>> Yeah, that didn't seem to help because the AI still typed what you said. >> Hello, everyone. We are about to start the plenary session today. We have 46 participants so far. Let me turn on the video. All right. Welcome, everyone. We will start the plenary session today. As in the other plenary sessions, we have professional captioning from White Coat Captioning. Today we have some issues with the embedding of the White Coat Captioning in Zoom but it is available in the URL which I will share with you in a moment. Today in this session we have first the presentation by Tor on activities in accelerated fron here and then a discussion led my Laura on EF needs. And then we continue with another session on the muon collider and technologies in R&D for trackers and calorimeters. Let's get started now. I will let Tor get the sharing of his slides. >> Tor: Great. Let me try. >> Recording in progress. I will start the recording of the meeting. >> Tor: Is that visible? >> Yes. >> Tor: I'm just going to cover the status of what we have been doing in the accelerator frontier. Obviously, most activities stopped or slowed down roughly nine months ago. What is the accelerator frontier focused on? We are trying to address what is needed to advance the fictions, what's currently available, meaning state of the around the world, and what state-of-the-art facilities could be available in the next decade or the next, next decade meaning the late 230s for large facilities -- 2030s. What R&D is necessary to enable these future opportunities. And what are the time and cost scales of the R&D and associated test facilities? That are required to get there and what is the scale and time and cost of the actual facility. This library is very important to feed into any strategy that is developed coming out of the Snowmass process presumably by P5. There are 10 different working groups. 9 formal topical groups. AF 1-7 and 7 is divided into different groups. Beam physics and accelerator education, accelerators for neutrinos, EW and Higgs, and multi TeV colliders and accelerators for PCC and rare processes and advanced accelerator concepts and then three technology groups. One focused on magnets. One focused on RF both normal connecting and connecting RF and one focused on targets and sources. The last group is what we refer to as the accelerator implementation task force. The goal there is to try and put really in a -- as rigorous as possible which isn't terribly rigorous but compare the readiness of the approaches. This goes back to the last bullet point I had shown. I can't seem to go back. Trying to understand what the time and cost scales of the R&D and facilities themselves and to do that in a way that can be understood and passed on. These are the 10 groups. We participated in the community planning sessions last year. And we had a lot of cross meetings where we tried to get feedback from different groups. Through the two days we had a lot of sessions where we were in breakouts with other groups whether groups whether that's energy or frontier Etc. Through the community planning meeting and the letters of interest, we got a large number of letters of interest. There were some 200 that were 250 that were submitted directly to the frontier and a bunch linked across from other groups and so the total number was 330 letters of interest. Again, there were something like 250 from the accelerator frontier and another 70 or so that joined. A lot in accelerator technology, a lot in education, but also a lot in the standard ones that link directly to the energy frontier meaning AF 3 and accelerators for the multi Higgs and colliders and accelerator concepts. What happens since? AF1 has been running a series. That ran through the spring of last year. The group AF 3 and AF4 which are focused on the Higgs and multi-G colliders have been pushing on the muon collider and this cool copper concept also. I will say more about both of those. AF6 I list as advanced colliders but advanced conception have been in conversation with members of the energy frontier members where the needs are and what they should focus on. I will go back to the comments at the end as to what additional input we could benefit from. There is the implementation task force meeting regularly broken into four groups and trying to come back with metrics we can use to compare across different concepts. One of the challenges is we have some concepts that have a CDR or technical design reports and other concepts which have little more than a parameter set. Trying to compare across those is challenging. Another thing that has been initiated is a collider forum. That's an initiative to bring in some of the collider components from the U.S. and includes membership from AF4 and outside of AF4 and across Snowmass. There is the group that is looking at the replacement of the fermilab booster and there is a group looking at what can be done on the fermilab side. A couple things about the ladder. Here are a couple options being considered by the fermilab. A ring and a collider. I should note when aisle C was in its infancy, after the technical -- after the technologying decision in 2004, Fermilab developed a proposal fitting ILC using a power line easement that is 30 kilometers long. Don't need to be limited to fitting on site but that is what is looked at here. This is based on the cool copper concept or a click base system. Again, the site filler here is either plus and minus Higgs factory or muon-based machine. Of course, the other thing that's been going on while we have been in a bit of a hiatus is the European planning process. In the European strategy for particle physics document it called for clarity in the accelerator R&D programs. That led the laboratory directors group, LDG, and the shared counsel to setup five panels that are trying to develop the program in accelerator physics aimed at high energy physics. There is a panel on high field magnets, high gradient acceleration focused on lasers and plasmas, a panel focused an high gradient AF acceleration for normal and circuit conducting. There is a panel focus on muons and energy recovery. They have a goal of providing a report by the end of the calendar year to the CERN counsel with solid drafts of these reports that get reviewed by council. I believe the day is the September meeting. We have these five panels going on in parallel with what we are doing in Snowmass. A new more words on the accelerator implementation task force. This is trying to address the question what is the cost and time scales of the R&D and there facility. There are a large number of projects being proposed and discussed. They are all in different states of readines. They have different counting rules and different regulations on what a schedule means. Do they take an aggressive schedule? Not an aggressive schedule? We put together a panel of 12 people that includes some members of Snowmass young. It is chaired my Thomas but it has membership going across both Europe, the U.S. and Asia. And the group is charged developing metrics so that we can try to compare projects in a semi-uniform manner. The CHABLTHS is -- the charge is to develop metrics. The topical groups are providing the information. And then develop ideas as to how to evaluate that and document them at the end. I will say more about the status of each of these groups in a few slides. AF1 has been running workshops all posted on Indico. Other detailed working info for the working groups. AF2 based on neutrinos largely took ahead, reestablished contact, they are remembering what they had been doing and trying to get back to it and they have started building up again tables of what the needs are and then what we actually have available or could have available. So they will have that documented and are working with the NF-9 topical groups. In terms of Higgs factories, ILC has been moving and maybe not as quickly as people like but there is progress of some form. There is going to be experimental workshop in October of this year. At CERN there was the F CC week in June. They are making detailed plans to update the design for the following European strategy and particle physic update that happens in 2026. This is investing a significant amount of work into an effort into having a -- well, when the U.S. might call a sort of CD2 level design for that. In China, CPC workshop is going to be held in November. I mentioned the cold copper or the cool copper collider. That design is beginning to be developed as an option for a fast and low-cost linear collider option in place of the ILC scalls. It is using advances that have been made in the normal conducting technology over the last 20 years to combat with something that is both less expensive and can be developed relatively quickly. And finally on the muon collider efforts have been on the 3 TeV or greater and there have been 2 or maybe 3 community workshops that the CERN-based Muon collider based collaboration