James Smallcombe: Okay, and then I will hand over and say, Dave, please take it away.
David O'Donnell: Thank you very much, James. Good afternoon, everyone. I'm speaking to you from not so sunny Glasgow.
David O'Donnell: Socially distancing and my house, which I've been doing four months now, it seems like probably March. I think I hope everyone out there is
David O'Donnell: Is is doing well. Staying staying safe and and well so on. But I really wanted to thank James and also also David Sharpe for organizing these seminars, because they have really been
David O'Donnell: Very, very helpful. I think in in this thing, not only just keeping us educated and up to date, but also some sort of
David O'Donnell: Some sort of links, even if it is electronically with with our community. So thank you very much. Those guys and long may it continue
David O'Donnell: So yes, I'm going to talk about some recent what we've been doing it, University of west of Scotland.
David O'Donnell: Where will be measuring Iwan transitions in accolade nuclei in particular I'm going to focus on 30 222 to eight. Sorry.
David O'Donnell: And some very preliminary work we've been doing on uranium 234 I'll explain why shortly. So it'd be good talk needs a motivational slave or a series of slides and
David O'Donnell: Some of you may have seen me give a similar talk last year at optimal workshop organized by my by my friend and office mid market share, which was fantastic.
David O'Donnell: And I told you, probably, then that essentially the real motivation for this work is that my when I joined UWS University west of Scotland.
David O'Donnell: My group leader told me we have a we have excess money and our budget needs to be spent. What can we buy in a the say that device on one from Broadway detectors, because we would get most bang for our buck and
David O'Donnell: As a result, I sort of looked around for things to do. So just forget I told you all of that and the real motivation here is we had this all planned all along. Right. But then know it. I thought about doing some experiments, for example, using
David O'Donnell: Using natural radioactive targets like 30 am to three to uranium two three yet and seeing what we could do with those
David O'Donnell: As you will know, and we'll go into in a bit more detail here, the story and 32 towers.
David O'Donnell: Starting to see through nuclei or the unanimity nuclei, they decay via long chains of either alpha decay is or Peter the case, and as a result you populate accepted status or some nuclei.
David O'Donnell: And some of these nuclei. And some of these excited states are really interesting from a perspective of optical correlations
David O'Donnell: Because many of the nuclear that are produced in these long chains are where are situated rate in the same through area of where we expect to find the largest octopus correlations
David O'Donnell: So on the on the top left hand side of this slide I'm showing a picture that I've, I've next from from Peter bottles review article from 2016
David O'Donnell: You're going to see Peters name a lot on the seeds. It's just a threat and so much and so much useful stuff that
David O'Donnell: Is going to crop up now and again, so please don't get bored of that. But this slide here shows basically what's happening in terms of
David O'Donnell: In terms of octopus correlations. These optimal correlations. The, the data associated with long range octopus octopus residual interactions.
David O'Donnell: And you typically get larger multiple correlations manifesting when you have single particle orbitals.
David O'Donnell: And you have nuclear arms and single particle orbitals near the feminist office which are separated in terms of their orbital angry momentum and the total angular momentum by value of the
David O'Donnell: And and when this happens, this is when you get a particular enhancement of these of these Dr. Paul correlations
David O'Donnell: And this happens at a number of places around the nucleus chart in the sacred chart.
David O'Donnell: Peter has highlighted the different places that he who study for n equals 34 then you have n equals 50 sex N equals it yet where
David O'Donnell: A lot of work, a lot of work, especially recent work has been going on in terms of bedrooms and that's just above, for example, 10 one feature where you see a really
David O'Donnell: Strong enhancement of optimal correlations and those nuclei. But I think that the classical place. So from observing multiple correlations is definitely above
David O'Donnell: lead to weight. So what we're talking about here are radium nuclei 30 am nuclear uranium nuclei. So these are the act in a classic activities and
David O'Donnell: These were foster scarf on this idea of optical correlations was first discovered as a result of alpha decay studies by ASARCO Stevens and Barrowman way back in the 50s.
David O'Donnell: And the observed the alpha decay of 13 to to be shown on the right hand side of the CTO and what the himself was the not only populated.
David O'Donnell: Positive states as even imagine. But the positive to the also populated lying negative policy states, for example, the one Magnus state in radium two to four I shown here at 217 ke VI.
David O'Donnell: Now that was a puzzle to them. I guess it may be a nationally but
David O'Donnell: Already I think in that paper, they had already stated that, well, this the fact that we have low lying low energy, negative, positive states may be indicative of some sort of shape the nucleus adopting a reflection asymmetric ship.
David O'Donnell: A ship which resembles a pair. I'm paraphrasing, but I'm pretty sure that it was not people that they had already put this idea forward and that was where it all started back in the 50s.
David O'Donnell: And I guess it took quite a long time to obtain concrete evidence that this was indeed result of reflection asymmetric shifts and that came in the form of performing
David O'Donnell: Cool meditation measurements. The first word was done in the 90s. It was done by Vol. Same with that all and they performed cool meditation measurement of radium to to sex and then medium two to 60 phone very, very high.
David O'Donnell: Up to Paul correlations I shown on this plot on the left hand side you can see radium two to six. Wait, the top of that plot.
David O'Donnell: And that was, that was the first evidence. And then there was some there was some PD of
David O'Donnell: Like say I don't know maybe 20 years I guess that between that measurement and then subsequent measurements which I've been performed in recent years, starting with
David O'Donnell: Liam golf on a Peter Butler market share lead experiment in which they studied read him to do for vehicle will make citation and they observed again a very high up to Paul correlations and not nucleus.
David O'Donnell: And and then in very recently, in the last few years. Additional radium intensity has been available at the ISO facilities like it I sold them.
David O'Donnell: And that has no opened up the possibility to manage that opened up the possibility to measure radium to to to on radium to to a vehicle on expectation and Peter a towel publish them the paper LL THIS YEAR AND PRL hopefully you can see the reference so
David O'Donnell: Now, the thing that really interests me though is that all of this work in the radium has been very, very successful and unambiguously
David O'Donnell: Shows that these nuclei have pear shaped stub stable pear shapes and their growth state. So that's great. But most of the theoretical work. I can see the term for example Luis's on the audience, but most of the theoretical work that's been done.
David O'Donnell: Suggests that radium is not necessarily the most optimal
David O'Donnell: radium is not the most octopus deformed or has the highest adoptable correlations in this region. In fact, it looks like from almost every calculation that's done.
