The same analysis procedures of 49Cl have performed in 49Ar. The resulting histogram
was shown in Fig. 4.11. An intense peak around 200 keV was fitted by a response function at
198 keV in this figure. The overlap of the Compton spectra included in the different response
functions is enough to reproduce correctly the energy range between 200 and 900 keV, without
evidence for another strong transition. The broad structure was reproduced mainly by three
response functions corresponding to transitions at 1050(29), 1340(14), and 1466(21) keV. The
fourth component at 1266(41) keV, non-significant on singles spectra, was added later on after
analysis of a 51K(p,2pn)49Ar channel. The last component between 1000 and 1600 keV might be
due to: i) an inaccurate shape of the background extrapolated from the high energy exponential
background after subtraction of the low-energy Bremsstrahlung; ii) weak unresolved transitions
involved in non-direct decays of higher energy states. We can conclude that the origin of that
component is not very well known. However, it does not affect the analysis conclusions except
for the intensity of the 198 keV transition and the underlying background. Therefore, we have
to consider these uncertainties to determine the exclusive cross-sections involving the 198 keV
transition. Two extreme cases have been considered for the fit: i) this component is simulated
by a series of transitions (six were necessary until a good χ2 is obtained); ii) addition of a second
low-energy exponential as shown in Fig. 4.11, which has a maximum effect on the intensity of the
lowest energy transition at 198 keV. This intensity increases by 27.2% from i) to ii), which can
be seen as the maximum uncertainty due to the fit procedure. Energies of transitions together
with relative intensities are listed in Tab. 4.6.
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ections are
obtained, using calculated C2S and single-particle cross sections from the TC and DWIA meth-
ods described in the text. The excitation energy range is limited to keV, as no state above this
energy with a sizeable spectroscopic factor has been obtained in the theoretical calculations.
The last two rows compare the measured inclusive cross section σinc to the sum of exclusive
cross sections
∑
σexi for the three employed calculations.
Experiment σljsp(E∗, Einc) SDPF-MUs
Eexp σexp ∆ℓ nlj σTC σDW State Energy
C2S
σth,TC σth,DWIA
(keV) (mb) (mb) (mb) (keV) (mb) (mb)
gs <17.2 (15) 1p3/2 7.4 8.0 3/2−1 gs 1.844 13.6 14.7
198 (3) 2.97 (64) 1 1/2−1 94 0.616 4.5 4.9
1050 (29) 1.52 (35) 5/2−1 923 0.006
1340 (14) 8.26 (66) 3 0f7/2 5.6 5.4 7/2−1 983 2.564 14.3 13.8
1466 (21) 6.34 (57) 1p3/2 6.4 7.0 3/2−2 1197 0.678 4.3 4.7
5/2−2 1460 0.233∑
σexi 35.5 37.5
Inclusive 36.3 (9)
Cross-section analysis of 49Ar isotope is similar to 49Cl, experimental values are com-
pared in Tab. 4.7 to the results of cross-section calculations σexi (E
∗) for excitation energies E∗
(see Eq. 4.1.4). Here, they were calculated with the TC [61] and DWIA [75] methods at 217
MeV/nucleon, which corresponds to the mid-target energy for 50Ar projectiles. Single-particle
σljsp(E∗, Einc) values were determined for the removal of one neutron in the different orbitals and
energies (1p3/2, gs), (0f7/2, 1340 keV) and (1p3/2, 1466 keV). Values are given in Tab. 4.7 and
used in the calculation of σth for the 3/2−1 , 7/2
−
1 and 3/2
−
2 states. Due to the weak dependence
with E∗, the same values were used for the 3/2−1 and 1/2
−
1 states. An overall agreement is
observed with experimental values, except for the large value obtained for the population of the
7/2−1 state, which possibly suggests a smaller spectroscopic factor.
Overall consistency may be tested through the reduction factor Rs = σinclusive /
∑
σexi ,
using the spectroscopic factor predictions of a shell model routinely used in this region like
SDPF-MUs calculation in Tab. 4.7. The values Rs = 1.09(11) and 1.03(11) are found with the
87
Results and Discussion
TC and DWIA reaction models, respectively, which places 50Ar(p,pn) (∆S = -17.8 MeV) in the
general trend observed for the one nucleon knockout reactions (see [77] and Fig.2 in Ref. [164]).
For the study of a new magic number at N = 32, 50Ar and the one neutron knockout is
a good tool to test the persistence of this shell effect with two protons less. In the shell-model
framework, one would expect, for a closed-shell nucleus at N = 32 in a spherical configuration,
the ν0f7/2 and ν1p3/2 orbitals to be filled, while ν1p1/2 and ν0f5/2 orbitals to be empty. In the
one-neutron removal, the occupancy number should be found 2j +1 for occupied orbitals and 0
for empty ones. Theoretical calculations have been performed for the one nucleon removal from
52Ca and 50Ar. Details of the calculations and the used interactions are given in Sec. 4.1 with
joined reference, in addition with the predictions of the HFB-D1S calculation in Ref. [165]. 52Ca
is predicted to be a spherical nucleus [165]. The 3/2−1 ground state and 7/2
−
1 state in
51Ca have
large spectroscopic factors in all theoretical calculations (Fig. 4.16), very close to the 2j+1 limit,
which is a signature of their single-particle character with a strong overlap with a neutron-hole
in the ν1p3/2 and ν0f7/2 orbitals of 52Ca, respectively. This is consistent with filled orbitals in
52Ca. At variance, the 1/2−1 state has a large excitation energy and a small spectroscopic factor,
if not null. This can be understood as the removal of a 1p1/2 neutron from a (ν1p3/2)2(ν1p1/2)2
configuration with a small weight in the 52Ca wave function and a large ν1p3/2−ν1p1/2 spherical
gap. This is what we expect for a closed shell nucleus at N = 32 in the shell model framework.
0 10000
1
2
3
4
49Ar-SM 49Ar-IMSRG 49Ar-GGF1 49Ar-GGF2 51Ca-SM 51Ca-IMSRG 51Ca-GGF1 51Ca-GGF2
C2 S
Energy (keV)
3/2-
0 1000 20000.0
0.2
0.4
0.6
0.8
1.0
Energy (keV)
1/2-
0 2000 40000
2
4
6
8
Energy (keV)
7/2-
Figure 4.16: Spectroscopic factor distributions for 3/2− (left), 1/2− (middle) and 7/2− (right)
states in 49Ar (full bars) and 51Ca (open bars) obtained with shell-model, IMSRG and GGF
calculations using the original SDPF-MU interaction (red), 1.8/2.0 (EM) interaction (blue) and
the NN + 3N(lnl) (green) and NNLOsat (black) interactions, respectively.
A rather different picture arises for 50Ar. The potential energy surface in Ref. [165] is
much softer than for 52Ca and a trend towards oblate deformation may be observed. This trend
in the argon isotopes below the Z = 20 magic number, is favored by the gain in energy for the
88
Results and Discussion
3/2+ [202] proton orbital, in the Nilsson model framework, as observed in Fig. 4.17. A secondary
shallow minimum is predicted at low energy and β ≃ −0.25.
