James Smallcombe: And then I will hand over to Constantine, please go ahead and tell us about your work.
Konstantin Mashtakov: With pleasure.
Konstantin Mashtakov: Thank you for the introduction.
Konstantin Mashtakov: Thank you, the organizers for keeping the seminars going. Thank you everyone for joining us today and I hope you're all staying safe and happening during such a complicated times
Konstantin Mashtakov: So my name is Constantine, and I'm from the University of the West of Scotland.
Konstantin Mashtakov: Recently, I have finished my PhD work, which is about studying the pygmy dipole resonance in 96 or quantum nucleus using the beta decay of its mother nucleus 96
Konstantin Mashtakov: And today I wanted to present you the findings of our work at the UWS but before I proceed.
Konstantin Mashtakov: Here is a quick reminder of what is the pygmy dipole resonance
Konstantin Mashtakov: So here you can see the plot of the electric dipole strength distribution over energy. It's quite a common plot shown on every big me dipole resonance talk and
Konstantin Mashtakov: So this electric dipole strength is set to be generated by the separation of the center of mass and charge inside the nucleus. On the right hand side, we can see this massive structure which is called the giant dipole resonance and in this case the
Konstantin Mashtakov: Dipole strength is generated by this separation of protons and neutrons and the escalations against each other. And on the left hand side there is this fragmented structure.
Konstantin Mashtakov: On the tail of the giant dipole resonance called the big me dipole resonance and the microscope microscopic interpretation of this resonance is said to be
Konstantin Mashtakov: The outer face movement of the proton, neutron ISIS been saturated core against an excess neutron skin.
Konstantin Mashtakov: So this generates this separation of their. This is what they start to be the mechanism behind this generation of the disciples thinking this energy region and it's super it is situated quite close to them nutrient separation threshold which has its own implications.
Konstantin Mashtakov: In different areas of physics. So the main motivation behind why is it, why it is interesting to study such an excitation mode is because it's
Konstantin Mashtakov: It's known to have a big influence on the neutron capture rates, for example, which is an important factor in the astrophysical nuclear synthesis calculations and on the left hand side you can see if I don't know if you can see the course or maybe I always depend. You hear
Konstantin Mashtakov: It. This is like the the black dots correspond to them more or less what we see in the solar system, the abundance
Konstantin Mashtakov: Then the red line here shows the calculations of the nucleus sicknesses using only Jain diaper resonance
Konstantin Mashtakov: It by taking only this into account and the green line shows. Also, what happens if you include pygmy dipole resonance to the picture and it can be seen that
Konstantin Mashtakov: The situation drastically improves and this is partially, one of the reasons why it's interesting to study this oscillation mode.
Konstantin Mashtakov: Another reason is that some some theoretical studies also suggest a strong correlation between them.
Konstantin Mashtakov: Big me dipole resonant strength with the symmetry and up determine the nuclear equation of state and this equation of state is also used in a variety of different the
Konstantin Mashtakov: theoretical calculations and, for example, some of them are also used to study the properties of the
Konstantin Mashtakov: Neutron stars. So if we know well this big me dipole resonance strength provides us a constraint to some theoretical quantities which are quite useful.
Konstantin Mashtakov: But those kinds of calculations and this is one of the motivations. So another point of why we've been doing what we've
Konstantin Mashtakov: What we were doing is because there is also some set of benefits that comes from studying this particular beta decay. And here I'm talking about 96 atrium grounds dedicated to the
Konstantin Mashtakov: So the most recent high resolution spectroscopy be that a study of this decay was performed by Henry Clark, and this was done roughly 30 years ago. So it was quite a long time ago and
Konstantin Mashtakov: At that time it is known that the data sets from from that period suffers from the so called pandemonium effect which stems from the
Konstantin Mashtakov: Law efficiency, especially at high gamma ray and objects of the detection system systems used at that time and
Konstantin Mashtakov: This effect into in turn leads to incorrect determination of the Peter feeding to the highlighting levels in in certain nuclei, especially the ones which have large Q values and
Konstantin Mashtakov: Incorrect knowledge of this beta feeding strength also leads to some serious well it may lead to some serious implications and one of them is that
Konstantin Mashtakov: The reactor easy to heat is not calculated as precisely as one can with the correct be the feeding intensities. And it can also serve as one of the reasons behind the so called reactor engineer three anomaly. And in this case, this particular beta decay is known to be
Konstantin Mashtakov: One of the three main contributors to the reactor Antony Trina energy spectrum and therefore it's really
Konstantin Mashtakov: Important. If one wants to solve the mystery behind the reactor anti neutrino normally to to have the correct be defeating distribution pattern.