held over the summer. This, of course, but there is also interest in whether muon collider could be relevant to low energies. This is a table of machines put together that address the energy frontier. There are different options. There is clic, there is collider in the sea, there is ideas for a hadron collider, various versions of gamma-gamma, there is ILC and ones that range from the baseline version going up to a TeV or multi TeV scale ILC with assumptions of increased gradient that are being developed for the connecting cavities. Various versions of the muon collider. This is Diane in both cases. And the names are incorrect here. Chris Rogers. There is the Lemma version of the muon collider and the SPPC in China. For plans to meet with all of the contacts here in the fall and they are coordinating for the -- this is the LDG and the FCHH and others. In terms of rare processes, AF5 largely went dormant when Snowmass got delayed but they are starting work up now. They are having a workshop on targetry later next month meaning September -- in about a month. And we will be posting details in a bit. And thren they will also be holding a workshop focused on facilities and that will be scheduled in the winter. Hopefully we will all be able to start moving around a little bit more by the time the winter comes. AF6, as I mentioned, it has been a little bit of a challenging trying to understand what the physics opportunities are for high energy electron positon collisions. They have been meeting with the members of the energy frontier to try and clarify those. They have also solicited a series of white papers that will help them write a summary. These will be contributed in addition to the LIOs that have been submitted but there is web paper on laser driven structures, one on nanostructures, test facilities that are available or possible. Laser drivers. If you are using a laser driver, if it is a plasma, it is a very intense laser system and developing that for high rate has been a challenge. What are the energy limits of the positive colliders? People talked about 3 TeV in the center of mass. Is 10 TeV in the center of the mass reasonable? What does that imply for the beam, and the IP system? And acceleration and novel particles. Plasma systems should be able to deliver very bright beams. Just a few notes. During the last nine months there have been some real progress made in near-term applications. There is a eupraxia project which is aimed at a 5 GeV stage ultimately for photon science but that has been submitted to the European EU and it is on the research infrastructure roadmap. It is about a 600 million ure oh prour -- euro project. One of the holy grails of plasma acceleration is showing you can preserve the beam phase space sufficiently and make an FEL out of plasma-based accelerators. And there was lasing at 27 nanometers and that's a significant wavelength similar to what was initially done with the super conducting technology at Daisy. That was published in nature over the summer. AF6 is coordinating with this LDG panel and working with them. They note that actually they are trying to coordinate but this LDG panel is way out in front and focused on what plasma can do for energy physics. AF7, targets and sources, there was a workshop held in April of last year. Simulations, radiation stations, and what one can do there. There was a workshop held in June. There is going to be a source workshop held later to be scheduled yet. And I mentioned there is a workshop on targetry that's being held with AF5 in late September. AF7 the technology for magnets. Again, they have been working at a slower rate but they have been going through and looking at the white papers that were submitted, providing some feedback, and we will go through all of them in more detail. They want to provide feedback by or finalize all of the white papers by March 15th and generate their contributions going through into May and into June. Finally, the ITF continues to meet on a monthly basis over the time. They divided into four groups trying to assess or develop a metrics for different issues and then they categorized things into one of the issues that I mentioned of course is all these things are different stages of development so they are weighing proposals into four categories. Existing facilities which provides a baseline across the metrics. Proposals with a T ' -- TDR or CDR or without but detailed sets of documentation or optics and then really concepts. The goal of the ITF is to have a draft report by the end of the calendar year with a final report by May of 2022 and be ready for the Snowmass discussions after that. This is a table of one parameter set they put together looking at luminosity versus site power. One can see ILC in different incarnations center of mass energy is listed here and then the site power is going up to 500 megawatts. Same thing with click here. And then there is others. So in summary, the accelerate frontier is reengaging. There has been progress in all topical groups over the nine months as well as the ITF. Something we would like from the energy frontier is really a better understanding of what you see as priorities for the next-generation facilities meaning the 2040 time scale and longer term. That's all I had. Questions? >> Thank you very much, Tor. That was very nice introduction. Also to the discussion we will have the structure discussions. One is happening later today new collider and new ideas and there will be another one tomorrow and another one on Thursday. We are looking forward to those discussions where, hopefully, we can have some brainstorming and address the question you asked with more detailed information on the type of colliders and parameter space we want to explore. >> Yeah, that would be great. >> Yeah. Before opening to questions, I want to say that now we have the closed captioning embedded in Zoom. If you want to see the transcript just click on the CC live transcript and you can see the captioning and we have Maggie from white coat doing that. We are very glad about that. You can also go to the link that I put in the chat. Both ways are working fine. With this, I will open the floor for questions. I see Richard is first. >> Yes. Hello, Tor. Glad to hear from you. I think you mentioned that some time the European panels one of the activities was the ERL and possibilities were to boost the luminosities from FECEE and by ILC by circulating and having a super conductive connection that brings you the possibility of having that. Is there a lack of interest? Or do you have any activity in the U.S. about that? >> Tor: There was a report by -- >> There was a report at LCWS about this possibility. >> Yeah, there was a paper but together by Telnov and this has been developed and promoted by folks at Brookhaven. >> For FCC? >> For linear collider. >> In general? >> In general, exactly. There is interest of -- I can't comment directly on the status of where that is right now. If somebody else has information speak up. >> Yes, Tor, let me help you. This is Dmitri speaking. Thomas Rosen is involved and I am not sure if he is connected. But there are activities related to FCCEE to develop URL based options and there is an investigation in this area and Thomas and his team are working on it. >> It would be nice to hear the opinion from the U.S. on the proposal. >> I think it will be nice also to see what comes out of the LDG panel. There are -- there is, of course, broad membership there. >> Richard: OK. That helps. Thank you. MODERATOR: Thank you. Now we go to Inez. >> Ayres: I was surprised to see the formilab website is considered as a plus and minus Higgs factory. Seems either would have low luminosity or otherwise prohibited amount of [indiscernible] for that. Wouldn't that be the case? >> Tor..for a Higgs factory? No, 7 kilometers is a standard length. >> Sorry. I meant a ring. >> Oh, the ring. Um. 16 kilometers was the length they had in there, I think? I didn't look at the parameters directly. >> The luminosity is proportional to circ -- circumference. Even that will be comparable or slightly higher than what ILC is proposing. Circle collider with the ILC comparable luminosity. >> Without polarization. >> Without polarization, yeah. >> OK. Thank you. MODERATOR: I don't see any other hands. Any last questions, please, speak up now. Or else, I think, everyone thank Tor for the very nice presentation. We invite you to participate to the unstructured discussion sessions later today, tomorrow, and Thursday where we will discuss much more the interplay between the accelerator frontier and the energy frontier. Thank you very much, Tor, again, and we move on to the next presentation by Laura Reina who leads the discussion on the needs of the energy frontier in so far as theoretical developments. >> Can you see my slides and hear me? >> Yes, we are good. >> Laura: Welcome to everybody who is staying for this discussion and is interested in this discussion. We