Yes, I think school can start. Yes, let's start the seminar today. Welcome, and thank you for joining. Let's start.
So, let me start by introducing our speaker today.
Rihanna. She's a lecturer at the University of Sheffield, and she has been widely involved in the Richard Alban nutrition experiments since 2015.
She's currently the co-convene of the oscillation Group. at the SBND experiment, and at the genes and is the dunes.
Physics calibration group convener. And today, this talk will introduce the SBND experiment. It's exciting physics goals and the expected impact on the future of particle physics. So join me in welcoming Brianna.
Yeah. So as as Ivana said, I will be talking to you today about SBMD. I don't believe Raoul is involved in Sbnd, and I'm going to be assuming that from now on. So I will introduce some of the sort of physics, the underlying physics that we are working towards sorting out. And then I will walk through how the detector works.
I will talk about as we move to my open slide here. I will.
Okay. Oh, you might need to click the.
Slides again to make it work. Uh, yeah, okay. Oh, I haven't, that's okay.
Ivana, are you recording? Yes, yes. It's still working, man.
If you click on the slides again. Ah, there you go. Oh, we have something. Okay, this is the slide I wanted. Let's see. Okay. We have movement. Great. Yes. So I will start by introducing the short baseline experimental neutrino physics landscape. I will then talk through liquid argon detection in general in the context of neutrino physics, experimental neutrino physics. I will then talk very much more specifically about the short.
which is the focus of this talk. And then I'll run through the SBMP Physics program in each of its three major parts. And then I'll get to talk to you about how we got to the point of operating SBND and where we are at right now.
Um, yeah, so getting straight into it. I'm hoping this is not news to anybody. But of course neutrino oscillations were discovered at the turn of the century through a combination of measurements by superkane snow and was awarded the 2015 Nobel Prize. And the reason I bring bringing this up is just to highlight the fact that basically, since then.
Um, experimental neutrino physics has largely been involved in trying to constrain the parameters of nuclear oscillations, um, get precision measurements from those, and decipher any anomalies that we see along the way.
Um, and so the equation at the top here is the equation that primarily governs neutrino oscillations. It's parameterized by the Pnx mixing matrix I highlighted in red, and a squared mass splitting that I've highlighted in blue.
And this is an expanded version here. And this is the current status of the measurement landscape for these parameters. Nufit was down two days ago, but thankfully Google Images changed the day. Um, so this is as of, I think, 2020, November 2025.
Um, and I've specifically just pulled out the normal ordering assumptions with the junk, uh, super atmospheric data as well. So this is kind of current status of neutrino oscillation physics in the broad scale. However.
Um, I'm not gonna talk specifically about active neutrino operations. I will get to that shortly, but I'm going to narrow us down towards the short baseline regime as we go through here now. Um, so yeah, the way that we measure these parameters is by setting up experiments with, um, specific.
And a few ranges, and what we call baselines, i.e. The distance of the detector to the source of the neutrinos. And these two parameters are L and E. And so this can be done to basically tune your experiment to any given set of parameters that you would like to measure.
Um, so for instance, in the react… what we call the reactor range, uh, reactor neutrino oscillation experiments, moving towards the solar range, although that baseline is so large, it's very hard to sort of show on a plot. Um, if you look at the x-axis of this distribution, we have an L over E, um, up to sort of.
200,000, um, and you can see the general shape of what we call the slow oscillations. And you can also see within that, uh, what we call fast oscillations. And this is because the, um.
oscillation probability is a summation over multiple mass listings, and mass wide splittings govern the frequency of the oscillations. And so at this rate, you are largely sensitive to delta M squared 2 to 1, um, which is the slow oscillation. So I've drawn sort of like dashed lines over it, so you can see the sort of shape.
But of course, it would be very, very difficult to unpick the really fast oscillations at this point.
So what you can do instead is you can place your experiment in a different location. I go backwards.
If you plan to experiment in a different location and effectively zoom in on this x-axis, you can then pick out the behavior of the faster oscillations, but you then leave sensitivities to the slower oscillations. So in the long baseline accelerator atmospheric region, we have allegories up to sort of a thousand, and you become more sensitive to the delta M squared 31 delta m squared through and if you zoom in even further.
what we're effectively doing is I've shown you the broad scale here for the long baseline observed and just to here, and then for the short baseline, I've zoomed in just to here. And so you can see that at this short baseline where Liver heads up to about 1, um, you should not be sensitive to any of these oscillations whatsoever.
Um, so yeah, that's why these experiments are set up are to be able to measure things that are not necessarily related to these oscillations. Um… That being said, short baseline experiments of gallium reactor and accelerator setups have all, um, many of them have reported anomalous data, so they weren't necessarily looking for oscillations, but they have observed signals which could be construed as an excess or a deficit in particular neutrino flavors.
One example, two examples are LSMD and Minibo, and they observe what we call the low energy access. So you can see the data sort of sitting quite high above the expectation at these low energies. And this is, like I say, called the low energy excess. And then.
From there, many, many, many theories, I believe about 100 theories exist to try and explain this, but the dominant one, which has been constructed to try and explain away this excess is the existence of sterile neutrinos. So the idea would be.
Um, if your active neutrinos oscillate away from the active regime into a sterile and then back into an active flavor, you would see an excess of electron neutrinos that are not accounted for in the standard active oscillation framework.
And so, because Alexand maybe observe this excess, MicroBoom was set up.
