation of faculty, so… 00:00:29.000 --> 00:00:34.000 Like, the universe compensate. So, yeah. So, a little takeaway. 00:00:34.000 --> 00:00:44.000 Hi. Hi, everyone, if you haven't met yet, as Nico just said, I'm Melissa Diamond. I'm a postdoc at McGill University, and I'll be talking to you about a combination of 00:00:44.000 --> 00:00:58.000 work that I've already finished, along with ongoing follow-up work that I've done with all of these great people, some of whom were working late last night to produce plots that I could share with you today. So you're getting these hot-off-the-press, 00:00:58.000 --> 00:01:03.000 Though they are still preliminary. So we know who's the boss now. 00:01:03.000 --> 00:01:07.000 So, uh, what I'll be talking to you about is, uh… 00:01:07.000 --> 00:01:18.000 Actually, we'll start here. But I'll be talking to you about is this basic idea that when I write down a model of dark matter, where I assume it interacts with one particle in the standard model, which is 00:01:18.000 --> 00:01:23.000 Often away, we think about it when we're designing dark matter experiments, um… 00:01:23.000 --> 00:01:37.000 That's not really the whole story, so out of automatically I going to pick up additional interactions. And sometimes these extra interactions that I get, these loop-level and effective interactions that I'll be showing you as we go through the presentation, 00:01:37.000 --> 00:01:45.000 are the more important piece of the puzzle. Sometimes those are the more constraining thing that we should be paying attention to. 00:01:45.000 --> 00:01:50.000 So, let's get into it. Now, I've been talking about dark matter, um… 00:01:50.000 --> 00:01:54.000 But let's just remind ourselves what dark matter is and why we love it. 00:01:54.000 --> 00:02:02.000 So, something like 80% of the gravitating matter in the universe does not interact with light. We've got evidence of this 00:02:02.000 --> 00:02:07.000 at all different levels of astronomical observation, from looking at 00:02:07.000 --> 00:02:11.000 The rotation girt curves of galaxies, where we see… 00:02:11.000 --> 00:02:17.000 sort of the velocity of stars that we would expect if the galaxy were made only out of ordinary matter, 00:02:17.000 --> 00:02:20.000 very… it looks very different from what we actually observe. 00:02:20.000 --> 00:02:28.000 This tells us that most of the mass in the galaxy is something else, something that is not the stars and the gas that we can see. 00:02:28.000 --> 00:02:32.000 The filler word we've been using for this dark, gravitating thing is 00:02:32.000 --> 00:02:43.000 Dark matter. We see it at a variety of other scales as well. We can look at the collision between two different galaxies, such as the bullet cluster, where 00:02:43.000 --> 00:02:48.000 This is two galaxies, or galaxy clusters that collided some time ago. 00:02:48.000 --> 00:02:53.000 In the purple region, that's where most of the mass is. We can see that via gravitational lensing. 00:02:53.000 --> 00:02:55.000 Uh, in the pink region, 00:02:55.000 --> 00:02:58.000 That's where we see X-ray radiation. 00:02:58.000 --> 00:03:06.000 They're not in the same spot. Why? Because in this collision, the stuff that had strong enough interactions got caught in the middle and heated up. 00:03:06.000 --> 00:03:14.000 And the XA radiation. The mass, though, seemed to have passed right through this collision as if there was nothing there. 00:03:14.000 --> 00:03:24.000 Within the standard model, we don't really have a lot of particles that do that, that don't interact with each other particularly strongly, where they'd be able to pass through just like this. 00:03:24.000 --> 00:03:29.000 And so again, we're seeing evidence of something that doesn't really interact with us, doesn't really interact with itself, 00:03:29.000 --> 00:03:33.000 But it is very gravitationally important. 00:03:33.000 --> 00:03:38.000 And of course, the final nail in the coffin, uh, what came from the Cosmic microwave background. 00:03:38.000 --> 00:03:44.000 We can look at the distribution of hot and cold patches left over from 00:03:44.000 --> 00:03:48.000 Uh, when the early universe first became translucent to light, 00:03:48.000 --> 00:03:54.000 And what we see is that the growth of these patches basically requires us to have 00:03:54.000 --> 00:04:02.000 some kind of material that does not interact strongly with light, otherwise they would not have the same distribution that we see today. 00:04:02.000 --> 00:04:07.000 So, most of the universe is made of something that's dark and heavy, 00:04:07.000 --> 00:04:10.000 We're calling it Dark Matter. We don't know what it is. 00:04:10.000 --> 00:04:14.000 But there's an exerted a large effort to figure that out. 00:04:14.000 --> 00:04:17.000 And I'll tell you about a piece of it today. 00:04:17.000 --> 00:04:19.000 So, as I was saying at the beginning, 00:04:19.000 --> 00:04:25.000 A lot of the time, we look for dark matter that has some kind of interaction with the Standard Model, because simply 00:04:25.000 --> 00:04:28.000 those models are easier to look for. 00:04:28.000 --> 00:04:32.000 Um, usually we'll think about dark matter interacting with one particle, 00:04:32.000 --> 00:04:42.000 But the standard model is a complicated beast. Once you introduce interactions with one thing, it's hard to avoid interactions with the rest. 00:04:42.000 --> 00:04:51.000 your standard model Lagrangian written out, and all of its beautiful glory. It's complicated enough, there are many particles, many interactions between them. 00:04:51.000 --> 00:05:03.000 When I introduce a dark matter interaction term with one of these particles, it's somewhat easy to see how that can start to grow and bring in other additional effective interactions. 00:05:03.000 --> 00:05:15.000 Now, this can actually work in two directions for us. On the one hand, what this means is that I can take existing dark matter constraints and pretty much for free, uh, well, for the low, low cost of 00:05:15.000 --> 00:05:20.000 me doing the calculations and slowly losing my mind. Um, we can figure out 00:05:20.000 --> 00:05:27.000 Uh, how to apply these constraints to multiple different dark matter models that they weren't necessarily designed for. 00:05:27.000 --> 00:05:38.000 It also means that you can take existing dark matter detectors and find new types of dark matter models that they can have reach for. Again, that maybe they weren't set up to do. 00:05:38.000 --> 00:05:43.000 The downside is that sometimes these detectors may be looking in parameter space that is already ruled out for 00:05:43.000 --> 00:05:46.000 the above reason. 00:05:46.000 --> 00:05:49.000 But let me get a little bit more concrete with what I'm talking about. 00:05:49.000 --> 00:06:04.000 So, the area… part of parameter space where this turns out to be most useful is in the sub-GEV mass range. The reason being that if I'm looking for dark matter that interacts with atomic nuclei, which is sort of a common target for a lot of experiments, 00:06:04.000 --> 00:06:13.000 As I go down to lower masses, usually these experiments rely on the dark matter entering the experiment and hitting something. 00:06:13.000 --> 00:06:18.000 And causing whatever it hit, usually a heavy nucleus, to respond in some way. 00:06:18.000 --> 00:06:31.000 As the dark matter gets lighter and lighter, it has less and less momentum to hit these nuclei with, and it becomes increasingly difficult to actually observe these events. So you can see these experiments pretty much all lose sensitivity, 00:06:31.000 --> 00:06:35.000 As you go to lower masses. Now, we are developing, uh, 00:06:35.000 --> 00:06:39.000 New experiments that can probe this parameter space, but… 00:06:39.000 --> 00:06:44.000 That requires developing new experiments, and maybe we can look in there for free. 00:06:44.000 --> 00:06:51.000 One thing that we could do, potentially, is think about, instead of scattering with nuclei, which are quite heavy, 00:06:51.000 --> 00:06:56.000 Can we relate these interactions to scattering with electrons? We already have, uh… 00:06:56.000 --> 00:07:06.000 Dark matter electron recoil Experiments, electrons are much lighter than nuclei, and so you can sort of more easily probe lower-mass particles that way. 00:07:06.000 --> 00:07:11.000 In addition, we could think about dark matter scattering and interacting with photons. There are a lot of… 00:07:11.000 --> 00:07:25.000 fairly strong limits on dark matter photon interactions. It's in the name, it's supposed to be dark. Um, and so there's a lot of cosmological constraints that you can start to pull on when we think about dark matter picking up effective couplings to photons. 00:07:25.000 --> 00:07:30.000 And then finally, a thing I'll be talking about is meson decays. 00:07:30.000 --> 00:07:32.000 I'll explain in a couple of slides. 00:07:32.000 --> 00:07:43.000 But once you have dark matter that talks to nuclei, you're also going to start picking up interactions with mesons, and you can start messing with meson decays. And those are things that we measure pretty well. 00:07:43.000 --> 00:07:53.000 Sorry, these are three examples of dark matter interactions through these things that would happen at the loop level? Yes. Okay, so it's like, your idea is that it… the model is that it only interacts with… 00:07:53.000 --> 00:08:02.000 nuclei to a tree level? Yes. And then it could pick up interactive… it would pick up interactions with these other things at the level? Yeah. And to some degree, it's… 00:08:02.000 --> 00:08:07.000 potentially better than loop level, but I'll… I'll show that further down. 00:08:07.000 --> 00:08:09.000 Like, tree level, yeah. 00:08:09.000 --> 00:08:18.000 Or if you… if you count, like, pion decays to photons as tree level, then tree level. 