Nuclear Physics A最新文献

{"title":"Elastic scattering and inclusive α angular distributions for 6Li+93Nb system around the Coulomb barrier","authors":"Arati Chavan ,&nbsp;S. Rathi ,&nbsp;K. Mahata ,&nbsp;S.K. Pandit ,&nbsp;V.V. Parkar ,&nbsp;A. Shrivastava ,&nbsp;K. Ramachandran ,&nbsp;Sangeeta Dhuri ,&nbsp;Satbir Kaur ,&nbsp;Prasanna M ,&nbsp;Vineet Kumar","doi":"10.1016/j.nuclphysa.2025.123303","DOIUrl":"10.1016/j.nuclphysa.2025.123303","url":null,"abstract":"<div><div>Elastic scattering and inclusive <em>α</em> particle angular distributions were measured for ⁶Li+⁹³Nb system at lab energies of 24.6 MeV and 34.7 MeV. Optical model analysis of the measured elastic scattering angular distributions were analysed to extract the reaction cross sections. The energy and angle integrated <em>α</em> particle cross sections were determined. The reaction cross sections and the <em>α</em> production cross sections from the present measurement are compared with the available experimental data for ⁶Li projectile on various targets, to study the systematic behaviour. Extracted reaction cross sections from the optical model fits and the measured inclusive <em>α</em> agree very well with the systematic behaviour of reaction cross section and inclusive <em>α</em> production cross sections (due to non-compound nuclear process), respectively.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123303"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733860","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":"Measurement and analysis of excitation function for 16O+89Y at energies 4–7 MeV/nucleon","authors":"Mohd Faizan Khan ,&nbsp;Avinash Agarwal ,&nbsp;I.A. Rizvi ,&nbsp;Anuj Kumar Jashwal ,&nbsp;Harsh Vardhan ,&nbsp;Munish Kumar ,&nbsp;S. Ali ,&nbsp;M. Gull ,&nbsp;Satyam Gangwar ,&nbsp;Kamal Kumar ,&nbsp;S. Dutt ,&nbsp;A.K. Chaubey","doi":"10.1016/j.nuclphysa.2026.123326","DOIUrl":"10.1016/j.nuclphysa.2026.123326","url":null,"abstract":"<div><div>In the last couple of years, fusion processes triggered by heavy ions (HIs) have been a primary focus of study in low-energy nuclear physics. Recent experiments have confirmed that complete fusion (CF) and incomplete fusion (ICF) are the most prevalent modes in heavy ion (HI) interactions at energies above the Coulomb barrier. The purpose of the present work is to exclusively explore and measure the excitation functions (EF) of the evaporation residues (ERs) populated in ¹⁶<em>O</em> +⁸⁹<em>Y</em> systems at energies  ≈  4 - 7 MeV / nucleon. A standard stacked foil activation technique followed by offline <em>γ</em>-ray spectroscopy with a high-resolution HPGe detector has been used. The theoretical predictions obtained from the statistical code have been assigned to scrutinise the experimentally measured EFs. In this present work, <em>xn, pxn, αxn</em> and 2<em>αxn</em> channels are investigated. Whereas, the measured excitation function of ERs populated via some <em>xn</em> (n = 2 and 3) channels has been observed to show a high-energy tail portion deviating from the trends of excitation functions as obtained by the statistical code at higher energies. This signifies the presence of pre-equilibrium (PE) emission for these reaction channels. A noticeable enhancement was observed in the production of reaction residues involving <em>α</em> particle(s) in the exit channels, even at energies close to the Coulomb barrier. This enhancement in the cross-section clearly demonstrates the incomplete fusion of the projectile with the target. The incomplete fusion probability has been calculated to better understand the reaction dynamics. The present findings and analysis of the data for various projectile-target combinations strongly suggest that entrance channel parameters like mass asymmetry (<em>μ_A</em>), Coulomb factor (<em>Z_PZ_T</em>) and the variation in neutron excess in the target nucleus (N-Z) play a significant role in the onset of incomplete fusion.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123326"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977051","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":"Nuclear shape transition of Th isotope at fission limits: a fourier shape parametrization approach","authors":"K. Jyothish,&nbsp;M.R. Asmitha,&nbsp;Rhine A.K. Kumar","doi":"10.1016/j.nuclphysa.2025.123291","DOIUrl":"10.1016/j.nuclphysa.2025.123291","url":null,"abstract":"<div><div>The deformation energy landscape of ²³²Th nucleus along its fission path is investigated using the Lublin-Strasbourg Drop (LSD) model with the Fourier shape parametrization. The nuclear surface is represented by a truncated Fourier series in terms of collective coordinates associated with elongation (<em>q</em>₂), mass asymmetry (<em>q</em>₃), and neck formation (<em>q</em>₄). This parametrization offers enhanced flexibility in describing fission pathways and the complex shape transitions of the thorium isotope up to the scission point. Studying fission characteristics in actinide nuclei such as ²³²Th is crucial to advance our understanding of nuclear energy production and structure.