Nuclear Physics A最新文献

{"title":"Triaxial shape evolution and shape coexistence in Radon isotopes within the covariant density functional theory","authors":"H.M. Elsharkawy ,&nbsp;M.M. Abdel Kader ,&nbsp;A.M. Basha ,&nbsp;A. Lotfy","doi":"10.1016/j.nuclphysa.2025.123059","DOIUrl":"10.1016/j.nuclphysa.2025.123059","url":null,"abstract":"<div><div>The Covariant Density Functional Theory (CDFT) is utilized to systematically study the triaxial shape evolution of even-even radon isotopic chain (N=104-150) within the framework of the Relativistic Hartree-Bogoliubov (RHB) mean-field model. In the present work we make use of two distinct effective interactions: the Density-Dependent Meson-Exchange (DD-ME2) and the Density-Dependent Point-Coupling interaction with parameter set DD-PCX.</div><div>Neutron deficient side of the considered isotopic chain shows several shape coexistence states accompanied by little remarkable triaxial states appeared in that region. Various ground state properties, such as the binding energy per nucleon, the two-neutron separation energy, and the proton, neutron, and charge radii are also presented and compared with alternative theoretical approaches like the Deformed Relativistic Hartree–Bogoliubov theory in Continuum (DRHBc), the Finite-Range Droplet Model (FRDM), the Infinite Nuclear Matter Model (INMM) and the proxy-SU(3) model.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123059"},"PeriodicalIF":1.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534870","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}

{"title":"Advanced predictive modelling of electric quadrupole transitions in even-even nuclei using various machine learning approaches","authors":"Sihem Berbache ,&nbsp;Serkan Akkoyun ,&nbsp;Ahmed H. Ali ,&nbsp;Sebahattin Kartal","doi":"10.1016/j.nuclphysa.2025.123058","DOIUrl":"10.1016/j.nuclphysa.2025.123058","url":null,"abstract":"<div><div>Empirical predictions of electric quadrupole transition probabilities, B (E2; 0⁺→2⁺), in even-even nuclei, are among the principles needed to solve the nuclear structure and collective behaviour. In this study, nine different ML algorithms, gradient boosting machine (GBM), random forest (RF), convolutional neural network (CNN), k-nearest neighbour (KNN), CatBoost, extreme gradient boosting (XGBoost), neural network (NN), support vector machine (SVM) and multiple linear regression (MLR), are evaluated as a different data-driven solution for the prediction of B(E2) values. The outcomes show that ensemble models, in particular GBMs, RF, and XGBoost, provide vastly improved predictive capabilities and generalizing influence while creating strong correlations to experimental data with small prediction errors. On the other hand, deep learning models such as CNN and NN is prone to overfitting, while simpler ones such as MLR and KNN fail to capture the non-linear relationships inherent in nuclear data. The findings underscore the promise of ensemble ML tools for nuclear physics in a scalable, accurate approach for predicting transition probabilities.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123058"},"PeriodicalIF":1.7,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519581","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}

{"title":"Investigation of ground state and the β-decay properties of 156−162Nd","authors":"Abdul Kabir ,&nbsp;Jameel-Un Nabi ,&nbsp;Noor-Ul Ain Raza ,&nbsp;Hamad Almujibah","doi":"10.1016/j.nuclphysa.2025.123057","DOIUrl":"10.1016/j.nuclphysa.2025.123057","url":null,"abstract":"<div><div>The nuclear ground state and beta decay properties for ^156−162Nd have been investigated within the framework of the relativistic mean field (RMF) approach and proton-neutron quasi-particles random phase approximation (pn-QRPA) model. The RMF model with density-dependent interactions DDME2 and DDPC1 is utilized to analyze the potential energy curves (PECs), potential energy surfaces (PESs), the nuclear ground state deformation parameter (<span><math><msub><mrow><mi>β</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>), neutron (proton) separation energies (S_<em>n</em>(S_<em>p</em>) and S<span><math><msub><mrow></mrow><mrow><mn>2</mn><mi>n</mi></mrow></msub></math></span>(S<span><math><msub><mrow></mrow><mrow><mn>2</mn><mi>p</mi></mrow></msub></math></span>)), neutron skin thickness (r<span><math><msub><mrow></mrow><mrow><mi>n</mi><mi>p</mi></mrow></msub></math></span>), and root mean square radius (r<span><math><msub><mrow></mrow><mrow><mi>r</mi><mi>m</mi><mi>s</mi></mrow></msub></math></span>). Furthermore, the <span><math><msub><mrow><mi>β</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> computed via the finite range droplet model (FRDM) and RMF with DDME2 and DDPC1-based interactions are employed in the pn-QRPA model as an input parameter for the calculations of the beta decay properties, including the Gamow Teller (GT) strength, log <em>ft</em> values, and half-lives of ^156−162Nd. The FRDM and RMF-DDPC1-based calculated log <em>ft</em> values show better consistency with the measured data. The present computed beta decay half-lives are in reasonable agreement with the experimental data.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1057 ","pages":"Article 123057"},"PeriodicalIF":1.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474967","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}

