Pub Date : 2024-09-05DOI: 10.1103/physrevc.110.034602
A. J. Smith, C. Hebborn, F. M. Nunes, R. G. T. Zegers
Charge-exchange reactions are versatile probes for nuclear structure. In particular, when populating isobaric analog states, these reactions are used to study isovector nuclear densities and neutron skins. The quality of the information extracted from charge-exchange data depends on the accuracy of the reaction models and their inputs; this work addresses these two points. First, we quantify the uncertainties due to effective nucleon-nucleus interactions by propagating the parameter posterior distributions of the recent global optical model KDUQ [C. D. Pruitt, J. E. Escher, and R. Rahman, Phys. Rev. C107, 014602 (2023)] to reaction observables populating the isobaric analog state, at beam energies in the range of 25–160 MeV. Our analysis, focusing on , shows that the total parametric uncertainties on the cross sections are around 60–100%. The source of this uncertainty is mainly the transition operator as the uncertainties from the distorted waves alone are less than about 15%. Second, we perform a comparison between two- and three-body models that both describe the dynamics of the reaction within the DWBA. The predictions from these two models are similar and generally agree with the available data, suggesting that one-step DWBA is sufficient to describe the reaction process. Only at a beam energy of 25 MeV are there possible signs that a one-step assumption is not fully correct. This work provides motivation for the quantification of uncertainties associated with the transition operator in three-body model. It also suggests that further constraint of the optical potential parameters is needed for increased model precision.
电荷交换反应是核结构的多功能探针。特别是在填充等压类似态时，这些反应可用于研究等向核密度和中子皮。从电荷交换数据中提取的信息的质量取决于反应模型及其输入的准确性；这项工作涉及这两点。首先，我们通过传播近期全球光学模型 KDUQ [C. D. Pruitt, J. E. Escher, and R. Rahman, Phys. Rev. C 107, 014602 (2023)]的参数后验分布，量化了有效核子-核相互作用引起的不确定性，并在 25-160 兆电子伏特的光束能量范围内，将（p,n）反应观测值填充到等压模拟态。我们以 Ca48 为重点进行的分析表明，横截面的总参数不确定性约为 60-100%。这种不确定性的来源主要是转换算子，因为仅来自扭曲波的不确定性就小于约 15%。其次，我们对描述 DWBA 内反应动力学的二体和三体模型进行了比较。这两种模型的预测结果相似，与现有数据基本吻合，表明一步 DWBA 足以描述反应过程。只有在束流能量为 25 MeV 时，才可能出现单步假设不完全正确的迹象。这项工作为量化与三体模型中转变算子相关的不确定性提供了动力。它还表明，要提高模型的精确度，还需要进一步限制光学势参数。
{"title":"Uncertainty quantification in (p,n) reactions","authors":"A. J. Smith, C. Hebborn, F. M. Nunes, R. G. T. Zegers","doi":"10.1103/physrevc.110.034602","DOIUrl":"https://doi.org/10.1103/physrevc.110.034602","url":null,"abstract":"Charge-exchange reactions are versatile probes for nuclear structure. In particular, when populating isobaric analog states, these reactions are used to study isovector nuclear densities and neutron skins. The quality of the information extracted from charge-exchange data depends on the accuracy of the reaction models and their inputs; this work addresses these two points. First, we quantify the uncertainties due to effective nucleon-nucleus interactions by propagating the parameter posterior distributions of the recent global optical model KDUQ [C. D. Pruitt, J. E. Escher, and R. Rahman, <span>Phys. Rev. C</span> <b>107</b>, 014602 (2023)] to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mo>(</mo><mi>p</mi><mo>,</mo><mi>n</mi><mo>)</mo></mrow></math> reaction observables populating the isobaric analog state, at beam energies in the range of 25–160 MeV. Our analysis, focusing on <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ca</mi><mprescripts></mprescripts><none></none><mn>48</mn></mmultiscripts></math>, shows that the total parametric uncertainties on the cross sections are around 60–100%. The source of this uncertainty is mainly the transition operator as the uncertainties from the distorted waves alone are less than about 15%. Second, we perform a comparison between two- and three-body models that both describe the dynamics of the reaction within the DWBA. The predictions from these two models are similar and generally agree with the available data, suggesting that one-step DWBA is sufficient to describe the reaction process. Only at a beam energy of 25 MeV are there possible signs that a one-step assumption is not fully correct. This work provides motivation for the quantification of uncertainties associated with the transition operator in three-body model. It also suggests that further constraint of the optical potential parameters is needed for increased model precision.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"33 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186728","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 : 2024-09-05DOI: 10.1103/physrevc.110.034603
Alan C. Shotter, Alessia Di Pietro
Internal surface standing wave resonances can occur when either electromagnetic or acoustic waves interact with cylindrical or spherical material structures. These resonances are often termed whispering gallery resonances, a reference to the focusing of sound within a cylindrical gallery. Here, a report is presented of an investigation to establish the importance of such surface standing wave resonances for nuclear wave scattering from unstable or weakly bound nuclei. To facilitate the investigation an analytical model, the transitional rotational model, has been developed to probe the occurrence of whispering gallery phenomena within nuclear wave scattering. Understanding such phenomena can be relevant when nuclear structure information are derived from scattering experiments. Moreover, it can also be important for the understanding of nuclear pathways leading to stellar explosions.
