 All right. Welcome, everybody. Let's go ahead and get started. So I don't have any announcements for today. So I'm just going to go ahead and turn the introductions over to Professor Pavel Ndolski. Yes. So hello, everyone. So today I welcome Professor Oror Kurtwa from National Autonomous University of Mexico. The seminar today is dedicated to a very interesting topic, physics of the electron ion collider. Now, Oror is an expert on the various aspects of non-potovative quantum chromodynamics. Oror got her PhD in 2009 in the University of Valencia in Spain, and then she had a number of full oppositions at the Pavia, Liège together with Rascati and Mexico Siki, before she came to our side of the Atlantic Ocean, where we initiated a new major project for the electron ion collider, which will study multiple aspects of the three-dimensional structure of the hydrants. So today we'll have a review talk dedicated to this very rapidly developing area. And for those who are interested on Wednesday, we will have a full appreciation at 3 to 5 p.m. in the room 202. So we can discuss further details, especially questions that we may have about the theory that will be discussed. With this, I welcome Oror Kurtwa. Thank you so much. Okay. Okay. Thank you very much. So I will talk about one aspect of DIC, which is a huge program. So I can't cover everything, also because I'm not an expert on everything, but I will talk especially on coagulant correlations. Okay. Okay. Okay. Okay. Wonderful. I think we're all used to the zoom sound now. Okay. Okay. So let me just, that's the first in-person talk in many years. So let's see if I remember how it works. Okay. So I copy this from the EIC web page. And there's this fundamental quest that we have, which basically consists in how can we break down the quest to understand the head unstructure. And if you go on the web page of the EIC, you will see there are many interesting points, like how to coaxing the makeup for the visible matter of the universe, precision 3D imaging of nucleons, solving the proton spin puzzle, the emergence of hydrodynamic mass, coagulant confinement, and all those things. Right. And I will talk just about, well, I will give, I won't talk about everything, but I will give my two cents on some of those topics, but not everything. Okay. And so those that I highlighted here actually can find answers or a partial answer or hints of answers to the study of pattern distribution functions, which I guess here you'll know because you have all this CTECH members. So you must know a lot about PDFs, but I will just review a few things about PDFs. And in particular, the hydron properties I've mentioned before, like the spin, the mass, most of them involve higher twist distributions. And what is really interesting is that those properties are accessible to manifestation of QCD at low energy. Okay. Which means that the hydron structure beyond leading twist, which I will mention, I will explain what it is in a few minutes, is relevant and accessible. So this talk will have those three main points, which will be what are higher twist distribution functions, what information do they encapsulate, and what can be learned from low energy experiment to higher Q square, which as we will see, EIC for us is higher Q square. Okay. It's really high for higher twist. Okay. So this is the picture of the degrees of freedom of the proton. So at low energy, you can consider it as a hydron is the degree of freedom. And as you increase, you increase the resolution, the Q square, you will see more and more inside the proton. And in low energies, you will consider that you have this constituent like quarks, and at high energy, very high energy, you would have all those pairs and gluins. And this is, of course, paired to the behavior of the Afastrong. Okay. And what we would like to study at really low energy, like a Jefferson lab, for example, would be this kind of energies here, mid range energies. And the EIC will discover a bit more. So the idea of that is that you've heard about this EIC, the glute that binds us all. So what is that glute that binds us all? So perhaps part of the answer is actually gluon of low energies. So gluon is radiation high energies, but even lower energy would have gluons coming as the dynamics of QCD. So how can we access that information? There are many observables, but in this talk, I will talk a bit about the squaggle interactions. Okay. So how can we go to the squaggle interactions in PDFs? So that will be PDFs of leading twist. This is the one that everybody knows, the most improvised PDF. Then you have two other PDFs of leading twist, which are the helicity that gives you the spin, and transversity, which gives you something similar to the spin, but in the transverse direction. Okay. And all three are complementary and really interesting. And the most famous one is the employer's PDF. And we know a bit less about helicity and transversity, but they still are leading twist PDFs. Okay. So they are defined on the light cone. So if you take the plus component, and you know that Birken X is the fraction of a momentum that carries the active quarks, and you can relate, you can plug them into observables thanks to fission theorems. And then you know the evolution too. Right. So now if you want to go a bit further in the, in the development, then you would have like on the composition. So you see they have this leading twist here. Let me just show them the PDFs. Okay. So the unpolarized helicity and transversity here, but as you can see, you can have transverse and negative components of the light cone too, which is going to give you twist three that are suppressed like M over P plus where P plus is the direction of the proton, the momentum in the proton. And then you would have twist four. Okay. And all those, those, those guys are suppressed like M over P plus or M square over P plus square. Okay. So, so it seems that if you go to really high energy, so P P plus