Pub Date : 2018-06-29DOI: 10.1103/PHYSREVC.97.064919
F. Gardim, F. Grassi, Pedro Ishida, M. Luzum, Pablo S. Magalhães, J. Noronha-Hostler
{"title":"Sensitivity of observables to coarse-graining size in heavy-ion collisions","authors":"F. Gardim, F. Grassi, Pedro Ishida, M. Luzum, Pablo S. Magalhães, J. Noronha-Hostler","doi":"10.1103/PHYSREVC.97.064919","DOIUrl":"https://doi.org/10.1103/PHYSREVC.97.064919","url":null,"abstract":"","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79477628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-21DOI: 10.1103/physrevc.97.065206
J. Dedonder, B. Loiseau, S. Wycech
The measurements of the $J/psi rightarrow gamma p overline{p}$ decays by the BES Collaboration indicate an enhancement at the $p overline{p}$ threshold which, however, is present neither in the J/$psi$ decays into $omega p overline{p}$ nor into $pi p overline{p}$. Here, two processes for describing the decays $J/psi rightarrow mathcal{B} poverline{p}$ where $mathcal{B} = gamma ,omega, phi,pi $ are presented. The first one, applied not only to the radiative decay to reproduce the threshold peak but also to the $omega p overline{p}$ decay channel to improve the description of the spectrum, postulates a direct emission of the boson before the baryon pair is formed. The second process assumes that the boson $mathcal{B}$ is emitted from the baryon pair following the $J/psi$ decay and includes for the decays into $gamma p overline{p}$ a final state nucleon-antinucleon interaction based on the Paris $N overline{N}$ potential. The reproduction of the $p overline{p}$ distribution in the $J/psi rightarrow omega p overline{p}$ decays needs a final state interaction involving a $N(2050) 3/2^-$ resonance. The photon- and meson-emission rates are reproduced in a semi-quantitative way.
BES协作对$J/psi rightarrow gamma p overline{p}$衰变的测量表明，在$p overline{p}$阈值处有增强，然而，在J/ $psi$衰变为$omega p overline{p}$和$pi p overline{p}$时没有出现这种增强。在这里，描述衰变的两个过程$J/psi rightarrow mathcal{B} p overline{p}$，其中$mathcal{B} = gamma, omega$给出了一些细节，并简要地介绍了两种情况$mathcal{B} =phi, pi $。第一种方法，不仅应用于辐射衰减以重现阈值峰值，而且应用于$omega p overline{p}$衰减通道以改进光谱描述，它假设在重子对形成之前玻色子直接发射。第二个过程假设玻色子$mathcal{B}$是由重子对在$J/psi$衰变之后发射的，并且在衰变到$gamma p overline{p}$的过程中包含基于巴黎$N overline{N}$势的最终态核子-反核子相互作用。在$J/psi rightarrow omega p overline{p}$衰减中再现$p overline{p}$分布需要一个涉及$N(2050) 3/2^-$共振的最终态相互作用。光子和介子发射率以半定量的方式再现。
{"title":"Photon or meson formation in \u0000J/ψ\u0000 decays into \u0000pp¯","authors":"J. Dedonder, B. Loiseau, S. Wycech","doi":"10.1103/physrevc.97.065206","DOIUrl":"https://doi.org/10.1103/physrevc.97.065206","url":null,"abstract":"The measurements of the $J/psi rightarrow gamma p overline{p}$ decays by the BES Collaboration indicate an enhancement at the $p overline{p}$ threshold which, however, is present neither in the J/$psi$ decays into $omega p overline{p}$ nor into $pi p overline{p}$. Here, two processes for describing the decays $J/psi rightarrow mathcal{B} poverline{p}$ where $mathcal{B} = gamma ,omega, phi,pi $ are presented. The first one, applied not only to the radiative decay to reproduce the threshold peak but also to the $omega p overline{p}$ decay channel to improve the description of the spectrum, postulates a direct emission of the boson before the baryon pair is formed. The second process assumes that the boson $mathcal{B}$ is emitted from the baryon pair following the $J/psi$ decay and includes for the decays into $gamma p overline{p}$ a final state nucleon-antinucleon interaction based on the Paris $N overline{N}$ potential. The reproduction of the $p overline{p}$ distribution in the $J/psi rightarrow omega p overline{p}$ decays needs a final state interaction involving a $N(2050) 3/2^-$ resonance. The photon- and meson-emission rates are reproduced in a semi-quantitative way.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2018-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76931333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-09-08DOI: 10.1103/PhysRevC.103.L061302