{"title":"Importance of whispering gallery resonances for nuclear scattering from weakly bound or unstable nuclei","authors":"Alan C. Shotter, Alessia Di Pietro","doi":"10.1103/physrevc.110.034603","DOIUrl":"https://doi.org/10.1103/physrevc.110.034603","url":null,"abstract":"Internal surface standing wave resonances can occur when either electromagnetic or acoustic waves interact with cylindrical or spherical material structures. These resonances are often termed whispering gallery resonances, a reference to the focusing of sound within a cylindrical gallery. Here, a report is presented of an investigation to establish the importance of such surface standing wave resonances for nuclear wave scattering from unstable or weakly bound nuclei. To facilitate the investigation an analytical model, the transitional rotational model, has been developed to probe the occurrence of whispering gallery phenomena within nuclear wave scattering. Understanding such phenomena can be relevant when nuclear structure information are derived from scattering experiments. Moreover, it can also be important for the understanding of nuclear pathways leading to stellar explosions.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"25 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186996","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 : 2024-09-04DOI: 10.1103/physrevc.110.034001
K. A. Shaulskyi, S. P. Maydanyuk, V. S. Vasilevsky
Background: Emission of bremsstrahlung photons in the scattering of protons off deuterons is investigated on the microscopic cluster basis in a wide region of beam energy from low energies up to 1.5 GeV.
{"title":"Structure of the deuteron from an analysis of bremsstrahlung emission in proton-deuteron scattering in cluster models","authors":"K. A. Shaulskyi, S. P. Maydanyuk, V. S. Vasilevsky","doi":"10.1103/physrevc.110.034001","DOIUrl":"https://doi.org/10.1103/physrevc.110.034001","url":null,"abstract":"<b>Background:</b> Emission of bremsstrahlung photons in the scattering of protons off deuterons is investigated on the microscopic cluster basis in a wide region of beam energy from low energies up to 1.5 GeV.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"59 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186729","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 : 2024-09-04DOI: 10.1103/physrevc.110.034305
Oliver C. Gorton, Calvin W. Johnson
The interacting shell model, a configuration-interaction method, is a venerable approach for low-lying nuclear structure calculations, but it is hampered by the exponential growth of its basis dimension as one increases the single-particle space and/or the number of active particles. Recent, quantum-information-inspired work has demonstrated that the proton and neutron sectors of a nuclear wave function are weakly entangled. Furthermore, the entanglement is smaller for nuclides away from , such as heavy, neutron-rich nuclides. Here we implement a weak entanglement approximation to bipartite configuration-interaction wave functions, approximating low-lying levels by coupling a relatively small number of many-proton and many-neutron states. This truncation scheme, which we present in the context of past approaches, reduces the basis dimension by many orders of magnitude while preserving essential features of nuclear spectra.
{"title":"Weak entanglement approximation for nuclear structure","authors":"Oliver C. Gorton, Calvin W. Johnson","doi":"10.1103/physrevc.110.034305","DOIUrl":"https://doi.org/10.1103/physrevc.110.034305","url":null,"abstract":"The interacting shell model, a configuration-interaction method, is a venerable approach for low-lying nuclear structure calculations, but it is hampered by the exponential growth of its basis dimension as one increases the single-particle space and/or the number of active particles. Recent, quantum-information-inspired work has demonstrated that the proton and neutron sectors of a nuclear wave function are weakly entangled. Furthermore, the entanglement is smaller for nuclides away from <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>N</mi><mo>=</mo><mi>Z</mi></mrow></math>, such as heavy, neutron-rich nuclides. Here we implement a weak entanglement approximation to bipartite configuration-interaction wave functions, approximating low-lying levels by coupling a relatively small number of many-proton and many-neutron states. This truncation scheme, which we present in the context of past approaches, reduces the basis dimension by many orders of magnitude while preserving essential features of nuclear spectra.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"30 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227675","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 : 2024-09-03DOI: 10.1103/physrevc.110.034301
H. D. Jiang, Y. Zhang, B. Qi, H. Zhang
A collective model Hamiltonian incorporating a potential is proposed to elucidate phenomena related to triaxiality in transitional systems. The solutions derived from the model built within the core-particle scheme can be approximated using Bessel functions and subsequently applied to describe the exotic high-spin phenomena observed in the mass region. The results indicate that chiral and wobbling rotations in a system may exhibit robustness against vibrations, suggesting a collective vibration mechanism for multiple chiral doublet bands and multiple rotation-wobbling bands in triaxial nuclei.