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123291"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682168","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":"Systematics of electric dipole excitations in rare-earth 146−156Sm nuclei","authors":"E. Guliyev ,&nbsp;H. Quliyev ,&nbsp;A.A. Kuliev ,&nbsp;A. Jalili","doi":"10.1016/j.nuclphysa.2025.123305","DOIUrl":"10.1016/j.nuclphysa.2025.123305","url":null,"abstract":"<div><div>The electric dipole responses of the even-even ^146–156Sm nuclei were studied using translational and Galilean invariant (TGI-) quasi-particle random-phase approximation (QRPA), with the highly fragmented E1 strength being predicted. By comparing these calculations with experimental data for the photon absorption cross section σ_γ, it was shown that the QRPA model can reproduce the shape of the GDR quite well. The excitation energies, transition probabilities, and splitting behaviors of the PDR into <em>K</em> = 0 and <em>K</em>=±1 branches and other properties were also investigated further. Calculations on one-phonon wave functions confirmed that the dipole states below the particle threshold energy have characteristics that are different from those exhibited by the giant dipole resonance. Using this difference, we thereby determined the character of the experimentally observed dipole excitations around 10 MeV and showed that the PDR can reach the 10 MeV region. For the first time, PDR and GDR calculations were performed specifically for the ¹⁴⁶Sm and ¹⁵⁶Sm isotopes, providing new insights into their dipole response characteristics.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123305"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682171","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":"Thermal evolution of shape coexistence in Mo and Ru isotopes","authors":"Mamta Aggarwal ,&nbsp;Pranali Parab ,&nbsp;A. Jain ,&nbsp;G. Saxena","doi":"10.1016/j.nuclphysa.2025.123321","DOIUrl":"10.1016/j.nuclphysa.2025.123321","url":null,"abstract":"<div><div>The temperature-driven shape dynamics of isotopic chains of Mo and Ru elements and their impact on decay modes have been investigated in a statistical theoretical framework with macroscopic-microscopic apporach. These isotopes located at the key points in r-process path are known for the rapid structural changes, shape instabilities and shape coexistence that impact the nuclear processes, decay modes and lifetimes. At high temperatures that may exist in stars or in various nuclear reaction processes, these nuclei undergo a variety of shape and deformation changes due to thermal shell quenching effects influencing the decay energies (Q value), and eventually life-time have been studied in detail. Our findings provide insight into the observed shift in the deformation, shapes and coexisting states due to the diminishing nuclear shell effects in hot nuclei, revealing that the structural changes influence the decay processes and significantly in the astrophysically relevant Mo-Ru region especially around A = 100.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123321"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924745","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":"Exploring the effect of entrance channel mass asymmetry in the fission of 197Tl* nucleus","authors":"Golda Komalan Satheedas ,&nbsp;H. Singh ,&nbsp;Kavita Kavita ,&nbsp;Mohit Kumar ,&nbsp;N. Saneesh ,&nbsp;A. Jhingan ,&nbsp;P. Sugathan ,&nbsp;C. Yadav ,&nbsp;R. Kumar ,&nbsp;R. Dubey ,&nbsp;Abhishek Yadav ,&nbsp;Neeraj Kumar ,&nbsp;A. Banerjee ,&nbsp;Anjali Rani ,&nbsp;Kavita Rani ,&nbsp;J.R. Acharya ,&nbsp;S. Noor ,&nbsp;S.K. Duggi","doi":"10.1016/j.nuclphysa.2025.123310","DOIUrl":"10.1016/j.nuclphysa.2025.123310","url":null,"abstract":"<div><div>Fission fragment mass ratio distributions have been measured for the reactions ¹⁹F+¹⁷⁸Hf and ¹⁶O + ¹⁸¹Ta, both leading to the same compound nucleus, ¹⁹⁷Tl, at near-Coulomb barrier energies. The measured fission fragment mass width for both these systems does not show any substantial deviation from the statistical model predictions, which indicates the absence of non-compound nuclear reactions like quasi-fission. The measured mass widths of both the reactions at the same excitation energy are comparable within the experimental uncertainty and show a gradual increase with excitation energy. No noticeable influence of effect of entrance channel mass asymmetry on fragment mass distribution in these reactions, which differs from the previously reported entrance channel-dependent variation in average pre-scission neutron multiplicity.