is like you, you go really high energy, it was high, it would just disappear. Okay. But if you consider lower energies, they will kind of matter. Okay. So just one slide of, of terminology of the, the zoo of, of the submission functions. So I mentioned PDFs. And they are what you call the collinear PDFs, the integrated PDF for whatever you want to call them. And they depend on X, B, and Q squared. Okay. But I will just mention a few things in the talk too about GPDs and TMDs. And so if you want to take this, this image of the proton that just, that goes really fast in one direction, you would have this transverse plane. And then you would, you would see, don't put your eye there, but you would see this image here. And X corresponds to this longitudinal momentum of the proton, of the quark. Okay. But then you want to add dimensions. And if you want to add dimensions, you could have, you could make two ways, or you can combine all those two ways. One way is to add the transverse momentum on the plane, which gives you TMDs. So with 3D. The other way is to go to GPDs when you have a momentum transfer, which gives you like the impact parameter here. Okay. And so GPDs are three-dimensional distributions, just like TMDs, just different representations. Okay. Excuse me. Yes, sorry. TMDs, transverse momentum distribution, and GPDs generalized. But we know that they're not so general, but it's called generalized quantum distribution. Yes. Yes, exactly. So I didn't put the picture here, but if you combine this one and this one, you would have a five-dimension. And yeah, but it's one another, not accessible to experiments yet, but okay. And I don't think I will mention them, but okay. So PDF, the one I'm going to talk about, I mentioned a few things about TMDs and about GPDs. And then of course, if you integrate PDFs over X, you get the charges. And if you integrate GPDs over X, you get form factors, which depend only on the transverse momentum square. And you can complete the cube, but the other ones are just more exotic things. But that's the cube of zero functions. Okay. So let's go back to to Bollinger PDFs. Okay. So still the emperor is helicity and transversity, just to show you here. So that's a plot of X and Q square ranges. So they have some magazine data. And then you would see the IC here, it's shown for helicity and transversity to give you an idea of what will be covered. But what I would like you to see here is that, so that's one. Okay. So there's a cut of one Q square, one here. Okay. And then what you can see that for some experiments, the ratio M over Q is not that small. Okay. So especially you see this range is right. So sometimes what would happen if you when you make your analysis, you would have some contamination coming from M over Q. Or what you can do to you is that you can define some asymmetries to get sensitive to this M over Q term. Right. So there are two ways. So what do I want to say by that is that you can see them as contamination or score your terms like you have here, I guess you're familiar with CJ 15 and they have a lower cut. So they would include more data in that closer to the Q square equal one. And so they have to take into account what they call HG, which is higher twists terms. And here we divide Q square, right. And so they have to feed them to get to get to their feet. They have to take into account those corrections. And so that that's the way you see the impact of higher twists. And also you can see if you only go further, higher twists, as I really explained in this talk, have a lot of physical content. And they can also play a role in duality, for example. But you can also see them as, okay, depending on the function you want to access, you can see that they also have genuine effects. And that really affects is really non perturbative. For example, you know, the analysis by the jam collaboration, they analyze the helicity, which is just this one here. That's this, this set of data here. And then they know they're going to have also a twist tree. And so they fit this function here. And you can see that would be the helicity to get. And then they also have the twist tree function. So there are these two sides. So if you don't have, don't know much, you put them as a as a contamination, and then you try to do something with them. And then you can try to go further as a way we've done with the Vigela with the IC and try to extract them. Okay. So what do I call genuine effects? And that's the interesting part of, so I will talk about, okay, I think I'm mentioning it here. So GT that I mentioned before is the same of the helicity and G2, which is the twist tree part. And so if you analyze from the metric sediment, and you can work out with the equation of motions, you can realize that as a relation of G2 can be reduced to at least two PDF, plus another term. Okay. But if you take this reduction, it's called the van der Waalschek relation. And what we call the van der Waalschek approximation is basically just that part here. So you can, in principle, know part of the twist tree thanks to the twist two PDF. But if you take into account the genuine effects, then you would have the quadruple correlation here in this teardrop term. So the teardrop term is actually the interesting part of G2 from my point of view. Okay. And you can, you can just work out the question of motion today. We'll find that you have the quadruple and quad correlation here. Another aspect too is that since we are on the light cone, there are some very close singularities, so data X. So it's the origin at X equals zero, you will find something like this in some models or and it can also be found to the question of motions. So you would have the same equation as this one here, but in some, some models, you would find the data function for the case of G2, right? And some models, we always have this, the singularity here. So it means that they are what you call this zero mode effects. Okay. So what I