W. Ma, D. Patel, Y. Yang, J. Wang, Y. Kanada-En’yo, R. F. Chen, J. Lubian, Y. Ye, Z. Yang, Z. Ren, S. Mukherjee, J. Ma, S. Jin, P. Ma, J. Li, Y. Song, Q. Hu, Z. Bai, M. Huang, X. Liu, Y. Zhou, J. Chen, Z. Gao, F. Duan, S. Jin, S. W. Xu, G. Yu, G. Shi, Q. Wang, T. Wang, X. Ju, Z. Hu, Y. Zhang, X. Zhou, H. Xu, G. Xiao, W. Zhan
$^{6}$He+$t$ cluster states of exited $^{9}$Li have been measured by 32.7 MeV/nucleon $^{9}$Li beams bombarding on $^{208}$Pb target. Two resonant states are clearly observed with the excitation energies at 9.8 MeV and 12.6 MeV and spin-parity of 3/2$^{-}$ and 7/2$^{-}$ respectively. These two states are considered to be members of K$^{pi}$=1/2$^{-}$ band. The spin-parity of them are identified by the method of angular correlation analysis and verified by the continuum discretized coupled channels (CDCC) calculation, which agrees with the prediction of the generator coordinate method (GCM). A monopole matrix element about 4 fm$^{2}$ for the 3/2$^{-}$ state is extracted from the distorted wave Born approximation (DWBA) calculation. These results strongly support the feature of clustering structure of two neutron-rich clusters in the neutron-rich nucleus $^{9}$Li for the first time.
{"title":"Observation of \u0000He6+t\u0000 cluster states in \u0000Li9","authors":"W. Ma, D. Patel, Y. Yang, J. Wang, Y. Kanada-En’yo, R. F. Chen, J. Lubian, Y. Ye, Z. Yang, Z. Ren, S. Mukherjee, J. Ma, S. Jin, P. Ma, J. Li, Y. Song, Q. Hu, Z. Bai, M. Huang, X. Liu, Y. Zhou, J. Chen, Z. Gao, F. Duan, S. Jin, S. W. Xu, G. Yu, G. Shi, Q. Wang, T. Wang, X. Ju, Z. Hu, Y. Zhang, X. Zhou, H. Xu, G. Xiao, W. Zhan","doi":"10.1103/PhysRevC.103.L061302","DOIUrl":"https://doi.org/10.1103/PhysRevC.103.L061302","url":null,"abstract":"$^{6}$He+$t$ cluster states of exited $^{9}$Li have been measured by 32.7 MeV/nucleon $^{9}$Li beams bombarding on $^{208}$Pb target. Two resonant states are clearly observed with the excitation energies at 9.8 MeV and 12.6 MeV and spin-parity of 3/2$^{-}$ and 7/2$^{-}$ respectively. These two states are considered to be members of K$^{pi}$=1/2$^{-}$ band. The spin-parity of them are identified by the method of angular correlation analysis and verified by the continuum discretized coupled channels (CDCC) calculation, which agrees with the prediction of the generator coordinate method (GCM). A monopole matrix element about 4 fm$^{2}$ for the 3/2$^{-}$ state is extracted from the distorted wave Born approximation (DWBA) calculation. These results strongly support the feature of clustering structure of two neutron-rich clusters in the neutron-rich nucleus $^{9}$Li for the first time.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2017-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86774490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-03-09DOI: 10.1103/PHYSREVC.95.035803
P. Ludwig, G. Rugel, I. Dillmann, T. Faestermann, L. Fimiani, K. Hain, G. Korschinek, J. Lachner, M. Poutivtsev, K. Knie, M. Heil, F. Käppeler, A. Wallner
The $^{58}$Ni$(n,gamma)^{59}$Ni cross section was measured with a combination of the activation technique and accelerator mass spectrometry (AMS). The neutron activations were performed at the Karlsruhe 3.7 MV Van de Graaff accelerator using the quasi-stellar neutron spectrum at $kT=25$ keV produced by the $^7$Li($p,n$)$^7$Be reaction. The subsequent AMS measurements were carried out at the 14 MV tandem accelerator of the Maier-Leibnitz-Laboratory in Garching using the Gas-filled Analyzing Magnet System (GAMS). Three individual samples were measured, yielding a Maxwellian-averaged cross section at $kT=30$ keV of $langlesigmarangle_{30text{keV}}$= 30.4 (23)$^{syst}$(9)$^{stat}$ mbarn. This value is slightly lower than two recently published measurements using the time-of-flight (TOF) method, but agrees within the uncertainties. Our new results also resolve the large discrepancy between older TOF measurements and our previous value.