Don't worry, I'll be the next question.
Okay, so, uh, Minivory has a baseline of around 500 meters from the source of the neutrinos, and microbium was built in pretty much exactly the same spot at 470 meters, but with a completely different detector technology in order to better characterize this excess and constrain the systematics that Miniboot and Allisonb were unable to.
um, nailed down. Um, and the main feature is that, um, Miniboo and LSND could not differentiate between electromagnetic showers produced by electrons and photons, whereas LARTPC, such as MicroBrooot, can distinguish between them.
And so that was then being systematic and microgrid was set up to try and mitigate that. Microbrew, however, did not see any hint of the low energy excess, and they've since also put out a sensitivity in the 3 plus 1 sterile oscillation hypothesis.
So 3 plus 1 is 3 active plus 1 hypothesized zero. They come in a large portion of the parameter space at 95% confidence level. And so, so far, the conclusion is steriles are not the answer to this problem, but it's not… 100% conclusive, because you can't forget to 100%, but Sb. The short baseline intrusion program at Fermilab will probe all 3 of the possible sterile solution channels we can search, which are newly adherent and new, new, and new disappearance in order to basically push these orange lines.
As far into these corners as you can to cover the majority of the parameter space, and once and for all rule out the existence. Sorry, confirm or rule out the existence. I am the oscillation convener, and I am a skeptic. Um, but yeah.
So that's kind of like the background, uh, that's the motivation for the construction of these experiments. So now I will talk about more of the detectors themselves. So… This is a blown-up cartoon diagram of the short baseline detector. The way that this works, we have two time projection chambers here, separated by a cathode plane with anode plane assemblies on either side, and photon detection systems at the back.
So if a neutrino enters the BMV, sort of in this direction, same as the page.
If it interacts within the detector, it will produce a combination of charged neutral particles, and those charged neutral particles will continue to propagate through the detector.
As the char particles propagate, they ionize the argon, electrons are produced, and they are directed under an electric field towards the anode plane. So the electric field is constructed throughout the… through the cathode anode system.
Um, simultaneously, as soon as those particles, um, deposit anything in the detector, scintillation photons are produced, and they are immediately collected instantaneously by our photon detection system. So that gives you what we call T0, the initial time.
Um, of the, uh, propagation of those, uh, parcels. And so what we can do is we can use a combination of, uh, geometric and kinematic and timing information to fully reconstruct three-dimensional images of the final safe particles produced by three units.
And the reason we have two drift volumes in SDMV is because the electrons can get absorbed and not make it to the anode plane. So you have to have an optimized drift distance for those electrons to travel in order to collect as many of them as possible.
So to maximize the size of the detector, we've split it in half so you have two drip volumes to maximize the electron collection efficiency.
That's D&D, so that sort of… that was LARTPCs in general under a cartoon of SEND. But I'll talk more about sort of SDN and Svend now as well. The short baseline neutrino program is located in the Booster neutrino beam line at Fermilab, so we have the target hole here.
Uh, the beam is fired through SBMD at 110 meters away from the source through microgrid at 470 to the far detection includes Icarus at 600 meters. Um… The SCM program currently consists of the 2, the naval architecture system. So just Sbnd and Icarus, both from the boost neutrino beam, and these have been designed to resolve more broadly the short baseline anomalies that have been observed in the search for active nutrient oscillations and more primarily to actually search for sterile neutrinos as well.
Um, but all three of these detectors have and will continue to make individual physics measurements as well. They've got reasonably large physics programs for sort of small-scale experiments and see what things. Um, and because they're all LARCPCs in effectively different generations, um, they are each testing components for Dune.
Um, and so we'll have some operational construction and expertise experience that will work with you as well. So loads of great reasons to use these detectors. Um, yeah, so a little bit about the beam.
The basic beam is primarily muonutrinos, around 94%, but it does have intrinsic contributions from antimuons, electrons, and anti-electron neutrinos as well. It's a really well understood beam. It was also used by Minibo, the predecessor to Micro Boon. So we've got excellent flux models. We still, of course, have the constraining uncertainties.
Um, the peak energy of the beam is around 0.8 GeV, and Sbnd will hopefully collect around 10E20 P of T of data in its lifetime. Um, and so what this corresponds to in terms of neutrinos.
is around, uh… Just under 3 million neutrinos per year.
And an interesting feature of the composition of our beam or the neutrinos in our beam, is that the muon neutrino and electron neutrino fluxes are primarily produced through 2 and 3 body decays, respectively, and we can use this in a.
particular way we can talk about trophy. Yeah, I'll refer back to this later.
Yeah. Send is a new attacker. I've already mentioned this in the short-based ID program. It has 112 tons of liquid argon in its full active volume, and it's 110 meters from the target. And, as I say, we say it records over 2 million, but I'm pretty sure we got just under 3 million in the first year of running.
Um, which corresponds to the total, it would be 10 to 20 times, or 20 to 30 times more neutrino-organ interaction data than is currently available. And so on the right-hand side here, um, I'm showing a breakdown at the top of muon neutrino.
final seats, and at the bottom, electron neutrino final states, um, all charge current were broken down into types of particles you can expect to see. So the dominant topology in both cases has no charge bounds in the final state, followed by one charge pion.
Followed by one followed by some higher multiplicity of any flavor of pi. And that is true for both muon neutrinos, and this is a really, really powerful fact that we can utilize to do precision physics, um, which I'll talk about later.