David O'Donnell: That the authority of nuclei and the uranium nuclear tend to be slightly more octopus deformed not shown here in the top part. This is a paper from 2016 by Ivan Martha and the group at Mississippi, where they performed multiple different
David O'Donnell: Energy density functional calculations and they were able to basically
David O'Donnell: They were able to predict what the beater to defamation B2C defamation and also this idea of the minimization that comes from triple A sort of stability that comes from the octopus their formation.
David O'Donnell: So when they, for example, in the bottom pain of these three plots, you see that the Delta he octopus reaches a minimum at some nuclear number. And that's where the octopus correlations are
David O'Donnell: Thought to be strongest but you will see that actually it's it's it's not a huge amount, but it is probably about 50% more Peter three defamation in, for example,
David O'Donnell: Some of authority of my talks and the uranium isotopes. When you compare them with radium. And so this is where I started to become interested in this work. And one of the problems with this is that thorium and uranium are particularly difficult to extract from an eyesore facility.
David O'Donnell: Mainly because of that, for example, the, the temperatures are involved in getting that getting thorium ions out, and to begin with, makes them very, very difficult to extract
David O'Donnell: So we need to find another way of extract of extracting this information we need another way of perhaps measuring this octopus correlations
David O'Donnell: In the story and uranium nuclei. And one way we can do that. It's not a. It's not a fantastic. It's not an unambiguous signature I'll speak to that in a second. But one way to do it is to look at the dipole moment that that cause due to this optimal
David O'Donnell: Shape. So on the left hand side there as bastardized the, the, the beautiful picture that
David O'Donnell: Gaffney a cow prepared for the for the Nature paper, the one that shows up everywhere. And what I've shown you is basically that when you get this octopus ship this pale ship.
David O'Donnell: You can have a separation, you would expect a separation of the center of mass in the center of Charles. Now why is that
David O'Donnell: Well, there's some people who would say that, for example, that that has a lightning rod effect that the protons are
David O'Donnell: Tend to be grouped together towards the narrow end of the payer IF YOU CAN SEE ME POINTING narrow into the fair because the surface coverage on his height is highest. At that point, and then I also
David O'Donnell: Also, I was in it was in the audience when
David O'Donnell: When a check Gorbachev ski was asked a question about, well, why would you expect that to be an asymmetric distribution of protons and neutrons. And he said, Well, if the sheep is the symmetric. Why would you expect it to be.
David O'Donnell: Anything other than asymmetric. And I thought that was a that was a pretty good answer to that.
David O'Donnell: But so what can happen is, essentially, is that you get a separation of the center of charge which moves in this case I'm, I'm assuming that
David O'Donnell: Excuse me, I'm assuming that the protons move towards this are there's a higher density of protons at this narrow end of the bear, and you, what you see is the center of charge moves towards that the center of mass is
David O'Donnell: Remains mostly the same and this gives rise to a dipole moment.
David O'Donnell: And so that you can end up with a non zero electric dipole moment. And what happens as a result is you get an enhancement of electric dipole transitions in this nucleus typically electric dipole transitions are very handled compared with
David O'Donnell: Other types of transitions to for example and but this can give you an enhancement of some two, sometimes three orders of magnitude compared with what one would expect for
David O'Donnell: Reflection symmetric nucleus.
David O'Donnell: Now they fall rates can be measured in a couple of different ways. One of the ways which has been very, very successful in the past is to measure.
David O'Donnell: You measure the Dickey have some high spin bonds and you observe both the eater transition. The between the states in the band. And you also observe
David O'Donnell: Dipole transition to electric right but they pulled transitions which connect an octopus band, for example, with
David O'Donnell: For example, a reflection symmetric band and let's see a green state buying something like this and you can observe that, and you can you can then measure what's known as a b one b two ratio.
David O'Donnell: And if you know some information about the quadruple moment or of that bond and you assume
David O'Donnell: That the nucleus is rotational which is often the case in these nuclei in these very heavy ones, then you can use a traditional model and you can determine it be one that way.
David O'Donnell: But often, you must, it must be treated with the electoral electoral bit of skepticism, simply because you don't always know the quadruple moment, but you may be using a quadruple moment from a lower energy state and you're extrapolating and assuming that it's the remaining the same.
David O'Donnell: Another way is to measure the lifting and if you measure the lace team and you know the branching ratios, then you can you can measure the be one, you can extract the transition rate that way.
David O'Donnell: And as you can see from from from this plot which comes from another work for the steam it was involving Luis Robledo and Peter together and
David O'Donnell: You can see we are, they're showing. For example, a number of different quantities, one would be the expectation energy of the one main estate to stay is typically found at low energy, as I said, as a sign or Stevens found
David O'Donnell: Back in the 50s, so you you can you can think of the one main estate. The expectation energy as being one measure of the octopus call activity.
David O'Donnell: Then another one would be this be one which I was talking about. But then on the top panel, you will see that they're plotting the D3, though. That's the unambiguous signature have multiple
David O'Donnell: Call activity or multiple correlation. Should I say, but the one can give you a good measure of this. But the problem with it is is that it can be, as I said earlier, it can be an ambiguous signature.
David O'Donnell: One of the reasons for that is that if we extract what's known as the intrinsic electric dipole moment this is this d zero quantity
David O'Donnell: Then what what what what the work of Butler and as a rubbish really pioneered in the main piece was basically that the d zero which you would measured in the lab.
David O'Donnell: Is a combination of the intrinsic electric dipole moment which is coming from the macroscopic shape of the nucleus itself.
David O'Donnell: But then also you have a single particle effect, which is what they call the shell. So you have an effect of electric that intrinsic electric De Palma when you have a contribution from the single particle
David O'Donnell: Nature of the nucleus as well. And both of those combined to give you the intrinsic dipole moment that you made in the lab. And as you can see, in certain cases, for example, radium two to four back in the 90s, and it was predicted that you would essentially have a large negative
David O'Donnell: Shell contribution and almost identical positive macroscopic contribution, therefore, giving rise to an effectively zero and DE DE not are intrinsic Archie dipole moment. And that was indeed confirmed in the study. The climax. Climax a decent study
David O'Donnell: Of Gaffney at the nature study where by the phone that for example in radium to to for the transition matrix element is extremely small.