want to say here is that we know part of this function, but we don't know the rest. Okay. So how do we know that those other effects are not zero, they are not zero. So the first thing that people have done is said, okay, we work in this approximation here and we just keep the twist to part. So we know G1, we can get G2. And so that's what people have done for a long time. And it could be worked out through experiments actually. And there are some studies, about 10 years ago, a bit more, that suggested that it was not enough. So if you compare the Banzer-Abyshek reduction here, approximation on G1 or G2, you realize that you need something else, right? So this data here, which is the blue curve here, it's non-zero, which suggests that you need the G tilde. So they are actually a quadruple interaction here. So the question was how to access it, right? So the good thing about G2 is that it is accessible to DIS, but here we talk about the DIC. But let me just mention here, JLAB 12, that's triangle here that you can see. So this is something from the yellow report of DIC, that's for polarized DIS data. And this is something for the white paper on signal interaction region for the DIC, which is being written right now. So what you can see is that what is covered from non-experiments would be this region here. So the DIC at a really high center of mass would be in that region. And if you have a lower center of mass, you would cover a slightly lower Q value and slightly larger XI, which would be ideal for higher twos, actually. So you can see here what is expected from this second interaction region, for example. So it's like a smallish Q-square and smallish X, but not too small X. We don't need to be too small in X. And so I will try to discuss the complementarity of this data. Okay, so why are higher twists so important? And what do we know about them now, right? And what do we need to do to know better? Okay, so that's the interesting part. Okay, so higher twists can contain quaggling quag correlations, quag marks term that I've not mentioned before, but they also have a quag because use a question of motion. So you would have a mass term of the quarks, and they can contain this single IOT of this zero mode, if you like. And what is also really interesting is that many properties of the hadrons are related to that. For example, if you take the proton spin, there's a component that comes from the quaggling quark correlations in GPDs. If you take the proton mass, there's a single IOT in the scalar PDF. And beyond that, there are this discussion about universality of PDFs, especially when we talk about sievers and choose the man-effects. So this is TMD and this is more complex, but there's a lot of discussion about that. Let's keep it simple for today, okay? So proton spin, quaggling quark correlation. So a few years ago, there was a discussion about the orbital angular momentum, and there are two definitions, right? So you want to understand which is the spin of the quarks, the contribution from the gluon, and the OAM, right? And as you can see, these fingers, there was always part of the pie that was in disagreement with everybody, right? And so this JM is for Jaffe Manohar, and it was shown that this piece of the pie is nothing else than quaggling quark correlation in GPDs. So it means it's higher twist. And this, why is it so helpful is that we can now try to fix observables. What would be the observables to understand that, right? So we know what is here, right? But that's interesting. But now the discussion moved to the proton mass. And so the proton mass is like a hot topic right now, especially with compass plus plus and EIC. And so what is the thing about the proton mass? But that's kind of a propaganda. Of course, the terms are kind of, you know, take it like just as a sum, okay? So if you take the Higgs mechanism, you expect to have, that's why we always say that the current quark mass at a given scale, I think that's about 2GV, don't make up for all the mass that we expected in the proton. So the mass of the proton is means that 99% comes from QCD, right? And how that's a big thing, we don't really know, but the question now is, how can you decompose it? So you have a big question, how do you generate that mass? And you make it like a slightly easier question, how can I compose the mass, right? And that's how we decompose the mass. There are also two different masses, the composition, there's the G and the Lose one. And so you would have like about 1GV here and you decompose it to mass of the quark, mass of, sorry, the trace anomaly, and the energy of quarks and glues, okay? And so just to make it a bit more clear, so this energy is related to the moment of the polarized PDFs. And the quark mass is the sigma terms, okay? And this one is, it will be the condensate of glues, okay? So what can we access from experiments that give us answer to that, right? So this, I think you have C-tech can do that, okay? So that's wonderful. The trace anomaly is the one that nobody knows exactly how to get to, but what we also need to get from experiments or from other approaches are the sigma terms. And the sigma terms are what I'm going to talk about now, okay? So you have this mass decomposition. So the sigma terms are just like a condensate of quarks, but between proton states, not of the vacuum, right? So they go on top of that. And so you have the sigma bionucleon, where you have up and down, and you have the strange. And so those have been determined from bionucleon data on the lattice as well, okay? So they're kind of known, but not from experiments. There's no phenomenological here, if you like, but there's a lot of process. But what is interesting here is that they are related to the PDF EFX by some rules. So if you take this PDF, that is the color PDF as shown in the beginning, you will have the sigma terms. Okay, so that's really interesting because that PDF is related to the mass of the proton. Okay, so