STFC-RAL-CR03 R61: The future possible business, and
STFC-RAL-CR03 R61: and in particular, one of the proposals for our pragmat, which is the future circular glider, and in particular also be focusing on the 1st stage of that which is a deeper fee minus machine.
STFC-RAL-CR03 R61: And on my way here today I was trying to think when the last time I was at Ravel was, I think it was the Iopp Conference back in 2022, which was actually the 1st time that many of us came together, post Covid. And so it's nice that there are now finally less masks.
STFC-RAL-CR03 R61: hey? Today? And yeah, we also got to visit back. Then the Williams Formula One center, which is pretty cool, and I tried to find pictures of me around, and I think I just found lots of pictures of formula, one simulators. So I'm sure we talk about lots of humiding physics, too.
STFC-RAL-CR03 R61: when giving a seminar. I sometimes like to be explicit about what I'm hoping to get out of it. So I'll give you my 3 A's, and I love you all to tell me a little bit after whether I've actually achieved those goals. So firstly, I want to commit to everyone at the importance of talking about features like this now, and I'll also be providing an overview. As I said at the future circular project, particularly, it's first, st
STFC-RAL-CR03 R61: and I'll also be discussing the opportunities and challenges associated with this 1st stage
STFC-RAL-CR03 R61: on the next slide on the left you can see. I kind of nice schematic that was taken from the recent snow math process in the us of big questions that we're trying to answer in terms of mental physics. How the early universe evolves, what's the origin of the matter? And matter as symmetry in the universe and the origin of nutrient masses. And what dark matter is
STFC-RAL-CR03 R61: and particle providers provide us one route to try and address these questions. But I think one thing that's really difficult. Now we think about future providers beyond the Lacc
STFC-RAL-CR03 R61: is that we don't have a clear idea of the energy scale where we think the new physics that might explain these questions. Comes in. So, you know, on some level, it could appear anywhere between the extra week scale and the plank scale and with that in mind being able to maximally explore frontiers of particle physics is really important, because that will hopefully maximize our senses of success in answering these big questions.
STFC-RAL-CR03 R61: On the right and the next slide you can see a diagram that's been used a lot by the DOE to discuss the kind of different frontiers that we can use to try and address questions about the universe. That's the energy frontier, like we're doing at the Lac, where we're trying to use high energy collisions to produce
STFC-RAL-CR03 R61: new hospitals that we can study. And that's a cosmic frontier making observations about the universe. And that's the intensity frontier where we back try to make very high precision measurements and things that we know to exist where deviations from those measurements. But again, the signs us to make new.
STFC-RAL-CR03 R61: And then what this diagram's trying to show is is that you know, we have to really combine information across all of these frontiers in order to have the best chance of answering these other questions.
STFC-RAL-CR03 R61: I thought on the top right of the slide that kind of plus quantum in question mark, because I think content technologies are a new and emerging way that we can also try to probe some of these questions so hopefully, and they'll make an update. My job, I mean, is
STFC-RAL-CR03 R61: the nice thing about the future sexual applied program is as with Lep and the Lac it's combining a kind of intensity frontier machine with Ebc minus visions, with a future energy frontier machine, and these provide complementary ways to probe new physics.
STFC-RAL-CR03 R61: We often think about precision programs. So high position, electric and some and some model measurements, as you know, measuring things and not thinking about discovery. But, and I was at a conference a couple of months ago, where Stephanie and Gory of the Us. Provided a really nice description of what we think for discovery to be
STFC-RAL-CR03 R61: so she said that that was detecting for the 1st kind of any fundamental process, or discovering new particles. And I think what that means is even measuring things in the standard model that we haven't been able to probe it for just classified as a discovery.
STFC-RAL-CR03 R61: And again and hopefully, by the end of the talk you'll see that whilst the focus to be booking mine is on precision. Actually a feature hink factory could meet. Both of these descriptions of a discovery. And to give a quick snapshot sec could provide the 1st evidence. To the Higgs coupling to the electron in a strange walk.
STFC-RAL-CR03 R61: and there could be direct discoveries of low mass. Phobe couples beyond standard model visits, and we could also get indirect discoveries up to the 50 to 100 TV mass range which could come from predict well, observing deviations in standard model predictions.
STFC-RAL-CR03 R61: I'm gonna try and make sure. I you've got some time at the end of this talk for questions. But I wanted to say before beginning, I'm really happy for anyone to interrupt me anytime, either to correct me because I'm wrong, or to ask questions, and so please feel free to do so, and you can also either grab me a coffee or email later on.
STFC-RAL-CR03 R61: following the Higgs discovery in 2,012, and there was lots of discussion in the field about what the next collider beyond a highly nasty Lac should be and the next slide shows my best attempt to make a kind of flow chart schematic of the differences and food makes
STFC-RAL-CR03 R61: so, firstly, I guess the 1st line of questions is, what do we want to collide together? We can collide electrons and positron, as was done at Lep and the large electron put from Collider, and these because that fundamental buzz was a really clean but we're ultimately limited and sit by synchrotron radiation to the center for finity mass entities.
STFC-RAL-CR03 R61: We could go for a mega Lacc approach and trying to push the energy frontier as high as we can and go for a high energy collider or another option that's become, increasingly popular in in some corners of the building recently is as a new collider, and this provides an interesting interplay between the center of mass energy. That you can get a hydro machine so new on gliders could go to the 10 TV range as well, but still probing these clean collisions.
STFC-RAL-CR03 R61: However, I think many people accept that the technological challenges we need to overcome to realize the newer glider means that these are probably looking at slightly longer time scales
STFC-RAL-CR03 R61: the E person machines. We also have to decide whether we want a linear machine or a circular machine.
STFC-RAL-CR03 R61: So an advantage of the circular machine is, you can get to much higher luminosities. By circulating the beams.
