Nuclear Physics APub Date : 2024-08-26DOI: 10.1016/j.nuclphysa.2024.122941
{"title":"Re-examination of nuclear structure properties and shape co-existence of nuclei around A ∼ 70","authors":"","doi":"10.1016/j.nuclphysa.2024.122941","DOIUrl":"10.1016/j.nuclphysa.2024.122941","url":null,"abstract":"<div><p>We re-examine the nuclear structure properties of waiting point nuclei around A ∼ 70 using the interacting boson model-1 (IBM-1) and the relativistic mean field (RMF) model. Effective density-dependent meson-exchange functional (DD-ME2) and density-dependent point-coupling functional (DD-PC1) were used for the RMF calculations. We calculated the energy levels, the geometric shapes, binding and separation energies of nucleons and quadrupole deformation parameters (<span><math><msub><mrow><mi>β</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>). The shape co-existence phenomena in A ∼ 70 nuclei (<sup>68</sup>Se, <sup>70</sup>Se, <sup>70</sup>Br, <sup>70</sup>Kr, <sup>72</sup>Kr, <sup>74</sup>Kr, <sup>74</sup>Rb and <sup>74</sup>Sr) was later investigated. Spherical and deformed shapes of the selected waiting point nuclei were computed using the IBM-1 and RMF models, respectively. The proton-neutron quasiparticle random phase approximation (pn-QRPA) model was used to calculate <em>β</em>-decay properties (Gamow-Teller strength distributions, <em>β</em>-decay half-lives and branching ratios) of selected nuclei as a function of <span><math><msub><mrow><mi>β</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>. The results revealed a significant variation in calculated half-lives and Gamow-Teller strength distributions as the shape parameter was changed. The <span><math><msub><mrow><mi>β</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> computed via DD-ME2 functional resulted in half-lives in best agreement with the measured data.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142129218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-08-08DOI: 10.1016/j.nuclphysa.2024.122940
{"title":"Rearrangement and breakup amplitudes from the solution of Faddeev-AGS equations by pseudo-state discretization of the two-particle continuum","authors":"","doi":"10.1016/j.nuclphysa.2024.122940","DOIUrl":"10.1016/j.nuclphysa.2024.122940","url":null,"abstract":"<div><p>The AGS equations for rearrangement transition operators in the three-particle problem are turned into a set of effective multi-channel two-body equations using the pseudo-state discretization of the two-particle resolvent. The resulting effective equations are LS-type integral equations in the spectator degrees of freedom, much like the LS equations of multichannel inelastic scattering. In particular, the effective potential matrix is real, energy-independent and non-singular, while the propagator matrix has only simple poles. Difficulties associated with the moving singularities of the effective potential matrix in the usual separable-T approach to AGS equations are avoided. After regularization of the kernel via subtraction procedures well known from two-particle scattering, the set of coupled LS-type equations in the spectator momenta are solved rather straightforwardly by the Nyström method. Solutions of effective two-body equations are then used to calculate the breakup amplitudes using the well-known relationship between rearrangement and breakup amplitudes. Calculations using a local momentum-space basis on a benchmark model of the n+d collision show that rather accurate results for elastic and breakup amplitudes can be obtained with rather small bases.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141964582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-08-02DOI: 10.1016/j.nuclphysa.2024.122939