{"title":"Rotation-vibration model for the chiral doublet bands and wobbling bands in transitional nuclei","authors":"H. D. Jiang, Y. Zhang, B. Qi, H. Zhang","doi":"10.1103/physrevc.110.034301","DOIUrl":"https://doi.org/10.1103/physrevc.110.034301","url":null,"abstract":"A collective model Hamiltonian incorporating a <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>β</mi><mtext>−</mtext><mi>soft</mi></mrow></math> potential is proposed to elucidate phenomena related to triaxiality in transitional systems. The solutions derived from the model built within the core-particle scheme can be approximated using Bessel functions and subsequently applied to describe the exotic high-spin phenomena observed in the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>A</mi><mo>≈</mo><mn>130</mn></mrow></math> mass region. The results indicate that chiral and wobbling rotations in a <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>β</mi><mtext>−</mtext><mi>soft</mi></mrow></math> system may exhibit robustness against <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>β</mi></math> vibrations, suggesting a collective vibration mechanism for multiple chiral doublet bands and multiple rotation-wobbling bands in triaxial nuclei.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"1 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186730","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 : 2024-09-03DOI: 10.1103/physrevc.110.034303
B. Alayedet al.
Excited states in the neutron-deficient nuclide have been investigated in experiments performed at the Accelerator Laboratory of the University of Jyväskylä. The nuclei were produced in fusion-evaporation reactions induced by beams of 295 and 315 MeV ions bombarding an isotopically enriched target and separated using the recoil mass separator MARA. An isomeric state having a half-life of 510(30) ns was discovered and is interpreted as a seniority configuration. The -ray transitions emitted in the deexcitation of the isomeric state to the ground state were identified and a level scheme was constructed, from which the excitation energy of the isomer was determined to be 2581.5(10) keV. A value of 0.45(3) W.u. was deduced for the 105.4 keV transition depopulating the isomeric state. The deduced level scheme and value are compared with systematics and shell-model calculations.
{"title":"Decay of a microsecond seniority 3 isomeric state in Hf155","authors":"B. Alayedet al.","doi":"10.1103/physrevc.110.034303","DOIUrl":"https://doi.org/10.1103/physrevc.110.034303","url":null,"abstract":"Excited states in the neutron-deficient nuclide <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Hf</mi><mprescripts></mprescripts><none></none><mn>155</mn></mmultiscripts></math> have been investigated in experiments performed at the Accelerator Laboratory of the University of Jyväskylä. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Hf</mi><mprescripts></mprescripts><none></none><mn>155</mn></mmultiscripts></math> nuclei were produced in fusion-evaporation reactions induced by beams of 295 and 315 MeV <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ni</mi><mprescripts></mprescripts><none></none><mn>58</mn></mmultiscripts></math> ions bombarding an isotopically enriched <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Pd</mi><mprescripts></mprescripts><none></none><mn>102</mn></mmultiscripts></math> target and separated using the recoil mass separator MARA. An isomeric state having a half-life of 510(30) ns was discovered and is interpreted as a seniority <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>υ</mi><mo>=</mo><mn>3</mn></mrow><mo>,</mo><mo> </mo><mrow><mrow><mo>(</mo><mi>π</mi><msubsup><mi>h</mi><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow><mn>2</mn></msubsup><mo>⊗</mo><mi>ν</mi><msub><mi>f</mi><mrow><mn>7</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mn>27</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></mrow></math> configuration. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>γ</mi></math>-ray transitions emitted in the deexcitation of the isomeric state to the ground state were identified and a level scheme was constructed, from which the excitation energy of the isomer was determined to be 2581.5(10) keV. A <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>B</mi><mo>(</mo><mi>E</mi><mn>2</mn><mo>)</mo></mrow></math> value of 0.45(3) W.u. was deduced for the 105.4 keV transition depopulating the isomeric state. The deduced level scheme and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>B</mi><mo>(</mo><mi>E</mi><mn>2</mn><mo>)</mo></mrow></math> value are compared with systematics and shell-model calculations.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"43 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186731","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 : 2024-09-03DOI: 10.1103/physrevc.110.l031301
D. Kostylevaet al.
We report on the observation of the previously unknown isotope , the first unbound aluminum isotope located beyond the proton dripline. The nucleus decays by one-proton () emission, and its in-flight decays were detected by tracking trajectories of the decay products with silicon microstrip detectors. The -emission processes were studied by analyzing the measured angular correlations of decay products . The -decay energies of the ground and low-lying excited states of , its mass excess, and the proton separation energy value MeV were determined.