Figure 4.17: The different plots are taken from Ref. [165] for 50Ar with HFB calculation and the
D1S interaction : (left) potential energy surface of 50Ar versus quadrupolar deformation; (right)
energy of the proton and neutron orbitals versus the quadrupolar deformation β parameter. The
orbitals discussed in text are labelled with the usual Nilsson K[N,nz,Λ]. The black dots stand
for the Fermi level. The red arrows correspond to β = 0.25 which is approximately the position
of the oblate minimum
Considering axially deformed nuclei, such as for the quadrupolar degree of freedom, J is
no longer a good quantum number, but the third component K of the total angular momentum
on the symmetry axis. At a given deformation, the wave function of each Kπ orbital is a mixing
of all the spherical orbitals with same Kπ, with phases related to the spectroscopic factors. For
a given K, an intrinsic j orbital may be projected over several physical states Jπ, following
−→
j =
−→
J +
−→
R . The band-head J = j state only, corresponding to R = 0, can be accessed in a prompt
direct reaction, such as a one-step nucleon transfer. Depending on the one-step character of
the (p,pn) reaction at 217 MeV/u or not, the states accessible will be also limited to R = 0 or
beyond.
For 50Ar, the spherical valence orbital ν1p3/2 is now splitted into two deformed orbitals,
labeled 1/2−[321] and 3/2−[312] in Fig. 4.17. At low deformation on the oblate side (β < 0), the
Fermi level coincides with the valence 1/2−[321] orbital. It is mainly of ν1p3/2 origin close to
β = 0. When β increases, the 1/2−[321] orbital is rapidly repulsed downwards by 1/2−[301] from
the spherical ν1p1/2, and further on by the others K = 1/2 orbitals , which results in a strong
89
Results and Discussion
mixing of the wave function. This could explain, at low β values, the population of two states,
3/2−1 and 1/2
−
1 . It is not possible to predict qualitatively which one would be the ground state,
but a low excitation energy for the excited state and high C2S values for both of them, while a
1/2− state in a spherical configuration should be found at much higher excitation energy, such
as for 51Ca. The slightly more bound 3/2−[312] is the next valence orbital, just below 1/2−[321].
Even at low oblate deformation, 3/2−[312] is repulsed upwards by the 3/2−[321] orbital of ν0f7/2
origin. The mixing is favored by the quadrupolar correlations between the ν1p3/2 and ν0f7/2
orbitals, for which ∆ℓ = 2. This could explain the 7/2−1 and 3/2
−
2 states at moderate excitation
energy. There is also a possible mixing due to the repulsion from the K = 3/2 orbital of ν0f5/2
origin, responsible for a 5/2− state with small C2S values at low deformation. The neutron
removal from the deeper orbitals originating from the spherical ν0f7/2, such as 1/2−[312] or
3/2−[321], will populate states at much higher excitation energy, considering the large N = 28
spherical energy gap.
1000 2000 3000 4000 5000 60000.0
0.5
1.0
1.5
2.0
2.5
3.0
C2 S
Energy (keV)
49Ar : 7/2-
49Ar : 3/2-
3500 4000 4500 50000
2
4
6
8
C2 S
Energy (keV)
51Ca : 7/2-
0 1000 2000 3000 4000 50000.0
0.4
0.8
1.2
1.6
2.0
C2 S
Energy (keV)
0 1000 2000 30000
2
4
C2 S
Energy (keV)
51Ca : 3/2-
Figure 4.18: Spectroscopic factor ||⟨A−1X + n ∥AX⟩||2 distributions for 7/2− and 3/2− states
in 49Ar (red) and 51Ca (blue) obtained for the shell-model calculation with the SDPF-MUs
interaction.
We will first consider the results of the shell-model calculation with SDPF-MUs interaction.
7/2−states
90
Results and Discussion
The C2S distribution is shown in Fig.4.18-(a) for the first 7/2− states in 49Ar. In spite
of the high excitation energy range, the sum
∑
i(C
2S)i = 6.95 is lower than the value for 7/2−1
in 51Ca, with evidence for a fragmentation of the distribution. Two states, 7/2−1 and 7/2
−
4 ,
have a large C2S value. The 7/2−1 state has a low excitation energy E
∗ = 983 keV and a large
value B(E2; 7/2−1 → 3/2−1 ) = 72.1 e2fm4 to the ground state. It is consistent with the neutron
removal from a deformed valence orbital. From what precedes, the origin could be from the
3/2−[312], but also possibly from 1/2−[321], as a member of the ground state band with R = 2,
if such a state is populated in the (p,pn) reaction. Moreover the excitation energy of the first 2+
state in 50Ar, E∗(2+1 ) = 1178 keV [9] is close to the 7/2
−
1 energy. The excitation energy E
∗ =
3245 keV of the 7/2−4 state, well above the S1n energy, is similar to the value obtained for 7/2
−
1
in 51Ca. It may be associated to the neutron removal from the spherical ν0f7/2 or the slightly
deformed orbitals, such as 1/2−[330].
3/2−states
The C2S distribution for 3/2− states is shown in Fig.4.18-(b). Here again the distribution
is more fragmented and the sum
∑
i(C
2S)i = 3.19 is lower than the value for 3/2−1 in
51Ca.
Besides the 3/2−1 ground state, a 3/2
−
2 state is found at about 1 MeV, which could be associated
to the removal from a deformed valence orbital. This is consistent with the measured cross
sections.
1/2−states
The energy difference between the ground and first excited stats is found to be quite small.
Comparably small values are obtained with the original SDPF-MU or SDPF-MUr interactions.
Whereas the C2S value for 3/2−1 , although large, is well reduced compared to the
51Ca
case, the C2S value for 1/2−1 significantly increases from
51Ca to 49Ar which is confirmed by the
experimental cross section measured for the first excited state, assumed to be 1/2−1 , in Tab. 4.7.
Here again we observe a striking deviation from a closed shell nucleus which is better illustrated
by 51Ca, for which the low C2S value of the 1/2−1 state at about 1 MeV is consistent with a
weak occupancy of the spherical ν1p1/2 orbital.
Numerical values for the neutron content Nν of the ν1p3/2 and ν1p1/2 orbitals are displayed
in Tab. 4.8 for the shell model calculation with SDPF-MUs interaction of 51Ca and 49Ar. This
change is not driven by the monopole gap between the ν1p3/2 and ν1p1/2 orbitals which does not
significantly change from one nucleus to the other, as already mentioned in [9]. Considering the
monopole matrix elements in the SDPF-MU hamiltonian = −0.66MeV and
91
Results and Discussion
< π0d3/2−ν1p1/2 = −0.57MeV , the removal of two protons from 51Ca to 49Ar is not expected
to impact much the energy gap ν1p3/2−ν1p1/2 and therefore Nν . The low excitation energy and
sizeable C2S value of the 1/2−1 state is a clear indication of collective effects present in
49Ar. This
change is not driven by the monopole gap between the ν1p3/2 and ν1p1/2 orbitals which does not
significantly change from one nucleus to the other, as already mentioned in [9]. Considering the
monopole matrix elements in the SDPF-MU hamiltonian = −0.66MeV
and < π0d3/2 − ν1p1/2 = −0.57MeV , the removal of two protons from 51Ca to 49Ar is not
expected to impact much the energy gap ν1p3/2 − ν1p1/2 and therefore Nν . The low excitation
energy and sizeable C2S value of the 1/2−1 state is a clear indication of collective effects present
in 49Ar
Table 4.8: Neutron content Nν of the different fp orbitals in the gs wave function of 52Ca and
50Ar obtained in the shell-model calculation using the SDPF-MUs interaction.
Nν(nlj) 52Ca 50Ar
ν0f7/2 7.95 7.61
ν0f5/2 0.13 0.41
ν1p3/2 3.76 3.28
ν1p1/2 0.17 0.70
Quadrupolar correlations may be put forward. A comparison may be drawn with the less
neutron-rich partners 48Ca and 46Ar nuclei at the N = 28 shell closure. It was suggested [20, 166]
that 46Ar has a vibrational structure and an oblate minimum is visible in the PES calculated [165,
167] with the 5DCH interaction [168]. Coming back to 50Ar, the SDPF-MU calculation in [12]
predicts a ratio E(4+1 )/E(2
+
1 ) = 2.05, consistent with a vibrational character. The PES shows
a soft behaviour of the ground state vs deformation, so that the measurement of E(4+1 ) would
provide information on the quadrupolar deformation of 50Ar.