Konstantin Mashtakov: So on this slide, you can see the most recent the
Konstantin Mashtakov: Be the feeding distribution again from the so called total absorption camera spectroscopy technique and basically this data is mostly pandemonium free and it can be used to simulate
Konstantin Mashtakov: Anti neutrino spectra with a nice precision and the improve the world kinda improve the situation with the reactor and 23 normally but if one wants to improve the quality of this
Konstantin Mashtakov: Simulation even further than the information about the spin parity configurations of the populated levels and some incidents relations precise energies of the levels populated all this information would ideally have to be known. If you want to simulate a nice
Konstantin Mashtakov: Aunty neutrino spectrum, and for this reason.
Konstantin Mashtakov: Our work will also complement to the work done by Charlie Roscoe by the
Konstantin Mashtakov: With their total absorption gamma ray spectroscopy and
Konstantin Mashtakov: We also know that our data will be able to also contribute slightly to their data because they were not sensitive to easier transitions present in 96 or Korean as well as
Konstantin Mashtakov: With high resolution spectroscopy, we have
Konstantin Mashtakov: Higher energy resolution and we will be able to see the levels populated steady state by state.
Konstantin Mashtakov: So, but that putting that aside, the main motivation behind studying this beta decay was because we wanted to study the big me dipole resonance in this nucleus.
Konstantin Mashtakov: And in order to study the pygmy dipole resonance. There are variety of experimental techniques used and in this table, which I shamelessly stolen from one of them review articles from sovereign
Konstantin Mashtakov: Here are presented the strong and weak points of each experimental technique that is commonly used to study this big me dipole resonance
Konstantin Mashtakov: And I will not go into details in on each experimental technique, but I just wanted to show what are the criteria that define the perfect experimental technique to study this PDF
Konstantin Mashtakov: So the first one is the energy resolution. If one wants to study defined structure of the pygmy dipole resonance state based on the state by state basis, then it's
Konstantin Mashtakov: really crucial to have a nice and the jury solution like typical germanium detectors somewhere in between five and 10 key and those cells are marked in green color.
Konstantin Mashtakov: So another important criteria is model independence. We want to extract all the quantities that describe the state's associated with the pygmy dipole resonance
Konstantin Mashtakov: Without relying too much on certain assumptions made on some statistical theories and stuff. So therefore on each method that
Konstantin Mashtakov: Extracts its quantities independently is marked as green. The other ones that are so to say model dependent are marked as red, and the result, like the average result that kinda relies on some assumptions is Martin yellow
Konstantin Mashtakov: Another important observed observable is the completeness of some dipole strength and the
Konstantin Mashtakov: This is a crucial factor for what I'm going to talk later. But yeah.
Konstantin Mashtakov: It's, it's important to have an idea.
About
Konstantin Mashtakov: About the this the total some strength of the PG era, because this one is used for some
Konstantin Mashtakov: Theoretical constraints to, if I remember correctly.
Konstantin Mashtakov: Then defined structure. It's
Konstantin Mashtakov: It's kind of similar to the typical resolution, but the
Konstantin Mashtakov: Typical energy resolution, but it's also important to know the fragmentation of the pygmy dipole resonance and the structure behind it. What is the microscopic structure of the levels involved and stuff like this.
Konstantin Mashtakov: And the final criteria for a experimental method is versatility is basically what is the range of available nuclear that we can study with a particular experimental method.
Konstantin Mashtakov: Some methods are constrained to only stable nuclei. Some methods are more general and can be used to study radioactive nuclear as well.
Konstantin Mashtakov: And if we want to perform nice systematic studies of the behavior of the pygmy diaper residents. Ideally, we would have a method that would cover a wide range of nuclei.
Konstantin Mashtakov: So, as can be seen from this table. There is no perfect method to us because each method has its own advantages and disadvantages. So it is a common practice to try to combine several method methods together in order to extract as much useful information as possible.
Konstantin Mashtakov: About the pygmy dipole resonance and in 2016
Konstantin Mashtakov: My supervisor proposed a new technique which on its own kind of works to study PDF, but it's best work when applied, together with the nuclear resonance fluorescence. And here I made a small table which compares the an RF
Konstantin Mashtakov: Alone and an RF combined to the ptk so all methods have similar advantages because the typical energy resolution that we can obtain achieve with each experimental technique depends on the equipment we use and both
Konstantin Mashtakov: And methods use high purity germanium detectors in order to do this.
Konstantin Mashtakov: Spectroscopy. So the energy resolution is
Konstantin Mashtakov: Is great. In this case, so all the quantities extracted in nuclear resonance for us since are said to be extracted in a model independent way because
Konstantin Mashtakov: The when when we are doing nuclear resonance for essence it's basically a photon scattering experiment electromagnetic interaction is used to evaluate all the
Konstantin Mashtakov: To evaluate the one strength and other cameras spectroscopy techniques are used to extract other quantities. Some, such as spins and priorities of the levels involved.