Um, the feature I said I come back to is the fact that SBND is positioned ever so slightly off the center of the beam line, and what this means is that, well, in general, what this means is that the neutrinos enter the detector from what we call off-axis angles, so the spread sort of demonstrated here.
Um, and that means we can separate… effectively separate the detector into off-axis angle segments. And it's if you're looking at the front face here, this sort of concentric circular effect is shown. So each of the concentric circles will be one off axis detector. And because of the high rate of neutrinos, we can expect to see at least 10,000 new neutrinos in every segment.
So we're still statistically significant as well. And just to give reference, a one degree of axis angle SBMD just corresponds to two meters at the front face, and it's got a 4 meter front face. Whereas in June, in the June prison setup.
one degree corresponds to 10 meters at the front base. So this means we can utilize the prism.
set up without moving the detector. We still get the impact of the off-axis angular effect, um, which again I'll talk about shortly. Um… without moving the detector, and with a huge abundance of statistics as well, and an initial demonstration here. This is the neutrino energy spectrum. The darkest line is the smallest off-axis angle, and the most yellow line is the largest off axis angle. So you can see that as you move further on back this.
The peak reduces, but it also narrows, so you have a much stronger handle on your flux by moving off-axis, and so you can do combinatorics at the near detector that better mimic your far detector, um, nutrient energy spectrum, just very helpful for hitting, um, an oscillations.
Okay. The TPC in general, we have a pretty normal function detection system. We are testing the XR poopas, which are contained light bars. The dune. This is what one photon detection system module looks like, and they're arranged in this array you can see here as a demonstration.
Like I said before, on the farthest face of the X dimension and the drift dimension. It will also have PMTs, and it's surrounded by a field cage to hold the electric field at 500 volts per centimeter. The electronics are fully submerged in the cold, so that minimizes… well, it optimizes our noise reduction.
Um, and then we'll have, uh, on the planes, so… In front of the PDFs, uh, the proton detection system, all the anode plane assemblies. So this is three wire planes, one after another, each with three millimeter separation on copper beryllium wires, and one playing the wires are at the vertical.
And the other two planes, they are plus and minus 60 degrees from the vertical, and this is what gives us millimeter scale precision on the electrons that we collect to reconstruct the, um, the final state particles. And finally, the cathode plane assembly is the one that splits the detector in two.
And this has TPD-coated reflective foils so that because the scintillating photons are produced isotropically, we can maximize the yield of our photons by allowing them to be reflected at the cathode and then collected again at the photon detection system. And so that.
Uh, the reason that people created is because the PMT.
Sorry, that, um, produce a VUV PMC performance. We also have a cosmic ray typing system. So Sbnd is located on the surface of the earth, and of course that means we have an abundance of cosmic rays, and because our primary signal is muon neutrinos, and therefore muons, cosmic ray muons are a very large background sort of dominant topologies. Um, so we have a really robust cosmic rig typing system.
With full pipe over to the detector, so it sits around all sides.
We have a bonus panel on the top as well, so you can do telescopic tagging, um, because most of our cosmic roads are going. Um, so you can… I think we get something like 99% projection, by my view. It's a very effective cosmic brain injection, um, capability.
And these are just constructive of scintillation strips that you can pinpoint the location of the cosmic brackets in.
So physics. As I mentioned before, Svend will provide the largest data of the largest neutrino log cross-section data set in our energy range. And he… One of the reasons this is super important is because we are dealing with argon. So the neutrino interaction models on sort of individual nuclei are reasonably well understood and well constrained. But as soon as you plot that initial interaction model.
Inside a heavy nucleus-like argon with faulty protons and neutrons, and at hour energy range you are dominated by intranuclear interactions. Anything can happen before those particles leave. So in this example, um, say your, uh, muon neutrino interacts with a proton to produce a neutron in a charged pound. This is very cartoonish, bear with me.
The new front would never escape the nucleus. The pione could do various different things to the point where, rather than seeing just a charged ion in the final state, you end up seeing 2 charged and 2 neutral times. So what this means is that we have to be able to model.
Um, everything, including the nutrient… the initial neutrino interruption with the nucleon, the nucleus itself to predict what could happen, and the final state interactions which could occur before anything leaves the nucleus, because it's the particles that we observe that we have to use to reconstruct exactly what the nutria did in the detector.
Um, so this is a real challenge for Liquid Argon, but it's a very, very interesting one in my opinion. Um… And so this is pretty much covered this. What this is like a cartognised version of what I was saying. So you have this primary interaction with the neutrino convolved with the nuclear model, um, hydron transport or FSI, and if hydronization occurs as well, we've got to model that.
Um, and so, what we're aiming to do is utilize the SBMD data set to constrain each of these components as best as we possibly can to then propagate those into our Monte Carlo models. Um… And the reason we can do this at SBND is that statistical significance not only puts us in a systematically limited program, but it means we can look at really, really neat final states to try and pinpoint correlations between particular final state.
configurations and final state interactions, nuclear modeling and initial interactions which take place. So you can break down, for instance, a topology that has no plans in the final state into really granular numbers of protons.
Um, you can, again, uh, have granularity in your time on final state, but you can also, with some significance, look at more exotic animals, like hayons, lambdas, pyglonds, and we can do that, um.
Yes, it can be reasonably. So this is the this is the breakdown of the muonutrient of charge current event rate. In general, that would be much truth level just looking at a gene interaction simulation, not by any, um, detector effects here.
