All right so
um so the best of luck on film is out in the maze on the case show some interesting
hints of physics with hints of physics beyond the standard model. And while these
are not conclusive to to a number of people, they are compelling but when taken
together, and they may well go with it with a new analyses and proved techniques,
experimental techniques. However, the main premise of this talk is that they hint
physics beyond the standard model. And, and then the clear call for theorists is
to do a bottom up model building adventure. So, what I mean by this is that
we should first try to, I will try to guide you through a number of steps to
establish the so called infrared consistency checks and meaning Can we have
new physics that a explains the anomalies both in charge in little currents and B
pass all experimental constraints that have been that are out there in particle
physics? So, the the question zero is to try to find an explanation within the so
called the Standard Model effective field theory, which is a motivated framework to
to parameterize many different short distance new physics models. So, if this
can can be done, then we should go and try to complete the effective operators by by
identifying the emerging set of new heavy mediator particles that generate these
operators. Then we will arrive to a new set of consistency checks for instance, do
these heavy mediators pass the Direct searches at the LSE. Once we have all this
then we can go off and try to work try to try to write down a full fledged model a
prototype, which is fully calculable hence we can really calculate many many
observables and cross check and to establish the IR infrared consistency
checks and we would like to this model to be to be able to extrapolate it to high
energies. At that point, we are ready to try to make connections with the
ultraviolet physics and try to ask questions How does that construction fits
into the UV picture? In other words, is it linked to to open problems so, the
standard model for example, the hierarchy problem the flavor puzzle etc. And then we
can also ask questions about the connections and links which come out from
those constructions with other sectors of high energy physics in general. And, and
to make predictions, where should we look further? All right. That's this slide
defines what I would call a bottom up model building. So, the zero exercise is
to perform the analysis of su to gauge invariant dimension six operators. We know
that the basis of these operators is quite big into there are a huge number of flavor
parameters and input flavor parameters. So the the way to navigate through this huge
parameter space is to employ flavor symmetries and symmetry breaking patterns,
which serve as the organizing principle. So we were able to To identify a coherent
picture of new physics based on two assumptions, the first one being that the
new physics come in specific dimension six in a few dimensions six operators
basically in semi electronic for firm operators, which involve left handed cork
and leptons tablets and they are written in the Lagrangian on this slide. And
second that the the flavor structure of these ij k l tensors follows the U to Q
cross u 12 favorite symmetry which has been which with the minimal breaking
spurious This was quite surprising and very was, you know, very interesting to
see that one can explain the anomalies in such a minimal framework and Be safe with
with respect to other constraints of low and high energies.
And the structure which emerges the flavor symmetry in particular, is something that
was proposed before the anomalies to try to address the problem of the puzzle of
from your masters and mixings youtube youtube flavors symmetries. So, that I
will leave the more details we can on this slide and links to to to a few references.
And, and just to mention that, for example, well young constraints are high
at from Atlas and CMS were important in this exercise as well as radiative induced
effects. And let me mention that, here we do not consider right handed current, and
the current data doesn't tell us whether we have them or not. However, they can be
added And they can in some cases they can be useful and future data. If this turns
out to be new physics future there are ways to say whether or not we have right
handed currents
alright. So, now we are good good to go
more towards higher energies and try to find
towards the model. So, new having mediators we generate these new family
interactions at three level at least can be nicely that we can have we can have a
we can basically make a catalogue of them and they are given in this slide. So,
these particles are like a w prime or or scalar and vector laptop work. Their
standard one quantum numbers are given in the brackets. So, models where you have a
single mediator particle are very predictive. So, they for example, they if
you exchange one mediator then you have a clear prediction between effective
operators at low energies
okay.
In fact they are so predictive that only one of them can is a successful
explanation of all of both charging local current anomalies and is consistent with
other with other constraints and this is the so called vector laptop work singlet
So, it's like so it is the most successful single media to model and, and its mass is
around TV scale. And it's coupling to third generation is of order one so it
also makes it a perfect candidate for direct contact dl hc which is also quite
exciting. Let me also mention that Other simplified models were put forward in the
literature, which contained multiple medic mediators playing the dominant role in the
anomaly, so giving a significant contribution for to formulate the
prototype model, I will go with the vector laptop work option. And the first thing
which which comes to attention is the the quantum numbers of this particle. It is
actually the party salame laptop work Quirk. It's the first Leftwich work that
was
proposed in the literature and studied in the literature.
And this rings a bell as to a profound question, an open problem of the standard
model, which is the puzzle of the charge quantization. The party Salam is one of
the you know celebrated extensions of the standard model which which resolves the
charged quantization puzzle by cork left on unification this connection comes comes
comes with the vector electric work solution. So, however the the vanilla
potty salon the original pet salon cannot be directly used here because because we
need a T scaler laptop work. And there are constraints from K on decays for instance
k long to new e on the original party Salaam. So, the The question is we have to
modify party Salam and the question for model building is how to achieve a
successful TV scale cork left on unification. And the answer to this
question goes under the name of the so called four three to one models which were
quite popular in recent years and in This slide you can find links to some selected
references. And if you would like to have to, to, for for more references, I will
give very quickly the the main idea of the 41 model, which is to say that we haven't
extended gauge symmetry at the TV scale broken down to the standard model. And in
this breaking we basically generate a massive electric vector electric or as a
massive gauge boson of this
of this symmetry.
