James Smallcombe: Okay, so with that I shall say, Mark, please tell us about your work.
Mark Spieker: We do and following
Mark Spieker: The Federal approach chosen here. Let's talk about something serious now.
Mark Spieker: And forget about the pandemic.
Mark Spieker: Um, so, as already introduced I'll be talking about assessment symmetry to 56 and some results that we got while I was a postdoc at Michigan State University, working with Alexandra gala and the advisor.
Mark Spieker: And I should mention right away in case I forget. In the end, that this work has been supported by the National Science Foundation.
Mark Spieker: Okay, so something
Mark Spieker: In the beginning, that we are all aware from our introductory nuclear physics classes as these equal and 28 that's actually the first one form solely due to the spin orbit coupling.
Mark Spieker: And from that, we would actually expect that 56 Nicole as a well behaved W magic nucleus and that the one f seven half shell is fully phones.
Mark Spieker: When we talk about the F7 half shell. We think about nuclei spending the range from above. Calcium 40 to 56 nickel and then we are subsequently filling the seven
Mark Spieker: Now for magic nucleus, that's also something we know from our nuclear physics textbooks, we would expect that the energy of the first excited state.
Mark Spieker: Which is the two plus energy in the evening. Nicole nuclei increases at the shell closure, which we observed for 56 nickel and that the B to decrease
Mark Spieker: Which we kind of observe is not as pronounced as we've seen for many other magic nuclei as systems can see here for class I magic nucleus located at mi n equal 40 sub shell closure where we see a much more pronounced decrease of the to value.
Mark Spieker: Following large scale shamrock calculations performed in the full FP models face. This was interpreted
Mark Spieker: By suggesting that only 60% of the ground state way function of 56 Nicola actually correspond to one f seven half configuration where all particles are placed in the one f seven additional
Mark Spieker: So this means that 56 Nicholas a soft core and that we're dealing with cross shell mixing in our say a bit few more things about that in a second. This can x and y, the beat to it's not as suppressed affected for w magic 56 Nicole and actually deals share model calculations.
Mark Spieker: Back in 2000 presented Bahama at all can reproduce the issue and 56 NATO, but also there are several mental of server that's
Mark Spieker: Actually show that we're dealing with a core broken nature here and that 56 Nicholas soft core nucleus where we have to consider cross shell mixing
Mark Spieker: What I mean by cross shall make saying is that in addition to having the F7 half or the PDF seven half configuration.
Mark Spieker: In your ground state way function. You also have contributions from to particle to whole excitations across the n equals equals 28
Mark Spieker: Toshio and if you look now at these shallow calculations you actually see that the occupation number numbers for
Mark Spieker: The f5 Pfaff the P3 have and the P word on have an odd zero, which is exactly due to this cross shall mixing and the expectations to particular to whole excitations actually across the 28th shaped closure.
Mark Spieker: Now this has also been verified experimentally Schiffer at all and also lead outperformed transfer experiments close to 56 Nicole, but on the next call it nutrient rich side of 56 NATO and you can see the data here.
Mark Spieker: As Phil symbols and what this plot Chelsea is the vacancy. So the vacancy in the F7 half shell and the closer we get
Mark Spieker: To 56 go the more vacant. The F seven half shell gets where we see that the experimental data seems to me that
Mark Spieker: Vacancies actually one while the shower model as you can also see up here where we have 7.59 instead of the eight particles in the F7 half shell.
Mark Spieker: Predict said it's only about half of it.
Mark Spieker: So there's also a already a discrepancy here between these Shyamalan calculations and the data that we helpful at the time.
Mark Spieker: Now there are a few open questions and that is what actually happened once we go below is equal and 28 shock closer of obviously we're not expecting affiliate fee of seven half in a simple picture here. And since the
Mark Spieker: The Holy Grail into action in this region.
Mark Spieker: I suspend conserving into action. There's of course also the question whether we expect the same trends. When we move towards and neutrons.
Mark Spieker: A few experiments have been performed before we analyze our data. And actually I'm
Mark Spieker: Following a beta decay experiments by Vandana Tripathi at are many states were established for the first time back in 2013 this beta decay experiment was performed at the NSC L.
Mark Spieker: And it was actually the first experiment to report to gamma TK branching for the low lying spin states in 55 nickel, even though in this specific publication of branching ratios of values for branching ratios were reported
Mark Spieker: The Office presented
Mark Spieker: Guidance for ISIS been mixing in 55 Nicole, but at high energies. And this was for the Asbury gamma look state of 55 copper in 55 nickel and there they found I suspend mixing between two 300 minus states have different with a different ISIS been quantum
Mark Spieker: Also from an experiment performed at the NSC L. This was a
Mark Spieker: DP experiment in inverse kinematics.