The deformed shallow minimum at low energy seen in Fig. 4.17 impacts the physical states
0+1 and 0
+
2 in also present in the shell model calculation, as shown in Tab.4.9. A stronger mixing
0p0h versus 2p2h is found in the wave functions of the 0+2 and 0
+
2 states in
50Ar compared to
52Ca. The resulting 0+2 state is predicted at much smaller excitation energy.
This discussion is consistent with a fast reduction of the magic number N = 32 due to
collective effects when protons are removed from 52Ca. It should be investigated in the further
N = 32 isotone 48S, for which the proton valence orbital from π1s1/2 origin has a very different
dependence versus quadrupolar deformation.
92
Results and Discussion
Table 4.9: 0p0h and 2p2h components of the wave function for the 0+ states for 52Ca and
50Ar, obtained in the shell-model calculation using the SDPF-MU interaction.
Energy 0p0h 2p2h
(keV) % %
52Ca 0+1 gs 87.1 12.4
52Ca 0+2 4007 7.3 88.9
50Ar 0+1 gs 54.0 28.8
50Ar 0+2 2412 25.4 58.5
Ab initio calculations were performed in the context of the valence-space in-medium simi-
larity renormalization group (VS-IMSRG) [67, 71] and the self-consistent Gorkov Green’s func-
tion (GGF) [65, 89] approaches. Results are displayed respectively in Tab. 4.10 and 4.11.
Table 4.10: Spin Jπ, excitation energies E∗ and spectroscopic factors ||⟨A+1X - n ∥AX⟩||2 for
levels of 49Ar and 51Ca obtained in shell-model calculation with the SDPF-MUs interaction and
IMSRG calculation with the 1.8/2.0 (EM) interaction.
SM (SDPF-MUs) IMSRG (1.8/2.0 EM)
49Ar 51Ca 49Ar 51Ca
State E∗ C2S E∗ C2S E∗ C2S E∗ C2S
(keV) (keV) (keV) (keV)
3/2−1 gs 1.84 gs 3.57 155 1.37 gs 3.69
1/2−1 95 0.61 1552 0.14 gs 0.94 2025 0.09
5/2−1 924 <0.01 2298 <0.01 1150 <0.01 2068 0.00
7/2−1 983 2.56 3374 7.56 1852 1.89 4197 7.59
3/2−2 1197 0.68 2893 0.09 1439 0.91 3081 0.06
7/2−2 2317 0.05 4622 0.07 3271 0.09
The predictions of the VS-IMSRG calculation with the 1.8/2.0 EM interaction are similar
to the SDPF-MU calculation for the low-lying states especially for 52Ca, except for i) a less
compressed level scheme in 50Ar, as seen in Fig. 4.15; ii) a spin inversion for the ground state
1/2−1 instead of 3/2
−
1 , although the two states are also very close to each other in excitation
energy. The spin inversion is also observed in the IMSRG calculations performed with other
interactions, such as NNLO or N3LO interactions.
93
Results and Discussion
Table 4.11: Spin Jπ, excitation energies E∗ and spectroscopic factors ||⟨A+1X - n ∥AX⟩||2 for
levels of 49Ar and 51Ca obtained in GGF calculations with the NN + 3N(lnl) and NNLOsat.
interactions.
GGF (NN + 3N(lnl)) GGF (NNLOsat)
49Ar 51Ca 49Ar 51Ca
State E∗ C2S E∗ C2S E∗ C2S E∗ C2S
(keV) (keV) (keV) (keV)
3/2− gs 2.68 gs 3.36 gs 3.17 gs 3.34
1/2− 180 0.22 1610 <0.01 330 0.02 3060 0.03
5/2− 440 0.10 1628 <0.01 1890 <0.01 2980 <0.01
7/2− 3590 0.10 3020 0.02 2480 0.48 4152 0.02
3/2− 3620 0.01 1740 0.02 2690 0.02 3010 0.03
7/2− 4390 3.64 3720 6.75 3980 5.59 4660 6.05
GGF calculations were performed with two different interactions, namely NNLOsat [91]
and NN + 3N(lnl) [89]. The calculated energies of the lowest-lying states in 49Ar (51Ca) and
the associated spectroscopic factors for one-neutron removal from 50Ar (52Ca) are displayed3 in
Tab. 4.11. As for the other theoretical approaches, the properties of the low-lying states in 51Ca
suggest that 52Ca is a closed-shell nucleus. First, the 3/2− ground state has a large C2S value,
similar to previous calculations. Second, the first 1/2− state appears at high excitation energy,
especially with NNLOsat, and has very small C2S values. Furthermore, the main 7/2− fragment
is also found at high excitation energy and has a C2S value that is close to the 2j+1 limit for both
interactions. In contrast, corresponding results for 49Ar point to the emergence of a qualitatively
different picture. The C2S values for the main 3/2− and 7/2− states decrease, although the
change is quantitatively different with the two interactions. While the reduction is significant
(around 30%) for NN + 3N(lnl), only a ∼ 5 − 10% decrease is observed for NNLOsat. This is
presumably due to the more perturbative character of the former, which favours fragmentation
of the spectral function at the current level of approximation in the GGF approach. Contrary
to valence-space calculations, here the energy of the 7/2− state changes by only a few hundred
keV and a component below 1 MeV is not observed for this angular momentum. Importantly,
together with the reduction of spectroscopic factors, a low-energy 1/2− state appears with both
interactions. In addition, the energy of the first 5/2− is lowered by more than 1 MeV. These
features all signal an increase of collectivity in 49Ar. All together, the changes observed in GGF
calculations when going from 51Ca to 49Ar are consistent with shell model results and point
to the deterioration of the N = 32 gap in argon. The quantitative differences emerging in the
two sets of results are very likely due to the missing collective degrees of freedom (i.e., lack of
deformation and low truncation in the particle-hole expansion) in the GGF approach.
3Only states with C2S > 0.01 are reported here.
94
Conclusion and future perspectives
In this work, the first in-beam gamma spectroscopy of 49Cl and 49Ar were investigated via
one nucleon removal from a 50Ar beam at 217 MeV per nucleon at the mid of the target. During
the experiment, the secondary beam of 50Ar were produced by in-flight fission of 70Zn-beam at
the Radioactive Isotope Beam Factory, RIKEN Nishina Center, Japan. A liquid-hydrogen target
coupled to a vertex tracker in the MINOS device was surrounded by the DALI2+ scintillator
array. This array was used to measure γ-ray from the reaction. Due to the large acceptance of
the SAMURAI spectrometer, the momentum distribution of one-nucleon removal reactions was
also analyzed. In addition, inclusive cross-sections, as well as cross-sections for the excitation
of a particular state, were performed. These results have been compared with the benchmark
of other neutron-rich nuclei in the same experiment. The method and results of the PID of the
SEASTAR experimental data are published in the article "Particle identification for Z = 25 –
28 exotic nuclei from SEASTAR experimental data" in Nuclear Science and Technology (ISSN
1810-5408), Vol. 7, No. 2, pp. 08-15 (2017).