STFC-RAL-CR03 R61: But of course you do have problems with energy efficiency due to the signal losses, particularly at the higher center of mass entities that I'll be talking about later on
STFC-RAL-CR03 R61: with a linear glider. You only have to a single pass at your collision, which means you need very high accelerating gradients, but you can exploit the polarization to actually give you an effective enhancement in your statistics, which means that actually, the physics, projections, millennia gliders are often very, very competitive in most areas with circular machines at much higher luminosities, because you can either right-funded or left handed polarizations to offset the background components.
STFC-RAL-CR03 R61: Another thing with the linear Klidas is the center of mass energy scales with length. So you can do a stage approach to reaching higher energies.
STFC-RAL-CR03 R61: and on the right you can see, and some diagrams of a few of the options. For different future colliders. With their proposed site. So there's click, which was a linear Collider at sun, and you can see a schematic at the top.
STFC-RAL-CR03 R61: On the right you can see a schematic of the Ilc project and since 2,013. There's been I guess, excitement and hope that the IC could be hosted in Japan. But as I guess at the current status at least is there hasn't progressed to its prelab phase.
STFC-RAL-CR03 R61: So it's the way to tip.
STFC-RAL-CR03 R61: There's also Cec at China, in China, which is another proposed circular Lepton Collider, and with that very similar parameters, Fcc. And I'll I'll say a little bit about that later on. And then finally on the bottom. There's the combined future circular collider program where we would basically build what we now understand to be a 90 kilometer tunnel in Geneva. We would 1st use it for e plus e minus, and then for hybrid collisions.
STFC-RAL-CR03 R61: and there are also options for doing high and busy, deep and elastic scattering as well.
STFC-RAL-CR03 R61: One thing I think that's important. And to remind ourselves, is, you know, we're very much a resource, limited field, both in terms of person resources, but also financial resources. So when we think about, for example, the future strategy person in Europe, we need to think about how that fits in globally and how we can best make use of our resources.
STFC-RAL-CR03 R61: Before going on to talk about Fcc. I also think we need to remind ourselves that time scale for particle physics are really long. If we think about the story of the Lx being installed in the tunnel that was originally used for the the left Collider. This was 1st proposed back in 1984. And it wasn't then approved as a project until 1995. And yeah, it wasn't then until 2012 that we saw discovery of the Higgs.
STFC-RAL-CR03 R61: The 1st European strategy for particle physics was done in 2,006 and A couple of years ago I really enjoyed going through some of the text for some of these older strategy updates. And I think in anticipation of the Lhc. Switching on the 1st European strategy, talked a lot about the excitement associated with the global adventure of really probing energy frontier at the Lhc for the 1st time.
STFC-RAL-CR03 R61: If you want to put this in a more visual context. On the slide. I've put some pictures of kind of music and film, and the music, also the modes in which you listen to it, or might listen to it. In 1984, 1995 in 2,012. And yeah, if you want, you can also guess that bells at the bottom. And you know for me what that kind of reminds me of is that you know
STFC-RAL-CR03 R61: there are lots of us that have only been really a very hot present for a very small part of the Ihc journey.
STFC-RAL-CR03 R61: my original slide for this, for seminars actually involved pictures of my parents on a great holiday in 1984, in some really retro one summer decades before, and Project Sarah was approved, as I put it, and then some very embarrassing pictures of me when I was growing up. But since I already showed these once at the Iep meeting this year, subjecting some of that you and to it twice.
STFC-RAL-CR03 R61: There's another relatively recent update to the European Strategy for particle physics in 2020, and this followed 2 years of consensus gathering within the community both within the national groups, but also various projects. And actually, this European strategy update made several key recommendations for the community.
STFC-RAL-CR03 R61: The 1st was that any 30 minus 8 factory is the highest priority next Slider. So this would allow us to make ultra precise measurements and ethics, which could, of course, be a really exciting new portal for new physics.
STFC-RAL-CR03 R61: It also, though noted that in the longer term the European community should be aiming to push the energy frontage, the highest achievable values.
STFC-RAL-CR03 R61: And so the second one said that together with international partners and Europe, should try to investigate the technical and financial feasibility of a future Hadron Collider and Sun, which could have any fuzzy minus machine as its 1st step
STFC-RAL-CR03 R61: and following this European strategy update sun. Then started the Fcc or future circular collider feasibility study, which is aiming to provide input by 2025 to feed into the next European strategy update.
STFC-RAL-CR03 R61: I wanted to pause at this point and give a kind of another plug slash reminder to everyone that actually the next European strategy process is upon us already. So, following the 2020 European strategy update in Europe.
STFC-RAL-CR03 R61: our colleagues over in North America have gone through that community process in the last few years. This is the snow mass, Mp 5, prioritization process, and it's recently been announced by some council, the Timescales for the next European strategy which actually hopes to close in 2026 with community input being requested by next March.
STFC-RAL-CR03 R61: So within actually, uk, a group of us have been working to I guess. Put together some workshops to encourage the community to come together ahead of this, to discuss both the physics, but also the technological challenges on the detection acceleration side. So there's a kick off workshop as 1st of May, but also planning a larger workshop. In September at the attribute
STFC-RAL-CR03 R61: the adorab that I would love you all to put in your diaries and and come to
STFC-RAL-CR03 R61: right I'm gonna now move away from the terrified means and talk about the integrated Fcc program. So this really would deliver you know, over half a century of exciting Collider physics, exploitation and son.
STFC-RAL-CR03 R61: So the idea is reading our tunnel, which you can see on the left, and and it would be 1st used for e plus C minus so fcc, and this would pre provide highly monothe at the Zh threshold. So for ultra precise case measurements. But it would also be an electrobeat and top factory with runs up like a tty bar threshold. But there's also the zephyr and the W threshold.