This is the fundamental what could happen. And then neutral current is listed at the bottom, and the intrinsic component of the electron, um.
neutrinos from the boost neutrino beam are also statistically significant, which is pretty unique. So we can make electron neutron cross-section measurements also broken down into those cyber states just by looking at the backgrounds of the beam, which is very helpful and very cool.
So that is that is the sort of way that we utilize the power of constraining our cross-section models. But we can also utilize the prism feature of Sbnd to better constrain our flux. And this is really important in the solution analysis in particular.
Because the flood type of neutrino is a neovrotector, and the flux of the neutrinos at the far detector, albeit from the same beam, because of dispersion, aren't necessarily a one-to-one mapping. But what you can do, if you separate the detector into the off-axis angles and pull out these different, um, energy.
spectrum distributions. You can almost do a summation of them to model the far detectors energy distribution better to the point where when you're fitting from there to hard detector, you can better constrain both the flux and the cross section and systematics.
Um, and one of the, um, another feature of the prison setup, which is very, very useful, is the fact that electrone is introduced in three-body things, and muon neutrinos are produced in two-body decays, because that quite significantly modifies the kinematics of moving on out of those.
interaction between the better one just understand your prospect differences in general, um, but you can also reduce your dominant backgrounds. So, the dominant backgrounds of an electron neutrino interaction is a muon neutrino, neutral point.
interaction. And so by improving your separation of neurons and electron neutrino, you can significantly reduce your time or induced backgrounds to electrons. And we can again test. We can use these sort of.
And ultimately, the systematics are using. Um, all of this, uh, is of course for its own physics goals, but in an ideal world, we'd also extend this to the next generation, which of course we can't do. And so I've highlighted here, this is again that material energy spectrum. The second furnace maximum.
Um, and the forward of looking up those reasons. This just goes to show that these cross-sectional measurements for me, the constraints that we will place on the daily models that we have will be applicable to students.
Um, yeah, so moving on from, sort of, improving directions into the oscillation routine.
So, um, SVMB is the NID from the short exam nutrition program, and in that role, it will have very, very little sensitivity to any stoke of any very little sensitivity to any sterile signal, which means we can simply use it to constrain those models, which I've talked about already.
Um, and so that's… that's the power of SEO in this SEM program. Um, and in two out of three of these panels, um, SEM is projected to have five Sigma coverage of previously explored phase space in this, um, surrounding trio.
So the orange line is a 5 sigma. Sorry, the solid orange line is 5 sigma in the back orange. And so you can see we're talking back out already from the allowed regions, um.
quite… quite readily. In both of these, uh, new and nutrients, and all that we bring our corn channels, and even in the electron neutrino disappearance channel, which is unique to SVM to some extent, um.
particularly the baseline program. We can even push push out to the allowed regions at the management level as well. And so Sbn is going to directly address the short baseline anomalies, and finally, I'm sure, I hope.
Finally, tell us what we need to know about serology. Of course, microbrewing have made a pretty confident statement. We just need to put a pit in it now, in my opinion.
Okay. On on the sort of nice nice bonus side to SBND. Again, because of the detective technology, the location and the performance of the photon detection system and the timing systems, we can also search for beyond the standard model phenomenon as well.
So just some of the examples of things we could potentially look for signatures of include dark neutrinos, the transition magnetic moment, both of which are alternatives to the mini boom low energy access, alternative theories. But you could also look for axion-like particles.
particles as well. Some of these are ongoing searches. Just before I move on to that, though, because it's kind of what they look like in an SBMB simulation. Um, yeah, just to give you an idea.
Some of these are under investigation already. We have a beyond the standard model sensitivity paper in the works. But these are 3 current sensitivities just using Monte Carlo in the dark photon heavy neutral lepton and axion particle searches. So that's really exciting, and, um.
Um, we're too sure we've got some data analyses, database analyses going on as well as the substance paper at the moment. So.
SBMD started taking data two years ago, yeah, um, but I was quite heavily involved in the construction of SBMD. I spent my LTA out there in 2018, um, so I was mostly involved in the anode assembly construction, but this is the same photo image, so it gives you the idea, and you can imagine the cathode sort of slicing in the middle of the slide there.
Um, but you can see the effect of the anode planes, the sort of shear lines, and the photon detection system. So this, um, this was completed in 2022, um, and I… that was in 2017. So that's the hit in 2017.
And then in November 2022, the cryostat was completed in the near the sector hall, which was nicely timed, of course.
Then, we have to transport the detector. So the internal detector I showed you on the first slide was constructed at the D 0 assembly building. It then had to be transported around the territory to the near detector hall, which they did very successfully in December of 2022.
So September through December 2022 is a great time, especially given the COVID situation at that point, it was all right but not great.
You then have to install the top half of the cryostat onto the assembly transport fixture. I always want to write that down because I can never remember that. But yeah, so the top cap was. So we've got the cryo stack. We've got the top cap ready, and the detector's on its way, and so effectively, you attach the detector to the base of the top cap and lower it into the the prime stuff.
So that was completed in March of 2023, and in April that indeed was done. So this is a photo of it being loaded in, which is really cool. The resolution on here is not not perfect. But yeah, um… Yeah, so that was April 23, the detector was placed inside the cryostat. It was then these aren't videos.