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123310"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840059","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":"Role of various nuclear densities and higher-order deformations on the dynamics of 16O+154Sm fusion reaction","authors":"M. Bhuyan ,&nbsp;Shilpa Rana ,&nbsp;Raj Kumar","doi":"10.1016/j.nuclphysa.2025.123314","DOIUrl":"10.1016/j.nuclphysa.2025.123314","url":null,"abstract":"<div><div>Understanding the role of nuclear structure in heavy-ion fusion reactions is crucial, especially in the low-energy regime where nuclear shape and density profiles significantly influence the reaction dynamics. In this work, we investigate the <span><math><mrow><msup><mrow></mrow><mn>16</mn></msup><mi>O</mi><msup><mo>+</mo><mn>154</mn></msup><mtext>Sm</mtext></mrow></math></span> fusion reaction as an illustrative case by employing three different nuclear density descriptions, namely the relativistic mean-field (RMF) formalism, the Skyrme-Hartree-Fock (SHF) approach, and the two-parameter Fermi (2pF) formula. These densities are folded with relativistic R3Y and non-relativistic M3Y effective nucleon-nucleon (NN) interactions to obtain six different nuclear potentials. Furthermore, the role of quadrupole <em>β</em>₂ and higher-order hexadecapole <em>β</em>₄ deformations of the target nucleus is included in the calculations of nuclear densities, fusion barrier characteristics, and cross-sections. By comparing barrier heights at different orientations, it is observed that the M3Y interaction provides higher barriers than the R3Y interaction. Among the densities, the 2pF yields the highest fusion barrier, while the SHF yields the lowest. The inclusion of <em>β</em>₂ and <em>β</em>₄ deformations results in strong orientation dependence, modifying the fusion barrier, especially at <span><math><mrow><msub><mi>θ</mi><mn>2</mn></msub><mo>=</mo><msup><mn>0</mn><mo>∘</mo></msup></mrow></math></span>. Further, the inclusion of <em>β</em>₄ deformation of the ¹⁵⁴Sm results in a lowering of the fusion barrier height compared to only <em>β</em>₂ deformation, except for target orientation angles 36^∘ &lt; <em>θ</em>₂ &lt; 72^∘. The highest cross-sections are obtained with SHF densities, followed by RMF densities, whereas the 2pF densities underestimate the experimental data. A better match with the experimental cross-section is achieved when structural effects, such as <em>β</em>₂ and <em>β</em>₄ deformations, are included in the SHF and RMF densities, along with the R3Y NN interaction. These findings underline the importance of incorporating detailed nuclear structure effects for a reliable description of heavy-ion fusion dynamics.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123314"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883371","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 role of nuclear symmetry energy and neutron skin thickness of 208Pb in controlling the underlying physics of neutron star","authors":"Queena,&nbsp;Mukul Kumar,&nbsp;Sunil Kumar,&nbsp;Raj K. Jagota,&nbsp;Shashi K. Dhiman","doi":"10.1016/j.nuclphysa.2025.123307","DOIUrl":"10.1016/j.nuclphysa.2025.123307","url":null,"abstract":"<div><div>The nuclear symmetry energy is fundamental in nuclear astrophysics, influencing phenomena from nuclear structure to gravitational collapse and neutron star formation. Both the symmetry energy and its linear density dependence (L), are critical inputs for numerous nuclear physics and astrophysics applications, as they play a key role in determining properties such as neutron skin thickness (Δ<em>r_np</em>) and neutron star radius. Recent results from parity-violating electron scattering experiments on ²⁰⁸Pb (PREX-II: The Lead Radius Experiment)) have offered new insights into these fields. Specifically, the PREX-II experiment has provided a neutron skin thickness for ²⁰⁸Pb of <span><math><mrow><mstyle><mi>Δ</mi></mstyle><msub><mi>r</mi><mrow><mi>n</mi><mi>p</mi></mrow></msub><mo>=</mo><mn>0.283</mn><mo>±</mo><mn>0.071</mn></mrow></math></span> fm. This measurement helps to constrain the nuclear symmetry energy in laboratory environments. In this study, we propose several interactions (SRQs) based on relativistic energy density functionals that correspond to different values of Δ<em>r_np</em> for ²⁰⁸Pb, as derived from the PREX-II limits. We observe a correlation between Δ<em>r_np</em> of ²⁰⁸Pb and L. We compute the equations of state for nucleonic matter under <em>β</em> - equilibrium conditions for proposed interactions. We also discuss in detail the effects of Δ<em>r_np</em> and <em>L</em> on nuclear matter and neutron star properties. Additionally, these interactions are utilized to explore the characteristics of rotating neutron stars.