STFC-RAL-CR03 R61: and this would then sometime in the late 20 sixties. Be upgraded to perform high energy Hadron collisions, and that's the Fcc. H. Which you can see on the right, would involve 100 TV proton collisions, but also you'd have the opportunity to do heavy iron collisions as we do at the Lac
STFC-RAL-CR03 R61: but also high energy. Ep collisions, and there's lots of complimentary in the physics, and that we could do. Sc and scc, one
STFC-RAL-CR03 R61: those with 3 lines also probably have noted yet. If you look at the time scales here Fcc. Comes in around 20 70, and I should note that optimistically, you know, I'm kind of bit of a size somewhere around here. So these really are ultra long time scales and actually planning as a community to realize projects that actually extend beyond an academic career is really turning
STFC-RAL-CR03 R61: that start date of 2020. That's when they started thinking about the tunnel. Is that is that? Yeah. So I mean, I think there are some more granular time scales now. So I guess you may say 2020 to 2040 is planning and building the machine. I think the earliest we could now get would be project approval at the end of this decade, and then you start thinking no tunnel in the 2030
STFC-RAL-CR03 R61: but one of the reasons for trying to get the feasibility study done and reach a point where we could commit to this in the coming years is that if you if we basically don't start digging the tunnel in the next 5 years or so then there's a quite big gap between the end of the hydrocetic team as well
STFC-RAL-CR03 R61: on the next slide, and you can see the running plans for the various options for sec. And I guess the ones that are important to Fcc ee are shown on the top road, so there would be a gradual increase in the center of mass energy of the glittens. Starting at the Zpol, go to the Ww. Threshold, and the Zh. Threshold at 240 Gb. Would then have scans at the Tt. Bar threshold.
STFC-RAL-CR03 R61: That's easy. Would provide ultra science measurements of the electric from top sectors which would give indirect sensitivity and to really high mass. Bsm, that could be entering processes at loop level. There are also exciting flavor opportunities, some of which I'll talk about later on as well as direct sensitivity to various facts and deeply interacting particle which would manifest themselves as long-lived particles.
STFC-RAL-CR03 R61: Fcc. The electron proton glider. And this would provide essentially the resolution on the proton structure that we need to really make the most of the fcc exclusion. So we'd be able to model the Pdf much higher energy for you.
STFC-RAL-CR03 R61: but also actually at Fcc. And we'd be able to do a lot of complementary physics, so the stuff you could do at e plus e minus and h for example, on the Bsm side, their sensitivity to leptocalks, but also you can do some very interesting things, scoping measurements.
STFC-RAL-CR03 R61: If you then go to the future header machine, Scc, these 100 TV and collisions would provide the high statistics that we need to access very rare pigs decays, for example, and it's new, but also, and would allow us to access the pixel interaction with the target being around 5% and accessing pixel cuts pigs. Self coupling is really important for understanding the origin of the universe.
STFC-RAL-CR03 R61: If we look how things behave in the standard model. The electro week phase transition in the other universes, what we call a crossover. However, if there was some Vsm that cause. A strong 1st order phase transition. Then this could be responsible for Barry Genesis, which, of course, we know used to happen.
STFC-RAL-CR03 R61: And also fcc updates. Would provide highly nasties and end use that we need and house sensitivity to a wide range of vsms, and a particular target would be fully covering the thermal surface for possible dramatic candidates.
STFC-RAL-CR03 R61: I'll say a bit in the next few slides. About the synergies between the differences. The program before I go on to talk mainly about fccce.
STFC-RAL-CR03 R61: So the high precision that we get at the 240 TV. Burn, Sc. Would really provide an order of magnitude improvement in most of the Higgs couplings. So on the slide. Sorry. In the picture on the left, you can see, and the precision we get on Higgs couplings within the Kappa framework, which is essentially an effective framework to model deviations from standard model Higgs couplings.
STFC-RAL-CR03 R61: The green is very effectively by the end of the high you must yell at C and the purple is what you get from adding an sec, and then blue is and green is H,
STFC-RAL-CR03 R61: so you can see, and there are lots of processes. For example, the W. And the Z, where you see? Almost the order of magnitude drop, compiling us. CL. Xc, going to Fcc.
STFC-RAL-CR03 R61: so these very large improvements in Brazil would then basically
STFC-RAL-CR03 R61: translate to significant sensitivity to indirect Bsn.
STFC-RAL-CR03 R61: and similarly to the hig sector, we get factors of 10 to 50 improvement in our entry precision observables at the Zen program at Fcc. E. As well.
STFC-RAL-CR03 R61: If you then go to Fcc. H. And we then get direct sensitivity to Bsm up to around 50 TV. And on the right hand side you can see the discovery reach, and for various levels of it, Fcch for a number of defined Bsn models. And as you can see, yeah, we're really pushing the multi TV
STFC-RAL-CR03 R61: range irrespective of the model. And I think the thing that's exciting about this is, if we were to infer the existence of somebody physics. Fcc. We then be able to discover it as cch, which I think is really cool.
STFC-RAL-CR03 R61: I've already mentioned on the previous slide. The Sec also provides a significant improvement in our and Higgs measurements, and one of the reasons for that is, actually, we're able to do a model independent extraction of the coupling of the Higgs boson to to the zet. And this is through something called the recoil mass method, which I'll talk about sooning events.
STFC-RAL-CR03 R61: through tagging the Z boson.
STFC-RAL-CR03 R61: So as soon as we have this model independent extraction of the hips design coupling. You can use that to normalize other measurements by providing some kind of standard candle, and this really allows us to push the precision for all of the hips couplings we can access.
STFC-RAL-CR03 R61: You can also do a similar thing in the top sector. So if you do our Tt. Bar threshold run sc. Then you can extract a very precise measurement of the Tt. Z. Coupling, and this, and then in turn, we use Sch to provide very precise measurements of the Tta and Triple H coupling.