00:08:18.000 --> 00:08:25.000 When you say that you're… you're gonna show me. Oh, no, no, you can go ahead. No, no, uh, when you say it's nuclear recall, so you're assuming coupling… 00:08:25.000 --> 00:08:28.000 Yeah, yeah. 00:08:28.000 --> 00:08:38.000 Um, so the question is, of course, how are we going about doing this? How are we relating these different types of interactions? What you pretty much got at, uh, we're going from tree level to loop level. 00:08:38.000 --> 00:08:43.000 But this itself isn't exactly a new idea. Um… 00:08:43.000 --> 00:08:57.000 So, this has been around, uh, people have done similar things, at least in 2014, but they did the reverse version of what we're doing. So, as an example, if I've got dark matter, which interacts, say, at tree level with electrons via a vector mediator, something heavy, 00:08:57.000 --> 00:09:00.000 then I could imagine just… 00:09:00.000 --> 00:09:08.000 embedding that whole, uh, diagram into a larger diagram. My external electrons now become part of a loop. 00:09:08.000 --> 00:09:14.000 And when I close my loop, I can get the whole thing to talk, uh, to nuclei via the… 00:09:14.000 --> 00:09:20.000 photons. So this has worked out in these papers in 2014. 00:09:20.000 --> 00:09:25.000 And they got some useful limits for, sort of, I think, a heavier dark matter. 00:09:25.000 --> 00:09:27.000 Um, I'll also point out that 00:09:27.000 --> 00:09:39.000 Effective interactions really aren't a new thing for dark matter searches. Most Axion searches are ultimately relying on an effective or a loop-level interaction. So, it shows up a lot, and it can be 00:09:39.000 --> 00:09:47.000 pretty useful. So the original paper where we explored this idea was called Limiting Light Dark Matter with Luminous Hadronic Loops. 00:09:47.000 --> 00:09:50.000 In that case, the first pass at this… 00:09:50.000 --> 00:09:56.000 We looked at relating the dark matter proton cross-section to just a dark matter-electron cross-section, 00:09:56.000 --> 00:10:04.000 In that case, we assumed we were working with a vector mediator. The relevant mass range where you got interesting results was about 1 to 100 MeV, 00:10:04.000 --> 00:10:10.000 And these were the sort of cross-sections that we were probing. You need heavy mediators, right? 00:10:10.000 --> 00:10:13.000 It doesn't have to be heavy. Okay. 00:10:13.000 --> 00:10:15.000 Yeah. 00:10:15.000 --> 00:10:19.000 Uh, I mean, the… 00:10:19.000 --> 00:10:27.000 I guess I'll show you when we have the dots. Sorry, the mascot here is the dark matter. Yes, it's the dark matter mass. 00:10:27.000 --> 00:10:38.000 Um, and so with this, you… we basically are able to show you can use electron recoil experiments to probe parameter space you can't reach easily with nuclear recoil experiments. 00:10:38.000 --> 00:10:46.000 Now, the reason that the earlier papers that had been done on the topic were in 2014, and it took a while for anyone to do this version, 00:10:46.000 --> 00:10:51.000 is that we need to call upon QCD to be able to think about this. 00:10:51.000 --> 00:10:59.000 Basically, if I'm talking about dark matter interacting with nuclei, what's really happening under the hood is that the dark matter has a coupling to quarks. 00:10:59.000 --> 00:11:04.000 And if my dark matter has a coupling to forks, I need to be thinking about QCD, which is… 00:11:04.000 --> 00:11:07.000 not the most enjoyable thing to do. 00:11:07.000 --> 00:11:10.000 Uh, fortunately… Says who? 00:11:10.000 --> 00:11:18.000 fortunately, uh, most scattering experiments, and honestly, most interactions that are relevant to dark matter limits are happening at low energies. 00:11:18.000 --> 00:11:28.000 And low energies, uh, the quarks are not the important players anymore. We use chiral effective field theory, and it's the light mesons, mostly the pion. 00:11:28.000 --> 00:11:31.000 Um, who come in and save the day. 00:11:31.000 --> 00:11:37.000 So, these guys are going to be the ones that are important for most of the interactions that we're dealing with. 00:11:37.000 --> 00:11:44.000 The way we'd go about doing these estimates is I would say, I'm going to write down a coupling between my mediator and quarks, 00:11:44.000 --> 00:11:49.000 So, in this case, in the first pass we took at it, we had, uh… 00:11:49.000 --> 00:11:52.000 a vector mediator, it's got a mass. 00:11:52.000 --> 00:11:55.000 Um, and it's… 00:11:55.000 --> 00:11:59.000 We're gonna couple it to the quarks, and then from that, we'll get 00:11:59.000 --> 00:12:04.000 An effective coupling to nuclei, so that we can compare it against the nuclear cross-section. 00:12:04.000 --> 00:12:15.000 Uh, protons and quarks, they're all fermions, so you end up getting a coupling that has the same form, and at least in the vector case, very conveniently, 00:12:15.000 --> 00:12:21.000 The effective coupling to protons comes out to just the sum of the coupleings to the quarks that 00:12:21.000 --> 00:12:27.000 more or less compose the protons. So for a proton, it's 2 up quarks and a down quark, 00:12:27.000 --> 00:12:36.000 The coupling looks like 2 times the up coupling plus the down coupling. They don't all work out like that, but in this case, it's pretty tidy. 00:12:36.000 --> 00:12:42.000 And then, you'll want to find the equivalent interaction with the mesons, because they'll become important. 00:12:42.000 --> 00:12:49.000 So, uh, for pions, if I use chiral effective field theory just to figure out what the interaction looks like, 00:12:49.000 --> 00:12:58.000 This is what we get. Uh, so we get this scalar derivative coupling to the charged pions, we get the same to the charged kaons, they're heavier, so… 00:12:58.000 --> 00:13:01.000 We include them in the calculation, but I'm not going to show it to you here. 00:13:01.000 --> 00:13:11.000 And then the effective coupling looks like this. It's up minus down, which, again, actually lines up with what the pions are made of, which is an up and an anti-down, so… 00:13:11.000 --> 00:13:15.000 still sort of following that story of what these things are composed of. 00:13:15.000 --> 00:13:22.000 That doesn't work out for the other mediators, but it's cute for the, uh, vector mediators. 00:13:22.000 --> 00:13:27.000 So then, now that we've got, uh, all the pieces of the puzzle, we can go about calculating our cross-sections. 00:13:27.000 --> 00:13:38.000 For proton scattering, it would look something like this. We're starting with this underlying theory, and we get this contribution from, uh, the strength of that vector term. 00:13:38.000 --> 00:13:46.000 We also automatically get these interactions as well. I don't get to have this guy without this… without these, at least not without some… 00:13:46.000 --> 00:13:49.000 sort of model-building trickery. 00:13:49.000 --> 00:13:55.000 These terms are going to, uh, have a factor of E times A up minus A down, 00:13:55.000 --> 00:14:11.000 That comes from connecting our maisons to a photon, and from connecting our dark mediator to the mesons. We'll also get a loop suppression, or just a loop term that comes from calculating this piece. 00:14:11.000 --> 00:14:22.000 No. Putting it all together, what I get is the ability to write down the dark matter electron cross-section in terms of a dark matter-proton cross-section, and then some model-specific terms. 00:14:22.000 --> 00:14:28.000 So, here is the tree-level cross-section, this is the loop-level cross-section, 00:14:28.000 --> 00:14:32.000 This is the piece that helps me get between the two of them. 00:14:32.000 --> 00:14:35.000 This piece comes from the loop contribution. 00:14:35.000 --> 00:14:48.000 This specifically is what we're getting out of the pion loop, and then this is just switching between scattering with electrons versus scattering with protons. So we get the extra E squared, because you've got an extra 00:14:48.000 --> 00:14:52.000 Coupling to electrons, and then you've got, uh… 00:14:52.000 --> 00:14:55.000 those reduced mass terms again, because I'm switching from… 00:14:55.000 --> 00:14:57.000 protons to electrons. 00:14:57.000 --> 00:15:00.000 Putting it together, this looks pretty bad. 00:15:00.000 --> 00:15:09.000 Putting it together, I electron cross-section is about 10 to the minus 14 times the proton cross-section times some model-dependent terms. 00:15:09.000 --> 00:15:14.000 But I've got these reduced mass pieces here, and so these can give me an extra factor of, like, 00:15:14.000 --> 00:15:21.000 2,000 squared, depending on the mass of my dark matter. So, this helps us out a bit. 00:15:21.000 --> 00:15:30.000 The other pieces you might be wondering about, like, what's this alpha? The alpha is the cutoff of the theory. It's when chiral effective field theory breaks down. 00:15:30.000 --> 00:15:37.000 Depending on where you want to put that, we can call it maybe about the proton mass, you can call it maybe a few hundred MeV. 00:15:37.000 --> 00:15:43.000 Um, it's not going to make a huge difference in our calculations, though, but it is something to be aware of. 00:15:43.000 --> 00:15:48.000 When we're deciding where it's appropriate to apply these calculations. 00:15:48.000 --> 00:15:50.000 So, putting this together, 00:15:50.000 --> 00:15:53.000 We get this as our end result. 00:15:53.000 --> 00:15:57.000 So, if I have dark matter that interacts with nuclei, 00:15:57.000 --> 00:16:08.000 I'll automatically get some electron cross-sections, and I can just recast existing limits on dark matter electron coupling to get limits on dark matter nucleon coupling. 