{"title":"Higher forbidden unique β− decay transitions and shell-model interpretation","authors":"","doi":"10.1016/j.nuclphysa.2024.122939","DOIUrl":"10.1016/j.nuclphysa.2024.122939","url":null,"abstract":"<div><p>In the present work, we have predicted the half-lives for the <span><math><msup><mrow><mi>β</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> decay for higher forbidden unique transitions in the mass range of nuclei from A = 40-138. For these transitions, the experimental data for half-lives are not available except for a few cases. The calculations for half-lives are performed within the framework of the nuclear shell model (SM). We have used the effective interactions sdpf-mu, gxpf1a, gwbxg, G-matrix, snet, sn100pn, and jj56pnb to perform the SM calculations in different mass regions. A comprehensive discussion has been made between the SM predicted half-lives and the scaled half-lives from proton-neutron quasiparticle random-phase approximation (pnQRPA). The results of the present study will be useful to plan new experiments to measure half-lives for these higher forbidden unique <span><math><msup><mrow><mi>β</mi></mrow><mrow><mo>−</mo></mrow></msup></math></span> transitions.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141951989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-07-29DOI: 10.1016/j.nuclphysa.2024.122931
{"title":"Study of the direct 16O(p,γ)17F astrophysical capture reaction within a potential model approach","authors":"","doi":"10.1016/j.nuclphysa.2024.122931","DOIUrl":"10.1016/j.nuclphysa.2024.122931","url":null,"abstract":"<div><p>A potential model is applied for the analysis of the astrophysical direct nuclear capture process <sup>16</sup>O(p,<span><math><msup><mrow><mi>γ</mi><mo>)</mo></mrow><mrow><mn>17</mn></mrow></msup></math></span>F. The phase-equivalent potentials of the Woods-Saxon form for the p<span><math><msup><mrow><mo>−</mo></mrow><mrow><mn>16</mn></mrow></msup></math></span>O interaction are examined which reproduce the binding energies and the empirical values of ANC for the <sup>17</sup>F(5/2<sup>+</sup>) ground and <sup>17</sup>F(1/2<sup>+</sup>) (<span><math><msup><mrow><mi>E</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>=0.495 MeV) excited bound states from different sources. The best description of the experimental data for the astrophysical <em>S</em> factor is obtained within the potential model which yields the ANC values of 1.043 fm<sup>−1/2</sup> and 75.484 fm<sup>−1/2</sup> for the <sup>17</sup>F(<span><math><mn>5</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msup></math></span>) ground and <sup>17</sup>F(<span><math><mn>1</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msup></math></span>) excited bound states, respectively. The zero-energy astrophysical factor <span><math><mi>S</mi><mo>(</mo><mn>0</mn><mo>)</mo><mo>=</mo><mn>9.321</mn></math></span> KeV b is obtained by using the asymptotic expansion method of D. Baye. The calculated reaction rates within the region up to 10<sup>10</sup> K are in good agreement with those from the R-matrix approach and the hierarchical Bayesian model in both absolute values and temperature dependence.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141962565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-07-26DOI: 10.1016/j.nuclphysa.2024.122930
{"title":"Spectral features of Mo isotopes","authors":"","doi":"10.1016/j.nuclphysa.2024.122930","DOIUrl":"10.1016/j.nuclphysa.2024.122930","url":null,"abstract":"<div><p>The sharp shape phase changes with increasing <em>N</em> of the <em>A</em> = 100–110 Mo isotopes, as associated with the deformed <em>N</em> = 60 shape turning point of the structure, are studied. In terms of the shape change with proton number <em>Z</em>, the Mo isotopes lie in between the Sr, Zr and Ru, Pd chain of isotopes. We have analyzed the special spectral features of these Mo isotopes through the energy level structures, in ground state bands, the K<sup>π</sup> = 2<sup>+</sup> and K<sup>π</sup> = 4<sup>+</sup> excited bands empirically. The unique features of the association of triaxiality, along with the rotational bands, are well illustrated. The interacting boson model (IBM-1) is used to reproduce the level structures of the Mo isotopes. An in-depth analysis of the spectral features of the Mo isotopes is presented. There is emphasis on the physics of the shape transitions.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141849515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-07-11DOI: 10.1016/j.nuclphysa.2024.122929