STFC-RAL-CR03 R61: Excuse me, could I just understand the Fcc. Does that have a single interaction region. I mean, it's a separate electron ring.
STFC-RAL-CR03 R61: Yeah? So I think it would. Yeah, you would just have one experiment. But you could. You could have runs that fit in with the Fcc. H. Phone schedule. I think one of the things that actually also is generating a lot of excitement about Fcc. H. Is, you could also use it for an energy recovery. Linux. It'd be very sustainable. And you get a lot of cool, new visits out of it
STFC-RAL-CR03 R61: right? So my next slide to is this more granular version of the time scales, and this is laid out at the Fcc. Week in London last year by Aviola and really, what I think they were trying to explain was the difference between the kind of
STFC-RAL-CR03 R61: most optimistic technical schedule and realist and a realistic schedule which takes into account other constraints, for example, that you know the time to see a tunnel, and also the fact that we need to be dedicating resources to ensuring success of the highly nasty all the way up to the end of the 2030 s.
STFC-RAL-CR03 R61: So putting all of this stuff and together means. And yeah, earliest that the project could be approved would be the end of the 2020 s. You then start digging your tunnel, and then as soon as the highly nasty Hc ends we can start preparation for fcc running.
STFC-RAL-CR03 R61: I've already said this once, but I'll say it again. These time scales are really long, and I guess to be a bit more explicit about what that means. The kind of engagement. And input from early career researchers is really important. And so I think we need to do some work in the coming year or so to convince ourselves that this is, you know, if we do go with this route, this is something we find exciting, and that you know, it will continue to engage, you know, the next.
STFC-RAL-CR03 R61: the coming generations of local searches that came to the end of this century. You know it's kind of very weird to think of. You know what your Phd. Students, Phd students, Phd student, will eventually be working on. And if you think that will be attracting the best people.
STFC-RAL-CR03 R61: I said, a few slides ago that sec. As the sec feasibility study is due to run until 2025 but actually earlier this year it has, and the Midterm Review. And I think this was met with a lot of positivity essentially, because no show stoppers were identified. And that's not to say
STFC-RAL-CR03 R61: there wouldn't be challenges along the way. But I think everyone was very pleased with that.
STFC-RAL-CR03 R61: A couple of big updates. From this feasibility study with the choice of the ring placement. It's very funny well, it's funny for me. I guess, comparing what I imagined a feasibility study to be
STFC-RAL-CR03 R61: to actually what a lot of the resources going into. One part was digging lots and lots holes to check geologically that we really could dig the tunnel in the chosen site, and that the plans, sites for detectors could be effectively powered by the electric, the electricity grid. And you know, assessing how many flaws of road you would have to build, and whether the local authorities were okay with that
STFC-RAL-CR03 R61: so actually, this choice of replacement is a huge achievement. And lots of different configurations were considered.
STFC-RAL-CR03 R61: There's also a decision to move from 2 interaction points to the fall. This gives increasing statistics. Which is great. But also meant that then the plans for the accelerator infrastructure had to be adjusted. To say.
STFC-RAL-CR03 R61: One thing I should say is that there's a lot of effort ongoing within the community to try and improve the energy efficiency of Fcc, particularly at the higher energy rooms. But because the accelerated infrastructure essentially, yes, upgraded every time you move to a new energy, there's a lot of opportunity for this optimization to continue and to try and make this progress.
STFC-RAL-CR03 R61: On the next slide you can see a summary of the B. Parameters at the different runs. Sorry with everyone. The Www. Run. There's an Hr. And the Tt. Bar everyone along with at the bottom. The kind of planned number of years you would run at that energy for, and the statistics you would reach.
STFC-RAL-CR03 R61: and there has been discussion about whether it be possible to change the running order, and part of that is driven by the desire to get these fixed cuffing measurements. And sooner in the program. And I think there are discussions ongoing about the feasibility of of swapping that
STFC-RAL-CR03 R61: I'm now gonna talk more about the physics landscape at Fcc leads. And I really like this thematic that was actually put together by collaborator for Fcc. Last year, which shows the physics landscape fcc, and the detector requirements that you need to fully reach those physics.
STFC-RAL-CR03 R61: So if we broadly divide it into pix measurements, labor and particular measurements of people being there to be prioritized, and the Sm, you can see, there's a really broad range of opportunities. And yeah, these lead to I guess different detector requirements on your possible identification. The granularity of your detectors and required to reach the resolution. And also,
STFC-RAL-CR03 R61: be able to very precisely measure your center of mass energy. And there's a lot of work on going within the sec. Community. To study in a lot of detail the impact of the detective design on the performance in these different visit areas.
STFC-RAL-CR03 R61: I'll now say a little bit more about precision at Fcc. The diagram on the left shows the lum musti profile against the center of mass energy for the different running points. The red line was the original Fcc proposal. With 2 interaction points.
STFC-RAL-CR03 R61: And it should be noted, that's basically the same as the current proposed luminosity for Cpc in China. And that was an update to the Cpc parameters. And last year. So basically, that's almost exactly to the yeah, the ftc, but the exception that I think the Tt bar is not included in the normal plan to see PC
STFC-RAL-CR03 R61: and the blue line down the middle is the Irc runs 15 TV, and the the green lines are are closed.
STFC-RAL-CR03 R61: The main thing here is we really do. Which, unprecedented, we must see across multiple center mass entities. And this increased luminosity is really giving the ultra high statistics that gives us these huge leaps and precision. And what I could do is list out the you know, number of
STFC-RAL-CR03 R61: the number of minutes. You need to reproduce lepper, f cce, or you know the number of pixels. But as I thought we played a game. I'm sure everyone wants to think about active learning and audience participation before that looks great on Wednesday. So what I well, originally I visited you would have put these numbers in ascending order, and I really guess them. But in the interest of time, what I'd like
STFC-RAL-CR03 R61: everyone to do is talk to someone near them. About which of these numbers you think is the highest? And which of these you think is the lowest?