It's not upside down for sure. I never assume I can show anything but a PDF, so I don't bother with videos. But in theory there is a video, um, and you can see this as empty, and then this is the films that are online. Um, so this is March 2024, so we've actually jumped.
A good year, though. Um… Don't ask me why I can't quite remember. There'll be summaries, I think.
But those again, and we build a detector in 1944. And then after a bit of a rocky start, we've successfully ramped up to, uh, high voltage in July of 2024, um, and you can see on our.
But that was that was an interesting couple of months. So yeah, we finally got our neutrinos in July, so these are our very first recorded neutrinos. So on the left, we've got an UBCC candidate, so you can see.
This is the long muon track. This is a little proton track. It's a lovely example of a quasi-elastic interaction because they're almost at 90 degrees from one another. So in an ideal world, they'd all look like this. We could just say, yeah, that's a quasielastic interaction. No FSI happened. Here's some physics, but it doesn't work like that. Most of the time they look like this.
So this is again the muon. And then you've got some combination of probably possibly a proton.
Possibly charge parents got a bit of cake, so maybe that could indicate to a muon. Um, and then because you have a distance from the neutrino interruption vertex to these electromagnetic showers, we know that this was very likely to be one, if not two, at neutral times that decayed two photons.
Um, but that's the kind of thing we're now trying to, like, you know, piece together, um, computationally. Um, and I've just said all different words. But yeah.
Um, what did I hypothesize? I wrote this slide a while ago. So I reckoned it was pretty much what I said. Most likely charge charge for residence interaction with some combinations of protons and charge times as visual contracts.
So yeah, in short, the neutrino, as I've mentioned already, neutrino interaction with argon look really nice in our detector, but they're very, very tricky to interpret, particularly at the point that the physics of the neutrino. Of course, that's why it's.
So now, I've whizzed through this. This is kind of where we're at. I've managed to sort of corral all the latest talks I can find with all the public information. This is what we're up to. So this is how the detector is forming on the right-hand side. So the plot at the top is the electron lifetime as a function of, sort of, little time.
Um, the nominal is around 3 milliseconds. So not just this dotted line here. This is what we've always quoted as nominal, but it's very much an electron lifetime. Right. So, you know how I said the electrons, um, drift towards the anode plane?
the charge ions ionize, the electrons drift. The lifetime governs how many of them will be absorbed before they reach the outer plane. So you want to maximize that line time to maximize your acceptance of the electrons.
So yeah, nominal has always been 3 milliseconds, and that's kind of what governs the 2 meter drift distance.
decision. Um, but we are consistently exceeding 30 milliseconds, apart from the pumping, so ignore it. Um, but yeah, we're consistently exceeding 30 milliseconds, um, and at one point, we thought it was close to infinite, which was really exciting, but not very realistic, but still.
This will do. We are very happy with this performance. Um, we've also recorded, so Protons on Target is the way we measure, um, exactly how much beam has been delivered to the detector. Um, so this is a recording of how much, um, how many protons on target we have had the opportunity to record.
And how many have reported, and because the lines largely overlap, um, the collection efficiency is 98.6%, which is exceptional, and that basically means that when our shifters are on shift, if the DAP goes down, they restart it very, very fast. So kudos to our shifters.
And then the photon detection system and the cosmic ray tagging system are both heavily involved in our timing reconstruction. And so, because you can see really clear peaks in these 2 plots, what that means is we have really fine granularity at the nanosecond level, which means we can basically look.
Every… every pulse of protons that enters, uh, that produces neutrinos, we can look between those pulses for potential beyond the sun model phenomena. So you can look, um, even at beam time for non-beam activity between the timing buckets, which is really cool.
Uh, but it also means that general when we're reconstructing our neutrinos, our T0 is really, really precise, which is ideal, um, and it's very, very good at tagging, um, scenario for removing our boundary background.
We also recently demonstrated our sensitivity to low energy activity. So this is the distribution. Well, this is just with.
This will just be our, sort of, open data sample, which is really small, but this is demonstrating the reconstructed energy of Michelle electrons, which are produced at the end of stopping neon tracks sometimes.
Um, and so they are very, very low energy. You can see around the tens of Meb range, which is very, very good that we can do for our electron searches. And you can also see really clear separation between muons and our protons. So this is the energy that monitored per unit length.
Versus the residual rate of the truck. So every hit on the anode that we record on the anode plane is some distance from the stopping point of the track, and that's known as the residual range. And so the smaller residual range, the closer you are to the stopping point.
Um, and stopping tracks characteristics, which is a high, um, increase in the, um, energy depositions. Um, for each particle, because of the mass differences, has characteristic stopping power, this distribution. And if you can separate those, you can separate the particles, you can form.
PRED knows and computational physics. So this is an example of a separation between the renal track numbers.
Um, so that's really good. Um, and what that means is that we can record all the images, and we can also use them very well for being able to analyze these by 3 million of them per year, we really have to be able to understand communication.
Um, okay, yeah, so this is… this is my final slide. This is the list of, sort of, ongoing and future measurements that are underway right now. Our primary programme is the cross-section program, as you can see. Um, we have a bunch of these exclusive topological channels under investigation, um, CC Inclusive always comes first.
generally, what is constructed that everybody else, uh, carries on from. Uh, but we're looking at 05 with one and two protons. These are characteristic of the initial state quasi-elastic interaction, and also short-range correlations within the nuclear whole thing.
one carbon, one neutral pion, one ether which decays to 2 photons in the same way as a neutral pile, but with a different invariant mass peak will be more sensitive to eaters. And so again, this could be good background rejection for our shower searches, and even coherent scattering.