00:16:08.000 --> 00:16:13.000 And that's what we did here. So, for these choices of, uh, quark, 00:16:13.000 --> 00:16:15.000 Uh, couplings. 00:16:15.000 --> 00:16:20.000 For a light mediator, and for a heavy mediator, these are the sorts of limits that we get. 00:16:20.000 --> 00:16:28.000 The gray are the ones that already exist, and the red is what we get out of this work. So, not a ton of new territory, 00:16:28.000 --> 00:16:31.000 But we do start to cover some new ground. 00:16:31.000 --> 00:16:39.000 In both the light mediator and heavy mediator cases. Maybe more excitingly is that, uh, electron recoil experiments 00:16:39.000 --> 00:16:43.000 dig very deeply into this parameter space, and… 00:16:43.000 --> 00:16:50.000 based on their projected sensitivity, should be quite sensitive to dark matter nucleon interactions, 00:16:50.000 --> 00:16:57.000 better than at least the existing experiments at the time were. 00:16:57.000 --> 00:17:04.000 Can I ask this, like, what is the status of Oscar? Like, have you turned log in? Like, that's gonna happen, or no? 00:17:04.000 --> 00:17:09.000 I know that you have, like, technical challenges, but… Oh, no, I… I'm not sure. Okay. 00:17:09.000 --> 00:17:12.000 Yeah, uh… 00:17:12.000 --> 00:17:18.000 Because it, yeah, I think, uh, we learned about it when we were talking about this elsewhere, and so we added it in, but I hadn't. 00:17:18.000 --> 00:17:21.000 heard about it since then, I don't think. 00:17:21.000 --> 00:17:23.000 Wait, so… 00:17:23.000 --> 00:17:25.000 Sensei… 00:17:25.000 --> 00:17:27.000 is… so these… 00:17:27.000 --> 00:17:30.000 These are real. Sunset is real, but is that…? 00:17:30.000 --> 00:17:33.000 that's measuring nuclear cross-section. 00:17:33.000 --> 00:17:39.000 So, the gray is nuclear cross-section, and the red is dark matter electron cross-section recasted. 00:17:39.000 --> 00:17:42.000 But you're parting the nuclear… 00:17:42.000 --> 00:17:46.000 the equivalent nuclear cross-section of the vertical. 00:17:46.000 --> 00:17:50.000 Yes. 00:17:50.000 --> 00:17:55.000 So, the actual Sensei limits for their electron cross-section would come down. 00:17:55.000 --> 00:18:00.000 A bit for… we'll come down further. 00:18:00.000 --> 00:18:05.000 Dominic and Oscar are the limits on scattering these electrons that you're then recasting to… 00:18:05.000 --> 00:18:08.000 they… that's the reach of the experiments. 00:18:08.000 --> 00:18:13.000 So they're not limits, it's, like, what… No, no, but, like, the projected… Yes. The projected limits, but it's just… 00:18:13.000 --> 00:18:18.000 I don't… I don't know anything about that experiment. Scattering against electron? Yes. And then you're just turning them on. 00:18:18.000 --> 00:18:20.000 Yes. Yeah. 00:18:20.000 --> 00:18:30.000 That was the nice thing about these calculations, is that you ended up just with a ratio between the electron cross-section and the proton cross-section, and so you could sort of easily recast them. 00:18:30.000 --> 00:18:35.000 As I'll explain with the other mediators, it's not quite as simple. 00:18:35.000 --> 00:18:37.000 But it's at least somewhat simple in this case. 00:18:37.000 --> 00:18:40.000 Um, I'm trying to understand… 00:18:40.000 --> 00:18:43.000 To what extent this is a… 00:18:43.000 --> 00:18:47.000 a sharp calculation as opposed to something that has some… 00:18:47.000 --> 00:18:51.000 quote, order one factor, saying that 00:18:51.000 --> 00:18:54.000 you don't really know better than Joe Kit later. 00:18:54.000 --> 00:18:59.000 So, I'm not used to seeing… 00:18:59.000 --> 00:19:05.000 proton things related to pion things without any. 00:19:05.000 --> 00:19:07.000 But too, so… 00:19:07.000 --> 00:19:12.000 incurable perturbations theory. You know, you usually… 00:19:12.000 --> 00:19:15.000 predict things about pione complex. 00:19:15.000 --> 00:19:21.000 wrapped up in something definite about protons. Sure, so I guess… 00:19:21.000 --> 00:19:26.000 For the proton case, we're pulling from the dark matter and the… 00:19:26.000 --> 00:19:29.000 like, experimental literature on how to relate. 00:19:29.000 --> 00:19:32.000 quart couplings to nucleon couplings. 00:19:32.000 --> 00:19:40.000 So, we didn't use chiral effective field theory to calculate the proton couplings. I sort of trusted… 00:19:40.000 --> 00:19:50.000 I trusted, basically, the scattering community on how to handle… yeah, I trusted the detection community on how to handle this. Also, to go from the park-level uplinks, 00:19:50.000 --> 00:19:52.000 to the pione couplings, 00:19:52.000 --> 00:19:57.000 There were 41 factors, right? You don't? 00:19:57.000 --> 00:20:01.000 You don't know how to do that transition without doing… 00:20:01.000 --> 00:20:04.000 Like the skage theory, so… 00:20:04.000 --> 00:20:09.000 Do order one factors matter when there's, uh, 12 orders of magnitude on the y-axis? 00:20:09.000 --> 00:20:19.000 No, no. Yeah, yeah, yeah, yeah. Yeah, and I think that's the answer, because, to be fair, I would say… 00:20:19.000 --> 00:20:25.000 Order one, squishiness in the calculations, I think, is reasonable to… 00:20:25.000 --> 00:20:26.000 to say this there. Okay. Yeah. 00:20:26.000 --> 00:20:31.000 I have a different question, though, about the… so, I guess, so you're trying to… 00:20:31.000 --> 00:20:35.000 Study a toy model where there's a Z prime that only talks to quarks, 00:20:35.000 --> 00:20:41.000 But then, the fact that loops can generate couplings to D plus E minus… 00:20:41.000 --> 00:20:43.000 seems to imply to me that 00:20:43.000 --> 00:20:47.000 nothing forbid that Z prime from talking to E plus C minus in the first place. 00:20:47.000 --> 00:20:53.000 So what… are these models, like, uh, I don't know, well-motivated? Yeah. Or are they kind of… 00:20:53.000 --> 00:20:56.000 like, why wouldn't a Z prime talk to everything with some… 00:20:56.000 --> 00:21:04.000 order one… I don't know. Yeah, yeah, that's fair. I think it's… 00:21:04.000 --> 00:21:09.000 Because these are called leptophobic wells, where are these leptophobic models come from? 00:21:09.000 --> 00:21:11.000 Uh, other than being, like, 00:21:11.000 --> 00:21:14.000 technically possible. 00:21:14.000 --> 00:21:18.000 I think it's just… 00:21:18.000 --> 00:21:23.000 I mean, if you're ending up with, like, a mix… like, you're mixing Z prime and the photon. 00:21:23.000 --> 00:21:26.000 loops, like, which… 00:21:26.000 --> 00:21:32.000 As, like, a whole literature for dark matter and dark protons. Yeah, I think it's more like this is, like… 00:21:32.000 --> 00:21:37.000 the minimum coupling you can get. So you… you can have naturally… 00:21:37.000 --> 00:21:42.000 Well, no, you could cancel this off of a tree-level coupling and make it zero. 00:21:42.000 --> 00:21:51.000 You wanted to? Sure, but that's sort of particular, isn't it? But I'm asking if this is particular, too. 00:21:51.000 --> 00:21:58.000 Well, would you be able to cancel it off a tree coupling? Because, like, presumably needs to be some integer 00:21:58.000 --> 00:22:00.000 charge for the tree. 00:22:00.000 --> 00:22:05.000 You're talking about canceling it against electrons. 00:22:05.000 --> 00:22:09.000 Mm-hmm. 00:22:09.000 --> 00:22:12.000 Well, a 2C prime, it's not a… 00:22:12.000 --> 00:22:14.000 This can't renormalize. 00:22:14.000 --> 00:22:19.000 Right, but it has to be some… presumably some, like, integer related to the chart coupling to. 00:22:19.000 --> 00:22:21.000 to U and D. 00:22:21.000 --> 00:22:24.000 Right? Otherwise, we may have run into… 00:22:24.000 --> 00:22:28.000 Anomalies. 00:22:28.000 --> 00:22:31.000 It can't be some, like, arbitrary… 00:22:31.000 --> 00:22:33.000 ratio of the… 00:22:33.000 --> 00:22:41.000 the tree level above the dead. 00:22:41.000 --> 00:22:44.000 If you tell me you can, that's a hurdle. 00:22:44.000 --> 00:22:46.000 Fine, I hope. 00:22:46.000 --> 00:22:56.000 I would have thought, if I want to build, like, an anomaly pre-model, I'm not allowed to pick the tree-level coupling to electrons. I can pick it to be zero, but I can't pick it to be… The ratio between up and down. 00:22:56.000 --> 00:22:59.000 up and down in E. 00:22:59.000 --> 00:23:03.000 Right? Depends what you want, right? With the Z prime… 00:23:03.000 --> 00:23:06.000 Like, if you have a unique complete theory, right? 00:23:06.000 --> 00:23:10.000 What's the charge there? Like, to be some… 00:23:10.000 --> 00:23:16.000 You can allocation right there on the number? Yeah… Yeah, sure. If you do it in a way that… Yeah. 00:23:16.000 --> 00:23:25.000 Yeah, it's very heavy. So you don't have to be… 00:23:25.000 --> 00:23:28.000 So you mentioned here? 00:23:28.000 --> 00:23:33.000 Uh… It depends out. 00:23:33.000 --> 00:23:38.000 No, so it doesn't matter for this code? No, for the heavy median? For the ratio… 00:23:38.000 --> 00:23:43.000 For the ratio with the proton coupling, the Z prime mass divides out. 00:23:43.000 --> 00:23:50.000 And so you… the reason we have the different plots is more an issue of, like, 00:23:50.000 --> 00:23:53.000 the existing constraint apply a bit differently. 00:23:53.000 --> 00:23:58.000 Or behave a bit differently, depending on if you have a light mediator or a heavy mediator. Um, but… 00:23:58.000 --> 00:24:04.000 In the other cases, we have to specify the mass of the mediator. Uh, in this one, um, 00:24:04.000 --> 00:24:10.000 Oh, I see, lightning heater. Yeah. What does light and heavy mean, though? I mean, what's the… relative to what… 00:24:10.000 --> 00:24:15.000 Uh, relative to the momentum exchanged. 00:24:15.000 --> 00:24:17.000 So, probably, like, the dark matter mass times. 