decided to have a discussion during the plen airtime -- plenary time. We heard many region talks and we are interested and not just very much interested in that but also interested in discussing different perspectives and experiences that after many years of some of the theorist or a year of Snowmass activity so far haven't merged. So, yeah. This question that we put as a title this discussion what EF most needs from theory is a theme that merged during the EF topical groups activity and has emerged in other discussions as well which many of us have participated for instance in the context of the theory frontier and in particular TF07 who is the theory frontier group dedicated to collider phenomenon and I see some of the conveners connected today so this is great. We are going to discuss this together. We thought the restart meeting was the right time to really focus on this question and identify or discuss what are the theoretical input or theoretical development/investigation that could be most beneficial to the work of EF or could have more impact in different context and frameworks. Now, this is clear, of course, a large fraction of theoretical work is not predictable and rightly so and luckily so. Of course, we cannot discuss about what we don't know or we cannot expect and anything that we don't know we cannot expect is very welcome as well, of course. What we want to discuss is based on WHOOINT -- what we know and the amazing progress in theoretical activities geared toward application colliders as we have witnessed in the history of particle physics and in particularly the last 20 years or so. Our aim is really to drays address these big questions and we stride to make it more systematic or if you want to give framework to the discussions which is not entirely easy. We have discussed with topical group conveners and got input from other fields and organized the discussion into two main areas that I am outlining in another couple of slides and I don't have more than this because this is really supposed to be a discussion so taking input from everyone. For each of these themes that we have here structured in the two main areas of refining and fully deploying existing techniques for calculating observables, modeling events, and importantly interpreting collider data and searching for new physics and confirming the standard model and not just searching for new physics is one big area. We have another big area we would like to identify as exploring cutting edge new ideas but sometimes may not yet be applied right now during Snowmass but they look so incredibly promising that it is worth discussing it in this context and when we talk about the FAR future of accelerators and colliders. Again, cutting edge ideas, for example calculating the observables and modeling events and interpreting collider data and confirming the standard model and precision of the standard model and searching for new physics -- these are the two main areas. We hope they are not too constraining to somehow make your contribution to the discussion too constrained. We hope they are broad enough. Of coursex we can identify some areas and sub-topics and we throe this out here. We have been brainstorming about this. We have identified some, if you want, focus points or needs or big questions that aren't very detailed. Just to go through them very, very quickly. For each one of them we could come up with examples. I am sure all of us have examples in mind. This is not a talk so instead of showing all these examples I will refer to them in words and you will bring them up during the discussion. One big issue that everybody works in collider phenomenon has been witnessing is the fact that with collider physicsb even hadron collider physics moving towards percent precision on many many different observables, the impact or limitation introduced by theoretical uncertainties is becoming prominent. It is becoming a really important factor in really, if you want, exploiting the physics potential of hadron collider machines and later on we will have to address the same problem for the plus and minus machine as well. At this level of precision, everything becomes an issue on the theoretical side starting from the description of the scattering or the initial state or the evolution of the event into the parton shower and activities feed to -- we need to take into account. Having a way to consistently and accurately estimate the theoretical accuracy and sometimes this goes beyond the traditional ways we had to do that. At the same time, we are getting better at describing collider events and need to embrace the complexity more thanwy did in the past. In the past, and so far even now, we try to simplify and give theoretical predictions that are approximately what event would be and what nature is. Because of the progress made into theories, now they are possible to model if you want, or calculate or describe things more precisely and we should not be shy of that. This include being able to describe processes with the larger and larger multiplicity which is an incredible plus and has surprises for us. Proper properties of events are not exactly there same of the ones that were in particular one we look at is trained precision or the precision that is offered to us by the experiments. When we look at the interpreting of the data in the context of ideas that are already there and we have already discussed is a big issue. Something that we need to discuss and we need our theory community to tell us how they would better interpret what is amerging in data collider both in terms of having the model independent versus a model dependent approach and the complimentary between the two. Interpretation of the complexity of global fields, electroweak and others is an interesting discussion but a discussion that requires a lot of input from theory community. We always have the input of saying specialize this discussion to certain colliders and see how it morphs in different environments. Let's look at the next big area as well before we take comments and contributions and questions. It is the one that's more open to cutting edge and new ideas. Things that can change pretty drastically how we approach things. The perspective of new strategies for collider data analysis that goes from machine learning, new geometric techniques and kinematic techniques. These are all ideas that are for the moment probably mainly discussed in the theory frontier. We have a typical example of that here. They are extremely important. This is something for which we want to have a connection as EF to the discussion that is going on because it can dramatically change our potential of what we can do and the impact that new theoretical idea can have in the close future and not just in the far future. This applies, of course, also to other realms and that's considering processes that at the moment we are not considering because they are limited in energy but much high energies become more similar to think that we are used to deal now with the radiation in QCD now become electroweak radiation like the processes proposed here. Think big and to these new environments. We need the theory input it in order to invite something that is concretely and qualitatively very informative. Always in the realm of the future and of the new ideas, of course, perspective on new strategies for theoretical calculations and this is very broad and is very open. We have seen in the last 15 years or so this has changed dramatically. Something not even imagineable 15 years ago is now in the past. This comes from theoretical new ideas applied to the calculation of scattering. Now the last point that I think is very interesting and it is a sort of the other way around and how we can test the principle at colliders. This new idea coming from theory, some are groundbreaking and some not applicable but maybe we can have a prototype of these ideas and use it in that way. If not, if you want, which kind of EF need from theory and somehow what theory needs from EF is the other way around. It is really complimentary. That's something that came in through the feedback in our discussion that I found very, very interesting and very important. I would rather -- I think I have given you the outcome of the first very broad brush brainstorming that we have done in throwing these out to the community and saying is this is a really important part of our discussion. This is something we need to have and want to have as part of the effort for Snowmass and I imagine also as part of the theory frontier community that is working on collider physics. Let's have this discussion together starting now and for the future after the preparation that we had independently in the two areas during the past several months. So with this said, my last slide is just pointing you or inviting this discussion and pointing to some specific subgroups or topical groups, sorry, of the theory frontier that are related to