now I get to that PDF. Remember, I said that you could have this single term or workout term, okay? That would be a data here. You would have the quaggling quaggling interaction. And because I have a mass term, right? So that PDF has everything on three terms. And now the question is that, okay, how can we access this information? So we would like to have all this information and we would like to understand the role of each of the terms, but first to get to the PDF. Okay, so how do we get to the PDF? So this one is skylight. So you cannot use, you cannot access it in the IS, in inclusive the IS, need to go to semi-inclusive the IS. So how do we do that? So once you add, so in semi-inclusive, you will detect say a pion or a pair of pion or chaos or the things. So you would have the PDF or the quaggulator here, but you also have a fragmentation part, right? And so the cross section would be a product of the quagg PDF or TMD, okay? And the fragmentation part. And this allows you to have much more structures because you would have, in that case you have, so the tron is momentum, which is KT, and you would have many things. So if you want to go to higher twist, you can decompose. So usually we'd have this quaggulator here as two PDFs, but you can also have M over P plus times the three PDFs, okay? And same on the top, right? You could also have the same thing for the fragmentation here. But on top of that, it's already included here too, but since those three PDFs contain a quaggulant quagg interaction, you can also have this kind of suppression here. So this Phi A contains the gluer into, right? And so you can work out how to write the mini asymmetries. So you would have the cross sections. You can define angles and asymmetries, and you would have a lot of different asymmetries that will give you access to three PDFs, okay? And actually, they were measured by Hermes and Klass, many of them, and they are not exactly zero, not all of them. Some are not small, and some are, some are not, right? The huge problem with this, this is a team, we need more of a team in the approach. And so the problem with that is that you have many functions. And what happened is that you have so many terms that you did all very intertwined, right? So there was an alternative to that. That was the proposed for the transversity, actually, is to go to semi-inclusive TIS for dihedron, or dihedron, see this if you like. So here you would just add one hadron, but here you would just detect, you would detect pair of pions. So you would have pion pairs here. So that would be the same kind of diagrams. And in that case, the good thing is that you don't have to be in the TMD framework, but you have a binary framework, okay? And that's what has been used for the transversity function as well. And so in that case, you would have symmetries of that type in which you would have three pdf times the two permutation function, and the two pdf times the three permutation function, okay? And that's how we're going to access this scalar pdf. And so the scalar pdf would be in that asymmetry. You can see it here. And I'm going to talk about that. Okay. Okay. So those are the dates, the whole data we have for this scalar pdf. So the funny part is that so class is Jefferson Lab. So this was the last paper of class with six gv, and that was the first paper of class with 12 gv. And as you can see, they are published in the same, yes, in the same issue of BRL. So the funny thing is that it was about the same asymmetry, right? And that was pretty cool. So we got three points from class and 12 points for class 12. So the first thing I want to mention is that only class 12 shows non-zero, clear non-zero twist tree asymmetry where it's not really clear for class. And the shortcomings that there's only one target, which is a proton target. So we can just access this combination of u and g. Okay. Okay. So the great news is that it's not vanishing, but we don't know if it comes from the fragmentation part or from the pdf part. And so we're going to study this slightly. Okay. So we just have this thing. Okay. So how do we access this twist tree pdf? We work out this asymmetry. And so we know that leading twist dihematometrician function that we have here. So this, all its fragments into two pions. We work that out. We know it from other analysis that we had from the transversity part. But then we have to see what you do with this order term. So that would be the unpolarized pdf and a twist tree, turning twist tree fragmentation part. And so there's not much we know about it. This was just one model talking about these kind of things. But there are other asymmetries from compass that help us do so, right? So we work that out. And this is very preliminary. So it's been there for seven years. We've worked the analysis again. And so we make two scenarios. I'm just going to discuss about the results. And that will be the combination of 4u minus ed divided by 9. So that's a combination of balance pdf. And so what I want you to see here is that we have two approximations, two different scenarios. And we just want to know how much is it different from zero? To which confidence level is it different from zero, right? And so you can see that class is not that much. Well, it could be zero. It's compatible with zero. But class 12 is not so much, right? So that's wonderful. So that will be this combination that we have here. So and I just want to mention here that this is a full uncertainty, right? So that will be the 100% of the, we use the bootstrap here technique to get that. It's 100% of the of the error band. So the good news is since that from class 12, we probably have non-zero combination of these effects, right? And that will be wonderful. We're going to finish the analysis pretty soon. But that's pretty good news because we can access this pdf to get information about the mass of the coagulant. But not everything at the same time, right? Okay. So how do we know about