David O'Donnell: And in fact, the, the, the one transition rate is less than five times 10 to the minus five. So it's very, very small. So this is where you can basically just look at the zero and say, okay, large the zero or small. The zero means something you can't necessarily just see
David O'Donnell: Just look at the dipole moment and say unambiguously are you as evidence of optical correlations. However, in some circumstances, right now it is the only tool that we have really available.
David O'Donnell: So what we can do is we can then measure this intrinsic dipole moment or the be one strength, for example, and then compare it with a theoretical calculations from our colleagues and then we might be able to understand a bit better. What's going on in this octopus call activity.
David O'Donnell: So one thing I wanted to move on now. It was basically just to highlight and another driver for this is that basically in so far, what we've looked at. There's all even even nuclei. But when you have an odd mass nucleus.
David O'Donnell: Like for example radium two to five.
David O'Donnell: Then what can happen is is that, well, if you have an octopus correlated. If you have strong multiple correlations, then the nucleus. If you think about it like
David O'Donnell: If you think about the pear shape. You can have the the narrow end of the pear shape. It can be pointing in one way
David O'Donnell: Or a component in the other way. Okay. And then when it basically those two states.
David O'Donnell: Will be mixed in somewhere so they will give your eyes to this tape of them. There's that it will give rise to this sort of potential energy.
David O'Donnell: Diagram, that is shown here. So as a function of beta three going from one of the states, but it's it's pointing. One way of pointing. Another way you can get to minima.
David O'Donnell: So you can have two states and there'll be mixing between them and you can tunnel in between these two states, but if you have an odd mass nucleus with an odd neutron, for example, or a neutron hole.
David O'Donnell: And then you can actually couple that neutron or indeed that proton to one of these and
David O'Donnell: Possibly both of these intrinsic states one where the the the octopus nucleus is pointing one way in its intrinsic frame and then other where it's pointing any other way. And that's in transit friends so you end up with two states and you end up with
David O'Donnell: Too low lying polity doublets. Okay, now in a in a in a perfect up to Paul deformed nucleus, one would have these, these two these two levels.
David O'Donnell: Which would observe in the expectation spectra would have the same energy.
David O'Donnell: In reality there are shifted a certain amount, but they tend to be shifted by a very small amount. When you consider typically what energies we would associate with with nuclear expectations so
David O'Donnell: You can't really see it too. Well, the way I have it on the side there. So I'm just highlighting here, the case of radium two to five.
David O'Donnell: Which is trying to attract a lot of attention for searching for atomic electric dipole moments.
David O'Donnell: But here the states of interest are, for example, the one half plus would be the neutron coupled to one of these
David O'Donnell: One of these states. One of these optimal states and then you would have the one half minus, which is coupled to the other one. And they're separated by only 55 kV so that's a relatively small.
Separation between those two and transit states.
David O'Donnell: So, well, what does that mean, so there's been a long debate about the existence of
David O'Donnell: Have a party double and protecting them to to name.
David O'Donnell: This this this part of the double it was predicted back and thinking at. So one year before I was born. I'm an old guy.
David O'Donnell: And Jasmine predicted that the existence of this low lying particle button. Perfect. Tell him to to name and then in 1982 about the authority from the evidence of the state but subsequent studies have shown
David O'Donnell: Have cast a bit of doubt on this, including a study by the same author, much later in 2015 where evidence for the existence of this has not been so forthcoming.
David O'Donnell: But should this protect any him to to name.
David O'Donnell: Nucleus have show exhibit signs of octopus have increased optical correlations, we may expect to the even even core for him to to eight, which is just which has just brought at 10am to, to name but a neutron remove so I have a thought. I put on earth to forgive me.
David O'Donnell: So we may expect them that thought him to do it, make sure things are permanent have significant damage multiple correlations or at least
David O'Donnell: show some signs of multiple vibrational behavior, but probably if the, if this product is double it really does exist at the level that it that it's actually
David O'Donnell: His claim to be, then we would expect quite a large octopus defamation, whether that be static or dynamic in a way we expect it to be quite large and the case of thought into it, though.
David O'Donnell: Even if it's
David O'Donnell: Even if, for example, that it's
David O'Donnell: Even if it's even if it's not, for example, and there's party doublet is truly as long as it is, it may still be the case it protected him through to name is of interest in the searches for an atomic electric dipole moment.
David O'Donnell: Since the beaker three may be, may be quite large of thought into it. But in addition to protect him to the name that's only one nucleus in this region.
David O'Donnell: And which is part of the dog, which are observed or predicted, including axiom two to seven and my good friend market share cars are very, very clever way of maybe interrogating this, but I'll leave that to him to talk about. If you want to
David O'Donnell: fire him an email and you explain it to you. And he talks to anyone about this. So you'll be happy to give you that information. And the thought him to to name has been talked about in terms of positive doublet. And in addition to protect and into tonight so
David O'Donnell: Moving on, what is it, what am I talking about when I talk about this atomic EDM. I mean, I'm not here to give an atomic EDM talk so
David O'Donnell: I couldn't, to be honest with you. So I'm just going to, I'm just going to be very, very broad strokes about this. But essentially, the atomic EDM, the standard model predicts very, very small vanishingly small electric dipole moment.
David O'Donnell: And
David O'Donnell: People are people. There's a number of experiments that are looking to basically try and measure this this this EDM if it exists, for example.
David O'Donnell: And I'm not going to go into too much detail, but if it exists, giving rise to for example CP
David O'Donnell: T violation, then it may help to explain, for example, the body on a cemetery that we observe and our universe. Currently, but the problem is, is that an item.
David O'Donnell: In according to what's going on as a shift and I an atom can exit can possess an electric dipole moment, simply because basically any electric dipole moment.
David O'Donnell: Possessed by the nucleus, yet the electrons rearrange themselves in such a way that the counteract that giving rise to what's effectively a net is, you know, atomic EDM.
David O'Donnell: However, the screening is not really complete and that's because of the Phoenix size of the nucleus. So in shifts the room. It's, it's just a an assumption that the nucleus is point like
David O'Donnell: And of course we know that it's not
David O'Donnell: So basically the Phoenix side means that the screening is not exactly complete and what happens is this do
David O'Donnell: what's known as a chef moment can be generated essentially an electric field which polarizes the atomic electrons, giving rise to an atomic EDM, which is aligned with the nucleus spin
David O'Donnell: Know it octopus octopus octopus collective nuclei have have attracted a lot of attention here because, for example, some people, including Victor flamborough and has
David O'Donnell: He has written many papers about this, suggesting that, for example, the chef moment of an octopus correlated nucleus might be
David O'Donnell: Particularly enhanced which therefore means that something if your nucleus is more optimal deformed you make that have an enhancement of this EDM.