Analysis of experimental data revealed clear signatures of the restoration of the natural
ordering of proton-hole states in 49Cl. In a simple single particle shell model framework, the
proton shell in the 50Ar isotope occupies the sd shell valence with a mix configuration πs1/2
and πd1/2 orbitals. According to our analysis results, the ground state of 49Cl has the unpaired
proton populated the πd3/2 orbital. Therefore, it is assigned to spin parity of 3/2+. The first
excited state is found at 350 keV and transferred from 1/2+ to 3/2+gs. A weak transition at 970
keV includes direct and cascade transitions, which is an unknown spin parity. Spin-parity of
5/2+ assigned to the population to the excited state at 1515 keV. This standard ordering for
3/2+ versus 1/2+ states is similar to the recently observed 51K, while spin inversion is still under
debate for less neutron-rich chlorine isotopes. Combining with other results of my analysis for
47Cl from multi-nucleon removal reactions, the investigation results are published in the article
"Investigation of the ground-state spin inversion in the neutron-rich 47,49Cl isotopes" in Physics
Review C 104, 044331 (2021).
For neutron configuration in the 50Ar isotope, the valence orbitals are νp1/2 and νp3/2.
In our experimental data combine theoretical calculation, the 49Ar ground state has spin parity
95
Results and Discussion
of 3/2− that populated the νp3/2 orbital. The first excitation state at 198 keV is assigned to
spin parity of 1/2−. The strength of 7/2− state at 1340 keV is very higher than the 5/2− state
at 1050 keV or 1464 keV. The energy at 1466 keV was assigned at the second 3/2−. We found
states at low excitation energy, possibly 1/2−1 and 7/2
−
1 , not compatible with a spherical
50Ar
and closed orbitals at N = 32 as observed for 52Ca. The spectroscopic factors of the low energy
spectroscopy of 49Ar are consistent with not only theoretical calculations but also collective
effects when two protons are removed from 52Ca. This result has been summarized in a draft,
which will be published in the Physics Review C journal in the future.
To finish, it would also be interesting to study the structure of 47Cl, near N = 28. Al-
though the structure of 47Cl was investigated in my article (Physics Review C 104, 044331
(2021)). However, 48Ar was poorly transmitted through BigRIPS, resulting in few events for
the one-proton knockout 48Ar(p,2p)47Cl reaction. Therefore, neither momentum distributions
nor spin assignment could be obtained for 47Cl. Other projectiles were better transmitted to
the target, resulting in various reaction channels, either multi-nucleon removal reactions like
50Ar(p,2p2n)47Cl or the one-neutron knockout reaction 48Cl(p,pn)47Cl. So, the energy gap be-
tween ν0d3/2 and ν1s1/2 proton orbitals evolves with the neutron number involving spin inversion
of the ground state and first excited state at low energy, either 1/2+ or 3/2+ is unsolved.
96
References
[1] I. Tanihata, “Neutron halo nuclei,” J. Phys. G: Nucl. Part. Phys., vol. 22, pp. 157–198,
feb 1996.
[2] L. X. Chung, O. A. Kiselev, D. T. Khoa, and P. Egelhof, “Elastic proton scattering at
intermediate energies as a probe of the 6,8He nuclear matter densities,” Phys. Rev. C,
vol. 92, p. 034608, Sep 2015.
[3] S. D. Pain, W. N. Catford, et al., “Structure of 12Be: Intruder d-Wave Strength at N = 8,”
Phys. Rev. Lett., vol. 96, p. 032502, Jan 2006.
[4] L. X. Chung, C. A. Bertulani, et al., “The dominance of the ν(0d5/2)2 configuration in the
N=8 shell in 12Be from the breakup reaction on a proton target at intermediate energy,”
Phys. Lett. B, vol. 774, pp. 559–563, 2017.
[5] O. Sorlin and M.-G. Porquet, “Nuclear magic numbers: New features far from stability,”
Prog. Part. Nucl. Phys., vol. 61, no. 2, pp. 602–673, 2008.
[6] B. Bastin, S. Grévy, et al., “Collapse of the N = 28 Shell Closure in 42Si,” Phys. Rev.
Lett., vol. 99, p. 022503, Jul 2007.
[7] E. Becheva, Y. Blumenfeld, et al., “N = 14 Shell Closure in 22O Viewed through a Neutron
Sensitive Probe,” Phys. Rev. Lett., vol. 96, p. 012501, Jan 2006.
[8] F. Wienholtz, D. Beck, et al., “Erratum: Masses of exotic calcium isotopes pin down
nuclear forces,” Nature, vol. 500, pp. 612–612, Aug 2013.
[9] D. Steppenbeck, S. Takeuchi, et al., “Evidence for a new nuclear ’magic number’ from the
level structure of 54Ca,” Nature, vol. 502, pp. 207–210, Oct 2013.
[10] D. Steppenbeck, S. Takeuchi, et al., “Low-Lying Structure of 50Ar and the N = 32 Subshell
Closure,” Phys. Rev. Lett., vol. 114, p. 252501, Jun 2015.
[11] M. Rosenbusch, P. Ascher, et al., “Probing the N = 32 Shell Closure below the Magic
Proton Number Z = 20: Mass Measurements of the Exotic Isotopes 52,53K,” Phys. Rev.
Lett., vol. 114, p. 202501, May 2015.
97
REFERENCES
[12] M. L. Cortés, W. Rodriguez, et al., “N = 32 shell closure below calcium: Low-lying
structure of 50Ar,” Phys. Rev. C, vol. 102, p. 064320, Dec 2020.
[13] P. Doll, G. Wagner, K. Kno¨pfle, and G. Mairle, “The quasihole aspect of hole strength
distributions in odd potassium and calcium isotopes,” Nucl. Phys. A, vol. 263, no. 2,
pp. 210–236, 1976.
[14] J. Papuga, M. L. Bissell, et al., “Spins and Magnetic Moments of 49K and 51K: Estab-
lishing the 1/2+ and 3/2+ Level Ordering Beyond N=28,” Phys. Rev. Lett., vol. 110,
p. 172503, Apr 2013.
[15] Y. Sun, A. Obertelli, et al., “Restoration of the natural E(1/21+) - E(3/21+) energy
splitting in odd-K isotopes towards N = 40,” Phys. Lett. B, vol. 802, p. 135215, 2020.
[16] L. A. Riley, P. Adrich, et al., “γ-ray spectroscopy of one-proton knockout from 45Cl,” Phys.
Rev. C, vol. 86, p. 047301, Oct 2012.
[17] P. Doornenbal and A. Obertelli, “RIKEN proposal for scientific program: Shell evolution
and search for two-plus stats at the RIBF (SEASTAR),” 2013. - Unpublished.
[18] Z. Meisel, S. George, et al., “Mass measurements demonstrate a strong n = 28 shell gap
in argon,” Phys. Rev. Lett., vol. 114, p. 022501, Jan 2015.
[19] M. Mougeot, D. Atanasov, et al., “Examining the N = 28 shell closure through high-
precision mass measurements of 46–48Ar,” Phys. Rev. C, vol. 102, p. 014301, Jul 2020.
[20] H. Scheit, T. Glasmacher, et al., “New region of deformation: The neutron-rich sulfur
isotopes,” Phys. Rev. Lett., vol. 77, pp. 3967–3970, Nov 1996.
[21] H. N. Liu, A. Obertelli, et al., “How Robust is the N = 34 Subshell Closure? First
Spectroscopy of 52Ar,” Phys. Rev. Lett., vol. 122, p. 072502, Feb 2019.
[22] A. Gade, D. Bazin, et al., “Detailed experimental study on intermediate-energy coulomb
excitation of 46Ar,” Phys. Rev. C, vol. 68, p. 014302, Jul 2003.
[23] R. Winkler, A. Gade, et al., “Quadrupole collectivity beyond n = 28: Intermediate-energy
coulomb excitation of 47,48Ar,” Phys. Rev. Lett., vol. 108, p. 182501, Apr 2012.