universality of non-partumative functions? So there are many things to say here about all this, this framework of dihedron or even TMDs is that first it's all the two leading order, okay? And there are not many, I mean, we talk about global fits. They're not really global fits, right? So this, this fragmentation function, I mean, it started from E plus and minus, and they have the news in series, okay? Analysis, because they see they have to be checked or tested against other data, right? So the only thing we can do so far to check consistency, to check that if you have the data from the variables of dihedron, when reconstructed from the dihedron function, you get something that is really similar, right? And that's what you can see here. So if I get the data and I reconstruct the symmetry from, from my fragmentation functions that we get from E plus and minus, we get pretty consistent, okay? And so about twist two and twist two and twist three pdfs. So if we talk about twist two, transversity is the one that we need to access to cities as well, because it's a chiroload pdf. And so this is, there are a few studies about the universality of those pdf, the same pp and in cities. And but it's still the global analysis of transversity has been done from the Bavia group and jump collaboration. And so now what about twist three pdfs are the universal? Oh, well, this is to be answered. So we don't know yet. And we hope that the Vdic we can have an answer. But there are examples to this TMD and what we call dynamic artist relations. And what's this code is the severs function is related to the choose them and function. So what is the goal of this extraction? And why is it going to be important form for the IC? So that's jail of analysis, completely class analysis. So the first question is our genuine twist three affects non zero. And I think we would say yes, up to a certain confidence level, and perhaps more for GT than for this effects. Okay. But can we access quaggle and quaggle relations, or the non perturbative information from those three is tree. So let's take this example of, of the effects. So that would be the combined and I combined the two things that are here. I combined them. Okay, that gives me this shared area. And so the question and that's part of the propaganda of the IC actually, is that some non perturbative effects are expected to actually in the smallish x region. Okay, and this is a sketch. Okay, a sketch. This is not real. Okay. And so I said it was a master. And I also said that it was a data function. So if I take a smear data function here, so look a zero must be here, right? It's not zero expect to have a delta function and the master here multiplied by the empire as PDF here. And so what we expect is that the small x region, which is not really just tiny x region is small, like about 10 to the minus two should give us some, some information about it's non perturbative effects. So is it really true? I wanted to insist that it's just a schematic model here to illustrate why we need the DIC because at the end what we matter are the moments because those guys will give us moments. And when you have the moments, you need the whole range in x, right? And of course, the small x kind of play a huge role in the moment, right? And okay, there was an extraction in the TMD framework years ago. And this is all compatible with that. Okay. So let's go about the DIC coverage. So this is the size of the asymmetries, as you can see. And so that's for the yellow report. So we made these projections. Since there's no fit for this EFX, we use models to extreme models, one from light cone quark model, another one where I just used the same thing as here, we used the master. Okay, then we put a huge master because we are low energy, it's low Q square. In principle, we're allowed to use a mechanical mass here, but constituent mass, about 300 MB. Okay. And so you can see that for different configuration of the beams, that will be the lowest one, slightly higher ones. And then we didn't do it for the rest because it was just nothing to see. And you can see that you can have about 1% to 1.5% asymmetries for this configuration here. So they are non-negotiable, but are really small. And so that's the archetype of observables for this second interaction region of the IC. So what is the second interaction of the region of the IC? So that would be a plot, not really formal plot about the coverage here. Okay. So I understand that all these light-scattered plots are not really observable. You should just focus on the really dense part of the plot. So that's JALAP-12 that I just talked about. That will be perhaps JALAP-24. But yeah, you see this slowest configuration here will give us access to this region. And then when you go to higher ones, then it's wonderful for other things, right? But not for higher twists. And so the idea is to cover this range here that would correspond to a lower center of mass to complement what is going to be accessed with this configuration here. So that's what is proposed here. It's going to be a higher limit to lower center of mass. And why is it so important? Because I haven't mentioned in this talk at all the Q-square evolution. And of course, it will matter, right? It will matter for the spin observables, for the mass observables, the mass will run, the spin moment will also run, all those PDFs will run. But that's something you have to study. And that would be perfect because we just need some span in Q-square that we didn't have a JALAP, for example. And so that would be wonderful to have a span of Q-square that is not too high, not too much, but enough to start for these three PDFs. So in most cases, we know the equation for the three parts. So you know the quadriline quark, then you know how it evolves for the collinear ones. So for some team these two. And why is it going to be helpful is that, as I said, there are different parts of the PDFs, three different contributions. And