 Hello everyone and welcome to a new webinar of this series of Latin American webinars on physics. My name is Hermán Gómez from Universidad Católica de Chile and I will be your host today. It's a pleasure to have today another Colombian physicist, Carlos Jaguna from Max Plan Institute for Nuclear Physics. And Carlos, today we will talk about dark matter, neutrino masses and lay-to-flay of violation processes in the scotogenic model. Carlos received his bachelor degree in physics from Universidad de Antioquia in Colombia and his PhD from CISA in Trieste. After post-doc positions in UCLA, Madrid and Monster University, now he is in Heidelberg in the Max Plan Institute for Nuclear Physics. Carlos talked today, his title, dark matter, neutrino masses and lay-to-flay of violation processes in the scotogenic model. Well, we are glad to have him speaking today and we remind all of you that you can write questions, comments using Google Plus Q&A system. Also, you can send us comments on YouTube or on Twitter with the hashtag Laofp. Okay, and now I let you with Carlos. Hi, Carlos. Okay, thank you very much for the introduction and to the organizers for the invitation to participate in this webinar. So I'm going to share now my screen so that we can have a look at these slides. Let's one second. I guess now you should be seeing my slides. Yeah, now it's okay. Okay, so I will be talking today about the scotogenic model, which is a model that can account for dark matter and neutrino masses. And as we will see, it has a very rich phenomenology regarding death-to-flagal violation. So this works is based on Muslim newspaper written with Abedino in the center. Okay, so the motivation for this work is the fact that we know new pieces require to account for neutrino masses on dark matter. Wait a minute, I'm having some problems. Okay, so give me a second because there seems to be something off. Let's see. Okay, so as I was saying, the motivation for this work is the fact that neutrino masses on dark matter require new physics. And these issues are strongly supported by the data. So these are not random fluctuations. The evidence, as we know, comes from most neutrino simulations in the case of neutrino masses. And from cosmology and astronomical observations in the case of dark matter. So I'm not going to go into the details of what this evidence is, but because I know you are familiar with it, but it's very strong. In terms of this, not much is known about dark matter of neutrino masses. So, for example, we don't know what is the origin of the neutrino mass, what is the mechanism that is behind it, or what are the properties of the dark matter factor. Things like the mass, the spin, or how it interacts with the standard model factor. And even though we have some data, it's not clear what the new physics required to account for these issues is. So in the neutrino case, for example, we do have some measurements of neutrino oscillation parameters, mass square differences, mixing angles. But this doesn't tell us how the standard model should be extended to account for neutrino masses. And for dark matter, it's even worse because we don't even have matching data, only some balance. So over the years, there have been many ideas about solving these issues. How to extend the standard model to account for neutrino masses and dark matter. So in the case of dark matter, for example, there are ideas based on supersymmetry, universal lecture dimension, and also so-called, minimum models. In the case of neutrino masses, there are also different mechanisms that have been postulated to account for them. They include the different grand stations of the system, mechanisms, the idea of using loops, the type of symmetries, and many others. And as you can see from this partial list, and usually what we have is some extension of the standard model to account for neutrino masses and some other extension to account for dark matter. And one idea that we are going to explore in this talk is the possibility that dark matter and neutrino masses are actually related. And then both come from the same new systems. So not separated, but the same set of fields. I will be more precise about what this means later, but they are both related. And in addition, they can go and be explained by physics of the TV scale. So in some cases, neutrino masses sometimes are postulated to account for them. This is at a very high unit scale, so instead they are concentrated on the possibility that this happens at the TV scale, which is the scale that is currently being brought by the agency. So the rest of the talk is divided into two parts. First, I will describe what this photogenic model is. So mostly the phenomenological features including neutrino masses, dark matter, and so on. And then I will describe our analysis and the main resource. So this photogenic model is a simple model that can account for neutrino masses and dark matter. It's actually quite simple. It contains only two new different fields. They are here. So this is one scanner doublet and some thermal signals. This model was originally proposed by mine in 2000s. And these new fields are assumed to be old and they are set to soon. This is important to prevent labor-changing neural currents and also to stabilize the dark matter. It's not a new model. It has indeed been studied extensively in the literature because it has also a very rich phenomenology regarding dark matter, neutrino masses, and also collided pieces. Regarding dark matter, in this model, neutrino masses are generated at the one level. So the relevant terms are written here. So this is the interaction between the singlet terms and the scanner doublet. And these are Majorana mass terms for the singlet terms. So I think that these two terms look very much like those in the standard CISO, but they are actually quite different. For instance, this term here is not a dirac mass term because this is colored out of the vision of the hits and this doesn't acquire up there. So this is simply an interaction term. That's also the reason why these singlet terms are not quite underneath the finger. So there is no mixing between these singlet terms and the standard neural terms. Another important difference with respect to the usual CISO is that these two terms are not enough to guarantee the violation of the electron number. And the reason is that we can assign 2H to electron number equal to 1 and 2M electron number equal to 0 and these two terms will be electron numbers, etc. And therefore, you wouldn't be able to generate these things. It turns out, however, that due to that electron number, the violation manifests to this other term, which is part of this color potential, the so-called lambda 5 term. As you see, we need H2 appear sporadically, so if you assign electron numbers, this will violate the electron number. So essentially, the idea is that you need the presence of these three terms in order to generate neural finality. Only when the 8 or 3 are present, electron numbers have to be valid. If you send one of these to 0, electron numbers will be stopped. So the diagram responsible for neutrinomases is shown in this preview. So essentially what you have is neutrinos