{"title":"An improved Gamow-like formula for cluster radioactivity","authors":"","doi":"10.1016/j.nuclphysa.2024.122929","DOIUrl":"10.1016/j.nuclphysa.2024.122929","url":null,"abstract":"<div><p>An improved Gamow-like (IMGL) formula for cluster radioactivity half-lives is proposed by introducing an accurate charge radius formula, an analytic expression of assault frequency, the angular momentum carried by the emitted cluster and the isospin effect. By using the IMGL formula, the cluster radioactivity half-lives of 20 nuclei are calculated. It is shown that the IMGL formula improves the agreement with experimental data compared to its predecessor. Then, several sets of other semi-empirical formulas, including the Ni-Ren-Dong-Xu (NRDX), universal decay law (UDL), Tavares-Medeiros (TM), Balasubramaniam-Kumarasamy-Arunachalam-Gupta (BKAG), Viola-Seaborg-Sobiczewski (VSS) and extended universal decay law (EUDL) formulas, are used to calculate the half-lives of cluster radioactivity. By comparing the agreement between the half-lives extracted from different semi-empirical formulas and the experimental data, it is found that the IMGL formula is more accurate than others. At last, within the IMGL formula the cluster radioactivity half-lives of Z=85-97 isotopes that are not available experimentally are predicted. It might be helpful for searching for the new cluster emitters in future measurements.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141629822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-07-10DOI: 10.1016/j.nuclphysa.2024.122928
{"title":"Excluded volume effects on cold neutron star phenomenology","authors":"","doi":"10.1016/j.nuclphysa.2024.122928","DOIUrl":"10.1016/j.nuclphysa.2024.122928","url":null,"abstract":"<div><p>Observable properties of neutron stars are studied within a hadronic equation of state derived from the quark level. The effect of short-range repulsion is incorporated within the excluded volume framework. It is found that one can sustain neutron stars with masses as large as 2.2<span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> even including hyperons in <em>β</em> equilibrium, while producing radii and tidal deformabilities consistent with current constraints.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375947424001106/pdfft?md5=064dd1b3f496236e31fec19a66b19d9d&pid=1-s2.0-S0375947424001106-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141638846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear Physics APub Date : 2024-07-09DOI: 10.1016/j.nuclphysa.2024.122927
{"title":"Regge trajectory relation for the universal description of the heavy-heavy systems: Diquarks, mesons, baryons and tetraquarks","authors":"","doi":"10.1016/j.nuclphysa.2024.122927","DOIUrl":"10.1016/j.nuclphysa.2024.122927","url":null,"abstract":"<div><p>By employing the nonlinear Regge trajectory relation <span><math><mi>M</mi><mo>=</mo><msub><mrow><mi>m</mi></mrow><mrow><mi>R</mi></mrow></msub><mo>+</mo><msub><mrow><mi>β</mi></mrow><mrow><mi>x</mi></mrow></msub><msup><mrow><mo>(</mo><mi>x</mi><mo>+</mo><msub><mrow><mi>c</mi></mrow><mrow><mn>0</mn><mi>x</mi></mrow></msub><mo>)</mo></mrow><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msup><mspace></mspace><mspace></mspace><mo>(</mo><mi>x</mi><mo>=</mo><mi>l</mi><mo>,</mo><mspace></mspace><msub><mrow><mi>n</mi></mrow><mrow><mi>r</mi></mrow></msub><mo>)</mo></math></span>, we investigate the heavy-heavy systems, such as the doubly heavy diquarks, the doubly heavy mesons, the heavy-heavy baryons, and the heavy-heavy tetraquarks. The fitted Regge trajectories illustrate that these heavy-heavy systems satisfy the above formula and show the existence of an universal description of the heavy-heavy systems. The universality embodies not only the universal behavior <span><math><mi>M</mi><mo>∼</mo><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msup></math></span> but also the universal parameters. The values of <span><math><msub><mrow><mi>c</mi></mrow><mrow><mi>f</mi><msub><mrow><mi>n</mi></mrow><mrow><mi>r</mi></mrow></msub></mrow></msub></math></span> and <span><math><msub><mrow><mi>c</mi></mrow><mrow><mi>f</mi><mi>l</mi></mrow></msub></math></span> vary with different heavy-heavy systems, but they are close to one. There is an inequality <span><math><msub><mrow><mi>β</mi></mrow><mrow><msub><mrow><mi>n</mi></mrow><mrow><mi>r</mi></mrow></msub></mrow></msub><mo>></mo><msub><mrow><mi>β</mi></mrow><mrow><mi>l</mi></mrow></msub></math></span>, and it holds for all the discussed heavy-heavy systems. Moreover, the expression of <span><math><msub><mrow><mi>β</mi></mrow><mrow><mi>x</mi></mrow></msub></math></span> [Eq. <span><span>(11)</span></span>] explains its variation with the change of the constituents' masses.