{"title":"Observation and spectroscopy of the proton-unbound nucleus Al21","authors":"D. Kostylevaet al.","doi":"10.1103/physrevc.110.l031301","DOIUrl":"https://doi.org/10.1103/physrevc.110.l031301","url":null,"abstract":"We report on the observation of the previously unknown isotope <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Al</mi><mprescripts></mprescripts><none></none><mn>21</mn></mmultiscripts></math>, the first unbound aluminum isotope located beyond the proton dripline. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Al</mi><mprescripts></mprescripts><none></none><mn>21</mn></mmultiscripts></math> nucleus decays by one-proton (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><mi>p</mi></mrow></math>) emission, and its in-flight decays were detected by tracking trajectories of the decay products with silicon microstrip detectors. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><mi>p</mi></mrow></math>-emission processes were studied by analyzing the measured angular correlations of decay products <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi>Mg</mi><mprescripts></mprescripts><none></none><mn>20</mn></mmultiscripts><mo>+</mo><mi>p</mi></mrow></math>. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>1</mn><mi>p</mi></mrow></math>-decay energies of the ground and low-lying excited states of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Al</mi><mprescripts></mprescripts><none></none><mn>21</mn></mmultiscripts></math>, its mass excess, and the proton separation energy value <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>S</mi><mi>p</mi></msub><mo>=</mo><mo>−</mo><mn>1</mn><mo>.</mo><msubsup><mn>15</mn><mrow><mo>−</mo><mn>0.07</mn></mrow><mrow><mo>+</mo><mn>0.10</mn></mrow></msubsup></mrow></math> MeV were determined.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"33 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186736","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 : 2024-09-03DOI: 10.1103/physrevc.110.034302
B. Li (李博), D. Vretenar, T. Nikšić, P. W. Zhao (赵鹏巍), J. Meng (孟杰)
A microscopic finite-temperature model based on time-dependent nuclear density functional theory (TDDFT) is employed to study the induced-fission process of . The saddle-to-scission dynamics of this process is explored, starting from various points on the deformation surface of Helmholtz free energy at a temperature that corresponds to the experimental excitation energy, and following self-consistent isentropic fission trajectories as they evolve toward scission. Dissipation effects and the formation of excited fragments are investigated and, in particular, the difference in the evolution of the local temperature along asymmetric and symmetric fission trajectories is studied. The relative entropies and entanglement between fission fragments emerging at scission are analyzed.
{"title":"Time-dependent density functional theory study of induced-fission dynamics of Th226","authors":"B. Li (李博), D. Vretenar, T. Nikšić, P. W. Zhao (赵鹏巍), J. Meng (孟杰)","doi":"10.1103/physrevc.110.034302","DOIUrl":"https://doi.org/10.1103/physrevc.110.034302","url":null,"abstract":"A microscopic finite-temperature model based on time-dependent nuclear density functional theory (TDDFT) is employed to study the induced-fission process of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Th</mi><mprescripts></mprescripts><none></none><mn>226</mn></mmultiscripts></math>. The saddle-to-scission dynamics of this process is explored, starting from various points on the deformation surface of Helmholtz free energy at a temperature that corresponds to the experimental excitation energy, and following self-consistent isentropic fission trajectories as they evolve toward scission. Dissipation effects and the formation of excited fragments are investigated and, in particular, the difference in the evolution of the local temperature along asymmetric and symmetric fission trajectories is studied. The relative entropies and entanglement between fission fragments emerging at scission are analyzed.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"50 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186734","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 : 2024-09-03DOI: 10.1103/physrevc.110.034304
J. Dudouetet al.
The first systematic experimental study of the neutron-rich Br isotopes with two complementary state-of-the-art techniques is presented. These isotopes were populated in the fission process at two different facilities, GANIL and ILL. New spectroscopic information was obtained for odd-even isotopes and the experimental results were compared with state-of-the-art large scale shell model (LSSM) and discrete nonorthogonal (DNO) shell model calculations. As a result of such theoretical approaches, a transition from prolate () to oblate () shapes is obtained from the subtle balance between proton and neutron quadrupole deformations, as a clear signature of a pseudo-SU3 quadrupole regime.