David O'Donnell: And for example, and flom bomb and Juba earlier on this year calculated that there may be a factor of 40 enhancement between product and into two main competitor three them two to five. Now why radium two to five or radium two to five is is is the is the concern of an ongoing experiment.
David O'Donnell: Are gone, for example, to look for this EDM, and they've made quite a significant amount of progress there.
And
David O'Donnell: It's still not as good as the best one. At the moment, which the atomic EDM limit has been set by by a mercury one a name.
David O'Donnell: Nucleus, and that's down as low as seven is the upper limit is seven times 10 to the minus 30 centimeters. So it's very, very small effect.
David O'Donnell: But the interesting thing that flood bomb has come up with is basically that well this shift moment this S which is down in this equation at the bottom via
David O'Donnell: It actually has a quadratic dependence on Peter three, so it'd be the three is essentially the optical defamation parameter. This is the
David O'Donnell: Parameter which basically describes how to order form. The nucleus is the higher the beta three, the more octopus deformed or the more pear shaped actually is. So it has a linear dependence on Peter to the quadratic defamation, but
David O'Donnell: But a quadratic dependence on on on Peter three also in the chef moment. You can see that the in the denominator. That is a email Enos main is a plus.
David O'Donnell: This is simply just these party goblets okay it's the energy difference between the one polity doublet member and another. So if that small
David O'Donnell: Right, then you get an enhancement and the chef moment. And if beta three as long as you get an enhancement in the chef moment.
David O'Donnell: So again, I don't want to go into too much detail. It's not really relevant to the stock, but I just wanted to highlight that that this is one of the ways. One of the things that's really interesting.
David O'Donnell: If you want to have more information about this, then I would really strongly advise you to be 10 chops a
David O'Donnell: really excellent review article from January of last year.
David O'Donnell: Okay, so this is the point where I have to, I have to come out of my notes.
Okay.
David O'Donnell: Okay, hopefully you can see that something happened there. But, and there seems to be a problem in the bottom there figure on the bottom right, showing up. So how, what are we doing it UWS well this is the apparatus that we use that UWS to perform our measurements.
David O'Donnell: We're using something called the middle symmetric central difference methods and I will go into that a little bit of detail. No.
David O'Donnell: So what happens is is we essentially use to lengthen on Broadway detectors to see the adult learners and Abramoff detector. So they're very fast gamma ray detectors centrally thing and we send we basically sandwich between them very thin foil of 30 and
David O'Donnell: Then some of the electronics is is shown here. This, this figure, and the electronic part was done by my PhD student majesty, who had a lot of
David O'Donnell: Who spent a lot of time on this experimental setup. And what happens is you then feed it into a CFD in order to determine attain Peck off method and then basically you put
David O'Donnell: You put one in straight into the tank amplitude converter or the tack and then you delete the other signal. So you've got effects delay on that all the time and that provides a stop to your tech and then what we do is we digitize all the signals. So we take the energies.
David O'Donnell: Of the linear find and find out. You put them straight into the digital user, we take the signal from attack and we put that also into the digitized and then once we're there. We basically
David O'Donnell: We perform I'm moving window we be an experiment because I'm greedy, we basically record all of the waveforms and just store them and then later stage we use our own
David O'Donnell: Moving window D conversion algorithm to extract the pulse eight. But essentially, I want to give you a brief overview of them of
David O'Donnell: Of what what it looks like. And I'm afraid that, then it's not as it's not nearly as interesting as some of the topics, you've seen in the past few weeks. Well, and you see these big, beautiful spectrometers like many ball, for example, or you've got your own damn
David O'Donnell: I get are. These are beautiful spectrometers with lots of money that has been spent on them and lots of very, very talented people designing them and running them. This is our motto, a
David O'Donnell: ghetto version of this essentially what we have is we have our to lengthen and Broadway detectors which are sticking out of a copper
David O'Donnell: copper plate here and we have an additional happy to jump in, in detector in here, which just helps us to
David O'Donnell: Understand, some of the spectra bit better and we can actually use it to get as well. It can be useful for that. But most of the day.
David O'Donnell: We are dealing with more multiplicity events and this and the law activity. So basically, we don't really
David O'Donnell: Have much of a need for gating with the German mainly helps us to understand what each of our pizza because the length of the brawl made resolution is so limited
David O'Donnell: So anyway, so how about how does this work. Well basically we walk in two different modes and the medicine metrics entry difference method, you have the delayed configuration. Well, that's where you're feeding gamma ray here.
David O'Donnell: And is detected as the start is detected in the stock detector and then you have your depopulated gamma ray, which is then detected those in the stock detector, the one that we put into the stock of the tech
David O'Donnell: And not make that make them give rise to this distribution here and read. Okay, this, this is the part that
David O'Donnell: Really show up when I go to full screen, so forgive me for that but them basically this is what you'll get. This is a table Gaussian distribution, you will see with a delayed configuration. And then what we do is we swap it around.
David O'Donnell: So it's the same data but we just say, well, did we detect that gamma ray
David O'Donnell: In the stop detector that if we if we see the feeder and stop detector and we see the D populating in a start where we get what's called the anti delayed configuration and you end up with the blue distribution here.
David O'Donnell: Okay. And essentially, the difference in the last moments of those. It's not really showing you
David O'Donnell: The difference in the first moment or half. Yeah, okay, definitely the first moment here.
David O'Donnell: Well actually will give will give you information about the listing
David O'Donnell: So he doesn't say that little copper plate. This is where I've got to be allowed to. I've got to sort of play design engineering as well. So we 3D printed this source holder.
David O'Donnell: Which you can then place either our file or very thin foiling or, for example, at the moment in this picture, we have
David O'Donnell: A calibration source, probably a European 152 calibration source and so got to design all that and 3D printed. So it's pretty good and good fun.
David O'Donnell: Doing all of this and but what I wanted to just highlight was basically that this we're using this middle symmetric central difference method, which was pioneered by john Mark Regis and the group at Cologne.
