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Elekes, Z.*; Juhsz, M. M.*; Sohler, D.*; Sieja, K.*; Yoshida, Kazuki; Ogata, Kazuyuki*; Doornenbal, P.*; Obertelli, A.*; Achouri, N. L.*; Baba, Hidetada*; et al.
Physical Review C, 106(6), p.064321_1 - 064321_10, 2022/12
Times Cited Count:0The low-lying level structure of V and
V was investigated for the first time. The neutron knockout reaction and inelastic proton scattering were applied for
V while the neutron knock-out reaction provided the data for
V. Four and five new transitions were determined for
V and
V, respectively. Based on the comparison to our shell-model calculations using the Lenzi-Nowacki-Poves-Sieja (LNPS) interaction, three of the observed
rays for each isotope could be placed in the level scheme and assigned to the decay of the first 11/2
and 9/2
levels. The (
,
) excitation cross sections for
V were analyzed by the coupled-channels formalism assuming quadrupole plus hexadecapole deformations. Due to the role of the hexadecapole deformation,
V could not be unambiguously placed on the island of inversion.
Enciu, M.*; Liu, H. N.*; Obertelli, A.*; Doornenbal, P.*; Nowacki, F.*; Ogata, Kazuyuki*; Poves, A.*; Yoshida, Kazuki; Achouri, N. L.*; Baba, Hidetada*; et al.
Physical Review Letters, 129(26), p.262501_1 - 262501_7, 2022/12
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)The one-neutron knockout from Ca was performed at
230 MeV/nucleon combined with prompt
spectroscopy. The momentum distributions corresponding to the removal of
and
neutrons were measured. The cross sections are consistent with a shell closure at the neutron number
, found as strong as at
and
in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron
and
orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the
orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.
Koiwai, Takuma*; Wimmer, K.*; Doornenbal, P.*; Obertelli, A.*; Barbieri, C.*; Duguet, T.*; Holt, J. D.*; Miyagi, Takayuki*; Navrtil, P.*; Ogata, Kazuyuki*; et al.
Physics Letters B, 827, p.136953_1 - 136953_7, 2022/04
Times Cited Count:2 Percentile:67.14(Astronomy & Astrophysics)no abstracts in English
Linh, B. D.*; Corsi, A.*; Gillibert, A.*; Obertelli, A.*; Doornenbal, P.*; Barbieri, C.*; Chen, S.*; Chung, L. X.*; Duguet, T.*; Gmez-Ramos, M.*; et al.
Physical Review C, 104(4), p.044331_1 - 044331_16, 2021/10
Times Cited Count:2 Percentile:32.08(Physics, Nuclear)no abstracts in English
Bhattacharyya, A.*; Datta, U.*; Rahaman, A.*; Chakraborty, S.*; Aumann, T.*; Beceiro-Novo, S.*; Boretzky, K.*; Caesar, C.*; Carlson, B. V.*; Catford, W. N.*; et al.
Physical Review C, 104(4), p.045801_1 - 045801_14, 2021/10
Times Cited Count:1 Percentile:32.08(Physics, Nuclear)no abstracts in English
Browne, F.*; Chen, S.*; Doornenbal, P.*; Obertelli, A.*; Ogata, Kazuyuki*; Utsuno, Yutaka; Yoshida, Kazuki; Achouri, N. L.*; Baba, Hidetada*; Calvet, D.*; et al.
Physical Review Letters, 126(25), p.252501_1 - 252501_7, 2021/06
Times Cited Count:4 Percentile:45.66(Physics, Multidisciplinary)Direct proton-knockout reactions of Sc were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of
Ca were investigated through
-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological inter-nucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of
Sc, valence proton removals populated predominantly the ground-state of
Ca. This counter-intuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei.
Juhsz, M. M.*; Elekes, Z.*; Sohler, D.*; Utsuno, Yutaka; Yoshida, Kazuki; Otsuka, Takaharu*; Ogata, Kazuyuki*; Doornenbal, P.*; Obertelli, A.*; Baba, Hidetada*; et al.