STFC-RAL-CR03 R61: So it's the number of zosons for our Fcc. The number of exposures today. Fcc. The number of zos produced in total L
STFC-RAL-CR03 R61: the number of Premix produced by the Birmingham Cadbury factory in a day. This I'm gonna go with a terrifying number and the number of pig photos produced by the IC in 2,017. So I'll give you all you know, 30 seconds to a minute. Talk to your partner, about which one you think is the highest or the lowest.
STFC-RAL-CR03 R61: I'll stop talking for a second.
STFC-RAL-CR03 R61: Okay, so if you just, you know, do one for 1, 2, 3, yeah. So which one do you think is the lowest? Number 1, 2, 3, 4, 5.
STFC-RAL-CR03 R61: There's 1, 4
STFC-RAL-CR03 R61: as 1, 5, 3 more 5, and which one do you all think is the highest
STFC-RAL-CR03 R61: 1 4. Okay. So the lowest is the number of pixos today. Fcc, and the highest is the number of advisors for our sec. But it is quite a terrifying
STFC-RAL-CR03 R61: number of previews. I did anticipate bringing Pre Meg to give a surprise for this. But it was really hot the other day.
STFC-RAL-CR03 R61: But yeah, any of you ever get to the bottom of why Birmingham need to make that many pre-med where they go, I'd be really interested to know.
STFC-RAL-CR03 R61: So yeah, hopefully, what this exercise is shown is really, you know, the statistics we're getting at Fcc are really, you know, pushing
STFC-RAL-CR03 R61: pushing the boundaries so far beyond what we've been able to reach in the past. And yeah, another way. This is often said is how quickly you can reach the left data set, Cce, and I think it's something like couple of minutes.
STFC-RAL-CR03 R61: I'll now talk a little bit more about the physics, and we can do fcc going through the different areas that I introduced a few slides ago. I'll talk about Higgs. First, st
STFC-RAL-CR03 R61: on the right hand part, you can actually see what the production Cross section, the different pigs production mechanisms does as a function of center of mass energy. So the dominant way it's produced is through this pig scroll and mechanism which is on the left, where you get associated with production, and this is very much dominant at the 240 GE. Burn.
STFC-RAL-CR03 R61: However, by this time you go to the Tt. Bathresh children, you can see that actually, we are also getting a reasonable number of Www. Fusion events, and the fact that we can do these measurements in different production modes is also really powerful.
STFC-RAL-CR03 R61: The fact that we have really high rates and a relatively clean experimental environment means that we really are going to be going to a new era pitch with British and physics, and, as I said earlier, the opportunity to remove the model independence sorry model dependence from these measurements is also really powerful.
STFC-RAL-CR03 R61: I mentioned before that this model, Independent and Higgs the Z coupling comes from this recoil mass method. And essentially what that involves is tagging the decay of this that goes on, and normally to add Leptons, which are very easy to reconstruct.
STFC-RAL-CR03 R61: And then, if you have a very precise determination of your center of mass energy. You can then construct the recoil mass associated with the reconstructed on, and then count events inside the speak, and by doing that you then get a cross section measurement which can be translated into an absolutely model, independent and set company measurement.
STFC-RAL-CR03 R61: So I mentioned before that one of the key inputs to this is very precise center of mass determination. And while circular colliders can't achieve longitudinal polarization like linear colliders. Can. There's something a process called resonant depolarization. That of the transverse polarizations allows us to get a really accurate measurement of the center of mass energy.
STFC-RAL-CR03 R61: And yeah, this ends up being one of the most important uncertainties to drive down to get these very impressive copy emissions.
STFC-RAL-CR03 R61: One question, that often gets asked. When discussing. Sc is why why do we need this paralegal run? So we get around 10 to the power. 12 of those ons at the the Z pole run
STFC-RAL-CR03 R61: and one of the big things this does is allow us to essentially get you know, factors of 10 to 50 improvements in the electorate decision. So on the right hand side, you can see the current unprotected. Uncertainty in various electorate decision.
STFC-RAL-CR03 R61: It's shown for the IoT I figure that the Ilc and Sc. And you can see that you know the reduction in the necessities there is is, is huge.
STFC-RAL-CR03 R61: Another thing you could do at the set fall run is also do a lot of exciting flavor associated with vv. Bar and house hers. And if you compare the expected final statistics at Bell to with that fcc, you also get around, you know, 10 times more statistics and a lot of your product channels. So yeah, this is also quite exciting.
STFC-RAL-CR03 R61: I said before that you can also do some cool things to tell the case. One thing you can do is a very precise, absolute measurement of the towel lifetime.
STFC-RAL-CR03 R61: and if you look on the right hand side you can see a plot that shows the Tell lifetime against this branching ratio to EU and the blue region is where we are. Stay, and it's yellow locked in the middle that might not even be visible at the back is where we get to that Cce, and the red is electronic line. So that's lots of opportunities to really stringently pro violation or universe.
STFC-RAL-CR03 R61: That's our team. In Italica's Fcc
STFC-RAL-CR03 R61: on the next slide. You can see a big table showing the projected statistical and systematic uncertainties on various Electra Week observables. Including, for example, the Z mast and width
STFC-RAL-CR03 R61: and I think one thing to, I guess highlight here is this green line is the statistical uncertainty. But actually, all of these are going to be systematically limited. And on the right, you can see the theory inputs. That has been identified. That would allow us to actually reduce these systemics even further. And a lot of these involve calculating higher order corrections and also
STFC-RAL-CR03 R61: calculations related to you and shape. And I think this again provides lots of opportunities, the experimental and theoretical community to work together in the coming years to try and drive these up.