Konstantin Mashtakov: Then I wanted to talk about the fine structure.
Konstantin Mashtakov: So it is in that article that is proposing to use nuclear resonance for us since, together with the beta decay. It is discussed that.
Konstantin Mashtakov: When we're studying
Konstantin Mashtakov: Pediatric with nuclear resonance fluorescence were mostly exciting the so called one particle one whole configurations in the nuclei, because the photons that are
Konstantin Mashtakov: Absorbed by the nucleus are typically coupled to one particle and they excited to another shell those creating this one particle one whole type of structure, while in the same article. It was also said that
Konstantin Mashtakov: In the beat, educate the most common type of excitations is the so called to particle to whole excitation, because one of the nutrients changes into a proton and those creating
Konstantin Mashtakov: A hole in the neutron sector and the particle there as well as an extra hole in the protons sector and the particles those in total created
Konstantin Mashtakov: A two particle to whole configuration. And if one compares the results of both methods, then we can say that the levels that are excited in both reactions.
Konstantin Mashtakov: Are most likely will have one most likely one particle one whole structure because in beta decay. It is also possible to reach one particle one whole X type of excitation, but it can only work in certain specific cases.
Konstantin Mashtakov: So, it is common to think that if we see transitions in both reactions, then most likely it's some certain type of one particular one call, which we can
Konstantin Mashtakov: Estimate using the
Konstantin Mashtakov: Some assumptions about the structure of the nucleus, we are studying and here is the quasi particle fundamental calculations should kind of proving the point
Konstantin Mashtakov: Where the one particle and one hole and to particle and to hold type of configurations are excited in both techniques and on the left hand side you can see
Konstantin Mashtakov: The structures excited in an RF and on the right hand side you can see this structure is excited in beta decay. And as we can see
Konstantin Mashtakov: In beta decay only certain type of fun particle one whole excitations are excited here. While most of the stuff in an RF is one particle one hole.
Konstantin Mashtakov: And then we move to to particle to whole configurations and in an RF we am we barely see anything while and be the GK, we can see that there is a massive structure.
Konstantin Mashtakov: erupting here.
Konstantin Mashtakov: So this can be used as an advantage. And it can reveal certain microscopic structures.
Konstantin Mashtakov: In the, in the levels that are presented in both
Konstantin Mashtakov: Techniques.
Konstantin Mashtakov: Then I just wanted to also point towards a problem that the nuclear resonance fluorescence method has it since.
Konstantin Mashtakov: It is a simple schematic of how it works. The gamma ray
Konstantin Mashtakov: Gamma rays used to excite the nucleus into the pygmy dipole resonance mode.
Konstantin Mashtakov: They get absorbed by the nucleus. And then after and then the dx side either straight to the ground state, or they can be excited to the lower line excited states and then we are secondary transitions. Go to the ground state straightaway and
Konstantin Mashtakov: Since
Konstantin Mashtakov: The gamma ray can be absorbed by the nucleus. There is also a chance of gamma ray being scattered of by the
Konstantin Mashtakov: By the item itself, but the electro electrons present there and this kind of effect produces a large background.
Konstantin Mashtakov: Which can be seen here, the large academic background. And because of this, it's those transitions that are decaying to the lower line excited states that are branching
Konstantin Mashtakov: They're often missed. And because of that, some of the big me diaper resonance strength is also missed with those transitions. And the advantage of using beta decay is that provided that we can populate the same state in the VT K
Konstantin Mashtakov: There is no atomic background present and if
Konstantin Mashtakov: If we use our standard the gamma ray spectroscopy techniques we can see those branches transitions without any problems. And we can also employ
Konstantin Mashtakov: Coincidence techniques to track those. So it's atomic background free and basically we can use the branching ratios from the beta decay data in order to compensate for the problem of the missing strength in nuclear resonance for a single fluorescence experiments.
Konstantin Mashtakov: So this leads us to that think that it's not well it's not easy to excite big me diaper resonant. States. States using beta decay because certain conditions has to have to be satisfied. So since the beta decay likes to connect the states with similar spin parity configurations
Konstantin Mashtakov: The
Konstantin Mashtakov: Spin parity of the ground state of the mother nucleus has to be close.
Konstantin Mashtakov: To one minus. And by that I mean it has to be either zero minus one minus or two minus and another condition is that
Konstantin Mashtakov: In order to reach the pygmy dipole resonance energy region which is situated close to the neutron separation threshold threshold roughly
Konstantin Mashtakov: The Q value of this vehicle has to be quite large. And those two conditions, limit the this these case studies that we can do quite drastically and additionally in nuclear resonance for essence only stable isotopes can be used in order to perform those
Konstantin Mashtakov: Experiments. And if we combine both together, then it means that the daughter nucleus has to be also stable if we want to study together with using beta decay and nuclear resonance for essence.