here, then the singlet terms in the loop with the neutral scalars. And these are the two scalars. And the expression for the neutrinomases is well known in the picture. And as expected, it's proportional to the eukaryotes in lambda 5 and also to this, neutrinomases, a singlet term in the process. The same processes that lead rise to neutrinomases also induce new to the SU2, C2, E3, leptome, lego-gravity processes. And some of these are illustrated in this slide. So in this first slide, we can show the diagrams continuing to the decay of a leptome to a leptome and a problem. Here, this second line is the new conversion in nuclei. And here, there are some box contributions to the decay of a leptome into three leptome. Notice that all these processes are mediated by the charge scalar. So the charge particle that is part of the second of the new HWW introduced and also by the new singlet term. So all these vertices that appear in these diagrams are the new eukaryotes. So all these processes depend on the eukaryotes. But since these processes do not violate leptome numbers, only leptome label, they are independent of lambda 5. So they do not depend on lambda 5 in contrast to neutrinomases. And in general, we can say that one can obtain observable rates for these processes when the eukaryotes are relatively large. So let's say larger than 0.1 or larger than 10 to the minus 2 or so, more or less in some cases. So as we will see, these leptome-gravity processes will play a very important role in our analysis. Regarding dark matter, the light-singlet fermion in this model is a dark matter candidate. Remember that it is stable because of this set-2 symmetry. So the lightest particle odd under the set-2 symmetry that we force is stable. So in particular, it is the light-singlet fermion that is a dark matter candidate. And it is electrophilic. It doesn't couples only two leptomes. It doesn't couples twice. And this implies that there are essentially no direct detection paths or they are very relaxing because these processes direct detection with nuclei happen only through loops. So regarding dark matter annihilation, well, annihilation of leptomes and this cross-section is proportional to the eukaryotes to the fourth valve. Imposing the relative density constraint so requiring that the relative density of the single fermion amounts to the observed value. The dark matter density implies that one obtains that the eukaryotes have to be for the one. And this also implies that there is a strong correlation with leptome-gravity and neutrino masses because they all depend on the same set of eukaryotes. Neutrino masses, depending on the addition to lambda-5, has leptome-gravity processes. And dark matter, they are all determined by the eukaryotes and also there is strong dependence with the masses of these eukaryotes and the single fermions of the new particle that are testing. So that's basically the main feature that I wanted to say about how the eukaryotic model so it generates neutrino masses, give rise to leptome-gravity processes and it also has a dark matter candidate. Moreover, there is some relation, we expect some relation between these three issues used to these eukaryocarpins to be entered into all of these effects. So now we go into the second part and present the analysis and our results. So an important part of, an important motivation to our world was the fact that recently leptome-gravity processes are very well constrained and this constraint will be significantly improved in the near future. So this table here illustrates one of these processes. So importantly, we look at Neury Gamma and the present balance 10 to the minus 13, 10 to the minus 7, 10 to the minus 13. For other Neury processes like Neury 3D, it's similar, it's 10 to the minus 12. For Neury combating Neutria, which is around here, it's 10 to the minus 12, 10 to the minus 13. For TAO processes involved in TAO, leptome-gravity case, so the branching ratio is typically, has to be the boundaries of order of 10 to the minus 8. So branching ratio is smaller than 10 to the minus 8 and that's Neury Gamma, Neury Gamma, also 10 to the minus 15. So it is already very important to these bounds and they will be significantly improved in the near future. For many processes, they will be improved by about one order of magnitude, that's the case with Neury Gamma for instance in the past year, and also for TAO decays. It goes from 10 to the minus 8 to about 10 to the minus 9. There are some other improvements which are quite remarkable. In the new three points, we will go from 10 to the minus 12 to 10 to the minus 16. This is 4 orders of minus. And in the case of the conversion of the nuclei, it may reach even 6 orders of minus, from 10 to the minus 12 to about 10 to the minus 18. So we wanted to study, even that in this model, what is the important bounds for electron field violation? What would be the impact on these new processes? So that was the question that we wanted to answer. So it was already known that Neury Gamma in particular provides important constraints. There were many changes in words related to this, but as we saw in the previous slide, the major improvement will not be in Neury Gamma, but in other processes. So we want to analyze those, and there were all these other range that have been computed recently by Thomas D. Sensen. But there have been no kind of global analysis so far studying the parameter space, the different constraints, and the prospects for future detection. And this is exactly what we do. So we are studying the parameter space of this model. It seems that we miss the audio from Carlos. Carlos, can you hear us? We are experimenting some issues with broadcasting with Carlos. We are working to solve it. Roberto, can you say something? His connection is down. So I'm trying to contact him, because it could be that there is a problem with the internet. But we still see his slides. Yes. Yeah, that is strange. Let me just one second. Okay, meanwhile we want to remind people following the webinars that you can send questions through the Google system, Q&A. Also, you can send questions through Twitter. And in this lab, if you have comments, you have time to send questions. It seems that he haven't realized that he lost the connection because due to the shared screen I'm trying to contact him in a different way. Soon he will resume. Meanwhile, if he connect, in this week there were some news about some analysis related with that matter in which they were studying the effect of black holes and the horizontal event with that matter. I don't know if some of the webinars have heard about that news, but maybe can comment something. I think we should stop somewhere because I don't think this is going Yes, let me just try to call the attention of Carlos. Maybe he's already in the conclusion of the webinar because if he haven't realized that it is this problem. I just will try again. It seems that he's not I would suggest to I mean if the cost agreed to many to stop here the webinar. We sorry a lot for the convenience for the viewers and we will try in the next webinar. Yeah, sure. We need to stop because it's too long simply then let's stop here and sorry with the video.