00:24:17.000 --> 00:24:20.000 velocity. It's very light. Mm-hmm. 00:24:20.000 --> 00:24:25.000 Alright, so these are all lights under the sound will come from. 00:24:25.000 --> 00:24:29.000 Uh… I mean, all the dark matter's less than a GEV. 00:24:29.000 --> 00:24:33.000 It's not like a… It could be heavy. It could be 30TV? Yeah. 00:24:33.000 --> 00:24:38.000 Well, I was just wondering if it's really that heavy, why wouldn't integrate that out, too? 00:24:38.000 --> 00:24:40.000 So you should have an effective theory that… 00:24:40.000 --> 00:24:47.000 doesn't have the mediator or the… I mean, you already integrated out Proton, right? So… Like, integrating it out should give us… 00:24:47.000 --> 00:24:50.000 Effectively the same result, shouldn't it? 00:24:50.000 --> 00:24:52.000 That's a heavy mediator. Yeah. 00:24:52.000 --> 00:24:55.000 So this is a little bit more general, because it lets us… 00:24:55.000 --> 00:24:58.000 play with either of the cases. 00:24:58.000 --> 00:25:00.000 You don't have in mind any, like… 00:25:00.000 --> 00:25:03.000 you know, your completion for this, right? No. Because… 00:25:03.000 --> 00:25:08.000 If you're doing a simplified model of your enemies a bunch of things, right, that can go into the loops. 00:25:08.000 --> 00:25:12.000 Sure. I mean, these were sort of the biggest things. 00:25:12.000 --> 00:25:17.000 That would come in the loop if we just assumed the, uh, the port coupling. But yeah, if you let it… 00:25:17.000 --> 00:25:20.000 couple directly to other things that… 00:25:20.000 --> 00:25:25.000 They'll get other extra interactions. The point is more that if… 00:25:25.000 --> 00:25:37.000 Even if you're just thinking about that one couple and you can't escape these other additional effects. 00:25:37.000 --> 00:25:40.000 Can I continue? Other questions? 00:25:40.000 --> 00:25:43.000 Okay. 00:25:43.000 --> 00:25:47.000 Um, so the other effect that we get to play with 00:25:47.000 --> 00:25:49.000 is that in this case, 00:25:49.000 --> 00:25:54.000 Uh, you'll pick up an effective millage charge, at least as long as the mediator is light. 00:25:54.000 --> 00:26:05.000 Um, and by light, I mean that the master, the mediator, is light compared to the momentum exchanged relative to these experiments, or these different, uh… 00:26:05.000 --> 00:26:10.000 limits, uh, so there are pretty strict limits on dark matter millicharge. 00:26:10.000 --> 00:26:16.000 Uh, so basically, if you're above these white lines, and you have a very light mediator, 00:26:16.000 --> 00:26:20.000 That dark matter would be problematic, because it would mess with, uh, 00:26:20.000 --> 00:26:22.000 the distribution of galaxy clusters. 00:26:22.000 --> 00:26:27.000 Or potentially introduce too much scattering in the Milky Way disk. 00:26:27.000 --> 00:26:30.000 Wait, so the galaxy cluster is like the bulb cluster bound. 00:26:30.000 --> 00:26:37.000 Where the… where does the… I think it's… I think it's, like, dwarf clusters around the… dwarf… 00:26:37.000 --> 00:26:41.000 This is the dark matter standard model. 00:26:41.000 --> 00:26:48.000 induced interaction, what's causing the problem here. Yes. 00:26:48.000 --> 00:26:51.000 It's too much scattering with electrons, or it's… it's… 00:26:51.000 --> 00:26:53.000 too much millitcharge dark matter. 00:26:53.000 --> 00:27:01.000 Oh, through, like, magnetic field, like, as it passes through the magnetic fields, the long-range magnetic fields of the galaxy? 00:27:01.000 --> 00:27:08.000 No, I'm sorry, I'm trying to remember. I think so. 00:27:08.000 --> 00:27:12.000 I'm just, um… 00:27:12.000 --> 00:27:17.000 Yeah, we can talk about it. I just… the spin-down one is not one I'm familiar with. Yeah. 00:27:17.000 --> 00:27:24.000 Curious. But I haven't thought about Millacharge dark matter. Yeah, yeah, no, I can pull up the citations after. 00:27:24.000 --> 00:27:34.000 Um, so that was the original project, and now, of course, the question is, can we expand beyond this? And that's the goal of our ongoing work. 00:27:34.000 --> 00:27:40.000 Which is, we didn't want to just limit ourselves to the vector mediator case, we wanted to see what can we do with, sort of, 00:27:40.000 --> 00:27:48.000 The remaining reasonable mediators. So we've got scalars. When I'm talking about axial vectors and pseudoscalers, what I'm really talking about is sort of… 00:27:48.000 --> 00:27:53.000 Whether there's a gamma 5 on the coupling with quarks or not. 00:27:53.000 --> 00:28:03.000 And then, with these new interactions, we do get new observables that were difficult to get in the vector case. So, now we can get dark matter-photon interactions, 00:28:03.000 --> 00:28:08.000 Those were suppressed or difficult to get with the vector mediator. 00:28:08.000 --> 00:28:14.000 What this leads to is dark matter overproduction via freezing. 00:28:14.000 --> 00:28:17.000 Also, we were this time focused more on… 00:28:17.000 --> 00:28:22.000 Maison decays, and there was a lot of interesting stuff in there. So… 00:28:22.000 --> 00:28:28.000 Put simply, we'll get neutral maisons that can decay directly to dark matter, as long as the dark matter is light enough. 00:28:28.000 --> 00:28:33.000 And we'll also get rare Kaon decays, where you get decayed dark matter plus pions. 00:28:33.000 --> 00:28:44.000 So those are sort of the new, fun things that we get as we think about these mediators. I think these will also apply to the vector mediators, but we didn't know that when we did the original paper. 00:28:44.000 --> 00:28:50.000 Um, yeah. Are you a throughout, or you're not assuming that these mediators give you the dark matter relic abundance? 00:28:50.000 --> 00:28:54.000 Where you are? No. Okay. Uh… 00:28:54.000 --> 00:28:58.000 Well, you do… you do worry if they overproduce. We worry if they overproduce. 00:28:58.000 --> 00:29:01.000 Um, and… 00:29:01.000 --> 00:29:05.000 Is that a line you can draw on your boss, though? Yes. Oh, like, if… 00:29:05.000 --> 00:29:11.000 Getting the right relic abundance? Uh, yeah, it probably is. 00:29:11.000 --> 00:29:14.000 Um, because I think it'll… 00:29:14.000 --> 00:29:17.000 Yeah, no, it probably is. We haven't, but… 00:29:17.000 --> 00:29:19.000 We definitely can. 00:29:19.000 --> 00:29:22.000 So, um… 00:29:22.000 --> 00:29:29.000 I'll also add that there's a group in Australia that's doing similar work. Um, they've only focused on 00:29:29.000 --> 00:29:36.000 They've only focused on, sort of, the heavy mediator cases, the ones that you can integrate out, but if you're curious, I can also… 00:29:36.000 --> 00:29:39.000 I'll show you some of that stuff afterward. 00:29:39.000 --> 00:29:45.000 So, the first case that we can look at, again, the simplest of the remaining three, is the scalar mediator case. 00:29:45.000 --> 00:29:49.000 Um, in this case, what you end up with 00:29:49.000 --> 00:29:55.000 is, uh, the scalar coupling to the charged pions, like so, and so we get 00:29:55.000 --> 00:30:03.000 These loops give us access to interactions with photons, and then we get this new decay channel for the k-on. 00:30:03.000 --> 00:30:09.000 Now, there are, I believe, probably several other fun, weird, new decay channels that you can get. 00:30:09.000 --> 00:30:18.000 This one is the relevant one, because this K-on decay to pion plus invisibles is rare and reasonably well measured. 00:30:18.000 --> 00:30:26.000 So, of the decays involving other mesons, this one is sort of the rarest, and while still being well-measured. 00:30:26.000 --> 00:30:30.000 You don't have, like, mix with the heat? 00:30:30.000 --> 00:30:33.000 Uh… 00:30:33.000 --> 00:30:38.000 How is coming to my mind from some reason, when I teach… 00:30:38.000 --> 00:30:41.000 But I don't know what I mean… 00:30:41.000 --> 00:30:43.000 Um… 00:30:43.000 --> 00:30:47.000 So, for a mediator of this variety, 00:30:47.000 --> 00:30:51.000 You've got a coupling that looks like this, and a coupling that looks like this. 00:30:51.000 --> 00:30:56.000 Uh, for these choices of quart couplings, we just set them all equal to each other. 00:30:56.000 --> 00:31:02.000 this, uh, I believe is one of the weaker combinations of quark couplings we could have picked. 00:31:02.000 --> 00:31:12.000 Uh, these are the sorts of limits that you get. So, for the light mediator, uh, the existing Planck constraints still dominate, uh, for a lot of the parameter space. 00:31:12.000 --> 00:31:22.000 This is the limit that we get from overproducing dark matter. This is what we get from archaeon decaying to pi plus just mediator, um, 00:31:22.000 --> 00:31:28.000 It's the same as the diagram I showed you on the last slide, just pretend the Kai-Kai bar isn't there. 00:31:28.000 --> 00:31:35.000 Uh, and so we get a little bit of new ground in that corner over here. There's clonk here is… 00:31:35.000 --> 00:31:42.000 You don't have to do the loops or anything? No, no, no, that's the existing cross-section we're competing with. 00:31:42.000 --> 00:31:44.000 Or those are the existing limits we're competing against? 00:31:44.000 --> 00:31:48.000 So this is dark matter scattering against… 00:31:48.000 --> 00:31:52.000 Protons? Yes. 00:31:52.000 --> 00:31:55.000 Again, it's nuclei. It's nuclei. 00:31:55.000 --> 00:31:59.000 Via a light spiller mediator, so it's, uh… 00:31:59.000 --> 00:32:01.000 what team does? 00:32:01.000 --> 00:32:03.000 I… okay, I'm updating. 00:32:03.000 --> 00:32:08.000 I mean, I'm aware that there clearly is a limit, I just, um… 00:32:08.000 --> 00:32:14.000 Oh, light mediator. Yes. Have I did the mediator there? Uh… Ballpark. I think he picked an Eevee. 