us. TF07 and also it the the the -- with this, I would like to open the discussion and get your input on anything that was mentioned and not mentioned and how you envision this discussion to continue and what we should add to these list of focus points. I see Michael. >> Thank you. This is a really nice presentation of the various points we need to discuss and also this is important because you mentioned the topics. This has been a discussion we have had going back as far as I remember on what uncertainties acheal -- actually mean and how they are correlated. There are experiments where the limiting certainty is theoretical whether they are coming from the PDF or another part of the theoretical chain. I think it would be really important for us to not only identify those linchpins but also identify strategies for, no one, correlating them better or having a better understanding of how to deal with them in the comparison between theory and experiment. If you go to the next slide, there is a lot and the first an are lot of new techniques, particularly machine learning there is a lot of techniques as well that are with various attempts to do AI techniques. I am curious to what extent there has been an evaluation of how well those techniques correlate in a single observable and theory. Given if you are training AI in theory to do something what you train on or determine in experiment may be something completely different. And so normally when we define an observability it is experimentally measurable and theoretically calculable. It isn't clear how someone does this in these new technologies that are coming out. >> Thank you. You raise very important points in particular the last one was something that was not coming out already explicitly from the bullet points so it would definitely be important to add. We have, of course, experts in the audience. If anybody want it to directly comment on these or add to what Michael just suggested just go ahead. Jessie? >> Thanks, Michael for the question. And indeed the question on how one goes about training and deploying machine learning is one a lot of people are thinking about. Just to give you another kind of extreme example of that where theory insight would be essential is the growing interest in anomaly detection, trying to find features in the data that differ from the standard model, and trying to precisely define what it means to identify an anomaly and how do you tell it is different from the standard model is something where theory input would be essential. And I will also say there is a lot of interest in trying to train directly on data and that raises interesting questions of the experiment boundary with dealing with things like detector effects on the context of learning directly on data. >> Thank you. Michael? >> Yes, Laura, I just feel that I must comment on something about your vision here which is that all the things you talked about are important and need to be worked on but there is another thing left out of these slides that I think the community really need to focus on. At Snowmass we are talking about machines of the next-generation after the LHC. 3 TeV or 10 TeV lepton colliders, we are talking about a 100 TeV proton colliders. But I think we don't have as a community a theoretical vision for why we need to go to these energies and what we expect to find there. We all know we have to go to higher energies and we will find the secrets we are looking for in that way. This has to be enuncated. What are the models we are looking at and what are the new versions of the model that require the energy scale to be so high? That has to come into the planning and there crucial experiments that will be done. We can't say we didn't find it at the LHC, let's try an energy 10 times greater. That would be fine if our experiments cost a $100 million but that's not where we are. We need a vision that supports the large amount of money you are going to ask for to build these future facilities. >> You are absolutely right. It is not that this is not part of our discussion. I think this the background of the discussion meaning in the introductory talks we had yesterday, all the highlights were pointing to answer that question. We had, you know, big key questions that are the leading key questions Terre -- for which we are having at Snowmass. Understanding crucial fundamental questions. Probably what we are discussing here is based on that and something more specific ho to a we envision the things we have to put in place within collider phenomenalology in order to be able to do that. >> No, I absolutely agree that everything you have talked about is extremely important. >> We are not for getting about the big picture. >> When people see this discussed in the big meetings they forget the metrics will be what the two Higgs dub sector is not at 1 TeV but 10 TeV. Things like that that are just turning the crank from what we have done in the past. And I think people have to ask themselves is this an adequate theoretical justification if we need more and if we need more how do we get it. >> Sure. >> Thank you. >> I totally agree with you, Michael. As Laura said this talk is not about building out the justification for colliders tow there is there last one connections with the specific colliders here it is. But the crux of what all we are doing is actually trying to understand why these high energy colliders are necessary and which one and which ones will get us to this point. That discussion started in the last years community which happened and, you know, where Patrick meets talk is focused on collider and energies. In the unstructured discussion this week we have three conversations with the accelerator folks. It isn't just the accelerator but what is the impact on the physics? Today you hear the muon and tomorrow Hongtao is giving a talk. This isn't the focus of this talk but this the key focus of what we are doing. We are find -- very mindful of it and haven't left it out. That's all I have to say. Thank you. >> Thank you. Kevin? >> I just wanted to say a couple things. I completely agree. If you have a study or particle or energy scale you know you need to explore that's the best possible thing because you can say look, I know that such particles exist and we want to build the machine to study them or have this strong theorem from quantum theory filter that tells us unless something is at this energy scale everything will break and so we know that. That would of course be spectacular. I don't think anyone doesn't agree with that. That would be the ideal thing. I am wondering how realistic that vision is giver n where we we are today because I don't think that really completely exists. I don't think we have a very firm, you know, specific thing we know that we want to build a particular energy scale and we know that we are going to find something or we can measure something spectacular there. You know, I have been doing a lot of reading on the history of particle physics during the pandemic and I know it is a long time ago and money scales were different but all the original justifications for the machines that we now think about whether it was the LHC to discover the Higgs or the machine that found the top quark, if you look back they were constructing the things and starting to think about what they should build in the '60s or '70s, these things, all these justifications that came later. In the third generation they didn't know about the theorems that would tell us they had to be les than theing TeV in the early '70s. The main justification at that point was indeed just to explore the high internally energy -- energy scale. It would be great if we had a specific justification we could go to people and say this what we want to do but there is also something, I think, that given where we are now if there is still no general feeling of like it is too early to tie all dreams about the high energy frontier about a particular thing out there we know we have to find because we have to also get back to the idea that what we are doing is exploration of this. Yes, the scales are high and long but I don't know if that those particular justifications or strong statements exist. >> I would love to be able to say that. But I agree with what you are saying. More comments or criticism? Or addition to the discussion? This is just the starting point. We hope that are going to make it much more concrete with specific even studies that we can develop on some of the points and as a matter of fact by the topical groups. It would be great to share those are theory frontier groups. Michael? >> Thanks. I agree this is a wonderful summary of the situation you have given us. Have a naive question. When you say colliders could be used to test quantum field theory, I guess you have something in mind other than pursuing models or a paradigm that might hint at where we can find new physics. I guess you mean something more fundamental than that. Can you