STFC-RAL-CR03 R61: I mentioned at the start that actually, rather than doing a single center of mass energy, Fcc would do a scan around the Tt Bar production threshold. And the reason for that is by scanning over and by scanning over the center of mass energies, you can exploit the fact that there's a complicated dependence on the shape of the function of the top mass and top one. So by doing a simultaneous fit multiple center of mass, you can get a really precise determination of these quantities.
STFC-RAL-CR03 R61: I've already said this stuff about payments. I'm not gonna say again. I shouldn't put that side in. I'll move on and talk about Dsm.
STFC-RAL-CR03 R61: I've already said that these precision measurements would allow us to reach sensitivity to particles coupling to either the Higgs or the electric Bosons up to and well, 7 or 50 TV. And these scales are really set by the precision you'd get the respectable examples.
STFC-RAL-CR03 R61: We can also do a test of Suzy at the loop level. In regards that you can't access at the Mit
STFC-RAL-CR03 R61: on the right. You can see a lot that shows the projected 2 thing there indirect, which to stop
STFC-RAL-CR03 R61: particles. These are the supersymmetric partners of the top hawk
STFC-RAL-CR03 R61: for various configurations, the lx. 7, 3 and 1, 4, and then sc, and h, but actually because the the Fcc are dominated. By precision measurements. Most of this coming from Scpe
STFC-RAL-CR03 R61: I've already mentioned. You can also do lots of cool tests and and violation in favor and the tell sector. But the one thing I want to talk about now is that also Fcc Ee has actually the best collider sensitivity to various relatively Lumas.
STFC-RAL-CR03 R61: Esm candidates which could explain, yeah. Dark matter, neutrino masses as well. So if you go up to around 90 Gb, and actually that the the sec. Ee sensibility is strongest.
STFC-RAL-CR03 R61: and I now talk a bit more about these longer classical
STFC-RAL-CR03 R61: signatures
STFC-RAL-CR03 R61: on the left. You can see a schematic that's often used in it talks I guess, showing the different signatures you would get from a longer parcel which we're gonna define here today as essentially any possible that's semi stable, such that it. You know, travels a a distance before decaying within the the detector.
STFC-RAL-CR03 R61: and these are predicted in a number of Bsm models. You could have heavy neutral leptons, which are heavier. 500, several neutrinos that can be introduced to explain a mass problem. You can have lps in our party violation super symmetry you can have axiom like particles where the axiom axiom, like particle, refers to a generic pseudo scalar
STFC-RAL-CR03 R61: tool that you could put in a variety of mass ranges, not just those required by the Qcd and Cp problem.
STFC-RAL-CR03 R61: And there are also lots of dark sector models that can produce predict longer particles.
STFC-RAL-CR03 R61: If we go back to our diagram on the left, and there's a huge range of signatures you can have here. If you have a charged Llp, you could get a disappearing track, and you can get emerging decays. So the space left ons, or space jets. And and yeah, space vertices in general are a common signature of Llps.
STFC-RAL-CR03 R61: and actually
STFC-RAL-CR03 R61: with the Lhc. Our sensitivity to lps has been kind of almost
STFC-RAL-CR03 R61: it should be celebrated because we didn't really design our detectors with lp. Such as in mind, and we have a great opportunity now, looking towards the sec. To actually make sure these things are considered in our detective design. Don't worry about the time thing. Oh, meeting again hopefully. Not too far behind, anyway. So yeah, it's really important to make sure we
STFC-RAL-CR03 R61: We consider Llp. Searches when designing our Fcc. Detectors, and there's a lot of work going on at that moment.
STFC-RAL-CR03 R61: On the right you can see some of the projections from the last European strategy to various Lp signatures. So on the top right, you've got serial neutrinos and this is assuming a single generation of sterile neutrinos as a function of the cereal neutrinos, and it's mixing with the mole neutrinos.
STFC-RAL-CR03 R61: There are a variety of different experimental constraints here. But the one I wanted to highlight is this pink one here, which is the Fcc projection? So this really is you know, going into areas that can't be covered elsewhere.
STFC-RAL-CR03 R61: And the way you access this is by looking for the Z and coupling to your Llp heavy neutral laptop
STFC-RAL-CR03 R61: on the bottom. But you've got the Alp case. So this is now the mass of the active microscope is on the bottom, and then it's coming to the photon is on the Y axis. And again, the kind of purple region is the Fcc. And projected sensitivity.
STFC-RAL-CR03 R61: And the reason that we get such huge sensitivity. These processes is that we don't have to worry about trigger requirements anymore as we do at the Lac, and you can also get extern and reconstruction and impact. Impact resolution that allows you to get down to relatively low Lp lifetimes compared to what we can do at the elect
STFC-RAL-CR03 R61: just to ask a question on one previous slide. You had Pid
STFC-RAL-CR03 R61: in reference to flavor physics. But isn't it also possible that it may be important in this sort of area, because I mean, actually knowing, hey pi separation up to high momentum could be could be relevant to understanding some of these.
STFC-RAL-CR03 R61: So these Llps, I would imagine. Yeah, that's a really good point, I think, at least in the Llp. We haven't been thinking about the Id yet, but I think. And because a lot of the time is the Vd Bar background, which is the dominant background, you know, I'm thinking, back to Sld. And it was really the the combination of a very good vertical and pid, which opened up a number of areas which were not accessible.
STFC-RAL-CR03 R61: At length, for example, it wasn't quite so good. It was that combination. It wasn't really anticipated at the beginning. So I mean, it's often something which they they can really work together.
STFC-RAL-CR03 R61: Yeah, I'll definitely have a look into that haven't yet
STFC-RAL-CR03 R61: So before I move on, I think one thing I did want to say is a lot of these protections assume entirely background researches which for anyone who works on searches of the A/C. That's kind of crazy. The idea that you really don't have any backgrounds. And and I think one thing we do need to be careful in the coming years is actually making sure that we do track these assumptions against kind of instrumental effects.
