Okay, thanks. Okay, so good afternoon. So I was asked to give this overview of the
physics case for future hadron colliders. And let me just start by giving a you
know, more more broad general view of what a future project in energy physics might
want to achieve. So, you know, as a first bullet you would like to explore the
energy frontier. And you would like, hopefully to address some of the questions
on physics beyond the Standard Model such as market nuclear mass, and the matter
antimatter symmetry. Of course, no collider experiment, actually, no hype
experiment can hope to answer decisively all of these questions, what you can
answer is yes or no to precise scenarios of such questions. And this is what you
can actually hope for a collider experiment on the other hand, We know that
the Higgs there so we have found it a galaxy. And this is kind of a guaranteed
deliverable if you can prove that your collider can measure very precisely the
parameters of the Higgs potential and Higgs couplings, you have a guaranteed
deliverable. So, what kind of hadron colliders that are on the market. So, as
you will imagine, I will talk mostly about the FCC Ah, I think Daniel shooty later
will give you an overview of all these various options probably with a focus on
the accelerator so I won't discuss them too much here. As I said, I would focus
mostly on the FSH which is a project for 100 TV Collider in 100 kilometer tunnel in
the scenario, so this would be the second step or the first e plus e minus Collider.
That will Be essentially electroweak and Higgs factory. You might know that there
are two other possible options on the tables which are less fashionable. So one
is the energetic shear or you take 16th as a magnet inside the UFC and you get the 27
pt Collider. Another option that came out during the European strategy is a so
called low energy FCC h h, which will have the 100 kilometer tunnel, you fill in with
the cheapest possible magnets you get to 37 TV, and you wait to have the technology
to get on the TVs. In case you don't want to start with any plus or minus Collider.
All of these options are described in various cdrs in European strategy. Now
more precisely 400 TV so this will be my benchmark for for assessing the potential
of a future Hadron Collider. More precisely, you would like to problem the
exact coupling to the percent level, measure percent level precision, the
Tokugawa and second generation so he's tomeo don't talk cetera and measure the
Standard Model parameter with high precision. And of course, what you have is
you really can explore the complementarity with the plus and minus machines because
you can access read case not only for the Higgs but also for you know, some other
processes. And also you have access to high dimensional parameters in unity. To
extend kinetic regime which you don't have any plus or minus, at least in circular
collider where you have limited amount of energy is not Rothko's, for clinical
either way, you can also higher energy and neon collider even more and on the other
hand, you know, if you're caught onto TV, you want this machine to be discovered a
machine is why you're caught for such high energy because you're no you're your
discovery potential in principle goes up by a factor 700 divided by 14. And in
fact, your targets will be known for you for this kind of math, very heavy
resonances in the range of 4050. TV for soaz 20, stops and 15. And what you can
see here is that, you know, it's very similar to get in the sense that the
physics problem program spans over a fairly wide range of characteristic energy
scales, but even more so, because you still want to measure stuff at the hundred
gv electroweak scale. But on the other hand, you also want to go possibly almost
an order of magnitude higher in energy to discover new states.