Mark Spieker: PD experiment.
Mark Spieker: The group of batted sang and bull Lynch were actually able to populate the first few excited states in
Mark Spieker: 55 Nico, and also to extract
Mark Spieker: Spectroscopic factors and interest what they saw was a very strong excitation off the
Mark Spieker: Dominant to S one half segment which is way below the F7 half over to right so in our experiment, since we would we would be seeing knockout data soon, that would mean that we actually knocked out a particle from this all the time.
Mark Spieker: Now another story in this mass retirement. This is may need the work of Mike Bentley and the your group and collaborators, they found that in addition to pull on contributions.
Mark Spieker: To the show model Hamiltonian, you actually had to include I suspend non conserving to body matrix elements to describe the mirror energy
Mark Spieker: In the F7 half shell and that actually bone, including the coolest you would not get
Mark Spieker: Good reproduction of the experimental data. They found by fitting to data. So they determined in him periodical is a vector I suspend on conserving matrix elements that there was pronounced independence, she can see down here.
Mark Spieker: And actually also if you restrict your bit just to a few nuclei this spin dependence becomes quite apparent.
Mark Spieker: Now looking at the triplet energy differences. It's basically the same story just including cooler and contributions to describe the energy differences.
Mark Spieker: Between nuclear belonging to an ISIS and Marty, but this case a triplet was not sufficient and
Mark Spieker: Mike and his collaborators actually saw that you had to include an ISO tensor in this, as has been non conserving matrix element, also with a pronounced independence.
Mark Spieker: And this is sort of mine up astrophysics slide. Since the states, we have to talk about
Mark Spieker: All the implications of our work for nuclear physics.
Mark Spieker: 56 NATO is interesting. In fact, and people are looking at 56 NATO and how it is synthesized into different astrophysical astrophysical scenarios.
Mark Spieker: For instance, here. This is a simulation done by the XML project. We were they simulated the abundance of 56 Nicola, and the late stage of core color supernova. And what they found here is this very interesting pattern where this mushrooms, develop, which you should be able to detect as
Mark Spieker: As well and as a tropic distribution and the sky when detecting the gamma rays from 56 nickel and
Mark Spieker: Not for this specific case, people have done that. But do you that are using the integral spectrometer have actually detected gamma rays coming from the decay of 56 nickel.
Mark Spieker: And they detach get them effectively early in the after the explosion that they had observed, and that was only 20 days after it.
Mark Spieker: From which they could have infer a scenario when accretion valid had been formed, which was discussed before, as a possible scenario for type one, a supernova.
Mark Spieker: But indications for that had not been seen based on memories. So this gave him this nice science on vacation. Okay. Now, coming to the nuclear structure part or going back to the structure part of my talk. We performed one nuclear knockout performance from 56 nickel and 55 toll roads.
Mark Spieker: So the nuclei that I'll be talking about that has been popular in the studies were for the knockout from
Mark Spieker: Cobalt and for the second part of my talk 54 cobalt and 54
Mark Spieker: As already mentioned the experiments have that the general superconducting secretarial of oratory at Michigan State University.
Mark Spieker: Using the couple of cyclotron our facility from which we got high intense primary 58 nickel beam and where we produced our 56 Nicole, the beam from Project fragmentation and then it was probably purified with the 1900 fragments separator and then sent to the satanic analysis beam line.
Mark Spieker: And in the middle of the array which I'll show you in a second, a knockoff reaction was induced gamma rays were detected a second. I'll give you a few details on that in a second. And the resurgent the knockout residuals were detected with the attendance factor well
Mark Spieker: Now,
Mark Spieker: As most of you will now I'm both the incoming beam and also the outgoing beam are detected on an event by event basis for the incoming beam.
Mark Spieker: And there's a time of flight measurement which unambiguously identifies the incoming beam. So now we're dealing with the cocktail been having the strongest component as 56 Nichols second strongest a 55 cobalt and the 50% component in the beam was about 4%
Mark Spieker: He as a time that analysis beam line and the exit fee Cincy lighters basically located at the focal plane point at the end of the 1900s 1900s, while the object since you later, which you use for the time of sentiment is placed at the beginning of the asset on that analysis be mine.
Mark Spieker: Um, so in general the asset on it allows for energy last time of five measurements position men measurements angle measurements and therefore also for long momentum reconstruction.
Mark Spieker: I mentioned the event by then particular identification, which is possible with the SF hundred
Mark Spieker: I guess most of you have seen this, the system particular identification part that you get from these kinds of experiments.