Scaptory? Scaptory. Um, we're also looking at some neutral current measurements, which are often characteristically harder, because if you don't have your lepton to pinpoint the vertex in the busyness of these event displays, it's quite difficult to, um.
determine what's actually from the neutrino interaction and what's just general noise or background. So neutral current interactions are very, very useful to, um, to get good at. Um, and we're also looking into electron neutrino inclusive, charge point inclusive, and one charge plan as well.
In the obsolation program, we have quite a few different measurements going on at the moment. Um… Because of all the characteristics of the detector I've discussed already, we've got a number of a number of analyses ongoing that are performing the oscillation search with different channels, and again, because of the increased ability to constrain the systematics with the near detector.
So we have a standard knee disappearance search with an inclusive sample. So all the muon neutrinos that interact via the charge current, which is the standard way of measuring these. But we also have a variety of measurements ongoing, which either look at just 0 pi1 protons. So you're looking for that.
really clean, muon proton, because again, it's often very characteristic of a very simple topology, so it means you have, um.
It means you can reconstruct your neutrino energy with sort of higher confidence level. But you can also separate into many of these different channels and fit them together to constrain multiple of the initial interaction possibilities at the name detector to then, again, um.
uh, send off those systematic constraints to the file detector.
Um, we're also looking at new ear pairings, which are inclusive, so that largely involves the bar detector. But again, at this point in time, we're focusing on CC Inclusive, the new E, but in theory, again, if we look at those exclusive channels.
And in the not-too-distant future, it has been dabbled with at the sensitivity level in the simulation. We're also looking to put out a joint fit of union disappearance and a new appearance search at the same time. Um… Yeah. And it's entitled sterile solution parameter spaces at times. And we're also looking into neutral current oscillation searches, which is a whole other cut of fish. We have one PhD student looking into this, um.
And it's reasonably early stages, but it should be quite amazing study. Um, and yeah, we have a whole BSM program, so I've already showed you the sensitivities of a few of these. Um, the sensitive paper is on its way out, um, and in parallel, they are also propagating through the unblinding process in order to actually search for these things.
So we have a lot of stuff going on. I can't show you an actual report right now, but we are into it. So yeah.
That's pretty much everything for me. Um, this is a really nice time to be on SBND. But the we have such a variety of physics programs that students and myself can get involved in, that includes.
So, it's like the youngest sibling in the micro family, um, but it's a really nice… it's a really nice collaboration. We took our first aid in 2024, and it's looking really good.
Um, so everybody's already happy. It's a testament to a huge amount of work over the last 10 years, um, and of course, we're hoping that this will pave the way nicely for June. Um, and I've listed all the measurements that are ongoing, and last year, Sheffield hosted the Cloud Overview meeting, which was, um.
Absolutely. Any questions or clarifications for Jarvon that's happening?
Yes. Any questions?
I probably explained it, but I didn't take any. What are you doing?
No, wait, so we… We're not doing the microbranded personnel, we're working with it first. I know, but I mean, why do you need to develop a new detector? Ah, what's the role of the new detector? Okay, so the role of the near detector is pretty much a constraint in systematics. So if I go right back to here.
If we did not have a near detector in oscillation search, you are fully relying on the model of your beam to tell you exactly how many muon neutrinos, electron neutrinos are to expect. Um, simultaneously, you're also relying on that to constrain this elective model as well, but.
With the near detector, particularly a near detector with the same technology, you can use it to constrain. Yeah, it's not… you were emphasizing the more modern sibling, and I wasn't sure… It's the more modern sibling came online last.
Yeah, so Icarus is all… Icarus also has a cross-section program. Um, Icarus and Microbone are also sensitive to the munib, which is the neutrino. I can't remember what it stands for. So they, um.
They can do a whole physics program with a different theme. Uh, microgrid has its cross-section program. Microgreen's sterile Neutrino Search was a joint fit between Booster Neutrino Beam and Newbie Beam data, which was really interesting and unique. But SDMD, yes, is the no detector.
Um, in the PMB zone.
Yes, go on. I mean, you're emphasizing the lifetime of electrons inside the sector. You didn't talk about diffusion. I vaguely understood from Gase that without a magnetic field that diffusion. Yeah, that's another reason for so I… Yeah. I like a lifetime of diffusion are both critical parameters we have to constrain for sure. Um, again, because of the size of the detector, diffusion is effect… it's not zero by extract, but it's minimized because of that, uh, that.
scale of choice. Um, so because they are only ever traveling a maximum of 2 meters, the fusion isn't, um, huge, and you can, um, and the diffusion constants are controlling the part of the calibration program. Um, so it's there. One of the things that, um, the calibration group are doing is.
you can group some of them, because they're 3mm separated. You can group some of the wires together to do, um, like, a lifetime measurements and see how many wires you have to group before things start.
A few ways you have to drink the book and start changing. So you can do quite a lot, um… to model the diffusion, and that's effectively what we do. We model it and constraints, but it does that.
So, actually, I had a similar question, but maybe just on that a little bit more. You quoted some numbers, and I could not quite remember what you… you said. I think you said you see a live time 30 microseconds.