Physics Letters B, 814, p.136108_1 - 136108_8, 2021/03
Times Cited Count:2 Percentile:32.08(Astronomy & Astrophysics)The nuclear structure of Ar was studied by the (
,2
) reaction using
-ray spectroscopy for the bound and unbound states. Comparing the results to our shell-model calculations, two bound and six unbound states were established. The low cross sections populating the two bound states of
Ar could be interpreted as a clear signature for the presence of significant sub-shell closures at neutron numbers 32 and 34 in argon isotopes.
Tanaka, Junki*; Yang, Z.*; Typel, S.*; Adachi, Satoshi*; Bai, S.*; Van Beek, P.*; Beaumel, D.*; Fujikawa, Yuki*; Han, J.*; Heil, S.*; et al.
Science, 371(6526), p.260 - 264, 2021/01
Times Cited Count:22 Percentile:98.85(Multidisciplinary Sciences)By employing quasi-free -cluster-knockout reactions, we obtained direct experimental evidence for the formation of
clusters at the surface of neutron-rich tin isotopes. The observed monotonous decrease of the reaction cross sections with increasing mass number, in excellent agreement with the theoretical prediction, implies a tight interplay between
-cluster formation and the neutron skin.
Corts, M. L.*; Rodriguez, W.*; Doornenbal, P.*; Obertelli, A.*; Holt, J. D.*; Men
ndez, J.*; Ogata, Kazuyuki*; Schwenk, A.*; Shimizu, Noritaka*; Simonis, J.*; et al.
Physical Review C, 102(6), p.064320_1 - 064320_9, 2020/12
Times Cited Count:7 Percentile:71.34(Physics, Nuclear)Low-lying excited states in the = 32 isotope
Ar were investigated by in-beam
-ray spectroscopy following proton- and neutron-knockout, multinucleon removal, and proton inelastic scattering at the RIKEN Radioactive Isotope Beam Factory. The energies of the two previously reported transitions have been confirmed, and five additional states are presented for the first time, including a candidate for a 3
state. The level scheme built using
coincidences was compared to shell-model calculations in the
model space and to
predictions based on chiral two- and three-nucleon interactions. Theoretical proton- and neutron-knockout cross sections suggest that two of the new transitions correspond to 2
states, while the previously proposed 4
state could also correspond to a 2
state.
Corts, M. L.*; Rodriguez, W.*; Doornenbal, P.*; Obertelli, A.*; Holt, J. D.*; Lenzi, S. M.*; Men
ndez, J.*; Nowacki, F.*; Ogata, Kazuyuki*; Poves, A.*; et al.
Physics Letters B, 800, p.135071_1 - 135071_7, 2020/01
Times Cited Count:22 Percentile:96.25(Astronomy & Astrophysics)Excited states in the = 40 isotone
Ti were populated via the
V(
,
)
Ti reaction at
200 MeV/nucleon at the Radioactive Isotope Beam Factory and studied using
-ray spectroscopy. The energies of the
and
transitions, observed here for the first time, indicate a deformed Ti ground state. These energies are increased compared to the neighboring
Cr and
Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings.
Chen, S.*; Lee, J.*; Doornenbal, P.*; Obertelli, A.*; Barbieri, C.*; Chazono, Yoshiki*; Navrtil, P.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Raimondi, F.*; et al.
Physical Review Letters, 123(14), p.142501_1 - 142501_7, 2019/10
Times Cited Count:37 Percentile:92.75(Physics, Multidisciplinary)no abstracts in English
Chakraborty, S.*; Datta, U.*; Aumann, T.*; Beceiro-Novo, S.*; Boretzky, K.*; Caesar, C.*; Carlson, B. V.*; Catford, W. N.*; Chartier, M.*; Cortina-Gil, D.*; et al.
Physical Review C, 96(3), p.034301_1 - 034301_9, 2017/09
Times Cited Count:2 Percentile:21.91(Physics, Nuclear)no abstracts in English
Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*
Proceedings of 11th Meeting of the Task Force on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-11), p.91 - 98, 2013/10
We have developed the displacement damage model in PHITS using the screened Coulomb scattering and the nuclear reaction model to evaluate the energy of the target PKA created by the projectile and the "secondary particles" which include all particles created from the sequential nuclear reactions. For the high-energy proton and neutron incident reactions, it was found that a target PKA created by the "secondary particles" is more dominant than a target PKA created by the projectile in DPA calculations. Recently, radiation damage models in other codes such as FLUKA, MARS, MCNP have also been developed. As there is few experimental data in a high energy region, an intercomparison of Monte Carlo codes used in the radiation damage calculation is very important for the improvement of models. In the meeting, we will also discuss the comparison between PHITS and FLUKA for the high-energy proton and neutron irradiation.
Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*
Nuclear Instruments and Methods in Physics Research B, 303, p.120 - 124, 2013/05
Times Cited Count:9 Percentile:59.92(Instruments & Instrumentation)Recently, the radiation damage model in PHITS has been developed using the screened Coulomb scattering to evaluate the energy of the target PKA (Primary Knock on Atom) created by the projectile and the "secondary particles" which include all particles created from the sequential nuclear reactions. For the high-energy proton and He incident reactions, a target PKA created by the "secondary particles" was more dominant than a target PKA created by the projectile in DPA calculations. Thus improved PHITS is applicable to evaluate the displacement cross sections for the various particles and over a wide energy range and to calculate DPA values determined by different particles and fluxes in an irradiation environment. In the meeting, we will also present DPA values and energy spectra for secondary particles created by neutrons in the energy ranges from thermal to around 1 GeV.
Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*
Nuclear Instruments and Methods in Physics Research B, 274, p.57 - 64, 2012/03
Times Cited Count:20 Percentile:82.68(Instruments & Instrumentation)The radiation damage model in the PHITS has been improved using the screened Coulomb scattering to evaluate the energy of the target PKA (Primary Knock on Atom) created by the projectile and the secondary particles from the nuclear reactions. For the high-energy proton and He incident reactions, a target PKA created by the secondary particles was more dominant than a target PKA created by the projectile in DPA calculations. Therefore, the improved PHITS can calculate DPA values at high energies and TRIM leads to severe underestimation where projectile energy is high enough to create nuclear reactions. Thus improved PHITS is applicable to evaluate the displacement cross sections for the various particles and over a wide energy range and to calculate DPA values determined by different particles and fluxes in an irradiation environment.
Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*
JAEA-Conf 2011-002, p.157 - 162, 2011/09
Radiation damage measured as a function of DPA is one of the critical issues for high-intensity beams, especially heavy-ions. The DPA model in PHITS has recently been extended to include contributions from Coulomb elastic scattering of transported charged particles. For the Coulomb elastic scattering, a universal one-parameter differential scattering cross section equation introduced by J. Lindhard et al. is employed instead of the differential Rutherford cross section which is a function of six parameters; charge and mass number of incident and produced particles, kinetic energy of incident particle and scattered angle. In this work, we compare PHITS results for the 130 MeV/u 6Ge+
W reaction with calculated results of TRIM which is two-dimensional damage calculation code. Then we calculate DPA for different ions, targets and energies in the energy region from 100 MeV/u to 1 GeV/u and evaluate the systematics of DPA.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count:169 Percentile:99.44(Physics, Nuclear)Transverse momentum distributions and yields for , and
in
collisions at
= 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different
collisions. We also present the scaling properties such as
and
scaling and discuss the mechanism of the particle production in
collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count:8 Percentile:51.17(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to
collisions.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03
Times Cited Count:161 Percentile:98.47(Astronomy & Astrophysics)The PHENIX experiment at RHIC has measured the invariant differential cross section for production of ,
,
and
mesons in
collisions at
= 200 GeV. The spectral shapes of all hadron transverse momentum distributions are well described by a Tsallis distribution functional form with only two parameters,
and
, determining the high
and characterizing the low
regions for the spectra, respectively. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.
Kanungo, R.*; Nociforo, C.*; Prochazka, A.*; Utsuno, Yutaka; Aumann, T.*; Boutin, D.*; Cortina-Gil, D.*; Davids, B.*; Diakaki, M.*; Farinon, F.*; et al.
Physics Letters B, 685(4-5), p.253 - 257, 2010/05
Times Cited Count:35 Percentile:87.33(Astronomy & Astrophysics)no abstracts in English