David O'Donnell: Yeah annually and Mathias regard as well. Among them and and this method is simply an extension by my back in the 80s and 90s where
David O'Donnell: My with by eating what's known as a central difference method and this method is a middle symmetric version of that.
David O'Donnell: And what allows you to do is then say, okay, the difference this delta. See the difference in the last moments of these distributions. We can then relate to the lightning.
David O'Donnell: Unfortunately, even though we use a CFD we really, really very finely tuned CFD to minimize any energy dependence any walk. We can't eliminate it completely. So as a result, you end up with an energy dependent walk
David O'Donnell: And in order to correct for that we need to then use transitions which have non life teams. Ideally, they'd be be very prompt, they would essentially have noise team that would be
David O'Donnell: Instantaneous to our to our apparatus.
David O'Donnell: And and then what we do is we use. For example, a European one, five to source which between some alien 152 and guide the linear 152. We have a number of levels. Level A things which we know very well or and De de very prompt
David O'Donnell: And we use noise to characterize our system, we characterize the walk that way. And that's what Sean and the top rate. That's what's called the pod.
David O'Donnell: So you have to subtract that off the walk that would naturally separate these two central is to begin with and then what you're left with is
David O'Donnell: Price of lifetime I shown in this little equation here. So basically, a PR dealership to characterize that and it's a very, very careful measurement, you have to make. And it was a measurement which magic.
David O'Donnell: Magic Chishti George your Italia and Pietro spaniel at the three of them. What very, very hard on this. And so I was very thankful to them for doing that.
David O'Donnell: So on with what with what we were doing is we were looking at for him to free to
David O'Donnell: Foil. So, as you all know authority to the case for many, many different steps and eventually ends up in lead to wait one way or another, it will end up and lead to it.
David O'Donnell: And at that point, that's where the that's where the chain stocks know if, for example, you've got
David O'Donnell: A foil like I was which some secular equilibrium then you have every single state every single step of that is happening all the time and our phone
David O'Donnell: So we have a foil that about six Keller Becker L's an activity. So really, very low activity, but it's great for us because we just coat for a long time.
David O'Donnell: Just see what happens. And then we're not in any rush. So it's quite nice. And what happens is is that during that process. You get to act any him through to it, which is the the parent of thought into it and the growth of idiom through
David O'Donnell: Nature has been really came to us. They're going state is three plus know when this three plus state then Peter the case. We then get relatively high spending. I mean, relatively
David O'Donnell: But you tend to populate states with to Angular angular momentum 234 maybe even five so you get relatively high spend States being populated the result of beta decay.
David O'Donnell: ACU value is about to MTV. So you get a pretty decent number of states populated. As you can see from this
David O'Donnell: Extract the sort of messy extract. They took from NBC. I don't want you to focus on anything in particular just highlighting the fact that
David O'Donnell: There is a large number of gallery transactions which you might observe. In fact, some of this case scheme is not even it's not it's not actually showing on here. There's some more to the rate of your screen. I'll probably go back to
David O'Donnell: To full screen mode so you can see it a bit better and
David O'Donnell: So some more on the right hand side of your screen. But I've just left that off. But as you can see we populate, for example, the three main estate with about 12% here. So we get really strong population of some of the really interesting states and thought into it.
Okay. Oh, something's happened here. Sorry.
David O'Donnell: Oh, this is missing here. So I need to. I'm sorry, forgive me for this. Here we go. Okay, so you'll have to look at it this way. I'm afraid I
David O'Donnell: Hope that's not a problem for you. But what we get is this is these are the gamma ray spectrum we observed. So the top one, there is from one from bomb a detector.
David O'Donnell: And the conditions that are not have been that, for example, we have to have detected an event A coincident event in both of the land from Broadway detectors, etc. Essential trigger. That's the only condition we set, then we'd record everything
David O'Donnell: Was what you see is the lantern broad spectrum. And then you see the equivalent spectrum from the high quality Germanium detector thereafter.
David O'Donnell: So like I said, we can use the ip of the German detector to basically see in between some of those little bumps and it helps us to identify what transitions. The are
David O'Donnell: The transitions which are labeled and black are those from the Dickey of at 10am 228 and two excited states of thought into it.
David O'Donnell: And the transitions that are labeled and read are those that are at the bottom of the kitchen from thallium to eat and to light to it.
David O'Donnell: So you see quite you see a number of different steps in this the kitchen, but luckily for us. You really only see dharma.
David O'Donnell: Intensity from the 20th to thorium stage and then the thallium to lead stage, you don't really see any gamma activity from the other stages.
David O'Donnell: They mostly progress the a high energy alpha decay is that go straight to the Golden State. So that's quite lucky. But as you can see we populate a great number of states here.
David O'Donnell: And importantly, like I said, we populate these three main mistakes. The one main estate, for example, and are really of interest octopus correlations. So what do we, what are the results we get well. Here is a spectrum of, for example,
David O'Donnell: This is a tax spectrum that we obtained by gating on the feeding name 11 transition which
David O'Donnell: feeds from a basically the keys out of the the the gamma bind to plus state and feeds 2468 or two plus state.
David O'Donnell: And we can see there was really interesting. As you can see two components in this decay.
David O'Donnell: And that's because this lifetime of the state is quite actually it's quite long. And if it's rowing the boat, more than 150 people seconds, then no setup that starts to show up as an exponential pill. So what you see is you see
David O'Donnell: A Gaussian distribution which comes from the prompt part and then you see superimposed on that you can see the exponential decay.
David O'Donnell: So when we measure the last name of this we get very good agreement with with Fletcher. So we were very happy with that.
David O'Donnell: We also measure the lifetime of the four plus date which was already known before this, and we got good agreement with that one, too. So we were quite confident that what is working.
David O'Donnell: And here what I'm showing now is the lifetime of spectral, for example, we get for the one minus. So I'm showing. For example, the gamma, gamma, gamma projections and see panel on the panel.
David O'Donnell: And for example, in the sea Parnell, this would be for the there's one main estate.
David O'Donnell: And n d panel. It's for the FEMA snake. But what we find is that we find the lake thing to be about four plus or minus three equals seconds. In the case of the one minus
David O'Donnell: And then in the case of the theme as we get something like 13 people seconds plus or minus two Pico second seconds.
David O'Donnell: So now we've got information. Well, what can we do with that. So for example, we can then calculate the big one. Okay, so what we do is we calculated the
David O'Donnell: Luis Luis and butlers and publication 2013 they published predictions for one of the one of the measures of octopus.