STFC-RAL-CR03 R61: Obviously, being modeling in e plus c minus is very different to the Lac. So yeah, I think there is some work to be done to make sure that we really are confident in these projections.
STFC-RAL-CR03 R61: On the next side you can see a few of the detector concepts that are already quite mature for Scpe so on the left and the Cld, which is the click flight detector. No prizes for guessing where that came from in the middle. This idea, which is actually a concept that was specifically designed for fcc
STFC-RAL-CR03 R61: and if you compare the different concepts. You know, the the pharmacies are often what technology you feel, vertex etc. tracker, and what colorimetry you do, and why you put the magnets. So, for example, the Cld, it's a full silicon vertex detector tracker, and with a high granularity calibrated and solid outside. And, on the other hand, idea is hoping to exploit, to read out color. And I know there's a lot of interest in that in the Uk
STFC-RAL-CR03 R61: new concepts continue to come out. So this one on the right. I think this time last year it was just called the kind of mobile, liquid ecal based concept, and it has name. I don't know what Oliver stands for, though. So I'll have to look that up
STFC-RAL-CR03 R61: but again, this is using the production territory. And one thing that's really powerful is that the way the sec, software is set up means you can plug these detector concepts in and out of your studies. See? The impact they make on the performance.
STFC-RAL-CR03 R61: Actually, you just reminded me of that, because Roger 40 is looking for the Cld at Pid with a very compact ring imaging system, and so on. Which I mean most people. Oh, no, it's gonna take up huge amount of space because it did in Delphi and Sld. But you could make it much more compact technology. So it is work going on on that. And you just reminded me to, at least on the Cld, so they might be, what's that space? I could say.
STFC-RAL-CR03 R61: Okay, yeah, I will do. There's another. Well, this big Scc. Week next week. So I think probably some of this will get updated that day. I don't get to go to San Francisco, so I hope that anyone that does have a has a great time.
STFC-RAL-CR03 R61: The next slide. I'm showing the kind of sec analysis setup and I think you know it's still relatively early, as a kind of proto collaboration of people working in the sec feasibility study. But it's quite impressive that there's already a kind of sophisticated ecosystem there for performing simulations and visits and detector studies. A lot of this is built on the key for hepstack.
STFC-RAL-CR03 R61: which is a software and setup that was has been developed to be shared across all future colleagues. That is
STFC-RAL-CR03 R61: And yeah, I think this allows hopefully again, more robust comparisons, but also and people to share resources.
STFC-RAL-CR03 R61: I 1st highlight, though, that I think one of the big hopes for the coming years will be to do more full simulation detector studies, a lot of the studies that have been done so far have been using kind of parameterized and detector responses. And again, for some of these instrumental backgrounds. It's important to make sure we can do these in full simulation.
STFC-RAL-CR03 R61: I said. Most of the thoughts on the next slide already. About. Keep ahead. But I think one thing that is worth highlighting is that one thing that provides us is a central event, data model. And for future glider studies. And again, this can be shared across. All the different future Collider options.
STFC-RAL-CR03 R61: And within the Fcc analysis software. We have code that allows you to take an Edm, perhaps file and take it all the way to a kind of final physics study whether that be a kind of clock or sensitivity. Projection. And yeah, so a lot of what we've been seeing in the midterm report for Fcc have been updates of studies using and that have been entirely done within this Fcc framework.
STFC-RAL-CR03 R61: Alright, so I said, I speak for approximately 45 min. And I've hopefully done that. I'm now gonna wrap up, and you can tell us whether I've done my 3 bullet points. Well enough. So why should we think about each providers now? Hopefully, you can all appreciate from the time scales that if we if we don't commit to what future provider. We want to have to be able to see in the next couple of years.
STFC-RAL-CR03 R61: Then, we will end up with a gap in base taking after the highly must see, and many think that would be detrimental to the field in terms of losing talent.
STFC-RAL-CR03 R61: Another reason it's important to think about now it's now is that we can't delay transferring knowledge and expertise to those that are gonna have to deliver this project. You know if we think about those that were involved in the kind of design of the Lac and it's detectors, accelerators, and so on. We really need to make sure that expertise.
STFC-RAL-CR03 R61: Another thing is, as I said at the start, we're really resource, limited and we also have a very clear mandate to make sure that the highly nasty is a success. And so, if we want to do that, and also plan for future colliders in parallel, we need to make sure we have consensus, and that we're not spreading ourselves across too many projects or going in different directions. But also we need strategic planning and collaboration within the community.
STFC-RAL-CR03 R61: I also said, I, talk or provide an overview of the integrated Scc project. So yeah, just to wrap up it really does combine a precision at the intensity frontier with the minus visions, with the opportunity to push the energy frontier to the highest achiever value. By the end of this century. So we get both indirect and direct sensitivity to vsm.
STFC-RAL-CR03 R61: and yeah, hopefully, this gives us the best chance to answer our fundamental questions that we talked about at the start of this presentation.
STFC-RAL-CR03 R61: I also said, I would be highlighting the opportunities and challenges associated with the Cce.
STFC-RAL-CR03 R61: So I think that you know the opportunities to me at least speak to themselves. We could have a Paralympic in our precision to an electro week. Ecd. And Higgs physics there are exciting flavor opportunities, and unprecedented sensitivity to Bsm. Both in terms of the low mass possible to be prepared Fcc. And the indirect access we could get and then test behind. CC, h
STFC-RAL-CR03 R61: I think when I was 1st putting some of these slides together, I was at a workshop in Switzerland and thinking about mountains. But, you know, I think it's safe to say that whatever journey we're on in the future road up a good physics. You know, we're part way up a kind of very windy, tricky path, and there are challenges we need to overcome in order to realize these projects. In order to exploit the physics.