explain maybe in 1-2 minutes what tests of quantum field theory itself principles that we could test at colliders? >> I think Hongtao is connected now. I will let you comment about that. I hope in introducing it, but if you want to add more, but I interpret it as consequences that you derive theoretically from a new interpretation of scattering amplitudes and that can be predictively give you tests that you can verify colliders. Maybe you have a more specific example in mind, Hongtao. Are you connected? Liantao. >> Sorry. I am on my phone. Yes, I think your interpretation is correct. I think I meaning -- I think in recent years there have been development of scattering amplitude techniques and the study of basic features. For example, on the EFT operators this actually has firm model independent predictions. Yeah, I think I am referring -- I had in mind like this kind of test which, you know, can be derived on the properties directly. >> Thank you. I think the discussion is very interesting. The proposal I have is that we make available Google spreadsheet so we can clarify and add more like what Michael said it is appropriate and it is the core of activities in the energy frontier and Snowmass. This is extra important. I think this process is very important because it can provide feedback to the theory frontier in so far as somehow wish list from the energy frontier. I propose we make available the Google sheet and everybody can type in add more or explain more what this bullet points mean. That can be the basis of further discussions. What do you think, Laura and everybody? >> No, no, that's exactly where we are heading. As well as, hopefully, have a more concrete discussion in the future in which we can come up with the specific ideas and studies that on top of what is Arlingtoned -- already embedded can maybe be a product of both sides. Interactions between EF and TF on maybe some more specific problems and studies. We want to close here and thank everybody for sharing your comments this morning and hopefully we will have an opportunity to continue the discussions during the Snowmass activities set to come in the future months. MODERATOR: Now we transition to the next session. One on muon collider and emerging ideas and the other on technologies linked with instrument frontier. I will let you, Laura, chair the meeting. >> I will go ahead. So the first talk of the new plenary session is on muon collider and other emerging ideas as Aleksandra just said. Sridhara, are you connected? >> Can you see the slides? >> Yes, and we can hear you well. Please go ahead. >> We see the presenter view. Can you put it full screen? >> I see. OK. That's the usual problem, I think, that I click on this. Is that better? >> No, we still see the presenter's view. Now is good. Now is good. >> Now is good? >> I was going to say seven years or so whether we came up with this formulating the goals there were three points where the energy frontier could play a role and using the boson Higgs tool. It was just discovered at the time and wanted to identify a dark matter candidate and new stuff. I think seven years have passed and we had another big run of LHCs and successful run in terms of accumulating data and understanding the Higgs better. But we are still exactly at the same point seven years later. The question is our plans going to be different at the end of the Snowmass period? If so, if there are emerging technologies we should acknowledge them and study them better. The question is why am I giving this talk and not an ex permeant -- expert? I haven't worked on any of the options. I lifted slides from other talks. I don't have any elective or selective position in the organization. I am just one of the people you can consider as a cheerleader for this type of stuff and also charismatic or you can think of me as not so innocent bystander if you like. What are my qualifications? I worked on electron particle machines and ET as well and the SLC machine at home and abroad. I sort of cowardly in my own way using the advantages of clean leptonenvironment. I may have observations and they are all biases of course. Let's consider those perceived points are debate points for the Q&A session and the afternoon session. I think that there is a general feeling in the community that measuring Higgs couplings to percent level is important. That's important for new physics in understanding the scale. If you see the deviation from the strong model and measuring. The self-coupling is going to be difficult in the Higgs factories but probably something higher in energy is needed for that. And Al-Shabaab -- and maybe a multi-TeV selection. Value provides direct access to the 10 TeV scale. It is established and as we just talked about before it is besides the point but I can it will give us -- I think it will give us access to a new scale and it will be nice to formulate it in a more theoretically important way. I think strategizing to realize both machines optimizing the interest of global hep community I think is necessary. And in that regard, I looked at the slide from just before the European study group met to talk about the options and there are quite a few options given at the time they were looking at it. They had deliberations over a couple years and ended up with the preferred option of the FCC through HH. We are still waiting for the Japanese position as we were some years ago. With this background, I thought we should look at where we go. One of the things I found kind of depressing, if you like, is that we talked always about three regions involved and I remember when [indiscernible] in news back page talking about how the three regions should collaborate with each other and go around building these various facilities. I think the high energy frontier should are those options too in some sense. Anyway, there are many options that vary in scale from a tiny muon collider for 125 GeV all of the way to a 100 kilometer circumference FCC. The luminosity is a key in all these things. How much we collect per year makes a difference too because it takes a while to accumulate stuff and then we can start making inferences. There are quite a few variables and I don't think the choices are clear as to what one needs to focus on but we need to come down and select a few of these options. In particular, in these studies, you know, there is a slide which I took from yesterday's opening presentation where we were talking in terms of what are the scenario of study. I am focus only on two things. One is the muon collider and another is the CQ minus collider for the two cases that we are talking about. I will say a few words about couple slides I got about the photon colliders and the tail independent of the thing. Any of these new facilities need to be compared with something or the other. I decided I will go and compare it to Higgs and future colliders Working Group outcome which was used in the study group document. Then, of course, they made some assumptions about the integrated luminosity and these are the assumptions under which they were comparing different colliders. I just pucked -- I just picked one plot. We are looking at the 10 parameter fit and looking at the deviation. You can see they should measure percent level in almost everything. I think let's focus on two things. The ILC which shown in green. And the lightest is the it 250 GeV and darkest is TeV ILC. You can see we get to a percent level in many of these couplings even with the 250 option and certainly with the ILC option. FCCE does a little better in some cases. For instance, if you look at some of these things here. I don't want to dive too much into the studied options. You know the papers better than me. This is from 2019 summary. The question is how do these two colliders that I am going to talk about compare to these? This is for the Higgs couplings to other particles and if you look at this Higgs sub-coupling, here 10% measurements will require going to something beyond the Higgs factories. You will have to go to the high energy options. With the FCCEE plus HH everything included is the 5% level. It is a while and even by there apt optimistic assumptions you have to assume this. I think we have time and probably emerging technologies can get us there in an alterinate path as well. One of those options, now, in case the ILC in Japan, which has been in waiting for a little too long even for the most patient but still waiting. Hopefully they will come up with something. But in case there is a backup needed, here is something that the group in California is investigating. There was a seminar to us describing it in detail. There will bow -- be a talk later today or I think tomorrow. You will hear more about the details there. I don't know much about it. But the point is with the new kind of structure here where each cell is coupled independently, you can build efficient machines and in particular their study -- the cavities and this is normal