[24] Gaudefroy, L., Sorlin, O., et al., “Study of the n = 28 shell closure in the ar isotopic chain -
a spiral experiment for nuclear astrophysics,” Eur. Phys. J. A, vol. 27, pp. 309–314, 2006.
[25] O. Haxel, J. H. D. Jensen, and H. E. Suess, “On the "Magic Numbers" in Nuclear Struc-
ture,” Phys. Rev., vol. 75, pp. 1766–1766, Jun 1949.
98
REFERENCES
[26] M. G. Mayer, “On Closed Shells in Nuclei. II,” Phys. Rev., vol. 75, pp. 1969–1970, Jun
1949.
[27] A. Huck, G. Klotz, et al., “Beta decay of the new isotopes 52K, 52Ca, and 52Sc; a test of
the shell model far from stability,” Phys. Rev. C, vol. 31, pp. 2226–2237, Jun 1985.
[28] A. Gade, B. A. Brown, et al., “Evolution of the E(1/2+1 ) − E(3/2+1 ) energy spacing in
odd-mass K, Cl, and P isotopes for N = 20−28,” Phys. Rev. C, vol. 74, p. 034322, Sep
2006.
[29] B. Bastin, S. Grévy, et al., “Collapse of the N = 28 Shell Closure in 42Si,” Phys. Rev.
Lett., vol. 99, p. 022503, Jul 2007.
[30] H. L. Crawford, P. Fallon, et al., “First spectroscopy of the near drip-line nucleus 40Mg,”
Phys. Rev. Lett., vol. 122, p. 052501, Feb 2019.
[31] X. Liang, R. Chapman, et al., “Observation of yrast states in neutron-rich 41Cl,” Phys.
Rev. C, vol. 66, p. 037301, Sep 2002.
[32] J. Ollier, R. Chapman, et al., “Yrast states in neutron-rich 41Cl,” Phys. Rev. C, vol. 67,
p. 024302, Feb 2003.
[33] S. Szilner, L. Corradi, et al., “Structure of chlorine isotopes populated by heavy ion transfer
reactions,” Phys. Rev. C, vol. 87, p. 054322, May 2013.
[34] J. A. Winger, H. H. Yousif, et al., “Low-energy structure of neutron-rich S, Cl and Ar
nuclides through β decay,” AIP Conf. Proc., vol. 455, no. 1, pp. 606–609, 1998.
[35] R. W. Ibbotson, T. Glasmacher, P. F. Mantica, and H. Scheit, “Coulomb excitation of
odd-A neutron-rich π(s−d) and ν(f − p) shell nuclei,” Phys. Rev. C, vol. 59, pp. 642–647,
Feb 1999.
[36] O. Sorlin, Z. Dombrádi, et al., “Structure of the neutron-rich 37,39P and 43,45Cl nuclei,”
Eur. Phys. J. A, vol. 22, pp. 173–178, Nov 2004.
[37] J. Papuga, M. L. Bissell, et al., “Shell structure of potassium isotopes deduced from their
magnetic moments,” Phys. Rev. C, vol. 90, p. 034321, Sep 2014.
[38] T. Otsuka, T. Suzuki, et al., “Evolution of Nuclear Shells due to the Tensor Force,” Phys.
Rev. Lett., vol. 95, p. 232502, Nov 2005.
[39] P. Doll, H. Mackh, G. Mairle, and G. Wagner, “Comparative spectroscopy with the (d, τ)
reaction on even Ar isotopes,” Nucl. Phys. A, vol. 230, no. 2, pp. 329–342, 1974.
99
REFERENCES
[40] G. Mairle, M. Seeger, et al., “The distribution of proton-hole strengths in the (2s,1d)-shell
of 35Cl, 37Cl and 39Cl,” Nucl. Phys. A, vol. 565, no. 3, pp. 543–562, 1993.
[41] J. A. Winger, P. F. Mantica, and R. M. Ronningen, “β decay of 40,42S and 43Cl,” Phys.
Rev. C, vol. 73, p. 044318, Apr 2006.
[42] S. R. Stroberg, A. Gade, et al., “In-beam γ-ray spectroscopy of 43−46Cl,” Phys. Rev. C,
vol. 86, p. 024321, Aug 2012.
[43] M. De Rydt, J. M. Daugas, et al., “g factor of the 44Cl ground state: Probing the reduced
Z = 16 and N = 28 gaps,” Phys. Rev. C, vol. 81, p. 034308, Mar 2010.
[44] Obertelli, A., “Direct reactions with exotic nuclei,” EPJ Web Conf., vol. 66, p. 01014, 2014.
[45] Y. Blumenfeld, T. Nilsson, and P. V. Duppen, “Facilities and methods for radioactive ion
beam production,” Physica Scripta, vol. T152, p. 014023, jan 2013.
[46] D. J. Morrissey and B. Sherrill, “In-Flight Separation of Projectile Fragments,” Lect. Notes
Phys., vol. 651, pp. 113–135, 2004.
[47] P. Van Duppen, “Isotope Separation On Line and Post Acceleration,” Lect. Notes Phys.,
vol. 700, pp. 37–77, 2006.
[48] H. Sakurai, “Physics opportunities with the RI Beam Factory at RIKEN,” Eur. Phys. J.:
Spec. Top., vol. 150, pp. 249–254, Nov 2007.
[49] A. Gade and B. M. Sherrill, “NSCL and FRIB at michigan state university: Nuclear science
at the limits of stability,” Physica Scripta, vol. 91, p. 053003, apr 2016.
[50] H. Geissel, P. Armbruster, et al., “The GSI projectile fragment separator (FRS): a versatile
magnetic system for relativistic heavy ions,” Nucl. Instr. Meth. In Phys. Res. B, vol. 70,
no. 1, pp. 286–297, 1992.
[51] T. Kubo, “In-flight RI beam separator BigRIPS at RIKEN and elsewhere in Japan,” Nucl.
Instr. Meth. In Phys. Res. B, vol. 204, pp. 97–113, 2003. 14th International Conference
on Electromagnetic Isotope Separators and Techniques Related to their Applications.
[52] T. Ohnishi, T. Kubo, et al., “Identification of New Isotopes 125Pd and 126Pd Produced
by In-Flight Fission of 345 MeV/nucleon 238U: First Results from the RIKEN RI Beam
Factory,” J. Phys. Soc. Jpn., vol. 77, no. 8, p. 083201, 2008.
[53] T. Kubo, D. Kameda, et al., “BigRIPS separator and ZeroDegree spectrometer at RIKEN
RI Beam Factory,” Prog. Theor. Exp. Phys., vol. 2012, 12 2012. 03C003.
100
REFERENCES
[54] T. Kubo, K. Kusaka, et al., “Status and Overview of Superconducting Radioactive Iso-
tope Beam Separator BigRIPS at RIKEN,” IEEE Trans. Appl. Supercond., vol. 17, no. 2,
pp. 1069–1077, 2007.
[55] N. Paul, First spectroscopy of 110Zr with MINOS. PhD thesis, Université Paris-Saclay,
2018.
[56] Obertelli, Alexandre, “Nuclear structure from direct reactions with rare isotopes: observ-
ables, methods and highlights,” Eur. Phys. J. Plus, vol. 131, no. 9, p. 319, 2016.
[57] P. Hansen and J. Tostevin, “Direct reaction with exotic nuclei,” Annu. Rev. Nucl. Part.
Sci., vol. 53, no. 1, pp. 219–261, 2003.
[58] A. Gade, P. Adrich, et al., “Reduction of spectroscopic strength: Weakly-bound and
strongly-bound single-particle states studied using one-nucleon knockout reactions,” Phys.
Rev. C, vol. 77, p. 044306, Apr 2008.
[59] K. Heyde, The Nuclear Shell Model. Springer-Verlag Berlin Heidelberg, 2 ed., 1994.