00:32:14.000 --> 00:32:17.000 Oh, okay, yeah, then I believe it. Yeah. 00:32:17.000 --> 00:32:30.000 Yeah, so generally, uh, he didn't put the light mediator mass in there, but I believe it's generally an EV for the light mediator cases, and then we specify for the heavy mediator. So this one is for a 1GEV mediator, 00:32:30.000 --> 00:32:34.000 For these bounds, the mass of the heavy mediator does start to make a difference. 00:32:34.000 --> 00:32:40.000 So, for a heavy mediator, this is the overproduction limit, this is the limit from producing 00:32:40.000 --> 00:32:47.000 canned debt decayed upon Kai Kai Bar. And then we've marked off this region here, 00:32:47.000 --> 00:32:50.000 Uh, as parameter space for not messing with. 00:32:50.000 --> 00:32:53.000 And that's just because… 00:32:53.000 --> 00:32:58.000 in order to get cross-sections this large for a mediator mass that we've chosen. 00:32:58.000 --> 00:33:00.000 the coupling to both 00:33:00.000 --> 00:33:03.000 Both of these couplings up here. 00:33:03.000 --> 00:33:11.000 would have to be 1, and so it becomes non-perturbative, and we don't really trust the calculations anymore above that, so… 00:33:11.000 --> 00:33:21.000 some other kind of behavior up there. Sorry, just to go back to your 1EV mediator, in this case, are you basically thermally ordering the… for a lot of that? 00:33:21.000 --> 00:33:24.000 scattering cross-section? Are you ending up in equilibrium? 00:33:24.000 --> 00:33:26.000 Like, do I have to worry about the… 00:33:26.000 --> 00:33:34.000 the dark radiation of your mediator. Is that part of your calculation? That's one of the next things we want to check. Okay, yeah. 00:33:34.000 --> 00:33:41.000 Yeah, is like, uh, so I've done the calculation for production of light mediator, um, 00:33:41.000 --> 00:33:48.000 Well, we haven't checked yet if that's going to cause problems. So, but this limit is really just your coupling, your baryons? 00:33:48.000 --> 00:33:53.000 to your dark matter too effectively, and so, like, when you do the… 00:33:53.000 --> 00:34:00.000 the CMB, you end up with, like, coupling your two fluids? Is that where the one is coming from? 00:34:00.000 --> 00:34:03.000 Oh, oh, oh, oh. Um… 00:34:03.000 --> 00:34:11.000 I guess so. Yeah, it's just, there's a lot of things that I could worry about with a light mediator in neural universe, and some of them are, like, extra… 00:34:11.000 --> 00:34:15.000 bells and whistles that you don't necessarily want, and this… 00:34:15.000 --> 00:34:19.000 think about which one is sort of the one I can't get away with. 00:34:19.000 --> 00:34:21.000 Oh, sorry, you had a question. 00:34:21.000 --> 00:34:24.000 I mean, any model like this, those… 00:34:24.000 --> 00:34:30.000 extremely fine-tuned from the get-go to give you a bit of flavor treaty. 00:34:30.000 --> 00:34:32.000 Neutral interactions, right? 00:34:32.000 --> 00:34:36.000 But Chris, you know, we could have had… 00:34:36.000 --> 00:34:41.000 slavery couplings between Fry and the Clarks. 00:34:41.000 --> 00:34:43.000 That would have been ruled out. 00:34:43.000 --> 00:34:49.000 from the beginning, we… Okay. And there's nothing that prevents us from being there. 00:34:49.000 --> 00:34:52.000 So, once you introduce that skill, or you… 00:34:52.000 --> 00:34:55.000 You've got a ton of problems in the… 00:34:55.000 --> 00:34:58.000 In the model completely from the beginning. 00:34:58.000 --> 00:35:04.000 So the minimal, like, the easiest way to get around that is to make it some extended eggs. 00:35:04.000 --> 00:35:09.000 Right. It was like, you make that some sort of extended haigs that has Yukawa kind of interactions. 00:35:09.000 --> 00:35:15.000 Generically… No, no, I agree, yeah. Supersymmetry. 00:35:15.000 --> 00:35:18.000 Gives you extra flavor-changing foods. 00:35:18.000 --> 00:35:21.000 You can always have a higher commitment. 00:35:21.000 --> 00:35:27.000 a hierarchy with columns. Mechanic field. 00:35:27.000 --> 00:35:34.000 Well, yeah. Yeah, you could have to force it, though. You'd have to do all kinds of work to… 00:35:34.000 --> 00:35:38.000 MFP is just an assumption. 00:35:38.000 --> 00:35:42.000 To explain why, yeah. 00:35:42.000 --> 00:35:46.000 Okay. Yeah, I mean, so a coupling like this… 00:35:46.000 --> 00:35:50.000 Yeah, yeah. So, a coupling that looks like this would correspond… 00:35:50.000 --> 00:35:55.000 to your, uh, spin-independent, sort of, 01, uh, 00:35:55.000 --> 00:35:57.000 coupling for… 00:35:57.000 --> 00:36:01.000 at least the heavy mediator case, and this is sort of… 00:36:01.000 --> 00:36:04.000 one of the more popular ones that they look for at detection. 00:36:04.000 --> 00:36:06.000 So… 00:36:06.000 --> 00:36:11.000 I would be… certainly believe that the more complex model is needed to handle the situation properly. 00:36:11.000 --> 00:36:17.000 Um, but models that look something like this are definitely a thing I'm looking forward detectors. 00:36:17.000 --> 00:36:22.000 So, this is created by… the letters come from caterpind. 00:36:22.000 --> 00:36:25.000 Yeah. 00:36:25.000 --> 00:36:28.000 Is there someone… isn't there, like, huh? 00:36:28.000 --> 00:36:35.000 Yes, yeah, I think it's either… 00:36:35.000 --> 00:36:40.000 Yeah, so we have CANs to invisibles, we have pions to invisibles as well. 00:36:40.000 --> 00:36:42.000 Um, and… 00:36:42.000 --> 00:36:51.000 those are weaker, generally, than these limits, and so we hadn't put them in yet. These are sort of the strongest ones that we… 00:36:51.000 --> 00:36:55.000 We're finding. 00:36:55.000 --> 00:37:03.000 Of the mediator? Yeah, Peyton, you… 00:37:03.000 --> 00:37:07.000 I don't remember correctly, but… 00:37:07.000 --> 00:37:13.000 Oh, no, I think… I'm not sure I understand what the question is. No, that you put only one… 00:37:13.000 --> 00:37:17.000 say, like, one limit from fluorophysics, right? 00:37:17.000 --> 00:37:21.000 Oh, yeah, yeah. …maybe tens of… 00:37:21.000 --> 00:37:26.000 related decays to this, right? Oh, yeah. 00:37:26.000 --> 00:37:28.000 for instance, this would be, I think, 00:37:28.000 --> 00:37:32.000 I remember that D2… sorry, D2… 00:37:32.000 --> 00:37:34.000 I left on this. 00:37:34.000 --> 00:37:41.000 But that's, uh… that's a different… that's not chiral effective field theory anymore, that's a different… 00:37:41.000 --> 00:37:44.000 No, it's just to limit the expense limit. 00:37:44.000 --> 00:37:46.000 You have a brochure, like… 00:37:46.000 --> 00:37:55.000 lifetimes. We looked… I looked at the lifetime, or I looked at… 00:37:55.000 --> 00:37:59.000 various, like, masonic decay modes. 00:37:59.000 --> 00:38:05.000 Um, at least of the Maisons that I could sort of easily do the calculations for, which is the Kons, the pions, the etas. 00:38:05.000 --> 00:38:10.000 Um, so for those, this was sort of the one that was… 00:38:10.000 --> 00:38:15.000 the best combination of being rare and, like, well-measured. 00:38:15.000 --> 00:38:17.000 But… 00:38:17.000 --> 00:38:26.000 If there's more that I haven't thought of, like, that… that's fine, we can… I'm happy to add more limits in here. Well, the one you mentioned, I mean, are you assuming it doesn't talk to Churn Quarks at all? 00:38:26.000 --> 00:38:35.000 Uh, yeah, we're… we're neglecting interactions with the heavy forks, because we're… 00:38:35.000 --> 00:38:44.000 So, so you say you did check, I guess, all the strange flavored meson, or not all, as many as you could think of, but strange-flavored, meson, rare case. 00:38:44.000 --> 00:38:47.000 I basically have pulled up the particle data group. 00:38:47.000 --> 00:38:50.000 page of all the different decays and looked through. 00:38:50.000 --> 00:38:56.000 Okay. I guess it's fair, if you're thinking about, like, you wanted to have the 00:38:56.000 --> 00:39:01.000 you wanted to compare to the scattering cross-section on… That's the thing. 00:39:01.000 --> 00:39:06.000 require a light-quark interaction, more or less. 00:39:06.000 --> 00:39:14.000 Or yeah, I want to compare to interactions with nuclei. If you scatter against charm and top and bottom, like… 00:39:14.000 --> 00:39:19.000 the vertical axis disappears because you don't… you have a really minimal coupling to the… 00:39:19.000 --> 00:39:25.000 to your museum on an experiment or whatever, right? Yeah, and we did actually see in… 00:39:25.000 --> 00:39:29.000 one of the Australian papers we were looking at. They got pretty strong limits from 00:39:29.000 --> 00:39:32.000 coupling their media… or coupling to the top. 00:39:32.000 --> 00:39:43.000 But… that doesn't really tell you much about how it couples to the proton or to the nuclei, so that felt a little bit like cheating to us to get a stronger limit. 00:39:43.000 --> 00:39:49.000 I guess I don't understand… maybe I missed it, but why are you cover this range? Why not just up and down? 00:39:49.000 --> 00:39:52.000 Um, what's that? 00:39:52.000 --> 00:39:54.000 Because… 00:39:54.000 --> 00:39:59.000 You could just say, okay, this encompass the first generation, and of course, and this prevail. 00:39:59.000 --> 00:40:02.000 the other generations. 00:40:02.000 --> 00:40:05.000 It'll be easier if… 00:40:05.000 --> 00:40:10.000 Well, I end up having to include in some of the other cases, like, 00:40:10.000 --> 00:40:17.000 the ADA and the ADA prime, um, because sometimes the coupling to the pions, like for some combinations, actually, 00:40:17.000 --> 00:40:23.000 For several mediators, this specific combination, uh, coupling to the pions, goes to zero. 00:40:23.000 --> 00:40:28.000 So then I wouldn't get anything. Uh, but including the strange cork. 00:40:28.000 --> 00:40:30.000 includes, uh… 00:40:30.000 --> 00:40:38.000 I guess the Kaons, as well as the Adas and the Ada Primes, and those end up being important in some of the other interactions. But things like over… 00:40:38.000 --> 00:40:46.000 production and funk and stuff like that, those are gonna be relatively insensitive to whether you go to… 00:40:46.000 --> 00:40:48.000 the strange, I'm guessing. 