Mark Spieker: In this case with the energy last measured in the ionization chamber of the asset hundred deception detection system on the Y axis and the time of flight between the
Mark Spieker: authenticator and the one you later place at the end of the 800 on the x axis. As you can see, for this case knockout from 56 NATO, the knockout residuals 55 cobalt and 50 fair nickel can be unambiguously identified
Mark Spieker: And as you'd expect from systematic scanned over the years from these kinds of
Mark Spieker: Reactions cross section for the knockout to 5555 cold it's larger than the one to 55 Neko which is
Mark Spieker: Of course, part of this story of the reduction of the spectroscopic factors observed from these kinds of experiments.
Mark Spieker: And shouldn't that we detect the in flight gamma rays following
Mark Spieker: excitation of the knockout residual with Sangha Sangha is segmented germanium array. In this case, consisting of 1632 Ford segmented her purity germanium detectors which are arranged in two rings seven of them place at 37 degrees and
Mark Spieker: Then place at 90 degrees. And this is the segmentation of Sega to give you an idea about the of the granularity of it.
Mark Spieker: Of course, if you performing experiments at 40% of the speed of light, you need to you need to perform a Doppler correction.
Mark Spieker: Otherwise he would not be able to identify the gamma rays coming from 55 cobalt. If you were only restricting yourself to the complete detection volume of your germanium detected now.
Mark Spieker: Bringing in the segmentation and actually performing the Doppler correction by identifying the position of the interaction as the segment with is energy to position, you can
Mark Spieker: Identify the gamma ray lines belonging to 52 the excitation of excited states 55 como
Mark Spieker: Now, going on to the results from these knockout experiments on 56 Nicole.
Mark Spieker: Studying actually this a 5051 half neuro pair.
Mark Spieker: These are the spectra that we've got first glance, they look quite similar, especially here at the high energy part above to MTV where we observe the the excitation of the
Mark Spieker: Few excited states. These two three f minus states and the first accepted five five minus stays short reminder. We're dealing with
Mark Spieker: cross channel accepted cross channel mixing here if we will only dealing with an F seven half configuration would not seeing any indications.
Mark Spieker: For the highlighting excited states have 55 Nico and 55 card so already seeing the gamma rays coming from the States tells us that we're not dealing with a pure F seven half configuration because otherwise we could not be knocking out particles from the average
Mark Spieker: Shown and read to G or four simulations. I'm taking into account for geometry of the Sega setup, but I see efficiencies benchmarks why several experiments and also source measurements.
Mark Spieker: Now this is the level scheme which we were able to construct partly known for 55 kilowatt and 55 nicker prior to our experiments.
Mark Spieker: And as mentioned in my introduction, just briefly, and if there were no no cool on effects you would actually expect that these two level schemes should be identical for the mirror pair.
Mark Spieker: And usually more energy differences are studied to unmask the different effects which cause energy differences between mirror pairs or nuclei belonging to a triplet, which we'll talk about later.
Mark Spieker: These are these men mirror energy differences in the case of 55 Nick and 55 Koba. This is the energy difference between states and
Mark Spieker: 55 nickel and cobalt and for the negative parity states we observed that this Mirror, mirror energy differences are around minus 100 kV
Mark Spieker: For the positive parity states which we populated. So, as in previous studies. We also populated.
Mark Spieker: The one half plus and the 300 plus states we knocked out.
Mark Spieker: New crayons from below the F7 half shell.
Mark Spieker: For them dinner energy differences. I actually above 200 KB and possible now from the negative Marissa energy differences we actually learned
Mark Spieker: That in order to describe them, we would need to increase the church radius of excited states relative to the non state by about 1% which corresponds to an increase the Cuban see of the two p three half all the to
Mark Spieker: The to the cluster on a cave inner energy differences for the positive parity state point actually at the necessary additional relativistic electromagnetic spin all the corrections. And as those of you. For those of you who are familiar with this field, you are now this is nothing new.
Mark Spieker: That's actually been realized before. And as I mentioned, this is the work
Mark Spieker: Among other authors by Mike Bentley. The your group and our collaborators.
Mark Spieker: So what we learned from this actually is has been non conserving effects have to be included. So their energy differences. Now going one step further and this is what we did is we studied the
Mark Spieker: Partial cross sections as well and compare them to the large scale model calculations and the full FP models based which I mentioned
Mark Spieker: Earlier. But now, including charge dependent contributions and US has been non conserving to them until onion.
Mark Spieker: To predict spectroscopic factors and then combine these with icon or reaction theory should have mentioned that
Mark Spieker: For the one half plus state and the 300 plus state the spectroscopic factors do not come the large scale model calculations that we perform, but we're, we're, put in by hand and taken from work published earlier.
Mark Spieker: Where spectroscopic factors for the one half plus and three of us were
Mark Spieker: Reported based on Sharma relations performed by that he's saying, and Bill engine tech collaborators.
Mark Spieker: Now this is this is the expectation coming from combining the spectroscopic factors with a common reaction theory, it's pretty much the same.