结合活化技术和加速器质谱法(AMS)测量了$^{58}$ Ni $(n,gamma)^{59}$ Ni截面。利用$^7$ Li($p,n$) $^7$ Be反应产生的$kT=25$ keV的准恒星中子谱，在卡尔斯鲁厄3.7 MV Van de Graaff加速器上进行了中子活化。随后的AMS测量在Garching的maier - leibnitz实验室的14 MV串联加速器上使用充气分析磁系统(GAMS)进行。测量了三个单独的样品，得到$kT=30$ keV处的麦克斯韦平均截面$langlesigmarangle_{30text{keV}}$ = 30.4 (23) $^{syst}$ (9) $^{stat}$ mbarn。这个值略低于最近发表的使用飞行时间(TOF)方法的两个测量值，但在不确定性范围内是一致的。我们的新结果也解决了旧TOF测量值与我们以前的值之间的巨大差异。
{"title":"Measurement of the stellar Ni 58 (n,γ) Ni 59 cross section with accelerator mass spectrometry","authors":"P. Ludwig, G. Rugel, I. Dillmann, T. Faestermann, L. Fimiani, K. Hain, G. Korschinek, J. Lachner, M. Poutivtsev, K. Knie, M. Heil, F. Käppeler, A. Wallner","doi":"10.1103/PHYSREVC.95.035803","DOIUrl":"https://doi.org/10.1103/PHYSREVC.95.035803","url":null,"abstract":"The $^{58}$Ni$(n,gamma)^{59}$Ni cross section was measured with a combination of the activation technique and accelerator mass spectrometry (AMS). The neutron activations were performed at the Karlsruhe 3.7 MV Van de Graaff accelerator using the quasi-stellar neutron spectrum at $kT=25$ keV produced by the $^7$Li($p,n$)$^7$Be reaction. The subsequent AMS measurements were carried out at the 14 MV tandem accelerator of the Maier-Leibnitz-Laboratory in Garching using the Gas-filled Analyzing Magnet System (GAMS). Three individual samples were measured, yielding a Maxwellian-averaged cross section at $kT=30$ keV of $langlesigmarangle_{30text{keV}}$= 30.4 (23)$^{syst}$(9)$^{stat}$ mbarn. This value is slightly lower than two recently published measurements using the time-of-flight (TOF) method, but agrees within the uncertainties. Our new results also resolve the large discrepancy between older TOF measurements and our previous value.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2017-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83626368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-28DOI: 10.1103/PhysRevC.94.034906
Y. Nara, H. Niemi, A. Ohnishi, H. Stoecker
We analyze the directed flow of protons and pions in high-energy heavy-ion collisions in the incident energy range from $sqrt{{s}_{NN}}=7.7$ to 27 GeV within a microscopic transport model. Standard hadronic transport approaches do not describe the collapse of directed flow below $sqrt{{s}_{NN}}ensuremath{simeq}20$ GeV. By contrast, a model that simulates effects of a softening of the equation of state descibes well the behavior of directed flow data recently obtained by the STAR Collaboration [Phys. Rev. Lett. 112, 162301 (2014)]. We give a detailed analysis of how directed flow is generated. Particularly, we found that softening of the effective equation of state at the overlapping region of two nuclei, i.e., the reaction stages where the system reaches high baryon density state, is needed to explain the observed collapse of proton directed flow within a hadronic transport approach.