evolution is going to help us disentangle and understanding each of them, right? And I understand that this is especially hard for TMD studies when they're going to have more effects to study. Okay. But this Q-square is going to require this interaction region, second definition of the IDIC here. Because as you've seen for the first study, we had some symmetries, but they're pretty small. So yeah. Okay. So talking about this multipart on distribution IDIC, so why is it so important? And I just want to say it again. So there's going to be a larger range, not so large, but large enough for us, a large range of Q-square value, and small ish, but not too small x regions. So that's complementary to what we had from fixed target experiments like Hermes and Klaas. And also there's going to be a sandbox for vectorization and evolution studies. So the golden channel here will be fully inclusive with access to GT. So those are the predictions from Jam. Let's take them from the yellow report. Okay. So there will be a, we would have proton and neutron. So we need both to have a separation, of course. And that's we, so Jam give us for now this yellow band. Okay. And that it looks like it's cut, but it means that this is only accessible with the IDIC. That's what they have now, and this is accessible with the IDIC, right? And you see how they're going to extend the analysis and all the plan to have more statistics in the analysis for GT. And the silver channel is actually semi-inclusive the IS today headroom, and perhaps two single headroom too, to access the HEAVX, right? And so the two chosen channels are collinear observables. They are not T and Ds, but they are a plethora of interesting T and Ds, GPDs, and all the things that the Hayatris do. And there was this on the sub working group on on the Hayatris of the IC. Okay. So I just want to mention, Twistree, HEAVX Scholar, Twistree in Mexico. So Salvador, I hope it is connected. And he's another grad student. I said yes. Angel Miramontes is a postdoc in Michoacán. Okay. And so, so Angel is doing the analysis of this EFX with me. And so I'm always doing the calculations in the back model. Okay. And so now one of the big points and one of the reasons why I'm here is that I can be the Twistree with Fantomas. So I guess some of you have heard about Fantomas. So Fantomas is a project between Unam and SMU here. You can see you can fly from one to the other really fast with the car. And so Fantomas has been developed with the students somewhere here. Barada is here. Downline. Look at this online, Ryan. Max is not going to, Maxis is not connected. And Paraná is getting myself. And it's, it's going to help us so not that we can extract this point by point EFX, try to parametrize this function and to get the most of it to a study of a functional form, right? So that's going to be a wonderful project. It's going to be used for other things too. That's how to study functional forms from a non-biased point of view, right? And perhaps we could use Fantomas to, to understand better Twistree PDFs. Okay. Let me go to the conclusions. Okay. So we have discussed the role of higher twist distribution to understand the Hadron structure. And there was a huge list from the EIC wish list. I say it's a wish list, but I really hope we can go through it one day. And they contribute, for example, to precision to the magic of nuclear emissions of Hadronic mass. That's really important. I think the mass of the proton is a really, really important thing. And as well as the proton speed puzzle, right? And, and of course, higher twist distributions can unveil aspects of Hadron dynamics. That's a non-partibutive picture. And we still have to bridge this non-partibutive picture with the perturbative picture, of course. And they are accessible for experiments that they still require more statistics and more analysis from the theory and the phenomenology point of view, right? And something that I did not mention, but it's, it's there. It's wonderful is that there are also efforts on the lattice community to get to, to charges, to quasi PDFs, to PDFs. And they actually are really interested in those functions too. So that will be great to, to combine the efforts with the lattice. Thank you. And this is where we're going to hit the limitation. Sure. Sure. Sorry. Sorry. Sorry. All right. So just to check, can somebody, maybe Lucas will pick on Lucas. Lucas, can you hear us online? Yes, I can hear you. Okay. So, so thank you very much at all. And this is a very informative presentation. And now we have time for questions. And we'll be okay if I have a quick question just to follow up right away. So there are two important physics questions that you mentioned. So the, well, we studied the proton and so there are two puzzles, how the mass of the proton is formed and how the spin of the proton is formed. And you mentioned this twist country contributions contribute to both. So what's the fraction of the contribution from this country? Well, hard terms you expect for the proton mass, in addition to the Higgs mechanism that gives you only 10 maybe very small fraction of the total mass, but also for the proton spin. Okay. So do you hear me? Lucas, can you confirm that you hear me? Yes, I can hear you as well. Okay, thank you. Thank you, Lucas. Yes. Okay. So from the proton mass, so all those masses will run. So there was always some up to, to, to give the mass of the proton that they will run. But it's about 10% from the sigma terms, which doesn't seem to be much, but we need the sigma terms to understand the other contributions as well. And from, from the spin. Yes, that's a good question. So I don't, I don't remember. I don't think it's, it's a lot. And I'm not sure their study is actually because it comes from three GPDs. It's, it's all dependent on, on, on the feeds of GPDs. So maybe I estimate some models, but I'm not sure. But is it correct? So basically this, this GPDs will contribute to the orbital