{"title":"The effect of three-body nucleon-nucleon interaction on the ground state binding energy of the light nuclei","authors":"F. Kamgar,&nbsp;G.H. Bordbar,&nbsp;S.M. Zebarjad,&nbsp;M.A. Rastkhadiv","doi":"10.1016/j.nuclphysa.2025.123056","DOIUrl":"10.1016/j.nuclphysa.2025.123056","url":null,"abstract":"&lt;div&gt;&lt;div&gt;We calculate the ground state binding energies of the light nuclei such as &lt;span&gt;&lt;math&gt;&lt;mmultiscripts&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mprescripts&gt;&lt;/mprescripts&gt;&lt;none&gt;&lt;/none&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/mmultiscripts&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mmultiscripts&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;/mrow&gt;&lt;mprescripts&gt;&lt;/mprescripts&gt;&lt;none&gt;&lt;/none&gt;&lt;mrow&gt;&lt;mn&gt;6&lt;/mn&gt;&lt;/mrow&gt;&lt;/mmultiscripts&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mmultiscripts&gt;&lt;mrow&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mprescripts&gt;&lt;/mprescripts&gt;&lt;none&gt;&lt;/none&gt;&lt;mrow&gt;&lt;mn&gt;12&lt;/mn&gt;&lt;/mrow&gt;&lt;/mmultiscripts&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mmultiscripts&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mprescripts&gt;&lt;/mprescripts&gt;&lt;none&gt;&lt;/none&gt;&lt;mrow&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/mmultiscripts&gt;&lt;/math&gt;&lt;/span&gt; by considering the effect of three-body nucleon-nucleon interaction. We use the effective two-body potential obtained from the lowest order constrained variational (LOCV) calculations of the nuclear matter for the &lt;span&gt;&lt;math&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mn&gt;68&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and &lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;18&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; nuclear potentials in different channels. To calculate the ground state binding energy, we implement the local density approximation by using the harmonic oscillator wave functions while the effect of three-body interaction is considered by employing the UIX potential. We compare the obtained two-body ground state binding energy with the energy related to the three-body effect. We also compare the obtained values with the experimental data and also work of others, and show that the results are relatively acceptable. We compute the root mean-square radius &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; of the above nuclei for the &lt;span&gt;&lt;math&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mn&gt;68&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;14&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and &lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;18&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; potentials and compare the results with the experiment. We also obtain the contribution of different channels by matching to the experimental values of the quadrupole moments and magnetic dipole moments. Furthermore, we calculate the three-body cluster energy of the above nuclei and compare the results with that of nuclear matter. According to the obtained results, we see that the three-body cluster energy contribution is small. For example, for &lt;span&gt;&lt;math&gt;&lt;mmultiscripts&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mprescripts&gt;&lt;/mprescripts&gt;&lt;none&gt;&lt;/none&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/mmultiscripts&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; nuclide, this value is 0.079 MeV with the &lt;spa","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1057 ","pages":"Article 123056"},"PeriodicalIF":1.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474969","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}

{"title":"Enhancing heavy ion accelerator capabilities in Australia","authors":"M. Dasgupta,&nbsp;S. Battisson,&nbsp;L.T. Bezzina,&nbsp;D.J. Hinde,&nbsp;N.R. Lobanov,&nbsp;P. Linardakis,&nbsp;T.R. McGoram,&nbsp;C. Notthoff,&nbsp;E.C. Simpson,&nbsp;D. Tempra,&nbsp;T. Tunningley","doi":"10.1016/j.nuclphysa.2025.123036","DOIUrl":"10.1016/j.nuclphysa.2025.123036","url":null,"abstract":"<div><div>Heavy Ion Accelerators is a network of ion accelerators in Australia, located in Canberra and Melbourne. The Heavy Ion Accelerators (HIA) network delivers ion-implantation capabilities and accelerated ion beams for a wide range of research and industrial applications including in nuclear, quantum, space, environmental and medical physics areas. Completed and planned enhancements to HIA capabilities are expanding the areas of applicability and strengthening Australia's training and research capabilities.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123036"},"PeriodicalIF":1.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479735","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}