STFC-RAL-CR03 R61: potential of Fcc, both. The Nh will need a big advances in theory, you know, if we're doing orders of magnitude in our precision, then they need to be matched by various populations.
STFC-RAL-CR03 R61: There are technological alternatives, both in terms of detective design and design, but also in computing. And how we will manage these data sets.
STFC-RAL-CR03 R61: And then the final 2 I put down is sociological and political. Which I guess one could also kind of translate to checking that we want to do it, and that this is a, you know, responsible route forward for our field, and then also convincing other people that we want to do it and getting it funded.
STFC-RAL-CR03 R61: So you know, after our war and d routes up mountain path. You know, I think it's worth it, and we would, you know, go into this glorious mountain where we get to explore lots of cool physics for half a century. But of course I'd be also be interested to know what you will disappoint as well.
STFC-RAL-CR03 R61: Before it goes. You know. Another thing that we often
STFC-RAL-CR03 R61: highlights within the sec. Community is, why did we call something. We want to realize future circular glider, because at some point we want it to no longer be in the future. So to, you know, start thinking about this a few months ago on default adjectives starting with F and eventually hope it into positive objectives. So starting with F, because we want people to think
STFC-RAL-CR03 R61: Fcc is a good thing. And it was quite funny that you know of. The words that came up.
STFC-RAL-CR03 R61: A lot of them. I I don't think we can take too seriously. You know one was free, Stephanie. Not free. Feasible. Yes. Fulfills on up here. Hopefully. And you know another favor. So I know it's not everyone's favorite future program. But again, I'd like to hear what your minutes?
STFC-RAL-CR03 R61: Okay. And so I think I will now close with a slide which shows a possible to the future. And going from you know, the mid 2025. I'm sorry mid twenties 20. So 25, when feasibility study will end, and we have another strategy update. To you know, project approval, and then instruction and preparation for operation in the mid 20 s.
STFC-RAL-CR03 R61: so, yeah, thanks a lot. Listening. And how to take questions.
STFC-RAL-CR03 R61: It's
STFC-RAL-CR03 R61: do we have any questions either in the room or on zoom.
STFC-RAL-CR03 R61: Alright! There was a message from Bill 1158. Sorry I missed that one that said, see did add the top red now. Oh.
STFC-RAL-CR03 R61: any questions, Sarah?
STFC-RAL-CR03 R61: I had a question. Oh, sorry, Colin.
STFC-RAL-CR03 R61: so you've mentioned about the 4 agents interaction points. So the what's the baseline
STFC-RAL-CR03 R61: Or there would be something similar. Yeah, I guess they would be different concepts. But it wouldn't be like at the lat where you have. You know, Alice and Alex be that are doing really specific programs.
STFC-RAL-CR03 R61: But again, that is, I'll admit that is the decision. So I understand the least about you know you get a game of statistics. You would have twice the number of experimental collaborations.
STFC-RAL-CR03 R61: and I've heard, you know, some arguments that I don't know if I buy that well, just being made on, you know, number of people that want to work on. It means you need needs multiple collaborations. I think one very strong advantage of having multiple detector concepts is that, assuming they would be designed such that systematics are really different.
STFC-RAL-CR03 R61: you would get kind of complimentary and measurements in terms of which systematics are important and different concepts.
STFC-RAL-CR03 R61: But that's on my list of things to understand better.
STFC-RAL-CR03 R61: Hey, there, Jim.
STFC-RAL-CR03 R61: have we deal with the technical people that much bigger than Nhs on the office.
STFC-RAL-CR03 R61: that I also don't know. And I don't know if I can argue that the humans are to scale or not. If they are, you can extrapolate. And I can get a picture about the stuff with the same humans.
STFC-RAL-CR03 R61: I. So I think in one thing that is, even, for example, the kind of designed reports is how big the cabins are based on the fact. You're using one tunnel for Fcc. E, then H, and I guess it's the Fcc. H detectors that are
STFC-RAL-CR03 R61: the biggest limit. But I'll look it up for you later.
STFC-RAL-CR03 R61: The other questions
STFC-RAL-CR03 R61: I was gonna ask if people want to get involved in Fcc, how did they go about it? What's the best way to get started. That's a really good question. You. So anyone that has questions is very welcome to grab me later today and or email me, within the Uk. There is an Sec Uk structure that is I guess, has been used to encourage people to talk to each other in the last couple of years.
STFC-RAL-CR03 R61: But the the kickoff meeting that I mentioned for these actual workshops on the 1st of May.
STFC-RAL-CR03 R61: one of the things we asked the people giving talks to do with sign host who you would contact if you wanted to get involved in studies ahead of the European strategy update within Fcc, I guess most of the effort is currently going towards finishing the feasibility study. Which they want to have everything done by the end of this year. But you know, let's take the optimistic
STFC-RAL-CR03 R61: view that it ends up, you know.
STFC-RAL-CR03 R61: coming up positivity of the project.
STFC-RAL-CR03 R61: I yes, there will be ways to get hold, and that's still lots to do. So yeah, I would recommend having a look through the slides from the pick up and contacting what the the people involved.
STFC-RAL-CR03 R61: There's a bit of context which is for
STFC-RAL-CR03 R61: the Fcc studies that also feeding into an extra initiative which is a kind of more provider agnostic, Ec. Minus study. And there's a workshops about Paris.
STFC-RAL-CR03 R61: Any other questions, Sarah.
STFC-RAL-CR03 R61: Zoom Phone was an unknown error code on Zoom. So I'm not sure I've got the zoom people anymore. Sorry zoom people if not, then let's say there again.
STFC-RAL-CR03 R61: Weeks come for lunch, so feel free to ask questions of lunch. Thank you.
STFC-RAL-CR03 R61: If they don't do it for me to upgrade.