Mark Spieker: The pattern, which you see the only slight differences. This energy change here between a five half excited state and seven half minus excited state. Now let's bring in the experimental
Mark Spieker: And as you can see it looks quite different already. Um, so as I mentioned before, the inclusive cross sections.
Mark Spieker: Follow the expected Trent, and from attracting the partial cross sections which will determine via the gamma ray years were able to upper limits for the cross section, leading to the ground state.
Mark Spieker: We might see some symmetry here, but I should say sort of
Mark Spieker: That he would be missing feeding.
Mark Spieker: This could also be an explanation for this difference here and the breadth of the counseling.
Mark Spieker: Okay, what we see as we excited several excited states, not just the ground state, which is an indication for the cross channel mixing and 56 nickel.
Mark Spieker: Sd states also populated in our studies, shown here in black for the one half plus state and in light blue for the three half plus state.
Mark Spieker: Means that in order to understand this fixed recipe of excited state in this mass region you actually need to include the ST orbitals, since you already find them quite low energies, where you also find the FP states.
Mark Spieker: And in addition to that we observe the week population compared to the ground state our core coupled group of states. In our case, nine half minus and 11
Mark Spieker: Nine half minus one half minus sort of spin assignment is not certain. In this case, which might end at did small contribution for more indirect the actual processes. So to step processes.
Mark Spieker: Because these nine half minus states or if it was an 11
Mark Spieker: True for both could not be populated in a one step knockout process from 56 naked bouncing you would actually need to include these two step processes to get to the states.
Mark Spieker: And this is something we've also been seen before, but not connected to such states is that we see actually for the simple states where we believe that they correspond to sing a whole states.
Mark Spieker: The parallel momentum distribution is centered and follows the prediction of the account reaction theory.
Mark Spieker: Wherefore these more complex states. Now here this state at 2.8 M e V which could correspond either to the nine half minus 11 x minus state the parallel momentum distribution is shifted so
Mark Spieker: To remind everyone, these parallel momentum distribution information on the outside in the knockout reaction.
Mark Spieker: Very similar to measuring Angular distributions and normal kinematic experiments and also in the normal like experiments in when we're dealing with power with
Mark Spieker: Complex configurations. So we have to include multi step. These anger distributions actually get this. However, right now converse kinematics and reaction theory such configurations cannot be explained so multi step processes are currently not included.
Mark Spieker: Okay, what is also unexpected was this very pronounced kitchen a cemetery quickly observed for the three half minus states actually the first two excited states of these two new API.
Mark Spieker: So you can see here and 55 Nicole basically all the strength, going to the three half minus states has concentrated and the first excited three f minus state.
Mark Spieker: The
Mark Spieker: Second three of my state after feeding correction is basically only weekly populated while in 55 cobalt, the two ships States share the cross sections.
Mark Spieker: And if you actually would be looking at the relative cross section and sum this up for the two states that be the same. It's around five 4.55%
Mark Spieker: So the total cross section, going to the three of mine estate seems to be the same, but the fragmentation of the strength quite different. And it's actually, as you can see down here not expected
Mark Spieker: By the shower model calculations which include cool long terms, and I suspect on concerning parts.
Mark Spieker: So what we did to try to get an idea what's happening is to with form simple to state mixing calculations.
Mark Spieker: And
Mark Spieker: Well, the reason why we why we can do this is that actually already looking at the population of these two, three of mine is now going from 55 iron to 55 so starting from the stable nuclear, we see that the share model does not get
Mark Spieker: The ratio between the two spec public factors. So the Shama does allow for some small mixing, which is on the order of one to 2% to describe the data that we from the
Mark Spieker: one proton adding I'm reaction on Iran going to 54 kilowatt so from that we got these mixing amplitude supplying that in
Mark Spieker: Unfortunately, we cannot describe the cross section of symmetry that we've seen can see here. So we only get small increase for the second three half minus state relative to the first three f minus state.
Mark Spieker: Okay so mixing is not sufficient, at least based on this little exercise to explain the cross section of a tree, which we observed in one cloud out resolve fetus could country that's always them if you
Mark Spieker: Determining this cross sections from gamma rays, however, I should mention that this feeling has to be significantly different between the two mirror nuclei. So already something different is gone.
Mark Spieker: If it's feeding related
Mark Spieker: However, we have another observable that we were able to look at. And this is actually he one decay from the one half plus stage to the to low lying three half minus states.
Mark Spieker: And good thing is that we do not observe a cross section a cemetery for the one half plus stage in our reaction. So again, this is the black bar, shown here.
Mark Spieker: In basis, the relative cross section is 6% so the structure of the one half plus state seems to be the same.
Mark Spieker: Now if we look at the DK and determine the ratio from it. We see that the yuan branching ratio between the two Iran nuclear is actually quite different.