{"title":"Examination of directed flow as a signature of the softest point of the equation of state in QCD matter","authors":"Y. Nara, H. Niemi, A. Ohnishi, H. Stoecker","doi":"10.1103/PhysRevC.94.034906","DOIUrl":"https://doi.org/10.1103/PhysRevC.94.034906","url":null,"abstract":"We analyze the directed flow of protons and pions in high-energy heavy-ion collisions in the incident energy range from $sqrt{{s}_{NN}}=7.7$ to 27 GeV within a microscopic transport model. Standard hadronic transport approaches do not describe the collapse of directed flow below $sqrt{{s}_{NN}}ensuremath{simeq}20$ GeV. By contrast, a model that simulates effects of a softening of the equation of state descibes well the behavior of directed flow data recently obtained by the STAR Collaboration [Phys. Rev. Lett. 112, 162301 (2014)]. We give a detailed analysis of how directed flow is generated. Particularly, we found that softening of the effective equation of state at the overlapping region of two nuclei, i.e., the reaction stages where the system reaches high baryon density state, is needed to explain the observed collapse of proton directed flow within a hadronic transport approach.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2016-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91323973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-01-13DOI: 10.1103/PhysRevC.91.015803
C. Fry, C. Wrede, S. Bishop, B. A. Brown, A. Chen, T. Faestermann, R. Hertenberger, A. Parikh, D. Pérez-Loureiro, H. Wirth, Alejandro García, R. Ortez
Background: The thermonuclear Cl-34g,Cl-m(p,gamma)Ar-35 reaction rates are unknown due to a lack of experimental nuclear physics data. Uncertainties in these rates translate to uncertainties in S-34 production in models of classical novae on oxygen-neon white dwarfs. S-34 abundances have the potential to aid in the classification of presolar grains.; Purpose: Determine resonance energies for the Cl-34g,Cl-m(p,gamma)Ar-35 reactions within the region of astrophysical interest for classical novae to a precision of a few keV as an essential first step toward constraining their thermonuclear reaction rates.; Method: Ar-35 excited states were populated by the Ar-36(d,t)Ar-35 reaction at E(d) = 22 MeV and reaction products were momentum analyzed by a high resolution quadrupole-dipole-dipole-dipole (Q3D) magnetic spectrograph.; Results: Seventeen new Ar-35 levels have been detected at a statistically significant level in the region E-x approximate to 5.9-6.7 MeV (E-r < 800 keV) and their excitation energies have been determined to typical uncertainties of 3 keV. The uncertainties for five previously known levels have also been reduced substantially. The measured level density was compared to those calculated using the WBMB Hamiltonian within the sd-pf model space.; Conclusions: Most of the resonances in the region of astrophysical interest have likely been discovered and their energies have been determined, but the resonance strengths are still unknown, and experimentally constraining the Cl-34g,Cl-m(p,gamma)Ar-35 reaction rates will require further experiments.
{"title":"Discovery of 34 g , m Cl ( p , γ ) 35 Ar resonances activated at classical nova temperatures","authors":"C. Fry, C. Wrede, S. Bishop, B. A. Brown, A. Chen, T. Faestermann, R. Hertenberger, A. Parikh, D. Pérez-Loureiro, H. Wirth, Alejandro García, R. Ortez","doi":"10.1103/PhysRevC.91.015803","DOIUrl":"https://doi.org/10.1103/PhysRevC.91.015803","url":null,"abstract":"Background: The thermonuclear Cl-34g,Cl-m(p,gamma)Ar-35 reaction rates are unknown due to a lack of experimental nuclear physics data. Uncertainties in these rates translate to uncertainties in S-34 production in models of classical novae on oxygen-neon white dwarfs. S-34 abundances have the potential to aid in the classification of presolar grains.; Purpose: Determine resonance energies for the Cl-34g,Cl-m(p,gamma)Ar-35 reactions within the region of astrophysical interest for classical novae to a precision of a few keV as an essential first step toward constraining their thermonuclear reaction rates.; Method: Ar-35 excited states were populated by the Ar-36(d,t)Ar-35 reaction at E(d) = 22 MeV and reaction products were momentum analyzed by a high resolution quadrupole-dipole-dipole-dipole (Q3D) magnetic spectrograph.; Results: Seventeen new Ar-35 levels have been detected at a statistically significant level in the region E-x approximate to 5.9-6.7 MeV (E-r < 800 keV) and their excitation energies have been determined to typical uncertainties of 3 keV. The uncertainties for five previously known levels have also been reduced substantially. The measured level density was compared to those calculated using the WBMB Hamiltonian within the sd-pf model space.; Conclusions: Most of the resonances in the region of astrophysical interest have likely been discovered and their energies have been determined, but the resonance strengths are still unknown, and experimentally constraining the Cl-34g,Cl-m(p,gamma)Ar-35 reaction rates will require further experiments.