angular momentum. Yes. What, what is the fraction of the proton spin that comes from not, not from the spins of the quarks, but from the orbital angular momentum? Well, it depends on, on the gluon, on the spin of the gluon. So there will be the speed, the, so the, you know, the speed of the quarks is not too much. And the speed of the gluon. So all those accessed as well to, to, to PDFs. So the helicity PDFs. And depending on which, if you use DSSV and NPDF or JAM, you will have a different answer. So depending on what you have for the, for the, the gluon contribution to the spin, the leftover is all OAM, OAM. By like 50% maybe. And I think a bit less. Yes. Okay. Okay. Let me give the mic, mic for Fred. Yeah. Thank you again for the overview. So, you know, for hard twist things, again, coming from PDF side, usually, you know, they're off in the corner and we cut on those hard so we can ignore those. But it looks like, I mean, if I saw in the slides, it looks like, for example, in the EIC, you're going to have a pretty good range over X that you can really probe that. Is that right? Could you come and make sure I understood that right? Yeah, that's the idea. So we'd have you see the plot. Okay. So this is, I'm not sure it's just for higher twist. That's, I think that's a general plot that has been made on, I don't know exactly which context, right? So, so, so yes. So the idea is to have X coverage and also Q square coverage because as you can see here, the X coverage for, so JLAB was pretty nice. So it was almost balanced region, but it was really low Q square, right? So you can still have contamination from other things, right? So the, the idea is to, to get something a bit higher. So you will be smaller hex, like 10 to the minus two, something like that, which is not bad. And, and slightly better range in Q square, which means we're going to have to take into account version effects, which will be great. So it requires still a lot of development from outside. I think GT has it. So, yeah. Okay. Any questions, Steve? Yeah, okay. So I wanted to talk a little bit about this interaction region dependence. So just out of curiosity, how recently has, is this particular plot showing what the EIC beam accelerator division thinks they can accomplish at the two IRs? How recently was that generated? Do you know? So I took it from, from the white paper that we are writing right now. So right now. Okay. So that's pretty recent. So they've been workshops. There was a workshop the last March, I think. So you can find those plots from some, some talks in last March. Yeah. And I think there are other talks from the Jefferson lab, but it is like in progress. I understand. Yeah. No, and that makes sense. I mean, the reason I was asking was I wanted to make sure it wasn't too out of date, because I know that the accelerator physicists have continued to, their projections continue to have continued to improve despite what they even thought had been the rosier scenarios, maybe a year, year and a half ago for this as a function of center of mass energy. But it's pretty clear that IP eight IR two is going to give you at low center of mass energy, better instantaneous luminosity. So integrating data for exactly these studies will be crucial there. So flipping this over to an experimental question, you talked about the golden and the silver channels, but within those, what are your what's your dream analysis? What's the analysis you want to see a team working on a detector experiment at IR to pursue as quickly as possible at any of these energies? Okay. So I'm not really involved with the whole desire to think of just the higher trees. So there's a huge program, which is basically what is, well, that comes from the job community. So it will be like T and these GPDs and the mass, the mass equation is part of it. So it's all this, this quantity is observable. So you would have that would benefit from a lower center of mass, right? So, so I don't know what's going to be chosen by by the whole group as as the as the key to pretend you get to dictate it. You get called in by that experiment, they say, okay, what should we measure first to address the concerns you raised in this presentation? My point of view, I'm biased, I will go for GT. Okay. Because it's been there for a long time, it's it's inclusive DIS. We do quite a lot of thoughts too, but that's not the cleanest, but that's that the one that have the path that is already taken. And then I would still go to the silver channel too. Oh, you know, I mean, of course, yeah. But I mean, with the kinds of coverage and efficiency and acceptance that the detector teams are talking about inclusive as I mean, if you can go for inclusive, go for it. Yeah, okay. So just to continue on this line of discussion, you also pointed out that the twist extracting two or three contributions is actually quite difficult even in the lowest order in QCT. So how can your car, how can the measurements at the first interaction point help you with extraction? Let's say of EX or GT. Okay, so there are many things. So yeah, that's something I forgot to mention, but it can depend on you, you know. Okay, here we go. So this is the MPOLA SPDF. Okay, so the MPOLA SPDF, because we always work with the symmetries for this kind of physics. And then in the case of the symmetries, you would always have the MPOLA SPDF in the denominator, right? So of course, since we work with feeding order, for example, what we often do, but okay, so for GT, they have next to leading role, right? And I think Jam, they also have their own MPOLA SPDF. But the role played by the MPOLA SPDF is actually really important, right? So to leading on the next to the order, we really need to understand what's going on here. And also the rest is, so in that case, that's the dihedron, but if you go to single hedron, you need a fragmentation part, right? So the fragmentation is crucial and I'm not sure that it's really not so, so yeah, so