Just some very naive characterization of what physics collision will look look like
in in 100. tv regime. So the first thing you'll notice in this plot or use or I
should the cross section is a function on this square root of s. terms of the pee
pee coalition. You already see that the pee pee cross section doesn't increase
much between 14 and 100 t. So basically what this means is that the levels of
pileup will scale as the as the level of the something luminosity and not a typical
BP cross section is not increasing that much. This also means that the interesting
physics sticks out more provided that you have the same luminosity, or at least the
same regime of luminosity, that you have a tidal menos etc. So, typically, for
example, for Higgs processes, you have a factor of 20 to 50 in case something as
that changes, or at least slightly shifts perspective at Hunter TV is that standard
model of physics or stuff that is produced basically a threshold when you don't
require high school class is produced more forward is because you have larger
possible imbalance between the two buttons inside the proton and any fact Something
you can see and it's something you have to address if you want to actually be the
detector that can collect these interesting physics is shown in the bottom
plot here. You see a Higgs to follow up on event that falls forward leptons as a
higher detail in rapidity. And for example, if ebf Victor Muslim fusion Higgs
process, where you have this characteristic forward jets, whereas the
30 DVDs picks around typically three or four inches of variability, a tablet TV
would pick around four and five. So you have to instrument these regions. If you
want to collect this physics or you, you have several experiments and we'd like to
see type CB use case for example. On the other on the other end of the spectrum,
you have the boosted physics case, want to make sure you can reconstruct these very
high p particles. This means for cracking, you have to have a large the square or a
single point resolution that can you know, that can that can cope with the With a
high momentum that can handle these high momenta particularly meters, you want to
make sure that you have enough you know, radiation and actual lengths to to stop
these high PT particles. You're lucky in the sense because you know the energy
growth is logarithmic. So, we just add one other additional length and you're
basically done, but this means the more material means that you have a Solomon
behind you know, the whole thing up just scales up by by by a large factor and of
course, this is also possible concern for the for the price, but a principle we
showed that in a car that is assumable to have this kind of to fulfill this kind of
requirement pretty easily provided you build a large enough detector, you have
something that also changes a bit to the in terms of, you know, phenomenology so
for example, a we are using At the NFC to reconstruct the moderately boasted
headphones. So you have this typical displacement of you know, 500 microns for
standard your threshold, you don't have so many one TVs and the LFC or four or five
TVs. Now, if you want to look at resonances, for example, in tops that will
contain 50 VPN and you have to keep in mind that, you know, you're typically the
head and we live 50 centimeter inside the detector and so it will decay later, look
more like you know, emerging chat or chat. So you have to think a bit how you're
designing a talker and you have kind of a dense, dense proportion of material even
even outside your, your your your pizza region. This will allow you to, you know,
to construct these very displaced topology, which is also important for for
new physics. And you're talking about a change in terms of algorithms, right. We
look at This kind of behavior ends in a different way because we look for example
from multiplicity jumps in science from earlier Congress also very highly boosted
WCS and Hicks, you know, attend TV, who will have its decay product which will be
separated by time units. Typically, this is already very short, very small four
kilometer cell and, you know, keep become more outrageous on a medical ultimatum.
So, you will have to rely more and more on tracking to reconstruct these kind of
particles. Now, maybe it's more on the physics program. So, let me start with the
Higgs. So, as I mentioned already, the
Higgs production rates at at FCC h 100. tv will increase by a factor of 20 to 60
depending on which process you're looking at. This gives you access to very early k
modes. Typically, for example, links to email and also which are very
complimentary, plus minus it will give you x Software, a large dynamic range for x
production would produce it addressed. And you will have millions of events with the
one TV Higgs, for example, which give you indirect sensitivity to get some effects,
for example, for particles running in the living room fusion. And also, of course,
the Higgs is a tool for doing Bs and discoveries, because you can have the
stuff that decays into the Higgs and also profitably. And we start with discussing
the rate of the stable so this would be the table of a list of the precision that
is achievable in terms of Higgs couplings at the end of high luminosity hc and
compared to FCC, and it's also to show a little bit of the complementarity between
the hardener experiment and the plasmonics experiment. You can see that for a bunch
of measurement, typical x to z, z, w, w and x two heavy quarks, as long as the
Higgs can came to them. Yes, he does. Very good because branching ratio is larger.