conducting copper cavities but they found the breakdown probability is lower and you can get to higher gradient if you cool the collider structure temperatures. Here is the data with 45 Calvin. I think they are talking about probably running liquid nitrogen temperatures and collider concept. To build a CQ structure and operate it at it -- and achieve high gradient. This high gradient enables this design. The proposal is to build something on the order of 7 kilometers in length which can do the 250 GeV and the 150 GeV option with the IF upgrades. The details of how the IF power is delegated and what kind of devices are needed and how to commercialize them, those studies need to be done. The IF upgrade will take some time but it appears that you could have a quick path to get to 250 GeV machine and possibly in the commissioning phase you can run it as well with not a huge mount of luminosity. It could be a compact machine and fit in the slide. There are some issues where in the sense that the beamed system here as shown here is just a little bit tighter but probably need to be redesigned. Apparently for the four kilometer length is optimized for 1 TeV but one could probably redesign it to fit a little bit better. I heard Tor say earlier that maybe we could go outside the site as well. But the quick time to get started is probably better to stable the boundaries if we were to take this path. I think this is a very interesting and emerging idea that we should study. The physics case for this is no different from the IRC physics case. I think that there is no process of preparing a conceptual design report and a technical design report will redo many of those studies. For the moment, it suffices to assume this collideable is similar to the ILC. That's all I will say about this. The feeling is this provides a path to 10 TeV scale colliders. There were issues that were addressed by map and mice in terms of cooling and the accelerator related thing studied earlier. Now had hope has shifted to CERN. We will talk a little bit about what the updates from that interview are. There are other ideas of producing muons using positive -- it is not quite as well vetted but there are experimental programs to validate some of these things. What's the advantage of the muon collider? Well, if you look at the comparison of a muon collider to a proton collider using what the particle rates would be. For instance, 14 TeV machine is comparable to a 100 TeV proton machine. And if you look at the di-Higgs cross production section, where boson fusion dominates significantly. One can get to the di-Higgs and I use that as a benchmark to compare how well the muon collider does compared to the FCCH. Before we get there from the accelerator point of view, we compare the muon colliders to the click machine with designs going all of the way to 3 TeV. What is plotted in this is on the horizontal axis is the ras energy and the vertical is the luminosity or power. You can see that for mew an collide Fe liders as you get higher and higher -- muon colliders -- center of mass energy, their luminosity achieved is quite significantly higher for the same power. This is only 6 TeV. Going further out you will get significant gains from the point of efficiency and operation muon colliders seem to bend from these considerations. How do you make the muons? That's a big challenge. There are several challenges and one of the challenges is to produce muons so they can get nice good beams with high luminosity. The experiment MICE in the UK did this. They use a struck CLR -- structure with a series of high field magnets. They have a tracker upstream and a tracker downstream and looking at particles with different transverse femtobarn here is and how it changes with it goes through the structure. If you look at, for instance, these four plots on the right-hand panel, what they are showing is for liquid hydrogen target and similarly without the lithium hydrate. You can see that the particles with high go down in count whereas the ones which are tightly packed or higher in ratio. They have demonstrated cooling ability of these absorbers and the energy is stored with the IF systems later to make the beams cooler if you like. It that will help package these things. This needs to be done quickly. The other problem has to do with muons decaying. We will talk about the challenges in the detector in the next slide. This is something surprising to me when I didn't know much about this 3-4 years ago. The neutrino radiation off-site is a problem apparently. The way to mitigate it and now is to go deeper in the ground in order to reduce and the other is probably with the magnetic field the beams and you can reduce the dose equivalent that people will probably hit on with the neutrino radiation. The red line here is where we want people and that's the idea. Going deeper in the ground will help. LHC tunnel may need to be further deeper. The detectors will, of course, see all of the showers coming from the electrons from the muon decay and the tails of that. It produces a huge number of beam-induced particles in the detector. Here they are plotting the momentum, the arrival times, and -- so, what I wanted to say here is if you have highly segmented detectors with good timing resolution and we probably use timing and energy cuts to mitigate this background so we can have intelligent design. This is a problem which is really nice for experimental physicist, particle physicist to have so they can design detectors. We will hear more hopefully from our next about how we could handle this. But it does look like the studies that we are looking at indicate we can probably solve this problem to some extent. Assuming the problem is solved, we just look at the type of simulations. People looked at 10 TeV if you like. Here are the Higgs parameters and again percent level. Higgs coupling measurements are feasible. I had to skip in the cross section slide but the tt edge cross section is actually quite low. Other than the tth everything is close but this is FCC 'ee plus pp from the future Working Group. The comparison, because there is more you could get over a period of time and accumulate the same assumptions Mark made here. And perhaps you can combine the plus and minus machines. I think that we can meet the challenge of the Higgs here. You will hear more about it from the Wednesday session. Taiwan company looked at self-coupling of the Higgs and what they concluded is you can get a few percent, you know, 5 or 3, depends on the energy and what benchmark Luke luminosity assumption you make. A 3-5 percent measurement could be obtained for self-couple. And looking further if you are looking at some new objects. Let's say signal scaler which mixes with the Higgs. You can see contures here in comparison to the HL-LHC and the machine. There are a lot more studies done which are discussed in the Higgs masher guide and by various papers from those who did this type of work for looking for various dark matter candidates and looked at discovery potential. A 10 TeV scale with WIMP access may be possible depending on the scenario of what multiplex we put for putting the particle in. The lightest of the particles in. If any of these would be potentially enough. We will discuss more about dense properties today. To me this sounds like an interesting thing we should pursue. The electron positron acceleration using new techniques whether it is plasma or laser driven or accelerated design groups. They are talking about -- the gradient for the CQ is on the order of 100-150. These gradients are significantly higher. 10 GeV per meter. We can actually imagine a multi 10 TeV collider. It is not clear to me plus or minus is possible but I understand it may be possible with collaborator techniques to accelerate and we can make plus and minus facilities with the multi-10 TeV scale. Certainly one can make a photon machine by converting the electron which are accelerated by the plasma driven accelerator to photons and collide photons. There are quite a few studies based on that and there is a session later in the workshop where you can learn more about it therefore talking about a 15 TeV machine at luminosities over 15 TeV. These ideas are slowly moving into the regime. There is a lot of collider activity going on. I think that we should look at them into the context of what has been discussed, studied and is previously part of the study group. In addition to these, we should look at CQ. If I put this time I move the things around using the plot from the archive paper there to the earliest start times these collider concepts were talking about except for in the FCC-hh they decided to put it on the same page rather than through the FCCE path. Here we are. I think a muon collider should be in the picture as well in our studies. So, if you asked a question, should there be emerging scenario be part of Snowmass ply my answer a resounding yes. I will conclude with that statement. We