Mark Spieker: So for 55 what we find something like 2.75 455 sneaker we have something like 3.9 instead the relative feeding to the to low lying three have minus states differs
Mark Spieker: And the one have class status, actually the main
Mark Spieker: And within uncertainties, these two values do not have an other engines.
Mark Spieker: For instance, for a 35 nuclear in a 67 nuclei these clear changes of each one of the one decay pattern between there are pears.
Mark Spieker: Have already been interpreted it I sort of spin symmetry violation, but also from this signature. We have some indications that either state mixing is going on, or we do see
Mark Spieker: Patients have ISIS been symmetry violation in
Mark Spieker: Decay observable. Now we can use the mixing that we determined previously in our to state model approach, which was wanted 2% and it's not necessarily I suspend mixing us
Mark Spieker: Data and since we know the lifetime in 55 Kobo arc for the for the one half busted and we now have measured the AMA TK branching ratios we determine the actual be one values to those too low lying.
Mark Spieker: To have minus states and even though the uncertainty of the lifetime is quite significant. These you want decay rates are enhanced
Mark Spieker: We can plug in the mixing and determine the be glaciers be one values we would expect for the unperturbed states. So, the non mix states and
Mark Spieker: Calculate the ratio from it. And what we see is that we get raised 2.3 which within uncertainty. So, taking into account the uncertainty from the matching ratios.
Mark Spieker: Is closer to the case of 55 nickel than 255 cobalt which could mean that the two states are mixing less than 55 Nico.
Mark Spieker: Based on this experimental observable and that would be an agreement with what we see for the cross sections. So summarizing this part.
Mark Spieker: I should also point out that for simple configuration. So if we're dealing with the one whole state for the one half plus state and a one.
Mark Spieker: Particle also one whole state for the P3 half state you want transitions between these two configurations would be forbidden because they would correspond to recoupling of two particles. So it wouldn't be a one particle transition. That means that also
Mark Spieker: We learned that at least more complex configuration must be at play.
Mark Spieker: The change in the one pattern could point at strong and mixing between the two, three have minor states and 55 1055 Nicole which agrees with what we see for the cross sections.
Mark Spieker: As I mentioned, the relative partial cross section going or for the one half plus states identical in America around 6%
Mark Spieker: So this supports our hypothesis that the one transitions are actually sensitive to the mixing between the two, three half minus states, rather than some mixing are playing into the structure of the one half plus
Mark Spieker: Okay. Now moving on to the second part of the one who can knock out data that we got
Mark Spieker: I'm not. I'm 55 core walks
Mark Spieker: And here we started the equal 54 to one is has been triplet are specific case we obtained data for 55 cold and 55 so one friend one neutral knockout from 55 calls
Mark Spieker: And also just as a reminder, I mentioned the triplet energy differences studied by Mike and his collaborators and the empirical I certain size has been on conserving to body matrix elements.
Mark Spieker: That they determined from their studies. What is missing here for the A 54 is has been triplet is actually the six pack which you'd expect for
Mark Spieker: Two whole configuration and BF seven half orbital. So you just couple of seven half and five half giving you the six plus, so six plus and 54 code is actually unknown and that's why the TD
Mark Spieker: Could not be added to this bigger it
Mark Spieker: Well, what are the goals and our field is, of course, to have theories which are based on up beneath your type approaches and
Mark Spieker: To describe experimental data based on this and for the case of the triplet energy differences or the see coefficients which are basically the same. Besides, bringing in the mass of the ground state and factor of two. And these have been
Mark Spieker: predicted by using up in Easter type potentials. So in this case, CD barn. The AV 18 arm developed at are gone and Kyra effective
Mark Spieker: The theory potential at next to next to next to next two or three next tues leading orders. So the expected structure, as I mentioned, for the six plus status primarily to whole structure in the F7 half and from these
Mark Spieker: Up. He needs to type
Mark Spieker: Of calculations, we expect that after we have identified the six plus and 54 cobalt, we would get a see coefficient of around open
And
Mark Spieker: Okay, I should also mention that the solid lines here correspond to the predictions when including both column and chart symmetry breaking contributions.
Mark Spieker: And that the church symmetry contribution of breaking contribution is shown here with dashed lines and actually this spin dependence, which has seen
Mark Spieker: Buying when you have included cool on and charged symmetry breaking contributions is almost entirely governed by the charge symmetry contributions and not the coolest part which is rather flat and that course agrees with what Mike sort of found
Mark Spieker: This pronounced independence of the ISO 10 science. He metrics element that they determined
Mark Spieker: Okay. Um, so there's one story though to these up and Easter type calculations and that is that they are mostly over predicting the experimental data and that the cemetery contribution has well they have to
Mark Spieker: Multiply it by factor smaller than one in all cases. So for the carrier effective theory potential actually almond and our at our meaning Alex brown
Mark Spieker: Introduced had to use an 80% scaling of this church cemetery code contribution that they determined to describe the experimental data for a quick 15 acre 46 nuclei and they saw significant discrepancies for the two particularly plan to home. Yeah.