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123307"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840063","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":"Accurate prediction of Gamow-Teller beta-decay matrix elements via machine learning: implications for nuclear structure","authors":"Cafer Mert Yeşilkanat ,&nbsp;Serkan Akkoyun","doi":"10.1016/j.nuclphysa.2025.123318","DOIUrl":"10.1016/j.nuclphysa.2025.123318","url":null,"abstract":"<div><div>Accurate prediction of Gamow-Teller (GT) beta decay matrix elements [<span><math><mrow><mi>M</mi><mo>(</mo><mrow><mi>G</mi><mi>T</mi></mrow><mo>)</mo></mrow></math></span>] is essential for elucidating complex nuclear structure phenomena and understanding astrophysical processes. In this study, we employed five advanced machine learning models (Cubist, Support Vector Regression, Extreme Gradient Boosting, Random Forest, and Bayesian Regularized Neural Networks) to predict GT beta decay matrix elements in <span><math><mrow><mi>s</mi><mi>d</mi></mrow></math></span>-shell nuclei, using experimental data from NNDC/ENSDF, NUBASE2016, and AME2016. This study systematically compared the predictive performance of traditional theoretical approaches (including the USDB, IM-SRG, CCEI, and CEFT) to that of advanced machine learning models trained based on experimental observations. Our primary objective was to determine whether data-driven models could achieve higher predictive accuracy than computationally expensive theoretical models by learning the complex and nonlinear relationships among experimental parameters that reflect nuclear structure and decay dynamics. The results demonstrate that the Cubist model achieves a significantly lower RMSE (0.073 in the full parameter modeling approach and 0.112 in the reduced parameter modeling approach) and high coefficients of determination (<em>R</em>² = 0.901 and 0.919, respectively), thereby outperforming traditional methods. Furthermore, SHapley Additive exPlanations (SHAP) analysis revealed that a minimal set of critical nuclear parameters predominantly governs GT decay dynamics, thereby enhancing model interpretability without compromising predictive accuracy. Complementing these findings, an online calculator was developed to facilitate rapid, high-fidelity predictions of GT matrix elements. Overall, our study demonstrates that a data-driven approach outperforms established theoretical models. More importantly, by identifying the minimal set of physical observables that govern GT transitions, our work provides crucial insights into the underlying physics of nuclear structure and offers a new benchmark for refining future theoretical models and astrophysical calculations.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123318"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840061","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":"Possible explanation of F2n/F2p at large x using quantum statistical mechanics","authors":"C. Bourrely ,&nbsp;F. Buccella ,&nbsp;W.C. Chang ,&nbsp;D. Di Bari ,&nbsp;P.H. Frampton ,&nbsp;J.C. Peng","doi":"10.1016/j.nuclphysa.2025.123300","DOIUrl":"10.1016/j.nuclphysa.2025.123300","url":null,"abstract":"<div><div>The recent accurate measurements of the scattering of electrons off of the mirror nuclei ³H and ³He show with small errors that the neutron to proton ratio <span><math><mrow><mi>r</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>=</mo><msubsup><mi>F</mi><mn>2</mn><mi>n</mi></msubsup><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>/</mo><msubsup><mi>F</mi><mn>2</mn><mi>p</mi></msubsup><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span>, approaches a value larger than 1/4 for <em>x</em> → 1. We suggest a possible explanation for this experimental result by studying the consequences of the Pauli exclusion principle for the parton distribution when the ratio is described by quantum statistical mechanics description in terms of three parameters inspired by the quantum statistical approach.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123300"},"PeriodicalIF":2.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733861","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}