have a few minutes maybe for some urgent question. >> We can't hear you yet. Want to type it in the chat? >> I hope you not going to ask me about raidative corrections. >> Questions while we wait. -- other questions while we wait? If not, I think we need to move on. If you can, you can type your comments or questions in the chat. Thank you very much. We move to the next speaker. We are now moving to another topic on instrumentation after Caterina's talk yesterday. It is from Artur. Technologies and R&D directions for trackers and calorimeters. >> I will just get going. This talk will be about a selection of R&D directions. Thanks to everyone who put it together. A novel disclaimer that it is such a broad selection of topics that I probably missed several important topics. Apologies for that. With that intro, let me get to it. We try to put together a summary -- >> We are not seeing it full screen. Can you go go to full screen? >> Let's see. I am going to try. >> Let me know if you can see that. >> This is an attempt to put together the activities that are happening in the frontier groups 3 and 6 which are trackers and calorimeters. We have been having regular meetings. Typically of the order of 20-30 participants. At the end of the submission process, we received about 60 each in 03 and 06 presenting a broad-spectrum from the energy field and beyond. I will overview the status as we have gathered so far in some of the outstanding needs. There was an excellent presentation by Caterina which has some overlap. I tried to avoid the overlap. A lot of motivation in dare variation -- in derivations are presented by Caterina. I will skip that and go directly to the technology part. I will go over the trackers, timing and the calorimeters. I will try to separate them a little bit. First, moving to trackers. You see here on the right these two plots which is just a really nice summary of many decades of development from many. You can see it has been growing. It an important area over time. We are now going into a billion number of channels. With all this expansion, many future detectors require silicon trackers as we get to more and more precision with less and less material. That is one of the key requirements to have this. Increased radiation machines and tolerance and several new physic driven specifications to enable particles, boosted object construction and improving construction, and good timing precision to address both the physic needs and reduce the pile-up. The systems are getting bigger and with all this complexity also a question of replaced and maintenance becomes a key driver. My goal of the drivers which were identified by community, we also are guided by the BRN directions which are listed here. It is deriving high spatial resolution and high timing resolution at each layer to work on new materials and processes and low scalable components for the tracking systems. The goals and systems have to be -- we have limited person power. It is best to get behind everything -- cutting out -- all the efforts look pretty and we did a correlated R&D. All the services behind such as the cooling power management. And moving more towards on detector processes and move as much as protosync as possible and reduce there -- the Dataflow. These slides highlight the work and the presentation we have seen. Snapshot of areas with active R&D going on with particular emphasis on things in the U.S. is the low gain avalanche detectors which provide good timing but have relatively large pads. A new direction is the AC-LGAD which provide good timing and precision resolution. Moving from design censors that are taking advantage of process improvements to do Boutique kind of designs. Diamond detectors, 3D censors and thin film detectors going toward the new materials. There are many common challenges for many of these technologies that I will also touch on. -- sensors. For the kind of one of the directions which is a key breakthrough in the recent developments of the trackers is the additional of timing to add the four vectors. That's being taken advantage ATLAS and CM S. The timing detectors are being worked on for phase two upgrades. Uniformity over here. We have achieved pretty good performance detectors for the HLHC. They don't receive a full factor. There are gaps. That's what the ACL gap eliminates with a different approach to the weight it is read out with the AC coupling. And promises to maintain the same time resolution with improved position resolution. There is active R&D and many different going on. And the principle operation is very similar to the standard DC gaps. The electrons are tied to AC coupling. There has been a test beam and measurements that show very good efficiency of charge collection. But the full service here is example of many that were done recently and there was a demonstration of sen -- sensor and that's a step in the direction of integrated 4D tracking. Other directions that are being studied now is, again, towards the same for the tracking ideas. That's LGADs with fine pixels. As you can see on the bottom of the page, you have basically two cutters that are used. A cutter divided into small pixels used to collect a delayed signal and the cut that the bottom collects a signal that's amplified and that's used as you can see on the right plot it is used to measure the time of arrival of the particle. And then depending on the angle that the particle goes through, the signal at each cut has a different time and shape and that can be used to derive the incident angle of the position. That can provide XYZ and T and fake angle and can help also to provide a level 1 track triggering directionality capability. A little ditched approach to achieve the same goals is the idea of this induced current sense sensors which are using currents. Again having a sense of this being segmented and when the charge particle passes through, this turns electrodes. This very small so you have very good resolution. And again, due to this dependence on the charge and I want to extract the angle of incidence of particles. Having an AC front end will have the example and the information can perform this on the front end. Another example of this are being applied to at the up grades and that's the CMOS sensors. Embedded in the front end read out. Improve a lot of things. This is a hybrid combination of sensors plus the read out chips and promises to move to a larger set. There is a lot on going. We will have a sense it will go into the LHC for ATLAS. And there is an active community working on it. An example is presented here. The tt path sensors which are produced with LGAD technology and achieve a very good time resolution. This is a jour germaneian process. Another project is to combine there LCA gads with this process. There was a presentation by Gregory in Snowmass that talks about the plan to fabricate this technology by combining the LGADs. And another very, I think rather interestinging direction is using detectors and processing on the front end. This makes sensors for boundaries. A couple examples shown here show very good efficiency. Here is a signal efficiency map of pretty heavily raidated sensors. That was better than test beams so that's another promising direction. Putting it all together, integration packaging can come as the next step. There is a lot of work on trying to put more power on the front end and cross tracking and triggering or on chip clustering to read out or reduce the data. There is work ongoing to implement wireless communication between the chips and layers of trackers. And new materials for the design of more power efficiency processing on the front end. In an extensiveD integration that can allow multiple stacking on the right. Multiple lays of electronics for different purposes. It is possible to integrate different technologies each optimized for separate tests. The mechanics and lightweight materials are the next work we need to do to improve this overall material budget question. Typically supports dominate at small and large data. There is work on going on a new layout, molding and curing methods and a few examples are shown here using carbon fiber foam. And the aim is to reduce the amount of radiation length all around. Currently, we are at this level. About 2% with silicon. With maps we are able to get the pixels typically about .4%. And the goal is to go even further down to .3%. There is also a potential to improve this with a future hybrid pixel system going down to about 1%. Going from 2 to 1% is also one of the directions this wafer can try to improve. And then on the cooling aspect, there was a very nice set of presentations. Now we have a lot of power and with all this advanced detector specific requirements with past timing, with more advanced processing on the front end, the power is going high. 10-200 kilowatts now. The cooling is probably not going to work. Only for low cycle machines. And for liquid cooling we are now approaching