Now, the there are now there are two options to embed fermions. In this model,
they can either be all three sample generation charged under the three to one
gauge group, in which case we need the regenerate interaction with the laptop
work through fermion to mix With the heavy fermions. Or we could for instance dialect
directly couple, a third generation to su four gauge group and then we the third
generation directly talks to laptop work. Now the given the time constraints, I just
want to make the point that this model is really, it's a normalizable model with all
details specified, it's weakly coupled. And one can calculate observables with it
and and do an exhaustive phenomenological studies, some of which were done in the
literature and calculate, for example, one new contribution to nasal mixing or some
exotic signatures at dl hc. So far, we think we have the working prototype model.
All right, so where does this lead us in terms of insights about the US Physics.
One possible answer to this could be the so called flavor deconstruction. So let's
go one step back and think about what leptons flavor universality is, well, long
distances, gauge interactions. And the sea electron Yuan and Tao the same and the
only difference between these three particles is data mass, otherwise they
look the same. This is left on play with universality. However, this might not be
true at short distances. In fact, we have a a great example. And so like the long
long wavelength photon sees positron and proton the same but we know very well when
we go to short distances to high energies. These are far apart. from each other. So,
flavored quantum number could be an indication that when we go to high
energies there could be this deconstruction where we have a gauge group
for each generation of fermions. So, the model that was put into literature it goes
under the name of parties alarm cubed, where there is a participant gauge group
per family. And then there is a series of hierarchical symmetry breaking, which then
go down to the fourth one model at a TV scale. Now this construction seems like a
horrible complication when you go to high energies, they're much more than there are
many particles, however, and the natural realization of this idea will go in in
extra dimensions and you'll follow the the idea of deconstruction in extra dimension.
And once again, it is not the number of particles which is a measure of
complexity. It's it's basically our simplicity. It's basically the number of
symmetries that we have in the, in the, in our theory. So we're what kinds of
connections we can make out of this. For instance, one obvious is the neutrino
mass, that where this neutrino is in the same multiplet as the top Quark, for
instance, then we have a disastrous prediction that the neutrino mass should
be of the order of electroweak scale. And, in fact, we are forced to, to have a very
specific nature of the neutrino mass something which goes under the name of
university so mechanism which were the neutrino masses protected by electron
number.
And my final slide is another interesting connection which has to do with the
gravitational waves. So by studying the cosmological history of this model, one
can realize that in large parameter space of the model, you can undergo a
hierarchical strongly first order phase transitions in the early universe, and
this can give you a footprint which is a stochastic gravitational wave radiation
that has this characteristic three peaks signatures per family. And the ratio of
the peak frequencies is related to the rate to the hierarchy of, of mass of Quark
masses. And this is interesting for as you can see from this plot to future
gravitational wave interferometers. Alright, so, this brings me to my
conclusion, which is very simple. A B anomalies show the power of data to
sparkle, new ideas and theorists are thankful to their colleagues for you know,
delivering fantastic results and looking forward It not only opened a new
directions in model building it also provided new connections and and new
spectacular signatures. And the footnote in the conclusion is that yes working
model exists. However the final judge is the experiment. Thank you
very much mirror question toward me.
Raise your hand
Okay, maybe I should start. So, that gives me some time. So,
regarding regarding the Smith discussion admin,
yes. So, you you focused on
for farming operators, right, which essentially match directly to the usual
operators that we have and you know, after we integrate this into W and so on, and
does this mean are you doing this because you know, that the others
cannot do the job like, you know, operators with the To send and engage
pauses and so on or just to start somewhere, well also those were studied
and then it showed that they cannot do the job. So, I see you can have a god operator
which goes there is a semiotic current times a gauge boss on with the with the
Higgs current. And those are so, not to say basically, you can't pass the
constraints from the modified gauge imposed on vertices like WD case and I say
things and these particular models essentially are a realization of the setup
right.
So, yes, those other operators are much more suppressed. Well, so, there are other
So, so, as you go more towards you know, UVI then you are getting more and more
consistency checks for instance. Then, then you have for example, for cork
operators like delta f To transitions and in particular in particular model what is
a quite important constraint is DD by mixing for instance. Yeah. And so as you
you know, and then you have more complicated direct search constraints. For
instance, color on is one example you have this particle which you don't see before
constructing the model, etc, and goes on. In even if you go to, you know, the first
site of party Salaam then gives you flavor changing the flow currents in K on the
case, so then you have to be careful where we're teason
Okay, see, there is another question from Giovanni. So just, we should be able now
to, to speak to try. Yes, much. Thanks for the nice talk. So my question is how much
these models are already constrained by direct searches, I mean how much parameter
space is still free to explore to be explored. Alright. So,
yeah. So, so, the, the precise answer to this question is, I believe in one or two
of these references where you can really show the plots that put combined together
the direct searches for the lepto Quark and the parameter space and they try to
you know, go through the parameter space of the of the of the, which is a, you
know, predicted from the from the anomalies and and there is still there is
still some, you know, large fraction of parameter space which is not not explored.
So, you can have Have a lepto quirk which is three TV for example, and has a
coupling of another one.
Yeah, so So
yeah, so I cannot claim that this model can be ruled out by the LFC searches. But
if we were to have some kind of future Collider, then like, let's say even
doubling the energy will be will be quite good. We actually done prospects for the
report for the high energy Collider, it really covered a lot of parameters. And of
course, this also depends on on the the statements that I make right now depends
on the on the on the status of the anomalies. For instance, before the the
latest bell to update is the model this was much more constrained because the the
anomaly was more profound, but Then the anomaly went down in the parameter space
is all of a sudden more relaxed. So yeah, I hope it is scan by by the detailed
answer to these questions can be found in these references.
Thank you.
Thank you very much. Other questions?
seems not. So, we are in time so I think that we can close the session. Thank you
very much again to all the speakers