Yeah. What was your predicted one? No, no, no, sorry. We see above 30, the, uh… I've seen the predicted, it's a bit of a legacy value, actually, and I suppose it was designed by 3 milliseconds is the min… is the… The minimum have to be above 3 milliseconds in order to record enough electrons to do with physics. And so anything above 3, preferably towards infinity, is ideal to the fact that we're 10 times more than that consistently, it's it's great. It means we kind of.
We still haven't completed a plot. It was a very nice plot, but we still measured the electron lifetime, um, routinely.
What? So imagine that the electronic prime because it's a it's a measure of the utility from the detector. So the more impurities you have, the more electrical puzzle for within the.
I'm a plane, and that manifests as a reduction in the form of that border reduced Wi-Fi. And what it means is on the slides.
it kind of means that the charge depositions you record at the animal end up being higher position before the cathode, because the ones that initiate the start of the catheter capture the hallway detector, and so you effectively have a reduction in how much charging.
So, ideally, that would be a difference, and so the electron lifetime sequence of the cathode, this is your anode.
This is John, the YX is mostly John's deposition. In an ideal world, you would have the same charge deposition if I'm unaware function from the detector. As for lifetime goes down, it goes like this, and so you have to recover.
artificially, we have somebody who wants to necessarily, and so we're sort of seeing a live value looks a bit like that. I'm not always that, but minimal as that, we're seeing that input is that.
So you were aiming at a minimum number, and what was your expected number?
Uh… We have pretty given expectations. The minimum is set based on systematic.
scale that that imposes. The reason I'm asking is because it imbued up being a lot longer than was originally anticipated. Yeah. So I'm just wondering how that matches with.
your original expectations… Yeah. This is kind of what I meant, so yeah, because of Protege, I think Proteogee gets around, like, 35?
And as you say, it's a critical design parameter. So for the model wave with much bigger spaces. The nominal comes for the same era of the June nominal at 3 milliseconds, because again, it's in design phase. Um, so our expectation, because of the performance of Protogue.
was that we can do better. Okay, so it's like you were using that for your… okay. Yeah, so the baseline is set based on the systematics we can allow, um, in the design phase, um, and… Yeah, so that just dictated the sort of size build. So one of the models we're going to be wider. Okay, so your expectation wasn't before. That's where it's coming from. Okay, yes. Even though the original.
uh, timeline. Sbnd encryptoGSB, but it's done all at the same time. I had a choice when I started my PhD. Okay. Made the right one. Sorry, that was a very long getting to this one. Thank you.
One of the other ones. I have another question.
I was just wondering what was the… Oh, it's gonna say the pump and then we covered it. So… the purification system tricks. So lots of impurities came in, and then I mean, that's a nice service. I don't actually know it just to test it. Is it really explored, or should we just try and doing it now?
I don't know if you can actually see that, but there is a band that gives the time of the song that trip and the end of that trip. And so you get something… And I fit the blue and the orange are the victims of the one. Sorry.
I just think your protectorism. broadest size, I mean, you won't be tempted to put a magnetic field.
I hope we have to cut costs, and so I mean, we were supposed to have an overburd. That didn't happen. Um, no, I don't… I don't think we necessarily need the magnetic field.
put the physics we want to do. I mean, yes, you could sort of separate your intrinsic anti-neutrinos, I suppose, by popping the electric field.
Yeah, I don't think… I don't think it was ever in the design. I know the overburden was, and then had to be cut for reasons. But yeah, I don't believe a bank was ever in there.
Building was constructed for the detector as well, so in theory they could have popped it in, but it was never never a choice that they made.
Yes, of course. Okay, thank you for the nice talk. Is it okay if I ask 2 questions?
So the first one is related to the prism. Yeah. Yeah.
Yeah. I should know more about this one. Uh, it's rather simple. So I was just curious if, uh, if SBND uses, uh, the same fitting method as numeracy.
Uh, so… I actually don't know. So the fitting groups we use.
I don't know, to be honest with you. Um, we've not really collaborated.
It's kind of on my to-do list, to be honest with you. Um, but… But for the junior, please.
That's your next question. Okay. Then I'll just ask my next question. The next question was, I was also curious, like, how do you reconstruct neutrino energy for a neutral current event?
The neutrino energy is largely reconstructed if it's not a nice simple quad elastic-like interaction, it's done with calorimetry.
Um, and then… for the neutrino. So what… What we probably wouldn't do for neutral current is use nature as a private event. We would use harmonica. That would be my… choice. In terms of how we're reconstructing neutrino energy.
Yeah, we would use hydraulic kinematics, and then some… I don't even think he could propose domestic energy. So I think you would just have to use a parameter that doesn't rely on it.
Also, some of the things that the Osolution Group is working on is looking at.
observable method rather than nuclear kinematics to better constrain things.
I don't know if that means also in my way.
Thank you. That makes sense. Um, yeah, I have another question about the prism bit of it. So, you know, you have your bins in these sort of, like, circular sections.
It's very vague question, but you know, I was interested in like how that circle bidding is chosen. Ah, it's very, it varies, actually. So this is one example. Yeah. One of my PhD students. One of my PhD students looked into this as part of her oscillation search.
So you can choose the first of winning in two ways. One of them is constant statistics, one of them is constant angle. And so she's looked at how that choice impacts the sensitivity. And in general, because the statistics are so high, I can work.
Um, another consideration is the 8 bins is a lot computationally. And so she's looked at only 3 bins and 5 bins and 8 bins, and compared the sensitivity impact on that as well. So this was the… this was the sort of poster child for the prism regime of Sbnd, which is the concentric circles with constant angle. But of course, these have very, very different areas, so you have very, very different statistics.