Now, when you go to more read case when the company is smaller, you see that the
FCC runs out of steam. Typically this is the case for external external, my gamma
is a branching ratio, the order of 10 to the minus 310 to the minus four. The
reason is because the SEC can produce only 1 million Hicks's so if you're not if
you're if you're lost a factor of 10 to the forward by by decaying them, you
simply run out of steam to measure them and so, this is what you have cch can
really make the difference. So, another another aspect in which the FCC h h is
complimentary FCC is that at the FCC, so, you can use the very precise measurement
of the SEC. For example, it was easy to normalize what would be relative measure
metal FCC church in order to collider you cannot really measure directly the
coupling of the Higgs you have to make assumption on the Higgs which is not true
at the FCC because at FCC you can measure directly the scalping zz because you
cannot have the Higgs Mass Effect measurement. And this is very interesting
because now once you have this measure this coupling which is precisely measured
at the level of one per minute sec, this gives you an absolute normalization
provided that you can measure these ratios at sec Ah, so maybe a bit more concrete
here what we studied this, for example, here I'm showing the ratio of Hicks to Mew
Mew two weeks to four leptons, which are it's very advantageous because you have
the same object in different states so most of the systematics will cancel out
all the production systematics cancel out and you know city theory uncertainties and
you can see that you can actually measure very precisely this ratio the FCC entered
at the level of 1% which means that since you know the denominator at the level of
one premedia a measurement of extreme you know, the level of 1% this is true also
for z two for a to z gamma for example, and Hicks to gamma gamma. Of course,
another very important measurement at cch is the exact coupling He's a measurement
which is hard even at the FCC ah because of course, this processes that is more
cross section because of these destructive interference between this box and triangle
diagrams. What is on your side is at the FCC church you have a factor 14 creating a
cross section and you have another factor turning your data to university which
gives you a factor for under the event here is an entry effective 20 position
assuming this is statistically limited, which is more or less the case. Now, we
studied this for traumas, which you can see on the right here the negative log
likelihood for each of the channels the most dominant the channel that drives the
sensitivities to be gamma gamma tonics with a precision between three and 8%
depending on which kind of systematic uncertainty you assume Of course, you have
to make a lot of assumption because this machine which will probably be seen today,
you know 50 to 50 years from now, we computed the combination which gives you a
measurement of level of 5% What is interesting is also to see how the self
coupling precision varies as a function of the integrated luminosity. Of course, with
the full ftth runtime you get to precision of order 5% but even if you work around
only three minutes at the bar, which is basically a couple of years of running the
FCC hh you can reach the 10% precision which is the precision you get click for
example or I NC. We also measure we also computed the the precision on k lambda. So
the Higgs f coupling as a function of the coupling of course, this assumes you have
standard model coupling and you don't bury the other couplings.
But this can be interesting for example, you know, for for scenarios or vertically
but identities where you have this large change index, self coupling. This is a
summary of the values Higgs measurements. Between FCC and FTC ah You can see that
there is this very nice complementarity or you get below 1% for most of them and you
will really have some of them which can be measured better with FCC and others which
can be measured with FCC judge because these are kth to me Mr. gamma gamma
described earlier and of course, acts of copying which you cannot measure it
directly can only do it to the oddity productions. Something I mentioned before
also, it's something which is very interesting at the FCC. hh is this
complementarity in the, in the in the measurement of the Higgs of coupling and
the search for, you know, the creation of the standard model which could explain the
larger volume of symmetry in our universe. So, you can have this extension of the
standard model with a with a singlet on the left plot, you can see what is covered
in these bands is basically these points that give you these stamps. First on the
first condition, and you can see that with 100 kV a 13, or sarcoma these red occur
allows you to exclude most of the of the of the point. And on the right block even
more interesting plot which gives you in the x axis the pressure on the Higgs of
coupling on the y axis, the precision on the X was easy coupling, which is
basically the flagship measurement of the SEC, all these thoughts are thoughts that
give you again, the strong first quarter 10th edition, the ones which are favored
by, by, by this theory, and in fact, what you can see is that the SEC can exclude
basically most of the points on the Z on the X on the y axis whereas your ch can
actually constrain the most on the x axis.
We have four minutes left,
okay, I will try to go fast, maybe I can skip this. So their hips too. Invisible is
also a very important measurement because it cannot It allows you to probe
directional Higgs to potentially a dark matter.
And this was studied also in the context of the cdr.
You have these very large sitting in your background, which you can constrain by by
measuring the CW and gamma spectra and you can also actually measure it, you know,
when you have high statistics from the past minus you control region. In fact,
you have so much statistical data that you can actually do even better than FCC and
you can actually even measure the standard model. It was easy to form a neutrino
the level of 10% I believe,
something else you can do of course, you know high energy collider as I mentioned
at the beginning, and this is something is the first thing you look at if you wish
when you start to assess these kind of options because you want to check whether
you can fulfill the promise Increasing these Kaveri rich. And so the first thing
to look at is resonances. So you can see primes to dialect on tops Graviton to W.
Of course, this will make use of stars, Jetstar, certainly because we look at
these in the Atlantic channel. So the two highly most tops, W's who educate
chronically as well. And of course, you have constraints from the tech revolution
because of the fact I mentioned earlier that is highly boost and jets will be
severely collimated and eventually will emerge and you won't be able to
distinguish them too much from QC digits.