fragmentation needs to be in the lowest region. So I think what would be important here would be the MPOLA SPDF, but then you already know it, but what would be nice is to have it at lower Q-bounds, right? So this is a two hedron fragmentation function? Yeah, that's dihedron, but you would have the same kind of behavior for the other symmetries in the case of single hedron. You would just have, so the good thing with dihedron is that you have simple products. In the case of TMDs, you would have convolutions. So if you say you would have the MPOLA, you have the multiplicity, so the multiplicity will always include the MPOLA SPDF. So from a low Q-square, right? So that's the thing that can depend on. And I think that's that that's also why it's CJ has the fit and Andrew, I'm also doing a piece to use it to lower Q-bounds. That's one thing, yes. Okay. Are there questions, Steve? So you were talking about single hedron here and then the challenge and then you have to know the form factors and fragmentation, things like that. I forget about that. Let's talk jets. Like what if we just reconstruct dijet or single jet systems to do these inclusive measurements? I mean, wouldn't that be much friendlier from a theoretical point of view anyway? So you mean jets as opposed to fragmentation? Yeah. Well, I understand that different functions, right? So yeah. Yeah. And the collisions that we have from the fragmentation function is really related, so that would be from here. But that's part of how can we improve this form of this, right? So they will be the cities form of this when you have this fragmentation here. So of course, you would see jets, but the way it is defined must be slightly different. Yeah. I mean, on the Athena protocol aberration, where a lot of us are just talking about going all in on large radius jets to get as much of the low energy fragmentation as possible to attempt to make the later interpretation back to the part on level more straightforward. That's a lot of this is going to depend on how much material is or isn't in front of a calorimeter and how we can calibrate the jets and things like that. But that's all part of the plan. So and I'm assuming our colleagues over at the competing interaction point are also thinking about some of the same things, right? So yeah. Are the questions, comments online or? Yeah. Okay. Lucas, maybe you can ask a question. Yeah, I just had a question to kind of shift topics here before you talked about like the universality of PDFs up to a certain confidence level, right? I guess out of curiosity, what would be the consequences if we couldn't assume universality of the PDFs? Okay. Okay. So maybe there are two things and might have said both things at the same time. Okay, let's go. There was something here. Okay. So there are two things. So we would like to have PDFs that are portable. So you can take them from one process to another process. That's the case of the polarized PDF because you have fragmentation theorems. And in the case of higher trees, there are, I think there are truths, but they are not too really high. I'm not sure about that. And so what happens, see for example, for the transversity, they are kind of proof of factorization, but then the point is that since you're not really sure that you can, the first time you do it, the first time you combine the experiments, there's always a doubt. That's gonna work, right? And so that's what I mentioned about this universality. So before there were like global analysis of this PDF, people checked that they seem to be compatible in some kind of this way, like checking, like reconstructing things. So what would be the consequences if you don't have this universality? Well, it means that we have not understood or to factorize them, right? Perhaps. And the consequences would be that we cannot have global analysis, which would be bad, very bad. And then there's another thing that I mentioned about universality. Okay, so maybe about, okay, so this one is a different example. So there are fancy trees, tree, TMDs, not trees, two, trees, two TMDs, the severs function in the boom of the functions, they have a balloon, okay? And they match a tree's tree, a tree's tree quadruple-unquad function that is a true thermo one. And why is it so important is because in that case, because of that balloon interaction that I have, the sign of the function will depend on the process. So if you extract those ones from semi-inclusive DIS or from Drillian, you expect to have a different sign. And that's also kind of a proof of universality, right? So all this is universality taken from a different point of view. Did I reply to your question? Yeah, thank you. That helps a lot more. Okay. Okay. Okay, I think, well, we had some very good discussion. And I think we are all ready to thank Aurora. And it was a very informative talk. And thank you for coming here and telling us about this interesting physics. And now my understanding is for Wednesday, well, we have some material prepared. But if you have questions, and basically we could work, go through some of the details of what was shown today. And so please send to me, and I will pass to Aurora. And again, on Wednesday, we'll meet at 3 p.m. in room 202. Yeah, so you know what you would like me to talk. Right. So again, we have a flexible agenda for Wednesday. Therefore, again, we could discuss any of these topics in more detail. We can start with this slide. Probably we'll start with these slides and bring them out and go through them one, well, one by one, and we can stop. Oh, and the other thing is that at 2.30, we will meet to congratulate, well, congratulate Gene on his PhD defense. So we'll have a coffee and then we'll go upstairs to what is recitation. And let's thank, also on Wednesday. Yeah. So let's thank Aurora again. And so. Thank you. Yeah. It wasn't a nice hybrid seminar. Yes. Okay, thank you. So now we're going to have a shutdown for everybody online. So thanks, everyone.