00:40:48.000 --> 00:40:53.000 Yeah, like, it's not… it's not a huge contributor to the, uh… 00:40:53.000 --> 00:40:58.000 I mean, unless you live in some weird thing where they exactly cancels, or… Oh, I mean, I… 00:40:58.000 --> 00:41:03.000 for… for this, like, even for, like, a simple choice like this, uh, this… it'll cancel off. 00:41:03.000 --> 00:41:06.000 For some of the mediators. 00:41:06.000 --> 00:41:11.000 Yeah. But you've obviously not turned to all of them off here, otherwise something… 00:41:11.000 --> 00:41:17.000 Yeah, and you can't. You, you can't actually find a combination that'll get rid of, like, 00:41:17.000 --> 00:41:22.000 every possible interaction with all of the mediators. When I include… 00:41:22.000 --> 00:41:26.000 all the different mesons that could be participating. 00:41:26.000 --> 00:41:33.000 Um, they'll always be kind of one of them showing up and mediating the interaction. You can make it weaker. 00:41:33.000 --> 00:41:35.000 But you can't totally get rid of it. 00:41:35.000 --> 00:41:38.000 By fiddling with the coupling to the quarks. 00:41:38.000 --> 00:41:42.000 And I guess Todori's point, you could just look up how 00:41:42.000 --> 00:41:47.000 the K on one depends on this exact coupling. Just rescale it if you put it your own. 00:41:47.000 --> 00:41:50.000 return on anything in particular. 00:41:50.000 --> 00:41:53.000 It is, um… 00:41:53.000 --> 00:41:59.000 Okay, this case is sort of specific. This case isn't terribly sensitive to it. 00:41:59.000 --> 00:42:08.000 Maybe I'll be able to say more in the other two cases, because I think they're more sensitive to our choices of relative couplings. 00:42:08.000 --> 00:42:11.000 Alright, so the other, uh, 00:42:11.000 --> 00:42:19.000 Scalar adjacent case, this one, uh, is where we've got a gamma 5 on the chi-bar coupling. 00:42:19.000 --> 00:42:25.000 I separate… I include this one with the last one, because usually what's important for… 00:42:25.000 --> 00:42:31.000 most of the phenomenology is more how our mediator couples to the quarks that's going to make 00:42:31.000 --> 00:42:33.000 Most of a difference. Uh… 00:42:33.000 --> 00:42:43.000 But for this case, this sort of interaction corresponds to a low-energy effective theory, uh, 05, if you've got a heavy mediator. 00:42:43.000 --> 00:42:51.000 Um, the constraints are a lot weaker for these types of models, because they're just not models that people have thought about as much. 00:42:51.000 --> 00:42:54.000 But we wanted to cover our bases. 00:42:54.000 --> 00:42:56.000 So, for a light mediator, 00:42:56.000 --> 00:42:59.000 this is how it looks. 00:42:59.000 --> 00:43:07.000 And then for a heavy mediator, uh, we've got sort of a similar situation as previously. 00:43:07.000 --> 00:43:15.000 what I'm calling the pseudoscalar mediator case is just saying that my coupling to quarks looks something like this. 00:43:15.000 --> 00:43:21.000 So if I've got a field that couples to quarks like that, then chiral effective field theory will give me a coupling 00:43:21.000 --> 00:43:24.000 to mesons that looks something like this. 00:43:24.000 --> 00:43:28.000 So, I've got these funky terms here. 00:43:28.000 --> 00:43:32.000 that are mixing my mediator with the Maisons. 00:43:32.000 --> 00:43:38.000 These are weird, um, but they have the exciting effect that 00:43:38.000 --> 00:43:47.000 My mediator picks up any of the couplings that the Maison had. My mesons pick up any of the couplings that the mediators had. 00:43:47.000 --> 00:43:56.000 The result is that if I've got an interaction like this, where there's a gamma 5 hanging out secretly down here with the porks, I get 00:43:56.000 --> 00:44:02.000 these interactions now, where the pine knot or the eta, and really the eta prime, if I want to include it, 00:44:02.000 --> 00:44:04.000 And our… 00:44:04.000 --> 00:44:07.000 Dark Mediator can all help. 00:44:07.000 --> 00:44:10.000 Dark matter talk to photons. 00:44:10.000 --> 00:44:14.000 The pine and the Ada cannot decay to kayakai bar. 00:44:14.000 --> 00:44:24.000 And all 3 of these particles can be involved in helping Kions decay into pions, plus invisibles. 00:44:24.000 --> 00:44:30.000 So, together, what this gives us are constraints that look like this. Uh, for this example, 00:44:30.000 --> 00:44:36.000 We're actually just showing coupling to the up and not coupling to the others, and that's just because the, uh… 00:44:36.000 --> 00:44:39.000 all equal coupling case is… 00:44:39.000 --> 00:44:44.000 a little bit suppressed, it behaves a little bit differently than the others, and we're still working on getting those plots together. 00:44:44.000 --> 00:44:47.000 Um, but… 00:44:47.000 --> 00:44:50.000 This over here is the light mediator case. We get… 00:44:50.000 --> 00:44:55.000 rather strong limits from just overproducing. 00:44:55.000 --> 00:44:57.000 For the heavy mediator case, 00:44:57.000 --> 00:44:59.000 It's a little bit trickier. 00:44:59.000 --> 00:45:03.000 Uh, basically for a heavy mediator that has a coupling that looks like this, 00:45:03.000 --> 00:45:08.000 the interaction with nuclei is very suppressed. It's… 00:45:08.000 --> 00:45:17.000 Uh, goes as velocity to the fourth, and so it's pretty difficult to actually see this thing at, uh, direct detection experiment. 00:45:17.000 --> 00:45:24.000 Um, so in this case, we've actually multiplied the cross-section by Q being the momentum exchange to the fourth. 00:45:24.000 --> 00:45:32.000 Go to the minus 4. If I didn't do that, these limits would go down to, like, 10 to the minus 80, and they would be a little bit deceptive. 00:45:32.000 --> 00:45:35.000 all that's happening here is that… 00:45:35.000 --> 00:45:41.000 the… basically, photon annihilation that produce these, and that decay rate, 00:45:41.000 --> 00:45:49.000 none of these have that V to the fourth suppression that you see in the nuclei scattering, and so actually, 00:45:49.000 --> 00:46:00.000 These effects end up being, like, cross-sections that are often larger and more relevant than the nucleon scattering one is. 00:46:00.000 --> 00:46:02.000 Oh, and this… if we're… 00:46:02.000 --> 00:46:08.000 thinking about, if we're talking to the experimentalists, this corresponds to O6. 00:46:08.000 --> 00:46:13.000 And then, finally, we've got the axial vector mediator case, which… 00:46:13.000 --> 00:46:21.000 has sort of proved to be the messiest, but you're not going to have to see that. Uh, in this case, what we've got, if I have a coupling that looks like this… 00:46:21.000 --> 00:46:24.000 Where I've got something vectoring, which has this… 00:46:24.000 --> 00:46:32.000 sort of coupling to the quarks, then what comes out is a derivative coupling between the… 00:46:32.000 --> 00:46:36.000 uh, mesons and my mediator. 00:46:36.000 --> 00:46:44.000 Uh, now, what this means is that, again, all of the mix, they mix a little bit differently than they did in the pseudoscaler case. 00:46:44.000 --> 00:46:57.000 So, the Maison's pick up any of the couplings that the mediator has, the mediator does not pick up the couplings that the mesons have, so now the mesons are sort of suddenly doing the heavy lifting of talking to dark matter. 00:46:57.000 --> 00:47:01.000 Uh, oh, okay. Um… 00:47:01.000 --> 00:47:11.000 So, the limits that we get as a result of that, we're focusing on sort of the same limiting behavior. We expect that there'll be a bit more, uh, as time goes on, but these are the ones we have. 00:47:11.000 --> 00:47:14.000 We can show you now. 00:47:14.000 --> 00:47:17.000 For, uh, this sort of behavior, we get… 00:47:17.000 --> 00:47:19.000 these limits from overproduction. 00:47:19.000 --> 00:47:25.000 We are covering a bit of new space, a bit of new space from Kayon Decay, and for a heavy mediator. 00:47:25.000 --> 00:47:27.000 We again sort of cover 00:47:27.000 --> 00:47:30.000 these cross-sections down here. 00:47:30.000 --> 00:47:33.000 Uh, so… 00:47:33.000 --> 00:47:36.000 I'll also note that if I were to 00:47:36.000 --> 00:47:42.000 take the gamma5 out of this end here, then the entire interaction goes away. 00:47:42.000 --> 00:47:47.000 it just goes to zero, so you don't… so if you wanted to get around the limits, 00:47:47.000 --> 00:47:55.000 Um, that would be one place that you could potentially hide, um, because we don't get any effective interactions at all, uh, when there's… 00:47:55.000 --> 00:48:00.000 sort of a mixed, no gamma 5 here, gamma 5 here, type coupling. 00:48:00.000 --> 00:48:02.000 to the quarks. 00:48:02.000 --> 00:48:09.000 So, thank you all for listening. Uh, one I'm hoping that you take away from this is that… 00:48:09.000 --> 00:48:21.000 Loop-level and effective interactions are important when we're thinking about dark matter models, when we're thinking about what parts of dark matter parameter space are worth looking for, or are worth building new experiments to dig into. 00:48:21.000 --> 00:48:24.000 Um, because… 00:48:24.000 --> 00:48:27.000 If you're assuming a simple model, 00:48:27.000 --> 00:48:33.000 your model might not be that simple. I guess, as you guys have all pointed out, there's a lot of places that we can introduce 00:48:33.000 --> 00:48:45.000 new interactions, but even a very naive model will automatically get additional interactions, um, via these loop terms, which are sometimes very strong and not very loopy. 