Mark Spieker: So again, going back to the large scale Shama calculations using the same scheme that
Mark Spieker: We also used for 55 Colada and 55 Nicole, we now expect because of this.
Mark Spieker: To whole structure in the F7 half shell at the six plus state should be strongly populated in one you can knock out from 55 cobalt just because the dominant structure of the 55 Colbert ground state is actually a hole in the 50
Mark Spieker: In the seven half shell that strong spec to the large spectroscopic factor and therefore to manage cross section for the state. So,
Mark Spieker: We should be able to see it.
Mark Spieker: Now, these are the spectra.
Mark Spieker: Doppler corrected. Again, we got 455 cobalt and 54 Iran.
Mark Spieker: VOC was again 40% in this case.
Mark Spieker: And the known six plus and 54 iron. You can see here, this funky shape because it could have a significant lifetime, which has been plucked in into the jail simulations and actually well we can even though the background is here. We can describe the shape quite nicely.
Mark Spieker: Now the head or 54 cobalt for the six plus need to actually found a 2.9 MTV, which is of course a significant
Mark Spieker: Event gamma ray energy and the
Mark Spieker: Which we have. So for 54 Iran, which is the case because you have these
Mark Spieker: Odd spin states because of the art, art nature of 54 cobalt at lower energies in 54 covert so that the
Mark Spieker: Even spin states today to the oxygen states via fast and one transition
Mark Spieker: While in 54 primarily the two transitions between the states and the other states. And so that basically just means six plus here candy K
Mark Spieker: By a fast and one transition to the seven plus Iceman, which we know exists and 34 colon, and that's why you have this high energy gamma ray
Mark Spieker: Now from the gamma ray yield. Again, we can determine cross sections, which is an see here as a function of energy.
Mark Spieker: Partial cross section on the Y axis, the relative cross section relative to the inclusive cross section on the right part of the figure, and this is the cross section for our candidate.
Mark Spieker: And this year. That's the partial cross section that will determine for the six plus state in 54
Mark Spieker: I run from one town knockout from 54 colon. Now we can compare this to the sham over calculations which expects that these two states both
Mark Spieker: Both cases show significant cross sections and also experiment. And I'm assuming that this is the six plus state. Yeah, we see their cross section agrees within uncertainties.
Mark Spieker: Now an additional signature that we use to identify this candidate and 54 cobalt was its gamma DK behavior.
Mark Spieker: predicted by the share model to be 80% to the seven plus state and 17% to the five played so what we would expect from this decay branch as a transition to appear around 1210 kV we deserve a transition at 1206 kV and then determine the
Mark Spieker: Gamma DK intensities. A years of these two lines. The two nine or three and the one to six nine that 89% plus minus six out of this.
Mark Spieker: Total year to the six goes to the seven plus while 11%
Mark Spieker: Go to the five plus which agrees nicely with what the sham model predicted
Mark Spieker: Now we can block in our candidate for the six prostate and here to the other nuclei of the equal 54 I suspend triplet and our candidate is right here. I'm having to fire, we can
Mark Spieker: Calculate the
Mark Spieker: See coefficient, which is the bullet here found at Jake six and it nicely with the predictions of the large scale model calculations using these
Mark Spieker: This up in new CEO type of potential I should mention that in between on new ground save energy for 54 Nico has been determined which brought down the experimental values to
Mark Spieker: The theoretical prediction. So that's the caveat for the see efficiency compared to the triplet energy differences that you also need to know the current state mass precisely
Mark Spieker: We also see now scaling the chart symmetry breaking part by 60% that we find nice agreement for equal 50
Mark Spieker: The agreement for a 46 is decent and it's actually not that good for a 42 but here we actually know that the agreement should get worse if you start from shell model calculations in the FP space, which were used here.
Mark Spieker: Since he has these states mix into the era states.
Mark Spieker: In the costume region.
Mark Spieker: And their
Mark Spieker: Recent experiment with agate I think it studied before configuration 42 calcium and actually also
Mark Spieker: supported this interpretation that the SD states mix into a structure of the US states and calcium 42
Mark Spieker: Okay. And that brings me to the end of my I hope I've convinced you that sneak up to
Mark Spieker: Have wouldn't agree on that or hadn't agree on that before so soft core nucleus that you have to consider. He shall mixing
Mark Spieker: And that our data. In addition to the their energy differences which were known before. And this mass region support the increase the frequency of the P3 half based on cross sections we determine
Mark Spieker: The US has been non conserving effects in this mass reach nine generate important to understand the experimental trance for them or energy differences as well as for the triplet energy differences.