Konstantin Mashtakov: And this kind of limits our choice of nuclear for studies and fortunately for us, this beat educate, to 96 or quantum from
Konstantin Mashtakov: satisfies all the criteria and we can we can use this as a case study for the test if this can be nation of experimental techniques works.
Konstantin Mashtakov: So,
Konstantin Mashtakov: I will go straight to the experiment that was performed
Konstantin Mashtakov: So it was performed at the Institute.
Konstantin Mashtakov: Allow alien given in France. I ll where we use the vision of 235 uranium and we separated deficient products using the so called glowing green mass separator and then the islands that we want to study the 996 it reminds they after they get separated the travel to the Experimental Station.
Konstantin Mashtakov: Here.
Konstantin Mashtakov: Which is surrounded by two clover germanium detectors to single crystal germanium detectors and one silicon detector to detect electrons.
Konstantin Mashtakov: And here is a rough
Konstantin Mashtakov: Here is a schematic view of the detector setup that we had here basically
Konstantin Mashtakov: On the left hand side, we can see the beam entering the from of ions have separated 96
Konstantin Mashtakov: He threw my hands. They go through the ionization chamber and then with the tech the gamma rays of the delivered ions in our clover germanium detectors and the unimportant quantity to know when looking at this data is the relative efficiency of the clovers that we were using and
Konstantin Mashtakov: According to some sources. It is 150% relative efficiency to the sodium iodine standard and compared to the previous high resolution spectroscopy studies which had 20 only 25% relative efficiency. This is a major improvement. So we can already see that the sensitivity limit is
Konstantin Mashtakov: Enhanced in this study. And we also had our silicon detector to monitor the
Konstantin Mashtakov: Beta electrons as well as internal conversion electrons. And we use that quite a lot in our analysis in order to
Konstantin Mashtakov: Clear our spectrum from the background, which is stemming from the reactor that is nearby.
Konstantin Mashtakov: So yeah, I'll go straight to that since we were exposed to the reactor background that is that was quite close to the Experimental Station. We had to basically gate on electrons that we saw in our spectrum in order to eliminate the peaks coming from the reactor and in on this graph.
Konstantin Mashtakov: The area of the. You can see the projection of the electron gamma matrix record that using our setup and what we've done, we basically get it on all the electrons present in the spectrum. I'm far from the internal conversion electrons which are kind of zoomed in here.
Konstantin Mashtakov: So we didn't get on those, but we get it on all the other electrons present in the spectrum and
Konstantin Mashtakov: Here is the result of this procedure. This is the high energy region.
Konstantin Mashtakov: Of the spectrum recorded from the big K and we can see that those large peaks go away after gating which also reduces our statistics, by the way, but the
Konstantin Mashtakov: On both of those graphs, I might the transitions that we saw which belong to 96 or quantum and
Konstantin Mashtakov: I think an important thing to note here is that
Konstantin Mashtakov: Most of the transitions that we see here are new and they were never previously reported, apart from this guy here and this transition here. So those transitions were previously seen in
Konstantin Mashtakov: The older high resolution spectroscopy. Be the case study of this ptk but the others are all new and this is only a part of the spectrum.
Konstantin Mashtakov: I will go straight to the results and we can already compare the P defeating intensities extracted from the current work with the ones extracted from the previous one and it's
Konstantin Mashtakov: What. Well, one thing to note is that most of the levels present in the previous work or basically all of the levels and also present in the current work while. Additionally, we have some
Konstantin Mashtakov: Weaker levels levels that a weekly populated in the beta decay also detected here and there is a big number of those that were not reported in the previous study. Additionally, due to some newly observed level branching. So we were able to
Konstantin Mashtakov: Kind of shuffle the distribution of the beta fishing intensities. And for example, some levels that were so to say.
Konstantin Mashtakov: Thought to be highly populated that we had to be less populated in comparison. Now, because of the additional branching extracted and it also goes the other way around. So we reshuffle the, the total the be defeating intensities after doing this work.
Konstantin Mashtakov: And here is the comparison of defeat defeat be defeating intensities extracted from the high resolution spectroscopy. Our, our study, which is marked in red.
Konstantin Mashtakov: With the total absorption camera spectroscopy, which is Martin blue. And here we can in order to make a fair comparison between both techniques we had to increase the bandwidth
Konstantin Mashtakov: Basically increase the bandwidth of each data set to roughly 100 ke VI admin. And we can see here that the high resolution spectroscopy.