David O'Donnell: Correlations which was this p one and we then thought, well, let's compare results with those guys. And what we found was super lab agreement.
David O'Donnell: And remember, this study was the study and by Luis and Peter was done. And, you know, seven years ago, seven years before we we started doing this so
David O'Donnell: Basically what we found was so we get a value of one thing since the main is T vice golf units, but the predictive value was about 1.3
David O'Donnell: So within uncertainties. We got excellent agreement with their prediction. It's always nice. I guess when you get agreement with theory that was already published right because
David O'Donnell: There's no one, no, no, no one can claim that you're fudging anything. So basically, that that so we get them.
David O'Donnell: We basically sure that those same calculations that those guys done sure that for him to to eat it strongly quadrupled the form, but only weekly octopus different
David O'Donnell: Know what, that'd be one value is comparable with, for example, the be one value that's been measured on the upper limit of the be one, which was measured them.
David O'Donnell: By gathering data and the way down to 20 experiments and that was their interpreted again has been octopus vibrational nucleus.
David O'Donnell: But we wanted to take this one step further. So we said that. Okay. Since we've got excellent agreement with this theory.
David O'Donnell: Then let's think. Let's see. Let's see where we can go with it. So basically you can you can extract the the zero value.
David O'Donnell: For this, and we got these values here. So, d zero. For example, in the case of them in the case of the one Mainers we get 0.17 plus on the industry to put these into it.
David O'Donnell: And that agrees reasonably well with the predictions for a high spend state by Butler and V tech back in the 90s, so it's
David O'Donnell: Is if you if you assume that, for example, there's probably there's probably a little bit of uncertainty on that predictive value. So I think probably broadly consistent with one another.
David O'Donnell: But we've measured slightly higher and higher value than, than the predicted nonetheless our values are in excellent agreement with the V1, V2 ratios, which had been measured
David O'Donnell: By Schuler at how back in 1980s, and I come in Italian, the 90s, so that we're getting good agreement. There are two. So we were fairly confident of them so
David O'Donnell: What we did then in order to maybe estimate we can't measure it. Unfortunately, but estimate the beater three value for thought into it. What we did was we looked at the equations of Leon Chen, one of the equations here. I think it's 2.27
David O'Donnell: Is shown here just wrapped up straight out of the manuscript. And what you can see is it's a very complicated equation with multiple terms.
David O'Donnell: But essentially, it's coupled to the fact that you've got average Peter three maybe three and you've got to beat the value. So you need to you need to just basically the
David O'Donnell: Couple of equation analysis but. So that's essentially what we did and we obtain results which are consistent with authority him to do it having
David O'Donnell: Beaten p value of 0.11 plus i mean it's enough is enough to which means that if you if you trust is 0.011 value.
David O'Donnell: And then it's one of the higher be etc values. It's about being measured. And even if you assume that the uncertainty and probably it's probably similar in terms of its optical defamation.
David O'Donnell: Compatible with, for example, reading through to for something like that. Now the interesting thing is, is that
David O'Donnell: Yeah. So the interesting thing is that basically that well if even if that is vibrational that beta three value may actually still make it a very useful and
David O'Donnell: It may make for example the odd mass nuclei like protecting him to to name authorial 229 or 10am 227 which have either neutron proton or holes coupled to this nucleus, it may make them very attractive for an atomic EDM search, simply because it may actually have
David O'Donnell: A large of B2C value and for example in in flung bombs analysis.
David O'Donnell: Of this he predicted the shift moment doesn't necessarily depend on where it's a stable walk to school defamation or whether it's a dynamic optical defamation, but simply just that the VTT it has this quadratic dependent. So maybe this nucleus is actually
David O'Donnell: Perhaps really useful noise or you click a couple to this nucleus.
David O'Donnell: So what we did was basically we then I used a code, which was a which was sent to me by Liam Gaffney
David O'Donnell: Who is the master of making these pictures and we then get a representation of the 32 to eight nucleus. And as you can see, I've called it nicely so that it looks a lot like a pair and
David O'Donnell: To really hammer that message home and you can never underestimate the power of a good damage.
David O'Donnell: Okay, so I want to quickly move on, probably only have five minutes or so. But I want to quickly move on to to the intrinsic dipole moment of uranium 234 and this was just another one of these, sort of, I can
David O'Donnell: fortuitous things that we did was we thought, well, we'll take a urine in yet foil and it turns out that you populate the one main estate and your name 234 as well, which again had never
David O'Donnell: Had never had a be one measurement and in this new place. As you can see, the, the, the beat of the show. The BV three has actually been measured in your entity for in the past.
David O'Donnell: And hopefully you can see on this part again, which is just that I showed earlier, but if you focus know in this part of the part you can see that your entity for it's it's not a it's not an insignificant.
David O'Donnell: Octopus defamation, but it's compatible with, for example, lead to weight. Okay, the strength, the multiple strength is compatible.
David O'Donnell: With like to wait, which we know is a reflection symmetric nucleus. So we may expect again that you know at your entity for would be a reflection symmetric nucleus.
David O'Donnell: Know flom bomb and failed my I have just a sheer earlier on this year they published a paper and Fisher. See, which looked at for candidates for potential
David O'Donnell: Nuclei in certain searches for atomic EDS and among them, for example, you're in 35 was one of them which one may expect, then if that was to be a useful nucleus.
David O'Donnell: Which would be simply because it has a longer halfway and you can get it more easily than, say, for example, radium to do five then if that has multiple correlations are enhanced up to boycott, which is one may expected in 234 to have that too.
David O'Donnell: So working assumption anyway and difference in this case. Unfortunately, when you use you read into the file you go through a very similar chain as you did for
David O'Donnell: Him to theater but protect any empty for the isometric state which most of the decay goes through that that overwhelmingly most of indicators for that. Hmm. Well, it only has a zero minus
David O'Donnell: Spending party, which therefore means that you only really populate more relatively more spending stakes.
David O'Donnell: Unfortunately, so you don't really get population or, for example, the theme anus. In this case, but nonetheless, you do get significant population of the one main estate for the first one, meanest it so we were able to make a measurement of that.
David O'Donnell: And this horrible thing is the camera spectra, you get for you to him to see for what he got for
David O'Donnell: Identity for mainly because its effect foil.