Mark Spieker: And we still have to understand, to what extent I suspend symmetries actually broken close to 56
Mark Spieker: Calculations only expected to be on the order of 5% or less.
Mark Spieker: So I'm also the open question whether we can understand why they are deviations. When we use up your type calculations which overestimate this non conserving part
Mark Spieker: And in fact, several experimental observers on via that farmers symmetries in the population care of excited states and we had still have to find out whether we're dealing with ISIS been mixing he or just simple state mixing
Mark Spieker: And the combination of Shama spectroscopic factors and I call my reaction theory has been extremely successful in the past and describing and also to up today.
Mark Spieker: In describing knockout data to pop like states, which means the one step processes, we have seen now that there are certain indications for two step or processes or complex configurations
Mark Spieker: And these configurations are currently outside of the simple I cannot reaction theory. So going forward,
Mark Spieker: I think some adjustments are needed here to understand the data and see whether our interpretation of it is actually correct and can be understood in reaction kinematic
Mark Spieker: I'm forgot you're interested, the results are actually published assessment work of several people. And I want to thank all of them and you for your attention. Thanks a lot.
James Smallcombe: Thank you very much, Mark. That's great. So do we have any questions for Martin, then
See if you
James Smallcombe: Collapse, which has now become appreciative audience don't yet see any questions. So I'm just in general question. What's next, is there more experimental what we can do, or do we need to wait for the theory on the reactions to catch up.
Mark Spieker: Well, of course it would be very nice. And as you'll notice this, our efforts currently being perceived to
Mark Spieker: Improve the reaction.
Theory.
Mark Spieker: But
Mark Spieker: As always, we also need other cases all that which show these shifts. We have a few of them now. I think they are five to six nuclei aware of where these seen these shifts of the momentum distributions.
Mark Spieker: Something which could also be done.
Mark Spieker: That's something that I'm showing here where I'm comparing now the cross sections that we determined for the April.
Mark Spieker: Nuclei to the A 42 particle nuclei, which looks quite similar, is that you extend these studies comparing knock out to DP or PD or similar reactions like three helium D.
Mark Spieker: Starting at effort, right. So with a few upgrades saying I'm using either Solaris or active target solutions.
James Smallcombe: Right. Excellent. So we put a question from Philip, actually, if you'd like to unmute yourself.
Philip Adsley: Is patent very much that can you hear me.
Yes, I
Philip Adsley: Thought I should check out. I have two questions. In fact, one of them is you saying about the the ground state branching out the cramps, a cross section there was some asymmetry, but that might be an artifact of the measurements, I think.
Philip Adsley: Yes, feeding. So is that is that a useful thing to know and how, how does it get found out because I do stable beam experiments. So this is very far away.
Mark Spieker: How we can
Philip Adsley: Yeah.
Mark Spieker: Sure that that feeding is
Philip Adsley: Contributing yeah and how, how might one find the
Mark Spieker: Ground. Okay, so, um,
Mark Spieker: So they are experiments where people were other sure that they have found all the strength that is expected
Mark Spieker: Right. And there's also the story of the reduction factor of the inclusive cross section that you find a knockout experiments relative expected share model plus icon reaction theory thing this band curve that Alex and Jeff work down
Mark Spieker: Now from that you, you could
Mark Spieker: If you trust it. You could calculate the inclusive cross section that you actually expect
Mark Spieker: Right.
Mark Spieker: So, and then say, okay,
Mark Spieker: If I'm using something like the FP model space for the share model. How much if even if I exclude or include all the states that this model predicts how much of this do I actually get
Mark Spieker: So, and from that you see that the Sherman was missing certain strength and we have seen that we do excite s amp D states right we do accept plus state and the three half past eight which outside of the FP model space.
Mark Spieker: But these two states do not carry all the spectroscopic strength which is expected for the one half plus and 300 plus
Mark Spieker: Senior Partner
Mark Spieker: Which means that the other is probably fragmented over a few more states.
Mark Spieker: Which could be excited and knock out
Mark Spieker: But have gamma ray energies which are higher.
Mark Spieker: Efficiency is low so that you can actually not resolve them and therefore also not subtract from the inclusive cross section because you only subtract states were actually resolve their gamma ray yields.
Mark Spieker: And from that you determine the ground state cross section. So that's why I'm saying it's an apple.
Mark Spieker: Yeah, so if you're not doing
Mark Spieker: Normal spectrometer experiments which you do a normal kinematics like DP way you detect the particle and you know directly that you're going to the state and you do gamma ray tech experiments, you have this sort of pandemonium effect. Right. Okay.