Konstantin Mashtakov: produces a result comparable to the one produced by total absorption camera spectroscopy and on this graph. We can also see some to the two striking differences one appears in this energy region and the other appears in the higher energy region and
Konstantin Mashtakov: This difference comes from the fact that
Konstantin Mashtakov: The electron detector efficiency used for
Konstantin Mashtakov: At the total absorption gamma ray spectroscopy study was not sensitive to the internal conversion electrons which were emitted in the easier transitions in
Konstantin Mashtakov: 96 or quantum and those transitions branching from the highlighting levels to the lower length is zero plus level, which then subsequently dictate, we had this easier of transitions. They were thought to be as transitions brushing directly to the ground state of the
Konstantin Mashtakov: While since our study was sensitive towards easier transitions, we were able to identify those as branching from higher levels and those this thing here.
Konstantin Mashtakov: Was displaced roughly here by the energy of the E zero
Konstantin Mashtakov: Transition
Konstantin Mashtakov: And another difference comes in here. As we can see, we're missing some is benefiting intensity towards the higher energies which is quite close to the key value of this beta decay, which is at 7.1 a movie. And this is mostly self inflicted because when we were
Konstantin Mashtakov: Setting up the conditions for our silicon detector. We set up a threshold, a low energy threshold to filter out some noise events at the quite a high energy
Konstantin Mashtakov: I think it was something around 300 kV which man that high energy electrons. I mean low energy electrons which are associated with high energy transitions were filtered out by us so
Konstantin Mashtakov: Since at the high energy. We were also exposed a large reactor background, we were kind of forced to use beta gated spectrum which is background free but but when doing this a beta tagging. We also lost
Konstantin Mashtakov: A lot of gamma ray efficiency of high energy due to this threshold effect and the basically this is one of the reasons we didn't observe within observed
Konstantin Mashtakov: Beta feeding transitions higher in energy.
Konstantin Mashtakov: So another task was to measure the branching ratios of the levels observed in 96 or cornea, which we did. And on this plot.
Konstantin Mashtakov: Those are displayed
Konstantin Mashtakov: Basically on the top one, we can see the the tradition traditions branching towards the ground state on this middle panel, we can see the transitions branching towards the
Konstantin Mashtakov: Second zero plus in
Konstantin Mashtakov: Which is
Konstantin Mashtakov: The transitions pricing branching to that level. And then we can see the transitions branching to this first is excited. The two plus situated at
Konstantin Mashtakov: 1751 kV and levels that are seen in both reactions. I mean, in beta decay and in nuclear resonance fluorescence are marked in red.
Konstantin Mashtakov: While the levels populated solely in beta decay are all marked in blue.
Konstantin Mashtakov: And for those levels that are populated in both reactions, knowing the ground state branching ratios, we were able to extract some of the missing be one strength and it is displayed on this plot.
Konstantin Mashtakov: So basically, the blue lines indicate the previously known be once thing for certain transitions and
Konstantin Mashtakov: The red bars indicate the extra additional even strings that we were able to recover using the branching ratios of the into in our current study
Konstantin Mashtakov: So I will yeah quickly go through this we compared to level population patterns in both beta decay and nuclear resonance for us and experiments.
Konstantin Mashtakov: And we thought, as mentioned earlier that the structures that were excited in both reactions which are here again marked in red will most most likely have one particle one whole configuration. And here, for those of you who are interested in the exact details here is the
Konstantin Mashtakov: Rush of show mode or a presentation of
Konstantin Mashtakov: And these are the possible one particle one call configurations that can be achieved in beta decay. So basically we what we tried to do we try to identify the transitions that are
Konstantin Mashtakov: Very prominent in both
Konstantin Mashtakov: Experiments. And we mostly think that those have those have them highlighted them the current slide mostly have the following components in their corresponding way functions. And additionally, what we also tried to do in order to extract some extra information about the
Konstantin Mashtakov: Way function about the structure of the way functions of the level single we try to look at the structure of the lower lying excited states.
Konstantin Mashtakov: There was a study performed in 2016 by Kramer and others which identify that the beach identified the major components of the lowest slaying
Konstantin Mashtakov: excited states in 96 so quantum and what we were trying to do. We were trying to use this information found in that study in order to to guess that probably the transitions that branch towards those levels. They must have
Konstantin Mashtakov: Come on components of the similar structure because due to the
Konstantin Mashtakov: Larger overlap between the components of the way functions.