{"title":"Estimating centrality in heavy-ion collisions using Transfer Learning technique","authors":"Dipankar Basak ,&nbsp;Kalyan Dey","doi":"10.1016/j.nuclphysa.2025.123043","DOIUrl":"10.1016/j.nuclphysa.2025.123043","url":null,"abstract":"<div><div>In this study, we explore the applicability of Transfer Learning techniques for estimating collision centrality in terms of the number of participants (<span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>part</mi></mrow></msub></math></span>) in high-energy heavy-ion collisions. In the present work, we leverage popular pre-trained CNN models such as VGG16, ResNet50, and DenseNet121 to determine <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>part</mi></mrow></msub></math></span> in Au+Au collisions at <span><math><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi>N</mi><mi>N</mi></mrow></msub></mrow></msqrt><mo>=</mo><mn>200</mn></math></span> GeV on an event-by-event basis. Remarkably, all three models achieved good performance despite the pre-trained models being trained for databases of other domains. Particularly noteworthy is the superior performance of the VGG16 model, showcasing the potential of transfer learning techniques for extracting diverse observables from heavy-ion collision data.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1057 ","pages":"Article 123043"},"PeriodicalIF":1.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445541","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}

{"title":"Quasifission and deep inelastic collisions competing with superheavy element creation","authors":"D.J. Hinde ,&nbsp;D.Y. Jeung ,&nbsp;M. Dasgupta ,&nbsp;J. Buete ,&nbsp;K.J. Cook ,&nbsp;C. Simenel ,&nbsp;E.C. Simpson ,&nbsp;H.M. Albers ,&nbsp;Ch.E. Düllmann ,&nbsp;J. Khuyagbaatar ,&nbsp;A. Yakushev","doi":"10.1016/j.nuclphysa.2025.123040","DOIUrl":"10.1016/j.nuclphysa.2025.123040","url":null,"abstract":"<div><div>Fusion forming superheavy elements is strongly inhibited by the faster non-equilibrium Deep Inelastic (DIC) and quasifission processes. These have often been considered as distinct processes, but recent measurements for reactions involving heavy nuclei such as ²⁰⁸Pb and lighter suggest that these two processes form a continuum. However, for reactions of heavy ions with actinide nuclei, binary mass-split spectra show reduced yields for fragments lighter than the target, resulting in a peak in yield close to ²⁰⁸Pb. This gives an apparent separation between DIC and quasifission outcomes. The ²⁰⁸Pb peak has generally been attributed to the ²⁰⁸Pb closed shells giving a valley in the potential energy surface, attracting quasifission trajectories. However, recent extensive binary and three-body cross-sections extracted for reactions of ⁵⁰Ti with actinide nuclides could not be explained in this framework. Rather, the big drop in yield observed for the heavier actinide targets is consistent with sequential fission of heavy deep inelastic/quasifission fragments.</div><div>To search for shell effects in quasifission independent of sequential fission, systematics of mass spectra in non-actinide reactions forming actinide compound nuclei were studied. These showed negligible effects of the shells <em>known</em> to cause low energy mass-asymmetric fission of these nuclei. All these results raise questions over the understanding of the effects of closed shells on the quasifission mechanism, and quasifission mass distributions.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123040"},"PeriodicalIF":1.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479734","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}

{"title":"The upgrade of the facility EXOTIC","authors":"S. Pigliapoco ,&nbsp;D. Brugnara ,&nbsp;M. Mazzocco ,&nbsp;J.J. Valiente-Dobon ,&nbsp;P. Aguilera ,&nbsp;G. Andreetta ,&nbsp;F. Angelini ,&nbsp;M. Balogh ,&nbsp;D. Bazzacco ,&nbsp;J. Benito Garcia ,&nbsp;G. Benzoni ,&nbsp;S. Bottoni ,&nbsp;S. Carollo ,&nbsp;S. Cherubini ,&nbsp;M. Costa ,&nbsp;F.C.L. Crespi ,&nbsp;G. D'Agata ,&nbsp;G. De Angelis ,&nbsp;M. Del Fabbro ,&nbsp;A. Di Pietro ,&nbsp;L. Zago","doi":"10.1016/j.nuclphysa.2025.123039","DOIUrl":"10.1016/j.nuclphysa.2025.123039","url":null,"abstract":"<div><div>With the installation of the <em>γ</em>-ray spectrometer AGATA at the Laboratori Nazionali di Legnaro (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN), the scientific activity with the Radioactive Ion Beam facility EXOTIC had to be temporarily suspended and the reaction chambers located at its final focal plane had to be removed. In this period of forced inactivity, we reorganized all the services, upgraded all control systems of the facility and developed a new event-by-event tracking system based on MicroChannelPlate (MCP) detectors. These interventions are preparing the ground for coupling EXOTIC and AGATA to perform experiments exploiting the unique features provided by both equipments.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1057 ","pages":"Article 123039"},"PeriodicalIF":1.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427633","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}