[60] C. A. Bertulani and P. G. Hansen, “Momentum distributions in stripping reactions of
radioactive projectiles at intermediate energies,” Phys. Rev. C, vol. 70, p. 034609, Sep
2004.
[61] A. M. Moro, “Three-body model for the analysis of quasifree scattering reactions in inverse
kinematics,” Phys. Rev. C, vol. 92, p. 044605, Oct 2015.
[62] N. Shimizu, T. Mizusaki, Y. Utsuno, and Y. Tsunoda, “Thick-restart block Lanczos method
for large-scale shell-model calculations,” Comput. Phys. Commun., vol. 244, pp. 372–384,
2019.
[63] N. Shimizu, “Nuclear shell-model code for massive parallel computation, KSHELL,”
arXiv:1310.5431 [nucl-th], 2013.
[64] Y. Utsuno, T. Otsuka, et al., “Shape transitions in exotic Si and S isotopes and tensor-
force-driven Jahn-Teller effect,” Phys. Rev. C, vol. 86, p. 051301, Nov 2012.
[65] V. Somà, T. Duguet, and C. Barbieri, “Ab initio self-consistent Gorkov-Green’s function
calculations of semimagic nuclei: Formalism at second order with a two-nucleon interac-
tion,” Phys. Rev. C, vol. 84, p. 064317, Dec 2011.
[66] V. Somà, “Self-consistent green’s function theory for atomic nuclei,” Front. Phys., vol. 8,
p. 340, 2020.
101
REFERENCES
[67] S. R. Stroberg, H. Hergert, S. K. Bogner, and J. D. Holt, “Nonempirical Interactions
for the Nuclear Shell Model: An Update,” Annu. Rev. Nucl. Part. Sci., vol. 69, no. 1,
pp. 307–362, 2019.
[68] E. Epelbaum, H.-W. Hammer, and U.-G. Meißner, “Modern theory of nuclear forces,” Rev.
Mod. Phys., vol. 81, pp. 1773–1825, Dec 2009.
[69] R. Machleidt and D. Entem, “Chiral effective field theory and nuclear forces,” Phys. Rep.,
vol. 503, no. 1, pp. 1 – 75, 2011.
[70] V. Somà, C. Barbieri, and T. Duguet, “Ab initio self-consistent Gorkov-Green’s function
calculations of semi-magic nuclei: Numerical implementation at second order with a two-
nucleon interaction,” Phys. Rev. C, vol. 89, p. 024323, Feb 2014.
[71] S. K. Bogner, H. Hergert, et al., “Nonperturbative Shell-Model Interactions from the In-
Medium Similarity Renormalization Group,” Phys. Rev. Lett., vol. 113, p. 142501, Oct
2014.
[72] J. Simonis, K. Hebeler, et al., “Exploring sd-shell nuclei from two- and three-nucleon
interactions with realistic saturation properties,” Phys. Rev. C, vol. 93, p. 011302, Jan
2016.
[73] R. Crespo, A. Deltuva, et al., “Multiple scattering effects in quasifree scattering from
halo nuclei: A test of the distorted-wave impulse approximation,” Phys. Rev. C, vol. 77,
p. 024601, Feb 2008.
[74] T. Aumann, C. A. Bertulani, and J. Ryckebusch, “Quasifree (p,2p) and (p,pn) reactions
with unstable nuclei,” Phys. Rev. C, vol. 88, p. 064610, Dec 2013.
[75] K. Ogata, K. Yoshida, and K. Minomo, “Asymmetry of the parallel momentum distribution
of (p, pN) reaction residues,” Phys. Rev. C, vol. 92, p. 034616, Sep 2015.
[76] T. Wakasa, K. Ogata, and T. Noro, “Proton-induced knockout reactions with polarized
and unpolarized beams,” Prog. Part. Nucl. Phys., vol. 96, pp. 32–87, 2017.
[77] T. Aumann, C. Barbieri, et al., “Quenching of single-particle strength from direct reactions
with stable and rare-isotope beams,” Prog. Part. Nucl. Phys., p. 103847, 2021.
[78] B. A. Brown and B. H. Wildenthal, “Status of the Nuclear Shell Model,” Annu. Rev. Nucl.
Part. Sci., vol. 38, no. 1, pp. 29–66, 1988.
102
REFERENCES
[79] M. Honma, T. Otsuka, and T. Mizusaki, “Shell-model description of neutron-rich Ca iso-
topes,” RIKEN Acc. Prog. Rep., vol. 41, p. 32, 2008.
[80] T. Otsuka, T. Suzuki, et al., “Novel Features of Nuclear Forces and Shell Evolution in
Exotic Nuclei,” Phys. Rev. Lett., vol. 104, p. 012501, Jan 2010.
[81] S. R. Stroberg, A. Calci, et al., “Nucleus-Dependent Valence-Space Approach to Nuclear
Structure,” Phys. Rev. Lett., vol. 118, p. 032502, Jan 2017.
[82] K. Hebeler, S. K. Bogner, et al., “Improved nuclear matter calculations from chiral low-
momentum interactions,” Phys. Rev. C, vol. 83, p. 031301, Mar 2011.
[83] D. R. Entem and R. Machleidt, “Accurate charge-dependent nucleon-nucleon potential at
fourth order of chiral perturbation theory,” Phys. Rev. C, vol. 68, p. 041001, Oct 2003.
[84] J. Simonis, S. R. Stroberg, et al., “Saturation with chiral interactions and consequences
for finite nuclei,” Phys. Rev. C, vol. 96, p. 014303, Jul 2017.
[85] T. D. Morris, J. Simonis, et al., “Structure of the lightest tin isotopes,” Phys. Rev. Lett.,
vol. 120, p. 152503, Apr 2018.
[86] S. R. Stroberg, J. D. Holt, A. Schwenk, and J. Simonis, “Ab initio limits of atomic nuclei,”
Phys. Rev. Lett., vol. 126, p. 022501, Jan 2021.
[87] E. Leistenschneider, M. P. Reiter, et al., “Dawning of the N = 32 Shell Closure Seen
through Precision Mass Measurements of Neutron-Rich Titanium Isotopes,” Phys. Rev.
Lett., vol. 120, p. 062503, Feb 2018.
[88] S. Chen, J. Lee, et al., “Quasifree Neutron Knockout from 54Ca Corroborates Arising
N = 34 Neutron Magic Number,” Phys. Rev. Lett., vol. 123, p. 142501, Sep 2019.
[89] V. Somà, P. Navrátil, et al., “Novel chiral Hamiltonian and observables in light and
medium-mass nuclei,” Phys. Rev. C, vol. 101, p. 014318, Jan 2020.
[90] V. Somà, C. Barbieri, T. Duguet, and P. Navrátil, “Moving away from singly-magic nuclei
with Gorkov Green’s function theory,” Eur. Phys. J. A, vol. 57, no. 4, p. 135, 2021.
[91] A. Ekstro¨m, G. R. Jansen, et al., “Accurate nuclear radii and binding energies from a
chiral interaction,” Phys. Rev. C, vol. 91, p. 051301, May 2015.
[92] F. Raimondi and C. Barbieri, “Nuclear electromagnetic dipole response with the self-
consistent Green’s function formalism,” Phys. Rev. C, vol. 99, p. 054327, May 2019.
103
REFERENCES
[93] C. Barbieri, N. Rocco, and V. Somà, “Lepton scattering from 40Ar and 48Ti in the
quasielastic peak region,” Phys. Rev. C, vol. 100, p. 062501, Dec 2019.
[94] H. Okuno, N. Fukunishi, and O. Kamigaito, “Progress of RIBF accelerators,” Prog. Theor.