Konstantin Mashtakov: Of each state one minus state that is branching towards the overlying state and just based on this judgment, we were able to
Konstantin Mashtakov: Suggest that the probably the transitions that branch towards the
Konstantin Mashtakov: Second zero plus in 96 silicone you are most likely the most likely have one
Konstantin Mashtakov: One g nine have components and the levels that are strongly branching towards the first excited to plus in 96 and quantum they mostly have dominant 3535 half component in their way function and
Konstantin Mashtakov: Yet these were our experiment of findings and then we were also using quality particle phone on model calculations in order to find out any extra information about the internal structure of the levels associated with the pygmy dipole resonance and
Konstantin Mashtakov: What we were able to find was quite
Konstantin Mashtakov: interesting and complicated at the same time. So on this plot, we can see the QPR calculations displaying the energy region that was accessed by both experiments here the qubit value is indicated
Konstantin Mashtakov: By the by the arrow, as well as the nutrient separation energy threshold. So the Qb value is the energy range of our beta decay experiment and the Newton separation threshold is the energy range of the nuclear business for us since experiments and
Konstantin Mashtakov: By by looking at the plots produced, we were able to find
Konstantin Mashtakov: Some similarities in both experimental
Konstantin Mashtakov: Spectra as well as in theoretically predicted one and, for example,
Konstantin Mashtakov: Here we display the GM of Teller strength that was called calculated using theoretical approach of quasi particle phone model. And just as a reference. We took a level at 4.8 a movie displayed here and we tried to come because it is the most
Konstantin Mashtakov: Strongly populated according to the calculations and in our experimental picture. We were also able to find one similar similar level at the similar similar energy
Konstantin Mashtakov: Here on the on the beta decay plot. We can see this big blue guy, so it is located roughly at the same energy range and it is also most strongly populated the one. So we tried to compare the characteristics of those levels between each other and see what kind of
Konstantin Mashtakov: Results, we can get from that comparison.
Konstantin Mashtakov: So you keep em calculations of this level.
Konstantin Mashtakov: reveal that it is populated in the following gm of Teller transition where our neutron into the five half shell changes to the proton into the 500 shell and this creates a two particles and two whole configuration in the
Konstantin Mashtakov: In the nucleus and
Konstantin Mashtakov: We were then able to compare some other quantities to to see how they
Konstantin Mashtakov: How they look in comparison with experiment. So energy wise, our experimental value for this level is
Konstantin Mashtakov: 4838 kV Well theoretically predicted. One is for 895 which is quite close agreement. Additionally, additionally, I was able to find out the look of the value of this level, which is
Konstantin Mashtakov: At six point 64 while the theoretically predicted. One is at six point 66 which is really, really close to what we have in our experiment. And then we've tried to find what is the then we try to compare them.
Konstantin Mashtakov: The structure.
Konstantin Mashtakov: Of this level. And we basically
Konstantin Mashtakov: Check the output of the quality particle phone on model calculations and we checked the most
Konstantin Mashtakov: The strongest component representing this one minus level in the way function of this one minus level and we checked the two phone on the most prominent to phone on components in its way function. And we see those structures.
Konstantin Mashtakov: Which have amplitude. The following attributes displayed on the second column. And another thing. One interesting thing to note is that not none of those two particle to hold configurations or two phone and components could be populated straight is strictly in the beta decay and
Konstantin Mashtakov: The way functions. It's a general feature for all one minus levels associated with the pygmy dipole resonance in this nucleus that most of the levels. Most of most of the way functions of those levels have extremely complicated the structure and the components there.
Konstantin Mashtakov: That can be directly accessed by a beta decay only have a really tiny contribution to the way function.
Konstantin Mashtakov: But despite that small contribution the ptk sometimes still proceeds through those components of the way function. And we think it's quite an interesting observation and yeah, in order to conclude, we were able to
Konstantin Mashtakov: Populate most of the levels that are associated with the pygmy dipole resonance in 96 or quantum to the Q value in both reactions and
Konstantin Mashtakov: By doing so, we were also able to do some microscopic some conclusions about the microscopic structure of those levels we also
Konstantin Mashtakov: Can make the conclusion that more than high resolution spectroscopy measurements.
Konstantin Mashtakov: Can be can compete with the total absorption gamma ray spectroscopy method and
Konstantin Mashtakov: That high resolutions measurements and not severely affected by the pandemonium effect but but it is still, it can still be present. If
Konstantin Mashtakov: You're if you're doing B2B marketing, for example, then our quasi particle funnel model calculations that were performed by the
Konstantin Mashtakov: boogeyman ponomaryov they they are in a good agreement with the something that we see in our experiment and those calculations also reveal the complex structure of the pygmy dipole resonances states and
Konstantin Mashtakov: Also without data, we were able to complement the total absorption gamma ray spectroscopy data because they were not sensitive towards easier transition. So we kind of shifted some of the even some, some of the beta feeding distribution towards
Konstantin Mashtakov: Higher energy also improving the quality of the engineer three now energy spectrum simulated from the data.
Konstantin Mashtakov: And we also complimented the the nuclear resonance fluorescence data without a branching ratios that we extracted from the beta decay.
Konstantin Mashtakov: And this is also I think a big achievement towards the studies of pygmy dipole resonance and I think on that I would like to end my talk. I'm sorry, it was a bit chaotic and
Konstantin Mashtakov: Yeah, I expect a lot of questions because I went really quickly without providing many details to
Konstantin Mashtakov: Do my talk. So I'm glad I'm glad to answer any question you have
James Smallcombe: Thanks. Thank you very much. Constantly. So, yes.