David O'Donnell: And it was what we could get available and good fellow. It was a thick file, which means that you get you get a lot of a
David O'Donnell: Brand strong coming from PETA stopping in a file and so on. So you get a very large background, but you can see these bumps. And again, like I say the hype. You did. You mean the technology is to actually see underneath want to improve my bumps and to identify which ones.
David O'Donnell: Were looking at. So essentially what happens is is we gated on the feeder and the one main is look at the Dickies. It is a spectra. So the first
David O'Donnell: Full Spectrum at the top there is an be that has been gifted on the 258 the feeder. And then the second one is gated on I think it must be the 743
David O'Donnell: And but both produce similar spectra and then you can see how clean the spectrum as at that point. So you see the feeding transition. The 258 and then Andy, we can see basically the tack distributions.
David O'Donnell: For these to delay the 90 delayed again. And what we get if we extract the leaf team we've done this three different ways know we've done it.
David O'Donnell: With a detectors far apart. We've done it with the detectors very close, and then a separate team.
David O'Donnell: And so we've got three different measurements which will men are breached and we get a life team of 14 plus or minus 44 seconds.
David O'Donnell: And that gives us a be one of 1.2 things gentlemen is five. So it's, it's, um, it's two orders of magnitude law that we got for for them to to wait and then the zero again is 0.01 name. So it's much, much smaller in terms of dipole moment here then isn't thorium to to wait.
David O'Donnell: And we believe that these logs are consistent with interpretation that you run into two year is a reflection symmetric nucleus.
David O'Donnell: Here is a comparison with CD, which has been provided by my by my good friend and collaborator lewisville bledel and he has been working with Dr. Porn quadruple coupling.
David O'Donnell: Model and he's improved calculations that he did back. I think in 2013 and as john orthotics GPA. But nonetheless, so we
David O'Donnell: What the calculation short is the be one strength and the calculations is still over predicting but I'm assured I'm assured by him that this is not a problem in a sense that they're very sensitive to the single particle orbitals and so on. And, and I would always trust whatever Luis's
David O'Donnell: So I just want to very quickly briefly mentioned what we're going to do in future.
David O'Donnell: We're going to make. We're going to modify all the technical setup to measure the be one measurement and reading two to four. This is the one which, for example, Gaffney a towel.
David O'Donnell: We're only able to prepare to purchase an upper limit for it'd be really nice to get an actual measurement of that to compare with the calculations.
David O'Donnell: And and I'll show you in the next agent, a couple of pictures to show you what we're doing with that the experiments on going right now. During lockdown. When I can't access the blog.
David O'Donnell: And and what we want to do is continue to measure these e one transaction rates in a number of uranium and 30, am I so talks.
David O'Donnell: And we may actually do a search for the easy and thought him to do a I have a, I have a really crazy scheme that suggests that it may actually be possible if I can get my hands on.
David O'Donnell: It and get if someone has a spell germanium Marie kicking about then you can send it my way and and have an idea for them for doing an experiment them to detect the EC Dickie it may not work, but it so
David O'Donnell: I have a feeling that, mate. And so this is our father work here. This is an experiment that we're running at the moment. Now in our lab and a little more this lab.
David O'Donnell: So basically we're now using plastic centimeter, coupled with the length and bromine detector. So we're not doing Alpha Gamma or beta gamma measurements and we're going to look for example for this a transit.
David O'Donnell: transition rate and raising two to four and but also populating some really nice, you know, plus states and you're in in 34 so that's all it's all going really well written and hopefully you'll see the results of this within a year or so.
David O'Donnell: I'm dying to get back into my lab, as you can imagine. Anyway, I want to summarize very quickly and basically that I've been measuring be one rates and for him to to it from the one minus t ministates
David O'Donnell: Seems like the values are agreement with the theoretical calculations which were already bomb. So that was really satisfying
David O'Donnell: And calculation suggest that and 32 we may have pronounced and
David O'Donnell: So it may have less pronounced reflection, the cemetery compared with two to 432 to 60 million. Nonetheless, it may be that there's Peter three this high B2C value may actually be that the nuclei of
David O'Donnell: An odd particle couple to this core may still be worth pursuing in terms of atomic EDM. And then we've measured to be one value for one main state and your name 234
David O'Donnell: And it looks like our results are consistent with reflection symmetric nucleus, which is perhaps with a large quadruple defamation, which is perhaps what you would have expected.
David O'Donnell: So I want to thank all my collaborators, especially Majid Chishti who is no at University of Sydney
David O'Donnell: Giorgio Battaglia who's a PhD student at the University of Strathclyde he's just finishing now.
David O'Donnell: And Pietro spinal it because these guys did a lot of the hardware walk or whether it be and get your helping those guys with the plda technique and so on. And then I want to thank Luis for sending me his
David O'Donnell: his his his calculations and we are, we're working on a paper that you should hopefully see something soon.
David O'Donnell: I want to thank st FC for the funding on the Scottish University physics Alliance, which is not a super
David O'Donnell: For the money to buy your detectors. And if you want more information, although you probably get more information from this talk and but you can check out our major physics paper, which was published in me.
David O'Donnell: So thank you very much for your attention, and I'm sorry for taking up a so long, an hour of your day.
James Smallcombe: Thank you very much. Day.
James Smallcombe: So do we have any questions, then
James Smallcombe: I see digital clapping. I always like, see that
James Smallcombe: The participants menu and there's a little raise hand button. If you've got any questions.
James Smallcombe: My start with a with a
James Smallcombe: General sort of question back when you were talking about the general premise of protons.
James Smallcombe: being collected towards the pointy end
Yeah.
James Smallcombe: So obviously we we always talk about these delta Jay was three states being being
James Smallcombe: Being where we expect to see this this behavior. So is this backed up by by the single particle calculation to expect.
David O'Donnell: And there are people in the audience who could answer this better than me. But I think so, yes. I think that I think that you do see, for example, the
David O'Donnell: half's and the gene Haas, these are the, I think that these are the orbitals that are that are at the family Sophos, and these nuclear but again like
David O'Donnell: Someone like Luis, for example, who is doing these calculations and as minimizing his his his calculations based, for example on on on where the single particle or but he could probably answer that much better than me. But I think so. I think so. James
David O'Donnell: Unfortunately, we seem to last release from okay but probably
James Smallcombe: Alright, so questions then from other people. We've got one from Georgia, Neil. You want to go ahead, George.