00:48:45.000 --> 00:48:52.000 Uh, so what we're doing right now is we've used existing constraints, existing detectors, as a way to probe 00:48:52.000 --> 00:48:59.000 Uh, additional dark matter interactions that these constraints and detectors hadn't normally originally originally been intended to do. 00:48:59.000 --> 00:49:14.000 Um, we get effective interactions with the mesons, and the light mesons are doing a lot of heavy lifting. They've allowed us to show that experiments like DOMIC-M can be very sensitive to dark matter-nucleon interactions, 00:49:14.000 --> 00:49:19.000 And they let us put limits on, uh, dark matter nucleon intercouplings, 00:49:19.000 --> 00:49:28.000 Due to how they connect dark matter to photons, and basically how these interactions mess with meson decays. 00:49:28.000 --> 00:49:37.000 So, thank you all for listening. 00:49:37.000 --> 00:49:43.000 Right? A couple of minutes for questions, if we have more questions. I think I have a… 00:49:43.000 --> 00:49:46.000 A workday game. 00:49:46.000 --> 00:49:49.000 Yeah, can I look this also in Mooth? 00:49:49.000 --> 00:49:57.000 With gamma… no gamma rays, but you know, like, something like MED, like, rates, or, like, where are you, like, uh… there's not, like, way that I can see, like, the decay of this, uh… 00:49:57.000 --> 00:50:12.000 Yeah, yeah, no, that'd be fine. So if you wanted to look at… But this not competitive enough, I guess, yeah. Yeah, yeah, so actually, uh… For some of them, it probably is. Yeah, exactly. For some of them, yeah. I don't know, but maybe that's better. Depending on the spin side. I mean, the… Uh… 00:50:12.000 --> 00:50:17.000 I think these might come from Dark Matter Annihilation. 00:50:17.000 --> 00:50:31.000 But for CMB, yes, but yeah, but I'm thinking about, like, yeah, like, I'm not, like, the center of the galaxy, or, like… Well, I mean, the mass scale and all… Yeah, exactly, like, you want to look through fairly Fermi go? 00:50:31.000 --> 00:50:33.000 And he goes down to… 00:50:33.000 --> 00:50:37.000 20 MEV is, like… 00:50:37.000 --> 00:50:41.000 Gamma ray E, right? Yes, it sounds absurd, so… so… 00:50:41.000 --> 00:50:44.000 Yeah, so I think we… 00:50:44.000 --> 00:50:52.000 at least thought about that idea, or thought about looking for lines. I don't know that we found anything that was, like, a dominant limit anywhere, though. 00:50:52.000 --> 00:50:55.000 And also, like, during this limit, I… 00:50:55.000 --> 00:51:00.000 Yeah, but you do totally get dark matter annihilating into photons, like, that's… 00:51:00.000 --> 00:51:05.000 a thing that happened. 00:51:05.000 --> 00:51:10.000 So you talk about that a little bit for me, yeah. 00:51:10.000 --> 00:51:13.000 Um, but I don't know, I was surprised. 00:51:13.000 --> 00:51:22.000 Uh, because we didn't know about these… it didn't occur to us to use these options right away, and they ended up being some of the strongest ones. So I'm definitely… 00:51:22.000 --> 00:51:31.000 interested, if people have ideas about other ways to get limits on these. So, why on these am I not seeing the direct detection? 00:51:31.000 --> 00:51:33.000 That's right. 00:51:33.000 --> 00:51:35.000 Um… 00:51:35.000 --> 00:51:38.000 I think they're… 00:51:38.000 --> 00:51:40.000 Is it just off the scale? 00:51:40.000 --> 00:51:42.000 I believe so. 00:51:42.000 --> 00:51:47.000 I mean, I guess it's one GEV is the right-hand side. Yeah. 00:51:47.000 --> 00:51:50.000 Okay. 00:51:50.000 --> 00:51:55.000 I'll also scale in the weak direction? No, there are OMS. 00:51:55.000 --> 00:52:03.000 They're too light, and they're sort of weirder, uh… these are, like, weirder couplings that I think a lot of the experiments are less sensitive to. Well, yeah, they want. 00:52:03.000 --> 00:52:06.000 I believe, even though there's no Dominic. 00:52:06.000 --> 00:52:13.000 Oh, well, this is… we didn't… we didn't calculate the electron coupling for these cases. 00:52:13.000 --> 00:52:16.000 We just did the photon coupling and the mason decays. 00:52:16.000 --> 00:52:24.000 Um, yeah, I think we'd have to go to, like, a second loop to get electron coupling. 00:52:24.000 --> 00:52:27.000 But for Sinon and all these things. 00:52:27.000 --> 00:52:29.000 Well, I can imagine, but they're not. 00:52:29.000 --> 00:52:31.000 Museen doesn't want to get the answer to you. 00:52:31.000 --> 00:52:38.000 Well, I guess moving goals. There might be something creeping in on the right. Yeah, exactly, maybe just a line or something. 00:52:38.000 --> 00:52:43.000 Oh, so if I wanted to do, uh, get coupling to electrons… 00:52:43.000 --> 00:52:48.000 Um, I think I'd have to go to a second loop. 00:52:48.000 --> 00:52:58.000 You don't worry. Uh… 00:52:58.000 --> 00:53:05.000 So, yeah, I guess the effective interactions that I get for at least pseudoscaler and the axial vector cases, um, 00:53:05.000 --> 00:53:09.000 Or at least the dominant ones would be, like, uh… 00:53:09.000 --> 00:53:12.000 So, I feel, yeah. 00:53:12.000 --> 00:53:17.000 I was trying to figure this out yesterday, which is why I've got it on the brain. 00:53:17.000 --> 00:53:21.000 Let's say I've got something like this. 00:53:21.000 --> 00:53:24.000 Um, so basically I'm just relying on, like, 00:53:24.000 --> 00:53:26.000 how well can I… 00:53:26.000 --> 00:53:29.000 Okay, yeah, sorry, I see your point. Um… 00:53:29.000 --> 00:53:37.000 Yeah, I could use the pion decay to E plus E minus. It's just suppressed by, I think, a factor of 10 to the 8 compared to the photon. 00:53:37.000 --> 00:53:43.000 coupling. So it's there, it's just the first one that I could think of was weaker, and then I think other ones I'd have to… 00:53:43.000 --> 00:53:47.000 After we've been together. 00:53:47.000 --> 00:53:57.000 You're saying the loop with Kai-Kai, then quarks in a loop? 00:53:57.000 --> 00:54:00.000 Wait, what's the diagram? They give you electron coupling before? 00:54:00.000 --> 00:54:11.000 Okay, so the one that gave me electron coupling before was Chi, Kai… 00:54:11.000 --> 00:54:13.000 I… aye. 00:54:13.000 --> 00:54:20.000 And I can either put a photon here, 00:54:20.000 --> 00:54:23.000 Yeah, this was the one. 00:54:23.000 --> 00:54:28.000 This is the one that got it from me before. Um, if I make this… 00:54:28.000 --> 00:54:33.000 a scalar in this loop is 0. I could replace this 00:54:33.000 --> 00:54:35.000 I couldn't finish here. 00:54:35.000 --> 00:54:38.000 Um, so that would be, I think… 00:54:38.000 --> 00:54:42.000 When you're down by the electron mitts. 00:54:42.000 --> 00:54:47.000 Yeah. Or you could put in some more weights off of the pione, maybe? 00:54:47.000 --> 00:54:51.000 That was not… Is that true, Lou? Yeah. Sweet. 00:54:51.000 --> 00:54:56.000 So it's there. I mean, it's definitely there. I think it's just smaller. Very small, yeah. 00:54:56.000 --> 00:55:03.000 It's… 00:55:03.000 --> 00:55:08.000 Okay. Just one question. So, kanos relations, that's… 00:55:08.000 --> 00:55:13.000 Because, you know, a box with the size inside. 00:55:13.000 --> 00:55:17.000 I don't know, Jake? No, this wasn't like Drake gave our mixed in. 00:55:17.000 --> 00:55:19.000 So, not if it slavor day, I can… 00:55:19.000 --> 00:55:22.000 Yeah, it's Labor Day, I can… 00:55:22.000 --> 00:55:26.000 You would need a SD bar, hopefully, or something. Yeah. 00:55:26.000 --> 00:55:38.000 Yeah, the Z prime… the Z prime is 5th, 70 or worse. 00:55:38.000 --> 00:55:42.000 It doesn't even have to be flavor and universal, does it? Just flavored diaga? 00:55:42.000 --> 00:55:47.000 Yeah, again, is the press belt? 00:55:47.000 --> 00:55:54.000 So, the question here. So, like, also you can, like, recit all these, like, Axion chaos and all these things, too. 00:55:54.000 --> 00:55:58.000 whatever it will break for, no, for days who's worst case. 00:55:58.000 --> 00:56:11.000 Probably. Yeah, because I know for the accent, there's, like, a bunch of these that I ordered already. Like, it acts like the pseudoscaler. Yeah, exactly, yeah, yeah, yeah, because they also have, like, inoculation, and also, like, a case, and these things from… 00:56:11.000 --> 00:56:14.000 Yeah. Yeah. 00:56:14.000 --> 00:56:17.000 It's… so what I was saying before, so… 00:56:17.000 --> 00:56:20.000 K0 that came along with the lifetime, yes. 00:56:20.000 --> 00:56:22.000 That's been a little miserable. 00:56:22.000 --> 00:56:24.000 This affects everything. 00:56:24.000 --> 00:56:30.000 Uh… I think that certainly the other set of scheduling. 00:56:30.000 --> 00:56:35.000 It doesn't… 00:56:35.000 --> 00:56:37.000 Right? 00:56:37.000 --> 00:56:40.000 It doesn't… it doesn't mix with the KLAM. 00:56:40.000 --> 00:56:44.000 Um, like, I don't have… I don't have a term of, like… 00:56:44.000 --> 00:56:48.000 I don't have a term like this. 00:56:48.000 --> 00:56:51.000 That's what you're asking about? 00:56:51.000 --> 00:56:56.000 No, I'm just asking the screen for the unions, these interactions that happen. 00:56:56.000 --> 00:56:59.000 Yes. 00:56:59.000 --> 00:57:03.000 It's time. 00:57:03.000 --> 00:57:11.000 You have that. I mean, I've got Kay… Kay's with my site, so I actually have Kayla. 00:57:11.000 --> 00:57:14.000 Now, I've been with so… 00:57:14.000 --> 00:57:22.000 It just… it didn't… I guess I'm… I guess I'll say it didn't fall out when I expanded the Lagrangian, I didn't get couplings that… 00:57:22.000 --> 00:57:28.000 would give that to me. 00:57:28.000 --> 00:57:30.000 K02 to side, so… 00:57:30.000 --> 00:57:32.000 Yeah, okay? 00:57:32.000 --> 00:57:34.000 plus 2. 