James Smallcombe: open the floor for questions, then follow up on that.
James Smallcombe: So as I mentioned before, if you go to participants menu. There's a little raise hand icon, you can click a little toes, you've got a question or you can get yourself down to the chat box and get typing, nice and quick, and I'll read your question down for you.
James Smallcombe: I don't see me yet. I have one question.
Konstantin Mashtakov: Yes.
James Smallcombe: Alone. I think I've just seen a hand go up. So I'll hand over to speak.
James Smallcombe: Speak your
Krzysztof Rykaczewski: Answer ski.
James Smallcombe: I saw Steve hanging up first. I'm gonna
Okay.
S Yates: Do you hear me okay
S Yates: Yes. Okay, first of all, congratulations on very nice work in a very good talk. So thank you.
Konstantin Mashtakov: Very much.
S Yates: I have just a one mundane question and one other question. First of all these high energies for the gamma rays. What do you use for calibrations of efficiency and energy.
Konstantin Mashtakov: So when we yeah the Q value for the for this decay. It goes up to 7.1 a movie and in order to calibrate the efficiency. I've been using internal
Konstantin Mashtakov: I've been using internal calibration sources, so to say. So in order to I've been using basically relying on the previous work done by Henrik mark.
Konstantin Mashtakov: Who whose energies external who murdered the gamma rays with energies up to 6.1 MTV. We also during the
Konstantin Mashtakov: Current experimental run, we were able to measure some of the decays from 86 bro mine and some of the lines from 86 Brahma and also extend up to high energies. So I use that for an internal color in beam calibration to and with respect to energies. We also use some
Konstantin Mashtakov: Some lines from the reactor background some iron capture lines to calibrate for energy to at
Konstantin Mashtakov: Those high energy region.
S Yates: Okay.
S Yates: Second question, I have has to do what the figure is that you showed very early, the pig, pig me dipole and the giant eyeball.
Konstantin Mashtakov: Oh yeah, okay.
S Yates: Back in the old days before we knew about pygmy dipole, we used to talk about the tale of the giant
Konstantin Mashtakov: Yes.
S Yates: How does that impact and effect you picture.
Konstantin Mashtakov: The tail.
Konstantin Mashtakov: Yeah, so
Konstantin Mashtakov: Yeah I know there is a mechanism called the damping. So the dipole resonance might be
Konstantin Mashtakov: How to say, yeah, so it's I think it's important to differentiate between the tale of the giant dipole resonance and the pygmy that resonance itself because they correspond to different
Konstantin Mashtakov: Modes of excitations and I believe in order to answer your question properly.
Konstantin Mashtakov: And in order to differentiate between those two we will need to have more experimental information on the pygmy diaper resonance about something like
Konstantin Mashtakov: The, the structure of those levels involved in the pygmy diaper resonance
Konstantin Mashtakov: And combining different experimental probes to see what are the conditions that can differentiate between the tale of the giant diaper resonance and the pygmy that resonance itself.
Konstantin Mashtakov: If we would be able to extract more of those than that would be, that would be awesome. That's I think that's one of the major goals for studying this pygmy dipole resonance energy region.
Konstantin Mashtakov: But yeah, well, in my case, since the beta decay goes up to 7.1 a movie.
Konstantin Mashtakov: And also falling from the
Konstantin Mashtakov: Those quasi particle phone on model calculations, it's safe to assume that those levels correspond to the pygmy dipole resonance
Konstantin Mashtakov: And
Konstantin Mashtakov: Yet
Konstantin Mashtakov: Some, some of the States might be also responding to the tale of the giant Apple resonance, but it's hard to say because the level then stick. It's quite high. As you go up and energy.
S Yates: Yeah. Okay, thank you very much.
Konstantin Mashtakov: Thanks for the question.
James Smallcombe: Okay. Just forget on the question I see marks made a comment in the chat that I've seen is relevant to the last person saying I suspend sensitive probes like complimentary experiment with alpha beans.
James Smallcombe: Mouse comment. So we've got another raised hand from Dr. Al Gore. You want to go ahead
algora: Thank you. I have
algora: Two comments, actually.
algora: In one of the first of all, congratulations consenting was a very nice talk. Thank you.
algora: And I think I have a comment. You mentioned that for you was not trivial to compare the feelings that you were, meaning your data.
algora: And I think another way, which is very useful for comparing the the this data is to do what what we call non Molly's accumulated feeling that the show in a figure you you add
algora: The feeling up to a certain excitation energy with okay and this might be very useful for comparing where you have pandemonium or or differences.