We also look at this flavor inspired
model where you have DC prime coupling to DNS only. That could explain in a minimal
way. The B to k star mimeo Family and we showed that we just checked you can
basically exclude all the allowed parameter space suit stops again we use
these very same boosted technique to construct these atomic jets. He came from
a highly massive stops which we'll get into how he was the top and you can show
that you can you can actually discover stops up to 10 TV more or less at the FCC
ah Finally, something which is also very interesting is exotic signatures such as
such as disappearing tax. So, you have this very simple with a type of dark
matter scenario that emulate with a dark force. Xenon when a dark matter, which are
favored in the range of one and three TV, it observes that Alec abundance, these are
very typical compressed my my spectrum which are these very characteristic
signatures Have a charged particle that will basically disappear in your detector
because it will decay to a very soft biome and missing energy and you cannot
reconstruct the soft pi and so, your your signal is basically this disappearing tax.
And this group of people from doctrine is very nice studies shows that you can
basically cover and actually discover both Xenon we know dark matter and Pshh should
properly design your packet volume. And so, I come to the conclusion, I will just
briefly summarize the bytes I went through. So, the large statistics are GCC
h h in terms of Higgs physics, so, we typically produce 10 to the 10 Higgs boson
open up a new range of possibilities, allowing both to measure or advocate
channel and measure the Higgs in eukaryotic genome and he's really
complimentary to that see. You can measure ratios of couplings or equivalent Key
ratios of branching ratios concept both systematics and to allow you to normalize
these measurement with respect to the SEC give you they're often the absolute
counting measurement, you can measure the Higgs coupling to a precision of about 5%
and the FC change which is among all proposed future options, they are the most
precise measurement and you can directly excluded these very simple models of or or
fine or discovered of for compatible with the first time that I took this position.
And of course, you have unprecedented reach for direct searches, evidence
associated searches. I hope I made it in time.
Yes, you did. Thanks. Let me kill
without warning open the panel for for questions or comments. So that's the usual
procedure please raise your hand and then we will give me
permission to speak
any questions?
If not maybe a naive one from from myself. I'm not an expert on on sushi but I always
had the impression that already with Elysee databases very much under pressure
to say the least.
How much
to do people actually still have hope to to find something yet at FCC or how much
are these models constructed actually true?
Well, I believe that Okay, these are these are modern, more fine tuned model, of
course, but I think that rather than, you know, giving a hope measures to find Susie
or not, Yes Ah, this is a way It's a well known and well studied model such that
people can refer to when you evaluate to the benchmark country to the doctor. I
mean, which is more the way I see this
community maybe
I can comment better on a
wireless has
been doing very bad Of course, but not that we we we have absolutely no no no
reason to stop searching directly for new resonances. supersymmetry may still be
there look a little bit different from what we thought and there are many there
can be many more scenario. So I totally agree with what you said. The the idea of
having these sushi benchmarks is simply because they are a lot of particles which
has been studied already. And we want to know how well we can be ready to discover
new particles of the broadest possible variety. So it's like a catalog. Okay, for
me, and I think we get like these So, I had a question. Yes. Oh, if you want so my
question was about this dispenser extra linear we always so you show that and you
comment on slide 15 that actually in most actually, as far as I know, almost all the
other Genesis models, the single leaks, it's enough right? Single leaks gathering
measuring very well at some collider closes a bit the door to these these
models. So what is actually left? I mean, we want to move to measure the cylinder
But why?
Well, I think this is a question for theorists like you but in from an
experimental perspective, if you're completely naive, you have a new particle
and you know, you have a unit you know, you have a predicted value for its
coupling and a standard model. And even if you you know, even if you don't have
anything in mind that you want measure is new, all its new couplings to death. And
the history of coupling is one of them. I mean, this is at least my perspective on
it. You're right. I mean, of course, it seems that measuring the zz and extra vv
couplings and naptime colliders will be enough to constrain these models. You
probably even know better than me. There might be even some models for Jewish this
is not the case.
It's difficult. It's difficult to find some there are corners of things. Now,
maybe I don't agree with what you're saying, don't you think is maybe that
measuring, I don't know, 10 times or 100 times better. The scalping to vector
vector may be more productive than measuring the extra linear, which doesn't
mean it is to say, we can put both things but yeah,
okay, this might be true. And I think we shouldn't do both.
In fact, I think probably the best way would be to start by measuring up to the
highest possible position with a plus or minus collider and then
then measure that the linear
Thomasina procedure with a Hadron Collider.
Okay,
thank you.
I don't see any further raised hands so let's think Michaela again. And then you