00:57:34.000 --> 00:57:38.000 5 plus side, side. 00:57:38.000 --> 00:57:41.000 should have played long. 00:57:41.000 --> 00:57:43.000 Tukai Kai. 00:57:43.000 --> 00:57:46.000 you just take a legit and… 00:57:46.000 --> 00:57:49.000 Oh, okay. 00:57:49.000 --> 00:57:52.000 With that… 00:57:52.000 --> 00:58:01.000 Do you think that's, like, a… So, the lifetime of Knong was really well measured. Okay. I remember doing this in the lab, so… I don't know if it's better than this, but… 00:58:01.000 --> 00:58:04.000 Yeah. And there are these other things that… 00:58:04.000 --> 00:58:08.000 I do remember there was, at least for the DMesos, this came up, 00:58:08.000 --> 00:58:13.000 Not in the neutral curse, but in the charge curves. This happens if we do also know that. 00:58:13.000 --> 00:58:17.000 People realize that, for instance, that specific decade. 00:58:17.000 --> 00:58:20.000 due to renew? Mm-hmm. 00:58:20.000 --> 00:58:23.000 was actually really good in. Okay. 00:58:23.000 --> 00:58:27.000 So I should… I should look into K-Long decay. 00:58:27.000 --> 00:58:31.000 Like, into invisibles? Because, like, you see what it decays into. 00:58:31.000 --> 00:58:36.000 Yeah, okay, but this… this is going to change their life? Yeah. 00:58:36.000 --> 00:58:39.000 you measure a problem with your lifetime. 00:58:39.000 --> 00:58:43.000 But I would… I could imagine that it's decay rate to invisibles is… 00:58:43.000 --> 00:58:45.000 measured, or is out there. Yeah. 00:58:45.000 --> 00:58:49.000 Because, yeah, this one, it's really the decay into nutrition moves, but… 00:58:49.000 --> 00:58:53.000 I mean, I don't know how you'd be measuring those neutrinos. 00:58:53.000 --> 00:59:01.000 If you're really confused how you're able to turn it into a pion if you don't have any flavor off the item or calculus. 00:59:01.000 --> 00:59:04.000 You'll have that diagram back. 00:59:04.000 --> 00:59:07.000 Yeah, I mean, I don't know that the diagram is the most insightful. 00:59:07.000 --> 00:59:12.000 to your question. 00:59:12.000 --> 00:59:15.000 It's, uh… 00:59:15.000 --> 00:59:18.000 It's a weak interaction. 00:59:18.000 --> 00:59:25.000 That phi coupling doesn't exist. 00:59:25.000 --> 00:59:27.000 This coupling? 00:59:27.000 --> 00:59:31.000 Yep. I mean, you assume it's diagonally? 00:59:31.000 --> 00:59:35.000 So… So, it comes from, like, this… 00:59:35.000 --> 00:59:41.000 weak, strange, changing… 00:59:41.000 --> 00:59:43.000 interaction. 00:59:43.000 --> 00:59:46.000 So it's not… it's not… Also known as the W? 00:59:46.000 --> 00:59:48.000 That first protects us. 00:59:48.000 --> 00:59:51.000 Yeah, so it is… it's… 00:59:51.000 --> 00:59:55.000 It's a weak interaction. It's suppressed by GF. 00:59:55.000 --> 00:59:57.000 GF squared. 00:59:57.000 --> 01:00:04.000 So the W… Yeah, so this vertex… 01:00:04.000 --> 01:00:06.000 Is it a youth? 01:00:06.000 --> 01:00:08.000 The new physics here is that 01:00:08.000 --> 01:00:14.000 The new physics here is down here. This exists. So, but how do you turn the… 01:00:14.000 --> 01:00:17.000 First of all, W would be charged current. This looks like it's mutual permit. 01:00:17.000 --> 01:00:19.000 So, like, the… the… 01:00:19.000 --> 01:00:23.000 This decay, or these are neutrinos, 01:00:23.000 --> 01:00:31.000 That exists. Oh, it's a Utah car. 01:00:31.000 --> 01:00:34.000 Maybe you've made a part of my miscellaneous. 01:00:34.000 --> 01:00:39.000 No, that would be a charge tube transition. 01:00:39.000 --> 01:00:42.000 So, I'm sure by zero on the 8th. 01:00:42.000 --> 01:00:55.000 Yeah, a K-plus can turn into .0 plus a W. Then how does that mix with the phi? Phi is… 01:00:55.000 --> 01:00:59.000 You can't turn it into a fight. 01:00:59.000 --> 01:01:01.000 the neutral. 01:01:01.000 --> 01:01:06.000 plus the 5's flavor diagas. 01:01:06.000 --> 01:01:14.000 We'll say for diagonals. 01:01:14.000 --> 01:01:19.000 So with the neutrino case… 01:01:19.000 --> 01:01:22.000 not be problematic for a different reason. 01:01:22.000 --> 01:01:30.000 Oh, so the… the decay is that it's pi-plus to neutrino, neutrino. 01:01:30.000 --> 01:01:34.000 Or that's, like, the decay that exists in the world that's been… 01:01:34.000 --> 01:01:37.000 at least searches for. 01:01:37.000 --> 01:01:41.000 K+. K plus to pi plus, plus two neutrinos. Yeah, yeah, yeah. 01:01:41.000 --> 01:01:46.000 That's a neutral… that's a flavor-changing neutral current. Yes. It's forbidden in the standard model. 01:01:46.000 --> 01:01:50.000 But it's a decay. Well, it is with super, super suppressed. 01:01:50.000 --> 01:01:52.000 Yeah. In the same room. 01:01:52.000 --> 01:01:59.000 That's what NA62 is looking for. It may be found, what, Three Sigma evidence of what they mean? 01:01:59.000 --> 01:02:02.000 No, 3 plus the pipe, but they don't care, wouldn't they? 01:02:02.000 --> 01:02:06.000 Yeah. So that… 01:02:06.000 --> 01:02:10.000 The vertex for that is the vertex. 01:02:10.000 --> 01:02:16.000 Here. 01:02:16.000 --> 01:02:20.000 Do you have to expand out whatever the standard model… 01:02:20.000 --> 01:02:23.000 the K… the K plus, pi plus, pi naught. 01:02:23.000 --> 01:02:32.000 interaction there. That's the one I think we're all having trouble with. The K plus the 5 plus new new in the standard model is a… is a one-loop… 01:02:32.000 --> 01:02:34.000 I think the one-loop diagram with, um… 01:02:34.000 --> 01:02:37.000 What, 30 CKM suppression or something? 01:02:37.000 --> 01:02:40.000 Yeah, that's why it's so small. 01:02:40.000 --> 01:02:42.000 instead of the triangle. Right. 01:02:42.000 --> 01:02:46.000 So… 01:02:46.000 --> 01:02:55.000 So I don't see where you stick the 5, I guess is what I'm saying. Oh, the 5 picks up whatever the pi and the eta have. 01:02:55.000 --> 01:03:05.000 You have to mix the phi into the pi zero. Yeah, so the phi is mixed into the Pi Zero and the eta, so if the Pi Zero and the eta have that couple inches high. I guess I'm not aware of this… 01:03:05.000 --> 01:03:09.000 effective description in the chiral-Lagrangian for describing 01:03:09.000 --> 01:03:14.000 big plus to pi plus, new, new. 01:03:14.000 --> 01:03:18.000 Is there a pi zero to mu nu? 01:03:18.000 --> 01:03:21.000 Hopefully, I'm not familiar with the Carlo Rengan. 01:03:21.000 --> 01:03:36.000 Yeah. I'd love to see the, uh, expanded out diagram, not in the Carl LeGranium. How you stick the five… where you stick the five? 01:03:36.000 --> 01:03:40.000 So, in the standard model, I think it's, like, you have the S coming in, 01:03:40.000 --> 01:03:45.000 And then there's a W, which can turn the S into, uh, up. 01:03:45.000 --> 01:03:50.000 And the up can, um, has to come back down. 01:03:50.000 --> 01:03:54.000 And… actually, it's not just HUP, it's UCT. 01:03:54.000 --> 01:04:01.000 that it comes back to Mary, the, um… 01:04:01.000 --> 01:04:03.000 Great. 01:04:03.000 --> 01:04:06.000 So the dam's just kind of there for the ride. 01:04:06.000 --> 01:04:14.000 the spectator… in the K+, yeah, the down is the spectator… well, no, it's K+, so there's a pump, right? 01:04:14.000 --> 01:04:20.000 Yeah. You have a chain plus, yeah, so you have UCT, and then it meets the W again, it becomes a D. 01:04:20.000 --> 01:04:25.000 So it's suppressed by… there's, like, a unitarity thing suppressed by… 01:04:25.000 --> 01:04:27.000 the CKM suppression. 01:04:27.000 --> 01:04:32.000 Yeah, and then from the W… 01:04:32.000 --> 01:04:35.000 blue. You can radiate off it. 01:04:35.000 --> 01:04:38.000 Or the cork running in the loop, you can radiate off the Z. 01:04:38.000 --> 01:04:41.000 Which maybe wants to make clearance. 01:04:41.000 --> 01:04:42.000 So I think that's the diagram in the… 01:04:42.000 --> 01:04:45.000 standard model. Okay. 01:04:45.000 --> 01:04:50.000 So, where does… where do you specify that? I guess? 01:04:50.000 --> 01:04:53.000 Uh, to the 5 couple… okay, the 5 couple set up. 01:04:53.000 --> 01:04:57.000 up so you could stick it by there. 01:04:57.000 --> 01:05:03.000 I see. Okay. 01:05:03.000 --> 01:05:06.000 the and the Z, essentially, okay? 01:05:06.000 --> 01:05:10.000 this. 01:05:10.000 --> 01:05:16.000 If the phi and the Zika mixes, there are electrical… That seems pretty predictive to all of a sudden, well… 01:05:16.000 --> 01:05:19.000 Yeah, have you checked the lecture week precision? Yes. 01:05:19.000 --> 01:05:22.000 Um, 01:05:22.000 --> 01:05:25.000 Not beyond, like, these sorts of… 01:05:25.000 --> 01:05:32.000 decays. Well, like, the Peskin Akiuchi S&T parameters. No, no, it's been suggested, so I'd be interested. 01:05:32.000 --> 01:05:38.000 Um, and seeing if there's, like, more limits I can pull out of those. 01:05:38.000 --> 01:05:41.000 I don't know what stronger those… Yeah. 01:05:41.000 --> 01:05:47.000 decision-let tests, or these European to check? Yeah, it's more, I don't know as much about. 01:05:47.000 --> 01:05:54.000 Is Peskin and Taguchi? Yeah, there's the… the one that changed the… 01:05:54.000 --> 01:06:00.000 Maso dei. 01:06:00.000 --> 01:06:08.000 Oh, yeah, Suki. 01:06:08.000 --> 01:06:10.000 That's different than EDM? 01:06:10.000 --> 01:06:13.000 Yeah, well, even… 01:06:13.000 --> 01:06:16.000 recent one? 01:06:16.000 --> 01:06:18.000 Darius in his past life as a… 01:06:18.000 --> 01:06:27.000 laborious. Oh, yeah. Yeah. 01:06:27.000 --> 01:06:29.000 This is good. It's giving me ideas. 01:06:29.000 --> 01:06:34.000 More ways to limit the dark. If you go back 5 years ago? 01:06:34.000 --> 01:06:38.000 Priya. 01:06:38.000 --> 01:06:46.000 a huge amount of literature of movie release type, and of course, they're much heavier. But it relies on recoupling to bees. 01:06:46.000 --> 01:06:49.000 Yeah, true. 01:06:49.000 --> 01:06:52.000 So? 01:06:52.000 --> 01:07:01.000 The normal discussion, or we can, like, discuss offline, yeah. Christina, thank you very much, and let's thank goodness again for the… 01:07:01.000 --> 01:07:03.000 Yay! 01:07:03.000 --> 01:07:07.000 We're