Exp. Phys., vol. 2012, 12 2012. 03C002.
[95] H. Okuno, J. Ohnishi, et al., “Magnets for the RIKEN Superconducting Ring Cyclotron,”
in 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18
- 22 Oct 2004, p. 373, 2005.
[96] T. Nakagawa, M. Kidera, et al., “New superconducting electron cyclotron resonance ion
source for RIKEN RI beam factory project,” Rev. Sci. Instrum., vol. 79, no. 2, p. 02A327,
2008.
[97] Y. Higurashi, J. Ohnishi, et al., “Results of RIKEN superconducting electron cyclotron
resonance ion source with 28 GHz,” Rev. Sci. Instrum., vol. 83, no. 2, p. 02A308, 2012.
[98] N. Sakamoto et al., “Performance of New Injector RILAC2 for Riken Ri-Beam Factory,”
in Proceedings, 27th Linear Accelerator Conference, LINAC2014: Geneva, Switzerland,
August 31-September 5, 2014, p. THPP116, 2014.
[99] N. Fukuda, T. Kubo, et al., “Identification and separation of radioactive isotope beams
by the BigRIPS separator at the RIKEN RI Beam Factory,” Nucl. Instr. Meth. In Phys.
Res. B, vol. 317, pp. 323 – 332, 2013.
[100] H. Kumagai, T. Ohnishi, et al., “Development of Parallel Plate Avalanche Counter (PPAC)
for BigRIPS fragment separator,” Nucl. Instr. Meth. In Phys. Res. B, vol. 317, pp. 717 –
727, 2013.
[101] H. Kumagai, A. Ozawa, et al., “Delay-line PPAC for high-energy light ions,” Nucl. Instr.
Meth. In Phys. Res. A, vol. 470, no. 3, pp. 562 – 570, 2001.
[102] “Technical Information of BigRIPS, ZeroDegree, SAMURAI Beam Line, and OEDO Beam-
line.” Accessed: 2019-05-10.
[103] G. F. Knoll, Radiation detection and measurement. John Wiley & Sons, Inc., fourth ed.,
2010.
[104] W. Christie, J. Romero, et al., “A multiple sampling ionization chamber (MUSIC) for mea-
suring the charge of relativistic heavy ions,” Nucl. Instr. Meth. In Phys. Res. A, vol. 255,
no. 3, pp. 466 – 476, 1987.
104
REFERENCES
[105] C. M. Shand, Shell Evolution Beyond N = 50 and Z = 28: Spectroscopy of 81,82,83,84Zn.
PhD thesis, University of Surrey, 2016.
[106] M. L. Cortes, Inelastic scattering of Ni and Zn isotopes off a proton target. PhD thesis,
Technische Universita¨t Darmstadt, 2016.
[107] Y. Shimizu, T. Kobayashi, et al., “SAMURAI project at RIBF,” J. Phys.: Conf. Ser.,
vol. 312, p. 052022, 09 2011.
[108] T. Kobayashi, N. Chiga, et al., “SAMURAI spectrometer for RI beam experiments,” Nucl.
Instr. Meth. In Phys. Res. B, vol. 317, pp. 294 – 304, 2013.
[109] A. Obertelli, A. Delbart, et al., “MINOS: A vertex tracker coupled to a thick liquid-
hydrogen target for in-beam spectroscopy of exotic nuclei,” Eur. Phys. J. A, vol. 50, 01
2014.
[110] C. Santamaria, Quest for new nuclear magic numbers with MINOS. PhD thesis, Université
Paris-Sud XI, 2015.
[111] P. Doornenbal, “In-beam gamma-ray spectroscopy at the RIBF,” Prog. Theor. Exp. Phys.,
vol. 2012, 12 2012. 03C004.
[112] S. Takeuchi, T. Motobayashi, et al., “DALI2: A NaI(Tl) detector array for measurements
of γ rays from fast nuclei,” Nucl. Instr. Meth. In Phys. Res. A, vol. 763, pp. 596 – 603,
2014.
[113] I. Murray, F. Browne, et al., “DALI2+ at the RIKEN Nishina Center RIBF,” RIKEN Acc.
Prog. Rep., vol. 51, p. 158, 2018.
[114] A. Obertelli and T. Uesaka, “Hydrogen targets for exotic-nuclei studies developed over the
past 10 years,” Eur. Phys. J. A, vol. 47, no. 9, p. 105, 2011.
[115] I. Giomataris, R. D. Oliveira, et al., “Micromegas in a bulk,” Nucl. Instr. Meth. In Phys.
Res. A, vol. 560, no. 2, pp. 405 – 408, 2006.
[116] C. Santamaria, A. Obertelli, et al., “Tracking with the MINOS Time Projection Chamber,”
Nucl. Instr. Meth. In Phys. Res. A, vol. 905, pp. 138 – 148, 2018.
[117] P. Hough, “Method and means for recognizing complex patterns.” US Patent 3, 069, 654,
December 18 1962.
[118] T. Nishio, T. Motobayasi, et al., “NaI(Tl) Detector Assembly for Low Intensity Radiation
(DALI),” RIKEN Acc. Prog. Rep., vol. 29, p. 184, 1995.
105
REFERENCES
[119] “SAMURAI038 & SAMURAI039.” Preparation of SEASTAR 3 experiment meeting on
April 26th 2017 . RIKEN, Janpan - Private Communication.
[120] S. Agostinelli, J. Allison, et al., “Geant4—a simulation toolkit,” Nucl. Instr. Meth. In
Phys. Res. A, vol. 506, no. 3, pp. 250 – 303, 2003.
[121] Y. Shimizu, H. Otsu, et al., “Vacuum system for the SAMURAI spectrometer,” Nucl.
Instr. Meth. In Phys. Res. B, vol. 317, pp. 739 – 742, 2013.
[122] H. Sato, T. Kubo, et al., “Superconducting Dipole Magnet for SAMURAI Spectrometer,”
IEEE Trans. Appl. Supercond., vol. 23, pp. 4500308–4500308, June 2013.
[123] “SAMURAI: ChargedParticleDetector.”
ChargedParticleDetector. Accessed: 2019-10-24.
[124] Y. Kondo, T. Nakamura, et al., “Calibration methods of the neutron detector array NEB-
ULA,” RIKEN Acc. Prog. Rep., vol. 45, p. 131, 2012.
[125] T. Nakamura and Y. Kondo, “Large acceptance spectrometers for invariant mass spec-
troscopy of exotic nuclei and future developments,” Nucl. Instr. Meth. In Phys. Res. B,
vol. 376, pp. 156 – 161, 2016.
[126] “SAMURAI.” Accessed: 2019-10-24.
[127] T. Aumann and The R3B Collaboration, “Technical Report for the Design, Construction
and Commissioning of NeuLAND: The High-Resolution Neutron Time-of-Flight Spectrom-
eter for R3B,” tech. rep., GSI Helmholtz Centre, 2011.
[128] J. Kahlbow, T. Aumann, et al., “NeuLAND demonstrator at SAMURAI: commissioning
and efficiency studies,” RIKEN Acc. Prog. Rep., vol. 49, p. 17, 2016.
[129] Z. Yang, F. Marqués, et al., Study of Multi-neutron Systems with SAMURAI Spectrometer,
pp. 529–534. Germany: Springer, 01 2020.
[130] F. Chateau and S. Anvar, “A Framework for the Development and Integration of Config-
urations within Real-time, Embedded and Distributed Software in HEP Experiments,” in
2007 15th IEEE-NPSS Real-Time Conference, pp. 1–6, April 2007.