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2015-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80727275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-14DOI: 10.1103/PhysRevC.91.024320
T. Togashi, N. Shimizu, Y. Utsuno, T. Otsuka, M. Honma
We investigate unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes using large-scale shell-model calculations. These shell-model calculations are carried out within the model space of $fptext{-shell}+0{g}_{9/2}+1{d}_{5/2}$ orbits with the truncation allowing $1ensuremath{hbar}ensuremath{omega}$ excitation of a neutron. The effective Hamiltonian consists of GXPF1Br for $fp$-shell orbits and ${V}_{mathrm{MU}}$ with a modification for the other parts. The present shell-model calculations can describe and predict the energy levels of both natural- and unnatural-parity states up to the high-spin states in Cr and Fe isotopes with $Nensuremath{le}35$. The total energy surfaces present prolate deformations on the whole and indicate that the excitation of one neutron into the $0{g}_{9/2}$ orbit plays the role of enhancing prolate deformation. For positive (unnatural)-parity states in odd-mass Cr and Fe isotopes, their energy levels and prolate deformations indicate the decoupling limit of the particle-plus-rotor model. The sharp drop of the $9/{2}_{1}^{+}$ levels in going from $N=29$ to $N=35$ in odd-mass Cr, Fe, and Ni isotopes is explained by the Fermi surface approaching the $ensuremath{nu}0{g}_{9/2}$ orbit.
{"title":"Large-scale shell-model calculations for unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes","authors":"T. Togashi, N. Shimizu, Y. Utsuno, T. Otsuka, M. Honma","doi":"10.1103/PhysRevC.91.024320","DOIUrl":"https://doi.org/10.1103/PhysRevC.91.024320","url":null,"abstract":"We investigate unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes using large-scale shell-model calculations. These shell-model calculations are carried out within the model space of $fptext{-shell}+0{g}_{9/2}+1{d}_{5/2}$ orbits with the truncation allowing $1ensuremath{hbar}ensuremath{omega}$ excitation of a neutron. The effective Hamiltonian consists of GXPF1Br for $fp$-shell orbits and ${V}_{mathrm{MU}}$ with a modification for the other parts. The present shell-model calculations can describe and predict the energy levels of both natural- and unnatural-parity states up to the high-spin states in Cr and Fe isotopes with $Nensuremath{le}35$. The total energy surfaces present prolate deformations on the whole and indicate that the excitation of one neutron into the $0{g}_{9/2}$ orbit plays the role of enhancing prolate deformation. For positive (unnatural)-parity states in odd-mass Cr and Fe isotopes, their energy levels and prolate deformations indicate the decoupling limit of the particle-plus-rotor model. The sharp drop of the $9/{2}_{1}^{+}$ levels in going from $N=29$ to $N=35$ in odd-mass Cr, Fe, and Ni isotopes is explained by the Fermi surface approaching the $ensuremath{nu}0{g}_{9/2}$ orbit.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2014-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75352961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-29DOI: 10.1103/PhysRevC.92.011303
Y. Iwata, T. Ichikawa, N. Itagaki, J. Maruhn, T. Otsuka
The stable existence of rod-shaped structures in highly excited states of $^{24}mathrm{Mg}$ is studied based on a systematic cranked Hartree-Fock calculation with various Skyrme-type interactions. Its stability is examined by allowing the transition of the clusterlike structure to the shell-model-like structure. Especially, the rod-shaped state is exposed to two major instabilities: the bending motion, which is the main path for the transition to low-lying states, and the spin-orbit interaction, which is the driving force to break the $ensuremath{alpha}$ clusters and enhance the independent motion of the nucleons. The rod-shaped structure with large angular momentum is obtained as a metastable stationary state.