{"title":"Review of nuclear structure N=86–118 of W isotopes","authors":"J.B. Gupta ,&nbsp;Vikas Katoch","doi":"10.1016/j.nuclphysa.2025.123032","DOIUrl":"10.1016/j.nuclphysa.2025.123032","url":null,"abstract":"<div><div>Nuclear structure of N = 86–118 W isotopes in even <em>Z</em> even N contains ground state band K^π=0⁺, K^π=0⁺ β-band and K^π=2⁺ γ-band. The energy <em>E</em>(2₁⁺) for spin I^π=2⁺ of ground state band shows minima at neutron number N = 108, which indicates shape phase transition. The energy ratio <em>R</em>_4/2 is maximum at N = 108 having nearly rotational symmetry and showed shape phase transition. The Power index ‘b’ in <em>E</em>=aI^b, shows minimum to maximum from N = 88 to N = 108 and again decreasing up to N = 116. The electromagnetic transition strength <strong><em>B</em>(<em>E2</em>)↑</strong> varies linearly with [1/ <em>E</em>(2₁⁺)]. The γ-band head difference with <em>E</em>(4₁⁺) is maximum at N = 108 and decreases for higher N, coming closer to the ground band. The band structure of W isotopes N = 108 to N = 112 is studied with the interacting boson model (IBM) and compared with experimental energies. Here the shape phase transitions, both sides of neutron number N = 108 ¹⁸²W is analyzed.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1057 ","pages":"Article 123032"},"PeriodicalIF":1.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465345","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}

{"title":"Particle-coupled octupole collectivity in 91Zr","authors":"P. Dey ,&nbsp;R. Palit ,&nbsp;E. Ideguchi ,&nbsp;T. Inakura ,&nbsp;F.S. Babra ,&nbsp;Biswajit Das ,&nbsp;U. Garg ,&nbsp;S.V. Jadhav ,&nbsp;A.K. Jain ,&nbsp;A. Kundu ,&nbsp;Md.S.R. Laskar ,&nbsp;B. Maheshwari ,&nbsp;Vishal Malik ,&nbsp;B.S. Naidu ,&nbsp;D. Negi ,&nbsp;S. Sihotra ,&nbsp;A.T. Vazhappilly","doi":"10.1016/j.nuclphysa.2025.123035","DOIUrl":"10.1016/j.nuclphysa.2025.123035","url":null,"abstract":"<div><div>Excited states in the semi-magic ⁹¹Zr nucleus have been populated by the heavy-ion fusion-evaporation reaction ⁸²Se(¹³C, 4<em>n</em>) at 52 MeV beam energy for investigating the phenomenon of octupole collectivity in odd-<em>A</em> nuclei. The half-life of the <span><math><mn>11</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>−</mo></mrow></msup></math></span> state at 2170.8 keV excitation energy has been measured by the electronic fast-timing technique using a hybrid array of clover HPGe and LaBr₃(Ce) detectors, and is found to be <span><math><msup><mrow><mi>τ</mi></mrow><mrow><mi>expt</mi></mrow></msup><mo>=</mo><mn>791.6</mn><mo>±</mo><mn>44.1</mn></math></span> ps. The reduced <em>E</em>3 transition probability <span><math><mi>B</mi><mo>(</mo><mi>E</mi><mn>3</mn><mo>;</mo><mn>11</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>−</mo></mrow></msup><mo>→</mo><mn>5</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msup><mo>)</mo><mo>=</mo><mn>18.5</mn><mo>±</mo><mn>1.2</mn></math></span> W.u. is significant and confirms its collective nature. The experimentally obtained <span><math><mi>B</mi><mo>(</mo><mi>E</mi><mn>3</mn><mo>)</mo></math></span> value along with the excitation energy of particle-coupled octupole state is well reproduced in the theoretical calculations performed using random-phase approximation with three different interactions. In contrast to ⁹⁰Zr where the large <span><math><mi>B</mi><mo>(</mo><mi>E</mi><mn>3</mn><mo>)</mo></math></span> value is made mainly by proton particle-hole excitations, the change in the <span><math><mi>B</mi><mo>(</mo><mi>E</mi><mn>3</mn><mo>)</mo></math></span> value in ⁹¹Zr is due to the valence neutron density of <span><math><mn>2</mn><msub><mrow><mi>d</mi></mrow><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> orbital to <span><math><mn>1</mn><msub><mrow><mi>h</mi></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> orbital.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1057 ","pages":"Article 123035"},"PeriodicalIF":1.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454851","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}