So it depends. It depends on the search of doing with it, in my opinion. I would always say run a quick sensitivity check to see which which choice will suit you best, but I'm not sure why the 8th bin was chosen in the first place.
We'll probably jump back into that. Maybe it was some statistical, uh… Remember that they sat as a minimum. But yeah, we… you can generally take that however it suits best. So just to follow up Amy, I was sort of thinking about it from the dean perspective, right? The difference here, right? If you don't move it, then I guess relying on your vertex reconstruction to make sure that. Oh yeah.
I was wondering, like, what that resolution looks like, and maybe what systematic uncertainty is thinking about, because I can imagine that events might have to move between bins if it's sort of like on those borders and whatnot. Yeah, so I've only looked at, I'd say, like, we… we have only looked at this at the Monte Carlo.
level at this point, and Doug. Well, um… The virtual… I think she ended up putting, like, an assumed vertex resolution. It wasn't actually qualified. So I can't really find a number. One other thing we have considered, sorry, just to your first point, um.
Like I've mentioned a few times, you can you can define these segments in such a way that you actually isolate the Icarus workplace effectively. And so we you can define an angular distribution or an angular component that effectively reconstructs the Icarus energy spectrum, which is super useful.
Because then you can sort of like use the rest of the SBMD detector as another sort of almost another detector that you know you have almost one-to-one mapping between your energy distribution in both cases. You can play around with it, um… Statistically at least.
What happened with the ramp up? You had a bit of history, and you sort of alluded to it.
Uh… what do you call it? Sunset. There was just… There was a moment, they got partly up the run for saying that. We got partway up the ramp up, and everything.
The… the… Um… The protector literally looked like a sunset, and it was… just terrifying, so we stopped it for a while. Um, and this was just upon neutrino 2024 as well. Um, and what they ended up doing was just going through carried on, and it all played out.
I don't know what the cause was, I don't know if they've sussed it out, um, I'm sure they must have done well, but two years down the line it's been fine. So yeah, it was they call it Sunset. I can't remember.
It was like, you can imagine the two youth.
I have some massive amount of electronic noise going on with distribution.
Yeah. So you referred to your overburden earlier in the absence of it. Yes. And you've got a cosmic veto. So I was wondering how… much of an impact cosmics have. So you're able to identify them and remove them. But does it lead to any amounts of…
It's pretty much face charge. Um, thankfully, because microbi and imperson both sort of before us, we've got, um, the methods of, sort of, prioritizing space charge down pretty well. We can kind of got the.
That happens, obviously, you have to prototype itself in the texture of interest. But yeah, what it effectively means is, um… Because you have so many cosmics traveling through the detector in one go, ionizing the argon, you can end up with an excess of ions that drift towards the cathode, which fires your electric field and end up shifting the charge deposition distributions as well. And so that is the model's a matter.
And, uh, back to the matrix that you can calibrate it out effectively. But that is the impact. It's… So you're not… you don't have any dead regions or anything, or dead time, you've just got to calibrate for it. Okay.
Another reason why the CRT is super helpful. And even… Where the actual… I don't know what the density ends up being. You don't have to declare any dead region around a particular track. No, we don't.
No, we just slice up the reconstruction to regions of interest to try and remove them, but you don't have to, uh… You don't have to declare anything like that. I mean, it's it's, of course, going to be harder to reconstruct a something that's very, very simultaneous or overlapping. But the text is generally large enough, and the neutrino, of course, neutrinos coming in along with that direction.
break down because of anything to not many of the meals are upwards. So there's a reasonable ability to separate the region from cosmic regions.
So on your BSM page, which was… So you whiz past it at high speed. Yeah, I couldn't tell, yeah.
Yeah, okay, so maybe start on Bill's one. So this was really nice. But I I just wondered maybe you've got.
Some, uh, examples of how you differentiate such signals. Oh, yeah, it's partly why I included the event displays. Um, so you can kind of see that largely most of them result in some configuration of an electromagnetic shower, and I think.
What you will end up doing… this is me fully hypothesizing I've never attended the Amazon call. Um, my hypothesis would be that these would have characteristic energy invariant masses, or, um… Something like that that you could then characterize as each one of these scenarios, um, based on the topological appearance in the detector and the hypothesized.
So your your dark neutrinos and your axion-like particles, you're you're using an invariant mass separation. Yes. To me it's two photons reconstruct two electrons. Yeah. And especially because they've.
Like, you look… you've got a vertex, you've got two showers, um, and again, you'll have, you know, depending on the energy, you'll have some expectation of the angular separation to do.
And is the group that's working on this BSM stuff?
Also working with the prism guys for BSN potential? I don't know, actually. The main… People like so the main groups, I think, are UCS Bailey.
And… remember that? I don't know if it's involved in… Did you go to the other slide? Pedro Machado definitely has done work… sorry, this one. Yes. Yeah.
Um, so that he's trying to answer still? I believe. And there is a generative.
Oh, really? Minnesota. Oh, okay.
I actually haven't updated these links in a little while, so the biggest ones. But yeah, there are some some slides.
Excellent. Yes, that was a very nice talk. I don't see questions.
But we will have to lunch, so if you would like to speak Julian, please join us.
Okay. And let's thank her again.
Okay.
Go ahead.
I want to