[131] H. Baba, T. Ichihara, et al., “New data acquisition system for the RIKEN Radioactive
Isotope Beam Factory,” Nucl. Instr. Meth. In Phys. Res. A, vol. 616, no. 1, pp. 65 – 68,
2010.
106
REFERENCES
[132] H. Baba, T. Ichihara, et al., “DAQ coupling in RIKEN RIBF,” in 2014 19th IEEE-NPSS
Real Time Conference, pp. 1–5, May 2014.
[133] H. Blok, E. Offermann, C. D. Jager, and H. D. Vries, “Path reconstruction and resolution
improvement in magnetic spectrometers,” Nucl. Instr. Meth. In Phys. Res. A, vol. 262,
no. 2, pp. 291 – 297, 1987.
[134] M. Berz, K. Joh, et al., “Reconstructive correction of aberrations in nuclear particle spec-
trographs,” Phys. Rev. C, vol. 47, pp. 537–544, Feb 1993.
[135] D. Bazin, J. Caggiano, et al., “The S800 spectrograph,” Nucl. Instr. Meth. In Phys. Res.
B, vol. 204, pp. 629 – 633, 2003. 14th International Conference on Electromagnetic Isotope
Separators and Techniques Related to their Applications.
[136] R. Grzywacz, R. Anne, et al., “Identification of µs-isomers produced in the fragmentation
of a 112Sn beam,” Phys. Lett. B, vol. 355, no. 3, pp. 439 – 446, 1995.
[137] B. D. Linh, N. D. Ton, et al., “Particle identification for Z = 25 – 28 exotic nuclei from
SEASTAR experimental data,” Nuclear Science and Technology, vol. 7, no. 2, pp. 08 – 15,
2017.
[138] J. Hwang, Study of 19C by One-Neutron Knockout Reaction with a Carbon Target. PhD
thesis, Deparment of Physics and Astronomy, College of Natural Sciences, SEOUL National
University, 2015.
[139] “smsimulator.” Accessed:
2020-05-10.
[140] T. Kobayashi, “Memo for S09 run,” tech. rep., RIKEN, 16-Apr-2017.
[141] S. Leblond, Structure des isotopes de bore et de carbone riches en neutrons aux limites de
la stabilité. PhD thesis, Université CAEN Normandie, 2016.
[142] Y. Kubota, Neutron-neutron correlation in Borromean nucleus 11Li via the (p, pn) reac-
tion. PhD thesis, University of Tokyo, 2017.
[143] B. M. Godoy, Structure and neutron decay of the unbound Beryllium isotopes 15,16Be. PhD
thesis, Université CAEN Normandie, 2019.
[144] “SEASTAR3 Analysis meeting.” Private Communication, 2017 - 2018.
[145] C. Sidong, “SEASTAR3 Analysis report.” Private Communication, 2017 - 2018.
107
REFERENCES
[146] E. Browne and J. Tuli, “Nuclear Data Sheets for A = 60,” Nucl. Data Sheets, vol. 114,
no. 12, pp. 1849 – 2022, 2013.
[147] E. McCutchan and A. Sonzogni, “Nuclear Data Sheets for A = 88,” Nucl. Data Sheets,
vol. 115, pp. 135 – 304, 2014.
[148] E. Browne and J. Tuli, “Nuclear Data Sheets for A = 137,” Nucl. Data Sheets, vol. 108,
no. 10, pp. 2173 – 2318, 2007.
[149] Y. Khazov, A. Rodionov, and F. Kondev, “Nuclear Data Sheets for A = 133,” Nucl. Data
Sheets, vol. 112, no. 4, pp. 855 – 1113, 2011.
[150] O. Tarasov and D. Bazin, “LISE++: Radioactive beam production with in-flight sep-
arators,” Nucl. Instr. Meth. In Phys. Res. B, vol. 266, no. 19, pp. 4657 – 4664, 2008.
Proceedings of the XVth International Conference on Electromagnetic Isotope Separators
and Techniques Related to their Applications.
[151] “The National Nuclear Data Center.” https://www.nishina.riken.jp/collaboration/
SUNFLOWER/misc/download/simulation.php. Accessed: 2020-07-10.
[152] C. Santamaria, C. Louchart, et al., “Extension of the N = 40 Island of Inversion towards
N = 50: Spectroscopy of 66Cr, 70,72Fe,” Phys. Rev. Lett., vol. 115, p. 192501, Nov 2015.
[153] N. Paul, A. Corsi, et al., “Are There Signatures of Harmonic Oscillator Shells Far from
Stability? First Spectroscopy of 110Zr,” Phys. Rev. Lett., vol. 118, p. 032501, Jan 2017.
[154] S. Chen, P. Doornenbal, et al., “Low-lying structure and shape evolution in neutron-rich
Se isotopes,” Phys. Rev. C, vol. 95, p. 041302, Apr 2017.
[155] L. Olivier, Nuclear structure in the vicinity of Ni : in-beam gamma-ray spectroscopy of Cu
through proton knockout. PhD thesis, Université Paris-Saclay, 2017.
[156] T. Lokotko, Shape Co-Existence of Neutron-Rich 69,71,73Co Nuclei. PhD thesis, The Uni-
versity of Hong Kong, 2019.
[157] S. Baker and R. D. Cousins, “Clarification of the use of CHI-square and likelihood functions
in fits to histograms,” Nucl. Instr. Meth. In Phys. Res., vol. 221, no. 2, pp. 437 – 442, 1984.
[158] R. Taniuchi, In-beam gamma-ray spectroscopy of 78Ni. PhD thesis, The University of
Tokyo, 2018.
[159] X. L. Chung, B. D. Linh, et al., “Spectroscopy of the neutron-rich iron isotope 68Fe,” - to
be published.
108
REFERENCES
[160] R. E. Kass and A. E. Raftery, “Bayes factors,” J. Am. Stat. Assoc., vol. 90, no. 430,
pp. 773–795, 1995.
[161] T. Werner, J. Sheikh, et al., “Shape coexistence around 1644s28: The deformed n = 28
region,” Phys. Lett. B, vol. 333, no. 3, pp. 303–309, 1994.
[162] R. Rodríguez-Guzmán, J. L. Egido, and L. M. Robledo, “Quadrupole collectivity in n ≈ 28
nuclei with the angular momentum projected generator coordinate method,” Phys. Rev.
C, vol. 65, p. 024304, Jan 2002.
[163] D. Sohler, Z. Dombrádi, et al., “Shape evolution in heavy sulfur isotopes and erosion of
the N = 28 shell closure,” Phys. Rev. C, vol. 66, p. 054302, Nov 2002.
[164] M. Gómez-Ramos and A. Moro, “Binding-energy independence of reduced spectroscopic
strengths derived from (p,2p) and (p,pn) reactions with nitrogen and oxygen isotopes,”
Phys. Lett. B, vol. 785, pp. 511–516, 2018.
[165] “Hartree-Fock-Bogoliubov results based on the Gogny force.”
cea.fr/science_en_ligne/carte_potentiels_microscopiques/carte_potentiel_
nucleaire_eng.htm. Accessed: 2022-03-12.
[166] Z. Dombrádi, D. Sohler, et al., “Search for particle–hole excitations across the n=28 shell
gap in 45,46ar nuclei,” Nuclear Physics A, vol. 727, no. 3, pp. 195–206, 2003.
[167] Hilaire, S. and Girod, M., “Large-scale mean-field calculations from proton to neutron drip
lines using the d1s gogny force,” Eur. Phys. J. A, vol. 33, no. 2, pp. 237–241, 2007.
[168] J. P. Delaroche, M. Girod, et al., “Structure of even-even nuclei using a mapped collective
hamiltonian and the d1s gogny interaction,” Phys. Rev. C, vol. 81, p. 014303, Jan 2010.
109