{"title":"High-resolution spectroscopy of neutron-rich Br isotopes and signatures for a prolate-to-oblate shape transition at N=56","authors":"J. Dudouetet al.","doi":"10.1103/physrevc.110.034304","DOIUrl":"https://doi.org/10.1103/physrevc.110.034304","url":null,"abstract":"The first systematic experimental study of the neutron-rich Br isotopes with two complementary state-of-the-art techniques is presented. These isotopes were populated in the fission process at two different facilities, GANIL and ILL. New spectroscopic information was obtained for odd-even <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Br</mi><mprescripts></mprescripts><none></none><mrow><mn>87</mn><mo>–</mo><mn>93</mn></mrow></mmultiscripts></math> isotopes and the experimental results were compared with state-of-the-art large scale shell model (LSSM) and discrete nonorthogonal (DNO) shell model calculations. As a result of such theoretical approaches, a transition from prolate (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Br</mi><mprescripts></mprescripts><none></none><mrow><mn>87</mn><mo>,</mo><mn>89</mn></mrow></mmultiscripts></math>) to oblate (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Br</mi><mprescripts></mprescripts><none></none><mrow><mn>91</mn><mo>,</mo><mn>93</mn></mrow></mmultiscripts></math>) shapes is obtained from the subtle balance between proton and neutron quadrupole deformations, as a clear signature of a pseudo-SU3 quadrupole regime.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"11 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186994","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 : 2024-09-03DOI: 10.1103/physrevc.110.034903
Zuo-Wen Liu, Shusu Shi
The E895 and STAR experiments demonstrate that the slopes of directed flow with respect to rapidity () of mesons are negative in the low transverse momentum () region, , in collisions at . Using the transport model JAM, we investigate the directed flow of , and as functions of rapidity, , and collision energy in collisions at the same energies as those in the E895 and STAR experiments. We find that the JAM model can qualitatively reproduce the antiflow of observed in the E895 experiment. The slopes of pions and kaons are analyzed as functions of the window, revealing a strong dependence of the slopes. Negative slopes are observed in the low region, , while positive slopes are shown in the higher region. We find that the shadowing effect from spectators is crucial in generating the antiflow of mesons at low
{"title":"Antiflow of mesons in the high baryon density region","authors":"Zuo-Wen Liu, Shusu Shi","doi":"10.1103/physrevc.110.034903","DOIUrl":"https://doi.org/10.1103/physrevc.110.034903","url":null,"abstract":"The E895 and STAR experiments demonstrate that the slopes of directed flow with respect to rapidity (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>d</mi><msub><mi>v</mi><mn>1</mn></msub><msub><mrow><mo>/</mo><mi>d</mi><mi>y</mi><mo>|</mo></mrow><mrow><mi>y</mi><mo>=</mo><mn>0</mn></mrow></msub></mrow></math>) of mesons are negative in the low transverse momentum (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi>T</mi></msub></math>) region, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>p</mi><mi>T</mi></msub><mo><</mo><mn>0.8</mn><mspace width=\"4pt\"></mspace><mi>GeV</mi><mo>/</mo><mi>c</mi></mrow></math>, in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>3.0</mn><mo>–</mo><mn>3.9</mn><mspace width=\"4pt\"></mspace><mi>GeV</mi></mrow></math>. Using the transport model JAM, we investigate the directed flow of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>π</mi><mo>±</mo></msup><mo>,</mo><mo> </mo><msup><mi>K</mi><mo>±</mo></msup></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>K</mi><mn>0</mn></msup></math> as functions of rapidity, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi>T</mi></msub></math>, and collision energy in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at the same energies as those in the E895 and STAR experiments. We find that the JAM model can qualitatively reproduce the antiflow of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup></math> observed in the E895 experiment. The <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>v</mi><mn>1</mn></msub></math> slopes of pions and kaons are analyzed as functions of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi>T</mi></msub></math> window, revealing a strong <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi>T</mi></msub></math> dependence of the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>v</mi><mn>1</mn></msub></math> slopes. Negative <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>v</mi><mn>1</mn></msub></math> slopes are observed in the low <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi>T</mi></msub></math> region, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>p</mi><mi>T</mi></msub><mo><</mo><mn>0.8</mn><mspace width=\"4pt\"></mspace><mi>GeV</mi><mo>/</mo><mi>c</mi></mrow></math>, while positive slopes are shown in the higher <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>p</mi><mi>T</mi></msub></math> region. We find that the shadowing effect from spectators is crucial in generating the antiflow of mesons at low <math xmln","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"7 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186735","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}
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