the limits of temperature with Co2. About minus 45. There is work ongoing to improve the various interfaces. There is, for example, a survey of various fillers that are shown here and trying to reduce basically the thermal resistance between the coolant and the material that we are trying to actually cool. And there is a need for work on advance on radiation of various proxies or new directions on putting various modules on the support trackers Etc. In some cases there is also ties to work that is going on in super conducting magnets which also have this need to reduce the strands on various structures. Those projects could be used in our group for applications in our field. And then going to actually shipping all the material out or bringing the power in there is a need to improve the efficiency of this powering or investigations of powering. Although, again, for example, for linear machines, power processing may be possible. For HLHC, for example, the data is 80% of the services in the forward direction. We need newer radiation hybrids to ship all this data out or reduce the data volume from the detector. We own the detector processing and the data compression. These areas are active indeed to put as much of the process on the frond ent. Moving on to calorimeters. A lot of work is on going. I cannot do justice to all the presentations that have been given so far. The priorities are to combine the several types of signals and integrate them moving towards particle flow ideas of trying to combine there data. There are listed priorities used as a guidance and that's to enhance calorimeter image resolution for missing mass and measurement. Advanced calorimeter with spatial timing resolution and radiation. And develop ultfast media time prove background rejection. These are the guiding principles for the community. The facility that have been presented or are active participants in the groups are from the areas that are listed here. From colliders, neutrino experiments, double decay, new emergency -- low energy experiments, dark matter searches and experiments in space. There are a variety of technology tools being used. Sampling or homogenous calorimeters. Various materials are used with high concentration. Liquid and various hybrid of these kind of materials. And mechanisms like detection, mechanisms, ionization and cryogenic. And fast timing has become one of the sort of new directions in the calorimeters as well. It is a kind of enablement for HLHC. It is one of the priorities in the future colliders that are being considered now. Measurements and specificifications for timing capabilities. And comparisons of simulations versus testing measurements. So you can see a few examples of those studies that are shown here. This is an example for a dual readout calorimeter that I will talk about a little bit later and what is projected resolution promises to be. And similarly what can be achieved from more hadronic calorimeters with excellent energy resolutions. >> Five more minutes. >> OK. Great. I am almost done. OK. A summary of all of these topics that have been received shown in the pie charts from the LOIs. You can see a lot of it is covered by the plus or minus targeted detectors. But there is also some going into the GP and neutrino directions. This some of the most active ones. There are areas that are kind of in all this technology like timing. It is a mix of technologies. The technology for calorimeter read out is broad. I will touch on this in the next couple slide. To go quickly through that. There are studies on electronic and hadronic in the implementation of various timing or lack local technologies on the front end. As an example, for the silicon based calorimeters in the current and future experiments, HGcal in CMS is the first generation. This aims to fully exploit the potential of highly granular calorimeter systems but extreme compactness to minimize the dead space. You can see the HG cal detector layout. And the work continues in the genetic R&D which is trying to optimize future plus and minus which has both going inside and that places a lot of constraints and needs to fully integrate into electronics to support all that high granularity and also ultra low power to reduce the cooling needs. The work has been going sort of in a direction of coming up with the first prototypes, putting the first prototypes together, and then increasing complexity and integration and going into the test beams which is then used to guide the next rounds of development. And the results have been really fascinating and amazing. There is ecal measurements I am going here. A full 15 layer prototype is available and it is going into testing this year. You can see the amazing noise separation on the left plot and the prototype has slant excellent performance. Similar, analog H cal with the SiPM on tie. And other ideas for semi-digital HCAL will integrate the electronics shown here on the right. Another option is the dual readout which is very active in the unit using cherenkov lith to measure shower by shower and then the scale correction depends on this ratio. And this allows us to get the sample in terms of 3% for electrons and 30% for hadrons. This has been following from the RD52 work and using all the advances in the materials which are becoming much more advanced and cheaper. On the bottom is an example layer of a detector we could have magnetic and electronic hadron sections. The advances in the technology have been critical for this. That allows us to really plan for detectors that can be excellent performance and affordable. Here are examples of the energy resolution in the electromagnetic session and the hadronic section. I think they are starting toal -- literally candidates for the future experiments. These suggests for example for the Higgs factor. Another direction is to -- for hadronic calorimeters is to measure, again, similar to kind of dual readout is to fully absorb the shower and measure a fraction of the energy again by comparing signals from simpleilation and sharing the like. And here, again, taking advantage of advances in the materials and silicon multipliers one can build a full calorimeter stack with high density increased and achieve an excellent energy resolution as shown on the left plot reaching 10%. So this advances are really exciting and the work is continuing to follow the construction of the prototypes. To summarize what has been presented. There is a significant need for detectors and advances for the collider experiments. There is a lot of work. We need to work together to find solutions for all the issues and questions we have. The time scale is around 10-20 years to develop technologies for LHC. It is a -- it is a long time to get to a fully producible system for real experiments and requires extra R&D funds. Those are some of the priorities we would like to really press on that the community that the community needs to get behind. To answer the questions of developing future needs through near term experiments, needs are in 20 years away but we need to work now. These are the issues that we are trying to kind of condense and organize. The next steps for the Snowmass process is to basically put all this together and to start with the outlines of the whitepapers. That's all. >> Thank you. Thank you very much. It completes the overview of highlights from detectors. It such a crucial component. We have time for a few questions or comments. >> I have just a comment. You mentioned explicitly EAC. I think it is very important that some of these technologies which are aiming towards a future colliders, FCC, can also use EAC as a stepping stone. Some of these technologies can be used in EAC sometimes to do that. Physics is part of energy frontier. We have a heavy ion collider. There is a big interplay between high energy physics and nuclear physics. Not in terms of physics but also in terms of detector development. I think that synergy should be explored as much as possible in imp instrumentation. >> It is considered and we have participation from that community. Or there was at least before the post. We hope it will continue. >> Thank you. Other questions or comments that you would like to bring up at this time? I don't see other raised hands. I think we can conclude here the morning session and thanking all the speakers again. Just a quick reminder. The afternoon will have a parallel session between 1-2:30. One on dark matter and the other is a joint session with the computation frontier. After a short break, we then have an instructor discussion about muon colliders and new ideas. Please join back for the afternoon sessions and discussions. Thank you very much and we go on break between 12-1pm. >> I want to remind everybody that we use the same Zoom link so this one will have two breakout rooms for the two parallel sessions that will be created so people can join a room or switch to the other quite easier. We will reconvene in 55 minutes.