Konstantin Mashtakov: Yeah, yeah, I was actually talking with the person who was doing the total absorption gamma ray spectroscopy for this beta decay and his suggestion was
Konstantin Mashtakov: See, yes, in order to provide more or less fair comparison between those both techniques, instead of accumulating
Konstantin Mashtakov: The whole the whole energy regionally suggested increasing their
Konstantin Mashtakov: bandwidth of the data, which would already kind of absorb the nearby beans in both experiment. Those making it more or less cumulative distribution as
algora: Well as you can do that. You accumulate up to a certain excitation in the daughter.
algora: Yeah, this is also a nice way of showing
algora: I have another comment.
algora: Which is related to one of the conclusions of you say that
algora: This new high resolution.
algora: Measurements do not suffer or may not suffer so seriously from Monday morning my comment, these are, this is
algora: heavily dependent on the case because I think we studied cases with both techniques, and I think we were not able to see feeling a very high tech citation, even with very
algora: Efficient gamma rays.
algora: So,
Konstantin Mashtakov: Yeah, your
algora: Your case.
Konstantin Mashtakov: It's case dependent because also because of the different. Q Was involved and the limitations of the experimental techniques and apparatus used
Konstantin Mashtakov: For example, we only use two clover detectors. Maybe if we had more, we would be able to see more, I can. My conclusion is not concrete and set stone, but a judging on what we were able to extract from to close it's more or less as
Konstantin Mashtakov: Well, we can we can say we can. Suppose that it's not entirely free of pandemonium but it's way better than it used to be the past
No problems.
James Smallcombe: Okay, Christoph, this is costing Ganymede chat wants to know how you determine the ground state to ground state feeding.
Konstantin Mashtakov: The ground state. The ground state feeding. I do not do that. In my case, because
Konstantin Mashtakov: I'm not a year in our spectra. We see beta decay, like the ground state. The ground state.
Konstantin Mashtakov: Beta case and we also see the isometric beta decay of 96 to 96 or quantum so everything below free movie is really convoluted and for that I had to rely on the previous data provided by
Konstantin Mashtakov: Previous high resolution spectroscopy study as well as recently confirmed by the new study newbie to the case study of
Konstantin Mashtakov: This particular DK with total absorption gamma ray spectroscopy, they confirm the ground state to Cranston's feeding to be 95.5% so basically majority of the big case go the other channel.
Konstantin Mashtakov: And for my analysis I use everything all the beat the feeding information below level. So for a movie.
Konstantin Mashtakov: I basically rely on other sources and above that value. I read normalize and I
Konstantin Mashtakov: Take into account the new
Konstantin Mashtakov: And new feedings discovered in the current work, but for the ground state grants that feeding. I can't. I wasn't, I wasn't able to identify in my current work I I took the value from the previous a measure of work.
Konstantin Mashtakov: The value of 95.5% okay
James Smallcombe: Question of my own. And can you get to that very nice electron spectrum you had
James Smallcombe: I'm sorry if you already
James Smallcombe: Answered the question to ask but you have these conversion electron peaks that you say you don't get on
James Smallcombe: Yes. Yeah, very good. But it seems that there's and you said that the the gamma absorption had because they weren't sensitive. This stage and some extra feature. But if you don't get on those, you get rid of that feature, but are you not also
James Smallcombe: Do not have to correct for the large amount of electrons that you've asked so excluded beneath the peaks.
Konstantin Mashtakov: Well,
Konstantin Mashtakov: Yeah. Well, I, I tried to minimize the area beneath the pics as much as I could, but due to the large area beneath and well I didn't really have to correct for for it because it's not really that much that is excluded from the total
Konstantin Mashtakov: Total spectrum, so to say.
Konstantin Mashtakov: So there I don't think I've done any corrections with regards to that. Okay.
James Smallcombe: Do we have any other questions I would also now at this point. Welcome, anybody who doesn't have the raise hand button, but would like to unmute themselves to ask a question to do so.
James Smallcombe: But I don't see anyone take me up on that offer so idle for quite some questions there and say thank you for talking discussion Constantine, I was very good.
Konstantin Mashtakov: Thank you for inviting me.
James Smallcombe: And just decided to everyone. General announcements. So again, no other talks this week. But again, if you are a student or if you have a student who's
James Smallcombe: missed out on opportunities to present them would like to give one of the students seminars, please get in contact with Dave char, either at David sharpe@manchester.co.uk I realized that confidence or there's also addressed in the lockdown seminars website.
James Smallcombe: But on that hopefully we'll see you next week, Monday 3pm PST as usual.
James Smallcombe: Where we've got casita Rosa and Lipsky from the heavy on barter university also going to be talking to us about Shakers distance studies with cumin expectation in the n equals one eye for an N equals 60 regions. So hopefully see you all again next week for that.
James Smallcombe: Nothing else for me to say, but thank you once again confident in giving a talk and thank you everyone for joining us. Have a good week. Goodbye. Thank you, you too. Bye.