Philip Adsley: And the second question I had was just briefly the you were talking about the radius effect and the, I guess.
Philip Adsley: And at some point, you were also talking about the
Philip Adsley: Transitions and I I know in the past people have looked at the changes in in he won intensities with with radius effects. And I was wondering whether that we had been included in what you've done. I haven't quite follow it. So,
Mark Spieker: Um, so
Mark Spieker: The thing is, so that usually people then when they looked at these radius is either looked at the ground state itself when they were talking about nutrient skins or Halo.
Mark Spieker: Radio
Mark Spieker: Now if you think about you on decay rate coming from excited state. You would be actually interested in the radius of that state. Right. And since we're dealing with a one half plus state which has a dominant s one half whole structure.
Mark Spieker: I guess that is already quite extended since we're dealing with an L equals zero WAV file. So that's also one reason why we're observing, I guess an enhanced you want UK from there.
Thank you.
James Smallcombe: Great. I've got more questions verde. You want to go ahead with your question.
Rolf-Dietmar Herzberg: Um, can you see and hear me, I trust you then. Okay. Very well, thank you very much for that very nice talk and go that tremendous, tremendous late and this is a region. I'm not very familiar with, so forgive me if this is a silly question, but if you if you see something leaking into the
Rolf-Dietmar Herzberg: F7 half shell for from above them. Of course you should also see something leaking out. So if you compared to the nuclear outside of the
Rolf-Dietmar Herzberg: 28 shell.
Rolf-Dietmar Herzberg: Is the picture consistent with how much F seven half contributions you see there
Mark Spieker: Yes, I'm so you can also see that in this pop that I showed in the beginning right where people did these proton adding and you turn adding reactions on nuclei above 56 nickel where they found that we
Mark Spieker: Seems like we have
Mark Spieker: One neutron out or proton out of the F7 half on average.
Mark Spieker: When getting close to 56 nickel and then subsequently be seven half his fault. Once you move away from 56 nickel and that is actually something that is produced by the show model. Even the trend is similar, but the magnitude is underestimated as it seems, by the show model. Okay.
Thank you.
James Smallcombe: Okay, and
James Smallcombe: Welcome, if you want to go ahead and do
Wilton Catford: Sure. So I have a slightly indulgent question my eyes weren't quite quick enough to to get everything from one of your even earlier transparencies
Wilton Catford: Okay, so from the show model, you had the occupancy. This is a one on the left hand side.
Wilton Catford: So could you just take us a bit through that top left picture exactly what we can see the
Mark Spieker: Play. So what you have is basically this region of the nuclear chart right here. Yeah, it's in this picture.
Mark Spieker: going a bit further. So we're going beyond the 28 shell closure so beyond 58 Nicole, which is right here.
Mark Spieker: And this is basically an ISO surface, right. So what you have here, this would be aligned where the F7 contribution to the ground state way function is 60%
Mark Spieker: Here's an island where
Mark Spieker: defamation sits in so the F7 half contribution gets even lower. And then with once the proton slow, of course, I mean you again somehow consider
Mark Spieker: 56 nickel.
Mark Spieker: F7 half 16 configuration. So this is basically everything relative to assuming 56 nickel as one f seven half 16 nuclear arms in that shell and the ground state function of 56 Nicole only corresponds for 60% to that for nuclei GOING CLOSER TO
Mark Spieker: To the calcium 90% of that mean that 56 Nico's W magic F one F seven half nucleus and father nuclei.
Wilton Catford: That aside, and guys that
Wilton Catford: Going up that N equals a line there is quite a lot of strength clustering around that line and then then as you get away from it, as you indicated, you've got the defamation region, whereas using more of the FP show Sarah.
Yes.
Wilton Catford: Yes, that's how I have this nice which calculations of those
Wilton Catford: This just
Mark Spieker: Comes from. Yeah, exactly. That's
Mark Spieker: That's the SPF one and coming from home, my doll. So you can find this paper.
Wilton Catford: Yeah. Okay. Thanks very much.
And welcome.
Wilton Catford: Great.
James Smallcombe: So if we have any other questions.
James Smallcombe: You want like if you're struggling with the raise hand button. You can either unmute yourself now or type very quickly in the text box before we say goodbye.
James Smallcombe: But I don't see anything else. So I think I'll say thank you to mark again for a great talk. And thank you to all of you for joining us.
Mark Spieker: Thanks for having me and listening.
James Smallcombe: And I do hope you'll all come back and join us on Monday. So again, 3pm PST, we have another talk for you. We've got teeth and I second.
James Smallcombe: Who's going to be talking to us about the structure of optical phones in nuclei. So have you all come back for that. So thank you all again for joining us. Thank you, Mark. Stay safe and happy weekend.
Mark Spieker: Car hopefully soon.