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141622477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Nuclear Physics APub Date : 2024-07-05DOI: 10.1016/j.nuclphysa.2024.122924
{"title":"Controlling volume fluctuations for studies of critical phenomena in nuclear collisions","authors":"","doi":"10.1016/j.nuclphysa.2024.122924","DOIUrl":"10.1016/j.nuclphysa.2024.122924","url":null,"abstract":"<div><p>We generalize and extend the recently proposed method <span><span>[1]</span></span> to account for contributions of system size (or volume/participant) fluctuations to the experimentally measured moments of particle multiplicity distributions. We find that in the general case there are additional biases which are not directly accessible to experiment. These biases are, however, parametrically suppressed if the multiplicity of the particles of interest is small compared to the total charged-particle multiplicity, e.g., in the case of proton number fluctuations at top RHIC and LHC energies. They are also small if the multiplicity distribution of charged particles per wounded nucleon is close to the Poissonian limit, which is the case at low energy nuclear collisions, e.g., at GSI/SIS18. We further find that mixed events are not necessarily needed to extract the correction for volume fluctuations. We provide the formulas to correct pure and mixed cumulants of particle multiplicity distributions up to any order together with their associated biases.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375947424001064/pdfft?md5=75464da240cea8d98ad1769205fb2c83&pid=1-s2.0-S0375947424001064-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141949873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear Physics APub Date : 2024-07-05DOI: 10.1016/j.nuclphysa.2024.122926
{"title":"Exploring asymmetric fission in 180Hg⁎ compound nucleus using dynamical cluster-decay model","authors":"","doi":"10.1016/j.nuclphysa.2024.122926","DOIUrl":"10.1016/j.nuclphysa.2024.122926","url":null,"abstract":"<div><p>The observed asymmetric fission of the <sup>180</sup>Hg<sup>⁎</sup> compound nucleus challenges conventional expectations of symmetric fission, which are attributed to the presence of shell closures at Z=40 (semi-magic) and N=50 (magic). To comprehend this novel phenomenon, the dynamical cluster-decay model has been employed. For the first time, this model incorporates the bulk and neutron-proton asymmetry coefficients of the nuclear shape-dependent mass excess formula which are tuned recently to the ground state mass excess data of AME2020 and/or FRDM(2012) along with the temperature dependence for the nuclear shape and the surface energy coefficient of the nuclear proximity potential. The calculations have considered nuclear shapes as both spherical and deformed (quadrupole), with and without temperature dependence for the quadrupole deformation. A new minimum appears in the symmetric mass region of the fragmentation potential for masses (80, 100), when the fragments are deformed and optimally oriented, at an energy lower than that obtained for masses (90, 90) where the fragments are assumed to be spherical or nearly spherical at higher temperatures. This new minimum seems equivalent to the appearance of a new shell gap with deformation and is responsible for the asymmetric fission of <sup>180</sup>Hg<sup>⁎</sup>. The most probable fission channel and the transition from asymmetric to symmetric mass distribution at higher excitation energies are consistent with experiments for the current temperature dependence assigned to the quadrupole deformation parameter.</p></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141622521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}