{"title":"Examination of the stability of a rod-shaped structure in $^{24}$Mg","authors":"Y. Iwata, T. Ichikawa, N. Itagaki, J. Maruhn, T. Otsuka","doi":"10.1103/PhysRevC.92.011303","DOIUrl":"https://doi.org/10.1103/PhysRevC.92.011303","url":null,"abstract":"The stable existence of rod-shaped structures in highly excited states of $^{24}mathrm{Mg}$ is studied based on a systematic cranked Hartree-Fock calculation with various Skyrme-type interactions. Its stability is examined by allowing the transition of the clusterlike structure to the shell-model-like structure. Especially, the rod-shaped state is exposed to two major instabilities: the bending motion, which is the main path for the transition to low-lying states, and the spin-orbit interaction, which is the driving force to break the $ensuremath{alpha}$ clusters and enhance the independent motion of the nucleons. The rod-shaped structure with large angular momentum is obtained as a metastable stationary state.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2014-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90462922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-16DOI: 10.1103/PhysRevC.86.014302
Lang Liu, T. Otsuka, N. Shimizu, Y. Utsuno, R. Roth
The low-lying excited states of $^{10}$Be and $^{12}$Be are investigated within a no-core Monte Carlo Shell Model (MCSM) framework employing a realistic potential obtained via the Unitary Correlation Operator Method. The excitation energies of the 2$^+_1$ and 2$^+_2$ states and the B(E2;$,2^+_{1,2}rightarrow$ 0$^+_{g.s.}$) for $^{10}$Be in the MCSM with a standard treatment of spurious center-of-mass motion show good agreement with experimental data. Some properties of low-lying states of $^{10}$Be are studied in terms of quadrupole moments, E2 transitions and single-particle occupation numbers. The E2 transition probability of $^{10}$C, the mirror nucleus of $^{10}$Be, is also presented with a good agreement to experiment. The triaxial deformation of $^{10}$Be and $^{10}$C is discussed in terms of the B(E2) values. The removal of the spurious center-of-mass motion affects differently on various states: for instance, negligible effects on the 2$^+_1$ and 2$^+_2$ levels of $^{10}$Be, while significant and favorable shift for the 1$^-_1$ level. It is suggested that the description of $^{12}$Be needs a larger model space as well as some other higher excited states of $^{10}$Be, as an indicator that these are dominated by intruder configurations.
{"title":"No-core Monte Carlo shell-model calculation for 10 Be and 12 Be low-lying spectra","authors":"Lang Liu, T. Otsuka, N. Shimizu, Y. Utsuno, R. Roth","doi":"10.1103/PhysRevC.86.014302","DOIUrl":"https://doi.org/10.1103/PhysRevC.86.014302","url":null,"abstract":"The low-lying excited states of $^{10}$Be and $^{12}$Be are investigated within a no-core Monte Carlo Shell Model (MCSM) framework employing a realistic potential obtained via the Unitary Correlation Operator Method. The excitation energies of the 2$^+_1$ and 2$^+_2$ states and the B(E2;$,2^+_{1,2}rightarrow$ 0$^+_{g.s.}$) for $^{10}$Be in the MCSM with a standard treatment of spurious center-of-mass motion show good agreement with experimental data. Some properties of low-lying states of $^{10}$Be are studied in terms of quadrupole moments, E2 transitions and single-particle occupation numbers. The E2 transition probability of $^{10}$C, the mirror nucleus of $^{10}$Be, is also presented with a good agreement to experiment. The triaxial deformation of $^{10}$Be and $^{10}$C is discussed in terms of the B(E2) values. The removal of the spurious center-of-mass motion affects differently on various states: for instance, negligible effects on the 2$^+_1$ and 2$^+_2$ levels of $^{10}$Be, while significant and favorable shift for the 1$^-_1$ level. It is suggested that the description of $^{12}$Be needs a larger model space as well as some other higher excited states of $^{10}$Be, as an indicator that these are dominated by intruder configurations.","PeriodicalId":48700,"journal":{"name":"Physical Review C","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2011-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82657925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：