George O'Neill: There we go. And I
George O'Neill: Was limit the activity that you can
George O'Neill: Use the setup for
David O'Donnell: Yeah, that's a really good question and that I that I've not actually tested.
David O'Donnell: So like I said, for example, with 100 kilobits girls.
David O'Donnell: We don't see any problems. And I think ultimately the limit would be
David O'Donnell: So, and by the way, the limit that we have would not necessarily be a real hard limit.
David O'Donnell: As I mentioned, daily are very briefly, but we take the whole wave form and there'll be process that we form off offline. So, and our limitation would then be that we would start to see lots of pale up
David O'Donnell: And I think we could probably go about
David O'Donnell: A factor of five activity higher, I suspect, just my knowledge of what the waveforms look like. I think if you went up by a factor of fire, you'd start to see a lot of pale up at that point.
David O'Donnell: And I don't really like to touch pale up with the with the moving window D convolution organism that we use at the moment. So I think that may be something like
David O'Donnell: Half a mega Becquerel but if I run the if I run the the onboard fun well for the digital user, which I have to admit I don't trust, but it's just me being very
David O'Donnell: Stressed over there. Basically, and if we run that that will probably increase it again, higher. So I, my question is answered the question is, I'm not really sure. To be honest, but hopefully you've gained something, it would be probably multiple megabit girls. I think
George O'Neill: What was the situation.
Okay.
James Smallcombe: All right.
James Smallcombe: Another question from Liam going to go ahead. Lynn.
Liam Gaffney: Yes. Hi Dave and I thought, so in your uranium 234 yes and you are gating on very weak transitions. Yeah, so you must have a high level of background, but the number of accounts that you have is also quite small. How do you treat the background in this case.
David O'Donnell: Yeah, that's a good question. So
Liam Gaffney: I mean, is it just disappearing three coincidences.
David O'Donnell: Yeah, it is mostly, I mean, you can see here, for example in this spectrum. This is a gate.
David O'Donnell: On. For example, this one here, the
David O'Donnell: 258 where it's very clear and you. This is a gate on. Let's see the 743 and you can see that, basically, there is a background here running from about 200
David O'Donnell: Down to about 300 years. So this peak is sitting on top of that, and I didn't go into it, but in the middle symmetric central difference method that Sean Mark has
David O'Donnell: Has has worked on it. Well, I have to be thankful to those guides and call on because they are documentation is excellent between multiple different papers and john Mark thesis. It's super well, it allows us to do a lot of stuff. So basically, they have
David O'Donnell: They've just recently published another paper and which they really detail and only how you handle the background.
David O'Donnell: So essentially, it gets weighted with a peek to background factor on the denominator. So, therefore, that means that in our case with this to five years. It's probably not that bad.
David O'Donnell: If you compare this for example with like some of the spectra that you get it, see from steps I ll something like that where you've got a really, really high level background this is relatively clean
David O'Donnell: And it probably adds on or subtracts depending on how the background is behaving, and it will add or subtract maybe a couple of Pico seconds here there. So ultimately, it's contained within Nepal, something is for them. That will be our
David O'Donnell: Preliminary talking about
Liam Gaffney: It's just a practice. If I see a single spectrum to so nicely.
David O'Donnell: Oh, well, this is
Liam Gaffney: Your song.
David O'Donnell: There's no, there's no single spectrum here at all. So the length and on broad spectrum there is a projection of gamma, gamma
David O'Donnell: And then
David O'Donnell: hype up germanium. One is a projection of gamma. Gamma cube.
David O'Donnell: Right, so it's on Broadway, lengthen and brawl made type you to germanium and then this one is projections of gated
David O'Donnell: Okay, to get this back. Does that make sense.
Liam Gaffney: Yeah. Yes.
James Smallcombe: Okay, great to see Liam, they're wearing his UWS shirts.
David O'Donnell: I was able to, I can't see because of this model.
David O'Donnell: I would, I wouldn't even well that
James Smallcombe: We have any other questions.
James Smallcombe: If you don't have the raise hand button for whatever reason, you're welcome to just unmute yourself.
James Smallcombe: I don't see any, in which case we'll, we'll end up at one. I mean,
James Smallcombe: Yeah, please go ahead
Praveen C Srivastava: Yeah. So, hello, Dave. This
Praveen C Srivastava: Is Praveen from India.
Praveen C Srivastava: Oh, yes. Nice to speak with you.
Praveen C Srivastava: Yeah. So I have a question. So the regarding two and 820 8:30am. So as you know, nowadays we have a possibility to perform larger scale, scale model calculation for these nuclear also
Praveen C Srivastava: So I just saw your presentation. Then I thought, it is also very interesting if we look a certain model calculation for these. This is also Lucy a comment us
Praveen C Srivastava: Apart from what you are doing. So we can also think about the nowadays we have a very high competition and physically. We can do some modern calculation.
David O'Donnell: Okay, that's, that's really interesting to hear. And I think I'd be very interested to see the results of those calculations, if you if you
Praveen C Srivastava: At some point
Praveen C Srivastava: Maybe I can just send you read later.
Praveen C Srivastava: So please do. Okay, thank you.
David O'Donnell: Great, so nice to nice to actually finally speak to you.
Yeah.
James Smallcombe: That's great. Do we have another connecting people Jim's yeah yeah I actually performing the function of keeping the community. And that's what we want, what we like to see
James Smallcombe: Great. So do we have any other questions, comments or new collaborations that we'd like to have it.
James Smallcombe: If not, then I will take my day. Thank you very much. Day for great talk. And thank you all for joining us.
David O'Donnell: Thank you, James I saw just now.
James Smallcombe: plug our upcoming talks so in the plenary session on Friday. So, same time 3pm PST, we can have James Cuba's university of you're talking about
James Smallcombe: Nuclear shape studies in the lead region through in source laser spectroscopy techniques. And then we also have on Wednesday we have a student session hosted
James Smallcombe: The other link by the University of Manchester, or we have to the umbrella Morales also UNIVERSITY OF YOUR they really pulling their weight unbound states in 1618 and 20 carbon
James Smallcombe: It's a long title.
James Smallcombe: So student talks on Wednesday of the other link and then plenary session here again on Friday 3pm PST. So please join us then. So once again, thank you everybody for your attention and thank you, Dave. For a great day. Bye for now.